WorldWideScience

Sample records for powerful young radio-loud

  1. The unification of powerful radio-loud AGN: the multi-wavelength balance

    NARCIS (Netherlands)

    Podigachoski, Pece; Barthel, Peter; Haas, Martin; Leipski, Christian; Wilkes, Belinda; Rocca-Volmerange, Brigitte; Drouart, Guillaume

    2016-01-01

    Powerful radio-loud AGN, by virtue of their optically-thin low-frequency radio emission, represent unique targets in orientation-based unification studies, and in searches for orientation indicators and orientation invariants. Central in these efforts is the landmark Third Cambridge Catalog of Radio

  2. IRAS observations of radio-quiet and radio-loud quasars

    Science.gov (United States)

    Neugebauer, G.; Soifer, B. T.; Miley, G.; Habing, H. J.; Young, E.; Low, F. J.; Beichman, C. A.; Clegg, P. E.; Harris, S.; Rowan-Robinson, M.

    1984-01-01

    Observations from 12 to 100 microns are presented of two radio-quiet and three radio-loud quasars. Over this wavelength range, all five have grossly similar continuum energy distributions. The continua of the radio-loud quasars are consistent with synchrotron radiation. There is an indication, however, of excess 100 micron emission in the two radio-quiet quasars.

  3. Radio Loud AGN Unification: Connecting Jets and Accretion

    Directory of Open Access Journals (Sweden)

    Meyer Eileen T.

    2013-12-01

    Full Text Available While only a fraction of Active Galactic Nuclei are observed to host a powerful relativistic jet, a cohesive picture is emerging that radio-loud AGN may represent an important phase in the evolution of galaxies and the growth of the central super-massive black hole. I will review my own recent observational work in radio-loud AGN unification in the context of understanding how and why jets form and their the connection to different kinds of accretion and growing the black hole, along with a brief discussion of possible connections to recent modeling work in jet formation. Starting from the significant observational advances in our understanding of jetted AGN as a population over the last decade thanks to new, more sensitive instruments such as Fermi and Swift as well as all-sky surveys at all frequencies, I will lay out the case for a dichotomy in the jetted AGN population connected to accretion mode onto the black hole. In recent work, we have identified two sub-populations of radio-loud AGN which appear to be distinguished by jet structure, where low-efficiency accreting systems produce ‘weak’ jets which decelerate more rapidly than the ’strong’ jets of black holes accreting near the Eddington limit. The two classes are comprised of: (1The weak jet sources, corresponding to the less collimated, edge-darkened FR Is, with a decelerating or spine-sheath jet with velocity gradients, and (2 The strong jet sources, having fast, collimated jets, and typically displaying strong emission lines. The dichotomy in the vp-Lp plane can be understood as a "broken power sequence" in which jets exist on one branch or the other based on the particular accretion mode (Georganopolous 2011.We suggest that the intrinsic kinetic power (as measured by low-frequency, isotropic radio emission, the orientation, and the accretion rate of the SMBH system are the the fundamental axes needed for unification of radio-loud AGN by studying a well-characterized sample

  4. The difference between radio-loud and radio-quiet active galaxies

    Science.gov (United States)

    Wilson, A. S.; Colbert, E. J. M.

    1995-01-01

    The recent development of unified theories of active galactic nuclei (AGNs) has indicated that there are two physically distinct classes of these objects--radio-loud and radio-quiet. Despite differences, the (probable) thermal emissions from the AGNs (continua and lines from X-ray to infrared wavelengths) are quite similar to the two classes of object. We argue that this last result suggests that the black hole masses and mass accretion rates in the two classes are not greatly different, and that the difference between the classes is associated with the spin of the black hole. We assume that the normal process of accretion through a disk does not lead to rapidly spinning holes and propose that galaxies (e.g., spirals) which have not suffered a recent major merger event contain nonrotating or only slowly rotating black holes. When two such galaxies merge, the two black holes are known to form a binary and we assume that they eventually coalesce. The ratio of the number of radio-loud to radio-quiet AGNs at a given thermal (e.g., optical) luminosity is determined by the galaxy merger rate. Comparisons between the predicted and observed radio luminosity functions constrain the efficiencies with which jet power is extracted from the spinning hole and radio emission is produced by the jet.

  5. Millimeter observations of radio-loud active galaxies

    NARCIS (Netherlands)

    van Bemmel, IM; Bertoldi, F

    In order to study the nature of the far-infrared emission observed in radio-loud active galaxies, we have obtained 1.2 mill observations with the IRAM 30 m telescope for a sample of eight radio-loud active galaxies. In all objects we find that the 1.2 mm emission is dominated by non-thermal

  6. Remnant radio-loud AGN in the Herschel-ATLAS field

    Science.gov (United States)

    Mahatma, V. H.; Hardcastle, M. J.; Williams, W. L.; Brienza, M.; Brüggen, M.; Croston, J. H.; Gurkan, G.; Harwood, J. J.; Kunert-Bajraszewska, M.; Morganti, R.; Röttgering, H. J. A.; Shimwell, T. W.; Tasse, C.

    2018-04-01

    Only a small fraction of observed active galactic nuclei (AGN) display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining the dynamics and energetics of the radio sources over cosmic time, a key question concerns what happens when their jets switch off. The resulting `remnant' radio-loud AGN have been surprisingly evasive in past radio surveys, and therefore statistical information on the population of radio-loud AGN in their dying phase is limited. In this paper, with the recent developments of Low-Frequency Array (LOFAR) and the Very Large Array, we are able to provide a systematically selected sample of remnant radio-loud AGN in the Herschel-ATLAS field. Using a simple core-detection method, we constrain the upper limit on the fraction of remnants in our radio-loud AGN sample to 9 per cent, implying that the extended lobe emission fades rapidly once the core/jets turn off. We also find that our remnant sample has a wide range of spectral indices (-1.5≤slant α ^{1400}_{150}≤slant -0.5), confirming that the lobes of some remnants may possess flat spectra at low frequencies just as active sources do. We suggest that, even with the unprecedented sensitivity of LOFAR, our sample may still only contain the youngest of the remnant population.

  7. Jet launching radius in low-power radio-loud AGNs in advection-dominated accretion flows

    Science.gov (United States)

    Le, Truong; Newman, William; Edge, Brinkley

    2018-06-01

    Using our theory for the production of relativistic outflows, we estimate the jet launching radius and the inferred mass accretion rate for 52 low-power radio-loud AGNs based on the observed jet powers. Our analysis indicates that (1) a significant fraction of the accreted energy is required to convert the accreted mass to relativistic energy particles for the production of the jets near the event horizon, (2) the jet's launching radius moves radially towards the horizon as the mass accretion rate or jet's power increases, and (3) no jet/outflow formation is possible beyond 44 gravitational radii.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. X-RAYS FROM A RADIO-LOUD COMPACT BROAD ABSORPTION LINE QUASAR 1045+352 AND THE NATURE OF OUTFLOWS IN RADIO-LOUD BROAD ABSORPTION LINE QUASARS

    International Nuclear Information System (INIS)

    Kunert-Bajraszewska, Magdalena; Katarzynski, Krzysztof; Siemiginowska, Aneta; Janiuk, Agnieszka

    2009-01-01

    We present new results on X-ray properties of radio-loud broad absorption line (BAL) quasars and focus on broadband spectral properties of a high-ionization BAL (HiBAL) compact steep spectrum (CSS) radio-loud quasar 1045+352. This HiBAL quasar has a very complex radio morphology indicating either strong interactions between a radio jet and the surrounding interstellar medium or a possible re-start of the jet activity. We detected 1045+352 quasar in a short 5 ksec Chandra ACIS-S observation. We applied theoretical models to explain spectral energy distribution of 1045+352 and argue that non-thermal, inverse-Compton (IC) emission from the innermost parts of the radio jet can account for a large fraction of the observed X-ray emission. In our analysis, we also consider a scenario in which the observed X-ray emission from radio-loud BAL quasars can be a sum of IC jet X-ray emission and optically thin corona X-ray emission. We compiled a sample of radio-loud BAL quasars that were observed in X-rays to date and report no correlation between their X-ray and radio luminosity. However, the radio-loud BAL quasars show a large range of X-ray luminosities and absorption columns. This is consistent with the results obtained earlier for radio-quiet BAL quasars and may indicate an orientation effect in BAL quasars or more complex dependence between X-ray emission, radio emission, and an orientation based on the radio morphology.

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

    Science.gov (United States)

    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.

  11. Ultra-Fast Outflows in Radio-Loud AGN: New Constraints on Jet-Disk Connection

    Science.gov (United States)

    Sambruna, Rita

    There is strong observational and theoretical evidence that outflows/jets are coupled to accretion disks in black hole accreting systems, from Galactic to extragalactic sizes. While in radio-quiet AGN there is ample evidence for the presence of Ultra-Fast Outflows (UFOs) from the presence of blue-shifted absorption features in their 4-10~keV spectra, sub-relativistic winds are expected on theoretical basis in radio-loud AGN but have not been observed until now. Our recent Suzaku observations of 5 bright Broad- Line Radio Galaxies (BLRGs, the radio-loud counterparts of Seyferts) has started to change this picture. We found strong evidence for UFOs in 3 out of 5 BLRGs, with ionization parameters, column densities, and velocities of the absorber similar to Seyferts. Moreover, the outflows in BLRGs are likely to be energetically very significant: from the Suzaku data of the three sources, outflow masses similar to the accretion masses and kinetic energies of the wind similar to the X-ray luminosity and radio power of the jet are inferred. Clearly, UFOs in radio-loud AGN represent a new key ingredient to understand their central engines and in particular, the jet-disk linkage. Our discovery of UFOs in a handful of BLRGs raises the questions of how common disk winds are in radio-loud AGN, what the absorber physical and dynamical characteristics are, and what is the outflow role in broader picture of galaxy-black hole connection for radio sources, i.e., for large-scale feedback models. To address these and other issues, we propose to use archival XMM-Newton and Suzaku spectra to search for Ultra-Fast Outflows in a large number of radio sources. Over a period of two years, we will conduct a systematic, uniform analysis of the archival X-ray data, building on our extensive experience with a similar previous project for Seyferts, and using robust analysis and statistical methodologies. As an important side product, we will also obtain accurate, self- consistent measurements

  12. Radio-loudness in black hole transients: evidence for an inclination effect

    Science.gov (United States)

    Motta, S. E.; Casella, P.; Fender, R.

    2018-06-01

    Accreting stellar-mass black holes appear to populate two branches in a radio:X-ray luminosity plane. We have investigated the X-ray variability properties of a large number of black hole low-mass X-ray binaries, with the aim of unveiling the physical reasons underlying the radio-loud/radio-quiet nature of these sources, in the context of the known accretion-ejection connection. A reconsideration of the available radio and X-ray data from a sample of black hole X-ray binaries confirms that being radio-quiet is the more normal mode of behaviour for black hole binaries. In the light of this we chose to test, once more, the hypothesis that radio loudness could be a consequence of the inclination of the X-ray binary. We compared the slope of the `hard-line' (an approximately linear correlation between X-ray count rate and rms variability, visible in the hard states of active black holes), the orbital inclination, and the radio-nature of the sources of our sample. We found that high-inclination objects show steeper hard-lines than low-inclination objects, and tend to display a radio-quiet nature (with the only exception of V404 Cyg), as opposed to low-inclination objects, which appear to be radio-loud(er). While in need of further confirmation, our results suggest that - contrary to what has been believed for years - the radio-loud/quiet nature of black-hole low mass X-ray binaries might be an inclination effect, rather than an intrinsic source property. This would solve an important issue in the context of the inflow-outflow connection, thus providing significant constraints to the models for the launch of hard-state compact jets.

  13. DIFFERENCES BETWEEN RADIO-LOUD AND RADIO-QUIET γ -RAY PULSARS AS REVEALED BY FERMI

    Energy Technology Data Exchange (ETDEWEB)

    Hui, C. Y.; Lee, Jongsu [Department of Astronomy and Space Science, Chungnam National University, Daejeon (Korea, Republic of); Takata, J. [Institute of Particle physics and Astronomy, Huazhong University of Science and Technology (China); Ng, C. W.; Cheng, K. S., E-mail: cyhui@cnu.ac.kr, E-mail: takata@hust.edu.cn [Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong)

    2017-01-10

    By comparing the properties of non-recycled radio-loud γ -ray pulsars and radio-quiet γ -ray pulsars, we have searched for the differences between these two populations. We found that the γ -ray spectral curvature of radio-quiet pulsars can be larger than that of radio-loud pulsars. Based on the full sample of non-recycled γ -ray pulsars, their distributions of the magnetic field strength at the light cylinder are also found to be different. We note that this might result from an observational bias. By reexamining the previously reported difference of γ -ray-to-X-ray flux ratios, we found that the significance can be hampered by their statistical uncertainties. In the context of the outer gap model, we discuss the expected properties of these two populations and compare with the possible differences that are identified in our analysis.

  14. Stellar Dynamics and Star Formation Histories of z ∼ 1 Radio-loud Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Barišić, Ivana; Van der Wel, Arjen; Chauké, Priscilla; Van Houdt, Josha; Straatman, Caroline [Max-Planck Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); Bezanson, Rachel [Department of Astrophysics, Princeton University, Princeton, NJ 08544 (United States); Pacifici, Camilla [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Noeske, Kai [experimenta gGmbH, Kranenstraße 14, 74072 Heilbronn (Germany); Muñoz-Mateos, Juan C. [European Southern Observatory, Alonso de Córdova 3107, Casilla 19001, Vitacura, Santiago (Chile); Franx, Marijn; Labbé, Ivo; Maseda, Michael V.; Sobral, David [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 AA Leiden (Netherlands); Smolčić, Vernesa [Department of Physics, Faculty of Science, University of Zagreb, Bijenicka cesta 32, 10000 Zagreb (Croatia); Bell, Eric F. [Department of Astronomy, University of Michigan, 1085 S. University Avenue, Ann Arbor, MI 48109 (United States); Brammer, Gabriel [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Calhau, João [Department of Physics, Lancaster University, Lancaster LA1 4 YB (United Kingdom); Van Dokkum, Pieter G. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Gallazzi, Anna [INAF-Osservatorio Astrofsico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Muzzin, Adam, E-mail: barisic@mpia.de [Department of Physics and Astronomy, York University, 4700 Keele Street, Toronto, Ontario, ON MJ3 1P3 (Canada); and others

    2017-09-20

    We investigate the stellar kinematics and stellar populations of 58 radio-loud galaxies of intermediate luminosities ( L {sub 3} {sub GHz} > 10{sup 23} W Hz{sup −1}) at 0.6 < z < 1. This sample is constructed by cross-matching galaxies from the deep VLT/VIMOS LEGA-C spectroscopic survey with the VLA 3 GHz data set. The LEGA-C continuum spectra reveal for the first time stellar velocity dispersions and age indicators of z ∼ 1 radio galaxies. We find that z ∼ 1 radio-loud active galactic nucleus (AGN) occur exclusively in predominantly old galaxies with high velocity dispersions: σ {sub *} > 175 km s{sup −1}, corresponding to black hole masses in excess of 10{sup 8} M {sub ⊙}. Furthermore, we confirm that at a fixed stellar mass the fraction of radio-loud AGN at z ∼ 1 is five to 10 times higher than in the local universe, suggesting that quiescent, massive galaxies at z ∼ 1 switch on as radio AGN on average once every Gyr. Our results strengthen the existing evidence for a link between high black hole masses, radio loudness, and quiescence at z ∼ 1.

  15. A Search for Radio-loud Quasars within the Epoch of Reionization

    OpenAIRE

    Jarvis, Matt J.; Rawlings, Steve; Barrio, F. Eugenio; Hill, Gary J.; Bauer, Amanda; Croft, Steve

    2003-01-01

    The Universe became fully reionized, and observable optically, at a time corresponding to redshift z~6.5, so it is only by studying the HI and molecular absorption lines against higher-redshift, radio-loud sources that one can hope to make detailed studies of the earliest stages of galaxy formation. At present no targets for such studies are known. In these proceedings we describe a survey which is underway to find radio-loud quasars at z > 6.5.

  16. Pair-Matching of Radio-Loud and Radio-Quiet AGNs

    Energy Technology Data Exchange (ETDEWEB)

    Kozieł-Wierzbowska, Dorota [Astronomical Observatory, Jagiellonian University, Krakow (Poland); Stasińska, Grażyna [LUTH, Observatoire de Paris, Centre National de la Recherche Scientifique, Université Paris Diderot, Meudon (France); Vale Asari, Natalia [Departamento de Física–CFM, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Sikora, Marek [Nicolaus Copernicus Astronomical Center, Warsaw (Poland); Goettems, Elisa [Departamento de Física–CFM, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Wójtowicz, Anna, E-mail: dorota.koziel@uj.edu.pl [Astronomical Observatory, Jagiellonian University, Krakow (Poland)

    2017-11-07

    Active galactic nuclei (AGNs) are known to cover an extremely broad range of radio luminosities and the spread of their radio-loudness is very large at any value of the Eddington ratio. This implies very diverse jet production efficiencies which can result from the spread of the black hole spins and magnetic fluxes. Magnetic fluxes can be developed stochastically in the innermost zones of accretion discs, or can be advected to the central regions prior to the AGN phase. In the latter case there could be systematic differences between the properties of galaxies hosting radio-loud (RL) and radio-quiet (RQ) AGNs. In the former case the differences should be negligible for objects having the same Eddington ratio. To study the problem we decided to conduct a comparison study of host galaxy properties of RL and RQ AGNs. In this study we selected type II AGNs from SDSS spectroscopic catalogs. Our RL AGN sample consists of the AGNs appearing in the Best and Heckman (2012) catalog of radio galaxies. To compare RL and RQ galaxies that have the same AGN parameters we matched the galaxies in black hole mass, Eddington ratio and redshift. We compared several properties of the host galaxies in these two groups of objects like galaxy mass, color, concentration index, line widths, morphological type and interaction signatures. We found that in the studied group RL AGNs are preferentially hosted by elliptical galaxies while RQ ones are hosted by galaxies of later type. We also found that the fraction of interacting galaxies is the same in both groups of AGNs. These results suggest that the magnetic flux in RL AGNs is advected to the nucleus prior to the AGN phase.

  17. DISCLOSING THE RADIO LOUDNESS DISTRIBUTION DICHOTOMY IN QUASARS: AN UNBIASED MONTE CARLO APPROACH APPLIED TO THE SDSS-FIRST QUASAR SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Balokovic, M. [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Smolcic, V. [Argelander-Institut fuer Astronomie, Auf dem Hugel 71, D-53121 Bonn (Germany); Ivezic, Z. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Zamorani, G. [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Schinnerer, E. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Kelly, B. C. [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106 (United States)

    2012-11-01

    We investigate the dichotomy in the radio loudness distribution of quasars by modeling their radio emission and various selection effects using a Monte Carlo approach. The existence of two physically distinct quasar populations, the radio-loud and radio-quiet quasars, is controversial and over the last decade a bimodal distribution of radio loudness of quasars has been both affirmed and disputed. We model the quasar radio luminosity distribution with simple unimodal and bimodal distribution functions. The resulting simulated samples are compared to a fiducial sample of 8300 quasars drawn from the SDSS DR7 Quasar Catalog and combined with radio observations from the FIRST survey. Our results indicate that the SDSS-FIRST sample is best described by a radio loudness distribution which consists of two components, with (12 {+-} 1)% of sources in the radio-loud component. On the other hand, the evidence for a local minimum in the loudness distribution (bimodality) is not strong and we find that previous claims for its existence were probably affected by the incompleteness of the FIRST survey close to its faint limit. We also investigate the redshift and luminosity dependence of the radio loudness distribution and find tentative evidence that at high redshift radio-loud quasars were rarer, on average louder, and exhibited a smaller range in radio loudness. In agreement with other recent work, we conclude that the SDSS-FIRST sample strongly suggests that the radio loudness distribution of quasars is not a universal function, and that more complex models than presented here are needed to fully explain available observations.

  18. DISCLOSING THE RADIO LOUDNESS DISTRIBUTION DICHOTOMY IN QUASARS: AN UNBIASED MONTE CARLO APPROACH APPLIED TO THE SDSS-FIRST QUASAR SAMPLE

    International Nuclear Information System (INIS)

    Baloković, M.; Smolčić, V.; Ivezić, Ž.; Zamorani, G.; Schinnerer, E.; Kelly, B. C.

    2012-01-01

    We investigate the dichotomy in the radio loudness distribution of quasars by modeling their radio emission and various selection effects using a Monte Carlo approach. The existence of two physically distinct quasar populations, the radio-loud and radio-quiet quasars, is controversial and over the last decade a bimodal distribution of radio loudness of quasars has been both affirmed and disputed. We model the quasar radio luminosity distribution with simple unimodal and bimodal distribution functions. The resulting simulated samples are compared to a fiducial sample of 8300 quasars drawn from the SDSS DR7 Quasar Catalog and combined with radio observations from the FIRST survey. Our results indicate that the SDSS-FIRST sample is best described by a radio loudness distribution which consists of two components, with (12 ± 1)% of sources in the radio-loud component. On the other hand, the evidence for a local minimum in the loudness distribution (bimodality) is not strong and we find that previous claims for its existence were probably affected by the incompleteness of the FIRST survey close to its faint limit. We also investigate the redshift and luminosity dependence of the radio loudness distribution and find tentative evidence that at high redshift radio-loud quasars were rarer, on average louder, and exhibited a smaller range in radio loudness. In agreement with other recent work, we conclude that the SDSS-FIRST sample strongly suggests that the radio loudness distribution of quasars is not a universal function, and that more complex models than presented here are needed to fully explain available observations.

  19. Interpreting radiative efficiency in radio-loud AGNs

    Science.gov (United States)

    Hardcastle, Martin

    2018-04-01

    Radiative efficiency in radio-loud active galactic nuclei is governed by the accretion rate onto the central black hole rather than directly by the type of accreted matter; while it correlates with real differences in host galaxies and environments, it does not provide unambiguous information about particular objects.

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

    Science.gov (United States)

    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.

  1. The X-Ray Reflection Spectrum of the Radio-loud Quasar 4C 74.26

    DEFF Research Database (Denmark)

    Lohfink, Anne M.; Fabian, Andrew C.; Ballantyne, David R.

    2017-01-01

    of the supermassive black hole, the presumed jet launching point, are potentially particularly valuable in illuminating the jet formation process. Here, we present the hard X-ray NuSTAR observations of the radio-loud quasar 4C 74.26 in a joint analysis with quasi-simultaneous, soft X-ray Swift observations. Our...... the three months covered by our NuSTAR campaign. This lack of variation could mean that the jet formation in this radio-loud quasar differs from what is observed in broad-line radio galaxies....

  2. A large area search for radio-loud quasars within the epoch of reionization

    OpenAIRE

    Jarvis, Matt J.; Rawlings, Steve; Barrio, F. Eugenio; Hill, Gary J.; Bauer, Amanda; Croft, Steve

    2004-01-01

    The Universe became fully reionized, and observable optically, at a time corresponding to redshift z ~ 6.5, so it is only by studying the HI and molecular absorption lines against higher-redshift, radio-loud sources that one can hope to make detailed studies of the earliest stages of galaxy formation. At present no targets for such studies are known. In these proceedings we describe a survey which is underway to find radio-loud quasars at z > 6.5, and present broad-band SEDs of our most promi...

  3. Fossil shell emission in dying radio loud AGNs

    Science.gov (United States)

    Kino, M.; Ito, H.; Kawakatu, N.; Orienti, M.; Nagai, H.; Wajima, K.; Itoh, R.

    2016-02-01

    We investigate shell emission associated with dying radio loud AGNs. First, based on our recent work by Ito et al. (2015), we describe the dynamical and spectral evolution of shells after stopping the jet energy injection. We find that the shell emission overwhelms that of the radio lobes soon after stopping the jet energy injection because fresh electrons are continuously supplied into the shell via the forward shock, while the radio lobes rapidly fade out without jet energy injection. We find that such fossil shells can be a new class of target sources for SKA telescope. Next, we apply the model to the nearby radio source 3C84. Then, we find that the fossil shell emission in 3C84 is less luminous in the radio band while it is bright in the TeV γ-ray band and can be detectable by CTA. Data from STELLA

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

    NARCIS (Netherlands)

    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

  5. SDSS J013127.34–032100.1: A NEWLY DISCOVERED RADIO-LOUD QUASAR AT z = 5.18 WITH EXTREMELY HIGH LUMINOSITY

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Wei-Min; Bai, Jin-Ming; Zhang, Ju-jia; Wang, Fang; Wang, Jian-Guo; Fan, Yu-Feng; Chang, Liang; Wang, Chuan-Jun; Lun, Bao-Li [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Wang, Feige; Wu, Xue-Bing; Yang, Jinyi; Ho, Luis C.; Zuo, Wenwen; Yang, Qian; Ai, Yanli [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Fan, Xiaohui [Steward Observatory, University of Arizona, Tucson, AZ 85721-0065 (United States); Brandt, William N. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Kim, Minjin [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Wang, Ran [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); and others

    2014-11-10

    Very few of the z > 5 quasars discovered to date have been radio-loud, with radio-to-optical flux ratios (radio-loudness parameters) higher than 10. Here we report the discovery of an optically luminous radio-loud quasar, SDSS J013127.34–032100.1 (J0131–0321 in short), at z = 5.18 ± 0.01 using the Lijiang 2.4 m and Magellan telescopes. J0131–0321 has a spectral energy distribution consistent with that of radio-loud quasars. With an i-band magnitude of 18.47 and a radio flux density of 33 mJy, its radio-loudness parameter is ∼100. The optical and near-infrared spectra taken by Magellan enable us to estimate its bolometric luminosity to be L {sub bol} ∼ 1.1 × 10{sup 48} erg s{sup –1}, approximately 4.5 times greater than that of the most distant quasar known to date. The black hole mass of J0131–0321 is estimated to be 2.7 × 10{sup 9} M {sub ☉}, with an uncertainty up to 0.4 dex. Detailed physical properties of this high-redshift, radio-loud, potentially super-Eddington quasar can be probed in the future with more dedicated and intensive follow-up observations using multi-wavelength facilities.

  6. Radio-loud magnetars as detectors for axions and axion-like particles

    International Nuclear Information System (INIS)

    Guendelman, E.I.; Chelouche, D.

    2011-01-01

    We show that, by studying the arrival times of radio pulses from highly-magnetized transient beamed sources, it may be possible to detect light pseudo-scalar particles, such as axions and axion-like particles, whose existence could have considerable implications for the strong-CP problem of QCD as well as the dark matter problem in cosmology. Specifically, such light bosons may be detected with a much greater sensitivity, over a broad particle mass range, than is currently achievable by terrestrial experiments, and using indirect astrophysical considerations. The observable effect was discussed in Chelouche & Guendelman (2009), and is akin to the Stern-Gerlach experiment: the splitting of a photon beam naturally arises when finite coupling exists between the electro-magnetic field and the axion field. The splitting angle of the light beams linearly depends on the photon wavelength, the size of the magnetized region, and the magnetic field gradient in the transverse direction to the propagation direction of the photons. If radio emission in radio-loud magnetars is beamed and originates in regions with strong magnetic field gradients, then splitting of individual pulses may be detectable. We quantify the effect for a simplified model for magnetars, and search for radio beam splitting in the 2GHz radio light curves of the radio loud magnetar XTEJ1810-197. (author)

  7. Particle content, radio-galaxy morphology, and jet power: all radio-loud AGN are not equal

    Science.gov (United States)

    Croston, J. H.; Ineson, J.; Hardcastle, M. J.

    2018-05-01

    Ongoing and future radio surveys aim to trace the evolution of black hole growth and feedback from active galactic nuclei (AGNs) throughout cosmic time; however, there remain major uncertainties in translating radio luminosity functions into a reliable assessment of the energy input as a function of galaxy and/or dark matter halo mass. A crucial and long-standing problem is the composition of the radio-lobe plasma that traces AGN jet activity. In this paper, we carry out a systematic comparison of the plasma conditions in Fanaroff & Riley class I and II radio galaxies to demonstrate conclusively that their internal composition is systematically different. This difference is best explained by the presence of an energetically dominant proton population in the FRI, but not the FRII radio galaxies. We show that, as expected from this systematic difference in particle content, radio morphology also affects the jet-power/radio-luminosity relationship, with FRII radio galaxies having a significantly lower ratio of jet power to radio luminosity than the FRI cluster radio sources used to derive jet-power scaling relations via X-ray cavity measurements. Finally, we also demonstrate conclusively that lobe composition is unconnected to accretion mode (optical excitation class): the internal conditions of low- and high-excitation FRII radio lobes are indistinguishable. We conclude that inferences of population-wide AGN impact require careful assessment of the contribution of different jet subclasses, particularly given the increased diversity of jet evolutionary states expected to be present in deep, low-frequency radio surveys such as the LOFAR Two-Metre Sky Survey.

  8. The cluster environments of powerful, high-redshift radio galaxies

    International Nuclear Information System (INIS)

    Yates, M.G.

    1989-01-01

    We present deep imaging of a sample of 25 powerful radio galaxies in the redshift range 0.15 gr ) about each source, a measure of the richness of environment. The powerful radio galaxies in this sample at z>0.3 occupy environments nearly as rich on average as Abell class 0 clusters of galaxies, about three times richer than the environments of the z<0.3 radio galaxies. This trend in cluster environment is consistent with that seen in radio-loud quasars over the same redshift range. Our previous work on the 3CR sample suggested that the fundamental parameter which correlates with the richness of environment might be the radio luminosity of the galaxy, rather than its redshift. Our direct imaging confirms that the most powerful radio galaxies do inhabit rich environments. (author)

  9. Fermi-LAT γ-ray anisotropy and intensity explained by unresolved radio-loud active galactic nuclei

    International Nuclear Information System (INIS)

    Mauro, Mattia Di; Cuoco, Alessandro; Donato, Fiorenza; Siegal-Gaskins, Jennifer M.

    2014-01-01

    Radio-loud active galactic nuclei (AGN) are expected to contribute substantially to both the intensity and anisotropy of the isotropic γ-ray background (IGRB). In turn, the measured properties of the IGRB can be used to constrain the characteristics of proposed contributing source classes. We consider individual subclasses of radio-loud AGN, including low-, intermediate-, and high-synchrotron-peaked BL Lacertae objects, flat-spectrum radio quasars, and misaligned AGN. Using updated models of the γ-ray luminosity functions of these populations, we evaluate the energy-dependent contribution of each source class to the intensity and anisotropy of the IGRB. We find that collectively radio-loud AGN can account for the entirety of the IGRB intensity and anisotropy as measured by the Fermi Large Area Telescope (LAT). Misaligned AGN provide the bulk of the measured intensity but a negligible contribution to the anisotropy, while high-synchrotron-peaked BL Lacertae objects provide the dominant contribution to the anisotropy. In anticipation of upcoming measurements with the Fermi-LAT and the forthcoming Cherenkov Telescope Array, we predict the anisotropy in the broader energy range that will be accessible to future observations

  10. Fermi-LAT γ-ray anisotropy and intensity explained by unresolved radio-loud active galactic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Mauro, Mattia Di; Cuoco, Alessandro; Donato, Fiorenza [Dipartimento di Fisica, Università di Torino, via P. Giuria 1, Torino, 10125 Italy (Italy); Siegal-Gaskins, Jennifer M., E-mail: mattia.dimauro@to.infn.it, E-mail: alessandro.cuoco@to.infn.it, E-mail: donato@to.infn.it, E-mail: jsg@tapir.caltech.edu [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, 91125 (United States)

    2014-11-01

    Radio-loud active galactic nuclei (AGN) are expected to contribute substantially to both the intensity and anisotropy of the isotropic γ-ray background (IGRB). In turn, the measured properties of the IGRB can be used to constrain the characteristics of proposed contributing source classes. We consider individual subclasses of radio-loud AGN, including low-, intermediate-, and high-synchrotron-peaked BL Lacertae objects, flat-spectrum radio quasars, and misaligned AGN. Using updated models of the γ-ray luminosity functions of these populations, we evaluate the energy-dependent contribution of each source class to the intensity and anisotropy of the IGRB. We find that collectively radio-loud AGN can account for the entirety of the IGRB intensity and anisotropy as measured by the Fermi Large Area Telescope (LAT). Misaligned AGN provide the bulk of the measured intensity but a negligible contribution to the anisotropy, while high-synchrotron-peaked BL Lacertae objects provide the dominant contribution to the anisotropy. In anticipation of upcoming measurements with the Fermi-LAT and the forthcoming Cherenkov Telescope Array, we predict the anisotropy in the broader energy range that will be accessible to future observations.

  11. Is Electronically Amplified Music too Loud? What do Young People Think?

    Science.gov (United States)

    Mercier, Vlasta; Hohmann, Beat W.

    2002-01-01

    Listening to loud music has been associated, in a number of studies, with hearing loss and tinnitus among young people. However an unanswered question is whether or not these same young people want to have their music so loud. In our study 533 young men and 167 young women, in the age group 16 to 25, who were attending a vocational training centre, responded to a questionnaire and volunteered to have their hearing assessed. The questionnaire sought information on listening habits, on the kinds of events attended, on whether the music at these events was too loud or not, and if the respondents considered their hearing had been impaired. Analysis of this data indicated that 79% of the subjects attend discotheques, 52% pop and rock concerts, and 35% techno parties (e.g. raves). A significant number considered the music at these venues was too loud. Some 42% considered this was the case at discos, 35% thought pop and rock concerts too loud, and 39% held a similar view of techno parties. Conversely, fewer than 3% considered sound levels at these events to be too low. On the basis of the response to the questionnaire we estimate that over half the respondents (56.6%) have a sound exposure (L(eq)) from music of over 87 dB(A). It is not surprising therefore that 71% reported that they had suffered tinnitus following attendance at a music event. The hearing capacity of the sample was measured by audiometry. These measurements detected hearing loss in 11% of the 700 individuals tested. However it was not possible to show that the risk of hearing loss increased with increasing exposure to loud music. We conclude that young people neither demand nor require the excessive sound levels typical of most music events.

  12. THE WISE BLAZAR-LIKE RADIO-LOUD SOURCES: AN ALL-SKY CATALOG OF CANDIDATE γ-RAY BLAZARS

    Energy Technology Data Exchange (ETDEWEB)

    D' Abrusco, R.; Paggi, A.; Smith, H. A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Massaro, F. [Dipartimento di Fisica, Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino (Italy); Masetti, N. [INAF/IASF di Bologna, via Gobetti 101, I-40129 Bologna (Italy); Landoni, M. [INAF/Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807 Merate (Italy); Tosti, G. [Dipartimento di Fisica, Università degli Studi di Perugia, I-06123 Perugia (Italy)

    2014-11-01

    We present a catalog of radio-loud candidate γ-ray emitting blazars with WISE mid-infrared colors similar to the colors of confirmed γ-ray blazars. The catalog is assembled from WISE sources detected in all four WISE filters, with colors compatible with the three-dimensional locus of the WISE γ-ray emitting blazars, and which can be spatially cross-matched with radio sources from one of the three radio surveys: NVSS, FIRST, and/or SUMSS. Our initial WISE selection uses a slightly modified version of previously successful algorithms. We then select only the radio-loud sources using a measure of the radio-to-IR flux, the q {sub 22} parameter, which is analogous to the q {sub 24} parameter known in the literature but which instead uses the WISE band-four flux at 22 μm. Our final catalog contains 7855 sources classified as BL Lacs, FSRQs, or mixed candidate blazars; 1295 of these sources can be spatially re-associated as confirmed blazars. We describe the properties of the final catalog of WISE blazar-like radio-loud sources and consider possible contaminants. Finally, we discuss why this large catalog of candidate γ-ray emitting blazars represents a new and useful resource to address the problem of finding low-energy counterparts to currently unidentified high-energy sources.

  13. Toward a New Paradigm for the Unification of Radio Loud AGN and its Connection to Accretion

    Science.gov (United States)

    Georganpoulos, Markos; Meyer, Eileen T.; Fossati, Giovanni; Lister, Matthew L.

    2012-01-01

    We recently argued [21J that the collective properties. of radio loud active galactic nuclei point to the existence of two families of sources, one of powerful sources with single velocity jets and one of weaker jets with significant velocity gradients in the radiating plasma. These families also correspond to different accretion modes and therefore different thermal and emission line intrinsic properties: powerful sources have radiatively efficient accretion disks, while in weak sources accretion must be radiatively inefficient. Here, after we briefly review of our recent work, we present the following findings that support our unification scheme: (i) along the broken sequence of aligned objects, the jet kinetic power increases. (ii) in the powerful branch of the sequence of aligned objects the fraction of BLLs decreases with increasing jet power. (iii) for powerful sources, the fraction of BLLs increases for more un-aligned objects, as measured by the core to extended radio emission. Our results are also compatible with the possibility that a given accretion power produces jets of comparable kinetic power.

  14. The contribution of unresolved radio-loud AGN to the extragalactic diffuse gamma-ray background

    DEFF Research Database (Denmark)

    Mucke, A.; Pohl, M.

    2000-01-01

    , and on the unification scheme of radio-loud AGN. According to this picture, blazars represent the beamed fraction of the Fanaroff-Riley radio galaxies (FR galaxies). The observed log N-log S distribution and redshift distribution of both FSRQs and BL Lacs constrain our model. Depending slightly on the evolutionary...

  15. DEEP SPITZER OBSERVATIONS OF INFRARED-FAINT RADIO SOURCES: HIGH-REDSHIFT RADIO-LOUD ACTIVE GALACTIC NUCLEI?

    International Nuclear Information System (INIS)

    Norris, Ray P.; Mao, Minnie; Afonso, Jose; Cava, Antonio; Farrah, Duncan; Oliver, Seb; Huynh, Minh T.; Mauduit, Jean-Christophe; Surace, Jason; Ivison, R. J.; Jarvis, Matt; Lacy, Mark; Maraston, Claudia; Middelberg, Enno; Seymour, Nick

    2011-01-01

    Infrared-faint radio sources (IFRSs) are a rare class of objects which are relatively bright at radio wavelengths but very faint at infrared and optical wavelengths. Here we present sensitive near-infrared observations of a sample of these sources taken as part of the Spitzer Extragalactic Representative Volume Survey. Nearly all the IFRSs are undetected at a level of ∼1 μJy in these new deep observations, and even the detections are consistent with confusion with unrelated galaxies. A stacked image implies that the median flux density is S 3.6μm ∼ 0.2 μJy or less, giving extreme values of the radio-infrared flux density ratio. Comparison of these objects with known classes of object suggests that the majority are probably high-redshift radio-loud galaxies, possibly suffering from significant dust extinction.

  16. The Origin of Powerful Radio Sources

    Science.gov (United States)

    Wilson, A. S.; Colbert, E. J. M.

    1995-05-01

    Radio-loud active galaxies are associated with elliptical or elliptical-like galaxies, many of which appear to be the result of a recent merger. In contrast, radio-quiet active galaxies prefer spiral hosts. Despite the very large difference in radio luminosities between the two classes, their continua and line spectra from infrared through X-ray frequencies are very similar. In this paper, we describe recent developments of our model (Ap. J. 438, 62 1995) in which the radio-loud phenomenon is the result of a merger of two galaxies, with each galaxy nucleus containing a slowly (or non-) rotating supermassive black hole. It is envisaged that the two black holes eventually coalesce. For the small fraction of mergers in which the two holes are both massive and of comparable mass, a rapidly-spinning, high-mass hole results. The spin energy of a rapidly rotating 10(8-9) solar mass hole suffices to provide the ~ 10(60) ergs in relativistic particles and magnetic fields in the most energetic radio sources. Luminous radio-quiet active galaxies contain high-mass, slowly-rotating holes, with the infrared through X-ray emission of both classes being fuelled by accretion as commonly assumed. We discuss constraints on the model from the luminosity functions of radio-loud and radio-quiet galaxies and from the known cosmological evolution of the radio source population; this evolution is assumed to reflect higher galaxy merger rates in the past.

  17. HST Grism Confirmation of 16 Structures at 1.4 < z < 2.8 from the Clusters Around Radio-Loud AGN (CARLA) Survey

    Science.gov (United States)

    Noirot, Gaël; Stern, Daniel; Mei, Simona; Wylezalek, Dominika; Cooke, Elizabeth A.; De Breuck, Carlos; Galametz, Audrey; Hatch, Nina A.; Vernet, Joël; Brodwin, Mark; Eisenhardt, Peter; Gonzalez, Anthony H.; Jarvis, Matt; Rettura, Alessandro; Seymour, Nick; Stanford, S. A.

    2018-05-01

    We report spectroscopic results from our 40-orbit Hubble Space Telescope slitless grism spectroscopy program observing the 20 densest Clusters Around Radio-Loud AGN (CARLA) candidate galaxy clusters at 1.4 targeting 420 distant radio-loud AGN. We report the spectroscopic confirmation of 16 distant structures at 1.4 targeted powerful high-redshift radio-loud AGN. We also report the serendipitous discovery and spectroscopic confirmation of seven additional structures at 0.87 targeted radio-loud AGN. We find that 1010–1011 M ⊙ member galaxies of our confirmed CARLA structures form significantly fewer stars than their field counterparts at all redshifts within 1.4 ≤ z ≤ 2. We also observe higher star-forming activity in the structure cores up to z = 2, finding similar trends as cluster surveys at slightly lower redshifts (1.0 strategy of obtaining just two grism orbits per field only obtains spectroscopic confirmation of emission line galaxies. Deeper spectroscopy will be required to study the population of evolved, massive galaxies in these (forming) clusters. Lacking multi-band coverage of the fields, we adopt a very conservative approach of calling all confirmations “structures,” although we note that a number of features are consistent with some of them being bona fide galaxy clusters. Together this survey represents a unique and large homogenous sample of spectroscopically confirmed structures at high redshifts, potentially more than doubling the census of confirmed, massive clusters at z > 1.4.

  18. The X-Ray Reflection Spectrum of the Radio-loud Quasar 4C 74.26

    DEFF Research Database (Denmark)

    Lohfink, Anne M.; Fabian, Andrew C.; Ballantyne, David R.

    2017-01-01

    The relativistic jets created by some active galactic nuclei are important agents of AGN feedback. In spite of this, our understanding of what produces these jets is still incomplete. X-ray observations, which can probe the processes operating in the central regions in the immediate vicinity of t...... the three months covered by our NuSTAR campaign. This lack of variation could mean that the jet formation in this radio-loud quasar differs from what is observed in broad-line radio galaxies.......The relativistic jets created by some active galactic nuclei are important agents of AGN feedback. In spite of this, our understanding of what produces these jets is still incomplete. X-ray observations, which can probe the processes operating in the central regions in the immediate vicinity...... of the supermassive black hole, the presumed jet launching point, are potentially particularly valuable in illuminating the jet formation process. Here, we present the hard X-ray NuSTAR observations of the radio-loud quasar 4C 74.26 in a joint analysis with quasi-simultaneous, soft X-ray Swift observations. Our...

  19. Social Representation of "Loud Music" in Young Adults: A Cross-Cultural Study.

    Science.gov (United States)

    Manchaiah, Vinaya; Zhao, Fei; Widen, Stephen; Auzenne, Jasmin; Beukes, Eldré W; Ahmadi, Tayebeh; Tomé, David; Mahadeva, Deepthi; Krishna, Rajalakshmi; Germundsson, Per

    2017-06-01

    Exposure to recreational noise, particularly music exposure, is considered one of the biggest public health hazards of our time. Some important influencing factors such as socioeconomic status, educational background, and cross-cultural perspectives have previously been found to be associated with attitudes toward loud music and the use of hearing protection. Although culture seems to play an important role, there is relatively little known about how it influences perceptions regarding loud music exposure in young adults. The present study was aimed to explore cross-cultural perceptions of and reactions to loud music in young adults (18-25 yr) using the theory of social representations. The study used a cross-sectional survey design. The study sample included young adults (n = 534) from five different countries (India, Iran, Portugal, the United States, and the United Kingdom) who were recruited using convenience sampling. Data were collected using a questionnaire. Data were analyzed using a content analysis, co-occurrence analysis, and also χ² analysis. Fairly equal numbers of positive and negative connotations (∼40%) were noted in all countries. However, the χ² analysis showed significant differences between the countries (most positive connotations were found in India and Iran, whereas the most negative connotations were found in the United Kingdom and Portugal) regarding the informants' perception of loud music. The co-occurrence analysis results generally indicate that the category "negative emotions and actions" occurred most frequently, immediately followed by the category "positive emotions and actions." The other most frequently occurring categories included "acoustics," "physical aliment," "location," and "ear and hearing problems." These six categories formed the central nodes of the social representation of loud music exposure in the global index. Although some similarities and differences were noted among the social representations toward loud

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Subjective difficulties in young people related to extensive loud music listening

    Directory of Open Access Journals (Sweden)

    Budimčić Milenko

    2010-01-01

    Full Text Available Introduction. For human ear, noise represents every undesirable and valueless sound. In disco clubs, as in some other places with loud music mostly attended by young people, the level of noise sometimes attains over 100 dB. As reported by numerous studies, a high noise level could induce subjective difficulties (ear buzzing, audition loss, vertigo and palpitations, anxiety, high blood pressure, decreased concentration, lowered memory storing. Objective. Assessment of subjective difficulties occurring in young people when staying in places with a high noise level (cafes, disco clubs, rock concerts, which can produce health problems, due to loud music, in association with demographic data, addictions and personal life style data. One of the goals is to find factors leading to subjective difficulties, which would be objectively studied in the second stage of the research and marked as early predictors of possible health problems. Methods. The study was conducted among 780 students of the Higher Healthcare School of Professional Studied in Belgrade. We used a questionnaire with 20 questions, divided into four categories: demographic data, case-history data, subjective problems and addictions of the subjects. In the statistical data processing we used the methods of descriptive and exploratory analysis, chi-square tests, correlation tests and Mantel-Haenszel odds ratio. Results. After listening loud music, 54.0% of examined subjects felt ear buzzing, and 4.6% had hearing damage. The habit of visiting places with loud music, mostly once a week in duration of 2-3 hours per visit had 80.4% of subjects. The presence of subjective complaints after listening of loud music was in association with loud music listening and disco clubs visits. The major reasons of the present subjective difficulties could be predicated by listening of loud music and club visits (r=0.918 and r=0.857. A relative risk for subjective difficulties presentation was 1.599. Conclusion

  2. [Subjective difficulties in young people related to extensive loud music listening].

    Science.gov (United States)

    Budimcić, Milenko; Ignatović, Snezana; Zivić, Ljubica

    2010-01-01

    For human ear, noise represents every undesirable and valueless sound. In disco clubs, as in some other places with loud music mostly attended by young people, the level of noise sometimes attains over 100 dB. As reported by numerous studies, a high noise level could induce subjective difficulties (ear buzzing, audition loss, vertigo and palpitations, anxiety, high blood pressure, decreased concentration, lowered memory storing). Assessment of subjective difficulties occurring in young people when staying in places with a high noise level (cafes, disco clubs, rock concerts), which can produce health problems, due to loud music, in association with demographic data, addictions and personal life style data. One of the goals is to find factors leading to subjective difficulties, which would be objectively studied in the second stage of the research and marked as early predictors of possible health problems. The study was conducted among 780 students of the Higher Healthcare School of Professional Studied in Belgrade. We used a questionnaire with 20 questions, divided into four categories: demographic data, case-history data, subjective problems and addictions of the subjects. In the statistical data processing we used the methods of descriptive and exploratory analysis, chi-square tests, correlation tests and Mantel-Haenszel odds ratio. After listening loud music, 54.0% of examined subjects felt ear buzzing, and 4.6% had hearing damage. The habit of visiting places with loud music, mostly once a week in duration of 2-3 hours per visit had 80.4% of subjects. The presence of subjective complaints after listening of loud music was in association with loud music listening and disco clubs visits.The major reasons of the present subjective difficulties could be predicated by listening of loud music and club visits (r = 0.918 and r = 0.857). A relative risk for subjective difficulties presentation was 1.599. According to the results of our study, over half of children

  3. The X-Ray Reflection Spectrum of the Radio-Loud Quasar 4C 74.26

    Science.gov (United States)

    Lohfink, Ann M.; Fabian, Andrew C.; Ballantyne, David R.; Boggs, S. E.; Boorman, Peter; Christensen, F. E.; Craig, W. W.; Farrah, Duncan; Garcia, Javier; Hailey, C. J.; hide

    2017-01-01

    The relativistic jets created by some active galactic nuclei are important agents of AGN feedback. In spite of this, our understanding of what produces these jets is still incomplete. X-ray observations, which can probe the processes operating in the central regions in the immediate vicinity of the supermassive black hole, the presumed jet launching point, are potentially particularly valuable in illuminating the jet formation process. Here, we present the hard X-ray NuSTAR observations of the radio-loud quasar 4C 74.26 in a joint analysis with quasi-simultaneous, soft X-ray Swift observations. Our spectral analysis reveals a high-energy cutoff of -183+3551 keV and confirms the presence of ionized reflection in the source. From the average spectrum we detect that the accretion disk is mildly recessed, with an inner radius of Rin4180 Rg. However, no significant evolution of the inner radius is seen during the three months covered by our NuSTAR campaign. This lack of variation could mean that the jet formation in this radio-loud quasar differs from what is observed in broad-line radio galaxies.

  4. THE JET POWER AND EMISSION-LINE CORRELATIONS OF RADIO-LOUD OPTICALLY SELECTED QUASARS

    International Nuclear Information System (INIS)

    Punsly, Brian; Zhang Shaohua

    2011-01-01

    In this Letter, the properties of the extended radio emission form Sloan Digital Sky Survey Data Release 7 quasars with 0.4 20-30 kpc). The frequency of quasars with FR II level extended radio emission is ∼2.3% and >0.4% of quasars have FR I level extended radio emission. The lower limit simply reflects the flux density limit of the survey. The distribution of the long-term time-averaged jet powers of these quasars, Q-bar , has a broad peak ∼3 x 10 44 erg s -1 that turns over below 10 44 erg s -1 and sources above 10 45 erg s -1 are extremely rare. It is found that the correlation between the bolometric (total thermal) luminosity of the accretion flow, L bol , and Q-bar is not strong. The correlation of Q-bar with narrow line luminosity is stronger than the correlation with broad line luminosity and the continuum luminosity. It is therefore concluded that previous interpretations of correlations of Q-bar with narrow line strengths in radio galaxies as a direct correlation of jet power and accretion power have been overstated. It is explained why this interpretation mistakenly overlooks the sizeable fraction of sources with weak accretion luminosity and powerful jets discovered by Ogle et al.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Population Studies of Radio and Gamma-Ray Pulsars

    Science.gov (United States)

    Harding, Alice K; Gonthier, Peter; Coltisor, Stefan

    2004-01-01

    Rotation-powered pulsars are one of the most promising candidates for at least some of the 40-50 EGRET unidentified gamma-ray sources that lie near the Galactic plane. Since the end of the EGRO mission, the more sensitive Parkes Multibeam radio survey has detected mere than two dozen new radio pulsars in or near unidentified EGRET sources, many of which are young and energetic. These results raise an important question about the nature of radio quiescence in gamma-ray pulsars: is the non-detection of radio emission a matter of beaming or of sensitivity? The answer is very dependent on the geometry of the radio and gamma-ray beams. We present results of a population synthesis of pulsars in the Galaxy, including for the first time the full geometry of the radio and gamma-ray beams. We use a recent empirically derived model of the radio emission and luminosity, and a gamma-ray emission geometry and luminosity derived theoretically from pair cascades in the polar slot gap. The simulation includes characteristics of eight radio surveys of the Princeton catalog plus the Parkes MB survey. Our results indicate that EGRET was capable of detecting several dozen pulsars as point sources, with the ratio of radio-loud to radio-quiet gamma-ray pulsars increasing significantly to about ten to one when the Parkes Survey is included. Polar cap models thus predict that many of the unidentified EGRET sources could be radio-loud gamma- ray pulsars, previously undetected as radio pulsars due to distance, large dispersion and lack of sensitivity. If true, this would make gamma-ray telescopes a potentially more sensitive tool for detecting distant young neutron stars in the Galactic plane.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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.

  9. Short-Term Variability and Power Spectral Density Analysis of the Radio-Loud Active Galactic Nucleus 3C 390.3

    Science.gov (United States)

    Gliozzi, Mario; Papadakis, Iossif E.; Eracleous, Michael; Sambruna, Rita M.; Ballantyne, David R.; Braito, Valentina; Reeves, James N.

    2009-09-01

    We investigate the short-term variability properties and the power spectral density (PSD) of the broad-line radio galaxy (BLRG) 3C 390.3 using observations made by XMM-Newton, RXTE, and Suzaku on several occasions between 2004 October and 2006 December. The main aim of this work is to derive model-independent constraints on the origin of the X-ray emission and on the nature of the central engine in 3C 390.3. On timescales of the order of few hours, probed by uninterrupted XMM-Newton light curves, the flux of 3C 390.3 is consistent with being constant in all energy bands. On longer timescales, probed by the 2-day RXTE and Suzaku observations, the flux variability becomes significant. The latter observation confirms that the spectral variability behavior of 3C 390.3 is consistent with the spectral evolution observed in (radio-quiet) Seyfert galaxies: the spectrum softens as the source brightens. The correlated variability between soft and hard X-rays, observed during the Suzaku exposure and between the two XMM-Newton pointings, taken 1 week apart, argues against scenarios characterized by the presence of two distinct variable components in the 0.5-10 keV X-ray band. A detailed PSD analysis carried out over five decades in frequency suggests the presence of a break at T br = 43+34 -25 days at a 92% confidence level. This is the second tentative detection of a PSD break in a radio-loud, non-jet dominated active galactic nucleus (AGN), after the BLRG 3C 120, and appears to be in general agreement with the relation between T br, M BH, and L bol, followed by Seyfert galaxies. Our results indicate that the X-ray variability properties of 3C 390.3 are broadly consistent with those of radio-quiet AGN, suggesting that the X-ray emission mechanism in 3C 390.3 is similar to that of nearby Seyfert galaxies without any significant contribution from a jet component.

  10. SHORT-TERM VARIABILITY AND POWER SPECTRAL DENSITY ANALYSIS OF THE RADIO-LOUD ACTIVE GALACTIC NUCLEUS 3C 390.3

    International Nuclear Information System (INIS)

    Gliozzi, Mario; Papadakis, Iossif E.; Eracleous, Michael; Sambruna, Rita M.; Ballantyne, David R.; Braito, Valentina; Reeves, James N.

    2009-01-01

    We investigate the short-term variability properties and the power spectral density (PSD) of the broad-line radio galaxy (BLRG) 3C 390.3 using observations made by XMM-Newton, RXTE, and Suzaku on several occasions between 2004 October and 2006 December. The main aim of this work is to derive model-independent constraints on the origin of the X-ray emission and on the nature of the central engine in 3C 390.3. On timescales of the order of few hours, probed by uninterrupted XMM-Newton light curves, the flux of 3C 390.3 is consistent with being constant in all energy bands. On longer timescales, probed by the 2-day RXTE and Suzaku observations, the flux variability becomes significant. The latter observation confirms that the spectral variability behavior of 3C 390.3 is consistent with the spectral evolution observed in (radio-quiet) Seyfert galaxies: the spectrum softens as the source brightens. The correlated variability between soft and hard X-rays, observed during the Suzaku exposure and between the two XMM-Newton pointings, taken 1 week apart, argues against scenarios characterized by the presence of two distinct variable components in the 0.5-10 keV X-ray band. A detailed PSD analysis carried out over five decades in frequency suggests the presence of a break at T br = 43 +34 -25 days at a 92% confidence level. This is the second tentative detection of a PSD break in a radio-loud, non-jet dominated active galactic nucleus (AGN), after the BLRG 3C 120, and appears to be in general agreement with the relation between T br , M BH , and L bol , followed by Seyfert galaxies. Our results indicate that the X-ray variability properties of 3C 390.3 are broadly consistent with those of radio-quiet AGN, suggesting that the X-ray emission mechanism in 3C 390.3 is similar to that of nearby Seyfert galaxies without any significant contribution from a jet component.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. RADIO-QUIET AND RADIO-LOUD PULSARS: SIMILAR IN GAMMA-RAYS BUT DIFFERENT IN X-RAYS

    Energy Technology Data Exchange (ETDEWEB)

    Marelli, M.; Mignani, R. P.; Luca, A. De; Salvetti, D. [INAF—Istituto di Astrofisica Spaziale e Fisica Cosmica Milano, via E. Bassini 15, I-20133, Milano (Italy); Parkinson, P. M. Saz [Santa Cruz Institute for Particle Physics, Department of Physics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Hartog, P. R. Den [Stanford University HEPL/KIPAC, 452 Lomita Mall, Stanford, CA 94305-4085 (United States); Wolff, M. T., E-mail: marelli@iasf-milano.inaf.it [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States)

    2015-04-01

    We present new Chandra and XMM-Newton observations of a sample of eight radio-quiet (RQ) γ-ray pulsars detected by the Fermi Large Area Telescope. For all eight pulsars we identify the X-ray counterpart, based on the X-ray source localization and the best position obtained from γ-ray pulsar timing. For PSR J2030+4415 we found evidence for a ∼10″-long pulsar wind nebula. Our new results consolidate the work from Marelli et al. and confirm that, on average, the γ-ray-to-X-ray flux ratios (F{sub γ}/F{sub X}) of RQ pulsars are higher than for the radio-loud (RL) ones. Furthermore, while the F{sub γ}/F{sub X} distribution features a single peak for the RQ pulsars, the distribution is more dispersed for the RL ones, possibly showing two peaks. We discuss possible implications of these different distributions based on current models for pulsar X-ray emission.

  13. Observations of neutral hydrogen in radio-loud and interacting galaxies

    Science.gov (United States)

    Heckman, T. M.; Balick, B.; Van Breugel, W. J. W.; Miley, G. K.

    1983-01-01

    The results of a survey of H I in radio-loud and interacting galaxies is presented. Four cases of H I absorption and five of emission are reported. The interesting features found for individual galaxies are described, and the systematic properties are discussed. Column densities of absorbing gas generally exceed those expected for a 'Milky Way' H I disk by more than an order of magnitude. The absorbing gas must have a flattened, disklike morphology oriented roughly parallel to the optical disk of the galaxy. Turbulent noncircular gas motions are evidently present, which are shown to be almost certainly induced by galaxy-galaxy interactions. The set of galaxies in which H I absorption has been detected is dominated by morphologically peculiar objects. It is concluded that the detection of H I seen in absorption against a nuclear radio source permits direct determination of the sense of radial flow of extranuclear material, and is direct evidence that potential 'food' for a compact object in the nucleus exists in the galaxy.

  14. THE UNIFICATION OF POWERFUL QUASARS AND RADIO GALAXIES AND THEIR RELATION TO OTHER MASSIVE GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Podigachoski, Pece; Barthel, Peter [Kapteyn Astronomical Institute, University of Groningen, 9747 AD Groningen (Netherlands); Haas, Martin [Astronomisches Institut, Ruhr Universität, D-44801 Bochum (Germany); Leipski, Christian [Max-Planck Institut für Astronomie (MPIA), D-69117 Heidelberg (Germany); Wilkes, Belinda, E-mail: podigachoski@astro.rug.nl [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2015-06-10

    The unification model for powerful radio galaxies (RGs) and radio-loud quasars postulates that these objects are intrinsically the same but viewed along different angles. Herschel Space Observatory data permit the assessment of that model in the far-infrared spectral window. We analyze photometry from Spitzer and Herschel for the distant 3CR hosts, and find that RGs and quasars have different mid-infrared, but indistinguishable far-infrared colors. Both these properties, the former being orientation dependent and the latter orientation invariant, are in line with expectations from the unification model. Adding powerful radio-quiet active galaxies and typical massive star-forming (SF) galaxies to the analysis, we demonstrate that infrared colors not only provide an orientation indicator, but can also distinguish active from SF galaxies.

  15. THE UNIFICATION OF POWERFUL QUASARS AND RADIO GALAXIES AND THEIR RELATION TO OTHER MASSIVE GALAXIES

    International Nuclear Information System (INIS)

    Podigachoski, Pece; Barthel, Peter; Haas, Martin; Leipski, Christian; Wilkes, Belinda

    2015-01-01

    The unification model for powerful radio galaxies (RGs) and radio-loud quasars postulates that these objects are intrinsically the same but viewed along different angles. Herschel Space Observatory data permit the assessment of that model in the far-infrared spectral window. We analyze photometry from Spitzer and Herschel for the distant 3CR hosts, and find that RGs and quasars have different mid-infrared, but indistinguishable far-infrared colors. Both these properties, the former being orientation dependent and the latter orientation invariant, are in line with expectations from the unification model. Adding powerful radio-quiet active galaxies and typical massive star-forming (SF) galaxies to the analysis, we demonstrate that infrared colors not only provide an orientation indicator, but can also distinguish active from SF galaxies

  16. New Insights on the Accretion Disk-Winds Connection in Radio-Loud AGNs from Suzaku

    Science.gov (United States)

    Tombesi, F.; Sambruna, R. M.; Reeves, J. N.; Braito, V.; Cappi, M.; Reynolds, S.; Mushotzky, R. F.

    2011-01-01

    From the spectral analysis of long Suzaku observations of five radio-loud AGNs we have been able to discover the presence of ultra-fast outflows with velocities ,,approx.0.1 c in three of them, namely 3C III, 3C 120 and 3C 390.3. They are consistent with being accretion disk winds/outflows. We also performed a follow-up on 3C III to monitor its outflow on approx.7 days time-scales and detected an anti-correlated variability of a possible relativistic emission line with respect to blue-shifted Fe K features, following a flux increase. This provides the first direct evidence for an accretion disc-wind connection in an AGN. The mass outflow rate of these outflows can be comparable to the accretion rate and their mechanical power can correspond to a significant fraction of the bolometric luminosity and is comparable to their typical jet power. Therefore, they can possibly play a significant role in the expected feedback from AGNs and can give us further clues on the relation between the accretion disk and the formation of winds/jets.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  19. Mean and Extreme Radio Properties of Quasars and the Origin of Radio Emission

    Science.gov (United States)

    Richards, Gordon T.; Kratzer, R.

    2014-01-01

    We explore the evolution of the fraction of radio loud quasars and the mean radio properties of quasars. Although any quasar has only a ~10% chance of being radio loud and the average quasar has a radio luminosity of ~4x10^30 ergs/s/Hz, these properties are strong functions of not only luminosity, redshift, black hole mass, and accretion rate, but also the strength of the accretion disk wind (as characterized by CIV emission line properties). Quasars with higher optical luminosity and/or lower redshift have a higher than average probability of being radio loud, but their median radio luminosity (relative to optical) is much lower than average. We find that, while radio properties of quasars generally cannot be predicted from their optical properties, objects where one expects a strong radiation line driven wind (based on emission line features) have virtually no chance of being radio loud. The redder quasars are in the optical, the more radio flux (relative to optical) they have; this trend holds even for quasars that are not expected to be significantly dust reddened/extincted in the optical. Finally, we consider the radio properties of quasars in the framework of models which describe the radio loud extrema as being due to particularly high spin resulting from second generation mergers and in the context of star formation at lower levels of radio flux. This work was supported by NSF AAG grant 1108798.

  20. Mean and extreme radio properties of quasars and the origin of radio emission

    Energy Technology Data Exchange (ETDEWEB)

    Kratzer, Rachael M.; Richards, Gordon T. [Department of Physics, Drexel University, Philadelphia, PA (United States)

    2015-02-01

    We investigate the evolution of both the radio-loud fraction (RLF) and (using stacking analysis) the mean radio loudness of quasars. We consider how these properties evolve as a function of redshift and luminosity, black hole (BH) mass and accretion rate, and parameters related to the dominance of a wind in the broad emission-line region. We match the FIRST source catalog to samples of luminous quasars (both spectroscopic and photometric), primarily from the Sloan Digital Sky Survey. After accounting for catastrophic errors in BH mass estimates at high redshift, we find that both the RLF and the mean radio luminosity increase for increasing BH mass and decreasing accretion rate. Similarly, both the RLF and mean radio loudness increase for quasars that are argued to have weaker radiation line driven wind components of the broad emission-line region. In agreement with past work, we find that the RLF increases with increasing optical/UV luminosity and decreasing redshift, while the mean radio loudness evolves in the exact opposite manner. This difference in behavior between the mean radio loudness and the RLF in L−z may indicate selection effects that bias our understanding of the evolution of the RLF; deeper surveys in the optical and radio are needed to resolve this discrepancy. Finally, we argue that radio-loud (RL) and radio-quiet (RQ) quasars may be parallel sequences, but where only RQ quasars at one extreme of the distribution are likely to become RL, possibly through slight differences in spin and/or merger history.

  1. NUCLEAR X-RAY PROPERTIES OF THE PECULIAR RADIO-LOUD HIDDEN AGN 4C+29.30

    International Nuclear Information System (INIS)

    Sobolewska, M. A.; Siemiginowska, Aneta; Migliori, G.; Evans, D.; Stawarz, Ł.; Jamrozy, M.; Cheung, C. C.

    2012-01-01

    We present results from a study of nuclear emission from a nearby radio galaxy, 4C+29.30, over a broad 0.5-200 keV X-ray band. This study used new XMM-Newton (∼17 ks) and Chandra (∼300 ks) data, and archival Swift/BAT data from the 58 month catalog. The hard (>2 keV) X-ray spectrum of 4C+29.30 can be decomposed into an intrinsic hard power law (Γ ∼ 1.56) modified by a cold absorber with an intrinsic column density N H,z ∼ 5 × 10 23 cm –2 , and its reflection (|Ω/2π| ∼ 0.3) from a neutral matter including a narrow iron Kα emission line at a rest-frame energy ∼6.4 keV. The reflected component is less absorbed than the intrinsic one with an upper limit on the absorbing column of N refl H,z 22 cm –2 . The X-ray spectrum varied between the XMM-Newton and Chandra observations. We show that a scenario invoking variations of the normalization of the power law is favored over a model with variable intrinsic column density. X-rays in the 0.5-2 keV band are dominated by diffuse emission modeled with a thermal bremsstrahlung component with temperature ∼0.7 keV, and contain only a marginal contribution from the scattered power-law component. We hypothesize that 4C+29.30 belongs to a class of 'hidden' active galactic nuclei containing a geometrically thick torus. However, unlike the majority of hidden AGNs, 4C+29.30 is radio-loud. Correlations between the scattering fraction and Eddington luminosity ratio, and between black hole mass and stellar velocity dispersion, imply that 4C+29.30 hosts a black hole with ∼10 8 M ☉ mass.

