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Sample records for narrow spectral lines

  1. SPECTRAL OPTICAL MONITORING OF THE NARROW-LINE SEYFERT 1 GALAXY Ark 564

    Shapovalova, A. I.; Burenkov, A. N.; Popović, L. Č.; Kovačević, J.; Chavushyan, V. H.; Valdes, J. R.; Torrealba, J.; Carrasco, L.; Ilić, D.; Kovačević, A.; Kollatschny, W.; Bochkarev, N. G.; León-Tavares, J.; Mercado, A.; Benítez, E.; Dultzin, D.; De la Fuente, E.

    2012-01-01

    We present the results of a long-term (1999-2010) spectral optical monitoring campaign of the active galactic nucleus (AGN) Ark 564, which shows a strong Fe II line emission in the optical. This AGN is a narrow-line Seyfert 1 (NLS1) galaxy, a group of AGNs with specific spectral characteristics. We analyze the light curves of the permitted Hα, Hβ, optical Fe II line fluxes, and the continuum flux in order to search for a time lag between them. Additionally, in order to estimate the contribution of iron lines from different multiplets, we fit the Hβ and Fe II lines with a sum of Gaussian components. We find that during the monitoring period the spectral variation (F max /F min ) of Ark 564 is between 1.5 for Hα and 1.8 for the Fe II lines. The correlation between the Fe II and Hβ flux variations is of higher significance than that of Hα and Hβ (whose correlation is almost absent). The permitted-line profiles are Lorentzian-like and do not change shape during the monitoring period. We investigate, in detail, the optical Fe II emission and find different degrees of correlation between the Fe II emission arising from different spectral multiplets and the continuum flux. The relatively weak and different degrees of correlations between permitted lines and continuum fluxes indicate a rather complex source of ionization of the broad-line emission region.

  2. SPECTRAL OPTICAL MONITORING OF THE NARROW-LINE SEYFERT 1 GALAXY Ark 564

    Shapovalova, A. I.; Burenkov, A. N. [Special Astrophysical Observatory of the Russian AS, Nizhnij Arkhyz, Karachaevo-Cherkesia 369167 (Russian Federation); Popovic, L. C.; Kovacevic, J. [Astronomical Observatory, Volgina 7, 11160 Belgrade 74 (Serbia); Chavushyan, V. H.; Valdes, J. R.; Torrealba, J.; Carrasco, L. [Instituto Nacional de Astrofisica, Optica y Electronica, Apartado Postal 51-216, 72000 Puebla (Mexico); Ilic, D.; Kovacevic, A. [Isaac Newton Institute of Chile, Yugoslavia Branch, Belgrade (Serbia); Kollatschny, W. [Institut fuer Astrophysik, Georg-August-Universitaet, Goettingen (Germany); Bochkarev, N. G. [Sternberg Astronomical Institute, Moscow (Russian Federation); Leon-Tavares, J. [Aalto University Metsaehovi Radio Observatory, Metsaehovintie 114, FIN-02540 Kylmaelae (Finland); Mercado, A. [Universidad Politecnica de Baja California, Av. de la Industria 291, 21010 Mexicali, B.C. (Mexico); Benitez, E.; Dultzin, D. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-264, Mexico, D.F. 04510 (Mexico); De la Fuente, E., E-mail: ashap@sao.ru [Instituto de Astronomia y Meteorologia, Dpto. de Fisica CUCEI, Universidad de Guadalajara, Av. Vallarta 2602, 44130 Guadalajara, Jalisco (Mexico)

    2012-09-15

    We present the results of a long-term (1999-2010) spectral optical monitoring campaign of the active galactic nucleus (AGN) Ark 564, which shows a strong Fe II line emission in the optical. This AGN is a narrow-line Seyfert 1 (NLS1) galaxy, a group of AGNs with specific spectral characteristics. We analyze the light curves of the permitted H{alpha}, H{beta}, optical Fe II line fluxes, and the continuum flux in order to search for a time lag between them. Additionally, in order to estimate the contribution of iron lines from different multiplets, we fit the H{beta} and Fe II lines with a sum of Gaussian components. We find that during the monitoring period the spectral variation (F{sub max}/F{sub min}) of Ark 564 is between 1.5 for H{alpha} and 1.8 for the Fe II lines. The correlation between the Fe II and H{beta} flux variations is of higher significance than that of H{alpha} and H{beta} (whose correlation is almost absent). The permitted-line profiles are Lorentzian-like and do not change shape during the monitoring period. We investigate, in detail, the optical Fe II emission and find different degrees of correlation between the Fe II emission arising from different spectral multiplets and the continuum flux. The relatively weak and different degrees of correlations between permitted lines and continuum fluxes indicate a rather complex source of ionization of the broad-line emission region.

  3. Spectral properties of X-ray selected narrow emission line galaxies

    Romero-Colmenero, E.

    1998-03-01

    This thesis reports a study of the X-ray and optical properties of two samples of X-ray selected Narrow Emission Line Galaxies (NELGs), and their comparison with the properties of broad line Active Galactic Nuclei (AGN). One sample (18 NELGs) is drawn from the ROSAT International X-ray Optical Survey (RIXOS), the other (19 NELGs and 33 AGN) from the ROSAT UK Deep Survey. ROSAT multi-channel X-ray spectra have been extracted and fitted with power-law, bremsstrahlung and black body models for the brighter RIXOS sources. In most cases, power-law and bremsstrahlung models provide the best results. The average spectral energy index, alpha, of the RIXOS NELGs is 0.96 +/- 0.07, similar to that of AGN (alpha~1). For the fainter RIXOS NELGs, as well as for all the UK Deep Survey sources, counts in three spectral bands have been extracted and fitted with a power-law model, assuming the Galactic value for N_H. The brighter RIXOS sources demonstrated that the results obtained by these two different extraction and fitting procedures provide consistent results. Two average X-ray spectra, one for the NELGs and another for the AGN, were created from the UK Deep Survey sources. The power-law slope of the average NELG is alpha = 0.45 +/- 0.09, whilst that of the AGN is alpha = 0.96 +/- 0.03. ROSAT X-ray surveys have shown that the fractional surface density of NELGs increases with respect to AGN at faint fluxes (case for NELGs to be major contributors to the XRB at the fainter fluxes. The analysis of optical spectroscopy, obtained on La Palma and Hawaii, shows that NELGs form a very heterogeneous group, made up of a mixture of Seyfert 2, LINER and HII-region like galaxies. Seyfert 2 galaxies are found to possess in general the steepest X-ray slopes. Ways to explain this in the context of the unified model of AGN are discussed. The FWHM of some emission lines (Halpha, Hbeta, [NII]) in the NELGs appears to increase with steepening X-ray spectral slope. In the case of the Balmer lines

  4. Spectral properties of the narrow-line region in Seyfert galaxies selected from the SDSS-DR7

    Vaona, L.; Ciroi, S.; Di Mille, F.; Cracco, V.; La Mura, G.; Rafanelli, P.

    2012-12-01

    Although the properties of the narrow-line region (NLR) of active galactic nuclei (AGN) have been deeply studied by many authors in the past three decades, many questions are still open. The main goal of this work is to explore the NLR of Seyfert galaxies by collecting a large statistical spectroscopic sample of Seyfert 2 and Intermediate-type Seyfert galaxies having a high signal-to-noise ratio in order to take advantage of a high number of emission lines to be accurately measured. 2153 Seyfert 2 and 521 Intermediate-type Seyfert spectra were selected from Sloan Digital Sky Survey Data Release 7 (SDSS-DR7) with a diagnostic diagram based on the oxygen emission-line ratios. All the emission lines, broad components included, were measured by means of a self-developed code, after the subtraction of the stellar component. Physical parameters, such as internal reddening, ionization parameter, temperature, density, gas and stellar velocity dispersion were determined for each object. Furthermore, we estimated mass and radius of the NLR, kinetic energy of the ionized gas and black hole accretion rate. From the emission-line analysis and the estimated physical properties, it appears that the NLR is similar in Seyfert 2 and Intermediate-Seyfert galaxies. The only differences, lower extinction, gas kinematics in general not dominated by the host galaxy gravitational potential and higher percentage of [O III]λ5007 blue asymmetries in Intermediate-Seyfert, can be ascribed to an effect of inclination of our line of sight with respect to the torus axis.

  5. QSOs with narrow emission lines

    Baldwin, J.A.; Mcmahon, R.; Hazard, C.; Williams, R.E.

    1988-01-01

    Observations of two new high-redshift, narrow-lined QSOs (NLQSOs) are presented and discussed together with observations of similar objects reported in the literature. Gravitational lensing is ruled out as a possible means of amplifying the luminosity for one of these objects. It is found that the NLQSOs have broad bases on their emission lines as well as the prominent narrow cores which define this class. Thus, these are not pole-on QSOs. The FWHM of the emission lines fits onto the smoothly falling tail of the lower end of the line-width distribution for complete QSO samples. The equivalent widths of the combined broad and narrow components of the lines are normal for QSOs of the luminosity range under study. However, the NLQSOs do show ionization differences from broader-lined QSOs; most significant, the semiforbidden C III/C IV intensity ratio is unusually low. The N/C abundance ratio in these objects is found to be normal; the Al/C abundance ratio may be quite high. 38 references

  6. A TALE OF TWO NARROW-LINE REGIONS: IONIZATION, KINEMATICS, AND SPECTRAL ENERGY DISTRIBUTIONS FOR A LOCAL PAIR OF MERGING OBSCURED ACTIVE GALAXIES

    Hainline, Kevin N.; Hickox, Ryan C.; Chen, Chien-Ting; Carroll, Christopher M.; Jones, Mackenzie L.; Zervos, Alexandros S. [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Goulding, Andrew D. [Department Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2016-05-20

    We explore the gas ionization and kinematics, as well as the optical-IR spectral energy distributions for UGC 11185, a nearby pair of merging galaxies hosting obscured active galactic nuclei (AGNs), also known as SDSS J181611.72+423941.6 and J181609.37+423923.0 (J1816NE and J1816SW, z ≈ 0.04). Due to the wide separation between these interacting galaxies (∼23 kpc), observations of these objects provide a rare glimpse of the concurrent growth of supermassive black holes at an early merger stage. We use BPT line diagnostics to show that the full extent of the narrow-line emission in both galaxies is photoionized by an AGN, and confirm the existence of a 10 kpc-scale ionization cone in J1816NE, while in J1816SW the AGN narrow-line region is much more compact (1–2 kpc) and relatively undisturbed. Our observations also reveal the presence of ionized gas that nearly spans the entire distance between the galaxies, which is likely in a merger-induced tidal stream. In addition, we carry out a spectral analysis of the X-ray emission using data from XMM-Newton . These galaxies represent a useful pair to explore how the [O iii] luminosity of an AGN is dependent on the size of the region used to explore the extended emission. Given the growing evidence for AGN “flickering” over short timescales, we speculate that the appearances and impacts of these AGNs may change multiple times over the course of the galaxy merger, which is especially important given that these objects are likely the progenitors of the types of systems commonly classified as “dual AGNs.”.

  7. Narrow-line external cavity diode laser micro-packaging in the NIR and MIR spectral range

    Jiménez, A.; Milde, T.; Staacke, N.; Aßmann, C.; Carpintero, G.; Sacher, J.

    2017-07-01

    Narrow-linewidth tunable diode lasers are an important tool for spectroscopic instrumentation. Conventional external cavity diode lasers offer high output power and narrow linewidth. However, most external cavity diode lasers are designed as laboratory instrument and do not allow portability. In comparison, other commonly used lasers, like distributed feedback lasers (DFB) that are capable of driving a handheld device, are limited in power and show linewidths which are not sufficiently narrow for certain applications. We present new miniaturized types of tunable external cavity diode laser which overcome the drawbacks of conventional external cavity diode lasers and which preserve the advantages of this laser concept. Three different configurations are discussed in this article. The three types of miniaturized external cavity diode laser systems achieve power values of more than 50 mW within the 1.4 μm water vapor absorption band with excellent side-mode suppression and linewidth below 100 kHz. Typical features outstand with respect to other type of laser systems which are of extended use such as DFB laser diodes. The higher output power and the lower linewidth will enable a higher sensitivity and resolution for a wide range of applications.

  8. Broadband spectral study of the jet-disc emission in the radio-loud narrow-line Seyfert 1 galaxy 1H 0323+342

    Ghosh, Ritesh; Dewangan, Gulab C.; Mallick, Labani; Raychaudhuri, Biplab

    2018-06-01

    We present a broadband spectral study of the radio-loud narrow-line Seyfert 1 galaxy 1H 0323+342 based on multi-epoch observations performed with NuSTAR on 2014 March 15, and two simultaneous observations performed with Suzaku and Swift on 2009 July 26 and 2013 March 1. We found the presence of a strong soft X-ray excess emission, a broad but weak Fe line and hard X-ray excess emission. We used the blurred reflection (relxill) and the intrinsic disc Comptonization (optxagnf), two physically motivated models, to describe the broadband spectra and to disentangle the disk/corona and jet emission. The relxill model is mainly constrained by the strong soft X-ray excess although the model failed to predict this excess when fitted above 3{keV} and extrapolated to lower energies. The joint spectral analysis of the three datasets above 3{keV} with this model resulted in a high black hole spin (a > 0.9) and moderate reflection fraction R ˜ 0.5. The optxagnf model fitted to the two simultaneous datasets resulted in an excess emission in the UV band. The simultaneous UV-to-hard X-ray spectra of 1H 0323+342 are best described by a model consisting of a primary X-ray power-law continuum with Γ ˜ 1.8, a blurred reflection component with R ˜ 0.5, Comptonised disk emission as the soft X-ray excess, optical/UV emission from a standard accretion disk around a black hole of mass ˜107M⊙ and a steep power law (Γ ˜ 3 - 3.5) component, most likely the jet emission in the UV band. The fractional RMS variability spectra suggest that both the soft excess and the powerlaw component are variable in nature.

  9. Spectral Line Shapes. Proceedings

    Zoppi, M.; Ulivi, L.

    1997-01-01

    These proceedings represent papers presented at the 13th International Conference on Spectral Line Shapes which was held in Firenze,Italy from June 16-21, 1996. The topics covered a wide range of subjects emphasizing the physical processes associated with the formation of line profiles: high and low density plasma; atoms and molecules in strong laser fields, Dopple-free and ultra-fine spectroscopy; the line shapes generated by the interaction of neutrals, atoms and molecules, where the relavant quantities are single particle properties, and the interaction-induced spectroscopy. There were 131 papers presented at the conference, out of these, 6 have been abstracted for the Energy Science and Technology database

  10. Optically trapped atomic resonant devices for narrow linewidth spectral imaging

    Qian, Lipeng

    This thesis focuses on the development of atomic resonant devices for spectroscopic applications. The primary emphasis is on the imaging properties of optically thick atomic resonant fluorescent filters and their applications. In addition, this thesis presents a new concept for producing very narrow linewidth light as from an atomic vapor lamp pumped by a nanosecond pulse system. This research was motivated by application for missile warning system, and presents an innovative approach to a wide angle, ultra narrow linewidth imaging filter using a potassium vapor cell. The approach is to image onto and collect the fluorescent photons emitted from the surface of an optically thick potassium vapor cell, generating a 2 GHz pass-band imaging filter. This linewidth is narrow enough to fall within a Fraunhefer dark zone in the solar spectrum, thus make the detection solar blind. Experiments are conducted to measure the absorption line shape of the potassium resonant filter, the quantum efficiency of the fluorescent behavior, and the resolution of the fluorescent image. Fluorescent images with different spatial frequency components are analyzed by using a discrete Fourier transform, and the imaging capability of the fluorescent filter is described by its Modulation Transfer Function. For the detection of radiation that is spectrally broader than the linewidth of the potassium imaging filter, the fluorescent image is seen to be blurred by diffuse fluorescence from the slightly off resonant photons. To correct this, an ultra-thin potassium imaging filter is developed and characterized. The imaging property of the ultra-thin potassium imaging cell is tested with a potassium seeded flame, yielding a resolution image of ˜ 20 lines per mm. The physics behind the atomic resonant fluorescent filter is radiation trapping. The diffusion process of the resonant photons trapped in the atomic vapor is theoretically described in this thesis. A Monte Carlo method is used to simulate the

  11. Acquisition and visualization techniques for narrow spectral color imaging.

    Neumann, László; García, Rafael; Basa, János; Hegedüs, Ramón

    2013-06-01

    This paper introduces a new approach in narrow-band imaging (NBI). Existing NBI techniques generate images by selecting discrete bands over the full visible spectrum or an even wider spectral range. In contrast, here we perform the sampling with filters covering a tight spectral window. This image acquisition method, named narrow spectral imaging, can be particularly useful when optical information is only available within a narrow spectral window, such as in the case of deep-water transmittance, which constitutes the principal motivation of this work. In this study we demonstrate the potential of the proposed photographic technique on nonunderwater scenes recorded under controlled conditions. To this end three multilayer narrow bandpass filters were employed, which transmit at 440, 456, and 470 nm bluish wavelengths, respectively. Since the differences among the images captured in such a narrow spectral window can be extremely small, both image acquisition and visualization require a novel approach. First, high-bit-depth images were acquired with multilayer narrow-band filters either placed in front of the illumination or mounted on the camera lens. Second, a color-mapping method is proposed, using which the input data can be transformed onto the entire display color gamut with a continuous and perceptually nearly uniform mapping, while ensuring optimally high information content for human perception.

  12. Narrow Quasar Absorption Lines and the History of the Universe

    Liebscher, Dierck-Ekkehard

    In order to get an estimation of the parameters of the cosmological model the statistics of narrow absorption lines in quasar spectra is evaluated. To this end a phenomenological model of the evolution of the corresponding absorbers in density, size, number and dimension is presented and compared with the observed evolution in the spectral density of the lines and their column density seen in the equivalent width. In spite of the wide range of possible models, the Einstein-deSitter model is shown to be unlikely because of the implied fast evolution in mass.

  13. Properties of Narrow line Seyfert 1 galaxies

    Rakshit, Suvendu; Stalin, Chelliah Subramonian; Chand, Hum; Zhang, Xue-Guang

    2018-04-01

    Narrow line Seyfert 1 (NLSy1) galaxies constitute a class of active galactic nuclei characterized by the full width at half maximum (FWHM) of the Hα broad emission line 10 pixel-1. A strong correlation between the Hα and Hα emission lines is found both in the FWHM and flux. The nuclear continuum luminosity is found to be strongly correlated with the luminosity of Hα, Hα and [O III] emission lines. The black hole mass in NLSy1 galaxies is lower compared to their broad line counterparts. Compared to BLSy1 galaxies, NLSy1 galaxies have a stronger FeII emission and a higher Eddington ratio that place them in the extreme upper right corner of the R4570 - λEdd diagram. The distribution of the radio-loudness parameter (R) in NLSy1 galaxies drops rapidly at R>10 compared to the BLSy1 galaxies that have powerful radio jets. The soft X-ray photon index in NLSy1 galaxies is on average higher (2.9 ± 0.9) than BLSy1 galaxies (2.4 ± 0.8). It is anti-correlated with the Hα width but correlated with the FeII strength. NLSy1 galaxies on average have a lower amplitude of optical variability compared to their broad lines counterparts. These results suggest Eddington ratio as the main parameter that drives optical variability in these sources.

  14. Multilayer Photonic Crystal for Spectral Narrowing of Emission

    Zhanfang LIU

    2017-08-01

    Full Text Available Multilayer colloidal crystal has been prepared by the layer-by-layer deposition of silica microspheres on a glass slide. Each layer is a slab consisting of a fcc close-packed colloidal arrays. By properly choosing the sizes of spheres, the whole spectral feature of multilayer colloidal crystal can be tuned. Here, we engineered a multilayer superlattice structure with an effective passband between two stop bands. This gives a strong narrowing effect on emission spectrum. With the stop bands at the shortwave and longwave edges of emission spectrum, the passband in the central wavelength region can be regarded as a strong decrease of suppression effect and enhancement of a narrow wavelength region of emission. The spectral narrowing modification effect of suitably engineered colloidal crystals shows up their importance in potential application as optical filters and lasing devices.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16320

  15. Laser linewidth narrowing using transient spectral hole burning

    Thiel, Charles W.; Cone, Rufus L. [Department of Physics, Montana State University, Bozeman, MT 59715 (United States); Böttger, Thomas, E-mail: tbottger@usfca.edu [Department of Physics and Astronomy, 2130 Fulton Street, University of San Francisco, San Francisco, CA 94117 (United States)

    2014-08-01

    We demonstrate significant narrowing of laser linewidths by high optical density materials with inhomogeneously broadened absorption. As a laser propagates through the material, the nonlinear spectral hole burning process causes a progressive self-filtering of the laser spectrum, potentially reaching values less than the homogeneous linewidth. The transient spectral hole dynamically adjusts itself to the instantaneous frequency of the laser, passively suppressing laser phase noise and side modes over the entire material absorption bandwidth without the need for electronic or optical feedback to the laser. Wide bandwidth laser phase noise suppression was demonstrated using Er{sup 3+} doped Y{sub 2}SiO{sub 5} and LiNbO{sub 3} at 1.5 μm by employing time-delayed self-heterodyne detection of an external cavity diode laser to study the spectral narrowing effect. Our method is not restricted to any particular wavelength or laser system and is attractive for a range of applications where ultra-low phase noise sources are required. - Highlights: • We demonstrate significant laser linewidths narrowing by high optical density materials. • Nonlinear spectral hole burning causes progressive self-filtering of laser spectrum. • Filter dynamically adjusts itself to the instantaneous frequency of the laser. • Demonstrated at 1.5 μm in Er{sup 3+} doped Y{sub 2}SiO{sub 5} and LiNbO{sub 3}. • Linewidth filtering is not restricted to any particular wavelength or laser system.

  16. Formation of extremely narrow metallic lines

    Harris, E.P.; Keyes, R.W.

    1979-01-01

    A method for forming metal lines, particularly lines which are superconductive, involves delineating a pattern on a thin metal film on a substrate by masking techniques, ion implanting the metal film to a desired depth, removing the mask and etching away the unimplanted portion of the metal film to leave the line whose width is equal to the implanted depth. (U.K.)

  17. Autoionization spectral line shapes in dense plasmas

    Rosmej, F.B.; Hoffmann, D.H.H.; Faenov, A.Ya.; Pikuz, T.A.; Suess, W.; Geissel, M.

    2001-01-01

    The distortion of resonance line shapes due to the accumulation of a large number of satellite transitions is discovered by means of X-ray optical methods with simultaneous high spectral (λ/δλ≅8000) and spatial resolution (δx≅7 μm). Disappearance of the He α resonance line emission near the target surface is observed while Rydberg satellite intensity accumulates near the resonance line position. He β and He γ resonance line shapes are also shown to be seriously affected by opacity, higher-order line emissions from autoionizing states and inhomogeneous spatial emission. Opposite to resonance line emissions the He β satellites originate only from a very narrow spatial interval. New temperature and density diagnostics employing the 1s2131' and 1s3131'-satellites are developed. Moreover, even-J components of the satellite line emissions were resolved in the present high resolution experiments. Line transitions from the autoionizing states 1s2131' are therefore also proposed for space resolved Stark broadening analysis and local high density probing. Theorists are encouraged to provide accurate Stark broadening data for the transitions 1s2131 ' →1s 2 21+hv

  18. Experimental studies of x-ray laser spectral profiles: Observation of gain narrowing and saturation behavior

    Koch, J.A.; MacGowan, B.J.; Da Silva, L.B.; Matthews, D.L.; Mrowka, S.; Underwood, J.H.; Batson, P.J.

    1992-01-01

    We discuss our recent measurements of the spectral width of the 206.38 Angstrom x-ray laser transition in Ne-like Se. These measurements used a high-resolution grating spectrometer and were performed over a wide range of laser amplifier lengths. The data have enabled us to extrapolate the intrinsic line width and to observe the effects of gain-narrowing and saturation on the line profile. We find an intrinsic width which is 1.4 times the Doppler width, we observe gain-narrowing in intermediate length amplifiers, and we observe no re-broadening in long, saturated amplifiers. These results suggest that collisional line-broadening has a significant effect on the line profile and saturation behavior of this laser. We discuss modeling we have performed in order to simulate the experimental data, and we discuss future experimental and theoretical efforts we believe are necessary in order to understand line broadening and line transfer issues in x-ray laser plasmas

  19. A long XMM-Newton observation of an extreme narrow-line Seyfert 1: PG 1244+026

    Jin, C.; Done, C.; Middleton, M.; Ward, M.

    2013-01-01

    We explore the origin of the strong soft X-ray excess in narrow-line Seyfert 1 galaxies using spectral-timing information from a 120 ks XMM-Newton observation of PG 1244+026. Spectral fitting alone cannot distinguish between a true additional soft X-ray continuum component and strongly

  20. Spectral narrowing of a 980 nm tapered diode laser bar

    Vijayakumar, Deepak; Jensen, Ole Bjarlin; Lucas Leclin, Ga"lle; Petersen, Paul Michael; Thestrup, Birgitte

    2011-03-01

    High power diode laser bars are interesting in many applications such as solid state laser pumping, material processing, laser trapping, laser cooling and second harmonic generation. Often, the free running laser bars emit a broad spectrum of the order of several nanometres which limit their scope in wavelength specific applications and hence, it is vital to stabilize the emission spectrum of these devices. In our experiment, we describe the wavelength narrowing of a 12 element 980 nm tapered diode laser bar using a simple Littman configuration. The tapered laser bar which suffered from a big smile has been "smile corrected" using individual phase masks for each emitter. The external cavity consists of the laser bar, both fast and slow axis micro collimators, smile correcting phase mask, 6.5x beam expanding lens combination, a 1200 lines/mm reflecting grating with 85% efficiency in the first order, a slow axis focusing cylindrical lens of 40 mm focal length and an output coupler which is 10% reflective. In the free running mode, the laser emission spectrum was 5.5 nm wide at an operating current of 30A. The output power was measured to be in excess of 12W. Under the external cavity operation, the wavelength spread of the laser could be limited to 0.04 nm with an output power in excess of 8 W at an operating current of 30A. The spectrum was found to be tuneable in a range of 16 nm.

  1. Investigating the Temperature Problem in Narrow Line Emitting AGN

    Jenkins, Sam; Richardson, Chris T.

    2018-06-01

    Our research investigates the physical conditions in gas clouds around the narrow line region of AGN. Specifically, we explore the necessary conditions for anomalously high electron temperatures, Te, in those clouds. Our 321 galaxy data set was acquired from SDSS DR14 after requiring S/N > 5.0 in [OIII] 4363 and S/N > 3.0 in all BPT diagram emission lines, to ensure both accurate Te and galaxy classification, with 0.04 study the effects these conditions have on gas cloud Te.

  2. Deconvolution of spectral line profile by FTS

    Lego, J.

    1977-01-01

    The possibility is studied of determining the components of the spectral line profile using Fourier transformation. The different types of the spectral line profiles are described and the conditions for their generation discussed. The main result is the discovery of the possibility to obtain the parameters of the different components directly from the interferogram without using the Fourier transformation. The method under discussion strongly simplifies evaluation while preserving or increasing accuracy. (author)

  3. Extended Narrow-Line Region in Seyfert Galaxies

    Enrico Congiu

    2017-10-01

    Full Text Available We present our recent results about the extended narrow-line region (ENLR of two nearby Seyfert 2 galaxies (IC 5063 and NGC 7212 obtained by modeling the observed line profiles and spectra with composite models (photoionization+shocks in the different regions surrounding the AGN. Then, we compare the Seyfert 2 ENLRs with the very extended one recently discovered in the narrow-line Seyfert 1 (NLS1 galaxy Mrk 783. We have found several evidences of interaction between the ISM of the galaxies and their radio jets, such as (a the contribution of shocks in ionizing the high velocity gas, (b the complex kinematics showed by the profile of the emission lines, (c the high fragmentation of matter, etc. The results suggest that the ENLR of IC 5063 have a hollow bi-conical shape, with one edge aligned to the galaxy disk, which may cause some kind of dependence on velocity of the ionization parameter. Regarding the Mrk 783 properties, it is found that the extension of the optical emission is almost twice the size of the radio one and it seems due to the AGN activity, although there is contamination by star formation around 12 arcsec from the nucleus. Diagnostic diagrams excluded the contribution of star formation in IC 5063 and NGC 7212, while the shock contribution was used to explain the spectra emitted by their high velocity gas.

  4. Extended Narrow-Line Region in Seyfert Galaxies

    Congiu, Enrico [Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova, Padova (Italy); Astronomical Observatory of Brera, National Institute for Astrophysics, Milan (Italy); Contini, Marcella [School of Physics and Astronomy, Tel Aviv University, Tel Aviv (Israel); Ciroi, Stefano; Cracco, Valentina [Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova, Padova (Italy); Di Mille, Francesco [Las Campanas Observatory, La Serena (Chile); Berton, Marco [Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova, Padova (Italy); Astronomical Observatory of Brera, National Institute for Astrophysics, Milan (Italy); Frezzato, Michele; La Mura, Giovanni; Rafanelli, Piero, E-mail: enrico.congiu@phd.unipd.it [Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova, Padova (Italy)

    2017-10-24

    We present our recent results about the extended narrow-line region (ENLR) of two nearby Seyfert 2 galaxies (IC 5063 and NGC 7212) obtained by modeling the observed line profiles and spectra with composite models (photoionization+shocks) in the different regions surrounding the AGN. Then, we compare the Seyfert 2 ENLRs with the very extended one recently discovered in the narrow-line Seyfert 1 (NLS1) galaxy Mrk 783. We have found several evidences of interaction between the ISM of the galaxies and their radio jets, such as (a) the contribution of shocks in ionizing the high velocity gas, (b) the complex kinematics showed by the profile of the emission lines, (c) the high fragmentation of matter, etc. The results suggest that the ENLR of IC 5063 have a hollow bi-conical shape, with one edge aligned to the galaxy disk, which may cause some kind of dependence on velocity of the ionization parameter. Regarding the Mrk 783 properties, it is found that the extension of the optical emission is almost twice the size of the radio one and it seems due to the AGN activity, although there is contamination by star formation around 12 arcsec from the nucleus. Diagnostic diagrams excluded the contribution of star formation in IC 5063 and NGC 7212, while the shock contribution was used to explain the spectra emitted by their high velocity gas.

  5. Extended Narrow-Line Region in Seyfert Galaxies

    Congiu, Enrico; Contini, Marcella; Ciroi, Stefano; Cracco, Valentina; Di Mille, Francesco; Berton, Marco; Frezzato, Michele; La Mura, Giovanni; Rafanelli, Piero

    2017-01-01

    We present our recent results about the extended narrow-line region (ENLR) of two nearby Seyfert 2 galaxies (IC 5063 and NGC 7212) obtained by modeling the observed line profiles and spectra with composite models (photoionization+shocks) in the different regions surrounding the AGN. Then, we compare the Seyfert 2 ENLRs with the very extended one recently discovered in the narrow-line Seyfert 1 (NLS1) galaxy Mrk 783. We have found several evidences of interaction between the ISM of the galaxies and their radio jets, such as (a) the contribution of shocks in ionizing the high velocity gas, (b) the complex kinematics showed by the profile of the emission lines, (c) the high fragmentation of matter, etc. The results suggest that the ENLR of IC 5063 have a hollow bi-conical shape, with one edge aligned to the galaxy disk, which may cause some kind of dependence on velocity of the ionization parameter. Regarding the Mrk 783 properties, it is found that the extension of the optical emission is almost twice the size of the radio one and it seems due to the AGN activity, although there is contamination by star formation around 12 arcsec from the nucleus. Diagnostic diagrams excluded the contribution of star formation in IC 5063 and NGC 7212, while the shock contribution was used to explain the spectra emitted by their high velocity gas.

  6. Spectral Line Shapes in Plasmas and Gases

    Oks, E.; Dalimier, D.; Stamm, R.; Stehle, CH.; Gonzalez, M.A.

    2011-01-01

    The subject of spectral line shapes (SLS), a.k.a. spectral line broadening, which embraces both shapes and shifts of spectral lines, is of both fundamental and practical importance. On the fundamental side, the study of the spectral line profiles reveals the underlying atomic and molecular interactions. On the practical side, the spectral line profiles are employed as powerful diagnostic tools for various media, such as neutral gases, technological gas discharges, magnetically confined plasmas for fusion, laser- and Z-pinch-produced plasmas (for fusion and other purposes), astrophysical plasmas (most importantly, solar plasmas), and planetary atmospheres. The research area covered by this special issue includes both the SLS dominated by various electric fields (including electron and ion micro fields in strongly ionized plasmas) and the SLS controlled by neutral particles. In the physical slang, the former is called plasma broadening while the latter is called neutral broadening (of course, the results of neutral broadening apply also to the spectral line broadening in neutral gases)

  7. Are Narrow Line Seyfert 1 Galaxies Viewed Pole-on?

    2011-04-01

    0.2’’ respectively. Figure 1 displays the position of each slit over a Barbosa et al. (2009) GMOS IFU image of the [S III] flux (which originates...C. Winge, H. Schmitt: Gemini/ GMOS IFU gas velocity ’tomography’ of the narrow line region of nearby active galaxies, MNRAS, 396 (2009) 2. [2] D...1995) 81. 4 P o S ( N L S 1 ) 0 5 0 Are NLS1s Pole-on? Travis C. Fischer 5 Figure 1: NGC 4051 GMOS IFU image showing integrated [SIII] flux

  8. GOSAT-2014 methane spectral line list

    Nikitin, A.V.; Lyulin, O.M.; Mikhailenko, S.N.; Perevalov, V.I.; Filippov, N.N.; Grigoriev, I.M.; Morino, I.; Yoshida, Y.; Matsunaga, T.

    2015-01-01

    The updated methane spectral line list GOSAT-2014 for the 5550–6240 cm −1 region with the intensity cutoff of 5×10 –25 cm/molecule at 296 K is presented. The line list is based on the extensive measurements of the methane spectral line parameters performed at different temperatures and pressures of methane without and with buffer gases N 2 , O 2 and air. It contains the following spectral line parameters of about 12150 transitions: line position, line intensity, energy of lower state, air-induced and self-pressure-induced broadening and shift coefficients and temperature exponent of air-broadening coefficient. The accuracy of the line positions and intensities are considerably improved in comparison with the previous version GOSAT-2009. The improvement of the line list is done mainly due to the involving to the line position and intensity retrieval of six new spectra recorded with short path way (8.75 cm). The air-broadening and air-shift coefficients for the J-manifolds of the 2ν 3 (F 2 ) band are refitted using the new more precise values of the line positions and intensities. The line assignment is considerably extended. The lower state J-value was assigned to 6397 lines representing 94.4% of integrated intensity of the considering wavenumber region. The complete assignment was done for 2750 lines. - Highlights: • The upgrade of the GOSAT methane line list in the 5550–6240 cm −1 region is done. • 12,146 experimental methane line positions and intensities are retrieved. • 6376 lower energy levels for methane lines are determined

  9. Chemical exchange effects in spectral line shapes

    Diaz, M.A.; Veguillas, J.

    1990-01-01

    A theory of spectral-line shapes has been extended to the case in which relaxation broadening may be influenced by reactive interactions. This extension is valid for gaseous systems in the same way it is valid for condensed media, and particularly, for such chemical mechanisms as isomerizations. The dependence of the spectral rate on the chemical exchange rate is clarified. Finally, a discussion concerning the above aspects and their applications has been included. (author)

  10. Constancy of spectral-line bisectors

    Gray, D.F.

    1983-01-01

    Bisectors of spectral line profiles in cool stars indicate the strength of convection in the photospheres of these objects. The present investigation is concerned with the feasibility of studying time variations in line bisectors, the reality of apparent line-to-line differences within the same stellar spectrum, and bisector differences between stars of identical spectral types. The differences considered pertain to the shape of the bisector. The material used in the investigation was acquired at the McDonald Observatory using a 1728 diode Reticon array at the coudefocus of the 2.1-m telescope. Observed bisector errors are discussed. It is established that different lines in the same star show significantly different bisectors. The observed error bands are shown by the shaded regions. The slope and curvature are unique for each case

  11. Spectral line polarimetry with a channeled polarimeter.

    van Harten, Gerard; Snik, Frans; Rietjens, Jeroen H H; Martijn Smit, J; Keller, Christoph U

    2014-07-01

    Channeled spectropolarimetry or spectral polarization modulation is an accurate technique for measuring the continuum polarization in one shot with no moving parts. We show how a dual-beam implementation also enables spectral line polarimetry at the intrinsic resolution, as in a classic beam-splitting polarimeter. Recording redundant polarization information in the two spectrally modulated beams of a polarizing beam-splitter even provides the possibility to perform a postfacto differential transmission correction that improves the accuracy of the spectral line polarimetry. We perform an error analysis to compare the accuracy of spectral line polarimetry to continuum polarimetry, degraded by a residual dark signal and differential transmission, as well as to quantify the impact of the transmission correction. We demonstrate the new techniques with a blue sky polarization measurement around the oxygen A absorption band using the groundSPEX instrument, yielding a polarization in the deepest part of the band of 0.160±0.010, significantly different from the polarization in the continuum of 0.2284±0.0004. The presented methods are applicable to any dual-beam channeled polarimeter, including implementations for snapshot imaging polarimetry.

  12. Spectral narrowing of a 980 nm tapered diode laser bar

    Vijayakumar, Deepak; Jensen, Ole Bjarlin; Lucas Leclin, Gaëlle

    2011-01-01

    High power diode laser bars are interesting in many applications such as solid state laser pumping, material processing, laser trapping, laser cooling and second harmonic generation. Often, the free running laser bars emit a broad spectrum of the order of several nanometres which limit their scope...... been "smile corrected" using individual phase masks for each emitter. The external cavity consists of the laser bar, both fast and slow axis micro collimators, smile correcting phase mask, 6.5x beam expanding lens combination, a 1200 lines/mm reflecting grating with 85% efficiency in the first order......, a slow axis focusing cylindrical lens of 40 mm focal length and an output coupler which is 10% reflective. In the free running mode, the laser emission spectrum was 5.5 nm wide at an operating current of 30A. The output power was measured to be in excess of 12W. Under the external cavity operation...

  13. Spectral classification of emission-line galaxies

    Veilleux, S.; Osterbrock, D.E.

    1987-01-01

    A revised method of classification of narrow-line active galaxies and H II region-like galaxies is proposed. It involves the line ratios which take full advantage of the physical distinction between the two types of objects and minimize the effects of reddening correction and errors in the flux calibration. Large sets of internally consistent data are used, including new, previously unpublished measurements. Predictions of recent photoionization models by power-law spectra and by hot stars are compared with the observations. The classification is based on the observational data interpreted on the basis of these models. 63 references

  14. Narrow spectral linewidth in InAs/InP quantum dot distributed feedback lasers

    Duan, J.; Huang, H.; Lu, Z. G.; Poole, P. J.; Wang, C.; Grillot, F.

    2018-03-01

    This paper reports on the spectral linewidth of InAs/InP quantum dot distributed feedback lasers. Owing to a low inversion factor and a low linewidth enhancement factor, a narrow spectral linewidth of 160 kHz (80 kHz intrinsic linewidth) with a low sensitivity to temperature is demonstrated. When using anti-reflection coatings on both facets, narrow linewidth operation is extended to high powers, believed to be due to a reduction in the longitudinal spatial hole burning. These results confirm the high potential of quantum dot lasers for increasing transmission capacity in future coherent communication systems.

  15. Phase coherence and Rabi frequency induced ultranarrow spectral line

    Dutta, Bibhas Kumar; Panchadhyayee, Pradipta; Mahapatra, Prasanta Kumar

    2012-01-01

    A scheme is proposed to achieve ultranarrow spectral line in the fluorescence spectrum of a lifetime broadened multilevel phase-coherent atom. It is shown that for weak-field coupling, ultranarrow spectral feature in the fluorescence spectrum can be generated by controlling the values of the Rabi frequencies involved in the coherent mechanism of the system. For fixed values of the Rabi frequencies in the weak-field limit, ultranarrow feature appears in the spectrum through the adjustment of the relative phase of the coherent fields. The results highlight that, larger the values of the decay rates associated with the field-driven channels, more pronounced is the phenomenon of narrowing in the spectrum.

  16. Production of highly polarized 3He using spectrally narrowed diode laser array bars

    Chann, B.; Babcock, E.; Anderson, L.W.; Walker, T.G.; Chen, W.C.; Smith, T.B.; Thompson, A.K.; Gentile, T.R.

    2003-01-01

    We have produced 70%-75% 3 He polarization by spin-exchange optical pumping in cells ≅100 cm 3 in volume. The polarization achieved is consistent with known spin-exchange and spin-relaxation rates, but only when the recently discovered temperature dependence of 3 He relaxation is included. Absolute 3 He polarization measurements were performed using two different methods in two different laboratories. The results were obtained with either a spectrally narrowed laser or one type of broadband laser. Based on tests of several larger cells at pressures near 1 bar, we find that the power required to reach the same polarization is typically three times lower for the spectrally narrowed laser. This last result indicates that spectrally narrowed lasers will be important for obtaining the highest polarization in large volume neutron spin filters. Polarization in excess of 55% as obtained in cells up to 640 cm 3 in volume and 70% polarization is anticipated with available increases in spectrally narrowed laser power

  17. Handbook of spectral lines in diamond

    Dischler, Bernhard

    2012-01-01

    This handbook is a breakthrough in the understanding of the large number of spectral lines in diamond. Data on more than 2000 lines and bands are presented in 200 tables, including many unpublished results. With a novel organization scheme, the search for a specific line is greatly simplified as a benefit for researchers and students. In order to meet the interest in the understanding of the spectra, structure assignments for 80 % of the lines are given, of which 15 % only were published before. The majority of the structures for the 300 centers is explained in most cases for the first time. A key instrument in the interpretation is the analysis by donor-acceptor pair transitions. In a special chapter 95 such centers are listed and discussed, of which only two have been published before, the first one by the present author in 1994.

  18. Narrow absorption lines with two observations from the Sloan Digital Sky Survey

    Chen, Zhi-Fu; Gu, Qiu-Sheng; Chen, Yan-Mei; Cao, Yue

    2015-07-01

    We assemble 3524 quasars from the Sloan Digital Sky Survey (SDSS) with repeated observations to search for variations of the narrow C IV λ λ 1548,1551 and Mg II λ λ 2796,2803 absorption doublets in spectral regions shortward of 7000 Å in the observed frame, which corresponds to time-scales of about 150-2643 d in the quasar rest frame. In these quasar spectra, we detect 3580 C IV absorption systems with zabs = 1.5188-3.5212 and 1809 Mg II absorption systems with zabs = 0.3948-1.7167. In term of the absorber velocity (β) distribution in the quasar rest frame, we find a substantial number of C IV absorbers with β Hacker et al. However, in our Mg II absorption sample, we find that neither shows variable absorption with confident levels of >4σ for λ2796 lines and >3σ for λ2803 lines.

  19. Distributed seeding for narrow-line width hard x-ray free-electron lasers

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Anisimov, Petr Mikhaylovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Buechler, Cynthia Eileen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lewellen, IV, John W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Marksteiner, Quinn R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-09

    We describe a new FEL line-narrowing technique called distributed seeding (DS), using Si(111) Bragg crystal monochromators to enhance the spectral brightness of the MaRIE hard X-ray freeelectron laser. DS differs from self-seeding in three important aspects. First, DS relies on spectral filtering of the radiation at multiple locations along the undulator, with a monochromator located every few power gain lengths. Second, DS performs filtering early in the exponential gain region before SASE spikes start to appear in the radiation longitudinal profile. Third, DS provides the option to select a wavelength longer than the peak of the SASE gain curve, which leads to improved spectral contrast of the seeded FEL over the SASE background. Timedependent Genesis simulations show the power-vs-z growth curves for DS exhibit behaviors of a seeded FEL amplifier, such as exponential growth region immediately after the filters. Of the seeding approaches considered, the two-stage DS spectra produce the highest contrast of seeded FEL over the SASE background and that the three-stage DS provides the narrowest linewidth with a relative spectral FWHM of 8 X 10-5 .

  20. Transparency or spectral narrowing for two-mode squeezing and entanglement

    Hu Xiangming; Oh, C. H.

    2011-01-01

    We analyze the nonadiabatic effects on the propagation of a two-mode squeezed field inside a medium of three-level Λ atoms that display the dark resonance. We identify the different effects for the two-mode quantum properties: (i) unconditional transparency for the sum squeezing and (ii) induced transparency or spectral narrowing for the difference squeezing depending on the relative widths of the initial correlation spectrum to the transparency window. These effects combine to induce transparency or spectrum narrowing for the bipartite entanglement. The potential applications range from quantum information to laser spectroscopy and frequency standards.

  1. Variable blurred reflection in the narrow-line Seyfert 1 galaxy Mrk 493

    Bonson, K.; Gallo, L. C.; Wilkins, D. R.; Fabian, A. C.

    2018-04-01

    We examine a 200 ks XMM-Newton observation of the narrow-line Seyfert 1 galaxy Mrk 493. The active galaxy was half as bright as in a previous 2003 snapshot observation and the current lower flux enables a study of the putative reflection component in detail. We determine the characteristics of the 2015 X-ray continuum by first analyzing the short-term variability using model-independent techniques. We then continue with a time-resolve analysis including spectral fitting and modelling the fractional variability. We determine that the variability arises from changes in the amount of primary flux striking the accretion disk, which induces changes in the ionization parameter and flux of the blurred reflection component. The observations seem consistent with the picture that the primary source is of roughly constant brightness and that variations arise from changes in the degree of light bending happening in the vicinity of the supermassive black hole.

  2. Optical Variability of Narrow-line and Broad-line Seyfert 1 Galaxies

    Rakshit, Suvendu; Stalin, C. S.

    2017-06-01

    We studied the optical variability (OV) of a large sample of narrow-line Seyfert 1 (NLSy1) and broad-line Seyfert 1 (BLSy1) galaxies with z anti-correlated with Fe II strength but correlated with the width of the Hβ line. The well-known anti-correlation of variability-luminosity and the variability-Eddington ratio is present in our data. Among the radio-loud sample, variability amplitude is found to be correlated with radio-loudness and radio-power, suggesting that jets also play an important role in the OV in radio-loud objects, in addition to the Eddington ratio, which is the main driving factor of OV in radio-quiet sources.

  3. ON THE APPARENT NARROWING OF RADIO RECOMBINATION LINES AT HIGH PRINCIPAL QUANTUM NUMBERS

    Alexander, J.; Gulyaev, S.

    2012-01-01

    We critically analyze the Bell et al. findings on 'anomalous' widths of high-order hydrogen radio recombination lines in the Orion Nebula at 6 GHz. We review their method of modified frequency switching and show that the way this method is used for large Δn is not optimal and can lead to misinterpretation of measured spectral line parameters. Using a model of the Orion Nebula, conventional broadening theory, and Monte Carlo simulation, we determine a transition zone n = 224, ..., 241 (Δn = 11, ..., 14), where measurement errors grow quickly with n and become comparable with the measurement values themselves. When system noise and spectrum channelization are accounted for, our simulation predicts 'processed' line narrowing in the transition zone similar to that reported by Bell et al. We find good agreement between our simulation results and their findings, both in line temperatures and widths. We conclude, therefore, that Bell et al.'s findings do not indicate a need to revise Stark broadening theory.

  4. Time-dependent narrow emission-line profiles of quasars and active galactic nuclei

    Capriotti, E.R.; Foltz, C.B.

    1982-01-01

    The narrow-line emitting regions of quasars and active nuclei of galaxies are assumed to consist of material undergoing gravitational infall due to acceleration by centrally located mass concentrations. Two cases are considered. In one, the material is assumed to be in the form of optically thick, similar clouds which emit line radiation monochromatically, isotropically and in inverse proportion to the square of the distance from the center of the system. In the other case, the material is assumed to be homogeneous, isothermal and to have the same ionization structure everywhere. The material is assumed to be excited by an ionizing continuum created ty a supernova-like outburst of radiation. Line profiles are computed for various combinations of epoch after outburst, continuum decay times, and spectral resolution. The computed profiles are clearly asymmetric to the blue of the profile peak and for certain combinations of epoch and decay time, clearly asymmetric to the blue of line center. The computed profiles compare well with many observed [O III] profiles

  5. Spectral design of temperature-invariant narrow bandpass filters for the mid-infrared

    Stolberg-Rohr, Thomine Kirstine; Hawkins, Gary J.

    2015-01-01

    The ability of narrow bandpass filters to discriminatewavelengths between closely-separated gas absorption lines is crucial inmany areas of infrared spectroscopy. As improvements to the sensitivity ofinfrared detectors enables operation in uncontrolled high-temperature environments, this imposes ...... presents the results of an investigation into the interdependence between multilayer bandpass designand optical materials together with a review on invariance at elevated temperatures....

  6. SBS 0846+513: a New Gamma-ray Emitting Narrow-line Seyfert 1 Galaxy

    D'Ammando, F.; Orienti, M.; Finke, J.; Raiteri, C. M.; Angelakis, E.; Fuhrmann, L.; Giroletti, M.; Hovatta, T.; Max-Moerbeck, W.; Perkins, J. S.; hide

    2012-01-01

    We report Fermi-LAT observations of the radio-loud AGN SBS 0846+513 (z=0.5835), optically classified as a Narrow-Line Seyfert 1 galaxy, together with new and archival radio-to-X-ray data. The source was not active at ?-ray energies during the first two years of Fermi operation. A significant increase in activity was observed during 2010 October-2011 August. In particular a strong gamma-ray flare was observed in 2011 June reaching an isotropic ?-ray luminosity (0.1-300 GeV) of 1.0×10(sup 48) erg s(sup -1), comparable to that of the brightest flat spectrum radio quasars, and showing spectral evolution in gamma rays. An apparent superluminal velocity of (8.2+/-1.5)c in the jet was inferred from 2011-2012 VLBA images, suggesting the presence of a highly relativistic jet. Both the power released by this object during the flaring activity and the apparent superluminal velocity are strong indications of the presence of a relativistic jet as powerful as those of blazars. In addition, variability and spectral properties in radio and gamma-ray bands indicate blazar-like behaviour, suggesting that, except for some distinct optical characteristics, SBS 0846+513 could be considered as a young blazar at the low end of the blazar's black hole mass distribution.

  7. Narrow linewidth operation of a spectral beam combined diode laser bar.

    Zhu, Zhanda; Jiang, Menghua; Cheng, Siqi; Hui, Yongling; Lei, Hong; Li, Qiang

    2016-04-20

    Our experiment is expected to provide an approach for realizing ultranarrow linewidth for a spectral beam combined diode laser bar. The beams of a diode laser bar are combined in a fast axis after a beam transformation system. With the help of relay optics and a transform lens with a long focal length of 1.5 m, the whole wavelength of a spectral combined laser bar can be narrowed down to 0.48 nm from more than 10 nm. We have achieved 56.7 W cw from a 19-element single bar with an M2 of 1.4  (in horizontal direction)×11.6  (in vertical direction). These parameters are good evidence that all the beams from the diode laser bar are combined together to increase the brightness.

  8. Occurrence and Global Properties of Narrow CIV lambda 1549 Absorption Lines in Moderate-Redshift Quasars

    Vestergaard, Marianne

    2003-01-01

    A statistical study is presented of (a) the frequency of narrow CIV lambda 1549 absorption lines in 1.5 ~50%) of narrow CIV absorbers is detected for the radio-quiet and radio-loud quasars, and a constant ~25% of all the quasars, irrespective of radio type display associated CIV absorbers stronger...

  9. Optocoupled line receiver input discriminates against narrow noise pulses

    Napier, T M

    1977-01-01

    Describes a simple optocoupled interface which connects a data line to the receiving end of a data link that features pulse length discrimination to enhance noise pulse rejection. A rugged red LED, D /sub 1/, can bypass any reasonable fault currents to protect the relatively fragile optocoupler input diode. (0 refs).

  10. Narrow-line laser cooling by adiabatic transfer

    Norcia, Matthew A.; Cline, Julia R. K.; Bartolotta, John P.; Holland, Murray J.; Thompson, James K.

    2018-02-01

    We propose and demonstrate a novel laser cooling mechanism applicable to particles with narrow-linewidth optical transitions. By sweeping the frequency of counter-propagating laser beams in a sawtooth manner, we cause adiabatic transfer back and forth between the ground state and a long-lived optically excited state. The time-ordering of these adiabatic transfers is determined by Doppler shifts, which ensures that the associated photon recoils are in the opposite direction to the particle’s motion. This ultimately leads to a robust cooling mechanism capable of exerting large forces via a weak transition and with reduced reliance on spontaneous emission. We present a simple intuitive model for the resulting frictional force, and directly demonstrate its efficacy for increasing the total phase-space density of an atomic ensemble. We rely on both simulation and experimental studies using the 7.5 kHz linewidth 1S0 to 3P1 transition in 88Sr. The reduced reliance on spontaneous emission may allow this adiabatic sweep method to be a useful tool for cooling particles that lack closed cycling transitions, such as molecules.

  11. Narrow absorption lines complex I: one form of broad absorption line

    Lu, Wei-Jian; Lin, Ying-Ru

    2018-03-01

    We discover that some of the broad absorption lines (BALs) are actually a complex of narrow absorption lines (NALs). As a pilot study of this type of BAL, we show this discovery through a typical example in this paper. Utilizing the two-epoch observations of J002710.06-094435.3 (hereafter J0027-0944) from the Sloan Digital Sky Survey (SDSS), we find that each of the C IV and Si IV BAL troughs contains at least four NAL doublets. By resolving the Si IV BAL into multiple NALs, we present the following main results and conclusions. First, all these NALs show coordinated variations between the two-epoch SDSS observations, suggesting that they all originate in the quasar outflow, and that their variations are due to global changes in the ionization condition of the absorbing gas. Secondly, a BAL consisting of a number of NAL components indicates that this type of BAL is basically the same as the intrinsic NAL, which tends to support the inclination model rather than the evolution model. Thirdly, although both the C IV and Si IV BALs originate from the same clumpy substructures of the outflow, they show different profile shapes: multiple absorption troughs for the Si IV BAL in a wider velocity range, while P-Cygni for the C IV BAL in a narrower velocity range. This can be interpreted by the substantial differences in fine structure and oscillator strength between the Si IVλλ1393, 1402 and C IVλλ1548, 1551 doublets. Based on the above conclusions, we consider that the decomposition of a BAL into NALs can serve as a way to resolve the clumpy structure for outflows, and it can be used to learn more about characteristics of the clumpy structure and to test the outflow model, when utilizing high-resolution spectra and photoionization model.

  12. Optical Variability of Narrow-line and Broad-line Seyfert 1 Galaxies

    Rakshit, Suvendu; Stalin, C. S., E-mail: suvenduat@gmail.com [Indian Institute of Astrophysics, Block II, Koramangala, Bangalore-560034 (India)

    2017-06-20

    We studied the optical variability (OV) of a large sample of narrow-line Seyfert 1 (NLSy1) and broad-line Seyfert 1 (BLSy1) galaxies with z < 0.8 to investigate any differences in their OV properties. Using archival optical V -band light curves from the Catalina Real Time Transient Survey that span 5–9 years and modeling them using damped random walk, we estimated the amplitude of variability. We found that NLSy1 galaxies as a class show lower amplitude of variability than their broad-line counterparts. In the sample of both NLSy1 and BLSy1 galaxies, radio-loud sources are found to have higher variability amplitude than radio-quiet sources. Considering only sources that are detected in the X-ray band, NLSy1 galaxies are less optically variable than BLSy1 galaxies. The amplitude of variability in the sample of both NLSy1 and BLSy1 galaxies is found to be anti-correlated with Fe ii strength but correlated with the width of the H β line. The well-known anti-correlation of variability–luminosity and the variability–Eddington ratio is present in our data. Among the radio-loud sample, variability amplitude is found to be correlated with radio-loudness and radio-power, suggesting that jets also play an important role in the OV in radio-loud objects, in addition to the Eddington ratio, which is the main driving factor of OV in radio-quiet sources.

  13. Laser-induced fluorescence line narrowing in atomic vapors

    Meier, T.; Schuessler, H.A.

    1983-01-01

    The use of highly monochromatic light allows the selective excitation of atoms in vapors if excitation and detection of the fluorescence is carried out collinearly. The atoms capable of absorbing light then form an atomic beam of well defined velocity along the direction of the laser beam, but no velocity selection occurs perpendicular to it. The potential of the technique for Doppler-free atomic spectroscopy and for the study of excited atom collisions is demonstrated using the Na D 1 line as an example

  14. Narrow line width operation of a 980 nm gain guided tapered diode laser bar

    Vijayakumar, Deepak; Jensen, Ole Bjarlin; Barrientos-Barria, Jessica

    2011-01-01

    We demonstrate two different schemes for the spectral narrowing of a 12 emitter 980 nm gain guided tapered diode laser bar. In the first scheme, a reflective grating has been used in a Littman Metcalf configuration and the wavelength of the laser emission could be narrowed down from more than 5.......5 nm in the free running mode to 0.04 nm (FWHM) at an operating current of 30 A with an output power of 8 W. The spectrum was found to be tunable within a range of 16 nm. In the second scheme, a volume Bragg grating has been used to narrow the wavelength of the laser bar from over 5 nm to less than 0.......2 nm with an output of 5 W at 20 A. To our knowledge, this is the first time spectral narrowing has been performed on a gain guided tapered diode laser bar. In the Littman Metcalf configuration, the spectral brightness has been increased by 86 times and in the volume Bragg grating cavity the spectral...

  15. Narrow CIV lambda 1549A Absorption Lines in Moderate-Redshift Quasars

    Vestergaard, Marianne

    2002-01-01

    A large, high-quality spectral data base of well-selected, moderate-redshift radio-loud and radio-quiet quasars is used to characterize the incidence of narrow associated CIV lambda 1549 absorption, and how this may depend on some quasar properties, including radio-type. Preliminary results...

  16. NARROW-LINE X-RAY-SELECTED GALAXIES IN THE CHANDRA -COSMOS FIELD. I. OPTICAL SPECTROSCOPIC CATALOG

    Pons, E.; Watson, M. G. [University of Leicester, Leicester (United Kingdom); Elvis, M.; Civano, F. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)

    2016-04-20

    The COSMOS survey is a large and deep survey with multiwavelength observations of sources from X-rays to the UV, allowing an extensive study of their properties. The central 0.9 deg{sup 2} of the COSMOS field have been observed by Chandra with a sensitivity up to 1.9 × 10{sup −16} erg cm{sup −2} s{sup −1} in the full (0.5–10 keV) band. Photometric and spectroscopic identification of the Chandra -COSMOS (C-COSMOS) sources is available from several catalogs and campaigns. Despite the fact that the C-COSMOS galaxies have a reliable spectroscopic redshift in addition to a spectroscopic classification, the emission-line properties of this sample have not yet been measured. We present here the creation of an emission-line catalog of 453 narrow-line sources from the C-COSMOS spectroscopic sample. We have performed spectral fitting for the more common lines in galaxies ([O ii] λ 3727, [Ne iii] λ 3869, H β , [O iii] λλ 4959, 5007, H α , and [N ii] λλ 6548, 6584). These data provide an optical classification for 151 (i.e., 33%) of the C-COSMOS narrow-line galaxies based on emission-line diagnostic diagrams.

  17. The peculiar radio-loud narrow line Seyfert 1 galaxy 1H 0323+342

    Paliya, Vaidehi S.; Stalin, C. S. [Indian Institute of Astrophysics, Block-II, Koramangala, Bangalore-560034 (India); Sahayanathan, S. [Astrophysical Science Division, Bhabha Atomic Research Center, Mumbai-400085 (India); Parker, M. L.; Fabian, A. C. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Anjum, Ayesha [Department of Physics, Christ University, Bangalore-560029 (India); Pandey, S. B., E-mail: vaidehi@iiap.res.in [Aryabhatta Research Institute of Observational Sciences, Manora peak, Nainital-263129 (India)

    2014-07-10

    We present a multiwavelength study of the radio-loud narrow-line Seyfert 1 galaxy (NLSy1) 1H 0323+342, detected by the Fermi Gamma-Ray Space Telescope. Multiband light curves show many orphan X-ray and optical flares having no corresponding γ-ray counterparts. Such anomalous variability behavior can be due to different locations of the emission region from the central source. During a large flare, a γ-ray flux doubling timescale as small as ∼3 hr is noticed. We built spectral energy distributions (SEDs) during different activity states and modeled them using a one-zone leptonic model. The shape of the optical/UV component of the SEDs is dominated by accretion disk emission in all the activity states. In the X-ray band, significant thermal emission from the hot corona is inferred during quiescent and first flaring states; however, during subsequent flares, the nonthermal jet component dominates. The γ-ray emission in all the states can be well explained by inverse-Compton scattering of accretion disk photons reprocessed by the broad-line region. The source showed violent intra-night optical variability, coinciding with one of the high γ-ray activity states. An analysis of the overall X-ray spectrum fitted with an absorbed power-law plus relativistic reflection component hints at the presence of an Fe Kα line and returns a high black hole spin value of a = 0.96 ± 0.14. We argue that 1H 0323+342 possesses dual characteristics, akin to both flat-spectrum radio quasars (FSRQs) and radio-quiet NLSy1 galaxies, though at a low jet power regime compared to powerful FSRQs.

  18. A study of the structure and kinematics of the narrow-line region in Seyfert galaxies

    Veilleux, S.

    1989-01-01

    The results of a high resolution study of the narrow emission line profiles of 16 Seyfert galaxies are presented. It is shown that the line profile parameters published in earlier low resolution studies are sometimes strongly influenced by resolution effects. In spite of these important systematic errors, many of the results derived from low resolution data are confirmed in the high resolution data. The narrow line profiles of Seyfert galaxies have a stronger base relative to core than a Gaussian. Most of the emission lines present a blueward asymmetry in the lower portion of their profile. In some galaxies, the line widths and/or line asymmetries are correlated with the ionization potential and/or critical density of the lines. There is a weak correlation between the line asymmetry and the dust content of the narrow line region (NLR). The large scatter in this relation, the absence of a similar correlation in Seyfert 1 to 1.5 galaxies, and the presence of a blue asymmetry in galaxies with dustfree line-emitting regions suggest that dust obscuration is not the only mechanism responsible for the line asymmetry in active galaxies. An optically-thick disk close to the nucleus is proposed as the other source of line asymmetry. An important result is that the host galaxy is probably playing a role in the kinematics of some of the gas in the NLR. A multicomponent model of the NLR is proposed to explain these results

  19. Effects of self-similar correlations on the spectral line shape in the neutral gas

    Kharintsev, S.S.; Salakhov, M.Kh.

    2001-01-01

    The paper is devoted to the study of the influence of self-similar correlations on the Doppler and pressure broadening within the non-equilibrium Boltzmann gas. The diffuse model for the thermal motion of the radiator and the self-similar mechanism of interference of scalar perturbations for phase shifts of an atomic oscillator are developed. It is shown that taking into account self-similar correlation in a description of the spectral line shape allows one to explain, on the one hand, the additional spectral line Dicke-narrowing in the Doppler regime, and, on the other hand, the asymmetry in wings of the spectral line in a high pressure region

  20. Relative spectral response calibration using Ti plasma lines

    Teng, FEI; Congyuan, PAN; Qiang, ZENG; Qiuping, WANG; Xuewei, DU

    2018-04-01

    This work introduces the branching ratio (BR) method for determining relative spectral responses, which are needed routinely in laser induced breakdown spectroscopy (LIBS). Neutral and singly ionized Ti lines in the 250–498 nm spectral range are investigated by measuring laser-induced micro plasma near a Ti plate and used to calculate the relative spectral response of an entire LIBS detection system. The results are compared with those of the conventional relative spectral response calibration method using a tungsten halogen lamp, and certain lines available for the BR method are selected. The study supports the common manner of using BRs to calibrate the detection system in LIBS setups.

  1. Fermi monitoring of radio-loud narrow-line Seyfert 1 galaxies

    Paliya, Vaidehi S.; Stalin, C. S.; Ravikumar, C. D.

    2015-01-01

    We present detailed analysis of the γ-ray flux variability and spectral properties of the five radio-loud narrow line Seyfert 1 (RL-NLSy1) galaxies, detected by the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope, namely 1H 0323+342, SBS 0846+513, PMN J0948+0022, PKS 1502+036, and PKS 2004−447. The first three sources show significant flux variations, including the rapid variability of a few hours by 1H 0323+342. The average γ-ray spectrum of 1H 0323+342 and PMN J0948+0022 shows deviation from a simple power-law (PL) behavior, whereas the PL model gives a better fit for the other three sources. The spectra of 1H 0323+342, SBS 0846+513, and PMN J0948+0022, which are in low, flaring, and moderately active states, respectively, show significant curvature. Such curvature in the γ-ray spectrum of 1H 0323+342 and PMN J0948+0022 could be due to the emission region located inside the broad line region (BLR) where the primary mechanism of the γ-ray emission is inverse-Compton (IC) scattering of BLR photons occurring in the Klein–Nishina regime. The γ-ray emission of SBS 0846+513 is explained by IC scattering of dusty torus photons, which puts the emission region outside the BLR and thus under the Thomson regime. Therefore, the observed curvature of SBS 0846+513 could be intrinsic to the particle energy distribution. The presence of curvature in the γ-ray spectrum and flux variability amplitudes of some of the RL-NLSy1 galaxies suggests that these sources could be akin to low/moderate jet power flat spectrum radio quasars.

  2. Fermi monitoring of radio-loud narrow-line Seyfert 1 galaxies

    Paliya, Vaidehi S.; Stalin, C. S. [Indian Institute of Astrophysics, Block II, Koramangala, Bangalore-560034 (India); Ravikumar, C. D., E-mail: vaidehi@iiap.res.in [Department of Physics, University of Calicut, Malappuram-673635 (India)

    2015-02-01

    We present detailed analysis of the γ-ray flux variability and spectral properties of the five radio-loud narrow line Seyfert 1 (RL-NLSy1) galaxies, detected by the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope, namely 1H 0323+342, SBS 0846+513, PMN J0948+0022, PKS 1502+036, and PKS 2004−447. The first three sources show significant flux variations, including the rapid variability of a few hours by 1H 0323+342. The average γ-ray spectrum of 1H 0323+342 and PMN J0948+0022 shows deviation from a simple power-law (PL) behavior, whereas the PL model gives a better fit for the other three sources. The spectra of 1H 0323+342, SBS 0846+513, and PMN J0948+0022, which are in low, flaring, and moderately active states, respectively, show significant curvature. Such curvature in the γ-ray spectrum of 1H 0323+342 and PMN J0948+0022 could be due to the emission region located inside the broad line region (BLR) where the primary mechanism of the γ-ray emission is inverse-Compton (IC) scattering of BLR photons occurring in the Klein–Nishina regime. The γ-ray emission of SBS 0846+513 is explained by IC scattering of dusty torus photons, which puts the emission region outside the BLR and thus under the Thomson regime. Therefore, the observed curvature of SBS 0846+513 could be intrinsic to the particle energy distribution. The presence of curvature in the γ-ray spectrum and flux variability amplitudes of some of the RL-NLSy1 galaxies suggests that these sources could be akin to low/moderate jet power flat spectrum radio quasars.

  3. Deconvolution of EPR spectral lines with an approximate method

    Jimenez D, H.; Cabral P, A.

    1990-10-01

    A recently reported approximation expression to deconvolution Lorentzian-Gaussian spectral lines. with small Gaussian contribution, is applied to study an EPR line shape. The potassium-ammonium solution line reported in the literature by other authors was used and the results are compared with those obtained by employing a precise method. (Author)

  4. Reddening and He i{sup ∗} λ 10830 Absorption Lines in Three Narrow-line Seyfert 1 Galaxies

    Zhang, Shaohua; Zhou, Hongyan; Shi, Xiheng; Pan, Xiang; Ji, Tuo; Jiang, Peng; Wang, Shufen [Polar Research Institute of China, 451 Jinqiao Road, Shanghai, 200136 (China); Liu, Wenjuan [Key Laboratory for the Structure and Evolution of Celestial Objects, Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China); Jiang, Ning, E-mail: zhangshaohua@pric.org.cn, E-mail: zhouhongyan@pric.org.cn [Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Sciences and Technology of China, Chinese Academy of Sciences, Hefei, Anhui, 230026 (China)

    2017-08-20

    We report the detection of heavy reddening and the He i* λ 10830 absorption lines at the active galactic nucleus (AGN) redshift in three narrow-line Seyfert 1 galaxies: SDSS J091848.61+211717.0, SDSS J111354.66+124439.0, and SDSS J122749.13+321458.9. They exhibit very red optical to near-infrared colors, narrow Balmer/Paschen broad emission lines and He i* λ 10830 absorption lines. The ultraviolet-optical-infrared nucleus continua are reddened by the SMC extinction law of E ( B − V ) ∼ 0.74, 1.17, and 1.24 mag for three objects, which are highly consistent with the values obtained from the broad-line Balmer decrements, but larger than those of narrow emission lines. The reddening analysis suggests that the extinction dust simultaneously obscures the accretion disk, the broad emission-line region, and the hot dust from the inner edge of the torus. It is possible that the dust obscuring the AGN structures is the dusty torus itself. Furthermore, the Cloudy analysis of the He i* λ 10830 absorption lines proposes the distance of the absorption materials to be the extend scale of the torus, which greatly increases probabilities of the obscure and absorption materials being the dusty torus.

  5. Two active states of the narrow-line gamma-ray-loud AGN GB 1310+487

    Sokolovsky, K. V.

    2014-01-01

    Context. Previously unremarkable, the extragalactic radio source GB1310+487 showed a γ-ray flare on 2009 November 18, reaching a daily flux of ~ 10"-"6 photons cm"-"2 s"-"1 at energies E > 100MeV and became one of the brightest GeV sources for about two weeks. Its optical spectrum shows strong forbidden-line emission while lacking broad permitted lines, which is not typical for a blazar. Instead, the spectrum resembles those of narrow emission-line galaxies. Aims. We investigate changes in the object’s radio-to-GeV spectral energy distribution (SED) during and after the prominent γ-ray flare with the aim of determining the nature of the object and of constraining the origin of the variable high-energy emission. Methods. The data collected by the Fermi and AGILE satellites at γ-ray energies; Swift at X-ray and ultraviolet (UV); the Kanata, NOT, and Keck telescopes at optical; OAGH andWISE at infrared (IR); and IRAM30m, OVRO 40m, Effelsberg 100m, RATAN-600, and VLBA at radio are analyzed together to trace the SED evolution on timescales of months. Results. The γ-ray/radio-loud narrow-line active galactic nucleus (AGN) is located at redshift z = 0.638. It shines through an unrelated foreground galaxy at z = 0.500. The AGN light is probably amplified by gravitational lensing. The AGN SED shows a two-humped structure typical of blazars and γ-ray-loud narrow-line Seyfert 1 galaxies, with the high-energy (inverse-Compton) emission dominating by more than an order of magnitude over the low-energy (synchrotron) emission during γ-ray flares. The difference between the two SED humps is smaller during the low-activity state. Fermi observations reveal a strong correlation between the γ-ray flux and spectral index, with the hardest spectrum observed during the brightest γ-ray state. The γ-ray flares occurred before and during a slow rising trend in the radio, but no direct association between γ-ray and radio flares could be established. Conclusions. If the

  6. An XMM-Newton Study of the Bright Ultrasoft Narrow-Line Quasar NAB 0205+024

    Brandt, Niel

    2004-01-01

    The broad-band X-ray continuum of NAB 0205424 is well constrained due to the excellent photon statistics obtained (about 97,700 counts), and its impressive soft X-ray excess is clearly apparent. The hard X-ray power law has become notably steeper than when NAB 0205424 was observed with ASCA, attesting to the presence of significant X-ray spectral variability. A strong and broad emission feature is detected from about 5 to 6.4 keV, and we have modeled this as a relativistic line emitted close to the black hole from a narrow annulus of the accretion disk. Furthermore, a strong X-ray flare is detected with a hard X-ray spectrum; this flare may be responsible for illuminating the inner line-emitting part of the accretion disk. The combined observational results can be broadly interpreted in terms of the "thundercloud model proposed by Merloni & Fabian (2001).

  7. CHEERS Results from NGC 3393. II. Investigating the Extended Narrow-line Region Using Deep Chandra Observations and Hubble Space Telescope Narrow-line Imaging

    Maksym, W. Peter; Fabbiano, Giuseppina; Elvis, Martin; Karovska, Margarita; Paggi, Alessandro; Raymond, John [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Wang, Junfeng [Department of Astronomy, Physics Building, Xiamen University Xiamen, Fujian, 361005 (China); Storchi-Bergmann, Thaisa, E-mail: walter.maksym@cfa.harvard.edu [Departamento de Astronomia, Universidade Federal do Rio Grande do Sul, IF, CP 15051, 91501-970 Porto Alegre, RS (Brazil)

    2017-07-20

    The CHandra Extended Emission Line Region Survey (CHEERS) is an X-ray study of nearby active galactic nuclei (AGNs) designed to take full advantage of Chandra 's unique angular resolution by spatially resolving feedback signatures and effects. In the second paper of a series on CHEERS target NGC 3393, we examine deep high-resolution Chandra images and compare them with Hubble Space Telescope narrow-line images of [O iii], [S ii], and H α , as well as previously unpublished mid-ultraviolet (MUV) images. The X-rays provide unprecedented evidence that the S-shaped arms that envelope the nuclear radio outflows extend only ≲0.″2 (≲50 pc) across. The high-resolution multiwavelength data suggest that the extended narrow-line region is a complex multiphase structure in the circumnuclear interstellar medium (ISM). Its ionization structure is highly stratified with respect to outflow-driven bubbles in the bicone and varies dramatically on scales of ∼10 pc. Multiple findings show likely contributions from shocks to the feedback in regions where radio outflows from the AGN most directly influence the ISM. These findings include H α evidence for gas compression and extended MUV emission and are in agreement with existing STIS kinematics. Extended filamentary structure in the X-rays and optical suggests the presence of an undetected plasma component, whose existence could be tested with deeper radio observations.

  8. CHEERS Results from NGC 3393. II. Investigating the Extended Narrow-line Region Using Deep Chandra Observations and Hubble Space Telescope Narrow-line Imaging

    Maksym, W. Peter; Fabbiano, Giuseppina; Elvis, Martin; Karovska, Margarita; Paggi, Alessandro; Raymond, John; Wang, Junfeng; Storchi-Bergmann, Thaisa

    2017-07-01

    The CHandra Extended Emission Line Region Survey (CHEERS) is an X-ray study of nearby active galactic nuclei (AGNs) designed to take full advantage of Chandra's unique angular resolution by spatially resolving feedback signatures and effects. In the second paper of a series on CHEERS target NGC 3393, we examine deep high-resolution Chandra images and compare them with Hubble Space Telescope narrow-line images of [O III], [S II], and Hα, as well as previously unpublished mid-ultraviolet (MUV) images. The X-rays provide unprecedented evidence that the S-shaped arms that envelope the nuclear radio outflows extend only ≲0.″2 (≲50 pc) across. The high-resolution multiwavelength data suggest that the extended narrow-line region is a complex multiphase structure in the circumnuclear interstellar medium (ISM). Its ionization structure is highly stratified with respect to outflow-driven bubbles in the bicone and varies dramatically on scales of ˜10 pc. Multiple findings show likely contributions from shocks to the feedback in regions where radio outflows from the AGN most directly influence the ISM. These findings include Hα evidence for gas compression and extended MUV emission and are in agreement with existing STIS kinematics. Extended filamentary structure in the X-rays and optical suggests the presence of an undetected plasma component, whose existence could be tested with deeper radio observations.

