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Sample records for chandra high energy

  1. Chandra High Energy Transmission Grating Spectrum of AE Aquarii

    CERN Document Server

    Mauche, Christopher W

    2009-01-01

    (Abridged) The results of a Chandra X-ray Observatory High-Energy Transmission Grating (HETG) observation of the nova-like cataclysmic binary AE Aqr are described. First, the X-ray spectrum is that of an optically thin multi-temperature thermal plasma; the X-ray emission lines are broad, with widths that increase with the line energy, from sigma~1 eV for O VIII to sigma~5.5 eV for Si XIV; the X-ray spectrum is reasonably well fit by a plasma model with a Gaussian emission measure distribution that peaks at log T(K)=7.16, has a width sigma=0.48, an Fe abundance equal to 0.44 times solar, and other metal (primarily Ne, Mg, and Si) abundances equal to 0.76 times solar; and for a distance d=100 pc, the total emission measure EM=8.0E53 cm^-3 and the 0.5-10 keV luminosity L_X=1.1E31 erg/s. Second, based on the f/(i+r) flux ratios of the forbidden (f), intercombination (i), and recombination (r) lines of the He alpha triplets of N VI, O VII, and Ne IX measured by Itoh et al. in the XMM-Newton Reflection Grating Spec...

  2. The Chandra High Energy Transmission Grating: Design, Fabrication, Ground Calibration and Five Years in Flight

    CERN Document Server

    Canizares, C R; Dewey, D; Flanagan, K A; Galton, E B; Huenemoerder, D P; Ishibashi, K; Markert, T H; Marshall, H L; McGuirk, M; Schattenburg, M L; Schulz, N S; Smith, H I; Wise, M; Canizares, Claude R.; Davis, John E.; Dewey, Daniel; Flanagan, Kathryn A.; Galton, Eugene B.; Huenemoerder, David P.; Ishibashi, Kazunori; Markert, Thomas H.; Marshall, Herman L.; Guirk, Michael Mc; Schattenburg, Mark L.; Schulz, Norbert S.; Smith, Henry I.; Wise, Michael

    2005-01-01

    Details of the design, fabrication, ground and flight calibration of the High Energy Transmission Grating, HETG, on the Chandra X-ray Observatory are presented after five years of flight experience. Specifics include the theory of phased transmission gratings as applied to the HETG, the Rowland design of the spectrometer, details of the grating fabrication techniques, and the results of ground testing and calibration of the HETG. For nearly six years the HETG has operated essentially as designed, although it has presented some subtle flight calibration effects.

  3. The Chandra High Energy Transmission Grating Observation of an X-ray Ionization Cone in Markarian 3

    OpenAIRE

    Sako, Masao; Kahn, Steven M.; Paerels, Frits; Liedahl, Duane A.

    2000-01-01

    We present a preliminary analysis of the first high-resolution X-ray spectrum of a Seyfert 2 galaxy, Mkn 3, obtained with the High Energy Transmission Grating Spectrometer onboard the Chandra X-ray Observatory. The high-energy spectrum (lambda < 4 Ang) is dominated by reflection of the AGN continuum radiation in a cold optically thick medium and contains bright K-alpha fluorescent lines from iron and silicon, as well as weak, blended lines from sulfur and magnesium. The soft X-ray emission (4...

  4. The Kinematics and Physical Conditions of the Ionized Gas in NGC 4593 from Chandra High-Energy Grating Spectroscopy

    CERN Document Server

    McKernan, B; George, I M; Turner, T J

    2003-01-01

    We observed the Seyfert 1 galaxy NGC 4593 with the Chandra high energy transmission gratings and present a detailed analysis of the soft X-ray spectrum. We measure strong absorption lines from He-like O, Ne, Mg, Si, H-like N, O, Ne, Mg, Si and highly ionized Fe XIX-XXV. Only the NLya, OLya and MgLya lines appear to be marginally resolved. We identify a spectral feature at $\\sim 0.707$ keV with a neutral Fe L edge, which might suggest that there is dust along the line-of-sight to \

  5. The Chandra High Energy Transmission Grating Observation of an X-ray Ionization Cone in Markarian 3

    CERN Document Server

    Sako, M; Paerels, F B S; Liedahl, D A; Sako, Masao; Kahn, Steven M.; Paerels, Frits; Liedahl, Duane A.

    2000-01-01

    We present a preliminary analysis of the first high-resolution X-ray spectrum of a Seyfert 2 galaxy, Mkn 3, obtained with the High Energy Transmission Grating Spectrometer onboard the Chandra X-ray Observatory. The high-energy spectrum (lambda < 4 Ang) is dominated by reflection of the AGN continuum radiation in a cold optically thick medium and contains bright K-alpha fluorescent lines from iron and silicon, as well as weak, blended lines from sulfur and magnesium. The soft X-ray emission (4 < lambda < 23 Ang) is spatially extended along the [O III] ionization cone and shows discrete signatures of emission following recombination and photoexcitation produced in a warm photoionized region. The measured iron L line fluxes indicate that emission from collisionally ionized plasma is almost completely negligible, and does not contribute significantly to the total energy budget of the X-ray emission. We find that significant fractions of the H- and He-like resonance lines, as well as the observed iron L l...

  6. What Did We Learn From Chandra, Xmm-Newton And Fermi-Lat About The High Energy Emission In Young Radio Sources?

    Science.gov (United States)

    Siemiginowska, Aneta; Guainazzi, M.; Hardcastle, M.; Kelly, B. C.; Kunert-Bajraszewska, M.; Migliori, G.; Sobolewska, M.; Stawarz, L.

    2013-04-01

    Giga-Hertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources comprise a large population of compact objects with radio emission fully contained within the innermost regions of the host galaxy (< a few kpc). Spectral and kinematic age measurements indicate their young age (typically < thousands years and in some cases less a few hundred years). These sources provide the important insights to the initial phase of the jet formation, radio source growth, source evolution and the jet impact on the ISM in the very central regions of the host galaxy. We have obtained Chandra and XMM-Newton observations for a large sample of these sources over several observing cycles. Our most recent Chandra observations targeted Compact Symmetric Objects (CSO) associated with the nuclear regions of nearby galaxies. All these CSO have measured kinematic ages within 100-3000 year old. I will present the results of our ongoing observing program focusing on the high energy properties of these young sources.

  7. High Resolution Spectroscopy of the X-ray Photoionized Wind in Cygnus X-3 with the Chandra High Energy Transmission Grating Spectrometer

    CERN Document Server

    Paerels, F B S; Sako, M; Liedahl, D A; Brinkman, A C; Van der Meer, R L J; Kaastra, J S; Predehl, P; Paerels, Frits; Cottam, Jean; Sako, Masao; Liedahl, Duane A.

    2000-01-01

    We present a preliminary analysis of the 1--10 keV spectrum of the massiveX-ray binary Cyg X-3, obtained with the High Energy Transmission GratingSpectrometer on the Chandra X-ray Observatory. The source reveals a richlydetailed discrete emission spectrum, with clear signatures ofphotoionization-driven excitation. Among the spectroscopic novelties in the data are the first astrophysicaldetections of a number of He-like 'triplets' (Si, S, Ar) with emission lineratios characteristic of photoionization equilibrium, fully resolved narrowradiative recombination continua of Mg, Si, and S, the presence of the H-likeFe Balmer series, and a clear detection of a ~ 800 km/s large scale velocityfield, as well as a ~1500 km/s FWHM Doppler broadening in the source. Webriefly touch on the implications of these findings for the structure of theWolf-Rayet wind.

  8. The Chandra High Energy Transmission Grating Spectrometer probes the dusty warm absorber in the Seyfert 1 galaxy MCG--6-30-15

    OpenAIRE

    Lee, J. C.; Canizares, C. R.; Marshall, H. L.; Fabian, A. C.; Morales, R.; Schulz, N. S.; Iwasawa, K.

    2001-01-01

    The Chandra HETGS spectra of the Seyfert 1 galaxy MCG--6-30-15 show numerous narrow, unresolved (FWHM 0.48 keV (< 26 A). We attribute previous reports of an apparently highly redshifted O VII edge to the neutral Fe L absorption complex and th...

  9. The Chandra High Energy Transmission Grating Spectrometer probes the dusty warm absorber in the Seyfert 1 galaxy MCG--6-30-15

    CERN Document Server

    Lee, J C; Marshall, H L; Fabian, A C; Morales, R; Schulz, N S; Iwasawa, K

    2001-01-01

    The Chandra HETGS spectra of the Seyfert 1 galaxy MCG--6-30-15 show numerous narrow, unresolved (FWHM 0.48 keV (< 26 A). We attribute previous reports of an apparently highly redshifted O VII edge to the neutral Fe L absorption complex and the O VII resonance series (by transitions higher than He $\\gamma$; He $\\alpha,\\beta,\\gamma$ are also seen at lower energies). The implied dust column density needed to explain the FeI L edge feature agrees with that obtained from earlier reddening studies, which had already concluded that the dust should be associated with the ionized absorber (given the relatively lower observed X-ray absorption by cold gas). Our findings contradict the interpretation of Branduardi-Raymont et al. (2001), based on XMM-Newton RGS spectra, that this spectral region is dominated by highly relativistic soft X-ray line emission originating near the central black hole. Here we review these issues pertaining to the soft X-ray spectral features as addressed by Lee et al., (2001). (Details foun...

  10. High-Resolution Chandra X-ray Imaging and Spectroscopy of the Sigma Orionis Cluster

    OpenAIRE

    Skinner, S.L.; Sokal, K. R.; Cohen, D. H.; Gagne, M.; Owocki, S.P.; Townsend, R. D.

    2008-01-01

    We present results of a 90 ksec Chandra X-ray observation of the young sigma Orionis cluster (age ~3 Myr) obtained with the High Energy Transmission Grating Spectrometer. We use the high resolution grating spectrum and moderate resolution CCD spectrum of the massive central star sigma Ori AB (O9.5V + B0.5V) to test wind shock theories of X-ray emission and also analyze the high spatial resolution zero-order ACIS-S image of the central cluster region. Chandra detected 42 X-ray sources on the p...

  11. Chandra Opens New Line of Investigation on Dark Energy

    Science.gov (United States)

    2004-05-01

    Astronomers have detected and probed dark energy by applying a powerful, new method that uses images of galaxy clusters made by NASA's Chandra X-ray Observatory. The results trace the transition of the expansion of the Universe from a decelerating to an accelerating phase several billion years ago, and give intriguing clues about the nature of dark energy and the fate of the Universe. "Dark energy is perhaps the biggest mystery in physics," said Steve Allen of the Institute of Astronomy (IoA) at the University of Cambridge in England, and leader of the study. "As such, it is extremely important to make an independent test of its existence and properties." Abell 2029 Chandra X-ray Image of Abell 2029 Allen and his colleagues used Chandra to study 26 clusters of galaxies at distances corresponding to light travel times of between one and eight billion years. These data span the time when the Universe slowed from its original expansion, before speeding up again because of the repulsive effect of dark energy. "We're directly seeing that the expansion of the Universe is accelerating by measuring the distances to these galaxy clusters," said Andy Fabian also of the IoA, a co-author on the study. The new Chandra results suggest that the dark energy density does not change quickly with time and may even be constant, consistent with the "cosmological constant" concept first introduced by Albert Einstein. If so, the Universe is expected to continue expanding forever, so that in many billions of years only a tiny fraction of the known galaxies will be observable. More Animations Animation of the "Big Rip" If the dark energy density is constant, more dramatic fates for the Universe would be avoided. These include the "Big Rip," where dark energy increases until galaxies, stars, planets and eventually atoms are eventually torn apart. The "Big Crunch," where the Universe eventually collapses on itself, would also be ruled out. Chandra's probe of dark energy relies on the unique

  12. Chandra Survey of Radio-quiet, High-redshift Quasars

    CERN Document Server

    Bechtold, J; Shields, J; Czerny, B; Janiuk, A; Hamann, F; Aldcroft, T L; Elvis, M; Dobrzycki, A; Bechtold, Jill; Siemiginowska, Aneta; Shields, Joseph; Czerny, Bozena; Janiuk, Agnieszka; Hamann, Fred; Aldcroft, Thomas L.; Elvis, Martin; Dobrzycki, Adam

    2003-01-01

    We observed 17 optically-selected, radio-quiet high-redshift quasars with the Chandra Observatory ACIS, and detected 16 of them. The quasars have redshift between 3.70 and 6.28 and include the highest redshift quasars known. When compared to low-redshift quasars observed with ROSAT, these high redshift quasars are significantly more X-ray quiet. We also find that the X-ray spectral index of the high redshift objects is flatter than the average at lower redshift. These trends confirm the predictions of models where the accretion flow is described by a cold, optically-thick accretion disk surrounded by a hot, optically thin corona, provided the viscosity parameter alpha >= 0.02. The high redshift quasars have supermassive black holes with masses ~10^{10} M_{sun}, and are accreting material at ~0.1 the Eddington limit. We detect 10 X-ray photons from the z=6.28 quasar SDS 1030+0524, which may have a Gunn-Peterson trough and be near the redshift of reionization of the intergalactic medium. The X-ray data place an...

  13. High-resolution X-ray spectroscopy of Procyon by Chandra and XMM-Newton

    OpenAIRE

    Raassen, A.J.J.; Mewe, R.; Audard, M.; Guedel, M.; Behar, E; Kaastra, J.S.; Van Der Meer, R.L.J.; Foley, C. R.; Ness, J.-U.

    2002-01-01

    We report the analysis of the high-resolution soft X-ray spectrum of the nearby F-type star Procyon in the wavelength range from 5 to 175 Angstrom obtained with the Low Energy Transmission Grating Spectrometer (LETGS) on board Chandra and with the Reflection Grating Spectrometers (RGS) and the EPIC-MOS CCD spectrometers on board XMM-Newton. Line fluxes have been measured separately for the RGS and LETGS. Spectra have been fitted globally to obtain self-consistent temperatures, emission measur...

  14. High-Resolution Chandra X-ray Imaging and Spectroscopy of the Sigma Orionis Cluster

    CERN Document Server

    Skinner, S L; Cohen, D H; Gagné, M; Owocki, S P; Townsend, R D

    2008-01-01

    We present results of a 90 ksec Chandra X-ray observation of the young sigma Orionis cluster (age ~3 Myr) obtained with the High Energy Transmission Grating Spectrometer. We use the high resolution grating spectrum and moderate resolution CCD spectrum of the massive central star sigma Ori AB (O9.5V + B0.5V) to test wind shock theories of X-ray emission and also analyze the high spatial resolution zero-order ACIS-S image of the central cluster region. Chandra detected 42 X-ray sources on the primary CCD (ACIS-S3). All but five have near-IR or optical counterparts and about one-fourth are variable. Notable high-mass stellar detections are sigma Ori AB, the magnetic B star sigma Ori E, and the B5V binary HD 37525. Most of the other detections have properties consistent with lower mass K or M-type stars. We present the first X-ray spectrum of the unusual infrared source IRS1 located 3.3 arc-sec north of sigma Ori AB, which is likely an embedded T Tauri star whose disk/envelope is being photoevaporated by sigma Or...

  15. High School Students Discover Neutron Star Using Chandra and VLA Data

    Science.gov (United States)

    2000-12-01

    Three high school students, using data from NASA's Chandra X-ray Observatory and the National Science Foundation's Very Large Array (VLA), have found the first evidence of a neutron star in the nearby supernova remnant IC443, a system long studied by professional astronomers. This remarkable discovery has led the team to the national finals and a 1st place finish in the team competition at the Siemens-Westinghouse Science and Technology Competition held today in Washington, DC. Charles Olbert (age 18), Christopher Clearfield (age 18), and Nikolas Williams (age 16), all of the North Carolina School for Science and Mathematics (NCSSM) in Durham, NC, found a point-like source of X rays embedded in the remains of the stellar explosion, or supernova. Based on both the X-ray and radio data, the students determined that the central object in IC443 is most likely a young and rapidly rotating neutron star -- an object known as a "pulsar." "This is a really solid scientific finding," said Bryan Gaensler of the Massachusetts Institute of Technology, a noted pulsar expert who reviewed the paper for the team. "Everyone involved should be really proud of this accomplishment." Taking advantage of Chandra's superior angular resolution, the North Carolina students found the source embedded in IC443, a region known to be emitting particularly high-energy X rays. In a highly unusual situation, the students got access to the Chandra data from their science teacher, Dr. Jonathan Keohane. Keohane applied for the observation time while still associated with NASA's Goddard Space Flight Center. "The students really went through the whole analysis process themselves," said Keohane. "And, they even lived together all summer near the school to complete the research." In order to confirm the evidence from Chandra, the students turned to the National Radio Observatory's Dale Frail who gave the student team VLA data on IC443. While the radio data did not reveal any periodicity, the VLA

  16. High-resolution X-ray spectroscopy of Procyon by Chandra and XMM-Newton

    CERN Document Server

    Raassen, A J J; Audard, M; Güdel, M; Behar, E; Kaastra, J S; Van der Meer, R L J; Foley, C R; Ness, J U

    2002-01-01

    We report the analysis of the high-resolution soft X-ray spectrum of the nearby F-type star Procyon in the wavelength range from 5 to 175 Angstrom obtained with the Low Energy Transmission Grating Spectrometer (LETGS) on board Chandra and with the Reflection Grating Spectrometers (RGS) and the EPIC-MOS CCD spectrometers on board XMM-Newton. Line fluxes have been measured separately for the RGS and LETGS. Spectra have been fitted globally to obtain self-consistent temperatures, emission measures, and abundances. The total volume emission measure is ~4.1 x 10e50/cm3 with a peak between 1 and 3 MK. No indications for a dominant hot component (T > 4 MK) were found. We present additional evidence for the lack of a solar-type FIP-effect, confirming earlier EUVE results.

  17. Composition of the Chandra ACIS contaminant

    OpenAIRE

    Marshall, Herman L.; Tennant, Allyn; Grant, Catherine E.; Hitchcock, Adam P.; O'Dell, Steve; Plucinsky, Paul P.

    2003-01-01

    The Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Observatory is suffering a gradual loss of low energy sensitivity due to a buildup of a contaminant. High resolution spectra of bright astrophysical sources using the Chandra Low Energy Transmission Grating Spectrometer (LETGS) have been analyzed in order to determine the nature of the contaminant by measuring the absorption edges. The dominant element in the contaminant is carbon. Edges due to oxygen and fluorine are also dete...

  18. High-Resolution X-Ray Spectroscopy of the Seyfert 2 Galaxy Circinus with Chandra

    Science.gov (United States)

    Sambruna, Rita M.; Netzer, Hagai; Kaspi, Shai; Brandt, W. N.; Chartas, G.; Garmire, G. P.; Nousek, John A.; Weaver, K. A.

    2000-01-01

    Results from a 60 ks Chandra High Energy Transmission Grating Spectrometer (HETGS) observation of the nearby Seyfert 2 Circinus are presented. The spectrum shows a wealth of emission lines at both soft and hard X-rays, including lines of Ne, Mg, Si, S, Ar, Ca, and Fe, and a prominent Fe K(alpha) line at 6.4 keV. We identify several of the He-like components and measure several of the Lyman lines of the N-like ions. The lines' profiles are unresolved at the limited signal-to-noise ratio of the data. Our analysis of the zeroth-order image in a companion paper constrains the size of the emission region to be 20-60 pc, suggesting that emission within this volume is almost entirely due to the reprocessing of the obscured central source. Here we show that a model containing two distinct components can reproduce almost all the observed properties of this gas. The ionized component can explain the observed intensities of the ionized species, assuming twice-solar composition and an N is proportional r(exp -1.5) density distribution. The neutral component is highly concentrated, well within the 0.8" point source, and is responsible for almost all of the observed K(alpha) (6.4 keV) emission. Circinus seems to be different than Mkn 3 in terms of its gas distribution.

  19. 1WGAJ1226.9+3332: a high redshift cluster discovered by Chandra

    OpenAIRE

    Cagnoni, I.; Elvis, M.; Kim, D. -W.; Mazzotta, P.; Huang, J. -S.; Celotti, A.

    2001-01-01

    We report the detection of 1WGAJ1226.9+3332 as an arcminute scale extended X-ray source with the Chandra X-ray Observatory. The Chandra observation and R and K band imaging strongly support the identification of 1WGAJ1226.9+3332 as a high redshift cluster of galaxies, most probably at z=0.85 +- 0.15, with an inferred temperature kT =10 (+4;-3) keV and an unabsorbed luminosity (in a r=120" aperture) of 1.3 (+0.16;-0.14) x 1e45 erg/s (0.5-10 keV). This indication of redshift is also supported b...

  20. Predicting Chandra CCD Degradation with the Chandra Radiation Model

    Science.gov (United States)

    Minow, Joseph I.; Blackwell, William C.; DePasquale, Joseph M.; Grant, Catherine E.; O'Dell, Stephen L.; Plucinsky, Paul P.; Schwartz, Daniel A.; Spitzbart, Bradley D.; Wolk, Scott J.

    2008-01-01

    Not long after launch of the Chandra X-Ray Observatory, it was discovered that the Advanced CCD Imaging Spectrometer (ACIS) detector was rapidly degrading due to radiation. Analysis by Chandra personnel showed that this degradation was due to 10w energy protons (100 - 200 keV) that scattered down the optical path onto the focal plane. In response to this unexpected problem, the Chandra Team developed a radiation-protection program that has been used to manage the radiation damage to the CCDs. This program consists of multiple approaches - scheduled sating of the ACIS detector from the radiation environment during passage through radiation belts, real-time monitoring of space weather conditions, on-board monitoring of radiation environment levels, and the creation of a radiation environment model for use in computing proton flux and fluence at energies that damage the ACIS detector. This radiation mitigation program has been very successful. The initial precipitous increase in the CCDs' charge transfer inefficiency (CTI) resulting from proton damage has been slowed dramatically, with the front-illuminated CCDS having an increase in CTI of only 2.3% per year, allowing the ASIS detector's expected lifetime to exceed requirements. This paper concentrates on one aspect of the Chandra radiation mitigation program, the creation of the Chandra Radiation Model (CRM). Because of Chandra's highly elliptical orbit, the spacecraft spends most of its time outside of the trapped radiation belts that present the severest risks to the ACIS detector. However, there is still a proton flux environment that must be accounted for in all parts of Chandra's orbit. At the time of Chandra's launch there was no engineering model of the radiation environment that could be used in the outer regions of the spacecraft's orbit, so the CRM was developed to provide the flux environment of 100 - 200 keV protons in the outer magnetosphere, magnetosheath, and solar wind regions of geospace. This

  1. LOCALIZING INTEGRAL SOURCES WITH CHANDRA: X-RAY AND MULTI-WAVELENGTH IDENTIFICATIONS AND ENERGY SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Tomsick, John A.; Bodaghee, Arash [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Chaty, Sylvain; Rodriguez, Jerome [AIM (UMR-E 9005 CEA/DSM-CNRS-Universite Paris Diderot) Irfu/Service d' Astrophysique, Centre de Saclay, FR-91191 Gif-sur-Yvette Cedex (France); Rahoui, Farid [Astronomy Department, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States); Halpern, Jules [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027-6601 (United States); Kalemci, Emrah [Faculty of Engineering and Natural Sciences, Sabanc Latin-Small-Letter-Dotless-I University, Orhanl Latin-Small-Letter-Dotless-I -Tuzla, Istanbul 34956 (Turkey); Oezbey Arabaci, Mehtap, E-mail: jtomsick@ssl.berkeley.edu [Physics Department, Middle East Technical University, Ankara 06531 (Turkey)

    2012-08-01

    We report on Chandra observations of 18 hard X-ray (>20 keV) sources discovered with the INTEGRAL satellite near the Galactic plane. For 14 of the INTEGRAL sources, we have uncovered one or two potential Chandra counterparts per source. These provide soft X-ray (0.3-10 keV) spectra and subarcsecond localizations, which we use to identify counterparts at other wavelengths, providing information about the nature of each source. Despite the fact that all of the sources are within 5 Degree-Sign of the plane, four of the IGR sources are active galactic nuclei (AGNs; IGR J01545+6437, IGR J15391-5307, IGR J15415-5029, and IGR J21565+5948) and four others are likely AGNs (IGR J03103+5706, IGR J09189-4418, IGR J16413-4046, and IGR J16560-4958) based on each of them having a strong IR excess and/or extended optical or near-IR emission. We compare the X-ray and near-IR fluxes of this group of sources to those of AGNs selected by their 2-10 keV emission in previous studies and find that these IGR AGNs are in the range of typical values. There is evidence in favor of four of the sources being Galactic (IGR J12489-6243, IGR J15293-5609, IGR J16173-5023, and IGR J16206-5253), but only IGR J15293-5609 is confirmed as a Galactic source as it has a unique Chandra counterpart and a parallax measurement from previous optical observations that puts its distance at 1.56 {+-} 0.12 kpc. The 0.3-10 keV luminosity for this source is (1.4{sup +1.0}{sub -0.4}) Multiplication-Sign 10{sup 32} erg s{sup -1}, and its optical/IR spectral energy distribution is well described by a blackbody with a temperature of 4200-7000 K and a radius of 12.0-16.4 R{sub Sun }. These values suggest that IGR J15293-5609 is a symbiotic binary with an early K-type giant and a white dwarf accretor. We also obtained likely Chandra identifications for IGR J13402-6428 and IGR J15368-5102, but follow-up observations are required to constrain their source types.

  2. 1WGAJ1226.9+3332 a high redshift cluster discovered by Chandra

    CERN Document Server

    Cagnoni, I; Kim, D W; Mazzotta, P; Huang, J S; Celotti, A

    2001-01-01

    We report the detection of 1WGAJ1226.9+3332 as an arcminute scale extended X-ray source with the Chandra X-ray Observatory. The Chandra observation and R and K band imaging strongly support the identification of 1WGAJ1226.9+3332 as a high redshift cluster of galaxies, most probably at z=0.85 +- 0.15, with an inferred temperature kT =10 (+4;-3) keV and an unabsorbed luminosity (in a r=120" aperture) of 1.3 (+0.16;-0.14) x 1e45 erg/s (0.5-10 keV). This indication of redshift is also supported by the K and R band imaging, and is in agreement with the spectroscopic redshift of 0.89 found by Ebeling et al. (2001). The surface brightness profile is consistent with a beta-model with beta=0.770 +- 0.025, rc=(18.1 +-0.9)" (corresponding to 101 +- 5 kpc at z=0.89), and S(0)=1.02 +- 0.08 counts/arcsec**2. 1WGAJ1226.9+3332 was selected as an extreme X-ray loud source with FX/FV>60; this selection method, thanks to the large area sampled, seems to be a highly efficient method for finding luminous high z clusters of galaxi...

  3. Highly Clumpy Structure of the Thermal Composite Supernova Remnant 3C391 Unveiled by Chandra

    CERN Document Server

    Chen, Y; Slane, P O; Wang, Q D; Chen, Yang; Su, Yang; Slane, Patrick O.

    2005-01-01

    The nature of the internal thermal X-ray emission seen in ``thermal composite" supernova remnants is still uncertain. Chandra observation of the 3C391 shows a southeast-northwest elongated morphology and unveils a highly clumpy structure of the remnant. Detailed spatially resolved spectral analysis for the small-scale features reveals normal metal abundance and uniform temperature for the interior gas. The properties of the hot gas comparatively favor the cloudlet evaporation model as a main mechanism for the ``thermal composite" X-ray appearance, though radiative rim and thermal conduction may also be effective. A faint protrusion is found in Si and S lines out of the southwest radio border.

  4. High-Resolution X-ray and Ultraviolet Spectroscopy of the Complex Intrinsic Absorption in NGC 4051 with Chandra and HST

    OpenAIRE

    Collinge, M. J.; Brandt, W. N.; Kaspi, Shai; Crenshaw, D. Michael; Elvis, Martin; Kraemer, Steven B.; Reynolds, Christopher S.; Sambruna, Rita M.; Wills, Beverley J.

    2001-01-01

    We present the results from simultaneous observations of the Narrow-Line Seyfert 1 galaxy NGC 4051 with the Chandra High Energy Transmission Grating Spectrometer and the HST Space Telescope Imaging Spectrograph. The X-ray grating spectrum reveals absorption and emission lines from hydrogen-like and helium-like ions of O, Ne, Mg and Si. We resolve two distinct X-ray absorption systems: a high-velocity blueshifted system at -2340+/-130 km/s and a low-velocity blueshifted system at -600+/-130 km...

  5. NASA's Chandra Finds Black Holes Are "Green"

    Science.gov (United States)

    2006-04-01

    Black holes are the most fuel efficient engines in the Universe, according to a new study using NASA's Chandra X-ray Observatory. By making the first direct estimate of how efficient or "green" black holes are, this work gives insight into how black holes generate energy and affect their environment. The new Chandra finding shows that most of the energy released by matter falling toward a supermassive black hole is in the form of high-energy jets traveling at near the speed of light away from the black hole. This is an important step in understanding how such jets can be launched from magnetized disks of gas near the event horizon of a black hole. Illustration of Fuel for a Black Hole Engine Illustration of Fuel for a Black Hole Engine "Just as with cars, it's critical to know the fuel efficiency of black holes," said lead author Steve Allen of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University, and the Stanford Linear Accelerator Center. "Without this information, we cannot figure out what is going on under the hood, so to speak, or what the engine can do." Allen and his team used Chandra to study nine supermassive black holes at the centers of elliptical galaxies. These black holes are relatively old and generate much less radiation than quasars, rapidly growing supermassive black holes seen in the early Universe. The surprise came when the Chandra results showed that these "quiet" black holes are all producing much more energy in jets of high-energy particles than in visible light or X-rays. These jets create huge bubbles, or cavities, in the hot gas in the galaxies. Animation of Black Hole in Elliptical Galaxy Animation of Black Hole in Elliptical Galaxy The efficiency of the black hole energy-production was calculated in two steps: first Chandra images of the inner regions of the galaxies were used to estimate how much fuel is available for the black hole; then Chandra images were used to estimate the power required to produce

  6. The high-redshift (z>3) AGN population in the 4 Ms Chandra Deep Field South

    CERN Document Server

    Vito, F; Gilli, R; Comastri, A; Iwasawa, K; Brandt, W N; Alexander, D M; Brusa, M; Lehmer, B; Bauer, F E; Schneider, D P; Xue, Y Q; Luo, B

    2012-01-01

    We present results from a spectral analysis of a sample of high-redshift (z>3) X-ray selected AGN in the 4 Ms Chandra Deep Field South (CDF-S), the deepest X-ray survey to date. The sample is selected using the most recent spectroscopic and photometric information available in this field. It consists of 34 sources with median redshift z=3.7, 80 median net counts in the 0.5-7 keV band and median rest-frame absorption-corrected luminosity $L_{2-10 \\rmn{keV}}\\approx1.5\\times10^{44}\\rmn{erg} \\rmn{s^{-1}}$. Spectral analysis for the full sample is presented and the intrinsic column density distribution, corrected for observational biases using spectral simulations, is compared with the expectations of X-ray background (XRB) synthesis models. We find that $\\approx57$ per cent of the sources are highly obscured ($N_H>10^{23}\\rmn{cm^{-2}}$). Source number counts in the $0.5-2\\rmn{keV}$ band down to flux $F_{0.5-2 \\rmn{keV}}\\approx4\\times10^{-17}\\rmn{erg} \\rmn{s^{-1}cm^{-2}}$ are also presented. Our results are consis...

  7. Are there cool-core clusters at high-redshift? Chandra results and prospects with WFXT

    CERN Document Server

    Santos, Joana S; Rosati, Piero

    2010-01-01

    In this contribution we trace the evolution of cool-core clusters out to z~1.3 using high-resolution Chandra data of three representative cluster samples spanning different redshift ranges. Our analysis is based on the measurement of the surface brightness (SB) concentration, c_SB, which strongly anti-correlates with the central cooling time and allows us to characterize the cool-core strength in low S/N data. We confirm a negative evolution in the fraction of cool-core clusters with redshift, in particular for very strong cool-cores. Still, we find evidence for a large population of well formed cool-cores at z ~ 1. This analysis is potentially very effective in constraining the nature and the evolution of the cool-cores, once large samples of high-z clusters will be available. In this respect, we explore the potential of the proposed mission Wide Field X-ray Telescope (WFXT) to address this science case. We conclude that WFXT provides the best trade-off of angular resolution, sensitivity and covered solid an...

  8. High Spatial Resolution Spectroscopy of G292.0+1.8 with Chandra

    CERN Document Server

    Yang, Xue-Juan; Li, Shun-yu; Lu, Fang-Jun

    2014-01-01

    We present high spatial resolution X-ray spectroscopy of supernova remnant G292.0+1.8 with the {\\sl Chandra} observations. The X-ray emitting region of this remnant was divided into 25 $\\times$ 25 pixels with a scale of 20$\\arcsec$ $\\times$ 20$\\arcsec$ each. Spectra of 324 pixels were created and fitted with an absorbed one component non-equilibrium ionization model. With the spectral analysis results we obtained maps of absorbing column density, temperature, ionization age, and the abundances for O, Ne, Mg, Si, S, and Fe. The abundances of O, Ne and Mg show tight correlations between each other in the range of about two orders of magnitude, suggesting them all from explosive C/Ne burning. Meanwhile, the abundances of Si and S are also well correlated, indicating them to be the ashes of explosive explosive O-burning or incomplete Si-burbing. The Fe emission lines are not prominent among the whole remnant, and its abundance are significantly deduced, indicating that the reverse shock may have not propagated to...

  9. Dark matter and Modified Newtonian Dynamics in a sample of high-redshift galaxy clusters observed with Chandra

    OpenAIRE

    Blaksley, Carl; Bonamente, Massimiliano

    2009-01-01

    We compare the measurement of the gravitational mass of 38 high-redshift galaxy clusters observed by Chandra using Modified Newtonian Dynamics (MOND) and standard Newtonian gravity. Our analysis confirms earlier findings that MOND cannot explain the difference between the baryonic mass and the total mass inferred from the assumption of hydrostatic equilibrium. We also find that the baryon fraction at $r_{2500}$ using MOND is consistent with the Wilkinson Microwave Anisotropy Probe (WMAP) valu...

  10. M31 in the Chandra Era: A High Definition Movie of a Nearby Galaxy

    Science.gov (United States)

    Kong, Albert; di Stefano, Rosanne

    2009-09-01

    M31 has been a prime targets for all X-ray missions since the first detection in 1974. With its superb spatial resolution, Chandra is unique in resolving dense source regions and detecting faint sources. Since the launch of Chandra, M31 has been regularly observed. It is perhaps the only nearby galaxy which is observed by an X-ray telescope regularly throughout operation. With 10 years of observations, the center of M31 has been observed with Chandra for nearly 1 Msec. The X-ray skies of M31 not only consist of many transients and variables, globular cluster X-ray sources in M31 are also different from our Milky Way. They are in general more luminous and one of them may even host an intermediate-mass black hole. Supersoft and quasi-soft X-ray sources in M31 are the best kept secret to unlock the nature of the progenitor of Type Ia supernova. In this talk, I will review some of the important Chandra discoveries in M31 in the past 10 years.

  11. Chandra survey of nearby highly inclined disk galaxies - IV. New insights into the working of stellar feedback

    Science.gov (United States)

    Wang, Q. Daniel; Li, Jiangtao; Jiang, Xiaochuan; Fang, Taotao

    2016-04-01

    Galaxy evolution is regulated by the interplay between galactic discs and their surrounding medium. We study this interplay by examining how the galactic coronal emission efficiency of stellar feedback depends on the (surface and specific) star formation rates (SFRs) and other parameters for a sample of 52 Chandra-observed nearby highly inclined disc galaxies. We first measure the star-forming galactic disc sizes, as well as the SFRs of these galaxies, using data from the Wide-Field Infrared Survey Explorer, and then show that (1) the specific 0.5-2 keV luminosity of the coronal emission correlates with the specific SFR in a sub-linear fashion: on average, LX/LK∝(SFR/M*)Γ with Γ = 0.29 ± 0.12; (2) the efficiency of the emission LX/SFR decreases with increasing surface SFR (ISFR; Γ = -0.44 ± 0.12); and (3) the characteristic temperature of the X-ray-emitting plasma weakly correlates with ISFR (Γ = 0.08 ± 0.04). These results, somewhat surprising and anti-intuitive, suggest that (i) the linear correlation between LX and SFR, as commonly presented, is largely due to the correlation of these two parameters with galaxy mass; (ii) much of the mechanical energy from stellar feedback likely drives global outflows with little X-ray cooling and with a mass-loading efficiency decreasing fast with increasing ISFR (Γ ≲ -0.5); (iii) these outflows heat and inflate the medium around the galactic disks of massive galaxies, reducing its radiative cooling rate, whereas for relatively low-mass galaxies, the energy in the outflows is probably dissipated in regions far away from the galactic discs.

  12. Chandra High-resolution Spectroscopy of the Circumnuclear Matter in the Broad-line Radio Galaxy 3C 445

    Science.gov (United States)

    Reeves, J. N.; Gofford, J.; Braito, V.; Sambruna, R.

    2010-12-01

    We present evidence for X-ray line emitting and absorbing gas in the nucleus of the broad-line radio galaxy 3C 445. A 200 ks Chandra Low Energy Transmission Grating observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft X-ray spectrum, primarily from the He- and H-like ions of O, Ne, Mg, and Si. Radiative recombination emission is detected from O VII and O VIII, indicating that the emitting gas is photoionized. The He-like emission appears to be resolved into forbidden and intercombination line components, which implies a high density of >1010 cm-3, while the oxygen lines are velocity broadened with a mean width of ~2600 km s-1 (FWHM). The density and widths of the ionized lines indicate an origin of the gas on sub-parsec scales in the broad-line region. The X-ray continuum of 3C 445 is heavily obscured either by a partial coverer or by a photoionized absorber of column density N H = 2 × 1023 cm-2 and ionization parameter log ξ = 1.4 erg cm s-1. However, the view of the X-ray line emission is unobscured, which requires the absorber to be located at radii well within any parsec-scale molecular torus. Instead we suggest that the X-ray absorber in 3C 445 may be associated with an outflowing but clumpy accretion disk wind, with an observed outflow velocity of ~10, 000 km s-1.

  13. The High Resolution Chandra X-Ray Spectrum of 3C273

    Science.gov (United States)

    Fruscione, Antonella; Lavoie, Anthony (Technical Monitor)

    2000-01-01

    The bright quasar 3C273 was observed by Chandra in January 2000 for 120 ksec as a calibration target. It was observed with all detector- plus-grating combinations (ACIS+HETG, ACIS+LETG, and HRC+LETG) yielding an X-ray spectrum across the entire 0.1-10 keV band with unprecedented spectral resolution. At about 10 arcsec from the nucleus, an X-ray jet is also clearly visible and resolved in the Oth order images. While the jet is much fainter than the nuclear source, the Chandra spatial resolution allows, for the first time, spectral analysis of both components separately. We will present detailed spectral analysis with particular emphasis on possible absorption features and comparison with simultaneous BeppoSAX data.

  14. Localizing INTEGRAL Sources with Chandra: X-Ray and Multi-Wavelength Identifications and Energy Spectra

    CERN Document Server

    Tomsick, John A; Chaty, Sylvain; Rodriguez, Jerome; Rahoui, Farid; Halpern, Jules; Kalemci, Emrah; Arabaci, Mehtap Ozbey

    2012-01-01

    We report on Chandra observations of 18 hard X-ray (>20 keV) sources discovered with the INTEGRAL satellite near the Galactic plane. For 14 of the INTEGRAL sources, we have uncovered one or two potential Chandra counterparts per source. These provide soft X-ray (0.3-10 keV) spectra and sub-arcsecond localizations, which we use to identify counterparts at other wavelengths, providing information about the nature of each source. Despite the fact that all of the sources are within 5 degrees of the plane, four of the IGR sources are AGN (IGR J01545+6437, IGR J15391-5307, IGR J15415-5029, and IGR J21565+5948) and four others are likely AGN (IGR J03103+5706, IGR J09189-4418, IGR J16413-4046, and IGR J16560-4958) based on each of them having a strong IR excess and/or extended optical or near-IR emission. We compare the X-ray and near-IR fluxes of this group of sources to those of AGN selected by their 2-10 keV emission in previous studies and find that these IGR AGN are in the range of typical values. There is evide...

  15. Composition of the Chandra ACIS contaminant

    CERN Document Server

    Marshall, H L; Grant, C E; Hitchcock, A P; O'Dell, S; Plucinsky, P P; Marshall, Herman L.; Tennant, Allyn; Grant, Catherine E.; Hitchcock, Adam P.; Dell, Steve O'; Plucinsky, Paul P.

    2003-01-01

    The Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Observatory is suffering a gradual loss of low energy sensitivity due to a buildup of a contaminant. High resolution spectra of bright astrophysical sources using the Chandra Low Energy Transmission Grating Spectrometer (LETGS) have been analyzed in order to determine the nature of the contaminant by measuring the absorption edges. The dominant element in the contaminant is carbon. Edges due to oxygen and fluorine are also detectable. Excluding H, we find that C, O, and F comprise >80%, 7%, and 7% of the contaminant by number, respectively. Nitrogen is less than 3% of the contaminant. We will assess various candidates for the contaminating material and investigate the growth of the layer with time. For example, the detailed structure of the C-K absorption edge provides information about the bonding structure of the compound, eliminating aromatic hydrocarbons as the contaminating material.

  16. Thin fused silica optics for a high angular resolution and large collecting area X Ray telescope after Chandra

    Science.gov (United States)

    Pareschi, Giovanni; Citterio, Oberto; Civitani, Marta M; Basso, Stefano; Campana, Sergio; Conconi, Paolo; Ghigo, Mauro; Mattaini, Enrico; Moretti, Alberto; Parodi, Giancarlo; Tagliaferri, Gianpiero

    2014-08-01

    The implementation of an X-ray mission with high imaging capabilities, similar to those achieved with Chandra (SMART-X project, led by CfA together with other US institutes. This project is based on adjustable segments of thin foil mirrors with piezo-electric actuators, aiming to achieve an effective area >2 m2 at 1 keV and an angular resolution better than 1 arcsec HEW. Another attractive technology to realize an X-ray telescope with similar characteristics is being developed at NASA/Goddard. In this case the mirrors are based on Si substrates that are super-polished and figured starting from a bulky Si ingot, from which they are properly cut. Here we propose an alternative method based on precise direct grinding, figuring and polishing of thin (a few mm) glass shells with innovative deterministic polishing methods. This is followed by a final correction via ion figuring to obtain the desired accuracy. For this purpose, a temporary stiffening structure is used to support the shell from the polishing operations up to its integration in the telescope supporting structure. This paper deals with the technological process under development, the results achieved so far and some mission scenarios based on this kind of optics, aiming to achieve an effective area more than 10 times larger than Chandra and an angular resolution of 1 arcsec HEW on axis and of a few arcsec off-axis across a large field of view (1o in diameter).

  17. X-ray lighthouses of the high-redshift Universe. Probing the most luminous z>4 Palomar Digital Sky Survey Quasars with Chandra

    OpenAIRE

    Vignali, C.; Brandt, W. N.; Schneider, D. P.; Garmire, G.P.; Kaspi, S.

    2002-01-01

    We present the results from exploratory Chandra observations of nine high-z (z=4.1-4.5) optically selected quasars. These quasars, taken from the DPOSS, are among the optically most luminous z>4 quasars known (M_B=-28.4 to -30.2). All have been detected by Chandra in exposure times of 5-6 ks, tripling the number of highly luminous quasars with X-ray detections at z>4. These quasars' average broad-band SEDs are characterized by steeper aox values (=-1.81+/-0.03) than those of lower-luminosity,...

  18. Chandra grating spectroscopy of three hot white dwarfs

    OpenAIRE

    Adamczak, J.; Werner, K.; Rauch, T.; Schuh, S.; Drake, J. J.; Kruk, J. W.

    2012-01-01

    Context. High-resolution soft X-ray spectroscopic observations of single hot white dwarfs are scarce. With the Chandra Low-Energy Transmission Grating, we have observed two white dwarfs, one is of spectral type DA (LB1919) and the other is a non-DA of spectral type PG1159 (PG1520+525). The spectra of both stars are analyzed, together with an archival Chandra spectrum of another DA white dwarf (GD246). Aims. The soft X-ray spectra of the two DA white dwarfs are investigated in orde...

  19. Chandra X-Ray Observatory Observation of the High-Redshift Cluster MS 1054-0321

    CERN Document Server

    Jeltema, T E; Bautz, M W; Malm, M R; Donahue, M; Garmire, G P; Jeltema, Tesla E.; Canizares, Claude R.; Bautz, Mark W.; Malm, Michael R.; Donahue, Megan; Garmire, Gordon P.

    2001-01-01

    We observed MS 1054-0321, the highest redshift cluster of galaxies in the Einstein Medium Sensitivity Survey (EMSS), with the Chandra ACIS-S detector. We find the X-ray temperature of the cluster to be 10.4 +1.7 -1.5 keV, lower than, but statistically consistent with, the temperature inferred previously. This temperature agrees well with the observed velocity dispersion and that found from weak lensing. We are also able to make the first positive identification of an iron line in this cluster and find a value of 0.26 +/- 0.15 for the abundance relative to solar, consistent with early enrichment of the ICM. We confirm significant substructure in the form of two distinct clumps in the X-ray distribution. The eastern clump seems to coincide with the main cluster component. It has a temperature of 10.5 +3.4 -2.1 keV, approximately the same as the average spectral temperature for the whole cluster. The western clump is cooler, with a temperature of 6.7 +1.7 -1.2 and may be a subgroup falling into the cluster. Thou...

  20. High Resolution Chandra Spectroscopy of Gamma Cassiopeia (B0.5IVe)

    CERN Document Server

    Smith, M A; Gu, M F; Robinson, R D; Evans, N R; Schran, P G

    2004-01-01

    gamma Cas has long been famous for its unique hard X-ray characteristics. We report herein on a 53 ks Chandra HETGS observation of this target. An inspection of our spectrum shows that it is quite atypical for a massive star, with abnormally weak Fe XXV, XXVI lines, Ly-alpha lines of H-like species from Fe XVII, XXIII, XXIV, S XVI, Si XIV, Mg XII, Ne X, O VII, VIII, and N VII. Also, line ratios of the rif-triplet of for a few He-like ions XVII are consistent with the dominance of collisional atomic processes. Yet, the presence of Fe and Si fluorescence K features indicates that photoionization also occurs in nearby cold gas. The line profiles indicate a mean velocity at rest and a broadening of 500 km/s. A global fitting analysis of the line and continuum spectrum finds that there are 3-4 plasma emission components. The dominant hot (12 keV) component and has a Fe abundance of 0.22 solar. Some fraction of this component (10-30%) is heavily absorbed. The other 2-3 components, with temperatures 0.1, 0.4, 3 keV,...