  2. A transient, flat spectrum radio pulsar near the Galactic Centre

    Science.gov (United States)

    Dexter, J.; Degenaar, N.; Kerr, M.; Deller, A.; Deneva, J.; Lazarus, P.; Kramer, M.; Champion, D.; Karuppusamy, R.

    2017-06-01

    Recent studies have shown possible connections between highly magnetized neutron stars ('magnetars'), whose X-ray emission is too bright to be powered by rotational energy, and ordinary radio pulsars. In addition to the magnetar SGR J1745-2900, one of the radio pulsars in the Galactic Centre (GC) region, PSR J1746-2850, had timing properties implying a large magnetic field strength and young age, as well as a flat spectrum. All characteristics are similar to those of rare, transient, radio-loud magnetars. Using several deep non-detections from the literature and two new detections, we show that this pulsar is also transient in the radio. Both the flat spectrum and large amplitude variability are inconsistent with the light curves and spectral indices of three radio pulsars with high magnetic field strengths. We further use frequent, deep archival imaging observations of the GC in the past 15 yr to rule out a possible X-ray outburst with a luminosity exceeding the rotational spin-down rate. This source, either a transient magnetar without any detected X-ray counterpart or a young, strongly magnetized radio pulsar producing magnetar-like radio emission, further blurs the line between the two categories. We discuss the implications of this object for the radio emission mechanism in magnetars and for star and compact object formation in the GC.

  3. The Suzaku observation of the nucleus of the radio loud active galaxy Centaurus A

    International Nuclear Information System (INIS)

    Markowitz, Alex

    2007-01-01

    A Suzaku observation of the nucleus of the radio-loud AGN Centaurus A in 2005 has yielded a broadband spectrum spanning 0.3 to 250 keV. The hard X-rays are fit by two power laws, absorbed by columns of 1.5 and 7x10 23 cm -2 respectively. The spectrum consistent with previous suggestions that the power-law components are X-ray emission from the sub-pc VLBI jet and from Bondi accretion at the core, or are consistent with a partial covering interpretation. The soft band is dominated by thermal emission from the diffuse plasma and is fit well by a two-temperature collisional ionization emission model, plus a third power-law component to account for scattered nuclear emission, kpc-scale jet emission, and emission from X-ray Binaries and other point sources. Narrow fluorescent emission lines from Fe, Si, S, Ar, Ca and Ni are detected. The width of the Fe Kα line yields a 200 light-day lower limit on the distance from the black hole to the line-emitting gas. K-shell absorption edges due to Fe, Ca, and S are detected. The high metallicity ([Fe/H]=+0.1) of the circumnuclear material suggests that the accreting material could not have originated in the metal-poor outer halo unless enrichment by local star formation has occurred. Relative element abundances are consistent with enrichment due to local star formation processes. (author)

  4. Spitzer mid-IR spectroscopy of powerful 2Jy and 3CRR radio galaxies. II. AGN power indicators and unification

    Energy Technology Data Exchange (ETDEWEB)

    Dicken, D. [CEA-Saclay, F-91191 Gif-sur-Yvette (France); Tadhunter, C. [University of Sheffield, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Morganti, R. [ASTRON, P.O. Box 2, 7990 AA Dwingeloo (Netherlands); Axon, D.; Robinson, A.; Magagnoli, M. [Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY 14623 (United States); Kharb, P. [Indian Institute of Astrophysics, II Block, Koramangala, Bangalore 560034 (India); Ramos Almeida, C. [Instituto de Astrofisica de Canarias (IAC), C/V ia Lactea, s/n, E-38205 La Laguna, Tenerife (Spain); Mingo, B. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Hardcastle, M. [School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Nesvadba, N. P. H.; Singh, V. [Institut d' Astrophysique Spatiale, CNRS, Université Paris Sud, F-91405 Orsay (France); Kouwenhoven, M. B. N. [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Haidian Qu, Beijing 100871 (China); Rose, M.; Spoon, H. [224 Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Inskip, K. J. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Holt, J., E-mail: daniel.dicken@cea.fr [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)

    2014-06-20

    It remains uncertain which continuum and emission line diagnostics best indicate the bolometric powers of active galactic nuclei (AGNs), especially given the attenuation caused by the circumnuclear material and the possible contamination by components related to star formation. Here we use mid-IR spectra along with multiwavelength data to investigate the merit of various diagnostics of AGN radiative power, including the mid-IR [Ne III] λ25.89 μm and [O IV] λ25.89 μm fine-structure lines, the optical [O III] λ5007 forbidden line, and mid-IR 24 μm, 5 GHz radio, and X-ray continuum emission, for complete samples of 46 2Jy radio galaxies (0.05 < z < 0.7) and 17 3CRR FRII radio galaxies (z < 0.1). We find that the mid-IR [O IV] line is the most reliable indicator of AGN power for powerful radio-loud AGNs. By assuming that the [O IV] is emitted isotropically, and comparing the [O III] and 24 μm luminosities of the broad- and narrow-line AGNs in our samples at fixed [O IV] luminosity, we show that the [O III] and 24 μm emission are both mildly attenuated in the narrow-line compared to the broad-line objects by a factor of ≈2. However, despite this attenuation, the [O III] and 24 μm luminosities are better AGN power indicators for our sample than either the 5 GHz radio or the X-ray continuum luminosities. We also detect the mid-IR 9.7 μm silicate feature in the spectra of many objects but not ubiquitously: at least 40% of the sample shows no clear evidence for these features. We conclude that, for the majority of powerful radio galaxies, the mid-IR lines are powered by AGN photoionization.

  5. Analysis of the correlation between γ-ray and radio emissions from γ-ray loud Blazar using the discrete correlation function

    International Nuclear Information System (INIS)

    Cheng Yong; Zhang Xiong; Wu Lin; Mao Weiming; You Lisha

    2006-01-01

    The authors collect 119 γ-ray-loud Blazar (97 flat spectrum radio quasars (FSRQs) and 22 BL Lacertae objects (BL Lac)), and investigate respectively the correlation between the γ-ray emission (maximum, minimum, and average data) at 1 GeV and the radio emission at 8.4 GHz by discrete correlation function (DCF) method. Our main results are as follows: there is good correlation between the γ-ray in high state and average state and radio emissions for the whole 119 Blazar and 97 FSRQs. And there are no correlation between γ-ray emission and radio emission in low state. Our result shows that the γ-rays are associated with the radio emission from the jet, and that the γ-ray emission is likely to have come from the synchrotron self-compton model (SSC) process in this case. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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.

  8. THE EXTREME ULTRAVIOLET DEFICIT AND MAGNETICALLY ARRESTED ACCRETION IN RADIO-LOUD QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Punsly, Brian, E-mail: brian.punsly1@verizon.net [1415 Granvia Altamira, Palos Verdes Estates, CA 90274 (United States); ICRANet, Piazza della Repubblica, I-65100 10 Pescara (Italy)

    2014-12-20

    The Hubble Space Telescope composite quasar spectra presented in Telfer et al. show a significant deficit of emission in the extreme ultraviolet for the radio-loud component of the quasar population (RLQs) compared to the radio-quiet component of the quasar population. The composite quasar continuum emission between 1100 Å and ∼580 Å is generally considered to be associated with the innermost regions of the accretion flow onto the central black hole. The deficit between 1100 Å and 580 Å in RLQs has a straightforward interpretation as a missing or a suppressed innermost region of local energy dissipation in the accretion flow. It is proposed that this can be the result of islands of large-scale magnetic flux in RLQs that are located close to the central black hole that remove energy from the accretion flow as Poynting flux (sometimes called magnetically arrested accretion). These magnetic islands are natural sites for launching relativistic jets. Based on the Telfer et al. data and the numerical simulations of accretion flows in Penna et al., the magnetic islands are concentrated between the event horizon and an outer boundary of <2.8 M (in geometrized units) for rapidly rotating black holes and <5.5 M for modestly rotating black holes.

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. The radio spectral energy distribution of infrared-faint radio sources

    Science.gov (United States)

    Herzog, A.; Norris, R. P.; Middelberg, E.; Seymour, N.; Spitler, L. R.; Emonts, B. H. C.; Franzen, T. M. O.; Hunstead, R.; Intema, H. T.; Marvil, J.; Parker, Q. A.; Sirothia, S. K.; Hurley-Walker, N.; Bell, M.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Cappallo, R. J.; Callingham, J. R.; Deshpande, A. A.; Dwarakanath, K. S.; For, B.-Q.; Greenhill, L. J.; Hancock, P.; Hazelton, B. J.; Hindson, L.; Johnston-Hollitt, M.; Kapińska, A. D.; Kaplan, D. L.; Lenc, E.; Lonsdale, C. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Morgan, J.; Oberoi, D.; Offringa, A.; Ord, S. M.; Prabu, T.; Procopio, P.; Udaya Shankar, N.; Srivani, K. S.; Staveley-Smith, L.; Subrahmanyan, R.; Tingay, S. J.; Wayth, R. B.; Webster, R. L.; Williams, A.; Williams, C. L.; Wu, C.; Zheng, Q.; Bannister, K. W.; Chippendale, A. P.; Harvey-Smith, L.; Heywood, I.; Indermuehle, B.; Popping, A.; Sault, R. J.; Whiting, M. T.

    2016-10-01

    Context. Infrared-faint radio sources (IFRS) are a class of radio-loud (RL) active galactic nuclei (AGN) at high redshifts (z ≥ 1.7) that are characterised by their relative infrared faintness, resulting in enormous radio-to-infrared flux density ratios of up to several thousand. Aims: Because of their optical and infrared faintness, it is very challenging to study IFRS at these wavelengths. However, IFRS are relatively bright in the radio regime with 1.4 GHz flux densities of a few to a few tens of mJy. Therefore, the radio regime is the most promising wavelength regime in which to constrain their nature. We aim to test the hypothesis that IFRS are young AGN, particularly GHz peaked-spectrum (GPS) and compact steep-spectrum (CSS) sources that have a low frequency turnover. Methods: We use the rich radio data set available for the Australia Telescope Large Area Survey fields, covering the frequency range between 150 MHz and 34 GHz with up to 19 wavebands from different telescopes, and build radio spectral energy distributions (SEDs) for 34 IFRS. We then study the radio properties of this class of object with respect to turnover, spectral index, and behaviour towards higher frequencies. We also present the highest-frequency radio observations of an IFRS, observed with the Plateau de Bure Interferometer at 105 GHz, and model the multi-wavelength and radio-far-infrared SED of this source. Results: We find IFRS usually follow single power laws down to observed frequencies of around 150 MHz. Mostly, the radio SEDs are steep (α IFRS show statistically significantly steeper radio SEDs than the broader RL AGN population. Our analysis reveals that the fractions of GPS and CSS sources in the population of IFRS are consistent with the fractions in the broader RL AGN population. We find that at least % of IFRS contain young AGN, although the fraction might be significantly higher as suggested by the steep SEDs and the compact morphology of IFRS. The detailed multi

  12. Observations Of Gamma-ray Loud Blazars With The VLBA At 5 GHz

    Science.gov (United States)

    Linford, Justin; Taylor, G. B.; Romani, R.; Readhead, A. C. S.; Reeves, R.; Richards, J. L.; Helmboldt, J. F.

    2011-01-01

    The Fermi Gamma-ray Space Telescope has been scanning the sky for more than a year. About half of the sources detected by Fermi's Large Area Telesope (LAT) are active galactic nuclei (AGN). Nearly all of these gamma-ray loud AGN are blazars; strong, compact radio emitters that exhibit variability in their flux and apparent superluminal motion in their jets. Several groups are currently monitoring the radio properties of these gamma-ray loud blazars. We present results from both archival and contemporaneous observations of 200 LAT-detected blazars using the Very Long Baseline Array (VLBA) at a frequency of 5 GHz (wavelength of 6 cm). Our large, flux-limited sample provides unique insights into the mechanism that produces strong gamma-ray emissions. We explore the parsec-scale properties of the cores and jets of these highly energetic objects, including core polarization. We compare the gamma-ray loud blazars to their gamma-ray quiet counterparts in the VLBA Imaging and Polarimetry Survey (VIPS). We also investigate the differences between the BL Lacertae objects (BL Lacs) and flat-spectrum radio quasars (FSRQs).

  13. THE COMPLEX NORTH TRANSITION REGION OF CENTAURUS A: RADIO STRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Neff, Susan G. [NASA' s Goddard Space Flight Center, Laboratory for Observational Cosmology, Mail Code 665, Greenbelt, MD 20771 (United States); Eilek, Jean A. [Physics Department, New Mexico Tech, Socorro, NM 87801 (United States); Owen, Frazer N., E-mail: susan.g.neff@nasa.gov [National Radio Astronomy Observatory, P.O. Box O,  Socorro, NM 87801 (United States)

    2015-04-01

    We present deep radio images of the inner ∼50 kpc of Centaurus A, taken with the Karl G. Jansky Very Large Array at 90 cm. We focus on the Transition Regions between the inner galaxy—including the active nucleus, inner radio lobes, and star-forming disk—and the outer radio lobes. We detect previously unknown extended emission around the Inner Lobes, including radio emission from the star-forming disk. We find that the radio-loud part of the North Transition Region (NTR), known as the North Middle Lobe, is significantly overpressured relative to the surrounding interstellar medium. We see no evidence for a collimated flow from the active galactic nucleus through this region. Our images show that the structure identified by Morganti et al. as a possible large-scale jet appears to be part of a narrow ridge of emission within the broader, diffuse, radio-loud region. This knotty radio ridge is coincident with other striking phenomena: compact X-ray knots, ionized gas filaments, and streams of young stars. Several short-lived phenomena in the NTR, as well as the frequent re-energization required by the Outer Lobes, suggest that energy must be flowing through both Transition Regions at the present epoch. We suggest that the energy flow is in the form of a galactic wind.

  14. RADIATION MECHANISM AND JET COMPOSITION OF GAMMA-RAY BURSTS AND GeV-TeV-SELECTED RADIO-LOUD ACTIVE GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jin; Lu Ye; Zhang Shuangnan [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Liang Enwei; Sun Xiaona [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning 530004 (China); Zhang Bing, E-mail: lew@gxu.edu.cn [Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154 (United States)

    2013-09-01

    Gamma-ray bursts (GRBs) and GeV-TeV-selected radio-loud active galactic nuclei (AGNs) are compared based on our systematic modeling of the observed spectral energy distributions of a sample of AGNs with a single-zone leptonic model. We show that the correlation between the jet power (P{sub jet}) and the prompt gamma-ray luminosity (L{sub jet}) of GRBs is consistent, within the uncertainties, with the correlation between jet power and the synchrotron peak luminosity (L{sub s,jet}) of flat spectrum radio quasars (FSRQs). Their radiation efficiencies ({epsilon}) are also comparable (>10% for most sources), which increase with the bolometric jet luminosity (L{sub bol,jet}) for FSRQs and with the L{sub jet} for GRBs with similar power-law indices. BL Lac objects (BL Lacs) do not follow the P{sub jet}-L{sub s,jet} relation of FSRQs. They have lower {epsilon} and L{sub bol,jet} values than FSRQs, and a tentative L{sub bol,jet}-{epsilon} relation is also found, with a power-law index different from that of the FSRQs. The magnetization parameters ({sigma}) of FSRQs are on average larger than that of BL Lacs. They are anti-correlated with {epsilon} for the FSRQs, but positively correlated with {epsilon} for the BL Lacs. GeV narrow-line Seyfert 1 galaxies potentially share similar properties with FSRQs. Based on the analogy between GRBs and FSRQs, we suggest that the prompt gamma-ray emission of GRBs is likely produced by the synchrotron process in a magnetized jet with high radiation efficiency, similar to FSRQs. The jets of BL Lacs, on the other hand, are less efficient and are likely more matter-dominated.

  15. MAPPING THE POLARIZATION OF THE RADIO-LOUD Ly α NEBULA B3 J2330+3927

    International Nuclear Information System (INIS)

    You, Chang; Zabludoff, Ann; Smith, Paul; Jannuzi, Buell; Yang, Yujin; Kim, Eunchong; Lee, Myung Gyoon; Prescott, Moire K. M.; Matsuda, Yuichi

    2017-01-01

    Ly α nebulae, or “Ly α blobs,” are extended (up to ∼100 kpc), bright (L Lyα  ≳ 10 43 erg s −1 ) clouds of Ly α emitting gas that tend to lie in overdense regions at z  ∼ 2–5. The origin of the Ly α emission remains unknown, but recent theoretical work suggests that measuring the polarization might discriminate among powering mechanisms. Here we present the first narrowband imaging polarimetry of a radio-loud Ly α nebula, B3 J2330+3927, at z = 3.09, with an embedded active galactic nucleus (AGN). The AGN lies near the blob’s Ly α emission peak, and its radio lobes align roughly with the blob’s major axis. With the SPOL polarimeter on the 6.5 m MMT telescope, we map the total (Ly α + continuum) polarization in a grid of circular apertures of a radius of 0.″6 (4.4 kpc), detecting a significant (>2 σ ) polarization fraction P % in nine apertures and achieving strong upper limits (as low as 2%) elsewhere. P % increases from <2% at ∼5 kpc from the blob center to 17% at ∼15–25 kpc. The detections are distributed asymmetrically, roughly along the nebula’s major axis. The polarization angles θ are mostly perpendicular to this axis. Comparing the Ly α flux to that of the continuum and conservatively assuming that the continuum is highly polarized (20%–100%) and aligned with the total polarization, we place lower limits on the polarization of the Ly α emission P %,Lyα ranging from no significant polarization at ∼5 kpc from the blob center to 3%–17% at 10–25 kpc. Like the total polarization, the Ly α polarization detections occur more often along the blob’s major axis.

  16. VizieR Online Data Catalog: Radio-loud AGN with relativistic jets (Olguin-Iglesias+, 2016)

    Science.gov (United States)

    Olguin-Iglesias, A.; Leon-Tavares, J.; Kotilainen, J. K.; Chavushyan, V.; Tornikoski, M.; Valtaoja, E.; Anorve, C.; Valdes, J.; Carrasco, L.

    2017-11-01

    The sample of sources analysed in this work is a sub-sample of variable radio-loud AGN monitored at 7mm (S7mm>1Jy) with the Aalto University Metsahovi Radio Observatory, in Finland (http://metsahovi.aalto.fi/en/) since the last 30 years (Terasranta et al., 1992A&AS...94..121T; Teraesranta et al., 1998, Cat. J/A+AS/132/305; Leon-Tavares et al., 2011A&A...532A.146L; Nieppola et al., 2011, Cat. J/A+A/535/A69). According to the AGN unification scheme (Antonucci, 1993ARA&A..31..473A; Urry & Padovani, 1995PASP..107..803U), FSRQ and BL Lacs are those AGN whose relativistic jets point towards the Earth. Observations were made with the Nordic Optical Telescope (NOT) at La Roque de los Muchachos, La Palma, Canarias, Spain. They were conducted between 2011 May 09 and September 15 using the near-infrared Camera (NOTCam)3 on the NOT. NOTcam field of view is 4'x4' with a pixel scale of 0.234-arcsec/pixel designed to be used in the range from 0.8 to 2.5um in the bands J, H and K. (1 data file).

  17. VizieR Online Data Catalog: Blazars equivalent widths and radio luminosity (Landt+, 2004)

    Science.gov (United States)

    Landt, H.; Padovani, P.; Perlman, E. S.; Giommi, P.

    2004-07-01

    Blazars are currently separated into BL Lacertae objects (BL Lacs) and flat spectrum radio quasars based on the strength of their emission lines. This is performed rather arbitrarily by defining a diagonal line in the Ca H&K break value-equivalent width plane, following Marcha et al. (1996MNRAS.281..425M). We readdress this problem and put the classification scheme for blazars on firm physical grounds. We study ~100 blazars and radio galaxies from the Deep X-ray Radio Blazar Survey (DXRBS, Cat. and ) and 2-Jy radio survey and find a significant bimodality for the narrow emission line [OIII]{lambda}5007. This suggests the presence of two physically distinct classes of radio-loud active galactic nuclei (AGN). We show that all radio-loud AGN, blazars and radio galaxies, can be effectively separated into weak- and strong-lined sources using the [OIII]{lambda}5007-[OII]{lambda}3727 equivalent width plane. This plane allows one to disentangle orientation effects from intrinsic variations in radio-loud AGN. Based on DXRBS, the strongly beamed sources of the new class of weak-lined radio-loud AGN are made up of BL Lacs at the ~75 per cent level, whereas those of the strong-lined radio-loud AGN include mostly (~97 per cent) quasars. (4 data files).

  18. THE VLA SURVEY OF CHANDRA DEEP FIELD SOUTH. V. EVOLUTION AND LUMINOSITY FUNCTIONS OF SUB-MILLIJANSKY RADIO SOURCES AND THE ISSUE OF RADIO EMISSION IN RADIO-QUIET ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Padovani, P.; Mainieri, V.; Rosati, P.; Miller, N.; Kellermann, K. I.; Tozzi, P.

    2011-01-01

    We present the evolutionary properties and luminosity functions of the radio sources belonging to the Chandra Deep Field South Very Large Array survey, which reaches a flux density limit at 1.4 GHz of 43 μJy at the field center and redshift ∼5 and which includes the first radio-selected complete sample of radio-quiet active galactic nuclei (AGNs). We use a new, comprehensive classification scheme based on radio, far- and near-IR, optical, and X-ray data to disentangle star-forming galaxies (SFGs) from AGNs and radio-quiet from radio-loud AGNs. We confirm our previous result that SFGs become dominant only below 0.1 mJy. The sub-millijansky radio sky turns out to be a complex mix of SFGs and radio-quiet AGNs evolving at a similar, strong rate; non-evolving low-luminosity radio galaxies; and declining radio powerful (P ∼> 3 x 10 24 W Hz -1 ) AGNs. Our results suggest that radio emission from radio-quiet AGNs is closely related to star formation. The detection of compact, high brightness temperature cores in several nearby radio-quiet AGNs can be explained by the coexistence of two components, one non-evolving and AGN related and one evolving and star formation related. Radio-quiet AGNs are an important class of sub-millijansky sources, accounting for ∼30% of the sample and ∼60% of all AGNs, and outnumbering radio-loud AGNs at ∼< 0.1 mJy. This implies that future, large area sub-millijansky surveys, given the appropriate ancillary multiwavelength data, have the potential of being able to assemble vast samples of radio-quiet AGNs, bypassing the problems of obscuration that plague the optical and soft X-ray bands.

  19. Temporal integration of loudness, loudness discrimination, and the form of the loudness function

    DEFF Research Database (Denmark)

    Buus, Søren; Florentine, Mary; Poulsen, Torben

    1997-01-01

    Temporal integration for loudness of 5-kHz tones was measured as a function of level between 2 and 60 dB SL. Absolute thresholds and levels required to produce equal loudness were measured for 2-, 10-, 50- and 250-ms tones using adaptive, two interval, two alternative forced choice procedures....... The procedure for loudness balances is new and obtained concurrent measurements for ten tone pairs in ten interleaved tracks. Each track converged at the level required to make the variable stimulus just louder than the fixed stimulus. Thus, the data yield estimates of the just noticeable difference...... for loudness level andtemporal integration for loudness. Results for four listeners show that the amount of temporal integration, defined as the level difference between equally loud short and long tones, varies markedly with level and is largest at moderate levels. The effect of level increases...

  20. A CHANDRA SURVEY OF THE X-RAY PROPERTIES OF BROAD ABSORPTION LINE RADIO-LOUD QUASARS

    International Nuclear Information System (INIS)

    Miller, B. P.; Brandt, W. N.; Garmire, G. P.; Gibson, R. R.; Shemmer, O.

    2009-01-01

    This work presents the results of a Chandra study of 21 broad absorption line (BAL) radio-loud quasars (RLQs). We conducted a Chandra snapshot survey of 12 bright BAL RLQs selected from Sloan Digital Sky Survey Data/Faint Images of the Radio Sky data and possessing a wide range of radio and C IV absorption properties. Optical spectra were obtained nearly contemporaneously with the Hobby-Eberly Telescope; no strong flux or BAL variability was seen between epochs. In addition to the snapshot targets, we include in our sample nine additional BAL RLQs possessing archival Chandra coverage. We compare the properties of (predominantly high-ionization) BAL RLQs to those of non-BAL RLQs as well as to BAL radio-quiet quasars (RQQs) and non-BAL RQQs for context. All 12 snapshots and 8/9 archival BAL RLQs are detected, with observed X-ray luminosities less than those of non-BAL RLQs having comparable optical/UV luminosities by typical factors of 4.1-8.5. (BAL RLQs are also X-ray weak by typical factors of 2.0-4.5 relative to non-BAL RLQs having both comparable optical/UV and radio luminosities.) However, BAL RLQs are not as X-ray weak relative to non-BAL RLQs as are BAL RQQs relative to non-BAL RQQs. While some BAL RLQs have harder X-ray spectra than typical non-BAL RLQs, some have hardness ratios consistent with those of non-BAL RLQs, and there does not appear to be a correlation between X-ray weakness and spectral hardness, in contrast to the situation for BAL RQQs. RLQs are expected to have X-ray continuum contributions from both accretion-disk corona and small-scale jet emission. While the entire X-ray continuum in BAL RLQs cannot be obscured to the same degree as in BAL RQQs, we calculate that the jet is likely partially covered in many BAL RLQs. We comment briefly on implications for geometries and source ages in BAL RLQs.

  1. A multi-wavelength investigation of the radio-loud supernova PTF11qcj and its circumstellar environment

    Energy Technology Data Exchange (ETDEWEB)

    Corsi, A. [Department of Physics, The George Washington University, 725 21st St, NW, Washington, DC 20052 (United States); Ofek, E. O.; Gal-Yam, A.; Xu, D. [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Frail, D. A. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Kulkarni, S. R.; Horesh, A.; Carpenter, J.; Arcavi, I.; Cao, Y.; Mooley, K.; Sesar, B. [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Fox, D. B. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Kasliwal, M. M. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Sullivan, M.; Maguire, K.; Pan, Y.-C. [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Cenko, S. B. [NASA Goddard Space Flight Center, Code 685, Greenbelt, MD 20771 (United States); Sternberg, A. [Max-Planck-Institut fur Astrophysik, D-85741 Garching (Germany); Bersier, D., E-mail: corsi@gwu.edu [Astrophysics Research Institute, Liverpool John Moores University, Liverpool (United Kingdom); and others

    2014-02-10

    We present the discovery, classification, and extensive panchromatic (from radio to X-ray) follow-up observations of PTF11qcj, a supernova (SN) discovered by the Palomar Transient Factory (PTF). Our observations with the Karl G. Jansky Very Large Array show that this event is radio-loud: PTF11qcj reached a radio peak luminosity comparable to that of the famous gamma-ray-burst-associated SN 1998bw (L {sub 5} {sub GHz} ≈ 10{sup 29} erg s{sup –1} Hz{sup –1}). PTF11qcj is also detected in X-rays with the Chandra Observatory, and in the infrared band with Spitzer. Our multi-wavelength analysis probes the SN interaction with circumstellar material. The radio observations suggest a progenitor mass-loss rate of ∼10{sup –4} M {sub ☉} yr{sup –1} × (v{sub w} /1000 km s{sup –1}), and a velocity of ≈0.3-0.5 c for the fastest moving ejecta (at ≈10 days after explosion). However, these estimates are derived assuming the simplest model of SN ejecta interacting with a smooth circumstellar wind, and do not account for possible inhomogeneities in the medium and asphericity of the explosion. The radio data show deviations from such a simple model, as well as a late-time re-brightening. The X-ray flux from PTF11qcj is compatible with the high-frequency extrapolation of the radio synchrotron emission (within the large uncertainties). A light echo from pre-existing dust is in agreement with our infrared data. Our pre-explosion data from the PTF suggest that a precursor eruption of absolute magnitude M{sub r} ≈ –13 mag may have occurred ≈2.5 yr prior to the SN explosion. Overall, PTF11qcj fits the expectations from the explosion of a Wolf-Rayet star. Precursor eruptions may be a feature characterizing the final pre-explosion evolution of such stars.

  2. Light-Curve Modelling Constraints on the Obliquities and Aspect Angles of the Young Fermi Pulsars

    Science.gov (United States)

    Pierbattista, M.; Harding, A. K.; Grenier, I. A.; Johnson, T. J.; Caraveo, P. A.; Kerr, M.; Gonthier, P. L.

    2015-01-01

    In more than four years of observation the Large Area Telescope on board the Fermi satellite has identified pulsed gamma-ray emission from more than 80 young or middle-aged pulsars, in most cases providing light curves with high statistics. Fitting the observed profiles with geometrical models can provide estimates of the magnetic obliquity alpha and of the line of sight angle zeta, yielding estimates of the radiation beaming factor and radiated luminosity. Using different gamma-ray emission geometries (Polar Cap, Slot Gap, Outer Gap, One Pole Caustic) and core plus cone geometries for the radio emission, we fit gamma-ray light curves for 76 young or middle-aged pulsars and we jointly fit their gamma-ray plus radio light curves when possible. We find that a joint radio plus gamma-ray fit strategy is important to obtain (alpha, zeta) estimates that can explain simultaneously detectable radio and gamma-ray emission: when the radio emission is available, the inclusion of the radio light curve in the fit leads to important changes in the (alpha, gamma) solutions. The most pronounced changes are observed for Outer Gap and One Pole Caustic models for which the gamma-ray only fit leads to underestimated alpha or zeta when the solution is found to the left or to the right of the main alpha-zeta plane diagonal respectively. The intermediate-to-high altitude magnetosphere models, Slot Gap, Outer Gap, and One pole Caustic, are favored in explaining the observations. We find no apparent evolution of a on a time scale of 106 years. For all emission geometries our derived gamma-ray beaming factors are generally less than one and do not significantly evolve with the spin-down power. A more pronounced beaming factor vs. spin-down power correlation is observed for Slot Gap model and radio-quiet pulsars and for the Outer Gap model and radio-loud pulsars. The beaming factor distributions exhibit a large dispersion that is less pronounced for the Slot Gap case and that decreases from

  3. How Loud Is Too Loud?

    Medline Plus

    Full Text Available ... Z Index Español Menu Home Health Info Hearing, Ear Infections, and Deafness Balance Taste and Smell Voice, Speech, ... Involved You are here Home » Health Info » Hearing, Ear Infections, and Deafness How Loud is Too Loud? Video ...

  4. MAPPING THE POLARIZATION OF THE RADIO-LOUD Ly α NEBULA B3 J2330+3927

    Energy Technology Data Exchange (ETDEWEB)

    You, Chang; Zabludoff, Ann; Smith, Paul; Jannuzi, Buell [Steward Observatory, University of Arizona, 933 N Cherry Avenue, Tucson, AZ 85721 (United States); Yang, Yujin [Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055 (Korea, Republic of); Kim, Eunchong; Lee, Myung Gyoon [Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 88226 (Korea, Republic of); Prescott, Moire K. M. [Department of Astronomy, New Mexico State University, 1320 Frenger Mall, Las Cruces, NM 88003 (United States); Matsuda, Yuichi, E-mail: yyang@kasi.re.kr [National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2017-01-10

    Ly α nebulae, or “Ly α blobs,” are extended (up to ∼100 kpc), bright (L{sub Lyα}  ≳ 10{sup 43} erg s{sup −1}) clouds of Ly α emitting gas that tend to lie in overdense regions at z  ∼ 2–5. The origin of the Ly α emission remains unknown, but recent theoretical work suggests that measuring the polarization might discriminate among powering mechanisms. Here we present the first narrowband imaging polarimetry of a radio-loud Ly α nebula, B3 J2330+3927, at z = 3.09, with an embedded active galactic nucleus (AGN). The AGN lies near the blob’s Ly α emission peak, and its radio lobes align roughly with the blob’s major axis. With the SPOL polarimeter on the 6.5 m MMT telescope, we map the total (Ly α + continuum) polarization in a grid of circular apertures of a radius of 0.″6 (4.4 kpc), detecting a significant (>2 σ ) polarization fraction P {sub %} in nine apertures and achieving strong upper limits (as low as 2%) elsewhere. P{sub %} increases from <2% at ∼5 kpc from the blob center to 17% at ∼15–25 kpc. The detections are distributed asymmetrically, roughly along the nebula’s major axis. The polarization angles θ are mostly perpendicular to this axis. Comparing the Ly α flux to that of the continuum and conservatively assuming that the continuum is highly polarized (20%–100%) and aligned with the total polarization, we place lower limits on the polarization of the Ly α emission P{sub %,Lyα} ranging from no significant polarization at ∼5 kpc from the blob center to 3%–17% at 10–25 kpc. Like the total polarization, the Ly α polarization detections occur more often along the blob’s major axis.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Duty-cycle and energetics of remnant radio-loud AGN

    Science.gov (United States)

    Turner, Ross J.

    2018-05-01

    Deriving the energetics of remnant and restarted active galactic nuclei (AGNs) is much more challenging than for active sources due to the complexity in accurately determining the time since the nucleus switched-off. I resolve this problem using a new approach that combines spectral ageing and dynamical models to tightly constrain the energetics and duty-cycles of dying sources. Fitting the shape of the integrated radio spectrum yields the fraction of the source age the nucleus is active; this, in addition to the flux density, source size, axis ratio, and properties of the host environment, provides a constraint on dynamical models describing the remnant radio source. This technique is used to derive the intrinsic properties of the well-studied remnant radio source B2 0924+30. This object is found to spend 50_{-12}^{+14} Myr in the active phase and a further 28_{-5}^{+6} Myr in the quiescent phase, have a jet kinetic power of 3.6_{-1.7}^{+3.0}× 10^{37} W, and a lobe magnetic field strength below equipartition at the 8σ level. The integrated spectra of restarted and intermittent radio sources are found to yield a `steep-shallow' shape when the previous outburst occurred within 100 Myr. The duty-cycle of B2 0924+30 is hence constrained to be δ < 0.15 by fitting the shortest time to the previous comparable outburst that does not appreciably modify the remnant spectrum. The time-averaged feedback energy imparted by AGNs into their host galaxy environments can in this manner be quantified.

  7. THE RADIO AND OPTICAL LUMINOSITY EVOLUTION OF QUASARS. II. THE SDSS SAMPLE

    International Nuclear Information System (INIS)

    Singal, J.; Petrosian, V.; Stawarz, Ł.; Lawrence, A.

    2013-01-01

    We determine the radio and optical luminosity evolutions and the true distribution of the radio-loudness parameter R, defined as the ratio of the radio to optical luminosity, for a set of more than 5000 quasars combining Sloan Digital Sky Survey optical and Faint Images of the Radio Sky at Twenty cm (FIRST) radio data. We apply the method of Efron and Petrosian to access the intrinsic distribution parameters, taking into account the truncations and correlations inherent in the data. We find that the population exhibits strong positive evolution with redshift in both wavebands, with somewhat greater radio evolution than optical. With the luminosity evolutions accounted for, we determine the density evolutions and local radio and optical luminosity functions. The intrinsic distribution of the radio-loudness parameter R is found to be quite different from the observed one and is smooth with no evidence of a bimodality in radio loudness for log R ≥ –1. The results we find are in general agreement with the previous analysis of Singal et al., which used POSS-I optical and FIRST radio data.

  8. Characteristics of Gamma-Ray Loud Blazars in the VLBA Imaging and Polarimetry Survey

    Science.gov (United States)

    Linford, J. D.; Taylor, G. B.; Romani, R. W.; Healey, S. E.; Helmboldt, J. F.; Readhead, A. C.; Reeves, R.; Richards, J. L.; Cotter, G.

    2010-01-01

    The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed as part of the VLBA Imaging and Polarimetry Survey. This large, flux-limited sample of active galactic nuclei (AGNs) provides insights into the mechanism that produces strong gamma-ray emission. At lower flux levels, radio flux density does not directly correlate with gamma-ray flux. We find that the LAT-detected BL Lac objects tend to be similar to the non-LAT BL Lac objects, but that the LAT-detected FSRQs are often significantly different from the non-LAT FSRQs. The differences between the gamma-ray loud and quiet FSRQS can be explained by Doppler boosting; these objects appear to require larger Doppler factors than those of the BL Lac objects. It is possible that the gamma-ray loud FSRQs are fundamentally different from the gamma-ray quiet FSRQs. Strong polarization at the base of the jet appears to be a signature for gamma-ray loud AGNs.

  9. CHARACTERISTICS OF GAMMA-RAY LOUD BLAZARS IN THE VLBA IMAGING AND POLARIMETRY SURVEY

    International Nuclear Information System (INIS)

    Linford, J. D.; Taylor, G. B.; Romani, R. W.; Healey, S. E.; Helmboldt, J. F.; Readhead, A. C. S.; Reeves, R.; Richards, J. L.; Cotter, G.

    2011-01-01

    The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed as part of the VLBA Imaging and Polarimetry Survey. This large, flux-limited sample of active galactic nuclei (AGNs) provides insights into the mechanism that produces strong γ-ray emission. At lower flux levels, radio flux density does not directly correlate with γ-ray flux. We find that the LAT-detected BL Lac objects tend to be similar to the non-LAT BL Lac objects, but that the LAT-detected FSRQs are often significantly different from the non-LAT FSRQs. The differences between the γ-ray loud and quiet FSRQs can be explained by Doppler boosting; these objects appear to require larger Doppler factors than those of the BL Lac objects. It is possible that the γ-ray loud FSRQs are fundamentally different from the γ-ray quiet FSRQs. Strong polarization at the base of the jet appears to be a signature for γ-ray loud AGNs.

  10. Characteristics of Gamma-ray Loud Blazars in the VLBA Imaging and Polarimetry Survey

    Science.gov (United States)

    Linford, J. D.; Taylor, G. B.; Romani, R. W.; Healey, S. E.; Helmboldt, J. F.; Readhead, A. C. S.; Reeves, R.; Richards, J. L.; Cotter, G.

    2011-01-01

    The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed as part of the VLBA Imaging and Polarimetry Survey. This large, flux-limited sample of active galactic nuclei (AGNs) provides insights into the mechanism that produces strong γ-ray emission. At lower flux levels, radio flux density does not directly correlate with γ-ray flux. We find that the LAT-detected BL Lac objects tend to be similar to the non-LAT BL Lac objects, but that the LAT-detected FSRQs are often significantly different from the non-LAT FSRQs. The differences between the γ-ray loud and quiet FSRQs can be explained by Doppler boosting; these objects appear to require larger Doppler factors than those of the BL Lac objects. It is possible that the γ-ray loud FSRQs are fundamentally different from the γ-ray quiet FSRQs. Strong polarization at the base of the jet appears to be a signature for γ-ray loud AGNs.

  11. Zero-Power Radio Device.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-02-01

    This report describes an unpowered radio receiver capable of detecting and responding to weak signals transmit ted from comparatively long distances . This radio receiver offers key advantages over a short range zero - power radio receiver previously described in SAND2004 - 4610, A Zero - Power Radio Receiver . The device described here can be fabricated as an integrated circuit for use in portable wireless devices, as a wake - up circuit, or a s a stand - alone receiver operating in conjunction with identification decoders or other electroni cs. It builds on key sub - components developed at Sandia National Laboratories over many years. It uses surface acoustic wave (SAW) filter technology. It uses custom component design to enable the efficient use of small aperture antennas. This device uses a key component, the pyroelectric demodulator , covered by Sandia owned U.S. Patent 7397301, Pyroelectric Demodulating Detector [1] . This device is also described in Sandia owned U.S. Patent 97266446, Zero Power Receiver [2].

  12. The three-dimensional properties and energetics of radio-jet-driven outflows

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Hsin-Yi; Stockton, Alan, E-mail: hsshih@ifa.hawaii.edu, E-mail: stockton@ifa.hawaii.edu [Institute for Astronomy, University of Hawai' i 2680 Woodlawn Dr, Honolulu, HI 96822 (United States)

    2014-05-01

    Extended emission-line regions (EELRs), found around radio-loud sources, are likely outflows driven by one form of powerful active galactic nucleus (AGN) feedback mechanism. We seek to constrain the three-dimensional gas properties and the outflow energetics of the EELRs in this study. We used an integral field unit to observe EELRs around two samples of radio-loud AGNs with similar radio properties, but different orientations: a sample of quasars and a sample of radio galaxies. A morphological comparison suggests a scenario where the three-dimensional EELR gas distribution follows rough biconical shapes with wide opening angles. The average extent of the EELRs is ∼18.5 kpc. The estimated average mass of the EELRs, with reasonable assumptions for gas densities, is ∼3 × 10{sup 8} M {sub ☉}, and the average mass outflow rate is ∼30 M {sub ☉} yr{sup –1}. The EELRs around quasars and radio galaxies share similar kinematic properties. Both samples have velocity structures that display a range of complexities, they do not appear to correlate with the jet orientations, and both span a similar range of velocity dispersions. Around 30% of the detected EELRs show large-scale rotational motions, which may have originated from recent mergers involving gas-rich disk galaxies.

  13. Radio imaging of core-dominated high redshift quasars

    DEFF Research Database (Denmark)

    Barthel, Peter D.; Vestergaard, Marianne; Lonsdale, Colin J.

    1999-01-01

    VLA imaging at kiloparsec-scale resolution of sixteen core-dominated radio-loud QSOs is presented. Many objects appear to display variable radio emission and their radio morphologies are significantly smaller than those of steep-spectrum quasars, consistent with these objects being observed...

  14. A composite plot of far-infrared versus radio luminosity, and the origin of far-infrared luminosity in quasars

    International Nuclear Information System (INIS)

    Sopp, H.M.; Alexander, P.

    1991-01-01

    We have constructed a composite plot of far-infrared versus radioluminosity for late-type galaxies, Seyferts, quasars and radio galaxies. The most striking result is that the radio and far-infrared luminosities of radio-quiet quasars are correlated and follow the same correlation as normal star-forming galaxies and ultra-luminous infrared galaxies, whereas the radio-loud quasars have luminosities in both bands similar to those of radio galaxies. We conclude that the far-infrared emission from radio-quiet quasars is from star-forming host galaxies and not from active galactic nuclei. The far-infrared radio plot may be a powerful discriminator between host galaxy type. (author)

  15. Extended Radio Emission in MOJAVE Blazars: Challenges to Unification

    Science.gov (United States)

    Kharb, P.; Lister, M. L.; Cooper, N. J.

    2010-02-01

    We present the results of a study on the kiloparsec-scale radio emission in the complete flux density limited MOJAVE sample, comprising 135 radio-loud active galactic nuclei. New 1.4 GHz Very Large Array (VLA) radio images of six quasars and previously unpublished images of 21 blazars are presented, along with an analysis of the high-resolution (VLA A-array) 1.4 GHz emission for the entire sample. While extended emission is detected in the majority of the sources, about 7% of the sources exhibit only radio core emission. We expect more sensitive radio observations, however, to detect faint emission in these sources, as we have detected in the erstwhile "core-only" source, 1548+056. The kiloparsec-scale radio morphology varies widely across the sample. Many BL Lac objects exhibit extended radio power and kiloparsec-scale morphology typical of powerful FRII jets, while a substantial number of quasars possess radio powers intermediate between FRIs and FRIIs. This poses challenges to the simple radio-loud unified scheme, which links BL Lac objects to FRIs and quasars to FRIIs. We find a significant correlation between extended radio emission and parsec-scale jet speeds: the more radio powerful sources possess faster jets. This indicates that the 1.4 GHz (or low-frequency) radio emission is indeed related to jet kinetic power. Various properties such as extended radio power and apparent parsec-scale jet speeds vary smoothly between different blazar subclasses, suggesting that, at least in terms of radio jet properties, the distinction between quasars and BL Lac objects, at an emission-line equivalent width of 5 Å, is essentially an arbitrary one. While the two blazar subclasses display a smooth continuation in properties, they often reveal differences in the correlation test results when considered separately. This can be understood if, unlike quasars, BL Lac objects do not constitute a homogeneous population, but rather include both FRI and FRII radio galaxies for

  16. EXTENDED RADIO EMISSION IN MOJAVE BLAZARS: CHALLENGES TO UNIFICATION

    International Nuclear Information System (INIS)

    Kharb, P.; Lister, M. L.; Cooper, N. J.

    2010-01-01

    We present the results of a study on the kiloparsec-scale radio emission in the complete flux density limited MOJAVE sample, comprising 135 radio-loud active galactic nuclei. New 1.4 GHz Very Large Array (VLA) radio images of six quasars and previously unpublished images of 21 blazars are presented, along with an analysis of the high-resolution (VLA A-array) 1.4 GHz emission for the entire sample. While extended emission is detected in the majority of the sources, about 7% of the sources exhibit only radio core emission. We expect more sensitive radio observations, however, to detect faint emission in these sources, as we have detected in the erstwhile 'core-only' source, 1548+056. The kiloparsec-scale radio morphology varies widely across the sample. Many BL Lac objects exhibit extended radio power and kiloparsec-scale morphology typical of powerful FRII jets, while a substantial number of quasars possess radio powers intermediate between FRIs and FRIIs. This poses challenges to the simple radio-loud unified scheme, which links BL Lac objects to FRIs and quasars to FRIIs. We find a significant correlation between extended radio emission and parsec-scale jet speeds: the more radio powerful sources possess faster jets. This indicates that the 1.4 GHz (or low-frequency) radio emission is indeed related to jet kinetic power. Various properties such as extended radio power and apparent parsec-scale jet speeds vary smoothly between different blazar subclasses, suggesting that, at least in terms of radio jet properties, the distinction between quasars and BL Lac objects, at an emission-line equivalent width of 5 A, is essentially an arbitrary one. While the two blazar subclasses display a smooth continuation in properties, they often reveal differences in the correlation test results when considered separately. This can be understood if, unlike quasars, BL Lac objects do not constitute a homogeneous population, but rather include both FRI and FRII radio galaxies for

  17. Gamma-Ray Loudness, Synchrotron Peak Frequency, and Parsec-scale Properties of Blazars Detected by the Fermi Large Area Telescope

    Science.gov (United States)

    Linford, J. D.; Taylor, G. B.; Schinzel, F. K.

    2012-09-01

    The parsec-scale radio properties of 232 active galactic nuclei, most of which are blazars, detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long Baseline Array (VLBA) at 5 GHz. Data from both the first 11 months (1FGL) and the first 2 years (2FGL) of the Fermi mission were used to investigate these sources' γ-ray properties. We use the ratio of the γ-ray-to-radio luminosity as a measure of γ-ray loudness. We investigate the relationship of several radio properties to γ-ray loudness and to the synchrotron peak frequency. There is a tentative correlation between γ-ray loudness and synchrotron peak frequency for BL Lac objects in both 1FGL and 2FGL, and for flat-spectrum radio quasars (FSRQs) in 2FGL. We find that the apparent opening angle tentatively correlates with γ-ray loudness for FSRQs, but only when we use the 2FGL data. We also find that the total VLBA flux density correlates with the synchrotron peak frequency for BL Lac objects and FSRQs. The core brightness temperature also correlates with synchrotron peak frequency, but only for the BL Lac objects. The low-synchrotron-peaked (LSP) BL Lac object sample shows indications of contamination by FSRQs which happen to have undetectable emission lines. There is evidence that the LSP BL Lac objects are more strongly beamed than the rest of the BL Lac object population.

  18. GAMMA-RAY LOUDNESS, SYNCHROTRON PEAK FREQUENCY, AND PARSEC-SCALE PROPERTIES OF BLAZARS DETECTED BY THE FERMI LARGE AREA TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Linford, J. D.; Taylor, G. B.; Schinzel, F. K., E-mail: jlinford@unm.edu [Department of Physics and Astronomy, University of New Mexico, MSC07 4220, Albuquerque, NM 87131-0001 (United States)

    2012-09-20

    The parsec-scale radio properties of 232 active galactic nuclei, most of which are blazars, detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long Baseline Array (VLBA) at 5 GHz. Data from both the first 11 months (1FGL) and the first 2 years (2FGL) of the Fermi mission were used to investigate these sources' {gamma}-ray properties. We use the ratio of the {gamma}-ray-to-radio luminosity as a measure of {gamma}-ray loudness. We investigate the relationship of several radio properties to {gamma}-ray loudness and to the synchrotron peak frequency. There is a tentative correlation between {gamma}-ray loudness and synchrotron peak frequency for BL Lac objects in both 1FGL and 2FGL, and for flat-spectrum radio quasars (FSRQs) in 2FGL. We find that the apparent opening angle tentatively correlates with {gamma}-ray loudness for FSRQs, but only when we use the 2FGL data. We also find that the total VLBA flux density correlates with the synchrotron peak frequency for BL Lac objects and FSRQs. The core brightness temperature also correlates with synchrotron peak frequency, but only for the BL Lac objects. The low-synchrotron-peaked (LSP) BL Lac object sample shows indications of contamination by FSRQs which happen to have undetectable emission lines. There is evidence that the LSP BL Lac objects are more strongly beamed than the rest of the BL Lac object population.

  19. GAMMA-RAY LOUDNESS, SYNCHROTRON PEAK FREQUENCY, AND PARSEC-SCALE PROPERTIES OF BLAZARS DETECTED BY THE FERMI LARGE AREA TELESCOPE

    International Nuclear Information System (INIS)

    Linford, J. D.; Taylor, G. B.; Schinzel, F. K.

    2012-01-01

    The parsec-scale radio properties of 232 active galactic nuclei, most of which are blazars, detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long Baseline Array (VLBA) at 5 GHz. Data from both the first 11 months (1FGL) and the first 2 years (2FGL) of the Fermi mission were used to investigate these sources' γ-ray properties. We use the ratio of the γ-ray-to-radio luminosity as a measure of γ-ray loudness. We investigate the relationship of several radio properties to γ-ray loudness and to the synchrotron peak frequency. There is a tentative correlation between γ-ray loudness and synchrotron peak frequency for BL Lac objects in both 1FGL and 2FGL, and for flat-spectrum radio quasars (FSRQs) in 2FGL. We find that the apparent opening angle tentatively correlates with γ-ray loudness for FSRQs, but only when we use the 2FGL data. We also find that the total VLBA flux density correlates with the synchrotron peak frequency for BL Lac objects and FSRQs. The core brightness temperature also correlates with synchrotron peak frequency, but only for the BL Lac objects. The low-synchrotron-peaked (LSP) BL Lac object sample shows indications of contamination by FSRQs which happen to have undetectable emission lines. There is evidence that the LSP BL Lac objects are more strongly beamed than the rest of the BL Lac object population.

  20. 47 CFR 2.815 - External radio frequency power amplifiers.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false External radio frequency power amplifiers. 2... AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.815 External radio frequency power amplifiers. (a) As used in this part, an external radio frequency power...

  1. A RADIO-LOUD MAGNETAR IN X-RAY QUIESCENCE

    International Nuclear Information System (INIS)

    Levin, Lina; Bailes, Matthew; Bhat, N. D. Ramesh; Burke-Spolaor, Sarah; Van Straten, Willem; Bates, Samuel; Kramer, Michael; Stappers, Ben; Burgay, Marta; D'Amico, Nichi; Milia, Sabrina; Possenti, Andrea; Johnston, Simon; Keith, Michael; Rea, Nanda

    2010-01-01

    As part of a survey for radio pulsars with the Parkes 64 m telescope, we have discovered PSR J1622-4950, a pulsar with a 4.3 s rotation period. Follow-up observations show that the pulsar has the highest inferred surface magnetic field of the known radio pulsars (B ∼3 x 10 14 G), and it exhibits significant timing noise and appears to have an inverted spectrum. Unlike the vast majority of the known pulsar population, PSR J1622-4950 appears to switch off for many hundreds of days and even in its on-state exhibits extreme variability in its flux density. Furthermore, the integrated pulse profile changes shape with epoch. All of these properties are remarkably similar to the only two magnetars previously known to emit radio pulsations. The position of PSR J1622-4950 is coincident with an X-ray source that, unlike the other radio pulsating magnetars, was found to be in quiescence. We conclude that our newly discovered pulsar is a magnetar-the first to be discovered via its radio emission.

  2. No evidence for radio-quiet BL Lacertae objects

    International Nuclear Information System (INIS)

    Stocke, J.T.; Morris, S.L.; Gioia, I.; Maccacaro, T.; Schild, R.E.

    1990-01-01

    Using a large, flux-limited sample of faint X-ray sources, a search has been conducted for radio-quiet BL Lacertae objects. None has been found. Thirty-two X-ray-selected BL Lac objects and BL Lac candidates have been found within the sources of the Einstein Medium Sensitivity Survey (EMSS). Thirty-one of these have been observed with the VLA and all have been detected at 5 GHz. While the optical magnitudes of the EMSS BL Lac objects range from 17 to 20.8, their radio-to-optical spectral indices occupy a very small range. The very bright X-ray-selected BL Lac objects like PKS 2155-304 and Markarian 501 have similar range values. Therefore, unlike the clear dichotomy between radio-loud quasars and radio-quiet QSOs, there is no evidence for two populations of Lacertids distinguished by radio loudness. 43 refs

  3. Testing the Young Neutron Star Scenario with Persistent Radio Emission Associated with FRB 121102

    International Nuclear Information System (INIS)

    Kashiyama, Kazumi; Murase, Kohta

    2017-01-01

    Recently a repeating fast radio burst (FRB) 121102 has been confirmed to be an extragalactic event and a persistent radio counterpart has been identified. While other possibilities are not ruled out, the emission properties are broadly consistent with Murase et al. that theoretically proposed quasi-steady radio emission as a counterpart of both FRBs and pulsar-driven supernovae. Here, we constrain the model parameters of such a young neutron star scenario for FRB 121102. If the associated supernova has a conventional ejecta mass of M ej ≳ a few M ⊙ , a neutron star with an age of t age ∼ 10–100 years, an initial spin period of P i ≲ a few ms, and a dipole magnetic field of B dip ≲ a few × 10 13 G can be compatible with the observations. However, in this case, the magnetically powered scenario may be favored as an FRB energy source because of the efficiency problem in the rotation-powered scenario. On the other hand, if the associated supernova is an ultra-stripped one or the neutron star is born by the accretion-induced collapse with M ej ∼ 0.1 M ⊙ , a younger neutron star with t age ∼ 1–10 years can be the persistent radio source and might produce FRBs with the spin-down power. These possibilities can be distinguished by the decline rate of the quasi-steady radio counterpart.

  4. Testing the Young Neutron Star Scenario with Persistent Radio Emission Associated with FRB 121102

    Energy Technology Data Exchange (ETDEWEB)

    Kashiyama, Kazumi [Department of Physics, The University of Tokyo, Bunkyo, Tokyo 113-0033 (Japan); Murase, Kohta [Department of Physics, The Pennsylvania State University, University Park, PA 16802 (United States)

    2017-04-10

    Recently a repeating fast radio burst (FRB) 121102 has been confirmed to be an extragalactic event and a persistent radio counterpart has been identified. While other possibilities are not ruled out, the emission properties are broadly consistent with Murase et al. that theoretically proposed quasi-steady radio emission as a counterpart of both FRBs and pulsar-driven supernovae. Here, we constrain the model parameters of such a young neutron star scenario for FRB 121102. If the associated supernova has a conventional ejecta mass of M {sub ej} ≳ a few M {sub ⊙}, a neutron star with an age of t {sub age} ∼ 10–100 years, an initial spin period of P{sub i} ≲ a few ms, and a dipole magnetic field of B {sub dip} ≲ a few × 10{sup 13} G can be compatible with the observations. However, in this case, the magnetically powered scenario may be favored as an FRB energy source because of the efficiency problem in the rotation-powered scenario. On the other hand, if the associated supernova is an ultra-stripped one or the neutron star is born by the accretion-induced collapse with M {sub ej} ∼ 0.1 M {sub ⊙}, a younger neutron star with t {sub age} ∼ 1–10 years can be the persistent radio source and might produce FRBs with the spin-down power. These possibilities can be distinguished by the decline rate of the quasi-steady radio counterpart.

  5. Psychoacoustic Tinnitus Loudness and Tinnitus-Related Distress Show Different Associations with Oscillatory Brain Activity

    Science.gov (United States)

    Balkenhol, Tobias; Wallhäusser-Franke, Elisabeth; Delb, Wolfgang

    2013-01-01

    Background The phantom auditory perception of subjective tinnitus is associated with aberrant brain activity as evidenced by magneto- and electroencephalographic studies. We tested the hypotheses (1) that psychoacoustically measured tinnitus loudness is related to gamma oscillatory band power, and (2) that tinnitus loudness and tinnitus-related distress are related to distinct brain activity patterns as suggested by the distinction between loudness and distress experienced by tinnitus patients. Furthermore, we explored (3) how hearing impairment, minimum masking level, and (4) psychological comorbidities are related to spontaneous oscillatory brain activity in tinnitus patients. Methods and Findings Resting state oscillatory brain activity recorded electroencephalographically from 46 male tinnitus patients showed a positive correlation between gamma band oscillations and psychoacoustic tinnitus loudness determined with the reconstructed tinnitus sound, but not with the other psychoacoustic loudness measures that were used. Tinnitus-related distress did also correlate with delta band activity, but at electrode positions different from those associated with tinnitus loudness. Furthermore, highly distressed tinnitus patients exhibited a higher level of theta band activity. Moreover, mean hearing loss between 0.125 kHz and 16 kHz was associated with a decrease in gamma activity, whereas minimum masking levels correlated positively with delta band power. In contrast, psychological comorbidities did not express significant correlations with oscillatory brain activity. Conclusion Different clinically relevant tinnitus characteristics show distinctive associations with spontaneous brain oscillatory power. Results support hypothesis (1), but exclusively for the tinnitus loudness derived from matching to the reconstructed tinnitus sound. This suggests to preferably use the reconstructed tinnitus spectrum to determine psychoacoustic tinnitus loudness. Results also support

  6. Loud Music Exposure and Cochlear Synaptopathy in Young Adults: Isolated Auditory Brainstem Response Effects but No Perceptual Consequences.

    Science.gov (United States)

    Grose, John H; Buss, Emily; Hall, Joseph W

    2017-01-01

    The purpose of this study was to test the hypothesis that listeners with frequent exposure to loud music exhibit deficits in suprathreshold auditory performance consistent with cochlear synaptopathy. Young adults with normal audiograms were recruited who either did ( n = 31) or did not ( n = 30) have a history of frequent attendance at loud music venues where the typical sound levels could be expected to result in temporary threshold shifts. A test battery was administered that comprised three sets of procedures: (a) electrophysiological tests including distortion product otoacoustic emissions, auditory brainstem responses, envelope following responses, and the acoustic change complex evoked by an interaural phase inversion; (b) psychoacoustic tests including temporal modulation detection, spectral modulation detection, and sensitivity to interaural phase; and (c) speech tests including filtered phoneme recognition and speech-in-noise recognition. The results demonstrated that a history of loud music exposure can lead to a profile of peripheral auditory function that is consistent with an interpretation of cochlear synaptopathy in humans, namely, modestly abnormal auditory brainstem response Wave I/Wave V ratios in the presence of normal distortion product otoacoustic emissions and normal audiometric thresholds. However, there were no other electrophysiological, psychophysical, or speech perception effects. The absence of any behavioral effects in suprathreshold sound processing indicated that, even if cochlear synaptopathy is a valid pathophysiological condition in humans, its perceptual sequelae are either too diffuse or too inconsequential to permit a simple differential diagnosis of hidden hearing loss.

  7. VERY LONG BASELINE ARRAY IMAGING OF PARSEC-SCALE RADIO EMISSIONS IN NEARBY RADIO-QUIET NARROW-LINE SEYFERT 1 GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    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 }.

  8. Infrared-faint radio sources in the SERVS deep fields. Pinpointing AGNs at high redshift

    Science.gov (United States)

    Maini, A.; Prandoni, I.; Norris, R. P.; Spitler, L. R.; Mignano, A.; Lacy, M.; Morganti, R.

    2016-12-01

    Context. Infrared-faint radio sources (IFRS) represent an unexpected class of objects which are relatively bright at radio wavelength, but unusually faint at infrared (IR) and optical wavelengths. A recent and extensive campaign on the radio-brightest IFRSs (S1.4 GHz≳ 10 mJy) has provided evidence that most of them (if not all) contain an active galactic nuclei (AGN). Still uncertain is the nature of the radio-faintest IFRSs (S1.4 GHz≲ 1 mJy). Aims: The scope of this paper is to assess the nature of the radio-faintest IFRSs, testing their classification and improving the knowledge of their IR properties by making use of the most sensitive IR survey available so far: the Spitzer Extragalactic Representative Volume Survey (SERVS). We also explore how the criteria of IFRSs can be fine-tuned to pinpoint radio-loud AGNs at very high redshift (z > 4). Methods: We analysed a number of IFRS samples identified in SERVS fields, including a new sample (21 sources) extracted from the Lockman Hole. 3.6 and 4.5 μm IR counterparts of the 64 sources located in the SERVS fields were searched for and, when detected, their IR properties were studied. Results: We compared the radio/IR properties of the IR-detected IFRSs with those expected for a number of known classes of objects. We found that IR-detected IFRSs are mostly consistent with a mixture of high-redshift (z ≳ 3) radio-loud AGNs. The faintest ones (S1.4 GHz 100 μJy), however, could be also associated with nearer (z 2) dust-enshrouded star-burst galaxies. We also argue that, while IFRSs with radio-to-IR ratios >500 can very efficiently pinpoint radio-loud AGNs at redshift 2 < z < 4, lower radio-to-IR ratios ( 100-200) are expected for higher redshift radio-loud AGNs.

  9. Design of ultra-low power impulse radios

    CERN Document Server

    Apsel, Alyssa; Dokania, Rajeev

    2014-01-01

    This book covers the fundamental principles behind the design of ultra-low power radios and how they can form networks to facilitate a variety of applications within healthcare and environmental monitoring, since they may operate for years off a small battery or even harvest energy from the environment. These radios are distinct from conventional radios in that they must operate with very constrained resources and low overhead.  This book provides a thorough discussion of the challenges associated with designing radios with such constrained resources, as well as fundamental design concepts and practical approaches to implementing working designs.  Coverage includes integrated circuit design, timing and control considerations, fundamental theory behind low power and time domain operation, and network/communication protocol considerations.   • Enables detailed understanding of the design space for ultra-low power radio; • Provides detailed discussion and examples of the design of a practical low power ...

  10. On the relation between peripheral compression and the growth of loudness

    DEFF Research Database (Denmark)

    Buus, Søren; Florentine, Mary; Poulsen, Torben

    1999-01-01

    This presentation reviews similarities and differences between normal listeners' pure-tone loudness functions and the compressive basilar-membrane, BM, input-output function. Loudness matches between pure tones and multitone complexes with widely separated components reveal that the loudness...... function can be modeled by a modified power function with local exponents around unity near threshold and 0.2 at moderate levels [S. Buus et al., J. Acoust. Soc. Am. 104, 399–410 (1998)]. Loudness matches between short and long tones show that the SPL difference at equal loudness is a nonmonotonic function...... of SPL and is largest at moderate levels [S. Buus et al., J. Acoust. Soc. Am. 101, 669–680 (1997)]. These data can be explained by a loudness function that is flattest at moderate levels, where its local exponent also is around 0.2. This value is close to that obtained for BM input-output functions...

  11. On the relations among temporal integration for loudness, loudness discrimination, and the form of the loudness function. (A)

    DEFF Research Database (Denmark)

    Poulsen, Torben; Buus, Søren; Florentine, M

    1996-01-01

    Temporal integration for loudness was measured as a function of level from 2 to 60 dB SL using 2-, 10-, 50-, and 250-ms tones at 5 kHz. The adaptive 2I,2AFC procedure converged at the level required to make the variable stimulus just louder than the fixed stimulus. Thus the data yield estimates...... of the levels required to make tones of different durations equally loud and of the just noticeable differences for loudness level. Results for four listeners with normal hearing show that the amount of temporal integration, defined as the level difference between equally loud short and long tones, varies...... markedly with level and is largest at moderate levels. The effect of level increases as the duration of the short stimulus decreases and is largest for comparisons between the 2- and 250-ms tones. The loudness-level jnds are also largest at moderate levels and, contrary to traditional jnds for the level...

  12. Suzaku View of the Swift/BAT Active Galactic Nuclei. V. Torus Structure of Two Luminous Radio-Loud Active Galactic Nuclei (3C 206 and PKS 0707-35)

    Science.gov (United States)

    Tazaki, Fumie; Ueda, Yoshihiro; Terashima, Yuichi; Mushotzky, Richard F.; Tombesi, Francesco

    2013-01-01

    We present the results from broadband X-ray spectral analysis of 3C 206 and PKS 0707-35 with Suzaku and Swift/BAT, two of the most luminous unobscured and obscured radio-loud active galactic nuclei (AGNs) with hard X-ray luminosities of 10(sup 45.5) erg per second and 10(sup 44.9) erg per second (14-195 keV), respectively. Based on the radio core luminosity, we estimate that the X-ray spectrum of 3C 206 contains a significant (60% in the 14-195 keV band) contribution from the jet, while it is negligible in PKS 0707-35.We can successfully model the spectra with the jet component (for 3C 206), the transmitted emission, and two reflection components from the torus and the accretion disk. The reflection strengths from the torus are found to be R(sub torus)(=Omega/2pi) = 0.29 +/- 0.18 and 0.41 +/- 0.18 for 3C 206 and PKS 0707-35, respectively, which are smaller than those in typical Seyfert galaxies. Utilizing the torus model by Ikeda et al., we quantify the relation between the half-opening angle of a torus (theta(sub oa)) and the equivalent width of an iron-K line. The observed equivalent width of 3C 206, less than 71 eV, constrains the column density in the equatorial plane to N(sup eq)(sub H) lesst han 10(sup 23) per square centimeter, or the half-opening angle to theta(sub oa) greater than 80 deg. if N(sup eq)(sub H) = 10(sup 24) per square centimeter is assumed. That of PKS 0707-35, 72 +/- 36 eV, is consistent with N(sup eq)(sub H) 10(sup 23) per square centimeter. Our results suggest that the tori in luminous radio-loud AGNs are only poorly developed. The trend is similar to that seen in radio-quiet AGNs, implying that the torus structure is not different between AGNs with jets and without jets.