  9. CHEERS Results from NGC 3393. II. Investigating the Extended Narrow-line Region Using Deep Chandra Observations and Hubble Space Telescope Narrow-line Imaging

    Maksym, W. Peter; Fabbiano, Giuseppina; Elvis, Martin; Karovska, Margarita; Paggi, Alessandro; Raymond, John; Wang, Junfeng; Storchi-Bergmann, Thaisa

    2017-01-01

    The CHandra Extended Emission Line Region Survey (CHEERS) is an X-ray study of nearby active galactic nuclei (AGNs) designed to take full advantage of Chandra 's unique angular resolution by spatially resolving feedback signatures and effects. In the second paper of a series on CHEERS target NGC 3393, we examine deep high-resolution Chandra images and compare them with Hubble Space Telescope narrow-line images of [O iii], [S ii], and H α , as well as previously unpublished mid-ultraviolet (MUV) images. The X-rays provide unprecedented evidence that the S-shaped arms that envelope the nuclear radio outflows extend only ≲0.″2 (≲50 pc) across. The high-resolution multiwavelength data suggest that the extended narrow-line region is a complex multiphase structure in the circumnuclear interstellar medium (ISM). Its ionization structure is highly stratified with respect to outflow-driven bubbles in the bicone and varies dramatically on scales of ∼10 pc. Multiple findings show likely contributions from shocks to the feedback in regions where radio outflows from the AGN most directly influence the ISM. These findings include H α evidence for gas compression and extended MUV emission and are in agreement with existing STIS kinematics. Extended filamentary structure in the X-rays and optical suggests the presence of an undetected plasma component, whose existence could be tested with deeper radio observations.

  10. Microsputterer with integrated ion-drag focusing for additive manufacturing of thin, narrow conductive lines

    Kornbluth, Y. S.; Mathews, R. H.; Parameswaran, L.; Racz, L. M.; Velásquez-García, L. F.

    2018-04-01

    We report the design, modelling, and proof-of-concept demonstration of a continuously fed, atmospheric-pressure microplasma metal sputterer that is capable of printing conductive lines narrower than the width of the target without the need for post-processing or lithographic patterning. Ion drag-induced focusing is harnessed to print narrow lines; the focusing mechanism is modelled via COMSOL Multiphysics simulations and validated with experiments. A microplasma sputter head with gold target is constructed and used to deposit imprints with minimum feature sizes as narrow as 9 µm, roughness as small as 55 nm, and electrical resistivity as low as 1.1 µΩ · m.

  11. THE RADIO PROPERTIES OF RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES ON PARSEC SCALES

    Gu, Minfeng; Chen, Yongjun; Shen, Zhiqiang [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China); Komossa, S.; Zensus, J. A. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Yuan, Weimin [Key Lab for Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Wajima, Kiyoaki [Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong, Daejeon 305-348 (Korea, Republic of); Zhou, Hongyan, E-mail: gumf@shao.ac.cn [Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136 (China)

    2015-11-15

    We present the detection of the compact radio structures of 14 radio-loud narrow-line Seyfert 1 (NLS1) galaxies from Very Long Baseline Array (VLBA) observations at 5 GHz performed in 2013. While 50% of the sources of our sample show a compact core only, the remaining 50% exhibit a core-jet structure. The measured brightness temperatures of the cores range from 10{sup 8.4} to 10{sup 11.4} K with a median value of 10{sup 10.1} K, indicating that the radio emission is from non-thermal jets, and that, likely, most sources are not strongly beamed, thus implying a low jet speed in these radio-loud NLS1 galaxies. In combination with archival data taken at multiple frequencies, we find that seven sources show flat or even inverted radio spectra, while steep spectra are revealed in the remaining seven objects. Although all of these sources are very radio-loud with R > 100, their jet properties are diverse in terms of their milliarcsecond (mas) scale (parsec scale) morphology and their overall radio spectral shape. The evidence for slow jet speeds (i.e., less relativistic jets), in combination with the low kinetic/radio power, may offer an explanation for the compact VLBA radio structure in most sources. The mildly relativistic jets in these high accretion rate systems are consistent with a scenario where jets are accelerated from the hot corona above the disk by the magnetic field and the radiation force of the accretion disk. Alternatively, a low jet bulk velocity can be explained by low spin in the Blandford–Znajek mechanism.

  12. Was the Narrow Line Seyfert 1 RGB J0044+193 ever radio loud?

    Maccarone, T.J.; Miller-Jones, J.C.A.; Fender, R.P.; Pooley, G.G.

    2005-01-01

    We show new radio data and a re-analysis of old data for the Narrow Line Seyfert 1 (NLSy1) galaxy RGB J0044+193. This galaxy has previously been suggested to be both radio loud, and highly variable in the radio. As most NLSy 1 galaxies are radio quiet, this was interpreted as possible evidence that

  13. The Size of Narrow Line Region and [OIII] Luminosity Analyzed from ...

    Abstract. In this work, we constructed a sample of 4002 quasars from. SDSS DR7 quasar catalogue to calculate the electron density and size of narrow line region. We find that the electron densities are ∼103/cm3, and the sizes are between 27 and 775 pc. We also find that, in the ionization cone, the sizes are tightly ...

  14. Spectral line profiles in weakly turbulent plasmas

    Capes, H.; Voslamber, D.

    1976-07-01

    The unified theory of line broadening by electron perturbers is generalized to include the case of a weakly turbulent plasma. The collision operator in the line shape expression is shown to be the sum of two terms, both containing effects arising from the non-equilibrium nature of the plasma. One of the two terms represents the influence of individual atom-particle interactions occuring via the nonequilibrium dielectric plasma medium. The other term is due to the interaction of the atom with the turbulent waves. Both terms contain damping and diffusion effects arising from the plasma turbulence

  15. Ultrafast method of calculating the dynamic spectral line shapes for integrated modelling of plasmas

    Lisitsa, V.S.

    2009-01-01

    An ultrafast code for spectral line shape calculations is presented to be used in the integrated modelling of plasmas. The code is based on the close analogy between two mechanisms: (i) Dicke narrowing of the Doppler-broadened spectral lines and (ii) transition from static to impact regime in the Stark broadening. The analogy makes it possible to describe the dynamic Stark broadening in terms of an analytical functional of the static line shape. A comparison of new method with the widely used Frequency Fluctuating Method (FFM) developed by the Marseille University group (B. Talin, R. Stamm, et al.) shows good agreement, with the new method being faster than the standard FFM by nearly two orders of magnitude. The method proposed may significantly simplify the radiation transport modeling and opens new possibilities for integrated modeling of the edge and divertor plasma in tokamaks. (author)

  16. Detecting Weak Spectral Lines in Interferometric Data through Matched Filtering

    Loomis, Ryan A.; Öberg, Karin I.; Andrews, Sean M.; Walsh, Catherine; Czekala, Ian; Huang, Jane; Rosenfeld, Katherine A.

    2018-04-01

    Modern radio interferometers enable observations of spectral lines with unprecedented spatial resolution and sensitivity. In spite of these technical advances, many lines of interest are still at best weakly detected and therefore necessitate detection and analysis techniques specialized for the low signal-to-noise ratio (S/N) regime. Matched filters can leverage knowledge of the source structure and kinematics to increase sensitivity of spectral line observations. Application of the filter in the native Fourier domain improves S/N while simultaneously avoiding the computational cost and ambiguities associated with imaging, making matched filtering a fast and robust method for weak spectral line detection. We demonstrate how an approximate matched filter can be constructed from a previously observed line or from a model of the source, and we show how this filter can be used to robustly infer a detection significance for weak spectral lines. When applied to ALMA Cycle 2 observations of CH3OH in the protoplanetary disk around TW Hya, the technique yields a ≈53% S/N boost over aperture-based spectral extraction methods, and we show that an even higher boost will be achieved for observations at higher spatial resolution. A Python-based open-source implementation of this technique is available under the MIT license at http://github.com/AstroChem/VISIBLE.

  17. Bioanalytical Applications of Fluorescence Line-Narrowing and Non-Line-Narrowing Spectroscopy Interfaced with Capillary Electrophoresis and High-Performance Liquid Chromatography

    Roberts, Kenneth Paul [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    Capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) are widely used analytical separation techniques with many applications in chemical, biochemical, and biomedical sciences. Conventional analyte identification in these techniques is based on retention/migration times of standards; requiring a high degree of reproducibility, availability of reliable standards, and absence of coelution. From this, several new information-rich detection methods (also known as hyphenated techniques) are being explored that would be capable of providing unambiguous on-line identification of separating analytes in CE and HPLC. As further discussed, a number of such on-line detection methods have shown considerable success, including Raman, nuclear magnetic resonance (NMR), mass spectrometry (MS), and fluorescence line-narrowing spectroscopy (FLNS). In this thesis, the feasibility and potential of combining the highly sensitive and selective laser-based detection method of FLNS with analytical separation techniques are discussed and presented. A summary of previously demonstrated FLNS detection interfaced with chromatography and electrophoresis is given, and recent results from on-line FLNS detection in CE (CE-FLNS), and the new combination of HPLC-FLNS, are shown.

  18. Spectrally narrowed leaky waveguide edge emission and transient electrluminescent dynamics of OLEDs

    Zhengqing, Gan

    2010-01-01

    In summary, there are two major research works presented in this dissertation. The first research project (Chapter 4) is spectrally narrowed edge emission from Organic Light Emitting Diodes. The second project (Chapter 5) is about transient electroluminescent dynamics in OLEDs. Chapter 1 is a general introduction of OLEDs. Chapter 2 is a general introduction of organic semiconductor lasers. Chapter 3 is a description of the thermal evaporation method for OLED fabrication. The detail of the first project was presented in Chapter 4. Extremely narrowed spectrum was observed from the edge of OLED devices. A threshold thickness exists, above which the spectrum is narrow, and below which the spectrum is broad. The FWHM of spectrum depends on the material of the organic thin films, the thickness of the organic layers, and length of the OLED device. A superlinear relationship between the output intensity of the edge emission and the length of the device was observed, which is probably due to the misalignment of the device edge and the optical fiber detector. The original motivation of this research is for organic semiconductor laser that hasn't been realized due to the extremely high photon absorption in OLED devices. Although we didn't succeed in fabricating an electrically pumped organic laser diode, we made a comprehensive research in edge emission of OLEDs which provides valuable results in understanding light distribution and propagation in OLED devices. Chapter 5 focuses on the second project. A strong spike was observed at the falling edge of a pulse, and a long tail followed. The spike was due to the recombination of correlated charge pair (CCP) created by trapped carriers in guest molecules of the recombination zone. When the bias was turned off, along with the decreasing of electric field in the device, the electric field induced quenching decreases and the recombination rate of the CCP increases which result in the spike. This research project provides a

  19. Spectrally narrowed leaky waveguide edge emission and transient electrluminescent dynamics of OLEDs

    Zhengqing, Gan [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    In summary, there are two major research works presented in this dissertation. The first research project (Chapter 4) is spectrally narrowed edge emission from Organic Light Emitting Diodes. The second project (Chapter 5) is about transient electroluminescent dynamics in OLEDs. Chapter 1 is a general introduction of OLEDs. Chapter 2 is a general introduction of organic semiconductor lasers. Chapter 3 is a description of the thermal evaporation method for OLED fabrication. The detail of the first project was presented in Chapter 4. Extremely narrowed spectrum was observed from the edge of OLED devices. A threshold thickness exists, above which the spectrum is narrow, and below which the spectrum is broad. The FWHM of spectrum depends on the material of the organic thin films, the thickness of the organic layers, and length of the OLED device. A superlinear relationship between the output intensity of the edge emission and the length of the device was observed, which is probably due to the misalignment of the device edge and the optical fiber detector. The original motivation of this research is for organic semiconductor laser that hasn't been realized due to the extremely high photon absorption in OLED devices. Although we didn't succeed in fabricating an electrically pumped organic laser diode, we made a comprehensive research in edge emission of OLEDs which provides valuable results in understanding light distribution and propagation in OLED devices. Chapter 5 focuses on the second project. A strong spike was observed at the falling edge of a pulse, and a long tail followed. The spike was due to the recombination of correlated charge pair (CCP) created by trapped carriers in guest molecules of the recombination zone. When the bias was turned off, along with the decreasing of electric field in the device, the electric field induced quenching decreases and the recombination rate of the CCP increases which result in the spike. This research project provides

  20. A Narrow-Linewidth Atomic Line Filter for Free Space Quantum Key Distribution under Daytime Atmospheric Conditions

    Brown, Justin; Woolf, David; Hensley, Joel

    2016-05-01

    Quantum key distribution can provide secure optical data links using the established BB84 protocol, though solar backgrounds severely limit the performance through free space. Several approaches to reduce the solar background include time-gating the photon signal, limiting the field of view through geometrical design of the optical system, and spectral rejection using interference filters. Despite optimization of these parameters, the solar background continues to dominate under daytime atmospheric conditions. We demonstrate an improved spectral filter by replacing the interference filter (Δν ~ 50 GHz) with an atomic line filter (Δν ~ 1 GHz) based on optical rotation of linearly polarized light through a warm Rb vapor. By controlling the magnetic field and the optical depth of the vapor, a spectrally narrow region can be transmitted between crossed polarizers. We find that the transmission is more complex than a single peak and evaluate peak transmission as well as a ratio of peak transmission to average transmission of the local spectrum. We compare filters containing a natural abundance of Rb with those containing isotopically pure 87 Rb and 85 Rb. A filter providing > 95 % transmission and Δν ~ 1.1 GHz is achieved.

  1. Spectrally narrowed emissions in 2,5-bis(4-biphenylyl)thiophene crystals pumped by fs laser pulse

    Kobayashi, S.; Sasaki, F.; Yanagi, H.; Hotta, S.; Ichikawa, M.; Taniguchi, Y.

    2005-01-01

    Spectrally narrowed emission (SNE) in 2,5-bis(4-biphenylyl)thiophene (BP1T) crystals is investigated using fs laser pulse. Two different types of narrowing are observed at different vibronic emission bands with increasing pump intensities. Based on their pump intensity dependence and illumination area dependence, we assign the SNE at 20,200 cm -1 (β-band) to amplified spontaneous emission (ASE) and the SNE at 21,600 cm -1 (α-band) to superfluorescence rather than ASE

  2. Neutral helium spectral lines in dense plasmas

    Omar, Banaz; Wierling, August; Roepke, Gerd; Guenter, Sibylle

    2006-01-01

    Shift and broadening of isolated neutral helium lines 7281 A ring (2 1 P-3 1 S), 7065 A ring (2 3 P-3 3 S), 6678 A ring (2 1 P-3 1 D), 5048 A ring (2 1 P-4 1 S), 4922 A ring (2 1 P-4 1 D), and 4713 A ring (2 3 P-4 3 S) in a dense plasma are investigated. Based on a quantum statistical theory, the electronic contributions to the shift and width are considered, using the method of thermodynamic Green functions. Dynamic screening of the electron-atom interaction is included. Compared to the width, the electronic shift is more affected by dynamical screening. This effect increases at high density. A cut-off procedure for strong collisions is used. The contribution of the ions is taken into account in a quasi-static approximation, with both the quadratic Stark effect and the quadrupole interaction included. The results for shift and width agree well with the available experimental and theoretical data

  3. Simultaneous NuSTAR and XMM-Newton 0.5-80 keV spectroscopy of the narrow-line Seyfert 1 galaxy SWIFT J2127.4+5654

    Marinucci, A.; Matt, G.; Kara, E.

    2014-01-01

    We present a broad-band spectral analysis of the joint XMM-Newton and Nuclear Spectroscopic Telescope Array observational campaign of the narrow-line Seyfert 1 SWIFT J2127.4+5654, consisting of 300 ks performed during three XMM-Newton orbits. We detect a relativistic broadened iron Kα line...

  4. Relativistic jets in narrow-line Seyfert 1 galaxies. New discoveries and open questions

    D’Ammando F.

    2013-12-01

    Full Text Available Before the launch of the Fermi satellite only two classes of AGNs were known to produce relativistic jets and thus emit up to the γ-ray energy range: blazars and radio galaxies, both hosted in giant elliptical galaxies. The first four years of observations by the Large Area Telescope on board Fermi confirmed that these two are the most numerous classes of identified sources in the extragalactic γ-ray sky, but the discovery of γ-ray emission from 5 radio-loud narrow-line Seyfert 1 galaxies revealed the presence of a possible emerging third class of AGNs with relativistic jets. Considering that narrow-line Seyfert 1 galaxies seem to be typically hosted in spiral galaxy, this finding poses intriguing questions about the nature of these objects, the onset of production of relativistic jets, and the cosmological evolution of radio-loud AGN. Here, we discuss the radio-to-γ-rays properties of the γ-ray emitting narrow-line Seyfert 1 galaxies, also in comparison with the blazar scenario.

  5. An extreme Fe II emitter the narrow line quasar PHL 1092

    Bergeron, J

    1980-01-01

    A search for Fe II emission in a sample of radio-quiet quasars has revealed the outstanding properties of PHL 1092. Intense Fe II lines dominate the entire spectrum, and the Fe II UV multiplets are nearly as strong as the optical ones. In contrast the extreme weakness of the Balmer and Mg II lines is striking. For the first time, Fe I lines are identified in an extra-galactic object. The lines are narrow, with a FWHM of 1300 km s/sup -1/. The presence of Fe II UV lines and Fe I lines from the ground state requires moderate column densities. However Fe/sup 0/ can exist only in a region completely shielded from the UV continuum. The weakness of Mg II and H beta relative to Fe II lines is best explained by their thermalization. The emitting region is of high electron density n/sub e/ approximately=10/sup 12/ cm/sup -3/, low temperature T approximately=10000K, and has an optical depth in the Fe II UV lines tau /sub UV/ approximately=10/sup 3/-10/sup 4/. It is speculated that for higher densities all the lines wou...

  6. Analysis of visible spectral lines in LHD helium discharge

    Wan, B.N.; Goto, M.; Morita, S.

    1999-06-01

    In this study, visible spectral lines in LHD helium discharges are analyzed and it was found that they could be well fitted with gaussian profile. The results reveal a simple mechanism of helium atom recycling. Ion temperatures were also derived from the fitting. A typical value of the ion temperature obtained was about 6 eV. (author)

  7. Narrow-line, cw orange light generation in a diode-pumped Nd:YVO4 laser using volume Bragg gratings.

    Chen, Y L; Chen, W W; Du, C E; Chang, W K; Wang, J L; Chung, T Y; Chen, Y H

    2009-12-07

    We report on the demonstration of a narrow-line, cw orange 593-nm laser achieved via intracavity sum-frequency generation (SFG) of a diode-pumped dual-wavelength (1064 and 1342 nm) Nd:YVO(4) laser using two volume Bragg grating (VBG) reflectors. At diode pump power of up to 3.6 W, the 593-nm intracavity SFG laser radiates at the single longitudinal mode of spectral linewidth as narrow as approximately 15 MHz. More than 23-mW single-longitudinal-mode or 40-mW, diode pump power) 593-nm orange lights can be obtained from this compact laser system. Spectral tuning of the orange light was performed via the temperature tuning of the two VBGs in this system, achieving an effective tuning rate of ~5 pm/degrees C.

  8. PROBING THE PHYSICS OF NARROW LINE REGIONS IN ACTIVE GALAXIES. II. THE SIDING SPRING SOUTHERN SEYFERT SPECTROSCOPIC SNAPSHOT SURVEY (S7)

    Dopita, Michael A.; Davies, Rebecca; Kewley, Lisa; Hampton, Elise; Sutherland, Ralph [RSAA, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Shastri, Prajval; Kharb, Preeti; Jose, Jessy; Bhatt, Harish; Ramya, S. [Indian Institute of Astrophysics, Koramangala 2 B Block, Bangalore 560034 (India); Scharwächter, Julia [LERMA, Observatoire de Paris, CNRS, UMR 8112, 61 Avenue de l’Observatoire, F-75014 Paris (France); Jin, Chichuan [Qian Xuesen Laboratory for Space Technology, Beijing (China); Banfield, Julie [CSIRO Astronomy and Space Science, P.O. Box 76, Epping NSW, 1710 Australia (Australia); Zaw, Ingyin [New York University (Abu Dhabi), 70 Washington Square South, New York, NY 10012 (United States); Juneau, Stéphanie [CEA-Saclay, DSM/IRFU/SAp, F-91191 Gif-sur-Yvette (France); James, Bethan [Institute of Astronomy, Cambridge University, Madingley Road, Cambridge CB3 0HA (United Kingdom); Srivastava, Shweta, E-mail: Michael.Dopita@anu.edu.au [Astronomy and Astrophysics Division, Physical Research Laboratory, Ahmedabad 380009 (India)

    2015-03-15

    Here we describe the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7) and present results on 64 galaxies drawn from the first data release. The S7 uses the Wide Field Spectrograph mounted on the ANU 2.3 m telescope located at the Siding Spring Observatory to deliver an integral field of 38 × 25 arcsec at a spectral resolution of R = 7000 in the red (530–710 nm), and R = 3000 in the blue (340–560 nm). From these data cubes we have extracted the narrow-line region spectra from a 4 arcsec aperture centered on the nucleus. We also determine the Hβ and [O iii] λ5007 fluxes in the narrow lines, the nuclear reddening, the reddening-corrected relative intensities of the observed emission lines, and the Hβ and [O iii] λ5007 luminosities determined from spectra for which the stellar continuum has been removed. We present a set of images of the galaxies in [O iii] λ5007, [N ii] λ6584, and Hα, which serve to delineate the spatial extent of the extended narrow-line region and also to reveal the structure and morphology of the surrounding H ii regions. Finally, we provide a preliminary discussion of those Seyfert 1 and Seyfert 2 galaxies that display coronal emission lines in order to explore the origin of these lines.

  9. NMR imaging of solids with multiple-pulse line narrowing and radiofrequency gradients

    Werner, M.H.

    1993-01-01

    The usual methods of magnetic resonance imaging fail in rigid solids due to the line-shape contributions of dipolar coupling, chemical shift dispersion and anisotropy, and bulk magnetic susceptibility. This dissertation presents a new method of solid-stage imaging by nuclear magnetic resonance which averages away these contributions with multiple-pulse line-narrowing and encodes spatial information with pulsed radiofrequency field gradients. This method is closely related to simultaneously developed methods utilizing pulsed DC gradients, and offers similar improvements in sensitivity and resolution. The advantage of rf gradients is that they can be rapidly switched without inducing eddy currents in the probe or the magnet. In addition, the phases and amplitudes of the rf gradients can be switched by equipment which is already part of an NMR spectrometer capable of solid-state spectroscopy. The line-narrowing and gradient pulses originate in separate rf circuits tuned to the same frequency. Interactions between the circuits have been minimized by a method of active Q-switching which employs PIN diodes in the matching networks of these circuits. Both one- and two-dimensional images are presented. The latter are obtained by a novel method in which the two dimensions of imaging transverse to the static magnetic field are encoded by two orthogonal components of a single rf gradient. A π/2 phase shift of the rf phase relative to that of the line-narrowing pulses selects one component or the other. This arrangement allows the solid-state analogs of versatile imaging sequences based on Fourier imaging and eliminates the need for sample rotation and back-projection methods. Coherent averaging theory is used to analyze this imaging technique and exact numerical simulations on several coupled spins are discussed. These lend insight to the residual linewidth and its dependence on pixel position as well as to the range of applicability of this technique

  10. Imaging spectrophotometry of ionized gas in NGC 1068. I - Kinematics of the narrow-line region

    Cecil, Gerald; Bland, Jonathan; Tully, R. Brent

    1990-01-01

    The kinematics of collisionally excited forbidden N II 6548, 6583 across the inner 1 arcmin diameter of the nearby Seyfert galaxy NGC 1068 is mapped using an imaging Fabry-Perot interferometer and low-noise CCD. The stack of monochromatic images, which spatially resolved the high-velocity gas, was analyzed for kinematic and photometric content. Profiles agree well with previous long-slit work, and their complete spatial coverage makes it possible to constrain the gas volume distribution. It is found that the narrow-line region is distributed in a thick center-darkened, line-emitting cylinder that envelopes the collimated radio jet. Three distinct kinematic subsystems, of which the cylinder is composed, are discussed in detail. Detailed behavior of the emission-line profiles, at the few points in the NE quadrant with simple kinematics, argues that the ionized gas develops a significant component of motion perpendicular to the jet axis.

  11. Identification and mitigation of narrow spectral artifacts that degrade searches for persistent gravitational waves in the first two observing runs of Advanced LIGO

    Covas, P. B.; Effler, A.; Goetz, E.; Meyers, P. M.; Neunzert, A.; Oliver, M.; Pearlstone, B. L.; Roma, V. J.; Schofield, R. M. S.; Adya, V. B.; Astone, P.; Biscoveanu, S.; Callister, T. A.; Christensen, N.; Colla, A.; Coughlin, E.; Coughlin, M. W.; Crowder, S. G.; Dwyer, S. E.; Eggenstein, H.-B.; Hourihane, S.; Kandhasamy, S.; Liu, W.; Lundgren, A. P.; Matas, A.; McCarthy, R.; McIver, J.; Mendell, G.; Ormiston, R.; Palomba, C.; Papa, M. A.; Piccinni, O. J.; Rao, K.; Riles, K.; Sammut, L.; Schlassa, S.; Sigg, D.; Strauss, N.; Tao, D.; Thorne, K. A.; Thrane, E.; Trembath-Reichert, S.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Adams, C.; Adhikari, R. X.; Ananyeva, A.; Appert, S.; Arai, K.; Aston, S. M.; Austin, C.; Ballmer, S. W.; Barker, D.; Barr, B.; Barsotti, L.; Bartlett, J.; Bartos, I.; Batch, J. C.; Bejger, M.; Bell, A. S.; Betzwieser, J.; Billingsley, G.; Birch, J.; Biscans, S.; Biwer, C.; Blair, C. D.; Blair, R. M.; Bork, R.; Brooks, A. F.; Cao, H.; Ciani, G.; Clara, F.; Clearwater, P.; Cooper, S. J.; Corban, P.; Countryman, S. T.; Cowart, M. J.; Coyne, D. C.; Cumming, A.; Cunningham, L.; Danzmann, K.; Costa, C. F. Da Silva; Daw, E. J.; DeBra, D.; DeRosa, R. T.; DeSalvo, R.; Dooley, K. L.; Doravari, S.; Driggers, J. C.; Edo, T. B.; Etzel, T.; Evans, M.; Evans, T. M.; Factourovich, M.; Fair, H.; Galiana, A. Fernández; Ferreira, E. C.; Fisher, R. P.; Fong, H.; Frey, R.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gateley, B.; Giaime, J. A.; Giardina, K. D.; Goetz, R.; Goncharov, B.; Gras, S.; Gray, C.; Grote, H.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hall, E. D.; Hammond, G.; Hanks, J.; Hanson, J.; Hardwick, T.; Harry, G. M.; Heintze, M. C.; Heptonstall, A. W.; Hough, J.; Inta, R.; Izumi, K.; Jones, R.; Karki, S.; Kasprzack, M.; Kaufer, S.; Kawabe, K.; Kennedy, R.; Kijbunchoo, N.; Kim, W.; King, E. J.; King, P. J.; Kissel, J. S.; Korth, W. Z.; Kuehn, G.; Landry, M.; Lantz, B.; Laxen, M.; Liu, J.; Lockerbie, N. A.; Lormand, M.; MacInnis, M.; Macleod, D. M.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Marsh, P.; Martin, I. W.; Martynov, D. V.; Mason, K.; Massinger, T. J.; Matichard, F.; Mavalvala, N.; McClelland, D. E.; McCormick, S.; McCuller, L.; McIntyre, G.; McRae, T.; Merilh, E. L.; Miller, J.; Mittleman, R.; Mo, G.; Mogushi, K.; Moraru, D.; Moreno, G.; Mueller, G.; Mukund, N.; Mullavey, A.; Munch, J.; Nelson, T. J. N.; Nguyen, P.; Nuttall, L. K.; Oberling, J.; Oktavia, O.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; Ottaway, D. J.; Overmier, H.; Palamos, J. R.; Parker, W.; Pele, A.; Penn, S.; Perez, C. J.; Phelps, M.; Pierro, V.; Pinto, I.; Principe, M.; Prokhorov, L. G.; Puncken, O.; Quetschke, V.; Quintero, E. A.; Radkins, H.; Raffai, P.; Ramirez, K. E.; Reid, S.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Romel, C. L.; Romie, J. H.; Ross, M. P.; Rowan, S.; Ryan, K.; Sadecki, T.; Sanchez, E. J.; Sanchez, L. E.; Sandberg, V.; Savage, R. L.; Sellers, D.; Shaddock, D. A.; Shaffer, T. J.; Shapiro, B.; Shoemaker, D. H.; Slagmolen, B. J. J.; Smith, B.; Smith, J. R.; Sorazu, B.; Spencer, A. P.; Staley, A.; Strain, K. A.; Sun, L.; Tanner, D. B.; Tasson, J. D.; Taylor, R.; Thomas, M.; Thomas, P.; Toland, K.; Torrie, C. I.; Traylor, G.; Tse, M.; Tuyenbayev, D.; Vajente, G.; Valdes, G.; van Veggel, A. A.; Vecchio, A.; Veitch, P. J.; Venkateswara, K.; Vo, T.; Vorvick, C.; Wade, M.; Walker, M.; Ward, R. L.; Warner, J.; Weaver, B.; Weiss, R.; Weßels, P.; Willke, B.; Wipf, C. C.; Wofford, J.; Worden, J.; Yamamoto, H.; Yancey, C. C.; Yu, Hang; Yu, Haocun; Zhang, L.; Zhu, S.; Zucker, M. E.; Zweizig, J.; LSC Instrument Authors

    2018-04-01

    Searches are under way in Advanced LIGO and Virgo data for persistent gravitational waves from continuous sources, e.g. rapidly rotating galactic neutron stars, and stochastic sources, e.g. relic gravitational waves from the Big Bang or superposition of distant astrophysical events such as mergers of black holes or neutron stars. These searches can be degraded by the presence of narrow spectral artifacts (lines) due to instrumental or environmental disturbances. We describe a variety of methods used for finding, identifying and mitigating these artifacts, illustrated with particular examples. Results are provided in the form of lists of line artifacts that can safely be treated as non-astrophysical. Such lists are used to improve the efficiencies and sensitivities of continuous and stochastic gravitational wave searches by allowing vetoes of false outliers and permitting data cleaning.

  12. CONSTRAINING JET PRODUCTION SCENARIOS BY STUDIES OF NARROW-LINE RADIO GALAXIES

    Sikora, Marek [Nicolaus Copernicus Astronomical Center, Bartycka 18, 00-716 Warsaw (Poland); Stasinska, Grazyna [LUTH, Observatoire de Paris, CNRS, Universite Paris Diderot, Place Jules Janssen, F-92190 Meudon (France); Koziel-Wierzbowska, Dorota [Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Krakow (Poland); Madejski, Greg M. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Asari, Natalia V., E-mail: sikora@camk.edu.pl [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)

    2013-03-01

    We study a large sample of narrow-line radio galaxies (NLRGs) with extended radio structures. Using 1.4 GHz radio luminosities L {sub 1.4}, narrow optical emission line luminosities L {sub [OIII]} and L{sub H{sub {alpha}}}, as well as black hole masses M {sub BH} derived from stellar velocity dispersions measured from the optical spectra obtained with the Sloan Digital Sky Survey, we find that (1) NLRGs cover about four decades of the Eddington ratio, {lambda} {identical_to} L {sub bol}/L {sub Edd}{proportional_to}L {sub line}/M {sub BH}; (2) L {sub 1.4}/M {sub BH} strongly correlates with {lambda}; and (3) radio loudness, R{identical_to}L{sub 1.4}/L{sub line}, strongly anti-correlates with {lambda}. A very broad range of the Eddington ratio indicates that the parent population of NLRGs includes both radio-loud quasars (RLQs) and broad-line radio galaxies (BLRGs). The correlations they obey and their high jet production efficiencies favor a jet production model which involves the so-called magnetically choked accretion scenario. In this model, production of the jet is dominated by the Blandford-Znajek mechanism, and the magnetic fields in the vicinity of the central black hole are confined by the ram pressure of the accretion flow. Since large net magnetic flux accumulated in central regions of the accretion flow required by the model can take place only via geometrically thick accretion, we speculate that the massive, 'cold' accretion events associated with luminous emission-line active galactic nucleus can be accompanied by an efficient jet production only if preceded by a hot, very sub-Eddington accretion phase.

  13. A search for spectral lines in gamma-ray bursts using TGRS

    Kurczynski, P.; Palmer, D.; Seifert, H.; Teegarden, B. J.; Gehrels, N.; Cline, T. L.; Ramaty, R.; Hurley, K.; Madden, N. W.; Pehl, R. H.

    1998-01-01

    We present the results of an ongoing search for narrow spectral lines in gamma-ray burst data. TGRS, the Transient Gamma-Ray Spectrometer aboard the Wind satellite is a high energy-resolution Ge device. Thus it is uniquely situated among the array of space-based, burst sensitive instruments to look for line features in gamma-ray burst spectra. Our search strategy adopts a two tiered approach. An automated 'quick look' scan searches spectra for statistically significant deviations from the continuum. We analyzed all possible time accumulations of spectra as well as individual spectra for each burst. Follow-up analysis of potential line candidates uses model fitting with F-test and χ 2 tests for statistical significance

  14. NARROW-LINE-WIDTH UV BURSTS IN THE TRANSITION REGION ABOVE SUNSPOTS OBSERVED BY IRIS

    Hou, Zhenyong; Huang, Zhenghua; Xia, Lidong; Li, Bo; Madjarska, Maria S.; Fu, Hui; Mou, Chaozhou; Xie, Haixia, E-mail: z.huang@sdu.edu.cn, E-mail: xld@sdu.edu.cn [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, 264209 Shandong (China)

    2016-10-01

    Various small-scale structures abound in the solar atmosphere above active regions, playing an important role in the dynamics and evolution therein. We report on a new class of small-scale transition region structures in active regions, characterized by strong emissions but extremely narrow Si iv line profiles as found in observations taken with the Interface Region Imaging Spectrograph (IRIS). Tentatively named as narrow-line-width UV bursts (NUBs), these structures are located above sunspots and comprise one or multiple compact bright cores at sub-arcsecond scales. We found six NUBs in two data sets (a raster and a sit-and-stare data set). Among these, four events are short-lived with a duration of ∼10 minutes, while two last for more than 36 minutes. All NUBs have Doppler shifts of 15–18 km s{sup −1}, while the NUB found in sit-and-stare data possesses an additional component at ∼50 km s{sup −1} found only in the C ii and Mg ii lines. Given that these events are found to play a role in the local dynamics, it is important to further investigate the physical mechanisms that generate these phenomena and their role in the mass transport in sunspots.

  15. Direct HST Dust Lane Detection in Powerful Narrow-Line Radio Galaxies

    Ramírez, Edgar A.; Aretxaga, Itziar [Instituto Nacional de Astrofísica, Óptica y Electrónica, Puebla (Mexico); Tadhunter, Clive N. [Department of Physics and Astronomy, University of Sheffield, Sheffield (United Kingdom); Lopez-Rodriguez, Enrique [NASA Ames Research Center, SOFIA Science Center, SOFIA/USRA, Mountain View, CA (United States); Department of Astronomy, University of Texas at Austin, Austin, TX (United States); McDonald Observatory, University of Texas at Austin, Austin, TX (United States); Packham, Chris, E-mail: e.ramirez@inaoep.mx [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX (United States); National Astronomical Observatory of Japan, Tokyo (Japan)

    2017-11-22

    We present the analysis of near-infrared Hubble Space Telescope imaging of 10 Fanaroff Riley II powerful radio galaxies at low redshift (0.03 < z < 0.11) optically classified as narrow-line radio galaxies. The photometric properties of the host galaxy are measured using galfit, and compared with those from the literature. Our high resolution near-infrared observations provide new and direct information on the central kpc-scale dust lanes in our sample that could be connected to the pc-scale torus structure. Moreover, analyzing the infrared spectrograph Spitzer spectra of our sample, we suggest properties of the dust size of the torus.

  16. PERSPECTIVES OF UKRAINIAN RAILWAY TOURISM DEVELOPMENT ON NARROW-GAUGE LINES OF ZAKARPATTIA

    V. G. Kuznetsov

    2015-07-01

    Full Text Available Purpose.The purpose of the paper is: (1 the definition of perspectives development of Ukrainian railway tourism on the narrow gauge lines of Zakarpattia; 2 technical condition analysis of Borzhava narrow gauge railway for the project to restore the effective functioning of mountain railways track, width 750 mm in the Carpathian region, with the possibility of their accession to the distributed travel network; 3 the study of the modern state and tendencies of development of tourist industry of Ukraine and the passenger economy of national railways; 4 clarification of the role and place of the railway tourism in the transportation system. Methodology. The expert group has carried out field inspections and field investigations of facilities track facilities and passenger infrastructure, rolling stock and ancillary industries involved in the functioning narrow-gauge railway. It was estimated the overall technical condition of the railway track and engineering structures section of narrow-gauge Railways in the Carpathian region. Findings. In the framework of on-site examinations of the expert group found that the objects of tracks, passenger and freight infrastructure, rolling stock and ancillary industries involved in the operation of narrow-gauge Railways are in poor condition and require significant updates and major repairs. But the routes of passenger trains remain fit for participation in the project of development of railway tourism of Ukraine Originality. For the first time the state of the narrow-gauge railway for further implementation of the project on the development of rail tourism in Ukraine was realized. The analysis of foreign experience of organization of railway tourism has been carried out. The modern state and tendencies of development of tourist industry of Ukraine was studied, the factors of competitiveness of rail transport for providing tourist transport in Ukraine were identified and systematized.Practical value. The recovery

  17. Spectral line intensity irreversibility in circulatory plasma magnetization processes

    Qu, Z. Q.; Dun, G. T.

    2012-01-01

    Spectral line intensity variation is found to be irreversible in circulatory plasma magnetization process by experiments described in this paper, i.e., the curves illustrating spectral line photon fluxes irradiated from a light source immerged in a magnetic field by increasing the magnetic induction cannot be reproduced by decreasing the magnetic induction within the errors. There are two plasma magnetization patterns found. One shows that the intensities are greater at the same magnetic inductions during the magnetic induction decreasing process after the increasing, and the other gives the opposite effect. This reveals that the magneto-induced excitation and de-excitation process is irreversible like ferromagnetic magnetization. But the two irreversible processes are very different in many aspects stated in the text.

  18. Opacity of expanding media: The effect of spectral lines

    Karp, A.H.; Lasher, G.; Chan, K.L.; Salpeter, E.E.

    1977-01-01

    Spectral lines are more effective in slowing the transport of radiation in expanding (or contracting) objects than in static ones. The velocity gradient associated with the expansion causes the frequency of the photons to be continuously redshifted relative to the rest frame of the gas through which they travel. Those photons which are redshifted to the frequency of a sufficiently strong line will be absorbed by the corresponding bound-bound transition, and the net effect will be to increase the effective opacity of the gas. In certain cases the effect can be taken into account by using an effective opacity, the expansion opacity, which is a function not only of the temperature and density but also of the velocity gradient.Practical formulae for computing the expansion opacity and its Rosseland mean in terms of sums over spectral lines are derived. It is shown that the cumulative effect of many weak lines can be important, implying that a large list of spectral lines is required to obtain results of even modest accuracy. Numerical computations using the 260,000-entry line list of Kurucz and Peytremann have been completed and some samples of the result are given. The general effect may be important in many astronomical objects, but only in some of these will be detailed approach of this paper be appropriate. In optically thick supernova shells, the effect is important both in maintaining the radiation in thermal equilibrium as it diffuses out of the shell and in increasing the value of the total opacity. The enhancement of the opacity ranges from less than 1% to more than an order of magnitude, depending on the temperature, density, and velocity gradient

  19. Modern quantum kinetic theory and spectral line shapes

    Monchick, L.

    1991-01-01

    The modern quantum kinetic theory of spectral line shapes is outlined and a typical calculation of a Raman scattered line shape described. The distinguishing feature of this calculation is that it was completely ab initio and therefore constituted a test of modern quantum kinetic theory, the state of the art in computing molecular-scattering cross sections, and novel methods of solving kinetic equations. The computation employed a large assortment of tools: group theory, finite-element methods, classic methods of solving coupled sets of ordinary differential equations, graph methods of combining angular momenta, and matrix methods of solving integral equations. Agreement with experimental results was excellent. 13 refs

  20. Anisotropic ionizing radiation in Seyfert galaxies. I - The extended narrow-line region in Markarian 573

    Tsvetanov, Zlatan; Walsh, J. R.

    1992-01-01

    The morphology, kinematics, and ionization state of the nuclear extended narrow-line region (ENLR) of the Seyfert 2 galaxy Mrk 573 are studied using narrow-band images of a grid of long-slit spectra. The entire ENLR is mapped spectroscopically, and velocity structure is studied. The velocity field map shows a typical galactic rotation picture with some important deviations. A simple geometric model, in accordance with the 'unified schemes', is employed to study the effects of various parameters of the observed picture. The best match is achieved when a biconical radiation field illuminates the ISM of the host galaxy that takes part in a normal galaxy rotation but also has radial motions close to the nucleus. The emission-line images reveal an ENLR elongated along the radio axis in the northwest-southeast direction, but a map of the flux ratio forbidden O III 5007/(H-alpha + forbidden N II) shows a different structure, with the highest excitation peak offset by about 4 arcsec along the radio axis to the southeast.

  1. An ultrafast line-by-line algorithm for calculating spectral transmittance and radiance

    Tan, X.

    2013-01-01

    An ultrafast line-by-line algorithm for calculating spectral transmittance and radiance of gases is presented. The algorithm is based on fast convolution of the Voigt line profile using Fourier transform and a binning technique. The algorithm breaks a radiative transfer calculation into two steps: a one-time pre-computation step in which a set of pressure independent coefficients are computed using the spectral line information; a normal calculation step in which the Fourier transform coefficients of the optical depth are calculated using the line of sight information and the coefficients pre-computed in the first step, the optical depth is then calculated using an inverse Fourier transform and the spectral transmittance and radiance are calculated. The algorithm is significantly faster than line-by-line algorithms that do not employ special speedup techniques by a factor of 10 3 –10 6 . A case study of the 2.7 μm band of H 2 O vapor is presented. -- Highlights: •An ultrafast line-by-line model based on FFT and a binning technique is presented. •Computationally expensive calculations are factored out into a pre-computation step. •It is 10 3 –10 8 times faster than LBL algorithms that do not employ speedup techniques. •Good agreement with experimental data for the 2.7 μm band of H 2 O

  2. Spectral Narrowing of a Varactor-Integrated Resonant-Tunneling-Diode Terahertz Oscillator by Phase-Locked Loop

    Ogino, Kota; Suzuki, Safumi; Asada, Masahiro

    2017-12-01

    Spectral narrowing of a resonant-tunneling-diode (RTD) terahertz oscillator, which is useful for various applications of terahertz frequency range, such as an accurate gas spectroscopy, a frequency reference in various communication systems, etc., was achieved with a phase-locked loop system. The oscillator is composed of an RTD, a slot antenna, and a varactor diode for electrical frequency tuning. The output of the RTD oscillating at 610 GHz was down-converted to 400 MHz by a heterodyne detection. The phase noise was transformed to amplitude noise by a balanced mixer and fed back into the varactor diode. The loop filter for a stable operation is discussed. The spectral linewidth of 18.6 MHz in free-running operation was reduced to less than 1 Hz by the feedback.

  3. High-q microring resonator with narrow free spectral range for pulse repetition rate multiplication

    Pu, Minhao; Ji, Hua; Frandsen, Lars Hagedorn

    2009-01-01

    We demonstrate a silicon-on-insulator microring resonator with a free-spectral-range of 0.32 nm, an extinction ratio of 27 dB, and a quality factor of ~140900 at 1550 nm that is used for pulse repetition-rate multiplication from 10 to 40 GHz.......We demonstrate a silicon-on-insulator microring resonator with a free-spectral-range of 0.32 nm, an extinction ratio of 27 dB, and a quality factor of ~140900 at 1550 nm that is used for pulse repetition-rate multiplication from 10 to 40 GHz....

  4. Extreme Gaseous Outflows in Radio-Loud Narrow-Line Seyfert 1 Galaxies

    Komossa, S.; Xu, D. W.; Wagner, A. Y.

    2018-04-01

    We present four radio-loud NLS1 galaxies with extreme emission-line shifts, indicating radial outflow velocities of the ionized gas of up to 2450 km/s, above the escape velocity of the host galaxies. The forbidden lines show strong broadening, up to 2270 km/s. An ionization stratification (higher line shift at higher ionization potential) implies that we see a large-scale outflow rather than single, localized jet-cloud interactions. Similarly, the paucity of zero-velocity [OIII]λ5007 emitting gas implies the absence of a second narrow-line region (NLR) component at rest, and therefore a large part of the high-ionization NLR is affected by the outflow. Given the radio loudness of these NLS1 galaxies, the observations are consistent with a pole on view onto their central engines, so that the effects of polar outflows are maximized. In addition, a very efficient driving mechanism is required, to reach the high observed velocities. We explore implications from recent hydrodynamic simulations of the interaction between fast winds or jets with the large-scale NLR. Overall, the best agreement with observations (and especially the high outflow speeds of the [NeV] emitting gas) can be reached if the NLS1 galaxies are relatively young sources with lifetimes not much exceeding 1 Myr. These systems represent sites of strong feedback at NLR scales at work, well below redshift one.

  5. Nonlocal electron kinetics and spectral line emission in the positive column of an argon glow discharge

    Golubovskii, Yu; Kalanov, D; Gorchakov, S; Uhrlandt, D

    2015-01-01

    Modern non-local electron kinetics theory predicts several interesting effects connected with spectral line emission from the positive column in the range of low and medium pressures and currents. Some theoretical works describe non-monotonic behavior of the radial profiles of line emission at intermediate pressures and currents between the validity ranges of the non-local and local approximation of the electron kinetics. Despite a great number of publications, there have been no systematic measurements attempting to confirm these theoretical predictions through experiments. In this work the radial profiles of the line emission from the positive column of an argon glow discharge have been measured with high spatial resolution and new effects caused by the narrowing and broadening of the spatial emission profiles with dependence on discharge conditions have been discovered. The effect of intensity maximum shift predicted by theory using a self-consistent model was not found in the experiment. The properties of the spectral line radiation are influenced by the peculiarities of the formation of the high-energy tail of the electron energy distribution function. An interpretation of the observed effects based on the non-local character of the electron kinetics in radially inhomogeneous fields is given. The obtained experimental data are compared with the results of calculations. (paper)

  6. PHYSICAL CONDITIONS IN THE INNER NARROW-LINE REGION OF THE SEYFERT 2 GALAXY MARKARIAN 573

    Kraemer, S. B.; Trippe, M. L.; Crenshaw, D. M.; Fischer, T. C.; Melendez, M.; Schmitt, H. R.

    2009-01-01

    We have examined the physical conditions within a bright emission-line knot in the inner narrow-line region (NLR) of the Seyfert 2 galaxy Mrk 573 using optical spectra and photoionization models. The spectra were obtained with the Hubble Space Telescope/Space Telescope Imaging Spectrograph, through the 0.''2 x 52.''0 slit, at a position angle of -71. 0 2, with the G430L and G750M gratings. Comparing the spatial emission-line profiles, we found [Fe X] λ 6734 barely resolved, [O III] λ5007 centrally peaked, but broader than [Fe X], and [O II] λ3727 the most extended. Spectra of the central knot were extracted from a region 1.''1 in extent, corresponding to the full width at zero intensity in the cross-dispersion direction, of the knot. The spectra reveal that [Fe X] is broader in velocity width and blueshifted compared with lines from less ionized species. Our estimate of the bolometric luminosity indicates that the active galactic nucleus (AGN) is radiating at or above its Eddington luminosity, which is consistent with its identification as a hidden Narrow-Line Seyfert 1. We were able to successfully match the observed emission-line ratios with a three-component photoionization model. Two components, one to account for the [O III] emission and another in which the [Fe X] arises, are directly ionized by the AGN, while [O II] forms in a third component, which is ionized by a heavily absorbed continuum. Based on our assumed ionizing continuum and the model parameters, we determined that the two directly ionized components are ∼55 pc from the AGN. We have found similar radial distances for the central knots in the Seyfert 2 galaxies Mrk 3 and NGC 1068, but much smaller radial distances for the inner NLR in the Seyfert 1 galaxies NGC 4151 and NGC 5548. Although in general agreement with the unified model, these results suggest that the obscuring material in Seyfert galaxies extends out to at least tens of parsecs from the AGN.

  7. Hemispherical-field-of-view, nonimaging narrow-band spectral filter

    Miles, R. B.; Webb, S. G.; Griffith, E. L.

    1981-01-01

    Two compound parabolic concentrators are used to create a 180-deg-field-of-view spectral filter. The collection optics are reflective and are designed to collimate the light through a multilayer interference filter and then to refocus it onto an optical detector. Assuming unit reflectance and no loss through the optical filter, this device operates at the thermodynamic collection limit.

  8. SPECTRALLY RESOLVED PURE ROTATIONAL LINES OF WATER IN PROTOPLANETARY DISKS

    Pontoppidan, Klaus M.; Salyk, Colette; Blake, Geoffrey A.; Kaeufl, Hans Ulrich

    2010-01-01

    We present ground-based high-resolution N-band spectra (Δv = 15 km s -1 ) of pure rotational lines of water vapor in two protoplanetary disks surrounding the pre-main-sequence stars AS 205N and RNO 90, selected based on detections of rotational water lines by the Spitzer InfraRed Spectrograph. Using VISIR on the Very Large Telescope, we spectrally resolve individual lines and show that they have widths of 30-60 km s -1 , consistent with an origin in Keplerian disks at radii of ∼1 AU. The water lines have similar widths to those of the CO at 4.67 μm, indicating that the mid-infrared water lines trace similar radii. The rotational temperatures of the water are 540 and 600 K in the two disks, respectively. However, the line ratios show evidence of non-LTE excitation, with low-excitation line fluxes being overpredicted by two-dimensional disk LTE models. Due to the limited number of observed lines and the non-LTE line ratios, an accurate measure of the water ortho/para (O/P) ratio is not available, but a best estimate for AS 205N is O/P =4.5 ± 1.0, apparently ruling out a low-temperature origin of the water. The spectra demonstrate that high-resolution spectroscopy of rotational water lines is feasible from the ground, and further that ground-based high-resolution spectroscopy is likely to significantly improve our understanding of the inner disk chemistry revealed by recent Spitzer observations.

  9. Probing the Physics of Narrow-line Regions in Active Galaxies. IV. Full Data Release of the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7)

    Thomas, Adam D.; Dopita, Michael A.; Davies, Rebecca; Hampton, Elise; Kewley, Lisa; Banfield, Julie; Groves, Brent; Sutherland, Ralph [RSAA, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Shastri, Prajval; Sairam, Lalitha [Indian Institute of Astrophysics, Sarjapur Road, Bengaluru 560034 (India); James, Bethan L. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Jin, Chichuan [Max-Planck-Institut für Extraterrestrische Physik, Garching (Germany); Juneau, Stéphanie [CEA-Saclay, DSM/IRFU/SAp, F-91191 Gif-sur-Yvette (France); Kharb, Preeti [National Centre for Radio Astrophysics—Tata Institute of Fundamental Research, Pune University Campus, Post Bag 3, Ganeshkhind Pune 411007 (India); Scharwächter, Julia [Gemini Observatory, Northern Operations Center, 670 N. A’ohoku Place, Hilo, Hawaii 96720 (United States); Shalima, P. [Regional Institute of Education, Manasagangotri, Mysore 570006 (India); Sundar, M. N. [Jain University, 3rd Block Jayanagar, Bengaluru 560011 (India); Zaw, Ingyin, E-mail: adam.thomas@anu.edu.au [New York University (Abu Dhabi), 70 Washington Sq. S, New York, NY 10012 (United States)

    2017-09-01

    We present the second and final data release of the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). Data are presented for 63 new galaxies not included in the first data release, and we provide 2D emission-line fitting products for the full S7 sample of 131 galaxies. The S7 uses the WiFeS instrument on the ANU 2.3 m telescope to obtain spectra with a spectral resolution of R  = 7000 in the red (540–700 nm) and R  = 3000 in the blue (350–570 nm), over an integral field of 25 × 38 arcsec{sup 2} with 1 × 1 arcsec{sup 2} spatial pixels. The S7 contains both the largest sample of active galaxies and the highest spectral resolution of any comparable integral field survey to date. The emission-line fitting products include line fluxes, velocities, and velocity dispersions across the WiFeS field of view, and an artificial neural network has been used to determine the optimal number of Gaussian kinematic components for emission-lines in each spaxel. Broad Balmer lines are subtracted from the spectra of nuclear spatial pixels in Seyfert 1 galaxies before fitting the narrow lines. We bin nuclear spectra and measure reddening-corrected nuclear fluxes of strong narrow lines for each galaxy. The nuclear spectra are classified on optical diagnostic diagrams, where the strength of the coronal line [Fe vii] λ 6087 is shown to be correlated with [O iii]/H β . Maps revealing gas excitation and kinematics are included for the entire sample, and we provide notes on the newly observed objects.

  10. Laser line shape and spectral density of frequency noise

    Stephan, G.M.; Blin, S.; Besnard, P.; Tam, T.T.; Tetu, M.

    2005-01-01

    Published experimental results show that single-mode laser light is characterized in the microwave range by a frequency noise which essentially includes a white part and a 1/f (flicker) part. We theoretically show that the spectral density (the line shape) which is compatible with these results is a Voigt profile whose Lorentzian part or homogeneous component is linked to the white noise and the Gaussian part to the 1/f noise. We measure semiconductor laser line profiles and verify that they can be fit with Voigt functions. It is also verified that the width of the Lorentzian part varies like 1/P where P is the laser power while the width of the Gaussian part is more of a constant. Finally, we theoretically show from first principles that laser line shapes are also described by Voigt functions where the Lorentzian part is the laser Airy function and the Gaussian part originates from population noise

  11. Fluorescence line-narrowing studies of rare earths in disordered solids

    Hall, D.W.

    1982-01-01

    This dissertation is made up of two experimental studies dealing with apparently diverse topics within the subject of rare earths (RE) in solids. The first study, described in Part II, concerns the vibrations of a disordered host material about an optically active rare-earth ion as manifested by vibrationally-assisted-electronic, or vibronic transitions. Part III of the dissertation describes an investigation of the influence of site anisotropy on the purely electronic, laser transition of Nd 3+ in glass. These two studies are bound together by the common experimental technique of laser-induced fluorescence line narrowing (FLN). By exciting fluorescence with monochromatic light of well-characterized polarization, one may select and observe the response of a single subset of the optically active ions and obtain information that is usually masked by the inhomogeneous nature of disordered solids

  12. Investigations of glass structure using fluorescence line narrowing and moleuclar dynamics simulations

    Weber, M.J.; Brawer, S.A.

    1982-01-01

    The local structure at individual ion sites in simple and multicomponent glasses is simulated using methods of molecular dynamics. Computer simulations of fluoroberyllate glasses predict a range of ion separations and coordination numbers that increases with increasing complexity of the glass composition. This occurs at both glass forming and glass modifying cation sites. Laser-induced fluorescence line-narrowing techniques provide a unique probe of the local environments of selected subsets of ions and are used to measure site to site variations in the electronic energy levels and transition probabilities of rare earth ions. These and additional results from EXAFS, neutron and x-ray diffraction, and NMR experiments are compared with simulated glass structures

  13. A catapult model for the narrow-line region in Seyferts and radio galaxies

    Smith, M.D.

    1984-01-01

    The kinematics and stability of clouds falling radially into a supersonic wind are studied. A critical parameter is found, the ejection coefficient, which separates clouds which continue to gravitate inwards from those which are catapulted out by the ram pressure of the wind. This leads to a maximum size for ejected clouds. The clouds are partially broken up by fluid dynamic instabilities and the fragments expelled with enhanced velocities. This model is applied to the narrow-line region of Seyferts and radio galaxies. A quasi-steady picture may be established for the wind-ambient medium interaction zone. The wind is shocked and escapes through jets or bubbles; the ambient medium cools, forming the clouds which gravitate inwards. (author)

  14. Generation of narrow-band polarization-entangled photon pairs at a rubidium D1 line

    Tian Long; Li Shujing; Yuan Haoxiang; Wang Hai

    2016-01-01

    Using the process of cavity-enhanced spontaneous parametric down-conversion (SPDC), we generate a narrow-band polarization-entangled photon pair resonant on the rubidium (Rb) D1 line (795 nm). The degenerate single-mode photon pair is selected by multiple temperature controlled etalons. The linewidth of generated polarization-entangled photon pairs is 15 MHz which matches the typical atomic memory bandwidth. The measured Bell parameter for the polarization-entangled photons S = 2.73 ± 0.04 which violates the Bell-CHSH inequality by ∼18 standard deviations. The presented entangled photon pair source could be utilized in quantum communication and quantum computing based on quantum memories in atomic ensemble. (author)

  15. Line narrowing spectroscopic studies of DNA-carcinogen adducts and DNA-dye complexes

    Suh, Myungkoo [Iowa State Univ., Ames, IA (United States)

    1995-12-06

    Laser-induced fluorescence line narrowing and non-line narrowing spectroscopic methods were applied to conformational studies of stable DNA adducts of the 7β, 8α-dihydoxy-9α, l0α-epoxy-7,8,9, 10-tetrahydrobenzo[α]pyrene (anti-BPDE). Stereochemically distinct (+)-trans-, (-)-trans-, (+)-cis- and (-)-cis adducts of anti-BPDE bound to exocyclic amino group of the central guanine in an 11-mer oligonucleotide, exist in a mixture of conformations in frozen aqueous buffer matrices. The (+)-trans adduct adopts primarily an external conformation with a smaller fraction ( ~25 %) exists in a partially base-stacked conformation. Both cis adducts were found to be intercalated with significant π-π stacking interactions between the pyrenyl residues and the bases. Conformations of the trans-adduct of (+)-anti -BPDE in 11-mer oligonucleotides were studied as a function of flanking bases. In single stranded form the adduct at G2 or G3 (5 ft-flanking, base guanine) adopts a conformation with strong, interaction with the bases. In contrast, the adduct with a 5ft-flanking, thymine exists in a primarily helixexternal conformation. Similar differences were observed in the double stranded oligonucleotides. The nature of the 3ft-flanking base has little influence on the conformational equilibrium of the (+)-trans-anti BPDE-dG adduct. The formation and repair of BPDE-N2-dG in DNA isolated from the skin of mice treated topically with benzo[α]pyrene (BP) was studied. Low-temperature fluorescence spectroscopy of the intact DNA identified the major adduct as (+)-trans-anti-BPDE-N-dG, and the minor adduct fraction consisted mainly of (+)-cis-anti-BPDE-N2-dG.

  16. Line narrowing spectroscopic studies of DNA-carcinogen adducts and DNA-dye complexes

    Suh, Myungkoo.

    1995-01-01

    Laser-induced fluorescence line narrowing and non-line narrowing spectroscopic methods were applied to conformational studies of stable DNA adducts of the 7β, 8α-dihydoxy-9α, l0α-epoxy-7,8,9, 10-tetrahydrobenzo[α]pyrene (anti-BPDE). Stereochemically distinct (+)-trans-, (-)-trans-, (+)-cis- and (-)-cis adducts of anti-BPDE bound to exocyclic amino group of the central guanine in an 11-mer oligonucleotide, exist in a mixture of conformations in frozen aqueous buffer matrices. The (+)-trans adduct adopts primarily an external conformation with a smaller fraction ( ∼ 25 %) exists in a partially base-stacked conformation. Both cis adducts were found to be intercalated with significant π-π stacking interactions between the pyrenyl residues and the bases. Conformations of the trans-adduct of (+)-anti -BPDE in 11-mer oligonucleotides were studied as a function of flanking bases. In single stranded form the adduct at G 2 or G 3 (5 ft-flanking, base guanine) adopts a conformation with strong, interaction with the bases. In contrast, the adduct with a 5ft-flanking, thymine exists in a primarily helixexternal conformation. Similar differences were observed in the double stranded oligonucleotides. The nature of the 3ft-flanking base has little influence on the conformational equilibrium of the (+)-trans-anti BPDE-dG adduct. The formation and repair of BPDE-N 2 -dG in DNA isolated from the skin of mice treated topically with benzo[α]pyrene (BP) was studied. Low-temperature fluorescence spectroscopy of the intact DNA identified the major adduct as (+)-trans-anti-BPDE-N-dG, and the minor adduct fraction consisted mainly of (+)-cis-anti-BPDE-N 2 -dG

  17. Stark Broadening of Cr III Spectral Lines: DO White Dwarfs

    Milan S. Dimitrijević

    2018-04-01

    Full Text Available Using the modified semiempirical method of Dimitrijević and Konjević, Stark widths have been calculated for six Cr III transitions, for an electron density of 10 17 cm ‒ 3 and for temperatures from 5000–80,000 K. Results have been used for the investigation of the influence of Stark broadening on spectral lines in cool DO white dwarf atmospheres. Calculated Stark widths will be implemented in the STARK-B database, which is also a part of the Virtual Atomic and Molecular Data Center (VAMDC.

  18. The extreme behavior of the radio-loud narrow-line Seyfert 1 galaxy J0849+5108

    Maune, Jeremy D.; Eggen, Joseph R.; Miller, H. Richard [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303-3083 (United States); Marshall, Kevin [Department of Physics and Astronomy, Widener University, Chester, PA 19013 (United States); Readhead, Anthony C. S.; Hovatta, Talvikki; King, Oliver, E-mail: maune@chara.gsu.edu [Cahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)

    2014-10-10

    Simultaneous radio, optical (both photometry and polarimetry), X-ray, and γ-ray observations of the radio-loud narrow-line Seyfert 1 (RL-NLSy1) galaxy J0849+5108 are presented. A massive three-magnitude optical flare across five nights in 2013 April is detected, along with associated flux increases in the γ-ray, infrared, and radio regimes; no comparable event was detected in the X-rays, though this may be due to poor coverage. A spectral energy distribution (SED) for the object using quasi-simultaneous data centered on the optical flare is compared to the previously published SEDs for the object by D'Ammando et al. The flare event coincided with a high degree of optical polarization. High amplitude optical microvariability is clearly detected, and is found to be of comparable amplitude when the object is observed in both faint and bright states. The object is also seen to undergo rapid shifts in polarization in both degree and electric vector position angle within a single night. J0849+5108 appears to show even more extreme variability than that previously reported for the similar object J0948+0022. These observations appear to support the growing claim that some RL-NLSy1 galaxies constitute a sub-class of blazar-like active galactic nuclei.

  19. The extreme behavior of the radio-loud narrow-line Seyfert 1 galaxy J0849+5108

    Maune, Jeremy D.; Eggen, Joseph R.; Miller, H. Richard; Marshall, Kevin; Readhead, Anthony C. S.; Hovatta, Talvikki; King, Oliver

    2014-01-01

    Simultaneous radio, optical (both photometry and polarimetry), X-ray, and γ-ray observations of the radio-loud narrow-line Seyfert 1 (RL-NLSy1) galaxy J0849+5108 are presented. A massive three-magnitude optical flare across five nights in 2013 April is detected, along with associated flux increases in the γ-ray, infrared, and radio regimes; no comparable event was detected in the X-rays, though this may be due to poor coverage. A spectral energy distribution (SED) for the object using quasi-simultaneous data centered on the optical flare is compared to the previously published SEDs for the object by D'Ammando et al. The flare event coincided with a high degree of optical polarization. High amplitude optical microvariability is clearly detected, and is found to be of comparable amplitude when the object is observed in both faint and bright states. The object is also seen to undergo rapid shifts in polarization in both degree and electric vector position angle within a single night. J0849+5108 appears to show even more extreme variability than that previously reported for the similar object J0948+0022. These observations appear to support the growing claim that some RL-NLSy1 galaxies constitute a sub-class of blazar-like active galactic nuclei.

  20. The radio structure of the peculiar narrow-line Seyfert 1 galaxy candidate J1100+4421

    Gabányi, K. É.; Frey, S.; Paragi, Z.; Järvelä, E.; Morokuma, T.; An, T.; Tanaka, M.; Tar, I.

    2018-01-01

    Narrow-line Seyfert 1 galaxies (NLS1) are an intriguing subclass of active galactic nuclei. Their observed properties indicate low central black hole mass and high accretion rate. The extremely radio-loud NLS1 sources often show relativistic beaming and are usually regarded as younger counterparts of blazars. Recently, the object SDSS J110006.07+442144.3 was reported as a candidate NLS1 source. The characteristics of its dramatic optical flare indicated its jet-related origin. The spectral energy distribution of the object was similar to that of the γ-ray detected radio-loud NLS1, PMN J0948+0022. Our high-resolution European very long baseline interferometry network observations at 1.7 and 5 GHz revealed a compact core feature with a brightness temperature of ≳1010 K. Using the lowest brightness temperature value and assuming a moderate Lorentz factor of ∼9, the jet viewing angle is ≲26°. Archival Very Large Array data show a large-scale radio structure with a projected linear size of ∼150 kpc reminiscent of double-sided morphology.

  1. Comparison of Scheimpflug imaging and spectral domain anterior segment optical coherence tomography for detection of narrow anterior chamber angles.

    Grewal, D S; Brar, G S; Jain, R; Grewal, S P S

    2011-05-01

    To compare the performance of anterior chamber volume (ACV) and anterior chamber depth (ACD) obtained using Scheimpflug imaging with angle opening distance (AOD500) and trabecular-iris space area (TISA500) obtained using spectral domain anterior segment optical coherence tomography (SD-ASOCT) in detecting narrow angles classified using gonioscopy. In this prospective, cross-sectional observational study, 265 eyes of 265 consecutive patients underwent sequential Scheimpflug imaging, SD-ASOCT imaging, and gonioscopy. Correlations between gonioscopy grading, ACV, ACD, AOD500, and TISA500 were evaluated. Area under receiver operating characteristic curve (AUC), sensitivity, specificity, and likelihood ratios (LRs) were calculated to assess the performance of ACV, ACD, AOD500, and TISA500 in detecting narrow angles (defined as Shaffer grade ≤1 in all quadrants). SD-ASOCT images were obtained at the nasal and temporal quadrants only. Twenty-eight eyes (10.6%) were classified as narrow angles on gonioscopy. ACV correlated with gonioscopy grading (P<0.001) for temporal (r=0.204), superior (r=0.251), nasal (r=0.213), and inferior (r=0.236) quadrants. ACV correlated with TISA500 for nasal (r=0.135, P=0.029) and temporal (P=0.160, P=0.009) quadrants and also with AOD500 for nasal (r=0.498, P<0.001) and temporal (r=0.517, P<0.001) quadrants. For detection of narrow angles, ACV (AUC=0.935; 95% confidence interval (CI) =0.898-0.961) performed similar to ACD (AUC=0.88, P=0.06) and significantly better than AOD500 nasal (AUC=0.761, P=0.001), AOD500 temporal (AUC=0.808, P<0.001), TISA500 nasal (AUC=0.756, P<0.001), and TISA500 temporal (AUC=0.738, P<0.001). Using a cutoff of 113 mm(3), ACV had 90% sensitivity and 88% specificity for detecting narrow angles. Positive and negative LRs for ACV were 8.63 (95% CI=7.4-10.0) and 0.11 (95% CI=0.03-0.4), respectively. ACV measurements using Scheimpflug imaging outperformed AOD500 and TISA500 using SD-ASOCT for detecting narrow angles.

  2. THE ROLE OF RADIATION PRESSURE IN THE NARROW LINE REGIONS OF SEYFERT HOST GALAXIES

    Davies, Rebecca L.; Dopita, Michael A.; Kewley, Lisa; Groves, Brent; Sutherland, Ralph; Hampton, Elise J.; Banfield, Julie [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Shastri, Prajval; Kharb, Preeti; Bhatt, Harish [Indian Institute of Astrophysics, Sarjapur Road, Bengaluru 560034 (India); Scharwächter, Julia [LERMA, Observatoire de Paris, PSL, CNRS, Sorbonne Universités, UPMC, F-75014 Paris (France); Jin, Chichuan [Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Zaw, Ingyin [New York University (Abu Dhabi), 70 Washington Square S, New York, NY 10012 (United States); James, Bethan [Institute of Astronomy, Cambridge University, Madingley Road, Cambridge CB3 0HA (United Kingdom); Juneau, Stéphanie [CEA-Saclay, DSM/IRFU/SAp, F-91191 Gif-sur-Yvette (France); Srivastava, Shweta, E-mail: Rebecca.Davies@anu.edu.au [Astronomy and Astrophysics Division, Physical Research Laboratory, Ahmedabad 380009 (India)

    2016-06-10

    We investigate the relative significance of radiation pressure and gas pressure in the extended narrow line regions (ENLRs) of four Seyfert galaxies from the integral field Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). We demonstrate that there exist two distinct types of starburst-active galactic nucleus (AGN) mixing curves on standard emission line diagnostic diagrams, which reflect the balance between gas pressure and radiation pressure in the ENLR. In two of the galaxies the ENLR is radiation pressure dominated throughout and the ionization parameter remains constant (log U ∼ 0). In the other two galaxies radiation pressure is initially important, but gas pressure becomes dominant as the ionization parameter in the ENLR decreases from log U ∼ 0 to −3.2 ≲ log U ≲ −3.4. Where radiation pressure is dominant, the AGN regulates the density of the interstellar medium on kiloparsec scales and may therefore have a direct impact on star formation activity and/or the incidence of outflows in the host galaxy to scales far beyond the zone of influence of the black hole. We find that both radiation pressure dominated and gas pressure dominated ENLRs are dynamically active with evidence for outflows, indicating that radiation pressure may be an important source of AGN feedback even when it is not dominant over the entire ENLR.

  3. SDSS J211852.96-073227.5: a new γ-ray flaring narrow-line Seyfert 1 galaxy

    Yang, Hui; Yuan, Weimin; Yao, Su; Li, Ye; Zhang, Jin; Zhou, Hongyan; Komossa, S.; Liu, He-Yang; Jin, Chichuan

    2018-04-01

    We report on the identification of a new γ-ray-emitting narrow-line Seyfert 1 (NLS1) galaxy, SDSS J211852.96-073227.5 (hereafter J2118-0732). The galaxy, at a redshift of 0.26, is associated with a radio source of flat/inverted spectrum at high radio frequencies. The analysis of its optical spectrum obtained in the Sloan Digital Sky Survey revealed a small linewidth of the broad component of the Hβ line (FWHM = 1585 km s-1), making it a radio-loud NLS1 galaxy - an intriguing class of active galactic nuclei with exceptional multi-wavelength properties. A new γ-ray source centred at J2118-0732 was sporadically detected during 2009-2013 in form of flares by the Fermi-LAT. Our XMM-Newton observations revealed a flat X-ray spectrum described by a simple power law, and a flux variation by a factor of ˜2.5 in 5 months. The source also shows intraday variability in the infrared band. Its broad-band spectral energy distribution can be modelled by emission from a simple one-zone leptonic jet model, and the flux drop from infrared to X-rays in five months can be explained by changes of the jet parameters, though the exact values may be subject to relatively large uncertainties. With the NLS1-blazar composite nucleus, the clear detection of the host galaxy and the synchronous variations in the multi-wavelength fluxes, J2118-0732 provides a new perspective on the formation and evolution of relativistic jets under the regime of relatively small black hole masses and high accretion rates.

  4. Fluorescence line-narrowing studies of Nd:glass laser materials

    Riseberg, L.A.; Brecher, C.

    The increasing importance of Nd glass lasers in laser fusion technology has emphasized the inadequacy in the understanding of the optical properties of rare earth ions in glasses. Indeed, it has been difficult to generate models for the performance of these devices, and the selection of host glasses could be done by little more than a trial-and-error approach. The technique of laser-induced fluorescence line-narrowing developed within the last few years provides a new and powerful tool for the study of these systems. In this technique, a laser excites within the inhomogeneously broadened absorption bands a selected subgroup of the ions in the system, namely those whose absorption energy is resonant with the laser. If the excitation does not migrate among the entire collection of ions prior to fluorescence, the fluorescence that is observed is only from the group that was excited and is narrowed. This permits the selective study of classes of ion sites within the ensemble. The concept is indicated schematically. By the use of a tunable laser, such as a dye laser, it is possible to vary the class of sites, defined by energy, that is excited and thereby study the important spectroscopic properties and their variations, unclouded by the averaging that occurs under excitation of the entire system. Furthermore, it is then possible to use the spectroscopic information to infer a description of the variation of the microscopic environment, and a rationalization of the effects of compositional changes. Use of a pulsed dye laser and time-resolved detection permits the study of the dynamics, including, for example, the energy transfer among ions of different energies within the inhomogeneously-broadened spectrum. The goal of this project has been to apply such studies to glasses of interest to glass laser technology, providing information for device modeling, and establishing design criteria for glass selection

  5. KILOPARSEC-SCALE RADIO STRUCTURES IN NARROW-LINE SEYFERT 1 GALAXIES

    Doi, Akihiro; Kino, Motoki [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuou-ku, Sagamihara, Kanagawa 252-5210 (Japan); Nagira, Hiroshi [Graduate School of Science and Engineering, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi 753-8512 (Japan); Kawakatu, Nozomu [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571 (Japan); Nagai, Hiroshi [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Asada, Keiichi, E-mail: akihiro.doi@vsop.isas.jaxa.jp [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China)

    2012-11-20

    We report the finding of kiloparsec (kpc)-scale radio structures in three radio-loud narrow-line Seyfert 1 (NLS1) galaxies from the Faint Images of the Radio Sky at Twenty-centimeters of the Very Large Array, which increases the number of known radio-loud NLS1s with kpc-scale structures to six, including two {gamma}-ray-emitting NLS1s (PMN J0948+0022 and 1H 0323+342) detected by the Fermi Gamma-ray Space Telescope. The detection rate of extended radio emissions in NLS1s is lower than that in broad-line active galactic nuclei (AGNs) with a statistical significance. We found both core-dominated (blazar-like) and lobe-dominated (radio-galaxy-like) radio structures in these six NLS1s, which can be understood in the framework of the unified scheme of radio-loud AGNs that considers radio galaxies as non-beamed parent populations of blazars. Five of the six NLS1s have (1) extended radio luminosities suggesting jet kinetic powers of {approx}> 10{sup 44} erg s{sup -1}, which is sufficient to make jets escape from hosts' dense environments; (2) black holes of {approx}> 10{sup 7} M {sub Sun }, which can generate the necessary jet powers from near-Eddington mass accretion; and (3) two-sided radio structures at kpc scales, requiring expansion rates of {approx}0.01c-0.3c and kinematic ages of {approx}> 10{sup 7} years. On the other hand, most typical NLS1s would be driven by black holes of {approx}< 10{sup 7} M {sub Sun} in a limited lifetime of {approx}10{sup 7} years. Hence, the kpc-scale radio structures may originate in a small window of opportunity during the final stage of the NLS1 phase just before growing into broad-line AGNs.

  6. Water vapor transmittance models for narrow bands in the 13 to 19 μm spectral region

    Weichel, R.L.

    1983-10-01

    The purpose of this report is to document the development of water vapor transmittance models for narrow bands (satellite sensor channels) in the 13 to 19 μm spectral region. The models are the result of research efforts of the author in 1971-1972 while on active duty with the US Air Force at the Air Force Global Weather Central (AFGWC). The models were developed for application in studies involving a temperature profiling sensor system carried aboard the satellites of the Defense Meteorological Satellite Program (DMSP), formerly DAPP. Recently, (Lovill et al., 1978; Luther et al., 1981) the models were implemented for studies concerned with methodologies to retrieve total atmospheric column ozone from measurements of newer DMSP Block 5D series satellite sensors with similar channels (see Nichols, 1975)

  7. PREFACE: XXII International Conference on Spectral Line Shapes 2014

    Parigger, C. G.