  1. Chandra Images Provide New Vision of Cosmic Explosions

    Science.gov (United States)

    1999-09-01

    Images from NASA's Chandra X-ray Observatory released today reveal previously unobserved features in the remnants of three different supernova explosions. Two of the remnants G21.5-0.9 and PSR 0540-69 show dramatic details of the prodigious production of energetic particles by a rapidly rotating, highly magnetized neutron star, as well as the enormous shell structures produced by the explosions. The image of the third remnant, E0102-72, reveals puzzling spoke-like structures in its interior. G21.5-0.9, in the constellation of Scutum, is about 16,000 light years (1 light year = 6 trillion miles) from Earth. Chandra's image shows a bright nebula surrounded by a much larger diffuse cloud. Inside the inner nebula is a bright central source that is thought to be a rapidly rotating highly magnetized neutron star. A rotating neutron star acts like a powerful generator, creating intense electric voltages that accelerate electrons to speeds close to the speed of light. The total output of this generator is greater than a thousand suns. The fluffy appearance of the central nebula is thought to be due to magnetic field lines which constrain the motions of the high-energy electrons. "It's a remarkable image," said Dr. Patrick Slane of the Harvard-Smithsonian Center for Astrophysics. "Neither the inner core nor the outer shell has ever been seen before." "It is as though we have a set of Russian dolls, with structures embedded within structures," said Professor Gordon Garmire of Penn State University, and principal investigator of the Advanced CCD Imaging Spectrometer, the X-ray camera that was used to make two of the images. NASA's project scientist, Dr. Martin Weisskopf of the Marshall Space Flight Center said, "Chandra's capability to provide surprises and insights continues." PSR 0540-69 PSR 0540-69 The existence of a rotating neutron star, or pulsar, in the center of G21.5-0.9 is inferred from the appearance of the nebula and the energy distribution of X-rays and radio

  2. High-Resolution X-ray and Ultraviolet Spectroscopy of the Complex Intrinsic Absorption in NGC 4051 with Chandra and HST

    CERN Document Server

    Collinge, M J; Kaspi, S; Crenshaw, D M; Elvis, M; Krämer, S B; Reynolds, C S; Sambruna, R M; Wills, B J; Kaspi, Shai; Elvis, Martin; Kraemer, Steven B.; Reynolds, Christopher S; Sambruna, Rita M.; Wills, Beverley J.

    2001-01-01

    We present the results from simultaneous observations of the Narrow-Line Seyfert 1 galaxy NGC 4051 with the Chandra High Energy Transmission Grating Spectrometer and the HST Space Telescope Imaging Spectrograph. The X-ray grating spectrum reveals absorption and emission lines from hydrogen-like and helium-like ions of O, Ne, Mg and Si. We resolve two distinct X-ray absorption systems: a high-velocity blueshifted system at -2340+/-130 km/s and a low-velocity blueshifted system at -600+/-130 km/s. In the UV spectrum we detect strong absorption, mainly from C IV, N V and Si IV, that is resolved into as many as nine different intrinsic absorption systems with velocities between -650 km/s and 30 km/s. Although the low-velocity X-ray absorption is consistent in velocity with many of the UV absorption systems, the high-velocity X-ray absorption seems to have no UV counterpart. In addition to the absorption and emission lines, we also observe rapid X-ray variability and a state of low X-ray flux during the last ~15 k...

  3. Chandra high resolution spectroscopy of the circumnuclear matter in the Broad Line Radio Galaxy 3C445

    CERN Document Server

    Reeves, J N; Braito, V; Sambruna, R

    2010-01-01

    We present evidence for X-ray line emitting and absorbing gas in the nucleus of the Broad-Line Radio Galaxy (BLRG), 3C 445. A 200ks Chandra LETG observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft X-ray spectrum, primarily from the He and H-like ions of O, Ne, Mg and Si. Radiative recombination emission is detected from O VII and O VIII, indicating that the emitting gas is photoionized. The He-like emission appears to be resolved into forbidden and intercombination line components, which implies a high density of >10^{10} cm^{-3}, while the Oxygen lines are velocity broadened with a mean width of ~2600 km s^{-1} (FWHM). The density and widths of the ionized lines indicate an origin of the gas on sub-parsec scales in the Broad Line Region (BLR).The X-ray continuum of 3C 445 is heavily obscured either by a partial coverer or by a photoionized absorber of column density N_{H}=2x10^{23} cm^{-2} and ionization parameter log(xi)=1.4 erg cm s^{-1}. However the view of the ...

  4. The Chandra X-Ray Observatory: Progress Report and Highlights

    CERN Document Server

    Weisskopf, Martin C

    2012-01-01

    Over the past 13 years, the Chandra X-ray Observatory's ability to provide high resolution X-ray images and spectra have established it as one of the most versatile and powerful tools for astrophysical research in the 21st century. Chandra explores the hot, x-ray-emitting regions of the universe, observing sources with fluxes spanning more than 10 orders of magnitude, from the X-ray brightest, Sco X-1, to the faintest sources in the Chandra Deep Field South survey. Thanks to its continuing operational life, the Chandra mission now also provides a long observing baseline which, in and of itself, is opening new research opportunities. In addition, observations in the past few years have deepened our understanding of the co-evolution of supermassive black holes and galaxies, the details of black hole accretion, the nature of dark energy and dark matter, the details of supernovae and their progenitors, the interiors of neutron stars, the evolution of massive stars, and the high-energy environment of protoplanetar...

  5. Highlights and Discoveries from the Chandra X-ray Observatory

    CERN Document Server

    Tananbaum, H; Tucker, W; Wilkes, B; Edmonds, P

    2014-01-01

    Within 40 years of the detection of the first extrasolar X-ray source in 1962,NASA's Chandra X-ray Observatory has achieved an increase in sensitivity of 10 orders of magnitude, comparable to the gain in going from naked-eye observations to the most powerful optical telescopes over the past 400 years. Chandra is unique in its capabilities for producing sub-arcsecond X-ray images with 100-200 eV energy resolution for energies in the range 0.08high precision, detecting extremely faint sources, and obtaining high resolution spectra of selected cosmic phenomena. The extended Chandra mission provides a long observing baseline with stable and well-calibrated instruments, enabling temporal studies over time-scales from milliseconds to years. In this report we present a selection of highlights that illustrate how observations using Chandra, sometimes alone, but often in conjunction with other telescopes, have deepened, and in some instances revolutionized, our understanding ...

  6. Faint high-redshift AGN in the Chandra Deep Field South: the evolution of the AGN luminosity function and black hole demography

    CERN Document Server

    Fiore, F; Grazian, A; Menci, N; Shankar, F; Santini, P; Piconcelli, E; Koekemoer, A M; Fontana, A; Boutsia, K; Castellano, M; Lamastra, A; Malacaria, C; Feruglio, C; Mathur, S; Miller, N; Pannella, M

    2011-01-01

    We present detection and analysis of faint X-ray sources in the Chandra deep field south (CDFS) using the 4 Msec Chandra observation and adopting a new detection algorithm, based on a targeted search at the position of known high-z galaxies. This optimized technique results in the identification of 54 z>3 AGNs, 29 of which are new detections. Applying stringent completeness criteria, we derive AGN luminosity functions in the redshift bins 3-4, 4-5 and >5.8 and for 42.753 (18+17-10%). Their optical counterparts are not strongly reddened and we thus conclude that the size of the X-ray absorber is likely smaller than the dust sublimation radius. We finally report the discovery of a highly star-forming galaxy at z=3.47. If confirmed, this would be one of the farthest objects in which stellar sources are detected in X-rays.

  7. Chandra survey of nearby highly inclined disk galaxies -- IV: New insights into the working of stellar feedback

    CERN Document Server

    Wang, Q Daniel; Jiang, Xiaochuan; Fang, Taotao

    2015-01-01

    Galaxy evolution is regulated by the interplay between galactic disks and their surrounding medium. We study this interplay by examining how the galactic coronal emission efficiency of stellar feedback depends on the (surface and specific) star formation rates (SFRs) and other parameters for a sample of 52 Chandra-observed nearby highly inclined disk galaxies. We first measure the star forming galactic disk sizes, as well as the SFRs of these galaxies, using data from the Wide-Field Infrared Survey Explorer, and then show that 1) the specific 0.5-2~keV luminosity of the coronal emission correlates with the specific SFR in a {\\sl sub-linear} fashion: on average, $L_X/L_K \\propto (SFR/M_*)^{\\Gamma}$ with $\\Gamma =0.29\\pm0.12$; 2) the efficiency of the emission $ L_X/SFR$ decreases with increasing surface SFR ($I_{SFR}$; $\\Gamma = -0.44\\pm0.12$); and 3) the characteristic temperature of the X-ray-emitting plasma weakly correlates with $I_{SFR}$ ($\\Gamma = 0.08\\pm0.04$). These results, somewhat surprising and ant...

  8. Physical properties of the interstellar medium using high-resolution Chandra spectra: O K-edge absorption

    Energy Technology Data Exchange (ETDEWEB)

    Gatuzz, E.; Mendoza, C. [Centro de Física, Instituto Venezolano de Investigaciones Científicas (IVIC), P.O. Box 20632, Caracas 1020A (Venezuela, Bolivarian Republic of); García, J. [Harvard-Smithsonian Center for Astrophysics, MS-6, 60 Garden Street, Cambridge, MA 02138 (United States); Kallman, T. R. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bautista, M. A.; Gorczyca, T. W., E-mail: egatuzz@ivic.gob.ve, E-mail: claudio@ivic.gob.ve, E-mail: javier@head.cfa.harvard.edu, E-mail: manuel.bautista@wmich.edu, E-mail: thomas.gorczyca@wmich.edu, E-mail: timothy.r.kallman@nasa.gov [Department of Physics, Western Michigan University, Kalamazoo, MI 49008 (United States)

    2014-08-01

    Chandra high-resolution spectra toward eight low-mass Galactic binaries have been analyzed with a photoionization model that is capable of determining the physical state of the interstellar medium. Particular attention is given to the accuracy of the atomic data. Hydrogen column densities are derived with a broadband fit that takes into account pileup effects, and in general are in good agreement with previous results. The dominant features in the oxygen-edge region are O I and O II Kα absorption lines whose simultaneous fits lead to average values of the ionization parameter of log ξ = –2.90 and oxygen abundance of A{sub O} = 0.70. The latter is given relative to the standard by Grevesse and Sauval, but rescaling with the revision by Asplund et al. would lead to an average abundance value fairly close to solar. The low average oxygen column density (N{sub O} = 9.2 × 10{sup 17} cm{sup –2}) suggests a correlation with the low ionization parameters, the latter also being in evidence in the column density ratios N(O II)/N(O I) and N(O III)/N(O I) that are estimated to be less than 0.1. We do not find conclusive evidence for absorption by any other compound but atomic oxygen in our oxygen-edge region analysis.

  9. Chandra Catches Cannibal Galaxy in the Act

    Science.gov (United States)

    2000-07-01

    NASA's Chandra X-ray Observatory image of Perseus A provides new insight into how this supergiant galaxy has grown by cannibalizing other galaxies and gas in the vicinity. For the first time astronomers see an X-ray shadow cast by a smaller galaxy as its gas is being stripped away by the enormous galaxy. The research was reported by Professor Andrew Fabian of the Institute of Astronomy, Cambridge, England on June 7 at the 196th National Meeting of the American Astronomical Society, in Rochester, NY. Other members of the research team are Jeremy Sanders, Stefano Ettori, Steve Allen, Carolin Crawford, Kazushi Iwasawa, and Roderick Johnstone of the Institute of Astronomy, Gregory Taylor on the National Radio Astronomy Observatory, Socorro, NM, and Patrick Ogle of the Massachusetts Institute of Technology, Cambridge, MA. Perseus A, or NGC 1275, is in the center of a large galaxy cluster 320 million light years from Earth. The cluster, which contains thousands of galaxies and enough gas to make thousands more, is one of the largest gravitationally bound objects in the universe. Over the eons, Perseus A has accumulated hundreds of billions of stars to become one of the most massive known galaxies as gas and galaxies have been pulled inward by gravity. The Chandra observation shows a region of hot gas that extends over several hundred thousand light years. The gas in the outer portion of the cluster has a temperature of 70 million degrees. The cluster gas cools gradually and settles toward the center of the cluster. A galaxy with "only" about 20 billion stars is falling into Perseus A (located at two o'clock from the center of the image) and appears as a small dark patch due to absorption of X rays by cool gas in the infalling galaxy. Another larger hole seen further out is thought to be due to a bubble of high-energy particles ejected in an explosion from Perseus A hundreds of millions of years ago. These outbursts are presumably fueled by matter releasing tremendous

  10. THE CHANDRA MULTI-WAVELENGTH PROJECT: OPTICAL SPECTROSCOPY AND THE BROADBAND SPECTRAL ENERGY DISTRIBUTIONS OF X-RAY-SELECTED AGNs

    International Nuclear Information System (INIS)

    From optical spectroscopy of X-ray sources observed as part of the Chandra Multi-wavelength Project (ChaMP), we present redshifts and classifications for a total of 1569 Chandra sources from our targeted spectroscopic follow-up using the FLWO/1.5 m, SAAO/1.9 m, WIYN 3.5 m, CTIO/4 m, KPNO/4 m, Magellan/6.5 m, MMT/6.5 m, and Gemini/8 m telescopes, and from archival Sloan Digital Sky Survey (SDSS) spectroscopy. We classify the optical counterparts as 50% broad-line active galactic nuclei (AGNs), 16% emission line galaxies, 14% absorption line galaxies, and 20% stars. We detect QSOs out to z ∼ 5.5 and galaxies out to z ∼ 3. We have compiled extensive photometry, including X-ray (ChaMP), ultraviolet (GALEX), optical (SDSS and ChaMP-NOAO/MOSAIC follow-up), near-infrared (UKIDSS, Two Micron All Sky Survey, and ChaMP-CTIO/ISPI follow-up), mid-infrared (WISE), and radio (FIRST and NVSS) bands. Together with our spectroscopic information, this enables us to derive detailed spectral energy distributions (SEDs) for our extragalactic sources. We fit a variety of template SEDs to determine bolometric luminosities, and to constrain AGNs and starburst components where both are present. While ∼58% of X-ray Seyferts (1042 erg s–1 2–10keV 44 erg s–1) require a starburst event (>5% starburst contribution to bolometric luminosity) to fit observed photometry only 26% of the X-ray QSO (L2–10keV >1044 erg s–1) population appear to have some kind of star formation contribution. This is significantly lower than for the Seyferts, especially if we take into account torus contamination at z > 1 where the majority of our X-ray QSOs lie. In addition, we observe a rapid drop of the percentage of starburst contribution as X-ray luminosity increases. This is consistent with the quenching of star formation by powerful QSOs, as predicted by the merger model, or with a time lag between the peak of star formation and QSO activity. We have tested the hypothesis that there should be a

  11. Chandra High Resolution Spectroscopy of the Circumnuclear Matter in the Broad Line Radio Galaxy, 3C 445

    Science.gov (United States)

    Reeves, J. N.; Gofford, J.; Braito, V.; Sambruna, R.

    2010-01-01

    We present evidence for X-ray line emitting and absorbing gas in the nucleus of the Broad-Line Radio Galaxy (BLRG), 3C445. A 200 ks Chandra LETG observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft X-ray spectrum, primarily from the He and H-like ions of O, Ne, Mg and Si. Radiative recombination emission is detected from O VII and O VIII, indicating that the emitting gas is photoionized. The He-like emission appears to be resolved into forbidden and intercombination line components, which implies a high density of greater than 10(sup 10) cm(sup -3), while the lines are velocity broadened with a mean width of 2600 km s(sup -1). The density and widths of the ionized lines indicate an origin of the gas on sub-parsec scales in the Broad Line Region (BLR). The X-ray continuum of 3C 445 is heavily obscured by a photoionized absorber of column density N(sub H) = 2 x 10(sup 23) cm(sup -2) and ionization parameter log xi = 1.4 erg cm s(sup -1). However the view of the X-ray line emission is unobscured, which requires the absorber to be located at radii well within any parsec scale molecular torus. Instead we suggest that the X-ray absorber in 3C 445 may be associated with an outflowing, but clumpy accretion disk wind, with an observed outflow velocity of approximately 10000 km s(sup -1).

  12. 75 FR 7471 - Chandra Coffee and Rabun Boatworks, Complainants v. Georgia Power Company, Respondent; Notice of...

    Science.gov (United States)

    2010-02-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Chandra Coffee and Rabun Boatworks, Complainants v. Georgia Power Company... January 8, 2010, Chandra Coffee and Rabun Boatworks (Complainants) filed with the Federal...

  13. Composition of the Chandra ACIS Contaminant

    Science.gov (United States)

    Marshall, Herman; Tennant, Allyn; Grant, Catherine; Hitchcock, Adam; ODell, Steve; Plucinsky, Paul

    2003-01-01

    The Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Observatory is suffering a gradual loss of low energy sensitivity due to a buildup of a contaminant. High resolution spectra of bright astrophysical sources using the Chandra Low Energy Transmission Grating Spectrometer (LETGS) have been analyzed in order to determine the nature of the contaminant by measuring the absorption edges. The dominant element in the contaminant is carbon. Edges due to oxygen and fluorine are also detectable. We can place stringent limits on nitrogen and high Z elements such as AI, Si, and Mg. Not including H, we find that C, O, and F comprise less than 80%, 7%, and 7% of the contaminant by number, respectively, Nitrogen is less than 3% of the contaminant. We will assess various candidates for the contaminating material and the time dependence. For example, the detailed structure of the absorption edges provides information about the bonding structure of the compound, eliminating aromatic hydrocarbons as the contaminating material.

  14. THE POPULATION OF HIGH-REDSHIFT ACTIVE GALACTIC NUCLEI IN THE CHANDRA-COSMOS SURVEY

    International Nuclear Information System (INIS)

    We present the high-redshift (3 phot phot + 1σ > 3. Eighty-one sources are selected in the 0.5-2 keV band, fourteen are selected in the 2-10 keV and six in the 0.5-10 keV bands. We sample the high-luminosity (log L(2-10keV) > 44.15 erg s–1) space density up to z ∼ 5 and a fainter luminosity range (43.5 erg s–1 (2-10keV) –1) than previous studies, up to z = 3.5. We weighted the contribution to the number counts and the space density of the sources with photometric redshift by using their probability of being at z > 3. We find that the space density of high-luminosity AGNs declines exponentially at all the redshifts, confirming the trend observed for optically selected quasars. At lower luminosity, the measured space density is not conclusive, and a larger sample of faint sources is needed. Comparisons with optical luminosity functions and black hole formation models are presented together with prospects for future surveys.

  15. Contributions of the NASA's Chandra X-Ray Observatory

    Science.gov (United States)

    Weisskopf, Martin C.

    2011-01-01

    NASA's Chandra X-ray Observatory performed its first observations over a decade ago. Chandra's spectacular images and detailed spectra of astrophysical systems ranging from solar system objects to distant galaxies and galaxy clusters have provided information on such diverse topics as the properties of planetary and cometary atmospheres, stellar formation and demise, black hole-galaxy-cluster interactions, and properties of dark matter and dark energy. This presentation highlights some discoveries made with Chandra and briefly discusses future prospects.

  16. The BMW-Chandra Serendipitous Source Catalog

    Science.gov (United States)

    Romano, P.; Campana, S.; Mignani, R. P.; Moretti, A.; Mottini, M.; Panzera, M. R.; Tagliaferri, G.

    2004-08-01

    We present the BMW-Chandra source catalog drawn from all Chandra ACIS-I pointed observations with an exposure time in excess of 10 ks public as of March 2003 (136 observations). Using the wavelet detection algorithm developed by Lazzati et al. (1999) and Campana et al. (1999), which can characterize point-like as well as extended sources, we identified 21325 sources. Among them, 16758 are serendipitous, i.e. not associated with the targets of the pointings, and do not require a non-automated analysis. This makes our catalog the largest compilation of Chandra sources to date. The 0.5--10 keV absorption corrected fluxes of these sources range from ˜ 3× 10-16 to 9×10-12 erg cm-2 s-1 with a median of 7× 10-15 erg cm-2 s-1. The catalog consists of count rates and relative errors in three energy bands (total, 0.5--7 keV; soft, 0.5--2 keV; and hard band, 2--7 keV), and source positions relative to the highest signal-to-noise detection among the three bands. The wavelet algorithm also provides an estimate of the extension of the source which we refined with a σ -clipping method. We report on the main properties of the sources in our catalog, such as sky coverage ( ˜ 8 deg2 at a limiting flux of ˜ 10-13 erg cm-2 s-1) and cosmological log N--log S for a subset at high Galactic latitude (∣ b ∣ > 20o) for a flux as low as ˜ 1.5 × 10-15 erg cm-2 s-1. Support for this work was provided by the Italian MIUR.

  17. The CHANDRA HETGS X-ray Grating Spectrum of Eta Carinae

    Science.gov (United States)

    Corcoran, M. F.; Swank, J. H.; Petre, R.; Ishibashi, K.; Davidson, K.; Townsley, L.; Smith, R.; White, S.; Viotti, R.; Damineli, A.; White, Nicholas E. (Technical Monitor)

    2001-01-01

    Eta Carinae may be the most massive and luminous star in the Galaxy and is suspected to be a massive, colliding wind binary system. The CHANDRA X-ray observatory has obtained a calibrated, high-resolution X-ray spectrum of the star uncontaminated by the nearby extended soft X-ray emission. Our 89 ksec CHANDRA observation with the High Energy Transmission Grating Spectrometer (HETGS) shows that the hot gas near the star is non-isothermal. The temperature distribution may represent the emission on either side of the colliding wind bow shock, effectively 'resolving' the shock. If so, the pre-shock wind velocities are approximately 700 and 1800 km/s in our analysis, and these velocities may be interpreted as the terminal velocities of the winds from 71 Carinae and from the hidden companion star. The forbidden-to-intercombination line ratios for the He-like ions of S, Si, and Fe are large, indicating that the line forming region lies far from the stellar photosphere. The iron fluorescent line at 1.93 angstroms, first detected by ASCA, is clearly resolved from the thermal iron line in the CHANDRA grating spectrum. The Fe fluorescent line is weaker in our CHANDRA observation than in any of the ASCA spectra. The CHANDRA observation also provides the first high-time resolution lightcurve of the uncontaminated stellar X-ray emission from 77 Carinae and shows that there is no significant, coherent variability during the CHANDRA observation. The 77 Carinae CHANDRA grating spectrum is unlike recently published X-ray grating spectra of single massive stars in significant ways and is generally consistent with colliding wind emission in a massive binary.

  18. The Chandra/HETG view of NGC 1365 in a Compton-thick state

    OpenAIRE

    Nardini, E.; Gofford, J; Reeves, JN; Braito, V.; Risaliti, G.; Costa, M.

    2015-01-01

    We present the analysis of a Chandra High-Energy Transmission Grating (HETG) observation of the local Seyfert galaxy NGC 1365. The source, well known for its dramatic X-ray spectral variability, was caught in a reflection-dominated, Compton-thick state. The high spatial resolution afforded by Chandra allowed us to isolate the soft X-ray emission from the active nucleus, neglecting most of the contribution from the kpc-scale starburst ring. The HETG spectra thus revealed a wealth of He- and H-...

  19. The CHANDRA HETGS X-ray Grating Spectrum of Eta Car

    OpenAIRE

    Corcoran, M. F; Swank, J.H.; Petre, R.; Ishibashi, K.; Davidson, K.; Townsley, L.; Smith, R.; S. White; Viotti, R; A. Damineli

    2001-01-01

    Eta Car may be the most massive and luminous star in the Galaxy and is suspected to be a massive, colliding wind binary system. The CHANDRA X-ray observatory has obtained a calibrated, high-resolution X-ray spectrum of the star uncontaminated by the nearby extended soft X-ray emisssion. Our 89 ksec CHANDRA observation with the High Energy Transmission Grating Spectrometer (HETGS) shows that the hot gas near the star is non-isothermal. The temperature distribution may represent the emission on...

  20. HST/Acs Weak-Lensing and Chandra X-Ray Studies of the High-Redshift Cluster MS 1054-0321

    CERN Document Server

    Jee, M J; Ford, H C; Blakeslee, J P; Illingworth, G D; Coe, D A; Tran, K V H

    2005-01-01

    We present Hubble Space Telescope/Advanced Camera for Surveys (ACS) weak-lensing and Chandra X-ray analyses of MS 1054-0321 at z=0.83, the most distant and X-ray luminous cluster in the Einstein Extended Medium-Sensitivity Survey (EMSS). The high-resolution mass reconstruction through ACS weak-lensing reveals the complicated dark matter substructure in unprecedented detail, characterized by the three dominant mass clumps with the four or more minor satellite groups within the current ACS field. The direct comparison of the mass map with the Chandra X-ray image shows that the eastern weak-lensing substructure is not present in the X-ray image and, more interestingly, the two X-ray peaks are displaced away from the hypothesized merging direction with respect to the corresponding central and western mass clumps, possibly because of ram pressure. In addition, as observed in our previous weak-lensing study of another high-redshift cluster CL 0152-1357 at z=0.84, the two dark matter clumps of MS 1054-0321 seem to b...

  1. Chandra and XMM–Newton Observations of H2O Maser Galaxy Mrk 266

    Indian Academy of Sciences (India)

    J. Wang; J. S. Zhang; J. H. Fan

    2011-03-01

    For H2O megamaser galaxy Mrk 266, its Chandra and XMM–Newton data are analyzed here. It shows existence of two obscured nuclei (separation is ∼ 5''). Our preferred model, the high energy reflected model can fit the hard component of both nuclei spectra well.

  2. Chandra Associates Pulsar and Historic Supernova

    Science.gov (United States)

    2001-01-01

    SAN DIEGO -- Scientists using NASA’s Chandra X-ray Observatory have found new evidence that a pulsar in the constellation of Sagittarius was created when a massive star exploded, witnessed by Chinese astronomers in the year 386 AD. If confirmed, this will be only the second pulsar to be clearly associated with a historic event. These results were presented today by Victoria Kaspi and Mallory Roberts of McGill University at the American Astronomical Society meeting. Also participating in the research were Gautum Vasisht from the Jet Propulsion Laboratory, Eric Gotthelf from Columbia University, Michael Pivovaroff from Therma-Wave, Inc., and Nobuyuki Kawai from the Institute of Physical and Chemical Research, Japan. The scientists used Chandra to locate the pulsar exactly at the geometric center of the supernova remnant known as G11.2-0.3. This location provides very strong evidence that the pulsar, a neutron star that is rotating 14 times a second, was formed in the supernova of 386 AD, and therefore has an age of 1615 years. "Determining the true ages of astronomical objects is notoriously difficult, and for this reason, historical records of supernovas are of great importance,"said Kaspi."In roughly the past 2,000 years, fewer than 10 reports of probable supernovae have been archived mostly by Asian astronomers. Of those handful, the remnant of 1054 AD, the Crab Nebula, was until now the only pulsar whose birth could be associated with a historic event - and, hence, the only neutron star that has a firm age." Between mid-April and mid-May in the year 386 AD, a young "guest star", presumably a supernova, was recorded by Chinese observers in the direction of the sky now known as the constellation of Sagittarius. In the 1970s, radio astronomers discovered an expanding nebula of gas and high-energy particles, called G11.2-0.3, that is believed to be the remnant of that explosion. In 1997, a team of X-ray astronomers used Japan’s ASCA satellite to discover a pulsar

  3. Chandra Data Reveal Rapidly Whirling Black Holes

    Science.gov (United States)

    2008-01-01

    A new study using results from NASA's Chandra X-ray Observatory provides one of the best pieces of evidence yet that many supermassive black holes are spinning extremely rapidly. The whirling of these giant black holes drives powerful jets that pump huge amounts of energy into their environment and affects galaxy growth. A team of scientists compared leading theories of jets produced by rotating supermassive black holes with Chandra data. A sampling of nine giant galaxies that exhibit large disturbances in their gaseous atmospheres showed that the central black holes in these galaxies must be spinning at near their maximum rates. People Who Read This Also Read... NASA’s Swift Satellite Catches First Supernova in The Act of Exploding Black Holes Have Simple Feeding Habits Jet Power and Black Hole Assortment Revealed in New Chandra Image Erratic Black Hole Regulates Itself "We think these monster black holes are spinning close to the limit set by Einstein's theory of relativity, which means that they can drag material around them at close to the speed of light," said Rodrigo Nemmen, a visiting graduate student at Penn State University, and lead author of a paper on the new results presented at American Astronomical Society in Austin, Texas. The research reinforces other, less direct methods previously used which have indicated that some stellar and supermassive black holes are spinning rapidly. According to Einstein's theory, a rapidly spinning black hole makes space itself rotate. This effect, coupled with gas spiraling toward the black hole, can produce a rotating, tightly wound vertical tower of magnetic field that flings a large fraction of the inflowing gas away from the vicinity of the black hole in an energetic, high-speed jet. Computer simulations by other authors have suggested that black holes may acquire their rapid spins when galaxies merge, and through the accretion of gas from their surroundings. "Extremely fast spin might be very common for large

  4. The First Chandra Field

    Energy Technology Data Exchange (ETDEWEB)

    Weisskopf, Martin C.; /NASA, Marshall; Aldcroft, Thomas L.; /Harvard-Smithsonian Ctr. Astrophys.; Cameron, Robert A.; /Harvard-Smithsonian Ctr. Astrophys. /SLAC; Gandhi,; Foellmi, Cedric; /European Southern Obs., Chile; Elsner, Ronald F.; /NASA, Marshall; Patel, Sandeep K.; /USRA, Huntsville; Wu, Kinwah; /Mullard Space Sci. Lab.; O' Dell, Stephen; /NASA, Marshall

    2005-09-09

    Before the official first-light images, the Chandra X-ray Observatory obtained an X-ray image of the field to which its focal plane was first exposed. We describe this historic observation and report our study of the first Chandra field. Chandra's Advanced CCD Imaging Spectrometer (ACIS) detected 15 X-ray sources, the brightest being dubbed ''Leon X-1'' to honor the Chandra Telescope Scientist, Leon Van Speybroeck. Based upon our analysis of the X-ray data and spectroscopy at the European Southern Observatory (ESO; La Silla, Chile), we find that Leon X-1 is a Type-1 (unobscured) active galactic nucleus (AGN) at a redshift z = 0.3207. Leon X-1 exhibits strong Fe II emission and a broad-line Balmer decrement that is unusually flat for an AGN. Within the context of the Eigenvector-1 correlation space, these properties suggest that Leon X-1 may be a massive ({ge} 10{sup 9} M{sub {circle_dot}}) black hole, accreting at a rate approaching its Eddington limit.

  5. Chandra Captures Flare From Brown Dwarf

    Science.gov (United States)

    2000-07-01

    only 16 light years from Earth. The absence of X-rays from LP 944-20 during the non-flaring period is in itself a significant result. It sets the lowest limit on steady X-ray power produced by a brown dwarf, and shows that the million degree Celsius upper atmospheres, or coronas, cease to exist as the surface temperature of a brown dwarf cools below about 2500 degrees Celsius. "This is an important confirmation of the trend that hot gas in the atmospheres of lower mass stars is produced only in flares," said Professor Lars Bildsten of the University of California, Santa Barbara, also a member of the team. Brown dwarfs have too little mass to sustain significant nuclear reactions in their cores. Their primary source of energy is the release of gravitational energy as they slowly contract. They are very dim ­ less than a tenth of a percent as luminous as the Sun -- and of great interest to astronomers because they are poorly understood and probably a very common class of objects that are intermediate between normal stars and giant planets. The 12-hour observation of LP 944-20 was made on December 15, 1999, using the Advanced CCD Imaging Spectrometer (ACIS). The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF) are available at the Internet sites listed above.

  6. Chandra Observes Cloud Powered by Black Hole in Distant Galaxy

    Science.gov (United States)

    2000-06-01

    NASA's Chandra X-ray Observatory has shown that a large gas cloud is being blasted by X rays from the vicinity of a giant black hole which lurks in its center. The observation is of special interest because it shows the disruptive effects that a massive black hole can have over thousands of light years. The results are being presented today by Drs. Patrick M. Ogle, Herman L. Marshall, Julia C. Lee, and Claude Canizares of the Massachusetts Institute of Technology (MIT), Cambridge, at the 196th national meeting of the American Astronomical Society in Rochester, NY. The observation also demonstrates that the searchlight beam of X rays from the black hole can be used to probe the environment around a black hole. The galaxy NGC 4151 is located at a distance of 50 million light years in a direction just south of the Big Dipper. It is a prominent example of a class of galaxies that show unusual energetic activity in their nucleus. This activity is now known to be due to the presence of a giant black hole in the nucleus with an estimated mass 10 million times that of the Sun. As matter swirls toward the black hole, it releases a prodigious amount of energy, much of it in X rays. Previous observations showed that X rays are also coming from an enormous cloud 3000 light years across that surrounds the black hole. The precise mirrors of Chandra allowed astronomers to make an X-ray image showing unprecedented detail of the massive cloud in the center of NGC 4151. The brightest regions in the cloud correspond to wisps that were previously observed in visible light by the Hubble Space Telescope. The shape of the cloud confirms that X rays from the black hole are collimated into a narrow beam, and illuminate only certain quadrants of the galaxy. "The black hole is shining an X-ray searchlight which illuminates the clouds in the night sky of NGC 4151" said Ogle. By using the High Energy Transmission Grating (HETG), astronomers were able to resolve the X-ray spectrum from the

  7. High Energy $\

    CERN Multimedia

    2002-01-01

    This experiment is a high statistics exposure of BEBC filled with hydrogen to both @n and &bar.@n beams. The principal physics aims are : \\item a) The study of the production of charmed mesons and baryons using fully constrained events. \\end{enumerate} b) The study of neutral current interactions on the free proton. \\item c) Measurement of the cross-sections for production of exclusive final state N* and @D resonances. \\item d) Studies of hadronic final states in charged and neutral current reactions. \\item e) Measurement of inclusive charged current cross-sections and structure functions. \\end{enumerate}\\\\ \\\\ The neutrino flux is determined by monitoring the flux of muons in the neutrino shield. The Internal Picket Fence and External Muon Identifier of BEBC are essential parts of the experiment. High resolution cameras are used to search for visible decays of short-lived particles.

  8. Beyond Chandra - the X-ray Surveyor

    CERN Document Server

    Weisskopf, Martin C; Tananbaum, Harvey; Vikhlinin, Alexey

    2015-01-01

    Over the past 16 years, NASA's Chandra X-ray Observatory has provided an unparalleled means for exploring the universe with its half-arcsecond angular resolution. Chandra studies have deepened our understanding of galaxy clusters, active galactic nuclei, galaxies, supernova remnants, planets, and solar system objects addressing almost all areas of current interest in astronomy and astrophysics. As we look beyond Chandra, it is clear that comparable or even better angular resolution with greatly increased photon throughput is essential to address even more demanding science questions, such as the formation and subsequent growth of black hole seeds at very high redshift; the emergence of the first galaxy groups; and details of feedback over a large range of scales from galaxies to galaxy clusters. Recently, NASA Marshall Space Flight Center, together with the Smithsonian Astrophysical Observatory, has initiated a concept study for such a mission named the X-ray Surveyor. This study starts with a baseline payloa...

  9. High energy

    International Nuclear Information System (INIS)

    We report here on progress made for the period from December 1, 1992 (the date of submission of our latest progress report) to November 30, 1993 for DOE Grant No. DE-FG05-92ER40717. The new results from the SMC experiment have generated a buzz of theoretical activity. Our involvement with the D0 experiment and the upgrade has increased substantially during the past two years so that we now have six people heavily committed and making what can only be described as a large and disproportionate impact on D0 physics output. Some of the new developments made here at Rice in Neural Network and Probability Density Estimation techniques for data analysis promise to have applications both in D0 and beyond. We report a load of new results from our high-pt jet photoproduction experiment. In addition we have been working on KTeV, albeit without having adequate funding for this work. Progress on the theoretical front has been nothing short of amazing, as is reported herein. In a grand lecture tour during this sabbatical year, Paul Stevenson has already reported his breakthroughs at ten institutions, including CERN, Oxford, Cambridge, Rutherford Lab, Imperial College, and Durham University. The group at Rice University has had an exceptionally productive year and we are justifiably proud of the progress which is reported here

  10. Chandra Reviews Black Hole Musical: Epic But Off-Key

    Science.gov (United States)

    2006-10-01

    A gigantic sonic boom generated by a supermassive black hole has been found with NASA's Chandra X-ray Observatory, along with evidence for a cacophony of deep sound. This discovery was made by using data from the longest X-ray observation ever of M87, a nearby giant elliptical galaxy. M87 is centrally located in the Virgo cluster of galaxies and is known to harbor one of the Universe's most massive black holes. Scientists detected loops and rings in the hot, X-ray emitting gas that permeates the cluster and surrounds the galaxy. These loops provide evidence for periodic eruptions that occurred near the supermassive black hole, and that generate changes in pressure, or pressure waves, in the cluster gas that manifested themselves as sound. Chandra Low Energy X-ray Images of M87 Chandra Low Energy X-ray Images of M87 "We can tell that many deep and different sounds have been rumbling through this cluster for most of the lifetime of the Universe," said William Forman of the Harvard-Smithsonian Center for Astrophysics (CfA). The outbursts in M87, which happen every few million years, prevent the huge reservoir of gas in the cluster from cooling and forming many new stars. Without these outbursts and resultant heating, M87 would not be the elliptical galaxy it is today. "If this black hole wasn't making all of this noise, M87 could have been a completely different type of galaxy," said team member Paul Nulsen, also of the CfA, "possibly a huge spiral galaxy about 30 times brighter than the Milky Way." Chandra High Energy X-ray Image of M87 Chandra High Energy X-ray Image of M87 The outbursts result when material falls toward the black hole. While most of the matter is swallowed, some of it was violently ejected in jets. These jets are launched from regions close to the black hole (neither light nor sound can escape from the black hole itself) and push into the cluster's gas, generating cavities and sound which then propagate outwards. Chandra's M87 observations also

  11. An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: High resolution 870um source counts

    CERN Document Server

    Karim, Alexander; Hodge, Jackie; Smail, Ian; Walter, Fabian; Biggs, Andy; Simpson, James; Danielson, Alice; Alexander, David; Bertoldi, Frank; Chapman, Scott; Coppin, Kristen; Dannerbauer, Helmut; Edge, Alastair; Greve, Thomas; Ivison, Rob; Knudsen, Kirsten; Menten, Karl; Schinnerer, Eva; Wardlow, Julie; Weiß, Axel; van der Werf, Paul

    2012-01-01

    We report the first counts of faint submillimetre galaxies (SMG) in the 870-um band derived from arcsecond resolution observations with the Atacama Large Millimeter Array (ALMA). We have used ALMA to map a sample of 122 870-um-selected submillimetre sources drawn from the (0.5x0.5)deg^2 LABOCA Extended Chandra Deep Field South Submillimetre Survey (LESS). These ALMA maps have an average depth of sigma(870um)~0.4mJy, some ~3x deeper than the original LABOCA survey and critically the angular resolution is more than an order of magnitude higher, FWHM of ~1.5" compared to ~19" for the LABOCA discovery map. This combination of sensitivity and resolution allows us to precisely pin-point the SMGs contributing to the submillimetre sources from the LABOCA map, free from the effects of confusion. We show that our ALMA-derived SMG counts broadly agree with the submillimetre source counts from previous, lower-resolution single-dish surveys, demonstrating that the bulk of the submillimetre sources are not caused by blendi...

  12. The Chandra Bibliography Database

    Science.gov (United States)

    Rots, A. H.; Winkelman, S. L.; Paltani, S.; Blecksmith, S. E.; Bright, J. D.

    2004-07-01

    Early in the mission, the Chandra Data Archive started the development of a bibliography database, tracking publications in refereed journals and on-line conference proceedings that are based on Chandra observations, allowing our users to link directly to articles in the ADS from our archive, and to link to the relevant data in the archive from the ADS entries. Subsequently, we have been working closely with the ADS and other data centers, in the context of the ADEC-ITWG, on standardizing the literature-data linking. We have also extended our bibliography database to include all Chandra-related articles and we are also keeping track of the number of citations of each paper. Obviously, in addition to providing valuable services to our users, this database allows us to extract a wide variety of statistical information. The project comprises five components: the bibliography database-proper, a maintenance database, an interactive maintenance tool, a user browsing interface, and a web services component for exchanging information with the ADS. All of these elements are nearly mission-independent and we intend make the package as a whole available for use by other data centers. The capabilities thus provided represent support for an essential component of the Virtual Observatory.

  13. Chandra Observatory Uncovers Hot Stars In The Making

    Science.gov (United States)

    2000-11-01

    Cambridge, Mass.--In resolving the hot core of one of the Earth's closest and most massive star-forming regions, the Chandra X-ray Observatory showed that almost all the young stars' temperatures are more extreme than expected. Orion Trapezium JPEG, TIFF, PS The Orion Trapezium as observed on October 31st UT 05:47:21 1999. The colors represent energy, where blue and white indicate very high energies and therefore exterme temperatures. The size of the X-ray source in the image also reflects its brightness, i.e. more bright sources appear larger in size. The is an artifact caused by the limiting blur of the telescope optics. The projected diameter of the field of view is about 80 light days. Credit: NASA/MIT Orion Trapezium JPEG, TIFF, PS The Orion Trapezium as observed on November 24th UT 05:37:54 1999. The colors represent energy, where blue and white indicate very high energies and therefore exterme temperatures. The size of the X-ray source in the image also reflects its brightness, i.e. more bright sources appear larger in size. The is an artifact caused by the limiting blur of the telescope optics. The projected diameter of the field of view is about 80 light days. Credit: NASA/MIT The Orion Trapezium Cluster, only a few hundred thousand years old, offers a prime view into a stellar nursery. Its X-ray sources detected by Chandra include several externally illuminated protoplanetary disks ("proplyds") and several very massive stars, which burn so fast that they will die before the low mass stars even fully mature. One of the major highlights of the Chandra observations are identification of proplyds as X-ray point source in the near vicinity of the most massive star in the Trapezium. Previous observations did not have the ability to separate the contributions of the different objects. "We've seen high temperatures in stars before, but what clearly surprised us was that nearly all the stars we see appear at rather extreme temperatures in X-rays, independent of

  14. Chandra Examines Black Holes Large and Small in Nearby Galaxy

    Science.gov (United States)

    2001-05-01

    's supermassive black hole." On astronomical scales, this galaxy is considered quite close, a mere13 million light years from Earth. Since it’s located near the plane of our own Milky Way Galaxy, the Circinus galaxy is partially hidden by intervening dust along our line of sight. As a result, the galaxy went unnoticed until about 25 years ago. Along with Sambruna and Bauer, the first research group included Hagai Netzer of Tel-Aviv University and the following collaborators from Penn State: Niel Brandt, George Chartas, Gordon Garmire, John Nousek, and Shai Kaspi. The University of Maryland team also included Andrew Wilson. The results of theses Chandra observations appear in recent and upcoming papers in The Astrophysical and Astronomical Journals. Observations with Chandra, using the Advanced CCD Imaging Spectrometer (ACIS) and the High Energy Transmission Grating Spectrometer (HETGS), were made on June 6-7, 2000 and observations without the HETGS were made on March 14, 2000. The HETG and ACIS instruments were built for NASA by the Massachusetts Institute of Technology, Cambridge, MA, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center, Huntsville, AL, manages the Chandra program for the Office of Space Science, Washington, DC. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

  15. Chandra Grating Spectroscopy of Three Hot White Dwarfs

    Science.gov (United States)

    Adamczak, J.; Werner, K.; Rauch, T.; Schuh, S.; Drake, J. J.; Kruk, J. W.

    2013-01-01

    High-resolution soft X-ray spectroscopic observations of single hot white dwarfs are scarce. With the Chandra Low-Energy Transmission Grating, we have observed two white dwarfs, one is of spectral type DA (LB1919) and the other is a non-DA of spectral type PG1159 (PG1520+525). The spectra of both stars are analyzed, together with an archival Chandra spectrum of another DA white dwarf (GD246). Aims. The soft X-ray spectra of the two DA white dwarfs are investigated in order to study the effect of gravitational settling and radiative levitation of metals in their photospheres. LB1919 is of interest because it has a significantly lower metallicity than DAs with otherwise similar atmospheric parameters. GD246 is the only white dwarf known that shows identifiable individual iron lines in the soft X-ray range. For the PG1159 star, a precise effective temperature determination is performed in order to confine the position of the blue edge of the GW Vir instability region in the HRD. Methods. The Chandra spectra are analyzed with chemically homogeneous as well as stratified NLTE model atmospheres that assume equilibrium between gravitational settling and radiative acceleration of chemical elements. Archival EUV and UV spectra obtained with EUVE, FUSE, and HST are utilized to support the analysis. Results. No metals could be identified in LB1919. All observations are compatible with a pure hydrogen atmosphere. This is in stark contrast to the vast majority of hot DA white dwarfs that exhibit light and heavy metals and to the stratified models that predict significant metal abundances in the atmosphere. For GD246 we find that neither stratified nor homogeneous models can fit the Chandra spectrum. The Chandra spectrum of PG1520+525 constrains the effective temperature to T(sub eff) = 150 000 +/- 10 000 K. Therefore, this nonpulsating star together with the pulsating prototype of the GWVir class (PG1159-035) defines the location of the blue edge of the GWVir instability region

  16. Chandra grating spectroscopy of three hot white dwarfs

    Science.gov (United States)

    Adamczak, J.; Werner, K.; Rauch, T.; Schuh, S.; Drake, J. J.; Kruk, J. W.