  13. THE DYNAMIC EVOLUTION OF YOUNG EXTRAGALACTIC RADIO SOURCES

    International Nuclear Information System (INIS)

    An Tao; Baan, Willem A.

    2012-01-01

    The evolution of symmetric extragalactic radio sources can be characterized by four distinct growth stages of the radio luminosity versus size of the source. The interaction of the jet with the ambient medium results in the formation and evolution of sources with non-standard (flaring) morphology. In addition, cessation or restarting of the jet power and obstruction of the jet will also result in distinct morphological structures. The radio source population may thus be classified in morphological types that indicate the prevailing physical processes. Compact symmetric objects (CSOs) occupy the earliest evolutionary phase of symmetric radio sources and their dynamical behavior is fundamental for any further evolution. Analysis of CSO dynamics is presented for a sample of 24 CSOs with known redshift and hotspot separation velocity and with a large range of radio power. Observables such as radio power, separation between two hotspots, hotspot separation velocity, and kinematic age of the source are found to be generally consistent with the self-similar predictions for individual sources that reflect the varying density structure of the ambient interstellar medium. Individual sources behave different from the group as a whole. The age and size statistics confirm that a large fraction of CSOs does not evolve into extended doubles.

  14. THE DYNAMIC EVOLUTION OF YOUNG EXTRAGALACTIC RADIO SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    An Tao [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 200030 Shanghai (China); Baan, Willem A., E-mail: antao@shao.ac.cn, E-mail: baan@astron.nl [ASTRON, P.O. Box 2, 7990-AA Dwingeloo (Netherlands)

    2012-11-20

    The evolution of symmetric extragalactic radio sources can be characterized by four distinct growth stages of the radio luminosity versus size of the source. The interaction of the jet with the ambient medium results in the formation and evolution of sources with non-standard (flaring) morphology. In addition, cessation or restarting of the jet power and obstruction of the jet will also result in distinct morphological structures. The radio source population may thus be classified in morphological types that indicate the prevailing physical processes. Compact symmetric objects (CSOs) occupy the earliest evolutionary phase of symmetric radio sources and their dynamical behavior is fundamental for any further evolution. Analysis of CSO dynamics is presented for a sample of 24 CSOs with known redshift and hotspot separation velocity and with a large range of radio power. Observables such as radio power, separation between two hotspots, hotspot separation velocity, and kinematic age of the source are found to be generally consistent with the self-similar predictions for individual sources that reflect the varying density structure of the ambient interstellar medium. Individual sources behave different from the group as a whole. The age and size statistics confirm that a large fraction of CSOs does not evolve into extended doubles.

  15. Sequential dependencies in magnitude scaling of loudness

    DEFF Research Database (Denmark)

    Joshi, Suyash Narendra; Jesteadt, Walt

    2013-01-01

    Ten normally hearing listeners used a programmable sone-potentiometer knob to adjust the level of a 1000-Hz sinusoid to match the loudness of numbers presented to them in a magnitude production task. Three different power-law exponents (0.15, 0.30, and 0.60) and a log-law with equal steps in d......B were used to program the sone-potentiometer. The knob settings systematically influenced the form of the loudness function. Time series analysis was used to assess the sequential dependencies in the data, which increased with increasing exponent and were greatest for the log-law. It would be possible......, therefore, to choose knob properties that minimized these dependencies. When the sequential dependencies were removed from the data, the slope of the loudness functions did not change, but the variability decreased. Sequential dependencies were only present when the level of the tone on the previous trial...

  16. The Suzaku Observation of the Nucleus of theRadio-Loud Active Galaxy Centaurus A: Constraints on Abundances of the Accreting Material

    Energy Technology Data Exchange (ETDEWEB)

    Markowitz, A.; Takahashi, T.; Watanabe, S.; Nakazawa, K.; Fukazawa, Y.; Kokubun, M.; Makishima, K.; Awaki, H.; Bamba, A.; Isobe, N.; Kataoka, J.; Madejski, G.; Mushotzky,; Okajima, T.; Ptak, A.; Reeves, J.N.; Ueda, Y.; Yamasaki, T.; Yaqoob, T.

    2007-06-27

    A Suzaku observation of the nucleus of the radio-loud AGN Centaurus A in 2005 has yielded a broadband spectrum spanning 0.3 to 250 keV. The net exposure times after screening were: 70 ks per X-ray Imaging Spectrometer (XIS) camera, 60.8 ks for the Hard X-ray Detector (HXD) PIN, and 17.1 ks for the HXD-GSO. The hard X-rays are fit by two power-laws of the same slope, absorbed by columns of 1.5 and 7 x 10{sup 23} cm{sup -2} respectively. The spectrum is consistent with previous suggestions that the power-law components are X-ray emission from the sub-pc VLBI jet and from Bondi accretion at the core, but it is also consistent with a partial covering interpretation. The soft band is dominated by thermal emission from the diffuse plasma and is fit well by a two-temperature vapec model, plus a third power-law component to account for scattered nuclear emission, jet emission, and emission from X-ray Binaries and other point sources. Narrow fluorescent emission lines from Fe, Si, S, Ar, Ca and Ni are detected. The Fe K{alpha} line width yields a 200 light-day lower limit on the distance from the black hole to the line-emitting gas. Fe, Ca, and S K-shell absorption edges are detected. Elemental abundances are constrained via absorption edge depths and strengths of the fluorescent and diffuse plasma emission lines. The high metallicity ([Fe/H]=+0.1) of the circumnuclear material suggests that it could not have originated in the relatively metal-poor outer halo unless enrichment by local star formation has occurred. Relative abundances are consistent with enrichment from Type II and Ia supernovae.

  17. Facets of radio-loud AGN evolution : a LOFAR surveys perspective

    NARCIS (Netherlands)

    Williams, Wendy L.

    2015-01-01

    Radio observations provide a unique view of black holes in the Universe. This thesis presents low frequency radio images and uses the radio sources in those images to study the evolution of black holes and galaxies through the age of the Universe.

  18. X-ray study of a sample of FR0 radio galaxies: unveiling the nature of the central engine

    Science.gov (United States)

    Torresi, E.; Grandi, P.; Capetti, A.; Baldi, R. D.; Giovannini, G.

    2018-06-01

    Fanaroff-Riley type 0 radio galaxies (FR0s) are compact radio sources that represent the bulk of the radio-loud active galactic nuclei (AGN) population, but they are still poorly understood. Pilot studies on these sources have been already performed at radio and optical wavelengths: here we present the first X-ray study of a sample of 19 FR0 radio galaxies selected from the Sloan Digital Sky Survey/NRAO VLA Sky Survey/Faint Images of the Radio Sky at Twenty-cm sample of Best & Heckman, with redshift ≤0.15, radio size ≤10 kpc, and optically classified as low-excitation galaxies. The X-ray spectra are modelled with a power-law component absorbed by Galactic column density with, in some cases, a contribution from thermal extended gas. The X-ray photons are likely produced by the jet as attested by the observed correlation between X-ray (2-10 keV) and radio (5 GHz) luminosities, similar to Fanaroff-Riley type I radio galaxies (FRIs). The estimated Eddington-scaled luminosities indicate a low accretion rate. Overall, we find that the X-ray properties of FR0s are indistinguishable from those of FRIs, thus adding another similarity between AGN associated with compact and extended radio sources. A comparison between FR0s and low-luminosity BL Lacs rules out important beaming effects in the X-ray emission of the compact radio galaxies. FR0s have different X-ray properties with respect to young radio sources (e.g. gigahertz-peaked spectrum/compact steep spectrum sources), generally characterized by higher X-ray luminosities and more complex spectra. In conclusion, the paucity of extended radio emission in FR0s is probably related to the intrinsic properties of their jets that prevent the formation of extended structures, and/or to intermittent activity of their engines.

  19. Directional loudness perception

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka

    developed. The research and modeling of loudness have mainly been concerned with the temporal and spectral aspects of sounds, while the spatial aspects have mostly been overlooked. This PhD thesis investigates the spatial aspects of loudness perception, namely, how does the direction from which a sound...

  20. A young source of optical emission from distant radio galaxies.

    Science.gov (United States)

    Hammer, F; Fèvre, O Le; Angonin, M C

    1993-03-25

    DISTANT radio galaxies provide valuable insights into the properties of the young Universe-they are the only known extended optical sources at high redshift and might represent an early stage in the formation and evolution of galaxies in general. This extended optical emission often has very complex morphologies, but the origin of the light is still unclear. Here we report spectroscopic observations for several distant radio galaxies (0.75≤ z ≤ 1.1) in which the rest-frame spectra exhibit featureless continua between 2,500 Å and 5,000 Å. We see no evidence for the break in the spectrum at 4,000 Å expected for an old stellar population 1-3 , and suggest that young stars or scattered emissions from the active nuclei are responsible for most of the observed light. In either case, this implies that the source of the optical emission is com-parable in age to the associated radio source, namely 10 7 years or less.

  1. Radio continuum emission from young stellar objects in L1641

    International Nuclear Information System (INIS)

    Morgan, J.A.; Snell, R.L.; Strom, K.M.

    1990-01-01

    The results of a 6 and 20 cm radio continuum survey of young stellar objects in the L1641 region located south of the Orion Nebula are presented. Four are identified as low-luminosity young stellar objects in L1641 and three more as Herbig-Haro or Herbig-Haro-like objects. These objects have bolometric luminosities between 80 and 300 solar, and their 6-20 cm spectral index suggests optically thick, free-free emission. They are characterized by a rising spectrum between 2.2 and 25 microns, have no optical counterparts, and are associated with stellar wind activity. Thus, detectable radio continuum emission may be produced only by the youngest and most luminous objects in L1641. 34 refs

  2. Ultra-low-power short-range radios

    CERN Document Server

    Chandrakasan, Anantha

    2015-01-01

    This book explores the design of ultra-low-power radio-frequency integrated circuits (RFICs), with communication distances ranging from a few centimeters to a few meters. Such radios have unique challenges compared to longer-range, higher-powered systems. As a result, many different applications are covered, ranging from body-area networks to transcutaneous implant communications and Internet-of-Things devices. A mix of introductory and cutting-edge design techniques and architectures which facilitate each of these applications are discussed in detail. Specifically, this book covers:.

  3. The Correlation between γ-Ray and Radio Emissions for the Fermi ...

    Indian Academy of Sciences (India)

    Abstract. Based upon the Fermi blazars sample, the radio and γ-ray emissions are compiled for a sample of 74 γ-ray loud blazars to calculate the radio to γ-ray effective spectrum index αRγ . The correlations between. αRγ and γ-ray luminosity, and between radio and γ-ray luminosity are also investigated. Key words.

  4. Tinnitus: distinguishing between subjectively perceived loudness and tinnitus-related distress.

    Directory of Open Access Journals (Sweden)

    Elisabeth Wallhäusser-Franke

    Full Text Available OBJECTIVES: Overall success of current tinnitus therapies is low, which may be due to the heterogeneity of tinnitus patients. Therefore, subclassification of tinnitus patients is expected to improve therapeutic allocation, which, in turn, is hoped to improve therapeutic success for the individual patient. The present study aims to define factors that differentially influence subjectively perceived tinnitus loudness and tinnitus-related distress. METHODS: In a questionnaire-based cross-sectional survey, the data of 4705 individuals with tinnitus were analyzed. The self-report questionnaire contained items about subjective tinnitus loudness, type of onset, awareness and localization of the tinnitus, hearing impairment, chronic comorbidities, sleep quality, and psychometrically validated questionnaires addressing tinnitus-related distress, depressivity, anxiety, and somatic symptom severity. In a binary step-wise logistic regression model, we tested the predictive power of these variables on subjective tinnitus loudness and tinnitus-related distress. RESULTS: The present data contribute to the distinction between subjective tinnitus loudness and tinnitus-related distress. Whereas subjective loudness was associated with permanent awareness and binaural localization of the tinnitus, tinnitus-related distress was associated with depressivity, anxiety, and somatic symptom severity. CONCLUSIONS: Subjective tinnitus loudness and the potential presence of severe depressivity, anxiety, and somatic symptom severity should be assessed separately from tinnitus-related distress. If loud tinnitus is the major complaint together with mild or moderate tinnitus-related distress, therapies should focus on auditory perception. If levels of depressivity, anxiety or somatic symptom severity are severe, therapies and further diagnosis should focus on these symptoms at first.

  5. Tinnitus: Distinguishing between Subjectively Perceived Loudness and Tinnitus-Related Distress

    Science.gov (United States)

    Wallhäusser-Franke, Elisabeth; Brade, Joachim; Balkenhol, Tobias; D'Amelio, Roberto; Seegmüller, Andrea; Delb, Wolfgang

    2012-01-01

    Objectives Overall success of current tinnitus therapies is low, which may be due to the heterogeneity of tinnitus patients. Therefore, subclassification of tinnitus patients is expected to improve therapeutic allocation, which, in turn, is hoped to improve therapeutic success for the individual patient. The present study aims to define factors that differentially influence subjectively perceived tinnitus loudness and tinnitus-related distress. Methods In a questionnaire-based cross-sectional survey, the data of 4705 individuals with tinnitus were analyzed. The self-report questionnaire contained items about subjective tinnitus loudness, type of onset, awareness and localization of the tinnitus, hearing impairment, chronic comorbidities, sleep quality, and psychometrically validated questionnaires addressing tinnitus-related distress, depressivity, anxiety, and somatic symptom severity. In a binary step-wise logistic regression model, we tested the predictive power of these variables on subjective tinnitus loudness and tinnitus-related distress. Results The present data contribute to the distinction between subjective tinnitus loudness and tinnitus-related distress. Whereas subjective loudness was associated with permanent awareness and binaural localization of the tinnitus, tinnitus-related distress was associated with depressivity, anxiety, and somatic symptom severity. Conclusions Subjective tinnitus loudness and the potential presence of severe depressivity, anxiety, and somatic symptom severity should be assessed separately from tinnitus-related distress. If loud tinnitus is the major complaint together with mild or moderate tinnitus-related distress, therapies should focus on auditory perception. If levels of depressivity, anxiety or somatic symptom severity are severe, therapies and further diagnosis should focus on these symptoms at first. PMID:22529921

  6. The Curious Molecular Gas Conditions in a z=2.6 Radio-loud Quasar

    Science.gov (United States)

    Sharon, Chelsea; Riechers, Dominik A.; Kuk Leung, Tsz; Weiss, Axel; Walter, Fabian; Carilli, Chris; Kraiburg Knudsen, Kirsten; Hodge, Jacqueline

    2018-01-01

    Theoretical work suggests that AGN play an important role in quenching star formation in massive galaxies. In addition to molecular outflows observed in the local universe, emission from very high-J CO rotational transitions has been one of the key pieces of evidence for AGN directly affecting the molecular gas reservoirs that fuel star formation. However, very few observations of Jupper>9 transitions exist for galaxies in the early universe. Here we will present the peculiar molecular gas conditions in MG 0414+0534 (MG 0414 hereafter), one of the few high-z galaxies with very high-J CO detections. MG 0414 is a strongly lensed IR-bright radio-loud quasar with broad Hα emission at z=2.6390. We recently confirmed the CO(3–2) detection from Barvainis et al. (1998), but were unable to detect the CO(1–0) line. The 3σ lower limit on the 3–2/1–0 line ratio (in units of brightness temperature) is r3,1>5.72, which is significantly higher than the r3,1≤1 typical for thermalized optically thick emission in other z˜2–3 AGN host galaxies. In addition, the CO(11–10) line was detected to high significance using the Atacama Large Millimeter/submillimeter Array, and the CO(11–10) line FWHM is nearly double that of the CO(3–2) line. We will discuss possible explanations for the peculiar line ratios in MG 0414 (such as optically thin emission, molecular outflows, and differential lensing) and what the origin of these ratios imply for molecular gas observations of other high-z AGN host galaxies.

  7. Temporal integration of loudness measured using categorical loudness scaling and matching procedures

    DEFF Research Database (Denmark)

    Valente, Daniel L.; Joshi, Suyash Narendra; Jesteadt, Walt

    2011-01-01

    integration of loudness and previously reported nonmonotonic behavior observed at mid-sound pressure level levels is replicated with this procedure. Stimuli that are assigned to the same category are effectively matched in loudness, allowing the measurement of temporal integration with CLS without curve...

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

    Science.gov (United States)

    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. Why Do People Like Loud Sound? A Qualitative Study.

    Science.gov (United States)

    Welch, David; Fremaux, Guy

    2017-08-11

    Many people choose to expose themselves to potentially dangerous sounds such as loud music, either via speakers, personal audio systems, or at clubs. The Conditioning, Adaptation and Acculturation to Loud Music (CAALM) Model has proposed a theoretical basis for this behaviour. To compare the model to data, we interviewed a group of people who were either regular nightclub-goers or who controlled the sound levels in nightclubs (bar managers, musicians, DJs, and sound engineers) about loud sound. Results showed four main themes relating to the enjoyment of loud sound: arousal/excitement, facilitation of socialisation, masking of both external sound and unwanted thoughts, and an emphasis and enhancement of personal identity. Furthermore, an interesting incidental finding was that sound levels appeared to increase gradually over the course of the evening until they plateaued at approximately 97 dBA Leq around midnight. Consideration of the data generated by the analysis revealed a complex of influential factors that support people in wanting exposure to loud sound. Findings were considered in terms of the CAALM Model and could be explained in terms of its principles. From a health promotion perspective, the Social Ecological Model was applied to consider how the themes identified might influence behaviour. They were shown to influence people on multiple levels, providing a powerful system which health promotion approaches struggle to address.

  10. DISCOVERY OF ULTRA-FAST OUTFLOWS IN A SAMPLE OF BROAD-LINE RADIO GALAXIES OBSERVED WITH SUZAKU

    International Nuclear Information System (INIS)

    Tombesi, F.; Sambruna, R. M.; Mushotzky, R. F.; Reeves, J. N.; Gofford, J.; Braito, V.; Ballo, L.; Cappi, M.

    2010-01-01

    We present the results of a uniform and systematic search for blueshifted Fe K absorption lines in the X-ray spectra of five bright broad-line radio galaxies observed with Suzaku. We detect, for the first time in radio-loud active galactic nuclei (AGNs) at X-rays, several absorption lines at energies greater than 7 keV in three out of five sources, namely, 3C 111, 3C 120, and 3C 390.3. The lines are detected with high significance according to both the F-test and extensive Monte Carlo simulations. Their likely interpretation as blueshifted Fe XXV and Fe XXVI K-shell resonance lines implies an origin from highly ionized gas outflowing with mildly relativistic velocities, in the range v ≅ 0.04-0.15c. A fit with specific photoionization models gives ionization parameters in the range log ξ ≅ 4-5.6 erg s -1 cm and column densities of N H ≅ 10 22 -10 23 cm -2 . These characteristics are very similar to those of the ultra-fast outflows (UFOs) previously observed in radio-quiet AGNs. Their estimated location within ∼0.01-0.3 pc of the central super-massive black hole suggests a likely origin related with accretion disk winds/outflows. Depending on the absorber covering fraction, the mass outflow rate of these UFOs can be comparable to the accretion rate and their kinetic power can correspond to a significant fraction of the bolometric luminosity and is comparable to their typical jet power. Therefore, these UFOs can play a significant role in the expected feedback from the AGN to the surrounding environment and can give us further clues on the relation between the accretion disk and the formation of winds/jets in both radio-quiet and radio-loud AGNs.

  11. BioRadioTransmitter: a self-powered wireless glucose-sensing system.

    Science.gov (United States)

    Hanashi, Takuya; Yamazaki, Tomohiko; Tsugawa, Wakako; Ikebukuro, Kazunori; Sode, Koji

    2011-09-01

    Although an enzyme fuel cell can be utilized as a glucose sensor, the output power generated is too low to power a device such as a currently available transmitter and operating system, and an external power source is required for operating an enzyme-fuel-cell-based biosensing system. We proposed a novel biosensor that we named BioCapacitor, in which a capacitor serves as a transducer. In this study, we constructed a new BioCapacitor-based system with an added radio-transmitter circuit and a miniaturized enzyme fuel cell. A miniaturized direct-electron-transfer-type compartmentless enzyme fuel cell was constructed with flavin adenine dinucleotide-dependent glucose dehydrogenase complex-based anode and a bilirubin-oxidase-based cathode. For construction of a BioRadioTransmitter wireless sensing system, a capacitor, an ultra-low-voltage charge-pump-integrated circuit, and Hartley oscillator circuit were connected to the miniaturized enzyme fuel cell. A radio-receiver circuit, comprising two field-effect transistors and a coil as an antenna, was used to amplify the signal generated from the biofuel cells. Radio wave signals generated by the BioRadioTransmitter were received, amplified, and converted from alternate to direct current by the radio receiver. When the capacitor discharges in the presence of glucose, the BioRadioTransmitter generates a radio wave, which is monitored by a radio receiver connected wirelessly to the sensing device. Magnitude of the radio wave transmission frequency change observed at the radio receiver was correlated to glucose concentration in the fuel cells. We constructed a stand-alone, self-powered, wireless glucose-sensing system called a BioRadioTransmitter by using a radio transmitter in which the radio wave transmission frequency changes with the glucose concentration in the fuel cell. The BioRadioTransmitter is a significant advance toward construction of an implantable continuous glucose monitor. © 2011 Diabetes Technology Society.

  12. Spectral and binaural loudness summation for hearing-impaired listeners.

    Science.gov (United States)

    Oetting, Dirk; Hohmann, Volker; Appell, Jens-E; Kollmeier, Birger; Ewert, Stephan D

    2016-05-01

    Sensorineural hearing loss typically results in a steepened loudness function and a reduced dynamic range from elevated thresholds to uncomfortably loud levels for narrowband and broadband signals. Restoring narrowband loudness perception for hearing-impaired (HI) listeners can lead to overly loud perception of broadband signals and it is unclear how binaural presentation affects loudness perception in this case. Here, loudness perception quantified by categorical loudness scaling for nine normal-hearing (NH) and ten HI listeners was compared for signals with different bandwidth and different spectral shape in monaural and in binaural conditions. For the HI listeners, frequency- and level-dependent amplification was used to match the narrowband monaural loudness functions of the NH listeners. The average loudness functions for NH and HI listeners showed good agreement for monaural broadband signals. However, HI listeners showed substantially greater loudness for binaural broadband signals than NH listeners: on average a 14.1 dB lower level was required to reach "very loud" (range 30.8 to -3.7 dB). Overall, with narrowband loudness compensation, a given binaural loudness for broadband signals above "medium loud" was reached at systematically lower levels for HI than for NH listeners. Such increased binaural loudness summation was not found for loudness categories below "medium loud" or for narrowband signals. Large individual variations in the increased loudness summation were observed and could not be explained by the audiogram or the narrowband loudness functions. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Fast Radio Bursts’ Emission Mechanism: Implication from Localization

    Energy Technology Data Exchange (ETDEWEB)

    Lyutikov, Maxim [Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907-2036 (United States)

    2017-03-20

    We argue that the localization of the repeating fast radio bursts (FRBs) at ∼1 Gpc excludes a rotationally powered type of radio emission (e.g., analogs of Crab’s giant pulses coming from very young energetic pulsars) as the origin of FRBs.

  14. Fast Radio Bursts’ Emission Mechanism: Implication from Localization

    International Nuclear Information System (INIS)

    Lyutikov, Maxim

    2017-01-01

    We argue that the localization of the repeating fast radio bursts (FRBs) at ∼1 Gpc excludes a rotationally powered type of radio emission (e.g., analogs of Crab’s giant pulses coming from very young energetic pulsars) as the origin of FRBs.

  15. Can Loud Music Hurt My Ears?

    Science.gov (United States)

    ... Videos for Educators Search English Español Can Loud Music Hurt My Ears? KidsHealth / For Kids / Can Loud Music Hurt My Ears? Print en español La música ... up? Oh! You want to know if loud music can hurt your ears . Are you asking because ...

  16. Toward Understanding the Fanaroff-Riley Dichotomy in Radio Source Morphology and Power

    Science.gov (United States)

    Baum, Stefi A.; Zirbel, Esther L.; O'Dea, Christopher P.

    1995-09-01

    of the total energy output from the AGNs into jet kinetic energy versus radiant energy than do FR 2 sources. If this interpretation is correct, then this suggests that there is a fundamental difference in the central engine and/or in the immediate "accretion region" around the engine in FR 1 and FR 2 radio galaxies. We note also the absence of FR 1 sources with nuclear broad line regions and suggest that the absence of the BLR is tied to the absence of the "isotropic" nuclear UV continuum source in FR 1 sources. We put forth the possibility that the FR 1/FR 2 dichotomy (i.e., the observed differences in the properties of low- and high-power radio sources) is due to qualitative differences in the structural properties of the central engines in these two types of sources. Following early work by Rees et al. (1982), we suggest the possibility that FR 1 sources are produced when the central engine is fed at a lower accretion rate, leading to the creation of a source in which the ratio of radiant to jet bulk kinetic energy is low, while FR 2 sources are produced when the central engine is fed at a higher accretion rate, causing the central engine to deposit a higher fraction of its energy in radiant energy. We further suggest the possibility that associated differences in the spin properties of the central black hole between FR 1 (lower spin) and FR 2 (higher spin) sources may be responsible for the different collimation properties and Mach numbers of the jets produced by these two types of radio-loud galaxies. This scenario, although currently clearly speculative, is nicely consistent with our current picture of the triggering, feeding, environments, and evolution of powerful radio galaxies. This model allows for evolution of these properties with time for example, the mass accretion rate and BH spin may decline with time causing an FR 2 radio source or quasar to evolve into a FR 1 radio source.

  17. Passive radio frequency peak power multiplier

    Science.gov (United States)

    Farkas, Zoltan D.; Wilson, Perry B.

    1977-01-01

    Peak power multiplication of a radio frequency source by simultaneous charging of two high-Q resonant microwave cavities by applying the source output through a directional coupler to the cavities and then reversing the phase of the source power to the coupler, thereby permitting the power in the cavities to simultaneously discharge through the coupler to the load in combination with power from the source to apply a peak power to the load that is a multiplication of the source peak power.

  18. Factors influencing tinnitus loudness and annoyance.

    Science.gov (United States)

    Hiller, Wolfgang; Goebel, Gerhard

    2006-12-01

    To evaluate the 2 major components of tinnitus severity, loudness and annoyance, and their degree of dependence on characteristics of tinnitus manifestation, history, and etiology. Cross-sectional survey performed during the first months of 2004. Nonclinical population. A total of 4995 members of the German Tinnitus League. Comprehensive screening questionnaire, including the Klockhoff and Lindblom loudness grading system and the miniversion of the Tinnitus Questionnaire. A moderate correlation of 0.45 was found between tinnitus loudness and annoyance. Both factors were generally higher in men, those older than 50 years, those with binaural and centrally perceived tinnitus, those with increased noise sensitivity, and those who had continuous tinnitus without interruptions. Tinnitus that lasted 12 months or less had a stronger influence on annoyance (odds ratio [OR], 1.96) than on loudness (OR, 0.45), whereas the contrary was found for tinnitus of more than 5 years' duration (ORs, 0.72 and 2.11, respectively). Loudness and annoyance were increased in subjects with coexisting hearing loss, vertigo, and hyperacusis. The impact of hyperacusis on annoyance was clearly stronger than on loudness (ORs, 21.91 vs 9.47). Several clinical factors of tinnitus influence perceived loudness and annoyance. Both are distinguishable components of tinnitus severity.

  19. Jet emission in young radio sources: A Fermi large area telescope gamma-ray view

    Energy Technology Data Exchange (ETDEWEB)

    Migliori, G.; Siemiginowska, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Kelly, B. C. [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93107 (United States); Stawarz, Ł. [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Celotti, A. [Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea, 265-34136 Trieste (Italy); Begelman, M. C., E-mail: migliori@cfa.harvard.edu [JILA, University of Colorado and National Institute of Standards and Technology, 440 UCB, Boulder, CO 80309-0440 (United States)

    2014-01-10

    We investigate the contribution of the beamed jet component to the high-energy emission in young and compact extragalactic radio sources, focusing for the first time on the γ-ray band. We derive predictions on the γ-ray luminosities associated with the relativistic jet assuming a leptonic radiative model. The high-energy emission is produced via Compton scattering by the relativistic electrons in a spherical region at the considered scales (≲10 kpc). Simulations show a wide range of γ-ray luminosities, with intensities up to ∼10{sup 46}-10{sup 48} erg s{sup –1} depending on the assumed jet parameters. We find a highly linear relation between the simulated X-ray and γ-ray luminosities that can be used to select candidates for γ-ray detection. We compare the simulated luminosity distributions in the radio, X-ray, and γ-ray regimes with observations for the largest sample of X-ray-detected young radio quasars. Our analysis of ∼4-yr Fermi Large Area Telescope (LAT) data does not yield any statistically significant detections. However, the majority of the model-predicted γ-ray fluxes for the sample are near or below the current Fermi-LAT flux threshold and compatible with the derived upper limits. Our study gives constraints on the minimum jet power (L {sub jet,} {sub kin}/L {sub disk} > 0.01) of a potential jet contribution to the X-ray emission in the most compact sources (≲ 1 kpc) and on the particle-to-magnetic field energy density ratio that are in broad agreement with equipartition assumptions.

  20. Development of an Improved Time Varying Loudness Model with the Inclusion of Binaural Loudness Summation

    Science.gov (United States)

    Charbonneau, Jeremy

    As the perceived quality of a product is becoming more important in the manufacturing industry, more emphasis is being placed on accurately predicting the sound quality of everyday objects. This study was undertaken to improve upon current prediction techniques with regard to the psychoacoustic descriptor of loudness and an improved binaural summation technique. The feasibility of this project was first investigated through a loudness matching experiment involving thirty-one subjects and pure tones of constant sound pressure level. A dependence of binaural summation on frequency was observed which had previously not been a subject of investigation in the reviewed literature. A follow-up investigation was carried out with forty-eight volunteers and pure tones of constant sensation level. Contrary to existing theories in literature the resulting loudness matches revealed an amplitude versus frequency relationship which confirmed the perceived increase in loudness when a signal was presented to both ears simultaneously as opposed to one ear alone. The resulting trend strongly indicated that the higher the frequency of the presented signal, the greater the increase in observed binaural summation. The results from each investigation were summarized into a single binaural summation algorithm and inserted into an improved time-varying loudness model. Using experimental techniques, it was demonstrated that the updated binaural summation algorithm was a considerable improvement over the state of the art approach for predicting the perceived binaural loudness. The improved function retained the ease of use from the original model while additionally providing accurate estimates of diotic listening conditions from monaural WAV files. It was clearly demonstrated using a validation jury test that the revised time-varying loudness model was a significant improvement over the previously standardized approach.

  1. THE SECOND FERMI LARGE AREA TELESCOPE CATALOG OF GAMMA-RAY PULSARS

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, A. A. [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030 (United States); Ajello, M. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Allafort, A.; Bloom, E. D.; Bottacini, E. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L. [Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d' Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Baring, M. G. [Rice University, Department of Physics and Astronomy, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Belfiore, A. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bhattacharyya, B. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune 411 007 (India); Bissaldi, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, and Università di Trieste, I-34127 Trieste (Italy); Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Brigida, M., E-mail: hartog@stanford.edu [Dipartimento di Fisica ' ' M. Merlin' ' dell' Università e del Politecnico di Bari, I-70126 Bari (Italy); and others

    2013-10-01

    This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

  2. The second FERMI large area telescope catalog of gamma-ray pulsars

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, A. A.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bhattacharyya, B.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burgay, M.; Burnett, T. H.; Busetto, G.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Camilo, F.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chaty, S.; Chaves, R. C. G.; Chekhtman, A.; Chen, A. W.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cognard, I.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D' Ammando, F.; de Angelis, A.; DeCesar, M. E.; De Luca, A.; den Hartog, P. R.; de Palma, F.; Dermer, C. D.; Desvignes, G.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Espinoza, C. M.; Falletti, L.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Freire, P. C. C.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gotthelf, E. V.; Grenier, I. A.; Grondin, M. -H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hessels, J.; Hewitt, J.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Jackson, M. S.; Janssen, G. H.; Jogler, T.; Jóhannesson, G.; Johnson, R. P.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Johnston, S.; Kamae, T.; Kataoka, J.; Keith, M.; Kerr, M.; Knödlseder, J.; Kramer, M.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Lyne, A. G.; Manchester, R. N.; Marelli, M.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; McLaughlin, M. A.; Mehault, J.; Michelson, P. F.; Mignani, R. P.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohno, M.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Perkins, J. S.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Pletsch, H. J.; Porter, T. A.; Possenti, A.; Rainò, S.; Rando, R.; Ransom, S. M.; Ray, P. S.; Razzano, M.; Rea, N.; Reimer, A.; Reimer, O.; Renault, N.; Reposeur, T.; Ritz, S.; Romani, R. W.; Roth, M.; Rousseau, R.; Roy, J.; Ruan, J.; Sartori, A.; Saz Parkinson, P. M.; Scargle, J. D.; Schulz, A.; Sgrò, C.; Shannon, R.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stappers, B. W.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Theureau, G.; Thompson, D. J.; Thorsett, S. E.; Tibaldo, L.; Tibolla, O.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Venter, C.; Vianello, G.; Vitale, V.; Wang, N.; Weltevrede, P.; Winer, B. L.; Wolff, M. T.; Wood, D. L.; Wood, K. S.; Wood, M.; Yang, Z.

    2013-09-19

    This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

  3. The second fermi large area telescope catalog of gamma-ray pulsars

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, A. A.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bhattacharyya, B.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burgay, M.; Burnett, T. H.; Busetto, G.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Camilo, F.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chaty, S.; Chaves, R. C. G.; Chekhtman, A.; Chen, A. W.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cognard, I.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D' Ammando, F.; de Angelis, A.; DeCesar, M. E.; De Luca, A.; den Hartog, P. R.; de Palma, F.; Dermer, C. D.; Desvignes, G.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Espinoza, C. M.; Falletti, L.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Freire, P. C. C.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gotthelf, E. V.; Grenier, I. A.; Grondin, M. -H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hessels, J.; Hewitt, J.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Jackson, M. S.; Janssen, G. H.; Jogler, T.; Jóhannesson, G.; Johnson, R. P.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Johnston, S.; Kamae, T.; Kataoka, J.; Keith, M.; Kerr, M.; Knödlseder, J.; Kramer, M.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Lyne, A. G.; Manchester, R. N.; Marelli, M.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; McLaughlin, M. A.; Mehault, J.; Michelson, P. F.; Mignani, R. P.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohno, M.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Perkins, J. S.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Pletsch, H. J.; Porter, T. A.; Possenti, A.; Rainò, S.; Rando, R.; Ransom, S. M.; Ray, P. S.; Razzano, M.; Rea, N.; Reimer, A.; Reimer, O.; Renault, N.; Reposeur, T.; Ritz, S.; Romani, R. W.; Roth, M.; Rousseau, R.; Roy, J.; Ruan, J.; Sartori, A.; Saz Parkinson, P. M.; Scargle, J. D.; Schulz, A.; Sgrò, C.; Shannon, R.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stappers, B. W.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Theureau, G.; Thompson, D. J.; Thorsett, S. E.; Tibaldo, L.; Tibolla, O.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Venter, C.; Vianello, G.; Vitale, V.; Wang, N.; Weltevrede, P.; Winer, B. L.; Wolff, M. T.; Wood, D. L.; Wood, K. S.; Wood, M.; Yang, Z.

    2013-09-19

    This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

  4. Fermi/LAT Observations of Swift/BAT Seyfert Galaxies: On the Contribution of Radio-Quiet Active Galactic Nuclei to the Extragalactic gamma-Ray Background

    Science.gov (United States)

    Teng, Stacy H.; Mushotzky, Richard F.; Sambruna, Rita M.; Davis, David S.; Reynolds, Christopher S.

    2011-01-01

    We present the analysis of 2.1 years of Fermi Large Area Telescope (LAT) data on 491 Seyfert galaxies detected by the Swift Burst Alert Telescope (BAT) survey. Only the two nearest objects, NGC 1068 and NGC 4945, which were identified in the Fermi first year catalog, are detected. Using Swift/BAT and radio 20 cm fluxes, we define a new radio-loudness parameter R(sub X,BAT) where radio-loud objects have logR(sub X,BAT) > -4.7. Based on this parameter, only radio-loud sources are detected by Fermi/LAT. An upper limit to the flux of the undetected sources is derived to be approx.2x10(exp -11) photons/sq cm/s, approximately seven times lower than the observed flux of NGC 1068. Assuming a median redshift of 0.031, this implies an upper limit to the gamma-ray (1-100 GeV) luminosity of BAT Seyfert galaxies with significant Fermi/LAT detections. A majority of these objects do not have Swift/BAT counterparts, but their possible optical counterparts include blazars, flat-spectrum radio quasars, and quasars.

  5. Directional dependence of binaural loudness

    DEFF Research Database (Denmark)

    Ellermeier, Wolfgang; Sivonen, Ville Pekka

    2006-01-01

    on binaural loudness summation, on the other hand, focuses on a highly artificial paradigm according to which unnatural combinations of sound pressure levels(such as monotic-diotic comparisons) are presented to listeners via headphones. In order to reconcile these two approaches, we recently started a series...... incidence angle, in order to relate the changes in actual at-ear exposure to the observed changes in loudness as a function of sound incidence. Combining the listening-test data with the physical measurements, an attempt was made to model the binaural summation underlying the directional loudness matches....

  6. The effect of loudness on the reverberance of music: reverberance prediction using loudness models.

    Science.gov (United States)

    Lee, Doheon; Cabrera, Densil; Martens, William L

    2012-02-01

    This study examines the auditory attribute that describes the perceived amount of reverberation, known as "reverberance." Listening experiments were performed using two signals commonly heard in auditoria: excerpts of orchestral music and western classical singing. Listeners adjusted the decay rate of room impulse responses prior to convolution with these signals, so as to match the reverberance of each stimulus to that of a reference stimulus. The analysis examines the hypothesis that reverberance is related to the loudness decay rate of the underlying room impulse response. This hypothesis is tested using computational models of time varying or dynamic loudness, from which parameters analogous to conventional reverberation parameters (early decay time and reverberation time) are derived. The results show that listening level significantly affects reverberance, and that the loudness-based parameters outperform related conventional parameters. Results support the proposed relationship between reverberance and the computationally predicted loudness decay function of sound in rooms. © 2012 Acoustical Society of America

  7. Reliability of procedures used for scaling loudness

    DEFF Research Database (Denmark)

    Jesteadt, Walt; Joshi, Suyash Narendra

    2013-01-01

    In this study, 16 normally-hearing listeners judged the loudness of 1000-Hz sinusoids using magnitude estimation (ME), magnitude production (MP), and categorical loudness scaling (CLS). Listeners in each of four groups completed the loudness scaling tasks in a different sequence on the first visit...... (ME, MP, CLS; MP, ME, CLS; CLS, ME, MP; CLS, MP, ME), and the order was reversed on the second visit. This design made it possible to compare the reliability of estimates of the slope of the loudness function across procedures in the same listeners. The ME data were well fitted by an inflected...... results were the most reproducible, they do not provide direct information about the slope of the loudness function because the numbers assigned to CLS categories are arbitrary. This problem can be corrected by using data from the other procedures to assign numbers that are proportional to loudness...

  8. POLARIZED EXTENDED Ly{alpha} EMISSION FROM A z = 2.3 RADIO GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    Humphrey, A. [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Vernet, J.; Fosbury, R. A. E. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Villar-Martin, M. [Centro de Astrobiologia (INTA-CSIC), Carretera de Ajalvir, km 4, E-28850 Torrejon de Ardoz, Madrid (Spain); Di Serego Alighieri, S. [INAF-Osservatorio Astrofisico di Arcetri, L.go E. Fermi 5, I-50125 Firenze (Italy); Cimatti, A., E-mail: andrew.humphrey@astro.up.pt [Dipartimento di Astronomia, Universita di Bologna, Via Ranzani 1, I-40127 Bologna (Italy)

    2013-05-01

    We present spatially resolved spectropolarimetric measurements of the 100 kpc scale gaseous environment of the z = 2.34 radio galaxy TXS 0211-122. The polarization level of the narrow Ly{alpha} emission is low centrally (P < 5%), but rises to P = 16.4% {+-} 4.6% in the eastern part of the nebula, indicating that the nebula is at least partly powered by the scattering of Ly{alpha} photons by H I. Not only is this the first detection of polarized Ly{alpha} around a radio-loud active galaxy, it is also the second detection to date for any kind of Ly{alpha} nebula. We also detect a pair of diametrically opposed UV continuum sources along the slit, at the outer edges of the Ly{alpha} nebula, which we suggest may be the limb of a dusty shell, related to the large-scale H I absorbers often associated with high-z radio galaxies.

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

    Science.gov (United States)

    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.

  10. CONSTRAINING RADIO EMISSION FROM MAGNETARS

    Energy Technology Data Exchange (ETDEWEB)

    Lazarus, P.; Kaspi, V. M.; Dib, R. [Department of Physics, Rutherford Physics Building, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Champion, D. J. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Hessels, J. W. T., E-mail: plazar@physics.mcgill.ca [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands)

    2012-01-10

    We report on radio observations of five magnetars and two magnetar candidates carried out at 1950 MHz with the Green Bank Telescope in 2006-2007. The data from these observations were searched for periodic emission and bright single pulses. Also, monitoring observations of magnetar 4U 0142+61 following its 2006 X-ray bursts were obtained. No radio emission was detected for any of our targets. The non-detections allow us to place luminosity upper limits of L{sub 1950} {approx}< 1.60 mJy kpc{sup 2} for periodic emission and L{sub 1950,single} {approx}< 7.6 Jy kpc{sup 2} for single pulse emission. These are the most stringent limits yet for the magnetars observed. The resulting luminosity upper limits together with previous results are discussed, as is the importance of further radio observations of radio-loud and radio-quiet magnetars.

  11. Reconfigurable Ultra-Low Power Miniaturized EVA Radio, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — EVA radio is an important integral part of lunar missions and beyond. To minimize power consumption and mass of an EVA radio, innovative solutions are needed for the...

  12. LOW-POWER RADIO GALAXIES IN THE DISTANT UNIVERSE: A SEARCH FOR FR I AT 1 < z < 2 IN THE COSMOS FIELD

    International Nuclear Information System (INIS)

    Chiaberge, Marco; Tremblay, Grant; Macchetto, F. Duccio; Sparks, W. B.; Capetti, Alessandro; Tozzi, Paolo

    2009-01-01

    We present a search for FR I radio galaxies between 1 < z < 2 in the COSMOS field. In absence of spectroscopic redshift measurements, the selection method is based on multiple steps which make use of both radio and optical constraints. The basic assumptions are that (1) the break in radio power between low-power FR Is and the more powerful FR IIs does not change with redshift, and (2) that the photometric properties of the host galaxies of low-power radio galaxies in the distant universe are similar to those of FR IIs in the same redshift bin, as is the case for nearby radio galaxies. We describe the results of our search, which yields 37 low-power radio galaxy candidates that are possibly FR Is. We show that a large fraction of these low-luminosity radio galaxies display a compact radio morphology that does not correspond to the FR I morphological classification. Furthermore, our objects are apparently associated with galaxies that show clear signs of interactions, at odds with the typical behavior observed in low-z FR I hosts. The compact radio morphology might imply that we are observing intrinsically small and possibly young objects that will eventually evolve into the giant FR Is we observe in the local universe. One of the objects appears as pointlike in Hubble Space Telescope (HST) images. This might belong to a population of FR I-QSOs, which however would represent a tiny minority of the overall population of high-z FR Is. As for the local FR Is, a large fraction of our objects are likely to be associated with groups or clusters, making them 'beacons' for high-redshift clusters of galaxies. Our search for candidate high-z FR Is we present in this paper constitutes a pilot study for objects to be observed with future high-resolution and high-sensitivity instruments such as the EVLA and ALMA in the radio band, HST/WFC3 in the optical and IR, James Webb Space Telescope in the IR, as well as future generation X-ray satellites.

  13. Evidence for Infrared-faint Radio Sources as z > 1 Radio-loud Active Galactic Nuclei

    Science.gov (United States)

    Huynh, Minh T.; Norris, Ray P.; Siana, Brian; Middelberg, Enno

    2010-02-01

    Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 μm) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the spectral energy distribution of these objects shows that they are consistent with high-redshift (z >~ 1) active galactic nuclei.

  14. Perceptual weights for loudness reflect central spectral processing

    DEFF Research Database (Denmark)

    Joshi, Suyash Narendra; Jesteadt, Walt

    2011-01-01

    Weighting patterns for loudness obtained using the reverse correlation method are thought to reveal the relative contributions of different frequency regions to total loudness, the equivalent of specific loudness. Current models of loudness assume that specific loudness is determined by peripheral...... processes such as compression and masking. Here we test this hypothesis using 20-tone harmonic complexes (200Hz f0, 200 to 4000Hz, 250 ms, 65 dB/Component) added in opposite phase relationships (Schroeder positive and negative). Due to the varying degree of envelope modulations, these time-reversed harmonic...... processes and reflect a central frequency weighting template....

  15. Mental imagery for musical changes in loudness

    Directory of Open Access Journals (Sweden)

    Freya eBailes

    2012-12-01

    Full Text Available Musicians imagine music during mental rehearsal, when reading from a score, and while composing. An important characteristic of music is its temporality. Among the parameters that vary through time is sound intensity, perceived as patterns of loudness. Studies of mental imagery for melodies (i.e. pitch and rhythm show interference from concurrent musical pitch and verbal tasks, but how we represent musical changes in loudness is unclear. Theories suggest that our perceptions of loudness change relate to our perceptions of force or effort, implying a motor representation. An experiment was conducted to investigate the modalities that contribute to imagery for loudness change. Musicians performed a within-subjects loudness change recall task, comprising 48 trials. First, participants heard a musical scale played with varying patterns of loudness, which they were asked to remember. There followed an empty interval of 8 seconds (nil distractor control, or the presentation of a series of 4 sine tones, or 4 visual letters or 3 conductor gestures, also to be remembered. Participants then saw an unfolding score of the notes of the scale, during which they were to imagine the corresponding scale in their mind while adjusting a slider to indicate the imagined changes in loudness. Finally, participants performed a recognition task of the tone, letter or gesture sequence. Based on the motor hypothesis, we predicted that observing and remembering conductor gestures would impair loudness change scale recall, while observing and remembering tone or letter string stimuli would not. Results support this prediction, with loudness change recalled less accurately in the gestures condition than in the control condition. An effect of musical training suggests that auditory and motor imagery ability may be closely related to domain expertise.

  16. Hearing aid processing of loud speech and noise signals: Consequences for loudness perception and listening comfort

    DEFF Research Database (Denmark)

    Schmidt, Erik

    2007-01-01

    sounds, has found that both normal-hearing and hearing-impaired listeners prefer loud sounds to be closer to the most comfortable loudness-level, than suggested by common non-linear fitting rules. During this project, two listening experiments were carried out. In the first experiment, hearing aid users......Hearing aid processing of loud speech and noise signals: Consequences for loudness perception and listening comfort. Sound processing in hearing aids is determined by the fitting rule. The fitting rule describes how the hearing aid should amplify speech and sounds in the surroundings......, such that they become audible again for the hearing impaired person. The general goal is to place all sounds within the hearing aid users’ audible range, such that speech intelligibility and listening comfort become as good as possible. Amplification strategies in hearing aids are in many cases based on empirical...

  17. Automatic loudness control in short-form content for broadcasting.

    Science.gov (United States)

    Pires, Leandro da S; Vieira, Maurílio N; Yehia, Hani C

    2017-03-01

    During the early years of the International Telecommunication Union (ITU) loudness calculation standard for sound broadcasting [ITU-R (2006), Rec. BS Series, 1770], the need for additional loudness descriptors to evaluate short-form content, such as commercials and live inserts, was identified. This work proposes a loudness control scheme to prevent loudness jumps, which can bother audiences. It employs short-form content audio detection and dynamic range processing methods for the maximum loudness level criteria. Detection is achieved by combining principal component analysis for dimensionality reduction and support vector machines for binary classification. Subsequent processing is based on short-term loudness integrators and Hilbert transformers. The performance was assessed using quality classification metrics and demonstrated through a loudness control example.

  18. Alcohol, young people and the media: a study of radio output in six radio stations in England.

    Science.gov (United States)

    Daykin, N; Irwin, R; Kimberlee, R; Orme, J; Plant, M; McCarron, L; Rahbari, M

    2009-03-01

    This research investigated the representation of alcohol in radio output. The study was prompted by concerns that media output might be part of a developing culture of excessive drinking among young people. Alcohol comments were examined across six radio stations in England. 1200 h of weekend output was screened and the sampling frame included periods when references to alcohol would be expected, such as the Christmas period. Statistical analysis identified the volume and proportion of comments, whereas qualitative analysis explored these in more depth, focusing on the themes and discourses surrounding alcohol talk. Of 703 alcohol comments identified, 244 involved presenters. The volume of comments about alcohol varied between stations, being lower on BBC than on commercial stations and being influenced by music genre. Seventy-three percent of comments initiated by presenters, compared with 45% of comments from all sources, encouraged drinking. The majority of comments by presenters support drinking in relation to partying and socializing. Alcohol comments seem to create identity for programmes and forge connections between presenters and audiences, although some presenters achieve this without mentioning drinking. The assumption that alcohol is necessary to have a good time is seldom directly challenged. While it may be unsurprising that much of this content reflected themes of weekend drinking and partying, the study suggests that alcohol comments play a particular role in marketing and branding of radio output. Comments about alcohol are shaped by broadcasting conventions that make it difficult to challenge discourses surrounding excessive drinking. Further research is needed on the influence that radio output may have on drinking behaviour among young people.

  19. LOFAR-Boötes: properties of high- and low-excitation radio galaxies at 0.5 < z < 2.0

    Science.gov (United States)

    Williams, W. L.; Calistro Rivera, G.; Best, P. N.; Hardcastle, M. J.; Röttgering, H. J. A.; Duncan, K. J.; de Gasperin, F.; Jarvis, M. J.; Miley, G. K.; Mahony, E. K.; Morabito, L. K.; Nisbet, D. M.; Prandoni, I.; Smith, D. J. B.; Tasse, C.; White, G. J.

    2018-04-01

    This paper presents a study of the redshift evolution of radio-loud active galactic nuclei (AGN) as a function of the properties of their galaxy hosts in the Boötes field. To achieve this we match low-frequency radio sources from deep 150-MHz LOFAR (LOw Frequency ARray) observations to an I-band-selected catalogue of galaxies, for which we have derived photometric redshifts, stellar masses, and rest-frame colours. We present spectral energy distribution (SED) fitting to determine the mid-infrared AGN contribution for the radio sources and use this information to classify them as high- versus low-excitation radio galaxies (HERGs and LERGs) or star-forming galaxies. Based on these classifications, we construct luminosity functions for the separate redshift ranges going out to z = 2. From the matched radio-optical catalogues, we select a sub-sample of 624 high power (P150 MHz > 1025 W Hz-1) radio sources between 0.5 ≤ z negative evolution of the LERG luminosity functions over this redshift range, is consistent with LERGs being fuelled by hot gas in quiescent galaxies.

  20. Powerful Radio Burst Indicates New Astronomical Phenomenon

    Science.gov (United States)

    2007-09-01

    Astronomers studying archival data from an Australian radio telescope have discovered a powerful, short-lived burst of radio waves that they say indicates an entirely new type of astronomical phenomenon. Region of Strong Radio Burst Visible-light (negative greyscale) and radio (contours) image of Small Magellanic Cloud and area where burst originated. CREDIT: Lorimer et al., NRAO/AUI/NSF Click on image for high-resolution file ( 114 KB) "This burst appears to have originated from the distant Universe and may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole," said Duncan Lorimer, Assistant Professor of Physics at West Virginia University (WVU) and the National Radio Astronomy Observatory (NRAO). The research team led by Lorimer consists of Matthew Bailes of Swinburne University in Australia, Maura McLaughlin of WVU and NRAO, David Narkevic of WVU, and Fronefield Crawford of Franklin and Marshall College in Lancaster, Pennsylvania. The astronomers announced their findings in the September 27 issue of the online journal Science Express. The startling discovery came as WVU undergraduate student David Narkevic re-analyzed data from observations of the Small Magellanic Cloud made by the 210-foot Parkes radio telescope in Australia. The data came from a survey of the Magellanic Clouds that included 480 hours of observations. "This survey had sought to discover new pulsars, and the data already had been searched for the type of pulsating signals they produce," Lorimer said. "We re-examined the data, looking for bursts that, unlike the usual ones from pulsars, are not periodic," he added. The survey had covered the Magellanic Clouds, a pair of small galaxies in orbit around our own Milky Way Galaxy. Some 200,000 light-years from Earth, the Magellanic Clouds are prominent features in the Southern sky. Ironically, the new discovery is not part of these galaxies, but rather is much more distant

  1. Loudness estimation of simultaneous sources using beamforming

    DEFF Research Database (Denmark)

    Song, Woo-keun; Ellermeier, Wolfgang; Minnaar, Pauli

    2006-01-01

    An algorithm is proposed for estimating the loudness of several simultaneous sound sources by means of microphone-array beamforming. The algorithm is derived from two listening experiments in which the loudness of two simultaneous sounds (narrow-band noises with 1-kHz and 3.15-kHz center...... frequencies) was matched to a single sound (2-kHz narrow-band noise). The simultaneous sounds were presented from either one sound source or two spatially separated sources, whereas the single sound was presented from the frontal direction. The results indicate that overall loudness can be calculated...... by summing the loudnesses of the individual sources according to a simple psychophysical relationship....

  2. Radio evolution of young supernova remnants

    International Nuclear Information System (INIS)

    Shirkey, R.C. Jr.

    1976-01-01

    A one dimensional spherically symmetric magnetohydrodynamic code was developed to describe the evolution of the dynamical and radio properties of young supernova remnants. The code contains subroutines which treat the development of Rayleigh-Taylor instabilities wherever they arise in the remnant. Under the assumption of quasi-stationary equilibrium (dynamical changes considered slow in comparison to the time it takes the instability to achieve equilibrium) determined that the velocity of the instability is W approximately (a lambda)/sup 1 / 2 /, where a is the Rayleigh-Taylor acceleration and lambda is the wavelength of the instability. Subsequent processing of the kinetic energy of expansion, through turbulence, resulted in an increase in temperature and magnetic field strength. The model was used to analyze instability effects of density inhomogeneities in the interstellar medium on magnetic field amplification. A model was constructed for Cassiopeia A which gave good agreement with the measured dynamics, radio structure, and secular flux density decrease for the remnant. In order to compare observation with theory a computer routine was written that convolves the surface brightness at the source. The resultant convolved surface brightness graph is in good agreement with Rosenberg's observed ''model profile;'' differences between the graphs can be attributed to the asymmetric expansion of Cassiopeia A

  3. The Origin of the Infrared Emission in Radio Galaxies : III. Analysis of 3CRR Objects

    NARCIS (Netherlands)

    Dicken, D.; Tadhunter, C.; Axon, D.; Robinson, A.; Morganti, R.; Kharb, P.

    2010-01-01

    We present Spitzer photometric data for a complete sample of 19 low-redshift (z <0.1) 3CRR radio galaxies as part of our efforts to understand the origin of the prodigious mid-to far-infrared (MFIR) emission from radio-loud active galactic nuclei (AGNs). Our results show a correlation between AGN

  4. Musical expertise and the ability to imagine loudness.

    Directory of Open Access Journals (Sweden)

    Laura Bishop

    Full Text Available Most perceived parameters of sound (e.g. pitch, duration, timbre can also be imagined in the absence of sound. These parameters are imagined more veridically by expert musicians than non-experts. Evidence for whether loudness is imagined, however, is conflicting. In music, the question of whether loudness is imagined is particularly relevant due to its role as a principal parameter of performance expression. This study addressed the hypothesis that the veridicality of imagined loudness improves with increasing musical expertise. Experts, novices and non-musicians imagined short passages of well-known classical music under two counterbalanced conditions: 1 while adjusting a slider to indicate imagined loudness of the music and 2 while tapping out the rhythm to indicate imagined timing. Subtests assessed music listening abilities and working memory span to determine whether these factors, also hypothesised to improve with increasing musical expertise, could account for imagery task performance. Similarity between each participant's imagined and listening loudness profiles and reference recording intensity profiles was assessed using time series analysis and dynamic time warping. The results suggest a widespread ability to imagine the loudness of familiar music. The veridicality of imagined loudness tended to be greatest for the expert musicians, supporting the predicted relationship between musical expertise and musical imagery ability.

  5. Musical expertise and the ability to imagine loudness.

    Science.gov (United States)

    Bishop, Laura; Bailes, Freya; Dean, Roger T

    2013-01-01

    Most perceived parameters of sound (e.g. pitch, duration, timbre) can also be imagined in the absence of sound. These parameters are imagined more veridically by expert musicians than non-experts. Evidence for whether loudness is imagined, however, is conflicting. In music, the question of whether loudness is imagined is particularly relevant due to its role as a principal parameter of performance expression. This study addressed the hypothesis that the veridicality of imagined loudness improves with increasing musical expertise. Experts, novices and non-musicians imagined short passages of well-known classical music under two counterbalanced conditions: 1) while adjusting a slider to indicate imagined loudness of the music and 2) while tapping out the rhythm to indicate imagined timing. Subtests assessed music listening abilities and working memory span to determine whether these factors, also hypothesised to improve with increasing musical expertise, could account for imagery task performance. Similarity between each participant's imagined and listening loudness profiles and reference recording intensity profiles was assessed using time series analysis and dynamic time warping. The results suggest a widespread ability to imagine the loudness of familiar music. The veridicality of imagined loudness tended to be greatest for the expert musicians, supporting the predicted relationship between musical expertise and musical imagery ability.

  6. FERMI/LAT OBSERVATIONS OF SWIFT/BAT SEYFERT GALAXIES: ON THE CONTRIBUTION OF RADIO-QUIET ACTIVE GALACTIC NUCLEI TO THE EXTRAGALACTIC γ-RAY BACKGROUND

    International Nuclear Information System (INIS)

    Teng, Stacy H.; Mushotzky, Richard F.; Reynolds, Christopher S.; Sambruna, Rita M.; Davis, David S.

    2011-01-01

    We present the analysis of 2.1 years of Fermi Large Area Telescope (LAT) data on 491 Seyfert galaxies detected by the Swift Burst Alert Telescope (BAT) survey. Only the two nearest objects, NGC 1068 and NGC 4945, which were identified in the Fermi first year catalog, are detected. Using Swift/BAT and radio 20 cm fluxes, we define a new radio-loudness parameter R X,BAT where radio-loud objects have log R X,BAT > –4.7. Based on this parameter, only radio-loud sources are detected by Fermi/LAT. An upper limit to the flux of the undetected sources is derived to be ∼2 × 10 –11 photons cm –2 s –1 , approximately seven times lower than the observed flux of NGC 1068. Assuming a median redshift of 0.031, this implies an upper limit to the γ-ray (1-100 GeV) luminosity of ∼ 41 erg s –1 . In addition, we identified 120 new Fermi/LAT sources near the Swift/BAT Seyfert galaxies with significant Fermi/LAT detections. A majority of these objects do not have Swift/BAT counterparts, but their possible optical counterparts include blazars, flat-spectrum radio quasars, and quasars.

  7. The nature of extragalactic radio-jets from high-resolution radio-interferometric observations

    OpenAIRE

    Perucho, Manel

    2014-01-01

    Extragalactic jets are a common feature of radio-loud active galaxies. The nature of the observed jets in relation to the bulk flow is still unclear. In particular it is not clear whether the observations of parsec-scale jets using the very long baseline interferometric technique (VLBI) reveal wave-like structures that develop and propagate along the jet, or trace the jet flow itself. In this contribution I review the evidence collected during the last years showing that the ridge-lines of he...

  8. Cognitive radio adaptation for power consumption minimization using biogeography-based optimization

    International Nuclear Information System (INIS)

    Qi Pei-Han; Zheng Shi-Lian; Yang Xiao-Niu; Zhao Zhi-Jin

    2016-01-01

    Adaptation is one of the key capabilities of cognitive radio, which focuses on how to adjust the radio parameters to optimize the system performance based on the knowledge of the radio environment and its capability and characteristics. In this paper, we consider the cognitive radio adaptation problem for power consumption minimization. The problem is formulated as a constrained power consumption minimization problem, and the biogeography-based optimization (BBO) is introduced to solve this optimization problem. A novel habitat suitability index (HSI) evaluation mechanism is proposed, in which both the power consumption minimization objective and the quality of services (QoS) constraints are taken into account. The results show that under different QoS requirement settings corresponding to different types of services, the algorithm can minimize power consumption while still maintaining the QoS requirements. Comparison with particle swarm optimization (PSO) and cat swarm optimization (CSO) reveals that BBO works better, especially at the early stage of the search, which means that the BBO is a better choice for real-time applications. (paper)

  9. Influence of radio frequency power on structure and ionic

    Indian Academy of Sciences (India)

    Lithium phosphorus oxynitride (LiPON) thin films as solid electrolytes were prepared by radio frequency magnetron sputtering of a Li3PO4 target in ambient nitrogen atmosphere. The influence of radio frequency (rf) power on the structure and the ionic conductivity of LiPON thin films has been investigated. The morphology ...

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

    International Nuclear Information System (INIS)

    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

  11. Radio Astronomers Get Their First Glimpse of Powerful Solar Storm

    Science.gov (United States)

    2001-08-01

    Astronomers have made the first radio-telescope images of a powerful coronal mass ejection on the Sun, giving them a long-sought glimpse of hitherto unseen aspects of these potentially dangerous events. "These observations are going to provide us with a new and unique tool for deciphering the mechanisms of coronal mass ejections and how they are related to other solar events," said Tim Bastian, an astronomer at the National Science Foundation's National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia. Radio image of coronal mass ejection; circle indicates the size and location of the Sun. White dots are where radio spectral measurements were made. Bastian, along with Monique Pick, Alain Kerdraon and Dalmiro Maia of the Paris Observatory, and Angelos Vourlidas of the Naval Research Laboratory in Washington, D.C., used a solar radio telescope in Nancay, France, to study a coronal mass ejection that occurred on April 20, 1998. Their results will be published in the September 1 edition of the Astrophysical Journal Letters. Coronal mass ejections are powerful magnetic explosions in the Sun's corona, or outer atmosphere, that can blast billions of tons of charged particles into interplanetary space at tremendous speeds. If the ejection is aimed in the direction of Earth, the speeding particles interact with our planet's magnetic field to cause auroral displays, radio-communication blackouts, and potentially damage satellites and electric-power systems. "Coronal mass ejections have been observed for many years, but only with visible-light telescopes, usually in space. While previous radio observations have provided us with powerful diagnostics of mass ejections and associated phenomena in the corona, this is the first time that one has been directly imaged in wavelengths other than visible light," Bastian said. "These new data from the radio observations give us important clues about how these very energetic events work," he added. The radio images show an

  12. Morphology and power of radio sources

    International Nuclear Information System (INIS)

    Scheuer, P.A.G.

    1982-01-01

    The author discusses two points: 1. Observations suggest that the hot-spots move about either because the beam precesses or more discontinuously, as in sources like 3C351 that have multiple hot-spots. The natural interpretation is that the hot-spot at the end of the beam slides over the inner surface of a 'cavity' filled with very hot dilute ex-hot-spot material, extending the cavity at various places at different times. 2. Most of the radio emission of most really powerful radio sources comes from their hot spots. Contrariwise, straightforward equipartition calculations on models lead to at least as much emission from the 'cavity' as from the hot-spots. (Auth.)

  13. Amplitude modulation reduces loudness adaptation to high-frequency tones.

    Science.gov (United States)

    Wynne, Dwight P; George, Sahara E; Zeng, Fan-Gang

    2015-07-01

    Long-term loudness perception of a sound has been presumed to depend on the spatial distribution of activated auditory nerve fibers as well as their temporal firing pattern. The relative contributions of those two factors were investigated by measuring loudness adaptation to sinusoidally amplitude-modulated 12-kHz tones. The tones had a total duration of 180 s and were either unmodulated or 100%-modulated at one of three frequencies (4, 20, or 100 Hz), and additionally varied in modulation depth from 0% to 100% at the 4-Hz frequency only. Every 30 s, normal-hearing subjects estimated the loudness of one of the stimuli played at 15 dB above threshold in random order. Without any amplitude modulation, the loudness of the unmodulated tone after 180 s was only 20% of the loudness at the onset of the stimulus. Amplitude modulation systematically reduced the amount of loudness adaptation, with the 100%-modulated stimuli, regardless of modulation frequency, maintaining on average 55%-80% of the loudness at onset after 180 s. Because the present low-frequency amplitude modulation produced minimal changes in long-term spectral cues affecting the spatial distribution of excitation produced by a 12-kHz pure tone, the present result indicates that neural synchronization is critical to maintaining loudness perception over time.