    2014-11-01

    The 22nd International Conference on Spectral Line Shapes (ICSLS) was convened at The University of Tennessee Space Institute (UTSI) at Tullahoma, Tennessee, USA, during June 1 to 6, 2014. A variety of topics of interest to the line shape community were addressed during invited and contributed oral and poster presentations. General categories of the ICSLS 2014 scientific contents included Astrophysics, Biomedical Physics, High and Low Temperature Plasma Physics, Magnetic Fusion Physics, Neutrals Atomic-Molecular-Optical (AMO) Physics, and Applied Physics. Research interests at UTSI and at the Center for Laser Applications (CLA) focus on Applied Physics and Plasma Physics areas such as laser-induced breakdown spectroscopy, spectroscopy with ultra-short light pulses, combustion diagnostics, to name a few. Consequently, the presentations during the conference addressed a variety of these topics. Attendance at the conference included researchers from North America, Africa, Asia and Europe, with an international representation showing 250 authors and co-authors with over 25 different citizenships, and 100 participants at the Conference. Figure 1 shows a photo of Conference attendees. The schedule included 82 contributions, 41 oral and 41 poster presentations. The 29 invited, 12 contributed oral and 41 contributed poster presentations were selected following communication with the international organizing committee members. A smart phone ''app'' was also utilized, thanks to Elsevier, to communicate electronic versions of the posters during the conference. Special thanks go to the members of the international and local committees for their work in organizing the 22nd ICSLS. In addition, thank you notes also go to the peer reviewers for the proceedings. Following the success of the IOP: Journal of Physics Conference Series selected for the 21st ICSLS publication, the proceedings papers report ongoing research activities. Papers submitted amount to 68 in number, or 83% of

  8. Theoretical profiles of the spectral lines of the hydrogen atom

    Nguyen, H.; Herman, L.; Drawin, H.W.

    1965-01-01

    The line-broadening problem of the hydrogen lines has been formulated in the quasistatic approximation as far as the ions are concerned, and in the classical path approximation as far as the broadening due to collisions with electrons is concerned. These electrons interfere in different numerical results only by the self-correlation function of the fluctuating electrical field strength created at each point in the plasma. The Lewis correction has been applied, but using the whole velocity distribution function of the electrons. The formula which represents the usual impact profile, valid only for frequencies much smaller than the plasma frequency, has been extended using another formula which will be valid up to the neighbourhood of that spectral region where the quasi-static approximation begins to be valid also for the electrons. As an example, the line profile of Ly α is given by some graphs for T = 10 4 deg. K and electron densities N = 10 17 cm -3 and N = 10 18 cm -3 . (authors) [fr

  9. The multi-spectral line-polarization MSE system on Alcator C-Mod

    Mumgaard, R. T.; Khoury, M.; Scott, S. D.

    2016-01-01

    A multi-spectral line-polarization motional Stark effect (MSE-MSLP) diagnostic has been developed for the Alcator C-Mod tokamak wherein the Stokes vector is measured in multiple wavelength bands simultaneously on the same sightline to enable better polarized background subtraction. A ten-sightline, four wavelength MSE-MSLP detector system was designed, constructed, and qualified. This system consists of a high-throughput polychromator for each sightline designed to provide large étendue and precise spectral filtering in a cost-effective manner. Each polychromator utilizes four narrow bandpass interference filters and four custom large diameter avalanche photodiode detectors. Two filters collect light to the red and blue of the MSE emission spectrum while the remaining two filters collect the beam pi and sigma emission generated at the same viewing volume. The filter wavelengths are temperature tuned using custom ovens in an automated manner. All system functions are remote controllable and the system can be easily retrofitted to existing single-wavelength line-polarization MSE systems.

  10. The multi-spectral line-polarization MSE system on Alcator C-Mod

    Mumgaard, R. T., E-mail: mumgaard@psfc.mit.edu; Khoury, M. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Scott, S. D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)

    2016-11-15

    A multi-spectral line-polarization motional Stark effect (MSE-MSLP) diagnostic has been developed for the Alcator C-Mod tokamak wherein the Stokes vector is measured in multiple wavelength bands simultaneously on the same sightline to enable better polarized background subtraction. A ten-sightline, four wavelength MSE-MSLP detector system was designed, constructed, and qualified. This system consists of a high-throughput polychromator for each sightline designed to provide large étendue and precise spectral filtering in a cost-effective manner. Each polychromator utilizes four narrow bandpass interference filters and four custom large diameter avalanche photodiode detectors. Two filters collect light to the red and blue of the MSE emission spectrum while the remaining two filters collect the beam pi and sigma emission generated at the same viewing volume. The filter wavelengths are temperature tuned using custom ovens in an automated manner. All system functions are remote controllable and the system can be easily retrofitted to existing single-wavelength line-polarization MSE systems.

  11. MULTI-WAVELENGTH PROBES OF OBSCURATION TOWARD THE NARROW-LINE REGION IN SEYFERT GALAXIES

    Kraemer, S. B.; Schmitt, H.R.; Crenshaw, D. M.; Melendez, M.; Turner, T.J.; Guainazzi, M.; Mushotzky, R.F.

    2011-01-01

    We present a study of reddening and absorption toward the narrow line regions (NLRs) in active galactic nuclei (AGNs) selected from the Revised Shapley-Ames, 12 μm, and Swift/Burst Alert Telescope samples. For the sources in host galaxies with inclinations of b/a > 0.5, we find that the mean ratio of [O III] λ5007, from ground-based observations, and [O IV] 28.59 μm, from Spitzer/Infrared Spectrograph observations, is a factor of two lower in Seyfert 2s than Seyfert 1s. The combination of low [O III]/[O IV] and [O III] λ4363/λ5007 ratios in Seyfert 2s suggests more extinction of emission from the NLR than in Seyfert 1s. Similar column densities of dusty gas, N H ∼ several x 10 21 cm -2 , can account for the suppression of both [O III] λ5007 and [O III] λ4363, as compared to those observed in Seyfert 1s. Also, we find that the X-ray line O VII λ22.1 A is weaker in Seyfert 2s, consistent with absorption by the same gas that reddens the optical emission. Using a Hubble Space Telescope/Space Telescope Imaging Spectrograph slitless spectrum of the Seyfert 1 galaxy NGC 4151, we estimate that only ∼30% of the [O III] λ5007 comes from within 30 pc of the central source, which is insufficient to account for the low [O III]/[O IV] ratios in Seyfert 2s. If Seyfert 2 galaxies have similar intrinsic [O III] spatial profiles, the external dusty gas must extend further out along the NLR, perhaps in the form of nuclear dust spirals that have been associated with fueling flows toward the AGN.

  12. KILOPARSEC-SCALE JETS IN THREE RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES

    Richards, Joseph L.; Lister, Matthew L., E-mail: jlr@purdue.edu [Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States)

    2015-02-10

    We have discovered kiloparsec-scale extended radio emission in three narrow-line Seyfert 1 galaxies (NLS1s) in sub-arcsecond resolution 9 GHz images from the Karl G. Jansky Very Large Array. We find all sources show two-sided, mildly core-dominated jet structures with diffuse lobes dominated by termination hotspots. These span 20–70 kpc with morphologies reminiscent of FR II radio galaxies, while the extended radio luminosities are intermediate between FR I and FR II sources. In two cases the structure is linear, while a 45° bend is apparent in the third. Very Long Baseline Array images at 7.6 GHz reveal parsec-scale jet structures, in two cases with extended structure aligned with the inner regions of the kiloparsec-scale jets. Based on this alignment, the ratio of the radio core–luminosity to the optical luminosity, the jet/counter-jet intensity and extension length ratios, and moderate core brightness temperatures (≲10{sup 10} K), we conclude these jets are mildly relativistic (β≲0.3, δ∼1−1.5) and aligned at moderately small angles to the line of sight (10–15°). The derived kinematic ages of ∼10{sup 6}–10{sup 7} yr are much younger than radio galaxies but comparable to other NLS1s. Our results increase the number of radio-loud NLS1s with known kiloparsec-scale extensions from 7 to 10 and suggest that such extended emission may be common, at least among the brightest of these sources.

  13. The Size-Luminosity Relationship of Quasar Narrow-Line Regions

    Dempsey, Ross; Zakamska, Nadia L.

    2018-04-01

    The presence of an active galactic nucleus (AGN) can strongly affect its host. Due to the copious radiative power of the nucleus, the effects of radiative feedback can be detected over the entire host galaxy and sometimes well into the intergalactic space. In this paper we model the observed size-luminosity relationship of the narrow-line regions (NLRs) of AGN. We model the NLR as a collection of clouds in pressure equilibrium with the ionizing radiation, with each cloud producing line emission calculated by Cloudy. The sizes of the NLRs of powerful quasars are reproduced without any free parameters, as long as they contain massive (105M⊙ to 107M⊙) ionization-bounded clouds. At lower AGN luminosities the observed sizes are larger than the model sizes, likely due to additional unmodeled sources of ionization (e.g., star formation). We find that the observed saturation of sizes at ˜10kpc which is observed at high AGN luminosities (Lion ≃ 1046erg/s) is naturally explained by optically thick clouds absorbing the ionizing radiation and preventing illumination beyond a critical distance. Using our models in combination with observations of the [O III]/IR ratio and the [O III] size - IR luminosity relationship, we calculate the covering factor of the obscuring torus (and therefore the type 2 fraction within the quasar population) to be f = 0.5, though this is likely an upper bound. Finally, because the gas behind the ionization front is invisible in ionized gas transitions, emission-based NLR mass calculations underestimate the mass of the NLR and therefore of the energetics of ionized-gas winds.

  14. Exploring the physics of the accretion and jet in nearby narrow-line Seyfert 1 galaxies

    Yao, Su; Qiao, Erlin; Wu, Xue-Bing; You, B.

    2018-06-01

    In this paper, we explore the physics of the accretion and jet in narrow-line Seyfert 1 (NLS1) galaxy. Specifically, we compile a sample composed of 16 nearby NLS1 with Lbol/LEdd ≳ 0.1. We investigate the mutual correlation between their radio luminosity LR, X-ray luminosity LX, optical luminosity L5100, and black hole mass MBH. By adopting partial correlation analysis, we find (1) a positive correlation between LX and MBH and (2) a weak positive correlation between LR and L5100. However, we don't find significant correlations between LR and LX or between LX and L5100 after considering the effect of the black hole mass, which leads to a finding that LX/LEdd is independent of L5100/LEdd. Interestingly, the findings that LX is correlated with MBH and LX/LEdd is not correlated with L5100/LEdd support that the X-ray emission is saturated with increasing \\dot{M} for Lbol/LEdd ≳ 0.1 in NLS1, which may be understood in the framework of slim disc scenario. Finally, we suggest that a larger NLS1 sample with high-quality radio and X-ray data is needed to further confirm this result in the future.

  15. A FANAROFF-RILEY TYPE I CANDIDATE IN NARROW-LINE SEYFERT 1 GALAXY Mrk 1239

    Doi, Akihiro [The Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuou-ku, Sagamihara, Kanagawa 252-5210 (Japan); Wajima, Kiyoaki [Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong, Daejeon 305-348 (Korea, Republic of); Hagiwara, Yoshiaki [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Inoue, Makoto, E-mail: akihiro.doi@vsop.isas.jaxa.jp [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China)

    2015-01-10

    We report finding kiloparsec-scale radio emissions aligned with parsec-scale jet structures in the narrow-line Seyfert 1 (NLS1) galaxy Mrk 1239 using the Very Large Array and the Very Long Baseline Array. Thus, this radio-quiet NLS1 has a jet-producing central engine driven by essentially the same mechanism as that of other radio-loud active galactic nuclei (AGNs). Most of the radio luminosity is concentrated within 100 parsecs and overall radio morphology looks edge-darkened; the estimated jet kinetic power is comparable to Fanaroff-Riley Type I radio galaxies. The conversion from accretion to jet power appears to be highly inefficient in this highly accreting low-mass black hole system compared with that in a low-luminosity AGN with similar radio power driven by a sub-Eddington, high-mass black hole. Thus, Mrk 1239 is a crucial probe to the unexplored parameter spaces of central engines for a jet formation.

  16. Searches for H2O masers toward narrow-line Seyfert 1 galaxies

    Yoshiaki, Hagiwara; Doi, Akihiro; Hachisuka, Kazuya; Horiuchi, Shinji

    2018-05-01

    We present searches for 22 GHz H2O masers toward 36 narrow-line Seyfert 1 galaxies (NLS1s), selected from known NLS1s with vsys ≲ 41000 km s-1. Out of the 36 NLS1s in our sample, 11 have been first surveyed in our observations, while the observations of other NLS1s were previously reported in literature. In our survey, no new water maser source from NLS1s was detected at the 3σ rms level of 8.4 mJy to 144 mJy, which depends on different observing conditions or inhomogeneous sensitivities of each observation using three different telescopes. It is likely that the non-detection of new masers in our NLS1 sample is primarily due to insufficient sensitivities of our observations. Including the five known NLS1 masers, the total detection rate of the H2O maser in NLS1s is not remarkably different from that of type 2 Seyfert galaxies or LINERs. However, more extensive and systematic searches of NLS1 would be required for a statistical discussion of the detection rate of the NLS1 maser, compared with that of type 2 Seyferts or LINERs.

  17. Numerical Study on Outflows in Seyfert Galaxies I: Narrow Line Region Outflows in NGC 4151

    Mou, Guobin; Wang, Tinggui; Yang, Chenwei, E-mail: gbmou@ustc.edu.cn [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei 230026 (China)

    2017-07-20

    The origin of narrow line region (NLR) outflows remains unknown. In this paper, we explore the scenario in which these outflows are circumnuclear clouds driven by energetic accretion disk winds. We choose the well-studied nearby Seyfert galaxy NGC 4151 as an example. By performing 3D hydrodynamical simulations, we are able to reproduce the radial distributions of velocity, mass outflow rate, and kinetic luminosity of NLR outflows in the inner 100 pc deduced from spatial resolved spectroscopic observations. The demanded kinetic luminosity of disk winds is about two orders of magnitude higher than that inferred from the NLR outflows, but is close to the ultrafast outflows (UFO) detected in the X-ray spectrum and a few times lower than the bolometric luminosity of the Seyfert. Our simulations imply that the scenario is viable for NGC 4151. The existence of the underlying disk winds can be confirmed by their impacts on higher density ISM, e.g., shock excitation signs, and the pressure in NLR.

  18. Numerical Study on Outflows in Seyfert Galaxies I: Narrow Line Region Outflows in NGC 4151

    Mou, Guobin; Wang, Tinggui; Yang, Chenwei

    2017-01-01

    The origin of narrow line region (NLR) outflows remains unknown. In this paper, we explore the scenario in which these outflows are circumnuclear clouds driven by energetic accretion disk winds. We choose the well-studied nearby Seyfert galaxy NGC 4151 as an example. By performing 3D hydrodynamical simulations, we are able to reproduce the radial distributions of velocity, mass outflow rate, and kinetic luminosity of NLR outflows in the inner 100 pc deduced from spatial resolved spectroscopic observations. The demanded kinetic luminosity of disk winds is about two orders of magnitude higher than that inferred from the NLR outflows, but is close to the ultrafast outflows (UFO) detected in the X-ray spectrum and a few times lower than the bolometric luminosity of the Seyfert. Our simulations imply that the scenario is viable for NGC 4151. The existence of the underlying disk winds can be confirmed by their impacts on higher density ISM, e.g., shock excitation signs, and the pressure in NLR.

  19. Numerical Study on Outflows in Seyfert Galaxies I: Narrow Line Region Outflows in NGC 4151

    Mou, Guobin; Wang, Tinggui; Yang, Chenwei

    2017-07-01

    The origin of narrow line region (NLR) outflows remains unknown. In this paper, we explore the scenario in which these outflows are circumnuclear clouds driven by energetic accretion disk winds. We choose the well-studied nearby Seyfert galaxy NGC 4151 as an example. By performing 3D hydrodynamical simulations, we are able to reproduce the radial distributions of velocity, mass outflow rate, and kinetic luminosity of NLR outflows in the inner 100 pc deduced from spatial resolved spectroscopic observations. The demanded kinetic luminosity of disk winds is about two orders of magnitude higher than that inferred from the NLR outflows, but is close to the ultrafast outflows (UFO) detected in the X-ray spectrum and a few times lower than the bolometric luminosity of the Seyfert. Our simulations imply that the scenario is viable for NGC 4151. The existence of the underlying disk winds can be confirmed by their impacts on higher density ISM, e.g., shock excitation signs, and the pressure in NLR.

  20. Overlapping communities detection based on spectral analysis of line graphs

    Gui, Chun; Zhang, Ruisheng; Hu, Rongjing; Huang, Guoming; Wei, Jiaxuan

    2018-05-01

    Community in networks are often overlapping where one vertex belongs to several clusters. Meanwhile, many networks show hierarchical structure such that community is recursively grouped into hierarchical organization. In order to obtain overlapping communities from a global hierarchy of vertices, a new algorithm (named SAoLG) is proposed to build the hierarchical organization along with detecting the overlap of community structure. SAoLG applies the spectral analysis into line graphs to unify the overlap and hierarchical structure of the communities. In order to avoid the limitation of absolute distance such as Euclidean distance, SAoLG employs Angular distance to compute the similarity between vertices. Furthermore, we make a micro-improvement partition density to evaluate the quality of community structure and use it to obtain the more reasonable and sensible community numbers. The proposed SAoLG algorithm achieves a balance between overlap and hierarchy by applying spectral analysis to edge community detection. The experimental results on one standard network and six real-world networks show that the SAoLG algorithm achieves higher modularity and reasonable community number values than those generated by Ahn's algorithm, the classical CPM and GN ones.

  1. GBTIDL: Reduction and Analysis of GBT Spectral Line Data

    Marganian, P.; Garwood, R. W.; Braatz, J. A.; Radziwill, N. M.; Maddalena, R. J.

    2013-03-01

    GBTIDL is an interactive package for reduction and analysis of spectral line data taken with the Robert C. Byrd Green Bank Telescope (GBT). The package, written entirely in IDL, consists of straightforward yet flexible calibration, averaging, and analysis procedures (the "GUIDE layer") modeled after the UniPOPS and CLASS data reduction philosophies, a customized plotter with many built-in visualization features, and Data I/O and toolbox functionality that can be used for more advanced tasks. GBTIDL makes use of data structures which can also be used to store intermediate results. The package consumes and produces data in GBT SDFITS format. GBTIDL can be run online and have access to the most recent data coming off the telescope, or can be run offline on preprocessed SDFITS files.

  2. Initial analyses of surface spectral radiance between observations and Line-By-Line calculations

    Brown, P.D.; Clough, S.A. [Atmospheric and Environmental Research, Inc., Cambridge, MA (United States); Miller, N.E.; Shippert, T.R.; Turner, D.D. [Pacific Northwest Lab., Richland, WA (United States)] [and others

    1996-04-01

    The evaluation an improvement of radiative transfer calculations are essential to attain improved performance of general circulation models (GCMs) for climate change applications. A Quality Measurement Experiment (QME) is being conducted to analyze the spectral residuals between the downwelling longwave radiance measured by the University of Wisconsin Atmospheric Emitted Radiance Interferometer (AERI) and spectral radiance calculated by the Line-By-Line Radiative Transfer Model (LBLRTM). The three critical components of this study are (1) the assessment of the quality of the high resolution AERI measurements, (2) the assessment of the ability to define the atmospheric state in the radiating column, and (3) the evaluation of the capability of LBLRTM. Validations have been performed on spectral radiance data, obtained from April 1994 through July 1994, through the analysis of the spectral interval and physical process. The results are archived as a function of time, enabling the retrieval of specific data and facilitating investigations and diurnal effects, seasonal effects, and longer-term trends. While the initial focus is restricted to clear-sky analyses, efforts are under way to include the effects of clouds and aerosols. Plans are well formulated for the extension of the current approach to the shortwave. An overview of the concept of the QME is described by Miller et al. (1994), and a detailed description of this study is provided by Clough et al. (1994).

  3. The size of the narrow-line-emitting region in the Seyfert 1 galaxy NGC 5548 from emission-line variability

    Peterson, B. M.; Denney, K. D.; De Rosa, G.; Grier, C. J.; Pogge, R. W.; Kochanek, C. S.; Bentz, M. C.; Vestergaard, M.; Kilerci-Eser, E.; G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" data-affiliation=" (Dipartimento di Fisica e Astronomia G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" >Dalla Bontà, E.; G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" data-affiliation=" (Dipartimento di Fisica e Astronomia G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" >Ciroi, S.

    2013-01-01

    The narrow [O III] λλ4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow-line-emitting region has a radius of only 1-3 pc and is denser (n e ∼ 10 5 cm –3 ) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass. Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad Hβ emission-line light curves for the period 1988-2008.

  4. The size of the narrow-line-emitting region in the Seyfert 1 galaxy NGC 5548 from emission-line variability

    Peterson, B. M.; Denney, K. D.; De Rosa, G.; Grier, C. J.; Pogge, R. W.; Kochanek, C. S. [Department of Astronomy, The Ohio State University, 140 W 18th Avenue, Columbus, OH 43210 (United States); Bentz, M. C. [Department of Physics and Astronomy, Georgia State University, 25 Park Place, Suite 610, Atlanta, GA 30303 (United States); Vestergaard, M.; Kilerci-Eser, E. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Dalla Bontà, E.; Ciroi, S. [Dipartimento di Fisica e Astronomia " G. Galilei," Università di Padova, Vicolo dell' Osservatorio 3 I-35122, Padova (Italy)

    2013-12-20

    The narrow [O III] λλ4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow-line-emitting region has a radius of only 1-3 pc and is denser (n {sub e} ∼ 10{sup 5} cm{sup –3}) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass. Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad Hβ emission-line light curves for the period 1988-2008.

  5. Diagnosing the Kinematics of the Tori in Active Galactic Nuclei with the Velocity-resolved Reverberation Mapping of the Narrow Iron K α Line

    Liu Yuan; Li Xiaobo, E-mail: liuyuan@ihep.ac.cn, E-mail: lixb@ihep.ac.cn [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918-3, Beijing 100049 (China)

    2017-07-20

    The properties of the dusty tori in active galactic nuclei (AGNs) have been investigated in detail, mainly focusing on the geometry and components; however, the kinematics of the torus are still not clear. The narrow iron K α line at 6.4 keV is thought to be produced by the X-ray reflection from the torus. Thus, the velocity-resolved reverberation mapping of it is able to constrain the kinematics of the torus. Such effort is limited by the spectral resolution of current charged coupled device (CCD) detectors and should be possible with the microcalorimeter on the next generation X-ray satellite. In this paper, we first construct the response functions of the torus under a uniform inflow, a Keplerian rotation, and a uniform outflow. Then the energy-dependent light curve of the narrow iron K α line is simulated according to the performance of the X-ray Integral Field Unit in Athena. Finally, the energy-dependent cross-correlation function is calculated to reveal the kinematic signal. According to our results, 100 observations with 5 ks exposure of each are sufficient to distinguish the above three velocity fields. Although the real geometry and velocity field of the torus could be more complex than we assumed, the present result proves the feasibility of the velocity-resolved reverberation mapping of the narrow iron K α line. The combination of the dynamics of the torus with those of the broad-line region and the host galaxy is instructive for the understanding of the feeding and feedback process of AGNs.

  6. Atomic data and spectral line intensities for Ne III

    Bhatia, A K; Landi, E

    2003-01-01

    Electron impact collision strengths, energy levels, oscillator strengths and spontaneous radiative decay rates are calculated for Ne III. The configurations used are 2s sup 2 2p sup 4 , 2s2p sup 5 , 2s sup 2 2p sup 3 3s, and 2s sup 2 2p sup 3 3d giving rise to 57 fine-structure levels in intermediate coupling. Collision strengths are calculated at five incident energies, 5, 15, 25, 35, and 45 Ry. Excitation rate coefficients are calculated by assuming a Maxwellian electron velocity distribution at an electron temperature of logT sub e (K)=5.0, corresponding to maximum abundance of Ne III. Using the excitation rate coefficients and the radiative transition rates, statistical equilibrium equations for level populations are solved at electron densities covering the range of 10 sup 8 -10 sup 1 sup 4 cm sup - sup 3. Relative spectral line intensities are calculated. Proton excitation rates between the lowest three levels have been included in the statistical equilibrium equations. The predicted Ne III line intensi...

  7. Narrow Line Cooling of 88Sr Atoms in the Magneto-optical Trap for Precision Frequency Standard

    Strelkin, S. A.; Galyshev, A. A.; Berdasov, O. I.; Gribov, A. Yu.; Sutyrin, D. V.; Khabarova, K. Yu.; Kolachevsky, N. N.; Slyusarev, S. N.

    We report on our progress toward the realization of a Strontium optical lattice clock, which is under development at VNIIFTRI as a part of GLONASS program. We've prepared the narrow line width laser system for secondary cooling of 88Sr atoms which allows us to reach atom cloud temperature below 3 μK after second cooling stage.

  8. VizieR Online Data Catalog: Quasars narrow absorption lines from SDSS (Chen+, 2015)

    Chen, Z.-F.; Gu, Q.-S.; Chen, Y.-M.; Cao, Y.

    2017-11-01

    The Baryon Oscillation Spectroscopic Survey (BOSS: Eisenstein et al. 2011AJ....142...72E; Paris et al. 2012, Cat. VII/269) is the main dark-time legacy survey of the third stage of the SDSS, which used the same 2.5-m telescope (Gunn et al. 2006AJ....131.2332G; Ross et al. 2012, J/ApJS/199/3) as the first and second stages of the SDSS (hereafter SDSS-I/II). SDSS-I/II spectra have a wavelength coverage from 3800-9200Å with a spectral resolution of 1800-2200 (e.g. York et al. 2000AJ....120.1579Y). BOSS spectra span a range from 3600-10500Å at a resolution of 1300-2500 (Paris et al. 2012, Cat. VII/269). During the first two years, BOSS detected 87822 quasars over an area of 3275 deg2, including 7932 quasars that were observed by SDSS-I/II as well. Quasars observed by both SDSS-I/II and BOSS provide a remarkable chance to study the variabilities of absorption lines in a large population. Throughout this work, we take the quasar emission redshifts provided by Hewett & Wild (2010, J/MNRAS/405/2302, http://das.sdss.org/va/HewettWilddr7qso_newz/) directly. (2 data files).

  9. Photoionization Models of the H_2 Emission of the Narrow Line Region of AGNs

    Aleman, I.; Gruenwald, R.

    2011-05-01

    The excitation mechanism of the narrow line region (NLR) of AGNs is still an open question. Excitation by UV radiation from O and B stars, x-rays from the central black hole, shock from supernovae or jets, or a combination of these mechanisms have been suggested. In the present work, we use photoionization models to study the excitation mechanisms of the H_2 infrared emission lines in the NLR. In the literature, analyzes of the H_2 emission have been done assuming that the molecules is present only in neutral regions (photodissociation regions, x-ray-dominated regions, or shocks; Veilleux et al. 1997, Krabbe et al. 2000, Rigopoulou et al. 2002, Rodriguez-Ardila et al. 2004, 2005, and Davies et al. 2005). However, they are not conclusive. In previous work (Aleman & Gruenwald 2004, 2011), we show that the H_2 emission from the ionized region of PNe can be significant for planetary nebulae (PNe) with hot central stars (T⋆ > 150000 K). Such stars produce copious amounts of high energy photons, which create an extended partially ionized region that favors the H_2 survival. The conditions in the NLR are similar to those in PNe with hot central stars, so we can expect that the H_2 emission might also be important. We obtain and analyze a grid of photoionization models for different NRL parameters. We study the resulting H_2 density and emission, as well as, the formation, destruction, excitation, and de-excitation mechanisms. The higher values observed for the H_2 1-0 S(1)/Brγ ratio cannot be reproduced by our models. The calculated ratios are between 10^-8 and 10^-1, while the observational ration can be as high as 10. The calculated ratio is strongly anti-correlated with the ionization parameter (U) and only models with U<10-3 result in ratios inside the observational range. We show that the NLR is an environment more hostile to the H_2 molecule than the ionized region of PNe. Another interesting result of our calculations is that the H_2 formation on grain surfaces

  10. PREFACE: XXI International Conference on Spectral Line Shapes (ICSLS 2012)

    Devdariani, Alexander Z.

    2012-12-01

    The 21st International Conference on Spectral Line Shapes, ICSLS, was held in the historic main building of St Petersburg State University (St. Petersburg, Russia) on 3-9 June 2012. The event continued the tradition started in 1978 in Meudon Observatory in Paris. Representatives of line shape physics have since met every two years in different locations in Europe and North America. The most recent events were held in St John's, Newfoundland, Canada (2010), Valladolid, Spain (2008), and Auburn, AL (USA). Traditionally, the conferences consider experimental and theoretical issues of studying spectral line shapes, diagnostic utilization of spectral line profiles observed in absorption, emission or scattering of electromagnetic radiation by atoms, molecules, and clusters in different environments, including neutral environments, laboratory low and fusion plasmas, astrophysical conditions, and planetary atmospheres. The Conference was attended by over 100 professionals from Europe, Asia, America, Africa and New Zealand. The conference program was put together in such a way so as to exclude any parallel sessions. Five afternoon sessions featured 19 invited talks and 20 oral contributions, and two evening sessions offered 61 poster presentations, including post-deadline posters. This setup allowed for a relaxed and unhurried discussion of results and facilitated productive networking. The invited talks were selected by recommendation of members of the International Scientific Committee. The Organizers would like to thank all the members of the International Scientific Committee for their proposals on the agenda and their valuable advice. When considering candidates for oral contributions, the organizers took into account the suggestions and preferences of potential conference participants. When selecting the theses of poster presentations, the organizers focused on the topics in line with the theme of the conference and studies with well-formulated results. It must be

  11. Narrow line-width Tm3+ doped double-clad silica fiber laser based on in-line cascade biconical tapers filter

    Tian, Y; Zhao, J Q; Wang, W; Wang, Y Z; Gao, W

    2010-01-01

    Narrow line-width 793 nm laser diode cladding pumped Tm 3+ doped double cladding silica fiber laser with in-line four concatenated tapers filter was reported for the first time to our knowledge. These cascade tapers located 3.6 cm from the output end of the fiber laser was fabricated by heating and stretching method. The taper's transmitted power response as a function of wavelength was described by using local mode coupling theory and successive tapers filter model. The wavelength filter function of the in-line cascade tapers in a linear cavity fiber laser was demonstrated, and the experimental result agreed with these theories. The maximum output laser power was 736 mW, corresponding to single peak of laser spectrum with narrow line-width of ∼ 60 pm

  12. Spectral narrowing and spin echo for localized carriers with heavy-tailed L evy distribution of hopping times

    Yue, Z. [Univ. of Utah, Salt Lake City, UT (United States); Mkhitaryan, Vagharsh [Ames Lab. and Iowa State Univ., Ames, IA (United States); Raikh, M. E. [Univ. of Utah, Salt Lake City, UT (United States)

    2016-02-02

    We study analytically the free induction decay and the spin echo decay originating from the localized carriers moving between the sites which host random magnetic fields. Due to disorder in the site positions and energies, the on-site residence times, , are widely spread according to the L evy distribution. The power-law tail ∝ τ-1-∝ in the distribution of does not affect the conventional spectral narrowing for α > 2, but leads to a dramatic acceleration of the free induction decay in the domain 2 > α > 1. The next abrupt acceleration of the decay takes place as becomes smaller than 1. In the latter domain the decay does not follow a simple-exponent law. To capture the behavior of the average spin in this domain, we solve the evolution equation for the average spin using the approach different from the conventional approach based on the Laplace transform. Unlike the free induction decay, the tail in the distribution of the residence times leads to the slow decay of the spin echo. The echo is dominated by realizations of the carrier motion for which the number of sites, visited by the carrier, is minimal.

  13. Outflows in the narrow-line region of bright Seyfert galaxies - I. GMOS-IFU data

    Freitas, I. C.; Riffel, R. A.; Storchi-Bergmann, T.; Elvis, M.; Robinson, A.; Crenshaw, D. M.; Nagar, N. M.; Lena, D.; Schmitt, H. R.; Kraemer, S. B.

    2018-05-01

    We present two-dimensional maps of emission-line fluxes and kinematics, as well as of the stellar kinematics of the central few kpc of five bright nearby Seyfert galaxies - Mrk 6, Mrk 79, Mrk 348, Mrk 607, and Mrk 1058 - obtained from observations with the Gemini Multi-Object Spectrograph Integral Field Unit on the Gemini North Telescope. The data cover the inner 3.5 arcsec × 5.0 arcsec - corresponding to physical scales in the range 0.6 × 0.9-1.5 × 2.2 kpc2 - at a spatial resolution ranging from 110 to 280 pc with a spectral coverage of 4300-7100 Å and velocity resolution of ≈90 km s-1. The gas excitation is Seyfert like everywhere but show excitation gradients that are correlated with the gas kinematics, reddening and/or the gas density. The gas kinematics show in all cases two components: a rotation one similar to that observed in the stellar velocity field, and an outflow component. In the case of Mrk607, the gas is counter-rotating relative to the stars. Enhanced gas velocity dispersion is observed in association with the outflows according to two patterns: at the locations of the highest outflow velocities along the ionization axis or perpendicularly to it in a strip centred at the nucleus that we attribute to an equatorial outflow. Bipolar outflows are observed in Mrk 348 and Mrk 79, while in Mrk 1058 only the blueshifted part is clearly observed, while in cases of Mrk 6 and Mrk 607, the geometry of the outflow needs further constraints from modelling to be presented in a forthcoming study, where the mass flow rate and powers will also be obtained.

  14. Ultraviolet SO lasers optically pumped by a tunable, line-narrowed KrF laser

    Stuart, B.C.D.

    1992-06-01

    The feasibility of an ultraviolet energy storage laser based on the long-lived sulfur monoxide A 3 π-χ 3 Σ - electronic transition was investigated, and an ultraviolet laser based on the short-lived SO(B 3 Σ - -χ 3 Σ - ) transition was demonstrated and modeled. Both were optically pumped by a continuously tunable, line-narrowed KrF laser developed for efficient rotationally resolved excitation of SO. SO was produced by both microwave discharge and excimer laser photolysis of the precursor molecules SO 2 and SOCl 2 , with a maximum SO concentration (10 16 cm -3 ) generated by ArF (193 nm) photodissociation of SO 2 . Laser induced fluorescence of SO was used to study the excitation spectroscopy, vibrational branching ratios, lifetimes and deactivation rates. The radiative lifetime of SO(A 3 π 2 ,v' = 5) was measured to be 6.9 μs and that of SO(B,v' = 1) to be 33 ns. Lifetimes in the highly perturbed SO(B,v' = 2) level ranged from 28--90 ns. Measurements and modeling of the excitation saturation fluence as a function of buffer gas pressure determined what fraction of the ground state SO(X) molecules could be excited to SO(A) or SO(B). No evidence of excited state absorption was seen. Lasing on six new ultraviolet SO(B-X) vibrational bands in the range 262--315 nm was demonstrated. SO(B-X) pulse energies of up to 11 μJ were obtained and the gain coefficient was estimated to be 0.1 cm -1 . A multi-level rate equation model of the SO(B-X) excitation and lasing transitions, including collisional rotational mixing, described the dynamics of the lasing and measured output very well. Modeling showed and experiments confirmed that the maximum possible SO laser gain simply corresponded to saturating the excitation of a single rotational level. Collisional coupling of the rotational levels increased the laser output energy

  15. X-ray monitoring of the radio and γ-ray loud Narrow-Line Seyfert 1 Galaxy PKS2004–447

    Kreikenbohm A.

    2013-12-01

    Full Text Available We present preliminary results of the X-ray analysis of XMM-Newton and Swift observations as part of a multi-wavelength monitoring campaign in 2012 of the radio-loud narrow line Seyfert 1 galaxy PKS 2004–447. The source was recently detected in γ-rays by Fermi/LAT among only four other galaxies of that type. The 0:5 – 10 keV X-ray spectrum is well-described by a simple absorbed powerlaw (Γ ∼ 1.6. The source brightness exhibits variability on timescales of months to years with indications for spectral variability, which follows a “bluer-when-brighter” behaviour, similar to blazars.

  16. CORRELATION ANALYSIS OF A LARGE SAMPLE OF NARROW-LINE SEYFERT 1 GALAXIES: LINKING CENTRAL ENGINE AND HOST PROPERTIES

    Xu Dawei; Komossa, S.; Wang Jing; Yuan Weimin; Zhou Hongyan; Lu Honglin; Li Cheng; Grupe, Dirk

    2012-01-01

    We present a statistical study of a large, homogeneously analyzed sample of narrow-line Seyfert 1 (NLS1) galaxies, accompanied by a comparison sample of broad-line Seyfert 1 (BLS1) galaxies. Optical emission-line and continuum properties are subjected to correlation analyses, in order to identify the main drivers of the correlation space of active galactic nuclei (AGNs), and of NLS1 galaxies in particular. For the first time, we have established the density of the narrow-line region as a key parameter in Eigenvector 1 space, as important as the Eddington ratio L/L Edd . This is important because it links the properties of the central engine with the properties of the host galaxy, i.e., the interstellar medium (ISM). We also confirm previously found correlations involving the line width of Hβ and the strength of the Fe II and [O III] λ5007 emission lines, and we confirm the important role played by L/L Edd in driving the properties of NLS1 galaxies. A spatial correlation analysis shows that large-scale environments of the BLS1 and NLS1 galaxies of our sample are similar. If mergers are rare in our sample, accretion-driven winds, on the one hand, or bar-driven inflows, on the other hand, may account for the strong dependence of Eigenvector 1 on ISM density.

  17. The origin of narrowing of the Si 2p coincidence photoelectron spectroscopy main line of Si(1 0 0) surface

    Ohno, Masahide

    2011-01-01

    Highlights: → The Si 2p coincidence photoelectron spectroscopy (PES) main line of Si(1 0 0) is calculated. → The PES main line shows an asymmetric line shape change compared to the singles one. → The narrowing of the coincidence Si 2p PES main line is well reproduced. → The inherent mechanism of APECS is explained by a many-body theory. - Abstract: The Si 2p photoelectron spectroscopy (PES) main line of Si(1 0 0) surface measured in coincidence with the singles (noncoincidence) Si L 2,3 -VV Auger-electron spectroscopy (AES) elastic peak is calculated. The agreement with the experiment is good. The present work is the first many-body calculation of the experimental coincidence PES spectrum of solid surface. The narrowing of the coincidence Si 2p PES main line compared to the singles one is due to the mechanism inherent in the coincidence PES. The inherent mechanism is explained by a many-body theory by which photoemission and Auger-electron emission are treated on the same footing.

  18. Atomic data and spectral line intensities for Fe XVII

    Bhatia, A.K.; Doschek, G.A.

    2003-01-01

    Electron impact collision strengths and spontaneous radiative decay rates are calculated for Fe XVII. The data pertain to the 73 levels of the configurations, 2s 2 2p 6 , 2s 2 2p 5 3s, 2s 2 2p 5 3p 2s 2 2p 5 3d, 2s2p 6 3s, 2s2p 6 3p, 2s2p 6 3d, 2s 2 2p 5 4s, 2s 2 2p 5 4p, 2s 2 2p 5 4d, 2s2p 6 4s, 2s2p 6 4p, and 2s2p 6 4d. Collision strengths are calculated at 11 incident electron energies: 58.5, 65.0, 70.0, 76.0, 85.0, 127.5, 170.0, 212.5, 255.0, 340.0, and 425.0 Ry. This work is an improvement over our earlier work on Fe XVII in two respects: (1) configurations involving 4s, 4p, and 4d electrons have been added and (2) a broader range of incident electron energies is used in the computation of collision strengths and excitation rate coefficients. Relative spectral line intensities are calculated for astrophysically important transitions. These are obtained by computing the excitation rate coefficients (cm 3 s -1 ), i.e., the collision strengths integrated over a Maxwellian electron distribution, and then solving the equations of detailed balance for the populations of the 73 energy levels, assuming a collisional excitation model and an electron temperature of 4 x 10 6 K. This temperature is typical for Fe XVII when formed in equilibrium by collisional ionization and recombination. Using the excitation rate coefficients and the radiative decay rates, level populations are computed for five electron densities and are given in this paper

  19. Heterodyne detection using spectral line pairing for spectral phase encoding optical code division multiple access and dynamic dispersion compensation.

    Yang, Yi; Foster, Mark; Khurgin, Jacob B; Cooper, A Brinton

    2012-07-30

    A novel coherent optical code-division multiple access (OCDMA) scheme is proposed that uses spectral line pairing to generate signals suitable for heterodyne decoding. Both signal and local reference are transmitted via a single optical fiber and a simple balanced receiver performs sourceless heterodyne detection, canceling speckle noise and multiple-access interference (MAI). To validate the idea, a 16 user fully loaded phase encoded system is simulated. Effects of fiber dispersion on system performance are studied as well. Both second and third order dispersion management is achieved by using a spectral phase encoder to adjust phase shifts of spectral components at the optical network unit (ONU).

  20. Unshifted Metastable He I* Mini-broad Absorption Line System in the Narrow-line Type 1 Quasar SDSS J080248.18+551328.9

    Ji, Tuo; Zhou, Hongyan; Jiang, Peng; Wang, Tinggui; Ge, Jian; Wang, Huiyuan; Komossa, S.; Hamann, Fred; Zuther, Jens; Liu, Wenjuan; Lu, Honglin; Zuo, Wenwen; Yang, Chenwei; Yuan, Weimin

    2015-02-01

    We report the identification of an unusual absorption-line system in the quasar SDSS J080248.18+551328.9 and present a detailed study of the system, incorporating follow-up optical and near-IR spectroscopy. A few tens of absorption lines are detected, including He I*, Fe II*, and Ni II*, which arise from metastable or excited levels, as well as resonant lines in Mg I, Mg II, Fe II, Mn II, and Ca II. All of the isolated absorption lines show the same profile of width Δv ~ 1500 km s-1 centered at a common redshift as that of the quasar emission lines, such as [O II], [S II], and hydrogen Paschen and Balmer series. With narrow Balmer lines, strong optical Fe II multiplets, and weak [O III] doublets, its emission-line spectrum is typical for that of a narrow-line Seyfert 1 galaxy (NLS1). We have derived reliable measurements of the gas-phase column densities of the absorbing ions/levels. Photoionization modeling indicates that the absorber has a density of n H ~ (1.0-2.5) × 105 cm-3 and a column density of N H ~ (1.0-3.2) × 1021 cm-2 and is located at R ~100-250 pc from the central supermassive black hole. The location of the absorber, the symmetric profile of the absorption lines, and the coincidence of the absorption- and emission-line centroid jointly suggest that the absorption gas originates from the host galaxy and is plausibly accelerated by stellar processes, such as stellar winds and/or supernova explosions. The implications for the detection of such a peculiar absorption-line system in an NLS1 are discussed in the context of coevolution between supermassive black hole growth and host galaxy buildup.

  1. Microscopic nature of inhomogeneous line broadening: Analysis of the excitation-line-narrowing spectra of Cf4+ in CeF4

    Liu, G.K.; Huang, J.; Beitz, J.V.

    1993-01-01

    Optical transitions between 5f states of tetravalent californium ion doped (1 metal-atom %) into CeF 4 exhibit unusually large inhomogeneous broadening. The nature of the inhomogeneous broadening in this system has been studied by using fluorescence line narrowing and excitation line narrowing (ELN). It is shown that the energy distributions of different electronic states of Cf 4+ in this system are correlated. In the ELN experiments, reduced excitation linewidth was obtained when selectively monitoring fluorescence emission. A linear relation was observed between the excitation energies of crystal-field states of the 5 G 4' manifold and the fluorescence wavelength monitored across the inhomogeneous profile of a 5 G 6' -- 7 F 6' transition. Analysis of these results by means of a microscopic theory proposed by Laird and Skinner [J. Chem. Phys. 90, 3880 (1989)] has provided insights into the structural properties of this disordered system

  2. NARROW Na AND K ABSORPTION LINES TOWARD T TAURI STARS: TRACING THE ATOMIC ENVELOPE OF MOLECULAR CLOUDS

    Pascucci, I.; Simon, M. N. [Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Edwards, S. [Five College Astronomy Department, Smith College, Northampton, MA 01063 (United States); Heyer, M. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003-9305 (United States); Rigliaco, E. [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); Hillenbrand, L. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Gorti, U.; Hollenbach, D., E-mail: pascucci@lpl.arizona.edu [SETI Institute, Mountain View, CA 94043 (United States)

    2015-11-20

    We present a detailed analysis of narrow Na i and K i absorption resonance lines toward nearly 40 T Tauri stars in Taurus with the goal of clarifying their origin. The Na i λ5889.95 line is detected toward all but one source, while the weaker K i λ7698.96 line is detected in about two-thirds of the sample. The similarity in their peak centroids and the significant positive correlation between their equivalent widths demonstrate that these transitions trace the same atomic gas. The absorption lines are present toward both disk and diskless young stellar objects, which excludes cold gas within the circumstellar disk as the absorbing material. A comparison of Na i and CO detections and peak centroids demonstrates that the atomic gas and molecular gas are not co-located, the atomic gas being more extended than the molecular gas. The width of the atomic lines corroborates this finding and points to atomic gas about an order of magnitude warmer than the molecular gas. The distribution of Na i radial velocities shows a clear spatial gradient along the length of the Taurus molecular cloud filaments. This suggests that absorption is associated with the Taurus molecular cloud. Assuming that the gradient is due to cloud rotation, the rotation of the atomic gas is consistent with differential galactic rotation, whereas the rotation of the molecular gas, although with the same rotation axis, is retrograde. Our analysis shows that narrow Na i and K i absorption resonance lines are useful tracers of the atomic envelope of molecular clouds. In line with recent findings from giant molecular clouds, our results demonstrate that the velocity fields of the atomic and molecular gas are misaligned. The angular momentum of a molecular cloud is not simply inherited from the rotating Galactic disk from which it formed but may be redistributed by cloud–cloud interactions.

  3. NARROW Na AND K ABSORPTION LINES TOWARD T TAURI STARS: TRACING THE ATOMIC ENVELOPE OF MOLECULAR CLOUDS

    Pascucci, I.; Simon, M. N.; Edwards, S.; Heyer, M.; Rigliaco, E.; Hillenbrand, L.; Gorti, U.; Hollenbach, D.

    2015-01-01

    We present a detailed analysis of narrow Na i and K i absorption resonance lines toward nearly 40 T Tauri stars in Taurus with the goal of clarifying their origin. The Na i λ5889.95 line is detected toward all but one source, while the weaker K i λ7698.96 line is detected in about two-thirds of the sample. The similarity in their peak centroids and the significant positive correlation between their equivalent widths demonstrate that these transitions trace the same atomic gas. The absorption lines are present toward both disk and diskless young stellar objects, which excludes cold gas within the circumstellar disk as the absorbing material. A comparison of Na i and CO detections and peak centroids demonstrates that the atomic gas and molecular gas are not co-located, the atomic gas being more extended than the molecular gas. The width of the atomic lines corroborates this finding and points to atomic gas about an order of magnitude warmer than the molecular gas. The distribution of Na i radial velocities shows a clear spatial gradient along the length of the Taurus molecular cloud filaments. This suggests that absorption is associated with the Taurus molecular cloud. Assuming that the gradient is due to cloud rotation, the rotation of the atomic gas is consistent with differential galactic rotation, whereas the rotation of the molecular gas, although with the same rotation axis, is retrograde. Our analysis shows that narrow Na i and K i absorption resonance lines are useful tracers of the atomic envelope of molecular clouds. In line with recent findings from giant molecular clouds, our results demonstrate that the velocity fields of the atomic and molecular gas are misaligned. The angular momentum of a molecular cloud is not simply inherited from the rotating Galactic disk from which it formed but may be redistributed by cloud–cloud interactions

  4. Theoretical description of spectral line profiles of parent molecules in cometary comae

    Hu, Hong-Yao; Larson, H.P.; Hsieh, K.C.

    1991-01-01

    The present overview of cometary spectral-line profiles obtainable through advancements in high-resolution spectroscopic studies, which allow the retrieval of coma kinematic properties from velocity-resolved spectral-line profiles, incorporates the most important gas dynamic processes into an outflow model which is tailored to the interpretation of spectroscopic observations of parent molecules. The model is then used to study the influence on parent-molecule spectral line profile formation of the field-of-view, the expansion velocity, the kinetic temperature, and the anisotropic outflow distributions. 31 refs

  5. RADIO-LOUD NARROW-LINE SEYFERT 1 AS A NEW CLASS OF GAMMA-RAY ACTIVE GALACTIC NUCLEI

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E. D.; Borgland, A. W.; Cameron, R. A.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bonamente, E.; Brigida, M.; Bruel, P.; Burnett, T. H.; Caliandro, G. A.

    2009-01-01

    We report the discovery with Fermi/LAT of γ-ray emission from three radio-loud narrow-line Seyfert 1 galaxies: PKS 1502+036 (z = 0.409), 1H 0323+342 (z = 0.061), and PKS 2004 - 447 (z = 0.24). In addition to PMN J0948+0022 (z = 0.585), the first source of this type to be detected in γ rays, they may form an emerging new class of γ-ray active galactic nuclei (AGNs). These findings can have strong implications on our knowledge about relativistic jets and the unified model of the AGN.

  6. Spectral function for a nonsymmetric differential operator on the half line

    Wuqing Ning

    2017-05-01

    Full Text Available In this article we study the spectral function for a nonsymmetric differential operator on the half line. Two cases of the coefficient matrix are considered, and for each case we prove by Marchenko's method that, to the boundary value problem, there corresponds a spectral function related to which a Marchenko-Parseval equality and an expansion formula are established. Our results extend the classical spectral theory for self-adjoint Sturm-Liouville operators and Dirac operators.

  7. FERMI/LARGE AREA TELESCOPE DISCOVERY OF GAMMA-RAY EMISSION FROM A RELATIVISTIC JET IN THE NARROW-LINE QUASAR PMN J0948+0022

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Bloom, E. D.; Borgland, A. W.; Axelsson, M.; Battelino, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bonamente, E.; Brigida, M.; Caliandro, G. A.; Bruel, P.

    2009-01-01

    We report the discovery by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope of high-energy γ-ray emission from the peculiar quasar PMN J0948+0022 (z = 0.5846). The optical spectrum of this object exhibits rather narrow Hβ (FWHM(Hβ) ∼1500 km s -1 ), weak forbidden lines, and is therefore classified as a narrow-line type I quasar. This class of objects is thought to have relatively small black hole mass and to accrete at a high Eddington ratio. The radio loudness and variability of the compact radio core indicate the presence of a relativistic jet. Quasi-simultaneous radio/optical/X-ray and γ-ray observations are presented. Both radio and γ-ray emissions (observed over five months) are strongly variable. The simultaneous optical and X-ray data from Swift show a blue continuum attributed to the accretion disk and a hard X-ray spectrum attributed to the jet. The resulting broadband spectral energy distribution (SED) and, in particular, the γ-ray spectrum measured by Fermi are similar to those of more powerful Flat-Spectrum Radio Quasars (FSRQs). A comparison of the radio and γ-ray characteristics of PMN J0948+0022 with the other blazars detected by LAT shows that this source has a relatively low radio and γ-ray power with respect to other FSRQs. The physical parameters obtained from modeling the SED also fall at the low power end of the FSRQ parameter region discussed in Celotti and Ghisellini. We suggest that the similarity of the SED of PMN J0948+0022 to that of more massive and more powerful quasars can be understood in a scenario in which the SED properties depend on the Eddington ratio rather than on the absolute power.

  8. VizieR Online Data Catalog: QSOs narrow absorption line variability (Hacker+, 2013)

    Hacker, T. L.; Brunner, R. J.; Lundgren, B. F.; York, D. G.

    2013-06-01

    Catalogues of 2,522 QAL systems and 33 variable NAL systems detected in SDSS DR7 quasars with repeat observations. The object identifiers, position coordinates, and plate-MJD-fibre designations are taken from the SpecObjAll table in the SDSS Catalogue Archive Server (CAS) while the quasar redshifts (zqso) are from Hewett & Wild (2010, Cat. J/MNRAS/405/2302). The absorption system redshift (zabs), system grade, and detected lines are outputs of the York et al. (2013, in. prep.) QAL detection pipeline. Some absorption lines are flagged based on alternate identifications (a), proximity of masked pixels (b), or questionable continuum fits (c). (3 data files).

  9. A Revised Broad-line Region Radius and Black Hole Mass for the Narrow-line Seyfert 1 NGC 4051

    Denney, K. D.; Watson, L. C.; Peterson, B. M.

    2009-01-01

    ) radius and the optical continuum luminosity—the R BLR-L relationship. Our new measurements of the lag time between variations in the continuum and Hß emission line made from spectroscopic monitoring of NGC 4051 lead to a measured BLR radius of R BLR = 1.87+0.54 -0.50 light days and black hole mass of M...

  10. THE GBT 67–93.6 GHz SPECTRAL LINE SURVEY OF ORION-KL

    Frayer, D. T.; Maddalena, Ronald J.; Meijer, M.; Hough, L.; White, S.; Norrod, R.; Watts, G.; Stennes, M.; Simon, R.; Woody, D.; Whitehead, M.; Ford, P.; Mello, M.; Bloss, M.; Srikanth, S.; Pospieszalski, M.; Bryerton, E.

    2015-01-01

    We present a 67–93.6 GHz spectral line survey of Orion-KL with the new 4 mm Receiver on the Green Bank Telescope (GBT). The survey reaches unprecedented depths and covers the low-frequency end of the 3 mm atmospheric window which has been relatively unexplored previously. The entire spectral-line survey is published electronically for general use by the astronomical community. The calibration and performance of the 4 mm Receiver on the GBT is also summarized

  11. LABORATORY MEASUREMENTS OF WHITE DWARF PHOTOSPHERIC SPECTRAL LINES: Hβ

    Falcon, Ross E.; Gomez, T. A.; Montgomery, M. H.; Winget, D. E.; Rochau, G. A.; Bailey, J. E.; Nagayama, T.

    2015-01-01

    We spectroscopically measure multiple hydrogen Balmer line profiles from laboratory plasmas to investigate the theoretical line profiles used in white dwarf (WD) atmosphere models. X-ray radiation produced at the Z Pulsed Power Facility at Sandia National Laboratories initiates plasma formation in a hydrogen-filled gas cell, replicating WD photospheric conditions. Here we present time-resolved measurements of Hβ and fit this line using different theoretical line profiles to diagnose electron density, n e , and n = 2 level population, n 2 . Aided by synthetic tests, we characterize the validity of our diagnostic method for this experimental platform. During a single experiment, we infer a continuous range of electron densities increasing from n e ∼ 4 to ∼30 × 10 16 cm −3 throughout a 120-ns evolution of our plasma. Also, we observe n 2 to be initially elevated with respect to local thermodynamic equilibrium (LTE); it then equilibrates within ∼55 ns to become consistent with LTE. This supports our electron-temperature determination of T e ∼ 1.3 eV (∼15,000 K) after this time. At n e ≳ 10 17 cm −3 , we find that computer-simulation-based line-profile calculations provide better fits (lower reduced χ 2 ) than the line profiles currently used in the WD astronomy community. The inferred conditions, however, are in good quantitative agreement. This work establishes an experimental foundation for the future investigation of relative shapes and strengths between different hydrogen Balmer lines

  12. Herschel SPIRE FTS spectral line source calibrators

    Hopwood, Rosalind; Polehampton, Edward; Valtchanov, Ivan

    2015-01-01

    We present a summary of the Herschel SPIRE/FTS calibration programme to monitor the repeatability of spectral lines. Observations of planetary nebulae and post-AGB stars are used to assess repeatability and model the asymmetry of the instrument line shape.......We present a summary of the Herschel SPIRE/FTS calibration programme to monitor the repeatability of spectral lines. Observations of planetary nebulae and post-AGB stars are used to assess repeatability and model the asymmetry of the instrument line shape....

  13. RAPID INFRARED VARIABILITY OF THREE RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES: A VIEW FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

    Jiang Ning; Zhou Hongyan; Wang Tinggui; Dong Xiaobo; Jiang Peng [Key Laboratory for Research in Galaxies and Cosmology, University of Science and Technology of China, Chinese Academy of Science, Hefei, Anhui 230026 (China); Ho, Luis C. [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Yuan Weimin [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Ji Tuo; Tian Qiguo, E-mail: jnac@mail.ustc.edu.cn [Polar Research Institute of China, 451 Jinqiao Road, Pudong, Shanghai 200136 (China)

    2012-11-10

    Using newly released data from the Wide-field Infrared Survey Explorer, we report the discovery of rapid infrared variability in three radio-loud narrow-line Seyfert 1 galaxies (NLS1s) selected from the 23 sources in the sample of Yuan et al. J0849+5108 and J0948+0022 clearly show intraday variability, while J1505+0326 has a longer measurable timescale within 180 days. Their variability amplitudes, corrected for measurement errors, are {approx}0.1-0.2 mag. The detection of intraday variability restricts the size of the infrared-emitting region to {approx}10{sup -3} pc, significantly smaller than the scale of the torus but consistent with the base of a jet. The three variable sources are exceptionally radio-loud, have the highest radio brightness temperature among the whole sample, and all show detected {gamma}-ray emission in Fermi/LAT observations. Their spectral energy distributions resemble those of low-energy-peaked blazars, with a synchrotron peak around infrared wavelengths. This result strongly confirms the view that at least some radio-loud NLS1s are blazars with a relativistic jet close to our line of sight. The beamed synchrotron emission from the jet contributes significantly to and probably dominates the spectra in the infrared and even optical bands.

  14. The Extended Narrow-line Region of Two Type-I Quasi-stellar Objects

    Oh, S.; Woo, J.-H.; Bennert, V.N.; Jungwiert, Bruno; Haas, M.; Leipski, C.; Albrecht, M.

    2013-01-01

    Roč. 767, č. 2 (2013), 117/1-117/7 ISSN 0004-637X Institutional support: RVO:67985815 Keywords : active galaxies * quasars * emission lines Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 6.280, year: 2013

  15. Multiwavelength Monitoring of the Enigmatic Narrow-Line Seyfert 1 PMN J0948 0022 in March-July 2009

    Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R. /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E. /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, T.H.; /Washington U., Seattle; Caliandro, G.A.; /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /NASA, Goddard /NASA, Goddard /CSST, Baltimore /SISSA, Trieste /Naval Research Lab, Wash., D.C. /George Mason U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Garching, Max Planck Inst., MPE /Stockholm U. /Stockholm U., OKC /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /ASDC, Frascati /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Ecole Polytechnique /Brera Observ. /INFN, Trieste /Bonn, Max Planck Inst., Radioastron. /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

    2012-03-29

    Following the recent discovery of {gamma} rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to {gamma} rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to {gamma}-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the {gamma}-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

  16. MULTIWAVELENGTH MONITORING OF THE ENIGMATIC NARROW-LINE SEYFERT 1 PMN J0948+0022 IN 2009 MARCH-JULY

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E. D.; Borgland, A. W.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bonamente, E.; Brigida, M.; Bruel, P.; Burnett, T. H.

    2009-01-01

    Following the recent discovery of γ rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to γ rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to γ-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the γ-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

  17. Improved documentation of spectral lines for inductively coupled plasma emission spectrometry

    Doidge, Peter S.

    2018-05-01

    An approach to improving the documentation of weak spectral lines falling near the prominent analytical lines used in inductively coupled plasma optical emission spectrometry (ICP-OES) is described. Measurements of ICP emission spectra in the regions around several hundred prominent lines, using concentrated solutions (up to 1% w/v) of some 70 elements, and comparison of the observed spectra with both recent published work and with the output of a computer program that allows calculation of transitions between the known energy levels, show that major improvements can be made in the coverage of spectral atlases for ICP-OES, with respect to "classical" line tables. It is argued that the atomic spectral data (wavelengths, energy levels) required for the reliable identification and documentation of a large majority of the weak interfering lines of the elements detectable by ICP-OES now exist, except for most of the observed lines of the lanthanide elements. In support of this argument, examples are provided from a detailed analysis of a spectral window centered on the prominent Pb II 220.353 nm line, and from a selected line-rich spectrum (W). Shortcomings in existing analyses are illustrated with reference to selected spectral interferences due to Zr. This approach has been used to expand the spectral-line library used in commercial ICP-ES instruments (Agilent 700-ES/5100-ES). The precision of wavelength measurements is evaluated in terms of the shot-noise limit, while the absolute accuracy of wavelength measurement is characterised through comparison with a small set of precise Ritz wavelengths for Sb I, and illustrated through the identification of Zr III lines; it is further shown that fractional-pixel absolute wavelength accuracies can be achieved. Finally, problems with the wavelengths and classifications of certain Au I lines are discussed.

  18. A universal representation of Rydberg spectral line shapes in plasmas

    Mosse, C.; Calisti, A.; Stamm, R.; Talin, B.; Bureyeva, L.; Lisitsa, V. S.

    2001-01-01

    A universal representation of Rydberg atom line shapes in plasmas is obtained. It bases on analytical formulas for intensity distribution in radiation transitions n→n' between highly excited atomic states with large values of principle quantum numbers n, n'>>1, Δn=n-n'<< n and the frequency fluctuation model (FFM) for account of ion thermal motion effects. The line shapes are presented in a universal manner as functions of plasma temperatures and densities

  19. Stark broadening measurements of Xe III spectral lines

    Pelaez, R J; Cirisan, M; Djurovic, S; Aparicio, J A; Mar, S

    2006-01-01

    This work reports measured Stark widths of doubly ionized xenon lines. Pulsed arc was used as a plasma source. Measured electron densities and temperatures were in the ranges of (0.2 - 1.6) x 10 23 m -3 and 18 300-25 500 K, respectively. Stark halfwidths of lines from 6s-6p, 6s-4f and 5d-6p transitions have been measured and compared with available experimental and theoretical data

  20. Phosphorus-31 MRI of bones using quadratic echo line-narrowing

    Frey, Merideth; Barrett, Sean; Insogna, Karl; Vanhouten, Joshua

    2012-02-01

    There is a great need to probe the internal composition of bone on the sub-0.1 mm length scale, both to study normal features and to look for signs of disease. Despite the obvious importance of the mineral fraction to the biomechanical properties of skeletal tissue, few non-destructive techniques are available to evaluate changes in its chemical structure and functional microarchitecture on the interior of bones. MRI would be an excellent candidate, but bone is a particularly challenging tissue to study given the relatively low water density and wider linewidths of its solid components. Recent fundamental research in quantum computing gave rise to a new NMR pulse sequence - the quadratic echo - that can be used to narrow the broad NMR spectrum of solids. This offers a new route to do high spatial resolution, 3D ^31P MRI of bone that complements conventional MRI and x-ray based techniques to study bone physiology and structure. We have used our pulse sequence to do 3D ^31P MRI of ex vivo bones with a spatial resolution of (sub-450 μm)^3, limited only by the specifications of a conventional 4 Tesla liquid-state MRI system. We will describe our plans to push this technique towards the factor of 1000 increase in spatial resolution imposed by fundamental limits.

  1. Narrow spectral emission CaMoO{sub 4}: Eu{sup 3+}, Dy{sup 3+}, Tb{sup 3+} phosphor crystals for white light emitting diodes

    Khanna, A. [Smart Lighting Engineering Research Center, 110, 8th Street, Troy, New York, 12180 (United States); Electrical, Computer and Systems Engineering Department, Rensselaer Polytechnic Institute, 110, 8th Street, Troy, New York, 12180 (United States); Dutta, P.S., E-mail: duttap@rpi.edu [Smart Lighting Engineering Research Center, 110, 8th Street, Troy, New York, 12180 (United States); Electrical, Computer and Systems Engineering Department, Rensselaer Polytechnic Institute, 110, 8th Street, Troy, New York, 12180 (United States)

    2013-02-15

    Alkaline earth metal molybdates are promising candidates as a host material for high efficiency narrow spectral emission phosphors. These phosphors could potentially be used for the fabrication of phosphor-converted light emitting diodes (pc-LEDs). Phosphor crystals of calcium molybdate doped with rare earth dopant Ln{sup 3+}(Ln=Eu, Dy, Tb) grown using flux growth method have been shown to exhibit higher excitation efficiency than the powders synthesized by solid-state reaction process. Molybdenum (VI) oxide has been found to be a suitable flux for growing large size optically transparent high quality crystals at a temperature around 1100 Degree-Sign C. Using the excitation wavelengths of 465 nm, 454 nm and 489 nm for CaMoO{sub 4}: Eu{sup 3+}, CaMoO{sub 4}: Dy{sup 3+} and CaMoO{sub 4}: Tb{sup 3+}, respectively, intense emission lines at wavelengths of 615 nm, 575 nm and 550 nm were observed. The optimized doping concentrations of 12%, 2% and 5% for Eu{sup 3+}, Dy{sup 3+} and Tb{sup 3+}, respectively, provided the highest luminescence intensity. - Graphical Abstract: CaMoO{sub 4}: Eu{sup 3+} phosphor crystals grown using a molybdenum (VI) oxide flux exhibited around 1.5 times the emission intensity of powders obtained from solid-state reaction at the same synthesis temperature. These crystals were found to efficiently emit 615 nm red light when excited by near UV light up to a wavelength of 395 nm. Highlights: Black-Right-Pointing-Pointer CaMoO{sub 4}: Ln{sup 3+} (Ln=Eu{sup 3+}, Dy{sup 3+}, Tb{sup 3+}) phosphor crystals were successfully grown using high temperature flux (solutions) containing molybdenum (VI) oxide or lithium chloride. Black-Right-Pointing-Pointer Narrow spectral emission at 615 nm, 575 nm and 550 nm, respectively, was observed from CaMoO{sub 4}: Ln{sup 3+} (Ln=Eu{sup 3+}, Dy{sup 3+}, Tb{sup 3+}) phosphor crystals. Black-Right-Pointing-Pointer The optimized doping concentrations of Eu{sup 3+}, Dy{sup 3+}, Tb{sup 3+} in CaMoO{sub 4} for highest

  2. A REVERBERATION LAG FOR THE HIGH-IONIZATION COMPONENT OF THE BROAD-LINE REGION IN THE NARROW-LINE SEYFERT 1 Mrk 335

    Grier, C. J.; Peterson, B. M.; Pogge, R. W.; Martini, Paul; Zu, Y.; Kochanek, C. S.; Shappee, B. J.; Stanek, K. Z.; Araya Salvo, C.; Beatty, T. G.; Bird, J. C.; Denney, K. D.; Bentz, M. C.; Sergeev, S. G.; Borman, G. A.; Kaspi, S.; Bord, D. J.; Che, X.; Chen, C.; Cohen, S. A.

    2012-01-01

    We present the first results from a detailed analysis of photometric and spectrophotometric data on the narrow-line Seyfert 1 (NLS1) galaxy Mrk 335, collected over a 120 day span in the fall of 2010. From these data we measure the lag in the He II λ4686 broad emission line relative to the optical continuum to be 2.7 ± 0.6 days and the lag in the Hβλ4861 broad emission line to be 13.9 ± 0.9 days. Combined with the line width, the He II lag yields a black hole mass M BH = (2.6 ± 0.8) × 10 7 M ☉ . This measurement is consistent with measurements made using the Hβλ4861 line, suggesting that the He II emission originates in the same structure as Hβ, but at a much smaller radius. This constitutes the first robust lag measurement for a high-ionization line in an NLS1 galaxy and supports a scenario in which the He II emission originates from gas in virial motion rather than outflow.

  3. A REVERBERATION LAG FOR THE HIGH-IONIZATION COMPONENT OF THE BROAD-LINE REGION IN THE NARROW-LINE SEYFERT 1 Mrk 335

    Grier, C. J.; Peterson, B. M.; Pogge, R. W.; Martini, Paul; Zu, Y.; Kochanek, C. S.; Shappee, B. J.; Stanek, K. Z.; Araya Salvo, C.; Beatty, T. G.; Bird, J. C. [Department of Astronomy, The Ohio State University, 140 W 18th Avenue, Columbus, OH 43210 (United States); Denney, K. D. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Bentz, M. C. [Department of Physics and Astronomy, Georgia State University, Astronomy Offices, One Park Place South SE, Suite 700, Atlanta, GA 30303 (United States); Sergeev, S. G.; Borman, G. A. [Crimean Astrophysical Observatory, P/O Nauchny Crimea 98409 (Ukraine); Kaspi, S. [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Bord, D. J. [Department of Natural Sciences, The University of Michigan-Dearborn, 4901 Evergreen Rd, Dearborn, MI 48128 (United States); Che, X. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 41809 (United States); Chen, C.; Cohen, S. A. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); and others

    2012-01-15

    We present the first results from a detailed analysis of photometric and spectrophotometric data on the narrow-line Seyfert 1 (NLS1) galaxy Mrk 335, collected over a 120 day span in the fall of 2010. From these data we measure the lag in the He II {lambda}4686 broad emission line relative to the optical continuum to be 2.7 {+-} 0.6 days and the lag in the H{beta}{lambda}4861 broad emission line to be 13.9 {+-} 0.9 days. Combined with the line width, the He II lag yields a black hole mass M{sub BH} = (2.6 {+-} 0.8) Multiplication-Sign 10{sup 7} M{sub Sun }. This measurement is consistent with measurements made using the H{beta}{lambda}4861 line, suggesting that the He II emission originates in the same structure as H{beta}, but at a much smaller radius. This constitutes the first robust lag measurement for a high-ionization line in an NLS1 galaxy and supports a scenario in which the He II emission originates from gas in virial motion rather than outflow.

  4. A REVISED BROAD-LINE REGION RADIUS AND BLACK HOLE MASS FOR THE NARROW-LINE SEYFERT 1 NGC 4051

    Denney, K. D.; Watson, L. C.; Peterson, B. M.

    2009-01-01

    We present the first results from a high sampling rate, multimonth reverberation mapping campaign undertaken primarily at MDM Observatory with supporting observations from telescopes around the world. The primary goal of this campaign was to obtain either new or improved Hβ reverberation lag measurements for several relatively low luminosity active galactic nuclei (AGNs). We feature results for NGC 4051 here because, until now, this object has been a significant outlier from AGN scaling relationships, e.g., it was previously a ∼2-3σ outlier on the relationship between the broad-line region (BLR) radius and the optical continuum luminosity-the R BLR -L relationship. Our new measurements of the lag time between variations in the continuum and Hβ emission line made from spectroscopic monitoring of NGC 4051 lead to a measured BLR radius of R BLR = 1.87 +0.54 -0.50 light days and black hole mass of M BH = (1.73 +0.55 -0.52 ) x 10 6 M sun . This radius is consistent with that expected from the R BLR -L relationship, based on the present luminosity of NGC 4051 and the most current calibration of the relation by Bentz et al.. We also present a preliminary look at velocity-resolved Hβ light curves and time delay measurements, although we are unable to reconstruct an unambiguous velocity-resolved reverberation signal.

  5. Internal Displacement Reactions in Multicomponent Oxides: Part I. Line Compounds with Narrow Homogeneity Range

    Reddy, SNS; Leonard, DN; Wiggins, LB; Jacob, KT

    2005-01-01

    As a model of an internal displacement reaction involving a ternary oxide line compound, the following reaction was studied at 1273 K as a function of time, t: $Fe+NiTiO_3 = Ni + FeTiO_3$ Both polycrystalline and single-crystal materials were used as the starting $NiTiO_3$ oxide. During the reaction, the Ni in the oxide compound is displaced by Fe and it precipitates as a \\gamma -(Ni-Fe) alloy. The reaction preserves the starting ilmenite structure. The product oxide has a consta...

  6. Stark broadening of Ca IV spectral lines of astrophysical interest

    Alonso-Medina, A.; Colón, C.

    2014-12-01

    Ca IV emission lines are under the preview of Solar Ultraviolet Measurements of Emitted Radiation device aboard the Solar and Heliospheric Observatory. Also, lines of the Ca IV in planetary nebulae NGC 7027 were detected with the Short Wavelength Spectrometer on board the Infrared Space Observatory. These facts justify an attempt to provide new spectroscopic parameters of Ca IV. There are no theoretical or experimental Stark broadening data for Ca IV. Using the Griem semi-empirical approach and the COWAN code, we report in this paper calculated values of the Stark broadening parameters for 467 lines of Ca IV. They were calculated using a set of wavefunctions obtained by using Hartree-Fock relativistic calculations. These lines arising from 3s23p4ns (n = 4, 5), 3s23p44p, 3s23p4nd (n = 3, 4) configurations. Stark widths and shifts are presented for an electron density of 1017 cm-3 and temperatures T = 10 000, 20 000 and 50 200 K. As these data cannot be compared to others in the literature, we present an analysis of the different regularities of the values presented in this work.

  7. THE SDSS-III APOGEE SPECTRAL LINE LIST FOR H-BAND SPECTROSCOPY

    Shetrone, M. [University of Texas at Austin, McDonald Observatory (United States); Bizyaev, D.; Chojnowski, D. [Apache Point Observatory and New Mexico State University, P.O. Box 59, Sunspot, NM, 88349-0059 (United States); Lawler, J. E. [Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706 (United States); Prieto, C. Allende; Zamora, O.; García-Hernández, D. A.; Souto, D. [Instituto de Astrofísica de Canarias, Calle Vía Lactea s/n, E-38205 La Laguna, Tenerife (Spain); Johnson, J. A. [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); Smith, V. V. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Cunha, K. [Observatório Nacional, Rua General Jose Cristino, 77, 20921-400 São Cristóvão, Rio de Janeiro, RJ (Brazil); Holtzman, J. [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Pérez, A. E. García; Sobeck, J.; Majewski, S. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Mészáros, Sz. [ELTE Gothard Astrophysical Observatory, H-9704 Szombathely, Szent Imre herceg st. 112 (Hungary); Koesterke, L. [The University of Texas at Austin, Texas Advanced Computing Center (United States); Zasowski, G. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2015-12-15

    We present the H-band spectral line lists adopted by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). The APOGEE line lists comprise astrophysical, theoretical, and laboratory sources from the literature, as well as newly evaluated astrophysical oscillator strengths and damping parameters. We discuss the construction of the APOGEE line list, which is one of the critical inputs for the APOGEE Stellar Parameters and Chemical Abundances Pipeline, and present three different versions that have been used at various stages of the project. The methodology for the newly calculated astrophysical line lists is reviewed. The largest of these three line lists contains 134,457 molecular and atomic transitions. In addition to the format adopted to store the data, the line lists are available in MOOG, Synspec, and Turbospectrum formats. The limitations of the line lists along with guidance for its use on different spectral types are discussed. We also present a list of H-band spectral features that are either poorly represented or completely missing in our line list. This list is based on the average of a large number of spectral fit residuals for APOGEE observations spanning a wide range of stellar parameters.

  8. Stark broadening of several Bi IV spectral lines of astrophysical interest

    Colón, C.; Moreno-Díaz, C.; de Andrés-García, I.; Alonso-Medina, A.

    2017-09-01

    The presence of spectral lines of bismuth in stellar atmospheres has been reported in different stars. The anomalous values of the spectral intensities of Bi II and Bi III, compared to the theoretical Local Termodinamic Equilibrium (LTE) standards of Bi I/Bi II/Bi III, have been reported in the spectra obtained with the High Resolution Spectrograph of the Hubble/Goddard Space Telescope in the chemically peculiar stars HgMn stars χ Lupi and HR 7775. Spectral lines of 1436.8, 1902.3, 2630.9 and 2936.7 Å of Bi II and 1423.4 Å of Bi III were reported and their relative intensities were measured in these studies Litzén & Wahlgren 2002. These lines are overlapped with spectral lines of 1437.65, 2630.1 and 2937.1 Å of Bi IV. A study of the Stark broadening parameters of Bi IV spectral lines can help to study these overlaps. In this paper, using the Griem semi-empirical approach, we report calculated values of the Stark parameters for 64 spectral lines of Bi IV. The matrix elements used in these calculations have been determined from 17 configurations of Bi IV. They were calculated using the cowan code including core polarization effects. Data are displayed for an electron density of 1017 cm-3 and temperatures T = 10 000-160 000 K. Also calculated radiative lifetimes for 12 levels with experimental lifetime are presented, in order to test the goodness of our calculations. Theoretical trends of the Stark width and shift parameters versus the temperature for spectral lines of astrophysical interest are displayed.