    2012-10-01

    Context. High-resolution soft X-ray spectroscopic observations of single hot white dwarfs are scarce. With the Chandra Low-Energy Transmission Grating, we have observed two white dwarfs, one is of spectral type DA (LB 1919) and the other is a non-DA of spectral type PG 1159 (PG 1520+525). The spectra of both stars are analyzed, together with an archival Chandra spectrum of another DA white dwarf (GD 246). Aims: The soft X-ray spectra of the two DA white dwarfs are investigated in order to study the effect of gravitational settling and radiative levitation of metals in their photospheres. LB 1919 is of interest because it has a significantly lower metallicity than DAs with otherwise similar atmospheric parameters. GD 246 is the only white dwarf known that shows identifiable individual iron lines in the soft X-ray range. For the PG 1159 star, a precise effective temperature determination is performed in order to confine the position of the blue edge of the GW Vir instability region in the HRD. Methods: The Chandra spectra are analyzed with chemically homogeneous as well as stratified NLTE model atmospheres that assume equilibrium between gravitational settling and radiative acceleration of chemical elements. Archival EUV and UV spectra obtained with EUVE, FUSE, and HST are utilized to support the analysis. Results: No metals could be identified in LB 1919. All observations are compatible with a pure hydrogen atmosphere. This is in stark contrast to the vast majority of hot DA white dwarfs that exhibit light and heavy metals and to the stratified models that predict significant metal abundances in the atmosphere. For GD 246 we find that neither stratified nor homogeneous models can fit the Chandra spectrum. The Chandra spectrum of PG 1520+525 constrains the effective temperature to Teff = 150 000 ± 10 000 K. Therefore, this nonpulsating star together with the pulsating prototype of the GW Vir class (PG 1159 - 035) defines the location of the blue edge of the GW Vir

  17. Spatially resolving a starburst galaxy at hard X-ray energies: NuSTAR, CHANDRA, AND VLBA observations of NGC 253

    DEFF Research Database (Denmark)

    Wik, D. R.; Lehmer, B. D.; Hornschemeier, A. E.;

    2014-01-01

    intermediate state black hole X-ray binaries. The global X-ray emission of the galaxy-dominated by the off-nuclear ULX and nuclear sources, which are also likely ULXs-falls steeply (photon index ≳ 3) above 10 keV, consistent with other NuSTAR-observed ULXs, and no significant excess above the background is...... the first time. As a follow up to our initial study of its nuclear region, we present the first results concerning the full galaxy from simultaneous NuSTAR, Chandra, and Very Long Baseline Array monitoring of the local starburst galaxy NGC 253. Above ~10 keV, nearly all the emission is concentrated...... within 100" of the galactic center, produced almost exclusively by three nuclear sources, an off-nuclear ultraluminous X-ray source (ULX), and a pulsar candidate that we identify for the first time in these observations. We detect 21 distinct sources in energy bands up to 25 keV, mostly consisting of...

  18. Spatially Resolving a Starburst Galaxy at Hard X-ray Energies: NuSTAR, Chandra, AND VLBA Observations of NGC 253

    CERN Document Server

    Wik, Daniel R; Hornschemeier, Ann E; Yukita, Mihoko; Ptak, Andrew; Zezas, Andreas; Antoniou, Vallia; Argo, Megan K; Bechtol, Keith; Boggs, Steven; Christensen, Finn; Craig, William; Hailey, Charles; Harrison, Fiona; Krivanos, Roman; Maccarone, Thomas J; Stern, Daniel; Venters, Tonia; Zhang, William W

    2014-01-01

    Prior to the launch of NuSTAR, it was not feasible to spatially resolve the hard (E > 10 keV) emission from galaxies beyond the Local Group. The combined NuSTAR dataset, comprised of three ~165 ks observations, allows spatial characterization of the hard X-ray emission in the galaxy NGC 253 for the first time. As a follow up to our initial study of its nuclear region, we present the first results concerning the full galaxy from simultaneous NuSTAR, Chandra, and VLBA monitoring of the local starburst galaxy NGC 253. Above ~10 keV, nearly all the emission is concentrated within 100" of the galactic center, produced almost exclusively by three nuclear sources, an off-nuclear ultraluminous X-ray source (ULX), and a pulsar candidate that we identify for the first time in these observations. We detect 21 distinct sources in energy bands up to 25 keV, mostly consisting of intermediate state black hole X-ray binaries. The global X-ray emission of the galaxy - dominated by the off-nuclear ULX and nuclear sources, whic...

  19. Six Years Into Its Mission, NASA's Chandra X-ray Observatory Continues to Achieve Scientific Firsts

    Science.gov (United States)

    2005-08-01

    In August 1999, NASA's Chandra X-ray Observatory opened for business. Six years later, it continues to achieve scientific firsts. "When Chandra opened its sunshade doors for the first time, it opened the possibility of studying the X-ray emission of the universe with unprecedented clarity," said Chandra project scientist Dr. Martin Weisskopf of NASA's Marshall Space Flight Center in Huntsville, Ala. "Already surpassing its goal of a five-year life, Chandra continues to rewrite textbooks with discoveries about our own solar system and images of celestial objects as far as billions of light years away." Based on the observatory's outstanding results, NASA Headquarters in Washington decided in 2001 to extend Chandra s mission from five years to ten. During the observatory s sixth year of operation, auroras from Jupiter, X-rays from Saturn, and the early days of our solar system were the focus of Chandra discoveries close to home -- discoveries with the potential to better understand the dynamics of life on Earth. Jupiter's auroras are the most spectacular and active auroras in the solar system. Extended Chandra observations revealed that Jupiter s auroral X-rays are caused by highly charged particles crashing into the atmosphere above Jupiter's poles. These results gave scientists information needed to compare Jupiter's auroras with those from Earth, and determine if they are triggered by different cosmic and planetary events. Mysterious X-rays from Saturn also received attention, as Chandra completed the first observation of a solar X-ray flare reflected from Saturn's low-latitudes, the region that correlates to Earth's equator and tropics. This observation led scientists to conclude the ringed planet may act as a mirror, reflecting explosive activity from the sun. Solar-storm watchers on Earth might see a surprising benefit. The results imply scientists could use giant planets like Saturn as remote-sensing tools to help monitor X-ray flaring on portions of the sun

  20. Chandra Observations of Supernova 1987A

    CERN Document Server

    Park, Sangwook; Garmire, Gordon P; McCray, Richard; Racusin, Judith L; Zhekov, Svetozar A

    2007-01-01

    We have been monitoring Supernova (SN) 1987A with {\\it Chandra X-Ray Observatory} since 1999. We present a review of previous results from our {\\it Chandra} observations, and some preliminary results from new {\\it Chandra} data obtained in 2006 and 2007. High resolution imaging and spectroscopic studies of SN 1987A with {\\it Chandra} reveal that X-ray emission of SN 1987A originates from the hot gas heated by interaction of the blast wave with the ring-like dense circumstellar medium (CSM) that was produced by the massive progenitor's equatorial stellar winds before the SN explosion. The blast wave is now sweeping through dense CSM all around the inner ring, and thus SN 1987A is rapidly brightening in soft X-rays. At the age of 20 yr (as of 2007 January), X-ray luminosity of SN 1987A is $L_{\\rm X}$ $\\sim$ 2.4 $\\times$ 10$^{36}$ ergs s$^{-1}$ in the 0.5$-$10 keV band. X-ray emission is described by two-component plane shock model with electron temperatures of $kT$ $\\sim$ 0.3 and 2 keV. As the shock front inter...

  1. X-ray observations of dust obscured galaxies in the Chandra Deep Field South

    CERN Document Server

    Corral, A; Comastri, A; Ranalli, P; Akylas, A; Salvato, M; Lanzuisi, G; Vignali, C; Koutoulidis, L

    2016-01-01

    We present the properties of X-ray detected dust obscured galaxies (DOGs) in the Chandra Deep Field South. In recent years, it has been proposed that a significant percentage of the elusive Compton-thick (CT) active galactic nuclei (AGN) could be hidden among DOGs. In a previous work, we presented the properties of X-ray detected DOGs by making use of the deepest X-ray observations available at that time, the 2Ms observations of the Chandra deep fields. In that work, we only found a moderate percentage ($<$ 50%) of CT AGN among the DOGs sample, but we were limited by poor photon statistics. In this paper, we use not only a deeper 6 Ms Chandra survey of the Chandra Deep Field South (CDF-S), but combine these data with the 3 Ms XMM-Newton survey of the CDF-S. We also take advantage of the great coverage of the CDF-S region from the UV to the far-IR to fit the spectral energy distributions (SEDs) of our sources. Out of the 14 AGN composing our sample, 9 are highly absorbed (but only 3 could be CT AGN), wherea...

  2. High resolution Chandra HETG and RXTE observations of GRS 1915+105 A hot disk atmosphere & cold gas enriched in Iron and Silicon

    CERN Document Server

    Lee, J C; Schulz, N S; Remillard, R A; Blackman, E G; Fabian, A C

    2001-01-01

    The time-averaged 30 ks Chandra HETGS observation of the micro-quasar GRS 1915+105 in the low hard state reveals for the first time in this source neutral K absorption edges from Fe, Si, Mg, & S. Ionized resonance absorption from H-, and He-like Fe (XXV, XXVI), Ca XX and possibly emission from neutral Fe Kalpha and ionized Fe XXV (forbidden, or the resonance emission component of a P-Cygni profile) are also seen. We report the tentative detection of the first astrophysical signature of XAFS in the photoelectric edge of Si (and possibly Fe and Mg), attributed to material in grains. The large column densities measured from the neutral edges reveal anomalous Si and Fe abundances. Scenarios for which the anomalous abundances can be attributed to surrounding cold material associated with GRS 1915+105 and/or that the enrichment may signify either a highly unusual supernova/hypernova, or external supernova activity local to the binary are discussed. We attribute the ionized features to a hot disk, disk-wind, or ...

  3. Chandra and NuSTAR studies of the ultraluminous X-ray sources in M82

    Science.gov (United States)

    Brightman, Murray; Harrison, Fiona; Walton, Dom; Fuerst, Felix; Bachetti, Matteo; Zezas, Andreas; Ptak, Andrew; Hornschemeier, Ann E.; Yukita, Mihoko; Tendulkar, Shriharsh P.; Grefenstette, Brian

    2016-04-01

    With the discovery of the ultraluminous X-ray pulsar in M82 by Bachetti et al (2014), there has been renewed interest in the galaxy, which also hosts one of the best candidates for an intermediate-mass black hole. We present results on the spectral and temporal properties of the pulsar from 15 years of Chandra observations with implications for theoretical modeling of the source, as well as the high-energy constraints on both sources from NuSTAR.

  4. Chandra Images the Seething Cauldron of Starburst Galaxy

    Science.gov (United States)

    2000-01-01

    or a black hole. "Several sources are so bright that they are probably black holes, perhaps left over from past starburst episodes," Garmire explained. The astronomers report that the X-ray emitting gas in the galaxy's core region has a surprisingly hot temperature. "Determining the source of high-energy X rays from M82 may elucidate whether starburst galaxies throughout the universe contribute significantly to the X-ray background radiation that pervades intergalactic space," said Griffiths."The image also shows a chimney-like structure at the base of the galactic wind, which may help us understand how metal-rich starburst gas is dispersed into intergalactic space." "What we don't see may be as important as what we do see," said Garmire. "There is no indication of a single, high luminosity, compact X-ray source from a supermassive black hole at the very center of the galaxy, although considerable evidence exists that such central black holes are present in many or most galaxies.". The astronomers note that recent optical and infrared data suggest most galaxies were starbursts when the universe was young and that their galactic winds may have distributed carbon, oxygen, iron and other heavy atoms that now pervade the Universe. The starburst in M82 is thought to have been caused by a near collision with a large spiral galaxy, M81, about 100 million years ago. At a distance of 11 million light years, M82 is the closest starburst galaxy to our Milky Way Galaxy and provides the best view of this type of galactic structure, which may have played a critical role in the early history of the Universe. The Chandra image was taken with the Advanced CCD Imaging Spectrometer (ACIS) on September 20, 1999 in an observation that lasted about 13 ½ hours. ACIS was built by Penn State Univ. and Massachusetts Institute of Technology, Cambridge. To follow Chandra's progress or download images visit the Chandra sites at: http://chandra.harvard.edu/photo/2000/0094/index.html AND http://chandra

  5. Chandra Cluster Cosmology Project III: Cosmological Parameter Constraints

    CERN Document Server

    Vikhlinin, A; Burenin, R A; Ebeling, H; Forman, W R; Hornstrup, A; Jones, C; Murray, S S; Nagai, D; Quintana, H; Voevodkin, A

    2008-01-01

    Chandra observations of large samples of galaxy clusters detected in X-rays by ROSAT provide a new, robust determination of the cluster mass functions at low and high redshifts. Statistical and systematic errors are now sufficiently small, and the redshift leverage sufficiently large for the mass function evolution to be used as a useful growth of structure based dark energy probe. In this paper, we present cosmological parameter constraints obtained from Chandra observations of 36 clusters with =0.55 derived from 400deg^2 ROSAT serendipitous survey and 49 brightest z=~0.05 clusters detected in the All-Sky Survey. Evolution of the mass function between these redshifts requires Omega_Lambda>0 with a ~5sigma significance, and constrains the dark energy equation of state parameter to w0=-1.14+-0.21, assuming constant w and flat universe. Cluster information also significantly improves constraints when combined with other methods. Fitting our cluster data jointly with the latest supernovae, WMAP, and baryonic aco...

  6. Jet Power and Black Hole Assortment Revealed in New Chandra Image

    Science.gov (United States)

    2008-01-01

    A dramatic new Chandra image of the nearby galaxy Centaurus A provides one of the best views to date of the effects of an active supermassive black hole. Opposing jets of high-energy particles can be seen extending to the outer reaches of the galaxy, and numerous smaller black holes in binary star systems are also visible. The image was made from an ultra-deep look at the galaxy Centaurus A, equivalent to more than seven days of continuous observations. Centaurus A is the nearest galaxy to Earth that contains a supermassive black hole actively powering a jet. X-ray Image of Centaurus A, Labeled X-ray Image of Centaurus A, Labeled A prominent X-ray jet extending for 13,000 light years points to the upper left in the image, with a shorter "counterjet" aimed in the opposite direction. Astronomers think that such jets are important vehicles for transporting energy from the black hole to the much larger dimensions of a galaxy, and affecting the rate at which stars form there. High-energy electrons spiraling around magnetic field lines produce the X-ray emission from the jet and counterjet. This emission quickly saps the energy from the electrons, so they must be continually reaccelerated or the X-rays will fade out. Knot-like features in the jets detected in the Chandra image show where the acceleration of particles to high energies is currently occurring, and provides important clues to understanding the process that accelerates the electrons to near-light speeds. People Who Read This Also Read... NASA’s Swift Satellite Catches First Supernova in The Act of Exploding Black Holes Have Simple Feeding Habits Chandra Data Reveal Rapidly Whirling Black Holes Erratic Black Hole Regulates Itself The inner part of the X-ray jet close to the black hole is dominated by these knots of X-ray emission, which probably come from shock waves -- akin to sonic booms -- caused by the jet. Farther from the black hole there is more diffuse X-ray emission in the jet. The cause of particle

  7. The CHANDRA X-ray Grating Spectrum of Eta Carinae

    CERN Document Server

    Corcoran, M F; Petre, R; Ishibashi, K; Davidson, K; Townsley, L K; Smith, R; White, S; Viotti, R; Damineli, A

    2001-01-01

    Eta Car may be the most massive and luminous star in the Galaxy and is suspected to be a massive, colliding wind binary system. The CHANDRA X-ray observatory has obtained a calibrated, high-resolution X-ray spectrum of the star uncontaminated by the nearby extended soft X-ray emisssion. Our 89 ksec CHANDRA observation with the High Energy Transmission Grating Spectrometer (HETGS) shows that the hot gas near the star is non-isothermal. The temperature distribution may represent the emission on either side of the colliding wind bow shock, effectively ``resolving'' the shock. The pre-shock wind velocities are ~500 and ~ 2000 km/s in our analysis, and these velocities are interpreted as the terminal velocities of the winds from Eta Car and from the hidden companion star. The abundances of Si and Fe are significantly non-solar based on the strengths of the observed H- and He-like emission lines. The iron fluorescent line at 1.93 Angstrom, first detected by ASCA, is clearly resolved from the thermal iron line in th...

  8. Catching a Galactic Football: Chandra Examines Cygnus A

    Science.gov (United States)

    2000-11-01

    Using NASA's Chandra X-ray Observatory, astronomers have found a giant football-shaped cavity within X-ray emitting hot gas surrounding the galaxy Cygnus A. The cavity in the hot gas has been created by two powerful jets emitted from the central black hole region in the nucleus of Cygnus A. Hot gas is steadily being piled up around the cavity as it continuously expands, creating a bright rim of X-ray emission. The jets themselves terminate in radio and X-ray emitting "hot spots" some 300,000 light years from the center of the galaxy. These results are being presented to the High Energy Astrophysics Division of the American Astronomical Society meeting in Honolulu, HI, by Andrew S. Wilson, Andrew J. Young (University of Maryland) and Patrick L. Shopbell (California Institute of Technology). "This is a spectacular cavity, which is inflated by jets and completely surrounds the Cygnus A galaxy," said Dr. Wilson, who is Professor of Astronomy at the University of Maryland, College Park. "We are witnessing a battle between the gravity of the Cygnus A galaxy, which is trying to pull the hot gas inwards, and the pressure of material created by the jets, which is trying to push the hot gas outwards." Cygnus A has long been famous as the brightest radio source in the sky. It is the nearest powerful radio galaxy. The Chandra X-ray image, which was taken with the Advanced CCD Imaging Spectrometer (ACIS), shows the cavity surrounded by a vast sea of extremely hot gas. The elongated oval shape comes from the force of the outwardly moving jets as they push through the hot gas. Bright bands around the "equator of the football" are also visible, and this may be evidence of material swirling toward the central black hole. Cygnus A Illustration Illustration of Cygnus A Credit: CXC Without the jets, an X-ray image of Cygnus A, which is about 700 million light years from Earth, would appear as a more or less spherical region (about 2 million light years across) of hot gas slowly

  9. NASA Chandra X-ray Observatory Selected as Editor's Choice in 2000 Discover Magazine Awards for Technological Innovation

    Science.gov (United States)

    2000-06-01

    The Chandra X-ray Observatory, NASA's newest and most powerful X-ray space telescope, has been selected as the winner of the Editor's Choice category of the 2000 Discover Magazine Awards for Technological Innovation. The team of government, industry, university and research institutions that designed, built and deployed Chandra for NASA's Marshall Space Flight Center, Huntsville, Ala, will be formally recognized June 24 at a gala awards celebration at Epcot at the Walt Disney World Resort in Orlando, Fl. Dr. Harvey Tananbaum, director of the Smithsonian Astrophysical Observatory's Chandra X-ray Science Center, Cambridge, Mass., which conducts the Chandra science mission for NASA, will receive the award on behalf of the team. "Chandra has opened a new window for astronomers into the universe of high-energy cosmic events such as pulsars, supernova remnants and black holes," said Tananbaum. "We're now able to create spectacularly detailed images of celestial phenomena whose mere existence we could only hypothesize before." Among Chandra's most significant discoveries to date, he lists the detection of a giant ring around the heart of the Crab Nebula, details of the shock wave created by an exploding star and resolution of the high-energy X-ray "glow" in the universe into millions of specific light sources. "The successful launch, deployment and on-orbit operations of NASA's Chandra X-ray Observatory is a testament to the solid partnership between TRW, NASA and the science community that has been enabling NASA's most important space science missions for the past 40 years," said Timothy W. Hannemann, executive vice president and general manager, TRW Space & Electronics Group. "The extraordinary images that Chandra is delivering daily speaks loudly not only to the quality of the science instruments on board, but also to the engineering talents and dedication to mission success exhibited by every member of NASA's Chandra mission team." Chandra, named in honor of Nobel

  10. XMM-Newton and Chandra observations of SHEEP sources

    CERN Document Server

    Georgantopoulos, I; Brotherton, M; Georgakakis, A; Papadakis, I E; O'Neill, P

    2006-01-01

    We present Chandra and XMM observations of 12 bright (f(2-10 keV) > 10^-13 cgs) sources from the ASCA SHEEP (Search for the High Energy Extragalactic Population) survey. Most of these have been either not observed or not detected previously with the ROSAT mission and therefore they constitute a sample biased towards hard sources. The Chandra observations are important in locating with accuracy the optical counterpart of the X-ray sources. Optical spectroscopic observations show that our sample is associated with both narrow-line (NL) (six objects), and Broad-Line (BL) AGN (five objects) with one source remaining unidentified. Our sources cover the redshift range 0.04 to 1.29 spanning luminosities from 10^42 to 10^45 cgs (2-10 keV). The NL sources have preferentially lower redshift (and luminosity) compared with the BL ones. This can be most easily explained in a model where the NL AGN are intrinsically less luminous than the BL ones in line with the results of Steffen et al. The X-ray spectral fittings show a...

  11. Chandra grating spectroscopy of three hot white dwarfs

    CERN Document Server

    Adamczak, J; Rauch, T; Schuh, S; Drake, J J; Kruk, J W

    2012-01-01

    High-resolution soft X-ray spectroscopic observations of single hot white dwarfs are scarce. With the Chandra Low-Energy Transmission Grating, we have observed two white dwarfs, one is of spectral type DA (LB 1919) and the other is a non-DA of spectral type PG1159 (PG 1520+525). The spectra of both stars are analyzed, together with an archival Chandra spectrum of another DA white dwarf (GD 246). The soft X-ray spectra of the two DA white dwarfs are investigated in order to study the effect of gravitational settling and radiative levitation of metals in their photospheres. LB 1919 is of interest because it has a significantly lower metallicity than DAs with otherwise similar atmospheric parameters. GD 246 is the only white dwarf known that shows identifiable individual iron lines in the soft X-ray range. For the PG1159 star, a precise effective temperature determination is performed in order to confine the position of the blue edge of the GW Vir instability region in the HRD. (abridged)

  12. Chandra Sees Shape of Universe During Formative, Adolescent Years

    Science.gov (United States)

    2003-03-01

    Scientists using NASA's Chandra X-ray Observatory have taken a snapshot of the adolescent universe from about five billion years ago when the familiar web-like structure of galaxy chains and voids first emerged. The observation reveals distant and massive galaxies dotting the sky, clustered together under the gravitational attraction of deep, unseen pockets of dark matter. This provides important clues of how the universe matured from its chaotic beginnings to its elegant structure we see today. These results are presented today in a press conference at the meeting of the High Energy Astrophysics Division of the American Astronomical Society at Mt. Tremblant, Quebec. "Piece by piece, we are assembling a photo album of the universe through the ages," said Yuxuan Yang, a doctorate candidate at the University of Maryland, College Park, who conducted the analysis. "Last month we saw a picture of the infant universe taken with the Wilkinson Microwave Anisotropy Probe. Now we can add a snapshot of its adolescence." The Chandra observation traced a patch of sky known as the Lockman Hole in the constellation Ursa Major (containing the Big Dipper). Chandra saw a rich density of active galaxies, seven times denser than what has been detected in previous optical and radio surveys at similar distances. This provides the clearest picture yet at the large-scale structure of the universe at such distances (and age), according to Dr. Richard Mushotzky of NASA Goddard Space Flight Center in Greenbelt, Md., who led the observation. Lockman Hole JPEG, TIFF, PS An image that has been "blurred" to allow better view of the structures outlined by the X-ray sources. The color represents the spectra of the AGN. The red color indicates the sources on average radiates at longer wavelength while green and blue colors indicates the sources radiates at shorter wavelength. The Green and blue regions appear to form a wall, or shows more lumpiness than the "red" sources. If one could capture the

  13. Dynamics of the Shocked Gas in the Eta Carinae System as Seen by Chandra

    Science.gov (United States)

    Corcoran, M. F.; Hamaguchi, K.; Henley, D. B.; Ishibashi, K.; Gull, T.; Nielsen, K.; Pittard, J. M.

    2006-01-01

    We report on a series of X-ray spectra of the supermassive star Eta Carinae obtained by the High Energy Transmission Grating Spectrometer on the CHANDRA X-ray observatory before, during and after the star's X-ray minimum in the summer of 2003. The X-ray spectra show significant variations in emission measure and absorption, in the strength of the iron K edge and fluorescent iron emission, but show little change in the distribution of emission measure with temperature. The CHANDRA spectra also resolve emission from Si, S, Fe and other elements in H-like and He-like configurations. The HETGS spectra show that these lines change in centroid energy along with evidence of changes in the forbidden-to-intercombination ratios of the He-like triplets. These spectra offer strong support that the X-ray emission originates within a shock cone around an unseen, massive companion. The variations of the X-ray line spectrum provide a direct measure of the dynamics of the shocked gas in this cone and also evidence that the hottest region of the shock is not always in collisional ionization equilibrium. We discuss these results in light of the recent discovery of He II 4686 emission and the reported discovery of FUV emission from the companion star. This work was supported by SAO/Chandra grant GO3-4008A.

  14. The high energy galaxy

    International Nuclear Information System (INIS)

    The galaxy is host to a wide variety of high energy events. I review here recent results on large scale galactic phenomena: cosmic-ray origin and confinement, the connexion to ultra high energy gamma-ray emission from X-ray binaries, gamma ray and synchrotron emission in interstellar space, galactic soft and hard X-ray emission

  15. Probing the wind-wind collision in Gamma Velorum with high-resolution Chandra X-ray spectroscopy: evidence for sudden radiative braking and non-equilibrium ionization

    OpenAIRE

    Henley, D. B.; Stevens, I. R.; Pittard, J. M.

    2004-01-01

    We present a new analysis of an archived Chandra HETGS X-ray spectrum of the WR+O colliding wind binary Gamma Velorum. The spectrum is dominated by emission lines from astrophysically abundant elements: Ne, Mg, Si, S and Fe. From a combination of broad-band spectral analysis and an analysis of line flux ratios we infer a wide range of temperatures in the X-ray emitting plasma (~4-40 MK). As in the previously published analysis, we find the X-ray emission lines are essentially unshifted, with ...

  16. Contemporaneous Chandra HETG and Suzaku X-ray Observations of NGC 4051

    OpenAIRE

    Lobban, AP; Reeves, JN; Miller, LL; Turner, TJ; Braito, V.; Kraemer, SB; Crenshaw, DM

    2011-01-01

    We present the results of a deep 300ks Chandra High Energy Transmission Grating (HETG) observation of the highly variable narrow-line Seyfert Type 1 galaxy NGC 4051. The HETG spectrum reveals 28 significant soft X-ray ionized lines in either emission or absorption; primarily originating from H-like and He-like K-shell transitions of O, Ne, Mg and Si (including higher order lines and strong forbidden emission lines from Ovii and Neix) plus high-ionization L-shell transitions from Fexvii to Fex...

  17. Nustar and Chandra Insight into the Nature of the 3-40 Kev Nuclear Emission in Ngc 253

    Science.gov (United States)

    Lehmer, Bret D.; Wik, Daniel R.; Hornschemeier, Ann E.; Ptak, Andrew; Antoniu, V.; Argo, M.K.; Bechtol, K.; Boggs, S.; Christensen, F.E.; Craig, W.W.; Hailey, C.J.; Harrison, F.A.; Krivonos, R.; Leyder, Jean-Christophe Xavier Georges; Maccarone, T.J.; Stern, D.; Venters, T.; Zezas, A.; Zhang, W.W.

    2013-01-01

    We present results from three nearly simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR) and Chandra monitoring observations between 2012 September 2 and 2012 November 16 of the local star-forming galaxy NGC 253. The 3-40 kiloelectron volt intensity of the inner approximately 20 arcsec (approximately 400 parsec) nuclear region, as measured by NuSTAR, varied by a factor of approximately 2 across the three monitoring observations. The Chandra data reveal that the nuclear region contains three bright X-ray sources, including a luminous (L (sub 2-10 kiloelectron volt) approximately few × 10 (exp 39) erg per s) point source located approximately 1 arcsec from the dynamical center of the galaxy (within the sigma 3 positional uncertainty of the dynamical center); this source drives the overall variability of the nuclear region at energies greater than or approximately equal to 3 kiloelectron volts. We make use of the variability to measure the spectra of this single hard X-ray source when it was in bright states. The spectra are well described by an absorbed (power-law model spectral fit value, N(sub H), approximately equal to 1.6 x 10 (exp 23) per square centimeter) broken power-law model with spectral slopes and break energies that are typical of ultraluminous X-ray sources (ULXs), but not active galactic nuclei (AGNs). A previous Chandra observation in 2003 showed a hard X-ray point source of similar luminosity to the 2012 source that was also near the dynamical center (Phi is approximately equal to 0.4 arcsec); however, this source was offset from the 2012 source position by approximately 1 arcsec. We show that the probability of the 2003 and 2012 hard X-ray sources being unrelated is much greater than 99.99% based on the Chandra spatial localizations. Interestingly, the Chandra spectrum of the 2003 source (3-8 kiloelectron volts) is shallower in slope than that of the 2012 hard X-ray source. Its proximity to the dynamical center and harder Chandra spectrum

  18. Chandra Observations of Variable Embedded X-ray sources in Orion. Paper I: Resolving Orion Trapezium

    OpenAIRE

    Schulz, N. S.; Canizares, C.; Huenemoerder, D.; Kastner, J.H.; Taylor, S. C.; Bergstrom, E. J.

    2000-01-01

    We used the High Energy Transmission Grating Spectrometer (HETGS) onboard the Chandra X-ray Observatory to perform two observations, separated by three weeks, of the Orion Trapezium region. The zeroth order images on the Advanced CCD Imaging Spectrometer (ACIS) provide spatial resolution of 0.5" and moderate energy resolution. Within a 160"x140" region around the Orion Trapezium we resolve 111 X-ray sources with luminosities between 7x10^{28} ergs/s and 2x10^{32} ergs/s. We do not detect any ...

  19. The Chandra Observation of the IP TX Col

    OpenAIRE

    Schlegel, Eric M.; Salinas, Anandi

    2003-01-01

    We present a preliminary look at the serendipitous observation of the intermediate polar TX Col by Chandra. The 52 ksec observation is uninterrupted, providing an opportunity to disentangle the light curve and power spectra components. We illustrate the energy-dependence of the power spectrum.

  20. Chandra Observations of SN 1987A: The Soft X-Ray Light Curve Revisited

    Science.gov (United States)

    Helder, E. A.; Broos, P. S.; Dewey, D.; Dwek, E.; McCray, R.; Park, S.; Racusin, J. L.; Zhekov, S. A.; Burrows, D. N.

    2013-01-01

    We report on the present stage of SN 1987A as observed by the Chandra X-Ray Observatory. We reanalyze published Chandra observations and add three more epochs of Chandra data to get a consistent picture of the evolution of the X-ray fluxes in several energy bands. We discuss the implications of several calibration issues for Chandra data. Using the most recent Chandra calibration files, we find that the 0.5-2.0 keV band fluxes of SN 1987A have increased by approximately 6 x 10(exp-13) erg s(exp-1)cm(exp-2) per year since 2009. This is in contrast with our previous result that the 0.5-2.0 keV light curve showed a sudden flattening in 2009. Based on our new analysis, we conclude that the forward shock is still in full interaction with the equatorial ring.

  1. High energy colliders

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, R.B.; Gallardo, J.C. [Brookhaven National Lab., Upton, NY (United States). Center for Accelerator Physics

    1997-02-01

    The authors consider the high energy physics advantages, disadvantages and luminosity requirements of hadron (pp, p{anti p}), lepton (e{sup +}e{sup {minus}}, {mu}{sup +}{mu}{sup {minus}}) and photon-photon colliders. Technical problems in obtaining increased energy in each type of machine are presented. The machines relative size are also discussed.

  2. High energy colliders

    International Nuclear Information System (INIS)

    The authors consider the high energy physics advantages, disadvantages and luminosity requirements of hadron (pp, p anti p), lepton (e+e-, μ+μ-) and photon-photon colliders. Technical problems in obtaining increased energy in each type of machine are presented. The machines relative size are also discussed

  3. High-energy detector

    Science.gov (United States)

    Bolotnikov, Aleksey E.; Camarda, Giuseppe; Cui, Yonggang; James, Ralph B.

    2011-11-22

    The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

  4. HDE 245059: A Weak-Lined T Tauri Binary Revealed by Chandra and Keck

    OpenAIRE

    Saavedra, C. Baldovin; Audard, M.; Duchêne, G.; Güdel, M.; Skinner, S.L.; Paerels, F. B. S.; Ghez, A.; McCabe, C.

    2009-01-01

    We present the Chandra High Energy Transmission Grating Spectrometer (HETGS) and Keck observations of HDE 245059, a young weak-lined T Tauri star (WTTS), member of the pre-main sequence group in the Lambda Orionis Cluster. Our high spatial resolution, near-infrared observations with Keck reveal that HDE 245059 a binary separated by 0.87". Based on this new information we have obtained an estimate of the masses of the binary components; 3M_{sun} and 2.5M_{sun} for the north and south component...

  5. High-Energy Emission at Shocks in Millisecond Pulsar Binaries

    Science.gov (United States)

    Kust Harding, Alice; Wadiasingh, Zorawar; Venter, Christo; Boettcher, Markus

    2016-04-01

    A large number of new Black Widow (BW) and Redback (RB) energetic millisecond pulsars have been discovered through radio searches of unidentified Fermi sources, increasing the known number of these systems from 4 to 28. We model the high-energy emission components from particles accelerated to several TeV in intrabinary shocks in BW and RB systems, and their predicted modulation at the binary orbital period. Synchrotron emission is expected at X-ray energies and such modulated emission has already been detected by Chandra and XMM. Inverse Compton emission from accelerated particles scattering the UV emission from the radiated companion star is expected in the Fermi and TeV bands. Detections or constraints on this emission will probe the unknown physics of pulsar winds.

  6. High Energy Continuum of High Redshift Quasars

    Science.gov (United States)

    Elvis, Martin

    2000-01-01

    Discussion with the RXTE team at GSFC showed that a sufficiently accurate background subtraction procedure had now, been derived for sources at the flux level of PKS 2126-158. However this solution does not apply to observations carried out before April 1997, including our observation. The prospect of an improved solution becoming available soon is slim. As a result the RXTE team agreed to re-observe PKS2126-158. The new observation was carried out in April 1999. Quasi-simultaneous optical observations were obtained, as Service observing., at the 4-meter Anglo-Australian Telescope, and ftp-ed from the AAT on 22April. The RXTE data was processed in late June, arriving at SAO in early July. Coincidentally, our collaborative Beppo-SAX observation of PKS2126-158 was made later in 1999, and a GTO Chandra observation (with which we are involved) was made on November 16. Since this gives us a unique monitoring data for a high redshift quasar over a broad pass-band we are now combining all three observations into a single comprehensive study Final publication of the RXTE data will thus take place under another grant.

  7. Historical Remembrances of the Chandra X-ray Observatory: How Partnerships Created Success

    Science.gov (United States)

    Burke, Robert

    2009-09-01

    As the astronomy community plans for new ventures in space, we're forced to find creative solutions to operate within the ever increasing fiscal constraints of the current economic environment. The Chandra X-ray Observatory program offers an example of how missions can be successfully developed within manageable budget constraints. The ten year anniversary offers us the chance to look back at the Chandra team's special partnership between scientists, managers, and industry that led to our success.Chandra experienced many of the challenges common to major observatories: state-of-the-art technical requirements, budget-induced slips, and restructurings. Yet the Chandra team achieved excellent performance for dramatically lower cost. In fact, Chandra completed its prime mission for billions of dollars less than originally planned. In 1992, NASA MSFC and Northrop Grumman (then TRW) together led a major restructure that saved approximately 3.4B in program cost, while we improved the imaging capability and observing efficiency of Chandra. This was accomplished by a combination of team-work, systems engineering, advanced technology insertion, and effective approaches for program implementation, combined with a high performance culture that aligned goals and focused on mission success. Northrop Grumman is proud of our role in supporting the NASA Marshall Space Flight Center and our academic partners in advancing the frontiers of x-ray astronomy and scientific discovery with Chandra. As Chandra continues its extended mission, the observatory continues to provide superb scientific performance.

  8. High energy photon response

    International Nuclear Information System (INIS)

    This study examines the response of the Hanford 4-chip and 5-chip dosimeter to high energy photons. The dose response of the Hanford Multipurpose Personnel Diometer (HMPD) to photons with energies greater than 0.65 MeV has been evaluated relative to the dose produced by photons from a 60Co. source. The penetrating dose determined with the HMPD is compared to the 1 cm depth dose in tissue measured with an extrapolation chamber. The results of the study indicate that the HMPD can be used to estimate the 1 cm depth dose in tissue from photons with energies between 0.65 MeV and 3.0 MeV to within an accuracy of 15%. However, the 1 cm depth dose is underestimated by 38% when the dosimeter is irradiated in a beam of very high energy photons produced by bombarding a tungsten target with 25 MeV electrons

  9. The Chandra COSMOS Legacy Survey

    Science.gov (United States)

    Civano, Francesca M.; Marchesi, Stefano; Elvis, Martin; Urry, C. Megan; Comastri, Andrea; Suh, Hyewon

    2016-01-01

    In this talk, I will present the 4016 sources sample of the Chandra COSMOS Legacy survey, a 4.6 Ms Chandra survey on the COSMOS field. We have multiwavelength information for 97% of the sources, including photometric and spectroscopic redshifts, and we can therefore study, in a statistical and complete way, the physical properties for all the sample including host galaxies properties. I will focus on the z>3 sample, the largest X-ray selected sample in this range of redshift on a contiguous field, presenting the space density and the clustering analysis using this sample, with a particular focus on how our results can put constraints on the predictions of both phenomenological and physical models of black hole and galaxy growth.

  10. Chandra and XMM-Newton view of the warm absorbing gas in Mrk 290

    Science.gov (United States)

    Zhang, S. N.; Ji, L.; Marshall, H. L.; Longinotti, A. L.; Evans, D.; Gu, Q. S.

    2011-02-01

    We present a detailed analysis of the Chandra High Energy Transmission Grating Spectrometer (HETGS) and XMM-Newton high-resolution spectra of the bright Seyfert 1 galaxy, Mrk 290. The Chandra HETGS spectra reveal complex absorption features that can be best described by a combination of three ionized absorbers. The outflow velocities of these warm absorbers are about 450 km s-1, consistent with the three absorption components found in a previous far-UV study. The ionizing continuum of Mrk 290 fluctuated by a factor of 1.4 during Chandra observations on a time-scale of 17 d. Using the response in opacity of the three absorbers to this fluctuation, we put a lower limit on the distance from the ionizing source of 0.9 pc for the medium ionized absorber and an upper limit on a distance of 2.5 pc for the lowest ionized absorber. The three ionization components lie on the stable branch of the thermal equilibrium curve, indicating roughly the same gas pressure. Therefore, the thermal wind from the torus is most likely the origin of warm absorbing gas in Mrk 290. During the XMM-Newton observation, the ionizing luminosity was 50 per cent lower compared to that in the Chandra observation. The Reflection Grating Spectrometer spectrum is well fitted by a two-phase warm absorber, with several additional absorption lines attributed to a Galactic high-velocity cloud, complex C. Neither the ionization parameter ξ nor the column density NH of the two absorbing components varied significantly, compared to the results from Chandra observations. The outflow velocities of both components were 1260 km s-1. We suggest that an entirely new warm absorber from the torus passed through our line of sight. Assuming the torus wind model, the estimated mass outflow rate is ˜0.1 M⊙ per year while the nuclear accretion rate is ˜0.04 M⊙ per year. The O VII and Ne IX forbidden lines are the most prominent soft X-ray emission lines, with a mean redshift of 700 km s-1 relative to the systematic

  11. High energy excitations

    International Nuclear Information System (INIS)

    Neutron studies at high energies and large momentum transfer Q (≥ 30 A-1) are described with respect to:- some forms of n(p) and S(Q, E) [where n(p) is the probability distribution for the particle momentum and S(Q, E) is the dynamic structure factor], final state interactions, and experimental results for current reactor neutrons. Neutron studies at high energies and small Q [≤ 5 A-1] are discussed, including:-free electron gas, semiconductors, effect of Coulomb interaction, and itinerant ferromagnets. (U.K.)

  12. Theoretical high energy physics

    International Nuclear Information System (INIS)

    This report discusses theoretical research in high energy physics at Columbia University. Some of the research topics discussed are: quantum chromodynamics with dynamical fermions; lattice gauge theory; scattering of neutrinos by photons; atomic physics constraints on the properties of ultralight-ultraweak gauge bosons; black holes; Chern- Simons physics; S-channel theory of superconductivity; charged boson system; gluon-gluon interactions; high energy scattering in the presence of instantons; anyon physics; causality constraints on primordial magnetic manopoles; charged black holes with scalar hair; properties of Chern-Aimona-Higgs solitons; and extended inflationary universe

  13. High energy magnetic spectroscopy

    International Nuclear Information System (INIS)

    The purpose of this paper is twofold: (i) to elucidate the possibilities and limitations of neutron scattering experiments with high energy transfers at low momentum transfers from the view point of the kinematical conditions of the scattering process and (ii) to discuss some examples of high energy magnetic excitations in the field of 4f- and 5f- magnetism. The outcome of point (i) will determine the range of possible energy transfer i.e. will give a reasonable upper bound of 0.5 to leV of energy transfer for momentum transfers around 2 to 5 A-1. This extends the available omega-range by roughly a factor of 10 compared to the conventional magnetic scattering at reactors. Any further, significant increase in energy transfer, however, is not very likely even with very powerful future spallation sources. Thus it is sufficient to restrict the discussion of possible magnetic experiments to energy transfer up to 0.5 or 1 eV

  14. NASA'S Chandra Finds New Evidence on Origin of Supernovas

    Science.gov (United States)

    2011-04-01

    CAMBRIDGE, Ma. -- Astronomers may now know the cause of an historic supernova explosion that is an important type of object for investigating dark energy in the universe. The discovery, made using NASA's Chandra X-ray Observatory, also provides strong evidence that a star can survive the explosive impact generated when a companion star goes supernova. The new study examined the remnant of a supernova observed by the Danish astronomer Tycho Brahe in 1572. The object, dubbed Tycho for short, was formed by a Type Ia supernova, a category of stellar explosion useful in measuring astronomical distances because of their reliable brightness. Type Ia supernovas have been used to determine that the universe is expanding at an accelerating rate, an effect attributed to the prevalence of an invisible, repulsive force throughout space called dark energy. A team of researchers analyzed a deep Chandra observation of Tycho and found an arc of X-ray emission in the supernova remnant. Evidence supports the conclusion that a shock wave created the arc when a white dwarf exploded and blew material off the surface of a nearby companion star. "There has been a long-standing question about what causes Type Ia supernovas," said Fangjun Lu of the Institute of High Energy Physics, Chinese Academy of Sciences in Beijing. "Because they are used as steady beacons of light across vast distances, it is critical to understand what triggers them." One popular scenario for Type Ia supernovas involves the merger of two white dwarfs. In this case, no companion star or evidence for material blasted off a companion should exist. In the other main competing theory, a white dwarf pulls material from a "normal," or sun-like, companion star until a thermonuclear explosion occurs. Both scenarios may actually occur under different conditions, but the latest Chandra result from Tycho supports the latter one. n addition, the Tycho study seems to show the remarkable resiliency of stars, as the supernova

  15. Chandra X-Ray Observatory (CXO) Overview

    CERN Document Server

    Weisskopf, M C; Van Speybroeck, L P; O'Dell, S L

    2000-01-01

    The Chandra X-Ray Observatory (CXO), the x-ray component of NASA's Great Observatories, was launched early in the morning of 1999, July 23 by the Space Shuttle Columbia. The Shuttle launch was only the first step in placing the observatory in orbit. After release from the cargo bay, the Inertial Upper Stage performed two firings, and separated from the observatory as planned. Finally, after five firings of Chandra's own Integral Propulsion System--- the last of which took place 15 days after launch--- the observatory was placed in its highly elliptical orbit of 140,000 km apogee and 10,000 km perigee. After activation, the first x-rays focussed by the telescope were observed on 1999, August 12. Beginning with these initial observations one could see that the telescope had survived the launch environment and was operating as expected. The month following the opening of the sunshade door was spent adjusting the focus for each set of instrument configurations, determining the optical axis, calibrating the star c...

  16. Chandra Observations of SNR RCW 103

    CERN Document Server

    Frank, Kari A; Park, Sangwook

    2015-01-01

    We analyze three Chandra observations, with a combined exposure time of 99 ks, of the Galactic supernova remnant RCW 103, a young supernova remnant, previously with no clear detection of metal-rich ejecta. Based on our imaging and spectral analyses of these deep Chandra data, we find evidence for metal-rich ejecta emission scattered throughout the remnant. X-ray emission from the shocked ejecta is generally weak, and the shocked circumstellar medium (CSM) is a largely dominant component across the entire remnant. The CSM component shows abundances of ~0.5 solar, while Ne, Mg, Si, S, and Fe abundances of the ejecta are up to a few times solar. Comparison of these ejecta abundances with yields from supernova nucleosynthesis models suggests, together with the existence of a central neutron star, a progenitor mass of ~18-20 M$_\\odot$, though the Fe/Si ratios are larger than predicted. The shocked CSM emission suggests a progenitor with high mass-loss rate and subsolar metallicity.

  17. High Energy Astroparticle Physics

    International Nuclear Information System (INIS)

    We give a brief (and highly incomplete) overview of the current experimental and theoretical status of high energy cosmic rays and their secondary γ-rays and neutrinos. We focus on the role of large scale magnetic fields and on multi-messenger aspects linking these three channels. We also recall that the flavor composition of neutrino fluxes from astrophysical sources contains information on both the source conditions and neutrino physics

  18. High Energy Astroparticle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Sigl, Guenter [APC - AstroParticules et Cosmologie, 10, rue Alice Domon et Lonie Duquet, 75205 Paris Cedex 13 (France) and Institut d' Astrophysique de Paris, 98bis Boulevard Arago, 75014 Paris (France)

    2007-06-15

    We give a brief (and highly incomplete) overview of the current experimental and theoretical status of high energy cosmic rays and their secondary {gamma}-rays and neutrinos. We focus on the role of large scale magnetic fields and on multi-messenger aspects linking these three channels. We also recall that the flavor composition of neutrino fluxes from astrophysical sources contains information on both the source conditions and neutrino physics.