  14. Radio Jets Clearing the Way Through a Galaxy: Watching Feedback in Action in the Seyfert Galaxy IC 5063

    NARCIS (Netherlands)

    Morganti, R.; Oosterloo, T. A.; Oonk, J. B. R.; Frieswijk, W.; Tadhunter, C. N.

    2015-01-01

    High-resolution (0.5 arcsec) CO(2-1) observations performed with the Atacama Large Millimetre/submillimetre Array have been used to trace the kinematics of the molecular gas in the Seyfert 2 galaxy{IC 5063}. Although one of the most radio-loud Seyfert galaxy, IC 5063 is a relatively weak radio

  15. 3C 254: the alignment effect and unification schemes

    Science.gov (United States)

    Bremer, M. N.

    1997-01-01

    3C 254 is a radio-loud quasar at z=0.734. Optical line and continuum emission from the underlying galaxy is clearly extended and aligned with the radio axis; the object shows the so-called `alignment effect' which is often seen in powerful radio galaxies. This is the clearest case yet of the continuum alignment effect in a radio-loud quasar. The object is one of the most lobe-dominated 3C quasars; the significance of the aligned emission in this source is discussed in terms of orientation-based unification schemes for radio-loud quasars and radio galaxies. 3C 254 is a very asymmetric radio source and it is shown that the radio structure on the side with the shortest nucleus-hotspot distance is interacting with the emission-line gas surrounding the quasar. It is also shown that the quasar is surrounded by an overdensity of faint objects, consistent with a cluster or group of galaxies around the object.

  16. Supplying the power requirements to a sensor network using radio frequency power transfer.

    Science.gov (United States)

    Percy, Steven; Knight, Chris; Cooray, Francis; Smart, Ken

    2012-01-01

    Wireless power transmission is a method of supplying power to small electronic devices when there is no wired connection. One way to increase the range of these systems is to use a directional transmitting antenna, the problem with this approach is that power can only be transmitted through a narrow beam and directly forward, requiring the transmitter to always be aligned with the sensor node position. The work outlined in this article describes the design and testing of an autonomous radio frequency power transfer system that is capable of rotating the base transmitter to track the position of sensor nodes and transferring power to that sensor node. The system's base station monitors the node's energy levels and forms a charge queue to plan charging order and maintain energy levels of the nodes. Results show a radio frequency harvesting circuit with a measured S11 value of -31.5 dB and a conversion efficiency of 39.1%. Simulation and experimentation verified the level of power transfer and efficiency. The results of this work show a small network of three nodes with different storage types powered by a central base node.

  17. Supplying the Power Requirements to a Sensor Network Using Radio Frequency Power Transfer

    Directory of Open Access Journals (Sweden)

    Steven Percy

    2012-06-01

    Full Text Available Wireless power transmission is a method of supplying power to small electronic devices when there is no wired connection. One way to increase the range of these systems is to use a directional transmitting antenna, the problem with this approach is that power can only be transmitted through a narrow beam and directly forward, requiring the transmitter to always be aligned with the sensor node position. The work outlined in this article describes the design and testing of an autonomous radio frequency power transfer system that is capable of rotating the base transmitter to track the position of sensor nodes and transferring power to that sensor node. The system’s base station monitors the node’s energy levels and forms a charge queue to plan charging order and maintain energy levels of the nodes. Results show a radio frequency harvesting circuit with a measured S11 value of −31.5 dB and a conversion efficiency of 39.1%. Simulation and experimentation verified the level of power transfer and efficiency. The results of this work show a small network of three nodes with different storage types powered by a central base node.

  18. Acoustical topology optimization of Zwicker's loudness with Padé approximation

    DEFF Research Database (Denmark)

    Kook, Junghwan; Jensen, Jakob Søndergaard; Wang, Semyung

    2013-01-01

    Zwicker's loudness is a conventional standard index for measuring human hearing annoyance and has been widely considered in many industrial fields for noise evaluations. The calculation of Zwicker's loudness, which is needed for a wide range of frequency responses with a fine frequency resolution......, this approach imposes prohibitively high computational costs. In this research, we propose a computationally-efficient approach to resolve the computational issue in the computation and optimization of Zwicker's loudness. We present an efficient approach which combines the finite element method (FEM......) with the Padé approximation (PA) procedure for obtaining Zwicker's loudness and for applying it in a gradient-based acoustical topology optimization procedure applied to the design of acoustic devices to minimize Zwicker's loudness. In this respect, the calculation of Zwicker's loudness is represented by the PA...

  19. Optical generation of radio-frequency power

    International Nuclear Information System (INIS)

    Hietala, V.M.; Vawter, G.A.; Brennan, T.M.; Hammons, B.E.; Meyer, W.J.

    1994-11-01

    An optical technique for high-power radio-frequency (RF) signal generation is described. The technique uses a unique photodetector based on a traveling-wave design driven by an appropriately modulated light source. The traveling-wave photodetector (TWPD) exhibits simultaneously a theoretical quantum efficiency approaching 100 % and a very large electrical bandwidth. Additionally, it is capable of dissipating the high-power levels required for the RF generation technique. The modulated light source is formed by either the beating together of two lasers or by the direct modulation of a light source. A system example is given which predicts RF power levels of 100's of mW's at millimeter wave frequencies with a theoretical ''wall-plug'' efficiency approaching 34%

  20. Perceived loudness of spatially distributed sound sources

    DEFF Research Database (Denmark)

    Song, Woo-keun; Ellermeier, Wolfgang; Minnaar, Pauli

    2005-01-01

    psychoacoustic attributes into account. Therefore, a method for deriving loudness maps was developed in an earlier study [Song, Internoise2004, paper 271]. The present experiment investigates to which extent perceived loudness depends on the distribution of individual sound sources. Three loudspeakers were...... positioned 1.5 m from the centre of the listener’s head, one straight ahead, and two 10 degrees to the right and left, respectively. Six participants matched the loudness of either one, or two simultaneous sounds (narrow-band noises with 1-kHz, and 3.15-kHz centre frequencies) to a 2-kHz, 60-dB SPL narrow......-band noise placed in the frontal loudspeaker. The two sounds were either originating from the central speaker, or from the two offset loudspeakers. It turned out that the subjects perceived the noises to be softer when they were distributed in space. In addition, loudness was calculated from the recordings...

  1. Rectifier analysis for radio frequency energy harvesting and power transport

    NARCIS (Netherlands)

    Keyrouz, S.; Visser, H.J.; Tijhuis, A.G.

    2012-01-01

    Wireless Power Transmission (WPT) is an attractive powering method for wireless sensor nodes, battery-less sensors, and Radio-Frequency Identification (RFID) tags. The key element on the receiving side of a WPT system is the rectifying antenna (rectenna) which captures the electromagnetic power and

  2. Individual and contextual variation in Thomas langur male loud calls

    NARCIS (Netherlands)

    Wich, S.A.; Koski, S.; Vries, Han de; Schaik, Carel P. van

    2003-01-01

    Individual and contextual differences in male loud calls of wild Thomas langurs (Presbytis thomasi) were studied in northern Sumatra, Indonesia. Loud calls were given in the following contexts: morning calls, vocal responses to other groups, between-group encounter calls and alarmcalls. Loud

  3. The B3-VLA CSS sample. VIII. New optical identifications from the Sloan Digital Sky Survey The ultraviolet-optical spectral energy distribution of the young radio sources

    Science.gov (United States)

    Fanti, C.; Fanti, R.; Zanichelli, A.; Dallacasa, D.; Stanghellini, C.

    2011-04-01

    Context. Compact steep-spectrum radio sources and giga-hertz peaked spectrum radio sources (CSS/GPS) are generally considered to be mostly young radio sources. In recent years we studied at many wavelengths a sample of these objects selected from the B3-VLA catalog: the B3-VLA CSS sample. Only ≈60% of the sources were optically identified. Aims: We aim to increase the number of optical identifications and study the properties of the host galaxies of young radio sources. Methods: We cross-correlated the CSS B3-VLA sample with the Sloan Digital Sky Survey (SDSS), DR7, and complemented the SDSS photometry with available GALEX (DR 4/5 and 6) and near-IR data from UKIRT and 2MASS. Results: We obtained new identifications and photometric redshifts for eight faint galaxies and for one quasar and two quasar candidates. Overall we have 27 galaxies with SDSS photometry in five bands, for which we derived the ultraviolet-optical spectral energy distribution (UV-O-SED). We extended our investigation to additional CSS/GPS selected from the literature. Most of the galaxies show an excess of ultra-violet (UV) radiation compared with the UV-O-SED of local radio-quiet ellipticals. We found a strong dependence of the UV excess on redshift and analyzed it assuming that it is generated either from the nucleus (hidden quasar) or from a young stellar population (YSP). We also compare the UV-O-SEDs of our CSS/GPS sources with those of a selection of large size (LSO) powerful radio sources from the literature. Conclusions: If the major process of the UV excess is caused by a YSP, our conclusion is that it is the result of the merger process that also triggered the onset of the radio source with some time delay. We do not see evidence for a major contribution from a YSP triggered by the radio sources itself. Appendices A-G are only available in electronic form at http://www.aanda.org

  4. RADIO-SELECTED QUASARS IN THE SLOAN DIGITAL SKY SURVEY

    International Nuclear Information System (INIS)

    McGreer, Ian D.; Helfand, David J.; White, Richard L.

    2009-01-01

    We have conducted a pilot survey for z > 3.5 quasars by combining the FIRST radio survey with the Sloan Digital Sky Survey (SDSS). While SDSS already targets FIRST sources for spectroscopy as quasar candidates, our survey includes fainter quasars and greatly improves the discovery rate by using strict astrometric criteria for matching the radio and optical positions. Our method allows for selection of high-redshift quasars with less color bias than with optical selection, as using radio selection essentially eliminates stellar contamination. We report the results of spectroscopy for 45 candidates, including 29 quasars in the range 0.37 3.5. We compare quasars selected using radio and optical criteria, and find that radio-selected quasars have a much higher fraction of moderately reddened objects. We derive a radio-loud quasar luminosity function at 3.5 < z < 4.0, and find that it is in good agreement with expectations from prior SDSS results.

  5. Radio and Gamma-Ray Monitoring of Strongly Lensed Quasars and Blazars

    NARCIS (Netherlands)

    Rumbaugh, Nick; Fassnacht, Chris; McKean, John; Koopmans, Leon; Auger, Matthew; Suyu, Sherry; Marshall, Philip J.

    2015-01-01

    We observed six strongly lensed, radio-loud quasars (MG 0414+0534, CLASS B0712+472, JVAS B1030+074, CLASS B1127+385, CLASS B1152+199, and JVAS B1938+666) in order to identify systems suitable for measuring cosmological parameters using time delays between their multiple images. Two separate

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. The Structure and Function of Male Thomas Langur Loud Calls

    NARCIS (Netherlands)

    Wich, Serge Alexander

    2002-01-01

    This study has addressed the acoustical structure of male loud calls and their function in Thomas langur social organisation. Thomas langurs are medium sized primate that lives in Sumatra, Indonesia. Ome of the characteristics of this species is the loud call of males. Several functions for loud

  9. The effects of music tempo and loudness level on treadmill exercise.

    Science.gov (United States)

    Edworthy, Judy; Waring, Hannah

    2006-12-15

    This study examined the effects of loudness and tempo of background music on exercise performance. A total of 30 volunteers performed five 10-min exercise sessions on a treadmill. The music listened to whilst exercising was either fast/loud, fast/quiet, slow/loud, slow/quiet or absent. Measures of running speed, heart rate, perceived exertion and affect were taken. Significant effects and interactions were found for running speed and heart rate across the different music tempo and loudness levels. More positive affect was observed during the music condition in comparison to the 'no music' condition. No significant differences for perceived exertion were found across conditions. These results confirm that fast, loud music might be played to enhance optimal exercising, and show how loudness and tempo interact.

  10. The infrared medium-deep survey. II. How to trigger radio AGNs? Hints from their environments

    Energy Technology Data Exchange (ETDEWEB)

    Karouzos, Marios; Im, Myungshin; Kim, Jae-Woo; Lee, Seong-Kook; Jeon, Yiseul; Choi, Changsu; Hong, Jueun; Hyun, Minhee; Jun, Hyunsung David; Kim, Dohyeong; Kim, Yongjung; Kim, Ji Hoon; Kim, Duho; Park, Won-Kee; Taak, Yoon Chan; Yoon, Yongmin [CEOU—Astronomy Program, Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Chapman, Scott [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia (Canada); Pak, Soojong [School of Space Research, Kyung Hee University, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Edge, Alastair, E-mail: mkarouzos@astro.snu.ac.kr [Department of Physics, University of Durham, South Road, Durham, DH1 3LE (United Kingdom)

    2014-12-10

    Activity at the centers of galaxies, during which the central supermassive black hole is accreting material, is nowadays accepted to be rather ubiquitous and most probably a phase of every galaxy's evolution. It has been suggested that galactic mergers and interactions may be the culprits behind the triggering of nuclear activity. We use near-infrared data from the new Infrared Medium-Deep Survey and the Deep eXtragalactic Survey of the VIMOS-SA22 field and radio data at 1.4 GHz from the FIRST survey and a deep Very Large Array survey to study the environments of radio active galactic nuclei (AGNs) over an area of ∼25 deg{sup 2} and down to a radio flux limit of 0.1 mJy and a J-band magnitude of 23 mag AB. Radio AGNs are predominantly found in environments similar to those of control galaxies at similar redshift, J-band magnitude, and (M{sub u} – M{sub r} ) rest-frame color. However, a subpopulation of radio AGNs is found in environments up to 100 times denser than their control sources. We thus preclude merging as the dominant triggering mechanism of radio AGNs. By fitting the broadband spectral energy distribution of radio AGNs in the least and most dense environments, we find that those in the least dense environments show higher radio-loudness, higher star formation efficiencies, and higher accretion rates, typical of the so-called high-excitation radio AGNs. These differences tend to disappear at z > 1. We interpret our results in terms of a different triggering mechanism for these sources that is driven by mass loss through winds of young stars created during the observed ongoing star formation.

  11. Radio frequency powering of microelectronic sensor modules

    Energy Technology Data Exchange (ETDEWEB)

    Boegel, Gerd vom; Meyer, Frederic; Kemmerling, Martin [Fraunhofer-Institut fuer Mikroelektronische Schaltungen und Systeme, Duisburg (Germany)

    2013-03-01

    In RFID applications the power supply of transponders via electromagnetic field is state-of-the-art. In this presentation the use of electromagnetic energy will be discussed for the operation of sensor modules. Starting with the question, whether the omnipresent radiation from power supply networks, radio transmitters, and mobile phone base stations is useable (energy harvesting), the feasibility of the operation of self-sufficient sensor modules is explained. Ancillary conditions of typical applications (e.g. operating range) and technology are considered. (orig.)

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

    Science.gov (United States)

    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.

  13. Fast radio bursts as giant pulses from young rapidly rotating pulsars

    Science.gov (United States)

    Lyutikov, Maxim; Burzawa, Lukasz; Popov, Sergei B.

    2016-10-01

    We discuss possible association of fast radio bursts (FRBs) with supergiant pulses emitted by young pulsars (ages ˜ tens to hundreds of years) born with regular magnetic field but very short - few milliseconds - spin periods. We assume that FRBs are extra-Galactic events coming from distances d ≲ 100 Mpc and that most of the dispersion measure (DM) comes from the material in the freshly ejected SNR shell. We then predict that for a given burst the DM should decrease with time and that FRBs are not expected to be seen below ˜300 MHz due to free-free absorption in the expanding ejecta. A supernova might have been detected years before the burst; FRBs are mostly associated with star-forming galaxies. The model requires that some pulsars are born with very fast spins, of the order of few milliseconds. The observed distribution of spin-down powers dot{E} in young energetic pulsars is consistent with equal birth rate per decade of dot{E}. Accepting this injection distribution and scaling the intrinsic brightness of FRBs with dot{E}, we predict the following properties of a large sample of FRBs: (I) the brightest observed events come from a broad distribution in distances; (II) for repeating bursts brightness either remains nearly constant (if the spin-down time is longer than the age of the pulsar) or decreases with time otherwise; in the latter case DM ∝ dot{E}.

  14. Quality and loudness judgments for music subjected to compression limiting.

    Science.gov (United States)

    Croghan, Naomi B H; Arehart, Kathryn H; Kates, James M

    2012-08-01

    Dynamic-range compression (DRC) is used in the music industry to maximize loudness. The amount of compression applied to commercial recordings has increased over time due to a motivating perspective that louder music is always preferred. In contrast to this viewpoint, artists and consumers have argued that using large amounts of DRC negatively affects the quality of music. However, little research evidence has supported the claims of either position. The present study investigated how DRC affects the perceived loudness and sound quality of recorded music. Rock and classical music samples were peak-normalized and then processed using different amounts of DRC. Normal-hearing listeners rated the processed and unprocessed samples on overall loudness, dynamic range, pleasantness, and preference, using a scaled paired-comparison procedure in two conditions: un-equalized, in which the loudness of the music samples varied, and loudness-equalized, in which loudness differences were minimized. Results indicated that a small amount of compression was preferred in the un-equalized condition, but the highest levels of compression were generally detrimental to quality, whether loudness was equalized or varied. These findings are contrary to the "louder is better" mentality in the music industry and suggest that more conservative use of DRC may be preferred for commercial music.

  15. INTERSTELLAR SCINTILLATION AND THE RADIO COUNTERPART OF THE FAST RADIO BURST FRB 150418

    International Nuclear Information System (INIS)

    Akiyama, Kazunori; Johnson, Michael D.

    2016-01-01

    Keane et al. have recently reported the discovery of a new fast radio burst (FRB), FRB 150418, with a promising radio counterpart at 5.5 and 7.5 GHz—a rapidly decaying source, falling from 200–300 μ Jy to 100 μ Jy on timescales of ∼6 days. This transient source may be associated with an elliptical galaxy at redshift z = 0.492, providing the first firm spectroscopic redshift for an FRB and the ability to estimate the density of baryons in the intergalactic medium via the combination of known redshift and radio dispersion of the FRB. An alternative explanation, first suggested by Williams and Berger, is that the identified counterpart may instead be a compact active galactic nucleus (AGN). The putative counterpart’s variation may then instead be extrinsic, caused by refractive scintillation in the ionized interstellar medium of the Milky Way, which would invalidate the association with FRB 150418. We examine this latter explanation in detail and show that the reported observations are consistent with scintillating radio emission from the core of a radio-loud AGN having a brightness temperature T _b ≳ 10"9 K. Using numerical simulations of the expected scattering for the line of sight to FRB 150418, we provide example images and light curves of such an AGN at 5.5 and 7.5 GHz. These results can be compared with continued radio monitoring to conclusively determine the importance of scintillation for the observed radio variability, and they show that scintillation is a critical consideration for continued searches for FRB counterparts at radio wavelengths.

  16. High-energy neutrinos from FR0 radio galaxies?

    Science.gov (United States)

    Tavecchio, F.; Righi, C.; Capetti, A.; Grandi, P.; Ghisellini, G.

    2018-04-01

    The sources responsible for the emission of high-energy (≳100 TeV) neutrinos detected by IceCube are still unknown. Among the possible candidates, active galactic nuclei with relativistic jets are often examined, since the outflowing plasma seems to offer the ideal environment to accelerate the required parent high-energy cosmic rays. The non-detection of single-point sources or - almost equivalently - the absence, in the IceCube events, of multiplets originating from the same sky position - constrains the cosmic density and the neutrino output of these sources, pointing to a numerous population of faint sources. Here we explore the possibility that FR0 radio galaxies, the population of compact sources recently identified in large radio and optical surveys and representing the bulk of radio-loud AGN population, can represent suitable candidates for neutrino emission. Modelling the spectral energy distribution of an FR0 radio galaxy recently associated with a γ-ray source detected by the Large Area Telescope onboard Fermi, we derive the physical parameters of its jet, in particular the power carried by it. We consider the possible mechanisms of neutrino production, concluding that pγ reactions in the jet between protons and ambient radiation is too inefficient to sustain the required output. We propose an alternative scenario, in which protons, accelerated in the jet, escape from it and diffuse in the host galaxy, producing neutrinos as a result of pp scattering with the interstellar gas, in strict analogy with the processes taking place in star-forming galaxies.

  17. The History and Evolution of Young and Distant Radio Sources

    Science.gov (United States)

    Collier, Jordan

    We study two classes of object to gain a better understanding of the evolution of Active Galactic Nuclei (AGN): Infrared-Faint Radio Sources (IFRSs) and Gigahertz Peaked Spectrum (GPS) / Compact Steep Spectrum (CSS) sources. IFRSs are a recently discovered rare class of object, which were found to be strong in the radio but undetectable in extremely sensitive infrared observations from the Spitzer Space Telescope, even in stacked images with sigma 3. Therefore, IFRSs may significantly increase the number of known high-redshift galaxies. However, their non-detections in the optical and infrared prevented confirmation of their nature. Previous studies of IFRSs focused on very sensitive observations of a few small regions of the sky, and the largest sample consisted of 55 IFRSs. However, we follow the strategy of combining radio data with IR and optical data for a large region of the sky. Using these data, we discover a population of >1300 brighter IFRSs which are, for the first time, reliably detected in the infrared and optical. We present the first spectroscopic redshifts of IFRSs and show that the brightest IFRSs are at z > 2. Furthermore, we rule out that IFRSs are Star Forming Galaxies, hotspots, lobes or misidentifications. We find the first X-ray counterparts of IFRSs, and increase the number of known polarised IFRSs five-fold. We present an analysis of their radio spectra and show that IFRSs consist of GPS, CSS and ultra-steep-spectrum sources. We follow up >50 of these using VLBI observations, and confirm the AGN status of IFRSs. GPS and CSS sources are compact radio sources with a convex radio spectrum. They are widely thought to represent young and evolving radio galaxies that have recently launched their jets. However, good evidence exists in individual cases that GPS and CSS sources are one of the following: 1) frustrated by interactions with dense gas and dust in their environment; 2) prematurely dying radio sources; 3) recurrent radio galaxies. Their

  18. Relativistic jets and the most powerful radio sources in the universe

    International Nuclear Information System (INIS)

    Bridle, A.

    1987-01-01

    Relativistic jets, which are beams of particles and magnetic fields emitting synchrotron radiation that emanate from black holes at the centers of galaxies and quasars, have been one of the most exciting discoveries made at the Very Large Array (VLA) operated by the National Radio Astronomy Observatory (NRAO). The VLA is an array of 27 antennas, each 25 meters in diameter, distributed in a Y-formation with two branches 21 kilometers long and one branch 19 kilometers long. Astronomers can use it to study relativistic jets that generate intense natural radio sources (or transmitters). These sources, associated with regions hundreds of thousands of light years across, are the most powerful in the universe in energy output. In his lecture, Bridle describes how consecutive advances in imaging techniques for radio astronomy have uncovered the properties of the powerful radio sources, culminating in the discovery at the VLA that many of these sources contain radio emitting jets. He then describes some of the NRAO's research on these jets, and discusses the jets' physical properties. He concludes with an outlook for the future: the NRAO's Very Long Baseline Array (VLBA) is to be completed in the early 1990's. The VLBA is an array of ten radio telescopes distributed from Hawaii to St. Croix, from the Canadian border to Texas. With the VLBA, astronomers plan to look more deeply into these radio sources. 15 figs

  19. FRESH ACTIVITY IN OLD SYSTEMS: RADIO AGNs IN FOSSIL GROUPS OF GALAXIES

    International Nuclear Information System (INIS)

    Hess, Kelley M.; Wilcots, Eric M.; Hartwick, Victoria L.

    2012-01-01

    We present the first systematic 1.4 GHz Very Large Array radio continuum survey of fossil galaxy group candidates. These are virialized systems believed to have assembled over a gigayear in the past through the merging of galaxy group members into a single, isolated, massive elliptical galaxy and featuring an extended hot X-ray halo. We use new photometric and spectroscopic data from Sloan Digital Sky Survey Data Release 7 to determine that three of the candidates are clearly not fossil groups. Of the remaining 30 candidates, 67% contain a radio-loud (L 1.4GHz > 10 23 W Hz –1 ) active galactic nucleus (AGN) at the center of their dominant elliptical galaxy. We find a weak correlation between the radio luminosity of the AGN and the X-ray luminosity of the halo suggesting that the AGN contributes to energy deposition into the intragroup medium. We only find a correlation between the radio and optical luminosity of the central elliptical galaxy when we include X-ray-selected, elliptically dominated non-fossil groups, indicating a weak relationship between AGN strength and the mass assembly history of the groups. The dominant elliptical galaxy of fossil groups is on average roughly an order of magnitude more luminous than normal group elliptical galaxies in optical, X-ray, and radio luminosities and our findings are consistent with previous results that the radio-loud fraction in elliptical galaxies is linked to the stellar mass of a population. The current level of activity in fossil groups suggests that AGN fueling continues long after the last major merger. We discuss several possibilities for fueling the AGN at the present epoch.

  20. A Loudness Function for Analog and Digital Sound Systems based on Equal Loudness Level Contours

    DEFF Research Database (Denmark)

    Nielsen, Sofus Birkedal

    2016-01-01

    frequency balance will been changed both for LL lower or higher than ML. The differences in ELLC ask for a level based equalization using fractional-order filters. A designing technique for both analog and digital fractional-order filters was developed. The analog solution is based on OPAMs and the digital......A new and better loudness compensation has been designed based on the differences between the Equal Loudness Level Contours (ELLC) in ISO 226:2003. Sound productions are normally being mixed at a high mixing level (ML) but often played at lower listening level (LL) which mean that the perceived...

  1. Loudness of tone pulses in a free field

    DEFF Research Database (Denmark)

    Poulsen, Torben

    1981-01-01

    Investigations of temporal loudness summation of tone pulses have been performed. The investigations comprised equal loudness determinations between pairs of tone pulses with a duration ratio of 1:2, and threshold determinations of the same tone pulses. Pulse durations ranged from 5 to 640 ms...

  2. [Factors influencing the pitch and loudness of tinnitus].

    Science.gov (United States)

    Ueda, S; Asoh, S; Watanabe, Y

    1992-11-01

    Pitch match and loudness balance tests were given to 397 cases with tinnitus. The factors which influenced tinnitus pitch and loudness were analyzed statistically from the clinical point of view. The results obtained were as follows: 1) Onomatopoeia of tinnitus, either [Keeeen] or [Jeeeen], were observed in a majority of cases. 2) Significantly sharp sounding onomatopoeia such as [Keeeen] or [Meeeen] had high pitches, over 4kHz, and dull sounds like [Gooooh] or [Buuuun] had low pitches, below 500Hz. 3) Acute stage tinnitus, within one month of onset, had a significantly depressed pitch and walked loudness, above 6dB. 4) The pitches observed in cases with Meniere's disease and chronic otitis media were distributed evenly from low frequencies to high. In other cases, especially presbyacusis and noise deafness, high pitch tinnitus (above 4kHz) was frequently noted. The loudness of tinnitus without hearing loss was significantly greater than in other diseases. 5) As a rule the more deteriorated the hearing level was, the lower the frequency of the pitch, and the smaller the loudness in tinnitus. 6) A high pitch of tinnitus nearly corresponded with hearing type, that is, the pitch of tinnitus was also in accordance with the disturbed frequency in the hearing threshold.

  3. Binaural loudness for artificial-head measurements in directional sound fields

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka; Ellermeier, Wolfgang

    2008-01-01

    The effect of the sound incidence angle on loudness was investigated for fifteen listeners who matched the loudness of sounds coming from five different incidence angles in the horizontal plane to that of the same sound with frontal incidence. The stimuli were presented via binaural synthesis...... by using head-related transfer functions measured for an artificial head. The results, which exhibited marked individual differences, show that loudness depends on the direction from which a sound reaches the listener. The average results suggest a relatively simple rule for combining the two signals...... at the ears of an artificial head for binaural loudness predictions....

  4. Sources of the Radio Background Considered

    Energy Technology Data Exchange (ETDEWEB)

    Singal, J.; /KIPAC, Menlo Park /Stanford U.; Stawarz, L.; /KIPAC, Menlo Park /Stanford U. /Jagiellonian U., Astron. Observ.; Lawrence, A.; /Edinburgh U., Inst. Astron. /KIPAC, Menlo Park /Stanford U.; Petrosian, V.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.

    2011-08-22

    We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub {mu}Jy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/{gamma}-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

  5. INTERSTELLAR SCINTILLATION AND THE RADIO COUNTERPART OF THE FAST RADIO BURST FRB 150418

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Kazunori [Massachusetts Institute of Technology, Haystack Observatory, Route 40, Westford, MA 01886 (United States); Johnson, Michael D., E-mail: kazu@haystack.mit.edu [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2016-06-10

    Keane et al. have recently reported the discovery of a new fast radio burst (FRB), FRB 150418, with a promising radio counterpart at 5.5 and 7.5 GHz—a rapidly decaying source, falling from 200–300 μ Jy to 100 μ Jy on timescales of ∼6 days. This transient source may be associated with an elliptical galaxy at redshift z = 0.492, providing the first firm spectroscopic redshift for an FRB and the ability to estimate the density of baryons in the intergalactic medium via the combination of known redshift and radio dispersion of the FRB. An alternative explanation, first suggested by Williams and Berger, is that the identified counterpart may instead be a compact active galactic nucleus (AGN). The putative counterpart’s variation may then instead be extrinsic, caused by refractive scintillation in the ionized interstellar medium of the Milky Way, which would invalidate the association with FRB 150418. We examine this latter explanation in detail and show that the reported observations are consistent with scintillating radio emission from the core of a radio-loud AGN having a brightness temperature T {sub b} ≳ 10{sup 9} K. Using numerical simulations of the expected scattering for the line of sight to FRB 150418, we provide example images and light curves of such an AGN at 5.5 and 7.5 GHz. These results can be compared with continued radio monitoring to conclusively determine the importance of scintillation for the observed radio variability, and they show that scintillation is a critical consideration for continued searches for FRB counterparts at radio wavelengths.

  6. Loudness of brief tones in listeners with normal hearing and sensorineural hearing loss

    DEFF Research Database (Denmark)

    Buus, Søren; Florentine, Mary; Poulsen, Torben

    1997-01-01

    To investigate how hearing loss affects the loudness of brief tones, loudness matches between 5- and 200-ms tones were obtained as a function of level. Loudness functions derived from these data indicated that the gain required to restore loudness usually is the same for short and long sounds....

  7. Statistical studies of powerful extragalactic radio sources

    Energy Technology Data Exchange (ETDEWEB)

    Macklin, J T

    1981-01-01

    This dissertation is mainly about the use of efficient statistical tests to study the properties of powerful extragalactic radio sources. Most of the analysis is based on subsets of a sample of 166 bright (3CR) sources selected at 178 MHz. The first chapter is introductory and it is followed by three on the misalignment and symmetry of double radio sources. The properties of nuclear components in extragalactic sources are discussed in the next chapter, using statistical tests which make efficient use of upper limits, often the only available information on the flux density from the nuclear component. Multifrequency observations of four 3CR sources are presented in the next chapter. The penultimate chapter is about the analysis of correlations involving more than two variables. The Spearman partial rank correlation coefficient is shown to be the most powerful test available which is based on non-parametric statistics. It is therefore used to study the dependences of the properties of sources on their size at constant redshift, and the results are interpreted in terms of source evolution. Correlations of source properties with luminosity and redshift are then examined.

  8. Morphometric Differences of Vocal Tract Articulators in Different Loudness Conditions in Singing.

    Science.gov (United States)

    Echternach, Matthias; Burk, Fabian; Burdumy, Michael; Traser, Louisa; Richter, Bernhard

    2016-01-01

    Dynamic MRI analysis of phonation has gathered interest in voice and speech physiology. However, there are limited data addressing the extent to which articulation is dependent on loudness. 12 professional singer subjects of different voice classifications were analysed concerning the vocal tract profiles recorded with dynamic real-time MRI with 25fps in different pitch and loudness conditions. The subjects were asked to sing ascending scales on the vowel /a/ in three loudness conditions (comfortable=mf, very soft=pp, very loud=ff, respectively). Furthermore, fundamental frequency and sound pressure level were analysed from the simultaneously recorded optical audio signal after noise cancellation. The data show articulatory differences with respect to changes of both pitch and loudness. Here, lip opening and pharynx width were increased. While the vertical larynx position was rising with pitch it was lower for greater loudness. Especially, the lip opening and pharynx width were more strongly correlated with the sound pressure level than with pitch. For the vowel /a/ loudness has an effect on articulation during singing which should be considered when articulatory vocal tract data are interpreted.

  9. The MASIV Survey - IV. Relationship between intra-day scintillation and intrinsic variability of radio AGNs

    Science.gov (United States)

    Koay, J. Y.; Macquart, J.-P.; Jauncey, D. L.; Pursimo, T.; Giroletti, M.; Bignall, H. E.; Lovell, J. E. J.; Rickett, B. J.; Kedziora-Chudczer, L.; Ojha, R.; Reynolds, C.

    2018-03-01

    We investigate the relationship between 5 GHz interstellar scintillation (ISS) and 15 GHz intrinsic variability of compact, radio-selected active galactic nuclei (AGNs) drawn from the Microarcsecond Scintillation-Induced Variability (MASIV) Survey and the Owens Valley Radio Observatory blazar monitoring program. We discover that the strongest scintillators at 5 GHz (modulation index, m5 ≥ 0.02) all exhibit strong 15 GHz intrinsic variability (m15 ≥ 0.1). This relationship can be attributed mainly to the mutual dependence of intrinsic variability and ISS amplitudes on radio core compactness at ˜ 100 μas scales, and to a lesser extent, on their mutual dependences on source flux density, arcsec-scale core dominance and redshift. However, not all sources displaying strong intrinsic variations show high amplitude scintillation, since ISS is also strongly dependent on Galactic line-of-sight scattering properties. This observed relationship between intrinsic variability and ISS highlights the importance of optimizing the observing frequency, cadence, timespan and sky coverage of future radio variability surveys, such that these two effects can be better distinguished to study the underlying physics. For the full MASIV sample, we find that Fermi-detected gamma-ray loud sources exhibit significantly higher 5 GHz ISS amplitudes than gamma-ray quiet sources. This relationship is weaker than the known correlation between gamma-ray loudness and the 15 GHz variability amplitudes, most likely due to jet opacity effects.

  10. Effect of direction on loudness in individual binaural synthesis

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka; Minnaar, Pauli; Ellermeier, Wolfgang

    2005-01-01

    The effect of sound incidence angle on loudness is investigated in this study using binaural synthesis. Individual head-related transfer functions (HRTFs) and headphone equalization are used to present narrow-band noises from different directions to listeners. Their task is to match the loudness...... of these stimuli in an adaptive procedure to a reference noise in front of the listeners. The results are compared to an earlier investigation with the same experimental design in a real sound field. Based on the results the role of the individual HRTFs in loudness judgments is inspected, and finally, binaural...

  11. The Radio/Gamma-Ray Connection from 120 MHz to 230 GHz

    Directory of Open Access Journals (Sweden)

    Marcello Giroletti

    2016-09-01

    Full Text Available Radio loud active galactic nuclei are composed of different spatial features, each one characterized by different spectral properties in the radio band. Among them, blazars are the most common class of sources detected at gamma-rays by Fermi, and their radio emission is dominated by the flat spectrum compact core. In this contribution, we explore the connection between emission at high energy revealed by Fermi and at radio frequencies. Taking as a reference the strong and very highly significant correlation found between gamma rays and cm-λ radio emission, we explore the different behaviours found as we change the energy range in gamma rays and in radio, therefore changing the physical parameters of the zones involved in the emitted radiation. We find that the correlation weakens when we consider (1 gamma rays of energy above 10 GeV (except for high synchrotron peaked blazars or (2 low frequency radio data taken by the Murchison Widefield Array; on the other hand, the correlation strengthens when we consider mm-λ data taken by Atacama Large Millimeter Array (ALMA.

  12. Morphometric Differences of Vocal Tract Articulators in Different Loudness Conditions in Singing.

    Directory of Open Access Journals (Sweden)

    Matthias Echternach

    Full Text Available Dynamic MRI analysis of phonation has gathered interest in voice and speech physiology. However, there are limited data addressing the extent to which articulation is dependent on loudness.12 professional singer subjects of different voice classifications were analysed concerning the vocal tract profiles recorded with dynamic real-time MRI with 25fps in different pitch and loudness conditions. The subjects were asked to sing ascending scales on the vowel /a/ in three loudness conditions (comfortable=mf, very soft=pp, very loud=ff, respectively. Furthermore, fundamental frequency and sound pressure level were analysed from the simultaneously recorded optical audio signal after noise cancellation.The data show articulatory differences with respect to changes of both pitch and loudness. Here, lip opening and pharynx width were increased. While the vertical larynx position was rising with pitch it was lower for greater loudness. Especially, the lip opening and pharynx width were more strongly correlated with the sound pressure level than with pitch.For the vowel /a/ loudness has an effect on articulation during singing which should be considered when articulatory vocal tract data are interpreted.

  13. From Radio with Love: An Overview of the Role of Radio Observations in Understanding High-Energy Emission from Active Galaxies

    Science.gov (United States)

    Ojha, Roopesh

    2012-01-01

    The gamma-ray satellite Fermi and the ground based TeV facilities MAGIC, VERITAS and HESS have ushered in a new era in the observation of high-energy emission from active galaxies. The energy budgets of these objects have a major contribution from gamma-rays and it is simply not possible to understand their physics without high-energy observations. Though the exact mechanisms for high-energy production in galaxies remains an open question, gamma-rays typically result from interactions between high-energy particles. Via different interactions these same particles can produce radio emission. Thus the non-thermal nature of gamma-ray emission practically guarantees that high-energy emitters are also radio loud. Aside from their obvious role as a component of multiwavelength analysis, radio observations provide two crucial elements essential to understanding the source structure and physical processes of high-energy emitters: very high timing resolution and very high spatial resolution. A brief overview of the unique role played by radio observations in unraveling the mysteries of the high energy Universe as presented here.

  14. Comparison of Multipole Stimulus Configurations With Respect to Loudness and Spread of Excitation.

    Science.gov (United States)

    Vellinga, Dirk; Briaire, Jeroen Johannes; van Meenen, David Michael Paul; Frijns, Johannes Hubertus Maria

    Current spread is a substantial limitation of speech coding strategies in cochlear implants. Multipoles have the potential to reduce current spread and thus generate more discriminable pitch percepts. The difficulty with multipoles is reaching sufficient loudness. The primary goal was to compare the loudness characteristics and spread of excitation (SOE) of three types of phased array stimulation, a novel multipole, with three more conventional configurations. Fifteen postlingually deafened cochlear implant users performed psychophysical experiments addressing SOE, loudness scaling, loudness threshold, loudness balancing, and loudness discrimination. Partial tripolar stimulation (pTP, σ = 0.75), TP, phased array with 16 (PA16) electrodes, and restricted phased array with five (PA5) and three (PA3) electrodes was compared with a reference monopolar stimulus. Despite a similar loudness growth function, there were considerable differences in current expenditure. The most energy efficient multipole was the pTP, followed by PA16 and PA5/PA3. TP clearly stood out as the least efficient one. Although the electric dynamic range was larger with multipolar configurations, the number of discriminable steps in loudness was not significantly increased. The SOE experiment could not demonstrate any difference between the stimulation strategies. The loudness characteristics all five multipolar configurations tested are similar. Because of their higher energy efficiency, pTP and PA16 are the most favorable candidates for future testing in clinical speech coding strategies.

  15. Communication Characteristics of Faulted Overhead High Voltage Power Lines at Low Radio Frequencies

    Directory of Open Access Journals (Sweden)

    Nermin Suljanović

    2017-11-01

    Full Text Available This paper derives a model of high-voltage overhead power line under fault conditions at low radio frequencies. The derived model is essential for design of communication systems to reliably transfer information over high voltage power lines. In addition, the model can also benefit advanced systems for power-line fault detection and classification exploiting the phenomenon of changed conditions on faulted power line, resulting in change of low radio frequency signal propagation. The methodology used in the paper is based on the multiconductor system analysis and propagation of electromagnetic waves over the power lines. The model for the high voltage power line under normal operation is validated using actual measurements obtained on 400 kV power line. The proposed model of faulted power lines extends the validated power-line model under normal operation. Simulation results are provided for typical power line faults and typical fault locations. Results clearly indicate sensitivity of power-line frequency response on different fault types.

  16. Individual, contextual, and age-related acoustic variation in Simakobu (Simias concolor loud calls.

    Directory of Open Access Journals (Sweden)

    Wendy M Erb

    Full Text Available Primate loud calls have the potential to encode information about the identity, arousal, age, or physical condition of the caller, even at long distances. In this study, we conducted an analysis of the acoustic features of the loud calls produced by a species of Asian colobine monkey (simakobu, Simias concolor. Adult male simakobu produce loud calls spontaneously and in response to loud sounds and other loud calls, which are audible more than 500 m. Individual differences in calling rates and durations exist, but it is unknown what these differences signal and which other acoustic features vary among individuals. We aimed to describe the structure and usage of calls and to examine acoustic features that vary within and among individuals. We determined the context of 318 loud calls and analyzed 170 loud calls recorded from 10 adult males at an undisturbed site, Pungut, Siberut Island, Indonesia. Most calls (53% followed the loud call of another male, 31% were spontaneous, and the remaining 16% followed a loud environmental disturbance. The fundamental frequency (F0 decreased while inter-unit intervals (IUI increased over the course of loud call bouts, possibly indicating caller fatigue. Discriminant function analysis indicated that calls were not well discriminated by context, but spontaneous calls had higher peak frequencies, suggesting a higher level of arousal. Individual calls were distinct and individuals were mainly discriminated by IUI, call duration, and F0. Loud calls of older males had shorter IUI and lower F0, while middle-aged males had the highest peak frequencies. Overall, we found that calls were individually distinct and may provide information about the age, stamina, and arousal of the calling male, and could thus be a way for males and females to assess competitors and mates from long distances.

  17. Influence of Loudness Compression on Hearing with Bone Anchored Hearing Implants

    OpenAIRE

    Kurz, Anja; Caversaccio, Marco; Kompis, Martin; Flynn, Marc

    2014-01-01

    Bone Anchored Hearing Implants (BAHI) are routinely used in patients with conductive or mixed hearing loss, e.g. if conventional air conduction hearing aids cannot be used. New sound processors and new fitting software now allow the adjustment of parameters such as loudness compression ratios or maximum power output separately. Today it is unclear, how the choice of these parameters influences aided speech understanding in BAHI users. In this prospective experimental study, the effect ...

  18. Effect of direction on loudness for wideband and reverberant sounds

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka; Ellermeier, Wolfgang

    2006-01-01

    The effect of incidence angle on loudness was investigated for wideband and reverberant sounds. In an adaptive procedure, five listeners matched the loudness of a sound coming from five incidence angles in the horizontal plane to that of the same sound with frontal incidence. The stimuli were...... presented to the listeners via individual binaural synthesis. The results confirm that loudness depends on sound incidence angle, as it does for narrow-band, anechoic sounds. The directional effects, however, were attenuated with the wideband and reverberant stimuli used in the present investigation....

  19. DISCOVERY OF A FLAT-SPECTRUM RADIO NUCLEUS IN NGC 3115

    Energy Technology Data Exchange (ETDEWEB)

    Wrobel, J. M. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Nyland, K., E-mail: jwrobel@nrao.edu, E-mail: knyland@nrao.edu [New Mexico Tech, Department of Physics, 801 Leroy Place, Socorro, NM 87801 (United States)

    2012-12-01

    The early-type galaxy NGC 3115, at a distance of 10.2 Mpc, hosts the nearest billion-solar-mass black hole. Wong et al. recently inferred a substantial Bondi accretion rate near the black hole. Bondi-like accretion is thought to fuel outflows, which can be traced through their radio emission. This paper reports the discovery of a radio nucleus in NGC 3115, with a diameter less than 0.''17 (8.4 pc), a luminosity at 8.5 GHz of 3.1 Multiplication-Sign 10{sup 35} erg s{sup -1}, and a flat spectrum ({alpha} = -0.23 {+-} 0.20, S{proportional_to}{nu}{sup {alpha}}). The radio source coincides with the galaxy's photocenter and candidate X-ray nucleus. The emission is radio loud, suggesting the presence of an outflow on scales less than 10 pc. On such scales, the Bondi accretion could be impeded by heating due to disruption of the outflow.

  20. A 6.45 μW Self-Powered SoC With Integrated Energy-Harvesting Power Management and ULP Asymmetric Radios for Portable Biomedical Systems.

    Science.gov (United States)

    Roy, Abhishek; Klinefelter, Alicia; Yahya, Farah B; Chen, Xing; Gonzalez-Guerrero, Luisa Patricia; Lukas, Christopher J; Kamakshi, Divya Akella; Boley, James; Craig, Kyle; Faisal, Muhammad; Oh, Seunghyun; Roberts, Nathan E; Shakhsheer, Yousef; Shrivastava, Aatmesh; Vasudevan, Dilip P; Wentzloff, David D; Calhoun, Benton H

    2015-12-01

    This paper presents a batteryless system-on-chip (SoC) that operates off energy harvested from indoor solar cells and/or thermoelectric generators (TEGs) on the body. Fabricated in a commercial 0.13 μW process, this SoC sensing platform consists of an integrated energy harvesting and power management unit (EH-PMU) with maximum power point tracking, multiple sensing modalities, programmable core and a low power microcontroller with several hardware accelerators to enable energy-efficient digital signal processing, ultra-low-power (ULP) asymmetric radios for wireless transmission, and a 100 nW wake-up radio. The EH-PMU achieves a peak end-to-end efficiency of 75% delivering power to a 100 μA load. In an example motion detection application, the SoC reads data from an accelerometer through SPI, processes it, and sends it over the radio. The SPI and digital processing consume only 2.27 μW, while the integrated radio consumes 4.18 μW when transmitting at 187.5 kbps for a total of 6.45 μW.

  1. Extreme Radio Flares and Associated X-Ray Variability from Young Stellar Objects in the Orion Nebula Cluster

    Energy Technology Data Exchange (ETDEWEB)

    Forbrich, Jan [Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Reid, Mark J.; Wolk, Scott J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138 (United States); Menten, Karl M. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Rivilla, Victor M. [Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125, Firenze (Italy); Rau, Urvashi; Chandler, Claire J. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States)

    2017-08-01

    Young stellar objects are known to exhibit strong radio variability on timescales of weeks to months, and a few reports have documented extreme radio flares with at least an order of magnitude change in flux density on timescales of hours to days. However, there have been few constraints on the occurrence rate of such radio flares or on the correlation with pre-main sequence X-ray flares, although such correlations are known for the Sun and nearby active stars. Here we report simultaneous deep VLA radio and Chandra X-ray observations of the Orion Nebula Cluster, targeting hundreds of sources to look for the occurrence rate of extreme radio variability and potential correlation with the most extreme X-ray variability. We identify 13 radio sources with extreme radio variability, with some showing an order of magnitude change in flux density in less than 30 minutes. All of these sources show X-ray emission and variability, but we find clear correlations with extreme radio flaring only on timescales <1 hr. Strong X-ray variability does not predict the extreme radio sources and vice versa. Radio flares thus provide us with a new perspective on high-energy processes in YSOs and the irradiation of their protoplanetary disks. Finally, our results highlight implications for interferometric imaging of sources violating the constant-sky assumption.

  2. Hardware Interface Description for the Integrated Power, Avionics, and Software (iPAS) Space Telecommunications Radio Ssystem (STRS) Radio

    Science.gov (United States)

    Shalkhauser, Mary Jo W.; Roche, Rigoberto

    2017-01-01

    The Space Telecommunications Radio System (STRS) provides a common, consistent framework for software defined radios (SDRs) to abstract the application software from the radio platform hardware. The STRS standard aims to reduce the cost and risk of using complex, configurable and reprogrammable radio systems across NASA missions. To promote the use of the STRS architecture for future NASA advanced exploration missions, NASA Glenn Research Center (GRC) developed an STRS-compliant SDR on a radio platform used by the Advance Exploration System program at the Johnson Space Center (JSC) in their Integrated Power, Avionics, and Software (iPAS) laboratory. The iPAS STRS Radio was implemented on the Reconfigurable, Intelligently-Adaptive Communication System (RIACS) platform, currently being used for radio development at JSC. The platform consists of a Xilinx ML605 Virtex-6 FPGA board, an Analog Devices FMCOMMS1-EBZ RF transceiver board, and an Embedded PC (Axiomtek eBox 620-110-FL) running the Ubuntu 12.4 operating system. Figure 1 shows the RIACS platform hardware. The result of this development is a very low cost STRS compliant platform that can be used for waveform developments for multiple applications.The purpose of this document is to describe how to develop a new waveform using the RIACS platform and the Very High Speed Integrated Circuits (VHSIC) Hardware Description Language (VHDL) FPGA wrapper code and the STRS implementation on the Axiomtek processor.

  3. Waveform Developer's Guide for the Integrated Power, Avionics, and Software (iPAS) Space Telecommunications Radio System (STRS) Radio

    Science.gov (United States)

    Shalkhauser, Mary Jo W.; Roche, Rigoberto

    2017-01-01

    The Space Telecommunications Radio System (STRS) provides a common, consistent framework for software defined radios (SDRs) to abstract the application software from the radio platform hardware. The STRS standard aims to reduce the cost and risk of using complex, configurable and reprogrammable radio systems across NASA missions. To promote the use of the STRS architecture for future NASA advanced exploration missions, NASA Glenn Research Center (GRC) developed an STRS-compliant SDR on a radio platform used by the Advance Exploration System program at the Johnson Space Center (JSC) in their Integrated Power, Avionics, and Software (iPAS) laboratory. The iPAS STRS Radio was implemented on the Reconfigurable, Intelligently-Adaptive Communication System (RIACS) platform, currently being used for radio development at JSC. The platform consists of a Xilinx(Trademark) ML605 Virtex(Trademark)-6 FPGA board, an Analog Devices FMCOMMS1-EBZ RF transceiver board, and an Embedded PC (Axiomtek(Trademark) eBox 620-110-FL) running the Ubuntu 12.4 operating system. The result of this development is a very low cost STRS compliant platform that can be used for waveform developments for multiple applications. The purpose of this document is to describe how to develop a new waveform using the RIACS platform and the Very High Speed Integrated Circuits (VHSIC) Hardware Description Language (VHDL) FPGA wrapper code and the STRS implementation on the Axiomtek processor.

  4. Temporal integration of loudness in listeners with hearing losses of primarily cochlear origin

    DEFF Research Database (Denmark)

    Buus, Søren; Florentine, Mary; Poulsen, Torben

    1999-01-01

    To investigate how hearing loss of primarily cochlear origin affects the loudness of brief tones, loudness matches between 5- and 200-ms tones were obtained as a function of level for 15 listeners with cochlear impairments and for seven age-matched controls. Three frequencies, usually 0.5, 1, and 4...... of temporal integration—defined as the level difference between equally loud short and long tones—varied nonmonotonically with level and was largest at moderate levels. No consistent effect of frequency was apparent. The impaired listeners varied widely, but most showed a clear effect of level on the amount...... of temporal integration. Overall, their results appear consistent with expectations based on knowledge of the general properties of their loudness-growth functions and the equal-loudness-ratio hypothesis, which states that the loudness ratio between equal-SPL long and brief tones is the same at all SPLs...

  5. Pitch and Loudness Tinnitus in Individuals with Presbycusis.

    Science.gov (United States)

    Seimetz, Bruna Macangnin; Teixeira, Adriane Ribeiro; Rosito, Leticia Petersen Schmidt; Flores, Leticia Sousa; Pappen, Carlos Henrique; Dall'igna, Celso

    2016-10-01

    Introduction  Tinnitus is a symptom that is often associated with presbycusis. Objective  This study aims to analyze the existence of association among hearing thresholds, pitch, and loudness of tinnitus in individuals with presbycusis, considering the gender variable. Methods  Cross-sectional, descriptive, and prospective study, whose sample consisted of individuals with tinnitus and diagnosis of presbycusis. For the evaluation, we performed anamnesis along with otoscopy, pure tone audiometry, and acuphenometry to analyze the psychoacoustic characteristics of tinnitus individuals. Results  The sample consisted of 49 subjects, with a mean age of 69.57 ± 6.53 years, who presented unilateral and bilateral tinnitus, therefore, a sample of 80 ears. In analyzing the results, as for acuphenometry, the loudness of tinnitus was more present at 0dB and the pitch was 6HKz and 8HKz. Regarding the analysis of the association between the frequency of greater hearing threshold and tinnitus pitch, no statistical significance ( p  = 0.862) was found. As for the association between the intensity of greater hearing threshold and tinnitus loudness, no statistical significance ( p  = 0.115) was found. Conclusion  There is no significant association between the hearing loss of patients with presbycusis and the pitch and loudness of tinnitus.

  6. Pitch and Loudness Tinnitus in Individuals with Presbycusis

    Directory of Open Access Journals (Sweden)

    Seimetz, Bruna Macangnin

    2016-02-01

    Full Text Available Introduction Tinnitus is a symptom that is often associated with presbycusis. Objective This study aims to analyze the existence of association among hearing thresholds, pitch, and loudness of tinnitus in individuals with presbycusis, considering the gender variable. Methods Cross-sectional, descriptive, and prospective study, whose sample consisted of individuals with tinnitus and diagnosis of presbycusis. For the evaluation, we performed anamnesis along with otoscopy, pure tone audiometry, and acuphenometry to analyze the psychoacoustic characteristics of tinnitus individuals. Results The sample consisted of 49 subjects, with a mean age of 69.57 ± 6.53 years, who presented unilateral and bilateral tinnitus, therefore, a sample of 80 ears. In analyzing the results, as for acuphenometry, the loudness of tinnitus was more present at 0dB and the pitch was 6HKz and 8HKz. Regarding the analysis of the association between the frequency of greater hearing threshold and tinnitus pitch, no statistical significance (p = 0.862 was found. As for the association between the intensity of greater hearing threshold and tinnitus loudness, no statistical significance (p = 0.115 was found. Conclusion There is no significant association between the hearing loss of patients with presbycusis and the pitch and loudness of tinnitus.

  7. Autonomous transmission power adaptation for multi-radio multi-channel wireless mesh networks

    CSIR Research Space (South Africa)

    Olwal, TO

    2009-09-01

    Full Text Available Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in WMNs. Previous studies have emphasized through- put maximization in such systems as the main design challenge and transmission power control treated as a secondary issue...

  8. Autonomous transmission power adaptation for multi-radio multi-channel wireless mesh networks

    CSIR Research Space (South Africa)

    Olwal, TO

    2008-09-01

    Full Text Available Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in WMNs. Previous studies have emphasized throughput maximization in such systems as the main design challenge and transmission power control treated as a secondary issue...

  9. Examining the validity of numerical ratios in loudness fractionation

    DEFF Research Database (Denmark)

    Zimmer, Karin

    2005-01-01

    was to adjust the loudness of a 1-kHz tone so that it reached a certain prespecified fraction of the loudness of a reference tone. The results of the first experiment suggest that the listeners were indeed able to make adjustments on a ratio scale level. It was not possible, however, to interpret the nominal...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Range based power control for multi-radio multi-channel wireless mesh networks

    CSIR Research Space (South Africa)

    Olwal, TO

    2009-08-01

    Full Text Available Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in Wireless Mesh Networks (WMNs). In this paper, researchers present a range based dynamic power control for MRMC WMNs. First, WMN is represented as a set of disjoint Unified...

  12. Local Mechanisms for Loud Sound-Enhanced Aminoglycoside Entry into Outer Hair Cells

    Directory of Open Access Journals (Sweden)

    Hongzhe eLi

    2015-04-01

    Full Text Available Loud sound exposure exacerbates aminoglycoside ototoxicity, increasing the risk of permanent hearing loss and degrading the quality of life in affected individuals. We previously reported that loud sound exposure induces temporary threshold shifts (TTS and enhances uptake of aminoglycosides, like gentamicin, by cochlear outer hair cells (OHCs. Here, we explore mechanisms by which loud sound exposure and TTS could increase aminoglycoside uptake by OHCs that may underlie this form of ototoxic synergy.Mice were exposed to loud sound levels to induce TTS, and received fluorescently-tagged gentamicin (GTTR for 30 minutes prior to fixation. The degree of TTS was assessed by comparing auditory brainstem responses before and after loud sound exposure. The number of tip links, which gate the GTTR-permeant mechanoelectrical transducer (MET channels, was determined in OHC bundles, with or without exposure to loud sound, using scanning electron microscopy.We found wide-band noise (WBN levels that induce TTS also enhance OHC uptake of GTTR compared to OHCs in control cochleae. In cochlear regions with TTS, the increase in OHC uptake of GTTR was significantly greater than in adjacent pillar cells. In control mice, we identified stereociliary tip links at ~50% of potential positions in OHC bundles. However, the number of OHC tip links was significantly reduced in mice that received WBN at levels capable of inducing TTS.These data suggest that GTTR uptake by OHCs during TTS occurs by increased permeation of surviving, mechanically-gated MET channels, and/or non-MET aminoglycoside-permeant channels activated following loud sound exposure. Loss of tip links would hyperpolarize hair cells and potentially increase drug uptake via aminoglycoside-permeant channels expressed by hair cells. The effect of TTS on aminoglycoside-permeant channel kinetics will shed new light on the mechanisms of loud sound-enhanced aminoglycoside uptake, and consequently on ototoxic

  13. Loudness of complex sounds as a function of the standard stimulus and the number of components

    DEFF Research Database (Denmark)

    Florentine, Mary; Buus, Søren; Bonding, Per

    1978-01-01

    The purpose of this study was twofold: to determine if the measured loudness level of a signal depends on the standard stimulus used and to measure loudness as a function of the number of components in a wide-band signal. The stimuli were a pure tone, tone complexes with frequency separations...... of 231 and 1592 Hz, and noise bands with widths of 220 and 1592 Hz. The center frequency was 1 kHz and the loudness level was approximately 65 phons. Loudness matches between all combinations of stimuli showed that the measured loudness of the sounds did not depend on the standard stimulus used...... and the measured loudness level of a wide-band sound increased as a function of the number of components. Individual observers were consistent in their loudness estimations; the greatest source of variability was among subjects. Additional measurements indicated that the rate at which loudness increased beyond...

  14. H I anisotropies associated with radio-polarimetric filaments . Steep power spectra associated with cold gas

    Science.gov (United States)

    Kalberla, P. M. W.; Kerp, J.; Haud, U.; Haverkorn, M.

    2017-10-01

    Context. LOFAR detected toward 3C 196 linear polarization structures which were found subsequently to be closely correlated with cold filamentary H I structures. The derived direction-dependent H I power spectra revealed marked anisotropies for narrow ranges in velocity, sharing the orientation of the magnetic field as expected for magneto-hydrodynamical (MHD) turbulence. Aims: Using the Galactic portion of the Effelsberg-Bonn H I Survey (EBHIS) we continue our study of such anisotropies in the H I distribution in direction of two WSRT fields, Horologium and Auriga; both are well known for their prominent radio-polarimetric depolarization canals. At 349 MHz the observed pattern in total intensity is insignificant but polarized intensity and polarization angle show prominent ubiquitous structures with so far unknown origin. Methods: Apodizing the H I survey data by applying a rotational symmetric 50% Tukey window, we derive average and position angle dependent power spectra. We fit power laws and characterize anisotropies in the power distribution. We used a Gaussian analysis to determine relative abundances for the cold and warm neutral medium. Results: For the analyzed radio-polarimetric targets significant anisotropies are detected in the H I power spectra; their position angles are aligned to the prominent depolarization canals, initially detected by WSRT. H I anisotropies are associated with steep power spectra. Steep power spectra, associated with cold gas, are detected also in other fields. Conclusions: Radio-polarimetric depolarization canals are associated with filamentary H I structures that belong to the cold neutral medium (CNM). Anisotropies in the CNM are in this case linked to a steepening of the power-spectrum spectral index, indicating that phase transitions in a turbulent medium occur on all scales. Filamentary H I structures, driven by thermal instabilities, and radio-polarimetric filaments are associated with each other. The magneto-ionic medium

  15. Star Formation Rates in Lyman Break Galaxies: Radio Stacking of LBGs in the COSMOS Field and the Sub-μJy Radio Source Population

    Science.gov (United States)

    Carilli, C. L.; Lee, Nicholas; Capak, P.; Schinnerer, E.; Lee, K.-S.; McCraken, H.; Yun, M. S.; Scoville, N.; Smolčić, V.; Giavalisco, M.; Datta, A.; Taniguchi, Y.; Urry, C. Megan

    2008-12-01

    We present an analysis of the radio properties of large samples of Lyman break galaxies (LBGs) at z ~ 3, 4, and 5 from the COSMOS field. The median stacking analysis yields a statistical detection of the z ~ 3 LBGs (U-band dropouts), with a 1.4 GHz flux density of 0.90 +/- 0.21 μJy. The stacked emission is unresolved, with a size = 3 is smaller than at lower redshifts. Conversely, the radio luminosity for a given star formation rate may be systematically lower at very high redshift. Two possible causes for a suppressed radio luminosity are (1) increased inverse Compton cooling of the relativistic electron population due to scattering off the increasing CMB at high redshift or (2) cosmic-ray diffusion from systematically smaller galaxies. The radio detections of individual sources are consistent with a radio-loud AGN fraction of 0.3%. One source is identified as a very dusty, extreme starburst galaxy (a "submillimeter galaxy"). Based on observations in the COSMOS Legacy Survey including those taken on the HST, Keck, NRAO-VLA, Subaru, KPNO 4 m, CTIO 4 m, and CFHT 3.6 m. The Very Large Array of the National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  16. Hard state neutron star and black hole X-ray binaries in the radio:X-ray luminosity plane

    Science.gov (United States)

    Gallo, Elena; Degenaar, Nathalie; van den Eijnden, Jakob

    2018-05-01

    Motivated by the large body of literature around the phenomenological properties of accreting black hole (BH) and neutron star (NS) X-ray binaries in the radio:X-ray luminosity plane, we carry out a comparative regression analysis on 36 BHs and 41 NSs in hard X-ray states, with data over 7 dex in X-ray luminosity for both. The BHs follow a radio to X-ray (logarithmic) luminosity relation with slope β = 0.59 ± 0.02, consistent with the NSs' slope (β =0.44^{+0.05}_{-0.04}) within 2.5σ. The best-fitting intercept for the BHs significantly exceeds that for the NSs, cementing BHs as more radio loud, by a factor ˜22. This discrepancy can not be fully accounted for by the mass or bolometric correction gap, nor by the NS boundary layer contribution to the X-rays, and is likely to reflect physical differences in the accretion flow efficiency, or the jet powering mechanism. Once importance sampling is implemented to account for the different luminosity distributions, the slopes of the non-pulsating and pulsating NS subsamples are formally inconsistent (>3σ), unless the transitional millisecond pulsars (whose incoherent radio emission mechanism is not firmly established) are excluded from the analysis. We confirm the lack of a robust partitioning of the BH data set into separate luminosity tracks.

  17. DISCOVERY OF γ -RAY EMISSION FROM THE RADIO-INTERMEDIATE QUASAR III ZW 2: VIOLENT JET ACTIVITY WITH INTRADAY γ -RAY VARIABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Neng-Hui; Xin, Yu-Liang; Fan, Yi-Zhong [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Fan, Xu-Liang [Graduate University of Chinese Academy of Sciences, Yuquan Road 19, Beijing 100049 (China); Weng, Shan-Shan [Department of Physics, Nanjing Normal University, Nanjing 210046 (China); Li, Shao-Kun [Key Laboratory for the Structure and Evolution of Celestial Objects, Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Chen, Liang, E-mail: liaonh@pmo.ac.cn, E-mail: yzfan@pmo.ac.cn [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)

    2016-10-01

    III Zw 2 is the prototype of radio-intermediate quasars. Although there is the evidence of possessing strong jet, significant γ -ray emission has not been reported before. In this work, we carry out a detailed analysis of the latest Fermi -LAT Pass  8 data. No significant γ -ray signal has been detected in the time-averaged 7-year Fermi -LAT data of III Zw 2; however, we have identified two distinct γ -ray flares with isotropic luminosities of ∼10{sup 45} erg s{sup −1}. Multiwavelength data analysis (also including the optical photometric observations from Yunnan Observatories) are presented and the main finding is simultaneous optical and γ -ray flares of III Zw 2 appearing in 2009 November. Violent γ -ray variability with a doubling timescale of 2.5 hr was detected in another γ -ray flare in May 2010, for which the 3-hr γ -ray peak flux is ∼250 times of the average flux in 7 years. Rather similar behaviors are observed in blazars and the blazar model can reasonably reproduce the spectral energy distribution of III Zw 2 in a wide energy range, strongly suggesting that its central engine resembles that of blazars. In view of its core, which shares radio similarities with young radio sources, together with weak extended radio lobe emission, we suggest that III Zw 2 harbors a recurrent activity core and thus serves as a valuable target for investigating the fueling and triggering of the activity in radio-loud active galactic nuclei.

  18. Evaluating the loudness of phantom auditory perception (tinnitus) in rats.

    Science.gov (United States)

    Jastreboff, P J; Brennan, J F

    1994-01-01

    Using our behavioral paradigm for evaluating tinnitus, the loudness of salicylate-induced tinnitus was evaluated in 144 rats by comparing their behavioral responses induced by different doses of salicylate to those induced by different intensities of a continuous reference tone mimicking tinnitus. Group differences in resistance to extinction were linearly related to salicylate dose and, at moderate intensities, to the reference tone as well. Comparison of regression equations for salicylate versus tone effects permitted estimation of the loudness of salicylate-induced tinnitus. These results extend the animal model of tinnitus and provide evidence that the loudness of phantom auditory perception is expressed through observable behavior, can be evaluated, and its changes detected.