  9. A variable-tune spatial heterodyne spectrometer for broadband spectral line studies in the visible and near-UV

    Dawson, Olivia R.; Harris, Walter M.

    2017-11-01

    Reflective Spatial Heterodyne Spectroscopy (SHS) is an interferometric technique that combines high resolving power and a large input acceptance angle in a format that is compact enough for use at small telescope focal planes and in spacecraft observations of targets in the visible to far ultra-violet (FUV) spectral range. SHS instruments are well suited to the study of faint, extended emission line sources, particularly in the UV where stellar background continuum becomes weak. Their primary limitation comes from the limited spatial sampling of the output interference pattern generated by the incoming spectral source, which limits their use to narrow bandpass near the central tuning wavelength. We describe a the first light results from a broadband SHS that can be used to scan the tuning wavelength across a bandpass extending from 300 to 700 nm. The limitations on the bandpass are arbitrary and can easily be extended into the UV or near infrared. We discuss the results of these validation program and the potential improvements that could be used to expand and/or improve the broadband spectral response of the instrument.

  10. Kinetic theory of spectral line broadening in plasmas

    Hussey, T.W.

    1974-01-01

    A formal kinetic theory is used to cast the line shape function into a form that, while similar to the ''unified'' theories of Smith, Cooper, and Vidal and of Voslamber, does not introduce some of the usual approximations. The resulting line shape function explicitly includes the initial correlations between the atom and perturbers, and also demonstrates the natural separation of plasma mean field and collisional effects. The classical path and no-quenching approximations are discussed and ultimately employed; however, they are not required in the formal development. The weak coupling limit is considered as a systematic approximation to the formal results. It is shown tha different ways of applying this limit lead to different expressions for the memory operator, some of which correspond to existing theories. One approximation is considered which systematically incorporates the effects of electron correlations within the framework of a unified theory. In addition, a practical approximation suitable for a strongly interacting plasma is discussed

  11. Suitable spectral line shape calculations for inertial confinement plasma diagnosis

    Lambert, D.; Louis-Jacquet, M.

    1982-09-01

    In plasma confinement experiments, the knowledge of the plasma state at the maximum compression time would be of utmost interest. For quite many experiments, this time can correspond to a stationary state during which the X emission conditions for a moderate Z element are maximum. Since this diagnosis mean deals with emission only, we need to get rid of reabsorption problems, since their calculation depends on the use of an ionization-excitation plasma model. That is the reason why we focus our attention onto the aspects of spectroscopic theory which control the low reabsorption line shapes - from high values of n - and more precisely the lesser reabsorbed parts of the line shapes - the wings instead of the center

  12. Observation of spectral gain narrowing in a high-order harmonic seeded soft-x-ray amplifier

    Tissandier, F.; Sebban, S.; Ribière, M.; Gautier, J.; Zeitoun, Ph.; Lambert, G.; Barszczak Sardinha, A.; Goddet, J.Ph.; Burgy, F.; Lefrou, T.; Valentin, C.; Rousse, A.; Guilbaud, O.; Klisnick, A.; Nejdl, Jaroslav; Mocek, Tomáš; Maynard, G.

    2010-01-01

    Roč. 81, č. 6 (2010), 063833/1-063833/4 ISSN 1050-2947 R&D Projects: GA AV ČR IAA100100911 Institutional research plan: CEZ:AV0Z10100523 Keywords : high-order harmonic * soft-x-ray * amplification * OFI * gain narrowing * Ni-like krypton plasma Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.861, year: 2010 http://pra.aps.org/abstract/PRA/v81/i6/e063833

  13. A statistical study of H i gas in nearby narrow-line AGN-hosting galaxies

    Zhu, Yi-Nan; Wu, Hong

    2015-01-01

    As a quenching mechanism, active galactic nucleus (AGN) feedback could suppress on going star formation in host galaxies. On the basis of a sample of galaxies selected from the Arecibo Legacy Fast ALFA (ALFALFA) H i survey, the dependence of the H i mass (M H i ), stellar mass (M * ), and H i-to-stellar mass ratio (M H i /M * ) on various tracers of AGN activity are presented and analyzed in this paper. Almost all the AGN hostings in this sample are gas-rich galaxies, and there is not any evidence to indicate that the AGN activity could increase or decrease either M H i or M H i /M * . The position of the cold neutral gas cannot be fixed accurately based only on available H i data, due to the large beam size of ALFALFA survey. In addition, even though AGN hostings are more easily detected by an H i survey compared with absorption line galaxies, these two types of galaxies show similar star formation history. If an AGN hosting would ultimately evolve into an old red galaxy with low cold gas, then when and how the gas has been exhausted must be solved by future hypotheses and observations.

  14. A statistical study of H i gas in nearby narrow-line AGN-hosting galaxies

    Zhu, Yi-Nan; Wu, Hong, E-mail: zyn@bao.ac.cn, E-mail: hwu@bao.ac.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2015-01-01

    As a quenching mechanism, active galactic nucleus (AGN) feedback could suppress on going star formation in host galaxies. On the basis of a sample of galaxies selected from the Arecibo Legacy Fast ALFA (ALFALFA) H i survey, the dependence of the H i mass (M{sub H} {sub i}), stellar mass (M{sub *}), and H i-to-stellar mass ratio (M{sub H} {sub i}/M{sub *}) on various tracers of AGN activity are presented and analyzed in this paper. Almost all the AGN hostings in this sample are gas-rich galaxies, and there is not any evidence to indicate that the AGN activity could increase or decrease either M{sub H} {sub i} or M{sub H} {sub i}/M{sub *}. The position of the cold neutral gas cannot be fixed accurately based only on available H i data, due to the large beam size of ALFALFA survey. In addition, even though AGN hostings are more easily detected by an H i survey compared with absorption line galaxies, these two types of galaxies show similar star formation history. If an AGN hosting would ultimately evolve into an old red galaxy with low cold gas, then when and how the gas has been exhausted must be solved by future hypotheses and observations.

  15. Narrow row and crossed lines associated with different plant densities of soybean

    Alvadi Antonio Balbinot Junior

    2015-10-01

    Full Text Available The spatial arrangement of soybean plants affects the intraspecific competition for light, water and nutrients, which can change the biomass production, incidence of pests, diseases and weeds, plant lodging, and grain yield. This work aimed to evaluate the agronomic performance under different row spacing, plant densities and crossed rows. Two field experiments were carried out in Campo Mourão, Paraná State, Southern Brazil, using the randomized complete block experimental design, in a 3x3x2 factorial arrangement, with four replications. The treatments were formed by the combination of three row spacings (0.30, 0.45, and 0.60 m, three plant densities (300,000; 450,000; and 600,000 plants ha-1, and two row design (crossed or parallel rows. For all variables, interaction of the experimental factors was not significant. The row spacing of 0.45 m provided the highest grain yield in relation to 0.30 and 0.60 m. The density of 300,000 plants ha-1 showed higher yield of soybeans in late sowing. The crossed lines did not increase the productive performance in soybean.

  16. Intra-night optical variability properties of X-ray bright Narrow-line Seyfert 1 galaxies

    Ojha, Vineet; Chand, Hum; Gopal-Krishna

    2018-04-01

    We present Intra Night Optical Variability (INOV) study of the 9 Narrow-line Seyfert 1 (NLSy 1) galaxies which are detected in X-ray at more than 3σ level. Our observations cover a total of 9 nights ( 36 hr) with each NLSy 1 monitored for ≥ 3.5 hr in each night. After applying F-test to assess variability status of these sources, we found none of these sources to be variable. Such non-variability nature of X-ray detected NLSy 1 galaxies suggests the lack of jet dominance as far as X-ray emission is concerned. Higher photometric accuracy for these faint sources, achievable with the newly installed ARIES 3.6m DOT will be helpful.

  17. Radio jets and gamma-ray emission in radio-silent narrow-line Seyfert 1 galaxies

    Lähteenmäki, A.; Järvelä, E.; Ramakrishnan, V.; Tornikoski, M.; Tammi, J.; Vera, R. J. C.; Chamani, W.

    2018-06-01

    We have detected six narrow-line Seyfert 1 (NLS1) galaxies at 37 GHz that were previously classified as radio silent and two that were classified as radio quiet. These detections reveal the presumption that NLS1 galaxies labelled radio quiet or radio silent and hosted by spiral galaxies are unable to launch jets to be incorrect. The detections are a plausible indicator of the presence of a powerful, most likely relativistic jet because this intensity of emission at 37 GHz cannot be explained by, for example, radiation from supernova remnants. Additionally, one of the detected NLS1 galaxies is a newly discovered source of gamma rays and three others are candidates for future detections. 37 GHz data are only available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/614/L1

  18. Generation of doublet spectral lines at self-seeded X-ray FELs

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-11-15

    Self-seeding schemes, consisting of two undulators with a monochromator in between, aim to reduce the bandwidth of SASE X-ray FELs. We recently proposed to use a new method of monochromatization exploiting a single crystal in Braggtransmission geometry for self-seeding in the hard X-ray range. The obvious and technically possible extension is to use such kind of monochromator setup with two -or more- crystals arranged in a series to spectrally filter the SASE radiation at two -or more- closely-spaced wavelengths within the FEL gain band. This allows for the production of doublet- or multiplet-spectral lines. Applications exist over a broad range of hard X-ray wavelengths involving any process where there is a large change in cross section over a narrow wavelength range, as in multiple wavelength anomalous diffraction techniques (MAD). In this paper we consider the simultaneous operation of the LCLS hard X-ray FEL at two closely spaced wavelengths. We present simulation results for the LCLS baseline, and we show that this method can produce fully coherent radiation shared between two longitudinal modes. Mode spacing can be easily tuned within the FEL gain band, i.e. within 10 eV. An interesting aspect of the proposed scheme is a way of modulating the electron bunch at optical frequencies without a seed quantum laser. In fact, the XFEL output intensity contains an oscillating ''mode-beat'' component whose frequency is related to the frequency difference between the pair of longitudinal modes considered. Thus, at saturation one obtains FEL-induced modulations of energy loss and energy spread in the electron bunch at optical frequency. These modulations can be converted into density modulation at the same optical frequency with the help of a weak chicane installed behind the baseline undulator. Powerful coherent radiation can then be generated with the help of an optical transition radiation (OTR) station,which have important applications. In this paper we briefly

  19. Generation of doublet spectral lines at self-seeded X-ray FELs

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2010-11-01

    Self-seeding schemes, consisting of two undulators with a monochromator in between, aim to reduce the bandwidth of SASE X-ray FELs. We recently proposed to use a new method of monochromatization exploiting a single crystal in Braggtransmission geometry for self-seeding in the hard X-ray range. The obvious and technically possible extension is to use such kind of monochromator setup with two -or more- crystals arranged in a series to spectrally filter the SASE radiation at two -or more- closely-spaced wavelengths within the FEL gain band. This allows for the production of doublet- or multiplet-spectral lines. Applications exist over a broad range of hard X-ray wavelengths involving any process where there is a large change in cross section over a narrow wavelength range, as in multiple wavelength anomalous diffraction techniques (MAD). In this paper we consider the simultaneous operation of the LCLS hard X-ray FEL at two closely spaced wavelengths. We present simulation results for the LCLS baseline, and we show that this method can produce fully coherent radiation shared between two longitudinal modes. Mode spacing can be easily tuned within the FEL gain band, i.e. within 10 eV. An interesting aspect of the proposed scheme is a way of modulating the electron bunch at optical frequencies without a seed quantum laser. In fact, the XFEL output intensity contains an oscillating ''mode-beat'' component whose frequency is related to the frequency difference between the pair of longitudinal modes considered. Thus, at saturation one obtains FEL-induced modulations of energy loss and energy spread in the electron bunch at optical frequency. These modulations can be converted into density modulation at the same optical frequency with the help of a weak chicane installed behind the baseline undulator. Powerful coherent radiation can then be generated with the help of an optical transition radiation (OTR) station,which have important applications. In this paper we briefly

  20. FBQS J1644+2619: multiwavelength properties and its place in the class of γ-ray emitting Narrow Line Seyfert 1s

    Larsson, J.; D'Ammando, F.; Falocco, S.; Giroletti, M.; Orienti, M.; Piconcelli, E.; Righini, S.

    2018-05-01

    A small fraction of Narrow Line Seyfert 1s (NLSy1s) are observed to be γ-ray emitters. Understanding the properties of these sources is of interest since the majority of NLSy1s are very different from typical blazars. Here, we present a multifrequency analysis of FBQS J1644+2619, one of the most recently discovered γ-ray emitting NLSy1s. We analyse an ˜80 ks XMM-Newton observation obtained in 2017, as well as quasi-simultaneous multiwavelength observations covering the radio-γ-ray range. The spectral energy distribution of the source is similar to the other γ-ray NLSy1s, confirming its blazar-like nature. The X-ray spectrum is characterized by a hard photon index (Γ = 1.66) above 2 keV and a soft excess at lower energies. The hard photon index provides clear evidence that inverse Compton emission from the jet dominates the spectrum, while the soft excess can be explained by a contribution from the underlying Seyfert emission. This contribution can be fitted by reflection of emission from the base of the jet, as well as by Comptonization in a warm, optically thick corona. We discuss our results in the context of the other γ-ray NLSy1s and note that the majority of them have similar X-ray spectra, with properties intermediate between blazars and radio-quiet NLSy1s.

  1. JET PROPERTIES OF GeV-SELECTED RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES AND POSSIBLE CONNECTION TO THEIR DISK AND CORONA

    Sun, Xiao-Na; Lin, Da-Bin; Liang, En-Wei [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning 530004 (China); Zhang, Jin [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Xue, Zi-Wei; Zhang, Shuang-Nan, E-mail: zhang.jin@hotmail.com [Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011 (China)

    2015-01-01

    The observed spectral energy distributions of five GeV-selected narrow-line Seyfert 1 (NLS1) galaxies are fitted with a model including the radiation ingredients from the relativistic jet, the accretion disk, and the corona. We compare the properties of these GeV NLS1 galaxies with flat spectrum radio quasars (FSRQs), BL Lacertae objects (BL Lacs), and radio-quiet (RQ) Seyfert galaxies, and explore possible hints for jet-disk/corona connection. Our results show that the radiation physics and the jet properties of the GeV NLS1 galaxies resemble that of FSRQs. The luminosity variations of PMN J0948+0022 and 1H 0323+342 at the GeV band is tightly correlated with the beaming factor (δ), similar to that observed in FSRQ 3C 279. The accretion disk luminosities and the jet powers of the GeV NLS1 galaxies cover both the ranges of FSRQs and BL Lacs. With the detection of bright corona emission in 1H 0323+342, we show that the ratio of the corona luminosity (L {sub corona}) to the accretion disk luminosity (L {sub d}) is marginally within the high end of this ratio distribution for an RQ Seyfert galaxy sample, and the variation of jet luminosity may connect with L {sub corona}. However, it is still unclear whether a system with a high L {sub corona}/L {sub d} ratio prefers to power a jet.

  2. Correlation function and electronic spectral line broadening in relativistic plasmas

    Douis S.

    2013-01-01

    Full Text Available The electrons dynamics and the time autocorrelation function Cee(t for the total electric microfield of the electrons on positive charge impurity embedded in a plasma are considered when the relativistic dynamic of the electrons is taken into account. We have, at first, built the effective potential governing the electrons dynamics. This potential obeys a nonlinear integral equation that we have solved numerically. Regarding the electron broadening of the line in plasma, we have found that when the plasma parameters change, the amplitude of the collision operator changes in the same way as the time integral of Cee(t. The electron-impurity interaction is taken at first time as screened Deutsh interaction and at the second time as Kelbg interaction. Comparisons of all interesting quantities are made with respect to the previous interactions as well as between classical and relativistic dynamics of electrons.

  3. Role of noise in the diode-laser spectroscopy of the spectral line profile

    Nadezhdinskii, Aleksandr I; Plotnichenko, V V; Ponurovskii, Ya Ya; Spiridonov, Maksim V

    2000-01-01

    Questions concerning precise measurements of the spectral-line-profile parameters by diode-laser spectroscopic methods were examined. The instrumental function of a distributed-feedback diode laser (λ =1.53 μm), consisting of the additive contributions of the noise due to spontaneous emission, frequency fluctuations, and intensity fluctuations, was investigated. An analytical formula was obtained for the spectrum of the diode-laser field formed by frequency fluctuations. The spectral density g 0 of the frequency fluctuations, determining the width of the central part of the emission line profile of a diode laser, was found by two independent methods (by fitting to a Doppler-broadened absorption line profile and by finding the intensity of the residual radiation and the saturated-absorption line width). The parameters Ω and Γ of the spectral density of the frequency fluctuations, coupled to the relaxation oscillations and determining the wing of the diode-laser emission line profile, were determined experimentally. By taking into account the instrumental function of the diode laser, involving successive convolution with the recorded emission spectra, it was possible to reproduce correctly the spectral line profile and to solve accurately the problem of the 'optical zero'. The role of the correlation between the intensity noise and the diode-laser frequency was considered. (laser applications and other topics in quantum electronics)

  4. A new method of organizing spectral line intensity ratio fluctuations of nightglow emissions

    Thelin, B.

    1986-02-01

    In this paper a new kind of linearization effect between the atmospheric night airglow emissions is presented. The same kind of linearization effect has previously been studied with spectrochemical light sources together with a spectrometer. A linear graph was obtained for atomic spectral lines and vibrational bandspectra when the spectral line intensity ratio fluctuations were plotted versus the photon energies of these emissions. To study this effect data from a number of different photometer investigations of night airglow emissions at different times and places have been used. (author)

  5. Indium determination by spectral overlappings of lines in atomic absorption spectrometry

    Gomez, J.J.; Huicque, L. d'; Garcia Vior, L.O.

    1991-01-01

    A molybdenum hollow-cathode lamp filled with neon can be used to determine indium. Characteristic concentration for this element is 4.5 mg/L in the 325 nm spectral region for the Mo(I) 325.621 nm line. In addition, values of 0.4 mg/L and 0.3 mg/L are obtained with the Mo(I) 410.215 nm and Ne(I) 451.151 nm lines, respectively. These spectral overlappings allow the determination of indium in silver-cadmium-indium alloys. (Author) [es

  6. Temporal evolution of the spectral lines emission and temperatures in laser induced plasmas through characteristic parameters

    Bredice, F.; Pacheco Martinez, P.; Sánchez-Aké, C.; Villagrán-Muniz, M.

    2015-01-01

    In this work, we propose an extended Boltzmann plot method to determine the usefulness of spectral lines for plasma parameter calculations. Based on the assumption that transient plasmas are under ideal conditions during an specific interval of time Δt, (i.e. thin, homogeneous and in local thermodynamic equilibrium (LTE)), the associated Boltzmann plots describe a surface in the space defined by the coordinates X = Energy, Y = Time and Z = ln (λ jl I j /g j A jl ), where I j is the integrated intensity of the spectral line, g j is the statistical weight of the level j, λ jl is the wavelength of the considered line and A jl is its transition rate. In order to express the Boltzmann plot surface in terms of a reduced set of constants B i , and δ i , we developed as a power series of time, the logarithm of I n (t)/I n (t 0 ), where I n (t) is the integrated intensity of any spectral line at time t, and I n (t 0 ) at initial time. Moreover, the temporal evolution of the intensity of any spectral line and consequently the temperature of the plasma can be also expressed with these constants. The comparison of the temporal evolution of the line intensity calculated using these constants with their experimental values, can be used as a criterion for selecting useful lines in plasma analysis. Furthermore, this method can also be applied to determine self-absorption or enhancement of the spectral lines, to evaluate a possible departure of LTE, and to check or estimate the upper level energy value of any spectral line. An advantage of this method is that the value of these constants does not depend on the spectral response of the detection system, the uncertainty of the transition rates belonging to the analyzed spectral lines or any other time-independent parameters. In order to prove our method, we determined the constants B i and δ i and therefore the Boltzmann plot surface from the temporal evolution of carbon lines obtained from a plasma generated by a Nd:YAG laser

  7. Temporal evolution of the spectral lines emission and temperatures in laser induced plasmas through characteristic parameters

    Bredice, F., E-mail: faustob@ciop.unlp.edu.ar [Centro de Investigaciones Ópticas, P.O. Box 3 C. P.1897 Gonnet, La Plata (Argentina); Pacheco Martinez, P. [Grupo de Espectroscopía Óptica de Emisión y Láser, Universidad del Atlántico, Barranquilla (Colombia); Sánchez-Aké, C.; Villagrán-Muniz, M. [Laboratorio de Fotofísica, Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Apartado Postal 70-186, México D.F. 04510 (Mexico)

    2015-05-01

    In this work, we propose an extended Boltzmann plot method to determine the usefulness of spectral lines for plasma parameter calculations. Based on the assumption that transient plasmas are under ideal conditions during an specific interval of time Δt, (i.e. thin, homogeneous and in local thermodynamic equilibrium (LTE)), the associated Boltzmann plots describe a surface in the space defined by the coordinates X = Energy, Y = Time and Z = ln (λ{sub jl}I{sub j}/g{sub j}A{sub jl}), where I{sub j} is the integrated intensity of the spectral line, g{sub j} is the statistical weight of the level j, λ{sub jl} is the wavelength of the considered line and A{sub jl} is its transition rate. In order to express the Boltzmann plot surface in terms of a reduced set of constants B{sub i}, and δ{sub i}, we developed as a power series of time, the logarithm of I{sub n}(t)/I{sub n}(t{sub 0}), where I{sub n}(t) is the integrated intensity of any spectral line at time t, and I{sub n}(t{sub 0}) at initial time. Moreover, the temporal evolution of the intensity of any spectral line and consequently the temperature of the plasma can be also expressed with these constants. The comparison of the temporal evolution of the line intensity calculated using these constants with their experimental values, can be used as a criterion for selecting useful lines in plasma analysis. Furthermore, this method can also be applied to determine self-absorption or enhancement of the spectral lines, to evaluate a possible departure of LTE, and to check or estimate the upper level energy value of any spectral line. An advantage of this method is that the value of these constants does not depend on the spectral response of the detection system, the uncertainty of the transition rates belonging to the analyzed spectral lines or any other time-independent parameters. In order to prove our method, we determined the constants B{sub i} and δ{sub i} and therefore the Boltzmann plot surface from the temporal

  8. Novel plasma source for safe beryllium spectral line studies in the presence of beryllium dust

    Stankov, B. D.; Vinić, M.; Gavrilović Božović, M. R.; Ivković, M.

    2018-05-01

    Plasma source for beryllium spectral line studies in the presence of beryllium dust particles was realised. The guideline during construction was to prevent exposure to formed dust, considering the toxicity of beryllium. Plasma source characterization through determination of optimal working conditions is described. The necessary conditions for Be spectral line appearance and optimal conditions for line shape measurements are found. It is proven experimentally that under these conditions dust appears coincidently with the second current maximum. The electron density measured after discharge current maximum is determined from the peak separation of the hydrogen Balmer beta spectral line, and the electron temperature is determined from the ratios of the relative intensities of Be spectral lines emitted from successive ionized stages of atoms. Maximum values of electron density and temperature are measured to be 9.3 × 1022 m-3 and 16 800 K, respectively. Construction details and testing of the BeO discharge tube in comparison with SiO2 and Al2O3 discharge tubes are also presented in this paper.

  9. Stochastic theory of relaxation and collisional broadening of spectral line shapes

    Faid, K.

    1986-01-01

    A complete stochastic theory of relaxation is developed in terms of a homogeneous equation for the averaged density matrix of a system immersed in a thermal bath. This theory is then used as the basis of a new stochastic approach to the phenomenon of collisional broadening of spectral line shapes. Single-photon and multiphoton processes are studied. The features of a line shape are linked by simple expressions to the statistical properties of a stochastic hermitian Hamiltonian. The ordinary line shape predicted by Kubo's approach is generalized. The present approach predicts broadening as well as asymmetry and shift. A representation of line shapes in multiphoton processes by diagrams is also developed

  10. Infrared spectral line parameters of HBr and DBr at elevated temperatures

    Stocker, R.N.; Goldman, A.

    1976-01-01

    The electric dipole matrix elements for pure rotation and vibration-rotation transitions, with /m/<=40 and v<=v'<=6, having derived for HBr and DBr by using the Rydberg-Klein-Rees (RKR) potentials and numerical solutions of the Schroedinger equation. An improved dipole-moment expansion was determined by fitting these matrix elements to the available experimental data on line intensities. A least squares analysis of the available line position constants gave an improved set of Dunham coefficients good for spectral lines with both large and small quantum numbers v and J. The results were then used to generate a compilation of individual line parameters for the Δv = 1 bands of HBr and DBr at temperatures up to 3000 K. These parameters, together with previously compiled line parameters for HCl, HF, CO and NO, are being used for line-by-line calculations of radiance from a hot source as seen through an atmospheric path. (author)

  11. [Analysis of software for identifying spectral line of laser-induced breakdown spectroscopy based on LabVIEW].

    Hu, Zhi-yu; Zhang, Lei; Ma, Wei-guang; Yan, Xiao-juan; Li, Zhi-xin; Zhang, Yong-zhi; Wang, Le; Dong, Lei; Yin, Wang-bao; Jia, Suo-tang

    2012-03-01

    Self-designed identifying software for LIBS spectral line was introduced. Being integrated with LabVIEW, the soft ware can smooth spectral lines and pick peaks. The second difference and threshold methods were employed. Characteristic spectrum of several elements matches the NIST database, and realizes automatic spectral line identification and qualitative analysis of the basic composition of sample. This software can analyze spectrum handily and rapidly. It will be a useful tool for LIBS.

  12. Detection of the power lines in UAV remote sensed images using spectral-spatial methods.

    Bhola, Rishav; Krishna, Nandigam Hari; Ramesh, K N; Senthilnath, J; Anand, Gautham

    2018-01-15

    In this paper, detection of the power lines on images acquired by Unmanned Aerial Vehicle (UAV) based remote sensing is carried out using spectral-spatial methods. Spectral clustering was performed using Kmeans and Expectation Maximization (EM) algorithm to classify the pixels into the power lines and non-power lines. The spectral clustering methods used in this study are parametric in nature, to automate the number of clusters Davies-Bouldin index (DBI) is used. The UAV remote sensed image is clustered into the number of clusters determined by DBI. The k clustered image is merged into 2 clusters (power lines and non-power lines). Further, spatial segmentation was performed using morphological and geometric operations, to eliminate the non-power line regions. In this study, UAV images acquired at different altitudes and angles were analyzed to validate the robustness of the proposed method. It was observed that the EM with spatial segmentation (EM-Seg) performed better than the Kmeans with spatial segmentation (Kmeans-Seg) on most of the UAV images. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. The measurement and interpretation of Ne VII spectral line intensity ratios

    Lang, J.

    1983-03-01

    Results are presented for the measurement, using the branching ratios calibration method, of the spectral intensities of Ne VII lines emitted from a theta-pinch plasma whose electron temperature and density have been found by laser scattering and alternate techniques. (author)

  14. Intensity and shape of spectral lines from laser-produced plasmas

    Jamelot, G; Jaegle, P; Carillon, A; Wehenkel, C [Centre National de la Recherche Scientifique, 91 - Orsay (France); Paris-11 Univ., 91 - Orsay (France); Ecole Polytechnique, 91 - Palaiseau (France))

    1979-01-01

    In starting from spectral studies of multicharged ions in dense laser-produced plasmas, the main processes which determine the intensity and the shape of lines in the X-UV range are described. The role of radiation transfer is underlined. Intensity anomalies resulting from occurrence of population inversions are considered and a recent experiment performed for investigating such anomalies is described.

  15. Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4

    Järvelä, Emilia [Metsähovi Radio Observatory, Aalto University, Espoo (Finland); Department of Electronics and Nanoengineering, Aalto University, Espoo (Finland); Lähteenmäki, A. [Metsähovi Radio Observatory, Aalto University, Espoo (Finland); Department of Electronics and Nanoengineering, Aalto University, Espoo (Finland); Tartu Observatory, Tõravere (Estonia); Lietzen, H., E-mail: emilia.jarvela@aalto.fi [Tartu Observatory, Tõravere (Estonia)

    2017-11-30

    The large-scale environment is believed to affect the evolution and intrinsic properties of galaxies. It offers a new perspective on narrow-line Seyfert 1 galaxies (NLS1) which have not been extensively studied in this context before. We study a large and diverse sample of 960 NLS1 galaxies using a luminosity-density field constructed using Sloan Digital Sky Survey. We investigate how the large-scale environment is connected to the properties of NLS1 galaxies, especially their radio loudness. Furthermore, we compare the large-scale environment properties of NLS1 galaxies with other active galactic nuclei (AGN) classes, for example, other jetted AGN and broad-line Seyfert 1 (BLS1) galaxies, to shed light on their possible relations. In general NLS1 galaxies reside in less dense large-scale environments than any of our comparison samples, thus supporting their young age. The average luminosity-density and distribution to different luminosity-density regions of NLS1 sources is significantly different compared to BLS1 galaxies. This contradicts the simple orientation-based unification of NLS1 and BLS1 galaxies, and weakens the hypothesis that BLS1 galaxies are the parent population of NLS1 galaxies. The large-scale environment density also has an impact on the intrinsic properties of NLS1 galaxies; the radio loudness increases with the increasing luminosity-density. However, our results suggest that the NLS1 population is indeed heterogeneous, and that a considerable fraction of them are misclassified. We support a suggested description that the traditional classification based on the radio loudness should be replaced with the division to jetted and non-jetted sources.

  16. NEAR-INFRARED SPECTROSCOPY OF NEARBY SEYFERT GALAXIES: IS THERE EVIDENCE FOR SHOCK EXCITATION IN NARROW-LINE REGIONS?

    Terao, K. [Graduate School of Science and Engineering, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); Nagao, T.; Toba, Y. [Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); Hashimoto, T. [National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan (China); Yanagisawa, K. [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Honjo 3037-5, Kamogata-cho, Asaguchi, Okayama 719-0232 (Japan); Matsuoka, K. [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Ikeda, H. [National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo, 181-8588 (Japan); Taniguchi, Y., E-mail: terao@cosmos.phys.sci.ehime-u.ac.jp [The Open University of Japan, Wakaba 2-11, Mihama-ku, Chiba 261-8586 (Japan)

    2016-12-20

    One of the important unsettled problems regarding active galactic nuclei (AGNs) is the major ionization mechanism of gas clouds in AGN narrow-line regions (NLRs). In order to investigate this issue, we present our J -band spectroscopic observations of a sample of 26 nearby Seyfert galaxies. In our study, we use the flux ratio of the following two forbidden emission lines, [Fe ii]1.257  μ m and [P ii]1.188  μ m, because it is known that this ratio is sensitive to the ionization mechanism. We obtain the [Fe ii]/[P ii] flux ratio or its lower limit for 19 objects. In addition to our data, we compile this flux ratio (or its lower limit) for 23 nearby Seyfert galaxies from the literature. Based on the collected data, we find that three Seyfert galaxies show very large lower limits of the [Fe ii]/[P ii] flux ratios (≳10): NGC 2782, NGC 5005, and Mrk 463. It is thus suggested that the contribution of the fast shock in the gas excitation is significantly large for them. However, more than half of the Seyfert galaxies in our sample show moderate [Fe ii]/[P ii] flux ratios (∼2), which is consistent with pure photoionization by power-law ionizing continuum emission. We also find that the [Fe ii]/[P ii] flux ratio shows no clear correlation with the radio loudness, suggesting that the radio jet is not the primary origin of shocks in NLRs of Seyfert galaxies.

  17. OFDM techniques for narrow-band power line communications; OFDM-Verfahren fuer die schmalbandige Datenuebertragung im elektrischen Energieversorgungsnetz

    Hoch, Martin

    2012-07-01

    In Power Line Communications (PLC) the power distribution grid is modelled by a frequency-selective time-variant channel. Therefore, OFDM techniques are suited very well for this application since they equalize the frequency-selective behaviour in a simple fashion. For narrow-band PLC, where only little amounts of data are to be transmitted, it is advantageous to employ a non-coherent system that does not need a training sequence for channel estimation. Such type of system can be brought up with CyclicPrefix OFDM in combination with Differential Phase-Shift Keying (DPSK). In an alternative, Unique-Word OFDM, the guard interval is not filled by a cyclic prefix, but a ''unique word'', which can be deployed for channel estimation. However, there is a loss in signal-to-noise power ratio due to the special type of signal generation. This loss can be more than regained in principle, but only by applying expensive detection. Another interesting technique is Wavelet-OFDM as its transmit spectrum can be formed outstandingly because of extended transmit pulses. This implies a large overhead when short packets of data are transmitted - additionally to a training sequence, for non-coherent detection is not possible. Cyclic-Prefix OFDM and DPSK are the basis of the Physical Layers of the PLC systems ''PLC G3'' and ''PRIME''. Comparing their specifications and analyzing simulation results ''PLC G3'' turns out to be the more reliable system. In order to equalize the time-variant behaviour of the power line channel, linear equalization and Multiple Symbol Differential Detection is studied as well as algorithms to estimate the time-variant envelope. (orig.)

  18. A SAMPLE OF SEYFERT-2 GALAXIES WITH ULTRALUMINOUS GALAXY-WIDE NARROW-LINE REGIONS: QUASAR LIGHT ECHOES?

    Schirmer, M.; Diaz, R.; Levenson, N. A.; Winge, C.; Holhjem, K.

    2013-01-01

    We report the discovery of Seyfert-2 galaxies in SDSS-DR8 with galaxy-wide, ultraluminous narrow-line regions (NLRs) at redshifts z = 0.2-0.6. With a space density of 4.4 Gpc –3 at z ∼ 0.3, these 'green beans' (GBs) are amongst the rarest objects in the universe. We are witnessing an exceptional and/or short-lived phenomenon in the life cycle of active galactic nuclei (AGNs). The main focus of this paper is on a detailed analysis of the GB prototype galaxy J2240–0927 (z = 0.326). Its NLR extends over 26 × 44 kpc and is surrounded by an extended NLR. With a total [O III] λ5008 luminosity of (5.7 ± 0.9) × 10 43 erg s –1 , this is one of the most luminous NLRs known around any type-2 galaxy. Using VLT/XSHOOTER, we show that the NLR is powered by an AGN, and we derive resolved extinction, density, and ionization maps. Gas kinematics is disturbed on a global scale, and high-velocity outflows are absent or faint. This NLR is unlike any other NLR or extended emission line region known. Spectroscopy with Gemini/GMOS reveals extended, high-luminosity [O III] emission also in other GBs. WISE 24 μm luminosities are 5-50 times lower than predicted by the [O III] fluxes, suggesting that the NLRs reflect earlier, very active quasar states that have strongly subsided in less than a galaxy's light-crossing time. These light echoes, or ionization echoes, are about 100 times more luminous than any other such echo known to date. X-ray data are needed for photoionization modeling and to verify the light echoes.

  19. BAT AGN Spectroscopic Survey - III. An Observed Link Between AGN Eddington Ratio and Narrow-Emission-Line Ratios

    Oh, Kyuseok; Schawinski, Kevin; Koss, Michael; Trakhtenbrot, Benny; Lamperti, Isabella; Ricci, Claudio; Mushotzky, Richard; Veilleux, Sylvain; Berney, Simon; Crenshaw, D. Michael; hide

    2016-01-01

    We investigate the observed relationship between black hole mass (M(sub BH)), bolometric luminosity (L(sub bol)) and Eddington ratio (lambda(sub Edd)) with optical emission-line ratios ([N II] lambda6583/Halpha, [S II]lambda-lamda6716, 6731/Halpha, [O I] lamda6300/Halpha, [O III] lamda5007/Hbeta, [Ne III] lamda3869/Hbeta and He II lamda4686/Hbeta) of hard X-ray-selected active galactic nuclei (AGN) from the BAT AGN Spectroscopic Survey. We show that the [N II] lamda6583/Halpha ratio exhibits a significant correlation with lamda(sub Edd) (R(sub Pear) = -0.44, p-value 3 x 10(exp. -13) sigma = 0.28 dex), and the correlation is not solely driven by M(sub BH) or L(sub bol). The observed correlation between [N II] lamda6583/Halpha ratio and M(sub BH) is stronger than the correlation with L(sub bol), but both are weaker than the lamda(sub Edd) correlation. This implies that the large-scale narrow lines of AGN host galaxies carry information about the accretion state of the AGN central engine. We propose that [N II] lamda6583/Halpha is a useful indicator of Eddington ratio with 0.6 dex of rms scatter, and that it can be used to measure lambda(sub Edd) and thus M(sub BH) from the measured L(sub bol), even for high-redshift obscured AGN. We briefly discuss possible physical mechanisms behind this correlation, such as the mass-metallicity relation, X-ray heating, and radiatively driven outflows.

  20. Interrogating Seyferts with NebulaBayes: Spatially Probing the Narrow-line Region Radiation Fields and Chemical Abundances

    Thomas, Adam D.; Dopita, Michael A.; Kewley, Lisa J.; Groves, Brent A.; Sutherland, Ralph S.; Hopkins, Andrew M.; Blanc, Guillermo A.

    2018-04-01

    NebulaBayes is a new Bayesian code that implements a general method of comparing observed emission-line fluxes to photoionization model grids. The code enables us to extract robust, spatially resolved measurements of abundances in the extended narrow-line regions (ENLRs) produced by Active Galactic Nuclei (AGN). We observe near-constant ionization parameters but steeply radially declining pressures, which together imply that radiation pressure regulates the ENLR density structure on large scales. Our sample includes four “pure Seyfert” galaxies from the S7 survey that have extensive ENLRs. NGC 2992 shows steep metallicity gradients from the nucleus into the ionization cones. An inverse metallicity gradient is observed in ESO 138-G01, which we attribute to a recent gas inflow or minor merger. A uniformly high metallicity and hard ionizing continuum are inferred across the ENLR of Mrk 573. Our analysis of IC 5063 is likely affected by contamination from shock excitation, which appears to soften the inferred ionizing spectrum. The peak of the ionizing continuum E peak is determined by the nuclear spectrum and the absorbing column between the nucleus and the ionized nebula. We cannot separate variation in this intrinsic E peak from the effects of shock or H II region contamination, but E peak measurements nevertheless give insights into ENLR excitation. We demonstrate the general applicability of NebulaBayes by analyzing a nuclear spectrum from the non-active galaxy NGC 4691 using a H II region grid. The NLR and H II region model grids are provided with NebulaBayes for use by the astronomical community.

  1. The first γ-ray detection of the narrow-line Seyfert 1 FBQS J1644+2619

    D'Ammando, F.; Istituto Nazionale di Astrofisica; Orienti, M.; Larsson, J.; Giroletti, M.

    2015-01-01

    Here, we report the discovery of γ-ray emission from the narrow-line Seyfert 1 (NLSy1) galaxy FBQS J1644+2619 by the Large Area Telescope on board the Fermi satellite. The Third Fermi LAT Source catalogue reports an unidentified γ-ray source, detected over the first four years of Fermi operation, 0.°23 from the radio position of the NLSy1. Analysing 76 months of γ-ray data (2008 August 4–2014 December 31) we are able to better constrain the localization of the γ-ray source. The new position of the γ- ray source is 0.°05 from FBQS J1644+2619, suggesting a spatial association with the NLSy1. This is the sixth NLSy1 detected at high significance by Fermi-LAT so far. Notably, a significant increase of activity was observed in γ-rays from FBQS J1644+2619 during 2012 July–October, and an increase of activity in V -band was detected by the Catalina Real-Time Sky Survey in the same period.

  2. Investigation of local environment around rare earths (La and Eu) by fluorescence line narrowing during borosilicate glass alteration

    Molières, Estelle; Panczer, Gérard; Guyot, Yannick; Jollivet, Patrick; Majérus, Odile; Aschehoug, Patrick; Barboux, Philippe; Gin, Stéphane; Angeli, Frédéric

    2014-01-01

    The local environment of europium in soda-lime borosilicate glasses with a range of La 2 O 3 content was probed by continuous luminescence and Fluorescence Line Narrowing (FLN) to investigate the local environment of rare earth elements in pristine and leached glass. After aqueous leaching at 90 °C at pH 7 and 9.5, rare earths were fully retained and homogeneously distributed in the amorphous alteration layer (commonly called gel). Two separate silicate environments were observed in pristine and leached glasses regardless of the lanthanum content and the leaching conditions. A borate environment surrounding europium was not observed in pristine and leached glasses. During glass alteration, OH groups were located around the europium environment, which became more organized (higher symmetry) in the first coordination shell. -- Highlights: • No borate environment surrounding europium was detected in pristine borosilicate glasses. • Up to 12 mol% of REE2O3 in glass, local environment of europium does not significantly change. • Europium environment becomes more ordered and symmetric in gels than in pristine glasses. • Two distinct silicate sites were observed, as well in pristine glass as in gels (leached glasses). • In altered glasses, OH groups were located around europium

  3. Observation of soft X-ray spectra from a Seyfert 1 and a narrow emission-line galaxy

    Singh, K.P.; Garmire, G.P.; Nousek, J.

    1985-01-01

    The 0.2-40 keV X-ray spectra of the Seyfert 1 galaxy Mrk 509 and the narrow emission-line galaxy NGC 2992 are analyzed. The results suggest the presence of a steep soft X-ray component in Mrk 509 in addition to the well-known Gamma = 1.7 component found in other active galactic nuclei in the 2-40 keV energy range. The soft X-ray component is interpreted as due to thermal emission from a hot gas, probably associated with the highly ionized gas observed to be outflowing from the galaxy. The X-ray spectrum of NGC 2992 does not show any steepening in the soft X-ray band and is consistent with a single power law (Gamma = 1.78) with very low absorbing column density of 4 x 10 to the 21st/sq cm. A model with partial covering of the nuclear X-ray source is preferred, however, to a simple model with a single power law and absorption. 34 references

  4. The host galaxy of the gamma-ray narrow-line Seyfert 1 galaxy 1H 0323+342

    León Tavares, J.; Chavushyan, V.; Puerari, I.; Patiño-Alvarez, V.; Carramiñana, A.; Carrasco, L.; Guichard, J.; Olguín-Iglesias, A.; Valdes, J. [Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE), Apartado Postal 51 y 216, 72000 Puebla (Mexico); Kotilainen, J. [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, FI-21500 Piikkiö (Finland); Añorve, C. [Facultad de Ciencias de la Tierra y del Espacio (FACITE) de la Universidad Autónoma de Sinaloa, Blvd. de la Americas y Av. Universitarios S/N, Ciudad Universitaria, C.P. 80010, Culiacán Sinaloa (Mexico); Cruz-González, I. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Ap. 70-264, 04510 DF (Mexico); Antón, S. [Instituto de Astrofísica de Andalucía-CSIC, E-18008 Granada (Spain); Karhunen, K.; Sanghvi, J., E-mail: leon.tavares@inaoep.mx [Tuorla Observatory, Department of Physics and Astronomy, University of Turku, FI-20100 Turku (Finland)

    2014-11-01

    We present optical and near-infrared (NIR) imaging data of the radio-loud, narrow-line Seyfert 1 galaxy 1H 0323+342, which shows intense and variable gamma-ray activity discovered by the Fermi satellite with the Large Area Telescope. Near-infrared and optical images are used to investigate the structural properties of the host galaxy of 1H 0323+342; this together with optical spectroscopy allows us to examine its black hole mass. Based on two-dimensional (2D) multiwavelength surface-brightness modeling, we find that statistically, the best model fit is a combination of a nuclear component and a Sérsic profile (n ∼ 2.8). However, the presence of a disk component (with a small bulge n ∼ 1.2) also remains a possibility and cannot be ruled out with the present data. Although at first glance a spiral-arm-like structure is revealed in our images, a 2D Fourier analysis of the imagery suggests that this structure corresponds to an asymmetric ring, likely associated with a recent violent dynamical interaction. We discuss our results in the context of relativistic jet production and galaxy evolution.

  5. Investigation of local environment around rare earths (La and Eu) by fluorescence line narrowing during borosilicate glass alteration

    Molières, Estelle [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Panczer, Gérard; Guyot, Yannick [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France); Jollivet, Patrick [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Majérus, Odile; Aschehoug, Patrick; Barboux, Philippe [Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, École Nationale Supérieure de Chimie de Paris (ENSCP Chimie-ParisTech), 11 rue Pierre et Marie Curie, 75231 Paris (France); Gin, Stéphane [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Angeli, Frédéric, E-mail: frederic.angeli@cea.fr [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France)

    2014-01-15

    The local environment of europium in soda-lime borosilicate glasses with a range of La{sub 2}O{sub 3} content was probed by continuous luminescence and Fluorescence Line Narrowing (FLN) to investigate the local environment of rare earth elements in pristine and leached glass. After aqueous leaching at 90 °C at pH 7 and 9.5, rare earths were fully retained and homogeneously distributed in the amorphous alteration layer (commonly called gel). Two separate silicate environments were observed in pristine and leached glasses regardless of the lanthanum content and the leaching conditions. A borate environment surrounding europium was not observed in pristine and leached glasses. During glass alteration, OH groups were located around the europium environment, which became more organized (higher symmetry) in the first coordination shell. -- Highlights: • No borate environment surrounding europium was detected in pristine borosilicate glasses. • Up to 12 mol% of REE2O3 in glass, local environment of europium does not significantly change. • Europium environment becomes more ordered and symmetric in gels than in pristine glasses. • Two distinct silicate sites were observed, as well in pristine glass as in gels (leached glasses). • In altered glasses, OH groups were located around europium.

  6. The gravitational microlens influence on X-ray spectral line generated by an AGN accretion disc

    Popović L.Č.

    2001-01-01

    Full Text Available The influence of gravitational microlensing on the X-ray spectral line profiles originated from a relativistic accretion disc has been studied. Using a disc model, we show that microlensing can induce noticeable changes in the line shapes when the Einstein ring radius associated with the microlens is of a size comparable to that of the accretion disc. Taking into account the relatively small size of the X-ray accretion disc, we found that compact objects (of about a Solar mass which belong to the bulge of the host galaxy can produce significant changes in the X-ray line profile of AGN.

  7. Stark shift measurements of Xe II and Xe III spectral lines

    Cirisan, M; Pelaez, R J; Djurovic, S; Aparicio, J A; Mar, S

    2007-01-01

    Stark shift measurements of singly and doubly ionized Xe spectral lines are presented in this paper. Shifts of 110 Xe II lines and 42 Xe III lines are reported, including a significant number of new results. A low-pressure-pulsed arc with 95% of He and 5% of Xe was used as a plasma source. All measurements were performed under the following plasma conditions: electron density (0.2-1.4) x 10 23 m -3 and electron temperature 18 000-23 000 K. The measured Stark shifts are compared with other experimental and theoretical data

  8. Utilize the spectral line pair of the same ionized state ion to measure the ion temperature of tokamak plasma

    Lin Xiaodong

    2000-01-01

    Making use of a Fabry-Perot interferometer driven by a piezoelectric crystal and selecting the suitable separation of plates, the ion temperature is defined by measuring the superimposed profile of the spectral line pair of the same ionized state ions in Tokamak. The advantage of this method is to higher spectral resolution and wider spectral range select

  9. Experimental Line List of Water Vapor Absorption Lines in the Spectral Ranges 1850 - 2280 CM-1 and 2390-4000 CM-1

    Loos, Joep; Birk, Manfred; Wagner, Georg

    2017-06-01

    A new experimental line parameter list of water vapor absorption lines in the spectral ranges 1850 - 2280 cm-1 and 2390 - 4000 cm-1 is presented. The line list is based on the analysis of several transmittance spectra measured using a Bruker IFS 125 HR high resolution Fourier transform spectrometer. A total of 54 measurements of pure water and water/air-mixtures at 296 K as well as water/air-mixtures at high and low temperatures were performed. A multispectrum fitting approach was used applying a quadratic speed-dependent hard collision line shape model in the Hartmann-Tran implementation extended to account for line mixing in the Rosenkranz approximation in order to retrieve line positions, intensities, self- and air-broadening parameters, their speed-dependence, self- and air-shifts as well as line mixing and in some cases collisional narrowing parameters. Additionally, temperature dependence parameters for widths, shifts and in a few cases line mixing were retrieved. For every parameter an extensive error estimation calculation was performed identifying and specifying systematic error sources. The resulting parameters are compared to the databases HITRAN12 as well as experimental values. For intensities, a detailed comparison to results of recent ab initio calculations performed at University College London was done showing an agreement within 2 % for a majority of the data. However, for some bands there are systematic deviations attributed to ab initio calculation errors. .H. Ngo et al. JQSRT 129, 89-100 (2013) doi:10.1016/j.jqsrt.2013.05.034; JQSRT 134, 105 (2014) doi:10.1016/j.jqsrt.2013.10.016. H. Tran et al. JQSRT 129, 199-203 (2013) doi:10.1016/j.jqsrt.2013.06.015; JQSRT 134, 104 (2014) doi:10.1016/j.jqsrt.2013.10.015. L.S. Rothman et al. JQSRT 130, 4-50 (2013) doi:10.1016/j.jqsrt.2013.07.002. N. Jacquinet-Husson et al. JMS 112, 2395-2445 (2016) doi:10.1016/j.jms.2016.06.007.

  10. Short-term radio variability and parsec-scale structure in A gamma-ray narrow-line Seyfert 1 galaxy 1H 0323+342

    Wajima, Kiyoaki [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Xuhui District, Shanghai 200030 (China); Fujisawa, Kenta [The Research Institute for Time Studies, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi 753-8511 (Japan); Hayashida, Masaaki [Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Isobe, Naoki [The Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Ishida, Takafumi [Graduate School of Science and Engineering, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi 753-8512 (Japan); Yonekura, Yoshinori, E-mail: kwajima@shao.ac.cn [Center for Astronomy, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512 (Japan)

    2014-02-01

    We made simultaneous single-dish and very long baseline interferometer (VLBI) observations of a narrow-line Seyfert 1 galaxy 1H 323+342, showing gamma-ray activity revealed by Fermi/Large Area Telescope observations. We found significant variation of the total flux density at 8 GHz on the timescale of one month by the single-dish monitoring. The total flux density varied by 5.5% in 32 days, which is comparable to the gamma-ray variability timescale, corresponding to the variability brightness temperature of 7.0 × 10{sup 11} K. The source consists of central and southeastern components on the parsec (pc) scale. Only the flux of the central component decreased in the same way as the total flux density, indicating that the short-term radio variability, and probably the gamma-ray-emitting region, is associated with this component. From the VLBI observations, we obtained brightness temperatures of greater than (5.2 ± 0.3) × 10{sup 10} K and derived an equipartition Doppler factor of greater than 1.7, a variability Doppler factor of 2.2, and an 8 GHz radio power of 10{sup 24.6} W Hz{sup –1}. Combining them, we conclude that acceleration of radio jets and creation of high-energy particles are ongoing in the central engine and that the apparent very radio-loud feature of the source is due to the Doppler boosting effect, resulting in the intrinsic radio loudness being an order of magnitude smaller than the observed values. We also conclude that the pc-scale jet represents recurrent activity from the spectral fitting and the estimated kinematic age of pc- and kpc-scale extended components with different position angles.

  11. Spectral shapes of Ar-broadened HCl lines in the fundamental band by classical molecular dynamics simulations and comparison with experiments

    Tran, H., E-mail: ha.tran@lisa.u-pec.fr [Laboratoire Interuniversitaire des Systèmes Atmosphériques, UMR CNRS 7583, Université Paris Est Créteil, Université Paris Diderot, Institut Pierre-Simon Laplace, 94010 Créteil Cedex (France); Domenech, J.-L. [Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, (IEM-CSIC), Serrano 123, 28006 Madrid (Spain)

    2014-08-14

    Spectral shapes of isolated lines of HCl perturbed by Ar are investigated for the first time using classical molecular dynamics simulations (CMDS). Using reliable intermolecular potentials taken from the literature, these CMDS provide the time evolution of the auto-correlation function of the dipole moment, whose Fourier-Laplace transform leads to the absorption spectrum. In order to test these calculations, room temperature spectra of various lines in the fundamental band of HCl diluted in Ar are measured, in a large pressure range, with a difference-frequency laser spectrometer. Comparisons between measured and calculated spectra show that the CMDS are able to predict the large Dicke narrowing effect on the shape of HCl lines and to satisfactorily reproduce the shapes of HCl spectra at different pressures and for various rotational quantum numbers.

  12. X-ray spectral line coincidences between fluorine VIII (and IX) and transition metal lines

    Charatis, G.; Rockett, P.D.; Burkhalter, P.G.

    1983-01-01

    X-ray spectroscopy was performed in the 12 to 15 A region, recording L-shell lines from selected laser-irradiated transition metals. Line coincidences and near coincidences were identified between Fe, Cr, Mn, and Ni L-spectra, and F VIII and F IX K-shell lines. Wavelengths were determined to accuracies of 1 to 3 mA and will be utilized in selecting potential pumping candidates in future x-ray lasing schemes. High-resolution x-ray spectra were collected under controlled illumination and target conditions using 1.05 μm and 0.527 μm laser excitation with the KMS CHROMA laser

  13. Universal FFM Hydrogen Spectral Line Shapes Applied to Ions and Electrons

    Mossé, C.; Calisti, A.; Ferri, S.; Talin, B.; Bureyeva, L. A.; Lisitsa, V. S.

    2008-10-01

    We present a method for the calculation of hydrogen spectral line shapes based on two combined approaches: Universal Model and FFM procedure. We start with the analytical functions for the intensities of the Stark components of radiative transitions between highly excited atomic states with large values of principal quantum numbers n,n'γ1, with Δn = n-n'≪n for the specific cases of Hn-α line (Δn = 1) and Hn-β line (Δn = 2). The FFM line shape is obtained by averaging on the electric field of the Hooper's field distribution for ion and electron perturber dynamics and by mixing the Stark components with a jumping frequency rate ve (vi) where v = N1/3u (N is electron density and u is the ion or electron thermal velocity). Finally, the total line shape is given by convolution of ion and electron line shapes. Hydrogen line shape calculations for Balmer Hα and Hβ lines are compared to experimental results in low density plasma (Ne˜1016-1017cm-3) and low electron temperature in order of 10 000K. This method relying on analytic expressions permits fast calculation of Hn-α and Hn-β lines of hydrogen and could be used in the study of the Stark broadening of radio recombination lines for high principal quantum number.

  14. Long term X-ray variability characteristics of the narrow-line Seyfert 1 galaxy RE J1034+396

    Chaudhury, K.; Chitnis, V. R.; Rao, A. R.; Singh, K. P.; Bhattacharyya, Sudip; Dewangan, G. C.; Chakraborty, S.; Chandra, S.; Stewart, G. C.; Mukerjee, K.; Dey, R. K.

    2018-05-01

    We present the results of our study of the long term X-ray variability characteristics of the Narrow Line Seyfert 1 galaxy RE J1034+396. We use data obtained from the AstroSat satellite along with the light curves obtained from XMM-Newton and Swift-XRT. We use the 0.3 - 7.0 keV and 3 - 20 keV data, respectively, from the SXT and the LAXPC of AstroSat. The X-ray spectra in the 0.3 - 20 keV region are well fit with a model consisting of a power-law and a soft excess described by a thermal-Compton emission with a large optical depth, consistent with the earlier reported results. We have examined the X-ray light curves in the soft and hard X-ray bands of SXT and LAXPC, respectively, and find that the variability is slightly larger in the hard band. To investigate the variability characteristics of this source at different time scales, we have used X-ray light curves obtained from XMM-Newton data (200 s to 100 ks range) and Swift-XRT data (1 day to 100 day range) and find that there are evidences to suggest that the variability sharply increases at longer time scales. We argue that the mass of the black hole in RE J1034+396 is likely to be ˜3 × 106 M⊙, based on the similarity of the observed QPO to the high frequency QPO seen in the Galactic black hole binary, GRS 1915+105.

  15. Embedded star formation in the extended narrow line region of Centaurus A: Extreme mixing observed by MUSE

    Santoro, F.; Oonk, J. B. R.; Morganti, R.; Oosterloo, T. A.; Tadhunter, C.

    2016-05-01

    We present a detailed study of the complex ionization structure in a small (~250 pc) extended narrow line region (ENLR) cloud near Centaurus A using the Multi Unit Spectroscopic Explorer. This cloud is located in the so-called outer filament of ionized gas (about 15 kpc from the nucleus) where jet-induced star formation has been suggested to occur by different studies. We find that, despite the small size, a mixture of ionization mechanisms is operating, resulting in considerable complexity in the spatial ionization structure. The area includes two H II regions where star formation is occurring and another location where star formation must have ceased very recently. Interestingly, the extreme Balmer decrement of one of the star forming regions (Hα/Hβobs ~ 6) indicates that it is still heavily embedded in its natal cocoon of gas and dust. At all three locations a continuum counterpart is found with spectra matching those of O/B stars local to Centaurus A. The H II regions are embedded in a larger gas complex which is photoionized by the radiation of the central active galactic nucleus (AGN), but the O/B stars affect the spatial ionization pattern in the ENLR cloud very locally. In particular, in the surroundings of the youngest star forming region, we can isolate a tight mixing sequence in the diagnostic diagram going from gas with ionization due to a pure stellar continuum to gas only photoionized by the AGN. These results emphasize the complexity and the mixture of processes occurring in star forming regions under the influence of an AGN radiation. This is relevant for our understanding of AGN-induced star formation suggested to occur in a number of objects, including this region of Centaurus A. They also illustrate that these young stars influence the gas over only a limited region.

  16. An Interferometric 270--355 GHz Spectral Line Survey of the Red Supergiant VY CMa

    Menten, K. M.; Young, K. H.; Patel, N. A.; Gottlieb, C. A.; Thaddeus, P.; McCarthy, M. C.; Gurwell, M. A.; Belloche, A.; Kaminski, T.; Verheyen, L.; Decin, L.; Brunken, S.; Holger, S. P. M.

    2011-05-01

    We have used the Submillimeter Array to image the molecular line emission in the circumstellar envelope of the peculiar red supergiant star VY Canis Majoris over the whole 870 μm atmospheric window. Employing adaptive calibration using the object's continuum emission we achieve high quality one arcsecond resolution imaging of the whole 280--355 GHz range within which we find 211 distinct spectral lines from 33 molecules (including isotopologues) plus 40 unidentified lines. From the distribution of molecules we are obtaining their abundances and isotopologic abundance ratios. Using data for multiple transitions in a number of molecules we are deriving the physical conditions in the circumstellar envelope to reach a picture of the star's chemistry that can be compared with models. Our legacy survey is accompanied by a strong laboratory effort that helps with the identification of possibly newly found molecules traced by unidentified lines. We shall create a publicly accessible database of spectral-line channel-maps of the emission from all the lines detected in the survey.

  17. A new method of organizing spectral line intensity ratio fluctuations of auroral emissions

    Thelin, B.

    1986-02-01

    In this paper a new kind of linearization effect between the atmospheric auroral emissions is presented. The same kind of linearization effect has previously been found in nightglow emissions from photometer measurements and in the spectrochemical field from studies of optical light sources. Linear graphs have been obtained for atomic spectral lines and vibrational bandspectra when the spectral line ratio fluctuations were plotted versus the photon energies of these emissions. This new effect has been studied with a spectrophotometer in auroral emissions, where linear graphs have been obtained on different auroral occasions. By doing such studies of auroral light it is possible to see the importance of the inelastic scattering cross section between electrons - atoms and electrons - molecules. In this way it has shown to be possible to determine the mean energy of the interacting thermal electrons that are active in the different auroral phases. (author)

  18. Solar Spectral Lines with Special Polarization Properties for the Calibration of Instrument Polarization

    Li, W.; Casini, R.; Alemán, T. del Pino; Judge, P. G. [High Altitude Observatory, National Center for Atmospheric Research 1, P.O. Box 3000, Boulder, CO 80307-3000 (United States)

    2017-10-20

    We investigate atomic transitions that have previously been identified as having zero polarization from the Zeeman effect. Our goal is to identify spectral lines that can be used for the calibration of instrumental polarization of large astronomical and solar telescopes, such as the Daniel K. Inouye Solar Telescope, which is currently under construction on Haleakala. We use a numerical model that takes into account the generation of scattering polarization and its modification by the presence of a magnetic field of arbitrary strength. We adopt values for the Landé factors from spectroscopic measurements or semi-empirical results, thus relaxing the common assumption of LS-coupling previously used in the literature. The mechanisms dominating the polarization of particular transitions are identified, and we summarize groups of various spectral lines useful for the calibration of spectropolarimetric instruments, classified according to their polarization properties.

  19. Investigation of Tree Spectral Reflectance Characteristics Using a Mobile Terrestrial Line Spectrometer and Laser Scanner

    Eetu Puttonen

    2013-07-01

    Full Text Available In mobile terrestrial hyperspectral imaging, individual trees often present large variations in spectral reflectance that may impact the relevant applications, but the related studies have been seldom reported. To fill this gap, this study was dedicated to investigating the spectral reflectance characteristics of individual trees with a Sensei mobile mapping system, which comprises a Specim line spectrometer and an Ibeo Lux laser scanner. The addition of the latter unit facilitates recording the structural characteristics of the target trees synchronously, and this is beneficial for revealing the characteristics of the spatial distributions of tree spectral reflectance with variations at different levels. Then, the parts of trees with relatively low-level variations can be extracted. At the same time, since it is difficult to manipulate the whole spectrum, the traditional concept of vegetation indices (VI based on some particular spectral bands was taken into account here. Whether the assumed VIs capable of behaving consistently for the whole crown of each tree was also checked. The specific analyses were deployed based on four deciduous tree species and six kinds of VIs. The test showed that with the help of the laser scanner data, the parts of individual trees with relatively low-level variations can be located. Based on these parts, the relatively stable spectral reflectance characteristics for different tree species can be learnt.

  20. Critically Evaluated Energy Levels, Spectral Lines, Transition Probabilities, and Intensities of Neutral Vanadium (V i)

    Saloman, Edward B. [Dakota Consulting, Inc., 1110 Bonifant Street, Suite 310, Silver Spring, MD 20910 (United States); Kramida, Alexander [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

    2017-08-01

    The energy levels, observed spectral lines, and transition probabilities of the neutral vanadium atom, V i, have been compiled. Also included are values for some forbidden lines that may be of interest to the astrophysical community. Experimental Landé g -factors and leading percentage compositions for the levels are included where available, as well as wavelengths calculated from the energy levels (Ritz wavelengths). Wavelengths are reported for 3985 transitions, and 549 energy levels are determined. The observed relative intensities normalized to a common scale are provided.

  1. Techniques for obtaining velocity distributions of atoms or ions from Doppler-broadened spectral line profiles

    Moran, T.G.

    1986-12-01

    Analysis of the doppler-broadened profiles of spectral lines radiated by atoms or ions in plasmas yields information about their velocity distributions. Researchers have analysed profiles of lines radiated by atoms in isotropic velocity distributions in several ways, one being the inversion of the integral equation which relates the velocity distribution to the line profile. This inversion formula was derived for a separate application and was given to within an arbitrary multiplicative constant. This paper presents a new derivation which obtains the inversion exactly, using a method which is easily generalized for determination of anisotropic velocity distribution functions. The technique to obtain an anisotropic velocity distribution function from line profiles measured at different angles is outlined

  2. Deep, Broadband Spectral Line Surveys of Molecule-rich Interstellar Clouds

    Widicus Weaver, Susanna L.; Laas, Jacob C.; Zou, Luyao; Kroll, Jay A.; Rad, Mary L.; Hays, Brian M.; Sanders, James L.; Cross, Trevor N.; Wehres, Nadine; McGuire, Brett A. [Department of Chemistry, Emory University, Atlanta, GA 30322 (United States); Lis, Dariusz C.; Sumner, Matthew C., E-mail: susanna.widicus.weaver@emory.edu [California Institute of Technology, Cahill Center for Astronomy and Astrophysics 301-17, Pasadena, CA 91125 (United States)

    2017-09-01

    Spectral line surveys are an indispensable tool for exploring the physical and chemical evolution of astrophysical environments due to the vast amount of data that can be obtained in a relatively short amount of time. We present deep, broadband spectral line surveys of 30 interstellar clouds using two broadband λ  = 1.3 mm receivers at the Caltech Submillimeter Observatory. This information can be used to probe the influence of physical environment on molecular complexity. We observed a wide variety of sources to examine the relative abundances of organic molecules as they relate to the physical properties of the source (i.e., temperature, density, dynamics, etc.). The spectra are highly sensitive, with noise levels ≤25 mK at a velocity resolution of ∼0.35 km s{sup −1}. In the initial analysis presented here, column densities and rotational temperatures have been determined for the molecular species that contribute significantly to the spectral line density in this wavelength regime. We present these results and discuss their implications for complex molecule formation in the interstellar medium.

  3. Determining fast orientation changes of multi-spectral line cameras from the primary images

    Wohlfeil, Jürgen

    2012-01-01

    Fast orientation changes of airborne and spaceborne line cameras cannot always be avoided. In such cases it is essential to measure them with high accuracy to ensure a good quality of the resulting imagery products. Several approaches exist to support the orientation measurement by using optical information received through the main objective/telescope. In this article an approach is proposed that allows the determination of non-systematic orientation changes between every captured line. It does not require any additional camera hardware or onboard processing capabilities but the payload images and a rough estimate of the camera's trajectory. The approach takes advantage of the typical geometry of multi-spectral line cameras with a set of linear sensor arrays for different spectral bands on the focal plane. First, homologous points are detected within the heavily distorted images of different spectral bands. With their help a connected network of geometrical correspondences can be built up. This network is used to calculate the orientation changes of the camera with the temporal and angular resolution of the camera. The approach was tested with an extensive set of aerial surveys covering a wide range of different conditions and achieved precise and reliable results.

  4. Investigation of oxygen impurity transport using the O4+ visible spectral line in the Aditya tokamak

    Chowdhuri, M.B.; Ghosh, J.; Banerjee, S.; Dey, Ritu; Manchanda, R.; Kumar, Vinay; Vasu, P.; Patel, K.M.; Atrey, P.K.; Shankara Joisa, Y.; Rao, C.V.S.; Tanna, R.L.; Raju, D.; Chattopadhyay, P.K.; Jha, R.; Gupta, C.N.; Bhatt, S.B.; Saxena, Y.C.

    2013-01-01

    Intense visible lines from Be-like oxygen impurity are routinely observed in the Aditya tokamak. The spatial profile of brightness of a Be-like oxygen spectral line (2p3p 3 D 3 –2p3d 3 F 4 ) at 650.024 nm is used to investigate oxygen impurity transport in typical discharges of the Aditya tokamak. A 1.0 m multi-track spectrometer (Czerny–Turner) capable of simultaneous measurements from eight lines of sight is used to obtain the radial profile of brightness of O 4+ spectral emission. The emissivity profile of O 4+ spectral emission is obtained from the spatial profile of brightness using an Abel-like matrix inversion. The oxygen transport coefficients are determined by reproducing the experimentally measured emissivity profiles of O 4+ , using a one-dimensional empirical impurity transport code, STRAHL. Much higher values of the diffusion coefficient compared with the neo-classical values are observed in both the high magnetic field edge region (D inboard max ∼30 m 2 s -1 ) and the low magnetic field edge region (D outboard max ∼45 m 2 s -1 ) of typical Aditya ohmic plasmas, which seems to be due to fluctuation-induced transport. The diffusion coefficient at the limiter radius in the low-field (outboard) region is typically ∼ twice as high as that at the limiter radius in the high-field (inboard) region. (paper)

  5. Search for gamma-ray spectral lines with the Fermi Large Area Telescope and dark matter implications

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Charles, E.; Chaves, R. C. G.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; D’Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Essig, R.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hayashida, M.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Inoue, Y.; Izaguirre, E.; Jogler, T.; Kamae, T.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Malyshev, D.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Romani, R. W.; Sánchez-Conde, M.; Schulz, A.; Sgrò, C.; Siegal-Gaskins, J.; Siskind, E. J.; Snyder, A.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Tibaldo, L.; Tinivella, M.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Winer, B. L.; Wood, K. S.; Wood, M.; Yang, Z.; Zaharijas, G.; Zimmer, S.

    2013-10-22

    Weakly interacting massive particles (WIMPs) are a theoretical class of particles that are excellent dark matter candidates. WIMP annihilation or decay may produce essentially monochromatic γ rays detectable by the Fermi Large Area Telescope (LAT) against the astrophysical γ -ray emission of the Galaxy. We have searched for spectral lines in the energy range 5–300 GeV using 3.7 years of data, reprocessed with updated instrument calibrations and an improved energy dispersion model compared to the previous Fermi-LAT Collaboration line searches. We searched in five regions selected to optimize sensitivity to different theoretically motivated dark matter density distributions. We did not find any globally significant lines in our a priori search regions and present 95% confidence limits for annihilation cross sections of self-conjugate WIMPs and decay lifetimes. Our most significant fit occurred at 133 GeV in our smallest search region and had a local significance of 3.3 standard deviations, which translates to a global significance of 1.5 standard deviations. We discuss potential systematic effects in this search, and examine the feature at 133 GeV in detail. We find that the use both of reprocessed data and of additional information in the energy dispersion model contributes to the reduction in significance of the linelike feature near 130 GeV relative to significances reported in other works. We also find that the feature is narrower than the LAT energy resolution at the level of 2 to 3 standard deviations, which somewhat disfavors the interpretation of the 133 GeV feature as a real WIMP signal.

  6. THE ULTRAVIOLET-TO-MID-INFRARED SPECTRAL ENERGY DISTRIBUTION OF WEAK EMISSION LINE QUASARS

    Lane, Ryan A.; Shemmer, Ohad; Diamond-Stanic, Aleksandar M.; Fan Xiaohui; Anderson, Scott F.; Brandt, W. N.; Schneider, Donald P.; Plotkin, Richard M.; Richards, Gordon T.; Strauss, Michael A.

    2011-01-01

    We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 ≤ z ≤ 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS spectra and ground-based, near-infrared (IR) photometry of these sources to produce a large inventory of spectral energy distributions (SEDs) of WLQs across the rest-frame ∼0.1-5 μm spectral band. The SEDs of our sources are inconsistent with those of BL Lacertae objects which are dominated by synchrotron emission due to a jet aligned close to our line of sight, but are consistent with the SED of ordinary quasars with similar luminosities and redshifts that exhibit a near-to-mid-IR 'bump', characteristic of hot dust emission. This indicates that broad emission lines in WLQs are intrinsically weak, rather than suffering continuum dilution from a jet, and that such sources cannot be selected efficiently from traditional photometric surveys.

  7. THE ULTRAVIOLET-TO-MID-INFRARED SPECTRAL ENERGY DISTRIBUTION OF WEAK EMISSION LINE QUASARS

    Lane, Ryan A.; Shemmer, Ohad [Department of Physics, University of North Texas, Denton, TX 76203 (United States); Diamond-Stanic, Aleksandar M. [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA 92093 (United States); Fan Xiaohui [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Brandt, W. N.; Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Plotkin, Richard M. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Science Park 904, NL-1098 XH Amsterdam (Netherlands); Richards, Gordon T. [Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Strauss, Michael A., E-mail: RyanLane@my.unt.edu, E-mail: ohad@unt.edu [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States)

    2011-12-20

    We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 {<=} z {<=} 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS spectra and ground-based, near-infrared (IR) photometry of these sources to produce a large inventory of spectral energy distributions (SEDs) of WLQs across the rest-frame {approx}0.1-5 {mu}m spectral band. The SEDs of our sources are inconsistent with those of BL Lacertae objects which are dominated by synchrotron emission due to a jet aligned close to our line of sight, but are consistent with the SED of ordinary quasars with similar luminosities and redshifts that exhibit a near-to-mid-IR 'bump', characteristic of hot dust emission. This indicates that broad emission lines in WLQs are intrinsically weak, rather than suffering continuum dilution from a jet, and that such sources cannot be selected efficiently from traditional photometric surveys.

  8. Narrow-stripe broad-area lasers with distributed-feedback surface gratings as brilliant sources for high power spectral beam combining systems

    Decker, J.; Crump, P.; Fricke, J.; Wenzel, H.; Maaβdorf, A.; Erbert, G.; Tränkle, G.

    2014-03-01

    Laser systems based on spectral beam combining (SBC) of broad-area (BA) diode lasers are promising tools for material processing applications. However, the system brightness is limited by the in-plane beam param- eter product, BPP, of the BA lasers, which operate with a BPP of BPP and vertical far eld angle (95% power content), μV 95. The resulting diode lasers are fabricated as mini- bars for reduced assembly costs. Gratings are integrated into the mini-bar, with each laser stripe emitting at a different wavelength. In this way, each emitter can be directed into a single bre via low-cost dielectric filters. Distributed-feedback narrow-stripe broad-area (DFB-NBA) lasers are promising candidates for these SBC sys- tems. We review here the design process and performance achieved, showing that DFB-NBA lasers with stripe width, W = 30 μm, successfully cut of higher-order lateral modes, improving BPP. Uniform, surface-etched, 80th-order Bragg gratings are used, with weak gratings essential for high e ciency. To date, such DFB-NBA sources operate with BPP BPP is half that of a DFB-BA lasers with W = 90 um. We conclude with a review of options for further performance improvements.

  9. CO Spectral Line Energy Distributions of Infrared-Luminous Galaxies and Active Galactic Nuclei

    Papadopoulos, Padeli P.; van der Werf, Paul; Isaak, Kate; Xilouris, Emmanuel M.

    2010-06-01

    We report on new sensitive CO J = 6-5 line observations of several luminous infrared galaxies (LIRGs; L IR(8-1000 μm) >~ 1011 L sun), 36% (8/22) of them ultraluminous infrared galaxies (ULIRGs) (L IR>1012 L sun), and two powerful local active galactic nuclei (AGNs)—the optically luminous QSO PG 1119+120 and the powerful radio galaxy 3C 293—using the James Clerk Maxwell Telescope on Mauna Kea in Hawaii. We combine these observations with existing low-J CO data and dust emission spectral energy distributions in the far-infrared-submillimeter from the literature to constrain the properties of the star-forming interstellar medium (ISM) in these systems. We then build the first local CO spectral line energy distributions (SLEDs) for the global molecular gas reservoirs that reach up to high J-levels. These CO SLEDs are neither biased by strong lensing (which affects many of those constructed for high-redshift galaxies), nor suffer from undersampling of CO-bright regions (as most current high-J CO observations of nearby extended systems do). We find: (1) a significant influence of dust optical depths on the high-J CO lines, suppressing the J = 6-5 line emission in some of the most IR-luminous LIRGs, (2) low global CO line excitation possible even in vigorously star-forming systems, (3) the first case of a shock-powered high-excitation CO SLED in the radio galaxy 3C 293 where a powerful jet-ISM interaction occurs, and (4) unusually highly excitated gas in the optically powerful QSO PG 1119+120. In Arp 220 and possibly other (U)LIRGs very faint CO J = 6-5 lines can be attributed to significant dust optical depths at short submillimeter wavelengths immersing those lines in a strong dust continuum, and also causing the C+ line luminosity deficit often observed in such extreme starbursts. Re-analysis of the CO line ratios available for submillimeter galaxies suggests that similar dust opacities also may be present in these high-redshift starbursts, with genuinely low

  10. CO SPECTRAL LINE ENERGY DISTRIBUTIONS OF INFRARED-LUMINOUS GALAXIES AND ACTIVE GALACTIC NUCLEI

    Papadopoulos, Padeli P.; Van der Werf, Paul; Isaak, Kate; Xilouris, Emmanuel M.