  19. High energy phonons: overview

    International Nuclear Information System (INIS)

    Neutron scattering has been important in the measurement and interpretation of phonon dispersion relations. As these measurements are extended to higher energies they may yield new types of information or information about different types of systems. Several examples are discussed including: dispersion in high frequency internal modes, application to molecular crystals and the use of vibrational modes of hydrogen as a structural probe

  20. Theoretical high energy physics

    International Nuclear Information System (INIS)

    This progress report discusses research by Columbia University staff in high energy physics. Some of the topics discussed are as follows: lattice gauge theory; quantum chromodynamics; parity doublets; solitons; baryon number violation; black holes; magnetic monopoles; gluon plasma; Chern-Simons theory; and the inflationary universe

  1. Chandra Catches "Piranha" Black Holes

    Science.gov (United States)

    2007-07-01

    Supermassive black holes have been discovered to grow more rapidly in young galaxy clusters, according to new results from NASA's Chandra X-ray Observatory. These "fast-track" supermassive black holes can have a big influence on the galaxies and clusters that they live in. Using Chandra, scientists surveyed a sample of clusters and counted the fraction of galaxies with rapidly growing supermassive black holes, known as active galactic nuclei (or AGN). The data show, for the first time, that younger, more distant galaxy clusters contained far more AGN than older, nearby ones. Galaxy clusters are some of the largest structures in the Universe, consisting of many individual galaxies, a few of which contain AGN. Earlier in the history of the universe, these galaxies contained a lot more gas for star formation and black hole growth than galaxies in clusters do today. This fuel allows the young cluster black holes to grow much more rapidly than their counterparts in nearby clusters. Illustration of Active Galactic Nucleus Illustration of Active Galactic Nucleus "The black holes in these early clusters are like piranha in a very well-fed aquarium," said Jason Eastman of Ohio State University (OSU) and first author of this study. "It's not that they beat out each other for food, rather there was so much that all of the piranha were able to really thrive and grow quickly." The team used Chandra to determine the fraction of AGN in four different galaxy clusters at large distances, when the Universe was about 58% of its current age. Then they compared this value to the fraction found in more nearby clusters, those about 82% of the Universe's current age. The result was the more distant clusters contained about 20 times more AGN than the less distant sample. AGN outside clusters are also more common when the Universe is younger, but only by factors of two or three over the same age span. "It's been predicted that there would be fast-track black holes in clusters, but we never

  2. Deeper Chandra Follow-up of Cygnus TeV Source Perpetuates Mystery

    CERN Document Server

    Butt, Y; Benaglia, P; Combi, J; Dame, T; Miniati, F; Romero, G; Butt, Yousaf; Drake, Jeremy; Benaglia, Paula; Combi, Jorge; Dame, Thomas; Miniati, Francesco; Romero, Gustavo

    2005-01-01

    A 50 ksec Chandra observation of the unidentified TeV source in Cygnus reported by the HEGRA collaboration reveals no obvious X-ray counterpart(s). 220 Point-like X-ray sources are detected within or nearby the extended TeV J2032+4130 source region, of which at least 30 are massive stars and 6 are known radio emitters. Based on the low X-ray and radio emissivity we favor a nucleonic rather than electronic origin of the very high energy gamma-ray flux and suspect it is related to the very massive and extremely powerful Cygnus OB2 stellar association.

  3. A Deep Chandra X-ray Spectrum of the Accreting Young Star TW Hydrae

    OpenAIRE

    Brickhouse, N. S.; Cranmer, S. R.; Dupree, A. K.; Luna, G. J. M.; Wolk, S.

    2010-01-01

    We present X-ray spectral analysis of the accreting young star TW Hydrae from a 489 ks observation using the Chandra High Energy Transmission Grating. The spectrum provides a rich set of diagnostics for electron temperature T_e, electron density N_e, hydrogen column density N_H, relative elemental abundances and velocities and reveals its source in 3 distinct regions of the stellar atmosphere: the stellar corona, the accretion shock, and a very large extended volume of warm postshock plasma. ...

  4. NASA Unveils First Images From Chandra X-Ray Observatory

    Science.gov (United States)

    1999-08-01

    Extraordinary first images from NASA's Chandra X-ray Observatory trace the aftermath of a gigantic stellar explosion in such stunning detail that scientists can see evidence of what may be a neutron star or black hole near the center. Another image shows a powerful X-ray jet blasting 200,000 light years into intergalactic space from a distant quasar. Released today, both images confirm that NASA's newest Great Observatory is in excellent health and its instruments and optics are performing up to expectations. Chandra, the world's largest and most sensitive X-ray telescope, is still in its orbital check-out and calibration phase. "When I saw the first image, I knew that the dream had been realized," said Dr. Martin Weisskopf, Chandra Project Scientist, NASA's Marshall Space Flight Center, Huntsville, AL. "This observatory is ready to take its place in the history of spectacular scientific achievements." "We were astounded by these images," said Harvey Tananbaum, Director of the Smithsonian Astrophysical Observatory's Chandra X- ray Center, Cambridge, MA. "We see the collision of the debris from the exploded star with the matter around it, we see shock waves rushing into interstellar space at millions of miles per hour, and, as a real bonus, we see for the first time a tantalizing bright point near the center of the remnant that could possibly be a collapsed star associated with the outburst." Chandra's PKS 0637-752 PKS 0637-752 After the telescope's sunshade door was opened last week, one of the first images taken was of the 320-year-old supernova remnant Cassiopeia A, which astronomers believe was produced by the explosion of a massive star. Material blasted into space from the explosion crashed into surrounding material at 10 million miles per hour. This collision caused violent shock waves, like massive sonic booms, creating a vast 50-million degree bubble of X-ray emitting gas. Heavy elements in the hot gas produce X-rays of specific energies. Chandra's ability

  5. Theoretical High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Christ, Norman H.; Weinberg, Erick J.

    2014-07-14

    we provide reports from each of the six faculty supported by the Department of Energy High Energy Physics Theory grant at Columbia University. Each is followed by a bibliography of the references cited. A complete list of all of the publications in the 12/1/2010-04/30/2014 period resulting from research supported by this grant is provided in the following section. The final section lists the Ph.D. dissertations based on research supported by the grant that were submitted during this period.

  6. High energy physics problems

    International Nuclear Information System (INIS)

    Described are modern views on the particle structure and particle interactions at high energies. According to the latest data recieved, all particles can be classified in three groups: 1) strong interacting hadrons; 2) leptons, having no strong interactions; 3) photon. The particle structure is described in a quark model, and with the use of gluons. The elementary particle theory is based on the quantum field theory. The energy increase of interacting particles enables to check the main theory principles, such as conventions for causality, relativistic invariance and unitarity. Investigations of weak interactions are of great importance. The progress in this field is connected with unified gauge theories of weak and electromagnetic interactions. For weak interactions promissing are the experiments with colliding electron-proton rings. The new data, especially at higher energies, will lead to a further refinement of the nature of particles and their interactions

  7. Highlights and discoveries from the Chandra X-ray Observatory.

    Science.gov (United States)

    Tananbaum, H; Weisskopf, M C; Tucker, W; Wilkes, B; Edmonds, P

    2014-06-01

    Within 40 years of the detection of the first extra-solar x-ray source in 1962, NASA's Chandra X-ray Observatory has achieved an increase in sensitivity of 10 orders of magnitude, comparable to the gain in going from naked-eye observations to the most powerful optical telescopes over the past 400 years. Chandra is unique in its capabilities for producing sub-arcsecond x-ray images with 100-200 eV energy resolution for energies in the range 0.08 black holes; the growth of supermassive black holes and their role in the regulation of star formation and growth of galaxies; impacts of collisions, mergers, and feedback on growth and evolution of groups and clusters of galaxies; and properties of dark matter and dark energy. PMID:24913425

  8. High energy applications

    International Nuclear Information System (INIS)

    Full text: From the point of view of high energy applications I would like to make the following recommendations: Neutron cross sections from the keV range up to 50 MeV are measured by dedicated mono- energetic fast neutron sources. For the design optimization of fast neutron sources, data files and models of proton and deuteron cross sections and their DDXs on Li and Be isotopes need to be improved utilizing recent experiments and new physics models for Ep dn,p < 2 GeV based on up-to-date physics models and available evaluated files, - identify target accuracies through sensitivity and uncertainty analyses using the recommended library; Inaccurate nuclear data can give rise to engineering margins of a factor 2 to 3 in high energy accelerator shielding design. Improving nuclear data of neutron inelastic scattering as well as activation cross sections for component, structural and shielding materials, such as Na, Al, Mn, Fe, Co, Ni, Cu, Zn for energies up to a few hundreds of MeV, is essential for the reduction of too conservative design margins, which in return would give a huge cost benefit; Radiation effects on micro-electronics (soft errors, damage) by cosmic-ray neutrons need to be predicted in a reliable way. Therefore, more reliable nuclear reaction models which can predict neutron-induced light-ion production from silicon in the incident energy range from MeV to GeV are strongly required. (author)

  9. High energy nuclear physics

    International Nuclear Information System (INIS)

    The 1988 progress report of the High Energy Nuclear Physics laboratory (Polytechnic School, France), is presented. The Laboratory research program is focused on the fundamental physics of interactions, on the new techniques for the acceleration of charged particles and on the nuclei double beta decay. The experiments are performed on the following topics: the measurement of the π0 inclusive production and the photons production in very high energy nuclei-nuclei interactions and the nucleon stability. Concerning the experiments under construction, a new detector for LEP, the study and simulation of the hadronic showers in a calorimeter and the H1 experiment (HERA), are described. The future research programs and the published papers are listed

  10. High Energy Particle Accelerators

    CERN Multimedia

    Audio Productions, Inc, New York

    1960-01-01

    Film about the different particle accelerators in the US. Nuclear research in the US has developed into a broad and well-balanced program.Tour of accelerator installations, accelerator development work now in progress and a number of typical experiments with high energy particles. Brookhaven, Cosmotron. Univ. Calif. Berkeley, Bevatron. Anti-proton experiment. Negative k meson experiment. Bubble chambers. A section on an electron accelerator. Projection of new accelerators. Princeton/Penn. build proton synchrotron. Argonne National Lab. Brookhaven, PS construction. Cambridge Electron Accelerator; Harvard/MIT. SLAC studying a linear accelerator. Other research at Madison, Wisconsin, Fixed Field Alternate Gradient Focusing. (FFAG) Oakridge, Tenn., cyclotron. Two-beam machine. Comments : Interesting overview of high energy particle accelerators installations in the US in these early years. .

  11. The BMW-Chandra Serendipitous Source Catalogue

    Science.gov (United States)

    Romano, P.; Campana, S.; Mignani, R. P.; Moretti, A.; Panzera, M. R.; Tagliaferri, G.

    We present the BMW-Chandra Source Catalogue drawn from all Chandra ACIS-I pointed observations with an exposure time in excess of 10 ks public as of March 2003 (136 observations). Using the wavelet detection algorithm developed by \\citep{Lazzatiea99} and \\citep{Campanaea99}, which can characterize point-like as well as extended sources, we identified 21325 sources which were visually inspected and verified. Among them, 16758 are not associated with the targets of the pointings and are considered certain; they have a 0.5-10 keV absorption corrected flux distribution median of ˜ 7 × 10-15 erg cm-2 s-1. The catalogue consists of source positions, count rates, extensions and relative errors in three energy bands (total, 0.5-7 keV; soft, 0.5-2 keV; and hard band, 2-7 keV), as well as the additional information drawn from the headers of the original files. We also extracted source counts in four additional energy bands, (0.5-1.0 keV, 1.0-2.0 keV, 2.0-4.0 keV and 4.0-7.0 keV). We compute the sky coverage in the soft and hard bands. The complete catalogue provides a sky coverage in the soft band (0.5-2 keV, S/N =3) of ˜ 8 deg2 at a limiting flux of ˜ 10-13 erg cm-2 s-1, and ˜ 2 deg2 at a limiting flux of ˜ 10-15 erg cm-2 s-1. http://www.merate.mi.astro.it/~xanadu/BMC/bmc_home.html

  12. High Energy Transients

    CERN Document Server

    Gehrels, Neil

    2012-01-01

    We present an overview of high energy transients in astrophysics, highlighting important advances over the past 50 years. We begin with early discoveries of gamma-ray transients, and then delve into physical details associated with a variety of phenomena. We discuss some of the unexpected transients found by Fermi and Swift, many of which are not easily classifiable or in some way challenge conventional wisdom. These objects are important insofar as they underscore the necessity of future, more detailed studies.

  13. Theoretical high energy physics

    International Nuclear Information System (INIS)

    This report discusses progress on theoretical high energy physics at Columbia University in New York City. Some of the topics covered are: Chern-Simons gauge field theories; dynamical fermion QCD calculations; lattice gauge theory; the standard model of weak and electromagnetic interactions; Boson-fermion model of cuprate superconductors; S-channel theory of superconductivity and axial anomaly and its relation to spin in the parton model

  14. First Terrestrial Soft X-ray Aurora Observations by Chandra

    Science.gov (United States)

    Bhardwaj, Anil; Elsner, Ronald F.; Gladstone, G. Randall; Waite, J. Hunter, Jr.; Cravens, Thomas E.; Ostgaard, Nikolai; Chang, Shen-Wu; Metzger, Albert E.; Majeed, Tariq

    2004-01-01

    Northern polar "auroral" regions of Earth was observed by High-Resolution Camera in imaging mode (T32C-I) aboard Chandra X-Ray Observatory (CXO) during mid December 2003 - mid April 2004. Ten CXO observations, each approximately 20 min duration, were made in a non-conventional method (due to CXO technical issues), such that Chandra was aimed at a fixed point in sky and the Earth's polar cusp was allowed to drift through the HRC-I field-of-view. The observations were performed when CXO was near apogee and timed during northern winter mostly near midnight (6 hr), except two observations which occurred around 1200 UT, so that northern polar region is entirely in dark and solar fluoresced x-ray contamination can be avoided. These observations were aimed at searching the Earth's soft x-ray aurora and to do a comparative study with Jupiter's x-ray aurora, where a pulsating x-ray hot-spot near the northern magnetic pole has been observed by Chandra that implies a particle source region near Jupiter's magnetopause, and entry of heavy solar wind ions due to high-latitude reconnection as a viable explanation for the soft x-ray emissions. The first Chandra soft (0.1-2 keV) x-ray observations of Earth's aurora show that it is highly variable (intense arc, multiple arcs, diffuse, at times almost absent). In at least one of the observations an isolated blob of emission is observed where we expect cusp to be: giving indication of solar wind charge-exchange signature in x-rays. We are comparing the Chandra x-ray observations with observations at other wavelengths and particle data from Earth-orbiting satellites and solar wind measurements from near-Earth ACE and SOH0 spacecraft. Preliminary results from these unique CXO-Earth observations will be presented and discussed.

  15. Very high energy colliders

    Energy Technology Data Exchange (ETDEWEB)

    Richter, B.

    1985-05-01

    The conclusions are relatively simple, but represent a considerable challenge to the machine builder. High luminosity is essential. We may in the future discover some new kind of high cross section physics, but all we know now indicates that the luminosity has to increase as the square of the center of mass energy. A reasonable luminosity to scale from for electron machines would be 10/sup 33/ cm/sup -2/ s/sup -1/ at a center of mass energy of 3 TeV. The required emittances in very high energy machines are small. It will be a real challenge to produce these small emittances and to maintain them during acceleration. The small emittances probably make acceleration by laser techniques easier, if such techniques will be practical at all. The beam spot sizes are very small indeed. It will be a challenge to design beam transport systems with the necessary freedom from aberration required for these small spot sizes. It would of course help if the beta functions at the collision points could be reduced. Beam power will be large - to paraphrase the old saying, ''power is money'' - and efficient acceleration systems will be required.

  16. A $Chandra-Swift$ View of Point Sources in Hickson Compact Groups: High AGN fraction but a dearth of strong AGNs

    CERN Document Server

    Tzanavaris, P; Hornschemeier, A E; Fedotov, K; Eracleous, M; Brandt, W N; Desjardins, T D; Charlton, J C; Gronwall, C

    2014-01-01

    We present $Chandra$ X-ray point source catalogs for 9 Hickson Compact Groups (HCGs, 37 galaxies) at distances $34 - 89$ Mpc. We perform detailed X-ray point source detection and photometry, and interpret the point source population by means of simulated hardness ratios. We thus estimate X-ray luminosities ($L_X$) for all sources, most of which are too weak for reliable spectral fitting. For all sources, we provide catalogs with counts, count rates, power-law indices ($\\Gamma$), hardness ratios, and $L_X$, in the full ($0.5-8.0$ keV), soft ($0.5-2.0$ keV) and hard ($2.0-8.0$ keV) bands. We use optical emission-line ratios from the literature to re-classify 24 galaxies as star-forming, accreting onto a supermassive black hole (AGNs), transition objects, or low-ionization nuclear emission regions (LINERs). Two-thirds of our galaxies have nuclear X-ray sources with $Swift$/UVOT counterparts. Two nuclei have $L_{X,{\\rm 0.5-8.0 keV}}$~$ > 10^{42}$ erg s$^{-1}$, are strong multi-wavelength AGNs and follow the known...

  17. Probing the wind-wind collision in Gamma Velorum with high-resolution Chandra X-ray spectroscopy: evidence for sudden radiative braking and non-equilibrium ionization

    CERN Document Server

    Henley, D B; Pittard, J M

    2004-01-01

    We present a new analysis of an archived Chandra HETGS X-ray spectrum of the WR+O colliding wind binary Gamma Velorum. The spectrum is dominated by emission lines from astrophysically abundant elements: Ne, Mg, Si, S and Fe. From a combination of broad-band spectral analysis and an analysis of line flux ratios we infer a wide range of temperatures in the X-ray emitting plasma (~4-40 MK). As in the previously published analysis, we find the X-ray emission lines are essentially unshifted, with a mean FWHM of 1240 +/- 30 km/s. Calculations of line profiles based on hydrodynamical simulations of the wind-wind collision predict lines that are blueshifted by a few hundred km/s. The lack of any observed shift in the lines may be evidence of a large shock-cone opening half-angle (> 85 degrees), and we suggest this may be evidence of sudden radiative braking. From the R and G ratios measured from He-like forbidden-intercombination-resonance triplets we find evidence that the Mg XI emission originates from hotter gas c...

  18. Chandra Observations of Eight Sources Discovered by INTEGRAL

    CERN Document Server

    Tomsick, John A; Wang, Qinan; Bodaghee, Arash; Chaty, Sylvain; Rahoui, Farid; Rodriguez, Jerome; Fornasini, Francesca M

    2015-01-01

    We report on 0.3-10 keV observations with the Chandra X-ray Observatory of eight hard X-ray sources discovered within 8 degrees of the Galactic plane by the INTEGRAL satellite. The short (5 ks) Chandra observations of the IGR source fields have yielded very likely identifications of X-ray counterparts for three of the IGR sources: IGR J14091-6108, IGR J18088-2741, and IGR J18381-0924. The first two have very hard spectra in the Chandra band that can be described by a power-law with photon indices of Gamma = 0.6+/-0.4 and -0.7(+0.4)(-0.3), respectively (90% confidence errors are given), and both have a unique near-IR counterpart consistent with the Chandra position. IGR J14091-6108 also displays a strong iron line and a relatively low X-ray luminosity, and we argue that the most likely source type is a Cataclysmic Variable (CV), although we do not completely rule out the possibility of a High Mass X-ray Binary. IGR J18088-2741 has an optical counterpart with a previously measured 6.84 hr periodicity, which may...

  19. Chandra Observations of Neutron Stars -- An Overview

    OpenAIRE

    Weisskopf, M. C.

    2002-01-01

    We present a brief review of Chandra observations of neutron stars, with a concentration on neutron stars in supernova remnants. The early Chandra results clearly demonstrate how critical the angular resolution has been in order to separate the neutron star emission from the surrounding nebulosity.

  20. Maximising the mileage from the Chandra podcasts

    Science.gov (United States)

    Arcand, K. K.; Watzke, M.

    2008-06-01

    NASA's Chandra X-ray Observatory captures X-ray images and measures spectra of many highenergy cosmic phenomena. There is a constant challenge to devise new and appropriate means to bring these potentially esoteric science results and concepts in a digestible way to the public. One of the ideas to address this challenge became the Chandra podcast.

  1. High frequency energy measurements

    International Nuclear Information System (INIS)

    High-frequency (> 100 MHz) energy measurements present special problems to the experimenter. Environment or available electronics often limit the applicability of a given detector type. The physical properties of many detectors are frequency dependent and in some cases, the physical effect employed can be frequency dependent. State-of-the-art measurements generally involve a detection scheme in association with high-speed electronics and a method of data recording. Events can be single or repetitive shot requiring real time, sampling, or digitizing data recording. Potential modification of the pulse by the detector and the associated electronics should not be overlooked. This presentation will review typical applications, methods of choosing a detector, and high-speed detectors. Special considerations and limitations of some applications and devices will be described

  2. Theoretical high energy physics

    International Nuclear Information System (INIS)

    Brief reports are given on the work of several professors. The following areas are included: quantum chromodynamics calculations using numerical lattice gauge theory and a high-speed parallel computer; the ''spin wave'' description of bosonic particles moving on a lattice with same-site exclusion; a high-temperature expansion to 13th order for the O(4)-symmetric φ4 model on a four-dimensional F4 lattice; spin waves and lattice bosons; superconductivity of C60; meson-meson interferometry in heavy-ion collisions; baryon number violation in the Standard Model in high-energy collisions; hard thermal loops in QCD; electromagnetic interactions of anyons; the relation between Bose-Einstein and BCS condensations; Euclidean wormholes with topology S1 x S2 x R; vacuum decay and symmetry breaking by radiative corrections; inflationary solutions to the cosmological horizon and flatness problems; and magnetically charged black holes

  3. High energy hadron colliders

    International Nuclear Information System (INIS)

    The more novel and important design considerations and features of high energy hadron colliders (pp or p anti p) are discussed. The paper does not attempt to be sufficient for making a complete design, but contains enough references to other papers necessary for doing so. Formulas are generally given without derivation, and notations are not consistent from section to section. For most formulas the derivation is transparent although the mathematics may be lengthy. Whenever obscure, an explanation of the procedure for derivation will be given in physical terms. Detailed mathematical derivations can be found in the references. 10 references

  4. High energy electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Parkhomchuk, V. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation)

    1997-09-01

    High energy electron cooling requires a very cold electron beam. The questions of using electron cooling with and without a magnetic field are presented for discussion at this workshop. The electron cooling method was suggested by G. Budker in the middle sixties. The original idea of the electron cooling was published in 1966. The design activities for the NAP-M project was started in November 1971 and the first run using a proton beam occurred in September 1973. The first experiment with both electron and proton beams was started in May 1974. In this experiment good result was achieved very close to theoretical prediction for a usual two component plasma heat exchange.

  5. COLOR-MAGNITUDE RELATIONS OF ACTIVE AND NON-ACTIVE GALAXIES IN THE CHANDRA DEEP FIELDS: HIGH-REDSHIFT CONSTRAINTS AND STELLAR-MASS SELECTION EFFECTS

    International Nuclear Information System (INIS)

    We extend color-magnitude relations for moderate-luminosity X-ray active galactic nucleus (AGN) hosts and non-AGN galaxies through the galaxy formation epoch (z ∼ 1-4) in the Chandra Deep Field-North and Chandra Deep Field-South (CDF-N and CDF-S, respectively; jointly CDFs) surveys. This study was enabled by the deepest available X-ray data from the 2 Ms CDF surveys as well as complementary ultradeep multiwavelength data in these regions. We utilized analyses of color-magnitude diagrams (CMDs) to assess the role of moderate-luminosity AGNs in galaxy evolution. First, we confirm some previous results and extend them to higher redshifts, finding, for example, that (1) there is no apparent color bimodality (i.e., the lack of an obvious red sequence and blue cloud) for AGN hosts from z ∼ 0to2, but non-AGN galaxy color bimodality exists up to z ∼ 3 and the relative fraction of red-sequence galaxies generally increases as the redshift decreases (consistent with a blue-to-red migration of galaxies), (2) most AGNs reside in massive hosts and the AGN fraction rises strongly toward higher stellar mass, up to z ∼ 2-3, and (3) the colors of both AGN hosts and non-AGN galaxies become redder as the stellar mass increases, up to z ∼ 2-3. Second, we point out that, in order to obtain a complete and reliable picture, it is critical to use mass-matched samples to examine color-magnitude relations of AGN hosts and non-AGN galaxies. We show that for mass-matched samples up to z ∼ 2-3, AGN hosts lie in the same region of the CMD as non-AGN galaxies; i.e., there is no specific clustering of AGN hosts in the CMD around the red sequence, the top of the blue cloud, or the green valley in between. The AGN fraction (∼ 10%) is mostly independent of host-galaxy color, providing an indication of the duty cycle of supermassive black hole growth in typical massive galaxies. These results are in contrast to those obtained with non-mass-matched samples where there is apparent AGN

  6. Chandra Finds Oxygen and Neon Ring in Ashes of Exploded Star

    Science.gov (United States)

    2000-01-01

    NASA's Chandra X-ray Observatory has revealed an expanding ring-like structure of oxygen and neon that was hurled into space by the explosion of a massive star. The image of E0102-72 provides unprecedented details about the creation and dispersal of heavy elements necessary to form planets like Earth. The results were reported by Professor Claude Canizares of the Massachusetts Institute of Technology (MIT), Cambridge, at the 195th national meeting of the American Astronomical Society in Atlanta, Ga. Drs. Kathryn Flanagan, David Davis, and John Houck of MIT collaborated with Canizares in this investigation. E0102-72 is the remnant of a supernova explosion located in our neighbor galaxy, the Small Magellanic Cloud, nearly 200,000 light years away. It was created by the explosion of a star that was more than ten times as massive as our Sun. We are seeing the aftermath of the explosion a thousand or more years after the outburst. Shock waves are heating gas to temperatures of nearly 10 million degrees, so it glows with X-rays that are detected by Chandra's instruments. By using the High Energy Transmission Grating Spectrometer (HETG), astronomers were able to pinpoint the distribution of each chemical element individually and measure the velocities of different parts of the expanding ring. They also show the shock wave in a kind of "freeze-frame," revealing the progressive heating of the stellar matter as it plows into the surrounding gas. This is the first time such detailed X-ray information has ever been obtained for a supernova remnant, and should provide critical clues to the nature of supernovas. The grating spectrometer, which was built by an MIT team led by Canizares, spreads the X-rays according to their wavelength, giving distinct images of the object at specific wavelengths characteristic of each chemical element. Small wavelength shifts caused by the Doppler effect are used to measure the expansion velocities of each element independently. "We've been

  7. Prospects at high energies

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, C.

    1988-11-01

    I discuss some possibilities for neutrino experiments in the fixed-target environment of the SPS, Tevatron, and UNK, with their primary proton beams of 0.4, 0.9, and 3.0 TeV. The emphasis is on unfinished business: issues that have been recognized for some time, but not yet resolved. Then I turn to prospects for proton-proton colliders to explore the 1-TeV scale. I review the motivation for new physics in the neighborhood of 1 TeV and mention some discovery possibilities for high-energy, high-luminosity hadron colliders and the implications they would have for neutrino physics. I raise the possibility of the direct study of neutrino interactions in hadron colliders. I close with a report on the status of the SSC project. 38 refs., 17 figs.

  8. Prospects at high energies

    International Nuclear Information System (INIS)

    I discuss some possibilities for neutrino experiments in the fixed-target environment of the SPS, Tevatron, and UNK, with their primary proton beams of 0.4, 0.9, and 3.0 TeV. The emphasis is on unfinished business: issues that have been recognized for some time, but not yet resolved. Then I turn to prospects for proton-proton colliders to explore the 1-TeV scale. I review the motivation for new physics in the neighborhood of 1 TeV and mention some discovery possibilities for high-energy, high-luminosity hadron colliders and the implications they would have for neutrino physics. I raise the possibility of the direct study of neutrino interactions in hadron colliders. I close with a report on the status of the SSC project. 38 refs., 17 figs

  9. A Full Year's Chandra Exposure on SDSS Quasars from the Chandra Multiwavelength Project

    CERN Document Server

    Green, Paul J; Richards, G T; Barkhouse, W A; Constantin, A; Haggard, D; Karovska, M; Kim, D -W; Kim, M; Vikhlinin, A; Mossman, A; Silverman, J D; Anderson, S F; Kashyap, V; Wilkes, B J; Tananbaum, H

    2008-01-01

    We study the spectral energy distributions and evolution of a large sample of optically selected quasars from the Sloan Digital Sky Survey (SDSS) that were observed in 323 Chandra images analyzed by the Chandra Multiwavelength Project (ChaMP). Our highest-confidence matched sample includes 1135 X-ray detected quasars in the redshift range 0.23 QSOs detected, we find no evidence for evolution out to z~5 for either the X-ray photon index Gamma or for the ratio of optical/UV to X-ray flux alpha_ox. About 10% of detected QSOs are obscured (Nh>1E22), but the fraction might reach ~1/3 if most non-detections are absorbed. We confirm a significant correlation between alpha_ox and optical luminosity, but it flattens or disappears for fainter AGN alone. Gamma hardens significantly both towards higher X-ray luminosity, and for relatively X-ray loud quasars. These trends may represent a relative increase in non-thermal X-ray emission, and our findings thereby strengthen analogies between Galactic black hole binaries and ...

  10. Flickering Quasar Helps Chandra Measure the Expansion Rate of the universe

    Science.gov (United States)

    2000-11-01

    Astronomers using the Chandra X-ray Observatory have identified a flickering, four-way mirage image of a distant quasar. A carefully planned observation of this mirage may be used to determine the expansion rate of the universe as well as to measure the distances to extragalactic objects, arguably two of the most important pursuits in modern astronomy. quasar RX J0911.4+0551 This figure is a composite of the X-ray image of the gravitational lens RX J0911.4+551 (top panel) and the light curves of the lensed images A2 (left panel) and A1 (right panel). Credit: NASA George Chartas, senior research associate at The Pennsylvania State University (Penn State) and Marshall W. Bautz, principal research scientist at the Massachusetts Institute of Technology (MIT) Center for Space Research, present their findings today at the meeting of the High Energy Astrophysics Division of the American Astronomical Society in Honolulu, Hawaii. "With a carefully planned follow-up, the Chandra observation of quasar RX J0911.4+0551 may lead to a measurement of the Hubble constant, the expansion rate of the universe, in less than a day," said Chartas. The observation would be done not with mirrors but with mirages--four images of a single quasar that capture the quasar's light at different moments of time due to the speed of light and the location of the mirages. Quasars are extremely distant galaxies with cores that glow with the intensity of 10 trillion Suns, a phenomenon likely powered by a supermassive black hole in the heart of the galaxy. This single "point source" image of a quasar may appear as four or five sources when the quasar--from our vantage point on Earth--is behind a massive intervening deflector, such as a dim galaxy. A mirage of images form when the gravity of the intervening deflector forces light rays to bend and take different paths to reach us. The time it takes for light to reach us from the distant object will depend on which path a ray decides to take. "An

  11. NuSTAR AND CHANDRA INSIGHT INTO THE NATURE OF THE 3-40 keV NUCLEAR EMISSION IN NGC 253

    Energy Technology Data Exchange (ETDEWEB)

    Lehmer, B. D. [Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Wik, D. R.; Hornschemeier, A. E.; Ptak, A.; Leyder, J.-C.; Venters, T.; Zhang, W. W. [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Antoniou, V. [Department of Physics and Astronomy, Iowa State University, 12 Physics Hall, Ames, IA 50011 (United States); Argo, M. K. [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Bechtol, K. [Kavli Institute for Cosmological Physics, Chicago, IL 60637 (United States); Boggs, S.; Craig, W. W.; Krivonos, R. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, F. E. [DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Harrison, F. A. [Caltech Division of Physics, Mathematics and Astronomy, Pasadena, CA 91125 (United States); Maccarone, T. J. [School of Physics and Astronomy, University of Southampton, Highfield SO17 IBJ (United Kingdom); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Zezas, A. [Physics Department, University of Crete, Heraklion (Greece)

    2013-07-10

    We present results from three nearly simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR) and Chandra monitoring observations between 2012 September 2 and 2012 November 16 of the local star-forming galaxy NGC 253. The 3-40 keV intensity of the inner {approx}20 arcsec ({approx}400 pc) nuclear region, as measured by NuSTAR, varied by a factor of {approx}2 across the three monitoring observations. The Chandra data reveal that the nuclear region contains three bright X-ray sources, including a luminous (L{sub 2-10{sub keV}} {approx} few Multiplication-Sign 10{sup 39} erg s{sup -1}) point source located {approx}1 arcsec from the dynamical center of the galaxy (within the 3{sigma} positional uncertainty of the dynamical center); this source drives the overall variability of the nuclear region at energies {approx}>3 keV. We make use of the variability to measure the spectra of this single hard X-ray source when it was in bright states. The spectra are well described by an absorbed (N{sub H} Almost-Equal-To 1.6 Multiplication-Sign 10{sup 23} cm{sup -2}) broken power-law model with spectral slopes and break energies that are typical of ultraluminous X-ray sources (ULXs), but not active galactic nuclei (AGNs). A previous Chandra observation in 2003 showed a hard X-ray point source of similar luminosity to the 2012 source that was also near the dynamical center ({theta} Almost-Equal-To 0.4 arcsec); however, this source was offset from the 2012 source position by Almost-Equal-To 1 arcsec. We show that the probability of the 2003 and 2012 hard X-ray sources being unrelated is >>99.99% based on the Chandra spatial localizations. Interestingly, the Chandra spectrum of the 2003 source (3-8 keV) is shallower in slope than that of the 2012 hard X-ray source. Its proximity to the dynamical center and harder Chandra spectrum indicate that the 2003 source is a better AGN candidate than any of the sources detected in our 2012 campaign; however, we were unable to rule out a ULX

  12. NuSTAR AND CHANDRA INSIGHT INTO THE NATURE OF THE 3-40 keV NUCLEAR EMISSION IN NGC 253

    International Nuclear Information System (INIS)

    We present results from three nearly simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR) and Chandra monitoring observations between 2012 September 2 and 2012 November 16 of the local star-forming galaxy NGC 253. The 3-40 keV intensity of the inner ∼20 arcsec (∼400 pc) nuclear region, as measured by NuSTAR, varied by a factor of ∼2 across the three monitoring observations. The Chandra data reveal that the nuclear region contains three bright X-ray sources, including a luminous (L2-10keV ∼ few × 1039 erg s–1) point source located ∼1 arcsec from the dynamical center of the galaxy (within the 3σ positional uncertainty of the dynamical center); this source drives the overall variability of the nuclear region at energies ∼>3 keV. We make use of the variability to measure the spectra of this single hard X-ray source when it was in bright states. The spectra are well described by an absorbed (NH ≈ 1.6 × 1023 cm–2) broken power-law model with spectral slopes and break energies that are typical of ultraluminous X-ray sources (ULXs), but not active galactic nuclei (AGNs). A previous Chandra observation in 2003 showed a hard X-ray point source of similar luminosity to the 2012 source that was also near the dynamical center (θ ≈ 0.4 arcsec); however, this source was offset from the 2012 source position by ≈1 arcsec. We show that the probability of the 2003 and 2012 hard X-ray sources being unrelated is >>99.99% based on the Chandra spatial localizations. Interestingly, the Chandra spectrum of the 2003 source (3-8 keV) is shallower in slope than that of the 2012 hard X-ray source. Its proximity to the dynamical center and harder Chandra spectrum indicate that the 2003 source is a better AGN candidate than any of the sources detected in our 2012 campaign; however, we were unable to rule out a ULX nature for this source. Future NuSTAR and Chandra monitoring would be well equipped to break the degeneracy between the AGN and ULX nature of the 2003

  13. High energy physics

    International Nuclear Information System (INIS)

    This proposal is for the continuation of the High Energy Physics program at the University of California at Riverside. In hadron collider physics the authors will complete their transition from experiment UA1 at CERN to the DZERO experiment at Fermilab. On experiment UA1 their effort will concentrate on data analysis at Riverside. At Fermilab they will coordinate the high voltage system for all detector elements. They will also carry out hardware/software development for the D0 muon detector. The TPC/Two-Gamma experiment has completed its present phase of data-taking after accumulating 160 pb-1 of luminosity. The UC Riverside group will continue data and physics analysis and make minor hardware improvement for the high luminosity run. The UC Riverside group is participating in design and implementation of the data acquisition system for the OPAL experiment at LEP. Mechanical and electronics construction of the OPAL hadron calorimeter strip readout system is proceeding on schedule. Data analysis and Monte Carlo detector simulation efforts are proceeding in preparation for the first physics run when IEP operation comenses in fall 1989

  14. High Energy Density Capacitors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA?s future space science missions cannot be realized without the state of the art energy storage devices which require high energy density, high reliability, and...

  15. High energy magnetic excitations

    International Nuclear Information System (INIS)

    The report emphasizes that the current development in condensed matter physics opens a research field fit to inelastic neutron scattering experiments in the eV range which is easilly accessed by spallation neutron sources. Several important subjects adopted at thermal reactors are shown. It is desired to extend the implementation of the spectroscopic experiments for investigation of higher energy magnetic excitations. For La2CuO4, which is the mother crystal of the first high Tc materials found by Bednortz and Muller, it seems to be believed that the magnetism is well characterized by the two-dimensional Heisenberg antiferromagnetic Hamiltonian, and it is widely accepted that the magnetism is a most probable progenitor of high Tc superconductors. The unusual properties of spin correlations in this crystal have been studied extensively by standard neutron scattering techniques with steady neutrons at BNL. FeSi is not ordered magnetically but shows a very unique feature of temperature induced magnetism, which also has been studied extensively by using the thermal neutron scattering technique at BNL. In these experiments, polarized neutrons are indispensable to extract the clean magnetic components out of other components of non-magnetic scattering. (N.K.)

  16. Chandra and Swift Observations of Unidentified Fermi-LAT Objects

    Science.gov (United States)

    Donato, Davide; Cheung, T.; Gehrels, N.

    2010-02-01

    In the last year we targeted some of the unidentified Fermi-LAT objects (UFOs) at high Galactic latitude with Chandra and Swift in order to determine the basic properties (positions, fluxes, hardness ratios) of all X-ray sources within the Fermi-LAT localization circles. These satellites enable us to detect the X-ray conterparts with a flux limit that is at least an order of magnitude lower than achieved in extant RASS data and to further follow-up at other wavelengths, with the ultimate goal to reveal the nature of these enigmatic gamma-ray sources. Here we present the results obtained with 5 Chandra pointings of high Galactic latitude UFOs in the Fermi-LAT 3-months bright source list. The association of detected X-ray sources within the improved 11-months Fermi-LAT localization circles with available optical and radio observations is discussed.

  17. Applications for edge detection techniques using Chandra and XMM-Newton data: galaxy clusters and beyond

    Science.gov (United States)

    Walker, S. A.; Sanders, J. S.; Fabian, A. C.

    2016-09-01

    The unrivalled spatial resolution of the Chandra X-ray observatory has allowed many breakthroughs to be made in high-energy astrophysics. Here we explore applications of Gaussian gradient magnitude (GGM) filtering to X-ray data, which dramatically improves the clarity of surface brightness edges in X-ray observations, and maps gradients in X-ray surface brightness over a range of spatial scales. In galaxy clusters, we find that this method is able to reveal remarkable substructure behind the cold fronts in Abell 2142 and Abell 496, possibly the result of Kelvin-Helmholtz instabilities. In Abell 2319 and Abell 3667, we demonstrate that the GGM filter can provide a straightforward way of mapping variations in the widths and jump ratios along the lengths of cold fronts. We present results from our ongoing programme of analysing the Chandra and XMM-Newton archives with the GGM filter. In the Perseus cluster, we identify a previously unseen edge around 850 kpc from the core to the east, lying outside a known large-scale cold front, which is possibly a bow shock. In MKW 3s we find an unusual `V' shape surface brightness enhancement starting at the cluster core, which may be linked to the AGN jet. In the Crab nebula a new, moving feature in the outer part of the torus is identified which moves across the plane of the sky at a speed of ˜0.1c, and lies much further from the central pulsar than the previous motions seen by Chandra.

  18. FSU High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Prosper, Harrison B. [Florida State University; Adams, Todd [Florida State University; Askew, Andrew [Florida State University; Berg, Bernd [Florida State University; Blessing, Susan K. [Florida State University; Okui, Takemichi [Florida State University; Owens, Joseph F. [Florida State University; Reina, Laura [Florida State University; Wahl, Horst D. [Florida State University

    2014-12-01

    The High Energy Physics group at Florida State University (FSU), which was established in 1958, is engaged in the study of the fundamental constituents of matter and the laws by which they interact. The group comprises theoretical and experimental physicists, who sometimes collaborate on projects of mutual interest. The report highlights the main recent achievements of the group. Significant, recent, achievements of the group’s theoretical physicists include progress in making precise predictions in the theory of the Higgs boson and its associated processes, and in the theoretical understanding of mathematical quantities called parton distribution functions that are related to the structure of composite particles such as the proton. These functions are needed to compare data from particle collisions, such as the proton-proton collisions at the CERN Large Hadron Collider (LHC), with theoretical predictions. The report also describes the progress in providing analogous functions for heavy nuclei, which find application in neutrino physics. The report highlights progress in understanding quantum field theory on a lattice of points in space and time (an area of study called lattice field theory), the progress in constructing several theories of potential new physics that can be tested at the LHC, and interesting new ideas in the theory of the inflationary expansion of the very early universe. The focus of the experimental physicists is the Compact Muon Solenoid (CMS) experiment at CERN. The report, however, also includes results from the D0 experiment at Fermilab to which the group made numerous contributions over a period of many years. The experimental group is particularly interested in looking for new physics at the LHC that may provide the necessary insight to extend the standard model (SM) of particle physics. Indeed, the search for new physics is the primary task of contemporary particle physics, one motivated by the need to explain certain facts, such as the

  19. The Chandra X-Ray Optics

    CERN Document Server

    Weisskopf, Martin C

    2011-01-01

    Significant advances in science always take place when the state of the art in instrumentation improves dramatically. NASA's Chandra X-Ray Observatory represents such an advance. Launched in July of 1999, Chandra is an observatory designed to study the x-ray emission from all categories of astronomical objects --- from comets, planets, and normal stars to quasars, galaxies, and clusters of galaxies. At the heart of this observatory is the precision X-Ray optic that has been vital for Chandra's outstanding success and which features an angular resolution improved by an order of magnitude compared to its forerunners. The Chandra mission is now entering its 13-th year of operation. Given that the Observatory was designed for a minimum of 3 years of operation testifies to its robust and carefully thought out design. We review the design and construction of the remarkable telescope, present examples of its usage for astronomy and astrophysics, and speculate upon the future.

  20. High energy plasma accelerators

    International Nuclear Information System (INIS)

    Colinear intense laser beams ω0, kappa0 and ω1, kappa1 shone on a plasma with frequency separation equal to the electron plasma frequency ω/sub pe/ are capable of creating a coherent large longitudinal electric field E/sub L/ = mc ω/sub pe//e of the order of 1GeV/cm for a plasma density of 1018 cm-3 through the laser beat excitation of plasma oscillations. Accompanying favorable and deleterious physical effects using this process for a high energy beat-wave accelerator are discussed: the longitudinal dephasing, pump depletion, the transverse laser diffraction, plasma turbulence effects, self-steepening, self-focusing, etc. The basic equation, the driven nonlinear Schroedinger equation, is derived to describe this system. Advanced accelerator concepts to overcome some of these problems are proposed, including the plasma fiber accelerator of various variations. An advanced laser architecture suitable for the beat-wave accelerator is suggested. Accelerator physics issues such as the luminosity are discussed. Applications of the present process to the current drive in a plasma and to the excitation of collective oscillations within nuclei are also discussed

  1. High energy physics research

    International Nuclear Information System (INIS)

    This is a progress report on the first year of the five year proposal of the UCSD high energy physics group. The main activity of our group continues to be the L3 experiment at LEP. During the last year in L3, we have worked principally on physics analysis. We have also fulfilled our duties in running the detector and contributing to L3 software and computing. In addition, we have made a major effort toward the development of the GEM detector at the SSC. Our SSC work is done in collaboration with the other UCSD groups which are primarily supported by the NSF. In this progress report, we will review our recent activities and describe the current status of the group. Some of the publications and documents which display the work of our group over the last year are included as appendices. We will also outline our research plan to continue our participation in L3 physics and upgrades and to work on the design and construction of the GEM detector

  2. HDE 245059: A Weak-Lined T Tauri Binary Revealed by Chandra and Keck

    CERN Document Server

    Saavedra, C Baldovin; Duchêne, G; Güdel, M; Skinner, S L; Paerels, F B S; Ghez, A; McCabe, C

    2009-01-01

    We present the Chandra High Energy Transmission Grating Spectrometer (HETGS) and Keck observations of HDE 245059, a young weak-lined T Tauri star (WTTS), member of the pre-main sequence group in the Lambda Orionis Cluster. Our high spatial resolution, near-infrared observations with Keck reveal that HDE 245059 a binary separated by 0.87". Based on this new information we have obtained an estimate of the masses of the binary components; 3M_{sun} and 2.5M_{sun} for the north and south components, respectively. We have estimated the age of the system to be ~2-3 Myr. We detect both components of the binary in the zeroth order Chandra image and in the grating spectra. Our fits to the spectrum of the binary have shown that the emission is dominated by a plasma between 8 and 15 MK, a soft component at 4 MK and a hard component at 50 MK are also detected. The value of the hydrogen column density was low, 8 x 10^{19} cm^{-2}, likely due to the clearing of the inner region of the Lambda Orionis cloud. The abundance pat...

  3. The Chandra/HETG view of NGC 1365 in a Compton-thick state

    CERN Document Server

    Nardini, E; Reeves, J N; Braito, V; Risaliti, G; Costa, M

    2015-01-01

    We present the analysis of a Chandra High-Energy Transmission Grating (HETG) observation of the local Seyfert galaxy NGC 1365. The source, well known for its dramatic X-ray spectral variability, was caught in a reflection-dominated, Compton-thick state. The high spatial resolution afforded by Chandra allowed us to isolate the soft X-ray emission from the active nucleus, neglecting most of the contribution from the kpc-scale starburst ring. The HETG spectra thus revealed a wealth of He- and H-like lines from photoionized gas, whereas in larger aperture observations these are almost exclusively produced through collisional ionization in the circumnuclear environment. Once the residual thermal component is accounted for, the emission-line properties of the photoionized region close to the hard X-ray continuum source indicate that NGC 1365 has some similarities to the local population of obscured active galaxies. In spite of the limited overall data quality, several soft X-ray lines seem to have fairly broad prof...

  4. Chandra Observations of SNR RCW 103

    OpenAIRE

    Frank, Kari A.; Burrows, David N.; Park, Sangwook

    2015-01-01

    We analyze three Chandra observations, with a combined exposure time of 99 ks, of the Galactic supernova remnant RCW 103, a young supernova remnant, previously with no clear detection of metal-rich ejecta. Based on our imaging and spectral analyses of these deep Chandra data, we find evidence for metal-rich ejecta emission scattered throughout the remnant. X-ray emission from the shocked ejecta is generally weak, and the shocked circumstellar medium (CSM) is a largely dominant component acros...