  19. Learning for Everyday Life: Students' standpoints on loud sounds and use of hearing protectors before and after a teaching-learning intervention

    Science.gov (United States)

    West, Eva

    2012-11-01

    Researchers have highlighted the increasing problem of loud sounds among young people in leisure-time environments, recently even emphasizing portable music players, because of the risk of suffering from hearing impairments such as tinnitus. However, there is a lack of studies investigating compulsory-school students' standpoints and explanations in connection with teaching interventions integrating school subject content with auditory health. In addition, there are few health-related studies in the international science education literature. This paper explores students' standpoints on loud sounds including the use of hearing-protection devices in connection with a teaching intervention based on a teaching-learning sequence about sound, hearing and auditory health. Questionnaire data from 199 students, in grades 4, 7 and 8 (aged 10-14), from pre-, post- and delayed post-tests were analysed. Additionally, information on their experiences of tinnitus as well as their listening habits regarding portable music players was collected. The results show that more students make healthier choices in questions of loud sounds after the intervention, and especially among the older ones this result remains or is further improved one year later. There are also signs of positive behavioural change in relation to loud sounds. Significant gender differences are found; generally, the girls show more healthy standpoints and expressions than boys do. If this can be considered to be an outcome of students' improved and integrated knowledge about sound, hearing and health, then this emphasizes the importance of integrating health issues into regular school science.

  20. Radio emission from embryonic superluminous supernova remnants

    Science.gov (United States)

    Omand, Conor M. B.; Kashiyama, Kazumi; Murase, Kohta

    2018-02-01

    It has been widely argued that Type-I superluminous supernovae (SLSNe-I) are driven by powerful central engines with a long-lasting energy injection after the core-collapse of massive progenitors. One of the popular hypotheses is that the hidden engines are fast-rotating pulsars with a magnetic field of B ˜ 1013-1015 G. Murase, Kashiyama & Mészáros proposed that quasi-steady radio/submm emission from non-thermal electron-positron pairs in nascent pulsar wind nebulae can be used as a relevant counterpart of such pulsar-driven supernovae (SNe). In this work, focusing on the nascent SLSN-I remnants, we examine constraints that can be placed by radio emission. We show that the Atacama Large Millimeter/submillimetre Array can detect the radio nebula from SNe at DL ˜ 1 Gpc in a few years after the explosion, while the Jansky Very Large Array can also detect the counterpart in a few decades. The proposed radio follow-up observation could solve the parameter degeneracy in the pulsar-driven SN model for optical/UV light curves, and could also give us clues to young neutron star scenarios for SLSNe-I and fast radio bursts.

  1. A Fundamental Study on Influence of Concurrently Presented Visual Stimulus Upon Loudness Perception

    Directory of Open Access Journals (Sweden)

    Koji Abe

    2011-10-01

    Full Text Available As a basic study on the influence of the dynamic properties of the audio-visual stimuli upon interaction between audition and vision, the effect of the simple movement involved in the visual stimulus on the loudness perception of the audio stimulus was investigated via psychophysical experiment. In this experiment, the visual stimulus given to subjects along with the audio stimulus is a bar appeared on a display, one side of which is flexibly expanding and contracting. The loudness of the audio stimulus with such a visual effect concurrently presented was rated as an absolute numerical value by using the Magnitude Estimation method. The reference of the bar length is determined so as to correspond to the Zwicker's loudness calculated for the given audio stimulus. As a result, the visual stimulus did not affect the loudness perception, when the bar was presented with its length same as the reference. On the other hand, the rating of the loudness for the same audio stimulus was significantly increased when the bar length was longer than the reference. This indicates that the change in the correspondence between the audio and the visual stimuli affect the loudness perception.

  2. Temporal integration of loudness as a function of level

    DEFF Research Database (Denmark)

    Florentine, Mary; Buus, Søren; Poulsen, Torben

    1996-01-01

    Absolute thresholds were measured for 5-, 30-, and 200-ms stimuli using an adaptive, forced choice procedure. Temporal integration of loudness for these durations was also measured for a 1-kHz tone and for broadband noises over a range of 5-80 dB SL (noise) and 5-90 dB SL (tones). Results show...... that temporal integration (defined as the level difference between equally loud 5- and 200-ms stimuli) varies non-monotonically with level. The temporal integration is about 10-12 dB near threshold, increases to 18-19 dB when the 5-ms signal is about 56 dB SPL (tone) and 76 dB SPL (noise), decreases again...... that the growth of loudness may, at least in part, be consistent with the nonlinear input/output function of the basilar membrane....

  3. Binaural loudness summation for directional sounds

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka; Ellermeier, Wolfgang

    2006-01-01

    the binaural loudness summation of the at-ear signals. Even though the effects of HRTFs were taken into account, considerable individual differences in the binaural summation of loudness remained. In order to create conditions in which the directional at-ear changes were identical for all participants......, the present experiment employed 'generic' HRTFs to create directional sounds via binaural synthesis. When inspecting the results of the listening tests, however, large individual differences were still evident, as in the earlier study. The generality of this finding was further corroborated by running...... an independent, inexperienced sample of ten participants exclusively being exposed to the present generic HRTFs. Despite the individual differences, the average results suggest a relatively simple rule for combining the binaural input when carrying out acoustical measurements using an artificial head...

  4. A SOUND SOURCE LOCALIZATION TECHNIQUE TO SUPPORT SEARCH AND RESCUE IN LOUD NOISE ENVIRONMENTS

    Science.gov (United States)

    Yoshinaga, Hiroshi; Mizutani, Koichi; Wakatsuki, Naoto

    At some sites of earthquakes and other disasters, rescuers search for people buried under rubble by listening for the sounds which they make. Thus developing a technique to localize sound sources amidst loud noise will support such search and rescue operations. In this paper, we discuss an experiment performed to test an array signal processing technique which searches for unperceivable sound in loud noise environments. Two speakers simultaneously played a noise of a generator and a voice decreased by 20 dB (= 1/100 of power) from the generator noise at an outdoor space where cicadas were making noise. The sound signal was received by a horizontally set linear microphone array 1.05 m in length and consisting of 15 microphones. The direction and the distance of the voice were computed and the sound of the voice was extracted and played back as an audible sound by array signal processing.

  5. When tinnitus loudness and annoyance are discrepant: audiological characteristics and psychological profile.

    Science.gov (United States)

    Hiller, Wolfgang; Goebel, Gerhard

    2007-01-01

    This study evaluates sociodemographic and clinical characteristics of patients reporting discrepant levels of tinnitus loudness and annoyance. 4958 subjects recruited from a national tinnitus association completed a comprehensive screening questionnaire including Klockhoff and Lindblom's loudness grading system and the psychometric Mini-TQ (Tinnitus Questionnaire). There was a moderate correlation of 0.45 between loudness and annoyance. Of the subjects reporting very loud tinnitus, about one third had only mild or moderate annoyance scores. They were not different from those with high annoyance regarding age, gender and tinnitus duration, but annoyance was increased when subjects had additional hearing loss (OR = 1.71), vertigo/dizziness (OR = 1.94) or hyperacusis (OR = 4.96). Another significant predictor was history of neurological disease (OR = 3.16). Subjects reported low annoyance despite high loudness more often if not feeling low/depressed and not considering themselves as victims of their noises. A specific psychological profile was found to characterize annoyed tinnitus sufferers. Permanent awareness of the noises, decreased ability to ignore them and concentration difficulties were reported frequently even when overall annoyance scores were comparatively low. It is concluded that the coexistence of tinnitus with hearing loss, vertigo/dizziness and hyperacusis as complicating otological conditions seems to be of clinical relevance for the prediction of high annoyance levels. Tinnitus loudness and annoyance are not necessarily congruent and should be assessed separately. (c) 2007 S. Karger AG, Basel.

  6. Multiple-state based power control for multi-radio multi-channel wireless mesh networks

    CSIR Research Space (South Africa)

    Olwal, TO

    2009-01-01

    Full Text Available Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh networks (WMNs). In this paper, we present asynchronous multiple-state based power control for MRMC WMNs. First, WMN is represented as a set of disjoint...

  7. `Zwicky's Nonet': a compact merging ensemble of nine galaxies and 4C 35.06, a peculiar radio galaxy with dancing radio jets

    Science.gov (United States)

    Biju, K. G.; Bagchi, Joydeep; Ishwara-Chandra, C. H.; Pandey-Pommier, M.; Jacob, Joe; Patil, M. K.; Kumar, P. Sunil; Pandge, Mahadev; Dabhade, Pratik; Gaikwad, Madhuri; Dhurde, Samir; Abraham, Sheelu; Vivek, M.; Mahabal, Ashish A.; Djorgovski, S. G.

    2017-10-01

    We report the results of our radio, optical and infrared studies of a peculiar radio source 4C 35.06, an extended radio-loud active galactic nucleus (AGN) at the centre of galaxy cluster Abell 407 (z = 0.047). The central region of this cluster hosts a remarkably tight ensemble of nine galaxies, the spectra of which resemble those of passive red ellipticals, embedded within a diffuse stellar halo of ˜1 arcmin size. This system (named 'Zwicky's Nonet') provides unique and compelling evidence for a multiple-nucleus cD galaxy precursor. Multifrequency radio observations of 4C 35.06 with the Giant Meterwave Radio Telescope (GMRT) at 610, 235 and 150 MHz reveal a system of 400-kpc scale helically twisted and kinked radio jets and outer diffuse lobes. The outer extremities of jets contain extremely steep-spectrum (spectral index -1.7 to -2.5) relic/fossil radio plasma with a spectral age of a few ×(107-108) yr. Such ultra-steep spectrum relic radio lobes without definitive hotspots are rare and they provide an opportunity to understand the life cycle of relativistic jets and physics of black hole mergers in dense environments. We interpret our observations of this radio source in the context of growth of its central black hole, triggering of its AGN activity and jet precession, all possibly caused by galaxy mergers in this dense galactic system. A slow conical precession of the jet axis due to gravitational perturbation between interacting black holes is invoked to explain the unusual jet morphology.

  8. Female listeners’ autonomic responses to dramatic shifts between loud and soft music/sound passages: a study of heavy metal songs

    Directory of Open Access Journals (Sweden)

    Tzu-Han eCheng

    2016-02-01

    Full Text Available Although music and the emotion it conveys unfold over time, little is known about how listeners respond to shifts in musical emotions. A special technique in heavy metal music utilizes dramatic shifts between loud and soft passages. Loud passages are penetrated by distorted sounds conveying aggression, whereas soft passages are often characterized by a clean, calm singing voice and light accompaniment. The present study used heavy metal songs and soft sea sounds to examine how female listeners’ respiration rates and heart rates responded to the arousal changes associated with auditory stimuli. The high-frequency power of heart rate variability (HF-HRV was used to assess cardiac parasympathetic activity. The results showed that the soft passages of heavy metal songs and soft sea sounds expressed lower arousal and induced significantly higher HF-HRVs than the loud passages of heavy metal songs. Listeners’ respiration rate was determined by the arousal level of the present music passage, whereas the heart rate was dependent on both the present and preceding passages. Compared with soft sea sounds, the loud music passage led to greater deceleration of the heart rate at the beginning of the following soft music passage. The sea sounds delayed the heart rate acceleration evoked by the following loud music passage. The data provide evidence that sound-induced parasympathetic activity affects listener’s heart rate in response to the following music passage. These findings have potential implications for future research of the temporal dynamics of musical emotions.

  9. POWERFUL RADIO EMISSION FROM LOW-MASS SUPERMASSIVE BLACK HOLES FAVORS DISK-LIKE BULGES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.; Xu, Y.; Xu, D. W.; Wei, J. Y., E-mail: wj@bao.ac.cn [CAS Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing (China)

    2016-12-10

    The origin of spin of low-mass supermassive black holes (SMBHs) is still a puzzle at present. We report here a study on the host galaxies of a sample of radio-selected nearby ( z < 0.05) Seyfert 2 galaxies with a BH mass of 10{sup 6–7} M{sub ⊙}. By modeling the SDSS r -band images of these galaxies through a two-dimensional bulge+disk decomposition, we identify a new dependence of SMBH's radio power on host bulge surface brightness profiles, in which more powerful radio emission comes from an SMBH associated with a more disk-like bulge. This result means low-mass and high-mass SMBHs are spun up by two entirely different modes that correspond to two different evolutionary paths. A low-mass SMBH is spun up by a gas accretion with significant disk-like rotational dynamics of the host galaxy in the secular evolution, while a high-mass one by a BH–BH merger in the merger evolution.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Geeks, meta-Geeks, and gender trouble: activism, identity, and low-power FM radio.

    Science.gov (United States)

    Dunbar-Hester, Christina

    2008-04-01

    In this paper, I consider the activities of a group of individuals who tinker with and build radio hardware in an informal setting called 'Geek Group'. They conceive of Geek Group as a radical pedagogical activity, which constitutes an aspect of activism surrounding citizen access to low-power FM radio. They are also concerned with combating the gendered nature of hardware skills, yet in spite of their efforts men tend to have more skill and familiarity with radio hardware than women. Radio tinkering has a long history as a masculine undertaking and a site of masculine identity construction. I argue that this case represents an interplay between geek, activist, and gendered identities, all of which are salient for this group, but which do not occur together without some tension.

  12. Perceptual Weights for Loudness Judgments of 6-Tone Complexes

    DEFF Research Database (Denmark)

    Jesteadt, Walt; Valente, Daniel L.; Joshi, Suyash Narendra

    In a series of studies, 6 subjects with normal hearing (NH) and 3 with sensorineural hearing loss (SNHL) judged the overall loudness of 6-tone complexes comprised of octave frequencies from 0.25 to 8 kHz. In two tasks, tones were equated in level in dB SPL or in sensation level (SL) and a range....... In the “loudness” task there was no difference in mean level across the two intervals. In the “sample discrimination” task, the two complexes differed by an average of 5 dB. For both tasks, perceptual weights were derived by correlating the differences in level between matched-frequency tones in the complexes...... and the loudness decision on each trial. Weights derived from the loudness task (no mean level difference) were highly correlated with weights derived from the sample discrimination task (5-dB difference). For SPL conditions, both NH and SNHL subjects placed less weight on the lowest frequency and greater weight...

  13. Architectures/Algorithms/Tools for Ultra-Low Power, Compact EVA Digital Radio, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The EVA digital radio imposes tight constraints on power consumption, latency, throughput, form factor, reconfigurability, single event upset and fault tolerance,...

  14. The impact of rate reduction and increased loudness on fundamental frequency characteristics in dysarthria.

    Science.gov (United States)

    Tjaden, Kris; Wilding, Greg

    2011-01-01

    This study examined the extent to which articulatory rate reduction and increased loudness were associated with adjustments in utterance-level measures of fundamental frequency (F(0)) variability for speakers with dysarthria and healthy controls that have been shown to impact on intelligibility in previously published studies. More generally, the current study sought to compare and contrast how a slower-than-normal rate and increased vocal loudness impact on a variety of utterance-level F(0) characteristics for speakers with dysarthria and healthy controls. Eleven speakers with Parkinson's disease, 15 speakers with multiple sclerosis, and 14 healthy control speakers were audio recorded while reading a passage in habitual, loud, and slow conditions. Magnitude production was used to elicit variations in rate and loudness. Acoustic measures of duration, intensity and F(0) were obtained. For all speaker groups, a slower-than-normal articulatory rate and increased vocal loudness had distinct effects on F(0) relative to the habitual condition, including a tendency for measures of F(0) variation to be greater in the loud condition and reduced in the slow condition. These results suggest implications for the treatment of dysarthria. Copyright © 2010 S. Karger AG, Basel.

  15. Perceptual Bias and Loudness Change: An Investigation of Memory, Masking, and Psychophysiology

    Science.gov (United States)

    Olsen, Kirk N.

    Loudness is a fundamental aspect of human auditory perception that is closely associated with a sound's physical acoustic intensity. The dynamic quality of intensity change is an inherent acoustic feature in real-world listening domains such as speech and music. However, perception of loudness change in response to continuous intensity increases (up-ramps) and decreases (down-ramps) has received relatively little empirical investigation. Overestimation of loudness change in response to up-ramps is said to be linked to an adaptive survival response associated with looming (or approaching) motion in the environment. The hypothesised 'perceptual bias' to looming auditory motion suggests why perceptual overestimation of up-ramps may occur; however it does not offer a causal explanation. It is concluded that post-stimulus judgements of perceived loudness change are significantly affected by a cognitive recency response bias that, until now, has been an artefact of experimental procedure. Perceptual end-level differences caused by duration specific sensory adaptation at peripheral and/or central stages of auditory processing may explain differences in post-stimulus judgements of loudness change. Experiments that investigate human responses to acoustic intensity dynamics, encompassing topics from basic auditory psychophysics (e.g., sensory adaptation) to cognitive-emotional appraisal of increasingly complex stimulus events such as music and auditory warnings, are proposed for future research.

  16. Influence of the radio-frequency power on the physical and optical properties of plasma polymerized cyclohexane thin films

    Energy Technology Data Exchange (ETDEWEB)

    Manaa, C., E-mail: chadlia.el.manaa@gmail.com [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Lejeune, M. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Kouki, F. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Durand-Drouhin, O. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Bouchriha, H. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); and others

    2014-06-02

    We investigate in the present study the effects of the radio-frequency plasma power on the opto-electronical properties of the polymeric amorphous hydrogenated carbon thin films deposited at room temperature and different radio-frequency powers by plasma-enhanced chemical vapor deposition method using cyclohexane as precursor. A combination of U.V.–Visible and infrared transmission measurements is applied to characterize the bonding and electronic properties of these films. Some film properties namely surface roughness, contact angle, surface energy, and optical properties are found to be significantly influenced by the radio-frequency power. The changes in these properties are analyzed within the microstructural modifications occurring during growth. - Highlights: • Effects of the radio-frequency power on the optoelectronic properties of thin films • Elaboration of plasma polymerized thin films using cyclohexane as precursor gas • The use of U.V.–Visible-infrared transmission, and optical gap • Study of the surface topography of the films by using Atomic Force microscopy • The use of a capacitively coupled plasma enhanced chemical vapor deposition method.

  17. Influence of the radio-frequency power on the physical and optical properties of plasma polymerized cyclohexane thin films

    International Nuclear Information System (INIS)

    Manaa, C.; Lejeune, M.; Kouki, F.; Durand-Drouhin, O.; Bouchriha, H.

    2014-01-01

    We investigate in the present study the effects of the radio-frequency plasma power on the opto-electronical properties of the polymeric amorphous hydrogenated carbon thin films deposited at room temperature and different radio-frequency powers by plasma-enhanced chemical vapor deposition method using cyclohexane as precursor. A combination of U.V.–Visible and infrared transmission measurements is applied to characterize the bonding and electronic properties of these films. Some film properties namely surface roughness, contact angle, surface energy, and optical properties are found to be significantly influenced by the radio-frequency power. The changes in these properties are analyzed within the microstructural modifications occurring during growth. - Highlights: • Effects of the radio-frequency power on the optoelectronic properties of thin films • Elaboration of plasma polymerized thin films using cyclohexane as precursor gas • The use of U.V.–Visible-infrared transmission, and optical gap • Study of the surface topography of the films by using Atomic Force microscopy • The use of a capacitively coupled plasma enhanced chemical vapor deposition method

  18. Workshop on Satellite Power Systems (SPS) effects on optical and radio astronomy

    International Nuclear Information System (INIS)

    Stokes, G.M.; Ekstrom, P.A.

    1980-04-01

    The impacts of the SPS on astronomy were concluded to be: increased sky brightness, reducing the effective aperture of terrestrial telescopes; microwave leakage radiation causing erroneous radioastronomical signals; direct overload of radioastronomical receivers at centimeter wavelengths; and unintentional radio emissions associated with massive amounts of microwave power or with the presence of large, warm structures in orbit causing the satellites to appear as individual stationary radio sources; finally, the fixed location of the geostationary satellite orbits would result in fixed regions of the sky being unusable for observations

  19. A Loudness Function for Maintaining Spectral Balance at Changing Sound Pressure Levels

    DEFF Research Database (Denmark)

    Nielsen, Sofus Birkedal

    Our perception of loudness is a function of frequency as well as sound pressure level as described in ISO226:2003: Normal Equal Loudness Level Contours, which describes the needed sound pressure level for pure tones to be perceived equally loud. At a music performance, this is taking care...... of by the sound engineer by listening to the individual sound sources and adjust and equalize them to the wanted spectral balance including the whole chain of audio equipment and surroundings. At a live venue the sound pressure level will normally change during a concert, and typically increase over time......B is doubling of the effect to the loudspeakers). A level depending digital loudness function has been made based on ISO226:2003, and will be demonstrated. It can maintain the spectral balance at alternating levels and is based on fractional order digital filters. Tutorial. Abstract T3.3 (30th August 16:00 - 17...

  20. Removing radio-active wastes from nuclear power stations by the STEAG system

    International Nuclear Information System (INIS)

    Baatz, H.

    1978-01-01

    The mobile STEAG System for conditioning radio-active wastes from nuclear power stations represents a particularly safe and economic method of removing them in present day conditions. Cementation by the FAFNIR System is used for the greater part of the waste, the liquid concentrate (evaporator concentrate and filter slurry). For the special case of the medium active resin balls from the primary circuits, embedding in plastic by the FAMA process has proved to be the only available successful process so far. The highly active solid waste from the reactor core is decomposed by the MOSAIK System, is packed in transportable and storable containers and is removed from the fuel element storage pond. The systems are so safe that faults or interruptions of power station operation due to faults in removing radio-active wastes can be excluded. (orig.) [de

  1. Designing movement-based play with young people using powered wheelchairs

    DEFF Research Database (Denmark)

    Gerling, Kathrin M; Hicks, Kieran C; Kalyn, Michael R

    2016-01-01

    people who have special needs) and 2) three case studies (4 participants) exploring player perspectives on a set of three wheelchair-controlled casual games. Our results show that movement-based playful experiences are engaging for young people using powered wheelchairs. However, the participatory design...... in the development of accessible, empowering movement-based games, which is crucial to the wider participation of young people using powered wheelchairs in play.......Young people using powered wheelchairs have limited access to engaging leisure activities. We address this issue through a two-stage project; 1) the participatory development of a set of wheelchair-controlled, movement-based games (with 9 participants at a school that provides education for young...

  2. 2.2 micron image of 3C 368 at z = 1.13, a galaxy with aligned radio and stellar axes

    International Nuclear Information System (INIS)

    Chambers, K.C.; Miley, G.K.; Joyce, R.R.

    1988-01-01

    A K-band IR image of the z = 1.13 radio galaxy 3C 368, one of the brightest examples of the recently discovered phenomenon of alignment between the optical and radio axes of powerful distant radio galaxies, is presented. The observations show that the IR morphology is also elongated and aligned along the optical and radio axes, but is not coincident with the radio emission. Various mechanisms for producing the IR and optical flux and the resultant constraints on the origin of the alignment effect in high-redshift radio galaxies are discussed. The most likely explanation is that the emission is produced mainly by young stars formed by interaction of the radio source with the ISM. The IR flux is then interpreted as dominated by a population of red supergiants. Independent of the origin of the emission, the observed alignment implies that powerful radio galaxies at high redshifts are distant from giant ellipticals, even in the IR. Hence, attempts to derive a cosmological standard candle using studies which combine these two types of galaxies are likely to be invalid. 32 references

  3. 78 FR 70907 - Implementation of the Commercial Advertisement Loudness Mitigation (CALM) Act

    Science.gov (United States)

    2013-11-27

    ... television industry can monitor and control the loudness level of digital TV programming. The rules took... references ITU-R BS.1770-3.''). As explained in the CALM Act Report and Order, the ITU-R BS.1770 measurement... includes improved guidance for measuring the loudness of surround programming in both its multichannel...

  4. SHORT- AND LONG-TERM RADIO VARIABILITY OF YOUNG STARS IN THE ORION NEBULA CLUSTER AND MOLECULAR CLOUD

    International Nuclear Information System (INIS)

    Rivilla, V. M.; Martín-Pintado, J.; Chandler, C. J.; Sanz-Forcada, J.; Jiménez-Serra, I.; Forbrich, J.

    2015-01-01

    young clusters detected at radio wavelengths, which will help us improve our understanding of the origin and nature of the radio emission

  5. Pitch and Loudness from Tinnitus in Individuals with Noise-induced Hearing Loss

    Directory of Open Access Journals (Sweden)

    Flores, Leticia Sousa

    2015-08-01

    Full Text Available Introduction Tinnitus is one of the symptoms that affects individuals suffering from noise induced hearing loss. This condition can be disabling, leading the affected individual to turn away from work. Objective This literature review aims to analyze the possible association between gender and tinnitus pitch and loudness, the degree of hearing loss and the frequencies affected in subjects with noise-induced hearing loss. Methods This contemporary cohort study was conducted through a cross-sectional analysis. The study sample consisted of adults with unilateral or bilateral tinnitus, who had been diagnosed with noise-induced hearing loss. The patients under analysis underwent an otorhinolaryngological evaluation, pure tone audiometry, and acuphenometry. Results The study included 33 subjects with noise-induced hearing loss diagnoses, of which 22 (66.7% were men. Authors observed no statistical difference between gender and loudness/pitch tinnitus and loudness/pitch in subjects with bilateral tinnitus. Authors found an inverse relation between tinnitus loudness with intensity greater hearing threshold and the average of the thresholds and the grade of hearing loss. The tinnitus pitch showed no association with higher frequency of hearing threshold. Conclusion Data analysis shows that, among the individuals evaluated, the greater the hearing loss, the lower the loudness of tinnitus. We did not observe an association between hearing loss and tinnitus pitch.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. MULTIWAVELENGTH OBSERVATIONS OF RADIO-QUIET QUASARS WITH WEAK EMISSION LINES

    International Nuclear Information System (INIS)

    Plotkin, Richard M.; Anderson, Scott F.; MacLeod, Chelsea L.; Brandt, W. N.; Schneider, Donald P.; Diamond-Stanic, Aleksandar M.; Fan Xiaohui; Shemmer, Ohad

    2010-01-01

    We present radio and X-ray observations, as well as optical light curves, for a subset of 26 BL Lac candidates from the Sloan Digital Sky Survey (SDSS) lacking strong radio emission and with z < 2.2. Half of these 26 objects are shown to be stars, galaxies, or absorbed quasars. We conclude that the other 13 objects are active galactic nuclei (AGNs) with abnormally weak emission features; 10 of those 13 are definitively radio quiet, and, for those with available optical light curves, their level of optical flux variability is consistent with radio-quiet quasars. We cannot exclude the possibility that some of these 13 AGNs lie on the extremely radio-faint tail of the BL Lac distribution, but our study generally supports the notion that all BL Lac objects are radio-loud. These radio-quiet AGNs appear to have intrinsically weak or absent broad emission line regions (BELRs), and, based on their X-ray properties, we argue that some are low-redshift analogs to weak line quasars (WLQs). SDSS BL Lac searches are so far the only systematic surveys of the SDSS database capable of recovering such exotic low-redshift WLQs. There are 71 more z < 2.2 radio-quiet BL Lac candidates already identified in the SDSS, but not considered here, and many of those might be best unified with WLQs as well. Future studies combining low- and high-redshift WLQ samples will yield new insight on our understanding of the structure and formation of AGN BELRs.

  8. Infrared-faint radio sources remain undetected at far-infrared wavelengths. Deep photometric observations using the Herschel Space Observatory

    Science.gov (United States)

    Herzog, A.; Norris, R. P.; Middelberg, E.; Spitler, L. R.; Leipski, C.; Parker, Q. A.

    2015-08-01

    Context. Showing 1.4 GHz flux densities in the range of a few to a few tens of mJy, infrared-faint radio sources (IFRS) are a type of galaxy characterised by faint or absent near-infrared counterparts and consequently extreme radio-to-infrared flux density ratios up to several thousand. Recent studies showed that IFRS are radio-loud active galactic nuclei (AGNs) at redshifts ≳2, potentially linked to high-redshift radio galaxies (HzRGs). Aims: This work explores the far-infrared emission of IFRS, providing crucial information on the star forming and AGN activity of IFRS. Furthermore, the data enable examining the putative relationship between IFRS and HzRGs and testing whether IFRS are more distant or fainter siblings of these massive galaxies. Methods: A sample of six IFRS was observed with the Herschel Space Observatory between 100 μm and 500 μm. Using these results, we constrained the nature of IFRS by modelling their broad-band spectral energy distribution (SED). Furthermore, we set an upper limit on their infrared SED and decomposed their emission into contributions from an AGN and from star forming activity. Results: All six observed IFRS were undetected in all five Herschel far-infrared channels (stacking limits: σ = 0.74 mJy at 100 μm, σ = 3.45 mJy at 500 μm). Based on our SED modelling, we ruled out the following objects to explain the photometric characteristics of IFRS: (a) known radio-loud quasars and compact steep-spectrum sources at any redshift; (b) starburst galaxies with and without an AGN and Seyfert galaxies at any redshift, even if the templates were modified; and (c) known HzRGs at z ≲ 10.5. We find that the IFRS analysed in this work can only be explained by objects that fulfil the selection criteria of HzRGs. More precisely, IFRS could be (a) known HzRGs at very high redshifts (z ≳ 10.5); (b) low-luminosity siblings of HzRGs with additional dust obscuration at lower redshifts; (c) scaled or unscaled versions of Cygnus A at any

  9. Loud Noise Exposure Produces DNA, Neurotransmitter and Morphological Damage within Specific Brain Areas

    Directory of Open Access Journals (Sweden)

    Giada Frenzilli

    2017-06-01

    Full Text Available Exposure to loud noise is a major environmental threat to public health. Loud noise exposure, apart from affecting the inner ear, is deleterious for cardiovascular, endocrine and nervous systems and it is associated with neuropsychiatric disorders. In this study we investigated DNA, neurotransmitters and immune-histochemical alterations induced by exposure to loud noise in three major brain areas (cerebellum, hippocampus, striatum of Wistar rats. Rats were exposed to loud noise (100 dBA for 12 h. The effects of noise on DNA integrity in all three brain areas were evaluated by using Comet assay. In parallel studies, brain monoamine levels and morphology of nigrostriatal pathways, hippocampus and cerebellum were analyzed at different time intervals (24 h and 7 days after noise exposure. Loud noise produced a sudden increase in DNA damage in all the brain areas under investigation. Monoamine levels detected at 7 days following exposure were differently affected depending on the specific brain area. Namely, striatal but not hippocampal dopamine (DA significantly decreased, whereas hippocampal and cerebellar noradrenaline (NA was significantly reduced. This is in line with pathological findings within striatum and hippocampus consisting of a decrease in striatal tyrosine hydroxylase (TH combined with increased Bax and glial fibrillary acidic protein (GFAP. Loud noise exposure lasting 12 h causes immediate DNA, and long-lasting neurotransmitter and immune-histochemical alterations within specific brain areas of the rat. These alterations may suggest an anatomical and functional link to explain the neurobiology of diseases which prevail in human subjects exposed to environmental noise.

  10. Energy-Efficient Power Allocation for Underlay Cognitive Radio Systems

    KAUST Repository

    Sboui, Lokman

    2015-09-01

    We present a power allocation framework for spectrum sharing Cognitive Radio (CR) systems based on maximizing the energy efficiency (EE). First, we show that the relation between the EE and the spectral efficiency (SE) is strictly increasing in contrast with the SE-EE trade-off discussed in the literature. We also solve a non-convex problem and explicitly derive the optimal power for the proposed average EE under either a peak or an average power constraint. We apply our results to the underlay CR systems where the power is limited by an additional interference constraint. When the instantaneous channel is not available, we provide a necessary and sufficient condition for the optimal power and present a simple sub-optimal power. In the numerical results, we show that the proposed EE corresponds to a higher SE at mid-range and high power regime compared to the classical EE. We also show that the sup-optimal solution is very close to the optimal solution. In addition, we deduce that the absence of instantaneous CSI affects the EE and the SE at high power regime compared to full CSI. In the CR context, we show that the interference threshold has a minimal effect on the EE compared to the SE.

  11. Energy-Efficient Power Allocation for Underlay Cognitive Radio Systems

    KAUST Repository

    Sboui, Lokman; Rezki, Zouheir; Alouini, Mohamed-Slim

    2015-01-01

    We present a power allocation framework for spectrum sharing Cognitive Radio (CR) systems based on maximizing the energy efficiency (EE). First, we show that the relation between the EE and the spectral efficiency (SE) is strictly increasing in contrast with the SE-EE trade-off discussed in the literature. We also solve a non-convex problem and explicitly derive the optimal power for the proposed average EE under either a peak or an average power constraint. We apply our results to the underlay CR systems where the power is limited by an additional interference constraint. When the instantaneous channel is not available, we provide a necessary and sufficient condition for the optimal power and present a simple sub-optimal power. In the numerical results, we show that the proposed EE corresponds to a higher SE at mid-range and high power regime compared to the classical EE. We also show that the sup-optimal solution is very close to the optimal solution. In addition, we deduce that the absence of instantaneous CSI affects the EE and the SE at high power regime compared to full CSI. In the CR context, we show that the interference threshold has a minimal effect on the EE compared to the SE.

  12. Visibility-based angular power spectrum estimation in low-frequency radio interferometric observations

    NARCIS (Netherlands)

    Choudhuri, Samir; Bharadwaj, Somnath; Ghosh, Abhik; Ali, Sk. Saiyad

    2014-01-01

    We present two estimators to quantify the angular power spectrum of the sky signal directly from the visibilities measured in radio interferometric observations. This is relevant for both the foregrounds and the cosmological 21-cm signal buried therein. The discussion here is restricted to the

  13. Too Loud for Too Long! PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the February 2017 CDC Vital Signs report. Being around too much loud noise-like a leaf blower or rock concert-can cause permanent hearing loss. Learn how to prevent hearing loss.

  14. PSR J1755-2550: a young radio pulsar with a massive, compact companion

    Science.gov (United States)

    Ng, C.; Kruckow, M. U.; Tauris, T. M.; Lyne, A. G.; Freire, P. C. C.; Ridolfi, A.; Caiazzo, I.; Heyl, J.; Kramer, M.; Cameron, A. D.; Champion, D. J.; Stappers, B.

    2018-06-01

    Radio pulsars found in binary systems with short orbital periods are usually fast spinning as a consequence of recycling via mass transfer from their companion stars; this process is also thought to decrease the magnetic field of the neutron star being recycled. Here, we report on timing observations of the recently discovered binary PSR J1755-2550 and find that this pulsar is an exception: with a characteristic age of 2.1 Myr, it is relatively young; furthermore, with a spin period of 315 ms and a surface magnetic field strength at its poles of 0.88 × 1012 G, the pulsar shows no sign of having been recycled. Based on its timing and orbital characteristics, the pulsar either has a massive white dwarf (WD) or a neutron star (NS) companion. To distinguish between these two cases, we searched radio observations for a potential recycled pulsar companion and analysed archival optical data for a potential WD companion. Neither work returned conclusive detections. We apply population synthesis modelling and find that both solutions are roughly equally probable. Our population synthesis also predicts a minimum mass of 0.90 M⊙ for the companion star to PSR J1755-2550 and we simulate the systemic runaway velocities for the resulting WDNS systems which may merge and possibly produce Ca-rich supernovae. Whether PSR J1755-2550 hosts a WD or a NS companion star, it is certainly a member of a rare subpopulation of binary radio pulsars.

  15. Acoustical topology optimization for Zwicker's loudness model - Application to noise barriers

    DEFF Research Database (Denmark)

    Kook, Junghwan; Koo, Kunmo; Hyun, Jaeyub

    2012-01-01

    acoustic properties may not represent adequate parameters for optimizing acoustic devices. In this paper, we first present a design method for acoustical topology optimization by considering human's subjective conception of sound. To consider human hearing characteristics. Zwicker's loudness is calculated...... according to DIN45631 (ISO 532B). The main objective of this work is to minimize the main specific loudness of a target critical band rate by optimizing the distribution of the reflecting material in a design domain. The Helmholtz equation is used to model acoustic wave propagation and, it is solved using...... the finite element method. The sensitivity of the main specific loudness is calculated using the adjoint variable method and the chain rule. To demonstrate the effectiveness of the proposed method, various examples of noise barriers are presented with different source and receiver locations. The results...

  16. The importance of Radio Quiet Zone (RQZ) for radio astronomy

    Science.gov (United States)

    Umar, Roslan; Abidin, Zamri Zainal; Ibrahim, Zainol Abidin

    2013-05-01

    Most of radio observatories are located in isolated areas. Since radio sources from the universe is very weak, astronomer need to avoid radio frequency interference (RFI) from active spectrum users and radio noise produced by human made (telecommunication, mobile phone, microwave user and many more. There are many observatories around the world are surrounded by a Radio Quiet Zone (RQZ), which is it was set up using public or state laws. A Radio Quiet Zone normally consists of two areas: an exclusive area in which totally radio emissions are forbidden, with restrictions for residents and business developments, and a larger (radius up to 100 km above) coordination area where the power of radio transmission limits to threshold levels. Geographical Information System (GIS) can be used as a powerful tool in mapping large areas with varying RQZ profiles. In this paper, we report the initial testing of the usage of this system in order to identify the areas were suitable for Radio Quiet Zone. Among the important parameters used to develop the database for our GIS are population density, information on TV and telecommunication (mobile phones) transmitters, road networks (highway), and contour shielding. We will also use other information gathered from on-site RFI level measurements on selected 'best' areas generated by the GIS. The intention is to find the best site for the purpose of establishing first radio quiet zones for radio telescope in Malaysia.

  17. Directional loudness in an anechoic sound field, head-related transfer functions, and binaural summation

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka; Ellermeier, Wolfgang

    2006-01-01

    planes. Matches were obtained via a two-interval, adaptive forced-choice (2AFC) procedure for three center frequencies (0.4, 1 and 5 kHz) and two overall levels (45 and 65 dB SPL). The results showed that loudness is not constant over sound incidence angles, with directional sensitivity varying over......The effect of sound incidence angle on loudness was investigated using real sound sources positioned in an anechoic chamber. Eight normal-hearing listeners produced loudness matches between a frontal reference location and seven sources placed at other directions, both in the horizontal and median...... a range of up to 10 dB, exhibiting considerable frequency dependence, but only minor effects of overall level. The pattern of results varied substantially between subjects, but was largely accounted for by variations in individual head-related transfer functions. Modeling of binaural loudness based...

  18. Satellites of radio AGN in SDSS: Insights into agn triggering and feedback

    Energy Technology Data Exchange (ETDEWEB)

    Pace, Cameron; Salim, Samir, E-mail: cjpace@indiana.edu, E-mail: salims@indiana.edu [Indiana University, Department of Astronomy, Swain Hall West 319, Bloomington, IN 47405-7105 (United States)

    2014-04-10

    We study the effects of radio jets on galaxies in their vicinity (satellites) and the role of satellites in triggering radio-loud active galactic nuclei (AGNs). The study compares the aggregate properties of satellites of a sample of 7220 radio AGNs at z < 0.3 (identified by Best and Heckman from the SDSS and NVSS+FIRST surveys) to the satellites of a control sample of radio-quiet galaxies, which are matched in redshift, color, luminosity, and axis ratio, as well as by environment type: field galaxies, cluster members, and brightest cluster galaxies (BCGs). Remarkably, we find that radio AGNs exhibit on average a 50% excess (17σ significance) in the number of satellites within 100 kpc even though the cluster membership was controlled (e.g., radio BCGs have more satellites than radio-quiet BCGs, etc.). Satellite excess is not confirmed for high-excitation sources, which are only 2% of radio AGN. Extra satellites may be responsible for raising the probability for hot gas AGN accretion via tidal effects or may otherwise enhance the intensity or duration of the radio-emitting phase. Furthermore, we find that the incidence of radio AGNs among potential hosts (massive ellipticals) is similar for field galaxies and for non-BCG cluster members, suggesting that AGN fueling depends primarily on conditions in the host halo rather than the parent, cluster halo. Regarding feedback, we find that radio AGNs, either high or low excitation, have no detectable effect on star formation in their satellites, as neither induced star formation nor star formation quenching is present in more than ∼1% of radio AGN.

  19. Satellites of radio AGN in SDSS: Insights into agn triggering and feedback

    International Nuclear Information System (INIS)

    Pace, Cameron; Salim, Samir

    2014-01-01

    We study the effects of radio jets on galaxies in their vicinity (satellites) and the role of satellites in triggering radio-loud active galactic nuclei (AGNs). The study compares the aggregate properties of satellites of a sample of 7220 radio AGNs at z < 0.3 (identified by Best and Heckman from the SDSS and NVSS+FIRST surveys) to the satellites of a control sample of radio-quiet galaxies, which are matched in redshift, color, luminosity, and axis ratio, as well as by environment type: field galaxies, cluster members, and brightest cluster galaxies (BCGs). Remarkably, we find that radio AGNs exhibit on average a 50% excess (17σ significance) in the number of satellites within 100 kpc even though the cluster membership was controlled (e.g., radio BCGs have more satellites than radio-quiet BCGs, etc.). Satellite excess is not confirmed for high-excitation sources, which are only 2% of radio AGN. Extra satellites may be responsible for raising the probability for hot gas AGN accretion via tidal effects or may otherwise enhance the intensity or duration of the radio-emitting phase. Furthermore, we find that the incidence of radio AGNs among potential hosts (massive ellipticals) is similar for field galaxies and for non-BCG cluster members, suggesting that AGN fueling depends primarily on conditions in the host halo rather than the parent, cluster halo. Regarding feedback, we find that radio AGNs, either high or low excitation, have no detectable effect on star formation in their satellites, as neither induced star formation nor star formation quenching is present in more than ∼1% of radio AGN.

  20. A DETAILED STUDY OF THE LOBES OF ELEVEN POWERFUL RADIO GALAXIES

    International Nuclear Information System (INIS)

    Daly, Ruth A.; Mory, Matthew P.; McKane, Justin; Altenderfer, Christopher; Beury, Michael; Kharb, Preeti; O'Dea, Christopher P.; Baum, Stefi A.

    2010-01-01

    Radio lobes of a sample of 11 very powerful classical double radio galaxies were studied. Each source was rotated so that the symmetry axis of the source was horizontal, and vertical cross-sectional cuts were taken across the source at intervals of one beam size. These were used to study the cross-sectional surface brightness profiles, the width of each slice, radio emissivity as a function of position across each slice, the first and second moments, and the average surface brightness, minimum-energy magnetic field strength, and pressure of each slice. Typically, a Gaussian provides a good description of the surface brightness profile of cross-sectional slices. The Gaussian full width at half-maximum (FWHM) as a function of distance from the hot spot first increases and then decreases with increasing distance from the hot spot. The width as a function of distance from the hot spot is generally highly symmetric on each side of the source. The radio emissivity is often close to flat across a slice, indicating a roughly constant emissivity and pressure for that slice. Some slices show variations in radio emissivity that indicate an 'edge-peaked' pressure profile for that slice. When this occurs, it is generally found in slices near the local maxima of the bridge width. The emissivity does not exhibit any signature of emission from a jet. The first moment is generally quite close to zero indicating only small excursions of the ridgeline from the symmetry axis of the source. The second moment indicates the same source shape as is found using the Gaussian FWHM. The average surface brightness is peaked at the hot spot, and is fairly flat across most of the radio lobes. The average magnetic field strength and pressure peak at the hot spot and gradually decrease with increasing distance from the hot spot, reaching a roughly constant value at a location that is typically just before the location of a local maximum of the bridge width. These results are interpreted in terms

  1. DISCOVERY OF A PSEUDOBULGE GALAXY LAUNCHING POWERFUL RELATIVISTIC JETS

    Energy Technology Data Exchange (ETDEWEB)

    Kotilainen, Jari K.; Olguín-Iglesias, Alejandro [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, FI-21500 Piikkiö (Finland); León-Tavares, Jonathan; Baes, Maarten [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281-S9, B-9000 Gent (Belgium); Anórve, Christopher [Facultad de Ciencias de la Tierra y del Espacio de la Universidad Autónoma de Sinaloa, Blvd. de la Americas y Av. Universitarios S/N, Ciudad Universitaria, C.P. 80010, Culiacán Sinaloa, México (Mexico); Chavushyan, Vahram; Carrasco, Luis, E-mail: jarkot@utu.fi [Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE), Apartado Postal 51 y 216, 72000 Puebla (Mexico)

    2016-12-01

    Supermassive black holes launching plasma jets at close to the speed of light, producing gamma-rays, have ubiquitously been found to be hosted by massive elliptical galaxies. Since elliptical galaxies are generally believed to be built through galaxy mergers, active galactic nuclei (AGN) launching relativistic jets are associated with the latest stages of galaxy evolution. We have discovered a pseudobulge morphology in the host galaxy of the gamma-ray AGN PKS 2004-447. This is the first gamma-ray emitter radio-loud AGN found to have been launched from a system where both the black hole and host galaxy have been actively growing via secular processes. This is evidence of an alternative black hole–galaxy co-evolutionary path to develop powerful relativistic jets, which is not merger driven.

  2. Lightning current distribution to ground at a power line tower carrying a radio base station

    NARCIS (Netherlands)

    Grcev, L.; Deursen, van A.P.J.; Waes, van J.B.M.

    2005-01-01

    Radio base stations are often mounted on towers of power transmission lines. They are usually powered from the low-voltage network through an isolating transformer, to separate the high- and low-voltage networks. The isolating transformer ensures security at customers' premises in the case of nearby

  3. Bandwidth and power allocation for two-way relaying in overlay cognitive radio systems

    KAUST Repository

    Alsharoa, Ahmad M.; Ghazzai, Hakim; Yaacoub, Elias E.; Alouini, Mohamed-Slim

    2014-01-01

    In this paper, the problem of both bandwidth and power allocation for two-way multiple relay systems in overlay cognitive radio (CR) setup is investigated. In the CR overlay mode, primary users (PUs) cooperate with cognitive users (CUs) for mutual

  4. Evolution of radio quasars from redshift 0.6-3.7

    International Nuclear Information System (INIS)

    Neff, S.G.; Hutchings, J.B.

    1990-01-01

    This paper presents the results of VLA radio imaging of 58 radio-loud quasars with redshift 2.0 or higher, which fill the redshift-luminosity plane as evenly as possible. This work completes a survey of about 250 quasars covering redshifts from 0.6-3.7, which attempts to sample luminosity and look-back time in a uniform way. Within the constraints of possible selection effects it is found that the relative population of extended and unresolved sources changes with redshift in a way that suggests that radio quasars may live longer and spend more time as large triple sources in the present epoch than in the earlier universe. There appear to be few low-luminosity radio quasars at high redshift. Ejection of material appears to occur on one side at a time, with usually at least one reversal of direction in the source lifetime. The velocity of ejection appears to be mildly relativistic at high redshift, but of lower velocity in the present epoch. There is also evidence suggestive of changes in the IGM with cosmic time; however, the data presented do not show the minimum in density at z about 2 that has been suggested for cluster environments. 11 refs

  5. Reduced-dimension power allocation over clustered channels in cognitive radios system under co-channel interference

    KAUST Repository

    Ben Ghorbel, Mahdi

    2014-05-12

    The objective of this paper is to propose a reduceddimension resource allocation scheme in the context of cognitive radio system in presence of co-channel interference between users. We assume a multicarrier transmission for both the primary and secondary systems. Instead of optimizing the powers over all sub-carriers, the sub-carriers are grouped into clusters of sub-carriers, where the power of each sub-carrier is directly related to the power of the correspondent cluster. The power optimization is done only over the set of clusters instead of all sub-carriers which can significantly reduce the complexity of the resource allocation problem. The performance loss of the reduced dimension solution with respect to the optimal solution, where the optimization is carried over all active sub-carriers, allows trading-off complexity versus performance. Numerical evaluation indeed revealed that a limited performance loss occurs by optimizing over a reduced set of clusters instead of the full optimization in the context of cognitive radio systems.

  6. Continuous loudness response to acoustic intensity dynamics in melodies: effects of melodic contour, tempo, and tonality.

    Science.gov (United States)

    Olsen, Kirk N; Stevens, Catherine J; Dean, Roger T; Bailes, Freya

    2014-06-01

    The aim of this work was to investigate perceived loudness change in response to melodies that increase (up-ramp) or decrease (down-ramp) in acoustic intensity, and the interaction with other musical factors such as melodic contour, tempo, and tonality (tonal/atonal). A within-subjects design manipulated direction of linear intensity change (up-ramp, down-ramp), melodic contour (ascending, descending), tempo, and tonality, using single ramp trials and paired ramp trials, where single up-ramps and down-ramps were assembled to create continuous up-ramp/down-ramp or down-ramp/up-ramp pairs. Twenty-nine (Exp 1) and thirty-six (Exp 2) participants rated loudness continuously in response to trials with monophonic 13-note piano melodies lasting either 6.4s or 12s. Linear correlation coefficients >.89 between loudness and time show that time-series loudness responses to dynamic up-ramp and down-ramp melodies are essentially linear across all melodies. Therefore, 'indirect' loudness change derived from the difference in loudness at the beginning and end points of the continuous response was calculated. Down-ramps were perceived to change significantly more in loudness than up-ramps in both tonalities and at a relatively slow tempo. Loudness change was also greater for down-ramps presented with a congruent descending melodic contour, relative to an incongruent pairing (down-ramp and ascending melodic contour). No differential effect of intensity ramp/melodic contour congruency was observed for up-ramps. In paired ramp trials assessing the possible impact of ramp context, loudness change in response to up-ramps was significantly greater when preceded by down-ramps, than when not preceded by another ramp. Ramp context did not affect down-ramp perception. The contribution to the fields of music perception and psychoacoustics are discussed in the context of real-time perception of music, principles of music composition, and performance of musical dynamics. Copyright © 2014

  7. Practical Ranges of Loudness Levels of Various Types of Environmental Noise, Including Traffic Noise, Aircraft Noise, and Industrial Noise

    Directory of Open Access Journals (Sweden)

    Sabine A. Janssen

    2011-05-01

    Full Text Available In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a noise signal varies considerably with the shape of the frequency spectrum of the noise signal. In particular the bandwidth of the spectrum has a large effect on the loudness level, due to the effect of critical bands in the human hearing system. The low-frequency content of the spectrum also has an effect on the loudness level. In this note the relation between loudness level and A-weighted sound level is analyzed for various environmental noise spectra, including spectra of traffic noise, aircraft noise, and industrial noise. From loudness levels calculated for these environmental noise spectra, diagrams are constructed that show the relation between loudness level, A‑weighted sound level, and shape of the spectrum. The diagrams show that the upper limits of the loudness level for broadband environmental noise spectra are about 20 to 40 phon higher than the lower limits for narrowband spectra, which correspond to the loudness levels of pure tones. The diagrams are useful for assessing limitations and potential improvements of environmental noise control methods and policy based on A-weighted sound levels.

  8. Optimal Energy-Efficient Sensing and Power Allocation in Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Xia Wu

    2014-01-01

    Full Text Available We consider a joint optimization of sensing parameter and power allocation for an energy-efficient cognitive radio network (CRN in which the primary user (PU is protected. The optimization problem to maximize the energy efficiency of CRN is formulated as a function of two variables, which are sensing time and transmit power, subject to the average interference power to the PU and the target detection probability. During the optimizing process, the quality of service parameter (the minimum rate acceptable to secondary users (SUs has also been taken into consideration. The optimal solutions are analyzed and an algorithm combined with fractional programming that maximizes the energy efficiency for CRN is presented. Numerical results show that the performance improvement is achieved by the joint optimization of sensing time and power allocation.

  9. Electrical field imaging as a means to predict the loudness of monopolar and tripolar stimuli in cochlear implant patients.

    Science.gov (United States)

    Berenstein, Carlo K; Vanpoucke, Filiep J; Mulder, Jef J S; Mens, Lucas H M

    2010-12-01

    Tripolar and other electrode configurations that use simultaneous stimulation inside the cochlea have been tested to reduce channel interactions compared to the monopolar stimulation conventionally used in cochlear implant systems. However, these "focused" configurations require increased current levels to achieve sufficient loudness. In this study, we investigate whether highly accurate recordings of the intracochlear electrical field set up by monopolar and tripolar configurations correlate to their effect on loudness. We related the intra-scalar potential distribution to behavioral loudness, by introducing a free parameter (α) which parameterizes the degree to which the potential field peak set up inside the scala tympani is still present at the location of the targeted neural tissue. Loudness balancing was performed on four levels between behavioral threshold and the most comfortable loudness level in a group of 10 experienced Advanced Bionics cochlear implant users. The effect of the amount of focusing on loudness was well explained by α per subject location along the basilar membrane. We found that α was unaffected by presentation level. Moreover, the ratios between the monopolar and tripolar currents, balanced for equal loudness, were approximately the same for all presentation levels. This suggests a linear loudness growth with increasing current level and that the equal peak hypothesis may predict the loudness of threshold as well as at supra-threshold levels. These results suggest that advanced electrical field imaging, complemented with limited psychophysical testing, more specifically at only one presentation level, enables estimation of the loudness growth of complex electrode configurations. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Low-Power Architectures for Large Radio Astronomy Correlators

    Science.gov (United States)

    D'Addario, Larry R.

    2011-01-01

    The architecture of a cross-correlator for a synthesis radio telescope with N greater than 1000 antennas is studied with the objective of minimizing power consumption. It is found that the optimum architecture minimizes memory operations, and this implies preference for a matrix structure over a pipeline structure and avoiding the use of memory banks as accumulation registers when sharing multiply-accumulators among baselines. A straw-man design for N = 2000 and bandwidth of 1 GHz, based on ASICs fabricated in a 90 nm CMOS process, is presented. The cross-correlator proper (excluding per-antenna processing) is estimated to consume less than 35 kW.

  11. In dubio pro silentio – Even Loud Music Does Not Facilitate Strenuous Ergometer Exercise

    Directory of Open Access Journals (Sweden)

    Gunter Kreutz

    2018-05-01

    Full Text Available Background: Music listening is wide-spread in amateur sports. Ergometer exercise is one such activity which is often performed with loud music.Aim and Hypotheses: We investigated the effects of electronic music at different intensity levels on ergometer performance (physical performance, force on the pedal, pedaling frequency, perceived fatigue and heart rate in healthy adults. We assumed that higher sound intensity levels are associated with greater ergometer performance and less perceived effort, particularly for untrained individuals.Methods: Groups of high trained and low trained healthy males (N = 40; age = 25.25 years; SD = 3.89 years were tested individually on an ergometer while electronic dance music was played at 0, 65, 75, and 85 dB. Participants assessed their music experience during the experiment.Results: Majorities of participants rated the music as not too loud (65%, motivating (77.50%, appropriate for this sports exercise (90%, and having the right tempo (67.50%. Participants noticed changes in the acoustical environment with increasing intensity levels, but no further effects on any of the physical or other subjective measures were found for neither of the groups. Therefore, the main hypothesis must be rejected.Discussion: These findings suggest that high loudness levels do not positively influence ergometer performance. The high acceptance of loud music and perceived appropriateness could be based on erroneous beliefs or stereotypes. Reasons for the widespread use of loud music in fitness sports needs further investigation. Reducing loudness during fitness exercise may not compromise physical performance or perceived effort.

  12. In dubio pro silentio – Even Loud Music Does Not Facilitate Strenuous Ergometer Exercise

    Science.gov (United States)

    Kreutz, Gunter; Schorer, Jörg; Sojke, Dominik; Neugebauer, Judith; Bullack, Antje

    2018-01-01

    Background: Music listening is wide-spread in amateur sports. Ergometer exercise is one such activity which is often performed with loud music. Aim and Hypotheses: We investigated the effects of electronic music at different intensity levels on ergometer performance (physical performance, force on the pedal, pedaling frequency), perceived fatigue and heart rate in healthy adults. We assumed that higher sound intensity levels are associated with greater ergometer performance and less perceived effort, particularly for untrained individuals. Methods: Groups of high trained and low trained healthy males (N = 40; age = 25.25 years; SD = 3.89 years) were tested individually on an ergometer while electronic dance music was played at 0, 65, 75, and 85 dB. Participants assessed their music experience during the experiment. Results: Majorities of participants rated the music as not too loud (65%), motivating (77.50%), appropriate for this sports exercise (90%), and having the right tempo (67.50%). Participants noticed changes in the acoustical environment with increasing intensity levels, but no further effects on any of the physical or other subjective measures were found for neither of the groups. Therefore, the main hypothesis must be rejected. Discussion: These findings suggest that high loudness levels do not positively influence ergometer performance. The high acceptance of loud music and perceived appropriateness could be based on erroneous beliefs or stereotypes. Reasons for the widespread use of loud music in fitness sports needs further investigation. Reducing loudness during fitness exercise may not compromise physical performance or perceived effort. PMID:29867622

  13. Four odontocete species change hearing levels when warned of impending loud sound.

    Science.gov (United States)

    Nachtigall, Paul E; Supin, Alexander Ya; Pacini, Aude F; Kastelein, Ronald A

    2018-03-01

    Hearing sensitivity change was investigated when a warning sound preceded a loud sound in the false killer whale (Pseudorca crassidens), the bottlenose dolphin (Tursiops truncatus), the beluga whale (Delphinaperus leucas) and the harbor porpoise (Phocoena phocoena). Hearing sensitivity was measured using pip-train test stimuli and auditory evoked potential recording. When the test/warning stimuli preceded a loud sound, hearing thresholds before the loud sound increased relative to the baseline by 13 to 17 dB. Experiments with multiple frequencies of exposure and shift provided evidence of different amounts of hearing change depending on frequency, indicating that the hearing sensation level changes were not likely due to a simple stapedial reflex. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  14. A relative rate utility based distributed power allocation algorithm for Cognitive Radio Networks

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Øien, G.E.; Lundheim, L.

    2012-01-01

    In an underlay Cognitive Radio Network, multiple secondary users coexist geographically and spectrally with multiple primary users under a constraint on the maximum received interference power at the primary receivers. Given such a setting, one may ask "how to achieve maximum utility benefit...

  15. Exposure to loud noise, bilateral high-frequency hearing loss and coronary heart disease.

    Science.gov (United States)

    Gan, Wen Qi; Moline, Jacqueline; Kim, Hyun; Mannino, David M

    2016-01-01

    Bilateral high-frequency hearing loss is an indicator for chronic exposure to loud noise. This study aimed to examine the association between bilateral high-frequency hearing loss and the presence of coronary heart disease (CHD). This study included 5223 participants aged 20-69 years who participated in the audiometry examination of the National Health and Nutrition Examination Survey 1999-2004. Bilateral high-frequency hearing loss was defined as the average high-frequency (3, 4 and 6 kHz) hearing threshold ≥25 dB in both ears. CHD was defined as self-reported diagnoses by doctors or other health professionals. Compared with those with normal high-frequency hearing, participants with bilateral high-frequency hearing loss were more likely to have CHD (OR 1.91; 95% CI 1.28 to 2.85) after adjustment for various covariates. This association was particularly strong for currently employed workers who were exposed to loud occupational noise (OR 4.23; 95% CI 1.32 to 13.55). For this subgroup, there was no significant association of CHD with unilateral high-frequency hearing loss, and unilateral or bilateral low-frequency hearing loss. Furthermore, there was no significant association of CHD with any types of hearing loss for participants who were not exposed to loud noise. Stratified analyses for participants exposed to loud noise showed that the observed association was particularly strong for those who were less than 50 years of age, less educated and current smokers. On the basis of an objective indicator for personal chronic exposure to loud noise, this study confirmed that exposure to loud occupational noise is associated with the presence of CHD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  16. Mortality of radio collared willow ptarmigan in Smoela wind-power plant

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Hans Chr.; Broeseth, Henrik; Nilsen, Erlend B.; Sandercock, Brett K.; Bevanger, Kjetil

    2011-07-01

    Full text: In the project Pre- and post-construction studies of conflicts between birds and wind turbines in coastal Norway (BirdWind), Smoela willow ptarmigan (Lagopus lagopus variegatus) has been one of the species studied. This sub-species represent gallinaceous birds, known to be bad flyers susceptible to collide with artificial structures, e.g. power lines. However, the possible impact of a wind-power plant on survival and behaviour in a willow ptarmigan population was unknown. The objectives of the study were therefore rather wide; to study direct and indirect effects of wind turbines on willow ptarmigan behaviour, habitat selection, reproduction and survival in areas where wind-power plants are established. To collect data on habitat selection, movements, collision risks, avoidance behaviour, survival and general population dynamic parameters, willow ptarmigan were radio-tagged in 2008-2010, using traditional VHF-transmitters (Holohill) with mortality switch, necklace mount, 12 g, lasting for approximately 24 months. Due to low population density and only occasional snow cover, a method using strong lights, dipnet and car was used to catch birds. In total, 34 willow ptarmigan were caught (19 males and 15 females). All birds were caught inside the wind-power plant area (WPA). The birds were radio-tracked at irregular intervals and almost all birds, when found, was located within the WPA. All carcasses of dead birds were examined. When possible, cause of death was determined as; predation (raptor), collision, unknown, other. In total, 28 of the radio-tagged birds have died since January 2008. A Kaplan-Meier analysis of cumulative survival rates, show an exceptionally low survival (<30%). Unlike other willow ptarmigan populations most of the mortality takes place during winter, from December throughout March. Although a thorough analysis of mortality causes has yet not been carried out, a majority of the birds have probably been killed by avian predators and to

  17. Discovery of Pulsed Gamma Rays from the Young Radio Pulsar PSR J1028-5819 with the Fermi Large Area Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Baring, Matthew G.; /Rice U.; Bastieri, Denis; /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, Elliott 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, Thompson H.; /Washington U., Seattle; Caliandro, G.A.; /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /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. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /NASA, Goddard /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Trieste /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

    2009-05-15

    Radio pulsar PSR J1028-5819 was recently discovered in a high-frequency search (at 3.1 GHz) in the error circle of the Energetic Gamma-Ray Experiment Telescope (EGRET) source 3EG J1027-5817. The spin-down power of this young pulsar is great enough to make it very likely the counterpart for the EGRET source. We report here the discovery of {gamma}-ray pulsations from PSR J1028-5819 in early observations by the Large Area Telescope (LAT) on the Fermi Gamma-Ray Space Telescope. The {gamma}-ray light curve shows two sharp peaks having phase separation of 0.460 {+-} 0.004, trailing the very narrow radio pulse by 0.200 {+-} 0.003 in phase, very similar to that of other known {gamma}-ray pulsars. The measured {gamma}-ray flux gives an efficiency for the pulsar of {approx}10-20% (for outer magnetosphere beam models). No evidence of a surrounding pulsar wind nebula is seen in the current Fermi data but limits on associated emission are weak because the source lies in a crowded region with high background emission. However, the improved angular resolution afforded by the LAT enables the disentanglement of the previous COS-B and EGRET source detections into at least two distinct sources, one of which is now identified as PSR J1028-5819.

  18. Radio frequency plasma nitriding of aluminium at higher power levels

    International Nuclear Information System (INIS)

    Gredelj, Sabina; Kumar, Sunil; Gerson, Andrea R.; Cavallaro, Giuseppe P.

    2006-01-01

    Nitriding of aluminium 2011 using a radio frequency plasma at higher power levels (500 and 700 W) and lower substrate temperature (500 deg. C) resulted in higher AlN/Al 2 O 3 ratios than obtained at 100 W and 575 deg. C. AlN/Al 2 O 3 ratios derived from X-ray photoelectron spectroscopic analysis (and corroborated by heavy ion elastic recoil time of flight spectrometry) for treatments preformed at 100 (575 deg. C), 500 (500 deg. C) and 700 W (500 deg. C) were 1.0, 1.5 and 3.3, respectively. Scanning electron microscopy revealed that plasma nitrided surfaces obtained at higher power levels exhibited much finer nodular morphology than obtained at 100 W

  19. CDC Vital Signs-Too Loud for Too Long!

    Centers for Disease Control (CDC) Podcasts

    This podcast is based on the February 2017 CDC Vital Signs report. Being around too much loud noise-like a leaf blower or rock concert-can cause permanent hearing loss. Learn how to prevent hearing loss.

  20. Cross-layer combining of power control and adaptive modulation with truncated ARQ for cognitive radios

    Institute of Scientific and Technical Information of China (English)

    CHENG Shi-lun; YANG Zhen

    2008-01-01

    To maximize throughput and to satisfy users' requirements in cognitive radios, a cross-layer optimization problem combining adaptive modulation and power control at the physical layer and truncated automatic repeat request at the medium access control layer is proposed. Simulation results show the combination of power control, adaptive modulation, and truncated automatic repeat request can regulate transmitter powers and increase the total throughput effectively.

  1. THE GALACTIC POPULATION OF YOUNG γ-RAY PULSARS

    International Nuclear Information System (INIS)

    Watters, Kyle P.; Romani, Roger W.

    2011-01-01

    We have simulated a Galactic population of young pulsars and compared with the Fermi LAT sample, constraining the birth properties, beaming and evolution of these spin-powered objects. Using quantitative tests of agreement with the distributions of observed spin and pulse properties, we find that short birth periods P 0 ∼ 50 ms and γ-ray beams arising in the outer magnetosphere, dominated by a single pole, are strongly preferred. The modeled relative numbers of radio-detected and radio-quiet objects agrees well with the data. Although the sample is local, extrapolation to the full Galaxy implies a γ-ray pulsar birthrate 1/(59 yr). This is shown to be in good agreement with the estimated Galactic core collapse rate and with the local density of OB star progenitors. We give predictions for the numbers of expected young pulsar detections if Fermi LAT observations continue 10 years. In contrast to the potentially significant contribution of unresolved millisecond pulsars, we find that young pulsars should contribute little to the Galactic γ-ray background.