    2010-01-01

    We report on new sensitive CO J = 6-5 line observations of several luminous infrared galaxies (LIRGs; L IR (8-1000 μm) ∼> 10 11 L sun ), 36% (8/22) of them ultraluminous infrared galaxies (ULIRGs) (L IR >10 12 L sun ), and two powerful local active galactic nuclei (AGNs)-the optically luminous QSO PG 1119+120 and the powerful radio galaxy 3C 293-using the James Clerk Maxwell Telescope on Mauna Kea in Hawaii. We combine these observations with existing low-J CO data and dust emission spectral energy distributions in the far-infrared-submillimeter from the literature to constrain the properties of the star-forming interstellar medium (ISM) in these systems. We then build the first local CO spectral line energy distributions (SLEDs) for the global molecular gas reservoirs that reach up to high J-levels. These CO SLEDs are neither biased by strong lensing (which affects many of those constructed for high-redshift galaxies), nor suffer from undersampling of CO-bright regions (as most current high-J CO observations of nearby extended systems do). We find: (1) a significant influence of dust optical depths on the high-J CO lines, suppressing the J = 6-5 line emission in some of the most IR-luminous LIRGs, (2) low global CO line excitation possible even in vigorously star-forming systems, (3) the first case of a shock-powered high-excitation CO SLED in the radio galaxy 3C 293 where a powerful jet-ISM interaction occurs, and (4) unusually highly excitated gas in the optically powerful QSO PG 1119+120. In Arp 220 and possibly other (U)LIRGs very faint CO J = 6-5 lines can be attributed to significant dust optical depths at short submillimeter wavelengths immersing those lines in a strong dust continuum, and also causing the C + line luminosity deficit often observed in such extreme starbursts. Re-analysis of the CO line ratios available for submillimeter galaxies suggests that similar dust opacities also may be present in these high-redshift starbursts, with genuinely low

  11. Improved Frequency Fluctuation Model for Spectral Line Shape Calculations in Fusion Plasmas

    Ferri, S.; Calisti, A.; Mosse, C.; Talin, B.; Lisitsa, V.

    2010-01-01

    A very fast method to calculate spectral line shapes emitted by plasmas accounting for charge particle dynamics and effects of an external magnetic field is proposed. This method relies on a new formulation of the Frequency Fluctuation Model (FFM), which yields to an expression of the dynamic line profile as a functional of the static distribution function of frequencies. This highly efficient formalism, not limited to hydrogen-like systems, allows to calculate pure Stark and Stark-Zeeman line shapes for a wide range of density, temperature and magnetic field values, which is of importance in plasma physics and astrophysics. Various applications of this method are presented for conditions related to fusion plasmas.

  12. An Interferometric Spectral Line and Imaging Survey of VY Canis Majoris in the 345 GHz Band

    Kamiński, T.; Gottlieb, C. A.; Young, K. H.; Menten, K. M.; Patel, N. A.

    2013-12-01

    A spectral line survey of the oxygen-rich red supergiant VY Canis Majoris was made between 279 and 355 GHz with the Submillimeter Array (SMA). Two hundred twenty-three spectral features from 19 molecules (not counting isotopic species of some of them) were observed, including the rotational spectra of TiO, TiO2, and AlCl for the first time in this source. The parameters and an atlas of all spectral features are presented. Observations of each line with a synthesized beam of ~0.''9, reveal the complex kinematics and morphology of the nebula surrounding VY CMa. Many of the molecules are observed in high-lying rotational levels or in excited vibrational levels. From these, it was established that the main source of the submillimeter-wave continuum (dust) and the high-excitation molecular gas (the star) are separated by about 0.''15. Apparent coincidences between the molecular gas observed with the SMA, and some of the arcs and knots observed at infrared wavelengths and in the optical scattered light by the Hubble Space Telescope are identified. The observations presented here provide important constraints on the molecular chemistry in oxygen-dominated circumstellar environments and a deeper picture of the complex circumstellar environment of VY CMa.

  13. Electron-phonon coupling in solubilized LHC II complexes of green plants investigated by line-narrowing and temperature-dependent fluorescence spectroscopy

    Pieper, J K; Renger, G; Schödel, R; Voigt, J

    2001-01-01

    Line-narrowed and temperature-dependent fluorescence spectra are reported for the solubilized trimeric light-harvesting complex of Photosystem II (LHC II). Special attention has been paid to eliminate effects owing to reabsorption and to ensure that the line-narrowed fluorescence spectra are virtually unaffected by hole burning or scattering artifacts. Analysis of line-narrowed fluorescence spectra at 4.2 K indicates that the lowest Q//y-state of LHC II is characterized by weak electron-phonon coupling with a Huang-Rhys factor of similar to 0.9 and a broad and strongly asymmetric one- phonon profile with a peak frequency omega//m of 15 cm**-**1 and a width of Gamma = 105 cm**-**1. The 4.2 K fluorescence data are further consistent with the assignment of the lowest Q//y-state at similar to 680.0 nm and an inhomogeneous width of similar to 80 cm**- **1 gathered from a recent hole-burning study (Pieper et al. J. Phys. Chem. A 1999, 103, 2412). The temperature dependence of the fluorescence spectra of LHC II is s...

  14. New assignment of 14N NQR spectral lines for tetrazoles derivatives

    Mamadazizov, Sultonazar; Shelyapina, Marina G.; Kupriyanova, Galina S.; Mozzhukhin, George V.

    2018-04-01

    In recent years, considerable interest has been shown in the study of tetrazole derivatives, which attract attention as highly nitrogenous compounds for use as an isosteric substitutes for various functional groups that leads to creation of novel biologically active substances. NQR techniques, being sensitive to the local environment of 14N nuclei, provide great opportunities to study these new substances. To make investigation of complex compounds containing tetrazoles derivatives easier and more reliable a correctly assigned 14N NQR spectra of tetrazoles are required. Here we report on the results of our DFT B3LYP calculations of 14N NQR spectral parameters (quadrupole coupling constant Qcc and the asymmetry parameter of the electric field gradient η) for tetrazole, 5-aminotetrazole and 5-aminotetrazole monohydrate. It has been found that the commonly accepted assignment of the 14N NQR spectral lines for these molecules is incorrect. A new assignment for these molecules is proposed.

  15. In-Flight Spectral Calibration of the APEX Imaging Spectrometer Using Fraunhofer Lines

    Kuhlmann, Gerrit; Hueni, Andreas; Damm, Aalexander; Brunner, Dominik

    2015-11-01

    The Airborne Prism EXperiment (APEX) is an imaging spectrometer which allows to observe atmospheric trace gases such as nitrogen dioxide (NO2). Using a high resolution spectrum of solar Fraunhofer lines, APEX measurements collected during flight have been spectrally calibrated for centre wavelength positions (CW) and instrument slit function (ISF) and compared to the laboratory calibration. We find that CWs depend strongly on both across- and along-track position due to spectral smile and CWs dependency on ambient pressure. The width of the ISF is larger than estimated from the laboratory calibration but can be described by a linear scaling of the laboratory values. The ISF width depends on across- but not on along-track direction. The results demonstrate the importance of characterizing and monitoring the instrument performance during flight and will be used to improve the Empa APEX NO2 retrieval algorithm.

  16. The Gamma-Ray Emitting Radio-Loud Narrow-Line Seyfert 1 Galaxy PKS 2004-447 II. The Radio View

    Schulz, R.; Kreikenbohm, A.; Kadler, M.; Ojha, R.; Ros, E.; Stevens, J.; Edwards, P. G.; Carpenter, B.; Elsaesser, D.; Gehrels, N.; hide

    2016-01-01

    Context. gamma-ray-detected radio-loud narrow-line Seyfert 1 (gamma-NLS1) galaxies constitute a small but interesting sample of the gamma-ray-loud AGN. The radio-loudest gamma-NLS1 known, PKS2004447, is located in the southern hemisphere and is monitored in the radio regime by the multiwavelength monitoring programme TANAMI. Aims. We aim for the first detailed study of the radio morphology and long-term radio spectral evolution of PKS2004447, which are essential for understanding the diversity of the radio properties of gamma-NLS1s. Methods. The TANAMI VLBI monitoring program uses the Australian Long Baseline Array (LBA) and telescopes in Antarctica, Chile, New Zealand, and South Africa to monitor the jets of radio-loud active galaxies in the southern hemisphere. Lower resolution radio flux density measurements at multiple radio frequencies over four years of observations were obtained with the Australia Telescope Compact Array (ATCA). Results. The TANAMI VLBI image at 8.4GHz shows an extended one-sided jet with a dominant compact VLBI core. Its brightness temperature is consistent with equipartition, but it is an order of magnitude below other gamma-NLS1s with the sample value varying over two orders of magnitude. We find a compact morphology with a projected large-scale size 11 kpc and a persistent steep radio spectrum with moderate flux-density variability. Conclusions. PKS2004447 appears to be a unique member of the gamma-NLS1 sample. It exhibits blazar-like features, such as a flat featureless X-ray spectrum and a core-dominated, one-sided parsec-scale jet with indications for relativistic beaming. However, the data also reveal properties atypical for blazars, such as a radio spectrum and large-scale size consistent with compact-steep-spectrum (CSS) objects, which are usually associated with young radio sources. These characteristics are unique among all gamma-NLS1s and extremely rare among gamma-ray-loud AGN.

  17. Type 2 Active Galactic Nuclei with Double-peaked [O III] Lines. II. Single AGNs with Complex Narrow-line Region Kinematics are More Common than Binary AGNs

    Shen, Yue; Liu, Xin; Greene, Jenny E.; Strauss, Michael A.

    2011-07-01

    Approximately 1% of low-redshift (z interpreted as either due to kinematics, such as biconical outflows and/or disk rotation of the narrow line region (NLR) around single black holes, or due to the relative motion of two distinct NLRs in a merging pair of AGNs. Here, we report follow-up near-infrared (NIR) imaging and optical slit spectroscopy of 31 double-peaked [O III] type 2 AGNs drawn from the Sloan Digital Sky Survey (SDSS) parent sample presented in Liu et al. The NIR imaging traces the old stellar population in each galaxy, while the optical slit spectroscopy traces the NLR gas. These data reveal a mixture of origins for the double-peaked feature. Roughly 10% of our objects are best explained by binary AGNs at (projected) kpc-scale separations, where two stellar components with spatially coincident NLRs are seen. ~50% of our objects have [O III] emission offset by a few kpc, corresponding to the two velocity components seen in the SDSS spectra, but there are no spatially coincident double stellar components seen in the NIR imaging. For those objects with sufficiently high-quality slit spectra, we see velocity and/or velocity dispersion gradients in [O III] emission, suggestive of the kinematic signatures of a single NLR. The remaining ~40% of our objects are ambiguous and will need higher spatial resolution observations to distinguish between the two scenarios. Our observations therefore favor the kinematics scenario with a single AGN for the majority of these double-peaked [O III] type 2 AGNs. We emphasize the importance of combining imaging and slit spectroscopy in identifying kpc-scale binary AGNs, i.e., in no cases does one of these alone allow an unambiguous identification. We estimate that ~0.5%-2.5% of the z ~ 150 km s-1. Based in part on observations obtained with the 6.5 m Magellan telescopes located at Las Campanas Observatory, Chile, and with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research

  18. Atlas of Atomic Spectral Lines of Neptunium Emitted by Inductively Coupled Plasma

    DeKalb, E.L. and Edelson, M. C.

    1987-08-01

    Optical emission spectra from high-purity Np-237 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 230-700 nm wavelength range are presented along with general commentary on the methodology used in collecting the data. The Ames Laboratory Nuclear Safeguards and Security Program has been charged with the task of developing optical spectroscopic methods to analyze the composition of spent nuclear fuels. Such materials are highly radioactive even after prolonged 'cooling' and are chemically complex. Neptunium (Np) is a highly toxic by-product of nuclear power generation and is found, in low abundance, in spent nuclear fuels. This atlas of the optical emission spectrum of Np, as produced by an inductively coupled plasma (ICP) spectroscopic source, is part of a general survey of the ICP emission spectra of the actinide elements. The ICP emission spectrum of the actinides originates almost exclusively from the electronic relaxation of excited, singly ionized species. Spectral data on the Np ion emission spectrum (i.e., the Np II spectrum) have been reported by Tomkins and Fred [1] and Haaland [2]. Tomkins and Fred excited the Np II spectrum with a Cu spark discharge and identified 114 Np lines in the 265.5 - 436.3 nm spectral range. Haaland, who corrected some spectral line misidentifications in the work of Tomkins and Fred, utilized an enclosed Au spark discharge to excite the Np II spectrum and reported 203 Np lines within the 265.4 - 461.0 nm wavelength range.

  19. Atlas of Atomic Spectral Lines of Neptunium Emitted by an Inductively Coupled Plasma

    DeKalb, E.L.; Edelson, M.C.

    1987-01-01

    Optical emission spectra from high-purity Np-237 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 230-700 nm wavelength range are presented along with general commentary on the methodology used in collecting the data. The Ames Laboratory Nuclear Safeguards and Security Program has been charged with the task of developing optical spectroscopic methods to analyze the composition of spent nuclear fuels. Such materials are highly radioactive even after prolonged 'cooling' and are chemically complex. Neptunium (Np) is a highly toxic by-product of nuclear power generation and is found, in low abundance, in spent nuclear fuels. This atlas of the optical emission spectrum of Np, as produced by an inductively coupled plasma (ICP) spectroscopic source, is part of a general survey of the ICP emission spectra of the actinide elements. The ICP emission spectrum of the actinides originates almost exclusively from the electronic relaxation of excited, singly ionized species. Spectral data on the Np ion emission spectrum (i.e., the Np II spectrum) have been reported by Tomkins and Fred (1) and Haaland (2). Tomkins and Fred excited the Np II spectrum with a Cu spark discharge and identified 114 Np lines in the 265.5 - 436.3 nm spectral range. Haaland, who corrected some spectral line misidentifications in the work of Tomkins and Fred, utilized an enclosed Au spark discharge to excite the Np II spectrum and reported 203 Np lines within the 265.4 - 461.0 nm wavelength range.

  20. Coulomb field strength measurement by electro-optic spectral decoding system at the CALIFES beam line

    Pan, R; Lefevre, T; Gillepsie, WA; CERN. Geneva. ATS Department

    2016-01-01

    Electro-optic (EO) techniques are increasingly used for longitudinal bunch profile measurements. A bunch profile monitor, based on electro-optic spectral decoding(EOSD), has been developed and demonstrated on the CALIFES beam line at CERN. The EO response is analysed using a frequency domain description, and two methods for extraction of absolute Coulomb field strengths from the electron bunch are demonstrated. Measurements at field strengths up to 1.3 MV/m agree with the expectation based on independent charge measurements.

  1. PROBING THE SOLAR ATMOSPHERE USING OSCILLATIONS OF INFRARED CO SPECTRAL LINES

    Penn, M. J.; Schad, T.; Cox, E.

    2011-01-01

    Oscillations were observed across the whole solar disk using the Doppler shift and line center intensity of spectral lines from the CO molecule near 4666 nm with the National Solar Observatory's McMath/Pierce solar telescope. Power, coherence, and phase spectra were examined, and diagnostic diagrams reveal power ridges at the solar global mode frequencies to show that these oscillations are solar p-modes. The phase was used to determine the height of formation of the CO lines by comparison with the IR continuum intensity phase shifts as measured in Kopp et al.; we find that the CO line formation height varies from 425 km μ > 0.5. The velocity power spectra show that while the sum of the background and p-mode power increases with height in the solar atmosphere as seen in previous work, the power in the p-modes only (background subtracted) decreases with height. The CO line center intensity weakens in regions of stronger magnetic fields, as does the p-mode oscillation power. Across most of the solar surface the phase shift is larger than the expected value of 90 0 for an adiabatic atmosphere. We fit the phase spectra at different disk positions with a simple atmospheric model to determine that the acoustic cutoff frequency is about 4.5 mHz with only small variations, but that the thermal relaxation frequency drops significantly from 2.7 to 0 mHz at these heights in the solar atmosphere.

  2. Laboratory calibration of density-dependent lines in the extreme ultraviolet spectral region

    Lepson, J. K.; Beiersdorfer, P.; Gu, M. F.; Desai, P.; Bitter, M.; Roquemore, L.; Reinke, M. L.

    2012-05-01

    We have been making spectral measurements in the extreme ultraviolet (EUV) from different laboratory sources in order to investigate the electron density dependence of various astrophysically important emission lines and to test the atomic models underlying the diagnostic line ratios. The measurement are being performed at the Livermore EBIT-I electron beam ion trap, the National Spherical Torus Experiment (NSTX) at Princeton, and the Alcator C-Mod tokamak at the Massachusetts Institute of Technology, which together span an electron density of four orders of magnitude and which allow us to test the various models at high and low density limits. Here we present measurements of Fe XXII and Ar XIV, which include new data from an ultra high resolution (λ/Δλ >4000) spectrometer at the EBIT-I facility. We found good agreement between the measurements and modeling calculations for Fe XXII, but poorer agreement for Ar XIV.

  3. Spitzer spectral line mapping of the HH211 outflow

    Dionatos, Odyssefs; Nisini, Brunella; Cabrit, Sylvie

    2010-01-01

    of emission line diagnostics and an existing grid of molecular shock models. The physical properties of the warm gas are compared against other molecular jet tracers and to the results of a similar study towards the L1448-C outflow. Results: We have detected and mapped the v=0-0 S(0) - S(7) H2 lines and fine...... compared to solar abundances by a factor ~10-50. Conclusions: Spitzer spectral mapping observations reveal for the first time a cool H$_2$ component towards the CO jet of HH211 consistent with the CO material being fully molecular and warm at ~ 300 K. The maps also reveal for the first time the existence...... uncertainties on jet speed and shock conditions are too large for a definite conclusion....

  4. An Interferometric Spectral-Line and Imaging Survey of VY Canis Majoris in the 345 GHz Band

    Kaminski, T.; Gottlieb, C. A.; Young, K. H.; Menten, K. M.; Patel, N. A.

    2013-01-01

    A spectral line survey of the oxygen-rich red supergiant VY Canis Majoris was made between 279 and 355 GHz with the Submillimeter Array. Two hundred twenty three spectral features from 19 molecules (not counting isotopic species of some of them) were observed, including the rotational spectra of TiO, TiO2, and AlCl for the first time in this source. The parameters and an atlas of all spectral features is presented. Observations of each line with a synthesized beam of ~0.9 arcsec, reveal the c...

  5. Spectral radiance of strong lines in positive column mercury discharges with argon carrier gas

    Sansonetti, Craig J; Reader, Joseph

    2006-01-01

    The spectral radiance of the 185 and 254 nm lines in two positive column mercury discharge lamps was measured over a wide range of operating conditions. The lamps had internal diameters of 5 and 23 mm. Argon was used as a carrier gas. The lamps were operated with cold spot temperatures of 20, 40 and 60 0 C. At each of these temperatures, results were obtained for five currents ranging from 20 to 100 mA for the 5 mm lamp and from 200 to 1000 mA for the 23 mm lamp. For each current studied, results were determined for argon pressures ranging from 66.6 to 666 Pa (0.5 to 5.0 Torr) in the 5 mm lamp and 26.6 to 666 Pa (0.2 to 5.0 Torr) in the 23 mm lamp. An argon miniarc was used as the radiometric standard. By calibrating the spectral response of the optical system with a well-characterized mercury pencil lamp, results were obtained for 12 additional Hg lines from 289 to 579 nm. For the 23 mm lamp the electric field in the positive column was measured. For this lamp the radiated power as a percentage of input power was also determined. The results provide an experimental basis for validating computer models of Hg fluorescent lamp discharges

  6. On-line spectral diagnostic system for Dalian Coherent Light Source

    Li, Chaoyang; Wei, Shen; Du, Xuewei [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Du, Liangliang [National Synchrotron Radiation Laboratory, University of Science & Technology of China, Hefei, Anhui 230029 (China); Wang, Qiuping, E-mail: qiuping@ustc.edu.cn [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Zhang, Weiqing; Wu, Guorong; Dai, Dongxu [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Yang, Xueming, E-mail: xmyang@dicp.ac.cn [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)

    2015-05-21

    The Dalian Coherent Light Source (DCLS) is a Free electron laser (FEL) user facility currently under construction in the northeast of China. It is designed to work on high gain high harmonic principle with the capability of wavelength continuously tunable in the EUV regime of 50–150 nm. The light source has unique features such as the turntable radiation frequency, wide spectral range, high brightness and peak power, very short pulse time structure, etc. A key diagnostic task in DCLS is the on-line source spectral characteristic recording during the source development, and for the definition of the experimental conditions. For this purpose, an online grazing incidence spectrometer with a toroidal mirror and a variable-line-spacing plane grating is designed and presented in this paper to monitor each single FEL pulse. A circular stage is chosen to fit the focal curve and to realize the wavelength scanning. This scanning mechanics is simpler and stable. Resolving power (λ/Δλ) of this spectrometer is better than 12,000 in the whole wavelength range.

  7. On-line spectral diagnostic system for Dalian Coherent Light Source

    Li, Chaoyang; Wei, Shen; Du, Xuewei; Du, Liangliang; Wang, Qiuping; Zhang, Weiqing; Wu, Guorong; Dai, Dongxu; Yang, Xueming

    2015-01-01

    The Dalian Coherent Light Source (DCLS) is a Free electron laser (FEL) user facility currently under construction in the northeast of China. It is designed to work on high gain high harmonic principle with the capability of wavelength continuously tunable in the EUV regime of 50–150 nm. The light source has unique features such as the turntable radiation frequency, wide spectral range, high brightness and peak power, very short pulse time structure, etc. A key diagnostic task in DCLS is the on-line source spectral characteristic recording during the source development, and for the definition of the experimental conditions. For this purpose, an online grazing incidence spectrometer with a toroidal mirror and a variable-line-spacing plane grating is designed and presented in this paper to monitor each single FEL pulse. A circular stage is chosen to fit the focal curve and to realize the wavelength scanning. This scanning mechanics is simpler and stable. Resolving power (λ/Δλ) of this spectrometer is better than 12,000 in the whole wavelength range

  8. Spatiotemporal Evolution of Hanle and Zeeman Synthetic Polarization in a Chromospheric Spectral Line

    Carlin, E. S.; Bianda, M., E-mail: escarlin@irsol.es [Istituto Ricerche Solari Locarno, 6600, Locarno, Switzerland, associated to USI, Università della Svizzera Italiana (Switzerland)

    2017-07-01

    Due to the quick evolution of the solar chromosphere, its magnetic field cannot be inferred reliably without accounting for the temporal variations of its polarized light. This has been broadly overlooked in the modeling and interpretation of the polarization, due to technical problems (e.g., lack of temporal resolution or of time-dependent MHD solar models) and/or because many polarization measurements can apparently be explained without dynamics. Here, we show that the temporal evolution is critical for explaining the spectral-line scattering polarization because of its sensitivity to rapidly varying physical quantities and the possibility of signal cancellations and attenuation during extended time integration. For studying the combined effect of time-varying magnetic fields and kinematics, we solved the 1.5D non-LTE problem of the second kind in time-dependent 3D R-MHD solar models and synthesized the Hanle and Zeeman polarization in forward scattering for the chromospheric λ 4227 line. We find that the quiet-Sun polarization amplitudes depend on the periodicity and spectral coherence of the signal enhancements produced by kinematics, but that substantially larger linear polarization signals should exist all over the solar disk for short integration times. The spectral morphology of the polarization is discussed as a combination of Hanle, Zeeman, partial redistribution and dynamic effects. We give physical references for observations by degrading and characterizing our slit time series in different spatiotemporal resolutions. The implications of our results for the interpretation of the second solar spectrum and for the investigation of the solar atmospheric heatings are discussed.

  9. Utilizing the ratio and the summation of two spectral lines for estimation of optical depth: Focus on thick plasmas

    Rezaei, Fatemeh; Tavassoli, Seyed Hassan

    2016-11-01

    In this paper, a study is performed on the spectral lines of plasma radiations created from focusing of the Nd:YAG laser on Al standard alloys at atmospheric air pressure. A new theoretical method is presented to investigate the evolution of the optical depth of the plasma based on the radiative transfer equation, in LTE condition. This work relies on the Boltzmann distribution, lines broadening equations, and as well as the self-absorption relation. Then, an experimental set-up is devised to extract some of plasma parameters such as temperature from modified line ratio analysis, electron density from Stark broadening mechanism, line intensities of two spectral lines in the same order of ionization from similar species, and the plasma length from the shadowgraphy section. In this method, the summation and the ratio of two spectral lines are considered for evaluation of the temporal variations of the plasma parameters in a LIBS homogeneous plasma. The main advantage of this method is that it comprises the both of thin and thick laser induced plasmas without straight calculation of self-absorption coefficient. Moreover, the presented model can also be utilized for evaluation the transition of plasma from the thin condition to the thick one. The results illustrated that by measuring the line intensities of two spectral lines at different evolution times, the plasma cooling and the growth of the optical depth can be followed.

  10. Atomic structure calculations and identification of EUV and SXR spectral lines in Sr XXX

    Goyal, Arun; Khatri, Indu; Aggarwal, Sunny; Singh, A.K.; Mohan, Man

    2015-01-01

    We report an extensive theoretical study of atomic data for Sr XXX in a wide range with L-shell electron excitations to the M-shell. We have calculated energy levels, wave-function compositions and lifetimes for lowest 113 fine structure levels and wavelengths of an extreme Ultraviolet (EUV) and soft X-ray (SXR) transitions. We have employed multi-configuration Dirac Fock method (MCDF) approach within the framework of Dirac–Coulomb Hamiltonian including quantum electrodynamics (QED) and Breit corrections. We have also presented the radiative data for electric and magnetic dipole (E1, M1) and quadrupole (E2, M2) transitions from the ground state. We have made comparisons with available energy levels compiled by NIST and achieve good agreement. But due to inadequate data in the literature, analogous relativistic distorted wave calculations have also been performed using flexible atomic code (FAC) to assess the reliability and accuracy of our results. Additionally, we have provided new atomic data for Sr XXX which is not published elsewhere in the literature and we believe that our results may be beneficial in fusion plasma research and astrophysical investigations and applications. - Highlights: • 113 Lowest levels for Sr XXX are calculated. • Extreme Ultraviolet (EUV) and soft-X ray (SXR) spectral lines are identified. • Wavelengths of EUV and SXR spectral lines are reported. • E1, E2, M1 and M2 transition rates, oscillator strengths and lines strengths for lowest 113 levels are presented. • Lifetimes for lowest 113 fine structure levels are provided

  11. A Deep Chandra ACIS Study of NGC 4151. III. The Line Emission and Spectral Analysis of the Ionization Cone

    Wang, Junfeng; Fabbiano, Giuseppina; Elvis, Martin; Risaliti, Guido; Karovska, Margarita; Zezas, Andreas; Mundell, Carole G.; Dumas, Gaelle; Schinnerer, Eva

    2011-11-01

    This paper is the third in a series in which we present deep Chandra ACIS-S imaging spectroscopy of the Seyfert 1 galaxy NGC 4151, devoted to study its complex circumnuclear X-ray emission. Emission features in the soft X-ray spectrum of the bright extended emission (L 0.3-2 keV ~ 1040 erg s-1) at r > 130 pc (2'') are consistent with blended brighter O VII, O VIII, and Ne IX lines seen in the Chandra HETGS and XMM-Newton RGS spectra below 2 keV. We construct emission line images of these features and find good morphological correlations with the narrow-line region clouds mapped in [O III] λ5007. Self-consistent photoionization models provide good descriptions of the spectra of the large-scale emission, as well as resolved structures, supporting the dominant role of nuclear photoionization, although displacement of optical and X-ray features implies a more complex medium. Collisionally ionized emission is estimated to be lsim12% of the extended emission. Presence of both low- and high-ionization spectral components and extended emission in the X-ray image perpendicular to the bicone indicates leakage of nuclear ionization, likely filtered through warm absorbers, instead of being blocked by a continuous obscuring torus. The ratios of [O III]/soft X-ray flux are approximately constant (~15) for the 1.5 kpc radius spanned by these measurements, indicating similar relative contributions from the low- and high-ionization gas phases at different radial distances from the nucleus. If the [O III] and X-ray emission arise from a single photoionized medium, this further implies an outflow with a wind-like density profile. Using spatially resolved X-ray features, we estimate that the mass outflow rate in NGC 4151 is ~2 M ⊙ yr-1 at 130 pc and the kinematic power of the ionized outflow is 1.7 × 1041 erg s-1, approximately 0.3% of the bolometric luminosity of the active nucleus in NGC 4151.

  12. Fermi LAT Detection of a GeV Flare from the Radio-Loud Narrow-Line Sy1 1H 0323+342

    Carpenter, Bryce; Ojha, Roopesh

    2013-08-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with 1H 0323+342 (RA=03h24m41.1613s, Dec=+34d10m45.856s, J2000; Beasley et al. 2002, ApJS, 141, 13) at z= 0.061 (Marcha et al. 1996, MNRAS, 281, 425). This is the second nearest radio-loud Narrow-Line Seyfert 1 galaxy, a small and important class of gamma-ray loud AGN (Abdo et al.

  13. THE ALMA SPECTROSCOPIC SURVEY IN THE HUBBLE ULTRA DEEP FIELD: IMPLICATIONS FOR SPECTRAL LINE INTENSITY MAPPING AT MILLIMETER WAVELENGTHS AND CMB SPECTRAL DISTORTIONS

    Carilli, C. L.; Walter, F. [National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801 (United States); Chluba, J. [Jodrell Bank Centre for Astrophysics, University of Manchester, Oxford Road, M13 9PL (United Kingdom); Decarli, R. [Max-Planck Institute for Astronomy, D-69117 Heidelberg (Germany); Aravena, M. [Nucleo de Astronomia, Facultad de Ingenieria, Universidad Diego Portales, Av. Ejercito 441, Santiago (Chile); Wagg, J. [Square Kilometre Array Organisation, Lower Withington, Cheshire (United Kingdom); Popping, G. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748, Garching (Germany); Cortes, P. [Joint ALMA Observatory—ESO, Av. Alonso de Cordova, 3104, Santiago (Chile); Hodge, J. [Leiden Observatory, Leiden University, Niels Bohrweg 2, NL2333 RA Leiden (Netherlands); Weiss, A. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Bertoldi, F. [Argelander Institute for Astronomy, University of Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); Riechers, D., E-mail: ccarilli@aoc.nrao.edu [Cornell University, 220 Space Sciences Building, Ithaca, NY 14853 (United States)

    2016-12-10

    We present direct estimates of the mean sky brightness temperature in observing bands around 99 and 242 GHz due to line emission from distant galaxies. These values are calculated from the summed line emission observed in a blind, deep survey for spectral line emission from high redshift galaxies using ALMA (the ALMA spectral deep field observations “ASPECS” survey). In the 99 GHz band, the mean brightness will be dominated by rotational transitions of CO from intermediate and high redshift galaxies. In the 242 GHz band, the emission could be a combination of higher order CO lines, and possibly [C ii] 158 μ m line emission from very high redshift galaxies ( z  ∼ 6–7). The mean line surface brightness is a quantity that is relevant to measurements of spectral distortions of the cosmic microwave background, and as a potential tool for studying large-scale structures in the early universe using intensity mapping. While the cosmic volume and the number of detections are admittedly small, this pilot survey provides a direct measure of the mean line surface brightness, independent of conversion factors, excitation, or other galaxy formation model assumptions. The mean surface brightness in the 99 GHZ band is: T{sub B}  = 0.94 ± 0.09 μ K. In the 242 GHz band, the mean brightness is: T{sub B}  = 0.55 ± 0.033 μ K. These should be interpreted as lower limits on the average sky signal, since we only include lines detected individually in the blind survey, while in a low resolution intensity mapping experiment, there will also be the summed contribution from lower luminosity galaxies that cannot be detected individually in the current blind survey.

  14. Survey for C-Band High Spectral Lines with the Arecibo Telescope

    Tan, Wei Siang

    High-mass stars have masses greater than 8 solar masses and are the main source of heavy elements such as iron in the interstellar medium. This type of stars form in giant molecular clouds. Studying the molecular environment in star-forming regions is crucial to understand the physical structure and conditions that lead to the formation of high-mass stars. This thesis presents observations conducted with the 305m Arecibo Telescope in Puerto Rico of twelve high-mass star forming regions. Every source was observed in multiple transitions of molecular species including CH, CH3OH, H2CS, and OH lines, and a radio recombination line. The observations were conducted with the C-Band High receiver of the Arecibo Telescope in the frequency range of 6.0 to 7.4GHz. The goals of the observations were to investigate the detectability of different molecular species (including new possible molecular masers) and obtain high sensitivity observations of the 6.7GHz CH3OH line to detect absorption and use it as a probe of the kinematics of the molecular material with respect to the ionized gas. Among the results of the observations, we report detection of 6.7GHz CH3OH masers toward nine regions, OH masers toward five sources, 6.7GHz CH3OH absorption toward four sources (including tentative detections), and detection of H2CS toward the star forming region G34.26+0.15. We also found a variable and recurrent 6.7GHz CH3OH maser in G45.12+0.13. The 6.7GHz CH 3OH and 6278.65MHz H2CS absorption lines were modeled using the radiative transfer code RADEX to investigate the physical conditions of the molecular clouds responsible for the absorption lines. Our analysis of the absorption lines supports the interpretation that the spectral lines are tracing molecular envelopes of HII regions. In the case of 6.7GHz CH 3OH absorption, our results and data from an extensive literature review indicate that absorption is rare, but that a population of 6.7GHz CH 3OH absorbers may be present at levels

  15. CO Spectral Line Energy Distributions in Galactic Sources: Empirical Interpretation of Extragalactic Observations

    Indriolo, Nick; Bergin, E. A. [Department of Astronomy, University of Michigan, 1085 S. University Avenue, Ann Arbor, MI 48109 (United States); Goicoechea, J. R.; Cernicharo, J. [Grupo de Astrofísica Molecular, Instituto de Ciencia de Materiales de Madrid (CSIC) E-28049 Madrid (Spain); Gerin, M.; Gusdorf, A. [LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, École normale supérieure, F-75005, Paris (France); Lis, D. C. [LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, F-75014, Paris (France); Schilke, P., E-mail: nindriolo@stsci.edu [I. Physikalisches Institut der Universität zu Köln, Zülpicher Str. 77, D-50937 Köln (Germany)

    2017-02-10

    The relative populations in rotational transitions of CO can be useful for inferring gas conditions and excitation mechanisms at work in the interstellar medium. We present CO emission lines from rotational transitions observed with Herschel /HIFI in the star-forming cores Orion S, Orion KL, Sgr B2(M), and W49N. Integrated line fluxes from these observations are combined with those from Herschel /PACS observations of the same sources to construct CO spectral line energy distributions (SLEDs) from 5≤ J{sub u} ≤ 48. These CO SLEDs are compared to those reported in other galaxies, with the intention of empirically determining which mechanisms dominate excitation in such systems. We find that CO SLEDs in Galactic star-forming cores cannot be used to reproduce those observed in other galaxies, although the discrepancies arise primarily as a result of beam filling factors. The much larger regions sampled by the Herschel beams at distances of several megaparsecs contain significant amounts of cooler gas, which dominate the extragalactic CO SLEDs, in contrast to observations of Galactic star-forming regions, which are focused specifically on cores containing primarily hot molecular gas.

  16. The influence of collisions with noble gases on spectral lines of hydrogen isotopes

    Hermans, P.

    1982-01-01

    In this thesis measurements on the collisional broadening of the depolarized Rayleigh line and the broadening and shift of the rotational Raman lines (radiative transitions 0→2, 1→3 and 2→4) are presented. The experiments were carried out as a function of temperature from 23 K to 311 K for three systems, viz. H 2 -He, H 2 -Ne and H 2 -Ar. Also results of close coupled calculations on the broadening and shift are presented as a function of temperature for the four spectral lines mentioned. The calculations were performed for two systems, viz H 2 -He and H 2 -Ne. For the system H 2 -He two interaction potentials were used as a starting point, and a comparison between these potentials was made. Now that it is possible to do computations on effects related to the non-spherical interaction of the pure hydrogen isotopes, the availability of experimental data is of great importance. Many experiments on these effects have been performed over the last two decades, but their results are scattered throughout the literature. Therefore, in the last chapter of this thesis the experimental results for the pure hydrogen isotopes and in mixtures with noble gases are compiled to serve as comparing material for the calculations. The presentation is such that a direct comparison with calculations is facilitated. (Auth.)

  17. The Bernese atmospheric multiple catalog access tool (BEAMCAT): a tool for users of popular spectral line catalogs

    Feist, D.G.Dietrich G.

    2004-01-01

    Users of spectroscopic data bases in the microwave region quickly realize that each existing spectral line catalog provide only part of the information that they would like to have. As a workaround for this problem, several merged spectral line data bases have been created by different groups. However, these merged data bases are usually very specific for a certain application and are difficult to maintain. The BEAMCAT data base takes a totally new approach that makes it possible to generate merged spectral line catalogs from any number of source catalogs in multiple user-defined formats. The current version of BEAMCAT contains the complete JPL and HITRAN catalog. Other catalogs like GEISA will soon be included, too. As a first application of the BEAMCAT data base, the author conducted a thorough intercomparison of spectral parameters for all the transitions that the JPL catalog and HITRAN have in common. The intercomparison shows that the spectral parameters in the catalogs are by no means identical. While the difference in center frequency is usually small, the differences in line intensity reach from almost exact match to discrepancies of several orders of magnitude. While it cannot be ruled out that some of the lines were matched incorrectly, this intercomparison might be helpful to identify problems with the original catalogs

  18. First application of the spectral difference method for lifetime measurements of doppler attenuated line shapes

    Duckwitz, Hannah [Institut fuer Kernphysik, Koeln Univ. (Germany); Petkov, Pavel [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria)

    2016-07-01

    In this new approach to lifetime measurements via Doppler attenuated line shapes, the spectra of a feeding f and a deexciting transition d of the level of interest are used to determine the lifetime without any lineshape analysis of the feeding transition (direct or indirect). Similarly to the DDC method, the decay function λ{sub d}n{sub d}(t) of the deexciting transition is determined. The feeding of the level is included via the spectral difference of the two successive decays. Consequently, the determined lifetime is the real lifetime. After transforming both transitions into the same energy region, their spectral difference D(v{sub θ}) = S{sub d}(v{sub θ})-S{sub f}(v{sub θ}) = ∫{sub 0}{sup ∞}(∂P{sub θ}(t,v{sub θ}))/(∂t)n{sub d}(t) dt, is solved for n{sub d}(t). Dividing n{sub d}(t) by the decay function λ{sub d}n{sub d}(t) should yield a constant τ value for the level lifetime as a function of the time t. After the development and test of the procedure in 2015, it is now applied for the first time. Two level lifetimes are determined in {sup 86}Sr for the 2{sup +}{sub 2} and the 2{sup +}{sub 3} levels.

  19. Studying the complex spectral line profiles in the spectra of hot emission stars and quasars .

    Danezis, E.; Lyratzi, E.; Antoniou, A.; Popović, L. Č.; Dimitrijević, M. S.

    Some Hot Emission Stars and AGNs present peculiar spectral line profiles which are due to DACs and SACs phenomena. The origin and the mechanisms which are responsible for the creation of DACs/SACs is an important problem that has been studied by many researchers. This paper is a review of our efforts to study the origin and the mechanisms of these phenomena. At first we present a theoretic ad hoc picture for the structure of the plasma that surrounds the specific category of hot emission stars that present DACs or SACs. Then we present the mathematical model that we constructed, which is based on the properties of the above ad hoc theoretical structure. Finally, we present some results from our statistical studies that prove the consistency of our model with the classical physical theory.

  20. Towards realistic modelling of spectral line formation - lessons learnt from red giants

    Lind, Karin

    2015-08-01

    Many decades of quantitative spectroscopic studies of red giants have revealed much about the formation histories and interlinks between the main components of the Galaxy and its satellites. Telescopes and instrumentation are now able to deliver high-resolution data of superb quality for large stellar samples and Galactic archaeology has entered a new era. At the same time, we have learnt how simplifying physical assumptions in the modelling of spectroscopic data can bias the interpretations, in particular one-dimensional homogeneity and local thermodynamic equilibrium (LTE). I will present lessons learnt so far from non-LTE spectral line formation in 3D radiation-hydrodynamic atmospheres of red giants, the smaller siblings of red supergiants.

  1. Semifragile Speech Watermarking Based on Least Significant Bit Replacement of Line Spectral Frequencies

    Mohammad Ali Nematollahi

    2017-01-01

    Full Text Available There are various techniques for speech watermarking based on modifying the linear prediction coefficients (LPCs; however, the estimated and modified LPCs vary from each other even without attacks. Because line spectral frequency (LSF has less sensitivity to watermarking than LPC, watermark bits are embedded into the maximum number of LSFs by applying the least significant bit replacement (LSBR method. To reduce the differences between estimated and modified LPCs, a checking loop is added to minimize the watermark extraction error. Experimental results show that the proposed semifragile speech watermarking method can provide high imperceptibility and that any manipulation of the watermark signal destroys the watermark bits since manipulation changes it to a random stream of bits.

  2. Oxygen, nitrogen and air broadening of HCN spectral lines at terahertz frequencies

    Yang Chun; Buldyreva, Jeanna; Gordon, Iouli E.; Rohart, Francois; Cuisset, Arnaud; Mouret, Gael; Bocquet, Robin; Hindle, Francis

    2008-01-01

    The room-temperature nitrogen- and oxygen-broadening coefficients of hydrogen cyanide spectral lines have been measured in the 0.5-3 THz (17-100 cm -1 ) frequency range (purely rotational transitions with 5≤J≤36) by a continuous-wave terahertz spectrometer based on a photomixing source. An improved version of the Robert and Bonamy semiclassical formalism has been used to calculate the oxygen-broadening coefficients and resulted in a good agreement with these measurements. The nitrogen and oxygen data are combined to provide the air-broadening coefficients as used by the HITRAN database. A significant difference is observed between the measured and tabulated values for transitions with high values of the rotational quantum number. A new polynomial representation is suggested for inclusion in HITRAN. A similar polynomial expression has been derived for the nitrogen broadening to aid the studies of Titan's atmosphere

  3. Oxygen, nitrogen and air broadening of HCN spectral lines at terahertz frequencies

    Yang Chun [Laboratoire de Physico-Chimie de l' Atmosphere, UMR CNRS 8101, Universite du Littoral Cote d' Opale, 189A Av. Maurice Schumann, 59140 Dunkerque (France); Buldyreva, Jeanna [Institut UTINAM, UMR CNRS 6213, Universite de Franche-Comte, 16, Route de Gray, 25030 Besancon Cedex (France); Gordon, Iouli E. [Harvard-Smithsonian Center for Astrophysics, Atomic and Molecular Physics Division, 60 Garden Street, Cambridge, MA 02138-1516 (United States); Rohart, Francois [Laboratoire de Physique des Lasers, Atomes et Molecules, UMR CNRS 8523, Batiment P5-135, Universite de Lille 1, 59655 Villeneuve d' Ascq Cedex (France); Cuisset, Arnaud; Mouret, Gael; Bocquet, Robin [Laboratoire de Physico-Chimie de l' Atmosphere, UMR CNRS 8101, Universite du Littoral Cote d' Opale, 189A Av. Maurice Schumann, 59140 Dunkerque (France); Hindle, Francis [Laboratoire de Physico-Chimie de l' Atmosphere, UMR CNRS 8101, Universite du Littoral Cote d' Opale, 189A Av. Maurice Schumann, 59140 Dunkerque (France)], E-mail: francis.hindle@univ-littoral.fr

    2008-11-15

    The room-temperature nitrogen- and oxygen-broadening coefficients of hydrogen cyanide spectral lines have been measured in the 0.5-3 THz (17-100 cm{sup -1}) frequency range (purely rotational transitions with 5{<=}J{<=}36) by a continuous-wave terahertz spectrometer based on a photomixing source. An improved version of the Robert and Bonamy semiclassical formalism has been used to calculate the oxygen-broadening coefficients and resulted in a good agreement with these measurements. The nitrogen and oxygen data are combined to provide the air-broadening coefficients as used by the HITRAN database. A significant difference is observed between the measured and tabulated values for transitions with high values of the rotational quantum number. A new polynomial representation is suggested for inclusion in HITRAN. A similar polynomial expression has been derived for the nitrogen broadening to aid the studies of Titan's atmosphere.

  4. Measurement of transition probabilities in Kr II UV and visible spectral lines

    Mar, S; Val, J A del; RodrIguez, F; Pelaez, R J; Gonzalez, V R; Gonzalo, A B; Castro, A de; Aparicio, J A

    2006-01-01

    This work reports an extensive collection of 120 atomic transition probabilities of Kr II lines in the spectral region 350-720 nm, all of them measured in an emission experiment. For many of them, these are the first data up to the authors' knowledge. Relative intensity measurements have been obtained on a pulsed discharge lamp and the absolute A ki -values have been calculated by considering the available data from the literature as reference for the plasma temperature diagnosis. Excitation temperature (14 000-28 000 K) has been determined by using the Boltzmann-plot method. The plasma electron density (0.2-0.8 x 10 23 m -3 ) has been determined by two-wavelength interferometry. This work extends a previous one already published by our laboratory [1, 2]. Comparisons have also been made with previous literature values

  5. SPECTRAL LINE SURVEY TOWARD MOLECULAR CLOUDS IN THE LARGE MAGELLANIC CLOUD

    Nishimura, Yuri; Watanabe, Yoshimasa; Yamamoto, Satoshi [Department of Physics, the University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Shimonishi, Takashi [Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramakiazaaoba 6-3, Aoba-ku, Sendai, Miyagi, 980-8578 (Japan); Sakai, Nami [RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Aikawa, Yuri [Center for Computational Sciences, The University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Kawamura, Akiko [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo, 181-8588 (Japan)

    2016-02-20

    Spectral line survey observations of seven molecular clouds in the Large Magellanic Cloud (LMC) have been conducted in the 3 mm band with the Mopra 22 m telescope to reveal chemical compositions in low metallicity conditions. Spectral lines of fundamental species such as CS, SO, CCH, HCN, HCO{sup +}, and HNC are detected in addition to those of CO and {sup 13}CO, while CH{sub 3}OH is not detected in any source and N{sub 2}H{sup +} is marginally detected in two sources. The molecular-cloud scale (10 pc scale) chemical composition is found to be similar among the seven sources regardless of different star formation activities, and hence, it represents the chemical composition characteristic of the LMC without influences by star formation activities. In comparison with chemical compositions of Galactic sources, the characteristic features are (1) deficient N-bearing molecules, (2) abundant CCH, and (3) deficient CH{sub 3}OH. Feature (1) is due to a lower elemental abundance of nitrogen in the LMC, whereas features (2) and (3) seem to originate from extended photodissociation regions and warmer temperature in cloud peripheries due to a lower abundance of dust grains in the low metallicity condition. In spite of general resemblance of chemical abundances among the seven sources, the CS/HCO{sup +} and SO/HCO{sup +} ratios are found to be slightly higher in a quiescent molecular cloud. An origin of this trend is discussed in relation to possible depletion of sulfur along the molecular cloud formation.

  6. Star formation relations and CO spectral line energy distributions across the J-ladder and redshift

    Greve, T. R. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Leonidaki, I.; Xilouris, E. M. [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, GR-15236 Penteli (Greece); Weiß, A.; Henkel, C. [Max-Planck-Institut fur Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Zhang, Z.-Y. [UK Astronomy Technology Centre, Science and Technology Facilities Council, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Van der Werf, P.; Meijerink, R. [Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden (Netherlands); Aalto, S. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Observatory, 43994 Onsala (Sweden); Armus, L.; Díaz-Santos, T. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Evans, A. S. [Astronomy Department, University of Virginia Charlottesville, VA 22904 (United States); Fischer, J. [Naval Research Laboratory, Remote Sensing Division, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China); González-Alfonso, E. [Universidad de Alcala de Henares, Departamento de Fśica, Campus Universitario, E-28871 Alcalá de Henares, Madrid (Spain); Harris, A. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Naylor, D. A. [Institute for Space Imaging Science, Department of Physics and Astronomy, University of Lethbridge, Lethbridge, AB T1K 3M4 (Canada); Smith, H. A. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spaans, M., E-mail: t.greve@ucl.ac.uk [Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen (Netherlands); and others

    2014-10-20

    We present FIR [50-300 μm]–CO luminosity relations (i.e., log L{sub FIR}=αlog L{sub CO}{sup ′}+β) for the full CO rotational ladder from J = 1-0 up to J = 13-12 for a sample of 62 local (z ≤ 0.1) (Ultra) Luminous Infrared Galaxies (LIRGs; L {sub IR[8-1000} {sub μm]} > 10{sup 11} L {sub ☉}) using data from Herschel SPIRE-FTS and ground-based telescopes. We extend our sample to high redshifts (z > 1) by including 35 submillimeter selected dusty star forming galaxies from the literature with robust CO observations, and sufficiently well-sampled FIR/submillimeter spectral energy distributions (SEDs), so that accurate FIR luminosities can be determined. The addition of luminous starbursts at high redshifts enlarge the range of the FIR–CO luminosity relations toward the high-IR-luminosity end, while also significantly increasing the small amount of mid-J/high-J CO line data (J = 5-4 and higher) that was available prior to Herschel. This new data set (both in terms of IR luminosity and J-ladder) reveals linear FIR–CO luminosity relations (i.e., α ≅ 1) for J = 1-0 up to J = 5-4, with a nearly constant normalization (β ∼ 2). In the simplest physical scenario, this is expected from the (also) linear FIR–(molecular line) relations recently found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However, from J = 6-5 and up to the J = 13-12 transition, we find an increasingly sublinear slope and higher normalization constant with increasing J. We argue that these are caused by a warm (∼100 K) and dense (>10{sup 4} cm{sup –3}) gas component whose thermal state is unlikely to be maintained by star-formation-powered far-UV radiation fields (and thus is no longer directly tied to the star formation rate). We suggest that mechanical heating (e.g., supernova-driven turbulence and shocks), and not cosmic rays, is the more likely source of energy for

  7. Modeling the Broad-Band Emission from the Gamma-Ray Emitting Narrow-Line Seyfert-1 Galaxies 1H 0323+342 and B2 0954+25A

    Arrieta-Lobo, Maialen; Boisson, Catherine; Zech, Andreas

    2017-01-01

    Prior to the Fermi-LAT era, only two classes of Active Galactic Nuclei (AGN) were thought to harbor relativistic jets that radiate up to gamma-ray energies: blazars and radio galaxies. The detection of variable gamma-ray emission from Narrow Line Seyfert 1 (NLSy1) galaxies has put them on the spotlight as a new class of gamma-ray emitting AGN. In this respect, gamma-ray emitting NLSy1s seem to be situated between blazars (dominated by non-thermal emission) and Seyferts (accretion disc dominated). In this work, we model the Spectral Energy Distribution (SED) of two gamma-loud NLSy1s, 1H 0323+342 and B2 0954+25A, during quiescent and flaring episodes via a multi-component radiative model that features a relativistic jet and external photon fields from the torus, disc, corona and Broad Line Region (BLR). We find that the interpretation of the high-energy emission of jetted NLSy1s requires taking into account Inverse Compton emission from particles in the relativistic jet that interact with external photon fields. Minimal changes are applied to the model parameters to transition from average to flaring states. In this scenario, the observed variability is explained mainly by means of changes in the jet density and Doppler factor.

  8. Modeling the Broad-Band Emission from the Gamma-Ray Emitting Narrow-Line Seyfert-1 Galaxies 1H 0323+342 and B2 0954+25A

    Arrieta-Lobo, Maialen; Boisson, Catherine; Zech, Andreas, E-mail: maialen.arrieta@obspm.fr [Laboratoire Univers et Theories, Observatoire de Paris, CNRS, Université Paris-Diderot, PSL Research University, Meudon (France)

    2017-12-08

    Prior to the Fermi-LAT era, only two classes of Active Galactic Nuclei (AGN) were thought to harbor relativistic jets that radiate up to gamma-ray energies: blazars and radio galaxies. The detection of variable gamma-ray emission from Narrow Line Seyfert 1 (NLSy1) galaxies has put them on the spotlight as a new class of gamma-ray emitting AGN. In this respect, gamma-ray emitting NLSy1s seem to be situated between blazars (dominated by non-thermal emission) and Seyferts (accretion disc dominated). In this work, we model the Spectral Energy Distribution (SED) of two gamma-loud NLSy1s, 1H 0323+342 and B2 0954+25A, during quiescent and flaring episodes via a multi-component radiative model that features a relativistic jet and external photon fields from the torus, disc, corona and Broad Line Region (BLR). We find that the interpretation of the high-energy emission of jetted NLSy1s requires taking into account Inverse Compton emission from particles in the relativistic jet that interact with external photon fields. Minimal changes are applied to the model parameters to transition from average to flaring states. In this scenario, the observed variability is explained mainly by means of changes in the jet density and Doppler factor.

  9. DISCOVERY OF DRAMATIC OPTICAL VARIABILITY IN SDSS J1100+4421: A PECULIAR RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXY?

    Tanaka, Masaomi [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Morokuma, Tomoki; Doi, Mamoru; Kikuchi, Yuki [Institute of Astronomy, School of Science, University of Tokyo, Mitaka, Tokyo 181-0015 (Japan); Itoh, Ryosuke [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Akitaya, Hiroshi; Tanaka, Yasuyuki T.; Kawabata, Koji S. [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Tominaga, Nozomu [Department of Physics, Faculty of Science and Engineering, Konan University, Kobe, Hyogo 658-8501 (Japan); Saito, Yoshihiko; Kawai, Nobuyuki [Department of Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Stawarz, Łukasz [Institute of Space and Astronautical Science, JAXA, Sagamihara, Kanagawa 252-5210 (Japan); Gandhi, Poshak [Department of Physics, Durham University, Durham DH1-3LE (United Kingdom); Ali, Gamal; Essam, Ahmad; Hamed, Gamal [National Research Institute of Astronomy and Geophysics, Helwan, Cairo (Egypt); Aoki, Tsutomu [Kiso Observatory, Institute of Astronomy, School of Science, The University of Tokyo, Kiso, Nagano 397-0101 (Japan); Contreras, Carlos; Hsiao, Eric Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Iwata, Ikuru, E-mail: masaomi.tanaka@nao.ac.jp [Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States); and others

    2014-10-01

    We present our discovery of dramatic variability in SDSS J1100+4421 by the high-cadence transient survey Kiso Supernova Survey. The source brightened in the optical by at least a factor of three within about half a day. Spectroscopic observations suggest that this object is likely a narrow-line Seyfert 1 galaxy (NLS1) at z = 0.840, however, with unusually strong narrow emission lines. The estimated black hole mass of ∼10{sup 7} M {sub ☉} implies bolometric nuclear luminosity close to the Eddington limit. SDSS J1100+4421 is also extremely radio-loud, with a radio loudness parameter of R ≅ 4 × 10{sup 2}-3 × 10{sup 3}, which implies the presence of relativistic jets. Rapid and large-amplitude optical variability of the target, reminiscent of that found in a few radio- and γ-ray-loud NLS1s, is therefore produced most likely in a blazar-like core. The 1.4 GHz radio image of the source shows an extended structure with a linear size of about 100 kpc. If SDSS J1100+4421 is a genuine NLS1, as suggested here, this radio structure would then be the largest ever discovered in this type of active galaxies.

  10. Spectrally narrow, long-term stable optical frequency reference based on a Eu3+:Y2SiO5 crystal at cryogenic temperature.

    Chen, Qun-Feng; Troshyn, Andrei; Ernsting, Ingo; Kayser, Steffen; Vasilyev, Sergey; Nevsky, Alexander; Schiller, Stephan

    2011-11-25

    Using an ultrastable continuous-wave laser at 580 nm we performed spectral hole burning of Eu(3+):Y(2)SiO(5) at a very high spectral resolution. The essential parameters determining the usefulness as a macroscopic frequency reference, linewidth, temperature sensitivity, and long-term stability, were characterized using a H-maser stabilized frequency comb. Spectral holes with a linewidth as low as 6 kHz were observed and the upper limit of the drift of the hole frequency was determined to be 5±3 mHz/s. We discuss the necessary requirements for achieving ultrahigh stability in laser frequency stabilization to these spectral holes.

  11. Unexpected temporal evolution of atomic spectral lines of aluminum in a laser induced breakdown spectroscopy experiment

    Saad, Rawad; L'Hermite, Daniel; Bousquet, Bruno

    2014-01-01

    The temporal evolution of the laser induced breakdown (LIBS) signal of a pure aluminum sample was studied under nitrogen and air atmospheres. In addition to the usual decrease of signal due to plasma cooling, unexpected temporal evolutions were observed for a spectral lines of aluminum, which revealed the existence of collisional energy transfer effects. Furthermore, molecular bands of AlN and AlO were observed in the LIBS spectra, indicating recombination of aluminum with the ambient gas. Within the experimental conditions reported in this study, both collisional energy transfer and recombination processes occurred around 1.5 μs after the laser shot. This highlights the possible influence of collisional and chemical effects inside the plasma that can play a role on LIBS signals. - Highlights: • Persistence of two Al I lines related to the 61,844 cm −1 energy level only under nitrogen atmosphere. • Collisional energy transfer effect exists between aluminum and nitrogen. • Observation of molecular band of AlN (under nitrogen) and AlO (under air) after a delay time of 1.5 µs. • 20% of oxygen in air is sufficient to annihilate both the collisional energy transfer effect and the AlN molecular formation

  12. Plasma density characterization at SPARC-LAB through Stark broadening of Hydrogen spectral lines

    Filippi, F.; Anania, M.P.; Bellaveglia, M.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Di Giovenale, D.; Di Pirro, G.; Ferrario, M.; Mostacci, A.; Palumbo, L.; Pompili, R.; Shpakov, V.; Vaccarezza, C.; Villa, F.; Zigler, A.

    2016-01-01

    Plasma-based acceleration techniques are of great interest for future, compact accelerators due to their high accelerating gradient. Both particle-driven and laser-driven Plasma Wakefield Acceleration experiments are foreseen at the SPARC-LAB Test Facility (INFN National Laboratories of Frascati, Italy), with the aim to accelerate high-brightness electron beams. In order to optimize the efficiency of the acceleration in the plasma and preserve the quality of the accelerated beam, the knowledge of the plasma electron density is mandatory. The Stark broadening of the Hydrogen spectral lines is one of the candidates used to characterize plasma density. The implementation of this diagnostic for plasma-based experiments at SPARC-LAB is presented. - Highlights: • Stark broadening of Hydrogen lines has been measured to determine plasma density. • Plasma density diagnostic tool for plasma-based experiments at SPARC-LAB is presented. • Plasma density in tapered laser triggered ablative capillary discharge was measured. • Results of plasma density measurements in ablative capillaries are shown.

  13. Plasma density characterization at SPARC-LAB through Stark broadening of Hydrogen spectral lines

    Filippi, F., E-mail: francesco.filippi@roma1.infn.it [Dipartimento di Scienze di Base e Applicate per l' Ingegneria (SBAI), ‘Sapienza’ Università di Roma, Via A. Scarpa 14-16, 00161 Roma (Italy); INFN-Roma1, Piazzale Aldo Moro, 2 00161 Roma (Italy); Anania, M.P.; Bellaveglia, M.; Biagioni, A.; Chiadroni, E. [Laboratori Nazionali di Frascati, INFN, Via E. Fermi, Frascati (Italy); Cianchi, A. [Dipartimento di Fisica, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Di Giovenale, D.; Di Pirro, G.; Ferrario, M. [Laboratori Nazionali di Frascati, INFN, Via E. Fermi, Frascati (Italy); Mostacci, A.; Palumbo, L. [Dipartimento di Scienze di Base e Applicate per l' Ingegneria (SBAI), ‘Sapienza’ Università di Roma, Via A. Scarpa 14-16, 00161 Roma (Italy); INFN-Roma1, Piazzale Aldo Moro, 2 00161 Roma (Italy); Pompili, R.; Shpakov, V.; Vaccarezza, C.; Villa, F. [Laboratori Nazionali di Frascati, INFN, Via E. Fermi, Frascati (Italy); Zigler, A. [Hebrew University of Jerusalem, Jerusalem 91904 (Israel)

    2016-09-01

    Plasma-based acceleration techniques are of great interest for future, compact accelerators due to their high accelerating gradient. Both particle-driven and laser-driven Plasma Wakefield Acceleration experiments are foreseen at the SPARC-LAB Test Facility (INFN National Laboratories of Frascati, Italy), with the aim to accelerate high-brightness electron beams. In order to optimize the efficiency of the acceleration in the plasma and preserve the quality of the accelerated beam, the knowledge of the plasma electron density is mandatory. The Stark broadening of the Hydrogen spectral lines is one of the candidates used to characterize plasma density. The implementation of this diagnostic for plasma-based experiments at SPARC-LAB is presented. - Highlights: • Stark broadening of Hydrogen lines has been measured to determine plasma density. • Plasma density diagnostic tool for plasma-based experiments at SPARC-LAB is presented. • Plasma density in tapered laser triggered ablative capillary discharge was measured. • Results of plasma density measurements in ablative capillaries are shown.

  14. Critically Evaluated Energy Levels, Spectral Lines, Transition Probabilities, and Intensities of Singly Ionized Vanadium (V ii)

    Saloman, Edward B. [Dakota Consulting, Inc., 1110 Bonifant Street, Suite 310, Silver Spring, MD 20910 (United States); Kramida, Alexander [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

    2017-08-01

    The energy levels, observed spectral lines, and transition probabilities of singly ionized vanadium, V ii, have been compiled. The experimentally derived energy levels belong to the configurations 3 d {sup 4}, 3 d {sup 3} ns ( n  = 4, 5, 6), 3 d {sup 3} np , and 3 d {sup 3} nd ( n  = 4, 5), 3 d {sup 3}4 f , 3 d {sup 2}4 s {sup 2}, and 3 d {sup 2}4 s 4 p . Also included are values for some forbidden lines that may be of interest to the astrophysical community. Experimental Landé g -factors and leading percentages for the levels are included when available, as well as Ritz wavelengths calculated from the energy levels. Wavelengths and transition probabilities are reported for 3568 and 1896 transitions, respectively. From the list of observed wavelengths, 407 energy levels are determined. The observed intensities, normalized to a common scale, are provided. From the newly optimized energy levels, a revised value for the ionization energy is derived, 118,030(60) cm{sup −1}, corresponding to 14.634(7) eV. This is 130 cm{sup −1} higher than the previously recommended value from Iglesias et al.

  15. No Photon Left Behind: How Billions of Spectral Lines are Transforming Planetary Sciences

    Villanueva, Geronimo L.

    2014-06-01

    With the advent of realistic potential energy surface (PES) and dipole moment surface (DMS) descriptions, theoretically computed linelists can now synthesize accurate spectral parameters for billions of spectral lines sampling the untamed high-energy molecular domain. Being the initial driver for these databases the characterization of stellar spectra, these theoretical databases, in combination with decades of precise experimental studies (nicely compiled in community databases such as HITRAN and GEISA), are leading to unprecedented precisions in the characterization of planetary atmospheres. Cometary sciences are among the most affected by this spectroscopic revolution. Even though comets are relatively cold bodies (T˜100 K), their infrared molecular emission is mainly defined by non-LTE solar fluorescence induced by a high-energy source (Sun, T˜5600 K). In order to interpret high-resolution spectra of comets acquired with extremely powerful telescopes (e.g., Keck, VLT, NASA-IRTF), we have developed advanced non-LTE fluorescence models that integrate the high-energy dynamic range of ab-initio databases (e.g., BT2, VTT, HPT2, BYTe, TROVE) and the precision of laboratory and semi-empirical compilations (e.g., HITRAN, GEISA, CDMS, WKMC, SELP, IUPAC). These new models allow us to calculate realistic non-LTE pumps, cascades, branching-ratios, and emission rates for a broad range of excitation regimes for H2O, HDO, HCN, HNC and NH3. We have implemented elements of these compilations to the study of Mars spectra, and we are now exploring its application to modeling non-LTE emission in exoplanets. In this presentation, we present application of these advanced models to interpret highresolution spectra of comets, Mars and exoplanets.

  16. TIMASSS: the IRAS 16293-2422 millimeter and submillimeter spectral survey. I. Observations, calibration, and analysis of the line kinematics

    Caux, E.; Kahane, C.; Castets, A.; Coutens, A.; Ceccarelli, C.; Bacmann, A.; Bisschop, S.; Bottinelli, S.; Comito, C.; Helmich, F. P.; Lefloch, B.; Parise, B.; Schilke, P.; Tielens, A. G. G. M.; van Dishoeck, E.; Vastel, C.; Wakelam, V.; Walters, A.

    Context. Unbiased spectral surveys are powerful tools to study the chemistry and the physics of star forming regions, because they can provide a complete census of the molecular content and the observed lines probe the physical structure of the source. Aims. While unbiased surveys at the millimeter

  17. Stark broadening of resonant Cr II 3d5-3d44p spectral lines in hot stellar atmospheres

    Simić, Z.; Dimitrijević, M. S.; Sahal-Bréchot, S.

    2013-07-01

    New Stark broadening parameters of interest for the astrophysical, laboratory and technological plasma modelling, investigations and analysis for nine resonant Cr II multiplets have been determined within the semiclassical perturbation approach. In order to demonstrate one possibility for their usage in astrophysical plasma research, obtained results have been applied to the analysis of the Stark broadening influence on stellar spectral line shapes.

  18. On the Origin of the Flare Emission in IRIS ’ SJI 2832 Filter:Balmer Continuum or Spectral Lines?

    Kleint, Lucia; Krucker, Säm [University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch (Switzerland); Heinzel, Petr [Astronomical Institute, The Czech Academy of Sciences, Fričova 298, 25165 Ondřejov (Czech Republic)

    2017-03-10

    Continuum (“white-light,” WL) emission dominates the energetics of flares. Filter-based observations, such as the IRIS SJI 2832 filter, show WL-like brightenings during flares, but it is unclear whether the emission arises from real continuum emission or enhanced spectral lines, possibly turning into emission. The difficulty in filter-based observations, contrary to spectral observations, is to determine which processes contribute to the observed brightening during flares. Here we determine the contribution of the Balmer continuum and the spectral line emission to IRIS ’ SJI 2832 emission by analyzing the appropriate passband in simultaneous IRIS NUV spectra. We find that spectral line emission can contribute up to 100% to the observed slitjaw images (SJI) emission, that the relative contributions usually temporally vary, and that the highest SJI enhancements that are observed are most likely because of the Balmer continuum. We conclude that care should be taken when calling SJI 2832 a continuum filter during flares, because the influence of the lines on the emission can be significant.

  19. On the Origin of the Flare Emission in IRIS ’ SJI 2832 Filter:Balmer Continuum or Spectral Lines?

    Kleint, Lucia; Krucker, Säm; Heinzel, Petr

    2017-01-01

    Continuum (“white-light,” WL) emission dominates the energetics of flares. Filter-based observations, such as the IRIS SJI 2832 filter, show WL-like brightenings during flares, but it is unclear whether the emission arises from real continuum emission or enhanced spectral lines, possibly turning into emission. The difficulty in filter-based observations, contrary to spectral observations, is to determine which processes contribute to the observed brightening during flares. Here we determine the contribution of the Balmer continuum and the spectral line emission to IRIS ’ SJI 2832 emission by analyzing the appropriate passband in simultaneous IRIS NUV spectra. We find that spectral line emission can contribute up to 100% to the observed slitjaw images (SJI) emission, that the relative contributions usually temporally vary, and that the highest SJI enhancements that are observed are most likely because of the Balmer continuum. We conclude that care should be taken when calling SJI 2832 a continuum filter during flares, because the influence of the lines on the emission can be significant.

  20. A tunable narrow-line-width multi-wavelength Er-doped fiber laser based on a high birefringence fiber ring mirror and an auto-tracking filter

    Jia, Xiu-jie; Liu, Yan-ge; Si, Li-bin; Guo, Zhan-cheng; Fu, Sheng-gui; Kai, Gui-yun; Dong, Xiao-yi

    2008-01-01

    A novel multi-wavelength erbium-doped fiber laser operating in C-band is proposed and successfully demonstrated. The wavelength interval between the wavelengths is about 0.22 nm. The 3 dB bandwidth of the laser is about 0.012 nm, and the output power reaches 4.8 mW. By using a high birefringence fiber ring mirror (HiBi-FLM) and a tunable FBG, the laser realizes switchable and tunable characteristic. The mode hopping can be effectively prevented. Moreover, this laser can improve wavelength stability significantly by taking advantage of an un-pumped Er3+-doped fiber at the standing-wave section. The laser can operate in stable narrow-line-width with single-, dual-wavelength, and unstable triple-wavelength output at room temperature.

  1. RECEIVER OPERATING CHARACTERISTICS MEASURE FOR THE RECOGNITION OF STUTTERING DYSFLUENCIES USING LINE SPECTRAL FREQUENCIES

    Nahrul Khair Alang Rashid

    2017-05-01

    Full Text Available Stuttering is a motor-speech disorder, having common features with other motor control disorders such as dystonia, Parkinson’s disease and Tourette’s syndrome. Stuttering results from complex interactions between factors such as motor, language, emotional and genetic. This study used Line Spectral Frequency (LSF for the feature extraction, while using three classifiers for the identification purpose, Multilayer Perceptron (MLP, Recurrent Neural Network (RNN and Radial Basis Function (RBF. The UCLASS (University College London Archive of Stuttered Speech release 1 was used as database in this research. These recordings were from people of ages 12y11m to 19y5m, who were referred to clinics in London for assessment of their stuttering. The performance metrics used for interpreting the results are sensitivity, accuracy, precision and misclassification rate. Only M1 and M2 had below 100% sensitivity for RBF. The sensitivity of M1 was found to be between 40 & 60%, therefore categorized as moderate, while that of M2 falls between 60 & 80%, classed as substantial. Overall, RBF outperforms the two other classifiers, MLP and RNN for all the performance metrics considered.

  2. Voigt equivalent widths and spectral-bin single-line transmittances: Exact expansions and the MODTRAN®5 implementation

    Berk, Alexander

    2013-03-01

    Exact expansions for Voigt line-shape total, line-tail and spectral bin equivalent widths and for Voigt finite spectral bin single-line transmittances have been derived in terms of optical depth dependent exponentially-scaled modified Bessel functions of integer order and optical depth independent Fourier integral coefficients. The series are convergent for the full range of Voigt line-shapes, from pure Doppler to pure Lorentzian. In the Lorentz limit, the expansion reduces to the Ladenburg and Reiche function for the total equivalent width. Analytic expressions are derived for the first 8 Fourier coefficients for pure Lorentzian lines, for pure Doppler lines and for Voigt lines with at most moderate Doppler dependence. A strong-line limit sum rule on the Fourier coefficients is enforced to define an additional Fourier coefficient and to optimize convergence of the truncated expansion. The moderate Doppler dependence scenario is applicable to and has been implemented in the MODTRAN5 atmospheric band model radiative transfer software. Finite-bin transmittances computed with the truncated expansions reduce transmittance residuals compared to the former Rodgers-Williams equivalent width based approach by ∼2 orders of magnitude.

  3. ON THE ANTI-CORRELATION BETWEEN SPECTRAL LINE BROADENING AND INTENSITY IN CORONAL STRUCTURES OBSERVED WITH EIS

    Scott, J. T.; Martens, P. C. H.

    2011-01-01

    The advance in spectral resolution of the Extreme Ultraviolet Imaging (EIS) spectrometer on board Hinode has allowed for more detailed analysis of coronal spectral lines. Large line broadening and blueshifted velocities have been found in the periphery of active region (AR) cores and near the footpoints of coronal loops. This line broadening is yet to be understood. We study the correlation of intensity and line width for entire ARs and sub-regions selected to include coronal features. The results show that although a slight positive correlation can be found when considering whole images, many sub-regions have a negative correlation between intensity and line width. Sections of a coronal loop display some of the largest anti-correlations found for this study with the increased line broadening occurring directly adjacent to the footpoint section of the loop structure, not at the footpoint itself. The broadened lines may be due to a second Doppler-shifted component that is separate from the main emitting feature such as a coronal loop, but related in their excitation. The small size of these features forces the considerations of investigator and instrumental effects. Preliminary analyses are shown that indicate the possibility of a point-spread function that is not azimuthally symmetric and may affect velocity and line profile measurements.

  4. On the influence of density and temperature fluctuations on the formation of spectral lines in stellar atmospheres

    Stahlberg, J.

    1985-01-01

    A method taking into account the influence of temperature and density fluctuations generated by the velocity field in stellar atmospheres on the formation of spectral lines is presented. The influenced line profile is derived by exchanging the values in a static atmosphere by a mean value and a fluctuating one. The correlations are calculated with the help of the well-know hydrodynamic eqs. It results, that in normal stellar atmospheres the visual lines are only very weakly influenced by such fluctuations due to the small values of the gradients of the pressure and density and of the velocity dispersion. (author)

  5. Experimental determination of the Stark broadening of Cu I spectral lines in a plasma of a capillary discharge

    Sandolache, G.; Zoita, V.; Bauchire, M.; Le Menn, E.; Gentils, F.; Fleurier, C.

    2001-01-01

    Copper lines are frequently observed in various types of plasma device and industrial plasmas and then it is desirable to develop methods of plasma diagnostics using the emission spectrum of copper lines. The aim of this work is to create a database for the neutral copper spectral lines directly usable for the diagnostic of plasmas with metal vapors. An experimental device has been developed to create a metal plasma having the required metrological properties to facilitate the spectroscopic measurements. A capillary discharge technique has been used to create a plasma jet representing a radially symmetric light source. The copper-hydrogen plasma jet was produced by the ablation of the capillary wall consisting of a copper-embedded elastomer. The plasma jet was observed side-on using the high-resolution spectrometers equipped with ICCD detectors. The 2D square matrix ICCD detectors have permitted the observation of cross sections of the plasma jet. The high-speed time resolved camera equipped with interference filters has been used to check the cylindrical shape and the homogeneity of the plasma jet. The electron density of the plasma jet was obtained by using the H α spectral line of the hydrogen component plasma. The temperature was determined by applying the relative intensity method to the measured intensities of the neutral copper spectral lines emitted by the plasma jet. The hydrogen and copper lines were broadened principally by the Stark effect. The measured temperatures were about 15,000 K and the electron density of about 2x10 17 cm -3 . The results of the Stark broadening of the neutral cooper concerned particularly the lines 453.9 nm, 465.1 nm, 515.3 nm and 529.2 nm. (authors)

  6. Spectral lines and characteristic of temporal variations in photoionized plasmas induced with laser-produced plasma extreme ultraviolet source

    Saber, I.; Bartnik, A.; Wachulak, P.; Skrzeczanowski, W.; Jarocki, R.; Fiedorowicz, H.

    2017-11-01

    Spectral lines for Kr/Ne/H2 photoionized plasma in the ultraviolet and visible (UV/Vis) wavelength ranges have been created using a laser-produced plasma (LPP) EUV source. The source is based on a double-stream gas puff target irradiated with a commercial Nd:YAG laser. The laser pulses were focused onto a gas stream, injected into a vacuum chamber synchronously with the EUV pulses. Spectral lines from photoionization in neutral Kr/Ne/H2 and up to few charged states were observed. The intense emission lines were associated with the Kr transition lines. Experimental and theoretical investigations on intensity variations for some ionic lines are presented. A decrease in the intensity with the delay time between the laser pulse and the spectrum acquisition was revealed. Electron temperature and electron density in the photoionized plasma have been estimated from the characteristic emission lines. Temperature was obtained using Boltzmann plot method, assuming that the population density of atoms and ions are considered in a local thermodynamic equilibrium (LTE). Electron density was calculated from the Stark broadening profile. The temporal evaluation of the plasma and the way of optimizing the radiation intensity of LPP EUV sources is discussed.