  5. X-ray Monitoring of Gravitational Lenses With Chandra

    CERN Document Server

    Chen, Bin; Kochanek, Christopher S; Chartas, George; Blackburne, Jeffery A; Morgan, Christopher W

    2012-01-01

    We present \\emph{Chandra} monitoring data for six gravitationally lensed quasars: QJ 0158$-$4325, HE 0435$-$1223, HE 1104$-$1805, SDSS 0924+0219, SDSS 1004+4112, and Q 2237+0305. We detect X-ray microlensing variability in all six lenses with high confidence. We detect energy dependent microlensing in HE 0435$-$1223, SDSS 1004+4112, SDSS 0924+0219 and Q 2237+0305. We present a detailed spectral analysis for each lens, and find that simple power-law models plus Gaussian emission lines give good fits to the spectra. We detect intrinsic spectral variability in two epochs of Q 2237+0305. We detect differential absorption between images in four lenses. We also detect the \\feka\\ emission line in all six lenses, and the Ni XXVII K$\\alpha$ line in two images of Q 2237+0305. The rest frame equivalent widths of the \\feka\\ lines are measured to be 0.4--1.2 keV, significantly higher than those measured in typical active galactic nuclei of similar X-ray luminosities. This suggests that the \\feka\\ emission region is more c...

  6. Chandra counterparts of CANDELS GOODS-S sources

    CERN Document Server

    Cappelluti, N; Fontana, A; Zamorani, G; Amorin, R; Castellano, M; Merlin, E; Santini, P; Elbaz, D; Schreiber, C; Shu, X; Wang, T; Dunlop, J S; Bourne, N; Bruce, V A; Buitrago, F; Michałowski, Michał J; Derriere, S; Ferguson, H C; Faber, S M; Vito, F

    2015-01-01

    Improving the capabilities of detecting faint X-ray sources is fundamental to increase the statistics on faint high-z AGN and star-forming galaxies.We performed a simultaneous Maximum Likelihood PSF fit in the [0.5-2] keV and [2-7] keV energy bands of the 4 Ms {\\em Chandra} Deep Field South (CDFS) data at the position of the 34930 CANDELS H-band selected galaxies. For each detected source we provide X-ray photometry and optical counterpart validation. We validated this technique by means of a raytracing simulation. We detected a total of 698 X-ray point-sources with a likelihood $\\mathcal{L}$$>$4.98 (i.e. $>$2.7$\\sigma$). We show that the prior knowledge of a deep sample of Optical-NIR galaxies leads to a significant increase of the detection of faint (i.e. $\\sim$10$^{-17}$ cgs in the [0.5-2] keV band) sources with respect to "blind" X-ray detections. By including previous catalogs, this work increases the total number of X-ray sources detected in the 4 Ms CDFS, CANDELS area to 793, which represents the large...

  7. Chandra X-Ray Observatory (CXO) on Orbit Animation

    Science.gov (United States)

    1999-01-01

    This is an on-orbit animation of the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF). In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the remnants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers worldwide better understand the structure and evolution of the universe by studying powerful sources of x-rays such as exploding stars, matter falling into black holes, and other exotic celestial objects. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission.

  8. TGCat : THE CHANDRA TRANSMISSION GRATING DATA CATALOG AND ARCHIVE

    International Nuclear Information System (INIS)

    The Chandra Transmission Grating Data Archive and Catalog (TGCat) provides easy access to analysis-ready products, specifically, high-resolution X-ray count spectra and their corresponding calibrations. The web interface makes it easy to find observations of a particular object, type of object, or type of observation; to quickly assess the quality and potential usefulness of the spectra from pre-computed summary plots; or to customize a view with an interactive plotter, optionally combining spectra over multiple orders or observations. Data and responses can be downloaded as a package or as individual files, and the query results themselves can be retrieved as ASCII or Virtual Observatory tables. Portable reprocessing scripts used to create the archive and which use the Chandra X-ray Center's (CXC's) software and other publicly available software are also available, facilitating standard or customized reprocessing from Level 1 CXC archival data to spectra and responses with minimal user interaction.

  9. High-energy neutrino fluxes from AGN populations inferred from X-ray surveys

    CERN Document Server

    Jacobsen, Idunn B; On, Alvina Y L; Saxton, Curtis J

    2015-01-01

    High-energy neutrinos and photons are complementary messengers, probing violent astrophysical processes and structural evolution of the Universe. X-ray and neutrino observations jointly constrain conditions in active galactic nuclei (AGN) jets: their baryonic and leptonic contents, and particle production efficiency. Testing two standard neutrino production models for local source Cen A \\citep{KT2008,BB2009}, we calculate the high-energy neutrino spectra of single AGN sources and derive the flux of high-energy neutrinos expected for the current epoch. Assuming that accretion determines both X-rays and particle creation, our parametric scaling relations predict neutrino yield in various AGN classes. We derive redshift-dependent number densities of each class, from {\\it Chandra} and {\\it Swift}/BAT X-ray luminosity functions \\citep{SGB2008,ACS2009}. We integrate the neutrino spectrum expected from the cumulative history of AGN (correcting for cosmological and source effects, e.g. jet orientation and beaming). B...

  10. NASA'S Chandra Finds Superfluid in Neutron Star's Core

    Science.gov (United States)

    2011-02-01

    NASA's Chandra X-ray Observatory has discovered the first direct evidence for a superfluid, a bizarre, friction-free state of matter, at the core of a neutron star. Superfluids created in laboratories on Earth exhibit remarkable properties, such as the ability to climb upward and escape airtight containers. The finding has important implications for understanding nuclear interactions in matter at the highest known densities. Neutron stars contain the densest known matter that is directly observable. One teaspoon of neutron star material weighs six billion tons. The pressure in the star's core is so high that most of the charged particles, electrons and protons, merge resulting in a star composed mostly of uncharged particles called neutrons. Two independent research teams studied the supernova remnant Cassiopeia A, or Cas A for short, the remains of a massive star 11,000 light years away that would have appeared to explode about 330 years ago as observed from Earth. Chandra data found a rapid decline in the temperature of the ultra-dense neutron star that remained after the supernova, showing that it had cooled by about four percent over a 10-year period. "This drop in temperature, although it sounds small, was really dramatic and surprising to see," said Dany Page of the National Autonomous University in Mexico, leader of a team with a paper published in the February 25, 2011 issue of the journal Physical Review Letters. "This means that something unusual is happening within this neutron star." Superfluids containing charged particles are also superconductors, meaning they act as perfect electrical conductors and never lose energy. The new results strongly suggest that the remaining protons in the star's core are in a superfluid state and, because they carry a charge, also form a superconductor. "The rapid cooling in Cas A's neutron star, seen with Chandra, is the first direct evidence that the cores of these neutron stars are, in fact, made of superfluid and

  11. Chandra Observes the End of an Era SN 1987A

    OpenAIRE

    Frank, Kari A.; Zhekov, Svetozar A.; Park, Sangwook; McCray, Richard; Dwek, Eli; Burrows, David N.

    2016-01-01

    Updated imaging and photometric results from Chandra observations of SN 1987A, covering the last 16 years, are presented. We find that the 0.5-2 keV light curve has remained constant at ~8x10^-12 erg s^-1 cm^-2 since 9500 days, with the 3-8 keV light curve continuing to increase until at least 10000 days. The expansion rate of the ring is found to be energy dependent, such that after day 6000 the ring expands faster in the 2-10 keV band than it does at energies

  12. Renewable Energy Riding High

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    China is putting greater emphasis on green energy as it tries to clean up industry and meet target for cuts in carbon emissions over the past two years, China has already leapfrogged competitors from Denmark, Germany, Spain and the United States to become the world's largest maker of wind turbines and solar panels. At the same time, the country is also taking steps to build more nuclear reactors and energy-efficient coal power plants.

  13. High energy neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Wiegand, C.

    1948-04-27

    It is the purpose of this paper to describe a neutron detector suitable for monitoring a flux of neutrons whose energy is greater than about 50 MeV. Detection of the neutrons is accomplished by their ability to induce fission in heavy elements. Kelly and Wiegand studied the neutron fission of Bi, Pb, Ti, Hg, Au, and Pt at various neutron energies and the presently described counter is an application of this work.

  14. Applications for edge detection techniques using Chandra and XMM-Newton data: galaxy clusters and beyond

    CERN Document Server

    Walker, S A; Fabian, A C

    2016-01-01

    The unrivalled spatial resolution of the Chandra X-ray observatory has allowed many breakthroughs to be made in high energy astrophysics. Here we explore applications of Gaussian Gradient Magnitude (GGM) filtering to X-ray data, which dramatically improves the clarity of surface brightness edges in X-ray observations, and maps gradients in X-ray surface brightness over a range of spatial scales. In galaxy clusters, we find that this method is able to reveal remarkable substructure behind the cold fronts in Abell 2142 and Abell 496, possibly the result of Kelvin Helmholtz instabilities. In Abell 2319 and Abell 3667, we demonstrate that the GGM filter can provide a straightforward way of mapping variations in the widths and jump ratios along the lengths of cold fronts. We present results from our ongoing programme of analysing the Chandra and XMM-Newton archives with the GGM filter. In the Perseus cluster we identify a previously unseen edge around 850 kpc from the core to the east, lying outside a known large ...

  15. A Deep Chandra X-ray Spectrum of the Accreting Young Star TW Hydrae

    CERN Document Server

    Brickhouse, N S; Dupree, A K; Luna, G J M; Wolk, S

    2010-01-01

    We present X-ray spectral analysis of the accreting young star TW Hydrae from a 489 ks observation using the Chandra High Energy Transmission Grating. The spectrum provides a rich set of diagnostics for electron temperature T_e, electron density N_e, hydrogen column density N_H, relative elemental abundances and velocities and reveals its source in 3 distinct regions of the stellar atmosphere: the stellar corona, the accretion shock, and a very large extended volume of warm postshock plasma. The presence of Mg XII, Si XIII, and Si XIV emission lines in the spectrum requires coronal structures at ~10 MK. Lower temperature lines (e.g., from O VIII, Ne IX, and Mg XI) formed at 2.5 MK appear more consistent with emission from an accretion shock. He-like Ne IX line ratio diagnostics indicate that T_e = 2.50 +/- 0.25 MK and N_e = 3.0 +/- 0.2 x 10^(12) cm^(-3) in the shock. These values agree well with standard magnetic accretion models. However, the Chandra observations significantly diverge from current model pred...

  16. EIS Data on the Chandra Deep Field South Released

    Science.gov (United States)

    2001-03-01

    The purpose of this note is to announce that the ESO Imaging Survey programme has released a full set of optical/infrared data covering the socalled Chandra Deep Field South (CDF-S) rapidly becoming a favoured target for cosmological studies in the southern hemisphere. The field was originally selected for deep X-ray observations with Chandra and XMM. The former have already been completed producing the deepest high-resolution X-ray image ever taken with a total integration time of one million seconds. The data obtained by EIS include J and Ks infrared observations of an area of 0.1 square degree nearly matching the Chandra image down to JAB ~ 23.4 and KAB ~ 22.6 and UU'BVRI optical observations over 0.25 square degree, matching the XMM field of view, reaching 5 s limiting magnitudes of U'AB = 26.0, UAB = 25.7, BAB = 26.4, VAB = 25.4, RA B = 25.5 and IA B = 24.7 mag, as measured within a 2 ´ FWHM aperture.

  17. High energy neutrinos from GRBs

    Energy Technology Data Exchange (ETDEWEB)

    De Paolis, F.; Ingrosso, G.; Orlando, D.; Perrone, L

    2001-05-01

    It is by now recognized that GRBs can accelerate protons to relativistic energies and that high density media may be present nearby the source. We compute the high-energy {gamma}-ray and neutrino fluxes from the decay of pions produced through the interaction of accelerated protons with nucleons in the surrounding medium. Then, we estimate the flux of high-energy muons induced on a detector by upward-going neutrinos interacting through charge current processes with the surrounding matter.

  18. High energy neutrinos from GRBs

    International Nuclear Information System (INIS)

    It is by now recognized that GRBs can accelerate protons to relativistic energies and that high density media may be present nearby the source. We compute the high-energy γ-ray and neutrino fluxes from the decay of pions produced through the interaction of accelerated protons with nucleons in the surrounding medium. Then, we estimate the flux of high-energy muons induced on a detector by upward-going neutrinos interacting through charge current processes with the surrounding matter

  19. A high-energy view of radio-loud AGN

    CERN Document Server

    Worrall, D M

    2004-01-01

    Seyfert galaxies and quasars were first discovered through optical and radio techniques, but in recent years high-energy emission, that can penetrate central gas and dust, has become essentially the defining characteristic of an AGN. AGNs with extended radio jets are of particular interest, since the jets signal source orientation. However, the jets extend into the cores, where they are faster and more compact. Special-relativistic effects then cause jet brightness and variability time-scales across the electromagnetic spectrum to be strong functions of jet orientation. Jet X-ray emission is confused, to varying degrees, with that from the central engine, but can be measured, at least in a statistical sense, through considerations of the multiwaveband spectrum and the level of intrinsic absorption. The rich high-energy structures found in jets which are resolved with Chandra inform our interpretation of the inner structures. In particular, it is found that shocks are prevalent and don't necessarily disrupt je...

  20. BROOKHAVEN: High energy gold

    International Nuclear Information System (INIS)

    On April 24, Brookhaven's Alternating Gradient Synchrotron (AGS) started to deliver gold ions at 11.4 GeV per nucleon (2,000 GeV per ion) to experimenters who were delighted not only to receive the world's highest energy gold beam but also to receive it on schedule

  1. High energy cosmic ray astronomy

    International Nuclear Information System (INIS)

    A brief introduction to High Energy Cosmic Ray Astronomy is presented. This field covers a 17 decade energy range (2.104-1020) eV. Recent discoveries done with gamma-ray detectors on-board satellites and ground-based Cherenkov devices are pushing for a fast development of new and innovative techniques, specially in the low energy region which includes the overlapping of satellite and ground-based measurements in the yet unexplored energy range 20 keV-250 GeV. Detection of unexpected extremely high energy events have triggered the interest of the international scientific community. (orig.)

  2. High energy nuclear structures

    International Nuclear Information System (INIS)

    Nuclear field theory has been applied to study nuclear matter as well as finite nuclei. Within the mean field approximation the known bulk properties of nuclei such as binding energy, density, and compressibility are well reproduced. Charge and matter distributions of closed shell nuclei are in good agreement with experimental results, so are rms radii and single-particle energy levels. In addition to the description of known nuclear structure the field theoretical approach may reveal entirely new nuclear phenomena, based on the explicite treatment of mesonic degrees of freedom. The existence of such abnormal nuclear states was proposed by Lee and Wick employing the sigma-model Lagrangian. There the non-linearity of the meson field equations allows for soliton solutions in the presence of nucleons, in particular the sigma-field may exhibit a kink. Some of these solutions are considered

  3. Computing in high energy physics

    International Nuclear Information System (INIS)

    The increasingly important role played by computing and computers in high energy physics is displayed in the 'Computing in High Energy Physics' series of conferences, bringing together experts in different aspects of computing - physicists, computer scientists, and vendors

  4. High Energy Vision: Processing X-rays

    CERN Document Server

    DePasquale, Joseph; Edmonds, Peter

    2015-01-01

    Astronomy is by nature a visual science. The high quality imagery produced by the world's observatories can be a key to effectively engaging with the public and helping to inspire the next generation of scientists. Creating compelling astronomical imagery can, however, be particularly challenging in the non-optical wavelength regimes. In the case of X-ray astronomy, where the amount of light available to create an image is severely limited, it is necessary to employ sophisticated image processing algorithms to translate light beyond human vision into imagery that is aesthetically pleasing while still being scientifically accurate. This paper provides a brief overview of the history of X-ray astronomy leading to the deployment of NASA's Chandra X-ray Observatory, followed by an examination of the specific challenges posed by processing X-ray imagery. The authors then explore image processing techniques used to mitigate such processing challenges in order to create effective public imagery for X-ray astronomy. ...

  5. Chandra Observations of Tycho’s Supernova Remnant

    Indian Academy of Sciences (India)

    U. Hwang; R. Petre; A. E. Szymkowiak; S. S. Holt

    2002-03-01

    We present a new Chandra observation of Tycho’s supernova remnant with the Advanced CCD Imaging Spectrometer. Multicolor X-ray imaging reveals new details of the outer shock and ejecta. At energies between 4 and 6 keV, the outline of the outer shock is clearly revealed in X-rays for the first time. The distribution of the emission from lines of Si and Fe are confirmed to have a different morphology from each other, and the Si ejecta are shown to extend to the blast shock at several locations. Characteristic spectra of the outer shock and ejecta are also presented.

  6. HIGH ENERGY LASER OPTICS

    OpenAIRE

    Christiansen, W.

    1980-01-01

    This paper reviews briefly the theoretical understanding and properties of optical resonators. Starting from the theory of stable laser resonators, unstable resonators are discussed with emphasis on understanding their properties that ensure near diffraction limited performance of high power lasers. The growing field of adaptive optics for laser transmission is also examined as an added means of improving far field performance of a laser under adverse circumstances. The improvements obtained ...

  7. High-energy communication

    CERN Multimedia

    CERN Communication Group

    2015-01-01

    On Wednesday at 10.40 a.m., the LHC operators declared “stable beams” after two years of technical stop and a few months of commissioning. It was an exciting day for all the teams involved, including those who worked on communicating the news to the public and the media on multiple platforms.   CERN’s most successful tweet on 3 June featured collision images from ALICE, ATLAS, CMS and LHCb and was shared 800 times by the Twitter audience. Live blogging, social media posts, a live webcast, and a constant outpouring of photos and videos: Wednesday morning was a crazy time for the communication teams from CERN, the experiments and various institutes around the world. Even though the event started very early in the morning (the live CCC blog started at 7 a.m. and the live webcast at 8.20 a.m.), the public and the media tuned in to follow and generously cover the start of the LHC’s physics run at an unprecedented energy of 13 TeV. The statistics showed th...

  8. Chandra Counterparts of CANDELS GOODS-S Sources

    Science.gov (United States)

    Cappelluti, N.; Comastri, A.; Fontana, A.; Zamorani, G.; Amorin, R.; Castellano, M.; Merlin, E.; Santini, P.; Elbaz, D.; Schreiber, C.; Shu, X.; Wang, T.; Dunlop, J. S.; Bourne, N.; Bruce, V. A.; Buitrago, F.; Michałowski, Michał J.; Derriere, S.; Ferguson, H. C.; Faber, S. M.; Vito, F.

    2016-06-01

    Improving the capabilities of detecting faint X-ray sources is fundamental for increasing the statistics on faint high-z active galactic nuclei (AGNs) and star-forming galaxies (SFGs). We performed a simultaneous maximum likelihood point-spread function fit in the [0.5–2] keV and [2–7] keV energy bands of the 4 Ms Chandra Deep Field South (CDFS) data at the position of the 34,930 CANDELS H-band selected galaxies. For each detected source we provide X-ray photometry and optical counterpart validation. We validated this technique by means of a ray-tracing simulation. We detected a total of 698 X-ray point sources with a likelihood { L }\\gt 4.98 (i.e., >2.7σ). We show that prior knowledge of a deep sample of optical–NIR galaxies leads to a significant increase in the detection of faint (i.e., ∼10‑17 cgs in the [0.5–2] keV band) sources with respect to “blind” X-ray detections. By including previous X-ray catalogs, this work increases the total number of X-ray sources detected in the 4 Ms CDFS, CANDELS area to 793, which represents the largest sample of extremely faint X-ray sources assembled to date. Our results suggest that a large fraction of the optical counterparts of our X-ray sources determined by likelihood ratio actually coincides with the priors used for the source detection. Most of the new detected sources are likely SFGs or faint, absorbed AGNs. We identified a few sources with putative photometric redshift z > 4. Despite the low number statistics and the uncertainties on the photo z, this sample significantly increases the number of X-ray-selected candidate high-z AGNs.

  9. Prospects of high energy physics

    International Nuclear Information System (INIS)

    High energy physics solves the question of the structure of matter. For experiments in this field using large accelerators it will be necessary to involve large groups of people of various orientations and specializations on a high professional level. This is manifest in the education of physicists at Moscow State University which for this purpose cooperates with the Joint Institute for Nuclear Research and the Institute for High Energy Physics in Serpukhov. International cooperation is immensely important for the development of high energy physics. Its interruption would have negative impact on development in this field both in the socialist and in the capitalist countries. The general relativity theory stands apart from this upsurge of high energy physics, mainly owing to the lack of experimental material. (Ha)

  10. High-energy spectroscopic astrophysics

    Science.gov (United States)

    Güdel, Manuel; Walter, Roland

    After three decades of intense research in X-ray and gamma-ray astronomy, the time was ripe to summarize basic knowledge on X-ray and gamma-ray spectroscopy for interested students and researchers ready to become involved in new high-energy missions. This volume exposes both the scientific basics and modern methods of high-energy spectroscopic astrophysics. The emphasis is on physical principles and observing methods rather than a discussion of particular classes of high-energy objects, but many examples and new results are included in the three chapters as well.

  11. Conference on High Energy Physics

    CERN Document Server

    2016-01-01

    Conference on High Energy Physics (HEP 2016) will be held from August 24 to 26, 2016 in Xi'an, China. This Conference will cover issues on High Energy Physics. It dedicates to creating a stage for exchanging the latest research results and sharing the advanced research methods. HEP 2016 will be an important platform for inspiring international and interdisciplinary exchange at the forefront of High Energy Physics. The Conference will bring together researchers, engineers, technicians and academicians from all over the world, and we cordially invite you to take this opportunity to join us for academic exchange and visit the ancient city of Xi’an.

  12. High energy physics

    International Nuclear Information System (INIS)

    Hadron collider studies will focus on: (i) the search for the top quark with the newly installed D0 detector at the Fermilab Tevatron collider, (ii) the upgrade of the D0 detector to match the new main injector luminosity and (iii) R ampersand D on silicon microstrip tracking devices for the SSC. High statistics studies of Z0 decay will continue with the OPAL detector at LEP. These studies will include a direct measurement of Z decay to neutrinos, the search for Higgs and heavy quark decays of Z. Preparations for the Large Scintillation Neutrino Detector (LSND) to measure neutrino oscillations at LAMPF will focus on data acquisition and testing of photomultiplier tubes. In the theoretical area E. Ma will concentrate on mass-generating radiative mechanisms for light quarks and leptons in renormalizable gauge field theories. J. Wudka's program includes a detailed investigation of the magnetic-flip approach to the solar neutrino

  13. High energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Kernan, A.; Shen, B.C.; Ma, E.

    1997-07-01

    Hadron collider studies will focus on: (i) the search for the top quark with the newly installed D0 detector at the Fermilab Tevatron collider, (ii) the upgrade of the D0 detector to match the new main injector luminosity and (iii) R&D on silicon microstrip tracking devices for the SSC. High statistics studies of Z{sup 0} decay will continue with the OPAL detector at LEP. These studies will include a direct measurement of Z decay to neutrinos, the search for Higgs and heavy quark decays of Z. Preparations for the Large Scintillation Neutrino Detector (LSND) to measure neutrino oscillations at LAMPF will focus on data acquisition and testing of photomultiplier tubes. In the theoretical area E. Ma will concentrate on mass-generating radiative mechanisms for light quarks and leptons in renormalizable gauge field theories. J. Wudka`s program includes a detailed investigation of the magnetic-flip approach to the solar neutrino.

  14. Deeper Chandra Follow-up of Cygnus TeV Source Perpetuates Mystery

    Science.gov (United States)

    Butt, Yousaf M.; Drake, Jeremy; Benaglia, Paula; Combi, Jorge A.; Dame, Thomas; Miniati, Francesco; Romero, Gustavo E.

    2006-05-01

    A 50 ks Chandra observation of the unidentified TeV source in Cygnus reported by the HEGRA collaboration reveals no obvious diffuse X-ray counterpart. However, 240 pointlike X-ray sources are detected within or nearby the extended TeV J2032+4130 source region, of which at least 36 are massive stars and two may be radio emitters. That the HEGRA source is a composite, having as a counterpart the multiple pointlike X-ray sources we observe, cannot be ruled out. Indeed, the distribution of pointlike X-ray sources appears nonuniform and concentrated broadly within the extent of the TeV source region. We offer a hypothesis for the origin of the very high energy gamma-ray emission in Cyg OB2 based on the local acceleration of TeV-range cosmic rays and the differential distribution of OB versus less massive stars in this association.

  15. High energy physics research

    International Nuclear Information System (INIS)

    The goal of this research is to understand the fundamental constituents of matter and their interactions. At this time, the following activities are underway: e+e- interactions and Z0 physics at CERN; studies to upgrade the L3 detector at LHC; very high statistics charm physics at Fermilab; search for the H particle at BNL; search for the fifth force; rare kaon decay experiments at BNL; study of B-meson physics at hadron colliders; e+e- pair creation by light at SLAC; R ampersand D related to SSC experiments and the GEM detector; and theoretical research in elementary particle physics and cosmology. The main additions to the activities described in detail in the original grant proposal are (1) an experiment at SLAC (E-144) to study strong-field QED effects in e-laser and γ-laser collisions, and (2) a search for the H particle at BNL (E-188). The R ampersand D efforts for the GEM detector have also considerably expanded. In this paper we give a brief status report for each activity currently under way

  16. [Research in high energy physics

    International Nuclear Information System (INIS)

    This report discusses progress in the following research in high energy physics: The crystal ball experiment; delco at PEP; proton decay experiment; MACRO detector; mark III detector; SLD detector; CLEO II detector; and the caltech L3 group

  17. High Energy Transport Code HETC

    International Nuclear Information System (INIS)

    The physics contained in the High Energy Transport Code (HETC), in particular the collision models, are discussed. An application using HETC as part of the CALOR code system is also given. 19 refs., 5 figs., 3 tabs

  18. Research in high energy physics

    International Nuclear Information System (INIS)

    This report discusses research being conducted in high energy physics in the following areas: quantum chromodynamics; drift chambers; proton-antiproton interactions; particle decays; particle production; polarimeters; quark-gluon plasma; and conformal field theory. (LSP)

  19. Computing in high energy physics

    International Nuclear Information System (INIS)

    Computing in high energy physics has changed over the years from being something one did on a slide-rule, through early computers, then a necessary evil to the position today where computers permeate all aspects of the subject from control of the apparatus to theoretical lattice gauge calculations. The state of the art, as well as new trends and hopes, were reflected in this year's 'Computing In High Energy Physics' conference held in the dreamy setting of Oxford's spires. The conference aimed to give a comprehensive overview, entailing a heavy schedule of 35 plenary talks plus 48 contributed papers in two afternoons of parallel sessions. In addition to high energy physics computing, a number of papers were given by experts in computing science, in line with the conference's aim – 'to bring together high energy physicists and computer scientists'

  20. Research in high energy physics

    International Nuclear Information System (INIS)

    This report discusses research being conducted in high energy physics in the following areas: quantum chromodynamics; drift chambers; proton-antiproton interactions; particle decays; particle production; polarimeters; quark-gluon plasma; and conformed field theory

  1. Problems of high energy physics

    International Nuclear Information System (INIS)

    Some problems of high energy physics are discussed. The main attention is paid to describibg the standard model. The model comprises quantum chromodynamics and electroweak interaction theory. The problem of CP breaking is considered as well. 8 refs.; 1 tab

  2. Research in high energy physics

    International Nuclear Information System (INIS)

    This report discusses research being conducted in high energy physics in the following areas; quantum chromodynamics; drift chambers; proton-antiproton interactions; particle decays; particle production; polarimeters; quark-gluon plasma; and conformed field theory

  3. Chandra-ASCA-RXTE observations of the micro-quasar GRS 1915+105

    CERN Document Server

    Lee, J C; Reynolds, C S; Fabian, A C; Blackman, E G

    2000-01-01

    A Chandra AO1 30ks HETGS observation of the X-ray transient micro-quasar GRS 1915+105 reveals absorption edges and faint line emission over the HETG energy range. We find from a preliminary analysis evidence for prominent neutral K edges associated with iron, silicon, magnesium, and tentatively sulphur. The column densities assuming solar abundances are consistent with ~ few x $10^{22} cm^{-2}$ in excess of the Galactic value, and may point to surrounding cold material associated with GRS 1915+105. Neutral Fe K$\\alpha$ emission, and ionized absorption from Fe XXV and Fe XXVI are resolved. We limit our discussion to the Chandra results.

  4. High energy physics

    International Nuclear Information System (INIS)

    The Counter Group continues to work on data analysis for Fermilab Experiment E653. Altogether, they expect several thousand reconstructed charm events and approximately 25 B pair events of which 12 have been observed thus far. Preparation continue for Fermilab Experiment E781, a high statistics study of charm baryon production. In the Theory Group, Cutkosky and collaborators study hadron phenomenology and non-perturbative QCD calculations. Levine has a long standing program in computational QED to obtain improved theoretical values for g-2 of the electron. Wolfenstein, Li, and their collaborators have worked on areas of weak interaction phenomenology that may yield insights beyond the standard model, e.g. CP violation and non-zero neutrino masses. Holman has been concerned with phase transitions in gauge theories relevant to cosmological problems. During 1991 most of the group effort was concentrated on the L3 experiment at CERN. Highlights of the results from the analysis of the Z degrees resonance include (a) a measurement of the strong coupling constant αs for b quarks (b) a precision measurement of the average time of B hadrons and (c) a direct determination of the number of light neutrino faculties from the reaction e+e- → ν bar νγ. We also began a major upgrade of the L3 luminosity monitor by replacing PWC chamber by a Si strip system in front of the BGO calorimeters. Finally we have continued our SSC R ampersand D work on BaF2 by joining the GEM collaboration

  5. HEASARC - The High Energy Astrophysics Science Archive Research Center

    Science.gov (United States)

    Smale, Alan P.

    2011-01-01

    The High Energy Astrophysics Science Archive Research Center (HEASARC) is NASA's archive for high-energy astrophysics and cosmic microwave background (CMB) data, supporting the broad science goals of NASA's Physics of the Cosmos theme. It provides vital scientific infrastructure to the community by standardizing science data formats and analysis programs, providing open access to NASA resources, and implementing powerful archive interfaces. Over the next five years the HEASARC will ingest observations from up to 12 operating missions, while serving data from these and over 30 archival missions to the community. The HEASARC archive presently contains over 37 TB of data, and will contain over 60 TB by the end of 2014. The HEASARC continues to secure major cost savings for NASA missions, providing a reusable mission-independent framework for reducing, analyzing, and archiving data. This approach was recognized in the NRC Portals to the Universe report (2007) as one of the HEASARC's great strengths. This poster describes the past and current activities of the HEASARC and our anticipated developments in coming years. These include preparations to support upcoming high energy missions (NuSTAR, Astro-H, GEMS) and ground-based and sub-orbital CMB experiments, as well as continued support of missions currently operating (Chandra, Fermi, RXTE, Suzaku, Swift, XMM-Newton and INTEGRAL). In 2012 the HEASARC (which now includes LAMBDA) will support the final nine-year WMAP data release. The HEASARC is also upgrading its archive querying and retrieval software with the new Xamin system in early release - and building on opportunities afforded by the growth of the Virtual Observatory and recent developments in virtual environments and cloud computing.

  6. The Chandra/HETG view of NGC 1365 in a Compton-thick state

    Science.gov (United States)

    Nardini, E.; Gofford, J.; Reeves, J. N.; Braito, V.; Risaliti, G.; Costa, M.

    2015-11-01

    We present the analysis of a Chandra High-Energy Transmission Grating (HETG) observation of the local Seyfert galaxy NGC 1365. The source, well known for its dramatic X-ray spectral variability, was caught in a reflection-dominated, Compton-thick state. The high spatial resolution afforded by Chandra allowed us to isolate the soft X-ray emission from the active nucleus, neglecting most of the contribution from the kpc-scale starburst ring. The HETG spectra thus revealed a wealth of He- and H-like lines from photoionized gas, whereas in larger aperture observations these are almost exclusively produced through collisional ionization in the circumnuclear environment. Once the residual thermal component is accounted for, the emission-line properties of the photoionized region close to the hard X-ray continuum source indicate that NGC 1365 has some similarities to the local population of obscured active galaxies. In spite of the limited overall data quality, several soft X-ray lines seem to have fairly broad profiles (˜800-1300 km s-1 full width at half-maximum), and a range of outflow velocities (up to ˜1600 km s-1, but possibly reaching a few thousand km s-1) appears to be involved. At higher energies, the Kα fluorescence line from neutral iron is resolved with >99 per cent confidence, and its width of ˜3000 km s-1 points to an origin from the same broad-line region clouds responsible for eclipsing the X-ray source and likely shielding the narrow-line region.

  7. High Energy Density Laboratory Astrophysics

    CERN Document Server

    Lebedev, Sergey V

    2007-01-01

    During the past decade, research teams around the world have developed astrophysics-relevant research utilizing high energy-density facilities such as intense lasers and z-pinches. Every two years, at the International conference on High Energy Density Laboratory Astrophysics, scientists interested in this emerging field discuss the progress in topics covering: - Stellar evolution, stellar envelopes, opacities, radiation transport - Planetary Interiors, high-pressure EOS, dense plasma atomic physics - Supernovae, gamma-ray bursts, exploding systems, strong shocks, turbulent mixing - Supernova remnants, shock processing, radiative shocks - Astrophysical jets, high-Mach-number flows, magnetized radiative jets, magnetic reconnection - Compact object accretion disks, x-ray photoionized plasmas - Ultrastrong fields, particle acceleration, collisionless shocks. These proceedings cover many of the invited and contributed papers presented at the 6th International Conference on High Energy Density Laboratory Astrophys...

  8. Chandra Observations of the A3266 Galaxy Cluster Merger

    OpenAIRE

    Henriksen, Mark J.; Tittley, Eric R.

    2002-01-01

    Analysis of a 30,000 s X-ray observation of the Abell 3266 galaxy cluster with the ACIS on board the Chandra Observatory has produced several new insights into the cluster merger. The intracluster medium has a non-monotonically decreasing radial abundance profile. We argue that the most plausible origin for the abundance enhancement is unmixed, high abundance subcluster gas from the merger. The enrichment consists of two stages: off-center deposition of a higher abundance material during a su...

  9. The discovery of X-rays from Venus with Chandra

    OpenAIRE

    Dennerl, K.; Burwitz, V.; Englhauser, J.; Lisse, C.; Wolk, S.

    2002-01-01

    On January 10 and 13, 2001, Venus was observed for the first time with an X-ray astronomy satellite. The observation, performed with the ACIS-I and LETG/ACIS-S instruments on Chandra, yielded data of high spatial, spectral, and temporal resolution. Venus is clearly detected as a half-lit crescent, with considerable brightening on the sunward limb. The morphology agrees well with that expected from fluorescent scattering of solar X-rays in the planetary atmosphere. The radiation is observed at...

  10. Discovery of X-rays from Venus with Chandra

    OpenAIRE

    Dennerl, K.; Burwitz, V.; Englhauser, J.; Lisse, C.; Wolk, S.

    2002-01-01

    On January 10 and 13, 2001, Venus was observed for the first time with an X-ray astronomy satellite. The observation, performed with the ACIS-I and LETG/ACIS-S instruments on Chandra, yielded data of high spatial, spectral, and temporal resolution. Venus is clearly detected as a half-lit crescent, with considerable brightening on the sunward limb. The morphology agrees well with that expected from fluorescent scattering of solar X-rays in the planetary atmosphere. The radiation is observed at...

  11. Discovery of X-rays from Mars with Chandra

    OpenAIRE

    Dennerl, Konrad

    2002-01-01

    On 4 July 2001, X-rays from Mars were detected for the first time. The observation was performed with the ACIS-I detector onboard Chandra and yielded data of high spatial and temporal resolution, together with spectral information. Mars is clearly detected as an almost fully illuminated disk, with an indication of limb brightening at the sunward side, accompanied by some fading on the opposite side. The morphology and the X-ray luminosity of ~4 MW are fully consistent with fluorescent scatter...

  12. X-Ray Spectroscopy of Optically Bright Planets using the Chandra Observatory

    Science.gov (United States)

    Ford, P. G.; Elsner, R. F.

    2005-01-01

    Since its launch in July 1999, Chandra's Advanced CCD Imaging Spectrometer (ACIS) has observed several planets (Venus, Mars, Jupiter and Saturn) and 6 comets. At 0.5 arc-second spatial resolution, ACIS detects individual x-ray photons with good quantum efficiency (25% at 0.6 KeV) and energy resolution (20% FWHM at 0.6 KeV). However, the ACIS CCDs are also sensitive to optical and near-infrared light, which is absorbed by optical blocking filters (OBFs) that eliminate optical contamination from all but the brightest extended sources, e.g., planets. .Jupiter at opposition subseconds approx.45 arc-seconds (90 CCD pixels.) Since Chandra is incapable of tracking a moving target, the planet takes 10 - 20 kiloseconds to move across the most sensitive ACIS CCD, after which the observatory must be re-pointed. Meanwhile, the OBF covering that CCD adds an opt,ical signal equivalent to approx.110 eV to each pixel that lies within thc outline of the Jovian disk. This has three consequences: (1) the observatory must be pointed away from Jupiter while CCD bias maps are constructed; (2) most x-rays from within the optical image will be misidentified as charged-particle background and ignored; and (3) those x-rays that are reported will bc assigned anomalously high energies. The same also applies to thc other planets, but is less serious since they are either dimmer at optical wavelengths, or they show less apparent motion across the sky, permitting reduced CCD exposure times: the optical contamination from Saturn acids approx.15 eV per pixel, and from Mars and Venus approx.31 eV. After analyzing a series of short .Jupiter observations in December 2000, ACIS parameters were optimized for the February 2003 opposition. CCD bias maps were constructed while Chandra pointed away from Jupiter, and the subsequent observations employed on-board software to ignore any pixel that contained less charge than that expected from optical leakage. In addition, ACIS was commanded to report 5 x 5

  13. Chandra Observes the End of an Era SN 1987A

    CERN Document Server

    Frank, Kari A; Park, Sangwook; McCray, Richard; Dwek, Eli; Burrows, David N

    2016-01-01

    Updated imaging and photometric results from Chandra observations of SN 1987A, covering the last 16 years, are presented. We find that the 0.5-2 keV light curve has remained constant at ~8x10^-12 erg s^-1 cm^-2 since 9500 days, with the 3-8 keV light curve continuing to increase until at least 10000 days. The expansion rate of the ring is found to be energy dependent, such that after day 6000 the ring expands faster in the 2-10 keV band than it does at energies <2 keV. Images show a reversal of the east-west asymmetry between 7000 and 8000 days after the explosion. The latest images suggest the southeastern side of the equatorial ring is beginning to fade. Consistent with the latest optical and infrared results, our Chandra analysis indicates the blast wave is now leaving the dense equatorial ring, which marks the beginning of a major change in the evolutionary phase of the supernova remnant 1987A.

  14. The BMW-Chandra survey. Serendipitous Source Catalogue

    CERN Document Server

    Romano, P; Campana, S; Moretti, A; Panzera, M R; Tagliaferri, G; Mottini, M

    2009-01-01

    We present the BMW-Chandra source catalogue derived from Chandra ACIS-I observations (exposure time >10ks) public as of March 2003 by using a wavelet detection algorithm (Lazzati et al. 1999; Campana et al. 1999). The catalogue contains a total of 21325 sources, 16758 of which are serendipitous. Our sky coverage in the soft band (0.5-2 keV, S/N =3) is ~8 deg^2 for F_X > 10^-13 erg cm^-2 s-1, and ~2 deg^2 for F_X >10^-15 erg cm^-2 s^-1. The catalogue contains information on positions, count rates (and errors) in three energy bands. (total, 0.5-7 keV; soft, 0.5-2 keV; and hard, 2-7keV), and in four additional energy bands, SB1 (0.5-1keV), SB2 (1-2 keV), HB1 (2-4 keV), and HB2 (4-7keV), as well as information on the source extension, and cross-matches with the FIRST, IRAS, 2MASS, and GSC-2 catalogues.

  15. The BMW-Chandra survey. Serendipitous Source Catalogue

    Science.gov (United States)

    Romano, P.; Mignani, R. P.; Campana, S.; Moretti, A.; Panzera, M. R.; Tagliaferri, G.; Mottini, M.

    2009-07-01

    We present the BMW-Chandra source catalogue derived from Chandra ACIS-I observations (exposure time > 10ks) public as of March 2003 by using a wavelet detection algorithm (Lazzati et al. 1999; Campana et al. 1999). The catalogue contains a total of 21325 sources, 16758 of which are serendipitous. Our sky coverage in the soft band (0.5-2keV, S/N=3) is ~ 8 deg2 for FX ≥ 10-13 erg cm-2 s-1, and ~ 2 deg2 for FX ≥ 10-15 erg cm-2 s-1. The catalogue contains information on positions, count rates (and errors) in three energy bands (total, 0.5-7keV; soft, 0.5-2keV; and hard, 2-7keV), and in four additional energy bands, SB1 (0.5-1keV), SB2 (1-2keV), HB1 (2-4keV), and HB2 (4-7keV), as well as information on the source extension, and cross-matches with the FIRST, IRAS, 2MASS, and GSC-2 catalogues.

  16. High Energy Neutrinos from Space

    CERN Document Server

    Gaisser, Thomas K

    2012-01-01

    This paper reviews the status of the search for high-energy neutrinos from astrophysical sources. Results from large neutrino telescopes in water (Antares, Baikal) and ice (IceCube) are discussed as well as observations from the surface with Auger and from high altitude with ANITA. Comments on IceTop, the surface component of IceCube are also included.

  17. Multiplicities in high energy interactions

    International Nuclear Information System (INIS)

    This paper reviews the data on multiplicities in high energy interactions. Results from e+e- annihilation, from neutrino interactions, and from hadronic collisions, both diffractive and nondiffractive, are compared and contrasted. The energy dependence of the mean charged multiplicity, , as well as the rapidity density at Y = 0 are presented. For hadronic collisions, the data on neutral pion production shows a strong correlation with . The heavy particle fractions increase with √s up to the highest energies. The charged particle multiplicity distributions for each type of reaction show a scaling behavior when expressed in terms of the mean. Attempts to understand this behavior, which was first predicted by Koba, Nielsen, and Olesen, are discussed. The multiplicity correlations and the energy variation of the shape of the KNO scaling distribution provide important constraints on models. Some extrapolations to the energies of the Superconducting Super Collider are made. 51 refs., 27 figs

  18. Assessing high wind energy penetration

    DEFF Research Database (Denmark)

    Tande, J.O.

    In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers...... expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project...... existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h....

  19. Chandra Captures Venus In A Whole New Light

    Science.gov (United States)

    2001-11-01

    Scientists have captured the first X-ray view of Venus using NASA's Chandra X-ray Observatory. The observations provide new information about the atmosphere of Venus and open a new window for examining Earth's sister planet. Venus in X-rays looks similar to Venus in visible light, but there are important differences. The optically visible Venus is due to the reflection of sunlight and, for the relative positions of Venus, Earth and Sun during these observations, shows a uniform half-crescent that is brightest toward the middle. The X-ray Venus is slightly less than a half-crescent and brighter on the limbs. The differences are due to the processes by which Venus shines in visible and X-ray light. The X-rays from Venus are produced by fluorescence, rather than reflection. Solar X-rays bombard the atmosphere of Venus, knock electrons out of the inner parts of the atoms, and excite the atoms to a higher energy level. The atoms almost immediately return to their lower energy state with the emission of a fluorescent X-ray. A similar process involving ultraviolet light produces the visible light from fluorescent lamps. For Venus, most of the fluorescent X-rays come from oxygen and carbon atoms between 120 and 140 kilometers (74 to 87 miles) above the planet's surface. In contrast, the optical light is reflected from clouds at a height of 50 to 70 kilometers (31 to 43 miles). As a result, Venus' Sun-lit hemisphere appears surrounded by an almost-transparent luminous shell in X-rays. Venus looks brightest at the limb since more luminous material is there. Venus X-ray/Optical Composite of Venus Credit: Xray: NASA/CXC/MPE/K.Dennerl et al., Optical: Konrad Dennerl "This opens up the exciting possibility of using X-ray observations to study regions of the atmosphere of Venus that are difficult to investigate by other means," said Konrad Dennerl of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, leader of an international team of scientists that

  20. High energy elastic hadron scattering

    International Nuclear Information System (INIS)

    The paper deals with the WA7 experiment at the CERN super proton synchrotron (SPS). The elastic differential cross sections of pion-proton, kaon-proton, antiproton-proton, and proton-proton at lower SPS energies over a wide range of momentum transfer were measured. Some theoretical models in the light of the experimental results are reviewed, and a comprehensive impact parameter analysis of antiproton-proton elastic scattering over a wide energy range is presented. A nucleon valence core model for high energy proton-proton and antiproton-proton elastic scattering is described

  1. High Energy Physics Departments - Overview

    International Nuclear Information System (INIS)

    Following the tradition, the activities of the seven new units created in 1997 on the basis of the former Department of High Energy Physics are presented under a common header, they are: Department of Particle Theory (Dept 5); Department of Leptonic Interactions (Dept 11); Department of Hadron Structure (Dept 12); Department of High Energy Nuclear Interactions (Dept 13); The ALICE Experiment Laboratory (NAL); The ATLAS Experiment Laboratory (NAT); High Energy Physics Detector Construction Group (PBD). The research covers a variety of problems of the experimental and theoretical high energy particle physics: the hadronic and leptonic interactions with nucleons and nuclei (characteristics of particle production, including heavy quark physics), e+e- interactions and tests of the Standard Model (also radiative corrections), ultrarelativistic heavy ion interactions and search for the quark-gluon plasma, as well as the spectra, composition and interactions of high energy cosmic ray particles. Research on detectors and accelerator components as well as the development of the apparatus for the high energy physics experiments at future accelerators: LHC (CERN, Geneva), RHIC (Brookhaven), B-Factory (KEK, Tsukuba) and TESLA (DESY) is also presented. The technology of new materials with unique properties such as carbon-carbon composites is also worked on from the point of view of their application in high energy physics experiments. The Division is located in a separate building on the campus of the University of Mining and Metallurgy (UMM). This location, close to the Jagiellonian University (JU), facilitates the collaboration with the latter and with the UMM. The joint weekly seminars carried out for nearly 40 years prove this long term tradition. A substantial part of the activities is teaching and training students from the academic community in Cracow. Joint research, teaching and academic training in the high energy physics are carried out within the M. Miesowicz Inter

  2. Extraterrestrial high energy neutrino fluxes

    International Nuclear Information System (INIS)

    With the aid of using the most recent cosmic ray spectra up to 2x1020 eV, production spectra of high-energy neutrinos from cosmic ray interactions with interstellar gas and extragalactic interactions of ultrahigh-energy cosmic rays with 3K universal background photons are presented and discussed. Estimates of the fluxes from cosmic diffuse sources and the nearby quasar 3C273 are made using the generic relationship between secondary neutrinos and gammas and using recent gamma ray satellite data. These gamma ray data provide important upper limits on cosmological neutrinos. Quantitative estimates of the observability of high-energy neutrinos from the inner galaxy and 3C273 above atmospheric background for a DUMAND-type detector are discussed in the context of the Weinberg-Salam model with sin2 theta/sub ω/ = 0.2 and including the atmospheric background from the decay of charmed mesons. Constraints on cosmological high-energy neutrino production models are also discussed. It appears that important high-energy neutrino astronomy may be possible with DUMAND, but very long observing times are required

  3. Extraterrestrial high energy neutrino fluxes

    Science.gov (United States)

    Stecker, F. W.