  2. Time monitoring of radio jets and magnetospheres in the nearby young stellar cluster R Coronae Australis

    International Nuclear Information System (INIS)

    Liu, Hauyu Baobab; Takami, Michihiro; Yan, Chi-Hung; Karr, Jennifer; Chou, Mei-Yin; Ho, Paul T.-P.; Galván-Madrid, Roberto; Costigan, Gráinne; Manara, Carlo Felice; Forbrich, Jan; Rodríguez, Luis F.; Zhang, Qizhou

    2014-01-01

    We report Karl G. Jansky Very Large Array 8-10 GHz (λ = 3.0-3.7 cm) monitoring observations toward the young stellar object (YSO) cluster R Coronae Australis (R CrA), taken from 2012 March 15 to 2012 September 12. These observations were planned to measure the radio flux variabilities in timescales from 0.5 hr to several days, to tens of days, and up to ∼200 days. We found that among the YSOs detectable in individual epochs, in general, the most reddened objects in the Spitzer observations show the highest mean 3.5 cm Stokes I emission, and the lowest fractional variabilities on <200 day timescales. The brightest radio flux emitters in our observations are the two reddest sources IRS7W and IRS7E. In addition, by comparing our observations with observations taken from 1996 to 1998 and 2005, we found that the radio fluxes of these two sources have increased by a factor of ∼1.5. The mean 3.5 cm fluxes of the three Class I/II sources, IRSI, IRS2, and IRS6, appear to be correlated with their accretion rates derived by a previous near-infrared line survey. The weakly accreting Class I/II YSOs, or those in later evolutionary stages, present radio flux variability on <0.5 hr timescales. Some YSOs were detected only during occasional flaring events. The source R CrA went below our detection limit during a few fading events.

  3. [Evaluation of a transient noise reduction strategy on the loudness perception and sound quality].

    Science.gov (United States)

    Liu, Haihong; Zhang, Hua; Chen, Xueqing; Wu, Yanjun; Kong, Ying; Wang, Shuo; Li, Jing

    2010-10-01

    A current technology for detecting and controlling transient noise in hearing aids (AntiShock) was evaluated. The objective was to evaluate AntiShock on loudness control and whether results in negative changes in sound quality of speech, transient noise and environmental noise and provide implications for hearing aid fitting. Twenty-four subjects with sensorineural hearing loss participated in the study. In a single-blinded paradigm, the subjects were asked to rate loudness of transient noise and distortion of speech, transient noise and environmental noise with the AntiShock in both on and off conditions. (1) The percentage of the transient noise rated as soft, comfortable, loud, too loud was 3.0%, 72.7%, 22.9% and 1.4%, respectively. There were significant differences in mean scores of loudness perception among listening conditions and between genders by a Two-Way ANOVA, the P values were 0.009 and 0.001, respectively. (2) The percentage of the speech rated as mild distorted, understandable, clear and very clear was 2.5%, 30.6%, 32.9% and 34.0%, respectively. There were significant differences in mean scores of speech distortion under different listening conditions by an One-Way ANOVA (P 0.05). (4) The percentage of the environmental noise rated as mild distorted, clear but soft, clear and natural was 0.4%, 0.8% and 98.8%, respectively. No significant differences in mean scores of nature of environmental noise was found between different listening conditions by an Independent-Samples T Test (P > 0.05). AntiShock showed positive effects on the loudness control of the transient noise. Quality of speech, transient noise and environmental noise were not impacted by AntiShock.

  4. Temporal and spectral interaction in loudness perception

    DEFF Research Database (Denmark)

    Pedersen, Benjamin; Ellermeier, Wolfgang

    An experiment was conducted to investigate how changes in spectral content influence loudness judgments. Six listeners were asked to discriminate sounds, which were of one second duration and changing in level every 0.1 s. In one condition the first half of the sound was low-pass filtered and the...

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

    Science.gov (United States)

    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.

  6. Active galactic nuclei cores in infrared-faint radio sources. Very long baseline interferometry observations using the Very Long Baseline Array

    Science.gov (United States)

    Herzog, A.; Middelberg, E.; Norris, R. P.; Spitler, L. R.; Deller, A. T.; Collier, J. D.; Parker, Q. A.

    2015-06-01

    Context. Infrared-faint radio sources (IFRS) form a new class of galaxies characterised by radio flux densities between tenths and tens of mJy and faint or absent infrared counterparts. It has been suggested that these objects are radio-loud active galactic nuclei (AGNs) at significant redshifts (z ≳ 2). Aims: Whereas the high redshifts of IFRS have been recently confirmed based on spectroscopic data, the evidence for the presence of AGNs in IFRS is mainly indirect. So far, only two AGNs have been unquestionably confirmed in IFRS based on very long baseline interferometry (VLBI) observations. In this work, we test the hypothesis that IFRS contain AGNs in a large sample of sources using VLBI. Methods: We observed 57 IFRS with the Very Long Baseline Array (VLBA) down to a detection sensitivity in the sub-mJy regime and detected compact cores in 35 sources. Results: Our VLBA detections increase the number of VLBI-detected IFRS from 2 to 37 and provide strong evidence that most - if not all - IFRS contain AGNs. We find that IFRS have a marginally higher VLBI detection fraction than randomly selected sources with mJy flux densities at arcsec-scales. Moreover, our data provide a positive correlation between compactness - defined as the ratio of milliarcsec- to arcsec-scale flux density - and redshift for IFRS, but suggest a decreasing mean compactness with increasing arcsec-scale radio flux density. Based on these findings, we suggest that IFRS tend to contain young AGNs whose jets have not formed yet or have not expanded, equivalent to very compact objects. We found two IFRS that are resolved into two components. The two components are spatially separated by a few hundred milliarcseconds in both cases. They might be components of one AGN, a binary black hole, or the result of gravitational lensing.

  7. Astrophysics. The exceptionally powerful TeV γ-ray emitters in the Large Magellanic Cloud.

    Science.gov (United States)

    2015-01-23

    The Large Magellanic Cloud, a satellite galaxy of the Milky Way, has been observed with the High Energy Stereoscopic System (H.E.S.S.) above an energy of 100 billion electron volts for a deep exposure of 210 hours. Three sources of different types were detected: the pulsar wind nebula of the most energetic pulsar known, N 157B; the radio-loud supernova remnant N 132D; and the largest nonthermal x-ray shell, the superbubble 30 Dor C. The unique object SN 1987A is, unexpectedly, not detected, which constrains the theoretical framework of particle acceleration in very young supernova remnants. These detections reveal the most energetic tip of a γ-ray source population in an external galaxy and provide via 30 Dor C the unambiguous detection of γ-ray emission from a superbubble. Copyright © 2015, American Association for the Advancement of Science.

  8. Comparisons between detection threshold and loudness perception for individual cochlear implant channels

    Science.gov (United States)

    Bierer, Julie Arenberg; Nye, Amberly D

    2014-01-01

    Objective The objective of the present study, performed in cochlear implant listeners, was to examine how the level of current required to detect single-channel electrical pulse trains relates to loudness perception on the same channel. The working hypothesis was that channels with relatively high thresholds, when measured with a focused current pattern, interface poorly to the auditory nerve. For such channels a smaller dynamic range between perceptual threshold and the most comfortable loudness would result, in part, from a greater sensitivity to changes in electrical field spread compared to low-threshold channels. The narrower range of comfortable listening levels may have important implications for speech perception. Design Data were collected from eight, adult cochlear implant listeners implanted with the HiRes90k cochlear implant (Advanced Bionics Corp.). The partial tripolar (pTP) electrode configuration, consisting of one intracochlear active electrode, two flanking electrodes carrying a fraction (σ) of the return current, and an extracochlear ground, was used for stimulation. Single-channel detection thresholds and most comfortable listening levels were acquired using the most focused pTP configuration possible (σ ≥ 0.8) to identify three channels for further testing – those with the highest, median, and lowest thresholds – for each subject. Threshold, equal-loudness contours (at 50% of the monopolar dynamic range), and loudness growth functions were measured for each of these three test channels using various partial tripolar fractions. Results For all test channels, thresholds increased as the electrode configuration became more focused. The rate of increase with the focusing parameter σ was greatest for the high-threshold channel compared to the median- and low-threshold channels. The 50% equal-loudness contours exhibited similar rates of increase in level across test channels and subjects. Additionally, test channels with the highest

  9. A Search for Blazar-Like Radio-Loud Narrow-Line Seyfert 1 Galaxies

    Directory of Open Access Journals (Sweden)

    Hugh R. Miller

    2017-03-01

    Full Text Available We report the results of an observational program to investigate the gamma-ray and optical variability properties of the vRL NLSY1 galaxies listed in the Yuan et al. sample. We have identified 17 members of the Yuan et al. sample possibly associated with gamma-ray sources based on a combination of their optical polarization and optical variability and their gamma-ray properties. Eight have previously been associated with gamma-ray sources. We find nine additional members that we predict are excellent candidates to be associated with gamma-ray sources in the future. All 17 sources have many properties in common with flat spectrum radio quasars (FSRQs, suggesting that they may, in fact, constitute a new subclass of FSRQs.

  10. Renyi Ma & Chong Ping

    Indian Academy of Sciences (India)

    Abstract. The similarities between blazars and radio-loud narrow-line. Seyfert 1 galaxies (RLNLS1s) have received much attention. In this paper, by using the magnetized slim disk model, we calculate the jet power and disk luminosity. It is found that the jet power is only a very small fraction of the disk luminosity, <10%.

  11. Output power distributions of mobile radio base stations based on network measurements

    International Nuclear Information System (INIS)

    Colombi, D; Thors, B; Persson, T; Törnevik, C; Wirén, N; Larsson, L-E

    2013-01-01

    In this work output power distributions of mobile radio base stations have been analyzed for 2G and 3G telecommunication systems. The approach is based on measurements in selected networks using performance surveillance tools part of the network Operational Support System (OSS). For the 3G network considered, direct measurements of output power levels were possible, while for the 2G networks, output power levels were estimated from measurements of traffic volumes. Both voice and data services were included in the investigation. Measurements were conducted for large geographical areas, to ensure good overall statistics, as well as for smaller areas to investigate the impact of different environments. For high traffic hours, the 90th percentile of the averaged output power was found to be below 65% and 45% of the available output power for the 2G and 3G systems, respectively.

  12. Output power distributions of mobile radio base stations based on network measurements

    Science.gov (United States)

    Colombi, D.; Thors, B.; Persson, T.; Wirén, N.; Larsson, L.-E.; Törnevik, C.

    2013-04-01

    In this work output power distributions of mobile radio base stations have been analyzed for 2G and 3G telecommunication systems. The approach is based on measurements in selected networks using performance surveillance tools part of the network Operational Support System (OSS). For the 3G network considered, direct measurements of output power levels were possible, while for the 2G networks, output power levels were estimated from measurements of traffic volumes. Both voice and data services were included in the investigation. Measurements were conducted for large geographical areas, to ensure good overall statistics, as well as for smaller areas to investigate the impact of different environments. For high traffic hours, the 90th percentile of the averaged output power was found to be below 65% and 45% of the available output power for the 2G and 3G systems, respectively.

  13. Temporal modulation transfer functions in cochlear implantees using a method that limits overall loudness cues

    Science.gov (United States)

    Fraser, Matthew; McKay, Colette M.

    2012-01-01

    Temporal modulation transfer functions (TMTFs) were measured for six users of cochlear implants, using different carrier rates and levels. Unlike most previous studies investigating modulation detection, the experimental design limited potential effects of overall loudness cues. Psychometric functions (percent correct discrimination of modulated from unmodulated stimuli versus modulation depth) were obtained. For each modulation depth, each modulated stimulus was loudness balanced to the unmodulated reference stimulus, and level jitter was applied in the discrimination task. The loudness-balance data showed that the modulated stimuli were louder than the unmodulated reference stimuli with the same average current, thus confirming the need to limit loudness cues when measuring modulation detection. TMTFs measured in this way had a low-pass characteristic, with a cut-off frequency (at comfortably loud levels) similar to that for normal-hearing listeners. A reduction in level caused degradation in modulation detection efficiency and a lower-cut-off frequency (i.e. poorer temporal resolution). An increase in carrier rate also led to a degradation in modulation detection efficiency, but only at lower levels or higher modulation frequencies. When detection thresholds were expressed as a proportion of dynamic range, there was no effect of carrier rate for the lowest modulation frequency (50 Hz) at either level. PMID:22146425

  14. A low-power photovoltaic system with energy storage for radio communications: Description and design methodology

    Science.gov (United States)

    Chapman, C. P.; Chapman, P. D.; Lewison, A. H.

    1982-01-01

    A low power photovoltaic system was constructed with approximately 500 amp hours of battery energy storage to provide power to an emergency amateur radio communications center. The system can power the communications center for about 72 hours of continuous nonsun operation. Complete construction details and a design methodology algorithm are given with abundant engineering data and adequate theory to allow similar systems to be constructed, scaled up or down, with minimum design effort.

  15. Temporal and spectral interaction in loudness perception

    Science.gov (United States)

    Pedersen, Benjamin; Ellermeier, Wolfgang

    2005-04-01

    An experiment was conducted to investigate how changes in spectral content influence loudness judgments. Six listeners were asked to discriminate sounds, which were of one second duration and changing in level every 0.1 s. In one condition the first half of the sound was low-pass filtered and the second half high-pass filtered. In a second condition the opposite order was used. In a third condition no filtering was applied and the frequency spectrum was simply white noise. The results were analyzed using a statistical method, which assigns relative weights to the ten temporal segments. In this way individual weighting curves were obtained for each condition. Listeners tended to emphasize the beginning of the sound in their loudness judgments. When the frequency spectrum changed in the middle of the sound, however, the weighting of the onset of the new spectral content was emphasized as well. This outcome is inconsistent with overall temporal integration, and argues for a cognitive mechanism allocating attention to changes in an event sequence.

  16. Low-Complexity Scheduling and Power Adaptation for Coordinated Cloud-Radio Access Networks

    KAUST Repository

    Douik, Ahmed

    2017-07-17

    In practical wireless systems, the successful implementation of resource allocation techniques strongly depends on the algorithmic complexity. Consider a cloud-radio access network (CRAN), where the central cloud is responsible for scheduling devices to the frames’ radio resources blocks (RRBs) of the single-antenna base-stations (BSs), adjusting the transmit power levels, and for synchronizing the transmit frames across the connected BSs. Previous studies show that the jointly coordinated scheduling and power control problem in the considered CRAN can be solved using an approach that scales exponentially with the number of BSs, devices, and RRBs, which makes the practical implementation infeasible for reasonably sized networks. This paper instead proposes a low-complexity solution to the problem, under the constraints that each device cannot be served by more than one BS but can be served by multiple RRBs within each BS frame, and under the practical assumption that the channel is constant during the duration of each frame. The paper utilizes graph-theoretical based techniques and shows that constructing a single power control graph is sufficient to obtain the optimal solution with a complexity that is independent of the number of RRBs. Simulation results reveal the optimality of the proposed solution for slow-varying channels, and show that the solution performs near-optimal for highly correlated channels.

  17. Categorical scaling of partial loudness in a condition of masking release.

    Science.gov (United States)

    Verhey, Jesko L; Heeren, Wiebke

    2015-08-01

    Categorical loudness scaling was used to measure suprathreshold release from masking. The signal was a 986-Hz sinusoid that was embedded in a bandpass-filtered masking noise. This noise was either unmodulated or was amplitude modulated with a square-wave modulator. The unmodulated noise had either the same level as the modulated noise or had a level that was reduced by the difference in thresholds for the 986-Hz signal obtained with the modulated and unmodulated noise masker presented at the same level (i.e., the masking release). A comparison with loudness matching data of the same set of subjects showed that the data obtained with loudness scaling capture main aspects of the change in suprathreshold perception of the sinusoid when the masker was modulated. The scaling data for the signal masked by the unmodulated noise with the reduced masker level were similar to that for the signal embedded in the modulated noise. This similarity supports the hypothesis that the mechanism eliciting the masking release is effectively reducing the masker level.

  18. Theoretical parameters of powerful radio galaxies. II. Generation of MHD turbulence by collisionless shock waves

    International Nuclear Information System (INIS)

    Baryshev, Yu.V.; Morozov, V.N.

    1988-01-01

    It is shown that MHD turbulence can be generated by collisionless shock waves due to anisotropy of the pressure behind the front of the reverse sock at the hot spot of a powerful radio galaxy. The energy density of the MHD turbulence generated behind the shock front is estimated. Analysis of the theoretical studies and experimental data on collisionless shock waves in the solar wind indicates that an important part is played by streams of ions reflected by the shock fronts, the streams generating plasma and MHD turbulence in the region ahead of the front. The extension of these ideas to shock waves in powerful radio galaxies must be made with care because of the great difference between the parameters of the shock waves in the two cases

  19. Promotion of public awareness relating nuclear power in young generation

    International Nuclear Information System (INIS)

    Kobayashi, Yoko

    2011-01-01

    Although nuclear power presents problems of waste, safety and non-proliferation, many people understand that it is an essential energy for addressing the global climate and reducing CO2. However, a vague negative-image to the radiation and nuclear power is deep-rooted among the public. Young generation is not an exception. It is very important to transfer many information from the experienced generation in the industry to young generations. In this paper, the research that applied the information intelligence to nuclear power, which involves of the nuclear fuel cycle, and the communication related activities for the social acceptance and improvement. (author)

  20. The faint radio source population at 15.7 GHz - II. Multi-wavelength properties

    Science.gov (United States)

    Whittam, I. H.; Riley, J. M.; Green, D. A.; Jarvis, M. J.; Vaccari, M.

    2015-11-01

    A complete, flux density limited sample of 96 faint (>0.5 mJy) radio sources is selected from the 10C survey at 15.7 GHz in the Lockman Hole. We have matched this sample to a range of multi-wavelength catalogues, including Spitzer Extragalactic Representative Volume Survey, Spitzer Wide-area Infrared Extragalactic survey, United Kingdom Infrared Telescope Infrared Deep Sky Survey and optical data; multi-wavelength counterparts are found for 80 of the 96 sources and spectroscopic redshifts are available for 24 sources. Photometric redshifts are estimated for the sources with multi-wavelength data available; the median redshift of the sample is 0.91 with an interquartile range of 0.84. Radio-to-optical ratios show that at least 94 per cent of the sample are radio loud, indicating that the 10C sample is dominated by radio galaxies. This is in contrast to samples selected at lower frequencies, where radio-quiet AGN and star-forming galaxies are present in significant numbers at these flux density levels. All six radio-quiet sources have rising radio spectra, suggesting that they are dominated by AGN emission. These results confirm the conclusions of Paper I that the faint, flat-spectrum sources which are found to dominate the 10C sample below ˜1 mJy are the cores of radio galaxies. The properties of the 10C sample are compared to the Square Kilometre Array Design Studies Simulated Skies; a population of low-redshift star-forming galaxies predicted by the simulation is not found in the observed sample.

  1. First detection in gamma-rays of a young radio galaxy: Fermi -LAT observations of the compact symmetric object PKS 1718−649

    Energy Technology Data Exchange (ETDEWEB)

    Migliori, G.; Loh, A.; Corbel, S. [Laboratoire AIM (CEA/IRFU—CNRS/INSU—Université Paris Diderot), CEA DSM/SAp, F-91191 Gif-sur-Yvette (France); Siemiginowska, A.; Sobolewska, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ostorero, L. [Dipartimento di Fisica, Università degli Studi di Torino and Istituto Nazionale di Fisica Nucleare (INFN), Via P. Giuria 1, I-10125 Torino (Italy); Stawarz, Ł., E-mail: giulia.migliori@cea.fr [Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Kraków (Poland)

    2016-04-20

    We report the γ -ray detection of a young radio galaxy, PKS 1718−649, belonging to the class of compact symmetric objects (CSOs), with the Large Area Telescope (LAT) on board the Fermi satellite. The third Fermi Gamma-ray LAT catalog (3FGL) includes an unassociated γ -ray source, 3FGL J1728.0−6446, located close to PKS 1718−649. Using the latest Pass 8 calibration, we confirm that the best-fit 1 σ position of the γ -ray source is compatible with the radio location of PKS 1718−649. Cross-matching of the γ -ray source position with the positions of blazar sources from several catalogs yields negative results. Thus, we conclude that PKS 1718−649 is the most likely counterpart to the unassociated LAT source. We obtain a detection test statistics TS ∼ 36 (>5 σ ) with a best-fit photon spectral index Γ = 2.9 ± 0.3 and a 0.1–100 GeV photon flux density F {sub 0.1−100} {sub GeV} = (11.5 ± 0.3) × 10{sup −9} ph cm{sup −2} s{sup −1}. We argue that the linear size (∼2 pc), the kinematic age (∼100 years), and the source distance ( z = 0.014) make PKS 1718−649 an ideal candidate for γ -ray detection in the framework of the model proposing that the most compact and the youngest CSOs can efficiently produce GeV radiation via inverse-Compton scattering of the ambient photon fields by the radio lobe non-thermal electrons. Thus, our detection of the source in γ -rays establishes young radio galaxies as a distinct class of extragalactic high-energy emitters and yields a unique insight on the physical conditions in compact radio lobes interacting with the interstellar medium of the host galaxy.

  2. Is there addiction to loud music? Findings in a group of non-professional pop/rock musicians.

    Science.gov (United States)

    Schmuziger, Nicolas; Patscheke, Jochen; Stieglitz, Rolf; Probst, Rudolf

    2012-01-09

    Listening to loud music may be connected to addictive behavior possibly leading to damaging effects on the cochlea. We hypothesized that members of non-professional pop/rock bands with regular exposure to loud music are more likely to show an addictive-like behavior for loud music than matched control subjects. Fifty non-professional musicians and 50 matched control subjects were asked to complete the Northeastern Music Listening Survey (NEMLS) with two basic components. The first comprises an adaptation of the validated Michigan Alcohol Screening Test (MAST) to study the addictive-like behavior towards loud music. The second comprises the criteria outlined by the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) of the American Psychiatric Society for the diagnosis of substance dependence. The NEMLS was scored using the same point system as used in the MAST. The DSM-IV criteria for substance dependence were met by nine of the musician group and by one control subject. Seven of these nine musicians also had a positive NEMLS score. Traits of addictive-like behavior to loud music were detected more often in members of nonprofessional pop/rock bands than in control subjects.

  3. Is there addiction to loud music? Findings in a group of non-professional pop/rock musicians

    Directory of Open Access Journals (Sweden)

    Nicolas Schmuziger

    2012-07-01

    Full Text Available Listening to loud music may be connected to addictive behavior possibly leading to damaging effects on the cochlea. We hypothesized that members of non-professional pop/rock bands with regular exposure to loud music are more likely to show an addictive-like behavior for loud music than matched control subjects. Fifty non-professional musicians and 50 matched control subjects were asked to complete the Northeastern Music Listening Survey (NEMLS with two basic components. The first comprises an adaptation of the validated Michigan Alcohol Screening Test (MAST to study the addictive-like behavior towards loud music. The second comprises the criteria outlined by the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV of the American Psychiatric Society for the diagnosis of substance dependence. The NEMLS was scored using the same point system as used in the MAST. The DSM-IV criteria for substance dependence were met by nine of the musician group and by one control subject. Seven of these nine musicians also had a positive NEMLS score. Traits of addictive-like behavior to loud music were detected more often in members of nonprofessional pop/rock bands than in control subjects.

  4. Coordinated Scheduling and Power Control in Cloud-Radio Access Networks

    KAUST Repository

    Douik, Ahmed

    2015-12-01

    This paper addresses the joint coordinated scheduling and power control problem in cloud-enabled networks. Consider the downlink of a cloud-radio access network (CRAN), where the cloud is only responsible for the scheduling policy, power control, and synchronization of the transmit frames across the single-antenna base-stations (BS). The transmit frame consists of several time/frequency blocks, called power-zones (PZ). The paper considers the problem of scheduling users to PZs and determining their power levels (PL), by maximizing the weighted sum-rate under the practical constraints that each user cannot be served by more than one base-station, but can be served by one or more power-zones within each base-station frame. The paper solves the problem using a graph theoretical approach by introducing the joint scheduling and power control graph formed by several clusters, where each is formed by a set of vertices, representing the possible association of users, BSs, and PLs for one specific PZ. The problem is, then, formulated as a maximumweight clique problem, in which the weight of each vertex is the sum of the benefits of the individual associations belonging to that vertex. Simulation results suggest that the proposed crosslayer scheme provides appreciable performance improvement as compared to schemes from recent literature.

  5. Coordinated Scheduling and Power Control in Cloud-Radio Access Networks

    KAUST Repository

    Douik, Ahmed; Dahrouj, Hayssam; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2015-01-01

    This paper addresses the joint coordinated scheduling and power control problem in cloud-enabled networks. Consider the downlink of a cloud-radio access network (CRAN), where the cloud is only responsible for the scheduling policy, power control, and synchronization of the transmit frames across the single-antenna base-stations (BS). The transmit frame consists of several time/frequency blocks, called power-zones (PZ). The paper considers the problem of scheduling users to PZs and determining their power levels (PL), by maximizing the weighted sum-rate under the practical constraints that each user cannot be served by more than one base-station, but can be served by one or more power-zones within each base-station frame. The paper solves the problem using a graph theoretical approach by introducing the joint scheduling and power control graph formed by several clusters, where each is formed by a set of vertices, representing the possible association of users, BSs, and PLs for one specific PZ. The problem is, then, formulated as a maximumweight clique problem, in which the weight of each vertex is the sum of the benefits of the individual associations belonging to that vertex. Simulation results suggest that the proposed crosslayer scheme provides appreciable performance improvement as compared to schemes from recent literature.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Radio Frequency Power in Plasmas: 12th Topical Conference. Proceedings

    International Nuclear Information System (INIS)

    Ryan, P.M.; Intrator, T.

    1997-01-01

    The twelfth Topical Conference on Radio Frequency Power in Plasmas was held in April, 1997, in Georgia, USA under the sponsorship of Oak Ridge National Laboratory of the US Department of Energy, the University of Wisconsin, and the American Physical Society. A large part of the conference was devoted to the ion cyclotron range of frequencies. Radio frequency contributions to the creation and maintenance of transport barriers to both particle and heat flux received a lot of attention. In addition to plasma heating, the use of RF as a versatile tool to drive current, shape profiles and stabilize plasmas was also discussed. The RF systems designs for ITER, ICRF heating advances on helical devices were among the topics of interest, so were progress in ion cyclotron codes, advanced launchers and technology, RF startup, general wave theory and the application of RF plasmas to material processing. A total of 103 papers were presented and are included in these proceedings. Out of these, 54 have been abstracted for the Energy Science and Technology database

  8. An innovative approach to using both cellphones and the radio to identify young people’s sexual concerns in Kinshasa, Democratic Republic of Congo

    OpenAIRE

    Nsakala, Gabriel Vodiena; Coppieters, Yves; Kayembe, Patrick Kalambayi

    2014-01-01

    Background: As teenagers have easy access to both radio programs and cell phones, the current study used these tools so that young people could anonymously identify questions about sex and other related concerns in the urban environment of the Democratic Republic of Congo. The purpose of this healthcare intervention was to identify and address concerns raised by young people, which are related to sexual health, and which promote youth health. Methods: This healthcare intervention was conducte...

  9. Requirements Specication for Ampliers and Power Supplies in Active Loudspeakers

    DEFF Research Database (Denmark)

    Schneider, Henrik; Jensen, Lasse Crone; Petersen, Lars Press

    2014-01-01

    This work aims to provide designers with a method to develop a requirements specication for power supplies and ampliers in active loudspeakers. The motivation is to avoid over-sizing and unnecessary cost. A realistic estimation of the power supplied during playback of audio in a given loudspeaker...... is obtained by considering a wide range of audio source material, loudness normalization of the source material, crossover ltering, driver characteristics as well as a perceived maximum loudness/volume level. The results from analysing a sub-woofer and a woofer reveals the peak power, peak voltage, peak...... current and apparent power - thus providing a solid foundation for a requirement specication....

  10. Discovery of large-scale diffuse radio emission in low-mass galaxy cluster Abell 1931

    Science.gov (United States)

    Brüggen, M.; Rafferty, D.; Bonafede, A.; van Weeren, R. J.; Shimwell, T.; Intema, H.; Röttgering, H.; Brunetti, G.; Di Gennaro, G.; Savini, F.; Wilber, A.; O'Sullivan, S.; Ensslin, T. A.; De Gasperin, F.; Hoeft, M.

    2018-04-01

    Extended, steep-spectrum radio synchrotron sources are pre-dominantly found in massive galaxy clusters as opposed to groups. LOFAR Two-Metre Sky Survey images have revealed a diffuse, ultra-steep spectrum radio source in the low-mass cluster Abell 1931. The source has a fairly irregular morphology with a largest linear size of about 550 kpc. The source is only seen in LOFAR observations at 143 MHz and GMRT observations at 325 MHz. The spectral index of the total source between 143 MHz and 325 MHz is α _{143}^{325} = -2.86 ± 0.36. The source remains invisible in Very Large Array (1-2 GHz) observations as expected given the spectral index. Chandra X-ray observations of the cluster revealed a bolometric luminosity of LX = (1.65 ± 0.39) × 1043 erg s-1 and a temperature of 2.92_{-0.87}^{+1.89} keV which implies a mass of around ˜1014M⊙. We conclude that the source is a remnant radio galaxy that has shut off around 200 Myr ago. The brightest cluster galaxy, a radio-loud elliptical galaxy, could be the source for this extinct source. Unlike remnant sources studied in the literature, our source has a steep spectrum at low radio frequencies. Studying such remnant radio galaxies at low radio frequencies is important for understanding the scarcity of such sources and their role in feedback processes.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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.

  13. The functions of sound production in the lined seahorse, Hippocampus erectus, and effects of loud ambient noise on its behavior and physiology in captive environments

    Science.gov (United States)

    Anderson, Paul August

    Loud noise in aquaria represents a cacophonous environment for captive fishes. I tested the effects of loud noise on acoustic communication, feeding behavior, courtship behavior, and the stress response of the lined seahorse, Hippocampus erectus. Total Root Mean Square (RMS) power of ambient noise to which seahorses are exposed in captivity varies widely but averages 126.1 +/- 0.8 deciBels with reference to one micropascal (dB re: 1 muPa) at the middle of the water column and 133.7 +/- 1.1 dB at the tank bottom, whereas ambient noise in the wild averages 119.6 +/- 3.5 dB. Hearing sensitivity of H. erectus, measured from auditory evoked potentials, demonstrated maximum spectrum-level sensitivities of 105.0 +/- 1.5 dB and 3.5 x 10-3 + 7.6 x 10-4 m/s2 at 200 Hz; which is characteristic of hearing generalists. H. erectus produces acoustic clicks with mean peak spectrum-level amplitudes of 94.3 +/- 0.9 dB at 232 +/- 16 Hz and 1.5 x 10 -3 +/- 1.9 x 10-4 m/s2 at 265 +/- 22 Hz. Frequency matching of clicks to best hearing sensitivity, and estimates of audition of broadband signals suggest that seahorses may hear conspecific clicks, especially in terms of particle motion. Behavioral investigations revealed that clicking did not improve prey capture proficiency. However, animals clicked more often as time progressed in a courtship sequence, and mates performed more courtship behaviors with control animals than with muted animals, lending additional evidence to the role of clicking as an acoustic signal during courtship. Despite loud noise and the role of clicking in communication, masking of the acoustic signal was not demonstrated. Seahorses exposed to loud noise in aquaria for one month demonstrated physiological, chronic stress responses: reduced weight and body condition, and increased heterophil to lymphocyte ratio. Behavioral alterations were characterized by greater mean and variance of activity among animals housed in loud tanks in the first week, followed by

  14. Assessment of annoyance, loudness and unpleasantness with different recording and playback techniques

    DEFF Research Database (Denmark)

    Celik, Emine; Persson Waye, Kerstin; Møller, Henrik

    2005-01-01

    if there is a difference in perception related to annoyance, loudness and unpleasantness between monophonic recordings played back through a loudspeaker and binaural recordings played back via headphones and to evaluate whether a possible difference depends on temporal and frequency characteristics as well as spatial...... through a loudspeaker and the binaural recordings were presented through both closed (circum-aural) and completely open (free of the ear) headphones. The results show that for all judgments (annoyance, loudness and unpleasantness), there was no significant main effect of recording and playback techniques...

  15. Applying the EBU R128 loudness standard in live-streaming sound sculptures

    DEFF Research Database (Denmark)

    Højlund, Marie Koldkjær; Riis, Morten S.; Rothmann, Daniel

    2017-01-01

    to preserve a natural sounding dynamic image from the varying sound sources that can be played back under varying conditions, an adaptation of the EBU R128 loudness measurement recommendation, originally developed for levelling non-real-time broadcast material, has been applied. The paper describes the Pure......This paper describes the development of a loudness-based compressor for live audio streams. The need for this device arose while developing the public sound art project The Overheard, which involves mixing together several live audio streams through a web based mixing interface. In order...

  16. Automated cross-identifying radio to infrared surveys using the LRPY algorithm: a case study

    Science.gov (United States)

    Weston, S. D.; Seymour, N.; Gulyaev, S.; Norris, R. P.; Banfield, J.; Vaccari, M.; Hopkins, A. M.; Franzen, T. M. O.

    2018-02-01

    Cross-identifying complex radio sources with optical or infra red (IR) counterparts in surveys such as the Australia Telescope Large Area Survey (ATLAS) has traditionally been performed manually. However, with new surveys from the Australian Square Kilometre Array Pathfinder detecting many tens of millions of radio sources, such an approach is no longer feasible. This paper presents new software (LRPY - Likelihood Ratio in PYTHON) to automate the process of cross-identifying radio sources with catalogues at other wavelengths. LRPY implements the likelihood ratio (LR) technique with a modification to account for two galaxies contributing to a sole measured radio component. We demonstrate LRPY by applying it to ATLAS DR3 and a Spitzer-based multiwavelength fusion catalogue, identifying 3848 matched sources via our LR-based selection criteria. A subset of 1987 sources have flux density values for all IRAC bands which allow us to use criteria to distinguish between active galactic nuclei (AGNs) and star-forming galaxies (SFG). We find that 936 radio sources ( ≈ 47 per cent) meet both of the Lacy and Stern AGN selection criteria. Of the matched sources, 295 have spectroscopic redshifts and we examine the radio to IR flux ratio versus redshift, proposing an AGN selection criterion below the Elvis radio-loud AGN limit for this dataset. Taking the union of all three AGNs selection criteria we identify 956 as AGNs ( ≈ 48 per cent). From this dataset, we find a decreasing fraction of AGNs with lower radio flux densities consistent with other results in the literature.

  17. A tale of two feedbacks: Star formation in the host galaxies of radio AGNs

    Energy Technology Data Exchange (ETDEWEB)

    Karouzos, Marios; Im, Myungshin; Jeon, Yiseul; Kim, Ji Hoon [CEOU-Astronomy Program, Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul (Korea, Republic of); Trichas, Markos [Airbus Defence and Space, Gunnels Wood Road, Stevenage SG1 2AS (United Kingdom); Goto, Tomo [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Malkan, Matt [Division of Astronomy and Astrophysics, 3-714 UCLA, CA 90095-1547 (United States); Ruiz, Angel [Inter-University Centre for Astronomy and Astrophysics (IUCAA), Post Bag 4, Ganeshkhind, 411 007 Pune (India); Lee, Hyung Mok; Kim, Seong Jin [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul (Korea, Republic of); Oi, Nagisa; Matsuhara, Hideo; Takagi, Toshinobu; Murata, K.; Wada, Takehiko; Wada, Kensuke [Institute of Space and Astronautical Science, JAXA, Yoshino-dai 3-1-1, Sagamihara, Kanagawa 229-8510 (Japan); Shim, Hyunjin [Department of Earth Science Education, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Hanami, Hitoshi [Physics Section, Faculty of Humanities, Iwate University, Ueda 3 chome, 18-34 Morioka, Morioka, Iwate 020-8550 (Japan); Serjeant, Stephen; White, Glenn J., E-mail: mkarouzos@astro.snu.ac.kr [Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes (United Kingdom); and others

    2014-04-01

    Several lines of argument support the existence of a link between activity at the nuclei of galaxies, in the form of an accreting supermassive black hole, and star formation activity in these galaxies. Radio jets have long been argued to be an ideal mechanism that allows active galactic nuclei (AGNs) to interact with their host galaxies and affect star formation. We use a sample of radio sources in the North Ecliptic Pole (NEP) field to study the nature of this putative link, by means of spectral energy distribution (SED) fitting. We employ the excellent spectral coverage of the AKARI infrared space telescope and the rich ancillary data available in the NEP to build SEDs extending from UV to far-IR wavelengths. We find a significant AGN component in our sample of relatively faint radio sources (radio luminosity. In contrast, for narrow redshift and AGN luminosity ranges, we find that increasing radio luminosity leads to a decrease in the specific star formation rate. The most radio-loud AGNs are found to lie on the main sequence of star formation for their respective redshifts. For the first time, we potentially see such a two-sided feedback process in the same sample. We discuss the possible suppression of star formation, but not total quenching, in systems with strong radio jets, that supports the maintenance nature of feedback from radio AGN jets.

  18. An innovative approach to using both cellphones and the radio to identify young people's sexual concerns in Kinshasa, Democratic Republic of Congo.

    Science.gov (United States)

    Nsakala, Gabriel Vodiena; Coppieters, Yves; Kayembe, Patrick Kalambayi

    2014-01-01

    As teenagers have easy access to both radio programs and cell phones, the current study used these tools so that young people could anonymously identify questions about sex and other related concerns in the urban environment of the Democratic Republic of Congo. The purpose of this healthcare intervention was to identify and address concerns raised by young people, which are related to sexual health, and which promote youth health. This healthcare intervention was conducted over a six month period and consisted of a survey carried out in Kinshasa. This focused on 14 to 24 old young people using phone calls on a radio program raising concerns related to sexuality. The radio program was jointly run by a journalist and a health professional who were required to reply immediately to questions from young people. All sexual health concerns were recorded and analyzed. Forty programs were broadcast in six months and 1,250 messages and calls were recorded: 880 (70%) from girls and 370 (30%) from boys, which represents an average of 32 interventions (of which 10 calls and 22 messages) per broadcast. Most questions came from 15-19- and 20-24-year-old girls and boys. Focus of girls' questions: menstrual cycle calculation and related concerns accounted for the majority (24%); sexual practices (16%), love relationships (15%) and virginity (14%). Boys' concerns are masturbation (and its consequences) (22%), sexual practices (19%), love relationships (18%) and worries about penis size (10%). Infections (genital and STI) and topics regarding HIV represent 9% and 4% of the questions asked by girls against 7% and 10% by boys. Concerns were mainly related to knowledge, attitudes and competences to be developed. Concerns and sexual practices raised by teens about their sexual and emotional life have inspired the design of a practical guide for youth self-training and have steered the second phase of this interactive program towards supporting their responsible sexuality.

  19. Loudness Change in Response to Dynamic Acoustic Intensity

    Science.gov (United States)

    Olsen, Kirk N.; Stevens, Catherine J.; Tardieu, Julien

    2010-01-01

    Three experiments investigate psychological, methodological, and domain-specific characteristics of loudness change in response to sounds that continuously increase in intensity (up-ramps), relative to sounds that decrease (down-ramps). Timbre (vowel, violin), layer (monotone, chord), and duration (1.8 s, 3.6 s) were manipulated in Experiment 1.…

  20. AN X-RAY VIEW OF THE JET CYCLE IN THE RADIO-LOUD AGN 3C120

    Energy Technology Data Exchange (ETDEWEB)

    Lohfink, Anne M.; Reynolds, Christopher S.; Mushotzky, Richard F.; Tombesi, Francesco [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Jorstad, Svetlana G.; Marscher, Alan P. [Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Miller, Eric D.; Nowak, Michael A. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics, Cambridge, MA 02139 (United States); Aller, Hugh; Aller, Margo F.; Miller, Jon M. [Department of Astronomy, University of Michigan, 830 Dennison Building, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Brenneman, Laura W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA (United States); Fabian, Andrew C., E-mail: alohfink@astro.umd.edu [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)

    2013-08-01

    We present a study of the central engine in the broad-line radio galaxy 3C120 using a multi-epoch analysis of a deep XMM-Newton observation and two deep Suzaku pointings (in 2012). In order to place our spectral data into the context of the disk-disruption/jet-ejection cycles displayed by this object, we monitor the source in the UV/X-ray bands, and in the radio band. We find three statistically acceptable spectral models: a disk-reflection model, a jet model, and a jet+disk model. Despite being good descriptions of the data, the disk-reflection model violates the radio constraints on the inclination, and the jet model has a fine-tuning problem, requiring a jet contribution exceeding that expected. Thus, we argue for a composite jet+disk model. Within the context of this model, we verify the basic predictions of the jet-cycle paradigm, finding a truncated/refilling disk during the Suzaku observations and a complete disk extending down to the innermost stable circular orbit during the XMM-Newton observation. The idea of a refilling disk is further supported by the detection of the ejection of a new jet knot approximately one month after the Suzaku pointings. We also discover a step-like event in one of the Suzaku pointings in which the soft band lags the hard band. We suggest that we are witnessing the propagation of a disturbance from the disk into the jet on a timescale set by the magnetic field.

  1. Acoustic structure of male loud-calls support molecular phylogeny of Sumatran and Javanese leaf monkeys (genus Presbytis

    Directory of Open Access Journals (Sweden)

    Meyer Dirk

    2012-02-01

    Full Text Available Abstract Background The degree to which loud-calls in nonhuman primates can be used as a reliable taxonomic tool is the subject of ongoing debate. A recent study on crested gibbons showed that these species can be well distinguished by their songs; even at the population level the authors found reliable differences. Although there are some further studies on geographic and phylogenetic differences in loud-calls of nonhuman primate species, it is unclear to what extent loud-calls of other species have a similar close relation between acoustic structure, phylogenetic relatedness and geographic distance. We therefore conducted a field survey in 19 locations on Sumatra, Java and the Mentawai islands to record male loud-calls of wild surilis (Presbytis, a genus of Asian leaf monkeys (Colobinae with disputed taxanomy, and compared the structure of their loud-calls with a molecular genetic analysis. Results The acoustic analysis of 100 surili male loud-calls from 68 wild animals confirms the differentiation of P.potenziani, P.comata, P.thomasi and P.melalophos. In a more detailed acoustic analysis of subspecies of P.melalophos, a further separation of the southern P.m.mitrata confirms the proposed paraphyly of this group. In concordance with their geographic distribution we found the highest correlation between call structure and genetic similarity, and lesser significant correlations between call structure and geographic distance, and genetic similarity and geographic distance. Conclusions In this study we show, that as in crested gibbons, the acoustic structure of surili loud-calls is a reliable tool to distinguish between species and to verify phylogenetic relatedness and migration backgrounds of respective taxa. Since vocal production in other nonhuman primates show similar constraints, it is likely that an acoustic analysis of call structure can help to clarify taxonomic and phylogenetic relationships.

  2. Constraining primordial non-Gaussianity with bispectrum and power spectrum from upcoming optical and radio surveys

    Science.gov (United States)

    Karagiannis, Dionysios; Lazanu, Andrei; Liguori, Michele; Raccanelli, Alvise; Bartolo, Nicola; Verde, Licia

    2018-07-01

    We forecast constraints on primordial non-Gaussianity (PNG) and bias parameters from measurements of galaxy power spectrum and bispectrum in future radio continuum and optical surveys. In the galaxy bispectrum, we consider a comprehensive list of effects, including the bias expansion for non-Gaussian initial conditions up to second order, redshift space distortions, redshift uncertainties and theoretical errors. These effects are all combined in a single PNG forecast for the first time. Moreover, we improve the bispectrum modelling over previous forecasts, by accounting for trispectrum contributions. All effects have an impact on final predicted bounds, which varies with the type of survey. We find that the bispectrum can lead to improvements up to a factor ˜5 over bounds based on the power spectrum alone, leading to significantly better constraints for local-type PNG, with respect to current limits from Planck. Future radio and photometric surveys could obtain a measurement error of σ (f_{NL}^{loc}) ≈ 0.2. In the case of equilateral PNG, galaxy bispectrum can improve upon present bounds only if significant improvements in the redshift determinations of future, large volume, photometric or radio surveys could be achieved. For orthogonal non-Gaussianity, expected constraints are generally comparable to current ones.

  3. Constraining Primordial non-Gaussianity with Bispectrum and Power Spectum from Upcoming Optical and Radio Surveys

    Science.gov (United States)

    Karagiannis, Dionysios; Lazanu, Andrei; Liguori, Michele; Raccanelli, Alvise; Bartolo, Nicola; Verde, Licia

    2018-04-01

    We forecast constraints on primordial non-Gaussianity (PNG) and bias parameters from measurements of galaxy power spectrum and bispectrum in future radio continuum and optical surveys. In the galaxy bispectrum, we consider a comprehensive list of effects, including the bias expansion for non-Gaussian initial conditions up to second order, redshift space distortions, redshift uncertainties and theoretical errors. These effects are all combined in a single PNG forecast for the first time. Moreover, we improve the bispectrum modelling over previous forecasts, by accounting for trispectrum contributions. All effects have an impact on final predicted bounds, which varies with the type of survey. We find that the bispectrum can lead to improvements up to a factor ˜5 over bounds based on the power spectrum alone, leading to significantly better constraints for local-type PNG, with respect to current limits from Planck. Future radio and photometric surveys could obtain a measurement error of σ (f_{NL}^{loc}) ≈ 0.2. In the case of equilateral PNG, galaxy bispectrum can improve upon present bounds only if significant improvements in the redshift determinations of future, large volume, photometric or radio surveys could be achieved. For orthogonal non-Gaussianity, expected constraints are generally comparable to current ones.

  4. Energetics of the molecular gas in the H2 luminous radio galaxy 3C 326: Evidence for negative AGN feedback

    Science.gov (United States)

    Nesvadba, N. P. H.; Boulanger, F.; Salomé, P.; Guillard, P.; Lehnert, M. D.; Ogle, P.; Appleton, P.; Falgarone, E.; Pineau Des Forets, G.

    2010-10-01

    We present a detailed analysis of the gas conditions in the H2 luminous radio galaxy 3C 326 N at z ~ 0.1, which has a low star-formation rate (SFR ~ 0.07 M⊙ yr-1) in spite of a gas surface density similar to those in starburst galaxies. Its star-formation efficiency is likely a factor ~10-50 lower than those of ordinary star-forming galaxies. Combining new IRAM CO emission-line interferometry with existing Spitzer mid-infrared spectroscopy, we find that the luminosity ratio of CO and pure rotational H2 line emission is factors 10-100 lower than what is usually found. This suggests that most of the molecular gas is warm. The Na D absorption-line profile of 3C 326 N in the optical suggests an outflow with a terminal velocity of ~-1800 km s-1 and a mass outflow rate of 30-40 M⊙ yr-1, which cannot be explained by star formation. The mechanical power implied by the wind, of order 1043 erg s-1, is comparable to the bolometric luminosity of the emission lines of ionized and molecular gas. To explain these observations, we propose a scenario where a small fraction of the mechanical energy of the radio jet is deposited in the interstellar medium of 3C 326 N, which powers the outflow, and the line emission through a mass, momentum and energy exchange between the different gas phases of the ISM. Dissipation times are of order 107-8 yrs, similar or greater than the typical jet lifetime. Small ratios of CO and PAH surface brightnesses in another 7 H2 luminous radio galaxies suggest that a similar form of AGN feedback could be lowering star-formation efficiencies in these galaxies in a similar way. The local demographics of radio-loud AGN suggests that secular gas cooling in massive early-type galaxies of ≥1011 M⊙ could generally be regulated through a fundamentally similar form of “maintenance-phase” AGN feedback. Based on observations carried out with the IRAM Plateau de Bure Interferometer.

  5. RADIO-WEAK BL LAC OBJECTS IN THE FERMI ERA

    Energy Technology Data Exchange (ETDEWEB)

    Massaro, F.; Marchesini, E. J. [Dipartimento di Fisica, Università degli Studi di Torino (UniTO), via Pietro Giuria 1, I-10125 Torino (Italy); D’Abrusco, R.; Smith, Howard A. [Smithsonian Astrophysical Observatory, 60 Garden Street, 02138 Cambridge, MA (United States); Masetti, N. [INAF—Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna, via Gobetti 101, I-40129, Bologna (Italy); Andruchow, I. [Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque, B1900FWA, La Plata (Argentina)

    2017-01-10

    The existence of “radio-weak BL Lac objects” (RWBLs) has been an open question, and has remained unsolved since the discovery that quasars could be radio-quiet or radio-loud. Recently, several groups identified RWBL candidates, mostly found while searching for low-energy counterparts of the unidentified or unassociated gamma-ray sources listed in the Fermi catalogs. Confirming RWBLs is a challenging task since they could be confused with white dwarfs (WDs) or weak emission line quasars (WELQs) when there are not sufficient data to precisely draw their broadband spectral energy distribution, and their classification is mainly based on a featureless optical spectra. Motivated by the recent discovery that Fermi BL Lacs appear to have very peculiar mid-IR emission, we show that it is possible to distinguish between WDs, WELQs, and BL Lacs using the [3.4]–[4.6]–[12] μ m color–color plot built using the WISE magnitudes when the optical spectrum is available. On the basis of this analysis, we identify WISE J064459.38+603131 and WISE J141046.00+740511.2 as the first two genuine RWBLs, both potentially associated with Fermi sources. Finally, to strengthen our identification of these objects as true RWBLs, we present multifrequency observations for these two candidates to show that their spectral behavior is indeed consistent with that of the BL Lac population.

  6. RADIO-WEAK BL LAC OBJECTS IN THE FERMI ERA

    International Nuclear Information System (INIS)

    Massaro, F.; Marchesini, E. J.; D’Abrusco, R.; Smith, Howard A.; Masetti, N.; Andruchow, I.

    2017-01-01

    The existence of “radio-weak BL Lac objects” (RWBLs) has been an open question, and has remained unsolved since the discovery that quasars could be radio-quiet or radio-loud. Recently, several groups identified RWBL candidates, mostly found while searching for low-energy counterparts of the unidentified or unassociated gamma-ray sources listed in the Fermi catalogs. Confirming RWBLs is a challenging task since they could be confused with white dwarfs (WDs) or weak emission line quasars (WELQs) when there are not sufficient data to precisely draw their broadband spectral energy distribution, and their classification is mainly based on a featureless optical spectra. Motivated by the recent discovery that Fermi BL Lacs appear to have very peculiar mid-IR emission, we show that it is possible to distinguish between WDs, WELQs, and BL Lacs using the [3.4]–[4.6]–[12] μ m color–color plot built using the WISE magnitudes when the optical spectrum is available. On the basis of this analysis, we identify WISE J064459.38+603131 and WISE J141046.00+740511.2 as the first two genuine RWBLs, both potentially associated with Fermi sources. Finally, to strengthen our identification of these objects as true RWBLs, we present multifrequency observations for these two candidates to show that their spectral behavior is indeed consistent with that of the BL Lac population.

  7. Interference-aware power control for multi-radio multi-channel wireless mesh networks

    CSIR Research Space (South Africa)

    Olwal, TO

    2009-09-01

    Full Text Available are well known in [9], [6]. The operation of multi-radio multi-channel (MRMC) WMNs generally requires sustainable energy supply. Substantial deployments of WMNs have recently been witnessed in rural and remote communities [4]. In such applications...]. Power resources are dynamically adjusted by each NIC using intra and inter-subsystem (channel) states. Due to the decentralized nature, each MP assumes imperfect knowledge about the global network. Further we assume that there exists...

  8. A customizable multi-channel loudness compensation method based on WDRC for digital hearing aids

    Science.gov (United States)

    Hu, Jiebin; Wang, Mingjiang; Ma, Min

    2017-08-01

    Loudness compensation is the most significant signal processing algorithm in digital hearing aids at present. An algorithm of multi-channel loudness compensation for embedded system has been put forward in this paper. The number of channels is customizable in this algorithm. The algorithm can set different number and different width of channels for each patient based on frequency domain wide dynamic range compression. First, according to the requirement of patient to divide the frequency domain into multiple unequal frequency bands. And then calculate the gain of each channel according to the input-output curve of sound pressure level. Finally, the time-domain impulse response of gain is computed from Mel filter banks. It is used in conjunction with speech enhancement processing in hearing aids. Simulation results show that the algorithm can effectively enhance the loudness for different frequencies.

  9. Compact radio sources

    International Nuclear Information System (INIS)

    Altschuler, D.R.

    1975-01-01

    Eighty-seven compact radio sources were monitored between 1971 and 1974 with the National Radio Astronomy Observatory interferometer. Both flux density and polarization were measured at intervals of about one month at wavelengths of 3.7 and 11.1 cms. Forty-four sources showed definite variability in their total and/or polarized flux density. The variations in polarization were of a shorter time scale than the corresponding flux density variations. Some of the qualitative features of an expanding source model were observed. The data suggest that some form of injection of relativistic electrons is taking place. The absence of significant depolarization in the variable sources indicates that only a small fraction of the mass of the radio outburst is in the form of non-relativistic plasma. Some of the objects observed belong to the BL-Lacertal class. It is shown that this class is very inhomogeneous in its radio properties. For the violently variable BL-Lacertal type objects the spectrum, flux variations and polarization data strongly suggest that these are very young objects

  10. Design, modeling and testing of the Askaryan Radio Array South Pole autonomous renewable power stations

    Energy Technology Data Exchange (ETDEWEB)

    Besson, D.Z., E-mail: zedlam@ku.edu [Department of Physics and Astronomy, University of Kansas, 1082 Malott Hall, 1251 Wescoe Hall Drive, Lawrence, KS 66045-7582 (United States); Moscow Engineering and Physics Institute, 31 Kashirskaya Highway, Moscow 115409 (Russian Federation); Kennedy, D.M., E-mail: dmkennedy@ku.edu [Department of Physics and Astronomy, University of Kansas, 1082 Malott Hall, 1251 Wescoe Hall Drive, Lawrence, KS 66045-7582 (United States); Ratzlaff, K., E-mail: ratzlaff@ku.edu [Instrumentation Design Laboratory, University of Kansas, 6042 Malott Hall, 1251 Wescoe Hall Drive, Lawrence, KS 66045-7582 (United States); Young, R., E-mail: rwyoung@ku.edu [Instrumentation Design Laboratory, University of Kansas, 6042 Malott Hall, 1251 Wescoe Hall Drive, Lawrence, KS 66045-7582 (United States)

    2014-11-01

    We describe the design, construction and operation of the Askaryan Radio Array (ARA) Autonomous Renewable Power Stations, initially installed at the South Pole in December, 2010 with the goal of providing an independently operating 100 W power source capable of year-round operation in extreme environments. In addition to particle astrophysics applications at the South Pole, such a station can easily be, and has since been, extended to operation elsewhere, as described herein.

  11. Design, modeling and testing of the Askaryan Radio Array South Pole autonomous renewable power stations

    International Nuclear Information System (INIS)

    Besson, D.Z.; Kennedy, D.M.; Ratzlaff, K.; Young, R.

    2014-01-01

    We describe the design, construction and operation of the Askaryan Radio Array (ARA) Autonomous Renewable Power Stations, initially installed at the South Pole in December, 2010 with the goal of providing an independently operating 100 W power source capable of year-round operation in extreme environments. In addition to particle astrophysics applications at the South Pole, such a station can easily be, and has since been, extended to operation elsewhere, as described herein

  12. Too Loud for Too Long! PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2017-02-07

    This 60 second public service announcement is based on the February 2017 CDC Vital Signs report. Being around too much loud noise—like a leaf blower or rock concert—can cause permanent hearing loss. Learn how to prevent hearing loss.  Created: 2/7/2017 by National Institute for Occupational Safety and Health (NIOSH).   Date Released: 2/7/2017.

  13. Radio frequency system for nuclear fusion

    International Nuclear Information System (INIS)

    Kozeki, Shoichiro; Sagawa, Norimoto; Takizawa, Teruhiro

    1987-01-01

    The importance of radio frequency waves has been increasing in the area of nuclear fusion since they are indispensable for heating of plasma, etc. This report outlines radio frequency techniques used for nuclear fusion and describes the development of radio frequency systems (radio frequency plasma heating system and current drive system). Presently, in-depth studies are underway at various research institutes to achieve plasma heating by injection of radio frequency electric power. Three ranges of frequencies, ICRF (ion cyclotron range of frequency), LHRF (lower hybrid range of frequency) and ECRF (electron cyclotron range of frequency), are considered promissing for radio frequency heating. Candidate waves for plasma current driving include ECW (electron cyclotron wave), LHW (lower hybrid wave), MSW (magnetic sound wave), ICW (ion cyclotron wave) with minority component, and FW (fast wave). FW is the greatest in terms of current drive efficiency. In general, a radio frequency system for nuclear fusion consists of a radio frequency power source, transmission/matching circuit component and plasma connection component. (Nogami, K.)

  14. An innovative approach to using both cellphones and the radio to identify young people’s sexual concerns in Kinshasa, Democratic Republic of Congo

    Science.gov (United States)

    2014-01-01

    Background As teenagers have easy access to both radio programs and cell phones, the current study used these tools so that young people could anonymously identify questions about sex and other related concerns in the urban environment of the Democratic Republic of Congo. The purpose of this healthcare intervention was to identify and address concerns raised by young people, which are related to sexual health, and which promote youth health. Methods This healthcare intervention was conducted over a six month period and consisted of a survey carried out in Kinshasa. This focused on 14 to 24 old young people using phone calls on a radio program raising concerns related to sexuality. The radio program was jointly run by a journalist and a health professional who were required to reply immediately to questions from young people. All sexual health concerns were recorded and analyzed. Results Forty programs were broadcast in six months and 1,250 messages and calls were recorded: 880 (70%) from girls and 370 (30%) from boys, which represents an average of 32 interventions (of which 10 calls and 22 messages) per broadcast. Most questions came from 15-19- and 20-24-year-old girls and boys. Focus of girls’ questions: menstrual cycle calculation and related concerns accounted for the majority (24%); sexual practices (16%), love relationships (15%) and virginity (14%). Boys’ concerns are masturbation (and its consequences) (22%), sexual practices (19%), love relationships (18%) and worries about penis size (10%). Infections (genital and STI) and topics regarding HIV represent 9% and 4% of the questions asked by girls against 7% and 10% by boys. Concerns were mainly related to knowledge, attitudes and competences to be developed. Conclusions Concerns and sexual practices raised by teens about their sexual and emotional life have inspired the design of a practical guide for youth self-training and have steered the second phase of this interactive program towards supporting

  15. Self-powered wireless carbohydrate/oxygen sensitive biodevice based on radio signal transmission.

    Science.gov (United States)

    Falk, Magnus; Alcalde, Miguel; Bartlett, Philip N; De Lacey, Antonio L; Gorton, Lo; Gutierrez-Sanchez, Cristina; Haddad, Raoudha; Kilburn, Jeremy; Leech, Dónal; Ludwig, Roland; Magner, Edmond; Mate, Diana M; Conghaile, Peter Ó; Ortiz, Roberto; Pita, Marcos; Pöller, Sascha; Ruzgas, Tautgirdas; Salaj-Kosla, Urszula; Schuhmann, Wolfgang; Sebelius, Fredrik; Shao, Minling; Stoica, Leonard; Sygmund, Cristoph; Tilly, Jonas; Toscano, Miguel D; Vivekananthan, Jeevanthi; Wright, Emma; Shleev, Sergey

    2014-01-01

    Here for the first time, we detail self-contained (wireless and self-powered) biodevices with wireless signal transmission. Specifically, we demonstrate the operation of self-sustained carbohydrate and oxygen sensitive biodevices, consisting of a wireless electronic unit, radio transmitter and separate sensing bioelectrodes, supplied with electrical energy from a combined multi-enzyme fuel cell generating sufficient current at required voltage to power the electronics. A carbohydrate/oxygen enzymatic fuel cell was assembled by comparing the performance of a range of different bioelectrodes followed by selection of the most suitable, stable combination. Carbohydrates (viz. lactose for the demonstration) and oxygen were also chosen as bioanalytes, being important biomarkers, to demonstrate the operation of the self-contained biosensing device, employing enzyme-modified bioelectrodes to enable the actual sensing. A wireless electronic unit, consisting of a micropotentiostat, an energy harvesting module (voltage amplifier together with a capacitor), and a radio microchip, were designed to enable the biofuel cell to be used as a power supply for managing the sensing devices and for wireless data transmission. The electronic system used required current and voltages greater than 44 µA and 0.57 V, respectively to operate; which the biofuel cell was capable of providing, when placed in a carbohydrate and oxygen containing buffer. In addition, a USB based receiver and computer software were employed for proof-of concept tests of the developed biodevices. Operation of bench-top prototypes was demonstrated in buffers containing different concentrations of the analytes, showcasing that the variation in response of both carbohydrate and oxygen biosensors could be monitored wirelessly in real-time as analyte concentrations in buffers were changed, using only an enzymatic fuel cell as a power supply.

  16. Self-powered wireless carbohydrate/oxygen sensitive biodevice based on radio signal transmission.

    Directory of Open Access Journals (Sweden)

    Magnus Falk

    Full Text Available Here for the first time, we detail self-contained (wireless and self-powered biodevices with wireless signal transmission. Specifically, we demonstrate the operation of self-sustained carbohydrate and oxygen sensitive biodevices, consisting of a wireless electronic unit, radio transmitter and separate sensing bioelectrodes, supplied with electrical energy from a combined multi-enzyme fuel cell generating sufficient current at required voltage to power the electronics. A carbohydrate/oxygen enzymatic fuel cell was assembled by comparing the performance of a range of different bioelectrodes followed by selection of the most suitable, stable combination. Carbohydrates (viz. lactose for the demonstration and oxygen were also chosen as bioanalytes, being important biomarkers, to demonstrate the operation of the self-contained biosensing device, employing enzyme-modified bioelectrodes to enable the actual sensing. A wireless electronic unit, consisting of a micropotentiostat, an energy harvesting module (voltage amplifier together with a capacitor, and a radio microchip, were designed to enable the biofuel cell to be used as a power supply for managing the sensing devices and for wireless data transmission. The electronic system used required current and voltages greater than 44 µA and 0.57 V, respectively to operate; which the biofuel cell was capable of providing, when placed in a carbohydrate and oxygen containing buffer. In addition, a USB based receiver and computer software were employed for proof-of concept tests of the developed biodevices. Operation of bench-top prototypes was demonstrated in buffers containing different concentrations of the analytes, showcasing that the variation in response of both carbohydrate and oxygen biosensors could be monitored wirelessly in real-time as analyte concentrations in buffers were changed, using only an enzymatic fuel cell as a power supply.

  17. Magnetar-like X-Ray Bursts Suppress Pulsar Radio Emission

    Energy Technology Data Exchange (ETDEWEB)

    Archibald, R. F.; Lyutikov, M.; Kaspi, V. M.; Tendulkar, S. P. [Department of Physics and McGill Space Institute, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada); Burgay, M.; Possenti, A. [INAF–Osservatorio Astronomico di Cagliari, Via della Scienza 5, I-09047 Selargius (Italy); Esposito, P.; Rea, N. [Anton Pannekoek Institute for Astronomy, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Israel, G. [INAF–Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monteporzio Catone, Roma (Italy); Kerr, M. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Sarkissian, J. [CSIRO Astronomy and Space Science, Parkes Observatory, P.O. Box 276, Parkes, NSW 2870 (Australia); Scholz, P., E-mail: archibald@astro.utoronto.ca [National Research Council of Canada, Herzberg Astronomy and Astrophysics, Dominion Radio Astrophysical Observatory, P.O. Box 248, Penticton, BC V2A 6J9 (Canada)

    2017-11-10

    Rotation-powered pulsars and magnetars are two different observational manifestations of neutron stars: rotation-powered pulsars are rapidly spinning objects that are mostly observed as pulsating radio sources, while magnetars, neutron stars with the highest known magnetic fields, often emit short-duration X-ray bursts. Here, we report simultaneous observations of the high-magnetic-field radio pulsar PSR J1119−6127 at X-ray, with XMM-Newton and NuSTAR , and at radio energies with the Parkes radio telescope, during a period of magnetar-like bursts. The rotationally powered radio emission shuts off coincident with the occurrence of multiple X-ray bursts and recovers on a timescale of ∼70 s. These observations of related radio and X-ray phenomena further solidify the connection between radio pulsars and magnetars and suggest that the pair plasma produced in bursts can disrupt the acceleration mechanism of radio-emitting particles.

  18. Precoder Design and Power Allocation for MIMO Cognitive Radio Two-Way Relaying Systems

    KAUST Repository

    Sboui, Lokman

    2016-08-11

    In this paper, we study a multiple-antenna two-way relaying (TWR) cognitive radio (CR) system. A space alignment (SA) technique is adopted by the secondary users (SUs) to avoid interference with the primary users (PUs). We derive the optimal power allocation that maximizes the TWR achievable SU sum- rate while respecting the total power budget and the relay power constraints. We also analyze the case in which the relay is able to optimize its gain matrix structure to enhance the SU sum-rate. In the numerical results, we quantify the sum-rate gain of using the SA in the TWR CR and we show that the SU sum-rate is very limited when the relay power is low or the PU power and its resulting interference are high. In addition, we optimize the relay gain using an iterative algorithm and compare between different relay matrix structures.

  19. 77 FR 28797 - Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection...

    Science.gov (United States)

    2012-05-16

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 12 and 90 [DA 11-1838] Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection and Assignment of Frequencies, and Transition of the Upper 200 Channels in the 800 MHz Band to EA Licensing AGENCY: Federal Communications...