  7. Silhouette and spectral line profiles in the special modification of the Kerr black hole geometry generated by quintessential fields

    Schee, Jan; Stuchlik, Zdenek [Silesian University in Opava, Faculty of Philosophy and Science, Institute of Physics and Research Centre for Theoretical Physics and Astrophysics, Opava (Czech Republic)

    2016-11-15

    We study optical effects in quintessential Kerr black hole spacetimes corresponding to the limiting case of the equation-of-state parameter ω{sub q} = -1/3 of the quintessence. In dependence on the dimensionless quintessential field parameter c, we determine the black hole silhouette and the spectral line profiles of Keplerian disks generated in this special quintessential Kerr geometry, representing an extension of the general modifications of the Kerr geometry introduced recently by Ghasemi-Nodehi and Bambi (Eur. Phys. J. C 56:290, 2016). We demonstrate that due to the influence of the parameter c, the silhouette is almost homogeneously enlarged, and the spectral line profiles are redshifted with almost conserved shape. (orig.)

  8. WHY IS NON-THERMAL LINE BROADENING OF SPECTRAL LINES IN THE LOWER TRANSITION REGION OF THE SUN INDEPENDENT OF SPATIAL RESOLUTION?

    De Pontieu, B.; Martinez-Sykora, J.; McIntosh, S.; Peter, H.; Pereira, T. M. D.

    2015-01-01

    Spectral observations of the solar transition region (TR) and corona show broadening of spectral lines beyond what is expected from thermal and instrumental broadening. The remaining non-thermal broadening is significant (5–30 km s −1 ) and correlated with intensity. Here we study spectra of the TR Si iv 1403 Å line obtained at high resolution with the Interface Region Imaging Spectrograph (IRIS). We find that the large improvement in spatial resolution (0.″33) of IRIS compared to previous spectrographs (2″) does not resolve the non-thermal line broadening which, in most regions, remains at pre-IRIS levels of about 20 km s −1 . This invariance to spatial resolution indicates that the processes behind the broadening occur along the line-of-sight (LOS) and/or on spatial scales (perpendicular to the LOS) smaller than 250 km. Both effects appear to play a role. Comparison with IRIS chromospheric observations shows that, in regions where the LOS is more parallel to the field, magneto-acoustic shocks driven from below impact the TR and can lead to significant non-thermal line broadening. This scenario is supported by MHD simulations. While these do not show enough non-thermal line broadening, they do reproduce the long-known puzzling correlation between non-thermal line broadening and intensity. This correlation is caused by the shocks, but only if non-equilibrium ionization is taken into account. In regions where the LOS is more perpendicular to the field, the prevalence of small-scale twist is likely to play a significant role in explaining the invariance and correlation with intensity. (letters)

  9. On increasing the spectral efficiency and transmissivity in the data transmission channel on the spacecraft-ground tracking station line

    Andrianov, M. N.; Kostenko, V. I.; Likhachev, S. F.

    2018-01-01

    The algorithms for achieving a practical increase in the rate of data transmission on the space-craft-ground tracking station line has been considered. This increase is achieved by applying spectral-effective modulation techniques, the technology of orthogonal frequency compression of signals using millimeterrange radio waves. The advantages and disadvantages of each of three algorithms have been revealed. A significant advantage of data transmission in the millimeter range has been indicated.

  10. Welcome to the 21st International Conference on Spectral Line Shapes

    2012-12-01

    organizing committee of the conference has not forgotten about the cultural and tourism significance of the host city, with Hermitage and the Russian Museum, memorial museums of Pushkin and Dostoevsky, Mariinsky and Mikhailovsky Theaters being only a few of the many places to visit. Early June is the time of white nights, the best time to visit the environs of St. Petersburg with its many imperial palaces and parks, and attend multiple music and theater festivals. This is just the right time to take a break from physics overall and spectral line shapes in particular. On behalf of the Rector's Office let me wish the Conference every success, and do not forget to take some time out to enjoy your visit. Welcome! Professor N G Skvortsov Vice-Rector for Research St. Petersburg University

  11. STRONG UV AND X-RAY VARIABILITY OF THE NARROW LINE SEYFERT 1 GALAXY WPVS 007-ON THE NATURE OF THE X-RAY LOW STATE

    Grupe, Dirk; Barlow, Brad N. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Komossa, S. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Scharwaechter, Julia [Research School of Astronomy and Astrophysics, Australian National University, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia); Dietrich, Matthias [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Leighly, Karen M.; Lucy, Adrian, E-mail: dxg35@psu.edu, E-mail: julia.scharwaechter@obspm.fr, E-mail: leighly@nhn.ou.edu [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States)

    2013-10-01

    We report on multi-wavelength observations of the X-ray transient Narrow Line Seyfert 1 (NLS1) galaxy WPVS 007. The galaxy was monitored with Swift between 2005 October and 2013 July, after it had previously undergone a dramatic drop in its X-ray flux. For the first time, we are able to repeatedly detect this NLS1 in X-rays again. This increased number of detections in the last couple of years may suggest that the strong absorber that has been found in this active galactic nucleus (AGN) is starting to become leaky and may eventually disappear. The X-ray spectra obtained for WPVS 007 are all consistent with a partial covering absorber model. A spectrum based on the data during the extreme low X-ray flux states shows that the absorption column density is of the order of 4 Multiplication-Sign 10{sup 23} cm{sup -2} with a covering fraction of 95%. WPVS 007 also displays one of the strongest UV variabilities seen in NLS1s. The UV continuum variability anti-correlates with the optical/UV slope {alpha}{sub UV}, which suggests that the variability may be primarily due to reddening. The UV variability timescales are consistent with moving dust ''clouds'' located beyond the dust sublimation radius of R{sub sub} Almost-Equal-To 20 lt-days. We present for the first time near-infrared JHK data of WPVS 007, which reveal a rich emission-line spectrum. Recent optical spectroscopy does not indicate significant variability in the broad permitted and Fe II emission lines, implying that the ionizing continuum seen by those gas clouds has not significantly changed over the last decades. All X-ray and UV observations are consistent with a scenario in which an evolving broad absorption line (BAL) flow obscures the continuum emission. As such, WPVS 007 is an important target for our understanding of BAL flows in low-mass AGNs.

  12. IDEN2-A program for visual identification of spectral lines and energy levels in optical spectra of atoms and simple molecules

    Azarov, V. I.; Kramida, A.; Vokhmentsev, M. Ya.

    2018-04-01

    The article describes a Java program that can be used in a user-friendly way to visually identify spectral lines observed in complex spectra with theoretically predicted transitions between atomic or molecular energy levels. The program arranges various information about spectral lines and energy levels in such a way that line identification and determination of positions of experimentally observed energy levels become much easier tasks that can be solved fast and efficiently.

  13. MINUTE-SCALE RAPID VARIABILITY OF THE OPTICAL POLARIZATION IN THE NARROW-LINE SEYFERT 1 GALAXY PMN J0948+0022

    Itoh, Ryosuke; Tanaka, Yasuyuki T.; Fukazawa, Yasushi; Kawaguchi, Kenji; Takaki, Katsutoshi; Ueno, Issei [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Kawabata, Koji S.; Moritani, Yuki; Uemura, Makoto; Akitaya, Hiroshi; Yoshida, Michitoshi; Ohsugi, Takashi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Hanayama, Hidekazu; Miyaji, Takeshi [Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, 1024-1 Arakawa, Ishigaki, Okinawa 907-0024 (Japan); Kawai, Nobuyuki, E-mail: itoh@hep01.hepl.hiroshima-u.ac.jp [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2013-09-20

    We report on optical photopolarimetric results of the radio-loud narrow-line Seyfert 1 (RL-NLSy1) galaxy PMN J0948+0022 on 2012 December to 2013 February triggered by flux enhancements in the near infrared and γ-ray bands. With the one-shot polarimetry of the Hiroshima One-shot Wide field Polarimeter installed on the Kanata Telescope, we detected very rapid variability in the polarized-flux (PF) light curve on MJD 56281 (2012 December 20). The rise and decay times were about 140 s and 180 s, respectively. The polarization degree (PD) reached 36% ± 3% at the peak of the short-duration pulse, while the polarization angle remained almost constant. In addition, temporal profiles of the total flux and PD showed highly variable but well correlated behavior and discrete correlation function analysis revealed that no significant time lag of more than 10 minutes was present. The high PD and minute-scale variability in PF provides clear evidence of synchrotron radiation from a very compact emission region of ∼10{sup 14} cm size with a highly ordered magnetic field. Such micro-variability of polarization is also observed in several blazar jets, but its complex relation between total flux and PD are explained by a multi-zone model in several blazars. The implied single emission region in PMN J0948+0022 might reflect a difference of jets between RL-NLSy1s and blazars.

  14. VERY LONG BASELINE ARRAY IMAGING OF PARSEC-SCALE RADIO EMISSIONS IN NEARBY RADIO-QUIET NARROW-LINE SEYFERT 1 GALAXIES

    Doi, Akihiro [The Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuou-ku, Sagamihara, Kanagawa 252-5210 (Japan); Asada, Keiichi; Inoue, Makoto [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Fujisawa, Kenta [The Research Institute of Time Studies, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi 753-8511 (Japan); Nagai, Hiroshi; Hagiwara, Yoshiaki [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Wajima, Kiyoaki, E-mail: akihiro.doi@vsop.isas.jaxa.jp [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China)

    2013-03-01

    We conducted Very Long Baseline Array (VLBA) observations of seven nearby narrow-line Seyfert 1 (NLS1) galaxies at 1.7 GHz ({lambda}18 cm) with milliarcsecond resolution. This is the first systematic very long baseline interferometry study focusing on the central parsec-scale regions of radio-quiet NLS1s. Five of the seven were detected at a brightness temperature of {approx}> 5 Multiplication-Sign 10{sup 6} K and contain radio cores with high brightness temperatures of >6 Multiplication-Sign 10{sup 7} K, indicating a nonthermal process driven by jet-producing central engines as in radio-loud NLS1s and other active galactic nucleus classes. VLBA images of MRK 1239, MRK 705, and MRK 766 exhibit parsec-scale jets with clear linear structures. A large portion of the radio power comes from diffuse emission components that are distributed within the nuclear regions ({approx}< 300 pc), which is a common characteristic throughout the observed NLS1s. Jet kinetic powers limited by the Eddington limit may be insufficient to allow the jets to escape to kiloparsec scales for these radio-quiet NLS1s with low-mass black holes of {approx}< 10{sup 7} M {sub Sun }.

  15. Determination of Seed Soundness in Conifers Cryptomeria japonica and Chamaecyparis obtusa Using Narrow-Multiband Spectral Imaging in the Short-Wavelength Infrared Range

    Matsuda, Osamu; Hara, Masashi; Tobita, Hiroyuki; Yazaki, Kenichi; Nakagawa, Toshinori; Shimizu, Kuniyoshi; Uemura, Akira; Utsugi, Hajime

    2015-01-01

    Regeneration of planted forests of Cryptomeria japonica (sugi) and Chamaecyparis obtuse (hinoki) is the pressing importance to the forest administration in Japan. Low seed germination rate of these species, however, has hampered low-cost production of their seedlings for reforestation. The primary cause of the low germinability has been attributed to highly frequent formation of anatomically unsound seeds, which are indistinguishable from sound germinable seeds by visible observation and other common criteria such as size and weight. To establish a method for sound seed selection in these species, hyperspectral imaging technique was used to identify a wavelength range where reflectance spectra differ clearly between sound and unsound seeds. In sound seeds of both species, reflectance in a narrow waveband centered at 1,730 nm, corresponding to a lipid absorption band in the short-wavelength infrared (SWIR) range, was greatly depressed relative to that in adjacent wavebands on either side. Such depression was absent or less prominent in unsound seeds. Based on these observations, a reflectance index SQI, abbreviated for seed quality index, was formulated using reflectance at three narrow SWIR wavebands so that it represents the extent of the depression. SQI calculated from seed area-averaged reflectance spectra and spatial distribution patterns of pixelwise SQI within each seed area were both proven as reliable criteria for sound seed selection. Enrichment of sound seeds was accompanied by an increase in germination rate of the seed lot. Thus, the methods described are readily applicable toward low-cost seedling production in combination with single seed sowing technology. PMID:26083366

  16. Intensities, broadening and narrowing parameters in the ν3 band of methane

    Es-sebbar, Et-touhami; Farooq, Aamir

    2014-01-01

    The P-branch of methane's ν3 band is probed to carry out an extensive study of the 2905-2908cm-1 infrared spectral region. Absolute line intensities as well as N2-, O2-, H2-, He-, Ar- and CO2-broadening coefficients are determined for nine transitions at room temperature. Narrowing parameters due to the Dicke effect have also been investigated. A narrow emission line-width (~0.0001cm-1) difference-frequency-generation (DFG) laser system is used as the tunable light source. To retrieve the CH4 spectroscopic parameters, Voigt and Galatry profiles were used to simulate the measured line shape of the individual transitions.

  17. The strongest spectral lines of stable elements with other interfering elements in compiled and plotted version

    Bauer, M.; Weitkamp, C.

    1977-01-01

    The strongest spectra lines of the 85 stable chemical elements have been compiled and plotted along with lines from other elements that may interfere in applications like spectroscopic multielement analysis. For each line a wavelength range of +- 0.25 A.U. around the line of interest has been considered. The tables contain the wavelength, intensity and assignment to an ionization state of the emitting atom, the plots visualize the lines with a doppler broadening corresponding to 8,000 K. (orig.) [de

  18. Full-zone spectral envelope function formalism for the optimization of line and point tunnel field-effect transistors

    Verreck, Devin, E-mail: devin.verreck@imec.be; Groeseneken, Guido [imec, Kapeldreef 75, 3001 Leuven (Belgium); Department of Electrical Engineering, KU Leuven, 3001 Leuven (Belgium); Verhulst, Anne S.; Mocuta, Anda; Collaert, Nadine; Thean, Aaron [imec, Kapeldreef 75, 3001 Leuven (Belgium); Van de Put, Maarten; Magnus, Wim [imec, Kapeldreef 75, 3001 Leuven (Belgium); Department of Physics, Universiteit Antwerpen, 2020 Antwerpen (Belgium); Sorée, Bart [imec, Kapeldreef 75, 3001 Leuven (Belgium); Department of Physics, Universiteit Antwerpen, 2020 Antwerpen (Belgium); Department of Electrical Engineering, KU Leuven, 3001 Leuven (Belgium)

    2015-10-07

    Efficient quantum mechanical simulation of tunnel field-effect transistors (TFETs) is indispensable to allow for an optimal configuration identification. We therefore present a full-zone 15-band quantum mechanical solver based on the envelope function formalism and employing a spectral method to reduce computational complexity and handle spurious solutions. We demonstrate the versatility of the solver by simulating a 40 nm wide In{sub 0.53}Ga{sub 0.47}As lineTFET and comparing it to p-n-i-n configurations with various pocket and body thicknesses. We find that the lineTFET performance is not degraded compared to semi-classical simulations. Furthermore, we show that a suitably optimized p-n-i-n TFET can obtain similar performance to the lineTFET.

  19. Improved phase sensitivity in spectral domain phase microscopy using line-field illumination and self phase-referencing

    Yaqoob, Zahid; Choi, Wonshik; Oh, Seungeun; Lue, Niyom; Park, Yongkeun; Fang-Yen, Christopher; Dasari, Ramachandra R.; Badizadegan, Kamran; Feld, Michael S.

    2010-01-01

    We report a quantitative phase microscope based on spectral domain optical coherence tomography and line-field illumination. The line illumination allows self phase-referencing method to reject common-mode phase noise. The quantitative phase microscope also features a separate reference arm, permitting the use of high numerical aperture (NA > 1) microscope objectives for high resolution phase measurement at multiple points along the line of illumination. We demonstrate that the path-length sensitivity of the instrument can be as good as 41 pm/Hz, which makes it suitable for nanometer scale study of cell motility. We present the detection of natural motions of cell surface and two-dimensional surface profiling of a HeLa cell. PMID:19550464

  20. Hydrogen Atom Collision Processes in Cool Stellar Atmospheres: Effects on Spectral Line Strengths and Measured Chemical Abundances in Old Stars

    Barklem, Paul S

    2012-01-01

    The precise measurement of the chemical composition of stars is a fundamental problem relevant to many areas of astrophysics. State-of-the-art approaches attempt to unite accurate descriptions of microphysics, non-local thermodynamic equilibrium (non-LTE) line formation and 3D hydrodynamical model atmospheres. In this paper I review progress in understanding inelastic collisions of hydrogen atoms with other species and their influence on spectral line formation and derived abundances in stellar atmospheres. These collisions are a major source of uncertainty in non-LTE modelling of spectral lines and abundance determinations, especially for old, metal-poor stars, which are unique tracers of the early evolution of our galaxy. Full quantum scattering calculations of direct excitation processes X(nl) + H ↔ X(n'l') + H and charge transfer processes X(nl) + H ↔ X + + H − have been done for Li, Na and Mg [1,2,3] based on detailed quantum chemical data, e.g. [4]. Rate coefficients have been calculated and applied to non-LTE modelling of spectral lines in stellar atmospheres [5,6,7,8,9]. In all cases we find that charge transfer processes from the first excited S-state are very important, and the processes affect measured abundances for Li, Na and Mg in some stars by as much as 60%. Effects vary with stellar parameters (e.g. temperature, luminosity, metal content) and so these processes are important not only for accurate absolute abundances, but also for relative abundances among dissimilar stars.

  1. AN INTERFEROMETRIC SPECTRAL LINE AND IMAGING SURVEY OF VY CANIS MAJORIS IN THE 345 GHz BAND

    Kamiński, T.; Menten, K. M.; Gottlieb, C. A.; Young, K. H.; Patel, N. A.

    2013-01-01

    A spectral line survey of the oxygen-rich red supergiant VY Canis Majoris was made between 279 and 355 GHz with the Submillimeter Array (SMA). Two hundred twenty-three spectral features from 19 molecules (not counting isotopic species of some of them) were observed, including the rotational spectra of TiO, TiO 2 , and AlCl for the first time in this source. The parameters and an atlas of all spectral features are presented. Observations of each line with a synthesized beam of ∼0.''9, reveal the complex kinematics and morphology of the nebula surrounding VY CMa. Many of the molecules are observed in high-lying rotational levels or in excited vibrational levels. From these, it was established that the main source of the submillimeter-wave continuum (dust) and the high-excitation molecular gas (the star) are separated by about 0.''15. Apparent coincidences between the molecular gas observed with the SMA, and some of the arcs and knots observed at infrared wavelengths and in the optical scattered light by the Hubble Space Telescope are identified. The observations presented here provide important constraints on the molecular chemistry in oxygen-dominated circumstellar environments and a deeper picture of the complex circumstellar environment of VY CMa

  2. Spectral Analysis of a Quantum System with a Double Line Singular Interaction

    Kondej, S.; Krejčiřík, David

    2013-01-01

    Roč. 49, č. 4 (2013), s. 831-859 ISSN 0034-5318 R&D Projects: GA ČR GAP203/11/0701 Institutional support: RVO:61389005 Keywords : Schrödinger operator * singular perturbation * spectral analysis * Hardy inequality * resonance Subject RIV: BE - Theoretical Physics Impact factor: 0.614, year: 2013

  3. Gemini long-slit observations of luminous obscured quasars: Further evidence for an upper limit on the size of the narrow-line region

    Hainline, Kevin N.; Hickox, Ryan C.; Greene, Jenny E.; Myers, Adam D.; Zakamska, Nadia L.; Liu, Guilin; Liu, Xin

    2014-01-01

    We examine the spatial extent of the narrow-line regions (NLRs) of a sample of 30 luminous obscured quasars at 0.4 < z < 0.7 observed with spatially resolved Gemini-N GMOS long-slit spectroscopy. Using the [O III] λ5007 emission feature, we estimate the size of the NLR using a cosmology-independent measurement: the radius where the surface brightness falls to 10 –15 erg s –1 cm –2 arcsec –2 . We then explore the effects of atmospheric seeing on NLR size measurements and conclude that direct measurements of the NLR size from observed profiles are too large by 0.1-0.2 dex on average, as compared to measurements made to best-fit Sérsic or Voigt profiles convolved with the seeing. These data, which span a full order of magnitude in IR luminosity (log (L 8 μm /erg s –1 ) = 44.4-45.4), also provide strong evidence that there is a flattening of the relationship between NLR size and active galactic nucleus luminosity at a seeing-corrected size of ∼7 kpc. The objects in this sample have high luminosities which place them in a previously under-explored portion of the size-luminosity relationship. These results support the existence of a maximal size of the NLR around luminous quasars; beyond this size, there is either not enough gas or the gas is over-ionized and does not produce enough [O III] λ5007 emission.

  4. Solar spectral irradiance variability of some chromospheric emission lines through the solar activity cycles 21-23

    Göker Ü.D.

    2017-01-01

    Full Text Available A study of variations of solar spectral irradiance (SSI in the wave-length ranges 121.5 nm-300.5 nm for the period 1981-2009 is presented. We used various data for ultraviolet (UV spectral lines and international sunspot number (ISSN from interactive data centers such as SME (NSSDC, UARS (GDAAC, SORCE (LISIRD and SIDC, respectively. We reduced these data by using the MATLsoftware package. In this respect, we revealed negative correlations of intensities of UV (289.5 nm-300.5 nm spectral lines originating in the solar chromosphere with the ISSN index during the unusually prolonged minimum between the solar activity cycles (SACs 23 and 24. We also compared our results with the variations of solar activity indices obtained by the ground-based telescopes. Therefore, we found that plage regions decrease while facular areas are increasing in SAC 23. However, the decrease in plage regions is seen in small sunspot groups (SGs, contrary to this, these regions in large SGs are comparable to previous SACs or even larger as is also seen in facular areas. Nevertheless, negative correlations between ISSN and SSI data indicate that these variations are in close connection with the classes of sunspots/SGs, faculae and plage regions. Finally, we applied the time series analysis of spectral lines corresponding to the wavelengths 121.5 nm-300.5 nm and made comparisons with the ISSN data. We found an unexpected increase in the 298.5 nm line for the Fe II ion. The variability of Fe II ion 298.5 nm line is in close connection with the facular areas and plage regions, and the sizes of these solar surface indices play an important role for the SSI variability, as well. So, we compared the connection between the sizes of faculae and plage regions, sunspots/SGs, chemical elements and SSI variability. Our future work will be the theoretical study of this connection and developing of a corresponding model.

  5. Testing of the method for water microleakage detection from OH hydroxyl spectral lines at the L-2M stellarator

    Voronov, G. S.; Berezhetskii, M. S.; Bondar’, Yu. F.; Vafin, I. Yu.; Vasil’kov, D. G.; Voronova, E. V.; Grebenshchikov, S. E.; Grishina, I. A.; Larionova, N. F.; Letunov, A. A.; Logvinenko, V. P.; Meshcheryakov, A. I.; Pleshkov, E. I.; Khol’nov, Yu. V.; Fedyanin, O. I.; Tsygankov, V. A.; Shchepetov, S. V.; Kurnaev, V. A.; Vizgalov, I. V.; Urusov, V. A.

    2013-01-01

    Results are presented from L-2M stellarator experiments on testing a possible method for detection of water microleakages in the cooling system of the first wall and vacuum chamber of ITER. The method consists in the spectroscopic detection of spectral lines of the OH hydroxyl, which forms via the dissociation of water molecules in plasma. Emission in the spectral band of 305–310 nm can be detected even at water leakage rates less than 10 −4 Pa m 3 /s. Chemical reactions between water and boron compounds on the vacuum chamber wall delay the detection of leakages up to ∼2000 s. A similar phenomenon can be expected when a leakage will occur in ITER, where the materials suggested for the first wall (Be, Li) can also chemically react with water.

  6. THE RISE OF AN IONIZED WIND IN THE NARROW-LINE SEYFERT 1 GALAXY Mrk 335 OBSERVED BY XMM-NEWTON AND HST

    Longinotti, A. L.; Krongold, Y.; Kriss, G. A.; Ely, J.; Gallo, L.; Grupe, D.; Komossa, S.; Mathur, S.; Pradhan, A.

    2013-01-01

    We present the discovery of an outflowing ionized wind in the Seyfert 1 galaxy Mrk 335. Despite having been extensively observed by most of the largest X-ray observatories in the last decade, this bright source was not known to host warm absorber gas until recent XMM-Newton observations in combination with a long-term Swift monitoring program have shown extreme flux and spectral variability. High-resolution spectra obtained by the XMM-Newton Reflection Grating Spectrometer (RGS) detector reveal that the wind consists of three distinct ionization components, all outflowing at a velocity of ∼5000 km s –1 . This wind is clearly revealed when the source is observed at an intermediate flux state (2-5 × 10 –12 erg cm –2 s –1 ). The analysis of multi-epoch RGS spectra allowed us to compare the absorber properties at three very different flux states of the source. No correlation between the warm absorber variability and the X-ray flux has been determined. The two higher ionization components of the gas (log ξ ∼ 2.3 and 3.3) may be consistent with photoionization equilibrium, but we can exclude this for the only ionization component that is consistently present in all flux states (log ξ ∼ 1.8). We have included archival, non-simultaneous UV data from Hubble Space Telescope (FOS, STIS, COS) with the aim of searching for any signature of absorption in this source that so far was known for being absorption-free in the UV band. In the Cosmic Origins Spectrograph (COS) spectra obtained a few months after the X-ray observations, we found broad absorption in C IV lines intrinsic to the active galactic nucleus and blueshifted by a velocity roughly comparable to the X-ray outflow. The global behavior of the gas in both bands can be explained by variation of the covering factor and/or column density, possibly due to transverse motion of absorbing clouds moving out of the line of sight at broad line region scale.

  7. Spectral line shapes in linear absorption and two-dimensional spectroscopy with skewed frequency distributions

    Farag, Marwa H.; Hoenders, Bernhard J.; Knoester, Jasper; Jansen, Thomas L. C.

    2017-01-01

    The effect of Gaussian dynamics on the line shapes in linear absorption and two-dimensional correlation spectroscopy is well understood as the second-order cumulant expansion provides exact spectra. Gaussian solvent dynamics can be well analyzed using slope line analysis of two-dimensional

  8. Theoretical profiles of the spectral lines of the hydrogen atom; Profils theoriques des raies spectrales de l'atome d'hydrogene

    Nguyen, H; Herman, L [Universite de la Sorbonne, Lab. de Recherche Physique, 75 - Paris (France); Drawin, H W [Commissariat a l' Energie Atomique, Fontenay-aux-Roses, Association Euratom-CEA, Groupe de Recherches sur la Fusion Controlee (France). Centre d' Etudes Nucleaires

    1965-07-01

    The line-broadening problem of the hydrogen lines has been formulated in the quasistatic approximation as far as the ions are concerned, and in the classical path approximation as far as the broadening due to collisions with electrons is concerned. These electrons interfere in different numerical results only by the self-correlation function of the fluctuating electrical field strength created at each point in the plasma. The Lewis correction has been applied, but using the whole velocity distribution function of the electrons. The formula which represents the usual impact profile, valid only for frequencies much smaller than the plasma frequency, has been extended using another formula which will be valid up to the neighbourhood of that spectral region where the quasi-static approximation begins to be valid also for the electrons. As an example, the line profile of Ly {alpha} is given by some graphs for T = 10{sup 4} deg. K and electron densities N = 10{sup 17} cm{sup -3} and N = 10{sup 18}cm{sup -3}. (authors) [French] Le probleme d'elargissement des raies de l'atome H est formule dans l'approximation quasi-statique en ce qui concerne les ions et dans l'approximation du chemin classique en ce qui concerne les electrons. Ceux-ci interviennent dans differents resultats uniquement par la fonction auto-correlation du champ electrique fluctuant qu'ils creent en chaque point du plasma. La correction de Lewis a ete appliquee mais en tenant compte de la distribution des vitesses electroniques. La formule donnant les profils d'impact habituels, valable seulement pour des frequences tres inferieures a la frequence du plasma, est ainsi prolongee de maniere continue par une autre formule, valable jusqu'au voisinage de la region spectrale ou l'approximation quasistatique commence a etre egalement justifiee pour les electrons. A titre d'illustration on represente graphiquement le profil de la raie Ly {alpha} pour T = 10{sup 4} deg. K et des densites electroniques de N = 10{sup

  9. Quantum Spectral Curve for a cusped Wilson line in N=4 SYM

    Gromov, Nikolay [King’s College London, Department of Mathematics, The Strand, London WC2R 2LS (United Kingdom); St. Petersburg INP,Gatchina, 188 300, St.Petersburg (Russian Federation); Levkovich-Maslyuk, Fedor [King’s College London, Department of Mathematics, The Strand, London WC2R 2LS (United Kingdom)

    2016-04-20

    We show that the Quantum Spectral Curve (QSC) formalism, initially formulated for the spectrum of anomalous dimensions of all local single trace operators in N=4 SYM, can be extended to the generalized cusp anomalous dimension for all values of the parameters. We find that the large spectral parameter asymptotics and some analyticity properties have to be modified, but the functional relations are unchanged. As a demonstration, we find an all-loop analytic expression for the first two nontrivial terms in the small |ϕ±θ| expansion. We also present nonperturbative numerical results at generic angles which match perfectly 4-loop perturbation theory and the classical string prediction. The reformulation of the problem in terms of the QSC opens the possibility to explore many open questions. We attach to this paper several Mathematica notebooks which should facilitate future studies.

  10. Quantum Spectral Curve for a cusped Wilson line in N=4 SYM

    Gromov, Nikolay; Levkovich-Maslyuk, Fedor

    2016-01-01

    We show that the Quantum Spectral Curve (QSC) formalism, initially formulated for the spectrum of anomalous dimensions of all local single trace operators in N=4 SYM, can be extended to the generalized cusp anomalous dimension for all values of the parameters. We find that the large spectral parameter asymptotics and some analyticity properties have to be modified, but the functional relations are unchanged. As a demonstration, we find an all-loop analytic expression for the first two nontrivial terms in the small |ϕ±θ| expansion. We also present nonperturbative numerical results at generic angles which match perfectly 4-loop perturbation theory and the classical string prediction. The reformulation of the problem in terms of the QSC opens the possibility to explore many open questions. We attach to this paper several Mathematica notebooks which should facilitate future studies.

  11. Herschel/HIFI spectral line survey of the Orion Bar. Temperature and density differentiation near the PDR surface

    Nagy, Z.; Choi, Y.; Ossenkopf-Okada, V.; van der Tak, F. F. S.; Bergin, E. A.; Gerin, M.; Joblin, C.; Röllig, M.; Simon, R.; Stutzki, J.

    2017-03-01

    Context. Photon dominated regions (PDRs) are interfaces between the mainly ionized and mainly molecular material around young massive stars. Analysis of the physical and chemical structure of such regions traces the impact of far-ultraviolet radiation of young massive stars on their environment. Aims: We present results on the physical and chemical structure of the prototypical high UV-illumination edge-on Orion Bar PDR from an unbiased spectral line survey with a wide spectral coverage which includes lines of many important gas coolants such as [Cii], [Ci], and CO and other key molecules such as H2CO, H2O, HCN, HCO+, and SO. Methods: A spectral scan from 480-1250 GHz and 1410-1910 GHz at 1.1 MHz resolution was obtained by the HIFI instrument on board the Herschel Space Observatory. We obtained physical parameters for the observed molecules. For molecules with multiple transitions we used rotational diagrams to obtain excitation temperatures and column densities. For species with a single detected transition we used an optically thin LTE approximation. In the case of species with available collisional rates, we also performed a non-LTE analysis to obtain kinetic temperatures, H2 volume densities, and column densities. Results: About 120 lines corresponding to 29 molecules (including isotopologues) have been detected in the Herschel/HIFI line survey, including 11 transitions of CO, 7 transitions of 13CO, 6 transitions of C18O, 10 transitions of H2CO, and 6 transitions of H2O. The rotational temperatures are in the range between 22 and 146 K and the column densities are in the range between 1.8 × 1012 cm-2 and 4.5 × 1017 cm-2. For species with at least three detected transitions and available collisional excitation rates we derived a best fit kinetic temperature and H2 volume density. Most species trace kinetic temperatures in the range between 100 and 150 K and H2 volume densities in the range between 105 and 106 cm-3. The species with temperatures and

  12. Instrumental broadening of spectral line profiles due to discrete representation of a continuous physical quantity

    Dulov, E.N.; Khripunov, D.M.

    2008-01-01

    It is the usual situation in spectroscopy that a continuous physical quantity, which plays the role of a spectral function argument (i.e. the abscissa of a spectrum), is sampled electronically as discrete point clouds or channels. Each channel corresponds to the midpoint of a small interval of the continuous argument. The experimentally registered value of intensity in the channel describes the averaged spectral intensity in this interval. However, an approximation of spectra by a continuous theoretical model function often assumes that the interval is small enough, and tabulation of the theoretical model function may be used without appreciable disadvantages for the fitting results. At this point, a new type of approximation error appears, such as the error of midpoint approximation to a definite integral in the rectangle method of numeric integration. This paper aims at quantitative estimation of this error in the cases of a pure Lorentz lineshape and a generalized Voigt contour. It is shown that discrete representation of continuous spectral data leads to some non-physical broadening in comparison with the tabulated model function. As a first approximation it is normal broadening. We show that even in the case of a Lorentz true lineshape we must use the tabulated Voigt function measured in channels fixed Gauss linewidth rather than a tabulated Lorentzian. Application of the results of this paper is demonstrated on Moessbauer spectra

  13. Collision-induced stimulated photon echo generated at transition 0-1 on broad spectral line conditions

    Rubtsova, N. N.; Gol'dort, V. G.; Ishchenko, V. N.; Khvorostov, E. B.; Kochubei, S. A.; Borisov, G. M.; Ledovskikh, D. V.; Reshetov, V. A.

    2018-04-01

    For the first time, the collision induced stimulated photon echo generated at transition 1S0 → 3 P1 of 174Yb (type 0-1) in the mixture of gases Yb  +  Xe was investigated in the presence of weak longitudinal magnetic field, with experimental parameters corresponding to broad spectral line conditions. Comparison of the experimental echo amplitude versus magnetic field strength dependence with the theoretical curve shows a very good agreement, giving rise to an improved estimate for the difference between alignment and orientation decay rates.

  14. High spectral resolution observations of the H2 2.12 micron line in Herbig-Haro objects

    Zinnecker, H.; Mundt, R.; Geballe, T.R.; Zealey, W.J.

    1989-01-01

    High-spectral-resolution Fabry-Perot observations of the H 2 2.12-micron line emissions of several Herbig-Haro (HH) objects are discussed. It is shown that H 2 emission by the shock heating of external molecular gas in the wings of the bow shock associated with the working surface of a high-velocity jet may occur for HH objects associated with the jet's end. The shock heating of external molecular gas entrained in the flow by internal shocks occurring in the jet itself and/or in its boundary layer may be the H 2 emission mechanism for HH objects observed along the flow axis. 59 refs

  15. Solar monochromatic images in magneto-sensitive spectral lines and maps of vector magnetic fields

    Shihui, Y.; Jiehai, J.; Minhan, J.

    1985-01-01

    A new method which allows by use of the monochromatic images in some magneto-sensitive spectra line to derive both the magnetic field strength as well as the angle between magnetic field lines and line of sight for various places in solar active regions is described. In this way two dimensional maps of vector magnetic fields may be constructed. This method was applied to some observational material and reasonable results were obtained. In addition, a project for constructing the three dimensional maps of vector magnetic fields was worked out.

  16. Spectral line shape simulation for electron stark-broadening of ion emitters in plasmas

    Dufour, Emmanuelle; Calisti, Annette; Talin, Bernard; Gigosos, Marco A.; Gonzalez, Manuel A.; Dufty, Jim W.

    2002-01-01

    Electron broadening for ions in plasmas is investigated in the framework of a simplified semi-classical model involving an ionic emitter imbedded in an electron gas. A regularized Coulomb potential that removes the divergence at short distances is postulated for the ion-electron interaction. Line shape simulations based on Molecular Dynamics for the ion impurity and the electrons, accounting for all the correlations, are reported. Comparisons with line shapes obtained with a quasi-particle model show expected correlation effects. Through an analysis of the results with the line shape code PPP, it is inferred that the correlation effect results mainly from the microfield dynamic properties

  17. O2 atmospheric band measurements with WINDII: Performance of a narrow band filter/wide angle Michelson combination in space

    Ward, W.E.; Hersom, C.H.; Tai, C.C.; Gault, W.A.; Shepherd, G.G.; Solheim, B.H.

    1994-01-01

    Among the emissions viewed by the Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite (UARS) are selected lines in the (0-0) transition of the O2 atmospheric band. These lines are viewed simultaneously using a narrow band filter/wide-angle Michelson interferometer combination. The narrow band filter is used to separate the lines on the CCD (spectral-spatial scanning) and the Michelson used to modulate the emissions so that winds and rotational temperatures may be measured from the Doppler shifts and relative intensities of the lines. In this report this technique will be outlined and the on-orbit behavior since launch summarized

  18. Collisional broadening of depolarized spectral lines of hydrogen gases at low temperatures

    Hout, K.D. van den.

    1978-01-01

    Experimental results are presented for the collisional broadening and shift of H 2 , D 2 and HD rotational Raman and depolarized Rayleigh lines at various temperatures between 25 K and 300 K. These are then discussed within the context of current theoretical concepts. For a few temperatures the line broadening cross sections are also reported as a function of the ortho-para composition for H 2 and D 2 . (C.F.)

  19. Spectral lines and coincidence tables for the determination of zirconium, niobium and tantalum with the ICP

    Wuensch, G.; Wennemer, A.

    1987-01-01

    Coincidence tables for ICP-AES are given for 20 Zr lines, 9 Nb lines and 7 Ta lines. They include 582 interferent lines of 49 elements. The specified interference data (IEC and CCR) hold for a bandwidth FWHM = 16 pm and an interferent concentration of 1,000 mg/l. For trace determinations of Zr, Nb, Ta in a matrix of Fe, Z, Zr, Nb, Ta the dependence of the interference on the matrix concentration is specified up to 10,000 mg/l. Interference data CCR calculated for the ICP from the NBS tables often differ from the measured data by several orders of magnitude. The spectrum of Zr measured at a high concentration shows many weak lines most of which are not even listed in the MIT tables. They give rise to a quasi-continuous background the intensity of which increases nearly linearly with the matrix concentration. Therefore, an increase of sample concentration will not lead to an improved detection limit. The line intensities found in our investigations match well with those listed in the Wohlers tables. (orig.)

  20. High-resolution measurements and multichannel quantum defect analysis of spectral line shapes of autoionizing Rydberg series

    Ueda, Kiyoshi

    1997-01-01

    Spectral line shapes for autoionizing Rydberg series are briefly reviewed within the framework of multichannel quantum defect theory (MQDT). Recent high-resolution measurements and MQDT analysis for the spectra line shapes are reviewed for the mp 5 ( 2 P 1/2 )ns ' and nd ' J=1 odd spectra of the Ar, Kr, and Xe atoms (m=3,4,5 for Ar, Kr, and Xe) and the 3p 5 ( 2 P 1/2 )nd ' J=2 and 3 odd spectra of Ar*3p 5 4p excited atoms. Some results are also discussed for the Ca 4p( 2 P 1/2,3/2 )ns and nd J=1 odd spectrum and the Ba 5d( 2 P 5/2 )nd J=1 odd spectrum

  1. Modeling and identification of ARMG models for stochastic processes: application to on-line computation of the power spectral density

    Zwingelstein, Gilles; Thabet, Gabriel.

    1977-01-01

    Control algorithms for components of nuclear power plants are currently based on external diagnostic methods. Modeling and identification techniques for autoregressive moving average models (ARMA) for stochastic processes are described. The identified models provide a means of estimating the power spectral density with improved accuracy and computer time compared with the classical methods. They are particularly will suited for on-line estimation of the power spectral density. The observable stochastic process y (t) is modeled assuming that it is the output of a linear filter driven by Gaussian while noise w (t). Two identification schemes were tested to find the orders m and n of the ARMA (m,n) models and to estimate the parameters of the recursion equation relating the input and output signals. The first scheme consists in transforming the ARMA model to an autoregressive model. The parameters of this AR model are obtained using least squares estimation techniques. The second scheme consists in finding the parameters of the ARMA by nonlinear programming techniques. The power spectral density of y(t) is instantaneously deduced from these ARMA models [fr

  2. Convex relaxations of spectral sparsity for robust super-resolution and line spectrum estimation

    Chi, Yuejie

    2017-08-01

    We consider recovering the amplitudes and locations of spikes in a point source signal from its low-pass spectrum that may suffer from missing data and arbitrary outliers. We first review and provide a unified view of several recently proposed convex relaxations that characterize and capitalize the spectral sparsity of the point source signal without discretization under the framework of atomic norms. Next we propose a new algorithm when the spikes are known a priori to be positive, motivated by applications such as neural spike sorting and fluorescence microscopy imaging. Numerical experiments are provided to demonstrate the effectiveness of the proposed approach.

  3. A DEEP CHANDRA ACIS STUDY OF NGC 4151. III. THE LINE EMISSION AND SPECTRAL ANALYSIS OF THE IONIZATION CONE

    Wang, Junfeng; Fabbiano, Giuseppina; Elvis, Martin; Risaliti, Guido; Karovska, Margarita; Zezas, Andreas; Mundell, Carole G.; Dumas, Gaelle; Schinnerer, Eva

    2011-01-01

    This paper is the third in a series in which we present deep Chandra ACIS-S imaging spectroscopy of the Seyfert 1 galaxy NGC 4151, devoted to study its complex circumnuclear X-ray emission. Emission features in the soft X-ray spectrum of the bright extended emission (L 0.3-2 k eV ∼ 10 40 erg s –1 ) at r > 130 pc (2'') are consistent with blended brighter O VII, O VIII, and Ne IX lines seen in the Chandra HETGS and XMM-Newton RGS spectra below 2 keV. We construct emission line images of these features and find good morphological correlations with the narrow-line region clouds mapped in [O III] λ5007. Self-consistent photoionization models provide good descriptions of the spectra of the large-scale emission, as well as resolved structures, supporting the dominant role of nuclear photoionization, although displacement of optical and X-ray features implies a more complex medium. Collisionally ionized emission is estimated to be ∼ ☉ yr –1 at 130 pc and the kinematic power of the ionized outflow is 1.7 × 10 41 erg s –1 , approximately 0.3% of the bolometric luminosity of the active nucleus in NGC 4151.

  4. Determination of edge plasma parameters by a genetic algorithm analysis of spectral line shapes

    Marandet, Y.; Genesio, P.; Godbert-Mouret, L.; Koubiti, M.; Stamm, R.; Capes, H.; Guirlet, R.

    2003-01-01

    Comparing an experimental and a theoretical line shape can be achieved by a genetic algorithm (GA) based on an analogy to the mechanisms of natural selection. Such an algorithm is able to deal with complex non-linear models, and can avoid local minima. We have used this optimization tool in the context of edge plasma spectroscopy, for a determination of the temperatures and fractions of the various populations of neutral deuterium emitting the D α line in 2 configurations of Tore-Supra: ergodic divertor and toroidal pumped limiter. Using the GA fit, the neutral emitters are separated into up to 4 populations which can be identified as resulting from molecular dissociation reactions, charge exchange, or reflection. In all the edge plasmas studied, a significant fraction of neutrals emit in the line wings, leading to neutrals with a temperature up to a few hundreds eV if a Gaussian line shape is assumed. This conclusion could be modified if the line wing exhibits a non Gaussian behavior

  5. On-line, continuous monitoring in solar cell and fuel cell manufacturing using spectral reflectance imaging

    Sopori, Bhushan; Rupnowski, Przemyslaw; Ulsh, Michael

    2016-01-12

    A monitoring system 100 comprising a material transport system 104 providing for the transportation of a substantially planar material 102, 107 through the monitoring zone 103 of the monitoring system 100. The system 100 also includes a line camera 106 positioned to obtain multiple line images across a width of the material 102, 107 as it is transported through the monitoring zone 103. The system 100 further includes an illumination source 108 providing for the illumination of the material 102, 107 transported through the monitoring zone 103 such that light reflected in a direction normal to the substantially planar surface of the material 102, 107 is detected by the line camera 106. A data processing system 110 is also provided in digital communication with the line camera 106. The data processing system 110 is configured to receive data output from the line camera 106 and further configured to calculate and provide substantially contemporaneous information relating to a quality parameter of the material 102, 107. Also disclosed are methods of monitoring a quality parameter of a material.

  6. Determination of edge plasma parameters by a genetic algorithm analysis of spectral line shapes

    Marandet, Y.; Genesio, P.; Godbert-Mouret, L.; Koubiti, M.; Stamm, R. [Universite de Provence (PIIM), Centre de Saint-Jerome, 13 - Marseille (France); Capes, H.; Guirlet, R. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    2003-07-01

    Comparing an experimental and a theoretical line shape can be achieved by a genetic algorithm (GA) based on an analogy to the mechanisms of natural selection. Such an algorithm is able to deal with complex non-linear models, and can avoid local minima. We have used this optimization tool in the context of edge plasma spectroscopy, for a determination of the temperatures and fractions of the various populations of neutral deuterium emitting the D{sub {alpha}} line in 2 configurations of Tore-Supra: ergodic divertor and toroidal pumped limiter. Using the GA fit, the neutral emitters are separated into up to 4 populations which can be identified as resulting from molecular dissociation reactions, charge exchange, or reflection. In all the edge plasmas studied, a significant fraction of neutrals emit in the line wings, leading to neutrals with a temperature up to a few hundreds eV if a Gaussian line shape is assumed. This conclusion could be modified if the line wing exhibits a non Gaussian behavior.

  7. Shape of argon spectral lines emitted from an electric arc (P=760 Torr). Study and application of pressure broadening

    Kretzas, Dimitrios.

    1978-01-01

    We have studied the broadening and shift of argon spectral lines corresponding to 3p 5 5p-3p 5 4s and 3p 5 4p-3p 5 4s transitions emitted from an electric arc burning under atmospheric pressure. We have revealed the broadening due to neutral atoms pressure effect, distinguishing the transitions whose lower level is a metastable one (1s 3 and 1s 5 ) or a level of strong (1s 2 ) or feeble resonance (1s 4 ). In this study we have employed a mixture of argon (98%) and hydrogen (2%); hydrogen's feeble proportion does not perturb much the discharge and is very suitable for the measure of the electronic density. The important departure of L.T.E. has guided us to imagine and apply an original method to measure the temperature and the overpopulation of the neutral atoms in the fondamental state. Our method which is independent of the existence of L.T.E. is based on the different behavior of the spectral lines which are under the influence of the resonance or Van der Waals broadening. The measure of the broadening constants which in the resonance case are independent of the temperature and vary as Tsup(0,3) for V.d.W's broadening, give us a suitable tool to measure the density and the temperature of the neutral atoms [fr

  8. MAPPING THE LINEARLY POLARIZED SPECTRAL LINE EMISSION AROUND THE EVOLVED STAR IRC+10216

    Girart, J. M. [Institut de Ciencies de l' Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciencies, C5p 2, 08193 Bellaterra, Catalunya (Spain); Patel, N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Vlemmings, W. H. T. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden); Rao, Ramprasad, E-mail: girart@ice.cat [Submillimeter Array, Academia Sinica Institute of Astronomy and Astrophysics, 645 N. Aohoku Place, Hilo, HI 96720 (United States)

    2012-05-20

    We present spectro-polarimetric observations of several molecular lines obtained with the Submillimeter Array toward the carbon-rich asymptotic giant branch star IRC+10216. We have detected and mapped the linear polarization of the CO 3-2, SiS 19-18, and CS 7-6 lines. The polarization arises at a distance of {approx_equal} 450 AU from the star and is blueshifted with respect to the Stokes I. The SiS 19-18 polarization pattern appears to be consistent with a locally radial magnetic field configuration. However, the CO 3-2 and CS 7-6 line polarization suggests an overall complex magnetic field morphology within the envelope. This work demonstrates the feasibility of using spectro-polarimetric observations to carry out tomographic imaging of the magnetic field in circumstellar envelopes.

  9. Fast analytic formulas for the modified Bessel functions of imaginary order for spectral line broadening calculations

    Poquerusse, A.; Alexiou, S.

    1999-01-01

    In this work we review the status of the standard line broadening theory for plasmas and fill in the existing gap, i.e., the partially overlapping case for ions lines, by deriving expressions as well as fast and accurate numerical approximations for the relevant functions, namely the modified Bessel function of imaginary order and its derivative with respect to argument. These functions also arise in the context of the theory of Coulomb excitation. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. TIMASSS: the IRAS 16293-2422 millimeter and submillimeter spectral survey. I. Observations, calibration, and analysis of the line kinematics

    Caux, E.; Kahane, C.; Castets, A.; Coutens, A.; Ceccarelli, C.; Bacmann, A.; Bisschop, S.; Bottinelli, S.; Comito, C.; Helmich, F. P.; Lefloch, B.; Parise, B.; Schilke, P.; Tielens, A. G. G. M.; van Dishoeck, E.; Vastel, C.; Wakelam, V.; Walters, A.

    2011-08-01

    Context. Unbiased spectral surveys are powerful tools to study the chemistry and the physics of star forming regions, because they can provide a complete census of the molecular content and the observed lines probe the physical structure of the source. Aims: While unbiased surveys at the millimeter and sub-millimeter wavelengths observable from ground-based telescopes have previously been performed towards several high mass protostars, very little exists on low mass protostars, which are believed to resemble our own Sun's progenitor. To help fill up this gap in our understanding, we carried out a complete spectral survey of the bands at 3, 2, 1, and 0.9 mm towards the solar type protostar IRAS 16293-2422. Methods: The observations covered a range of about 200 GHz and were obtained with the IRAM-30 m and JCMT-15 m telescopes during about 300 h of observations. Particular attention was devoted to the inter-calibration of the acquired spectra with previous observations. All the lines detected with more than 3σ confidence-interval certainty and free from obvious blending effects were fitted with Gaussians to estimate their basic kinematic properties. Results: More than 4000 lines were detected (with σ ≥ 3) and identified, yielding a line density of approximatively 20 lines per GHz, comparable to previous surveys in massive hot cores. The vast majority (about two-thirds) of the lines are weak and produced by complex organic molecules. The analysis of the profiles of more than 1000 lines belonging to 70 species firmly establishes the presence of two distinct velocity components associated with the two objects, A and B, forming the IRAS 16293-2422 binary system. In the source A, the line widths of several species increase with the upper level energy of the transition, a behavior compatible with gas infalling towards a ~1 M⊙ object. The source B, which does not show this effect, might have a much lower central mass of ~0.1 M⊙. The difference in the rest velocities

  11. Spectral survey of helium lines in a linear plasma device for use in HELIOS imaging

    Ray, H. B., E-mail: rayhb@ornl.gov [University of Tennessee, Knoxville, Tennessee 37996 (United States); Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Biewer, T. M.; Fehling, D. T.; Isler, R. C.; Unterberg, E. A. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2016-11-15

    Fast visible cameras and a filterscope are used to examine the visible light emission from Oak Ridge National Laboratory’s Proto-MPEX. The filterscope has been configured to perform helium line ratio measurements using emission lines at 667.9, 728.1, and 706.5 nm. The measured lines should be mathematically inverted and the ratios compared to a collisional radiative model (CRM) to determine T{sub e} and n{sub e}. Increasing the number of measurement chords through the plasma improves the inversion calculation and subsequent T{sub e} and n{sub e} localization. For the filterscope, one spatial chord measurement requires three photomultiplier tubes (PMTs) connected to pellicle beam splitters. Multiple, fast visible cameras with narrowband filters are an alternate technique for performing these measurements with superior spatial resolution. Each camera contains millions of pixels; each pixel is analogous to one filterscope PMT. The data can then be inverted and the ratios compared to the CRM to determine 2-dimensional “images” of T{sub e} and n{sub e} in the plasma. An assessment is made in this paper of the candidate He I emission lines for an imaging technique.

  12. Spectral survey of helium lines in a linear plasma device for use in HELIOS imaging

    Ray, H. B.; Biewer, T. M.; Fehling, D. T.; Isler, R. C.; Unterberg, E. A.

    2016-11-01

    Fast visible cameras and a filterscope are used to examine the visible light emission from Oak Ridge National Laboratory's Proto-MPEX. The filterscope has been configured to perform helium line ratio measurements using emission lines at 667.9, 728.1, and 706.5 nm. The measured lines should be mathematically inverted and the ratios compared to a collisional radiative model (CRM) to determine Te and ne. Increasing the number of measurement chords through the plasma improves the inversion calculation and subsequent Te and ne localization. For the filterscope, one spatial chord measurement requires three photomultiplier tubes (PMTs) connected to pellicle beam splitters. Multiple, fast visible cameras with narrowband filters are an alternate technique for performing these measurements with superior spatial resolution. Each camera contains millions of pixels; each pixel is analogous to one filterscope PMT. The data can then be inverted and the ratios compared to the CRM to determine 2-dimensional "images" of Te and ne in the plasma. An assessment is made in this paper of the candidate He I emission lines for an imaging technique.

  13. Combined pseudo-spectral / actuator line model for wind turbine applications

    Dag, Kaya Onur

    2017-01-01

    of the developed code is presented and verifications are carried out. In the second part, by using the new LES code, a comprehensive investigation is made for the well-known actuator line model (ALM), which is cost-efficient for investigation of the loading estimations on wind turbine blades. In ALM, the body...

  14. Getting Your Peaks in Line: A Review of Alignment Methods for NMR Spectral Data

    Trung Nghia Vu

    2013-04-01

    Full Text Available One of the most significant challenges in the comparative analysis of Nuclear Magnetic Resonance (NMR metabolome profiles is the occurrence of shifts between peaks across different spectra, for example caused by fluctuations in pH, temperature, instrument factors and ion content. Proper alignment of spectral peaks is therefore often a crucial preprocessing step prior to downstream quantitative analysis. Various alignment methods have been developed specifically for this purpose. Other methods were originally developed to align other data types (GC, LC, SELDI-MS, etc., but can also be applied to NMR data. This review discusses the available methods, as well as related problems such as reference determination or the evaluation of alignment quality. We present a generic alignment framework that allows for comparison and classification of different alignment approaches according to their algorithmic principles, and we discuss their performance.

  15. Using spectral characteristics to interpret auroral imaging in the 731.9 nm O+ line

    H. Dahlgren

    2008-07-01

    Full Text Available Simultaneous observations were made of dynamic aurora during substorm activity on 26 January 2006 with three high spatial and temporal resolution instruments: the ASK (Auroral Structure and Kinetics instrument, SIF (Spectrographic Imaging Facility and ESR (EISCAT Svalbard Radar, all located on Svalbard (78° N, 16.2° E. One of the narrow field of view ASK cameras is designed to detect O+ ion emission at 731.9 nm. From the spectrographic data we have been able to determine the amount of contaminating N2 and OH emission detected in the same filter. This is of great importance to further studies using the ASK instrument, when the O+ ion emission will be used to detect flows and afterglows in active aurora. The ratio of O+ to N2 emission is dependent on the energy spectra of electron precipitation, and was found to be related to changes in the morphology of the small-scale aurora. The ESR measured height profiles of electron densities, which allowed estimates to be made of the energy spectrum of the precipitation during the events studied with optical data from ASK and SIF. It was found that the higher energy precipitation corresponded to discrete and dynamic features, including curls, and low energy precipitation corresponded to auroral signatures that were dominated by rays. The evolution of these changes on time scales of seconds is of importance to theories of auroral acceleration mechanisms.

  16. UV and X-ray spectral lines of Be-like Fe ion for plasma diagnostics

    Murakami, Izumi; Kato, Takako; Dubau, J.

    1996-04-01

    We have calculated X-ray and UV spectra of the Be-like Fe (FeXXIII) ion using collisional-radiative model including all fine-structure transitions among the 2s 2 , 2s2p, 2p 2 , 2snl, and 2pnl levels where n = 3 and 4, adopting data for the collision strengths by Zhang and Sampson (1992) and by Sampson, Goett, and Clark (1984). Some line intensity ratios can be used for the temperature diagnostic. We show 5 ratios in UV region and 9 ratios in X-ray region as functions of electron temperature and density at 0.3keV e e = 1-10 25 cm -3 . The effect of cascade in these line ratios is discussed. (author)

  17. A Modified Generalized Laguerre Spectral Method for Fractional Differential Equations on the Half Line

    D. Baleanu

    2013-01-01

    fractional derivatives is based on modified generalized Laguerre polynomials Li(α,β(x with x∈Λ=(0,∞, α>−1, and β>0, and i is the polynomial degree. We implement and develop the modified generalized Laguerre collocation method based on the modified generalized Laguerre-Gauss points which is used as collocation nodes for solving nonlinear multiterm FDEs on the half line.

  18. A Spectral-line Analysis of the G8 III Standard ε VIR

    Gray, David F., E-mail: dfgray@uwo.ca [Department of Physics and Astronomy University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada)

    2017-08-10

    Eleven seasons of spectroscopic data comprised of 107 exposures for the stable G8 III standard star, ε Vir are analyzed for projected rotation rate and granulation parameters. A Fourier analysis of the line shapes yield v sin i = 3.06 ± 0.20 km s{sup −1} and a radial-tangential macroturbulence dispersion ζ {sub RT} = 5.16 ± 0.08 km s{sup −1}. The radial velocity over nine seasons is constant to 18 m s{sup −1}. The absolute radial velocity with granulation blueshifts (but not gravitational redshift) removed is −14120 ± 75 m s{sup −1}. Line-depth ratios show the temperature to be constant to 0.7 K over 11 years, although a small secular rise or cyclic variation ∼1 K cannot be ruled out. The third-signature plot shows that the star has granulation velocities 10% larger than the Sun's. Mapping the Fe i λ 6253 line bisector on to the third-signature plot indicates a normal-for-giants flux deficit area of 12.8%, indicating ∼134 K temperature difference between granules and lanes. Deficit velocities of GK giants are seen to shift to higher values with higher luminosity, ∼0.75 km s{sup −1} over Δ M {sub V} ∼ 1.5, indicating larger velocity differences between granules and lanes for giants higher in the HR diagram.

  19. Infrared Line Intensities for Formaldehyde from Simultaneous Measurements in the Infrared and Far Infrared Spectral Ranges

    Fissiaux, L.; Földes, T.; Tchana, F. Kwabia; Daumont, L.; Lepère, M.; Vander Auwera, J.

    2011-06-01

    Formaldehyde (H_2CO) is an important intermediate compound in the degradation of the volatile organic compounds (VOCs), including methane, in the terrestrial troposphere. Its observation using optical remote sensing in the infrared range relies on the 3.6 and 5.7 μm absorption bands. Band and individual line intensities have been reported in both ranges. With the present work, we aim to also derive infrared line intensities for formaldehyde, however relying on pure rotation line intensities and the known electric dipole moment to determine the particle density. Indeed, because formaldehyde polymerizes or degrades easily, the gas phase may contain polymerization or degradation products. Spectra of H_2CO diluted in 10 hPa of N_2 were therefore simultaneously recorded in the 20-60 Cm-1 and 3.6 μm ranges, respectively using a Bruker IFS125HR Fourier transform spectrometer and a tunable diode laser. see A. Perrin, D. Jacquemart, F. Kwabia Tchana, N. Lacome, J. Quant. Spectrosc. Radiat. Transfer 110 (2009) 700-716, and references therein

  20. Jupiter's Deep Cloud Structure Revealed Using Keck Observations of Spectrally Resolved Line Shapes

    Bjoraker, G. L.; Wong, M.H.; de Pater, I.; Adamkovics, M.

    2015-01-01

    Technique: We present a method to determine the pressure at which significant cloud opacity is present between 2 and 6 bars on Jupiter. We use: a) the strength of a Fraunhofer absorption line in a zone to determine the ratio of reflected sunlight to thermal emission, and b) pressure- broadened line profiles of deuterated methane (CH3D) at 4.66 meters to determine the location of clouds. We use radiative transfer models to constrain the altitude region of both the solar and thermal components of Jupiter's 5-meter spectrum. Results: For nearly all latitudes on Jupiter the thermal component is large enough to constrain the deep cloud structure even when upper clouds are present. We find that Hot Spots, belts, and high latitudes have broader line profiles than do zones. Radiative transfer models show that Hot Spots in the North and South Equatorial Belts (NEB, SEB) typically do not have opaque clouds at pressures greater than 2 bars. The South Tropical Zone (STZ) at 32 degrees South has an opaque cloud top between 4 and 5 bars. From thermochemical models this must be a water cloud. We measured the variation of the equivalent width of CH3D with latitude for comparison with Jupiter's belt-zone structure. We also constrained the vertical profile of H2O in an SEB Hot Spot and in the STZ. The Hot Spot is very dry for a probability less than 4.5 bars and then follows the H2O profile observed by the Galileo Probe. The STZ has a saturated H2O profile above its cloud top between 4 and 5 bars.

  1. Spectral line profile analysis for evaluation of Gaussian and Lorentzian widths and collisional broadening coefficient

    Nakhate, S.G.; Ahmad, S.A.; Pushpa; Rao, M.; Saksena, G.D.

    1991-01-01

    Deconvolution of atomic line profiles, recorded on PC interfaced recording Fabry-Perot spectrometer, into its Lorentzian and Gaussian component has been carried out. Effect of various parameters of hollow cathode discharge lamp (light source) such as discharge current, bath temperature and gas pressure on Lorentzian and Gaussian width has been studied. The value of the self-broadening coefficient for neon-neon atomic interaction for the transition 2p 5 4P-2P 5 3s (λ=3472.571 A) has been determined. (author). 15 refs., 6 figs., 4 tabs

  2. Operation of Small Radio Telescope (SRT) recorded 21 cm spectral line of Hydrogen at VATLY Laboratory

    Pham Ngoc Dong; Pham Tuan Anh; Pham Ngoc Diep; Pham Thi Tuyet Nhung; Nguyen Van Hiep

    2013-01-01

    A small radio telescope (SRT) has been installed on the roof of the Hanoi astrophysics laboratory VATLY. It is equipped with a 2.6 m diameter mobile parabolic dish remotely controlled in elevation and azimuth and with super-heterodyne detection around the 21 cm hydrogen line. They demonstrate the high quality of the telescope performance and are used to evaluate lobe size, signal to noise ratios, anthropogenic interferences and measurement accuracies. Particular attention is given to the measurement of the pointing accuracy. First results of observations of the Sun and of the centre of the Milky Way are presented. (author)

  3. X-ray spectral models of Galactic bulge sources - the emission-line factor

    Vrtilek, S.D.; Swank, J.H.; Kallman, T.R.

    1988-01-01

    Current difficulties in finding unique and physically meaningful models for the X-ray spectra of Galactic bulge sources are exacerbated by the presence of strong, variable emission and absorption features that are not resolved by the instruments observing them. Nine Einstein solid state spectrometer (SSS) observations of five Galactic bulge sources are presented for which relatively high resolution objective grating spectrometer (OGS) data have been published. It is found that in every case the goodness of fit of simple models to SSS data is greatly improved by adding line features identified in the OGS that cannot be resolved by the SSS but nevertheless strongly influence the spectra observed by SSS. 32 references

  4. Some new ideas for the study of the complex spectral line profiles of hot emission stars and quasars

    Danezis, E.

    2013-01-01

    Some Hot Emission Stars and AGNs present peculiar spectral line profiles which are due to DACs and SACs phenomena. The origin and the mechanisms which are responsible for the creation of DACs/SACs is an important problem that has been studied by many researchers. This paper is a review of our efforts to study the origin and the mechanisms of these phenomena. At first we present a theoretic ad hoc picture for the structure of the plasma that surrounds the specific category of hot emission stars that present DACs or SACs. Then we present the mathematical model that we constructed, which is based on the properties of the above ad hoc theoretical structure. Finally, we present some results from our statistical studies that prove the consistency of our model with the classical physical theory.

  5. On-line database of the spectral properties of polycyclic aromatic hydrocarbons

    Malloci, Giuliano; Joblin, Christine; Mulas, Giacomo

    2007-01-01

    We present an on-line database of computed molecular properties for a large sample of polycyclic aromatic hydrocarbons in four charge states: -1, 0, +1, and +2. At present our database includes 40 molecules ranging in size from naphthalene and azulene (C 10 H 8 ) up to circumovalene (C 66 H 20 ). We performed our calculations in the framework of the density functional theory (DFT) and the time-dependent DFT to obtain the most relevant molecular parameters needed for astrophysical applications. For each molecule in the sample, our database presents in a uniform way the energetic, rotational, vibrational, and electronic properties. It is freely accessible on the web at (http://astrochemistry.ca.astro.it/database/) and (http://www.cesr.fr/~joblin/database/)

  6. X-ray spectral line shapes for the excimer-laser-produced high density plasma diagnostics

    Magunov, A.; Faenov, A.; Skobelev, I.; Pikuz, T.; Batani, D.; Milani, M.; Conti, A.; Masini, A.; Costato, M.; Pozzi, A.; Turcu, E.; Allot, R.; Lisi, N.; Koenig, M.; Benuzzi, A.; Flora, F.; Letardi, T.; Palladino, L.; Reale, A.

    1997-01-01

    The time and space-integrated emission spectra measurements have been performed in plasma produced by 308 nm wavelength XeCl laser radiation (I L =(4-10)·10 12 W/cm 2 , τ=10 ns) and by 248 nm wavelength KrF laser pulse train radiation (I L =5·10 15 W/cm 2 , τ=7 ps, 16 pulses in train) on CF n plane target. The lines' shapes and intensities modeling of Lyman series and He-like ion resonance series of fluorine up to n=7 by fitting experimental data shows the considerable difference of plasma formation features for these two sets of the laser pulse parameters

  7. Python Radiative Transfer Emission code (PyRaTE): non-LTE spectral lines simulations

    Tritsis, A.; Yorke, H.; Tassis, K.

    2018-05-01

    We describe PyRaTE, a new, non-local thermodynamic equilibrium (non-LTE) line radiative transfer code developed specifically for post-processing astrochemical simulations. Population densities are estimated using the escape probability method. When computing the escape probability, the optical depth is calculated towards all directions with density, molecular abundance, temperature and velocity variations all taken into account. A very easy-to-use interface, capable of importing data from simulations outputs performed with all major astrophysical codes, is also developed. The code is written in PYTHON using an "embarrassingly parallel" strategy and can handle all geometries and projection angles. We benchmark the code by comparing our results with those from RADEX (van der Tak et al. 2007) and against analytical solutions and present case studies using hydrochemical simulations. The code will be released for public use.

  8. Spectral Line Shapes in the ν_3 Q Branch of ^{12}CH_4 Near 3.3 μm

    Devi, V. Malathy; Benner, D. Chris; Gamache, Robert R.; Smith, Mary Ann H.; Sams, Robert L.

    2017-06-01

    Detailed knowledge of spectroscopic parameters for prominent Q branches of methane is necessary for interpretation and modeling of high resolution infrared spectra of terrestrial and planetary atmospheres. We have measured air-broadened line shape parameters in the Q branch of ^{12}CH_4 in the ν_3 fundamental band for a large number of transitions in the 3000 to 3023 cm^{-1} region by analyzing 13 room-temperature laboratory absorption spectra. Twelve of these spectra were recorded with 0.01 cm^{-1} resolution using the McMath-Pierce Fourier transform spectrometer (FTS) of the National Solar Observatory (NSO) on Kitt Peak, and one higher-resolution (˜0.0011 cm^{-1}) low pressure (˜1 Torr) spectrum of methane was obtained using the Bruker IFS 120HR FTS at the Pacific Northwest National Laboratory (PNNL) in Richland, WA. The air-broadened spectra were recorded using various absorption cells with path lengths of 5, 20, 25, and 150 cm, total sample pressures between 50 and 500 Torr, and CH_4 volume mixing ratios of 0.01 or less. All 13 spectra were fit simultaneously covering the 3000-3023 cm^{-1} spectral region using a multispectrum nonlinear least squares technique to retrieve accurate line positions, absolute intensities, Lorentz air-broadened widths and pressure-shift coefficients. Line mixing using the off-diagonal relaxation matrix element formalism was measured for a number of pairs of transitions for the CH_4-air collisional system. The results will be compared to values reported in the literature. D. C. Benner, C. P. Rinsland, V. Malathy Devi, M. A. H. Smith, D. Atkins, JQSRT 53 (1995) 705-721. A. Levy, N. Lacome, C. Chackerian, Collisional line mixing, in Spectroscopy of the Earth's Atmosphere and Interstellar Medium, Academic Press, Inc., Boston (1992) 261-337.

  9. Fast algorithm for spectral processing with application to on-line welding quality assurance

    Mirapeix, J.; Cobo, A.; Jaúregui, C.; López-Higuera, J. M.

    2006-10-01

    A new technique is presented in this paper for the analysis of welding process emission spectra to accurately estimate in real-time the plasma electronic temperature. The estimation of the electronic temperature of the plasma, through the analysis of the emission lines from multiple atomic species, may be used to monitor possible perturbations during the welding process. Unlike traditional techniques, which usually involve peak fitting to Voigt functions using the Levenberg-Marquardt recursive method, sub-pixel algorithms are used to more accurately estimate the central wavelength of the peaks. Three different sub-pixel algorithms will be analysed and compared, and it will be shown that the LPO (linear phase operator) sub-pixel algorithm is a better solution within the proposed system. Experimental tests during TIG-welding using a fibre optic to capture the arc light, together with a low cost CCD-based spectrometer, show that some typical defects associated with perturbations in the electron temperature can be easily detected and identified with this technique. A typical processing time for multiple peak analysis is less than 20 ms running on a conventional PC.

  10. An unbiased spectral line survey toward R CrA IRS7B in the 345 GHz window with ASTE

    Watanabe, Yoshimasa; Sakai, Nami; Lindberg, Johan

    2012-01-01

    We have conducted a spectral line survey in the 332-364 GHz region with the Atacama Submillimeter Telescope Experiment 10 m telescope toward R CrA IRS7B, a low-mass protostar in the Class 0 or Class 0/I transitional stage. We have also performed some supplementary observations in the 450 GHz band...... corino. These results suggest a weak hot corino activity in R CrA IRS7B. On the other hand, the carbon-chain related molecules, CCH and c-C3H2, are found to be abundant. However, this source cannot be classified as a WCCC source, since long carbon-chain molecules are not detected. If WCCC and hot corino...... chemistry represent the two extremes in chemical compositions of low-mass Class 0 sources, R CrA IRS7B would be a source with a mixture of these two chemical characteristics. The UV radiation from the nearby Herbig Ae star R CrA may also affect the chemical composition. The present line survey demonstrates...

  11. Molecular-cloud-scale Chemical Composition. II. Mapping Spectral Line Survey toward W3(OH) in the 3 mm Band

    Nishimura, Yuri [Institute of Astronomy, The University of Tokyo, 2-21-1, Osawa, Mitaka, Tokyo 181-0015 (Japan); Watanabe, Yoshimasa; Yamamoto, Satoshi [Department of Physics, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Harada, Nanase [Academia Sinica Institute of Astronomy and Astrophysics, No.1, Sec. 4, Roosevelt Road, 10617 Taipei, Taiwan, R.O.C. (China); Shimonishi, Takashi [Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramakiazaaoba 6-3, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Sakai, Nami [RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Aikawa, Yuri [Department of Astronomy, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kawamura, Akiko [Chile Observatory, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2017-10-10

    To study a molecular-cloud-scale chemical composition, we conducted a mapping spectral line survey toward the Galactic molecular cloud W3(OH), which is one of the most active star-forming regions in the Perseus arm. We conducted our survey through the use of the Nobeyama Radio Observatory 45 m telescope, and observed the area of 16′ × 16′, which corresponds to 9.0 pc × 9.0 pc. The observed frequency ranges are 87–91, 96–103, and 108–112 GHz. We prepared the spectrum averaged over the observed area, in which eight molecular species (CCH, HCN, HCO{sup +}, HNC, CS, SO, C{sup 18}O, and {sup 13}CO) are identified. On the other hand, the spectrum of the W3(OH) hot core observed at a 0.17 pc resolution shows the lines of various molecules such as OCS, H{sub 2}CS CH{sub 3}CCH, and CH{sub 3}CN in addition to the above species. In the spatially averaged spectrum, emission of the species concentrated just around the star-forming core, such as CH{sub 3}OH and HC{sub 3}N, is fainter than in the hot core spectrum, whereas emission of the species widely extended over the cloud such as CCH is relatively brighter. We classified the observed area into five subregions according to the integrated intensity of {sup 13}CO, and evaluated the contribution to the averaged spectrum from each subregion. The CCH, HCN, HCO{sup +}, and CS lines can be seen even in the spectrum of the subregion with the lowest {sup 13}CO integrated intensity range (<10 K km s{sup −1}). Thus, the contributions of the spatially extended emission is confirmed to be dominant in the spatially averaged spectrum.

  12. AN UNBIASED SPECTRAL LINE SURVEY TOWARD R CrA IRS7B IN THE 345 GHz WINDOW WITH ASTE

    Watanabe, Yoshimasa; Sakai, Nami; Yamamoto, Satoshi; Lindberg, Johan E.; Bisschop, Suzanne E.; Jørgensen, Jes K.

    2012-01-01

    We have conducted a spectral line survey in the 332-364 GHz region with the Atacama Submillimeter Telescope Experiment 10 m telescope toward R CrA IRS7B, a low-mass protostar in the Class 0 or Class 0/I transitional stage. We have also performed some supplementary observations in the 450 GHz band. In total, 16 molecular species are identified in the 332-364 GHz region. Strong emission lines of CN and CCH are observed, whereas complex organic molecules and long carbon-chain molecules, which are characteristics of hot corino and warm carbon-chain chemistry (WCCC) source, respectively, are not detected. The rotation temperature of CH 3 OH is evaluated to be 31 K, which is significantly lower than that reported for the prototypical hot corino IRAS 16293-2422 (∼85 K). The deuterium fractionation ratios for CCH and H 2 CO are obtained to be 0.038 and 0.050, respectively, which are much lower than those in the hot corino. These results suggest a weak hot corino activity in R CrA IRS7B. On the other hand, the carbon-chain related molecules, CCH and c-C 3 H 2 , are found to be abundant. However, this source cannot be classified as a WCCC source, since long carbon-chain molecules are not detected. If WCCC and hot corino chemistry represent the two extremes in chemical compositions of low-mass Class 0 sources, R CrA IRS7B would be a source with a mixture of these two chemical characteristics. The UV radiation from the nearby Herbig Ae star R CrA may also affect the chemical composition. The present line survey demonstrates further chemical diversity in low-mass star-forming regions.

  13. The application of the piecewise linear approximation to the spectral neighborhood of soil line for the analysis of the quality of normalization of remote sensing materials

    Kulyanitsa, A. L.; Rukhovich, A. D.; Rukhovich, D. D.; Koroleva, P. V.; Rukhovich, D. I.; Simakova, M. S.