    1979-01-01

    Using the most recent cosmic ray spectra up to 2x10 to the 20th power eV, production spectra of high energy neutrinos from cosmic ray interactions with interstellar gas and extragalactic interactions of ultrahigh energy cosmic rays with 3K universal background photons are presented and discussed. Estimates of the fluxes from cosmic diffuse sources and the nearby quasar 3C273 are made using the generic relationship between secondary neutrinos and gammas and using recent gamma ray satellite data. These gamma ray data provide important upper limits on cosmological neutrinos. Quantitative estimates of the observability of high energy neutrinos from the inner galaxy and 3C273 above atmospheric background for a DUMAND type detector are discussed in the context of the Weinberg-Salam model with sq sin theta omega = 0.2 and including the atmospheric background from the decay of charmed mesons. Constraints on cosmological high energy neutrino production models are also discussed. It appears that important high energy neutrino astronomy may be possible with DUMAND, but very long observing times are required.

  4. Extraterrestrial high energy neutrino fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Stecker, F.W.

    1979-06-01

    With the aid of using the most recent cosmic ray spectra up to 2x10/sup 20/ eV, production spectra of high-energy neutrinos from cosmic ray interactions with interstellar gas and extragalactic interactions of ultrahigh-energy cosmic rays with 3K universal background photons are presented and discussed. Estimates of the fluxes from cosmic diffuse sources and the nearby quasar 3C273 are made using the generic relationship between secondary neutrinos and gammas and using recent gamma ray satellite data. These gamma ray data provide important upper limits on cosmological neutrinos. Quantitative estimates of the observability of high-energy neutrinos from the inner galaxy and 3C273 above atmospheric background for a DUMAND-type detector are discussed in the context of the Weinberg-Salam model with sin/sup 2/ theta/sub ..omega../ = 0.2 and including the atmospheric background from the decay of charmed mesons. Constraints on cosmological high-energy neutrino production models are also discussed. It appears that important high-energy neutrino astronomy may be possible with DUMAND, but very long observing times are required.

  5. Simulation of High Energy Muons

    CERN Document Server

    Mashtakov, Konstantin

    2015-01-01

    Under the scope of a CERN summer student project, a Geant4 physical model has been developed and committed to the Geant4 repository to allow precise simulation of high-energy muons and hadrons transport inside a material. Resulted angular distributions produced by this model have small deviations from those that were obtained by the Geant4 model used by default. High-energetic muons energy losses inside the CMS tracker have also been estimated and may vary from 0.05% up to 2.5%.

  6. Chandra Discovers the X-ray Signature of a Powerful Wind from a Galactic Microquasar

    Science.gov (United States)

    2000-11-01

    NASA's Chandra X-ray Observatory has detected, for the first time in X rays, a stellar fingerprint known as a P Cygni profile--the distinctive spectral signature of a powerful wind produced by an object in space. The discovery reveals a 4.5-million-mile-per-hour wind coming from a highly compact pair of stars in our galaxy, report researchers from Penn State and the Massachusetts Institute of Technology in a paper they will present on 8 November 2000 during a meeting of the High-Energy Astrophysics Division of the American Astronomical Society in Honolulu, Hawaii. The paper also has been accepted for publication in The Astrophysical Journal Letters. "To our knowledge, these are the first P Cygni profiles reported in X rays," say researchers Niel Brandt, assistant professor of astronomy and astrophysics at Penn State, and Norbert S. Schulz, research scientist at the Massachusetts Institute of Technology. The team made the discovery during their first observation of a binary-star system with the Chandra X-ray Observatory, which was launched into space in July 1999. The system, known as Circinus X-1, is located about 20,000 light years from Earth in the constellation Circinus near the Southern Cross. It contains a super-dense neutron star in orbit around a normal fusion-burning star like our Sun. Although Circinus X-1 was discovered in 1971, many properties of this system remain mysterious because Circinus X-1 lies in the galactic plane where obscuring dust and gas have blocked its effective study in many wavelengths. The P Cygni spectral profile, previously detected primarily at ultraviolet and optical wavelengths but never before in X rays, is the textbook tool astronomers rely on for probing stellar winds. The profile looks like the outline of a roller coaster, with one really big hill and valley in the middle, on a data plot with velocity on one axis and the flow rate of photons per second on the other. It is named after the famous star P Cygni, in which such

  7. High energy astrophysics. An introduction

    International Nuclear Information System (INIS)

    Based on observational examples this book reveals and explains high-energy astrophysical processes. Presents the theory of astrophysical processes in a didactic approach by deriving equations step by step. With several attractive astronomical pictures. High-energy astrophysics has unveiled a Universe very different from that only known from optical observations. It has revealed many types of objects in which typical variability timescales are as short as years, months, days, and hours (in quasars, X-ray binaries, and other objects), and even down to milli-seconds in gamma ray bursts. The sources of energy that are encountered are only very seldom nuclear fusion, and most of the time gravitation, a paradox when one thinks that gravitation is, by many orders of magnitude, the weakest of the fundamental interactions. The understanding of these objects' physical conditions and the processes revealed by high-energy astrophysics in the last decades is nowadays part of astrophysicists' culture, even of those active in other domains of astronomy. This book evolved from lectures given to master and PhD students at the University of Geneva since the early 1990s. It aims at providing astronomers and physicists intending to be active in high-energy astrophysics a broad basis on which they should be able to build the more specific knowledge they will need. While in the first part of the book the physical processes are described and derived in detail, the second part studies astrophysical objects in which high-energy astrophysics plays a crucial role. This two-pronged approach will help students recognise physical processes by their observational signatures in contexts that may differ widely from those presented here.

  8. High energy astrophysics. An introduction

    Energy Technology Data Exchange (ETDEWEB)

    Courvoisier, Thierry J.L. [Geneva Univ., Versoix (Switzerland). ISDC, Data Centre for Astrophysics

    2013-07-01

    Based on observational examples this book reveals and explains high-energy astrophysical processes. Presents the theory of astrophysical processes in a didactic approach by deriving equations step by step. With several attractive astronomical pictures. High-energy astrophysics has unveiled a Universe very different from that only known from optical observations. It has revealed many types of objects in which typical variability timescales are as short as years, months, days, and hours (in quasars, X-ray binaries, and other objects), and even down to milli-seconds in gamma ray bursts. The sources of energy that are encountered are only very seldom nuclear fusion, and most of the time gravitation, a paradox when one thinks that gravitation is, by many orders of magnitude, the weakest of the fundamental interactions. The understanding of these objects' physical conditions and the processes revealed by high-energy astrophysics in the last decades is nowadays part of astrophysicists' culture, even of those active in other domains of astronomy. This book evolved from lectures given to master and PhD students at the University of Geneva since the early 1990s. It aims at providing astronomers and physicists intending to be active in high-energy astrophysics a broad basis on which they should be able to build the more specific knowledge they will need. While in the first part of the book the physical processes are described and derived in detail, the second part studies astrophysical objects in which high-energy astrophysics plays a crucial role. This two-pronged approach will help students recognise physical processes by their observational signatures in contexts that may differ widely from those presented here.

  9. X-ray Sources in the Magellanic Clouds: analysis of 15 Years of XMM-Newton and Chandra Observations

    Science.gov (United States)

    Yang, J.; Laycock, S.; Christodoulou, D.; Drake, J.; Fingerman, S.; Hong, J.; Zezas, A.; Antoniou, V.; Coe, M.; Ho, W.

    2016-06-01

    Using ˜160 XMM-Newton, ˜180 Chandra, and all weekly RXTE observations, we have generated a comprehensive library of the known pulsars in the Small and Large Magellanic Clouds (SMC, LMC). We classify various pulsar properties in the range of log L_{X}=32-38 erg s^{-1} and incorporate related parameters in theoretical models. With the high time-resolution data of the EPIC and Chandra cameras and the latest calibration files and software, our 15 year pipeline generates a suite of useful products for each pulsar detection: event lists, high time-resolution light curves, periodograms, spectra, and complete histories of the dot{P}, the pulse fraction, etc., in the broad, soft (0.2-2 keV), and hard (2-12 keV) energy bands. After combining the observations from these telescopes, we found that 15 pulsars are clearly spinning up and another 15 pulsars are distinctly spinning down. We also used the faintest and brightest sources to map out the propeller line and the Eddington line, respectively. We compared the observed pulse profiles to geometric models of X-ray emission in order to constrain the physical parameters of the pulsars. We are preparing a public release of this library so that it can be used by other groups as well.

  10. High-energy atomic physics

    CERN Document Server

    Drukarev, Evgeny G

    2016-01-01

    This self-contained text introduces readers to the field of high-energy atomic physics - a new regime of photon-atom interactions in which the photon energies significantly exceed the atomic or molecular binding energies, and which opened up with the recent advent of new synchrotron sources. From a theoretical point of view, a small-parameter characteristic of the bound system emerged, making it possible to perform analytic perturbative calculations that can in turn serve as benchmarks for more powerful numerical computations. The first part of the book introduces readers to the foundations of this new regime and its theoretical treatment. In particular, the validity of the small-parameter perturbation expansion and of the lowest-order approximation is critically reviewed. The following chapters then apply these insights to various atomic processes, such as photoionization as a many-body problem, dominant mechanisms for the production of ions at higher energies, Compton scattering and ionization accompanied b...

  11. Photoproduction at High Energy and High Intensity

    CERN Multimedia

    2002-01-01

    The photon beam used for this programme is tagged and provides a large flux up to very high energies (150-200 GeV). It is also hadron-free, since it is obtained by a two-step conversion method. A spectrometer is designed to exploit this beam and to perform a programme of photoproduction with a high level of sensitivity (5-50 events/picobarn).\\\\ \\\\ Priority will be given to the study of processes exhibiting the point-like behaviour of the photon, especially deep inelastic Compton scattering. The spectrometer has two magnets. Charged tracks are measured by MWPC's located only in field-free regions. Three calorimeters provide a large coverage for identifying and measuring electrons and photons. An iron filter downstream identifies muons. Most of the equipment is existing and recuperated from previous experiments.

  12. Statistical Characterization of the Chandra Source Catalog

    CERN Document Server

    Primini, Francis A; Davis, John E; Nowak, Michael A; Evans, Ian N; Glotfelty, Kenny J; Anderson, Craig S; Bonaventura, Nina R; Chen, Judy C; Doe, Stephen M; Evans, Janet D; Fabbiano, Giuseppina; Galle, Elizabeth C; Gibbs, Danny G; Grier, John D; Hain, Roger M; Hall, Diane M; Harbo, Peter N; Xiangqun,; He,; Karovska, Margarita; Kashyap, Vinay L; Lauer, Jennifer; McCollough, Michael L; McDowell, Jonathan C; Miller, Joseph B; Mitschang, Arik W; Morgan, Douglas L; Mossman, Amy E; Nichols, Joy S; Plummer, David A; Refsdal, Brian L; Rots, Arnold H; Siemiginowska, Aneta; Sundheim, Beth A; Tibbetts, Michael S; Van Stone, David W; Winkelman, Sherry L; Zografou, Panagoula

    2011-01-01

    The first release of the Chandra Source Catalog (CSC) contains ~95,000 X-ray sources in a total area of ~0.75% of the entire sky, using data from ~3,900 separate ACIS observations of a multitude of different types of X-ray sources. In order to maximize the scientific benefit of such a large, heterogeneous data-set, careful characterization of the statistical properties of the catalog, i.e., completeness, sensitivity, false source rate, and accuracy of source properties, is required. Characterization efforts of other, large Chandra catalogs, such as the ChaMP Point Source Catalog (Kim et al. 2007) or the 2 Mega-second Deep Field Surveys (Alexander et al. 2003), while informative, cannot serve this purpose, since the CSC analysis procedures are significantly different and the range of allowable data is much less restrictive. We describe here the characterization process for the CSC. This process includes both a comparison of real CSC results with those of other, deeper Chandra catalogs of the same targets and e...

  13. An X-ray photometry system I: Chandra ACIS

    CERN Document Server

    Grimm, H -J; Fabbiano, G; Elvis, M

    2008-01-01

    We present a system of X-ray photometry for the Chandra satellite. X-ray photometry can be a powerful tool to obtain flux estimates, hardness ratios, and colors unbiased by assumptions about spectral shape and independent of temporal and spatial changes in instrument characteristics. The system we have developed relies on our knowledge of effective area and the energy-to-channel conversion to construct filters similar to photometric filters in the optical bandpass. We show that the filters are well behaved functions of energy and that this X-ray photometric system is able to reconstruct fluxes to within about 20%, without color corrections, for non-pathological spectra. Even in the worst cases it is better than 50%. Our method also treats errors in a consistent manner, both statistical as well as systematic.

  14. The Chandra Deepest Fields in the Infrared: Making the Connection between Normal Galaxies and AGN

    Science.gov (United States)

    Grogin, N. A.; Ferguson, H. C.; Dickinson, M. E.; Giavalisco, M.; Mobasher, B.; Padovani, P.; Williams, R. E.; Chary, R.; Gilli, R.; Heckman, T. M.; Stern, D.; Winge, C.

    2001-12-01

    Within each of the two Chandra Deepest Fields (CDFs), there are ~10'x15' regions targeted for non-proprietary, deep SIRTF 3.6--24μ m imaging as part of the Great Observatories Origins Deep Survey (GOODS) Legacy program. In advance of the SIRTF observations, the GOODS team has recently begun obtaining non-proprietary, deep ground-based optical and near-IR imaging and spectroscopy over these regions, which contain virtually all of the current ≈1 Msec CXO coverage in the CDF North and much of the ≈1 Msec coverage in the CDF South. In particular, the planned depth of the near-IR imaging (JAB ~ 25.3; HAB ~ 24.8; KAB ~ 24.4) combined with the deep Chandra data can allow us to trace the evolutionary connection between normal galaxies, starbursts, and AGN out to z ~ 1 and beyond. We describe our CDF Archival program, which is integrating these GOODS-supporting observations together with the CDF archival data and other publicly-available datasets in these regions to create a multi-wavelength deep imaging and spectroscpic database available to the entire community. We highlight progress toward near-term science goals of this program, including: (a) pushing constraints on the redshift distribution and spectral-energy distributions of the faintest X-ray sources to the deepest possible levels via photometric redshifts; and (b) better characterizing the heavily-obscured and the high-redshift populations via both a near-IR search for optically-undetected CDF X-ray sources and also X-ray stacking analyses on the CXO-undetected EROs in these fields.

  15. High energy astrophysics an introduction

    CERN Document Server

    Courvoisier, Thierry J -L

    2013-01-01

    High-energy astrophysics has unveiled a Universe very different from that only known from optical observations. It has revealed many types of objects in which typical variability timescales are as short as years, months, days, and hours (in quasars, X-ray binaries, and other objects), and even down to milli-seconds in gamma ray bursts. The sources of energy that are encountered are only very seldom nuclear fusion, and most of the time gravitation, a paradox when one thinks that gravitation is, by many orders of magnitude, the weakest of the fundamental interactions. The understanding of these objects' physical conditions and the processes revealed by high-energy astrophysics in the last decades is nowadays part of astrophysicists' culture, even of those active in other domains of astronomy. This book evolved from lectures given to master and PhD students at the University of Geneva since the early 1990s. It aims at providing astronomers and physicists intending to be active in high-energy astrophysics a broad...

  16. High-energy atmospheric neutrinos

    CERN Document Server

    Sinegovsky, S I; Sinegovskaya, T S

    2010-01-01

    High-energy neutrinos, arising from decays of mesons that were produced through the cosmic rays collisions with air nuclei, form unavoidable background noise in the astrophysical neutrino detection problem. The atmospheric neutrino flux above 1 PeV should be supposedly dominated by the contribution of charmed particle decays. These (prompt) neutrinos originated from decays of massive and shortlived particles, $D^\\pm$, $D^0$, $\\bar{D}{}^0$, $D_s^\\pm$, $\\Lambda^+_c$, form the most uncertain fraction of the high-energy atmospheric neutrino flux because of poor explored processes of the charm production. Besides, an ambiguity in high-energy behavior of pion and especially kaon production cross sections for nucleon-nucleus collisions may affect essentially the calculated neutrino flux. There is the energy region where above flux uncertainties superimpose. A new calculation presented here reveals sizable differences, up to the factor of 1.8 above 1 TeV, in muon neutrino flux predictions obtained with usage of known...

  17. High energy ion beam mixing

    International Nuclear Information System (INIS)

    Experimental investigations have been made on the parameters which can be used to control the mixing profiles, and the width of intermixed layers in film-substrate systems being irradiated by high energy heavy ion beams. The samples were irradiated by ion beams of Au, Cu, and Si with energies of 1.5 to 3 MeV. Typical examples of the RBS spectra are presented and discussions are made on the extent of contribution of binary collisions on the interfacial mixing. The experimental and simulation results show that the interfacial mixing is dominated by the binary collisions. (author)

  18. VizieR Online Data Catalog: HIFLUGCS XMM/Chandra cross-calibration (Schellenberger+, 2015)

    Science.gov (United States)

    Schellenberger, G.; Reiprich, T. H.; Lovisari, L.; Nevalainen, J.; David, L.

    2015-06-01

    Robust X-ray temperature measurements of the intracluster medium (ICM) of galaxy clusters require an accurate energy-dependent effective area calibration. Since the hot gas X-ray emission of galaxy clusters does not vary on relevant timescales, they are excellent cross-calibration targets. Moreover, cosmological constraints from clusters rely on accurate gravitational mass estimates, which in X-rays strongly depend on cluster gas temperature measurements. Therefore, systematic calibration differences may result in biased, instrument-dependent cosmological constraints. This is of special interest in light of the tension between the Planck results of the primary temperature anisotropies of the cosmic microwave background (CMB) and Sunyaev-Zel'dovich-plus-X-ray cluster-count analyses. We quantify in detail the systematics and uncertainties of the cross-calibration of the effective area between five X-ray instruments, EPIC-MOS1/MOS2/PN onboard XMM-Newton and ACIS-I/S onboard Chandra, and the influence on temperature measurements. Furthermore, we assess the impact of the cross-calibration uncertainties on cosmology. Using the HIFLUGCS sample, consisting of the 64 X-ray brightest galaxy clusters, we constrain the ICM temperatures through spectral fitting in the same, mostly isothermal regions and compare the different instruments. We use the stacked residual ratio method to evaluate the cross-calibration uncertainties between the instruments as a function of energy. Our work is an extension to a previous one using X-ray clusters by the International Astronomical Consortium for High Energy Calibration (IACHEC) and is carried out in the context of IACHEC. Performing spectral fitting in the full energy band, (0.7-7)keV, as is typical of the analysis of cluster spectra, we find that best-fit temperatures determined with XMM-Newton/EPIC are significantly lower than Chandra/ACIS temperatures. This confirms the previous IACHEC results obtained with older calibrations with high

  19. Multiwavelength campaign on Mrk 509 XIV. Chandra HETGS spectra

    CERN Document Server

    Kaastra, J S; Arav, N; Behar, E; Bianchi, S; Branduardi-Raymont, G; Cappi, M; Costantini, E; Kriss, G A; De Marco, B; Mehdipour, M; Paltani, S; Petrucci, P -O; Pinto, C; Ponti, G; Steenbrugge, K C; de Vries, C P

    2014-01-01

    We present in this paper the results of a 270 ks Chandra HETGS observation in the context of a large multiwavelength campaign on the Seyfert galaxy Mrk 509. The HETGS spectrum allows us to study the high ionisation warm absorber and the Fe-K complex in Mrk 509. We search for variability in the spectral properties of the source with respect to previous observations in this campaign, as well as for evidence of ultra-fast outflow signatures. The Chandra HETGS X-ray spectrum of Mrk 509 was analysed using the SPEX fitting package. We confirm the basic structure of the warm absorber found in the 600 ks XMM-Newton RGS observation observed three years earlier, consisting of five distinct ionisation components in a multikinematic regime. We find little or no variability in the physical properties of the different warm absorber phases with respect to previous observations in this campaign, except for component D2 which has a higher column density at the expense of component C2 at the same outflow velocity (-240 km/s). ...

  20. High-energy irradiation and mass loss rates of hot Jupiters in the solar neighborhood

    CERN Document Server

    Salz, M; Czesla, S; Schmitt, J H M M

    2015-01-01

    Giant gas planets in close proximity to their host stars experience strong irradiation. In extreme cases photoevaporation causes a transonic, planetary wind and the persistent mass loss can possibly affect the planetary evolution. We have identified nine hot Jupiter systems in the vicinity of the Sun, in which expanded planetary atmospheres should be detectable through Lyman alpha transit spectroscopy according to predictions. We use X-ray observations with Chandra and XMM-Newton of seven of these targets to derive the high-energy irradiation level of the planetary atmospheres and the resulting mass loss rates. We further derive improved Lyman alpha luminosity estimates for the host stars including interstellar absorption. According to our estimates WASP-80 b, WASP-77 b, and WASP-43 b experience the strongest mass loss rates, exceeding the mass loss rate of HD 209458 b, where an expanded atmosphere has been confirmed. Furthermore, seven out of nine targets might be amenable to Lyman alpha transit spectroscopy...

  1. Preliminary Results from a Coordinated Hisaki/Chandra/XMM-Newton Study of the Jovian Aurora and Io Plasma Torus

    Science.gov (United States)

    Kraft, Ralph; Kimura, Tomoki; Elsner, Ronald; Branduardi-Raymont, Graziella; Gladstone, Randy; Badman, Sarah Victoria; Ezoe, Yuichiro; Murakami, Go; Murray, Stephen S.; Roediger, Elke; Tsuchiya, Fuminori; Yamazaki, Atsushi; Yoshikawa, Ichiro; Yoshioka, Kazuo

    2014-01-01

    We present preliminary results from a coordinated Hisaki/Chandra/XMM-Newton observational campaign of the Jovian aurora and Io plasma torus. The data were taken over a three week period in April, 2014. Jupiter was observed continuously with Hisaki, six times with the Chandra/HRC instrument for roughly 12 hours per observation, and twice by XMM-Newton. The goal of this observational campaign was to understand how energy and matter are exchanged between the Jovian aurora, the IPT, and the Solar wind. X-ray observations provide key diagnostics on highly stripped ions and keV electrons in the Jovian magnetosphere. We use the temporal, spatial, and spectral capabilities of the three instruments to search for correlated variability between the Solar wind, the EUV-emitting plasma of the IPT and UV aurora, and the ions responsible for the X-ray aurora. Preliminary analysis suggests a strong 45 min periodicity in the EUV emission from the electron aurora. There is some evidence for complex variability of the X-ray auroras on scales of tens of minutes. There is also clear morphological changes in the X-ray aurora that do not appear to be correlated with either variations in the IPT or Solar wind.

  2. Comparative Analysis and Variability of the Jovian X-Ray Spectra Detected by the Chandra and XMM-Newton Observatories

    International Nuclear Information System (INIS)

    Expanding upon recent work, a more comprehensive spectral model based on charge exchange induced X-ray emission by ions precipitating into the Jovian atmosphere is used to provide new understanding of the polar auroras. In conjunction with the Xspec spectral fitting software, the model is applied to analyze observations from both Chandra and XMM-Newton by systematically varying the initial precipitating ion parameters to obtain the best fit model for the observed spectra. In addition to the oxygen and sulfur ions considered previously, carbon is included to discriminate between solar wind and Jovian magnetospheric ion origins, enabled by the use of extensive databases of both atomic collision cross sections and radiative transitions. On the basis of fits to all the Chandra observations, we find that carbon contributes negligibly to the observed polar X-ray emission suggesting that the highly accelerated precipitating ions are of magnetospheric origin. Most of the XMM-Newton fits also favor this conclusion with one exception that implies a possible carbon contribution. Comparison among all the spectra from these two observatories in light of the inferred initial energies and relative abundances of precipitating ions from the modeling show that they are significantly variable in time (observation date) and space (north and south polar X-ray auroras).

  3. High energy electron crystal spectrometer

    International Nuclear Information System (INIS)

    A spectrometer has been developed to measure relativistic electrons produced in different types of plasmas, such as tokamak plasmas and laser produced plasmas. The spectrometer consists of nine Y2SiO5:Ce crystals, which are shielded by stainless steel filters. The absolute calibration of the spectrometer was performed at the superconducting electron linear accelerator Electron Linac for beams with high Brilliance and low Emittance. The spectrometer can provide information about energy distribution of electrons and their numbers for the energy range between 4 and 30 MeV. The spectrum is analyzed by means of the Monte Carlo three-dimensional GEANT4 code. An energy resolution of about 10% is achieved.

  4. Chandra view of the warm-hot intergalactic medium toward 1ES 1553+113: Absorption-line detections and identifications. I

    OpenAIRE

    F. Nicastro; Barcons, Xavier; Paerels, F. B. S.

    2013-01-01

    We present the first results from our pilot 500 ks Chandra Low Energy Transmission Grating Large Program observation of the soft X-ray brightest source in the z ≳ 0.4 sky, the blazar 1ES 1553+113, aimed to secure the first uncontroversial detections of the missing baryons in the X-rays. We identify a total of 11 possible absorption lines, with single-line statistical significances between 2.2σ and 4.1σ. Six of these lines are detected at high single-line statistical significance (3.6 ≤ σ ≤ 4....

  5. An X-ray look at the Seyfert 1 Galaxy Mrk 590: XMM-Newton and Chandra reveal complexity in circumnuclear gas

    OpenAIRE

    Longinotti, A. L.; Bianchi, S.; Santos-Lleo, M.; Rodriguez-Pascual, P.; Guainazzi, M.; Cardaci, M.; Pollock, A.M.T.

    2007-01-01

    This paper reports on a partially simultaneous observation of the bright Seyfert 1 Galaxy Mrk590, performed by XMM-Newton and Chandra. The long exposure (~100 ks) allows to investigate with great detail the Fe K complex at 6-7 keV and the presence of soft X-ray spectral features. We have analysed XMM-Newton data from the European Photon Imaging Camera (EPIC) in the 0.5-12 keV band and from the Reflection Grating Spectrometer (RGS) in the 0.35-2.5 keV band, and data from the High Energy Transm...

  6. NASA'S Chandra Finds Superfluid in Neutron Star's Core

    Science.gov (United States)

    2011-02-01

    NASA's Chandra X-ray Observatory has discovered the first direct evidence for a superfluid, a bizarre, friction-free state of matter, at the core of a neutron star. Superfluids created in laboratories on Earth exhibit remarkable properties, such as the ability to climb upward and escape airtight containers. The finding has important implications for understanding nuclear interactions in matter at the highest known densities. Neutron stars contain the densest known matter that is directly observable. One teaspoon of neutron star material weighs six billion tons. The pressure in the star's core is so high that most of the charged particles, electrons and protons, merge resulting in a star composed mostly of uncharged particles called neutrons. Two independent research teams studied the supernova remnant Cassiopeia A, or Cas A for short, the remains of a massive star 11,000 light years away that would have appeared to explode about 330 years ago as observed from Earth. Chandra data found a rapid decline in the temperature of the ultra-dense neutron star that remained after the supernova, showing that it had cooled by about four percent over a 10-year period. "This drop in temperature, although it sounds small, was really dramatic and surprising to see," said Dany Page of the National Autonomous University in Mexico, leader of a team with a paper published in the February 25, 2011 issue of the journal Physical Review Letters. "This means that something unusual is happening within this neutron star." Superfluids containing charged particles are also superconductors, meaning they act as perfect electrical conductors and never lose energy. The new results strongly suggest that the remaining protons in the star's core are in a superfluid state and, because they carry a charge, also form a superconductor. "The rapid cooling in Cas A's neutron star, seen with Chandra, is the first direct evidence that the cores of these neutron stars are, in fact, made of superfluid and

  7. Harvard University High Energy Physics

    International Nuclear Information System (INIS)

    The mainly experimental research program in high energy physics at Harvard is summarized in a descriptive fashion according to the following outline: Proton endash antiproton colliding beam program at Fermilab -- CDF (forward/backward electromagnetic calorimeters -- FEM, central muon extension -- CMX, gas calorimetry and electronics development, front-end electronics upgrades, software development, physics analysis, timetable), electron -- positron collisions in the upsilon region -- CLEO (the hardware projects including CLEO II barrel TOF system and silicon drift detector R ampersand D, physics analysis), search for νμ to ντ oscillations with the NOMAD experiment at CERN, the solenoidal detector collaboration at the SSC, muon scattering at FNAL -- E665, the L3 experiment, and phenomenological analysis of high-energy bar pp cross sections. 149 refs

  8. A possible Chandra and Hubble Space Telescope detection of extragalactic WHIM towards PG 1116+215

    Science.gov (United States)

    Bonamente, M.; Nevalainen, J.; Tilton, E.; Liivamägi, J.; Tempel, E.; Heinämäki, P.; Fang, T.

    2016-04-01

    We have analysed Chandra low energy transmission grating and XMM-Newton Reflection Grating Spectrometer (RGS) spectra towards the z = 0.177 quasar PG 1116+215, a sightline that is rendered particularly interesting by the Hubble Space Telescope (HST) detection of several O VI and H I broad Lyman α absorption (BLA) lines that may be associated with the warm-hot intergalactic medium (WHIM). We performed a search for resonance Kα absorption lines from O VII and O VIII at the redshifts of the detected far-ultraviolet lines. We detected an absorption line in the Chandra spectra at the 5.2σ confidence level at wavelengths corresponding to O VIII Kα at z = 0.0911 ± 0.0004 ± 0.0005 (statistical followed by systematic error). This redshift is within 3σ of that of an H I broad Lyman α of b ≃ 130 km s-1 (corresponding to a temperature of log T(K) ≃ 6.1) at z = 0.092 79 ± 0.000 05. We have also analysed the available XMM-Newton RGS data towards PG 1116+215. Unfortunately, the XMM-Newton data are not suitable to investigate this line because of instrumental features at the wavelengths of interest. At the same redshift, the Chandra and XMM-Newton spectra have O VII Kα absorption-line features of significance 1.5σ and 1.8σ, respectively. We also analysed the available Sloan Digital Sky Survey (SDSS) spectroscopic galaxy survey data towards PG 1116+215 in the redshift range of interest. We found evidence for a galaxy filament that intersect the PG 1116+215 sightline and additional galaxy structures that may host WHIM. The H I BLA and the O VIII Kα absorbers are within a few Mpc of the filament (assuming that redshifts track Hubble flow distances) or consistent with gas accreting on to the filament from either direction relative to the sightline with velocities of a few × 100 km s-1. The combination of HST, Chandra, XMM-Newton and SDSS data indicates that we have likely detected a multi-temperature WHIM at z ≃ 0.091-0.093 towards PG 1116+215. The O VIII K

  9. A high energy physics perspective

    International Nuclear Information System (INIS)

    The status of the Standard model and role of symmetry in its development are reviewed. Some outstanding problems are surveyed and possible solutions in the form of additional open-quotes Hidden Symmetries close quotes are discussed. Experimental approaches to uncover open-quotes New Physicsclose quotes associated with those symmetries are described with emphasis on high energy colliders. An outlook for the future is given

  10. A high energy physics perspective

    Energy Technology Data Exchange (ETDEWEB)

    Marciano, W.J.

    1997-01-13

    The status of the Standard model and role of symmetry in its development are reviewed. Some outstanding problems are surveyed and possible solutions in the form of additional {open_quotes}Hidden Symmetries {close_quotes} are discussed. Experimental approaches to uncover {open_quotes}New Physics{close_quotes} associated with those symmetries are described with emphasis on high energy colliders. An outlook for the future is given.

  11. Cosmology for high energy physicists

    International Nuclear Information System (INIS)

    The standard big bang model of cosmology is presented. Although not perfect, its many successes make it a good starting point for most discussions of cosmology. Places are indicated where well understood laboratory physics is incorporated into the big bang, leading to successful predictions. Much less established aspects of high energy physics and some of the new ideas they have introduced into the field of cosmology are discussed, such as string theory, inflation and monopoles. 49 refs., 5 figs

  12. Future High Energy Neutrino Telescopes

    CERN Document Server

    Spiering, C

    2000-01-01

    This talk summarizes the main physics goals and basic methods of telescopes for high energy neutrinos. It reviews the present status of deep underwater telescopes and sketches the ICECUBE project as an example for a cube kilometer detector. It is suggested to develop techniques for radio and acoustic detection hand in hand with big optical arrays. These large arrays should be complemented by medium-size detectors in the Megaton range.

  13. [Research in high energy physics

    International Nuclear Information System (INIS)

    We review the efforts of the Notre Dame non accelerator high energy physics group. Our major effort has been directed toward the IMB deep underground detector. Since the departure of the Michigan group our responsibilities to the group have grown. We are also very active in pursuing physics with the IMB 3 detector. Currently we are studying proton decay, point neutrino sources and neutrino oscillations with the contained event sample

  14. Chandra "Hears" A Black Hole For The First Time

    Science.gov (United States)

    2003-09-01

    NASA's Chandra X-ray Observatory detected sound waves, for the first time, from a super-massive black hole. The "note" is the deepest ever detected from an object in the universe. The tremendous amounts of energy carried by these sound waves may solve a longstanding problem in astrophysics. The black hole resides in the Perseus cluster, located 250 million light years from Earth. In 2002, astronomers obtained a deep Chandra observation that shows ripples in the gas filling the cluster. These ripples are evidence for sound waves that have traveled hundreds of thousands of light years away from the cluster's central black hole. perseus animation Illustration of Ripples in Perseus "We have observed the prodigious amounts of light and heat created by black holes, now we have detected the sound," said Andrew Fabian of the Institute of Astronomy (IoA) in Cambridge, England, and leader of the study. In musical terms, the pitch of the sound generated by the black hole translates into the note of B flat. But, a human would have no chance of hearing this cosmic performance, because the note is 57 octaves lower than middle-C (by comparison a typical piano contains only about seven octaves). At a frequency over a million, billion times deeper than the limits of human hearing, this is the deepest note ever detected from an object in the universe. "The Perseus sound waves are much more than just an interesting form of black hole acoustics," said Steve Allen, also of the IoA and a co-investigator in the research. "These sound waves may be the key in figuring out how galaxy clusters, the largest structures in the universe, grow," Allen said. For years astronomers have tried to understand why there is so much hot gas in galaxy clusters and so little cool gas. Hot gas glowing with X-rays should cool, and the dense central gas should cool the fastest. The pressure in this cool central gas should then fall, causing gas further out to sink in towards the galaxy, forming trillions of

  15. The Brera Multi-scale Wavelet Chandra Survey. The serendipitous source catalogue

    CERN Document Server

    Romano, P; Mignani, R P; Moretti, A; Panzera, M R; Tagliaferri, G; Mottini, M

    2009-01-01

    We present the Brera Multi-scale Wavelet Chandra (BMW-Chandra) source catalogue drawn from essentially all Chandra ACIS-I pointed observations with an exposure time in excess of 10ks public as of March 2003 (136 observations). Using the wavelet detection algorithm developed by Lazzati et al. (1999) and Campana et al. (1999), which can characterise both point-like and extended sources, we identified 21325 sources. Among them, 16758 are serendipitous, i.e. not associated with the targets of the pointings. This makes our catalogue the largest compilation of Chandra sources to date. The 0.5-10keV absorption corrected fluxes of these sources range from 3E-16 to 9E-12 erg/cm2/s with a median of 7E-15 erg/cm2/s. The catalogue consists of count rates and relative errors in three energy bands (total, 0.5-7keV; soft, 0.5-2keV; and hard, 2-7keV), where the detection was performed, and source positions relative to the highest signal-to-noise detection among the three bands. The wavelet algorithm also provides an estimate...

  16. Quantum chromodynamics at high energy

    CERN Document Server

    Kovchegov, Yuri V

    2012-01-01

    Filling a gap in the current literature, this book is the first entirely dedicated to high energy QCD including parton saturation. It presents groundbreaking progress on the subject and describes many of the problems at the forefront of research, bringing postgraduate students, theorists and advanced experimentalists up to date with the current status of the field. A broad range of topics in high energy QCD are covered, most notably on the physics of parton saturation and the Color Glass Condensate (CGC). The material is presented in a pedagogical way, with numerous examples and exercises. Discussion ranges from the quasi-classical McLerran–Venugopalan model to the linear and non-linear BFKL/BK/JIMWLK small-x evolution equations. The authors adopt both a theoretical and experimental outlook and present the physics of strong interactions in a universal way, making it useful to physicists from various sub-communities and applicable to processes studied at high energy accelerators around the world.

  17. Astrophysics at very high energies

    International Nuclear Information System (INIS)

    Presents three complementary lectures on very-high-energy astrophysics given by worldwide leaders in the field. Reviews the recent advances in and prospects of gamma-ray astrophysics and of multi-messenger astronomy. Prepares readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors. With the success of Cherenkov Astronomy and more recently with the launch of NASA's Fermi mission, very-high-energy astrophysics has undergone a revolution in the last years. This book provides three comprehensive and up-to-date reviews of the recent advances in gamma-ray astrophysics and of multi-messenger astronomy. Felix Aharonian and Charles Dermer address our current knowledge on the sources of GeV and TeV photons, gleaned from the precise measurements made by the new instrumentation. Lars Bergstroem presents the challenges and prospects of astro-particle physics with a particular emphasis on the detection of dark matter candidates. The topics covered by the 40th Saas-Fee Course present the capabilities of current instrumentation and the physics at play in sources of very-high-energy radiation to students and researchers alike. This book will encourage and prepare readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors.

  18. IV. Workshop on High Energy Spin Physics

    International Nuclear Information System (INIS)

    In this proceedings the results on high energy spin physics are summarized. The theory of spin phenomenon and the experimental results at intermediate energy and at high energy spin physics and new technical developments in polarization experiments are presented

  19. First Terrestrial Soft X-Ray Auroral Observation by the Chandra X-Ray Observatory

    Science.gov (United States)

    Bhardwaj, Anil; Gladstone, G. Randall; Elsner, Ronald F.; Oestgaard, Nikolai; Waite, J. Hunter, Jr.; Cravens, Thomas E.; Chang, Shen-Wu; Majeed, Tariq; Metzger, Albert E.

    2007-01-01

    Northern auroral regions of Earth were imaged with energetic photons in the 0.1-10keV range using the High-Resolution Camera (HRC-I) aboard the Chandra X-ray Observatory at 10 epochs (each approx.20 min duration) between mid- December 2003 and mid-April 2004. These observations aimed at searching for Earth's soft (X-ray aurora in a comparative study with Jupiter's X-ray aurora, where a pulsating X-ray "hot-spot" has been previously observed by Chandra. The first Chandra soft X-ray observations of Earth's aurora show that it is highly variable 0ntense arcs, multiple arcs, diffuse patches, at times absent). In at least one of the observations an isolated blob of emission is observed near the expected cusp location. A fortuitous overflight of DMSP satellite F13 provided SSJ/4 energetic particle measurements above a bright arc seen by Chandra on 24 January 2004, 20:01-20:22 UT. A model of the emissions expected strongly suggests that the observed soft X-ray signal is bremsstrahlung and characteristic K-shell line emissions of nitrogen and oxygen in the atmosphere produced by electrons.

  20. Developments in high energy theory

    Indian Academy of Sciences (India)

    Sunil Mukhi; Probir Roy

    2009-07-01

    This non-technical review article is aimed at readers with some physics back-ground, including beginning research students. It provides a panoramic view of the main theoretical developments in high energy physics since its inception more than half a century ago, a period in which experiments have spanned an enormous range of energies, theories have been developed leading up to the Standard Model, and proposals – including the radical paradigm of String Theory – have been made to go beyond the Standard Model. The list of references provided here is not intended to properly credit all original work but rather to supply the reader with a few pointers to the literature, specifically highlighting work done by Indian authors.

  1. Assessing high wind energy penetration

    International Nuclear Information System (INIS)

    In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project settings are close to ideal, including a very capable national utility company, Electra, a conventional power supply system based on imported heavy fuel and gas oil, and favourable wind conditions with an estimated annual average of 9.3 m/s at the hub height of the wind turbines. With the applied case study assumptions, simulations with WINSYS over the lifetime of the assessed wind power investment show that investments up to 4.2 MW are economically viable. The economic optimum is found at 2.4 MW reaching an internal rate of return of almost 8% p.a. This 2.4 MW of wind power would, together with the existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h. (Author)

  2. Swift J1644+57: Chandra observations

    Science.gov (United States)

    Levan, A. J.; Tanvir, N. R.

    2012-11-01

    We observed the X-ray counterpart to the candidate relativistic tidal disruption event Swift J1644+57 (Levan et al. 2011 Science, 333 199; Bloom et al. 2011 Science 333 202; Burrows et al. 2011 Nature 476 421; Zauderer et al. 2011 Nature 476 425) with the Chandra X-ray Observatory, beginning on 26 November 2012 at 10:25 UT. A total integration of 24.7 ks was obtained, and the object was placed at the default position on the ACIS S3 chip.

  3. High Energy Gas Fracturing Test

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, R.

    2001-02-27

    The Rocky Mountain Oilfield Testing Center (RMOTC) has recently completed two tests of a high-energy gas fracturing system being developed by Western Technologies of Crossville, Tennessee. The tests involved the use of two active wells located at the Naval Petroleum Reserve No. 3 (NPR-3), thirty-five miles north of Casper, Wyoming (See Figure 1). During the testing process the delivery and operational system was enhanced by RMOTC, Western Technologies, and commercial wireline subcontractors. RMOTC has assisted an industrial client in developing their technology for high energy gas fracturing to a commercial level. The modifications and improvements implemented during the technology testing process are instrumental in all field testing efforts at RMOTC. The importance of well selection can also be critical in demonstrating the success of the technology. To date, significant increases in well productivity have been clearly proven in well 63-TPX-10. Gross fluid production was initially raised by a factor of three. Final production rates increased by a factor of six with the use of a larger submersible pump. Well productivity (bbls of fluid per foot of drawdown) increased by a factor of 15 to 20. The above results assume that no mechanical damage has occurred to the casing or cast iron bridge plug which could allow well production from the Tensleep ''B'' sand. In the case of well 61-A-3, a six-fold increase in total fluid production was seen. Unfortunately, the increase is clouded by the water injection into the well that was necessary to have a positive fluid head on the propellant tool. No significant increase in oil production was seen. The tools which were retrieved from both 63-TPX-10 and 61-A-3 indicated a large amount of energy, similar to high gram perforating, had been expended downhole upon the formation face.

  4. Weak interactions at high energies

    International Nuclear Information System (INIS)

    Review lectures are presented on the phenomenological implications of the modern spontaneously broken gauge theories of the weak and electromagnetic interactions, and some observations are made about which high energy experiments probe what aspects of gauge theories. Basic quantum chromodynamics phenomenology is covered including momentum dependent effective quark distributions, the transverse momentum cutoff, search for gluons as sources of hadron jets, the status and prospects for the spectroscopy of fundamental fermions and how fermions may be used to probe aspects of the weak and electromagnetic gauge theory, studies of intermediate vector bosons, and miscellaneous possibilities suggested by gauge theories from the Higgs bosons to speculations about proton decay. 187 references

  5. High temperature thermoelectric energy conversion

    International Nuclear Information System (INIS)

    Considerable advances were made in the late '50's and early early '60's in the theory and development of materials for high-temperature thermoelectric energy conversion. This early work culminated in a variety of materials, spanning a range of temperatures, with the product of the figure of merit, Z, and temperature, T, i.e., the dimensionless figure of merit, ZT, of the order of one. This experimental limitation appeared to be universal and led a number of investigators to explore the possibility that a ZT- also represents a theoretical limitation. It was found not to be so

  6. High energy laser meteorology (HELMET)

    Science.gov (United States)

    Pries, Tom

    1990-05-01

    The present consideration of the atmospheric sensitivities of high-energy lasers intended for meteorological studies gives attention to the absorption effects of deuterium fluoride and CO2 lasers for several atmospheric gaseous species and aerosols, cloud and precipitation effects, and optical turbulence. Such nonlinear effects as thermal blooming and thermal shock waves are characterized, and the measurement characteristics of modulation transfer function devices, stellar scintillometers, isoplanometers, thermosondes, RF radars, FM-CW radars, molecular absorption/extinction lidars, wind lidars, and passive microwave temperature and humidity profilers, are presented for state-of-the-art devices.