  20. OPTICAL SPECTRA OF CANDIDATE INTERNATIONAL CELESTIAL REFERENCE FRAME (ICRF) FLAT-SPECTRUM RADIO SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Titov, O.; Stanford, Laura M. [Geoscience Australia, P.O. Box 378, Canberra, ACT 2601 (Australia); Johnston, Helen M.; Hunstead, Richard W. [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia); Pursimo, T. [Nordic Optical Telescope, Nordic Optical Telescope Apartado 474E-38700 Santa Cruz de La Palma, Santa Cruz de Tenerife (Spain); Jauncey, David L. [CSIRO Astronomy and Space Science, ATNF and Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Maslennikov, K. [Central Astronomical Observatory at Pulkovo, Pulkovskoye Shosse, 65/1, 196140, St. Petersburg (Russian Federation); Boldycheva, A., E-mail: oleg.titov@ga.gov.au [Ioffe Physical Technical Institute, 26 Polytekhnicheskaya, St. Petersburg, 194021 (Russian Federation)

    2013-07-01

    Continuing our program of spectroscopic observations of International Celestial Reference Frame (ICRF) sources, we present redshifts for 120 quasars and radio galaxies. Data were obtained with five telescopes: the 3.58 m European Southern Observatory New Technology Telescope, the two 8.2 m Gemini telescopes, the 2.5 m Nordic Optical Telescope (NOT), and the 6.0 m Big Azimuthal Telescope of the Special Astrophysical Observatory in Russia. The targets were selected from the International VLBI Service for Geodesy and Astrometry candidate International Celestial Reference Catalog which forms part of an observational very long baseline interferometry (VLBI) program to strengthen the celestial reference frame. We obtained spectra of the potential optical counterparts of more than 150 compact flat-spectrum radio sources, and measured redshifts of 120 emission-line objects, together with 19 BL Lac objects. These identifications add significantly to the precise radio-optical frame tie to be undertaken by Gaia, due to be launched in 2013, and to the existing data available for analyzing source proper motions over the celestial sphere. We show that the distribution of redshifts for ICRF sources is consistent with the much larger sample drawn from Faint Images of the Radio Sky at Twenty cm (FIRST) and Sloan Digital Sky Survey, implying that the ultra-compact VLBI sources are not distinguished from the overall radio-loud quasar population. In addition, we obtained NOT spectra for five radio sources from the FIRST and NRAO VLA Sky Survey catalogs, selected on the basis of their red colors, which yielded three quasars with z > 4.

  1. Distance Dependent Model for the Delay Power Spectrum of In-room Radio Channels

    DEFF Research Database (Denmark)

    Steinböck, Gerhard; Pedersen, Troels; Fleury, Bernard Henri

    2013-01-01

    A model based on experimental observations of the delay power spectrum in closed rooms is proposed. The model includes the distance between the transmitter and the receiver as a parameter which makes it suitable for range based radio localization. The experimental observations motivate the proposed...... model of the delay power spectrum with a primary (early) component and a reverberant component (tail). The primary component is modeled as a Dirac delta function weighted according to an inverse distance power law (d-n). The reverberant component is an exponentially decaying function with onset equal...... to the propagation time between transmitter and receiver. Its power decays exponentially with distance. The proposed model allows for the prediction of e.g. the path loss, mean delay, root mean squared (rms) delay spread, and kurtosis versus the distance. The model predictions are validated by measurements...

  2. CLUSTERING OF γ-RAY-SELECTED 2LAC FERMI BLAZARS

    Energy Technology Data Exchange (ETDEWEB)

    Allevato, V.; Finoguenov, A. [Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-00014 Helsinki (Finland); Cappelluti, N. [University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States)

    2014-12-20

    We present the first measurement of the projected correlation function of 485 γ-ray-selected blazars, divided into 175 BL Lacertae (BL Lacs) and 310 flat-spectrum radio quasars (FSRQs) detected in the 2 year all-sky survey by the Fermi-Large Area Telescope. We find that Fermi BL Lacs and FSRQs reside in massive dark matter halos (DMHs) with log M{sub h} = 13.35{sub −0.14}{sup +0.20} and log M{sub h} = 13.40{sub −0.19}{sup +0.15} h {sup –1} M {sub ☉}, respectively, at low (z ∼ 0.4) and high (z ∼ 1.2) redshift. In terms of clustering properties, these results suggest that BL Lacs and FSRQs are similar objects residing in the same dense environment typical of galaxy groups, despite their different spectral energy distributions, power, and accretion rates. We find no difference in the typical bias and hosting halo mass between Fermi blazars and radio-loud active galactic nuclei (AGNs), supporting the unification scheme simply equating radio-loud objects with misaligned blazar counterparts. This similarity in terms of the typical environment they preferentially live in, suggests that blazars tend to occupy the center of DMHs, as already pointed out for radio-loud AGNs. This implies, in light of several projects looking for the γ-ray emission from DM annihilation in galaxy clusters, a strong contamination from blazars to the expected signal from DM annihilation.

  3. Evaluating standard airborne sound insulation measures in terms of annoyance, loudness, and audibility ratings.

    Science.gov (United States)

    Park, H K; Bradley, J S

    2009-07-01

    This paper reports the results of an evaluation of the merits of standard airborne sound insulation measures with respect to subjective ratings of the annoyance and loudness of transmitted sounds. Subjects listened to speech and music sounds modified to represent transmission through 20 different walls with sound transmission class (STC) ratings from 34 to 58. A number of variations in the standard measures were also considered. These included variations in the 8-dB rule for the maximum allowed deficiency in the STC measure as well as variations in the standard 32-dB total allowed deficiency. Several spectrum adaptation terms were considered in combination with weighted sound reduction index (R(w)) values as well as modifications to the range of included frequencies in the standard rating contour. A STC measure without an 8-dB rule and an R(w) rating with a new spectrum adaptation term were better predictors of annoyance and loudness ratings of speech sounds. R(w) ratings with one of two modified C(tr) spectrum adaptation terms were better predictors of annoyance and loudness ratings of transmitted music sounds. Although some measures were much better predictors of responses to one type of sound than were the standard STC and R(w) values, no measure was remarkably improved for predicting annoyance and loudness ratings of both music and speech sounds.

  4. Radio Observations of Ultra-Luminous X-Ray Sources and their Implication for Models

    Science.gov (United States)

    Koerding, E. G.; Colbert, E. J. M.; Falcke, H.

    2004-05-01

    We present the results of a radio monitoring campaign to search for radio emission from nearby ultra-luminous X-ray sources (ULXs). These intriguing sources are bright off-nuclear X-ray point sources with luminosities exceeding LX > 1039 erg/sec. Assuming isotropic emission the Eddington Limit suggests that they harbor intermediate mass black holes. Due to the problems of this explanation also other possibilities are currently discussed, among them are anisotropic emission, super-Eddington accretion flows or relativistically beamed emission from microquasars. Detections of compact radio cores at the positions of ULXs would be a direct hint to jet-emission. However, as the ULX phenomenom is connected to star formation we have to assume that they are strongly accreting objects. Thus, similar to their nearest Galactic cousins, the very high state X-ray binaries (see e.g., GRS 1915), ULXs may show radio flares. A well-defined sample of the 9 nearest ULXs has been monitored eight times during 5 months with the Very Large Array in A and B configuration. Our limiting sensitivity is 0.15 mJy (4 σ ) for flares and 68 μ Jy for continuous emission. In M82 some ULXs seem to be connected to radio supernova remnants. Besides that no flare or continuous emission has been detected. As the timescales of radio flares in ULXs are highly uncertain, it could well be that we have undersampled the lightcurve. However, upper bounds for the probability to detect a flare can be given. The upper limits for the continuous emission are compared with the emission found in NGC 5408 X-1 and with quasars and microquasars. We show that these limits are well in agreement with the microblazar model using the Radio/X-ray correlation of XRBs and AGN. Thus, it could well be that ULXs are microblazers which may be radio loud.

  5. AN X-RAY COOLING-CORE CLUSTER SURROUNDING A LOW-POWER COMPACT STEEP SPECTRUM RADIO SOURCE 1321+045

    International Nuclear Information System (INIS)

    Kunert-Bajraszewska, M.; Siemiginowska, A.; Labiano, A.

    2013-01-01

    We discovered an X-ray cluster in a Chandra observation of the compact steep spectrum (CSS) radio source 1321+045 (z = 0.263). CSS sources are thought to be young radio objects at the beginning of their evolution and can potentially test the cluster heating process. 1321+045 is a relatively low-luminosity source and its morphology consists of two radio lobes on the opposite sides of a radio core with no evidence for jets or hotspots. The optical emission line ratios are consistent with an interstellar medium dominated by active galactic nucleus photoionization with a small contribution from star formation, and no contributions from shocks. Based on these ratios, we classify 1321+045 as a low excitation galaxy (LEG) and suggest that its radioactivity is in a coasting phase. The X-ray emission associated with the radio source is detected with 36.1 ± 8.3 counts, but the origin of this emission is highly uncertain. The current X-ray image of the cluster does not show any signatures of a radio source impact on the cluster medium. Chandra detects the cluster emission at >3σ level out to ∼60'' (240 kpc). We obtain the best-fit beta model parameters of the surface brightness profile of β = 0.58 ± 0.2 and a core radius of 9.4 +1.1 -0.9 arcsec. The average temperature of the cluster is equal to kT = 4.4 +0.5 -0.3 keV, with a temperature and cooling profile indicative of a cooling core. We measure the cluster luminosity L (0.5-2 k eV) = 3 × 10 44 erg s –1 and mass 1.5 × 10 14 M ☉

  6. AN X-RAY COOLING-CORE CLUSTER SURROUNDING A LOW-POWER COMPACT STEEP SPECTRUM RADIO SOURCE 1321+045

    Energy Technology Data Exchange (ETDEWEB)

    Kunert-Bajraszewska, M. [Torun Centre for Astronomy, Faculty of Physics, Astronomy and Informatics, NCU, Grudziacka 5, 87-100 Torun (Poland); Siemiginowska, A. [Harvard Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 (United States); Labiano, A., E-mail: magda@astro.uni.torun.pl [Centro de Astrobiologia (CSIC-INTA), Carretera de Ajalvir km. 4, E-28850 Torrejon de Ardoz, Madrid (Spain)

    2013-07-20

    We discovered an X-ray cluster in a Chandra observation of the compact steep spectrum (CSS) radio source 1321+045 (z = 0.263). CSS sources are thought to be young radio objects at the beginning of their evolution and can potentially test the cluster heating process. 1321+045 is a relatively low-luminosity source and its morphology consists of two radio lobes on the opposite sides of a radio core with no evidence for jets or hotspots. The optical emission line ratios are consistent with an interstellar medium dominated by active galactic nucleus photoionization with a small contribution from star formation, and no contributions from shocks. Based on these ratios, we classify 1321+045 as a low excitation galaxy (LEG) and suggest that its radioactivity is in a coasting phase. The X-ray emission associated with the radio source is detected with 36.1 {+-} 8.3 counts, but the origin of this emission is highly uncertain. The current X-ray image of the cluster does not show any signatures of a radio source impact on the cluster medium. Chandra detects the cluster emission at >3{sigma} level out to {approx}60'' (240 kpc). We obtain the best-fit beta model parameters of the surface brightness profile of {beta} = 0.58 {+-} 0.2 and a core radius of 9.4{sup +1.1}{sub -0.9} arcsec. The average temperature of the cluster is equal to kT = 4.4{sup +0.5}{sub -0.3} keV, with a temperature and cooling profile indicative of a cooling core. We measure the cluster luminosity L{sub (0.5-2{sub keV)}} = 3 Multiplication-Sign 10{sup 44} erg s{sup -1} and mass 1.5 Multiplication-Sign 10{sup 14} M{sub Sun}.

  7. Young People's Exposure to Loud Music. A Summary of the Literature

    NARCIS (Netherlands)

    Vogel, I.; Brug, J.; Ploeg, C.P.B. van der; Raat, H.

    2007-01-01

    Objectives: This descriptive summary of the literature provides an overview of the available studies (published before October 2006) on sociodemographic, psychosocial, and other correlates of risk and protective behaviors for hearing loss in young people aged 12 to 25 years. Methods: Publications

  8. Miniature EVA Software Defined Radio

    Science.gov (United States)

    Pozhidaev, Aleksey

    2012-01-01

    As NASA embarks upon developing the Next-Generation Extra Vehicular Activity (EVA) Radio for deep space exploration, the demands on EVA battery life will substantially increase. The number of modes and frequency bands required will continue to grow in order to enable efficient and complex multi-mode operations including communications, navigation, and tracking applications. Whether conducting astronaut excursions, communicating to soldiers, or first responders responding to emergency hazards, NASA has developed an innovative, affordable, miniaturized, power-efficient software defined radio that offers unprecedented power-efficient flexibility. This lightweight, programmable, S-band, multi-service, frequency- agile EVA software defined radio (SDR) supports data, telemetry, voice, and both standard and high-definition video. Features include a modular design, an easily scalable architecture, and the EVA SDR allows for both stationary and mobile battery powered handheld operations. Currently, the radio is equipped with an S-band RF section. However, its scalable architecture can accommodate multiple RF sections simultaneously to cover multiple frequency bands. The EVA SDR also supports multiple network protocols. It currently implements a Hybrid Mesh Network based on the 802.11s open standard protocol. The radio targets RF channel data rates up to 20 Mbps and can be equipped with a real-time operating system (RTOS) that can be switched off for power-aware applications. The EVA SDR's modular design permits implementation of the same hardware at all Network Nodes concept. This approach assures the portability of the same software into any radio in the system. It also brings several benefits to the entire system including reducing system maintenance, system complexity, and development cost.

  9. Intensive Voice Treatment (LSVT[R]LOUD) for Parkinson's Disease Following Deep Brain Stimulation of the Subthalamic Nucleus

    Science.gov (United States)

    Spielman, Jennifer; Mahler, Leslie; Halpern, Angela; Gilley, Phllip; Klepitskaya, Olga; Ramig, Lorraine

    2011-01-01

    Purpose: Intensive voice therapy (LSVT[R]LOUD) can effectively manage voice and speech symptoms associated with idiopathic Parkinson disease (PD). This small-group study evaluated voice and speech in individuals with and without deep brain stimulation of the subthalamic nucleus (STN-DBS) before and after LSVT LOUD, to determine whether outcomes…

  10. Energy-Aware Cognitive Radio Systems

    KAUST Repository

    Bedeer, Ebrahim

    2016-01-15

    The concept of energy-aware communications has spurred the interest of the research community in the most recent years due to various environmental and economical reasons. It becomes indispensable for wireless communication systems to shift their resource allocation problems from optimizing traditional metrics, such as throughput and latency, to an environmental-friendly energy metric. Although cognitive radio systems introduce spectrum efficient usage techniques, they employ new complex technologies for spectrum sensing and sharing that consume extra energy to compensate for overhead and feedback costs. Considering an adequate energy efficiency metric—that takes into account the transmit power consumption, circuitry power, and signaling overhead—is of momentous importance such that optimal resource allocations in cognitive radio systems reduce the energy consumption. A literature survey of recent energy-efficient based resource allocations schemes is presented for cognitive radio systems. The energy efficiency performances of these schemes are analyzed and evaluated under power budget, co-channel and adjacent-channel interferences, channel estimation errors, quality-of-service, and/or fairness constraints. Finally, the opportunities and challenges of energy-aware design for cognitive radio systems are discussed.

  11. The width of jets in powerful edge-brightened extragalactic double radio sources

    International Nuclear Information System (INIS)

    Banhatti, D.G.

    1987-01-01

    The widths of primary and secondary jets are derived from a sample of 14 double hotspots in powerful extended extragalactic double radio sources. In the model employed, the primary jet extends from the core to the more compact primary hotspot and the secondary jet emerges from the primary hotspot and dissipates to form the diffuse secondary hotspot. Mean values of hotspot size/jet extent imply that the primary and secondary jets, if free, must be 2 0 and > 27 0 wide, respectively. (author)

  12. Hearing loss induced by loud music among musicians of symphonic orchestra

    Directory of Open Access Journals (Sweden)

    Tanja Carli

    2012-12-01

    Full Text Available Noise-induced hearing loss is an important public health issue, especially among musicians who are, more than any other occupation, dependent on their hearing. For them, hearing impairment is due to too loud music, the effect of which, if exceeding the limit depending on the individual sensitivity of one’s ear, can be compared with theeffect of noise on the ear. Risk factors for its development are: the type of musical instrument and sound character, the way of playing, music genre or composition, duration of exposure to loud music, sound source and its distance from the ear, intervals of acoustic stimuli, individual factors and the musician’s position in the orchestra. Hearing impairment is greater at higher frequencies; in pure tone audiogram it is shown as notches between 3000 and 6000 Hz and is most frequent in the wind and brass section. Hearing loss is greater among violinists and typically affects the left ear owing to the sound source proximity and their position in the orchestra. The most common health problems take the form of diplacusis, algiacusis and tinnitus, as exposure to the loud acoustic stimulus above 90 dB(A cause damage to the inner ear, the so-called acoustic trauma. Use of personal protective equipment among musicians is low especially because of too much high-frequency attenuation and occlusion effect.

  13. How Loud Is Too Loud?

    Medline Plus

    Full Text Available ... Director Mission Strategic Plans NIDCD History and ... News: NIDCD-Supported Research Subtle hearing loss while young changes brain function, study finds: Early damage could open ...

  14. Clues to quasar broad-line region geometry and kinematics

    NARCIS (Netherlands)

    Vestergaard, M; Wilkes, BJ; Barthel, PD

    2000-01-01

    We present evidence that the high-velocity C IV lambda 1549 emission-line gas of radio-loud quasars may originate in a disklike configuration, in close proximity to the accretion disk often assumed to emit the low-ionization lines. For a sample of 36 radio-loud z approximate to 2 quasars, we find

  15. The Large Area Radio Galaxy Evolution Spectroscopic Survey (LARGESS): survey design, data catalogue and GAMA/WiggleZ spectroscopy

    Science.gov (United States)

    Ching, John H. Y.; Sadler, Elaine M.; Croom, Scott M.; Johnston, Helen M.; Pracy, Michael B.; Couch, Warrick J.; Hopkins, A. M.; Jurek, Russell J.; Pimbblet, K. A.

    2017-01-01

    We present the Large Area Radio Galaxy Evolution Spectroscopic Survey (LARGESS), a spectroscopic catalogue of radio sources designed to include the full range of radio AGN populations out to redshift z ˜ 0.8. The catalogue covers ˜800 deg2 of sky, and provides optical identifications for 19 179 radio sources from the 1.4 GHz Faint Images of the Radio Sky at Twenty-cm (FIRST) survey down to an optical magnitude limit of Imod point-like objects are included, and no colour cuts are applied. In collaboration with the WiggleZ and Galaxy And Mass Assembly (GAMA) spectroscopic survey teams, we have obtained new spectra for over 5000 objects in the LARGESS sample. Combining these new spectra with data from earlier surveys provides spectroscopic data for 12 329 radio sources in the survey area, of which 10 856 have reliable redshifts. 85 per cent of the LARGESS spectroscopic sample are radio AGN (median redshift z = 0.44), and 15 per cent are nearby star-forming galaxies (median z = 0.08). Low-excitation radio galaxies (LERGs) comprise the majority (83 per cent) of LARGESS radio AGN at z < 0.8, with 12 per cent being high-excitation radio galaxies (HERGs) and 5 per cent radio-loud QSOs. Unlike the more homogeneous LERG and QSO sub-populations, HERGs are a heterogeneous class of objects with relatively blue optical colours and a wide dispersion in mid-infrared colours. This is consistent with a picture in which most HERGs are hosted by galaxies with recent or ongoing star formation as well as a classical accretion disc.

  16. Radio Jets Clearing the Way Through a Galaxy: Watching Feedback in Action in the Seyfert Galaxy IC 5063

    Science.gov (United States)

    Morganti, R.; Oosterloo, T. A.; Oonk, J. B. R.; Frieswijk, W.; Tadhunter, C. N.

    2015-12-01

    High-resolution (0.5 arcsec) CO(2-1) observations performed with the Atacama Large Millimetre/submillimetre Array have been used to trace the kinematics of the molecular gas in the Seyfert 2 galaxy{IC 5063}. Although one of the most radio-loud Seyfert galaxy, IC 5063 is a relatively weak radio source (P1.4GHz=3 ×1023 W Hz-1). The data reveal that the kinematics of the gas is very complex. A fast outflow of molecular gas extends along the entire radio jet (˜ 1 kpc), with the highest outflow velocities about 0.5 kpc from the nucleus, at the location of the brighter hot-spot in the W lobe. All the observed characteristics can be described by a scenario of a radio plasma jet expanding into a clumpy medium, interacting directly with the clouds and inflating a cocoon that drives a lateral outflow into the interstellar medium. This suggests that most of the observed cold molecular outflow is due to fast cooling of the gas after the passage of a shock and that it is the end product of the cooling process.

  17. Interstellar Scintillation and Scattering of Micro-arc-second AGN

    Directory of Open Access Journals (Sweden)

    David L. Jauncey

    2016-11-01

    Full Text Available The discovery of the first quasar 3C 273 led directly to the discovery of their variability at optical and radio wavelengths. We review the radio variability observations, in particular the variability found at frequencies below 1 GHz, as well as those exhibiting intra-day variability (IDV at cm wavelengths. Observations have shown that IDV arises principally from scintillation caused by scattering in the ionized interstellar medium of our Galaxy. The sensitivity of interstellar scintillation towards source angular sizes has provided a powerful tool for studying the most compact components of radio-loud AGN at microarcsecond and milliarcsecond scale resolution.

  18. Interference Information Based Power Control for Cognitive Radio with Multi-Hop Cooperative Sensing

    Science.gov (United States)

    Yu, Youngjin; Murata, Hidekazu; Yamamoto, Koji; Yoshida, Susumu

    Reliable detection of other radio systems is crucial for systems that share the same frequency band. In wireless communication channels, there is uncertainty in the received signal level due to multipath fading and shadowing. Cooperative sensing techniques in which radio stations share their sensing information can improve the detection probability of other systems. In this paper, a new cooperative sensing scheme that reduces the false detection probability while maintaining the outage probability of other systems is investigated. In the proposed system, sensing information is collected using multi-hop transmission from all sensing stations that detect other systems, and transmission decisions are based on the received sensing information. The proposed system also controls the transmit power based on the received CINRs from the sensing stations. Simulation results reveal that the proposed system can reduce the outage probability of other systems, or improve its link success probability.

  19. Modelling a reliable wind/PV/storage power system for remote radio base station sites without utility power

    Energy Technology Data Exchange (ETDEWEB)

    Bitterlin, Ian F [Emerson Network Power Ltd., Globe Park, Marlow, SL7 1YG (United Kingdom)

    2006-11-22

    The development of photovoltaic (PV) cells has made steady progress from the early days, when only the USA space program could afford to deploy them, to now, seeing them applied to roadside applications even in our Northern European climes. The manufacturing cost per watt has fallen and the daylight-to-power conversion efficiency increased. At the same time, the perception that the sun has to be directly shining on it for a PV array to work has faded. On some of those roadside applications, particularly for remote emergency telephones or for temporary roadwork signage where a utility electrical power connection is not practical, the keen observer will spot, usually in addition to a PV array, a small wind-turbine and an electrical cabinet quite obviously (by virtue of its volume) containing a storage battery. In the UK, we have the lions share (>40%) of Europe's entire wind power resource although, despite press coverage of the 'anti-wind' lobby to the contrary, we have hardly started to harvest this clean and free energy source. Taking this (established and proven) roadside solution one step further, we will consider higher power applications. A cellular phone system is one where a multitude of remote radio base stations (RBS) are required to provide geographical coverage. With networks developing into the so called '3G' technologies the need for base stations has tripled, as each 3G cell covers only 1/3 the geographical area of its '2G' counterpart. To cover >90% of the UK's topology (>97% population coverage) with 3G cellular technology will requires in excess of 12,000 radio base stations per operator network. In 2001, there were around 25,000 established sites and, with an anticipated degree of collocation by necessity, that figure is forecast to rise to >47,000. Of course, the vast majority of these sites have a convenient grid connection. However, it is easy to see that the combination of wind and PV power generation and an energy storage system may be an

  20. On the assessment of shooting sounds : Loudness-level weightings versus A- and C-weighted sound exposure levels (L)

    NARCIS (Netherlands)

    Vos, J.; Geurtsen, F.W.M.

    2003-01-01

    As an alternative to the A-weighted sound exposure level (ASEL) Schomer et al. [J. Acoust. Soc. Am. 110, 2390-2397 (2001)] used the equal-loudness level contours as a dynamic filter to determine the loudness-level-weighted sound exposure level (LLSEL). From their analyses they concluded that the

  1. JVLA Observations of Young Brown Dwarfs

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Luis F.; Zapata, Luis A.; Palau, Aina, E-mail: l.rodriguez@crya.unam.mx, E-mail: l.zapata@crya.unam.mx, E-mail: a.palau@crya.unam.mx [Instituto de Radioastronomía y Astrofísica, UNAM, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Michoacán, México (Mexico)

    2017-05-01

    We present sensitive 3.0 cm JVLA radio continuum observations of six regions of low-mass star formation that include twelve young brown dwarfs (BDs) and four young BD candidates. We detect a total of 49 compact radio sources in the fields observed, of which 24 have no reported counterparts and are considered new detections. Twelve of the radio sources show variability in timescales of weeks to months, suggesting gyrosynchrotron emission produced in active magnetospheres. Only one of the target BDs, FU Tau A, was detected. However, we detected radio emission associated with two of the BD candidates, WL 20S and CHLT 2. The radio flux densities of the sources associated with these BD candidates are more than an order of magnitude larger than expected for a BD and suggest a revision of their classification. In contrast, FU Tau A falls on the well-known correlation between radio luminosity and bolometric luminosity, suggesting that the emission comes from a thermal jet and that this BD seems to be forming as a scaled-down version of low-mass stars.

  2. Milliarcsecond Imaging of the Radio Emission from the Quasar with the Most Massive Black Hole at Reionization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ran; Wu, Xue-Bing; Jiang, Linhua [Kavli Institute of Astronomy and Astrophysics at Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing 100871 (China); Momjian, Emmanuel; Carilli, Chris L. [National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801 (United States); Fan, Xiaohui [Steward Observatory, University of Arizona, 933 N Cherry Avenue, Tucson, AZ 85721 (United States); Walter, Fabian [Max-Planck-Institute for Astronomy, Königsstuhl 17, D-69117 Heidelberg (Germany); Strauss, Michael A. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Wang, Feige [Department of Astronomy, School of Physics, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing 100871 (China)

    2017-02-01

    We report Very Long Baseline Array (VLBA) observations of the 1.5 GHz radio continuum emission of the z = 6.326 quasar SDSS J010013.02+280225.8 (hereafter J0100+2802). J0100+2802 is by far the most optically luminous and is a radio-quiet quasar with the most massive black hole known at z > 6. The VLBA observations have a synthesized beam size of 12.10 mas ×5.36 mas (FWHM), and detected the radio continuum emission from this object with a peak surface brightness of 64.6 ± 9.0 μ Jy beam{sup −1} and a total flux density of 88 ± 19 μ Jy. The position of the radio peak is consistent with that from SDSS in the optical and Chandra in the X-ray. The radio source is marginally resolved by the VLBA observations. A 2D Gaussian fit to the image constrains the source size to (7.1 ± 3.5) mas × (3.1 ± 1.7) mas. This corresponds to a physical scale of (40 ± 20) pc × (18 ± 10) pc. We estimate the intrinsic brightness temperature of the VLBA source to be T {sub B} = (1.6 ± 1.2) × 10{sup 7} K. This is significantly higher than the maximum value in normal star-forming galaxies, indicating an active galactic nucleus (AGN) origin for the radio continuum emission. However, it is also significantly lower than the brightness temperatures found in highest-redshift radio-loud quasars. J0100+2802 provides a unique example for studying the radio activity in optically luminous and radio-quiet AGNs in the early universe. Further observations at multiple radio frequencies will accurately measure the spectral index and address the dominant radiation mechanism of the radio emission.

  3. How Loud Is Too Loud?

    Medline Plus

    Full Text Available ... and Childhood Hearing Loss Hearing Loss and Older Adults Journey of Sound to the Brain ... News: NIDCD-Supported Research Subtle hearing loss while young changes brain function, study finds: Early damage could ...

  4. fMRI activation in relation to sound intensity and loudness

    NARCIS (Netherlands)

    Langers, Dave R. M.; van Dijk, Pirn; Schoemaker, Esther S.; Backes, Walter H.

    2007-01-01

    The aim of this fMRI study was to relate cortical fMRI responses to both physical and perceptual sound level characteristics. Besides subjects with normal hearing, subjects with high-frequency sensorineural hearing loss were included, as distortion of loudness perception is a characteristic of such

  5. NUCLEAR RADIO JET FROM A LOW-LUMINOSITY ACTIVE GALACTIC NUCLEUS IN NGC 4258

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Akihiro [The Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuou-ku, Sagamihara, Kanagawa 252-5210 (Japan); Kohno, Kotaro [Institute of Astronomy, The University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Nakanishi, Kouichiro [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Kameno, Seiji [Department of Physics, Faculty of Science, Kagoshima University, 1-21-35 Korimoto, Kagoshima, Kagoshima 890-0065 (Japan); Inoue, Makoto [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Hada, Kazuhiro [INAF, Istituto di Radioastronomia, via Gobetti 101, Bologna I-40129 (Italy); Sorai, Kazuo [Department of Physics, Graduate School of Science, Hokkaido University, Kita 10 Nishi 8, Sapporo 060-0810 (Japan)

    2013-03-01

    The nearby low-luminosity active galactic nucleus (LLAGN) NGC 4258 has a weak radio continuum component at the galactic center. We investigate its radio spectral properties on the basis of our new observations using the Nobeyama Millimeter Array at 100 GHz and archival data from the Very Large Array at 1.7-43 GHz and the James Clerk Maxwell telescope at 347 GHz. The NGC 4258 nuclear component exhibits (1) an intra-month variable and complicated spectral feature at 5-22 GHz and (2) a slightly inverted spectrum at 5-100 GHz ({alpha} {approx} 0.3; F {sub {nu}}{proportional_to}{nu}{sup {alpha}}) in time-averaged flux densities, which are also apparent in the closest LLAGN M81. These similarities between NGC 4258 and M81 in radio spectral natures in addition to previously known core shift in their AU-scale jet structures produce evidence that the same mechanism drives their nuclei. We interpret the observed spectral property as the superposition of emission spectra originating at different locations with frequency-dependent opacity along the nuclear jet. Quantitative differences between NGC 4258 and M81 in terms of jet/counter jet ratio, radio loudness, and degree of core shift can be consistently understood by fairly relativistic speeds ({Gamma} {approx}> 3) of jets and their quite different inclinations. The picture established from the two closest LLAGNs is useful for understanding the physical origin of unresolved and flat/inverted spectrum radio cores that are prevalently found in LLAGNs, including Sgr A*, with starved supermassive black holes in the present-day universe.

  6. Transmit Antenna Selection for Power Adaptive Underlay Cognitive Radio with Instantaneous Interference Constraint

    KAUST Repository

    Hanif, Muhammad

    2017-03-31

    The high hardware cost associated with multiple antennas at the secondary transmitter of an underlay cognitive radio (CR) can be reduced by antenna selection. This paper analyzes different power adaptive transmit antenna selection (TAS) schemes for an underlay CR, which ensure that the instantaneous interference caused by the secondary transmitter to the primary receiver is below a predetermined level. We consider the optimal continuous power adaptive TAS and present a low-complexity antenna and power level selection scheme, named sequential antenna and power level selection scheme (SAPS), for discrete power adaptation. Exact statistical characterizations of the signal-to-interference plus noise ratio at the secondary receiver are derived for the considered schemes. Based on the newly derived statistics, we prove that the considered schemes achieve the highest diversity order equaling the number of antennas at the secondary transmitter. Further, we also derive a closed-form expression of the ergodic capacity for the underlay CR with SAPS scheme. Finally, we show that the proposed scheme outperforms existing schemes in terms of ergodic capacity.

  7. MP3 players and hearing loss: adolescents' perceptions of loud music and hearing conservation.

    Science.gov (United States)

    Vogel, Ineke; Brug, Johannes; Hosli, Esther J; van der Ploeg, Catharina P B; Raat, Hein

    2008-03-01

    To explore adolescents' behaviors and opinions about exposure to loud music from MP3 players. We conducted a qualitative analysis of focus-group discussions with adolescents aged 12 to 18 years from 2 large secondary schools (1 urban and 1 rural) for pre-vocational and pre-university education. The semi-structured question route was theoretically framed within the protection motivation theory. Most adolescents-especially male students and students from pre-vocational schools-indicated that they often played their MP3 players at maximum volume. Although they appeared to be generally aware of the risks of exposure to loud music, they expressed low personal vulnerability to music-induced hearing loss. Most adolescents said that they would not accept any interference with their music-exposure habits. Interventions should target students from pre-vocational schools and should focus on increasing adolescents' knowledge of the risks of loud music and how to protect themselves. Besides hearing education for adolescents and technical modifications of MP3 players, volume-level regulations for MP3 players may be warranted.

  8. Effect of Size Change and Brightness Change of Visual Stimuli on Loudness Perception and Pitch Perception of Auditory Stimuli

    Directory of Open Access Journals (Sweden)

    Syouya Tanabe

    2011-10-01

    Full Text Available People obtain a lot of information from visual and auditory sensation on daily life. Regarding the effect of visual stimuli on perception of auditory stimuli, studies of phonological perception and sound localization have been made in great numbers. This study examined the effect of visual stimuli on perception in loudness and pitch of auditory stimuli. We used the image of figures whose size or brightness was changed as visual stimuli, and the sound of pure tone whose loudness or pitch was changed as auditory stimuli. Those visual and auditory stimuli were combined independently to make four types of audio-visual multisensory stimuli for psychophysical experiments. In the experiments, participants judged change in loudness or pitch of auditory stimuli, while they judged the direction of size change or the kind of a presented figure in visual stimuli. Therefore they cannot neglect visual stimuli while they judged auditory stimuli. As a result, perception in loudness and pitch were promoted significantly around their difference limen, when the image was getting bigger or brighter, compared with the case in which the image had no changes. This indicates that perception in loudness and pitch were affected by change in size and brightness of visual stimuli.

  9. 77 FR 40276 - Implementation of the Commercial Advertisement Loudness Mitigation (CALM) Act

    Science.gov (United States)

    2012-07-09

    ... the dialnorm to the consumer's reception equipment.\\40\\ Specifically, the RP provides operators with...''); and Sec. K.2 (``The Operator's goal is to present to the audience consistent audio loudness''). \\71...

  10. Distributed Robust Power Minimization for the Downlink of Multi-Cloud Radio Access Networks

    KAUST Repository

    Dhifallah, Oussama Najeeb

    2017-02-07

    Conventional cloud radio access networks assume single cloud processing and treat inter-cloud interference as background noise. This paper considers the downlink of a multi-cloud radio access network (CRAN) where each cloud is connected to several base-stations (BS) through limited-capacity wireline backhaul links. The set of BSs connected to each cloud, called cluster, serves a set of pre-known mobile users (MUs). The performance of the system becomes therefore a function of both inter-cloud and intra-cloud interference, as well as the compression schemes of the limited capacity backhaul links. The paper assumes independent compression scheme and imperfect channel state information (CSI) where the CSI errors belong to an ellipsoidal bounded region. The problem of interest becomes the one of minimizing the network total transmit power subject to BS power and quality of service constraints, as well as backhaul capacity and CSI error constraints. The paper suggests solving the problem using the alternating direction method of multipliers (ADMM). One of the highlight of the paper is that the proposed ADMM-based algorithm can be implemented in a distributed fashion across the multi-cloud network by allowing a limited amount of information exchange between the coupled clouds. Simulation results show that the proposed distributed algorithm provides a similar performance to the centralized algorithm in a reasonable number of iterations.

  11. Evaluation of power transfer efficiency for a high power inductively coupled radio-frequency hydrogen ion source

    Science.gov (United States)

    Jain, P.; Recchia, M.; Cavenago, M.; Fantz, U.; Gaio, E.; Kraus, W.; Maistrello, A.; Veltri, P.

    2018-04-01

    Neutral beam injection (NBI) for plasma heating and current drive is necessary for International Thermonuclear Experimental reactor (ITER) tokamak. Due to its various advantages, a radio frequency (RF) driven plasma source type was selected as a reference ion source for the ITER heating NBI. The ITER relevant RF negative ion sources are inductively coupled (IC) devices whose operational working frequency has been chosen to be 1 MHz and are characterized by high RF power density (˜9.4 W cm-3) and low operational pressure (around 0.3 Pa). The RF field is produced by a coil in a cylindrical chamber leading to a plasma generation followed by its expansion inside the chamber. This paper recalls different concepts based on which a methodology is developed to evaluate the efficiency of the RF power transfer to hydrogen plasma. This efficiency is then analyzed as a function of the working frequency and in dependence of other operating source and plasma parameters. The study is applied to a high power IC RF hydrogen ion source which is similar to one simplified driver of the ELISE source (half the size of the ITER NBI source).

  12. The optical, infrared and radio properties of extragalactic sources observed by SDSS, 2mass and first surveys

    International Nuclear Information System (INIS)

    Z. Ivezic et al.

    2002-01-01

    We positionally match sources observed by the Sloan Digital Sky Survey (SDSS), the Two Micron All Sky Survey (2MASS), and the Faint Images of the Radio Sky at Twenty-cm (FIRST) survey. Practically all 2MASS sources are matched to an SDSS source within 2 arcsec; ∼ 11% of them are optically resolved galaxies and the rest are dominated by stars. About 1/3 of FIRST sources are matched to an SDSS source within 2 arcsec; ∼ 80% of these are galaxies and the rest are dominated by quasars. Based on these results, we project that by the completion of these surveys the matched samples will include about 10 7 and 10 6 galaxies observed by both SDSS and 2MASS, and about 250,000 galaxies and 50,000 quasars observed by both SDSS and FIRST. Here we present a preliminary analysis of the optical, infrared and radio properties for the extragalactic sources from the matched samples. In particular, we find that the fraction of quasars with stellar colors missed by the SDSS spectroscopic survey is probably not larger than ∼ 10%, and that the optical colors of radio-loud quasars are ∼ 0.05 mag. redder (with 4σ significance) than the colors of radio-quiet quasars

  13. Open-source implementation of an ad-hoc IEEE802.11a/g/p software-defined radio on low-power and low-cost general purpose processors

    Directory of Open Access Journals (Sweden)

    S. Ciccia

    2017-12-01

    Full Text Available This work proposes a low-cost and low-power software-defined radio open-source platform with IEEE 802.11 a/g/p wireless communication capability. A state-of-the-art version of the IEEE 802.11 a/g/p software for GNU Radio (a free and open-source software development framework is available online, but we show here that its computational complexity prevents operations in low-power general purpose processors, even at throughputs below the standard. We therefore propose an evolution of this software that achieves a faster and lighter IEEE 802.11 a/g/p transmitter and receiver, suitable for low-power general purpose processors, for which GNU Radio provides very limited support; we discuss and describe the software radio processing structuring that is necessary to achieve the goal, providing a review of signal processing techniques. In particular, we emphasize the advanced reduced-instruction set (RISC machine (ARM study case, for which we also optimize some of the processing libraries. The presented software will remain open-source.

  14. Low Power, Small Form Factor, High Performance EVA Radio Employing Micromachined Contour Mode Piezoelectric Resonators and Filters, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In Phase I Harmonic Devices proposes to investigate the feasibility of a low-power, low-volume, lightweight, frequency agile, and fault tolerant EVA radio based on...

  15. radio frequency based radio frequency based water level monitor

    African Journals Online (AJOL)

    eobe

    ABSTRACT. This paper elucidates a radio frequency (RF) based transmission and reception system used to remotely monitor and .... range the wireless can cover but in this prototype, it ... power supply to the system, the sensed water level is.

  16. Long reach and enhanced power budget DWDM radio-over-fibre link supported by Raman amplification and coherent detection

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Guerrero Gonzalez, Neil; Fernandez, Amaya

    2009-01-01

    We report on a scalable and enhanced power budget radio-over-fibre system for hybrid-wireless access networks operating at 12.5 GHz DWDM spacing for 5 GHz RF carriers over a 60 km fibre link with Raman amplification....

  17. Jugando en el Pidi: Active Learning, Early Child Development and Interactive Radio Instruction. Supporting Caregivers, Parents, and Young Children. LearnTech Case Study Series, No. 4.

    Science.gov (United States)

    Bosch, Andrea; Crespo, Cecilia

    In 1993, Bolivia was selected as a site to pilot an interactive radio instruction (IRI) project that would provide practical support to adult caregivers and children around early childhood development. Through linkages with health and education networks, PIDI (Programa Integral de Desarrollo Infantil) provided young children under the age of six…

  18. A revisit to self-excited push pull vacuum tube radio frequency oscillator for ion sources and power measurements

    International Nuclear Information System (INIS)

    Hlondo, L. R.; Lalremruata, B.; Punte, L. R. M.; Rebecca, L.; Lalnunthari, J.; Thanga, H. H.

    2016-01-01

    Self-excited push-pull vacuum tube oscillator is one of the most commonly used oscillators in radio frequency (RF)-ion plasma sources for generation of ions using radio frequency. However, in spite of its fundamental role in the process of plasma formation, the working and operational characteristics are the most frequently skip part in the descriptions of RF ion sources in literatures. A more detailed treatment is given in the present work on the RF oscillator alone using twin beam power tetrodes 829B and GI30. The circuit operates at 102 MHz, and the oscillation conditions, stability in frequency, and RF output power are studied and analyzed. A modified form of photometric method and RF peak voltage detection method are employed to study the variation of the oscillator output power with plate voltage. The power curves obtained from these measurements are quadratic in nature and increase with increase in plate voltage. However, the RF output power as measured by photometric methods is always less than the value calculated from peak voltage measurements. This difference is due to the fact that the filament coil of the ordinary light bulb used as load/detector in photometric method is not a perfect inductor. The effect of inductive reactance on power transfer to load was further investigated and a technique is developed to estimate the amount of power correction needed in the photometric measurement result.

  19. Practical ranges of loudness levels of various types of environmental noise, including traffic noise, aircraft noise, and industrial noise

    NARCIS (Netherlands)

    Salomons, E.M.; Janssen, S.A.

    2011-01-01

    In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a

  20. How Loud Is Too Loud?

    Medline Plus

    Full Text Available ... and Meeting Reports Meet NIDCD Scientists and Grantees Research Resources Clinical Studies Funding Types of Grants and Funding How to ... Services Administration Hearing in the News: ... Subtle hearing loss while young changes brain function, study finds: Early damage could open door to dementia, ...

  1. Galaxy And Mass Assembly (GAMA): A “No Smoking” Zone for Giant Elliptical Galaxies?

    International Nuclear Information System (INIS)

    Khosroshahi, Habib G.; Raouf, Mojtaba; Miraghaei, Halime; Brough, Sarah; Croton, Darren J.; Graham, Alister; Driver, Simon; Baldry, Ivan; Brown, Michael; Prescott, Matt; Wang, Lingyu

    2017-01-01

    We study the radio emission of the most massive galaxies in a sample of dynamically relaxed and unrelaxed galaxy groups from the Galaxy and Mass Assembly survey. The dynamical state of the group is defined by the stellar dominance of the brightest group galaxy (BGG), e.g., the luminosity gap between the two most luminous members, and the offset between the position of the BGG and the luminosity centroid of the group. We find that the radio luminosity of the largest galaxy in the group strongly depends on its environment, such that the BGGs in dynamically young (evolving) groups are an order of magnitude more luminous in the radio than those with a similar stellar mass but residing in dynamically old (relaxed) groups. This observation has been successfully reproduced by a newly developed semi-analytic model that allows us to explore the various causes of these findings. We find that the fraction of radio-loud BGGs in the observed dynamically young groups is ∼2 times that of the dynamically old groups. We discuss the implications of this observational constraint on the central galaxy properties in the context of galaxy mergers and the super massive black hole accretion rate.

  2. Galaxy And Mass Assembly (GAMA): A “No Smoking” Zone for Giant Elliptical Galaxies?

    Energy Technology Data Exchange (ETDEWEB)

    Khosroshahi, Habib G.; Raouf, Mojtaba; Miraghaei, Halime [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), Tehran, 19395-5746 (Iran, Islamic Republic of); Brough, Sarah [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia); Croton, Darren J.; Graham, Alister [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, Victoria 3122 (Australia); Driver, Simon [International Centre for Radio Astronomy Research (ICRAR), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Baldry, Ivan [Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Brown, Michael [School of Physics, Monash University, Clayton, VIC 3800 (Australia); Prescott, Matt [Astrophysics Group, The University of Western Cape, Robert Sobukwe Road, Bellville 7530 (South Africa); Wang, Lingyu, E-mail: habib@ipm.ir [SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD, Groningen (Netherlands)

    2017-06-20

    We study the radio emission of the most massive galaxies in a sample of dynamically relaxed and unrelaxed galaxy groups from the Galaxy and Mass Assembly survey. The dynamical state of the group is defined by the stellar dominance of the brightest group galaxy (BGG), e.g., the luminosity gap between the two most luminous members, and the offset between the position of the BGG and the luminosity centroid of the group. We find that the radio luminosity of the largest galaxy in the group strongly depends on its environment, such that the BGGs in dynamically young (evolving) groups are an order of magnitude more luminous in the radio than those with a similar stellar mass but residing in dynamically old (relaxed) groups. This observation has been successfully reproduced by a newly developed semi-analytic model that allows us to explore the various causes of these findings. We find that the fraction of radio-loud BGGs in the observed dynamically young groups is ∼2 times that of the dynamically old groups. We discuss the implications of this observational constraint on the central galaxy properties in the context of galaxy mergers and the super massive black hole accretion rate.

  3. Acoustic reflex measurements and the loudness function in sensorineural hearing loss

    Directory of Open Access Journals (Sweden)

    Sheila Uliel

    1980-11-01

    Full Text Available The suprathreshold acoustic reflex responses of forty two ears affected by sensorineural hearing loss of cochlear origin and fifty-eight ears demonstrating normal hearing, were recorded by means of an electro-acoustic impedance meter and attached X-Y recorder. The recordings were done in ascending and descending fashion,  at successively increasing and decreasing 5dB intensity levels from 90-120-90 dB HL respectively, for the individual pure-tone frequencies of 500, 1 000, 2 000 and 4 000 Hz. The contralateral mode of measurement was employed. Analysis of  these recordings indicated that the acoustic reflex  responses could be differentiated into five  characteristic patterns of  growth, which could be depicted upon a continuum of peaked, peaked-rounded, rounded, rounded-flat,  and flat  shapes. The peaked and peaked-rounded patterns were found  to predominate at all four pure-tone frequencies  in the normal ears, while the rounded-fiat  and flat  patterns were found  to predominate only at the higher pure-tone frequencies of 2 000 and 4 000 Hz in the ears affected  by sensorineural hearing loss. This latter relationship was also able to be applied to two disorders of  the loudness functio— loudness recruitment and hyperacusis. It was concluded that the flattened  acoustic reflex  patterns at the higher pure-tone frequencies  constituted a potential diagnostic cue related to the differential  diagnosis of sensorineural hearing loss, and to disorders of  the loudness function.

  4. NuSTAR Observations of the Powerful Radio-Galaxy Cygnus A

    DEFF Research Database (Denmark)

    Reynolds, Christopher S.; Lohfink, Anne M.; Ogle, Patrick M.

    2015-01-01

    We present NuSTAR observations of the powerful radio galaxy Cygnus A,focusing on the central absorbed active galactic nucleus (AGN). Cygnus A is embedded in a cool-core galaxy cluster, and hence we also examine archival XMM-Newton data to facilitate the decomposition of the spectrum into the AGN...... and intracluster medium (ICM) components. NuSTAR gives a source-dominated spectrum of the AGN out to >70keV. In gross terms, the NuSTAR spectrum of the AGN has the form of a power law (Γ~1.6-1.7) absorbed by a neutral column density of NH~1.6x1023 cm-2. However, we also detect curvature in the hard (>10ke......V (90% confidence). Interestingly, the absorbed power-law plus reflection modelleaves residuals suggesting the absorption/emission from a fast(15,000-26,000km/s), high column-density (NW>3x1023 cm-2), highly ionized (ξ~2,500 erg cm/s-1) wind. A second, even faster ionized wind component is also...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. The lower ionosphere response to its disturbances by powerful radio waves

    Science.gov (United States)

    Bakhmetieva, N. V.; Frolov, V. L.; Vyakhirev, V. D.; Kalinina, E. E.; Akchurin, A. D.; Zykov, E. Yu.

    2018-04-01

    The paper presents data from some campaigns at Sura heating facility in 2011-1016. The experiments on probing of the artificial disturbed region of the lower ionosphere were carried out at two observation sites. One of them was located near Vasil'sursk 1 km from Sura facility (56.1°N; 46.1°E) and the other site was located at the Observatory (55.85°N; 48.8°E) of Kazan State University, 170 km to the East. Investigation of the features of the disturbed region of the lower ionosphere based on its diagnostics by the methods of the vertical sounding and oblique backscattering is the main goal of this paper. Ionosphere disturbance was fulfilled by the effect of the powerful radio wave of the ordinary or extraordinary polarization emitted by transmitters of the Sura facility with effective radiated power ERP = 50-120 MW at the frequency of 4.3, 4.7 and 5.6 MHz. Pumping waves were emitted with period from 30 s to 15 min. The disturbed region of the ionosphere in Vasil'sursk was probed by the vertical sounding technique using the partial reflexion radar at the frequency of 2.95 and 4.7 MHz. For the oblique sounding of the disturbed region the modified ionosonde Cyclon-M, operating at ten frequencies from 2.01 to 6.51 MHz was used at the Observatory site. On many heating sessions simultaneous variations of the probing partial reflection signals in Vasil'sursk and backscattered signals in Observatory were observed at the height at 40-100 km below the reflection height of the pumping wave. These observations were correlated with the pumping periods of the Sura facility. Possible mechanisms of the appearance of the disturbance in the lower ionosphere and its effect on the probing radio waves are discussed.

  7. Multi-epoch intranight optical monitoring of eight radio-quiet BL Lac candidates

    Science.gov (United States)

    Kumar, P.; Gopal-Krishna; Stalin, C. S.; Chand, H.; Srianand, R.; Petitjean, P.

    2017-10-01

    For a new sample of eight weak-line quasars (WLQs) we report a sensitive search in 20 intranight monitoring sessions, for blazar-like optical flux variations on hour-like and longer time-scale (day/month/year-like). The sample consists exclusively of the WLQs that are not radio-loud and either have been classified as 'radio-weak probable BL Lac candidates' and/or are known to have exhibited at least one episode of large, blazar-like optical variability. Whereas only a hint of intranight variability is seen for two of these WLQs, J104833.5+620305.0 (z = 0.219) and J133219.6+622715.9 (z = 3.15), statistically significant internight variability at a few per cent level is detected for three of the sources, including the radio-intermediate WLQ J133219.6+622715.9 (z = 3.15) and the well-known bona fide radio-quiet WLQs J121221.5+534128.0 (z = 3.10) and WLQ J153259.9-003944.1 (z = 4.62). In the rest frame, this variability is intraday and in the far-ultraviolet band. On the time-scale of a decade, we find for three of the WLQs large brightness changes, amounting to 1.655 ± 0.009, 0.163 ± 0.010 and 0.144 ± 0.018 mag, for J104833.5+620305.0, J123743.1+630144.9 and J232428.4+144324.4, respectively. Whereas the latter two are confirmed radio-quiet WLQs, the extragalactic nature of J104833.5+620305.0 remains to be well established, thanks to the absence of any feature(s) in its available optical spectra. This study forms a part of our ongoing campaign of intranight optical monitoring of radio-quiet WLQs, in order to improve the understanding of this enigmatic class of active galactic nuclei and to look among them for a possible tiny, elusive population of radio-quiet BL Lacs.

  8. Reconfigurable Power-Aware EVA Radio, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Extra Vehicular Activity (EVA) radio system is a pivotal technology for the successful support of the International Space Station beyond 2020 and future...

  9. Emotional states as mediators between tinnitus loudness and tinnitus distress in daily life: Results from the “TrackYourTinnitus” application

    Science.gov (United States)

    Probst, Thomas; Pryss, Rüdiger; Langguth, Berthold; Schlee, Winfried

    2016-01-01

    The psychological process how tinnitus loudness leads to tinnitus distress remains unclear. This cross-sectional study investigated the mediating role of the emotional state “stress level” and of the two components of the emotional state “arousal” and “valence” with N = 658 users of the “TrackYourTinnitus” smartphone application. Stress mediated the relationship between tinnitus loudness and tinnitus distress in a simple mediation model and even in a multiple mediation model when arousal and valence were held constant. Arousal mediated the loudness-distress relationship when holding valence constant, but not anymore when controlling for valence as well as for stress. Valence functioned as a mediator when controlling for arousal and even when holding arousal and stress constant. The direct effect of tinnitus loudness on tinnitus distress remained significant in all models. This study demonstrates that emotional states affect the process how tinnitus loudness leads to tinnitus distress. We thereby could show that the mediating influence of emotional valence is at least equally strong as the influence of stress. Implications of the findings for future research, assessment, and clinical management of tinnitus are discussed. PMID:26853815

  10. Survey of ambient electromagnetic and radio-frequency interference levels in nuclear power plants

    International Nuclear Information System (INIS)

    Kercel, S.W.; Moore, M.R.; Blakeman, E.D.; Ewing, P.D.; Wood, R.T.

    1996-11-01

    This document reports the results of a survey of ambient electromagnetic conditions in representative nuclear power plants. The U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research engaged the Oak Ridge National Laboratory (ORNL) to perform these measurements to characterize the electromagnetic interference (EMI) and radio-frequency interference (RFI) levels that can be expected in nuclear power plant environments. This survey is the first of its kind, being based on long-term unattended observations. The data presented in this report were measured at eight different nuclear units and required 14 months to collect. A representative sampling of power plant conditions (reactor type, operating mode, site location) monitored over extended observation periods (up to 5 weeks) were selected to more completely determine the characteristic electromagnetic environment for nuclear power plants. Radiated electric fields were measured over the frequency range of 5 MHz to 8 GHz. Radiated magnetic fields and conducted EMI events were measured over the frequency range of 305 Hz to 5 MHz. Highest strength observations of the electromagnetic ambient environment across all measurement conditions at each site provide frequency-dependent profiles for EMI/RFI levels in nuclear power plants

  11. Physical processes in extragalactic radio sources

    NARCIS (Netherlands)

    Carilli, CL; Perley, R; Harris, DE; Barthel, PD

    This paper summarizes extensive observational studies of the closest ultraluminous radio galaxy Cygnus A. These data are used to test jet theory for powering the double-lobed radio emitting structures. Issues addressed include: (i) jet stability, confinement, composition, and velocity, (ii) the

  12. DEEP X-RAY OBSERVATIONS OF THE YOUNG HIGH-MAGNETIC-FIELD RADIO PULSAR J1119-6127 AND SUPERNOVA REMNANT G292.2-0.5

    Energy Technology Data Exchange (ETDEWEB)

    Ng, C.-Y.; Kaspi, V. M. [Department of Physics, McGill University, Montreal, QC H3A 2T8 (Canada); Ho, W. C. G. [School of Mathematics, University of Southampton, Southampton SO17 1BJ (United Kingdom); Weltevrede, P. [Jodrell Bank Centre for Astrophysics, University of Manchester, Alan Turing Building, Manchester M13 9PL (United Kingdom); Bogdanov, S. [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Shannon, R. [CSIRO Astronomy and Space Sciences, Australia Telescope National Facility, Marsfield, NSW 2210 (Australia); Gonzalez, M. E., E-mail: ncy@physics.mcgill.ca [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada)

    2012-12-10

    High-magnetic-field radio pulsars are important transition objects for understanding the connection between magnetars and conventional radio pulsars. We present a detailed study of the young radio pulsar J1119-6127, which has a characteristic age of 1900 yr and a spin-down-inferred magnetic field of 4.1 Multiplication-Sign 10{sup 13} G, and its associated supernova remnant G292.2-0.5, using deep XMM-Newton and Chandra X-ray Observatory exposures of over 120 ks from each telescope. The pulsar emission shows strong modulation below 2.5 keV with a single-peaked profile and a large pulsed fraction of 0.48 {+-} 0.12. Employing a magnetic, partially ionized hydrogen atmosphere model, we find that the observed pulse profile can be produced by a single hot spot of temperature 0.13 keV covering about one-third of the stellar surface, and we place an upper limit of 0.08 keV for an antipodal hot spot with the same area. The non-uniform surface temperature distribution could be the result of anisotropic heat conduction under a strong magnetic field, and a single-peaked profile seems common among high-B radio pulsars. For the associated remnant G292.2-0.5, its large diameter could be attributed to fast expansion in a low-density wind cavity, likely formed by a Wolf-Rayet progenitor, similar to two other high-B radio pulsars.

  13. The detectability of radio emission from exoplanets

    Science.gov (United States)

    Lynch, C. R.; Murphy, Tara; Lenc, E.; Kaplan, D. L.

    2018-05-01

    Like the magnetised planets in our Solar System, magnetised exoplanets should emit strongly at radio wavelengths. Radio emission directly traces the planetary magnetic fields and radio detections can place constraints on the physical parameters of these features. Large comparative studies of predicted radio emission characteristics for the known population of exoplanets help to identify what physical parameters could be key for producing bright, observable radio emission. Since the last comparative study, many thousands of exoplanets have been discovered. We report new estimates for the radio flux densities and maximum emission frequencies for the current population of known exoplanets orbiting pre-main sequence and main-sequence stars with spectral types F-M. The set of exoplanets predicted to produce observable radio emission are Hot Jupiters orbiting young stars. The youth of these system predicts strong stellar magnetic fields and/or dense winds, which are key for producing bright, observable radio emission. We use a new all-sky circular polarisation Murchison Widefield Array survey to place sensitive limits on 200 MHz emission from exoplanets, with 3σ values ranging from 4.0 - 45.0 mJy. Using a targeted Giant Metre Wave Radio Telescope observing campaign, we also report a 3σ upper limit of 4.5 mJy on the radio emission from V830 Tau b, the first Hot Jupiter to be discovered orbiting a pre-main sequence star. Our limit is the first to be reported for the low-frequency radio emission from this source.

  14. Loudness and acoustic parameters of popular children's toys.

    Science.gov (United States)

    Ghavami, Yaser; Bhatt, Jay; Maducdoc, Marlon; Yau, Amy; Mahboubi, Hossein; Ziai, Kasra; Lin, Harrison W; Djalilian, Hamid R

    2015-12-01

    This project was conducted to evaluate the loudness and acoustic parameters of toys designed for children. In addition, we investigated whether occluding the toys' speaker with tape would result in a significant loudness reduction; thereby potentially reducing the risk of noise induced hearing loss. Twenty-six toys were selected after an initial screening at two national retailers. Noise amplitudes at 0.25, 0.5, 1, 2, 4, and 8kHz were measured using a digital sound level meter at a distance of 0 and 30cm. The toys' speakers were then occluded using adhesive tape and the same acoustic parameters were re-measured. Mean maximum noise amplitude of the toys at 0cm and 30cm was 104dBA (range, 97-125dBA) and 76dBA (range, 67-86dBA), respectively. Mean maximum noise amplitude after occlusion at 0cm and 30cm distances was 88dBA (range, 73-110dBA) and 66dBA (range, 55-82dBA), respectively, with a p-value toys at a distant of 30cm between the speaker and the child's ear will likely not pose a risk of noise-induced hearing loss. However, since most toys are used at closer distances, use of adhesive tape is recommended as an effective modification to decrease the risk of hearing loss. Published by Elsevier Ireland Ltd.

  15. How Loud Is Too Loud?

    Medline Plus

    Full Text Available ... NIDCD History and Milestones Organizational Structure and Staff Job Opportunities Congressional Testimony and the NIDCD Budget Advisory ... and Childhood Hearing Loss Hearing Loss and Older Adults Journey of Sound to the Brain ... News: NIDCD-Supported Research Subtle hearing loss while young changes brain function, study finds: Early damage could ...

  16. RAiSE III: 3C radio AGN energetics and composition

    Science.gov (United States)

    Turner, Ross J.; Shabala, Stanislav S.; Krause, Martin G. H.

    2018-03-01

    Kinetic jet power estimates based exclusively on observed monochromatic radio luminosities are highly uncertain due to confounding variables and a lack of knowledge about some aspects of the physics of active galactic nuclei (AGNs). We propose a new methodology to calculate the jet powers of the largest, most powerful radio sources based on combinations of their size, lobe luminosity, and shape of their radio spectrum; this approach avoids the uncertainties encountered by previous relationships. The outputs of our model are calibrated using hydrodynamical simulations and tested against independent X-ray inverse-Compton measurements. The jet powers and lobe magnetic field strengths of radio sources are found to be recovered using solely the lobe luminosity and spectral curvature, enabling the intrinsic properties of unresolved high-redshift sources to be inferred. By contrast, the radio source ages cannot be estimated without knowledge of the lobe volumes. The monochromatic lobe luminosity alone is incapable of accurately estimating the jet power or source age without knowledge of the lobe magnetic field strength and size, respectively. We find that, on average, the lobes of the Third Cambridge Catalogue of Radio Sources (3C) have magnetic field strengths approximately a factor three lower than the equipartition value, inconsistent with equal energy in the particles and the fields at the 5σ level. The particle content of 3C radio lobes is discussed in the context of complementary observations; we do not find evidence favouring an energetically dominant proton population.

  17. Radio synchrotron spectra of star-forming galaxies

    Science.gov (United States)

    Klein, U.; Lisenfeld, U.; Verley, S.

    2018-03-01

    We investigated the radio continuum spectra of 14 star-forming galaxies by fitting nonthermal (synchrotron) and thermal (free-free) radiation laws. The underlying radio continuum measurements cover a frequency range of 325 MHz to 24.5 GHz (32 GHz in case of M 82). It turns out that most of these synchrotron spectra are not simple power-laws, but are best represented by a low-frequency spectrum with a mean slope αnth = 0.59 ± 0.20 (Sν ∝ ν-α), and by a break or an exponential decline in the frequency range of 1-12 GHz. Simple power-laws or mildly curved synchrotron spectra lead to unrealistically low thermal flux densities, and/or to strong deviations from the expected optically thin free-free spectra with slope αth = 0.10 in the fits. The break or cutoff energies are in the range of 1.5-7 GeV. We briefly discuss the possible origin of such a cutoff or break. If the low-frequency spectra obtained here reflect the injection spectrum of cosmic-ray electrons, they comply with the mean spectral index of Galactic supernova remnants. A comparison of the fitted thermal flux densities with the (foreground-corrected) Hα fluxes yields the extinction, which increases with metallicity. The fraction of thermal emission is higher than believed hitherto, especially at high frequencies, and is highest in the dwarf galaxies of our sample, which we interpret in terms of a lack of containment in these low-mass systems, or a time effect caused by a very young starburst.

  18. Mean value-based power allocation and ratio selection for MIMO cognitive radio systems

    KAUST Repository

    Tourki, Kamel; Qaraqe, Khalid A.; Alouini, Mohamed-Slim

    2013-01-01

    In this paper, we consider a spectrum sharing cognitive radio system with ratio selection using a mean value-based power allocation strategy. We first provide the exact statistics in terms of probability density function and cumulative density function of the secondary channel gain as well as of the interference channel gain. These statistics are then used to derive exact closed form expression of the secondary outage probability. Furthermore, asymptotical analysis is derived and generalized diversity gain is deduced. We validate our analysis with simulation results in a Rayleigh fading environment. © 2013 IEEE.

  19. Mean value-based power allocation and ratio selection for MIMO cognitive radio systems

    KAUST Repository

    Tourki, Kamel

    2013-06-01

    In this paper, we consider a spectrum sharing cognitive radio system with ratio selection using a mean value-based power allocation strategy. We first provide the exact statistics in terms of probability density function and cumulative density function of the secondary channel gain as well as of the interference channel gain. These statistics are then used to derive exact closed form expression of the secondary outage probability. Furthermore, asymptotical analysis is derived and generalized diversity gain is deduced. We validate our analysis with simulation results in a Rayleigh fading environment. © 2013 IEEE.

  20. Astronomers Detect Powerful Bursting Radio Source Discovery Points to New Class of Astronomical Objects

    Science.gov (United States)

    2005-03-01

    Astronomers at Sweet Briar College and the Naval Research Laboratory (NRL) have detected a powerful new bursting radio source whose unique properties suggest the discovery of a new class of astronomical objects. The researchers have monitored the center of the Milky Way Galaxy for several years and reveal their findings in the March 3, 2005 edition of the journal, “Nature”. This radio image of the central region of the Milky Way Galaxy holds a new radio source, GCRT J1745-3009. The arrow points to an expanding ring of debris expelled by a supernova. CREDIT: N.E. Kassim et al., Naval Research Laboratory, NRAO/AUI/NSF Principal investigator, Dr. Scott Hyman, professor of physics at Sweet Briar College, said the discovery came after analyzing some additional observations from 2002 provided by researchers at Northwestern University. “"We hit the jackpot!” Hyman said referring to the observations. “An image of the Galactic center, made by collecting radio waves of about 1-meter in wavelength, revealed multiple bursts from the source during a seven-hour period from Sept. 30 to Oct. 1, 2002 — five bursts in fact, and repeating at remarkably constant intervals.” Hyman, four Sweet Briar students, and his NRL collaborators, Drs. Namir Kassim and Joseph Lazio, happened upon transient emission from two radio sources while studying the Galactic center in 1998. This prompted the team to propose an ongoing monitoring program using the National Science Foundation’s Very Large Array (VLA) radio telescope in New Mexico. The National Radio Astronomy Observatory, which operates the VLA, approved the program. The data collected, laid the groundwork for the detection of the new radio source. “Amazingly, even though the sky is known to be full of transient objects emitting at X- and gamma-ray wavelengths,” NRL astronomer Dr. Joseph Lazio pointed out, “very little has been done to look for radio bursts, which are often easier for astronomical objects to produce

  1. Power allocation, bit loading and sub-carrier bandwidth sizing for OFDM-based cognitive radio

    Directory of Open Access Journals (Sweden)

    Desai Uday

    2011-01-01

    Full Text Available Abstract The function of the Radio Resource Management module of a Cognitive Radio (CR system is to evaluate the available resources and assign them to meet the Quality of Service (QoS objectives of the Secondary User (SU, within some constraints on factors which limit the performance of the Primary User (PU. While interference mitigation to the PU spectral band from the SU's transmission has received a lot of attention in recent literature; the novelty of our work is in considering a more realistic and effective approach of dividing the PU into sub-bands, and ensuring that the interference to each of them is below a specified threshold. With this objective, and within a power budget, we execute the tasks of power allocation, bit loading and sizing the sub-carrier bandwidth for an orthogonal frequency division multiplexing (OFDM-based SU. After extensively analyzing the solution form of the optimization problems posed for the resource allocation, we suggest iterative algorithms to meet the aforementioned objectives. The algorithm for sub-carrier bandwidth sizing is novel, and not previously presented in literature. A multiple SU scenario is also considered, which entails assigning sub-carriers to the users, besides the resource allocation. Simulation results are provided, for both single and multi-user cases, which indicate the effectiveness of the proposed algorithms in a CR environment.