    2017-04-01

    The concept of soil line can be to describe the temporal distribution of spectral characteristics of the bare soil surface. In this case, the soil line can be referred to as the multi-temporal soil line, or simply temporal soil line (TSL). In order to create TSL for 8000 regular lattice points for the territory of three regions of Tula oblast, we used 34 Landsat images obtained in the period from 1985 to 2014 after their certain transformation. As Landsat images are the matrices of the values of spectral brightness, this transformation is the normalization of matrices. There are several methods of normalization that move, rotate, and scale the spectral plane. In our study, we applied the method of piecewise linear approximation to the spectral neighborhood of soil line in order to assess the quality of normalization mathematically. This approach allowed us to range normalization methods according to their quality as follows: classic normalization > successive application of the turn and shift > successive application of the atmospheric correction and shift > atmospheric correction > shift > turn > raw data. The normalized data allowed us to create the maps of the distribution of a and b coefficients of the TSL. The map of b coefficient is characterized by the high correlation with the ground-truth data obtained from 1899 soil pits described during the soil surveys performed by the local institute for land management (GIPROZEM).

  14. Review of Langmuir-wave-caused dips and charge-exchange-caused dips in spectral lines from plasmas and their applications

    Dalimier, E.; Oks, E.; Renner, Oldřich

    2014-01-01

    Roč. 2, č. 2 (2014), s. 178-194 ISSN 2218-2004 Grant - others:AVČR(CZ) M100101208 Institutional support: RVO:68378271 Keywords : Laser-matter interaction * spectral line profiles * Langmuir waves * plasma electron density * charge exchange rates Subject RIV: BL - Plasma and Gas Discharge Physics

  15. Influence of Laser Radiation Power Density on the Intensity of Spectral Lines for Main Components in a Clay Laser-Induced Plasma

    Anufrik, S. S.; Kurian, N. N.; Znosko, K. F.; Belkov, M. V.

    2018-05-01

    We have studied the intensity of the spectral lines for the main components in clay: Al I 309.4 nm, Al II 358.7 nm, Mg II 279.6 nm, Ti II 323.6 nm vs. the position of the object relative to the focus of the optical system when the samples are exposed to single laser pulses from a YAG:Nd3+ laser. We have determined the permissible ranges for positioning the object relative to the focus of the optical system (positive and negative defocusing) for which there is practically no change in the reproducibility of the intensity for the spectral lines for red and white clay samples. We show that the position of the object relative to the focus of the optical system should be within the range ΔZ ±1.5 mm for optimal laser pulse energies for the analyte spectral lines. We have calculated the radiation flux density for different laser pulse energies and different distances from the focus to the object. We have shown experimentally that reducing the radiation flux density leads to a decrease in the intensity of the analyte spectral lines.

  16. Using RADMC-3D to model the radiative transfer of spectral lines in protoplanetary disks and envelopes

    DeVries, John; Terebey, Susan

    2018-06-01

    Protoplanetary disks are the birthplaces of planets in our universe. Observations of these disks with radio telescopes like the Atacama Large Millimeter Array (ALMA) offer great insight into the star and planet formation process. Comparing theories of formation with observations requires tracing the energy transfer via electromagnetic radiation, known as radiative transfer. To determine the temperature distribution of circumstellar material, a Monte Carlo code (Whitney et al. [1]) was used to to perform the radiative transfer through dust. The goal of this research is to utilize RADMC-3D [2] to handle the spectral line radiative transfer computations. An existing model of a rotating ring was expanded to include emission from the C18O isotopologue of carbon monoxide using data from the Leiden Atomic and Molecular Database (LAMDA). This feature of our model compliments ALMA's ability to measure C18O line emission, a proxy for disk rotation. In addition to modeling gas in the protoplanetary disk, dust also plays an important role. The generic description of absorption and scattering for dust provided by RADMC-3D was changed in favor of a more physically-realistic description with OH5 grains. This description is more appropriate in high-density regions of the envelope around a protostar. Further improvements, such as consideration for the finite resolution of observations, have been implemented. The task at present is to compare our model with observations of protoplanetary systems like L1527. Some results of these comparisons will be presented.[1] Whitney et al. 2013, ApJS, 207:30[2] RADMC-3D: http://www.ita.uni-heidelberg.de/~dullemond/software/radmc-3d/

  17. New luminescence lines in nanodiamonds obtained by chemical vapor deposition

    Golubev, V. G.; Grudinkin, S. A.; Davydov, V. Yu.; Smirnov, A. N.; Feoktistov, N. A.

    2017-12-01

    The spectral characteristics of the photoluminescence lines detected for nanodiamonds obtained by the reactive ion etching of diamond particles in oxygen plasma, deposited by chemical vapor deposition on a silicon substrate, are studied. At room temperature, narrow lines are observed in the visible and infrared spectral regions, with a full width at half-maximum in the range of 1-2 nm at an almost complete absence of a broadband photoluminescence background signal. At decreasing temperature, the lines narrowed to 0.2-0.6 nm at T = 79 K, and the minimum line width was 0.055 nm at T = 10 K. With increasing temperature, the narrow lines shifted to the long-wavelength region of the spectrum, and their intensity decreased.

  18. Dicke coherent narrowing in two-photon and Raman spectroscopy of thin vapor cells

    Dutier, Gabriel; Todorov, Petko; Hamdi, Ismahene; Maurin, Isabelle; Saltiel, Solomon; Bloch, Daniel; Ducloy, Martial

    2005-01-01

    The principle of coherent Dicke narrowing in a thin vapor cell, in which sub-Doppler spectral line shapes are observed under a normal irradiation for a λ/2 thickness, is generalized to two-photon spectroscopy. Only the sum of the two wave vectors must be normal to the cell, making the two-photon scheme highly versatile. A comparison is provided between the Dicke narrowing with copropagating fields, and the residual Doppler broadening occurring with counterpropagating geometries. The experimental feasibility is discussed on the basis of a first observation of a two-photon resonance in a 300-nm-thick Cs cell. Extension to the Raman situation is finally considered

  19. X-ray diffraction patterns and diffracted intensity of Kα spectral lines of He-like ions

    Goyal, Arun; Khatri, Indu; Singh, A. K.; Sharma, Rinku; Mohan, Man

    2017-09-01

    In the present paper, we have calculated fine-structure energy levels related to the configurations 1s2s, 1s2p, 1s3s and 1s3p by employing GRASP2K code. We have also computed radiative data for transitions from 1s2p 1 P1o, 1s2p 3 P2o, 1s2p 3 P1o and 1s2s 3S1 to the ground state 1s2. We have made comparisons of our presented energy levels and transition wavelengths with available results compiled by NIST and good agreement is achieved. We have also provided X-ray diffraction (XRD) patterns of Kα spectral lines, namely w, x, y and z of Cu XXVIII, Kr XXXV and Mo with diffraction angle and maximum diffracted intensity which is not published elsewhere in the literature. We believe that our presented results may be beneficial in determination of the order parameter, X-ray crystallography, solid-state drug analysis, forensic science, geological and medical applications.

  20. Estimation of Signal Coherence Threshold and Concealed Spectral Lines Applied to Detection of Turbofan Engine Combustion Noise

    Miles, Jeffrey Hilton

    2010-01-01

    Combustion noise from turbofan engines has become important, as the noise from sources like the fan and jet are reduced. An aligned and un-aligned coherence technique has been developed to determine a threshold level for the coherence and thereby help to separate the coherent combustion noise source from other noise sources measured with far-field microphones. This method is compared with a statistics based coherence threshold estimation method. In addition, the un-aligned coherence procedure at the same time also reveals periodicities, spectral lines, and undamped sinusoids hidden by broadband turbofan engine noise. In calculating the coherence threshold using a statistical method, one may use either the number of independent records or a larger number corresponding to the number of overlapped records used to create the average. Using data from a turbofan engine and a simulation this paper shows that applying the Fisher z-transform to the un-aligned coherence can aid in making the proper selection of samples and produce a reasonable statistics based coherence threshold. Examples are presented showing that the underlying tonal and coherent broad band structure which is buried under random broadband noise and jet noise can be determined. The method also shows the possible presence of indirect combustion noise. Copyright 2011 Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America.

  1. Argus+: The Future of Wide-Field, Spectral-Line Imaging at 3-mm with the Green Bank Telescope

    Maddalena, Ronald; Frayer, David; Lockman, Felix; O'Neil, Karen; White, Steven; Argus+ Collaboration

    2018-01-01

    The Robert C Byrd Green Bank Telescope has met its design goal of providing high-quality observations at 115 GHz. Observers also have access to the new, 16-pixel, 3-mm Argus receiver, which is providing high-dynamic range images over wide fields for the multitude of spectral lines between 85 and 115 GHz, including CO, 13CO, C18O, SiO, HCN, HCO+, HNC, N2H+, and CS. The small number of pixels in Argus limits its ability to map many of the most interesting objects whose extent exceeds many arc-minutes. The successful performance of Argus, and its modular design, demonstrates that receivers with many more pixels could be built for the GBT. A 12 x 12 array of the Argus design would have mapping speeds about nine times faster than Argus without suffering any degradation in performance for the outer pixels in the array. We present our plans to build the next-generation Argus instrument (Argus+) with 144-pixels, a footprint 5’x5’, and 7" resolution at 110 GHz. The project will be a collaboration between the Green Bank Observatory and university groups, who will supply key components. The key science drivers for Argus+ are studies of molecular filaments in the Milky Way, studies of molecular clouds in nearby galaxies, and the observations of rapidly evolving solar system objects.

  2. The importance of nuclear quantum effects in spectral line broadening of optical spectra and electrostatic properties in aromatic chromophores

    Law, Y. K.; Hassanali, A. A.

    2018-03-01

    In this work, we examine the importance of nuclear quantum effects on capturing the line broadening and vibronic structure of optical spectra. We determine the absorption spectra of three aromatic molecules indole, pyridine, and benzene using time dependent density functional theory with several molecular dynamics sampling protocols: force-field based empirical potentials, ab initio simulations, and finally path-integrals for the inclusion of nuclear quantum effects. We show that the absorption spectrum for all these chromophores are similarly broadened in the presence of nuclear quantum effects regardless of the presence of hydrogen bond donor or acceptor groups. We also show that simulations incorporating nuclear quantum effects are able to reproduce the heterogeneous broadening of the absorption spectra even with empirical force fields. The spectral broadening associated with nuclear quantum effects can be accounted for by the broadened distribution of chromophore size as revealed by a particle in the box model. We also highlight the role that nuclear quantum effects have on the underlying electronic structure of aromatic molecules as probed by various electrostatic properties.

  3. Plasma satellites of X-ray spectral lines of ions in a plasma of solid-state targets, heated by a picosecond laser pulse

    Belyaev, V.S.; Vinogradov, V.I.; Kurilov, A.S.; Matafonov, A.P.; Lisitsa, V.S.; Gavrilenko, V.P.; Faenov, A.Ya.; Pikuz, T.A.; Skobelev, I.Yu.; Magunov, A.I.; Pikuz, S.A.

    2003-01-01

    The results of measuring the ions X-ray spectral lines by the interaction of the picosecond laser pulses with the solid-state target are presented. The spectra of the X-ray radiation were observed on the fluorine ion line. The spectral lines satellites, testifying to the availability, are identified. The position of the satellites and the distance between them make it possible to connect them with the intensive electrostatic oscillations with the amplitude, exceeding 10 8 V/cm, and the frequency close to 7 x 10 14 s -1 , substantially lower than the laser wave frequency. The experimental results are compared with the calculated data on the multicharge ions spectra [ru

  4. Study of Unwanted Emissions in the CENELEC-A Band Generated by Distributed Energy Resources and Their Influence over Narrow Band Power Line Communications

    Noelia Uribe-Pérez

    2016-11-01

    Full Text Available Distributed Energy Resources might have a severe influence on Power Line Communications, as they can generate interfering signals and high frequency emissions or supraharmonics that may cause loss of metering and control data. In this paper, the influence of various energy resources on Narrowband Power Line Communications is described and analyzed through several test measurements performed in a real microgrid. Accordingly, the paper describes the effects on smart metering communications through the Medium Access Control (MAC layer analysis. Results show that the switching frequency of inverters and the presence of battery chargers are remarkable sources of disturbance in low voltage distribution networks. In this sense, the results presented can contribute to efforts towards standardization and normative of emissions at higher frequencies higher, such as CENELEC EN 50160 and IEC/TS 62749.

  5. Influence of dust particles on the neon spectral line intensities at the uniform positive column of dc discharge at the space apparatus “Plasma Kristall-4”

    Usachev, A. D.; Zobnin, A. V.; Shonenkov, A. V.; Lipaev, A. M.; Molotkov, V. I.; Petrov, O. F.; Fortov, V. E.; Pustyl'nik, M. Y.; Fink, M. A.; Thoma, M. A.; Thomas, H. M.; Padalka, G. I.

    2018-01-01

    Influence of the elongated dust cloud on the intensities of different neon spectral lines in visible and near ir spectral ranges in the uniform positive column has been experimentally investigated using the Russian-European space apparatus “Plasma Kristall-4” (SA PK-4) on board of the International Space Station (ISS). The investigation was performed in the low pressure (0.5 mbar) direct current (dc, 1 mA) gas discharge in neon. Microgravity allowed us to perform experiments with a large dust cloud in the steady-state regime. To avoid the dust cloud drift in the dc electric field a switching dc polarity discharge mode has been applied. During the experiment a dust cloud of 9 mm in diameter in the discharge tube of 30 mm in diameter with the length of about 100 mm has been observed in the steady-state regime. In this regard, the intensities of neon spectral lines corresponding to 3p → 3s electronic transitions have increased by a factor of 1.4 times, while the intensities of neon spectral lines corresponding to 3d → 3p electronic transitions have increased by a factor of 1.6 times. The observed phenomenon is explained on the basis of the Schottky approach by a self-consistent rising dc electric field in the dusty plasma cloud resulting in an increase of the electron temperature.

  6. Spectral line survey toward the spiral arm of M51 in the 3 and 2 mm bands

    Watanabe, Yoshimasa; Sakai, Nami; Yamamoto, Satoshi [Department of Physics, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Sorai, Kazuo, E-mail: nabe@taurus.phys.s.u-tokyo.ac.jp [Department of Physics/Department of Cosmoscience, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810 (Japan)

    2014-06-10

    We have conducted a spectral line survey in the 3 and 2 mm bands toward two positions in a spiral arm of M51 (NGC 5194) with the Institut de Radioastronomie Millimétrique 30 m telescope. In this survey, we have identified 13 molecular species, including CN, CCH, N{sub 2}H{sup +}, HNCO, and CH{sub 3}OH. Furthermore, six isotopologues of the major species have been detected. On the other hand, SiO, HC{sub 3}N, CH{sub 3}CN, and deuterated species such as DCN and DCO{sup +} were not detected. The deuterium fractionation ratios are evaluated to be less than 0.8% and 1.2% for DCN/HCN and DCO{sup +}/HCO{sup +}, respectively. By comparing the results of the two positions with different star formation activities, we have found that the observed chemical compositions do not strongly depend on star formation activities. They seem to reflect a chemical composition averaged over the 1 kpc scale region including many giant molecular clouds. Among the detected molecules CN, CCH, and CH{sub 3}OH are found to be abundant. High abundances of CN and CCH are consistent with the above picture of a widespread distribution of molecules because they can be produced by photodissociation. On the other hand, it seems likely that CH{sub 3}OH is liberated in the gas phase by shocks associated with large-scale phenomena such as cloud-cloud collisions and/or by nonthermal desorption processes such as photoevaporation due to cosmic-ray-induced UV photons. The present result demonstrates a characteristic chemical composition of a giant molecular cloud complex in the spiral arm, which can be used as a standard reference for studying chemistry in active galactic nuclei and starbursts.

  7. Amide I SFG Spectral Line Width Probes the Lipid-Peptide and Peptide-Peptide Interactions at Cell Membrane In Situ and in Real Time.

    Zhang, Baixiong; Tan, Junjun; Li, Chuanzhao; Zhang, Jiahui; Ye, Shuji

    2018-06-13

    The balance of lipid-peptide and peptide-peptide interactions at cell membrane is essential to a large variety of cellular processes. In this study, we have experimentally demonstrated for the first time that sum frequency generation vibrational spectroscopy can be used to probe the peptide-peptide and lipid-peptide interactions in cell membrane in situ and in real time by determination of the line width of amide I band of protein backbone. Using a "benchmark" model of α-helical WALP23, it is found that the dominated lipid-peptide interaction causes a narrow line width of the amide I band, whereas the peptide-peptide interaction can markedly broaden the line width. When WALP23 molecules insert into the lipid bilayer, a quite narrow line width of the amide I band is observed because of the lipid-peptide interaction. In contrast, when the peptide lies down on the bilayer surface, the line width of amide I band becomes very broad owing to the peptide-peptide interaction. In terms of the real-time change in the line width, the transition from peptide-peptide interaction to lipid-peptide interaction is monitored during the insertion of WALP23 into 1,2-dipalmitoyl- sn-glycero-3-phospho-(1'- rac-glycerol) (DPPG) lipid bilayer. The dephasing time of a pure α-helical WALP23 in 1-palmitoyl-2-oleoyl- sn-glycero-3-phospho-(1'- rac-glycerol) and DPPG bilayer is determined to be 2.2 and 0.64 ps, respectively. The peptide-peptide interaction can largely accelerate the dephasing time.

  8. Measured, calculated and predicted Stark widths of the singly ionized C, N, O, F, Ne, Si, P, S, Cl and Ar spectral lines

    Djeniže S.

    2000-01-01

    Full Text Available In order to find reliable Stark width data, needed in plasma spectroscopy comparision between the existing measured, calculated and predicted Stark width values was performed for ten singly ionized emitters: C, N, O, F, Ne Si, P, S, Cl and Ar in the lower lying 3s - 3p, 3p - 3d and 4s - 4p transitions. These emitters are present in many cosmic light sources. On the basis of the agreement between mentioned values 17 spectral lines from six singly ionized spectra have been recommended, for the first time, for plasma spectroscopy as spectral lines with reliable Stark width data. Critical analysis of the existing Stark width data is also given.

  9. Theoretical Stark broadening parameters for spectral lines arising from the 2p5ns, 2p5np and 2p5nd electronic configurations of Mg III

    Colón, C.; Moreno-Díaz, C.; Alonso-Medina, A.

    2013-10-01

    In the present work we report theoretical Stark widths and shifts calculated using the Griem semi-empirical approach, corresponding to 237 spectral lines of Mg III. Data are presented for an electron density of 1017 cm-3 and temperatures T = 0.5-10.0 (104K). The matrix elements used in these calculations have been determined from 23 configurations of Mg III: 2s22p6, 2s22p53p, 2s22p54p, 2s22p54f and 2s22p55f for even parity and 2s22p5ns (n = 3-6), 2s22p5nd (n = 3-9), 2s22p55g and 2s2p6np (n = 3-8) for odd parity. For the intermediate coupling (IC) calculations, we use the standard method of least-squares fitting from experimental energy levels by means of the Cowan computer code. Also, in order to test the matrix elements used in our calculations, we present calculated values of 70 transition probabilities of Mg III spectral lines and 14 calculated values of radiative lifetimes of Mg III levels. There is good agreement between our calculations and experimental radiative lifetimes. Spectral lines of Mg III are relevant in astrophysics and also play an important role in the spectral analysis of laboratory plasma. Theoretical trends of the Stark broadening parameter versus the temperature for relevant lines are presented. No values of Stark parameters can be found in the bibliography.

  10. Intensities, broadening and narrowing parameters in the ν3 band of methane

    Es-sebbar, Et-touhami

    2014-12-01

    The P-branch of methane\\'s ν3 band is probed to carry out an extensive study of the 2905-2908cm-1 infrared spectral region. Absolute line intensities as well as N2-, O2-, H2-, He-, Ar- and CO2-broadening coefficients are determined for nine transitions at room temperature. Narrowing parameters due to the Dicke effect have also been investigated. A narrow emission line-width (~0.0001cm-1) difference-frequency-generation (DFG) laser system is used as the tunable light source. To retrieve the CH4 spectroscopic parameters, Voigt and Galatry profiles were used to simulate the measured line shape of the individual transitions.

  11. Using the van der Waals broadening of the spectral atomic lines to measure the gas temperature of an argon microwave plasma at atmospheric pressure

    Yubero, C.; Dimitrijevic, M.S.; Garcia, M.C.; Calzada, M.D.

    2007-01-01

    The ro-vibrational emission spectra of the molecular species are usually used to measure the gas temperature of a discharge at atmospheric pressure. However, under some experimental conditions, it is difficult to detect them. In order to overcome this difficulty and obtain the temperature, there are methods based on the relation between the gas temperature and the van der Waals broadening of argon atomic spectral lines with a Stark contribution negligible. In this work, we propose a method based on this relation but for lines with a Stark broadening comparable with the van der Waals one

  12. Modeling of the He-like magnesium spectral lines radiation from the plasma created by XeCl and Nd-glass lasers

    Stepanov, A. E.; Starostin, A. N.; Roerich, V. C.; Makhrov, V. A.; Faenov, A. Ya.; Magunov, A. I.; Pikuz, T. A.; Skobelev, I. Yu.; Flora, F.; Bollanti, S.; Di Lazzaro, P.; Lisi, N.; Letardi, T.; Palladino, L.; Reale, A.; Batani, D.; Bossi, S.; Bornadinelo, A.; Scafati, A.; Reale, L.

    1997-01-01

    Resonant and intercombination spectral lines formation of He-like magnesium is analyzed both experimentally and numerically. It is shown that in plasma created by XeCl laser at flux density 8·10 12 W/cm 2 the peak of electron temperature is placed downstream from the critical surface at density significantly smaller than critical, and radiation in both resonant and recombination lines is also produced by the plasma region with density below critical. Simulations also show significant line radiation at large distances (1-2 mm) from the target as it was observed in experiments. This secondary peak is produced by a compression wave forming near the plasma front. As opposite, radiation in these lines in plasma created by Nd-glass laser at flux density 5·10 13 W/cm 2 comes from the plasma region placed deeper than the critical surface and has no tail at large distances

  13. Theoretical Stark widths and shifts of spectral lines of 2p5nf and 2p55g configurations of Mg III

    Moreno-Díaz, Cristina; Alonso-Medina, Aurelia; Colón, Cristóbal

    2014-01-01

    In this paper, we report theoretical Stark widths and shifts calculated using the Griem semi-empirical approach, which corresponds to 111 spectral lines of Mg III. The values of these Stark broadening parameters of spectral lines that arise from levels of 2p 5 nf and 2p 5 5g configurations of Mg III are presented in the literature for the first time. The aim of this work is to provide values to estimate the electron density of plasma Mg III in astrophysics and industrial applications. The data are presented for the temperatures T = 0.5–10.0 (10 4 K) and for an electron density of 10 17 cm −3 . The matrix of elements used in these calculations has been determined from 23 configurations of Mg III: 2s 2 2p 6 , 2s 2 2p 5 3p, 2s 2 2p 5 4p, 2s 2 2p 5 4f and 2s 2 2p 5 5f for the even parity and 2s 2 2p 5 ns (n = 3–6), 2s 2 2p 5 nd (n = 3–9), 2s 2 2p 5 5g and 2s2p 6 np (n = 3–8) for the odd parity. For the intermediate coupling calculations, we use the standard method of least square fitting from experimental energy levels by means of Cowan’s computer code. Lines with wavelengths of 134.6460, 135.2800, 189.0380, 190.0043, 192.8424, 408.2939 and 409.4375 nm have high probabilities and also have high values of broadening. Therefore, these lines can be used in some applications. A common regularity for the Stark width of the 189.038 nm spectral line of Mg III is discussed. (paper)

  14. Narrow linewidth pulsed optical parametric oscillator

    Tunable narrow linewidth radiation by optical parametric oscillation has many applications, particularly in spectroscopic investigation. In this paper, different techniques such as injection seeding, use of spectral selecting element like grating, grating and etalon in combination, grazing angle of incidence, entangled cavity ...

  15. Validation of spectral gas radiation models under oxyfuel conditions

    Becher, Johann Valentin

    2013-05-15

    Combustion of hydrocarbon fuels with pure oxygen results in a different flue gas composition than combustion with air. Standard computational-fluid-dynamics (CFD) spectral gas radiation models for air combustion are therefore out of their validity range in oxyfuel combustion. This thesis provides a common spectral basis for the validation of new spectral models. A literature review about fundamental gas radiation theory, spectral modeling and experimental methods provides the reader with a basic understanding of the topic. In the first results section, this thesis validates detailed spectral models with high resolution spectral measurements in a gas cell with the aim of recommending one model as the best benchmark model. In the second results section, spectral measurements from a turbulent natural gas flame - as an example for a technical combustion process - are compared to simulated spectra based on measured gas atmospheres. The third results section compares simplified spectral models to the benchmark model recommended in the first results section and gives a ranking of the proposed models based on their accuracy. A concluding section gives recommendations for the selection and further development of simplified spectral radiation models. Gas cell transmissivity spectra in the spectral range of 2.4 - 5.4 {mu}m of water vapor and carbon dioxide in the temperature range from 727 C to 1500 C and at different concentrations were compared in the first results section at a nominal resolution of 32 cm{sup -1} to line-by-line models from different databases, two statistical-narrow-band models and the exponential-wide-band model. The two statistical-narrow-band models EM2C and RADCAL showed good agreement with a maximal band transmissivity deviation of 3 %. The exponential-wide-band model showed a deviation of 6 %. The new line-by-line database HITEMP2010 had the lowest band transmissivity deviation of 2.2% and was therefore recommended as a reference model for the

  16. Hyperfine Structure of Spectral Lines of 143Nd+, 145Nd+, 139La+, 141Pr+ and 137Ba+ Investigated by Collinear Laser Ion Beam Spectroscopy

    Anjum, N.

    2012-01-01

    In this research work the hyperfine structures of spectral lines of barium (Ba) and three lanthanides elements; praseodymium (Pr), lanthanum (La) and neodymium (Nd) have been investigated. The hyperfine splitting factors A and B of the involved levels have been determined with high accuracy and the data are compared with other published results. This research work is divided in four parts. In the 1st part, the hyperfine structures of the spectral lines of the singly ionized praseodymium (Pr II) are investigated by three different laser spectroscopic techniques; laser induced fluorescence (LIF) spectroscopy, inter-modulated saturation spectroscopy and collinear laser ion beam spectroscopy (CLIBS). The 2nd part is concerned with the a control-check of the Marburg mass separator (MARS-II), as it was shifted from the University of Marburg, Germany, to Graz University of Technology in 2002. The check is performed using a well known spectral line 5853.67 Å of the odd isotope of singly ionized barium (137Ba II). In the 3rd part of this work the hyperfine structure of spectral lines of lanthanum-139 ions (139La II) is investigated. The 4th part is devoted to the investigation of the hyperfine structure of spectral lines of two odd isotopes of singly ionized neodymium (143Nd II and 145Nd II) and the determination of the coupling constants A and B of the involved levels. To determine the hyperfine anomaly the ratios of the magnetic dipole constants, i.e A143/A145, and the electric quadrupole constants B143/B145 of the corresponding levels are also calculated. The last three parts of this research project are executed using the high resolution, Doppler reduced method of CLIBS. In CLIBS technique the ions are accelerated by applying a high potential difference (∼ 20 kV). Due to the accelerating cooling (kinematic compression) the spread in velocities in the direction of the flight is reduced several times, hence the Doppler width is reduced. The accelerated ion beam is mass

  17. FIRST LONG-TERM OPTICAL SPECTRAL MONITORING OF A BINARY BLACK HOLE CANDIDATE E1821+643. I. VARIABILITY OF SPECTRAL LINES AND CONTINUUM

    Shapovalova, A. I.; Burenkov, A. N.; Zhdanova, V. E.; Popović, L. Č.; Chavushyan, V. H.; Valdés, J. R.; Patiño-Álvarez, V.; León-Tavares, J.; Torrealba, J.; Ilić, D.; Kovačević, A.; Kollatschny, W.

    2016-01-01

    We report the results of the first long-term (1990–2014) optical spectrophotometric monitoring of a binary black hole candidate QSO E1821+643, a low-redshift, high-luminosity, radio-quiet quasar. In the monitored period, the continua and Hγ fluxes changed about two times, while the Hβ flux changed about 1.4 times. We found periodical variations in the photometric flux with periods of 1200, 1850, and 4000 days, and 4500-day periodicity in the spectroscopic variations. However, the periodicity of 4000–4500 days covers only one cycle of variation and should be confirmed with a longer monitoring campaign. There is an indication of the period around 1300 days in the spectroscopic light curves, buts with small significance level, while the 1850-day period could not be clearly identified in the spectroscopic light curves. The line profiles have not significantly changed, showing an important red asymmetry and broad line peak redshifted around +1000 km s −1 . However, Hβ shows a broader mean profile and has a larger time lag (τ ∼ 120 days) than Hγ (τ ∼ 60 days). We estimate that the mass of the black hole is ∼2.6 × 10 9 M ⊙ . The obtained results are discussed in the frame of the binary black hole hypothesis. To explain the periodicity in the flux variability and high redshift of the broad lines, we discuss a scenario where dense, gas-rich, cloudy-like structures are orbiting around a recoiling black hole

  18. Magnetic fields in proton solar flare of X17.2/4B class according to data of simultaneous measurements in a few spectral lines

    Lozitsky, V.; Lozitska, N.

    2017-06-01

    Spectral-polarized magnetic field measurements in solar flare of 28 October 2003 of X17.2/4B class are compared in six FeI lines and in Hα line. Observations were carried out on Echelle spectrograph of horizontal solar telescope of Astronomical Observatory of Taras Shevchenko National University of Kyiv. Presented data relate to peak phase of flare and a place of photosphere outside sunspots where effective (average) magnetic field in FeI 6302.5 line was about 100 G and had S polarity. Measured splitting of emissive peaks in cores of strong FeI lines of 15th multiplet correspond to stronger fields, in range 550-700 G and S polarity too. Noticeablre splitting of emissive peaks (11-20 mÅ) were found also in Fe I 5434.527 line with effective Lande factor geff = -0.014. Value of this splitting and its sign indicate the existence of extremely strong fields of 25-50 kG of opposite (N) polarity which had negative Doppler velocities (lifting of plasma) on level of 1.7-2.2 km/sec. Magnetic field according to Hα line was 300 G and N polarity. Presented results indicate the essential inhomogeneity of magnetic field in flare volume which include the opposite polarities along the line of sight and wide range of effective magnetic fields.

  19. Curves of growth of spectral lines emitted by a laser-induced plasma: influence of the temporal evolution and spatial inhomogeneity of the plasma

    Aguilera, J.A.; Bengoechea, J.; Aragon, C. E-mail: carlos.aragon@unavarra.es

    2003-02-03

    The curves of growth (COG) of five Fe I lines emitted from a laser-induced plasma, generated with Fe-Ni alloys in air at atmospheric pressure, have been investigated. Spectral lines with different energy levels and line widths, emitted with a broad range of optical depths, have been included in the study in order to check the validity of theoretical models proposed for COG generation, based in the radiative transfer within a plasma in local thermodynamic equilibrium. The COGs have been measured at time windows of 4-5 {mu}s and 15-18 {mu}s. The Stark widths of the Fe I lines have been obtained, and the line widths have been determined by measuring the plasma electron density at the time windows selected. It is shown that at a time window of 4-5 {mu}s, the inhomogeneity of the plasma magnitudes has an important influence on the COGs of intense lines. For this time window, a two-region model of the plasma has been used to generate theoretical COGs that describe satisfactorily the experimental curves of all the lines using a single set of plasma parameters. The results reveal the existence of considerable gradients between the inner and the outer plasma regions in the temperature (9400-7800 K) and in the density of Fe atoms (4x10{sup 16}-0.02x10{sup 16} cm{sup -3} for a sample with 100% Fe). On the contrary, at the time window 15-18 {mu}s, at which the plasma has suffered most of its expansion and cooling process, the COGs of all the lines may be described by a single-region model, corresponding to a plasma with uniform temperature (6700 K) and density of Fe atoms (0.06x10{sup 16} cm{sup -3} for a sample with 100% Fe). It is also shown that at initial times, the plasma inhomogeneity has an important effect in the line profiles of intense spectral lines, which are described by using the two-region model of the laser-induced plasma.

  20. Narrow-Line Seyfert 1 Galaxies

    Komossa, S.

    2007-01-01

    Presento una revisión breve de las propiedades conocidas de las galaxias Seyfert 1 con líneas angostas (NLS1) en todo el espectro electromagnético y de los modelos propuestos para explicarlas. Sus propiedades de continuo y de emisión de líneas manifiestan una forma extrema de la actividad Seyfert. Las galaxias NLS1 en sí pueden ofrecer pistas importantes para discernir los parámetros que impulsan la actividad nuclear. Sus tasas de acreción altas y cercanas a la tasa de Eddington proveen...

  1. A narrow pH range supports butanol, hexanol, and octanol production from syngas in a continuous co-culture of Clostridium ljungdahlii and Clostridium kluyveri with in-line product extraction

    Hanno Richter

    2016-11-01

    Full Text Available Carboxydotrophic bacteria (CTB have received attention due to their ability to synthesize commodity chemicals from producer gas and synthesis gas (syngas. CTB have an important advantage of a high product selectivity compared to chemical catalysts. However, the product spectrum of wild-type CTB is narrow. Our objective was to investigate whether a strategy of combining two wild-type bacterial strains into a single, continuously fed bioprocessing step would be promising to broaden the product spectrum. Here, we have operated a syngas-fermentation process with Clostridium ljungdahlii and Clostridium kluyveri with in-line product extraction through gas stripping and product condensing within the syngas recirculation line. The main products from C. ljungdahlii fermentation at a pH of 6.0 were ethanol and acetate at net volumetric production rates of 65.5 and 431 mmol C•L-1•d-1, respectively. An estimated 2/3 of total ethanol produced was utilized by C. kluyveri to chain elongate with the reverse β-oxidation pathway, resulting in n-butyrate and n-caproate at net rates of 129 and 70 mmol C•L-1•d-1, respectively. C. ljungdahlii likely reduced the produced carboxylates to their corresponding alcohols with the reductive power from syngas. This resulted in the longer-chain alcohols n-butanol, n-hexanol, and n-octanol at net volumetric production rates of 39.2, 31.7, and 0.045 mmol C•L-1•d-1, respectively. The continuous production of the longer-chain alcohols occurred only within a narrow pH spectrum of 5.7-6.4 due to the pH discrepancy between the two strains. Regardless whether other wild-type strains could overcome this pH discrepancy, the specificity (mol carbon in product per mol carbon in all other liquid products for each longer-chain alcohol may never be high in a single bioprocessing step. This, because two bioprocesses compete for intermediates (i.e., carboxylates: 1 chain elongation; and 2 biological reduction. This innate

  2. THE AKARI 2.5-5.0 μm SPECTRAL ATLAS OF TYPE-1 ACTIVE GALACTIC NUCLEI: BLACK HOLE MASS ESTIMATOR, LINE RATIO, AND HOT DUST TEMPERATURE

    Kim, Dohyeong; Im, Myungshin; Kim, Ji Hoon; Jun, Hyunsung David; Lee, Seong-Kook [Center for the Exploration of the Origin of the Universe (CEOU), Astronomy Program, Department of Physics and Astronomy, Seoul National University, Shillim-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Woo, Jong-Hak; Lee, Hyung Mok; Lee, Myung Gyoon [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Shillim-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Nakagawa, Takao; Matsuhara, Hideo; Wada, Takehiko; Takagi, Toshinobu [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 252-5210 (Japan); Oyabu, Shinki [Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan); Ohyama, Youichi, E-mail: dohyeong@astro.snu.ac.kr, E-mail: mim@astro.snu.ac.kr [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 106, Taiwan (China)

    2015-01-01

    We present 2.5-5.0 μm spectra of 83 nearby (0.002 < z < 0.48) and bright (K < 14 mag) type-1 active galactic nuclei (AGNs) taken with the Infrared Camera on board AKARI. The 2.5-5.0 μm spectral region contains emission lines such as Brβ (2.63 μm), Brα (4.05 μm), and polycyclic aromatic hydrocarbons (3.3 μm), which can be used for studying the black hole (BH) masses and star formation activity in the host galaxies of AGNs. The spectral region also suffers less dust extinction than in the ultra violet (UV) or optical wavelengths, which may provide an unobscured view of dusty AGNs. Our sample is selected from bright quasar surveys of Palomar-Green and SNUQSO, and AGNs with reverberation-mapped BH masses from Peterson et al. Using 11 AGNs with reliable detection of Brackett lines, we derive the Brackett-line-based BH mass estimators. We also find that the observed Brackett line ratios can be explained with the commonly adopted physical conditions of the broad line region. Moreover, we fit the hot and warm dust components of the dust torus by adding photometric data of SDSS, 2MASS, WISE, and ISO to the AKARI spectra, finding hot and warm dust temperatures of ∼1100 K and ∼220 K, respectively, rather than the commonly cited hot dust temperature of 1500 K.

  3. Measurements of radiation near an atomic spectral line from the interaction of a 30 GeV electron beam and a long plasma

    Catravas, P.E.; Chattopadhyay, S.; Esarey, E.; Leemans, W.P.; Assmann, R.; Decker, F.-J.; Hogan, M.J.; Iverson, R.; Siemann, R.H.; Walz, D.; Whittum, D.; Blue, B.; Clayton, C; Joshi, C.; Marsh, K.A.; Mori, W.B.; Wang, S.; Katsouleas, T.; Lee, S.; Muggli, P.

    2000-01-01

    Emissions produced or initiated by a 30 GeV electron beam propagating through a ∼ 1 m long heat pipe oven containing neutral and partially ionized vapor have been measured near atomic spectral lines in a beam-plasma wakefield experiment. The Cerenkov spatial profile has been studied as a function of oven temperature and pressure, observation wavelength, and ionizing laser intensity and delay. The Cerenkov peak angle is affected by the creating of plasma, and estimates of neutral and plasma density have been extracted. Increases in visible background radiation, consistent with increased plasma recombination emissions due to dissipation of wakefields, were simultaneously measured

  4. Narrow dibaryon resonances

    Kajdalov, A.B.

    1986-01-01

    Experimental data on np interactions indicating to existence of narrow resonances in pp-system are discussed. Possible theoretical interpretations of these resonances are given. Experimental characteristics of the dibaryon resonances with isospin I=2 are considered

  5. Hexa pyranoside homologation: use of spectral width narrowing, and the chemical shift homonuclear correlation for characterization of the 4,6-0-benzylidene-2,3-di des oxy-3-C-hydroxymethyl-{alpha}-D-methyl ribopyranoside; Homologacao de hexopiranosideos: utilizacao de reducao da largura espectral e de correlacao homonuclear de deslocamentos quimicos para a caracterizacao do 4,6-O-benzilideno-2,3-didesoxi-3-C-hidroximetil-{alpha}-D- ribopiranosideo de metila (7)

    Souza Filho, J D; Silva, L.G. Fonseca e; Oliveira, A Braga de; Alves, R Jose [Minas Gerais Univ., Belo Horizonte, MG (Brazil); Lukacs, G [Centre National de la Recherche Scientifique (CNRS), 91 - Gif-sur-Yvette (France). Inst. de Chimie des Substances Naturelles

    1992-12-31

    The discovery of ramified sugars as various antibiotics constituents, leads to the development of various preparation technologies. In the framework of hexapiranose analogues synthesis, the alcohol-7 was the intermediary on which functional group interconversion reactions were performed. The carbonyl group reduction with Na B H{sub 4} in MeOH{sup 5} was performed, for obtaining the ethyl alcohol-6 a (99%). Later on, the reaction of stereoselective reduction of the double binding between C-2 and C-3 was conducted in presence of Ni-Ra in Ac O Et, allowing to obtain the two epimer 7 and 7 a alcohols, with 86.9 and 7.5% yield respectively. The 7 {sup 1} H NMR signals were easily assigned by analysing the extended spectrum obtained by narrowing the spectral line. In accordance with predictable multiplicity and H-6{alpha} (Triplet at 3.7 ppm) patterns, the triple doublet H-5, at 4.1 ppm has been assigned. The assignments were confirmed by a chemical shift homonuclear correlation experiment (COSY H-H). H-7, H-7{sup `} and H-4 have been assigned through the H-3. The use of hydroxyl proton as reference (d d, 2.72 ppm) allowed the confirmation of the chemical shift assigned to H-7 and H-7{sup `} 5 refs., 6 figs.

  6. Pressure effects on some argon spectral lines belonging to the 3p54p-3p5nd (n=5-7) transitions

    Wolnikowski, J.; Wawrzynski, J.; Bielski, A.; Szudy, J.

    1987-01-01

    Low pressure broadening and shift of four spectral lines of argon: 518.7 nm (3p 5 4p-3p 5 5d'), 522.1 nm (3p 5 4p-3p 5 7d), 549.6 nm (3p 5 4p-3p 5 6d) and 603.2 nm (3p 5 4p-3p 5 5d) have been investigated by means of a Fabry-Perot interferometer. The values of the pressure broadening and shift coefficients for argon-argon, argon-neon and argon-helium interactions in the low-current glow discharge conditions are determined. For all lines in the pure argon a red shift and in the argon-neon and argon-helium mixtures a blue shift has been found. The results cannot be interpreted on the basis of the existing simple interaction potential models within the framework of the adiabatic impact broadening theory. (orig.)

  7. Magnetic field effects on spectrally resolved lifetime of on-line oxygen monitoring using magneto-optic probes

    Mermut, O.; Gallant, P.; Le Bouch, N.; Leclair, S.; Noiseux, I.; Vernon, M.; Morin, J.-F.; Diamond, K.; Patterson, M. S.; Samkoe, K.; Pogue, B.

    2009-02-01

    Multimodal agents that serve as both probes for contrast and light-activated effectors of cellular processes in diseased tissue were developed. These agents were introduced into multicellular tumor spheroids (3D tissue models) and in the chorioallantoic membrane (CAM) of a chicken embryo. The luminescence decay was examined using a novel technique involving a spectrally-resolved fluorescence lifetime apparatus integrated with a weak electromagnet. A spectrallyresolved lifetime setup was used to identify magneto-optic species sensitive to magnetic field effects and distinguish from background emissions. We demonstrate that the applied magnetic fields can alter reaction rates and product distribution of some dyes detected by time- and spectrally-resolved luminescence changes. We will discuss the use of exogenous magneto-optical probes taken up in tumors to both induce phototoxicity, a process that is governed by complex and dynamically evolving mechanisms involving reactive oxygen species, and monitor treatment progress. The magnetic field enhancement, measured over a range of weak fields (0-300 mT) is correlated to oxygenation and may be used to monitor dynamic changes occurring due to oxygen consumption over the course of photodynamic therapy. Such online measurements provide the possibility to derive real-time information about response to treatment via monitoring magnetic field enhancement/suppression of the time-resolved, spectrally-resolved luminescence of the probe at the site of the treatment directly. Magnetic perturbation of lifetime can serve as a status reporter, providing optical feedback of oxygen-mediated treatments in situ and allowing for real-time adjustment of a phototherapy treatment plan.

  8. Mid-Infrared Interferometry on Spectral Lines. III. Ammonia and Silane around IRC +10216 and VY Canis Majoris

    Monnier, J. D.; Danchi, W. C.; Hale, D. S.; Tuthill, P. G.; Townes, C. H.

    2000-11-01

    Using the University of California Berkeley Infrared Spatial Interferometer with a radio frequency (RF) filter bank, the first interferometric observations of mid-infrared molecular absorption features of ammonia (NH3) and silane (SiH4) with very high spectral resolution (λ/Δλ~105) were made. Under the assumptions of spherical symmetry and uniform outflow, these new data permitted the molecular stratification around carbon star IRC +10216 and red supergiant VY CMa to be investigated. For IRC +10216, both ammonia and silane were found to form in the dusty outflow significantly beyond both the dust formation and gas acceleration zones. Specifically, ammonia was found to form before silane in a region of decaying gas turbulence (>~20R*), while the silane is produced in a region of relatively smooth gas flow much farther from the star (>~80R*). The depletion of gas-phase SiS onto grains soon after dust formation may fuel silane-producing reactions on the grain surfaces. For VY CMa, a combination of interferometric and spectral observations suggest that NH3 is forming near the termination of the gas acceleration phase in a region of high gas turbulence (~40R*).

  9. A New Radio Spectral Line Survey of Planetary Nebulae: Exploring Radiatively-driven Heating and Chemistry of Molecular Gas

    Bublitz, Jesse; Kastner, Joel H.; Santander-García, Miguel; Montez, Rodolfo; Alcolea, Javier; Balick, Bruce; Bujarrabal, Valentín

    2018-01-01

    We report the results of a survey of mm-wave molecular line emission from nine nearby (Radioastronomie Millimétrique (IRAM) 30 m telescope. Our sample comprises molecule-rich PNe spanning a wide range of central star UV luminosities as well as central star and nebular X-ray emission properties. Nine molecular line frequencies were chosen to investigate the molecular chemistry of these nebulae. New detections of one or more of five molecules -- the molecular mass tracer 13CO and the chemically important trace species HCO+, CN, HCN, and HNC -- were made in at least one PN. We present analysis of emission line flux ratios that are potential diagnostics of the influence that ultraviolet and X-ray radiation have on the chemistry of residual molecular gas in PNe.

  10. LINES

    Minas Bakalchev

    2015-10-01

    Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.

  11. Experimental transition probabilities for several spectral lines arising from the 5d10 6s{8s, 7p, 5f, 5g} electronic configurations of Pb III

    Alonso-Medina, A.

    2010-01-01

    Transition probabilities for 30 spectral lines, arising from the 5d 10 6s{8s, 7p, 5f, 5g} electronic configurations of Pb III (20 measured for the first time), have been experimentally determined from measurements of emission line intensities in a plasma lead induced by ablation with a Nd:YAG laser. The line intensities were obtained with the target placed in molecular argon at 6 Torr, recorded at a 400 ns delay from the laser pulse, which provides appropriate measurement conditions, and analysed between 200 and 700 nm. They are measured when the plasma reaches local thermodynamic equilibrium (LTE). The plasma under study had an electron temperature (T) of 21,400 K and an electron number density (N e ) of 7x10 16 cm -3 . The influence of self-absorption has been estimated for every line, and plasma homogeneity has been checked. The values obtained were compared with previous experimental values and theoretical estimates where possible.

  12. Adding the s-Process Element Cerium to the APOGEE Survey: Identification and Characterization of Ce II Lines in the H-band Spectral Window

    Cunha, Katia; Smith, Verne V.; Hasselquist, Sten; Souto, Diogo; Shetrone, Matthew D.; Allende Prieto, Carlos; Bizyaev, Dmitry; Frinchaboy, Peter; García-Hernández, D. Anibal; Holtzman, Jon; Johnson, Jennifer A.; Jőnsson, Henrik; Majewski, Steven R.; Mészáros, Szabolcs; Nidever, David; Pinsonneault, Mark; Schiavon, Ricardo P.; Sobeck, Jennifer; Skrutskie, Michael F.; Zamora, Olga; Zasowski, Gail; Fernández-Trincado, J. G.

    2017-08-01

    Nine Ce II lines have been identified and characterized within the spectral window observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey (between λ1.51 and 1.69 μm). At solar metallicities, cerium is an element that is produced predominantly as a result of the slow capture of neutrons (the s-process) during asymptotic giant branch stellar evolution. The Ce II lines were identified using a combination of a high-resolution (R=λ /δ λ ={{100,000}}) Fourier Transform Spectrometer (FTS) spectrum of α Boo and an APOGEE spectrum (R = 22,400) of a metal-poor, but s-process enriched, red giant (2M16011638-1201525). Laboratory oscillator strengths are not available for these lines. Astrophysical gf-values were derived using α Boo as a standard star, with the absolute cerium abundance in α Boo set by using optical Ce II lines that have precise published laboratory gf-values. The near-infrared Ce II lines identified here are also analyzed, as consistency checks, in a small number of bright red giants using archival FTS spectra, as well as a small sample of APOGEE red giants, including two members of the open cluster NGC 6819, two field stars, and seven metal-poor N- and Al-rich stars. The conclusion is that this set of Ce II lines can be detected and analyzed in a large fraction of the APOGEE red giant sample and will be useful for probing chemical evolution of the s-process products in various populations of the Milky Way.

  13. Spectral Filtering Criteria for U-Band Test Light for In-Service Line Monitoring in Optical Fiber Networks

    Honda, Nazuki; Izumita, Hisashi; Nakamura, Minoru

    2006-06-01

    In the fiber-to-the-home era, thousands of optical fibers will have to be accommodated in the central offices of optical access networks. To reduce maintenance costs and improve the service reliability of optical fiber networks, the authors must develop an optical fiber line testing system with a function for in-service line monitoring that uses a test light with a wavelength different from the communication light wavelength. To monitor an in-service line in an optical network, the effective rejection ratio of the test light must be taken into account. This ratio depends on the spectrum of the test light from the optical time-domain reflectometer and the rejection band of the filter in front of the optical network unit. The dependence of the effective rejection ratio as a function of the sideband suppression ratio (SBSR) and of the ratio of the rejection band to the bandwidth of the sideband noise d/D is clarified. When d/D =0.1 and the target effective rejection ratio of the filter is -40 dB, the SBSR and the filter loss of the termination cable must be -70 and -43 dB, respectively, or the SBSR must be -80 dB. When d/D service line monitoring for a 10-Gb/s transmission using a 1650-nm test light with an SBSR of -80 dB is also demonstrated.

  14. A New Radio Spectral Line Survey of Planetary Nebulae: Exploring Radiatively Driven Heating and Chemistry of Molecular Gas

    Bublitz, Jesse

    Planetary nebulae contain shells of cold gas and dust whose heating and chemistry is likely driven by UV and X-ray emission from their central stars and from wind-collision-generated shocks. We present the results of a survey of molecular line emissions in the 88 - 235 GHz range from nine nearby (Radioastronomie Millimetrique. Rotational transitions of nine molecules, including the well-studied CO isotopologues and chemically important trace species, were observed and the results compared with and augmented by previous studies of molecular gas in PNe. Lines of the molecules HCO+, HNC, HCN, and CN, which were detected in most objects, represent new detections for five planetary nebulae in our study. Flux ratios were analyzed to identify correlations between the central star and/or nebular ultraviolet/X-ray luminosities and the molecular chemistries of the nebulae. Analysis reveals the apparent dependence of the HNC/HCN line ratio on PN central star UV luminosity. There exists no such clear correlation between PN X-rays and various diagnostics of PN molecular chemistry. The correlation between HNC/HCN ratio and central star UV luminosity hints at the potential of molecular emission line studies of PNe for improving our understanding of the role that high-energy radiation plays in the heating and chemistry of photodissociation regions.

  15. Jihadism, Narrow and Wide

    Sedgwick, Mark

    2015-01-01

    The term “jihadism” is popular, but difficult. It has narrow senses, which are generally valuable, and wide senses, which may be misleading. This article looks at the derivation and use of “jihadism” and of related terms, at definitions provided by a number of leading scholars, and at media usage....... It distinguishes two main groups of scholarly definitions, some careful and narrow, and some appearing to match loose media usage. However, it shows that even these scholarly definitions actually make important distinctions between jihadism and associated political and theological ideology. The article closes...

  16. Late-time spectral line formation in Type IIb supernovae, with application to SN 1993J, SN 2008ax, and SN 2011dh

    Jerkstrand, A.; Ergon, M.; Smartt, S. J.; Fransson, C.; Sollerman, J.; Taubenberger, S.; Bersten, M.; Spyromilio, J.

    2015-01-01

    We investigate line formation processes in Type IIb supernovae (SNe) from 100 to 500 days post-explosion using spectral synthesis calculations. The modelling identifies the nuclear burning layers and physical mechanisms that produce the major emission lines, and the diagnostic potential of these. We compare the model calculations with data on the three best observed Type IIb SNe to-date - SN 1993J, SN 2008ax, and SN 2011dh. Oxygen nucleosynthesis depends sensitively on the main-sequence mass of the star and modelling of the [O I] λλ6300, 6364 lines constrains the progenitors of these three SNe to the MZAMS = 12-16 M⊙ range (ejected oxygen masses 0.3-0.9 M⊙), with SN 2011dh towards the lower end and SN 1993J towards the upper end of the range. The high ejecta masses from MZAMS ≳ 17 M⊙ progenitors give rise to brighter nebular phase emission lines than observed. Nucleosynthesis analysis thus supports a scenario of low-to-moderate mass progenitors for Type IIb SNe, and by implication an origin in binary systems. We demonstrate how oxygen and magnesium recombination lines may be combined to diagnose the magnesium mass in the SN ejecta. For SN 2011dh, a magnesium mass of 0.02-0.14 M⊙ is derived, which gives a Mg/O production ratio consistent with the solar value. Nitrogen left in the He envelope from CNO burning gives strong [N II] λλ6548, 6583 emission lines that dominate over Hα emission in our models. The hydrogen envelopes of Type IIb SNe are too small and dilute to produce any noticeable Hα emission or absorption after ~150 days, and nebular phase emission seen around 6550 Å is in many cases likely caused by [N II] λλ6548, 6583. Finally, the influence of radiative transport on the emergent line profiles is investigated. Significant line blocking in the metal core remains for several hundred days, which affects the emergent spectrum. These radiative transfer effects lead to early-time blueshifts of the emission line peaks, which gradually

  17. Correlates of Narrow Bracketing

    Koch, Alexander; Nafziger, Julia

    We examine whether different phenomena of narrow bracketing can be traced back to some common characteristic and whether and how different phenomena are related. We find that making dominated lottery choices or ignoring the endowment when making risky choices are related phenomena and are both as...

  18. GAS MOTION STUDY OF Lyα EMITTERS AT z ∼ 2 USING FUV AND OPTICAL SPECTRAL LINES ,

    Hashimoto, Takuya; Shimasaku, Kazuhiro; Nakajima, Kimihiko; Ouchi, Masami; Ono, Yoshiaki; Rauch, Michael; Janice Lee; Okamura, Sadanori

    2013-01-01

    We present the results of Magellan/MMIRS and Keck/NIRSPEC spectroscopy for five Lyα emitters (LAEs) at z ≅ 2.2 for which high-resolution FUV spectra from Magellan/MagE are available. We detect nebular emission lines including Hα on the individual basis and low-ionization interstellar (LIS) absorption lines in a stacked FUV spectrum, and measure average offset velocities of the Lyα line, Δv Lyα , and LIS absorption lines, Δv abs , with respect to the systemic velocity defined by the nebular lines. For a sample of eight z ∼ 2-3 LAEs without active galactic nucleus from our study and the literature, we obtain Δv Lyα = 175 ± 35 km s –1 , which is significantly smaller than that of Lyman-break Galaxies (LBGs), Δv Lyα ≅ 400 km s –1 . The stacked FUV spectrum gives Δv abs = –179 ± 73 km s –1 , comparable to that of LBGs. These positive Δv Lyα and negative Δv abs suggest that LAEs also have outflows. In contrast to LBGs, however, the LAEs' Δv Lyα is as small as |Δv abs |, suggesting low neutral hydrogen column densities. Such a low column density with a small number of resonant scattering may cause the observed strong Lyα emission of LAEs. We find an anti-correlation between Lyα equivalent width (EW) and Δv Lyα in a compilation of LAE and LBG samples. Although its physical origin is not clear, this anti-correlation result appears to challenge the hypothesis that a strong outflow, by means of a reduced number of resonant scattering, produces a large EW. If LAEs at z > 6 have similarly small Δv Lyα values, constraints on the reionization history derived from the Lyα transmissivity may need to be revised.

  19. GAS MOTION STUDY OF Ly{alpha} EMITTERS AT z {approx} 2 USING FUV AND OPTICAL SPECTRAL LINES {sup ,}

    Hashimoto, Takuya; Shimasaku, Kazuhiro; Nakajima, Kimihiko [Department of Astronomy, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan); Ouchi, Masami; Ono, Yoshiaki [Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Rauch, Michael; Janice Lee [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Okamura, Sadanori, E-mail: thashimoto@astron.s.u-tokyo.ac.jp [Department of Advanced Sciences, Faculty of Science and Engineering, Hosei University, 3-7-2 Kajino-cho, Koganei-shi, Tokyo 184-8584 (Japan)

    2013-03-01

    We present the results of Magellan/MMIRS and Keck/NIRSPEC spectroscopy for five Ly{alpha} emitters (LAEs) at z {approx_equal} 2.2 for which high-resolution FUV spectra from Magellan/MagE are available. We detect nebular emission lines including H{alpha} on the individual basis and low-ionization interstellar (LIS) absorption lines in a stacked FUV spectrum, and measure average offset velocities of the Ly{alpha} line, {Delta}v {sub Ly{alpha}}, and LIS absorption lines, {Delta}v {sub abs}, with respect to the systemic velocity defined by the nebular lines. For a sample of eight z {approx} 2-3 LAEs without active galactic nucleus from our study and the literature, we obtain {Delta}v {sub Ly{alpha}} = 175 {+-} 35 km s{sup -1}, which is significantly smaller than that of Lyman-break Galaxies (LBGs), {Delta}v {sub Ly{alpha}} {approx_equal} 400 km s{sup -1}. The stacked FUV spectrum gives {Delta}v {sub abs} = -179 {+-} 73 km s{sup -1}, comparable to that of LBGs. These positive {Delta}v {sub Ly{alpha}} and negative {Delta}v {sub abs} suggest that LAEs also have outflows. In contrast to LBGs, however, the LAEs' {Delta}v {sub Ly{alpha}} is as small as |{Delta}v {sub abs}|, suggesting low neutral hydrogen column densities. Such a low column density with a small number of resonant scattering may cause the observed strong Ly{alpha} emission of LAEs. We find an anti-correlation between Ly{alpha} equivalent width (EW) and {Delta}v {sub Ly{alpha}} in a compilation of LAE and LBG samples. Although its physical origin is not clear, this anti-correlation result appears to challenge the hypothesis that a strong outflow, by means of a reduced number of resonant scattering, produces a large EW. If LAEs at z > 6 have similarly small {Delta}v {sub Ly{alpha}} values, constraints on the reionization history derived from the Ly{alpha} transmissivity may need to be revised.

  20. 3D Doppler Tomography of the X-Ray Binary System Cygnus X-1 from Spectral Observations in 2007 in the HeII λ 4686 Å Line

    Agafonov, M. I.; Karitskaya, E. A.; Sharova, O. I.; Bochkarev, N. G.; Zharikov, S. V.; Butenko, G. Z.; Bondar', A. V.; Sidorov, M. Yu.

    2018-02-01

    The results of a 3D Doppler tomography analysis for the X-ray binary system Cyg X-1 in the HeII λ 4686 Å line are presented. Information about the motions of gaseous flows outside the orbital plane has been obtained for the first time. Line profiles obtained in June 2007 on the 2-m telescope of the Terskol Branch of the Institute of Astronomy (Russia) and on the 2.1-m telescope of the National Astronomical Observatory of Mexico were used. A detailed analysis of these spectral data is presented: the distribution of the data in time, distribution of orbital phases for the projections, comparison of the line profile shapes for the data from two observatories. The geometry of the total transfer function obtained in the reconstruction is considered. The possibility of applying the profiles obtained to realize 3D tomography is justified. The resolution of the constructed 3D tomogram in velocity space is 60 × 60 × 40 km/s for V x , V y , V z . Fifteen cross sections for 15 different V z values perpendicular to the orbital plane are presented. The intensity distributions corresponding to the velocities of gaseous structures in the binary system are obtained. The reconstruction was realized using the radio-astronomical approach, developed for solving problems in tomography with a limited number of projections.

  1. XMM-Newton observation of the NLS1 galaxy Ark 564. I. Spectral analysis of the time-average spectrum

    Papadakis, I.E.; Brinkmann, W.; Page, M.J.; McHardy, I.; Uttley, P.

    2007-01-01

    Context: .We present the results from the spectral analysis of the time-average spectrum of the Narrow Line Seyfert 1 (NLS1) galaxy Ark 564 from a ~100 ks XMM-Newton observation. Aims: .Our aim is to characterize accurately the shape of the time-average, X-ray continuum spectrum of the source and

  2. Multiphoton spectral analysis of benzo[a]pyrene uptake and metabolism in a rat liver cell line

    Barhoumi, Rola; Mouneimne, Youssef; Ramos, Ernesto; Morisseau, Christophe; Hammock, Bruce D.; Safe, Stephen; Parrish, Alan R.; Burghardt, Robert C.

    2011-01-01

    Dynamic analysis of the uptake and metabolism of polycyclic aromatic hydrocarbons (PAHs) and their metabolites within live cells in real time has the potential to provide novel insights into genotoxic and non-genotoxic mechanisms of cellular injury caused by PAHs. The present work, combining the use of metabolite spectra generated from metabolite standards using multiphoton spectral analysis and an 'advanced unmixing process', identifies and quantifies the uptake, partitioning, and metabolite formation of one of the most important PAHs (benzo[a]pyrene, BaP) in viable cultured rat liver cells over a period of 24 h. The application of the advanced unmixing process resulted in the simultaneous identification of 8 metabolites in live cells at any single time. The accuracy of this unmixing process was verified using specific microsomal epoxide hydrolase inhibitors, glucuronidation and sulfation inhibitors as well as several mixtures of metabolite standards. Our findings prove that the two-photon microscopy imaging surpasses the conventional fluorescence imaging techniques and the unmixing process is a mathematical technique that seems applicable to the analysis of BaP metabolites in living cells especially for analysis of changes of the ultimate carcinogen benzo[a]pyrene-r-7,t-8-dihydrodiol-t-9,10-epoxide. Therefore, the combination of the two-photon acquisition with the unmixing process should provide important insights into the cellular and molecular mechanisms by which BaP and other PAHs alter cellular homeostasis.

  3. Non-impact modeling of electron broadening of hydrogen spectral lines in dense but relatively cold plasmas

    Ferri, S.; Buescher, S.; Wrubel, Th.; Kunze, H.-J.; Calisti, A.; Stamm, R.; Talin, B.

    2001-01-01

    The standard static-ion/impact-electron theory of line broadening is assessed with calculations of hydrogen lines over a broad range of plasma conditions. In most cases, discrepancies between results from theory and experiments are explained by the neglect of ion-dynamics effects. Nevertheless, recent experiments involving high density but low temperature plasmas indicate that ion-dynamics/impact-electron models may seriously overestimate the broadening for such conditions. We show that the observed discrepancies are not due to the ion modeling but due to the impact approximation of the electrons in the Original Frequency Fluctuation Model (FFM). This situation arises for plasma conditions where the interactions with the electrons are a major broadening mechanism and quasi-static, i.e. non-binary, electron effects are important. An alternative approach to a binary collision operator is therefore proposed by means of the FFM code generalized to the two components (ions and electrons) of the plasma. Accurate simulations accounting for the electron plus ion field dynamics have been used to corroborate the FFM as applied to both ion and electron perturbers, and good agreement is found with recent experiments on H α and P α for dense but relatively cold plasmas

  4. Measurement of high-energy (10–60 keV) x-ray spectral line widths with eV accuracy

    Seely, J. F., E-mail: seelyjf@gmail.com; Feldman, U. [Artep Inc., 2922 Excelsior Springs Court, Ellicott City, Maryland 21042 (United States); Glover, J. L.; Hudson, L. T.; Ralchenko, Y.; Henins, Albert [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Pereira, N. [Ecopulse Inc., P. O. Box 528, Springfield, Virginia 22152 (United States); Di Stefano, C. A.; Kuranz, C. C.; Drake, R. P. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Chen, Hui; Williams, G. J.; Park, J. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    2014-11-15

    A high resolution crystal spectrometer utilizing a crystal in transmission geometry has been developed and experimentally optimized to measure the widths of emission lines in the 10–60 keV energy range with eV accuracy. The spectrometer achieves high spectral resolution by utilizing crystal planes with small lattice spacings (down to 2d = 0.099 nm), a large crystal bending radius and Rowland circle diameter (965 mm), and an image plate detector with high spatial resolution (60 μm in the case of the Fuji TR image plate). High resolution W L-shell and K-shell laboratory test spectra in the 10–60 keV range and Ho K-shell spectra near 47 keV recorded at the LLNL Titan laser facility are presented. The Ho K-shell spectra are the highest resolution hard x-ray spectra recorded from a solid target irradiated by a high-intensity laser.

  5. Using the van der Waals broadening of spectral atomic lines to measure the gas temperature of an argon-helium microwave plasma at atmospheric pressure

    Munoz, J.; Dimitrijevic, M.S.; Yubero, C.; Calzada, M.D.

    2009-01-01

    The applications of plasmas generated with gas mixtures have become increasingly common in different scientific and technological fields. In order to understand the advantages of these discharges, for instance in chemical analysis, it is necessary to know the gas temperature (T g , kinetic energy of the heavy particles) since it has a great influence on the atomization reactions of the molecules located in the discharge, along with the dependence of the reaction rate on this parameter. The ro-vibrational emission spectra of the molecular species are usually used to measure the gas temperature of a discharge at atmospheric pressure although under some experimental conditions, these are difficult to detect. In such cases, the gas temperature can be determined from the van der Waals broadening of the emitted atomic spectral lines related to this parameter. The method proposed is based on the van der Waals broadening taking into account two perturbers

  6. Review of Langmuir-Wave-Caused Dips and Charge-Exchange-Caused Dips in Spectral Lines from Plasmas and their Applications

    Elisabeth Dalimier

    2014-05-01

    Full Text Available We review studies of two kinds of dips in spectral line profiles emitted by plasmas—dips that have been predicted theoretically and observed experimentally: Langmuir-wave-caused dips (L-dips and charge-exchange-caused dips (X-dips. There is a principal difference with respect to positions of L-dips and X-dips relative to the unperturbed wavelength of a spectral line: positions of L-dips scale with the electron density Ne roughly as Ne1/2, while positions of X-dips are almost independent of Ne (the dependence is much weaker than for L-dips. L-dips and X-dips phenomena are important, both fundamentally and practically. The fundamental importance is due to a rich physics behind each of these phenomena. L-dips are a multi-frequency resonance phenomenon caused by a single-frequency (monochromatic electric field. X-dips are due to charge exchange at anticrossings of terms of a diatomic quasi-molecule, whose nuclei have different charges. As for important practical applications, they are as follows: observations of L-dips constitute a very accurate method to measure the electron density in plasmas—a method that does not require knowledge of the electron temperature. L-dips also allow measuring the amplitude of the electric field of Langmuir waves—the only spectroscopic method available for this purpose. Observations of X-dips provide an opportunity to determine rate coefficient of charge exchange between multi-charged ions. This is an important reference data, virtually inaccessible by other experimental methods. The rate coefficients of charge exchange are important for magnetic fusion in Tokamaks, for population inversion in the soft x-ray and VUV ranges, for ion storage devices, as well as for astrophysics (e.g., for the solar plasma and for determining the physical state of planetary nebulae.

  7. Quantum-mechanical vs. semi-classical spectral-line widths and shifts from the line core in the non-impact region for the Ar-perturbed/ K-radiator system

    Kreye, W.C.

    2007-01-01

    New quantum-mechanical (QM) and semi-classical (SC) shifts (d's) and widths (HWHM's, w's) were measured from the line core of computed full spectral-line shapes for the Ar-perturbed/K-radiator system (K/Ar). The initial state of our model was based on a 4p 2 P 3/2,1/2 pseudo-potential for the K/Ar system, and the final state on a zero potential. The Fourier transform of the line shape formed the basis for the computations. Excellent agreement was found between the QM and SC values of d and of w in a high-pressure (P) non-impact region, which was characterized by a √P dependence of w and a P dependence of d. These agreements were shown to be another example of a correspondence between classical (SC) quantities and QM quantities in the limit of large quantum numbers. Typically at P=1x10 6 Torr and T=400 K, w QM =448 cm -1 and w SC =479 cm -1 , where the deviation from the mean is ±3.3%. Also, d QM =-3815 cm -1 and d SC =-3716 cm -1 , where the deviation from the mean is ±1.3%. A new general method was formulated which yielded a definite pressure P 0 , which was defined as an upper limit to the low-pressure impact approximation and a lower limit to the non-impact region

  8. Spectral lines of methane measured up to 2.6 THz at sub-MHz accuracy with a CW-THz photomixing spectrometer: Line positions of rotational transitions induced by centrifugal distortion

    Bray, C.; Cuisset, A.; Hindle, F.; Mouret, G.; Bocquet, R.; Boudon, V.

    2017-12-01

    Several Doppler-limited rotational transitions of methane induced by centrifugal distortion have been measured with an unprecedented frequency accuracy using a THz photomixing synthesizer based on a frequency comb. Compared to previous synchrotron based FT-Far-IR measurements of Boudon et al. (Ref. [1]), the accuracy of the line frequency measurements is improved by one order of magnitude; this yields a corresponding increase of two orders of magnitude to the weighting of these transitions in the global fit. The rotational transitions in the ν4 ←ν4 hot band are measured for the first time by the broad spectral coverage of the photomixing CW-THz spectrometer providing access up to R(5) transitions at 2.6 THz. The new global fit including the present lines has been used to update the methane line list of the HITRAN database. Some small, but significant variations of the parameter values are observed and are accompanied by a reduction of the 1-σ uncertainties on the rotational (B0) and centrifugal distortion (D0) constants.

  9. Model calculations for a 600 A laser based on photopumping of Mo6+ by a spectral line of Mo11+

    Klapisch, M.; Cohen, M.; Goldstein, W.H.; Feldman, U.

    1990-01-01

    We assess aspects of the feasibility of a recent proposal to use the coincidence between a Mo 11+ , 136.499 A, line and a 4p 6 -(4p 5 ) 1/2 6s, J=1, transition of Mo 6+ , to obtain amplified spontaneous emission around 600 A. A collisional-radiative model for the Mo 6+ ion, including resonant photoexcitation of the 4p 5 1/2 6s level, was constructed using the HULLAC atomic physics package. The model included the 4s 2 4p 6 ; 4p 5 4d, 4f; 4p 5 5s, 5p, 5d; 4p 5 6s, 6p, 6d; 4s4p 6 4d, 4f; 4p 6 4d 2 and 4s 2 4p 4 4d 2 configurations, amounting to 193 levels. All configuration interactions and collisional mixing were taken into account. A gain of 3 cm -1 is obtained for the 4p 5 6s(J = 1)-4p 5 5p(J = 2) transition at 645 A with T e = 5 eV, n e = 10 18 cm -3 , and an effective radiation temperature of T rad > 40 eV for the pump transition. Other transitions exhibit lower gains. (orig.)

  10. [Study on the Effects and Compensation Effect of Recording Parameters Error on Imaging Performance of Holographic Grating in On-Line Spectral Diagnose].

    Jiang, Yan-xiu; Bayanheshig; Yang, Shuo; Zhao, Xu-long; Wu, Na; Li, Wen-hao

    2016-03-01

    To making the high resolution grating, a numerical calculation was used to analyze the effect of recording parameters on groove density, focal curve and imaging performance of the grating and their compensation. Based on Fermat' s principle, light path function and aberration, the effect on imaging performance of the grating was analyzed. In the case of fixed using parameters, the error of the recording angle has a greater influence on imaging performance, therefore the gain of the weight of recording angle can improve the accuracy of the recording angle values in the optimization; recording distance has little influence on imaging performance; the relative errors of recording parameters cause the change of imaging performance of the grating; the results indicate that recording parameter errors can be compensated by adjusting its corresponding parameter. The study can give theoretical guidance to the fabrication for high resolution varied-line-space plane holographic grating in on-line spectral diagnostic and reduce the alignment difficulty by analyze the main error effect the imaging performance and propose the compensation method.

  11. High-resolution measurement, line identification, and spectral modeling of the Kβ spectrum of heliumlike argon emitted by a laser-produced plasma using a gas-puff target

    Skobelev, I.Y.; Faenov, A.Y.; Dyakin, V.M.; Fiedorowicz, H.; Bartnik, A.; Szczurek, M.; Beiersdorfer, P.; Nilsen, J.; Osterheld, A.L.

    1997-01-01

    We present an analysis of the spectrum of satellite transitions to the He-β line in ArXVII. High-resolution measurements of the spectra from laser-heated Ar-gas-puff targets are made with spectral resolution of 10000 and spatial resolution of better than 50 μm. These are compared with tokamak measurements. Several different lines are identified in the spectra and the spectral analysis is used to determine the plasma parameters in the gas-puff laser-produced plasma. The data complement those from tokamak measurements to provide more complete information on the satellite spectra. copyright 1997 The American Physical Society

  12. Infrared studies of galactic nebulae. IV - Continuum and line radiation from planetary nebulae.

    Gillett, F. C.; Merrill, K. M.; Stein, W. A.

    1972-01-01

    Observations are reported of the detection of IR radiation from several planetary nebulae not previously known to be radiating at these wavelengths. Broad spectral bandwidth observations indicate that ir radiation in excess of that expected from atomic processes is a common phenomenon among these objects. Investigations with narrow spectral bandwidth show that in a few cases the energy in the 10.52-micron line is a significant fraction of the total energy observed in the broad-band measurements and in other cases a relatively small fraction of the total radiation. Other observations on two sources with narrow spectral bandwidth adjacent to the 10.52-micron line indicate that at these wavelengths a true continuum of radiation exists as well as lines. The results are discussed in relation to visual and radio-wavelength data.

  13. Spectral Monitoring of AGN: Preliminary Results for Ark 564 and Arp 102B

    Shapovalova A. I.

    2011-09-01

    Full Text Available We present preliminary results of the long-term spectral monitoring of two active galactic nuclei with different broad line shapes: Ark 564 and Arp 102B. Ark 564 is a bright nearby narrow-line Syfert 1 (NLS1 galaxy with relatively narrow permitted optical emission lines and a high Fe II/Hβ ratio, while Arp 102B is a nearby broad-line radio galaxy with broad double-peaked Balmer emission lines. The spectra of Ark 564 were observed during 11-year period (1999-2009 and the spectra of Arp 102B in the 12-year period (1998-2009, with SAO 6 m and 1 m telescopes (Russia and the OAGH 2.1 m telescope (Cananea, Mexico.

  14. Novel preconcentration technique for on-line coupling to high-speed narrow-bore capillary gas chromatography: sample enrichment by equilibrium (ab)sorption, I: Principles and theoretical aspects

    Pham Tuan, H.; Janssen, J.G.M.; Cramers, C.A.M.G.

    1997-01-01

    In recent years, there has been substantial progress in the field of high-speed narrow-bore capillary gas chromatography (GC) in general, and in the development of (trans)portable gas chromatographs for fast and accurate analysis in field applications in particular. Due to the limited

  15. Spectral shape of one-photon luminescence from single gold nanorods

    Te Wen

    2017-12-01

    Full Text Available Light emission from gold nanoparticles was investigated with ultra-narrow-band notch filters to obtain the complete spectral shape. The anti-Stokes emission band was observed at all excitation wavelengths. The spectral shape of the anti-Stokes emission could be well fitted by a Fermi–Dirac-like line shape, while the spectral profile of the Stokes emission could be fitted by a Lorentzian line shape. The electron distribution and local surface plasmon resonance jointly determined the spectral shape. Additionally, we found that the anti-Stokes emission intensity increased more rapidly compared with that of the Stokes emission as illumination power was increased. This phenomenon can be understood from the temperature dependence of the electron distribution owing to photothermal effects.

  16. Narrow beam neutron dosimetry.

    Ferenci, M Sutton

    2004-01-01

    Organ and effective doses have been estimated for male and female anthropomorphic mathematical models exposed to monoenergetic narrow beams of neutrons with energies from 10(-11) to 1000 MeV. Calculations were performed for anterior-posterior, posterior-anterior, left-lateral and right-lateral irradiation geometries. The beam diameter used in the calculations was 7.62 cm and the phantoms were irradiated at a height of 1 m above the ground. This geometry was chosen to simulate an accidental scenario (a worker walking through the beam) at Flight Path 30 Left (FP30L) of the Weapons Neutron Research (WNR) Facility at Los Alamos National Laboratory. The calculations were carried out using the Monte Carlo transport code MCNPX 2.5c.

  17. Selenium x-ray laser line profile measurements

    Koch, J.A.; MacGowan, B.J.; Da Silva, L.; Matthews, D.L.; Mrowka, S.; Underwood, J.H.; Batson, P.J.