  7. High-Energy-Density Capacitors

    Science.gov (United States)

    Slenes, Kirk

    2003-01-01

    Capacitors capable of storing energy at high densities are being developed for use in pulse-power circuits in such diverse systems as defibrillators, particle- beam accelerators, microwave sources, and weapons. Like typical previously developed energy-storage capacitors, these capacitors are made from pairs of metal/solid-dielectric laminated sheets that are wound and pressed into compact shapes to fit into cans, which are then filled with dielectric fluids. Indeed, these capacitors can be fabricated largely by conventional fabrication techniques. The main features that distinguish these capacitors from previously developed ones are improvements in (1) the selection of laminate materials, (2) the fabrication of the laminated sheets from these materials, and (3) the selection of dielectric fluids. In simplest terms, a high-performance laminated sheet of the type used in these capacitors is made by casting a dielectric polymer onto a sheet of aluminized kraft paper. The dielectric polymer is a siloxane polymer that has been modified with polar pendant groups to increase its permittivity and dielectric strength. Potentially, this polymer is capable of withstanding an energy density of 7.5 J/cm3, which is four times that of the previous state-of-the-art-capacitor dielectric film material. However, the full potential of this polymer cannot be realized at present because (1) at thicknesses needed for optimum performance (.8.0 m), the mechanical strength of a film of this polymer is insufficient for incorporation into a wound capacitor and (2) at greater thickness, the achievable energy density decreases because of a logarithmic decrease in dielectric strength with increasing thickness. The aluminized kraft paper provides the mechanical strength needed for processing of the laminate and fabrication of the capacitor, and the aluminum film serves as an electrode layer. Because part of the thickness of the dielectric is not occupied by the modified siloxane polymer, the

  8. High energy physics and cosmology

    International Nuclear Information System (INIS)

    This research will focus on the implications of recent theories and experiments in high energy physics of the evolution of the early universe, and on the constraints that cosmological considerations can place on such theories. Several problems are under investigation, including studies of the nature of dark matter and the signature of annihilations in the galactic halo, where the resulting γ-ray fluxes are potentially observable, and in stars, where stellar evolution may be affects. We will develop constraints on the inflationary predictions of scale-free primordial fluctuations in a universe at critical closure density by studying their linear and non-linear evolution after they re-enter the particle horizon, examining the observable imprint of primordial density fluctuations on the cosmic microwave background radiation in both flat and curved cosmological models, and implications for observations of large-scale galaxy clustering and structure formation theories. We will also study spectral distortions in the microwave background radiation that are produced by exotic particle decays in the very early universe. We expect such astrophysical considerations to provide fruitful insights both into high-energy particle physics and into possible cosmological for the early universe

  9. Duke University High Energy Physics

    International Nuclear Information System (INIS)

    The research program of the Duke High Energy Physics Group is described in this Progress Report and a separate Proposal containing their plans for 1994. These two documents are supplemented by compilations of selected publications, thesis abstracts, and the curriculum vitae of the eleven Ph.D. physicists who are carrying out this research program. This Progress Report contains a review of the research which has been done over the first half (1992 and 1993 to date) of the current three-year DOE grant, plus some earlier research to establish a broader perspective of the research interests. High energy physics research at Duke has three components. The first, Task A, is based upon experiments carried out at Fermilab's Tevatron Collider. The group is finishing the analysis of data from their first collider experiment (E735), a study of inclusive particle production from bar p p collisions at √ bar s = 1.8 TeV. The second component of the research, Task B, deals primarily with heavy flavor physics. The third part of the research program, Task D, deals with preparation for research at the SSC. The authors have been active in the development of tracking detectors for the SSC since 1989, and are now concentrating on the design and construction of straw tube drift chambers for the solenoid detector

  10. Approaches to high energy physics

    International Nuclear Information System (INIS)

    An overview of the present state of the art in high energy physics is presented highlighting the developments in hadron physics, field theory and nuclear democracy. To begin with, description of 'hadrons' is given on the basis of quantum electrodynamics. The role of the quantum numbers assigned to quarks are explained. Lepton-hadron scattering and hadron-hadron scattering are discussed. The quark-parton model of the nucleon is explained. The recently discovered Psi resonances and the consequent introduction of new quantum number 'charm' are mentioned. Next, Yang-Mills Gauge theories, the unification of weak and electromagnetic interactions and the concept of weak neutral currents are discussed. Gauge theories of strong interactions, quantum chromodynamics and the concept of 'Bags' are explained. Magnetic monopoles (solitons) are described with basis on non-linear field theories. High energy bounds in the axiomatic field theory are formulated. The general properties of S-matrix elements obtained in a quantum local field theory are mentioned. Lastly, the shifting of the reliance on field concepts to other approaches, specially through S-matrix and the application of Regge poles and cuts is explained. The duality hypothesis is postulated to explain processes such as pp→pp with the 'pomeron exchange' concept. Dual models of strong interactions are discussed. Future trends are indicated. (A.K.)

  11. High energy beam manufacturing technologies

    International Nuclear Information System (INIS)

    Technological progress continues to enable us to utilize ever widening ranges of physical and chemical conditions for material processing. The increasing cost of energy, raw materials and environmental control make implementation of advanced technologies inevitable. One of the principal avenues in the development of material processing is the increase of the intensity, accuracy, flexibility and stability of energy flow to the processing site. The use of different forms of energy beams is an effective way to meet these sometimes incompatible requirements. The first important technological applications of high energy beams were welding and flame cutting. Subsequently a number of different kinds of beams have been used to solve different problems of part geometry control and improvement of surface characteristics. Properties and applications of different specific beams were subjects of a number of fundamental studies. It is important now to develop a generic theory of beam based manufacturing. The creation of a theory dealing with general principles of beam generation and beam-material interaction will enhance manufacturing science as well as practice. For example, such a theory will provide a format approach for selection and integration of different kinds of beams for a particular application. And obviously, this theory will enable us to integrate the knowledge bases of different manufacturing technologies. The War of the Worlds by H. G. Wells, as well as a number of more technical, although less exciting, publications demonstrate both the feasibility and effectiveness of the generic approach to the description of beam oriented technology. Without any attempt to compete with Wells, we still hope that this volume will contribute to the creation of the theory of beam oriented manufacturing

  12. When Worlds Collide: Chandra Observes Titanic Merger

    Science.gov (United States)

    2002-04-01

    NASA's Chandra X-ray Observatory has provided the best X-ray image yet of two Milky Way-like galaxies in the midst of a head-on collision. Since all galaxies - including our own - may have undergone mergers, this provides insight into how the universe came to look as it does today. Astronomers believe the mega-merger in the galaxy known as Arp 220 triggered the formation of huge numbers of new stars, sent shock waves rumbling through intergalactic space, and could possibly lead to the formation of a supermassive black hole in the center of the new conglomerate galaxy. The Chandra data also suggest that merger of these two galaxies began only 10 million years ago, a short time in astronomical terms. "The Chandra observations show that things really get messed up when two galaxies run into each other at full speed," said David Clements of the Imperial College, London, one of the team members involved in the study. "The event affects everything from the formation of massive black holes to the dispersal of heavy elements into the universe." Arp 220 is considered to be a prototype for understanding what conditions were like in the early universe, when massive galaxies and supermassive black holes were presumably formed by numerous galaxy collisions. At a relatively nearby distance of about 250 million light years, Arp 220 is the closest example of an "ultra-luminous" galaxy, one that gives off a trillion times as much radiation as our Sun. The Chandra image shows a bright central region at the waist of a glowing, hour-glass-shaped cloud of multimillion-degree gas. Rushing out of the galaxy at hundreds of thousands of miles per hour, the super-heated as forms a "superwind," thought to be due to explosive activity generated by the formation of hundreds of millions of new stars. Farther out, spanning a distance of 75,000 light years, are giant lobes of hot gas that could be galactic remnants flung into intergalactic space by the early impact of the collision. Whether the

  13. Spectral Analysis of the Chandra Comet Survey

    CERN Document Server

    Bodewits, D; Torney, M; Dryer, M; Lisse, C M; Dennerl, K; Zurbuchen, T H; Wolk, S J; Tielens, A G G M; Hoekstra, R

    2007-01-01

    We present results of the analysis of cometary X-ray spectra with an extended version of our charge exchange emission model (Bodewits et al. 2006). We have applied this model to the sample of 8 comets thus far observed with the Chandra X-ray observatory and ACIS spectrometer in the 300-1000 eV range. The surveyed comets are C/1999 S4 (LINEAR), C/1999 T1 (McNaught-Hartley), C/2000 WM1 (LINEAR), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), C/2001 Q4 (NEAT), 9P/2005 (Tempel 1) and 73P/2006-B (Schwassmann-Wachmann 3) and the observations include a broad variety of comets, solar wind environments and observational conditions. The interaction model is based on state selective, velocity dependent charge exchange cross sections and is used to explore how cometary X-ray emission depend on cometary, observational and solar wind characteristics. It is further demonstrated that cometary X-ray spectra mainly reflect the state of the local solar wind. The current sample of Chandra observations was fit using the constrains of ...

  14. Chandra mission scheduling on-orbit experience

    Science.gov (United States)

    Bucher, Sabina; Williams, Brent; Pendexter, Misty; Balke, David

    2008-07-01

    Scheduling observatory time to maximize both day-to-day science target integration time and the lifetime of the observatory is a formidable challenge. Furthermore, it is not a static problem. Of course, every schedule brings a new set of observations, but the boundaries of the problem change as well. As spacecraft ages, its capabilities may degrade. As in-flight experience grows, capabilities may expand. As observing programs are completed, the needs and expectations of the science community may evolve. Changes such as these impact the rules by which a mission scheduled. In eight years on orbit, the Chandra X-Ray Observatory Mission Planning process has adapted to meet the challenge of maximizing day-to-day and mission lifetime science return, despite a consistently evolving set of scheduling constraints. The success of the planning team has been achieved, not through the use of complex algorithms and optimization routines, but through processes and home grown tools that help individuals make smart short term and long term Mission Planning decisions. This paper walks through the processes and tools used to plan and produce mission schedules for the Chandra X-Ray Observatory. Nominal planning and scheduling, target of opportunity response, and recovery from on-board autonomous safing actions are all addressed. Evolution of tools and processes, best practices, and lessons learned are highlighted along the way.

  15. Chandra Resolves Cosmic X-ray Glow and Finds Mysterious New Sources

    Science.gov (United States)

    2000-01-01

    While taking a giant leap towards solving one of the greatest mysteries of X-ray astronomy, NASA's Chandra X-ray Observatory also may have revealed the most distant objects ever seen in the universe and discovered two puzzling new types of cosmic objects. Not bad for being on the job only five months. Chandra has resolved most of the X-ray background, a pervasive glow of X-rays throughout the universe, first discovered in the early days of space exploration. Before now, scientists have not been able to discern the background's origin, because no X-ray telescope until Chandra has had both the angular resolution and sensitivity to resolve it. "This is a major discovery," said Dr. Alan Bunner, Director of NASA's Structure andEvolution of the universe science theme. "Since it was first observed thirty-seven years ago, understanding the source of the X-ray background has been aHoly Grail of X-ray astronomy. Now, it is within reach." The results of the observation will be discussed today at the 195th national meeting of the American Astronomical Society in Atlanta, Georgia. An article describing this work has been submitted to the journal Nature by Dr. Richard Mushotzky, of NASA Goddard Space Flight Center, Greenbelt, Md., Drs. Lennox Cowie and Amy Barger at the University of Hawaii, Honolulu, and Dr. Keith Arnaud of the University of Maryland, College Park. "We are all very excited by this finding," said Mushotzky. "The resolution of most of the hard X-ray background during the first few months of the Chandra mission is a tribute to the power of this observatory and bodes extremely well for its scientific future," Scientists have known about the X-ray glow, called the X-ray background, since the dawn of X-ray astronomy in the early 1960s. They have been unable to discern its origin, however, for no X-ray telescope until Chandra has had both the angular resolution and sensitivity to resolve it. The German-led ROSAT mission, now completed, resolved much of the lower-energy

  16. Chandra And HST Observations of Gamma-Ray Blazars: Comparing Jet Emission at Small And Large Scales

    Energy Technology Data Exchange (ETDEWEB)

    Tavecchio, Fabrizio; Maraschi, L.; Wolter, A.; /Brera Observ.; Cheung, C.C.; /KIPAC, Menlo Park; Sambruna, R.M.; /NASA, Goddard; Urry, C.M.; /Yale U., Dept. Astron.

    2007-03-20

    We present new Chandra and HST data for four gamma-ray blazars selected on the basis of radio morphology with the aim of revealing X-ray and optical emission from their jets at large scales. All the sources have been detected. Spectral Energy Distributions of the large scale jets are obtained as well as new X-ray spectra for the blazar cores. Modeling for each object the core (sub-pc scale) and large-scale ({approx}> 100 kpc) jet SEDs, we derive the properties of the same jet at the two scales. The comparison of speeds and powers at different scales supports a simple scenario for the dynamics and propagation of high power relativistic jets.

  17. The origin of emission and absorption features in Ton S180 Chandra observations

    OpenAIRE

    Różańska, A.; Czerny, B.; Siemiginowska, A.; Dumont, A. -M.; Kawaguchi, T.

    2003-01-01

    We present new interpretation of Ton S180 spectrum obtained by {\\it Chandra} Spectrometer (Low Energy Transmission Grating). Several narrow absorption lines and a few emission disk lines have been successfully fitted to the data. We have not found any significant edges accompanying line emission. We propose the interpretation of narrow lines consistent with the paper recently written by Krolik (2002), where warm absorber is strongly inhomogeneous. Such situation is possible in so called multi...

  18. Oxides having high energy densities

    Science.gov (United States)

    Ceder, Gerbrand; Kang, Kisuk

    2013-09-10

    Certain disclosed embodiments generally relate to oxide materials having relatively high energy and/or power densities. Various aspects of the embodiments are directed to oxide materials having a structure B.sub.i(M.sub.jY.sub.k)O.sub.2, for example, a structure Li.sub.j(Ni.sub.jY.sub.k)O.sub.2 such as Li(Ni.sub.0.5Mn.sub.0.5)O.sub.2. In this structure, Y represents one or more atoms, each independently selected from the group consisting of alkaline earth metals, transition metals, Group 14 elements, Group 15, or Group 16 elements. In some embodiments, such an oxide material may have an O3 crystal structure, and/or a layered structure such that the oxide comprises a plurality of first, repeating atomic planes comprising Li, and a plurality of second, repeating atomic planes comprising Ni and/or Y.

  19. Lasers and future high energy colliders

    International Nuclear Information System (INIS)

    Future high energy colliders, directions for particle physics and relationship to new technology such as lasers are discussed. Experimental approaches to explore New Physics with emphasis on the utility of high energy colliders are also discussed

  20. ChanPlaNS: The Chandra Planetary Nebula Survey

    Science.gov (United States)

    Kastner, Joel; Montez, Rodolfo; Freeman, Marcus; ChanPlaNS Team

    2015-01-01

    The physical mechanisms responsible for the morphological diversity among planetary nebulae (PNe) have been the subject of intense interest and hot debate among PN researchers over the past two decades. The PN shaping problem is multifaceted, with connections to (and implications for) a wide variety of astrophysical systems. Two areas of particular importance are (1) binary star astrophysics and (2) wind interactions and their implications for nebular shaping. X-ray observations play a pivotal role in the study of both of these fundamental aspects of PNe, by revealing (1) point-like X-ray sources at PN central stars that may be indicative of binary companions, and (2) diffuse X-ray emission generated by energetic, PN-shaping shocks. To assess the frequency of appearance and characteristics of these respective PN X-ray sources, we have undertaken the Chandra Planetary Nebula Survey (ChanPlaNS), the first comprehensive X-ray survey of planetary nebulae (PNe) in the solar neighborhood. ChanPlaNS began with a combined Cycle 12 Large Program and archival survey of 35 PNe, with emphasis on high-excitation nebulae, and continued via a Cycle 14 Large Program targeting an additional 24 known compact (R_neb central stars (~60%) and for the compact (young) PN subsample (~50%). These results demonstrate the potential for insight into PN shaping processes provided by ChanPlaNS. In companion presentations at this meeting (Montez et al.; Freeman et al.), we present highlights of the astrophysics gleaned to date from these Chandra detections (and nondetections) of X-ray emission from PNe and their central stars.

  1. A DEEP CHANDRA VIEW OF THE NGC 404 CENTRAL ENGINE

    International Nuclear Information System (INIS)

    We present the results of a 100 ks Chandra observation of the NGC 404 nuclear region. The long exposure and excellent spatial resolution of Chandra have enabled us to critically examine the nuclear environment of NGC 404, which is known to host a nuclear star cluster and potentially an intermediate-mass black hole (IMBH; on the order of a few times 105 Msun). We find two distinct X-ray sources: a hard, central point source coincident with the optical and radio centers of the galaxy, and a soft extended region that is coincident with areas of high Hα emission and likely recent star formation. When we fit the 0.3-8 keV spectra of each region separately, we find the hard nuclear point source to be dominated by a power law (Γ = 1.88), while the soft off-nuclear region is best fit by a thermal plasma model (kT = 0.67 keV). We therefore find evidence for both a power-law component and hot gas in the nuclear region of NGC 404. We estimate the 2-10 keV luminosity to be 1.3+0.8-0.5 x 1037 erg s-1. A low level of diffuse X-ray emission was detected out to ∼15'' (∼0.2 kpc) from the nucleus. We compare our results to the observed relationships between power-law photon index and Eddington ratio for both X-ray binaries and low-luminosity active galaxies and find NGC 404 to be consistent with other low-luminosity active galaxies. We therefore favor the conclusion that NGC 404 harbors an IMBH accreting at a very low level.

  2. High energy physics and cosmology

    International Nuclear Information System (INIS)

    This research will focus on the implications of recent theories and experiments in high energy physics for the evolution of the early Universe, and on the constraints that cosmological considerations can place on such theories. Several problems are under investigation, including the development of constraints on the inflationary predictions of scale--free primordial fluctuations in a universe at critical closure density by studying their linear and non-linear evolution after they re-enter the particle horizon. We will examine the observable imprint of primordial density fluctuations on the cosmic microwave background radiation curved cosmological models. Most astronomical evidence points to an open universe: one of our goals is to reconcile this conclusion with the particle physics input. We will investigate the response of the matter distribution to a network of cosmic strings produced during an early symmetry-breaking transition, and compute the resulting cosmic microwave background anisotropies. We will simulate the formation of large-scale structures whose dynamics are dominated by weakly interacting particles such as axions, massive neutrinos or photinos in order to model the formation of galaxies, galaxy clusters and superclusters. We will study of the distortions in the microwave background radiation, both spectral and angular, that are produced by ionized gas associated with forming clusters and groups of galaxies. We will also study constraints on exotic cooling mechanisms involving axions and majorons set by stellar evolution and the energy input into low mass stars by cold dark matter annihilation galactic nuclei. We will compute the detailed gamma ray spectrum predicted by various cold dark matter candidates undergoing annihilation in the galactic halo and bulge

  3. [High energy physics and cosmology

    International Nuclear Information System (INIS)

    This research will focus on the implications of recent theories and experiments in high energy physics for the evolution of the early Universe, and on the constraints that cosmological considerations can place on such theories. Several problems are under investigation, including the development of constraints on the inflationary predictions of scale-free primordial fluctuations in a universe at critical closure density by studying their linear and non-linear evolution after they re-enter the particle horizon. We will examine the observable imprint of primordial density fluctuations on the cosmic microwave background radiation in curved cosmological models. Most astronomical evidence points to an open universe: one of our goals is to reconcile this conclusion with the particle physics input. We will investigate the response of the matter distribution to a network of cosmic strings produced during an early symmetry--breaking transition, and compute the resulting cosmic microwave background anisotropies. We will simulate the formation of large--scale structures whose dynamics are dominated by weakly interacting particles such as axions massive neutrinos or photinos in order to model the formation of galaxies, galaxy clusters and superclusters. We will study the distortions in the microwave background radiation, both spectral and angular, that are produced by ionized gas associated with forming clusters and groups of galaxies. We will also study constraints on exotic cooling mechanisms involving axions and majorons set by stellar evolution and the energy input into low mass stars by cold dark matter annihilation in galactic nuclei. We will compute the detailed gamma ray spectrum predicted by various cold dark matter candidates undergoing annihilation in the galactic halo and bulge

  4. Modeling Contamination Migration on the Chandra X-ray Observatory II

    Science.gov (United States)

    O'Dell, Steve; Swartz, Doug; Tice, Neil; Plucinsky, Paul; Grant, Catherine; Marshall, Herman; Vikhlinin, Alexey

    2013-01-01

    During its first 14 years of operation, the cold (about -60degC) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X-ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low-energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition may have changed, perhaps partially related to changes in the operating temperature of the ACIS housing. This evolution of the accumulation of the molecular contamination has motivated further analysis of contamination migration on the Chandra X-ray Observatory, particularly within and near the ACIS cavity. To this end, the current study employs a higher-fidelity geometric model of the ACIS cavity, detailed thermal modeling based upon monitored temperature data, and an accordingly refined model of the molecular transport.

  5. A Chandra/HETGS Census of X-ray Variability From Sgr A* During 2012

    CERN Document Server

    Neilsen, J; Gammie, C; Dexter, J; Markoff, S; Haggard, D; Nayakshin, S; Wang, Q D; Grosso, N; Porquet, D; Tomsick, J A; Degenaar, N; Fragile, P C; Wijnands, R; Miller, J M; Baganoff, F K

    2013-01-01

    We present the first systematic analysis of the X-ray variability of Sgr A* during the Chandra X-ray Observatory's 2012 Sgr A* X-ray Visionary Project (XVP). With 38 High Energy Transmission Grating Spectrometer (HETGS) observations spaced an average of 7 days apart, this unprecedented campaign enables detailed study of the X-ray emission from this supermassive black hole at high spatial, spectral and timing resolution. In 3 Ms of observations, we detect 39 X-ray flares from Sgr A*, lasting from a few hundred seconds to approximately 8 ks, and ranging in 2-10 keV luminosity from ~1e34 erg/s to 2e35 erg/s. Despite tentative evidence for a gap in the distribution of flare peak count rates, there is no evidence for X-ray color differences between faint and bright flares. Our preliminary X-ray flare luminosity distribution dN/dL is consistent with a power law with index -1.9 (+0.3 -0.4); this is similar to some estimates of Sgr A*'s NIR flux distribution. The observed flares contribute one-third of the total X-ra...

  6. High sensitivity fluid energy harvester

    CERN Document Server

    Morarka, Amit

    2016-01-01

    An ambient energy harvesting device was design and fabricated. It can harness kinetic energy of rain droplets and low velocity wind flows. The energy converted into electrical energy by using a single device. The technique used by the device was based on the principles of electromagnetic induction and cantilever. Readily available materials were characterized and used for the fabrication of cantilever. Under the laboratory conditions, water droplets having diameter 4mm and wind with speed 0.5m/s were used as the two distinct sources. Without making any changes in the geometry or the materials used, the device was able to convert kinetic energy from both the sources to provide voltage in the range of 0.7-1VAC. The work was conceptualized to provide an autonomous device which can harness energy from both the renewable energy sources.

  7. High Energy Plasma Space Propulsion

    Science.gov (United States)

    Wu, S. T.

    2000-01-01

    In order to meet NASA's challenge on advanced concept activity in the propulsion area, we initiated a new program entitled "High Energy Plasma Space Propulsion Studies" within the current cooperative agreement in 1998. The goals of this work are to gain further understanding of the engine of the AIMStar spacecraft, a concept which was developed at Penn State University, and to develop a prototype concept for the engine. The AIMStar engine concept was developed at Penn State University several years ago as a hybrid between antimatter and fusion technologies. Because of limited amounts of antimatter available, and concurrently the demonstrated ability for antiprotons to efficiently ignite nuclear fusion reactions, it was felt that this was a very good match. Investigations have been made concerning the performance of the reaction trap. This is a small Penning-like electromagnetic trap, which is used to simultaneously confine antiprotons and fusion fuels. Small DHe3 or DT droplets, containing a few percent molar of a fissile material, are injected into the trap, filled with antiprotons. We have found that it is important to separate the antiprotons into two adjacent wells, to inject he droplet between them and to simultaneously bring the antiprotons to the center of the trap, surrounding the droplet. Our previous concept had the droplet falling onto one cloud of antiprotons. This proved to be inefficient, as the droplet tended to evaporate away from the cloud as it interacted on its surface.

  8. High resolution energy analysers for the 'High Throughput Inelastic Spectrometer'

    International Nuclear Information System (INIS)

    Calculations of energy transfer resolution and count rate for different filter materials and various high resolution energy analysers for the 'High Throughput Inelastic Spectrometer', HTIS, on the SNS, are presented. A graphite filter is shown to be complementary to the existing beryllium filter analyser, improving the energy transfer resolution for energy transfers < approximately equal to 50 meV. Narrow energy band pass analysers are shown to be limited in energy transfer resolution by variations in the scattered flight path, rather than by the intrinsic band widths. The Be/MgO difference filter provides improved energy transfer resolution and high count rates over a wide range of energy transfers, and is felt to be the most appropriate high resolution energy analyser for HTIS. (author)

  9. Using ACIS on the Chandra X-ray Observatory as a particle radiation monitor II

    CERN Document Server

    Grant, C E; Bautz, M W; O'Dell, S L

    2012-01-01

    The Advanced CCD Imaging Spectrometer is an instrument on the Chandra X-ray Observatory. CCDs are vulnerable to radiation damage, particularly by soft protons in the radiation belts and solar storms. The Chandra team has implemented procedures to protect ACIS during high-radiation events including autonomous protection triggered by an on-board radiation monitor. Elevated temperatures have reduced the effectiveness of the on-board monitor. The ACIS team has developed an algorithm which uses data from the CCDs themselves to detect periods of high radiation and a flight software patch to apply this algorithm is currently active on-board the instrument. In this paper, we explore the ACIS response to particle radiation through comparisons to a number of external measures of the radiation environment. We hope to better understand the efficiency of the algorithm as a function of the flux and spectrum of the particles and the time-profile of the radiation event.

  10. A Deep Chandra X-Ray Spectrum of the Accreting Young Star TW Hydrae

    Science.gov (United States)

    Brickhouse, N. S.; Cranmer, S. R.; Dupree, A. K.; Luna, G. J. M.; Wolk, S.

    2010-02-01

    We present X-ray spectral analysis of the accreting young star TW Hydrae from a 489 ks observation using the Chandra High Energy Transmission Grating. The spectrum provides a rich set of diagnostics for electron temperature Te , electron density Ne , hydrogen column density NH , relative elemental abundances, and velocities, and reveals its source in three distinct regions of the stellar atmosphere: the stellar corona, the accretion shock, and a very large extended volume of warm postshock plasma. The presence of Mg XII, Si XIII, and Si XIV emission lines in the spectrum requires coronal structures at ~10 MK. Lower temperature lines (e.g., from O VIII, Ne IX, and Mg XI) formed at 2.5 MK appear more consistent with emission from an accretion shock. He-like Ne IX line ratio diagnostics indicate that Te = 2.50 ± 0.25 MK and Ne = 3.0 ± 0.2 × 1012 cm-3 in the shock. These values agree well with standard magnetic accretion models. However, the Chandra observations significantly diverge from current model predictions for the postshock plasma. This gas is expected to cool radiatively, producing O VII as it flows into an increasingly dense stellar atmosphere. Surprisingly, O VII indicates Ne = 5.7+4.4 -1.2 × 1011 cm-3, 5 times lower than Ne in the accretion shock itself and ~7 times lower than the model prediction. We estimate that the postshock region producing O VII has roughly 300 times larger volume and 30 times more emitting mass than the shock itself. Apparently, the shocked plasma heats the surrounding stellar atmosphere to soft X-ray emitting temperatures and supplies this material to nearby large magnetic structures—which may be closed magnetic loops or open magnetic field leading to mass outflow. Our model explains the soft X-ray excess found in many accreting systems as well as the failure to observe high Ne signatures in some stars. Such accretion-fed coronae may be ubiquitous in the atmospheres of accreting young stars.

  11. A Joint Chandra and Swift View of the 2015 X-Ray Dust Scattering Echo of V404 Cygni

    OpenAIRE

    Heinz, S.; Corrales, L.; Smith, R.; Brandt, W. N.; Jonker, P.G.; Plotkin, R.M.; Neilsen, J.

    2016-01-01

    We present a combined analysis of the Chandra and Swift observations of the 2015 X-ray echo of V404 Cygni. Using stacking analysis, we identify eight separate rings in the echo. We reconstruct the soft X-ray lightcurve of the June 2015 outburst using the high-resolution Chandra images and cross-correlations of the radial intensity profiles, indicating that about 70% of the outburst fluence occurred during the bright flare at the end of the outburst on MJD 57199.8.By deconvolving the intensity...

  12. Ultra High Energy Cosmic Rays and Neutrinos

    CERN Document Server

    Aloisio, Roberto

    2016-01-01

    We discuss the production of ultra high energy neutrinos coming from the propagation of ultra high energy cosmic rays and in the framework of top-down models for the production of these extremely energetic particles. We show the importance of the detection of ultra high energy neutrinos that can be a fundamental diagnostic tool to solve the discrepancy in the observed chemical composition of ultra high energy cosmic rays and, at the extreme energies, can unveil new physics in connection with the recent cosmological observations of the possible presence of tensor modes in the fluctuation pattern of the cosmic microwave background.

  13. High-Energy Astrophysics: An Overview

    Science.gov (United States)

    Fishman, Gerald J.

    2007-01-01

    High-energy astrophysics is the study of objects and phenomena in space with energy densities much greater than that found in normal stars and galaxies. These include black holes, neutron stars, cosmic rays, hypernovae and gamma-ray bursts. A history and an overview of high-energy astrophysics will be presented, including a description of the objects that are observed. Observing techniques, space-borne missions in high-energy astrophysics and some recent discoveries will also be described. Several entirely new types of astronomy are being employed in high-energy astrophysics. These will be briefly described, along with some NASA missions currently under development.

  14. [High energy physics]: Progress report

    International Nuclear Information System (INIS)

    During calendar year 1986 the high energy physics group at the University of Massachusetts continued its study of electron-positron annihilation reactions along with the TPC collaboration at the PEP facility of the Stanford Linear Accelerator Center (SLAC). During this year the TPC detector completed its 4th year of data collection including the 2nd year of data gathering with its full momentum resolution capabilities. In addition to assisting in the data collection, the UMass group has participated in hardware monitoring and improvement efforts, and has contributed to a number of diverse data analysis projects. The TPC collaboration has continued to publish numerous analysis results and new publications from the current data sample will continue for at least several years. Continued data taking has been approved at the PEP facility with two major improvements: the PEP luminosity will be increased by a factor of 4 or more, and the TPC will be further enhanced with the addition of a vertex detector. In addition to its continuing work with the TPC collaboration the UMass group has expanded its efforts to include a participation in the SLD project at the new linear collider (SLC) facility at SLAC. This expansion of effort has been facilitated by the addition of another UMass faculty member, Stanley Hertzbach, whose full year sabbatical, beginning this fall, will be spent working full time on the SLC project at SLAC. The UMass group has joined the ''beamline'' subgroup of the SLD project and is working on the design of the masking which is necessary near the interaction point to shield the detector from the intense halo of synchrotron radiation that accompanies the electron and positron beams

  15. Six Years of Chandra Observations of Supernova Remnants

    OpenAIRE

    Weisskopf, Martin C.; Hughes, John P.

    2005-01-01

    We present a review of the first six years of Chandra X-ray Observatory observations of supernova remnants. From the official "first-light" observation of Cassiopeia A that revealed for the first time the compact remnant of the explosion, to the recent million-second spectrally-resolved observation that revealed new details of the stellar composition and dynamics of the original explosion, Chandra observations have provided new insights into the supernova phenomenon. We present an admittedly ...

  16. Finding Rare AGN: XMM-Newton and Chandra Observations of SDSS Stripe 82

    CERN Document Server

    LaMassa, Stephanie M; Cappelluti, Nico; Civano, Francesca; Ranalli, Piero; Glikman, Eilat; Treister, Ezequiel; Richards, Gordon; Ballantyne, David; Stern, Daniel; Comastri, Andrea; Cardamone, Carie; Schawinski, Kevin; Boehringer, Hans; Chon, Gayoung; Murray, Stephen S; Green, Paul; Nandra, Kirpal

    2013-01-01

    We have analyzed the {\\it XMM-Newton} and {\\it Chandra} data overlapping $\\sim$16.5 deg$^2$ of Sloan Digital Sky Survey Stripe 82, including $\\sim$4.6 deg$^2$ of proprietary {\\it XMM-Newton} data that we present here. In total, 3362 unique X-ray sources are detected at high significance. We derive the {\\it XMM-Newton} number counts and compare them with our previously reported {\\it Chandra} Log$N$-Log$S$ relations and other X-ray surveys. The Stripe 82 X-ray source lists have been matched to multi-wavelength catalogs using a maximum likelihood estimator algorithm. We discovered the highest redshift ($z=5.86$) quasar yet identified in an X-ray survey. We find 2.5 times more high luminosity (L$_x \\geq 10^{45}$ erg s$^{-1}$) AGN than the smaller area {\\it Chandra} and {\\it XMM-Newton} survey of COSMOS and 1.3 times as many identified by XBo\\"otes. Comparing the high luminosity AGN we have identified with those predicted by population synthesis models, our results suggest that this AGN population is a more import...

  17. Chandra LETGS observation of the variable NLS1 galaxy Ark 564

    Science.gov (United States)

    Ramírez, J. M.

    2013-03-01

    We present an analysis of the 100 ks X-ray spectrum of the narrow-line Seyfert 1 Galaxy Ark 564, taken with the Low Energy Transmission Grating Spectrometer (LETGS) on board Chandra. Using χ2 statistics, several continuum models of the time-averaged spectrum of this object are compared, obtaining a semi-empirical solution for the description of the intrinsic emission continuum and a physical solution for the intrinsic absorption of the system. We find that the 0.1-10 keV spectrum can be well described by a power law plus two thermal components that account for the soft step. We are also able to detect and measure several narrow, unresolved absorption lines arising from highly ionized species of C, N, O, and Fe. The material seems to have a velocity consistent with the systemic velocity of the galaxy. This piece of evidence, in addition to the very low observed column density of NH ~ 1020 cm-2, is in good agreement with the scenario of a transverse biconical outflow with a gas density of n ≲ 3 × 1012 cm-3 at distances beyond the broad-line region r ≳ 10 lt-days, but a dust torus origin cannot be ruled out. The reduced spectrum is only available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr(130.79.128.5) or via cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/551/A95

  18. CHANDRA-LETGS X-ray observations of Capella Temperature, density and abundance diagnostics

    CERN Document Server

    Ness, J U; Schmitt, J H M M; Raassen, A J J; Porquet, D; Kaastra, J S; Van der Meer, R L J; Burwitz, V; Predehl, P

    2001-01-01

    Electron density diagnostics based on the triplets of Helium-like CV, NVI, and OVII are applied to the X-ray spectra of Capella and Procyon measured with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra X-ray Observatory. New theoretical models for the calculation of the line ratios between the forbidden (f), intercombination (i), and the resonance (r) lines of the helium-like triplets are used. The derived densities are quite typical of densities found in the solar active regions, and also pressures and temperatures in Procyon's and Capella's corona at a level of T=10^6K are quite similar. We find no evidence for densities as high as measured in solar flares. Comparison of our Capella and Procyon measurements with the Sun shows little difference in the physical properties of the layers producing the CV, NVI, and OVII emission. Assuming the X-ray emitting plasma to be confined in magnetic loops, we obtain typical loop length scales of L_Capella > 8 L_Procyon from the loop scaling ...

  19. States of high energy density

    International Nuclear Information System (INIS)

    The transverse energy, E/sub tau/ spectra for O16 and S32 incident for various elements at 200 GeVnucleon are shown. The target and projectile dependencies of the data are discussed. The energy density achieved is estimated. For O16 on Tungsten the multiplicity spectrum is also presented as well as the pseudorapidity spectra as a function of the transverse energy. The multiplicity cross section dσdN as measured in the backward hemisphere (0.9 < /eta/ < 2.9/ is found to be very similar in shape to the transverse energy distribution dσdE/tau/ reflecting the particular geometry of nucleus nucleus nucleus collisions. The dependence on the atomic mass of the target, A/sub tau/ and projectile A/sub p/ is not what one would expect from naive considerations

  20. Spatially Resolved Chandra HETG Spectroscopy of the NLR Ionization Cone in NGC 1068

    CERN Document Server

    Evans, Daniel A; Marshall, Herman L; Nowak, Mike A; Bianchi, Stefano; Guainazzi, Matteo; Longinotti, Anna Lia; Dewey, Dan; Schulz, Norbert S; Noble, Mike S; Houck, John; Canizares, Claude R

    2009-01-01

    We present initial results from a new 440-ks Chandra HETG GTO observation of the canonical Seyfert 2 galaxy NGC 1068. The proximity of NGC 1068, together with Chandra's superb spatial and spectral resolution, allow an unprecedented view of its nucleus and circumnuclear NLR. We perform the first spatially resolved high-resolution X-ray spectroscopy of the `ionization cone' in any AGN, and use the sensitive line diagnostics offered by the HETG to measure the ionization state, density, and temperature at discrete points along the ionized NLR. We argue that the NLR takes the form of outflowing photoionized gas, rather than gas that has been collisionally ionized by the small-scale radio jet in NGC 1068. We investigate evidence for any velocity gradients in the outflow, and describe our next steps in modeling the spatially resolved spectra as a function of distance from the nucleus.

  1. Managing Radiation Degradation of CCDs on the Chandra X-Ray Observatory--III

    Science.gov (United States)

    O'Dell, Stephen L.; Aldcroft, Thomas L.; Blackwell, William C.; Bucher, Sabina L.; Chappell, Jon H.; DePasquale, Joseph M.; Grant, Catherine E.; Juda, Michael; Martin, Eric R.; Minow, Joseph I.; Murray, Stephen S.; Plucinsky, Paul P.; Shropshire, Daniel P.; Spitzbart, Bradley J.; Viens, Paul R.; Wolk, Scott J.; Schwartz, Daniel A.

    2007-01-01

    The CCDs on the Chandra X-ray Observatory are vulnerable to radiation damage from low-energy protons scattered off the telescope's mirrors onto the focal plane. Following unexpected damage incurred early in the mission, the Chandra team developed, implemented, and maintains a radiation-protection program. This program--involving scheduled radiation safing during radiation-belt passes, intervention based upon real-time space-weather conditions and radiation-environment modeling, and on-board radiation monitoring with autonomous radiation safing--has successfully managed the radiation damage to the CCDs. Since implementing the program, the charge-transfer inefficiency (CTI) has increased at an average annual rate of only 3.2x 10(exp -6) (2.3 percent) for the front-illuminated CCDs and 1.0x10(exp -6) (6.7 percent) for the back-illuminated CCDs. This paper describes the current status of the Chandra radiation-management program, emphasizing enhancements implemented since the previous papers.

  2. The Brera Multi-scale Wavelet Chandra Survey. I. Serendipitous source catalogue

    CERN Document Server

    Romano, P; Mignani, R P; Moretti, A; Mottini, M; Panzera, M R; Tagliaferri, G

    2008-01-01

    We present the BMW-Chandra source catalogue drawn from essentially all Chandra ACIS-I pointed observations with an exposure time in excess of 10ks public as of March 2003 (136 observations). Using the wavelet detection algorithm developed by Lazzati et al. (1999) and Campana et al. (1999), which can characterise both point-like and extended sources, we identified 21325 sources. Among them, 16758 are serendipitous, i.e. not associated with the targets of the pointings, and do not require a non-automated analysis. This makes our catalogue the largest compilation of Chandra sources to date. The 0.5--10 keV absorption corrected fluxes of these sources range from ~3E-16 to 9E-12 erg cm^-2 s^-1 with a median of 7E-15 erg cm^-2 s^-1. The catalogue consists of count rates and relative errors in three energy bands (total, 0.5-7keV; soft, 0.5-2keV; and hard, 2-7keV), and source positions relative to the highest signal-to-noise detection among the three bands. The wavelet algorithm also provides an estimate of the exten...

  3. High Energy Observations of XRF 030723: Evidence for an Off-axis Gamma-Ray Burst?

    CERN Document Server

    Butler, N R; Suzuki, M; Kawai, N; Lamb, D Q; Graziani, C; Donaghy, T Q; Dullighan, A; Vanderspek, R; Crew, G B; Ford, P; Ricker, G; Atteia, J L; Yoshida, A; Shirasaki, Y; Tamagawa, T; Torii, K; Matsuoka, M; Fenimore, E E; Galassi, M; Doty, J; Villaseñor, J D; Prigozhin, G Y; Jernigan, J G; Barraud, C; Boër, M; Dezalay, J P; Olive, J F; Hurley, K; Levine, A; Martel, F; Morgan, E; Woosley, S E; Cline, T; Braga, J; Manchanda, R K; Pizzichini, G

    2004-01-01

    We report High Energy Transient Explorer 2 (HETE-2) Wide Field X-ray Monitor/French Gamma Telescope observations of XRF030723 along with observations of the XRF afterglow made using the 6.5m Magellan Clay telescope and the Chandra X-ray Observatory. The observed peak energy E_pk_obs of the nu F_nu burst spectrum is found to lie within (or below) the WXM 2-25 keV passband at 98.5% confidence, and no counts are detected above 30 keV. Our best fit value is E_pk_obs=8.4+3.5/-3.4 keV. The ratio of X-ray to Gamma-ray flux for the burst follows a correlation found for GRBs observed with HETE-2, and the duration of the burst is similar to that typical of long-duration GRBs. If we require that the burst isotropic equivalent energy E_iso and E_pk_rest satisfy the relation discovered by Amati et al. (2002), a redshift of z=0.38+0.36/-0.18 can be determined, in agreement with constraints determined from optical observations. We are able to fit the X-ray afterglow spectrum and to measure its temporal fade. Although the be...

  4. Theory of high-energy messengers

    CERN Document Server

    Dermer, Charles D

    2016-01-01

    Knowledge of the distant high-energy universe comes from photons, ultra-high energy cosmic rays (UHECRs), high-energy neutrinos, and gravitational waves. The theory of high-energy messengers reviewed here focuses on the extragalactic background light at all wavelengths, cosmic rays and magnetic fields in intergalactic space, and neutrinos of extragalactic origin. Comparisons are drawn between the intensities of photons and UHECRs in intergalactic space, and the high-energy neutrinos recently detected with IceCube at about the Waxman-Bahcall flux. Source candidates for UHECRs and high-energy neutrinos are reviewed, focusing on star-forming and radio-loud active galaxies. HAWC and Advanced LIGO are just underway, with much anticipation.

  5. High energy hadrons in extensive air showers

    Science.gov (United States)

    Tonwar, S. C.

    1985-01-01

    Experimental data on the high energy hadronic component in extensive air showers of energies approx. 10 to the 14 to 10 to the 16 eV when compared with expectations from Monte Carlo simulations have shown the observed showers to be deficient in high energy hadrons relative to simulated showers. An attempt is made to understand these anomalous features with more accurate comparison of observations with expectations, taking into account the details of the experimental system. Results obtained from this analysis and their implications for the high energy physics of particle interactions at energy approx. 10 to the 15 eV are presented.

  6. Harvard University High Energy Physics progress report

    International Nuclear Information System (INIS)

    The principal goals of this work are to carry out forefront programs in high energy physics research and to provide first rate educational opportunities for students. The experimental program supported through HEPL is carried out at the major accelerator centers in the world and addresses some of the most important questions in high energy physics. The program is based at Harvard's High Energy Physics Laboratory, which has offices, computing facilities, and engineering support, and both electronics and machine shops

  7. Ultra high energy cosmic ray horizons

    International Nuclear Information System (INIS)

    We calculate the horizons of ultra high energy cosmic rays assuming different primary nuclei ranging from proton to iron at ultra high energies (6.1019 eV). We show that sources of ultra high energy protons and heavy nuclei can originate from distances up to ∼180 Mpc, while low and intermediate mass nuclei can only originate in the local universe (<50 Mpc).

  8. Ultra high energy cosmic ray horizons

    Energy Technology Data Exchange (ETDEWEB)

    Busca, N.G. [Laboratoire d' Astroparticules at Cosmologie, 10, rue Alice Domon et Lonie Duquet, 75205 Paris Cedex 13 (France)

    2009-05-15

    We calculate the horizons of ultra high energy cosmic rays assuming different primary nuclei ranging from proton to iron at ultra high energies (6.10{sup 19} eV). We show that sources of ultra high energy protons and heavy nuclei can originate from distances up to approx180 Mpc, while low and intermediate mass nuclei can only originate in the local universe (<50 Mpc).

  9. Split School of High Energy Physics 2015

    CERN Document Server

    2015-01-01

    Split School of High Energy Physics 2015 (SSHEP 2015) was held at the Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture (FESB), University of Split, from September 14 to September 18, 2015. SSHEP 2015 aimed at master and PhD students who were interested in topics pertaining to High Energy Physics. SSHEP 2015 is the sixth edition of the High Energy Physics School. Previous five editions were held at the Department of Physics, University of Sarajevo, Bosnia and Herzegovina.

  10. Chandra X-ray spectroscopy of a clear dip in GX 13+1

    CERN Document Server

    D'Aì, A; Di Salvo, T; Riggio, A; Burderi, L; Robba, N R

    2014-01-01

    The source GX 13+1 is a persistent, bright Galactic X-ray binary hosting an accreting neutron star. It shows highly ionized absorption features, with a blueshift of $\\sim$ 400 km s$^{-1}$ and an outflow-mass rate similar to the accretion rate. Many other X-ray sources exhibit warm absorption features, and they all show periodic dipping behavior at the same time. Recently, a dipping periodicity has also been determined for GX 13+1 using long-term X-ray folded light-curves, leading to a clear identification of one of such periodic dips in an archival Chandra observation. We give the first spectral characterization of the periodic dip of GX 13+1 found in this archival Chandra observation performed in 2010. We used Chandra/HETGS data (1.0--10 keV band) and contemporaneous RXTE/PCA data (3.5--25 keV) to analyze the broadband X-ray spectrum. We adopted different spectral models to describe the continuum emission and used the XSTAR-derived warm absorber component to constrain the highly ionized absorption features. ...

  11. High Energy Astrophysics Science Archive Research Center

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Energy Astrophysics Science Archive Research Center (HEASARC) is the primary archive for NASA missions dealing with extremely energetic phenomena, from...

  12. High energy physics and cloud computing

    International Nuclear Information System (INIS)

    High Energy Physics (HEP) has been a strong promoter of computing technology, for example WWW (World Wide Web) and the grid computing. In the new era of cloud computing, HEP has still a strong demand, and major international high energy physics laboratories have launched a number of projects to research on cloud computing technologies and applications. It describes the current developments in cloud computing and its applications in high energy physics. Some ongoing projects in the institutes of high energy physics, Chinese Academy of Sciences, including cloud storage, virtual computing clusters, and BESⅢ elastic cloud, are also described briefly in the paper. (authors)

  13. High education and nuclear energy

    International Nuclear Information System (INIS)

    The Faculty of Energy of the University 'Politecnica' in Bucharest is the only faculty in Romania in the field of nuclear energy education. With an experience of more than 29 years, the Faculty of Energy offers the major 'Nuclear Power Plants', which students graduate after a 5-year education as engineers in the Nuclear Power Plant major. Among the principal objectives of the development and reshape of the Romanian education system was mentioned the upgrading of organizational forms by introducing the transfer credit system, and starting in the fall '97 by accrediting Radioprotection and Nuclear Safety Master education. As a result of co-operation and assistance offered by TEMPUS-SENECA program, the new major is shaped and endowed with a modern curriculum harmonized with UE and IAEA requirements and a modern and performing laboratory. This way the Romanian higher education offers a fully correct and concordant structure with UE countries education. (authors)

  14. Chandra Observations of Comets C/2012 S1 (ISON) and C/2011 L4 (PanSTARRS)

    Science.gov (United States)

    Snios, Bradford; Kharchenko, Vasili; Lisse, Carey M.; Wolk, Scott J.; Dennerl, Konrad; Combi, Michael R.