  2. Inverse Compton X-Ray Halos Around High-z Radio Galaxies: A Feedback Mechanism Powered by Far-Infrared Starbursts or the Cosmic Microwave Background?

    Science.gov (United States)

    Small, Ian; Blundell, Katherine M.; Lehmer, B. D.; Alexander, D. M.

    2012-01-01

    We report the detection of extended X-ray emission around two powerful radio galaxies at z approx. 3.6 (4C 03.24 and 4C 19.71) and use these to investigate the origin of extended, inverse Compton (IC) powered X-ray halos at high redshifts. The halos have X-ray luminosities of L(sub X) approx. 3 x 10(exp 44) erg/s and sizes of approx.60 kpc. Their morphologies are broadly similar to the approx.60 kpc long radio lobes around these galaxies suggesting they are formed from IC scattering by relativistic electrons in the radio lobes, of either cosmic microwave background (CMB) photons or far-infrared photons from the dust-obscured starbursts in these galaxies. These observations double the number of z > 3 radio galaxies with X-ray-detected IC halos. We compare the IC X-ray-to-radio luminosity ratios for the two new detections to the two previously detected z approx. 3.8 radio galaxies. Given the similar redshifts, we would expect comparable X-ray IC luminosities if millimeter photons from the CMB are the dominant seed field for the IC emission (assuming all four galaxies have similar ages and jet powers). Instead we see that the two z approx. 3.6 radio galaxies, which are 4 fainter in the far-infrared than those at z 3.8, also have approx.4x fainter X-ray IC emission. Including data for a further six z > or approx. 2 radio sources with detected IC X-ray halos from the literature, we suggest that in the more compact, majority of radio sources, those with lobe sizes < or approx.100-200 kpc, the bulk of the IC emission may be driven by scattering of locally produced far-infrared photons from luminous, dust-obscured starbursts within these galaxies, rather than millimeter photons from the CMB. The resulting X-ray emission appears sufficient to ionize the gas on approx.100-200 kpc scales around these systems and thus helps form the extended, kinematically quiescent Ly(alpha) emission line halos found around some of these systems. The starburst and active galactic nucleus

  3. INVERSE COMPTON X-RAY HALOS AROUND HIGH-z RADIO GALAXIES: A FEEDBACK MECHANISM POWERED BY FAR-INFRARED STARBURSTS OR THE COSMIC MICROWAVE BACKGROUND?

    Energy Technology Data Exchange (ETDEWEB)

    Smail, Ian [Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE (United Kingdom); Blundell, Katherine M. [Department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Lehmer, B. D. [Department of Physics and Astronomy, The Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Alexander, D. M. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)

    2012-12-01

    We report the detection of extended X-ray emission around two powerful radio galaxies at z {approx} 3.6 (4C 03.24 and 4C 19.71) and use these to investigate the origin of extended, inverse Compton (IC) powered X-ray halos at high redshifts. The halos have X-ray luminosities of L {sub X} {approx} 3 Multiplication-Sign 10{sup 44} erg s{sup -1} and sizes of {approx}60 kpc. Their morphologies are broadly similar to the {approx}60 kpc long radio lobes around these galaxies suggesting they are formed from IC scattering by relativistic electrons in the radio lobes, of either cosmic microwave background (CMB) photons or far-infrared photons from the dust-obscured starbursts in these galaxies. These observations double the number of z > 3 radio galaxies with X-ray-detected IC halos. We compare the IC X-ray-to-radio luminosity ratios for the two new detections to the two previously detected z {approx} 3.8 radio galaxies. Given the similar redshifts, we would expect comparable X-ray IC luminosities if millimeter photons from the CMB are the dominant seed field for the IC emission (assuming all four galaxies have similar ages and jet powers). Instead we see that the two z {approx} 3.6 radio galaxies, which are {approx}4 Multiplication-Sign fainter in the far-infrared than those at z {approx} 3.8, also have {approx}4 Multiplication-Sign fainter X-ray IC emission. Including data for a further six z {approx}> 2 radio sources with detected IC X-ray halos from the literature, we suggest that in the more compact, majority of radio sources, those with lobe sizes {approx}<100-200 kpc, the bulk of the IC emission may be driven by scattering of locally produced far-infrared photons from luminous, dust-obscured starbursts within these galaxies, rather than millimeter photons from the CMB. The resulting X-ray emission appears sufficient to ionize the gas on {approx}100-200 kpc scales around these systems and thus helps form the extended, kinematically quiescent Ly{alpha} emission line

  4. A Cognitive Radio-Based Energy-Efficient System for Power Transmission Line Monitoring in Smart Grids

    Directory of Open Access Journals (Sweden)

    Saeed Ahmed

    2017-01-01

    Full Text Available The research in industry and academia on smart grids is predominantly focused on the regulation of generated power and management of its consumption. Because transmission of bulk-generated power to the consumer is immensely reliant on secure and efficient transmission grids, comprising huge electrical and mechanical assets spanning a vast geographic area, there is an impending need to focus on the transmission grids as well. Despite the challenges in wireless technologies for SGs, cognitive radio networks are considered promising for provisioning of communications services to SGs. In this paper, first, we present an IEEE 802.22 wireless regional area network cognitive radio-based network model for smart monitoring of transmission lines. Then, for a prolonged lifetime of battery finite monitoring network, we formulate the spectrum resource allocation problem as an energy efficiency maximization problem, which is a nonlinear integer programming problem. To solve this problem in an easier way, we propose an energy-efficient resource-assignment scheme based on the Hungarian method. Performance analysis shows that, compared to a pure opportunistic assignment scheme with a throughput maximization objective and compared to a random scheme, the proposed scheme results in an enhanced lifetime while consuming less battery energy without compromising throughput performance.

  5. Do Talkativeness and Vocal Loudness Correlate With Laryngeal Pathology? A Study of the Vocal Overdoer/Underdoer Continuum.

    Science.gov (United States)

    Bastian, Robert W; Thomas, James P

    2016-09-01

    Assess the correlation between self-rating scales of talkativeness and loudness with various types of voice disorders. This is a retrospective study. A total of 974 patients were analyzed. The cohort study included 430 consecutive patients presenting to the senior author with voice complaints from December 1995 to December 1998. The case-control study added 544 consecutive patients referred to the same examiner from January 1988 to December 1998 for vocal fold examination before thyroid, parathyroid, and carotid surgery. Patient responses on seven-point Likert self-rating scales of talkativeness and loudness were compared with laryngeal disease. Mucosal lesions clearly associated with vibratory trauma are strongly associated with a high self-rating of talkativeness. Laryngeal deconditioning disorders were associated with a low self-rating of talkativeness. Use of a simple self-rating scale of vocal loudness and talkativeness during history taking can reliably orient the examiner to the types of voice disorders likely to be diagnosed subsequently during vocal capability testing and visual laryngeal examination. The high degree of talkativeness and loudness seen in vocal overdoers correlates well with mucosal disorders such as nodules, polyps, capillary ectasia, epidermoid inclusion cysts, and hemorrhage. A lower degree of talkativeness correlates with muscle deconditioning disorders such as vocal fold bowing, atrophy, presbyphonia, and vocal fatigue syndrome. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  6. SMC SMP 24: A newly radio-detected planetary nebula in the small Magellanic cloud

    Directory of Open Access Journals (Sweden)

    Bojičić I.S.

    2010-01-01

    Full Text Available In this paper we report a new radio-continuum detection of an extragalactic planetary nebula (PN: SMC SMP 24. We show the radio-continuum image of this PN and present the measured radio data. The newly reduced radio observations are consistent with the multi-wavelength data and derived parameters found in the literature. SMC SMP 24 appears to be a young and compact PN, optically thick at frequencies below 2 GHz.

  7. SMC SMP 24: A Newly Radio-Detected Planetary Nebula in the Small Magellanic Cloud

    Directory of Open Access Journals (Sweden)

    Bojicic, I. S.

    2010-12-01

    Full Text Available In this paper we report a new radio-continuum detection of an extragalactic planetary nebula (PN: SMC~SMP~24. We show the radio-continuum image of this PN and present the measured radio data. The newly reduced radio observations are consistent with the multi-wavelength data and derived parameters found in the literature. SMC~SMP~24 appears to be a young and compact PN, optically thick at frequencies below 2~GHz.

  8. A CLUSTER OF COMPACT RADIO SOURCES IN W40

    International Nuclear Information System (INIS)

    RodrIguez, Luis F.; Rodney, Steven A.; Reipurth, Bo

    2010-01-01

    We present deep 3.6 cm radio continuum observations of the H II region W40 obtained using the Very Large Array (VLA) in its A and B configurations. We detect a total of 20 compact radio sources in a region of 4' x 4', with 11 of them concentrated in a band with 30'' of extent. We also present JHK photometry of the W40 cluster taken with the QUIRC instrument on the University of Hawaii 2.2 m telescope. These data reveal that 15 of the 20 VLA sources have infrared counterparts, and 10 show radio variability with periods less than 20 days. Based on these combined radio and IR data, we propose that eight of the radio sources are candidate ultracompact H II regions, seven are likely to be young stellar objects, and two may be shocked interstellar gas.

  9. Achievable rate of spectrum sharing cognitive radio systems over fading channels at low-power regime

    KAUST Repository

    Sboui, Lokman

    2014-11-01

    We study the achievable rate of cognitive radio (CR) spectrum sharing systems at the low-power regime for general fading channels and then for Nakagami fading. We formally define the low-power regime and present the corresponding closed-form expressions of the achievable rate lower bound under various types of interference and/or power constraints, depending on the available channel state information of the cross link (CL) between the secondary-user transmitter and the primary-user receiver. We explicitly characterize two regimes where either the interference constraint or the power constraint dictates the optimal power profile. Our framework also highlights the effects of different fading parameters on the secondary link (SL) ergodic achievable rate. We also study more realistic scenarios when there is either 1-bit quantized channel feedback from the CL alone or 2-bit feedback from both the CL and the SL and propose simple power control schemes and show that these schemes achieve the previously achieved rate at the low-power regime. Interestingly, we show that the low-power regime analysis provides a specific insight into the maximum achievable rate behavior of CR that has not been reported by previous studies.

  10. Radio-frequency energy in fusion power generation

    International Nuclear Information System (INIS)

    Lawson, J.Q.; Becraft, W.R.; Hoffman, D.J.

    1983-01-01

    The history of radio-frequency (rf) energy in fusion experiments is reviewed, and the status of current efforts is described. Potential applications to tasks other than plasma heating are described, as are the research and development needs of rf energy technology

  11. Coronal mass ejections, type II radio bursts, and solar energetic particle events in the SOHO era

    Directory of Open Access Journals (Sweden)

    N. Gopalswamy

    2008-10-01

    Full Text Available Using the extensive and uniform data on coronal mass ejections (CMEs, solar energetic particle (SEP events, and type II radio bursts during the SOHO era, we discuss how the CME properties such as speed, width and solar-source longitude decide whether CMEs are associated with type II radio bursts and SEP events. We discuss why some radio-quiet CMEs are associated with small SEP events while some radio-loud CMEs are not associated with SEP events. We conclude that either some fast and wide CMEs do not drive shocks or they drive weak shocks that do not produce significant levels of particle acceleration. We also infer that the Alfvén speed in the corona and near-Sun interplanetary medium ranges from <200 km/s to ~1600 km/s. Radio-quiet fast and wide CMEs are also poor SEP producers and the association rate of type II bursts and SEP events steadily increases with CME speed and width (i.e. energy. If we consider western hemispheric CMEs, the SEP association rate increases linearly from ~30% for 800 km/s CMEs to 100% for ≥1800 km/s. Essentially all type II bursts in the decametre-hectometric (DH wavelength range are associated with SEP events once the source location on the Sun is taken into account. This is a significant result for space weather applications, because if a CME originating from the western hemisphere is accompanied by a DH type II burst, there is a high probability that it will produce an SEP event.

  12. A repeating fast radio burst.

    Science.gov (United States)

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  13. A CLOSER VIEW OF THE RADIO-FIR CORRELATION: DISENTANGLING THE CONTRIBUTIONS OF STAR FORMATION AND ACTIVE GALACTIC NUCLEUS ACTIVITY

    International Nuclear Information System (INIS)

    Moric, I.; Smolcic, V.; Riechers, D. A.; Scoville, N.; Kimball, A.; Ivezic, Z.

    2010-01-01

    We extend the Unified Radio Catalog, a catalog of sources detected by various (NVSS, FIRST, WENSS, GB6) radio surveys, and SDSS, to IR wavelengths by matching it to the IRAS Point and Faint Source catalogs. By fitting each NVSS-selected galaxy's NUV-NIR spectral energy distribution (SED) with stellar population synthesis models we add to the catalog star formation rates (SFRs), stellar masses, and attenuations. We further add information about optical emission-line properties for NVSS-selected galaxies with available SDSS spectroscopy. Using an NVSS 20 cm (F 1.4 G Hz ∼> 2.5 mJy) selected sample, matched to the SDSS spectroscopic ('main' galaxy and quasar) catalogs and IRAS data (0.04 < z ∼< 0.2) we perform an in-depth analysis of the radio-FIR correlation for various types of galaxies, separated into (1) quasars, (2) star-forming, (3) composite, (4) Seyfert, (5) LINER, and (6) absorption line galaxies using the standard optical spectroscopic diagnostic tools. We utilize SED-based SFRs to independently quantify the source of radio and FIR emission in our galaxies. Our results show that Seyfert galaxies have FIR/radio ratios lower than, but still within the scatter of, the canonical value due to an additional (likely active galactic nucleus (AGN)) contribution to their radio continuum emission. Furthermore, IR-detected absorption and LINER galaxies are on average strongly dominated by AGN activity in both their FIR and radio emission; however their average FIR/radio ratio is consistent with that expected for star-forming galaxies. In summary, we find that most AGN-containing galaxies in our NVSS-IRAS-SDSS sample have FIR/radio flux ratios indistinguishable from those of the star-forming galaxies that define the radio-FIR correlation. Thus, attempts to separate AGNs from star-forming galaxies by their FIR/radio flux ratios alone can separate only a small fraction of the AGNs, such as the radio-loud quasars.

  14. Adaptive Decision-Making Scheme for Cognitive Radio Networks

    KAUST Repository

    Alqerm, Ismail

    2014-05-01

    Radio resource management becomes an important aspect of the current wireless networks because of spectrum scarcity and applications heterogeneity. Cognitive radio is a potential candidate for resource management because of its capability to satisfy the growing wireless demand and improve network efficiency. Decision-making is the main function of the radio resources management process as it determines the radio parameters that control the use of these resources. In this paper, we propose an adaptive decision-making scheme (ADMS) for radio resources management of different types of network applications including: power consuming, emergency, multimedia, and spectrum sharing. ADMS exploits genetic algorithm (GA) as an optimization tool for decision-making. It consists of the several objective functions for the decision-making process such as minimizing power consumption, packet error rate (PER), delay, and interference. On the other hand, maximizing throughput and spectral efficiency. Simulation results and test bed evaluation demonstrate ADMS functionality and efficiency.

  15. Effects of pedagogical ideology on the perceived loudness and noise levels in preschools.

    Science.gov (United States)

    Jonsdottir, Valdis; Rantala, Leena M; Oskarsson, Gudmundur Kr; Sala, Eeva

    2015-01-01

    High activity noise levels that result in detrimental effects on speech communication have been measured in preschools. To find out if different pedagogical ideologies affect the perceived loudness and levels of noise, a questionnaire study inquiring about the experience of loudness and voice symptoms was carried out in Iceland in eight private preschools, called "Hjalli model", and in six public preschools. Noise levels were also measured in the preschools. Background variables (stress level, age, length of working career, education, smoking, and number of children per teacher) were also analyzed in order to determine how much they contributed toward voice symptoms and the experience of noisiness. Results indicate that pedagogical ideology is a significant factor for predicting noise and its consequences. Teachers in the preschool with tighter pedagogical control of discipline (the "Hjalli model") experienced lower activity noise loudness than teachers in the preschool with a more relaxed control of behavior (public preschool). Lower noise levels were also measured in the "Hjalli model" preschool and fewer "Hjalli model" teachers reported voice symptoms. Public preschool teachers experienced more stress than "Hjalli model" teachers and the stress level was, indeed, the background variable that best explained the voice symptoms and the teacher's perception of a noisy environment. Discipline, structure, and organization in the type of activity predicted the activity noise level better than the number of children in the group. Results indicate that pedagogical ideology is a significant factor for predicting self-reported noise and its consequences.

  16. Peak radiated power measurement of the DOE Mark II container tag with integrated ST-676 sensor radio frequency identification device.

    Energy Technology Data Exchange (ETDEWEB)

    Jursich, Mark

    2010-04-01

    The total peak radiated power of the Department of Energy Mark II container tag was measured in the electromagnetic reverberation chamber facility at Sandia National Laboratories. The tag's radio frequency content was also evaluated for possible emissions outside the intentional transmit frequency band. No spurious emissions of any significance were found, and the radiated power conformed to the manufacturer's specifications.

  17. Receiver system for radio observation of high-energy cosmic ray air showers and its behaviour in self trigger mode

    International Nuclear Information System (INIS)

    Kroemer, Oliver

    2008-04-01

    The observation of high-energy cosmic rays is carried out by indirect measurements. Thereby the primary cosmic particle enters into the earth's atmosphere and generates a cosmic ray air shower by interactions with the air molecules. The secondary particles arriving at ground level are detected with particle detector arrays. The fluorescence light from the exited nitrogen molecules along the shower axis is observed with reflector telescopes in the near-ultraviolet range. In addition to these well-established detection methods, the radio observation of the geosynchrotron emission from cosmic ray air showers is investigated at present as a new observation method. Geosynchrotron emission is generated by the acceleration of the relativistic electron-positron-pairs contained in the air shower by Lorentz forces in the earth's magnetic field. At ground level this causes a single pulse of the electric field strength with a continuous frequency spectrum ranging from a few MHz to above 100 MHz. In this work, a suitable receiver concept is developed based on the signal properties of the geosynchrotron emission and the analysis of the superposed noise and radio frequency interferences. As the required receiver system was not commercially available, it was designed in the framework of this work and realised as system including the antenna, the receiver electronics and suitable data acquisition equipment. In this concept considerations for a large scale radio detector array have already been taken into account, like low power consumption to enable solar power supply and cost effectiveness. The result is a calibrated, multi-channel, digital wideband receiver for the complete range from 40 MHz to 80 MHz. Its inherent noise and RFI suppression essentially results from the antenna directional characteristic and frequency selectivity and allows effective radio observation of cosmic ray air showers also in populated environment. Several units of this receiver station have been deployed

  18. Radio follow-up observations of stellar tidal disruption flares: Constraints on off-axis jets

    Directory of Open Access Journals (Sweden)

    Körding E.

    2012-12-01

    Full Text Available Observations of active galactic nuclei (AGN and X-ray binaries have shown that relativistic jets are ubiquitous when compact objects accrete. One could therefore anticipate the launch of a jet after a star is disrupted and accreted by a massive black hole. This birth of a relativistic jet may have been observed recently in two stellar tidal disruption flares (TDFs, which were discovered in gamma-rays by Swift. Yet no transient radio emission has been detected from the tens of TDF candidates that were discovered at optical to soft X-ray frequencies. Because the sample that was followed-up at radio frequencies is small, the non-detections can be explained by Doppler boosting, which reduces the jet flux for off-axis observers. Plus, the existing followup observation are mostly within ∼ 10 months of the discovery, so the non-detections can also be due to a delay of the radio emission with respect to the time of disruption. To test the conjecture that all TDFs launch jets, we obtained 5 GHz follow-up observations with the Jansky VLA of six known TDFs. To avoid missing delayed jet emission, our observations probe 1–8 years since the estimated time of disruption. None of the sources are detected, with very deep upper limits at the 10 micro Jansky level. These observations rule out the hypothesis that these TDFs launched jets similar to radio-loud quasars. We also constrain the possibility that the flares hosted a jet identical to Sw 1644+57.

  19. Radio-emission of pre-main sequence stars of the Rho Ophiuchi cloud: observations and interpretation

    International Nuclear Information System (INIS)

    Andre, P.

    1987-11-01

    Observations of the radio continuum emission of a young star population have been made at VLA on the whole molecular cloud Rho Ophiuchi, one of the closest site of star formation. A dozen of stellar sources have been detected. Radio emission of some identified objects seems to have a magnetic nature and be produced by gyrosynchrotron mechanism. In particular, one of the sources shows a radio radiation circularly polarized; two other stars have a radiation strongly variable probably due to magnetic eruptions more important than those detected in X radiation. More generally, radio observations select probably a specific population of young stars characterized by magnetic field presence extended on several stellar radii and by absence of dense circumstellar environment. Spatial distribution of these objects suggest, they are younger than most of the pre-main sequence stars [fr

  20. FM Radio and Youth: Listeners or Users?

    Directory of Open Access Journals (Sweden)

    Marina Mučalo

    2014-06-01

    Full Text Available A survey conducted in the spring of 2013, says that Zagreb’s high school students are not regular listeners to FM radio programs. The dominant media is the Internet, which is used a few hours a day, mostly for Facebook. Despite the expressed need for music, the linear and passive nature of FM radio, does not correspond to the individual requirements of young and networked users. The Internet is the most popular daily source for music, with ability to download, while smartphones are becoming devices for storage and playback. However, this survey has shown that students are interested in web radio sites. Changes in media preferences and habits caused by the Internet show us the importance of information literacy, as a basic skill for participation in a networked society.

  1. Individual differences in the biomechanical effect of loudness and tempo on upper-limb movements during repetitive piano keystrokes.

    Science.gov (United States)

    Furuya, Shinichi; Aoki, Tomoko; Nakahara, Hidehiro; Kinoshita, Hiroshi

    2012-02-01

    The present study addressed the effect of loudness and tempo on kinematics and muscular activities of the upper extremity during repetitive piano keystrokes. Eighteen pianists with professional music education struck two keys simultaneously and repetitively with a combination of four loudness levels and four tempi. The results demonstrated a significant interaction effect of loudness and tempo on peak angular velocity for the shoulder, elbow, wrist and finger joints, mean muscular activity for the corresponding flexors and extensors, and their co-activation level. The interaction effect indicated greater increases with tempo when eliciting louder tones for all joints and muscles except for the elbow velocity showing a greater decrease with tempo. Multiple-regression analysis and K-means clustering further revealed that 18 pianists were categorized into three clusters with different interaction effects on joint kinematics. These clusters were characterized by either an elbow-velocity decrease and a finger-velocity increase, a finger-velocity decrease with increases in shoulder and wrist velocities, or a large elbow-velocity decrease with a shoulder-velocity increase when increasing both loudness and tempo. Furthermore, the muscular load considerably differed across the clusters. These findings provide information to determine muscles with the greatest potential risk of playing-related disorders based on movement characteristics of individual pianists. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. DEEP X-RAY OBSERVATIONS OF THE YOUNG HIGH-MAGNETIC-FIELD RADIO PULSAR J1119–6127 AND SUPERNOVA REMNANT G292.2–0.5

    International Nuclear Information System (INIS)

    Ng, C.-Y.; Kaspi, V. M.; Ho, W. C. G.; Weltevrede, P.; Bogdanov, S.; Shannon, R.; Gonzalez, M. E.

    2012-01-01

    High-magnetic-field radio pulsars are important transition objects for understanding the connection between magnetars and conventional radio pulsars. We present a detailed study of the young radio pulsar J1119–6127, which has a characteristic age of 1900 yr and a spin-down-inferred magnetic field of 4.1 × 10 13 G, and its associated supernova remnant G292.2–0.5, using deep XMM-Newton and Chandra X-ray Observatory exposures of over 120 ks from each telescope. The pulsar emission shows strong modulation below 2.5 keV with a single-peaked profile and a large pulsed fraction of 0.48 ± 0.12. Employing a magnetic, partially ionized hydrogen atmosphere model, we find that the observed pulse profile can be produced by a single hot spot of temperature 0.13 keV covering about one-third of the stellar surface, and we place an upper limit of 0.08 keV for an antipodal hot spot with the same area. The non-uniform surface temperature distribution could be the result of anisotropic heat conduction under a strong magnetic field, and a single-peaked profile seems common among high-B radio pulsars. For the associated remnant G292.2–0.5, its large diameter could be attributed to fast expansion in a low-density wind cavity, likely formed by a Wolf-Rayet progenitor, similar to two other high-B radio pulsars.

  3. Quasars: Active nuclei of young galaxies

    Science.gov (United States)

    Komberg, B. V.

    1980-01-01

    The hypothetical properties of 'young' galaxies and possible methods of observing them are discussed. It is proposed that star formation first takes place in the central regions of protogalaxies which may appear as quasar-like objects. An evolutionary scheme is outlined in which the radio quasars are transformed in time into the nuclei of radio galaxies.

  4. Broad Line Radio Galaxies Observed with Fermi-LAT: The Origin of the GeV Gamma-Ray Emission

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, J.; /Waseda U., RISE; Stawarz, L.; /JAXA, Sagamihara /Jagiellonian U., Astron. Observ.; Takahashi, Y.; /Waseda U., RISE; Cheung, C.C.; /Natl. Acad. Sci. /Naval Research Lab, Wash., D.C.; Hayashida, M.; /SLAC /Stanford U., HEPL /KIPAC, Menlo Park; Grandi, P.; /Bologna Observ.; Burnett, T.H.; /Washington U., Seattle; Celotti, A.; /SISSA, Trieste; Fegan, S.J.; Fortin, P.; /Ecole Polytechnique; Maeda, K.; Nakamori, T.; /Waseda U., RISE; Taylor, G.B.; /New Mexico U.; Tosti, G.; /INFN, Perugia /Perugia U.; Digel, S.W.; /SLAC /Stanford U., HEPL /KIPAC, Menlo Park; McConville, W.; /NASA, Goddard /Maryland U.; Finke, J.; /Naval Research Lab, Wash., D.C.; D' Ammando, F.; /IASF, Palermo /INAF, Rome

    2012-06-07

    We report on a detailed investigation of the {gamma}-ray emission from 18 broad line radio galaxies (BLRGs) based on two years of Fermi Large Area Telescope (LAT) data. We confirm the previously reported detections of 3C 120 and 3C 111 in the GeV photon energy range; a detailed look at the temporal characteristics of the observed {gamma}-ray emission reveals in addition possible flux variability in both sources. No statistically significant {gamma}-ray detection of the other BLRGs was however found in the considered dataset. Though the sample size studied is small, what appears to differentiate 3C 111 and 3C 120 from the BLRGs not yet detected in {gamma}-rays is the particularly strong nuclear radio flux. This finding, together with the indications of the {gamma}-ray flux variability and a number of other arguments presented, indicate that the GeV emission of BLRGs is most likely dominated by the beamed radiation of relativistic jets observed at intermediate viewing angles. In this paper we also analyzed a comparison sample of high accretion-rate Seyfert 1 galaxies, which can be considered radio-quiet counterparts of BLRGs, and found none were detected in {gamma}-rays. A simple phenomenological hybrid model applied for the broad-band emission of the discussed radio-loud and radio-quiet type 1 active galaxies suggests that the relative contribution of the nuclear jets to the accreting matter is {ge} 1% on average for BLRGs, while {le} 0.1% for Seyfert 1 galaxies.

  5. 1/f noise in music and speech. [Power spectrum studies

    Energy Technology Data Exchange (ETDEWEB)

    Voss, R.F.; Clarke, J.

    1975-11-27

    The power spectrum, S(f), of many fluctuating physical variables, V(t), is approximately ''1/f-like.'' Loudness fluctuations in music and speech and pitch (melody) fluctuations in music were found to exhibit 1/f power spectra. This observation has implications for stochastic music composition. 3 figures. (RWR)

  6. Tongue- and Jaw-Specific Contributions to Acoustic Vowel Contrast Changes in the Diphthong /ai/ in Response to Slow, Loud, And Clear Speech

    Science.gov (United States)

    Mefferd, Antje S.

    2017-01-01

    Purpose: This study sought to determine decoupled tongue and jaw displacement changes and their specific contributions to acoustic vowel contrast changes during slow, loud, and clear speech. Method: Twenty typical talkers repeated "see a kite again" 5 times in 4 speech conditions (typical, slow, loud, clear). Speech kinematics were…

  7. AIDS radio triggers.

    Science.gov (United States)

    Elias, A M

    1991-07-01

    In April 1991, the Ethnic Communities' Council of NSW was granted funding under the Community AIDS Prevention and Education Program through the Department of Community Services and Health, to produce a series of 6x50 second AIDS radio triggers with a 10-second tag line for further information. The triggers are designed to disseminate culturally-sensitive information about HIV/AIDS in English, Italian, Greek, Spanish, Khmer, Turkish, Macedonian, Serbo-Croatian, Arabic, Cantonese, and Vietnamese, with the goal of increasing awareness and decreasing the degree of misinformation about HIV/AIDS among people of non-English-speaking backgrounds through radio and sound. The 6 triggers cover the denial that AIDS exists in the community, beliefs that words and feelings do not protect one from catching HIV, encouraging friends to be compassionate, compassion within the family, AIDS information for a young audience, and the provision of accurate and honest information on HIV/AIDS. The triggers are slated to be completed by the end of July 1991 and will be broadcast on all possible community, ethnic, and commercial radio networks across Australia. They will be available upon request in composite form with an information kit for use by health care professionals and community workers.

  8. Electron Acceleration by High Power Radio Waves in the Ionosphere

    Science.gov (United States)

    Bernhardt, Paul

    2012-10-01

    At the highest ERP of the High Altitude Auroral Research Program (HAARP) facility in Alaska, high frequency (HF) electromagnetic (EM) waves in the ionosphere produce artificial aurora and electron-ion plasma layers. Using HAARP, electrons are accelerated by high power electrostatic (ES) waves to energies >100 times the thermal temperature of the ambient plasma. These ES waves are driven by decay of the pump EM wave tuned to plasma resonances. The most efficient acceleration process occurs near the harmonics of the electron cyclotron frequency in earth's magnetic field. Mode conversion plays a role in transforming the ES waves into EM signals that are recorded with ground receivers. These diagnostic waves, called stimulated EM emissions (SEE), show unique resonant signatures of the strongest electron acceleration. This SEE also provides clues about the ES waves responsible for electron acceleration. The electron gas is accelerated by high frequency modes including Langmuir (electron plasma), upper hybrid, and electron Bernstein waves. All of these waves have been identified in the scattered EM spectra as downshifted sidebands of the EM pump frequency. Parametric decay is responsible low frequency companion modes such as ion acoustic, lower hybrid, and ion Bernstein waves. The temporal evolution of the scattered EM spectrum indicates development of field aligned irregularities that aid the mode conversion process. The onset of certain spectral features is strongly correlated with glow plasma discharge structures that are both visible with the unaided eye and detectable using radio backscatter techniques at HF and UHF frequencies. The primary goals are to understand natural plasma layers, to study basic plasma physics in a unique ``laboratory with walls,'' and to create artificial plasma structures that can aid radio communications.

  9. Tinnitus: Distinguishing between Subjectively Perceived Loudness and Tinnitus-Related Distress

    OpenAIRE

    Wallhäusser-Franke, Elisabeth; Brade, Joachim; Balkenhol, Tobias; D'Amelio, Roberto; Seegmüller, Andrea; Delb, Wolfgang

    2012-01-01

    OBJECTIVES: Overall success of current tinnitus therapies is low, which may be due to the heterogeneity of tinnitus patients. Therefore, subclassification of tinnitus patients is expected to improve therapeutic allocation, which, in turn, is hoped to improve therapeutic success for the individual patient. The present study aims to define factors that differentially influence subjectively perceived tinnitus loudness and tinnitus-related distress. METHODS: In a questionnaire-based cross-section...

  10. Dispersion induced power fading for radio frequency signals and its application for fast online PMD and CD monitoring

    Science.gov (United States)

    Ning, G.; Shum, P.

    2007-06-01

    We derive the expressions for the power fading including first-order polarization mode dispersion (PMD), chromatic dispersion, chirp parameter as well as polarization-dependent chromatic dispersion (PCD), which is dependent on the angle of precession of output state of polarization around the PMD vector. From the expression for radio frequency (RF) signals power fading, we get the average power fading for chromatic dispersion, chirp parameter, first-order PMD and PCD for both double sideband (DSB) modulation and single sideband (SSB) modulation. We also demonstrate a fast PMD and chromatic dispersion monitoring technology with reduced polarization-dependent gain. The measured results agree well with theoretical analysis.

  11. Musicians are more consistent: Gestural cross-modal mappings of pitch, loudness and tempo in real-time.

    Science.gov (United States)

    Küssner, Mats B; Tidhar, Dan; Prior, Helen M; Leech-Wilkinson, Daniel

    2014-01-01

    Cross-modal mappings of auditory stimuli reveal valuable insights into how humans make sense of sound and music. Whereas researchers have investigated cross-modal mappings of sound features varied in isolation within paradigms such as speeded classification and forced-choice matching tasks, investigations of representations of concurrently varied sound features (e.g., pitch, loudness and tempo) with overt gestures-accounting for the intrinsic link between movement and sound-are scant. To explore the role of bodily gestures in cross-modal mappings of auditory stimuli we asked 64 musically trained and untrained participants to represent pure tones-continually sounding and concurrently varied in pitch, loudness and tempo-with gestures while the sound stimuli were played. We hypothesized musical training to lead to more consistent mappings between pitch and height, loudness and distance/height, and tempo and speed of hand movement and muscular energy. Our results corroborate previously reported pitch vs. height (higher pitch leading to higher elevation in space) and tempo vs. speed (increasing tempo leading to increasing speed of hand movement) associations, but also reveal novel findings pertaining to musical training which influenced consistency of pitch mappings, annulling a commonly observed bias for convex (i.e., rising-falling) pitch contours. Moreover, we reveal effects of interactions between musical parameters on cross-modal mappings (e.g., pitch and loudness on speed of hand movement), highlighting the importance of studying auditory stimuli concurrently varied in different musical parameters. Results are discussed in light of cross-modal cognition, with particular emphasis on studies within (embodied) music cognition. Implications for theoretical refinements and potential clinical applications are provided.

  12. Musicians are more consistent: Gestural cross-modal mappings of pitch, loudness and tempo in real-time

    Science.gov (United States)

    Küssner, Mats B.; Tidhar, Dan; Prior, Helen M.; Leech-Wilkinson, Daniel

    2014-01-01

    Cross-modal mappings of auditory stimuli reveal valuable insights into how humans make sense of sound and music. Whereas researchers have investigated cross-modal mappings of sound features varied in isolation within paradigms such as speeded classification and forced-choice matching tasks, investigations of representations of concurrently varied sound features (e.g., pitch, loudness and tempo) with overt gestures—accounting for the intrinsic link between movement and sound—are scant. To explore the role of bodily gestures in cross-modal mappings of auditory stimuli we asked 64 musically trained and untrained participants to represent pure tones—continually sounding and concurrently varied in pitch, loudness and tempo—with gestures while the sound stimuli were played. We hypothesized musical training to lead to more consistent mappings between pitch and height, loudness and distance/height, and tempo and speed of hand movement and muscular energy. Our results corroborate previously reported pitch vs. height (higher pitch leading to higher elevation in space) and tempo vs. speed (increasing tempo leading to increasing speed of hand movement) associations, but also reveal novel findings pertaining to musical training which influenced consistency of pitch mappings, annulling a commonly observed bias for convex (i.e., rising–falling) pitch contours. Moreover, we reveal effects of interactions between musical parameters on cross-modal mappings (e.g., pitch and loudness on speed of hand movement), highlighting the importance of studying auditory stimuli concurrently varied in different musical parameters. Results are discussed in light of cross-modal cognition, with particular emphasis on studies within (embodied) music cognition. Implications for theoretical refinements and potential clinical applications are provided. PMID:25120506

  13. Musicians are more consistent: Gestural cross-modal mappings of pitch, loudness and tempo in real-time

    Directory of Open Access Journals (Sweden)

    Mats B. Küssner

    2014-07-01

    Full Text Available Cross-modal mappings of auditory stimuli reveal valuable insights into how humans make sense of sound and music. Whereas researchers have investigated cross-modal mappings of sound features varied in isolation within paradigms such as speeded classification and forced-choice matching tasks, investigations of representations of concurrently varied sound features (e.g., pitch, loudness and tempo with overt gestures—accounting for the intrinsic link between movement and sound—are scant. To explore the role of bodily gestures in cross-modal mappings of auditory stimuli we asked sixty-four musically trained and untrained participants to represent pure tones—continually sounding and concurrently varied in pitch, loudness and tempo—with gestures while the sound stimuli were played. We hypothesised musical training to lead to more consistent mappings between pitch and height, loudness and distance/height, and tempo and speed of hand movement and muscular energy.Our results corroborate previously reported pitch vs. height (higher pitch leading to higher elevation in space and tempo vs. speed (increasing tempo leading to increasing speed of hand movement associations, but also reveal novel findings pertaining to musical training which influenced consistency of pitch mappings, annulling a commonly observed bias for convex (i.e. rising-falling pitch contours. Moreover, we reveal effects of interactions between musical parameters on cross-modal mappings (e.g., pitch and loudness on speed of hand movement, highlighting the importance of studying auditory stimuli concurrently varied in different musical parameters. Results are discussed in light of cross-modal cognition, with particular emphasis on studies within (embodied music cognition. Implications for theoretical refinements and potential clinical applications are provided.

  14. Loud preimpact tones reduce the cervical multifidus muscle response during rear-end collisions: a potential method for reducing whiplash injuries.

    Science.gov (United States)

    Mang, Daniel W H; Siegmund, Gunter P; Brown, Harrison J; Goonetilleke, Samanthi C; Blouin, Jean-Sébastien

    2015-01-01

    Neck muscle responses after unexpected rear-end collisions consist of a stereotypical combination of postural and startle responses. Prior work using surface electromyography (EMG) has shown that the superficial neck muscle responses can be attenuated when a loud tone (105 dB) is presented 250 milliseconds before impact, but the accompanying response of the deeper multifidus muscles remains unknown. Quantifying this response in multifidus is important because this muscle attaches directly to the cervical facet capsule and can potentially increase the strain in the capsule during an impact and contribute to whiplash injury. To investigate if a loud preimpact tone decreases the cervical multifidus muscle response during rear-end perturbations. After approval by the University Clinical Ethics Review Board, human volunteers experienced a series of three whiplash-like perturbations. Twelve subjects with no history of neurologic disorders or whiplash injury were recruited to participate in this experiment. Bilateral indwelling EMG of multifidus at the C4 and C6 levels, surface EMG of sternocleidomastoid (SCM) and C4 paraspinals (PARAs), and kinematics of the head/neck were measured. Subjects experienced three whiplash-like perturbations (peak acceleration of 19.5 m/s(2)) preceded by either no tone or a loud tone (105 dB) presented 250 milliseconds before sled acceleration onset. The loud tone decreased the muscle activity of C6 multifidus (42%) and C4 PARAs (30%), but did not affect the C4 multifidus or SCM activity. Peak head kinematic responses (extension angle: 6%, retraction: 9%, linear forward acceleration: 9%, and angular acceleration in extension: 13%) were also decreased by the loud preimpact tone. The attenuation of peak C6 multifidus activity and head kinematic responses suggests that a loud preimpact tone may reduce the strain in the cervical facet capsule, which may reduce the risk of whiplash injury during rear-end collisions. Copyright © 2015 Elsevier Inc

  15. Radio Videos of Orion Protostars (with X-ray Colors!)

    Science.gov (United States)

    Forbrich, Jan; Wolk, Scott; Menten, Karl; Reid, Mark; Osten, Rachel

    2013-07-01

    High-energy processes in Young Stellar Objects (YSOs) can be observed both in X-rays and in the centimetric radio wavelength range. While the past decade has brought a lot of progress in the field of X-ray observations of YSOs, (proto)stellar centimetric radio astronomy has only recently begun to catch up with the advent of the newly expanded Karl G. Jansky Very Large Array (JVLA). The enhanced sensitivity is fundamentally improving our understanding of YSO radio properties by providing unprecedented sensitivity and thus spectral as well as temporal resolution. As a result, it is becoming easier to disentangle coronal-type nonthermal radio emission emanating from the immediate vicinity of YSOs from thermal emission on larger spatial scales, for example ionized material at the base of outflows. Of particular interest is the correlation of the by now relatively well-characterized X-ray flaring variability with the nonthermal radio variability. We present first results of multi-epoch simultaneous observations using Chandra and the JVLA, targeting the Orion Nebula Cluster and highlighting the capabilities of the JVLA for radio continuum observations of YSOs.

  16. Loud music listening.

    Science.gov (United States)

    Petrescu, Nicolae

    2008-07-01

    Over the past four decades, there has been increasing interest in the effects of music listening on hearing. The purpose of this paper is to review published studies that detail the noise levels, the potential effects (e.g. noise-induced hearing loss), and the perceptions of those affected by music exposure in occupational and non-occupational settings. The review employed Medline, PubMed, PsychINFO, and the World Wide Web to find relevant studies in the scientific literature. Considered in this review are 43 studies concerning the currently most significant occupational sources of high-intensity music: rock and pop music playing and employment at music venues, as well as the most significant sources of non-occupational high-intensity music: concerts, dicotheques (clubs), and personal music players. Although all of the activities listed above have the potential for hearing damage, the most serious threat to hearing comes from prolonged exposures to amplified live music (concerts). The review concludes that more research is needed to clarify the hearing loss risks of music exposure from personal music players and that current scientific literature clearly recognizes an unmet hearing health need for more education regarding the risks of loud music exposure and the benefits of wearing hearing protection, for more hearing protection use by those at risk, and for more regulations limiting music intensity levels at music entertainment venues.

  17. Topographic power spectral density study of the effect of surface treatment processes on niobium for superconducting radio frequency accelerator cavities

    Science.gov (United States)

    Xu, Chen; Tian, Hui; Reece, Charles E.; Kelley, Michael J.

    2012-04-01

    Microroughness is viewed as a critical issue for attaining optimum performance of superconducting radio frequency accelerator cavities. The principal surface smoothing methods are buffered chemical polish (BCP) and electropolish (EP). The resulting topography is characterized by atomic force microscopy (AFM). The power spectral density (PSD) of AFM data provides a more thorough description of the topography than a single-value roughness measurement. In this work, one dimensional average PSD functions derived from topography of BCP and EP with different controlled starting conditions and durations have been fitted with a combination of power law, K correlation, and shifted Gaussian models to extract characteristic parameters at different spatial harmonic scales. While the simplest characterizations of these data are not new, the systematic tracking of scale-specific roughness as a function of processing is new and offers feedback for tighter process prescriptions more knowledgably targeted at beneficial niobium topography for superconducting radio frequency applications.

  18. Topographic power spectral density study of the effect of surface treatment processes on niobium for superconducting radio frequency accelerator cavities

    International Nuclear Information System (INIS)

    Reece, Charles; Tian, Hui; Kelley, Michael; Xu, Chen

    2012-01-01

    Microroughness is viewed as a critical issue for attaining optimum performance of superconducting radio frequency accelerator cavities. The principal surface smoothing methods are buffered chemical polish (BCP) and electropolish (EP). The resulting topography is characterized by atomic force microscopy (AFM). The power spectral density (PSD) of AFM data provides a more thorough description of the topography than a single-value roughness measurement. In this work, one dimensional average PSD functions derived from topography of BCP and EP with different controlled starting conditions and durations have been fitted with a combination of power law, K correlation, and shifted Gaussian models to extract characteristic parameters at different spatial harmonic scales. While the simplest characterizations of these data are not new, the systematic tracking of scale-specific roughness as a function of processing is new and offers feedback for tighter process prescriptions more knowledgably targeted at beneficial niobium topography for superconducting radio frequency applications.

  19. Energy-Efficient Power Allocation of Cognitive Radio Systems without CSI at the Transmitter

    KAUST Repository

    Sboui, Lokman

    2015-01-07

    Two major issues are facing today’s wireless communications evolution: -Spectrum scarcity: Need for more bandwidth. As a solution, the Cognitive Radio (CR) paradigm, where secondary users (unlicensed) share the spectrum with licensed users, was introduced. -Energy consumption and CO2 emission: The ICT produce 2% of global CO2 emission (equivalent to the aviation industry emission). The cellular networks produces 0.2%. As solution energy efficient systems should be designed rather than traditional spectral efficient systems. In this work, we aim to determine the optimal energy efficient power allocation of CR when the channel state information at the transmitter CSI-T is not available.

  20. Energy-Efficient Power Allocation of Cognitive Radio Systems without CSI at the Transmitter

    KAUST Repository

    Sboui, Lokman; Rezki, Zouheir; Alouini, Mohamed-Slim

    2015-01-01

    Two major issues are facing today’s wireless communications evolution: -Spectrum scarcity: Need for more bandwidth. As a solution, the Cognitive Radio (CR) paradigm, where secondary users (unlicensed) share the spectrum with licensed users, was introduced. -Energy consumption and CO2 emission: The ICT produce 2% of global CO2 emission (equivalent to the aviation industry emission). The cellular networks produces 0.2%. As solution energy efficient systems should be designed rather than traditional spectral efficient systems. In this work, we aim to determine the optimal energy efficient power allocation of CR when the channel state information at the transmitter CSI-T is not available.

  1. Identification af explosive power factors as predictors of player quality in young female volleyball players.

    Science.gov (United States)

    Grgantov, Zoran; Milić, Mirjana; Katić, Ratko

    2013-05-01

    With the purpose of determining the factor structure of explosive power, as well as the influence of each factor on situational efficiency, 56 young female volleyball players were tested using 14 tests for assessing nonspecific and specific explosive power. By factor analysis, 4 significant factors were isolated which explained the total of over 80% of the common variability in young female volleyball players. The first factor was defined as volleyball-specific jumping, the second factor as nonspecific jumping and sprinting, the third factor as throwing explosive power, while the fourth factor was interpreted as volleyball-specific throwing and spiking speed from the ground. Results obtained by regression analysis in the latent space of explosive power indicate that the identified factors are good predictors of player quality in young female volleyball players. The fourth factor defined as throwing and spiking speed from the ground had the largest influence on player quality, followed by volleyball-specific jumping and nonspecific jumping and sprinting, and to a much lesser extent, by throwing explosive power The results obtained in this age group bring to the fore the ability of spiking and serving a ball of high speed, which hinders the opponents from playing those balls in serve reception and field defence. This ability, combined with a high standing vertical jump reach and spike approach vertical jump reach (which is the basis of the 1st varimax factor) enables successful performance of all volleyball elements by which points are won in complex 1 (spike) and complex 2 (serve and block). Even though the 2nd factor (nonspecific jumping and sprinting) has a slightly smaller impact on situational efficiency in young players, this ability provides preconditions i.e. preparation for successful realisation of all volleyball elements, so greater attention must be paid to perfecting it in young female volleyball players.

  2. RELATIVISTIC PLASMA AS THE DOMINANT SOURCE OF THE OPTICAL CONTINUUM EMISSION IN THE BROAD-LINE RADIO GALAXY 3C 120

    International Nuclear Information System (INIS)

    Leon-Tavares, J.; Lobanov, A. P.; Arshakian, T. G.; Chavushyan, V. H.; Doroshenko, V. T.; Sergeev, S. G.; Efimov, Y. S.; Nazarov, S. V.

    2010-01-01

    We report a relation between radio emission in the inner jet of the Seyfert galaxy 3C 120 and optical continuum emission in this galaxy. Combining the optical variability data with multi-epoch high-resolution very long baseline interferometry observations reveals that an optical flare rises when a superluminal component emerges into the jet, and its maxima is related to the passage of such component through the location of a stationary feature at a distance of ∼1.3 pc from the jet origin. This indicates that a significant fraction of the optical continuum produced in 3C 120 is non-thermal, and it can ionize material in a sub-relativistic wind or outflow. We discuss implications of this finding for the ionization and structure of the broad emission line region, as well as for the use of broad emission lines for determining black hole masses in radio-loud active galactic nucleus.

  3. Radio morphing - towards a full parametrisation of the radio signal from air showers

    Science.gov (United States)

    Zilles, A.; Charrier, D.; Kotera, K.; Le Coz, S.; Martineau-Huynh, O.; Medina, C.; Niess, V.; Tueros, M.; de Vries, K.

    2017-12-01

    Over the last decades, radio detection of air showers has been established as a detection technique for ultra-high-energy cosmic-rays impinging on the Earth's atmosphere with energies far beyond LHC energies. Today’s second-generation of digital radio-detection experiments, as e.g. AERA or LOFAR, are becoming competitive in comparison to already standard techniques e.g. fluorescence light detection. Thanks to a detailed understanding of the physics of the radio emission in extensive air showers, simulations of the radio signal are already successfully tested and applied in the reconstruction of cosmic rays. However the limits of the computational power resources are easily reached when it comes to computing electric fields at the numerous positions requested by large or dense antenna arrays. In the case of mountainous areas as e.g. for the GRAND array, where 3D shower simulations are necessary, the problem arises with even stronger acuity. Therefore we developed a full parametrisation of the emitted radio signal on the basis of generic shower simulations which will reduce the simulation time by orders of magnitudes. In this talk we will present this concept after a short introduction to the concept of the radio detection of air-shower induced by cosmic rays.

  4. The energy distribution of electrons in radio jets

    Science.gov (United States)

    Tsouros, Alexandros; Kylafis, Nikolaos D.

    2017-07-01

    Context. Black-hole and neutron-star X-ray binaries exhibit compact radio jets, when they are in the so called quiescent, hard, or hard intermediate states. The radio spectrum in these states is flat to slightly inverted, I.e., the spectral index of the observed flux density is in the range 0 ≲ α ≲ 0.5. It is widely accepted that the energy distribution of the electrons, in the rest frame of the jet, is a power law with index in the range 3 ≲ p ≲ 5. Aims: Contrary to what our thinking was decades ago, now we know that the jets originate in the hot, inner flow around black holes and neutron stars. So it is worth investigating the radio spectrum that is emitted by a thermal jet as a function of direction. Methods: As an example, we consider a parabolic jet and, with the assumption of flux freezing, we compute the emitted spectrum in all directions, from radio to near infrared, using either a thermal distribution of electrons or a power-law one. Results: We have found that parabolic jets with a thermal distribution of electrons give also flat to slightly inverted spectra. In particular, for directions along the jet (θ = 0), both distributions of electron energies give α = 0 ± 0.01. The index α increases as the viewing angle θ increases and for directions perpendicular to the jet (θ = π/ 2), the thermal distribution gives α = 0.40 ± 0.05, while the power-law distribution gives α = 0.20 ± 0.05. The break frequency νb, which marks the transition from partially optically thick to optically thin synchrotron emission, is comparable for the power-law and the thermal distributions. Conclusions: Contrary to common belief, it is not necessary to invoke a power-law energy distribution of the electrons in a jet to explain its flat to slightly inverted radio spectrum. A relativistic Maxwellian produces similar radio spectra. Thus, the jet may be the widely invoked "corona" around black holes in X-ray binaries.

  5. Effects of pedagogical ideology on the perceived loudness and noise levels in preschools

    Science.gov (United States)

    Jonsdottir, Valdis; Rantala, Leena M.; Oskarsson, Gudmundur Kr.; Sala, Eeva

    2015-01-01

    High activity noise levels that result in detrimental effects on speech communication have been measured in preschools. To find out if different pedagogical ideologies affect the perceived loudness and levels of noise, a questionnaire study inquiring about the experience of loudness and voice symptoms was carried out in Iceland in eight private preschools, called “Hjalli model”, and in six public preschools. Noise levels were also measured in the preschools. Background variables (stress level, age, length of working career, education, smoking, and number of children per teacher) were also analyzed in order to determine how much they contributed toward voice symptoms and the experience of noisiness. Results indicate that pedagogical ideology is a significant factor for predicting noise and its consequences. Teachers in the preschool with tighter pedagogical control of discipline (the “Hjalli model”) experienced lower activity noise loudness than teachers in the preschool with a more relaxed control of behavior (public preschool). Lower noise levels were also measured in the “Hjalli model” preschool and fewer “Hjalli model” teachers reported voice symptoms. Public preschool teachers experienced more stress than “Hjalli model” teachers and the stress level was, indeed, the background variable that best explained the voice symptoms and the teacher's perception of a noisy environment. Discipline, structure, and organization in the type of activity predicted the activity noise level better than the number of children in the group. Results indicate that pedagogical ideology is a significant factor for predicting self-reported noise and its consequences. PMID:26356370

  6. Automatic feedback to promote safe walking and speech loudness control in persons with multiple disabilities: two single-case studies.

    Science.gov (United States)

    Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Green, Vanessa A; Alberti, Gloria; Boccasini, Adele; Smaldone, Angela; Oliva, Doretta; Bosco, Andrea

    2014-08-01

    Assessing automatic feedback technologies to promote safe travel and speech loudness control in two men with multiple disabilities, respectively. The men were involved in two single-case studies. In Study I, the technology involved a microprocessor, two photocells, and a verbal feedback device. The man received verbal alerting/feedback when the photocells spotted an obstacle in front of him. In Study II, the technology involved a sound-detecting unit connected to a throat and an airborne microphone, and to a vibration device. Vibration occurred when the man's speech loudness exceeded a preset level. The man included in Study I succeeded in using the automatic feedback in substitution of caregivers' alerting/feedback for safe travel. The man of Study II used the automatic feedback to successfully reduce his speech loudness. Automatic feedback can be highly effective in helping persons with multiple disabilities improve their travel and speech performance.

  7. Bandwidth and power allocation for two-way relaying in overlay cognitive radio systems

    KAUST Repository

    Alsharoa, Ahmad M.

    2014-12-01

    In this paper, the problem of both bandwidth and power allocation for two-way multiple relay systems in overlay cognitive radio (CR) setup is investigated. In the CR overlay mode, primary users (PUs) cooperate with cognitive users (CUs) for mutual benefits. In our framework, we propose that the CUs are allowed to allocate a part of the PUs spectrum to perform their cognitive transmission. In return, acting as an amplify-and-forward two-way relays, they are used to support PUs to achieve their target data rates over the remaining bandwidth. More specifically, CUs acts as relays for the PUs and gain some spectrum as long as they respect a specific power budget and primary quality-of-service constraints. In this context, we first derive closed-form expressions for optimal transmit power allocated to PUs and CUs in order to maximize the cognitive objective. Then, we employ a strong optimization tool based on particle swarm optimization algorithm to find the optimal relay amplification gains and optimal cognitive released bandwidths as well. Our numerical results illustrate the performance of our proposed algorithm for different utility metrics and analyze the impact of some system parameters on the achieved performance.

  8. Efficient Design of OFDMA-Based Programmable Wireless Radios

    Directory of Open Access Journals (Sweden)

    Shah SFA

    2008-01-01

    Full Text Available With the increasing demand for efficient spectrum management, programmable wireless radios can potentially play a key role in shaping our future spectrum use. In this paper, we consider the design of low-power programmable wireless radios based on orthogonal frequency division multiple access (OFDMA. To meet the demands of higher data rate communications, we split OFDMA symbols carrying multiuser data across several noncontiguous bands of available spectrum. To relax power consumption in analog-to-digital and digital-to-analog converters, we use a programmable narrowband RF front end comprising of programmable synthesizers and fixed low-pass filters. To perform digital baseband signal processing in an energy efficient manner, we propose efficient designs for the fast Fourier transform (FFT and inverse FFT (IFFT modules. Our designs of the FFT/IFFT modules reduce power consumption and chip area, and are capable of handling the dynamic nature of spectrum in programmable radios. To recover data that falls within the transition band of the filters, we propose a combiner similar to maximal ratio combiner. We also present the complete design of programmable wireless radios in accordance with the IEEE 802.22 (draft standard.

  9. Efficient Design of OFDMA-Based Programmable Wireless Radios

    Directory of Open Access Journals (Sweden)

    A. H. Tewfik

    2008-03-01

    Full Text Available With the increasing demand for efficient spectrum management, programmable wireless radios can potentially play a key role in shaping our future spectrum use. In this paper, we consider the design of low-power programmable wireless radios based on orthogonal frequency division multiple access (OFDMA. To meet the demands of higher data rate communications, we split OFDMA symbols carrying multiuser data across several noncontiguous bands of available spectrum. To relax power consumption in analog-to-digital and digital-to-analog converters, we use a programmable narrowband RF front end comprising of programmable synthesizers and fixed low-pass filters. To perform digital baseband signal processing in an energy efficient manner, we propose efficient designs for the fast Fourier transform (FFT and inverse FFT (IFFT modules. Our designs of the FFT/IFFT modules reduce power consumption and chip area, and are capable of handling the dynamic nature of spectrum in programmable radios. To recover data that falls within the transition band of the filters, we propose a combiner similar to maximal ratio combiner. We also present the complete design of programmable wireless radios in accordance with the IEEE 802.22 (draft standard.

  10. Joint Bandwidth and Power Allocation for MIMO Two-Way Relays-Assisted Overlay Cognitive Radio Systems

    KAUST Repository

    Alsharoa, Ahmad; Ghazzai, Hakim; Yaacoub, Elias; Alouini, Mohamed-Slim; Kamal, Ahmed

    2015-01-01

    This paper studies the achievable cognitive sum rate of an overlay cognitive radio (CR) system assisted with multiple antennas two-way relays in which primary users (PUs) cooperate with cognitive users (CUs) for mutual benefits. In this context, the problem of both bandwidth and power allocation is investigated. We propose that the CUs are allowed to allocate a part of the PUs spectrum to perform their cognitive transmission. In return, acting as amplify-and-forward two-way relays, they are exploited to support PUs to reach their target data rates over the remaining bandwidth. Power expressions for optimal transmit power allocated per PU and CU antenna are derived under primary quality-of-service constraint in addition to bandwidth and power budget constraints. More specifically, CUs act as relays for the PUs transmission and gain some spectrum as long as they respect these constraints. After deriving the optimal transmit powers, we employ a strong optimization tool based on swarm intelligence to optimize the full and complex relay amplification gain matrices in addition to the bandwidths released to primary and cognitive transmission. Furthermore, three different utility functions are considered in our optimization problems depending on the level of fairness among CUs.

  11. Joint Bandwidth and Power Allocation for MIMO Two-Way Relays-Assisted Overlay Cognitive Radio Systems

    KAUST Repository

    Alsharoa, Ahmad

    2015-10-08

    This paper studies the achievable cognitive sum rate of an overlay cognitive radio (CR) system assisted with multiple antennas two-way relays in which primary users (PUs) cooperate with cognitive users (CUs) for mutual benefits. In this context, the problem of both bandwidth and power allocation is investigated. We propose that the CUs are allowed to allocate a part of the PUs spectrum to perform their cognitive transmission. In return, acting as amplify-and-forward two-way relays, they are exploited to support PUs to reach their target data rates over the remaining bandwidth. Power expressions for optimal transmit power allocated per PU and CU antenna are derived under primary quality-of-service constraint in addition to bandwidth and power budget constraints. More specifically, CUs act as relays for the PUs transmission and gain some spectrum as long as they respect these constraints. After deriving the optimal transmit powers, we employ a strong optimization tool based on swarm intelligence to optimize the full and complex relay amplification gain matrices in addition to the bandwidths released to primary and cognitive transmission. Furthermore, three different utility functions are considered in our optimization problems depending on the level of fairness among CUs.

  12. Mixed-Methods Resistance Training Increases Power and Strength of Young and Older Men.

    Science.gov (United States)

    Newton, Robert U.; Hakkinen, Keijo; Hakkinen, Arja; McCormick, Matt; Volek, Jeff; Kraemer, William J.

    2002-01-01

    Examined the effects of a 10-week, mixed-methods resistance training program on young and older men. Although results confirmed some age-related reductions in muscle strength and power, the older men demonstrated similar capacity to the younger men for increases in muscle strength and power via an appropriate, periodized resistance training…

  13. Effect of Pulse Polarity on Thresholds and on Non-monotonic Loudness Growth in Cochlear Implant Users.

    Science.gov (United States)

    Macherey, Olivier; Carlyon, Robert P; Chatron, Jacques; Roman, Stéphane

    2017-06-01

    Most cochlear implants (CIs) activate their electrodes non-simultaneously in order to eliminate electrical field interactions. However, the membrane of auditory nerve fibers needs time to return to its resting state, causing the probability of firing to a pulse to be affected by previous pulses. Here, we provide new evidence on the effect of pulse polarity and current level on these interactions. In experiment 1, detection thresholds and most comfortable levels (MCLs) were measured in CI users for 100-Hz pulse trains consisting of two consecutive biphasic pulses of the same or of opposite polarity. All combinations of polarities were studied: anodic-cathodic-anodic-cathodic (ACAC), CACA, ACCA, and CAAC. Thresholds were lower when the adjacent phases of the two pulses had the same polarity (ACCA and CAAC) than when they were different (ACAC and CACA). Some subjects showed a lower threshold for ACCA than for CAAC while others showed the opposite trend demonstrating that polarity sensitivity at threshold is genuine and subject- or electrode-dependent. In contrast, anodic (CAAC) pulses always showed a lower MCL than cathodic (ACCA) pulses, confirming previous reports. In experiments 2 and 3, the subjects compared the loudness of several pulse trains differing in current level separately for ACCA and CAAC. For 40 % of the electrodes tested, loudness grew non-monotonically as a function of current level for ACCA but never for CAAC. This finding may relate to a conduction block of the action potentials along the fibers induced by a strong hyperpolarization of their central processes. Further analysis showed that the electrodes showing a lower threshold for ACCA than for CAAC were more likely to yield a non-monotonic loudness growth. It is proposed that polarity sensitivity at threshold reflects the local neural health and that anodic asymmetric pulses should preferably be used to convey sound information while avoiding abnormal loudness percepts.

  14. Real-Time Measurements for Adaptive and Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Hüseyin Arslan

    2009-01-01

    Full Text Available Adaptive and cognitive radios (CR have been becoming popular for optimizing mobile radio system transmission and reception. One of the most important elements of the adaptive radio and CR concepts is the ability to measure, sense, learn about, and be aware of parameters related to the radio channel characteristics, availability of spectrum and power, interference and noise temperature, operational environment of radio, user requirements and applications, available networks and infrastructures, local policies, other operating restrictions, and so on. This paper discusses some of the important measurement parameters for enabling adaptive radio and CR systems along with their relationships and impacts on the performance including relevant challenges.

  15. CDC Vital Signs–Too Loud for Too Long!

    Centers for Disease Control (CDC) Podcasts

    2017-02-07

    This podcast is based on the February 2017 CDC Vital Signs report. Being around too much loud noise—like a leaf blower or rock concert—can cause permanent hearing loss. Learn how to prevent hearing loss.  Created: 2/7/2017 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 2/7/2017.

  16. Open ends: an ethnographic radio montage about post-diagnosis lives in Denmark and South Africa

    DEFF Research Database (Denmark)

    Houmøller, Kathrin; Steno, Anne Mia

    This presentation takes the form of a radio montage and presents stories of post-diagnosis lives in Denmark and urban South Africa. Based on ethnographic fieldworks with young people in psychiatric treatment (Denmark) and among hiv-positive people in anti-retroviral therapy (South Africa), the mo......This presentation takes the form of a radio montage and presents stories of post-diagnosis lives in Denmark and urban South Africa. Based on ethnographic fieldworks with young people in psychiatric treatment (Denmark) and among hiv-positive people in anti-retroviral therapy (South Africa...

  17. Cognitive Radio for Smart Grid: Theory, Algorithms, and Security

    Directory of Open Access Journals (Sweden)

    Raghuram Ranganathan

    2011-01-01

    Full Text Available Recently, cognitive radio and smart grid are two areas which have received considerable research impetus. Cognitive radios are intelligent software defined radios (SDRs that efficiently utilize the unused regions of the spectrum, to achieve higher data rates. The smart grid is an automated electric power system that monitors and controls grid activities. In this paper, the novel concept of incorporating a cognitive radio network as the communications infrastructure for the smart grid is presented. A brief overview of the cognitive radio, IEEE 802.22 standard and smart grid, is provided. Experimental results obtained by using dimensionality reduction techniques such as principal component analysis (PCA, kernel PCA, and landmark maximum variance unfolding (LMVU on Wi-Fi signal measurements are presented in a spectrum sensing context. Furthermore, compressed sensing algorithms such as Bayesian compressed sensing and the compressed sensing Kalman filter is employed for recovering the sparse smart meter transmissions. From the power system point of view, a supervised learning method called support vector machine (SVM is used for the automated classification of power system disturbances. The impending problem of securing the smart grid is also addressed, in addition to the possibility of applying FPGA-based fuzzy logic intrusion detection for the smart grid.

  18. Curved Radio Spectra of