    1992-01-01

    We discuss our recent measurements of the spectral width of the 206.38 Angstrom laser in Ne-like Se. These measurements were performed over a wide range of amplifier length indicate an intrinsic line width of 50 m Angstrom FWHM (full-width at half-maximum), show gain narrowing to 10 m Angstrom in intermediate length amplifiers and show no significant re-broadening in We briefly discuss the experiments and interpretations

  18. Narrow, duplicated internal auditory canal

    Ferreira, T. [Servico de Neurorradiologia, Hospital Garcia de Orta, Avenida Torrado da Silva, 2801-951, Almada (Portugal); Shayestehfar, B. [Department of Radiology, UCLA Oliveview School of Medicine, Los Angeles, California (United States); Lufkin, R. [Department of Radiology, UCLA School of Medicine, Los Angeles, California (United States)

    2003-05-01

    A narrow internal auditory canal (IAC) constitutes a relative contraindication to cochlear implantation because it is associated with aplasia or hypoplasia of the vestibulocochlear nerve or its cochlear branch. We report an unusual case of a narrow, duplicated IAC, divided by a bony septum into a superior relatively large portion and an inferior stenotic portion, in which we could identify only the facial nerve. This case adds support to the association between a narrow IAC and aplasia or hypoplasia of the vestibulocochlear nerve. The normal facial nerve argues against the hypothesis that the narrow IAC is the result of a primary bony defect which inhibits the growth of the vestibulocochlear nerve. (orig.)

  19. Laser-produced lithium plasma as a narrow-band extended ultraviolet radiation source for photoelectron spectroscopy.

    Schriever, G; Mager, S; Naweed, A; Engel, A; Bergmann, K; Lebert, R

    1998-03-01

    Extended ultraviolet (EUV) emission characteristics of a laser-produced lithium plasma are determined with regard to the requirements of x-ray photoelectron spectroscopy. The main features of interest are spectral distribution, photon flux, bandwidth, source size, and emission duration. Laser-produced lithium plasmas are characterized as emitters of intense narrow-band EUV radiation. It can be estimated that the lithium Lyman-alpha line emission in combination with an ellipsoidal silicon/molybdenum multilayer mirror is a suitable EUV source for an x-ray photoelectron spectroscopy microscope with a 50-meV energy resolution and a 10-mum lateral resolution.

  20. Spectral narrowing of coherent population trapping resonance in ...

    2014-02-15

    Feb 15, 2014 ... Quantum interference; ultracold atoms; thermal averaging. ... interference effect, where two excitation pathways with one common energy level are ... hyperfine ground state separation (1.517866 GHz) by a RF generator. The.

  1. The Spectral Energy Distributions of z ~ 8 Galaxies from the IRAC Ultra Deep Fields: Emission Lines, Stellar Masses, and Specific Star Formation Rates at 650 Myr

    Labbé, I.; Oesch, P. A.; Bouwens, R. J.; Illingworth, G. D.; Magee, D.; González, V.; Carollo, C. M.; Franx, M.; Trenti, M.; van Dokkum, P. G.; Stiavelli, M.

    2013-11-01

    Using new ultradeep Spitzer/InfraRed Array Camera (IRAC) photometry from the IRAC Ultra Deep Field program, we investigate the stellar populations of a sample of 63 Y-dropout galaxy candidates at z ~ 8, only 650 Myr after the big bang. The sources are selected from HST/ACS+WFC3/IR data over the Hubble Ultra Deep Field (HUDF), two HUDF parallel fields, and wide area data over the CANDELS/GOODS-South. The new Spitzer/IRAC data increase the coverage in [3.6] and [4.5] to ~120h over the HUDF reaching depths of ~28 (AB,1σ). The improved depth and inclusion of brighter candidates result in direct >=3σ InfraRed Array Camera (IRAC) detections of 20/63 sources, of which 11/63 are detected at >=5σ. The average [3.6]-[4.5] colors of IRAC detected galaxies at z ~ 8 are markedly redder than those at z ~ 7, observed only 130 Myr later. The simplest explanation is that we witness strong rest-frame optical emission lines (in particular [O III] λλ4959, 5007 + Hβ) moving through the IRAC bandpasses with redshift. Assuming that the average rest-frame spectrum is the same at both z ~ 7 and z ~ 8 we estimate a rest-frame equivalent width of {W}_{[O\\,\\scriptsize{III}]\\ \\lambda \\lambda 4959,5007+H\\beta }=670^{+260}_{-170} Å contributing 0.56^{+0.16}_{-0.11} mag to the [4.5] filter at z ~ 8. The corresponding {W}_{H\\alpha }=430^{+160}_{-110} Å implies an average specific star formation rate of sSFR=11_{-5}^{+11} Gyr-1 and a stellar population age of 100_{-50}^{+100} Myr. Correcting the spectral energy distribution for the contribution of emission lines lowers the average best-fit stellar masses and mass-to-light ratios by ~3 ×, decreasing the integrated stellar mass density to \\rho ^*(z=8,M_{\\rm{UV}}Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #11563, 9797. Based on observations with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of

  2. THE SPECTRAL ENERGY DISTRIBUTIONS OF z ∼ 8 GALAXIES FROM THE IRAC ULTRA DEEP FIELDS: EMISSION LINES, STELLAR MASSES, AND SPECIFIC STAR FORMATION RATES AT 650 MYR

    Labbé, I.; Bouwens, R. J.; Franx, M. [Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands); Oesch, P. A.; Illingworth, G. D.; Magee, D.; González, V. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Carollo, C. M. [Institute for Astronomy, ETH Zurich, 8092 Zurich (Switzerland); Trenti, M. [Kavli Institute for Cosmology and Institute of Astronomy, University of Cambridge, Cambridge (United Kingdom); Van Dokkum, P. G. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Stiavelli, M. [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

    2013-11-10

    Using new ultradeep Spitzer/InfraRed Array Camera (IRAC) photometry from the IRAC Ultra Deep Field program, we investigate the stellar populations of a sample of 63 Y-dropout galaxy candidates at z ∼ 8, only 650 Myr after the big bang. The sources are selected from HST/ACS+WFC3/IR data over the Hubble Ultra Deep Field (HUDF), two HUDF parallel fields, and wide area data over the CANDELS/GOODS-South. The new Spitzer/IRAC data increase the coverage in [3.6] and [4.5] to ∼120h over the HUDF reaching depths of ∼28 (AB,1σ). The improved depth and inclusion of brighter candidates result in direct ≥3σ InfraRed Array Camera (IRAC) detections of 20/63 sources, of which 11/63 are detected at ≥5σ. The average [3.6]-[4.5] colors of IRAC detected galaxies at z ∼ 8 are markedly redder than those at z ∼ 7, observed only 130 Myr later. The simplest explanation is that we witness strong rest-frame optical emission lines (in particular [O III] λλ4959, 5007 + Hβ) moving through the IRAC bandpasses with redshift. Assuming that the average rest-frame spectrum is the same at both z ∼ 7 and z ∼ 8 we estimate a rest-frame equivalent width of contributing 0.56{sup +0.16}{sub -0.11} mag to the [4.5] filter at z ∼ 8. The corresponding W{sub Hα}=430{sup +160}{sub -110} Å implies an average specific star formation rate of sSFR=11{sub -5}{sup +11} Gyr{sup –1} and a stellar population age of 100{sub -50}{sup +100} Myr. Correcting the spectral energy distribution for the contribution of emission lines lowers the average best-fit stellar masses and mass-to-light ratios by ∼3 ×, decreasing the integrated stellar mass density to ρ{sup *}(z=8,M{sub UV}<-18)=0.6{sup +0.4}{sub -0.3}×10{sup 6} M{sub sun} Mpc{sup –3}.

  3. Predicting soil nitrogen content using narrow-band indices from ...

    Optimal fertiliser applications for sustainable forest stand productivity management, whilst protecting the environment, is vital. This study estimated soil nitrogen content using leaf-level narrow-band vegetation indices derived from a hand-held 350–2 500 nm spectroradiometer. Leaf-level spectral data were collected and ...

  4. Measurements of Narrow Mg II Associated Absorption Doublets with ...

    2016-01-27

    Jan 27, 2016 ... The measurement of the variations of absorption lines over time is a good method to study the physical conditions of absorbers. In this paper, we measure the variations of the line strength of 36 narrow Mg II2796, 2803 associated absorption doublets, which are imprinted on 31 quasar spectra with two ...

  5. Generation of spectral clusters in a mixture of noble and Raman-active gases.

    Hosseini, Pooria; Abdolvand, Amir; St J Russell, Philip

    2016-12-01

    We report a novel scheme for the generation of dense clusters of Raman sidebands. The scheme uses a broadband-guiding hollow-core photonic crystal fiber (HC-PCF) filled with a mixture of H2, D2, and Xe for efficient interaction between the gas mixture and a green laser pump pulse (532 nm, 1 ns) of only 5 μJ of energy. This results in the generation from noise of more than 135 rovibrational Raman sidebands covering the visible spectral region with an average spacing of only 2.2 THz. Such a spectrally dense and compact fiber-based source is ideal for applications where closely spaced narrow-band laser lines with high spectral power density are required, such as in spectroscopy and sensing. When the HC-PCF is filled with a H2-D2 mixture, the Raman comb spans the spectral region from the deep UV (280 nm) to the near infrared (1000 nm).

  6. Selection of the optimal combination of water vapor absorption lines for detection of temperature in combustion zones of mixing supersonic gas flows by diode laser absorption spectrometry

    Mironenko, V.R.; Kuritsyn, Yu.A.; Bolshov, M.A.; Liger, V.V.

    2017-01-01

    Determination of a gas medium temperature by diode laser absorption spectrometry (DLAS) is based on the measurement of integral intensities of the absorption lines of a test molecule (generally water vapor molecule). In case of local thermodynamic equilibrium temperature is inferred from the ratio of the integral intensities of two lines with different low energy levels. For the total gas pressure above 1 atm the absorption lines are broadened and one cannot find isolated well resolved water vapor absorption lines within relatively narrow spectral interval of fast diode laser (DL) tuning range (about 3 cm"−"1). For diagnostics of a gas object in the case of high temperature and pressure DLAS technique can be realized with two diode lasers working in different spectral regions with strong absorption lines. In such situation the criteria of the optimal line selection differs significantly from the case of narrow lines. These criteria are discussed in our work. The software for selection the optimal spectral regions using the HITRAN-2012 and HITEMP data bases is developed. The program selects spectral regions of DL tuning, minimizing the error of temperature determination δT/T, basing on the attainable experimental error of line intensity measurement δS. Two combinations of optimal spectral regions were selected – (1.392 & 1.343 μm) and (1.392 & 1.339 μm). Different algorithms of experimental data processing are discussed.

  7. Flooding correlations in narrow channel

    Kim, S. H.; Baek, W. P.; Chang, S. H.

    1999-01-01

    Heat transfer in narrow gap is considered as important phenomena in severe accidents in nuclear power plants. Also in heat removal of electric chip. Critical heat flux(CHF) in narrow gap limits the maximum heat transfer rate in narrow channel. In case of closed bottom channel, flooding limited CHF occurrence is observed. Flooding correlations will be helpful to predict the CHF in closed bottom channel. In present study, flooding data for narrow channel geometry were collected and the work to recognize the effect of the span, w and gap size, s were performed. And new flooding correlations were suggested for high-aspect-ratio geometry. Also, flooding correlation was applied to flooding limited CHF data

  8. Narrow n anti n resonances

    Bogdanova, L.N.; Dalkarov, O.D.; Kerbikov, B.O.; Shapiro, I.S.

    1975-01-01

    The present status of the problem of quasinuclear states in systems of nucleons and antinucleons is reviewed. The theoretical predictions are compared with experimental data on narrow meson resonances near N anti N threshold which appeared in 1971-74

  9. Spectral Variability of the Herbig Ae/Be Star HD 37806

    Pogodin, M. A.; Pavlovskiy, S. E.; Kozlova, O. V.; Beskrovnaya, N. G.; Alekseev, I. Yu.; Valyavin, G. G.

    2018-03-01

    Results are reported from a spectroscopic study of the Herbig Ae/Be star HD 37806 from 2009 through 2017 using high resolution spectrographs at the Crimean Astrophysical Observatory and the OAN SPM Observatory in Mexico. 72 spectra of this object near the Hα, Hβ, HeI 5876 and D NaI lines are analyzed. The following results were obtained: 1. The type of spectral profile of the Hα line can change from P Cyg III to double emission and vice versa over a time scale on the order of a month. 2. Narrow absorption components are observed in the profiles of the Hα and D NaI lines with radial velocities that vary over a characteristic time on the order of a day. 3. On some days, the profiles of the Hβ, HeI 5876, and D NaI lines show signs of accretion of matter to the star with a characteristic lifetime of a few days. A possible interpretation of these phenomena was considered. The transformation of the Hα profile may be related to a change in the outer latitudinal width of the boundary of the wind zone. The narrow variable absorption lines may be caused by the rotation of local azimuthal inhomogeneities in the wind zone owing to the interaction of the disk with the star's magnetosphere in a propeller regime. Several current theoretical papers that predict the formation of similar inhomogeneous wind structures were examined. It is suggested that the episodes with signs of accretion in the spectral line profiles cannot be a consequence of the modulation of these profiles by the star's rotation but are more likely caused by sudden, brief changes in the accretion rate. These spectral observations of HD 37806 should be continued in a search for cyclical variability in the spectral parameters in order to identify direct signs of magnetospheric accretion and detect possible binary behavior in this object.

  10. Temperature Dependences of the Quantum-Mechanical and Semi-Classical Spectral-Line Widths and the Separation 0 of the Impact and Non-Impact Regions for an Ar-Perturbed/K-Radiator System

    W. C. Kreye

    2010-01-01

    Full Text Available Quantum-mechanical and semi-classical spectral-line shapes are computed at =400, 800, and 1000 K for the line core of the 5802 Å line of the Ar-Perturbed/K-Radiator system. HWHMs ('s are measured from computed full spectral-line shapes. The final-state pseudopotential is for the 721/2 state, and the initial-state potential is for the 423/2,3/2 state. Three high-pressure (P log(—versus—log( curves, corresponding to the non-impact region, intersect a similar set of low-P, impact-region curves at intersections, 0's. Similarly, for two sets of log(—versus—log( curves, which yield intersections, 0's, where is the perturber density. These 0's and 0's separate the two regions and represent the upper limits of the impact regions. A specific validity condition for the impact region is given by the equation ≤0. From an earlier spectroscopic, Fabry-Perot paper, expt=0.021 cm−1 at =400 K and =10 torr. Two theoretical values, theor=0.025 and 0.062 cm−1 corresponding to two different pseudo-potentials, are reported. Two -dependent figures are given, in which the first shows an increase in the impact region with , based on as the basic parameter, and the second which shows a decrease in the impact region with , based on as the basic parameter.

  11. Vision and spectroscopic sensing for joint tracing in narrow gap laser butt welding

    Nilsen, Morgan; Sikström, Fredrik; Christiansson, Anna-Karin; Ancona, Antonio

    2017-11-01

    The automated laser beam butt welding process is sensitive to positioning the laser beam with respect to the joint because a small offset may result in detrimental lack of sidewall fusion. This problem is even more pronounced in case of narrow gap butt welding, where most of the commercial automatic joint tracing systems fail to detect the exact position and size of the gap. In this work, a dual vision and spectroscopic sensing approach is proposed to trace narrow gap butt joints during laser welding. The system consists of a camera with suitable illumination and matched optical filters and a fast miniature spectrometer. An image processing algorithm of the camera recordings has been developed in order to estimate the laser spot position relative to the joint position. The spectral emissions from the laser induced plasma plume have been acquired by the spectrometer, and based on the measurements of the intensities of selected lines of the spectrum, the electron temperature signal has been calculated and correlated to variations of process conditions. The individual performances of these two systems have been experimentally investigated and evaluated offline by data from several welding experiments, where artificial abrupt as well as gradual deviations of the laser beam out of the joint were produced. Results indicate that a combination of the information provided by the vision and spectroscopic systems is beneficial for development of a hybrid sensing system for joint tracing.

  12. Japanese VLBI Network Observations of a Gamma-Ray Narrow ...

    J. Astrophys. Astr. (2014) 35, 215–218 c Indian Academy of Sciences. Japanese VLBI Network Observations of a Gamma-Ray. Narrow-Line Seyfert 1 Galaxy 1H 0323+342. Kiyoaki Wajima1,∗. , Kenta Fujisawa2, Masaaki Hayashida3. & Naoki Isobe4. 1Shanghai Astronomical Observatory, Chinese Academy of Sciences,.

  13. Absolute radiant power measurement for the Au M lines of laser-plasma using a calibrated broadband soft X-ray spectrometer with flat-spectral response.

    Troussel, Ph; Villette, B; Emprin, B; Oudot, G; Tassin, V; Bridou, F; Delmotte, F; Krumrey, M

    2014-01-01

    CEA implemented an absolutely calibrated broadband soft X-ray spectrometer called DMX on the Omega laser facility at the Laboratory for Laser Energetics (LLE) in 1999 to measure radiant power and spectral distribution of the radiation of the Au plasma. The DMX spectrometer is composed of 20 channels covering the spectral range from 50 eV to 20 keV. The channels for energies below 1.5 keV combine a mirror and a filter with a coaxial photo-emissive detector. For the channels above 5 keV the photoemissive detector is replaced by a conductive detector. The intermediate energy channels (1.5 keV power measurements with the new MLM channel and with the usual channel composed of a thin titanium filter and a coaxial detector (without mirror) are compared. All elements of the channel have been calibrated in the laboratory of the Physikalisch-Technische Bundesanstalt, Germany's National Metrology Institute, at the synchrotron radiation facility BESSY II in Berlin using dedicated well established and validated methods.

  14. Simultaneous measure of a spectral line profile and the apparatus function of a Fabry-Perot spectrometer when continuous background is present

    Moreno, J.M.; Quintanilla, M.; Mar, S.

    1978-01-01

    A deconvolution method of registered profile on a Fabry-Perot spectrometer is developed, when the actual profile of the source is a Voigt pattern together with a continuous background. The reliability and accuracy of the method is tested with theoreticaly simulated profiles. The method is applied both to measure the real line profiles and to find the Fabry-Perot parameters, as a test of its validity on studies of experimental profiles. Both measure types -source profile and apparatus function- are made simultaneously by means of analysis of the variations of registered profile, at 6438.5A Cd line and 6328A He-Ne laser line, varying the optical path between interferometer mirrors. (author) [es

  15. Rare-earth doped transparent ceramics for spectral filtering and quantum information processing

    Kunkel, Nathalie; Ferrier, Alban; Thiel, Charles W.; Ramírez, Mariola O.; Bausá, Luisa E.; Cone, Rufus L.; Ikesue, Akio; Goldner, Philippe

    2015-09-01

    Homogeneous linewidths below 10 kHz are reported for the first time in high-quality Eu3+ doped Y 2O3 transparent ceramics. This result is obtained on the 7F0→5D0 transition in Eu3+ doped Y 2O3 ceramics and corresponds to an improvement of nearly one order of magnitude compared to previously reported values in transparent ceramics. Furthermore, we observed spectral hole lifetimes of ˜15 min that are long enough to enable efficient optical pumping of the nuclear hyperfine levels. Additionally, different Eu3+ concentrations (up to 1.0%) were studied, resulting in an increase of up to a factor of three in the peak absorption coefficient. These results suggest that transparent ceramics can be useful in applications where narrow and deep spectral holes can be burned into highly absorbing lines, such as quantum information processing and spectral filtering.

  16. Development of on-line sorting system for detection of infected seed potatoes using visible near-infrared transmittance spectral technique

    Kim, Dae Yong; Cho, Byoung Kwan [Dept. of Biosystems Engineering, Chungnam National University, Daejeon (Korea, Republic of); Mo, Chang Yeun [Rural Development Administration, National Institute of Agricultural Engineering, Jeonju (Korea, Republic of); Kang, Jun Soon [Dept. of Horticultural Bioscience, Pusan National University, Pusan (Korea, Republic of)

    2015-02-15

    In this study, an online seed potato sorting system using a visible and near infrared (40 1100 nm) transmittance spectral technique and statistical model was evaluated for the nondestructive determination of infected and sound seed potatoes. Seed potatoes that had been artificially infected with Pectobacterium atrosepticum, which is known to cause a soil borne disease infection, were prepared for the experiments. After acquiring transmittance spectra from sound and infected seed potatoes, a determination algorithm for detecting infected seed potatoes was developed using the partial least square discriminant analysis method. The coefficient of determination(R{sup 2}{sub p}) of the prediction model was 0.943, and the classification accuracy was above 99% (n = 80) for discriminating diseased seed potatoes from sound ones. This online sorting system has good potential for developing a technique to detect agricultural products that are infected and contaminated by pathogens.

  17. Spectral features in the cosmic ray fluxes

    Lipari, Paolo

    2018-01-01

    The cosmic ray energy distributions contain spectral features, that is narrow energy regions where the slope of the spectrum changes rapidly. The identification and study of these features is of great importance to understand the astrophysical mechanisms of acceleration and propagation that form the spectra. In first approximation a spectral feature is often described as a discontinuous change in slope, however very valuable information is also contained in its width, that is the length of the energy interval where the change in spectral index develops. In this work we discuss the best way to define and parameterize the width a spectral feature, and for illustration discuss some of the most prominent known structures.

  18. PORTA: A three-dimensional multilevel radiative transfer code for modeling the intensity and polarization of spectral lines with massively parallel computers

    Štěpán, Jiří; Trujillo Bueno, J.

    2013-01-01

    Roč. 557, September (2013), A143/1-A143/15 ISSN 0004-6361 R&D Projects: GA ČR GPP209/12/P741 Grant - others:EU(XE) COST action MP1104 Institutional support: RVO:67985815 Keywords : line formation * magnetic fields * numerical methods Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.479, year: 2013

  19. Spectral stratigraphy

    Lang, Harold R.

    1991-01-01

    A new approach to stratigraphic analysis is described which uses photogeologic and spectral interpretation of multispectral remote sensing data combined with topographic information to determine the attitude, thickness, and lithology of strata exposed at the surface. The new stratigraphic procedure is illustrated by examples in the literature. The published results demonstrate the potential of spectral stratigraphy for mapping strata, determining dip and strike, measuring and correlating stratigraphic sequences, defining lithofacies, mapping biofacies, and interpreting geological structures.

  20. First line shape analysis and spectroscopic parameters for the ν11 band of 12C2H4

    Es-sebbar, Et-touhami

    2016-08-11

    An accurate knowledge of line intensities, collisional broadening coefficients and narrowing parameters is necessary for the interpretation of high-resolution infrared spectra of the Earth and other planetary atmospheres. One of the most promising spectral domains for (C2H4)-C-12 monitoring in such environments is located near the 336 gm window, through its v(11) C-H stretching mode. In this paper, we report an extensive study in which we precisely determine spectroscopic parameters of (C2H4)-C-12 v(11) band at 297 +/- 1 K, using a narrow Difference-Frequency-Generation (DFG) laser with 10(-4) cm(-1) resolution. Absorption measurements were performed in the 2975-2980 cm(-1) spectral window to investigate 32 lines corresponding to where, J\\'ka\\',kc\\'<- Jka,kc, 5 <= J <= 7; 0.5 <= K-a <= 6 and 1 <= K-c <= 14. Spectroscopic parameters are retrieved using either Voigt or appropriate Galatry profile to simulate the measured (C2H4)-C-12 line shape. Line intensities along with self-broadening coefficients are reported for all lines. Narrowing coefficients for each isolated line are also derived. To our knowledge, the current study reports the first extensive spectroscopic parameter measurements of the (C2H4)-C-12 v(11) band in the 2975-2980 cm(-1) range. (C) 2016 Elsevier Ltd. All rights reserved.

  1. First line shape analysis and spectroscopic parameters for the ν11 band of 12C2H4

    Es-sebbar, Et-touhami; Mantzaras, John; Benilan, Yves; Farooq, Aamir

    2016-01-01

    An accurate knowledge of line intensities, collisional broadening coefficients and narrowing parameters is necessary for the interpretation of high-resolution infrared spectra of the Earth and other planetary atmospheres. One of the most promising spectral domains for (C2H4)-C-12 monitoring in such environments is located near the 336 gm window, through its v(11) C-H stretching mode. In this paper, we report an extensive study in which we precisely determine spectroscopic parameters of (C2H4)-C-12 v(11) band at 297 +/- 1 K, using a narrow Difference-Frequency-Generation (DFG) laser with 10(-4) cm(-1) resolution. Absorption measurements were performed in the 2975-2980 cm(-1) spectral window to investigate 32 lines corresponding to where, J'ka',kc'<- Jka,kc, 5 <= J <= 7; 0.5 <= K-a <= 6 and 1 <= K-c <= 14. Spectroscopic parameters are retrieved using either Voigt or appropriate Galatry profile to simulate the measured (C2H4)-C-12 line shape. Line intensities along with self-broadening coefficients are reported for all lines. Narrowing coefficients for each isolated line are also derived. To our knowledge, the current study reports the first extensive spectroscopic parameter measurements of the (C2H4)-C-12 v(11) band in the 2975-2980 cm(-1) range. (C) 2016 Elsevier Ltd. All rights reserved.

  2. Dosimetry of narrow band UVB treatments

    Goode, D.H.; Mannering, D.M.

    1996-01-01

    Full text: For many years psoriasis has been treated with broad band UVB lamps. These lamps have a bell shaped spectrum which peaks at 305 nm and extends from 280 nm to 350 nm. However research with monochromatic UV radiation has shown that wavelengths between 300 nm and 320 nm are the most efficacious for clearing psoriasis while wavelengths below 305 nm are most effective for producing the undesirable side effect of erythema (sunburn). In response to these findings Philips developed a narrow band UVB tube in which a large fraction of the output was confined to a narrow peak (bandwidth 2.5 nm) situated at 311 nm. Christchurch Hospital replaced broad band UVB with narrow band treatments in August 1995 and as this required UV exposures to be substantially increased new protocols had to be developed. Three aspects needed to be addressed. These were translating the dose from broad band to narrow band for current patients, determining the initial dose for new patients and developing a formula for increasing subsequent exposures to both types of patient. To translate doses the spectral irradiance (μW/cm 2 /nm) that would fall on the patient was measured in both the old broad band and the new narrow band treatment units and from this UV doses were calculated. All doses were expressed in mJ/cm 2 of unweighted UV over the range 250 nm to 400 nm. The erythemal effectiveness of the two units were compared by using the CIE 1987 curve to express doses in terms of the equivalent exposure of monochromatic 297 nm radiation. It was found that an exposure of 3.96 mJ/cm 2 from the broad band FS40 tubes and 12.79 mJ/cm 2 from the narrow band TL/01 tubes were both equivalent to 1.00 mJ/cm 2 of monochromatic 297 nm radiation so when transferring patients all broad band doses needed to be increased by a factor of 3.2. Before transferring any patients this factor was confirmed by conducting two minimal erythema dose (MED) tests on a normal subject, one in each unit. For new patients a

  3. Line-narrowing in proton-detected nitrogen-14 NMR

    Cavadini, Simone; Vitzthum, Veronika; Ulzega, Simone; Abraham, Anuji; Bodenhausen, Geoffrey

    2010-01-01

    In solids spinning at the magic angle, the indirect detection of single-quantum (SQ) and double-quantum (DQ) 14N spectra ( I = 1) via spy nuclei S = 1/2 such as protons can be achieved in the manner of heteronuclear single- or multiple-quantum correlation (HSQC or HMQC) spectroscopy. The HMQC method relies on the excitation of two-spin coherences of the type T11IT11S and T21IT11S at the beginning of the evolution interval t1. The spectra obtained by Fourier transformation from t1 to ω1 may be broadened by the homogenous decay of the transverse terms of the spy nuclei S. This broadening is mostly due to homonuclear dipolar S- S' interactions between the proton spy nuclei. In this work we have investigated the possibility of inserting rotor-synchronized symmetry-based C or R sequences and decoupling schemes such as Phase-Modulated Lee-Goldburg (PMLG) sequences in the evolution period. These schemes reduce the homonuclear proton-proton interactions and lead to an enhancement of the resolution of both SQ and DQ proton-detected 14N HMQC spectra. In addition, we have investigated the combination of HSQC with symmetry-based sequences and PMLG and shown that the highest resolution in the 14N dimension is achieved by using HSQC in combination with symmetry-based sequences of the R-type. We show improvements in resolution in samples of L-alanine and the tripeptide ala-ala-gly (AAG). In particular, for L-alanine the width of the 14N SQ peak is reduced from 2 to 1.2 kHz, in agreement with simulations. We report accurate measurements of quadrupolar coupling constants and asymmetry parameters for amide 14N in AAG peptide bonds.

  4. Thermoelectricity in correlated narrow-gap semiconductors

    Tomczak, Jan M.

    2018-05-01

    We review many-body effects, their microscopic origin, as well as their impact on thermoelectricity in correlated narrow-gap semiconductors. Members of this class—such as FeSi and FeSb2—display an unusual temperature dependence in various observables: insulating with large thermopowers at low temperatures, they turn bad metals at temperatures much smaller than the size of their gaps. This insulator-to-metal crossover is accompanied by spectral weight-transfers over large energies in the optical conductivity and by a gradual transition from activated to Curie–Weiss-like behaviour in the magnetic susceptibility. We show a retrospective of the understanding of these phenomena, discuss the relation to heavy-fermion Kondo insulators—such as Ce3Bi4Pt3 for which we present new results—and propose a general classification of paramagnetic insulators. From the latter, FeSi emerges as an orbital-selective Kondo insulator. Focussing on intermetallics such as silicides, antimonides, skutterudites, and Heusler compounds we showcase successes and challenges for the realistic simulation of transport properties in the presence of electronic correlations. Further, we explore new avenues in which electronic correlations may contribute to the improvement of thermoelectric performance.

  5. Thermal tuning On narrow linewidth fiber laser

    Han, Peiqi; Liu, Tianshan; Gao, Xincun; Ren, Shiwei

    2010-10-01

    At present, people have been dedicated to high-speed and large-capacity optical fiber communication system. Studies have been shown that optical wavelength division multiplexing (WDM) technology is an effective means of communication to increase the channel capacity. Tunable lasers have very important applications in high-speed, largecapacity optical communications, and distributed sensing, it can provide narrow linewidth and tunable laser for highspeed optical communication. As the erbium-doped fiber amplifier has a large gain bandwidth, the erbium-doped fiber laser can be achieved lasing wavelength tunable by adding a tunable filter components, so tunable filter device is the key components in tunable fiber laser.At present, fiber laser wavelength is tuned by PZT, if thermal wavelength tuning is combined with PZT, a broader range of wavelength tuning is appearance . Erbium-doped fiber laser is used in the experiments,the main research is the physical characteristics of fiber grating temperature-dependent relationship and the fiber grating laser wavelength effects. It is found that the fiber laser wavelength changes continuously with temperature, tracking several temperature points observed the self-heterodyne spectrum and found that the changes in spectra of the 3dB bandwidth of less than 1kHz, and therefore the fiber laser with election-mode fiber Bragg grating shows excellent spectral properties and wavelength stability.

  6. Full-sky survey searching for ultra-narrow-band artificial CW signals: analysis of the results of Project META

    Lemarchand, Guillermo A.

    1996-06-01

    Project META (Megachannel ExtraTerrestrial Assay), a full-sky survey for artificial narrow-band signals, has been conducted from the Harvard/Smithsonian 26 m radiotelescope at Agassiz Station and from one of the two 30 m radiotelescopes of the Instituto Argentino de Radioastronomia (IAR). The search was performed near the 1420 MHz line of neutral hydrogen, and its second harmonic, using two 8.4 X 10(superscript 6) channel Fourier spectrometers of 0.05 Hz resolution and 400 kHz of instantaneous bandwidth. The observing frequency was corrected both for motions with respect to three astronomical inertial frames, and for the effect of Earth's rotation, which provides a characteristic changing signature for narrow-band signals of extraterrestrial origin. Among the 6 X 10(superscript 13) spectral channels searched in the northern hemisphere, Horowitz and Sagan reported 37 candidates events exceeding the average threshold of 1.7 X 10(superscript -23) W m(superscript -2), while in the southern hemisphere among 2 X 10(superscript 13) spectral channels analyzed we found 19 events exceeding the same threshold. The strongest signals that survive culling for terrestrial interference lie in or near the Galactic Plane. The first high resolution southern target search around 71 stars (-90 degrees intelligence. It is showed that these narrow-band non-repeating 'events' found by Project META can be generated by (a) radiometer noise fluctuations, (b) a population of constant galactic sources which undergo deep fading and amplification due to interstellar scintillation, consistent with ETI transmissions and (c) real, transient signals of either terrestrial or extraterrestrial origin. The Bayesian test shows that hypothesis (b) and (c) are both highly preferred to (a), but the first two are about equally likely. Using this analysis we discuss the best observing strategies to determine the real origin of these 'events'.

  7. Models of Emission-Line Profiles and Spectral Energy Distributions to Characterize the Multi-Frequency Properties of Active Galactic Nuclei

    Giovanni La Mura

    2017-11-01

    Full Text Available The spectra of active galactic nuclei (AGNs are often characterized by a wealth of emission lines with different profiles and intensity ratios that lead to a complicated classification. Their electromagnetic radiation spans more than 10 orders of magnitude in frequency. In spite of the differences between various classes, the origin of their activity is attributed to a combination of emitting components, surrounding an accreting supermassive black hole (SMBH, in the unified model. Currently, the execution of sky surveys, with instruments operating at various frequencies, provides the possibility to detect and to investigate the properties of AGNs on very large statistical samples. As a result of the spectroscopic surveys that allow the investigation of many objects, we have the opportunity to place new constraints on the nature and evolution of AGNs. In this contribution, we present the results obtained by working on multi-frequency data, and we discuss their relations with the available optical spectra. We compare our findings with the AGN unified model predictions, and we present a revised technique to select AGNs of different types from other line-emitting objects. We discuss the multi-frequency properties in terms of the innermost structures of the sources.

  8. A narrow-band k-distribution model with single mixture gas assumption for radiative flows

    Jo, Sung Min; Kim, Jae Won; Kwon, Oh Joon

    2018-06-01

    In the present study, the narrow-band k-distribution (NBK) model parameters for mixtures of H2O, CO2, and CO are proposed by utilizing the line-by-line (LBL) calculations with a single mixture gas assumption. For the application of the NBK model to radiative flows, a radiative transfer equation (RTE) solver based on a finite-volume method on unstructured meshes was developed. The NBK model and the RTE solver were verified by solving two benchmark problems including the spectral radiance distribution emitted from one-dimensional slabs and the radiative heat transfer in a truncated conical enclosure. It was shown that the results are accurate and physically reliable by comparing with available data. To examine the applicability of the methods to realistic multi-dimensional problems in non-isothermal and non-homogeneous conditions, radiation in an axisymmetric combustion chamber was analyzed, and then the infrared signature emitted from an aircraft exhaust plume was predicted. For modeling the plume flow involving radiative cooling, a flow-radiation coupled procedure was devised in a loosely coupled manner by adopting a Navier-Stokes flow solver based on unstructured meshes. It was shown that the predicted radiative cooling for the combustion chamber is physically more accurate than other predictions, and is as accurate as that by the LBL calculations. It was found that the infrared signature of aircraft exhaust plume can also be obtained accurately, equivalent to the LBL calculations, by using the present narrow-band approach with a much improved numerical efficiency.

  9. Importance of Cross-redistribution in Scattering Polarization of Spectral Lines: The Cases of {sup 3}P−{sup 3}S Triplets of Mg i and Ca i

    Sampoorna, M.; Nagendra, K. N., E-mail: sampoorna@iiap.res.in, E-mail: knn@iiap.res.in [Indian Institute of Astrophysics, Koramangala, Bengaluru 560 034 (India)

    2017-04-01

    Scattering on a multi-level atomic system has dominant contributions from resonance and Raman scattering. While initial and final levels are the same for resonance scattering, they are different for Raman scattering. The frequency redistribution for resonance scattering is described by the usual partial frequency redistribution functions of Hummer, while that for Raman scattering is described by cross-redistribution (XRD) function. In the present paper, we investigate the importance of XRD on linear polarization profiles of {sup 3}P−{sup 3}S triplets of Mg i and Ca i formed in an isothermal one-dimensional atmosphere. We show that XRD produces significant effects on the linear polarization profiles when the wavelength separations between the line components of the multiplet are small, like in the cases of Mg i b and Ca i triplets.

  10. The STARK-B database VAMDC node: a repository for spectral line broadening and shifts due to collisions with charged particles

    Sahal-Bréchot, S.; Dimitrijević, M. S.; Moreau, N.; Ben Nessib, N.

    2015-05-01

    Accurate spectroscopic diagnostics and modeling require the knowledge of numerous collisional line profiles. Access to such data via an online database has become indispensable. The STARK-B database is aimed at meeting these needs for widths and shifts of isolated lines of neutral and ionized elements due to electron and ion impacts. This database of the Paris Observatory is a result of scientific cooperation between S Sahal-Bréchot (LERMA) and M S Dimitrijević (AOB). Access to it is free, and it was opened online at the end of 2008. STARK-B is a node of the Virtual Atomic and Molecular Data Centre (VAMDC) and thus complies with VAMDC and Virtual Observatory standards. VAMDC is a European Union-funded collaboration among groups involved in the generation and use of interoperable atomic and molecular data. STARK-B now contains all our semiclassical-perturbation (SCP) calculated data for more than 123 neutral or ionized elements as published in international refereed journals. It is devoted to modeling and spectroscopic diagnostics of stellar atmospheres and envelopes, laboratory plasmas, laser equipment, and technological plasmas. Hence, the range of temperatures and densities covered by the tables is broad and depends on the ionization degree of the radiating atom. The modified semiempirical (MSE) results of calculations have begun to be implemented. In this paper, we highlight the key points of the method and the assumptions used in the calculations, which have lately been revisited. Then we present the database and its recent developments, as well as our ongoing work and our plans for the future.

  11. The STARK-B database VAMDC node: a repository for spectral line broadening and shifts due to collisions with charged particles

    Sahal-Bréchot, S; Moreau, N; Dimitrijević, M S; Nessib, N Ben

    2015-01-01

    Accurate spectroscopic diagnostics and modeling require the knowledge of numerous collisional line profiles. Access to such data via an online database has become indispensable. The STARK-B database is aimed at meeting these needs for widths and shifts of isolated lines of neutral and ionized elements due to electron and ion impacts. This database of the Paris Observatory is a result of scientific cooperation between S Sahal-Bréchot (LERMA) and M S Dimitrijević (AOB). Access to it is free, and it was opened online at the end of 2008. STARK-B is a node of the Virtual Atomic and Molecular Data Centre (VAMDC) and thus complies with VAMDC and Virtual Observatory standards. VAMDC is a European Union-funded collaboration among groups involved in the generation and use of interoperable atomic and molecular data. STARK-B now contains all our semiclassical-perturbation (SCP) calculated data for more than 123 neutral or ionized elements as published in international refereed journals. It is devoted to modeling and spectroscopic diagnostics of stellar atmospheres and envelopes, laboratory plasmas, laser equipment, and technological plasmas. Hence, the range of temperatures and densities covered by the tables is broad and depends on the ionization degree of the radiating atom. The modified semiempirical (MSE) results of calculations have begun to be implemented. In this paper, we highlight the key points of the method and the assumptions used in the calculations, which have lately been revisited. Then we present the database and its recent developments, as well as our ongoing work and our plans for the future. (paper)

  12. Multi-Spectral Imaging from an Unmanned Aerial Vehicle Enables the Assessment of Seasonal Leaf Area Dynamics of Sorghum Breeding Lines

    Andries B. Potgieter

    2017-09-01

    Full Text Available Genetic improvement in sorghum breeding programs requires the assessment of adaptation traits in small-plot breeding trials across multiple environments. Many of these phenotypic assessments are made by manual measurement or visual scoring, both of which are time consuming and expensive. This limits trial size and the potential for genetic gain. In addition, these methods are typically restricted to point estimates of particular traits, such as leaf senescence or flowering and do not capture the dynamic nature of crop growth. In water-limited environments in particular, information on leaf area development over time would provide valuable insight into water use and adaptation to water scarcity during specific phenological stages of crop development. Current methods to estimate plant leaf area index (LAI involve destructive sampling and are not practical in breeding. Unmanned aerial vehicles (UAV and proximal-sensing technologies open new opportunities to assess these traits multiple times in large small-plot trials. We analyzed vegetation-specific crop indices obtained from a narrowband multi-spectral camera on board a UAV platform flown over a small pilot trial with 30 plots (10 genotypes randomized within 3 blocks. Due to variable emergence we were able to assess the utility of these vegetation indices to estimate canopy cover and LAI over a large range of plant densities. We found good correlations between the Normalized Difference Vegetation Index (NDVI and the Enhanced Vegetation Index (EVI with plant number per plot, canopy cover and LAI both during the vegetative growth phase (pre-anthesis and at maximum canopy cover shortly after anthesis. We also analyzed the utility of time-sequence data to assess the senescence pattern of sorghum genotypes known as fast (senescent or slow senescing (stay-green types. The Normalized Difference Red Edge (NDRE index which estimates leaf chlorophyll content was most useful in characterizing the leaf area

  13. Efficient high-power narrow-linewidth all-fibred linearly polarized ytterbium laser source

    Bertrand, Anthony; Liégeois, Flavien; Hernandez, Yves; Giannone, Domenico

    2012-06-01

    We report on experimental results on a high power, all-fibred, linearly polarized, mode-locked laser at 1.03 μm. The laser generates pulses of 40 ps wide at a repetition rate of 52 MHz, exhibiting 12 kW peak power. Dispersion in optical fibres is controlled to obtain both high power and narrow spectral linewidth. The average output power reached is 25 W with a spectral linewidth of 380 pm and a near diffraction limit beam (M2 < 1.2). This laser is an ideal candidate for applications like IR spectroscopy, where high peak power and narrow linewidth are required for subsequent wavelength conversion.

  14. The matrix effect study in the spectrographic analysis of rare earth elements. Pt. 1. The influence of Sn, Pb, Sb, Bi, Cu, Ag, Zn and Cd on the spectral lines intensity of Y, La, Ce, Pr, Nd and Sm in the current arc exciting between C-electrodes

    Wysocka-Lisek, J.; Paszkowska, B.; Mularczyk, K.

    1976-01-01

    In the beginning the influence of Sn, Pb, Sb, Bi, Cu, Ag, Zn and Cd on the light rare earth spectral lines using Ni as the internal standard, during the intermittent current arc excitation between C-electrodes was studied. On the basis of the spectral lines intensity measurements, it was stated that one may apply the addition of Ni as the internal standard by the quantitative determination of Sn, Pb, Sb, Bi, Zn and Cd in the light rare earth mixtures with one of the above. Also a great influence of the presence of the individually studied metal was observed on the spectral line intensity of rare earth elements and nickel. The differences of the thermo-chemical reactions nature between excited elements and the carbon of the electrodes may cause that influence. (author)

  15. Experimental study of population inversion and spectral line broadening in a plasma containing a mixture of high Z and low Z ions

    Griem, H.R.

    1988-10-01

    In our work this past year at the University of Rochester's Laboratory for Laser Energetics we have studied laser-produced plasmas using spherical targets continuing layers of high Z and low Z materials. Our emphasis was on quantitative spectroscopy of ions in a very dense, recombining plasma. The targets used consisted of carbon-copper, carbon-gold, and aluminum-gold mixtures, instead of the originally proposed Fe or Mo mixtures with carbon. The thickness of the Cu and the Au layers were varied in order to study the effect of higher Z ions cooling the plasma. Indeed a pronounced cooling effect was observed by increasing the thickness of the Au layer in targets with Al-Au layers. Electron temperatures were studied by measuring the 1s-2p/1s 2 -1s2p line ratio of Al XIII to Al XII. Our experimental measurements, together with a collisional-radiative model and a 1-D hydrodynamic code, indicate that the electron temperature falls from 1500 eV with no gold to 950 eV with a 500 angstrom layer of gold. A detailed discussion of our results with Al-Au targets can be found in the enclosed preprint entitled Radiation Cooling in Laser-Produced Plasmas Due to High-Z Layers

  16. Nonlinear narrow Doppler-free resonances for optical transitions and annihilation radiation of a positronium atom

    Letokhov, V.S.; Minogin, V.G.

    1976-01-01

    The possibilities of obtaining narrow resonances without the Doppler broadening for transition between the fine structure levels of the ground and first excited states of a positronium atom are considered. An analysis is carried out of the conditions required for observation of the narrow resonances of saturation of single quantum absorption in the 1S-2P transitions and observation of narrow two-photon absorption resonances in the 1S-2S transitions. It is shown that narrow 2γ annihilation radiation lines of a positronium atom may be obtained with a width much smaller than the Doppler one

  17. Narrow gap electronegative capacitive discharges

    Kawamura, E.; Lieberman, M. A.; Lichtenberg, A. J. [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States)

    2013-10-15

    Narrow gap electronegative (EN) capacitive discharges are widely used in industry and have unique features not found in conventional discharges. In this paper, plasma parameters are determined over a range of decreasing gap length L from values for which an electropositive (EP) edge exists (2-region case) to smaller L-values for which the EN region connects directly to the sheath (1-region case). Parametric studies are performed at applied voltage V{sub rf}=500 V for pressures of 10, 25, 50, and 100 mTorr, and additionally at 50 mTorr for 1000 and 2000 V. Numerical results are given for a parallel plate oxygen discharge using a planar 1D3v (1 spatial dimension, 3 velocity components) particle-in-cell (PIC) code. New interesting phenomena are found for the case in which an EP edge does not exist. This 1-region case has not previously been investigated in detail, either numerically or analytically. In particular, attachment in the sheaths is important, and the central electron density n{sub e0} is depressed below the density n{sub esh} at the sheath edge. The sheath oscillations also extend into the EN core, creating an edge region lying within the sheath and not characterized by the standard diffusion in an EN plasma. An analytical model is developed using minimal inputs from the PIC results, and compared to the PIC results for a base case at V{sub rf}=500 V and 50 mTorr, showing good agreement. Selected comparisons are made at the other voltages and pressures. A self-consistent model is also developed and compared to the PIC results, giving reasonable agreement.

  18. Broadening of spectral lines of CO2, N2O , H2CO, HCN, and H2S by pressure of gases dominant in planetary atmospheres (H2, He and CO2)

    Samuels, Shanelle; Gordon, Iouli; Tan, Yan

    2018-01-01

    HITRAN1,2 is a compilation of spectroscopic parameters that a variety of computer codes use to predict and simulate the transmission and emission of light in planetary atmospheres. The goal of this project is to add to the potential of the HITRAN database towards the exploration of the planetary atmospheres by including parameters describing broadening of spectral lines by H2, CO2, and He. These spectroscopic data are very important for the study of the hydrogen and helium-rich atmospheres of gas giants as well as rocky planets with volcanic activities, including Venus and Mars, since their atmospheres are dominated by CO2. First step in this direction was accomplished by Wilzewski et al.3 where this was done for SO2, NH3, HF, HCl, OCS and C2H2. The molecules investigated in this work were CO2, N2O, H2CO, HCN and H2S. Line-broadening coefficients, line shifts and temperature-dependence exponents for transitions of these molecules perturbed by H2, CO2 and He have been assembled from available peer-reviewed experimental and theoretical sources. The data was evaluated and the database was populated with these data and their extrapolations/interpolations using semi-empirical models that were developed to this end.Acknowledgements: Financial support from NASA PDART grant NNX16AG51G and the Smithsonian Astrophysical Observatory Latino Initiative Program from the Latino Initiatives Pool, administered by the Smithsonian Latino Center is gratefully acknowledged.References: 1. HITRAN online http://hitran.org/2. Gordon, I.E., Rothman, L.S., Hill, C., Kochanov, R.V., Tan, Y., et al., 2017. The HITRAN2016 Molecular Spectroscopic Database. J. Quant. Spectrosc. Radiat. Transf. doi:10.1016/j.jqsrt.2017.06.0383. Wilzewski, J.S., Gordon, I.E., Kochanov, R. V., Hill, C., Rothman, L.S., 2016. H2, He, and CO2 line-broadening coefficients, pressure shifts and temperature-dependence exponents for the HITRAN database. Part 1: SO2, NH3, HF, HCl, OCS and C2H2. J. Quant. Spectrosc. Radiat

  19. Hyperspectral data mining to identify relevant canopy spectral features for estimating durum wheat growth, nitrogen status, and yield

    Modern hyperspectral sensors permit reflectance measurements of crop canopies in hundreds of narrow spectral wavebands. While these sensors describe plant canopy reflectance in greater detail than multispectral sensors, they also suffer from issues with data redundancy and spectral autocorrelation. ...

  20. Intensity Conserving Spectral Fitting

    Klimchuk, J. A.; Patsourakos, S.; Tripathi, D.

    2015-01-01

    The detailed shapes of spectral line profiles provide valuable information about the emitting plasma, especially when the plasma contains an unresolved mixture of velocities, temperatures, and densities. As a result of finite spectral resolution, the intensity measured by a spectrometer is the average intensity across a wavelength bin of non-zero size. It is assigned to the wavelength position at the center of the bin. However, the actual intensity at that discrete position will be different if the profile is curved, as it invariably is. Standard fitting routines (spline, Gaussian, etc.) do not account for this difference, and this can result in significant errors when making sensitive measurements. Detection of asymmetries in solar coronal emission lines is one example. Removal of line blends is another. We have developed an iterative procedure that corrects for this effect. It can be used with any fitting function, but we employ a cubic spline in a new analysis routine called Intensity Conserving Spline Interpolation (ICSI). As the name implies, it conserves the observed intensity within each wavelength bin, which ordinary fits do not. Given the rapid convergence, speed of computation, and ease of use, we suggest that ICSI be made a standard component of the processing pipeline for spectroscopic data.

  1. Five years of Project META - An all-sky narrow-band radio search for extraterrestrial signals

    Horowitz, Paul; Sagan, Carl

    1993-01-01

    We have conducted a five-year search of the northern sky (delta between 30 and 60 deg) for narrow-band radio signals near the 1420 MHz line of neutral hydrogen, and its second harmonic, using an 8.4 x 10 exp 6 channel Fourier spectrometer of 0.05 Hz resolution and 400 kHz instantaneous bandwidth. The observing frequency was corrected both for motions with respect to three astronomical inertial frames, and for the effect of Earth's rotation, which provides a characteristic changing Doppler signature for narrow-band signals of extraterrestrial origin. Among the 6 x 10 exp 13 spectral channels searched, we have found 37 candidate events exceeding the average detection threshold of 1.7 x 10 exp -23 W/sq m, none of which was detected upon reobservation. The strongest of these appear to be dominated by rare processor errors. However, the strongest signals that survive culling for terrestrial interference lie in or near the Galactic plane. We describe the search and candidate events, and set limits on the prevalence of supercivilizations transmitting Doppler-precompensated beacons at H I or its second harmonic. We conclude with recommendations for future searches, based upon these findings, and a description of our next-generation search system.

  2. ULTRA-NARROW NEGATIVE FLARE FRONT OBSERVED IN HELIUM-10830 Å USING THE 1.6 m NEW SOLAR TELESCOPE

    Xu, Yan; Liu, Chang; Jing, Ju; Wang, Haimin [Space Weather Research Lab, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Blvd, Newark, NJ 07102-1982 (United States); Cao, Wenda; Gary, Dale [Big Bear Solar Observatory, New Jersey Institute of Technology 323 Martin Luther King Blvd, Newark, NJ 07102-1982 (United States); Ding, Mingde [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Kleint, Lucia [Fachhochschule Nordwestschweiz (FHNW), Institute of 4D technologies Bahnhofstr. 6, CH-5210 Windisch (Switzerland); Su, Jiangtao [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Ji, Haisheng [Purple Mountain Observatory, 2 Beijing Xi Lu, Nanjing, 210008 (China); Chae, Jongchul; Cho, Kyuhyoun [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Cho, Kyungsuk [Korea Astronomy and Space Science Institute, Daedeokdae-ro 776, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)

    2016-03-10

    Solar flares are sudden flashes of brightness on the Sun and are often associated with coronal mass ejections and solar energetic particles that have adverse effects on the near-Earth environment. By definition, flares are usually referred to as bright features resulting from excess emission. Using the newly commissioned 1.6 m New Solar Telescope at Big Bear Solar Observatory, we show a striking “negative” flare with a narrow but unambiguous “dark” moving front observed in He i 10830 Å, which is as narrow as 340 km and is associated with distinct spectral characteristics in Hα and Mg ii lines. Theoretically, such negative contrast in He i 10830 Å can be produced under special circumstances by nonthermal electron collisions or photoionization followed by recombination. Our discovery, made possible due to unprecedented spatial resolution, confirms the presence of the required plasma conditions and provides unique information in understanding the energy release and radiative transfer in astronomical objects.

  3. ULTRA-NARROW NEGATIVE FLARE FRONT OBSERVED IN HELIUM-10830 Å USING THE 1.6 m NEW SOLAR TELESCOPE

    Xu, Yan; Liu, Chang; Jing, Ju; Wang, Haimin; Cao, Wenda; Gary, Dale; Ding, Mingde; Kleint, Lucia; Su, Jiangtao; Ji, Haisheng; Chae, Jongchul; Cho, Kyuhyoun; Cho, Kyungsuk

    2016-01-01

    Solar flares are sudden flashes of brightness on the Sun and are often associated with coronal mass ejections and solar energetic particles that have adverse effects on the near-Earth environment. By definition, flares are usually referred to as bright features resulting from excess emission. Using the newly commissioned 1.6 m New Solar Telescope at Big Bear Solar Observatory, we show a striking “negative” flare with a narrow but unambiguous “dark” moving front observed in He i 10830 Å, which is as narrow as 340 km and is associated with distinct spectral characteristics in Hα and Mg ii lines. Theoretically, such negative contrast in He i 10830 Å can be produced under special circumstances by nonthermal electron collisions or photoionization followed by recombination. Our discovery, made possible due to unprecedented spatial resolution, confirms the presence of the required plasma conditions and provides unique information in understanding the energy release and radiative transfer in astronomical objects

  4. Microwave spectral lines in galactic dust globules

    Martin, R.N.; Barrett, A.H.

    1978-01-01

    In order to better understand galactic dust globules, a program of mapping several molecular transitions in these clouds has been undertaken. The results of observations of the J=1→0 rotational transitions of CO, 13 CO, C 18 O, and CS, the J=2→1rotational transitions of CS and C 34 S, the J, K=1, 1 and J, K=2, 2 inversion transitions of NH 3 , the J/sub KKprime/=1 11 →1 10 and J/sub KKprime/=2 12 →2 11 transitions of H 2 CO, and the OH 2 Pi/sub 3/2/F=2→2 and F=1→1 transitions are reported here. Twelve globules have been selected for observation; seven of these were studied in detail and the remainder observed only sparsely. A strong positive correlation appears to exist between the spatial extent of the molecular emission (or absorption) and the optical features of the globule. Even the main isotope of CO shows this correlation between dust extinction and molecular emission. Close examination of the Palomar prints reveals dust wherever CO is observed, and CO is probably a good tracer of dust extinction.The simultaneous observation of many molecular transitions has proven useful in obtaining reliable physical parameters for the dust globules. For example, CO and NH 3 are reliable thermometers of the kinetic temperature, and CS and NH 3 are indicators of the total gas density. The kinetic temperatures of the globules are almost always approx.10 K, and the derived H 2 densities are 10/sup 3.4/-10/sup 4.5/ cm -3 . The density in the core of the globules could well be larger than these value, which represent an average for the entire cloud. The kinetic temperature appears uniform across each cloud (within a few kelvins), in agreement with theoretical predictions. All of the globules studied in detail appear to be gravitationally bound and collapsing objects. Rotation has been observed in at least two globules (B163 and B163 SW). The projected axis of rotation is in a direction opposite to that of the Galaxy

  5. Many-body calculation of the coincidence L3 photoelectron spectroscopy main line of Ni metal

    Ohno, Masahide

    2008-01-01

    The partial singles L 3 photoelectron spectroscopy (PES) main line of Ni metal correlated with Auger electrons emitted by the localized L 3 -VV Auger decay is calculated by a many-body theory. The partial singles L 3 PES main line of Ni metal almost coincides in both line shape and peak kinetic energy (KE) with the singles one. The former main line peak shows a KE shift of only 0.01 eV toward the lower KE and a very small asymmetric line shape change compared to the singles one. The asymmetric line shape change and the peak KE shift of the partial singles L 3 main line are very small. However, they are due to the variation with photoelectron KE in the branching ratio of the partial Auger decay width in the partial singles L 3 PES main line by the photoelectron KE dependent imaginary part of the shakeup self-energy. The L 3 PES main line of Ni metal measured in coincidence with the L 3 -VV ( 1 G) Auger electron spectroscopy (AES) main line peak is the partial singles one modulated by a spectral function R a of a fixed energy Auger electron analyzer so that it should show only a symmetric line narrowing by R a compared to the singles one. The L 3 PES main line peak of Ni metal measured in coincidence with the delocalized band-like L 3 -VV AES peak or not completely split-off (or not completely localized) L 3 -VV ( 3 F) AES peak, will show an asymmetric line narrowing and a KE shift compared to the singles one. Thus, the L 3 PES main line of Ni metal in coincidence with various parts of the L 3 -VV AES spectrum depends on which part of the L 3 -VV AES spectrum a fixed energy Auger electron analyzer is set. The experimental verification is in need

  6. Spectral Ly{alpha}, Ly{beta}, and H{alpha} line shapes for the H atom in the presence of a magnetic field in a plasma; Profils des raies spectrales Ly{alpha}, Ly{beta}, et H{alpha} de l'atome H en presence d'un champ magnetique dans un plasma

    Nguyen, H; Herman, L [Laboratoire de Recherches Physiques, Faculte des sciences, 9 Quai Saint Bernard, 75 - Paris (France); Drawin, H W [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1967-02-15

    This report contains numerical data of the line shapes of Ly{alpha}, Ly{beta}, and H{alpha} for the following parameters: 1. 10{sup 2} {<=} H [gauss] {<=} 1.2. 10{sup 5} 1. 10{sup 15}{<=} N [cm{sup -3}] {<=} 1. 10{sup 18} cm{sup -3} 1. 10{sup 4} {<=} T [deg. K] {<=} 4. 10{sup 4} where H = magnetic field strength, K = density of plasma ions, T = electron temperature. (authors) [French] Dans ce rapport, on donne les valeurs numeriques des contours des raies spectrales Ly{alpha}, Ly{beta}, et H{alpha} pour les valeurs suivantes des parametres H, N et T 1. 10{sup 2} {<=} H [gauss] {<=} 1.2. 10{sup 5} 1. 10{sup 15}{<=} N [cm{sup -3}] {<=} 1. 10{sup 18} cm{sup -3} 1. 10{sup 4} {<=} T [deg. K] {<=} 4. 10{sup 4} ou H intensite du champ magnetique, N = densite des ions, T = temperature electronique. (auteurs)

  7. Spectral Compressive Sensing with Polar Interpolation

    Fyhn, Karsten; Dadkhahi, Hamid; F. Duarte, Marco

    2013-01-01

    . In this paper, we introduce a greedy recovery algorithm that leverages a band-exclusion function and a polar interpolation function to address these two issues in spectral compressive sensing. Our algorithm is geared towards line spectral estimation from compressive measurements and outperforms most existing...

  8. Large-amplitude and narrow-band vibration phenomenon of a foursquare fix-supported flexible plate in a rigid narrow channel

    Liu Lifang, E-mail: liu_lifang1106@yahoo.cn [School of Nuclear Science and Engineering, North China Electric Power University, Zhuxinzhuang, Dewai, Beijing 102206 (China); Lu Daogang, E-mail: ludaogang@ncepu.edu.cn [School of Nuclear Science and Engineering, North China Electric Power University, Zhuxinzhuang, Dewai, Beijing 102206 (China); Li Yang, E-mail: qinxiuyi@sina.com [School of Nuclear Science and Engineering, North China Electric Power University, Zhuxinzhuang, Dewai, Beijing 102206 (China); Zhang Pan, E-mail: zhangpan@ncepu.edu.cn [School of Nuclear Science and Engineering, North China Electric Power University, Zhuxinzhuang, Dewai, Beijing 102206 (China); Niu Fenglei, E-mail: niufenglei@ncepu.edu.cn [School of Nuclear Science and Engineering, North China Electric Power University, Zhuxinzhuang, Dewai, Beijing 102206 (China)

    2011-08-15

    Highlights: > FIV of a foursquare fix-supported flexible plate exposed to axial flow was studied. > Special designed test section and advanced measuring equipments were adopted. > The narrow-band vibration phenomenon with large amplitude was observed. > Line of plate's vibration amplitude and flow rate was investigated. > The phenomenon and the measurement error were analyzed. - Abstract: An experiment was performed to analyze the flow-induced vibration behavior of a foursquare fix-supported flexible plate exposed to the axial flow within a rigid narrow channel. The large-amplitude and narrow-band vibration phenomenon was observed in the experiment when the flow velocity varied with the range of 0-5 m/s. The occurring condition and some characteristics of the large-amplitude and narrow-band vibrations were investigated.

  9. Revealing the ultrafast outflow in IRAS 13224-3809 through spectral variability

    Parker, M. L.; Alston, W. N.; Buisson, D. J. K.; Fabian, A. C.; Jiang, J.; Kara, E.; Lohfink, A.; Pinto, C.; Reynolds, C. S.

    2017-08-01

    We present an analysis of the long-term X-ray variability of the extreme narrow-line Seyfert 1 galaxy IRAS 13224-3809 using principal component analysis (PCA) and fractional excess variability (Fvar) spectra to identify model-independent spectral components. We identify a series of variability peaks in both the first PCA component and Fvar spectrum which correspond to the strongest predicted absorption lines from the ultrafast outflow (UFO) discovered by Parker et al. (2017). We also find higher order PCA components, which correspond to variability of the soft excess and reflection features. The subtle differences between RMS and PCA results argue that the observed flux-dependence of the absorption is due to increased ionization of the gas, rather than changes in column density or covering fraction. This result demonstrates that we can detect outflows from variability alone and that variability studies of UFOs are an extremely promising avenue for future research.

  10. Application of the Spectral Neighborhood of Soil Line Technique to Analyze the Intensity of Soil Use in 1985-2014 (by the Example of Three Districts of Tula Oblast)

    Rukhovich, D. I.; Rukhovich, A. D.; Rukhovich, D. D.; Simakova, M. S.; Kulyanitsa, A. L.; Koroleva, P. V.

    2018-03-01

    The technique of separation of the spectral neighborhood of soil line (SNSL) makes it possible to perform quantitative estimates of the intensity of agricultural land use. This is achieved via calculation of the frequency of occurrence of bare soil surface (BSS). It is shown that the frequency of occurrence of BSS in 1984-1994 was linearly related to the soil type within the sequence of soddy strongly podzolic, soddy moderately podzolic, soddy slightly podzolic (Eutric Albic Glossic Retisols (Loamic, Aric, Cutanic, Differentic, Ochric)); light gray forest (Eutric Retisols (Loamic, Aric, Cutanic, Differentic, Ochric)), gray forest (Eutric Retisols (Loamic, Aric, Cutanic, Ochric)), and dark gray forest soils (Luvic Retic Greyzemic Phaeozems (Loamic, Aric)); podzolized chernozems (Luvic Greyzemic Chernic Phaeozems (Loamic, Aric, Pachic)) and leached chernozems (Luvic Chernic Phaeozems (Loamic, Aric, Pachic)). The intensity of exploitation of the least and most fertile soils in this sequence comprised 28 and 48%, respectively. In the next decade (1995-2004) the relationship between the type of soil and the intensity of its exploitation drastically changed; the intensity of exploitation of the leas and most fertile soils comprised 14 and 43%, respectively. Nearly a half of agricultural lands in the zones of soddy-podzolic and gray forest soils were abandoned, because the cultivation of the soils with the natural fertility below that in the podzolized chernozems became economically unfeasible under conditions of the economic crisis of the 1990s. The spatiotemporal relationships between the character of the soil cover and the intensity of exploitation of the agricultural lands manifest themselves by the decreasing frequency of occurrence of BSS from leached chernozems to soddy strongly podzolic soils and from 1985 to 2014.

  11. Analysis of 3D Doppler Tomography of the X-ray Binary System Cygnus X-1 from Spectral Observations in 2007 in the HeII λ 4686 Å Line

    Agafonov, M. I.; Karitskaya, E. A.; Sharova, O. I.; Bochkarev, N. G.; Zharikov, S. V.; Butenko, G. Z.; Bondar', A. V.; Bubukin, I. T.

    2018-03-01

    This is the second paper in a series dedicated to studies of the X-ray binary Cyg X-1 in the HeII λ 4686 Å line using 3D Doppler tomography. A detailed analysis of the tomogram constructed has made it possible for the first time to obtain information about the motions of gaseous flows including all three velocity components. The observations were obtained in June 2007 at the Terskol Branch of the Institute of Astronomy (Russia) and the National Astronomical Observatory of Mexico. The correctness of the tomographic results and their discussion is analyzed. The results are compared with a 2D Doppler tomogram reconstruction. Model-atmosphere computations of HeII λ 4686 Å line profiles are used to estimate the influence of absorption features of the Osupergiant on the emission structure in the tomogram. The correctness of the 3D solutions is confirmed by the good agreement between the original sequence of spectral data and a control data set computed using the constructed 3D Doppler tomogram. Tomograms constructed using the data of each of the two observatories are compared. The results of the reconstruction for inclinations of the system of 40° and 45° essentially coincide. The maximum absorption (corresponding to the O supergiant) and emission structural features in the 3D tomogram are located in its central ( V x , V y ) section, where the velocity component perpendicular to the orbital plane V z is zero. The emission is generated mainly in the outer part of the accretion structure, close to the supergiant. A gaseous stream from the Lagrangian point L1 with its motion close to the orbital plane can be distinguished. Its maximum velocity reaches 800 km/s. The identification of an emission structure with V z 300 km/s and with V x , V y in the velocity interval corresponding to the donor star was unexpected. Its presence may indicate, for example, an outflow of matter from a magnetic pole of the supergiant.

  12. Dynamic Stark broadening as the Dicke narrowing effect

    Calisti, A.; Mosse, C.; Ferri, S.; Talin, B.; Rosmej, F.; Bureyeva, L. A.; Lisitsa, V. S.

    2010-01-01

    A very fast method to account for charged particle dynamics effects in calculations of spectral line shape emitted by plasmas is presented. This method is based on a formulation of the frequency fluctuation model (FFM), which provides an expression of the dynamic line shape as a functional of the static distribution of frequencies. Thus, the main numerical work rests on the calculation of the quasistatic Stark profile. This method for taking into account ion dynamics allows a very fast and accurate calculation of Stark broadening of atomic hydrogen high-n series emission lines. It is not limited to hydrogen spectra. Results on helium-β and Lyman-α lines emitted by argon in microballoon implosion experiment conditions compared with experimental data and simulation results are also presented. The present approach reduces the computer time by more than 2 orders of magnitude as compared with the original FFM with an improvement of the calculation precision, and it opens broad possibilities for its application in spectral line-shape codes.

  13. Device Physics of Narrow Gap Semiconductors

    Chu, Junhao

    2010-01-01

    Narrow gap semiconductors obey the general rules of semiconductor science, but often exhibit extreme features of these rules because of the same properties that produce their narrow gaps. Consequently these materials provide sensitive tests of theory, and the opportunity for the design of innovative devices. Narrow gap semiconductors are the most important materials for the preparation of advanced modern infrared systems. Device Physics of Narrow Gap Semiconductors offers descriptions of the materials science and device physics of these unique materials. Topics covered include impurities and defects, recombination mechanisms, surface and interface properties, and the properties of low dimensional systems for infrared applications. This book will help readers to understand not only the semiconductor physics and materials science, but also how they relate to advanced opto-electronic devices. The last chapter applies the understanding of device physics to photoconductive detectors, photovoltaic infrared detector...

  14. Accurate powder patterns and new spectral shape in orthorrombic symmetry

    Gonzalez-Tovany, L.

    1991-01-01

    The shape of the powder pattern of the center resonance line (M= 1/2 ↔ -1/2) for electron paramagnetic resonance (EPR) in orthorhombic symmetry, or nuclear magnetic resonance (NMR) with quadrupole interaction, is determined for all values of the crystal field symmetry parameter N by means of a general analytical method developed by Beltran-Lopez and Castro-Tello. Analytical functions in terms of elliptical integrals are obtained which are good approximations to the true powder pattern except in a narrow region around the field value corresponding to E=-2n 2 /3. numerical gaussian quadrature of the powder pattern from the single-variable integral arising in the analytical method is shown to be a very efficient semianalytical method of calculation for computer work, being much smoother and requiring only a few seconds of CPU time versus the several minutes needed with the grid of the Monte Carlo methods. The semianalytical powder patterns reveal the existence of a previous unknown EPR spectral feature in orthorhombic symmetry resembling a divergence. This feature which should appear at E=-2n 2 /3 for asymmetry parameter values near N=√ of 2/3, is hidden in the experimental spectra by the broadening effect of the linewidth of the individual crystallites. Comparison of experimental and simulated spectra obtained by convoluting powder patterns with first-derivate lorentzian lineshapes of convenient width are also shown. Semianalytical spectra are much smoother than Monte Carlo simulated spectra, revealing finer spectral features. (Author)

  15. Ultrabright, narrow-band photon-pair source for atomic quantum memories

    Tsai, Pin-Ju; Chen, Ying-Cheng

    2018-06-01

    We demonstrate an ultrabright, narrow-band and frequency-tunable photon-pair source based on cavity-enhanced spontaneous parametric down conversion (SPDC) which is compatible with atomic transition of rubidium D 2-line (780 nm) or cesium D 2-line (852 nm). With the pump beam alternating between a high and a low power phase, the output is switching between the optical parametric oscillator (OPO) and photon-pair generation mode. We utilize the OPO output light to lock the cavity length to maintain the double resonances of signal and idler, as well as to lock the signal frequency to cesium atomic transition. With a type-II phase matching and a double-passed pump scheme such that the cluster frequency spacing is larger than the SPDC bandwidth, the photon-pair output is in a nearly single-mode operation as confirmed by a scanning Fabry–Perot interferometer with its output detected by a photomultiplier. The achieved generation and detection rates are 7.24× {10}5 and 6142 s‑1 mW‑1, respectively. The correlation time of the photon pair is 21.6(2.2) ns, corresponding to a bandwidth of 2π × 6.6(6) MHz. The spectral brightness is 1.06× {10}5 s‑1 mW‑1 MHz‑1. This is a relatively high value under a single-mode operation with the cavity-SPDC scheme. The generated single photons can be readily used in experiments related to atomic quantum memories.

  16. Narrow-front loop migration in a population of the common cuckoo Cuculus canorus, as revealed by satellite telemetry

    Willemoes, Mikkel; Strandberg, Roine; Klaassen, Raymond H. G.; Tottrup, Anders P.; Vardanis, Yannis; Howey, Paul W.; Thorup, Kasper; Wikelski, Martin; Alerstam, Thomas

    2014-01-01

    Narrow migration corridors known in diurnal, social migrants such as raptors, storks and geese are thought to be caused by topographical leading line effects in combination with learning detailed routes across generations. Here, we document narrow-front migration in a nocturnal, solitary migrant,

  17. Plasma Reflection in Multigrain Layers of Narrow-Bandgap Semiconductors

    Zhukov, N. D.; Shishkin, M. I.; Rokakh, A. G.

    2018-04-01

    Qualitatively similar spectral characteristics of plasma-resonance reflection in the region of 15-25 μm were obtained for layers of electrodeposited submicron particles of InSb, InAs, and GaAs and plates of these semiconductors ground with M1-grade diamond powder. The most narrow-bandgap semiconductor InSb (intrinsic absorption edge ˜7 μm) is characterized by an absorption band at 2.1-2.3 μm, which is interpreted in terms of the model of optical excitation of electrons coupled by the Coulomb interaction. The spectra of a multigrain layer of chemically deposited PbS nanoparticles (50-70 nm) exhibited absorption maxima at 7, 10, and 17 μm, which can be explained by electron transitions obeying the energy-quantization rules for quantum dots.

  18. Novel structural flexibility identification in narrow frequency bands

    Zhang, J; Moon, F L

    2012-01-01

    A ‘Sub-PolyMAX’ method is proposed in this paper not only for estimating modal parameters, but also for identifying structural flexibility by processing the impact test data in narrow frequency bands. The traditional PolyMAX method obtains denominator polynomial coefficients by minimizing the least square (LS) errors of frequency response function (FRF) estimates over the whole frequency range, but FRF peaks in different structural modes may have different levels of magnitude, which leads to the modal parameters identified for the modes with small FRF peaks being inaccurate. In contrast, the proposed Sub-PolyMAX method implements the LS solver in each subspace of the whole frequency range separately; thus the results identified from a narrow frequency band are not affected by FRF data in other frequency bands. In performing structural identification in narrow frequency bands, not in the whole frequency space, the proposed method has the following merits: (1) it produces accurate modal parameters, even for the modes with very small FRF peaks; (2) it significantly reduces computation cost by reducing the number of frequency lines and the model order in each LS implementation; (3) it accurately identifies structural flexibility from impact test data, from which structural deflection under any static load can be predicted. Numerical and laboratory examples are investigated to verify the effectiveness of the proposed method. (paper)

  19. Water-vapor absorption line measurements in the 940-nm band by using a Raman-shifted dye laser

    Chu, Zhiping; Wilkerson, Thomas D.; Singh, Upendra N.

    1993-01-01

    We report water-vapor absorption line measurements that are made by using the first Stokes radiation (930-982 nm) with HWHM 0.015/cm generated by a narrow-linewidth, tunable dye laser. Forty-five absorption line strengths are measured with an uncertainty of 6 percent and among them are fourteen strong lines that are compared with previous measurements for the assessment of spectral purity of the light source. Thirty air-broadened linewidths are measured with 8 percent uncertainty at ambient atmospheric pressure with an average of 0.101/cm. The lines are selected for the purpose of temperature-sensitive or temperature-insensitive lidar measurements. Results for these line strengths and linewidths are corrected for broadband radiation and finite laser linewidth broadening effects and compared with the high-resolution transmission molecular absorption.

  20. Spectral analysis of IGR J01572-7259 during its 2016 outburst

    La Palombara, N.; Esposito, P.; Mereghetti, S.; Pintore, F.; Sidoli, L.; Tiengo, A.

    2018-03-01

    We report on the results of the XMM-Newton observation of IGR J01572-7259 during its most recent outburst in 2016 May, the first since 2008. The source reached a flux f ˜ 10-10 erg cm-2 s-1, which allowed us to perform a detailed analysis of its timing and spectral properties. We obtained a pulse period Pspin = 11.58208(2) s. The pulse profile is double peaked and strongly energy dependent, as the second peak is prominent only at low energies and the pulsed fraction increases with energy. The main spectral component is a power-law model, but at low energies, we also detected a soft thermal component, which can be described with either a blackbody or a hot plasma model. Both the EPIC and RGS spectra show several emission lines, which can be identified with the transition lines of ionized N, O, Ne, and Fe and cannot be described with a thermal emission model. The phase-resolved spectral analysis showed that the flux of both the soft excess and the emission lines vary with the pulse phase: the soft excess disappears in the first pulse and becomes significant only in the second, where also the Fe line is stronger. This variability is difficult to explain with emission from a hot plasma, while the reprocessing of the primary X-ray emission at the inner edge of the accretion disc provides a reliable scenario. On the other hand, the narrow emission lines can be due to the presence of photoionized matter around the accreting source.