    2016-02-01

    We present our results on the Chandra X-ray Observatory Advanced CCD Imaging Spectrometer (ACIS) observations of the bright Oort Cloud comets C/2012 S1 (ISON) and C/2011 L4 (PanSTARRS). ISON was observed between 2013 October 31-November 06 during variable speed solar wind (SW), and PanSTARRS was observed between 2013 April 17-23 during fast SW. ISON produced an extended parabolic X-ray morphology consistent with a collisionally thick coma, while PanSTARRS demonstrated only a diffuse X-ray-emitting region. We consider these emissions to be from charge exchange (CX) and model each comet's emission spectrum from first principles accordingly. Our model agrees with the observational spectra and also generates composition ratios for heavy, highly charged SW ions interacting with the cometary atmosphere. We compare our derived SW ion compositions to observational data and find a strong agreement between them. These results further demonstrate the utility of CX emissions as a remote diagnostics tool of both astrophysical plasma interaction and SW composition. In addition, we observe potential soft X-ray emissions via ACIS around 0.2 keV from both comets that are correlated in intensity to the hard X-ray emissions between 0.4-1.0 keV. We fit our CX model to these emissions, but our lack of a unique solution at low energies makes it impossible to conclude if they are cometary CX in origin. Finally, we discuss probable emission mechanism sources for the soft X-rays and explore new opportunities these findings present in understanding cometary emission processes via Chandra.

  15. XMM-Newton and Chandra cross-calibration using HIFLUGCS galaxy clusters . Systematic temperature differences and cosmological impact

    Science.gov (United States)

    Schellenberger, G.; Reiprich, T. H.; Lovisari, L.; Nevalainen, J.; David, L.

    2015-03-01

    Context. Robust X-ray temperature measurements of the intracluster medium (ICM) of galaxy clusters require an accurate energy-dependent effective area calibration. Since the hot gas X-ray emission of galaxy clusters does not vary on relevant timescales, they are excellent cross-calibration targets. Moreover, cosmological constraints from clusters rely on accurate gravitational mass estimates, which in X-rays strongly depend on cluster gas temperature measurements. Therefore, systematic calibration differences may result in biased, instrument-dependent cosmological constraints. This is of special interest in light of the tension between the Planck results of the primary temperature anisotropies of the cosmic microwave background (CMB) and Sunyaev-Zel'dovich-plus-X-ray cluster-count analyses. Aims: We quantify in detail the systematics and uncertainties of the cross-calibration of the effective area between five X-ray instruments, EPIC-MOS1/MOS2/PN onboard XMM-Newton and ACIS-I/S onboard Chandra, and the influence on temperature measurements. Furthermore, we assess the impact of the cross-calibration uncertainties on cosmology. Methods: Using the HIFLUGCS sample, consisting of the 64 X-ray brightest galaxy clusters, we constrain the ICM temperatures through spectral fitting in the same, mostly isothermal regions and compare the different instruments. We use the stacked residual ratio method to evaluate the cross-calibration uncertainties between the instruments as a function of energy. Our work is an extension to a previous one using X-ray clusters by the International Astronomical Consortium for High Energy Calibration (IACHEC) and is carried out in the context of IACHEC. Results: Performing spectral fitting in the full energy band, (0.7-7) keV, as is typical of the analysis of cluster spectra, we find that best-fit temperatures determined with XMM-Newton/EPIC are significantly lower than Chandra/ACIS temperatures. This confirms the previous IACHEC results obtained

  16. Chandra Observations of QSO 2237+0305

    CERN Document Server

    Dai, X; Agol, E; Bautz, M W; Garmire, G P

    2003-01-01

    We present the observations of the gravitationally lensed system QSO 2237+0305 performed with the Chandra X-ray Observatory on 2000 Sept. 6, and on 2001 Dec. 8 for 30.3 ks and 9.5 ks, respectively. Imaging analysis resolves the four X-ray images of the Einstein Cross. A possible fifth image is detected; however, this detection less certain. Fits to the combined spectrum of all images of the Einstein Cross assuming a simple power law with Galactic and intervening absorption at the lensing galaxy yield a photon index of 1.90(+0.05,-0.05). For the first observation, this spectral model yields a 0.4-8.0 keV X-ray flux of 4.6e-13 erg cm-2 s-1 and a 0.4-8.0 keV lensed luminosity of 1.0e46 erg s-1. The source exhibits variability both over long and short time scales. The X-ray flux has dropped by 20% between the two observations, and the K-S test showed that image A is variable at the 97% confidence level within the first observation. Furthermore, a possible time-delay of 2.7(+0.5,-0.9) hours between images A and B ...

  17. Deep Chandra observations of Pictor A

    CERN Document Server

    Hardcastle, M J; Birkinshaw, M; Croston, J H; Goodger, J L; Marshall, H L; Perlman, E S; Siemiginowska, A; Stawarz, L; Worrall, D M

    2015-01-01

    We report on deep Chandra observations of the nearby broad-line radio galaxy Pictor A, which we combine with new Australia Telescope Compact Array (ATCA) observations. The new X-ray data have a factor 4 more exposure than observations previously presented and span a 15-year time baseline, allowing a detailed study of the spatial, temporal and spectral properties of the AGN, jet, hotspot and lobes. We present evidence for further time variation of the jet, though the flare that we reported in previous work remains the most significantly detected time-varying feature. We also confirm previous tentative evidence for a faint counterjet. Based on the radio through X-ray spectrum of the jet and its detailed spatial structure, and on the properties of the counterjet, we argue that inverse-Compton models can be conclusively rejected, and propose that the X-ray emission from the jet is synchrotron emission from particles accelerated in the boundary layer of a relativistic jet. For the first time, we find evidence that...

  18. Chandra Observations of Black-Widow Pulsars

    CERN Document Server

    Gentile, Peter; Roberts, Mallory; Camilo, Fernando; Hessels, Jason; Kerr, Matthew; Ransom, Scott; Ray, Paul; Stairs, Ingrid

    2012-01-01

    We describe the first X-ray observations of binary millisecond pulsars PSRs J0023+0923, J1810+1744, J2215+5135, and J2256-1024. All four are Fermi gamma-ray sources and three are 'black-widow' pulsars, with companions of mass < 0.1 solar masses. Data were taken using the Chandra X-Ray Observatory and covered a full binary orbit for each pulsar. Two pulsars, PSRs J2215+5135 and J2256-1024, show significant orbital variability and X-ray flux minima at the times of eclipses observed at radio wavelengths. This phenomenon is consistent with intrabinary shock emission characteristic of black-widow pulsars. The other two pulsars, PSRs J0023+0923 and J1810+1744, do not demonstrate significant variability, but are fainter than the other two sources. Spectral fits yield power-law indices that range from 1.4 to 2.3 and blackbody temperatures in the hundreds of eV. The spectrum for PSR J2215+5135 shows a significant hard X-ray component (41% of counts are above 2 keV), which is additional evidence for the presence of ...

  19. An X-ray look at the Seyfert 1 Galaxy Mrk 590: XMM-Newton and Chandra reveal complexity in circumnuclear gas

    CERN Document Server

    Longinotti, A L; Santos-Lleó, M; Rodriguez-Pascual, P; Guainazzi, M; Cardaci, M; Pollock, A M T

    2007-01-01

    This paper reports on a partially simultaneous observation of the bright Seyfert 1 Galaxy Mrk590, performed by XMM-Newton and Chandra. The long exposure (~100 ks) allows to investigate with great detail the Fe K complex at 6-7 keV and the presence of soft X-ray spectral features. We have analysed XMM-Newton data from the European Photon Imaging Camera (EPIC) in the 0.5-12 keV band and from the Reflection Grating Spectrometer (RGS) in the 0.35-2.5 keV band, and data from the High Energy Transmission Gratings (HETGs) onboard Chandra. UV and optical data from the Optical Monitor (OM) onboard XMM-Newton are also included in the analysis. The broad band spectrum is well described by an unabsorbed power law and three unresolved Fe~K lines in the 6-7 keV range. The presence of a Compton reflection component and a narrow Fe K line at 6.4 keV is consistent with an origin via torus reflection. The ionised Fe lines at ~6.7 and 7 keV are instead most likely originated by scattering on a warm and ionised gas. The soft X-r...

  20. The interaction region of high energy protons

    OpenAIRE

    Dremin, I. M.; White, S. N.

    2016-01-01

    The spatial view of the interaction region of colliding high energy protons (in terms of impact parameter) is considered. It is shown that the region of inelastic collisions has a very peculiar shape. It saturates for central collisions at an energy of 7 TeV. We speculate on the further evolution with energy, which is contrasted to the "black disk" picture.

  1. URBox : High tech energy and informal housing

    NARCIS (Netherlands)

    Cuperus, Y.J.; Smets, D.

    2011-01-01

    This paper reports on the URBox concept encompassing the high tech end of solar energy and informal low cost and affordable housing. It aims to contribute to solving the global energy crisis by building solar energy settlements in deserts where land is affordable and sunshine in abundance. First the

  2. Chandra Phase-Resolved Spectroscopy of the Crab Pulsar

    CERN Document Server

    Weisskopf, M C; Paerels, F; Becker, W; Tennant, A F; Swartz, D A; Weisskopf, Martin C.; Dell, Stephen L. O'; Paerels, Frits; Becker, Werner; Tennant, Allyn F.; Swartz, Douglas A.

    2004-01-01

    We present the first phase-resolved study of the X-ray spectral properties of the Crab Pulsar that covers all pulse phases. The superb angular resolution of the Chandra X-ray Observatory enables distinguishing the pulsar from the surrounding nebulosity, even at pulse minimum. Analysis of the pulse-averaged spectrum measures interstellar X-ray extinction due primarily to photoelectric absorption and secondarily to scattering by dust grains in the direction of the Crab Nebula. We confirm previous findings that the line-of-sight to the Crab is underabundant in oxygen, although more-so than recently measured. Using the abundances and cross sections from Wilms, Allen & McCray (2000) we find [O/H] = (3.33 +/-0.25) x 10**-4. Analysis of the spectrum as a function of pulse phase measures the low-energy X-ray spectral index even at pulse minimum -- albeit with large statistical uncertainty -- and we find marginal evidence for variations of the spectral index. The data are also used to set a new (3-sigma) upper lim...

  3. Polarimeter for high energy photons

    Science.gov (United States)

    Wojtsekhowski, Bogdan; Vlahovic, Branislav; Tedeschi, David; Danagulian, Samuel; Litvienko, Vladimir; Pinayev, Igor

    1999-11-01

    The physics program at TJNAF includes fundamental experiments with polarized photon beam in few GeV energy range. Development of the Polarimeter for use in Hall B experiments is the subject of present abstract. We have proposed to take advantage of the recent progress in silicon micro strip detectors for measurement of the geometry and angle correlation in electron positron pair production from an amorphous converter. A detailed analysis of the setup including MC simulation shows an experimental asymmetry σ_allel/σ_⊥ ~ 1.7 in a wide range of the photon energies. This asymmetry value is confirmed by our experimental results obtained using 100 percent polarized 40 MeV γ rays at Duke FEL.

  4. Renewable energy at high altitudes

    International Nuclear Information System (INIS)

    Improving environmental performance by paying greater attention to the environment factor is becoming the prime objective of many companies and organizations in general. But not theirs alone. Even the tourism sector is making a number of efforts in this direction. This is the case, for example, of the Regina Margherita Refuge located on Point Gnifetti on the Monte Rosa massif, where a research project called Crest was conducted. This was a study on the feasibility of meeting the refuge's energy sources, that is, by using a photovoltaic or hybrid (wind-based and photovoltaic) energy production system. A plant thus able to exploit the landscape and meteorological characteristics typical of a mountain refuge, saving money and reducing the pollution load

  5. Contemporaneous Chandra HETG and Suzaku X-ray observations of NGC 4051

    Science.gov (United States)

    Lobban, A. P.; Reeves, J. N.; Miller, L.; Turner, T. J.; Braito, V.; Kraemer, S. B.; Crenshaw, D. M.

    2011-07-01

    We present the results of a deep 300 ks Chandra High Energy Transmission Grating (HETG) observation of the highly variable narrow-line Seyfert Type 1 galaxy NGC 4051. The HETG spectrum reveals 28 significant soft X-ray ionized lines in either emission or absorption; primarily originating from H-like and He-like K-shell transitions of O, Ne, Mg and Si (including higher order lines and strong forbidden emission lines from O VII and Ne IX) plus high-ionization L-shell transitions from Fe XVII to Fe XXII and lower ionization inner-shell lines (e.g. O VI). Modelling the data with XSTAR requires four distinct ionization zones for the gas, all outflowing with velocities X-ray Imaging Spectrometer (XIS) spectrum reveals strong evidence for blueshifted absorption lines at ˜6.8 and ˜7.1 keV, consistent with previous findings. Modelling with XSTAR suggests that this is the signature of a highly ionized, high-velocity outflow (log ξ= 4.1+0.2-0.1; vout˜-0.02c) which potentially may have a significant effect on the host galaxy environment via feedback. Finally, we also simultaneously model the broad-band 2008 XIS+HXD (Hard X-ray Detector) Suzaku data with archival Suzaku data from 2005 when the source was observed to have entered an extended period of low flux in an attempt to analyse the cause of the long-term spectral variability. We find that we can account for this by allowing for large variations in the normalization of the intrinsic power-law component which may be interpreted as being due to significant changes in the covering fraction of a Compton-thick partial-coverer obscuring the central continuum emission.

  6. X-ray luminous galaxies I. Chandra observations of IRAS00317-2142

    CERN Document Server

    Georgantopoulos, I; Ward, M J

    2003-01-01

    We present Chandra observations of the enigmatic galaxy IRAS00317-2142, which is classified as a star-forming galaxy on the basis of the ionization level of its emission lines. However, a weak broad H\\alpha wing and a high X-ray luminosity give away the presence of an active nucleus. The Chandra image reveals a nuclear point source (L_(2-10 keV) 6x10^{41} erg s-1), contributing over 80% of the galaxy X-ray counts in the 0.3-8 keV band. This is surrounded by some fainter nebulosity extending up to 6 kpc. The nucleus does not show evidence for short-term variability. However, we detect long term variations between the ROSAT, ASCA and Chandra epoch. Indeed,the source has decreased its flux by over a factor of 25 in a period of about 10 years. The nuclear X-ray spectrum is well represented by a power-law with a photon index of 1.91^{+0.17}_{-0.15} while the extended emission by a Raymond-Smith component with a temperature of 0.6 keV. We find no evidence for the presence of an Fe line. The nucleus is absorbed by a...

  7. Chandra and XMM Observations of the Composite Supernova Remnant G327.1-1.1

    CERN Document Server

    Temim, Tea; Gaensler, B M; Hughes, John P; van der Swaluw, Eric

    2008-01-01

    We present new X-ray imaging and spectroscopy of a composite supernova remnant G327.1-1.1 using the Chandra and XMM-Newton X-ray observatories. G327.1-1.1 has an unusual morphology consisting of a symmetric radio shell and an off center nonthermal component that indicates the presence of a pulsar wind nebula (PWN). Radio observations show a narrow finger of emission extending from the PWN structure towards the northwest. X-ray studies with ASCA, ROSAT, and BeppoSAX revealed elongated extended emission and a compact source at the tip of the finger that may be coincident with the actual pulsar. The high resolution Chandra observations provide new insight into the structure of the inner region of the remnant. The images show a compact source embedded in a cometary structure, from which a trail of X-ray emission extends in the southeast direction. The Chandra images also reveal two prong-like structures that appear to originate from the vicinity of the compact source and extend into a large bubble that is oriente...

  8. High energy physics in the United States

    International Nuclear Information System (INIS)

    The US program in high energy physics from 1985 to 1995 is reviewed. The program depends primarily upon work at the national accelerator centers, but includes a modest but diversified nonaccelerator program. Involvement of universities is described. International cooperation in high energy physics is discussed, including the European, Japanese, USSR, and the People's Republic of China's programs. Finally, new facilities needed by the US high energy physics program are discussed, with particular emphasis given to a Superconducting Super Collider for achieving ever higher energies in the 20 TeV range

  9. HIGH ENERGY PHYSICS POTENTIAL AT MUON COLLIDERS

    Energy Technology Data Exchange (ETDEWEB)

    PARSA,Z.

    2000-04-07

    In this paper, high energy physics possibilities and future colliders are discussed. The {mu}{sup +} {mu}{sup {minus}} collider and experiments with high intensity muon beams as the stepping phase towards building Higher Energy Muon Colliders (HEMC) are briefly reviewed and encouraged.

  10. Expectations for ultra-high energy interactions

    International Nuclear Information System (INIS)

    Strong interactions at ultra-high energies are discussed with emphasis on the hadrons produced in high energy collisions. Evidence is considered that quantum chromodynamics might be the right theory, and also some estimates are given of quantum chromodynamics asymptotic-freedom phenomena, the work under discussion being very preliminary. 6 references

  11. New aspects of high energy density plasma

    International Nuclear Information System (INIS)

    The papers presented at the symposium on 'New aspects of high energy density plasma' held at National Institute for Fusion Science are collected in this proceedings. The papers reflect the present status and recent progress in the experiments and theoretical works on high energy density plasma produced by pulsed power technology. The 13 of the presented papers are indexed individually. (J.P.N.)

  12. Black holes and high energy physics

    Science.gov (United States)

    Grib, A. A.; Pavlov, Yu. V.

    2016-01-01

    Three mechanisms of getting high energies in particle collisions in the ergosphere of the rotating black holes are considered. The consequences of these mechanisms for observation of ultra high energy cosmic rays particles on the Earth as result of conversion of superheavy dark matter particles into ordinary particles are discussed.

  13. CAMAC high energy physics electronics hardware

    International Nuclear Information System (INIS)

    CAMAC hardware for high energy physics large spectrometers and control systems is reviewed as is the development of CAMAC modules at the High Energy Laboratory, JINR (Dubna). The total number of crates used at the Laboratory is 179. The number of CAMAC modules of 120 different types exceeds 1700. The principles of organization and the structure of developed CAMAC systems are described. (author)

  14. URBox : High tech energy and informal housing

    OpenAIRE

    Cuperus, Y.J.; Smets, D.

    2011-01-01

    This paper reports on the URBox concept encompassing the high tech end of solar energy and informal low cost and affordable housing. It aims to contribute to solving the global energy crisis by building solar energy settlements in deserts where land is affordable and sunshine in abundance. First the award winning Solar City 2050 is described and already existing technology is mentioned. In addition to the energy crisis there are the potential food, water, health, housing and immigration crise...

  15. The Chandra Carina Complex Project View of Trumpler 16

    CERN Document Server

    Wolk, Scott J; Getman, Konstantin V; Feigelson, Eric D; Preibisch, Thomas; Townsley, Leisa K; Wang, Junfeng; Stassun, Keivan G; King, Robert R; McCaughrean, Mark J; Moffat, Anthony F J; Zinnecker, Hans

    2011-01-01

    Trumpler 16 is a well--known rich star cluster containing the eruptive supergiant $\\eta$ Carin\\ae\\ and located in the Carina star-forming complex. In the context of the Chandra Carina Complex Project, we study Trumpler 16 using new and archival X-ray data. A revised X-ray source list of the Trumpler 16 region contains 1232 X-ray sources including 1187 likely Carina members. These are matched to 1047 near-infrared counterparts detected by the HAWK-I instrument at the VLT allowing for better selection of cluster members. The cluster is irregular in shape. Although it is roughly circular, there is a high degree of sub-clustering, no noticeable central concentration and an extension to the southeast. The high--mass stars show neither evidence of mass segregation nor evidence of strong differential extinction. The derived power-law slope of the X-ray luminosity function for Trumpler 16 reveals a much steeper function than the Orion Nebula Cluster implying different ratio of solar- to higher-mass stars. We estimate...

  16. High Energy Density Capacitors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Capacitor size and reliability are often limiting factors in pulse power, high speed switching, and power management and distribution (PMAD) systems. T/J...

  17. Assessing high wind energy penetration

    DEFF Research Database (Denmark)

    Tande, J.O.

    1995-01-01

    settings are close to ideal, including a very capable national utility company, Electra, a conventional power supply system based on imported heavy fuel and gas oil, and favourable wind conditions with an estimated annual average of 9.3 m/s at the hub height of the wind turbines. With the applied case...... existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h....

  18. The complex circumnuclear environment of the broad-line radio galaxy 3C 390.3 revealed by Chandra HETG

    CERN Document Server

    Tombesi, F; Kallman, T; Reynolds, C S; Mushotzky, R F; Braito, V; Behar, E; Leutenegger, M A; Cappi, M

    2016-01-01

    We present the first high spectral resolution X-ray observation of the broad-line radio galaxy 3C 390.3 obtained with the high energy transmission grating (HETG) spectrometer on board the Chandra X-ray Observatory. The spectrum shows complex emission and absorption features in both the soft X-rays and Fe K band. We detect emission and absorption lines in the energy range between E = 700-1000 eV associated with ionized Fe L transitions (Fe XVII-XX). An emission line at the energy of E=6.4 keV consistent with the Fe K\\alpha is also observed. Our best-fit model requires at least three different components: (i) a hot emission component likely associated with the hot interstellar medium in this elliptical galaxy with temperature kT=0.5+/-0.1 keV; (ii) a warm absorber with ionization parameter log\\xi=2.3+/-0.5 erg s^{-1} cm, column density logN_H=20.7+/-0.1 cm^{-2}, and outflow velocity of v_{out}<150 km s^{-1}; (iii) a lowly ionized reflection component in the Fe K band likely associated with the optical broad ...

  19. Ultra high energy cosmic rays: the highest energy frontier

    CERN Document Server

    Neto, João R T de Mello

    2015-01-01

    Ultra-high energy cosmic rays (UHECRs) are the highest energy messengers of the present universe, with energies up to $10^{20}$ eV. Studies of astrophysical particles (nuclei, electrons, neutrinos and photons) at their highest observed energies have implications for fundamental physics as well as astrophysics. The primary particles interact in the atmosphere and generate extensive air showers. Analysis of those showers enables one not only to estimate the energy, direction and most probable mass of the primary cosmic particles, but also to obtain information about the properties of their hadronic interactions at an energy more than one order of magnitude above that accessible with the current highest energy human-made accelerator. In this contribution we will review the state-of-the-art in UHECRs detection. We will present the leading experiments Pierre Auger Observatory and Telescope Array and discuss the cosmic ray energy spectrum, searches for directional anisotropy, studies of mass composition, the determ...

  20. High-Energy Neutrino Interactions

    CERN Multimedia

    2002-01-01

    This experiment studies neutrino interactions in iron at the highest available energies using the narrow-band neutrino beam N3 and the wide-band neutrino beam N1. The basis of the detector is a massive target-calorimeter in which the energy deposited by a neutrino (or antineutrino) is measured by electronic techniques and the momentum of outgoing muons is determined by magnetic deflection. The detector is constructed in the form of a 20 m long iron-cored toroidal magnet, composed of modules of length 70~cm and 90~cm, and of 3.75~m diameter. Drift chambers placed in between each module measure the trajectory of muons from the neutrino interactions. The modules are of three types. The first ten modules are constructed of 2.5~cm iron plates with 20~scintillator planes inserted between the plates. The next five modules are constructed of 5~cm plates with 15~planes of scintillator and the last six modules are constructed of 15~cm plates with 5~planes of scintillators. The total mass of the detector is @=~1400 tons...

  1. High-Energy X-ray Imaging of the Pulsar Wind Nebula MSH~15-52: Constraints on Particle Acceleration and Transport

    CERN Document Server

    An, Hongjun; Reynolds, Stephen P; Kaspi, Victoria M; Harrison, Fiona A; Boggs, Steven E; Christensen, Finn E; Craig, William W; Fryer, Chris L; Grefenstette, Brian W; Hailey, Charles J; Mori, Kaya; Stern, Daniel; Zhang, William W

    2014-01-01

    We present the first images of the pulsar wind nebula (PWN) MSH 15-52 in the hard X-ray band (>8 keV), as measured with the Nuclear Spectroscopic Telescope Array (NuSTAR). Overall, the morphology of the PWN as measured by NuSTAR in the 3-7 keV band is similar to that seen in Chandra high-resolution imaging. However, the spatial extent decreases with energy, which we attribute to synchrotron energy losses as the particles move away from the shock. The hard-band maps show a relative deficit of counts in the northern region towards the RCW 89 thermal remnant, with significant asymmetry. We find that the integrated PWN spectra measured with NuSTAR and Chandra suggest that there is a spectral break at 6 keV which may be explained by a break in the synchrotron-emitting electron distribution at ~200 TeV and/or imperfect cross calibration. We also measure spatially resolved spectra, showing that the spectrum of the PWN softens away from the central pulsar B1509-58, and that there exists a roughly sinusoidal variation...

  2. High energy accelerating structures for high gradient proton linac applications

    International Nuclear Information System (INIS)

    The high-energy part of a proton linac, following a drift tube section, accelerates protons and H- ions of energies above 150 MeV. High efficiency and high gradients in the accelerating structure considered for this part of a proton linac are studied. Several known and improved structures working at 1350 MHz were optimized for maximum shunt impedance. The study was performed with the extensive use of a computer code--SUPERFISH. The theoretical results of this study are presented

  3. The galaxy cluster outskirts probed by Chandra

    Science.gov (United States)

    Morandi, Andrea; Sun, Ming; Forman, William; Jones, Christine

    2015-08-01

    Exploring the virialization region of galaxy clusters has recently raised the attention of the scientific community, offering a direct view of structure formation. In this talk, I will present recent results on the physical properties of the intracluster medium in the outer volumes of a sample of 320 clusters (0.056 3 keV) in the Chandra archive, with a total integration time of ~20 Ms. We stacked the emission measure profiles of the clusters to detect a signal out to R_{100}. We then measured the average emission measure, gas density and gas fraction, which scale according to the self-similar model of cluster formation. We observe a steepening of the density profiles beyond R_{500} with slope beta ~ 0.68 at R_{500} and beta ~ 1 at R_{200} and beyond. By tracking the direction of the cosmic filaments where the clusters are embedded, we report that galaxy clusters deviate from spherical symmetry. We also did not find evolution of the gas density with redshift, confirming the self-similar evolution of the gas density. The value of the baryon fraction reaches the cosmic value at R_{200}: however, systematics due to non-thermal pressure support and clumpiness might enhance the measured gas fraction, leading to an actual deficit of the baryon budget with respect to the primordial value). This novel method, the stacking the X-ray signal of cluster outskirts, has the capacity to provide a generational leap forward in our understanding of cluster physics and formation, and the use of clusters as cosmological probes.

  4. X-ray emission line spectroscopy of cataclysmic variables. II. Temperatures and densities from line ratios in the Chandra HETG band

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, E. M.; Shipley, H. V. [Department of Physics and Astronomy, University of Texas-San Antonio, San Antonio, TX 78249 (United States); Rana, V. R. [Space Radiation Laboratory, Caltech, Pasadena, CA 91125 (United States); Barrett, P. E. [US Naval Observatory, Washington, DC 20392-5420 (United States); Singh, K. P., E-mail: eric.schlegel@utsa.edu, E-mail: vrana@srl.caltech.edu, E-mail: barrett.paul@usno.navy.mil, E-mail: singh@tifr.res.in [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai (India)

    2014-12-10

    We summarize the results of a line-by-line fitting analysis of the available spectra obtained using the Chandra High-Energy Transmission Grating. We confirm the existence of broad ionization and electron temperature ranges and high number densities in cataclysmic variables (CVs) of all subtypes. Temperatures range from ∼0.4 keV to ∼5-10 keV or more with a broad range detected in any given CV. In other words, single-temperature models do not describe the line emission. Number densities also cover a broad range, from 10{sup 12} to >10{sup 16} cm{sup –3}. We demonstrate that much of the plasma is in a nonequilibrium state; the Fe emission, however, may arise from plasma in the ionization equilibrium.

  5. X-ray emission line spectroscopy of cataclysmic variables. II. Temperatures and densities from line ratios in the Chandra HETG band

    International Nuclear Information System (INIS)

    We summarize the results of a line-by-line fitting analysis of the available spectra obtained using the Chandra High-Energy Transmission Grating. We confirm the existence of broad ionization and electron temperature ranges and high number densities in cataclysmic variables (CVs) of all subtypes. Temperatures range from ∼0.4 keV to ∼5-10 keV or more with a broad range detected in any given CV. In other words, single-temperature models do not describe the line emission. Number densities also cover a broad range, from 1012 to >1016 cm–3. We demonstrate that much of the plasma is in a nonequilibrium state; the Fe emission, however, may arise from plasma in the ionization equilibrium.

  6. High energy density lithium batteries

    CERN Document Server

    Aifantis, Katerina E; Kumar, R Vasant

    2010-01-01

    Cell phones, portable computers and other electronic devices crucially depend on reliable, compact yet powerful batteries. Therefore, intensive research is devoted to improving performance and reducing failure rates. Rechargeable lithium-ion batteries promise significant advancement and high application potential for hybrid vehicles, biomedical devices, and everyday appliances. This monograph provides special focus on the methods and approaches for enhancing the performance of next-generation batteries through the use of nanotechnology. Deeper understanding of the mechanisms and strategies is

  7. CHANDRA OBSERVATIONS OF SGR 1627–41 NEAR QUIESCENCE

    International Nuclear Information System (INIS)

    We report on an observation of SGR 1627–41 made with the Chandra X-Ray Observatory on 2011 June 16. Approximately three years after its outburst activity in 2008, the source's flux has been declining, as it approaches its quiescent state. For an assumed power-law spectrum, we find that the absorbed 2-10 keV flux for the source is 1.0+0.3–0.2 × 10–13 erg cm–2 s–1 with a photon index of 2.9 ± 0.8 (NH = 1.0 × 1023 cm–2). This flux is approximately consistent with that measured at the same time after the source's outburst in 1998. With measurements spanning three years after the 2008 outburst, we analyze the long-term flux and spectral evolution of the source. The flux evolution is well described by a double exponential with decay times of 0.5 ± 0.1 and 59 ± 6 days, and a thermal cooling model fit suggests that SGR 1627–41 may have a hot core (Tc ∼ 2 × 108 K). We find no clear correlation between flux and spectral hardness as found in other magnetars. We consider the quiescent X-ray luminosities of magnetars and the subset of rotation-powered pulsars with high magnetic fields (B ∼> 1013 G) in relation to their spin-inferred surface magnetic field strength and find a possible trend between the two quantities.

  8. Broad Iron Emission from Gravitationally Lensed Quasars Observed by Chandra

    CERN Document Server

    Walton, D J; Miller, J M; Reis, R C; Stern, D; Harrison, F A

    2015-01-01

    Recent work has demonstrated the potential of gravitationally lensed quasars to extend measurements of black hole spin out to high-redshift with the current generation of X-ray observatories. Here we present an analysis of a large sample of 27 lensed quasars in the redshift range 1.0Chandra, utilizing over 1.6 Ms of total observing time, focusing on the rest-frame iron K emission from these sources. Although the X-ray signal-to-noise (S/N) currently available does not permit the detection of iron emission from the inner accretion disk in individual cases in our sample, we find significant structure in the stacked residuals. In addition to the narrow core, seen almost ubiquitously in local AGN, we find evidence for an additional underlying broad component from the inner accretion disk, with a clear red wing to the emission profile. Based on simulations, we find the detection of this broader component to be significant at greater than the 3-sigma level. This implies that iron emission...

  9. The Chandra COSMOS-Legacy Survey: The z>3 Sample

    Science.gov (United States)

    Marchesi, S.; Civano, F.; Salvato, M.; Shankar, F.; Comastri, A.; Elvis, M.; Lanzuisi, G.; Trakhtenbrot, B.; Vignali, C.; Zamorani, G.; Allevato, V.; Brusa, M.; Fiore, F.; Gilli, R.; Griffiths, R.; Hasinger, G.; Miyaji, T.; Schawinski, K.; Treister, E.; Urry, C. M.

    2016-08-01

    We present the largest high-redshift (3 detected in the Chandra COSMOS-Legacy survey. The sample contains 174 sources, 87 with spectroscopic redshift and the other 87 with photometric redshift (z phot). In this work, we treat z phot as a probability-weighted sum of contributions, adding to our sample the contribution of sources with z phot 0 at z > 3. We compute the number counts in the observed 0.5–2 keV band, finding a decline in the number of sources at z > 3 and constraining phenomenological models of the X-ray background. We compute the AGN space density at z > 3 in two different luminosity bins. At higher luminosities (logL(2–10 keV) > 44.1 erg s‑1), the space density declines exponentially, dropping by a factor of ∼20 from z ∼ 3 to z ∼ 6. The observed decline is ∼80% steeper at lower luminosities (43.55 erg s‑1 44.1 erg s‑1, unobscured and obscured objects may have different evolution with redshift, with the obscured component being three times higher at z ∼ 5. Finally, we compare our space density with predictions of quasar activation merger models, whose calibration is based on optically luminous AGNs. These models significantly overpredict the number of expected AGNs at logL (2–10 keV) > 44.1 erg s‑1 with respect to our data.

  10. Echoes of multiple outbursts of Sagittarius A* revealed by Chandra

    CERN Document Server

    Clavel, Maïca; Goldwurm, A; Morris, M R; Ponti, G; Soldi, S; Trap, G

    2013-01-01

    The relatively rapid spatial and temporal variability of the X-ray radiation from some molecular clouds near the Galactic center shows that this emission component is due to the reflection of X-rays generated by a source that was luminous in the past, most likely the central supermassive black hole, Sagittarius A*. Studying the evolution of the molecular cloud reflection features is therefore a key element to reconstruct Sgr A*'s past activity. The aim of the present work is to study this emission on small angular scales in order to characterize the source outburst on short time scales. We use Chandra high-resolution data collected from 1999 to 2011 to study the most rapid variations detected so far, those of clouds between 5' and 20' from Sgr A* towards positive longitudes. Our systematic spectral-imaging analysis of the reflection emission, notably of the Fe Kalpha line at 6.4 keV and its associated 4-8 keV continuum, allows us to characterize the variations down to 15" angular scale and 1-year time scale. ...

  11. Chandra's Darkest Bright Star: not so Dark after All?

    Science.gov (United States)

    Ayres, Thomas R.

    2008-11-01

    The Chandra High Resolution camera (HRC) has obtained numerous short exposures of the ultraviolet (UV)-bright star Vega (α Lyrae; HD 172167: A0 V), to calibrate the response of the detector to out-of-band (non-X-ray) radiation. A new analysis uncovered a stronger "blue leak" in the imaging section (HRC-I) than reported in an earlier study of Vega based on a subset of the pointings. The higher count rate—a factor of nearly 2 above prelaunch estimates—raised the possibility that genuine coronal X-rays might lurk among the out-of-band events. Exploiting the broader point-spread function of the UV leak compared with soft X-rays identified an excess of counts centered on the target, technically at 3σ significance. A number of uncertainties, however, prevent a clear declaration of a Vegan corona. A more secure result would be within reach of a deep uninterrupted HRC-I pointing.

  12. Chandra observation of the relativistic binary J1906+0746

    CERN Document Server

    Kargaltsev, O

    2009-01-01

    PSR J1906+0746 is a 112-kyr-old radio pulsar in a tight relativistic binary with a compact high-mass companion, at the distance of about 5 kpc. We observed this unique system with the Chandra ACIS detector for 31.6 ks. Surprisingly, not a single photon was detected within the 3" radius from the J1906+0746 radio position. For a plausible range of hydrogen column densities, n_H=(0.5-1)\\times10^{22} cm^{-2}, the nondetection corresponds to the 90% upper limit of (3-5)\\times10^{30} erg s^{-1} on the unabsorbed 0.5-8 keV luminosity for the power-law model with Gamma=1.0-2.0, and ~10^{32} erg s^{-1} on the bolometric luminosity of the thermal emission from the NS surface. The inferred limits are the lowest known for pulsars with spin-down properties similar to those of PSR J1906+0746. We have also tentatively detected a puzzling extended structure which looks like a tilted ring with a radius of 1.6' centered on the pulsar. The measured 0.5-8 keV flux of the feature, 3.1\\times10^{-14} erg cm^{-2} s^{-1}, implies an ...

  13. Discovery of X-rays from Mars with Chandra

    CERN Document Server

    Dennerl, K

    2002-01-01

    On 4 July 2001, X-rays from Mars were detected for the first time. The observation was performed with the ACIS-I detector onboard Chandra and yielded data of high spatial and temporal resolution, together with spectral information. Mars is clearly detected as an almost fully illuminated disk, with an indication of limb brightening at the sunward side, accompanied by some fading on the opposite side. The morphology and the X-ray luminosity of ~4 MW are fully consistent with fluorescent scattering of solar X-rays in the upper Mars atmosphere. The X-ray spectrum is dominated by a single narrow emission line, which is most likely caused by O-K_alpha fluorescence. No evidence for temporal variability is found. This is in agreement with the solar X-ray flux, which was almost constant during the observation. In addition to the X-ray fluorescence, there is evidence for an additional source of X-ray emission, indicated by a faint X-ray halo which can be traced to about three Mars radii, and by an additional component ...

  14. High energy physics at UCR

    Energy Technology Data Exchange (ETDEWEB)

    Kernan, A.; Shen, B.C.

    1997-07-01

    The hadron collider group is studying proton-antiproton interactions at the world`s highest collision energy 2 TeV. Data-taking with the D0 detector is in progress at Fermilab and the authors have begun the search for the top quark. S. Wimpenny is coordinating the effort to detect t{bar t} decaying to two leptons, the most readily identifiable channel. At UC Riverside design and testing for a silicon tracker for the D0 upgrade is in progress; a parallel development for the SDC detector at SSC is also underway. The major group effort of the lepton group has been devoted to the OPAL experiment at LEP. They will continue to focus on data-taking to improve the quality and quantity of their data sample. A large number of papers have been published based on approximately 500,000 events taken so far. The authors will concentrate on physics analysis which provides stringent tests of the Standard Model. The authors are continuing participation in the RD5 experiment at the SPS to study muon triggering and tracking. The results of this experiment will provide critical input for the design of the Compact Muon Solenoid experiment being proposed for the LHC. The theory group has been working on problems concerning the possible vilation of e-{mu}-{tau} universality, effective Lagrangians, neutrino physics, as well as quark and lepton mass matrices.

  15. High energy physics at UCR

    International Nuclear Information System (INIS)

    The hadron collider group is studying proton-antiproton interactions at the world's highest collision energy 2 TeV. Data-taking with the D0 detector is in progress at Fermilab and the authors have begun the search for the top quark. S. Wimpenny is coordinating the effort to detect t bar t decaying to two leptons, the most readily identifiable channel. At UC Riverside design and testing for a silicon tracker for the D0 upgrade is in progress; a parallel development for the SDC detector at SSC is also underway. The major group effort of the lepton group has been devoted to the OPAL experiment at LEP. They will continue to focus on data-taking to improve the quality and quantity of their data sample. A large number of papers have been published based on approximately 500,000 events taken so far. The authors will concentrate on physics analysis which provides stringent tests of the Standard Model. The authors are continuing participation in the RD5 experiment at the SPS to study muon triggering and tracking. The results of this experiment will provide critical input for the design of the Compact Muon Solenoid experiment being proposed for the LHC. The theory group has been working on problems concerning the possible vilation of e-μ-τ universality, effective Lagrangians, neutrino physics, as well as quark and lepton mass matrices

  16. A Lightweight, Precision-Deployable, Optical Bench for High Energy Astrophysics Missions

    Science.gov (United States)

    Danner, Rolf; Dailey, D.; Lillie, C.

    2011-09-01

    The small angle of total reflection for X-rays, forcing grazing incidence optics with large collecting areas to long focal lengths, has been a fundamental barrier to the advancement of high-energy astrophysics. Design teams around the world have long recognized that a significant increase in effective area beyond Chandra and XMM-Newton requires either a deployable optical bench or separate X-ray optics and instrument module on formation flying spacecraft. Here, we show that we have in hand the components for a lightweight, precision-deployable optical bench that, through its inherent design features, is the affordable path to the next generation of imaging high-energy astrophysics missions. We present our plans for a full-scale engineering model of a deployable optical bench for Explorer-class missions. We intend to use this test article to raise the technology readiness level (TRL) of the tensegrity truss for a lightweight, precision-deployable optical bench for high-energy astrophysics missions from TRL 3 to TRL 5 through a set of four well-defined technology milestones. The milestones cover the architecture's ability to deploy and control the focal point, characterize the deployed dynamics, determine long-term stability, and verify the stowed load capability. Our plan is based on detailed design and analysis work and the construction of a first prototype by our team. Building on our prior analysis and the high TRL of the architecture components we are ready to move on to the next step. The key elements to do this affordably are two existing, fully characterized, flight-quality, deployable booms. After integrating them into the test article, we will demonstrate that our architecture meets the deployment accuracy, adjustability, and stability requirements. The same test article can be used to further raise the TRL in the future.

  17. Coordinated Optical/X-ray observations of the CTTS V2129 Oph The Chandra View

    Science.gov (United States)

    Flaccomio, E.; Argiroffi, C.; Alencar, S. H. P.; Bouvier, J.; Donati, J.-F.; Getman, K.; Gregory, S. G.; Hussain, G.; Ibrahimov, M.; Jardine, M. M.; Skelly, M.; Walter, F.

    2011-12-01

    Young low-mass accreting stars (classical T Tauri stars; CTTSs) possess strong magnetic fields that are responsible for the regulation of the accretion and outflow processes, and the confinement and heating of coronal plasma. Understanding the physics of CTTS magnetospheres and of their interaction with circumstellar disks can elucidate the history and evolution of our own Sun and Solar System, at the stage when planets were being formed. In June 2009 we have conducted an extensive multi-wavelength observing campaign of V2129 Oph, a K5 CTTS in the ρ Ophiuchi molecular cloud, with the goal of obtaining a synoptic view of its photosphere, magnetic field, coronal plasma, and of its accretion spot(s) and funnel flow(s). We here report on the X-ray emission, as observed by the Chandra High Energy Transmission Grating (HETG). High-density plasma, presumably from the accretion shock, is responsible for the soft X-ray emission, at least during the first half of the observation. The X-ray emission from both the coronal plasma (T˜20MK) and the cooler and denser material from the accretion spot (T˜3MK) is observed to vary between the first and second half of the observation. From the high-resolution X-ray spectra we constrain the emission measure of the two components and the density of the cool plasma. Finally we interpret the time variability of the cool plasma component in terms of stellar rotation and the time-changing viewing angle of the accretion stream, as constrained by simultaneous optical observations.

  18. On the Future High Energy Colliders

    CERN Document Server

    Shiltsev, Vladimir

    2015-01-01

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of the next generation collider facilities have been proposed and are currently under consideration for the medium and far-future of accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance potential and cost range.

  19. New accelerators in high-energy physics

    International Nuclear Information System (INIS)

    First, I should like to mention a few new ideas that have appeared during the last few years in the accelerator field. A couple are of importance in the design of injectors, usually linear accelerators, for high-energy machines. Then I shall review some of the somewhat sensational accelerator projects, now in operation, under construction or just being proposed. Finally, I propose to mention a few applications of high-energy accelerators in fields other than high-energy physics. I realize that this is a digression from my title but I hope that you will find it interesting

  20. High Energy Physics Research at Louisiana Tech

    Energy Technology Data Exchange (ETDEWEB)

    Sawyer, Lee [Louisiana State Univ., Baton Rouge, LA (United States); Greenwood, Zeno [Louisiana State Univ., Baton Rouge, LA (United States); Wobisch, Marcus [Louisiana State Univ., Baton Rouge, LA (United States)

    2013-06-28

    The goal of this project was to create, maintain, and strengthen a world-class, nationally and internationally recognized experimental high energy physics group at Louisiana Tech University, focusing on research at the energy frontier of collider-based particle physics, first on the DØ experiment and then with the ATLAS experiment, and providing leadership within the US high energy physics community in the areas of jet physics, top quark and charged Higgs decays involving tau leptons, as well as developing leadership in high performance computing.

  1. CERN and the high energy frontier

    Directory of Open Access Journals (Sweden)

    Tsesmelis Emmanuel

    2014-04-01

    Full Text Available This paper presents the particle physics programme at CERN at the high-energy frontier. Starting from the key open questions in particle physics and the large-scale science facilities existing at CERN, concentrating on the Large Hadron Collider(LHC, this paper goes on to present future possibilities for global projects in high energy physics. The paper presents options for future colliders, all being within the framework of the recently updated European Strategy for Particle Physics, and all of which have a unique value to add to experimental particle physics. The paper concludes by outlining key messages for the way forward for high-energy physics research.

  2. Practical neutron dosimetry at high energies

    International Nuclear Information System (INIS)

    Dosimetry at high energy particle accelerators is discussed with emphasis on physical measurements which define the radiation environment and provide an immutable basis for the derivation of any quantities subsequently required for risk evaluation. Results of inter-laboratory dosimetric comparisons are reviewed and it is concluded that a well-supported systematic program is needed which would make possible detailed evaluations and inter-comparisons of instruments and techniques in well characterized high energy radiation fields. High-energy dosimetry is so coupled with radiation transport that it is clear their study should proceed concurrently

  3. The Chandra X-ray Survey of Planetary Nebulae (ChanPlaNS): Probing Binarity, Magnetic Fields, and Wind Collisions

    CERN Document Server

    Kastner, J H; Balick, B; Frew, D J; Miszalski, B; Sahai, R; Blackman, E; Chu, Y -H; De Marco, O; Frank, A; Guerrero, M A; Lopez, J A; Rapson, V; Zijlstra, A; Behar, E; Bujarrabal, V; Corradi, R L M; Nordhaus, J; Parker, Q; Sandin, C; Schönberner, D; Soker, N; Sokoloski, J L; Steffen, M; Ueta, T; Villaver, E

    2012-01-01

    We present an overview of the initial results from the Chandra Planetary Nebula Survey (ChanPlaNS), the first systematic (volume-limited) Chandra X-ray Observatory survey of planetary nebulae (PNe) in the solar neighborhood. The first phase of ChanPlaNS targeted 21 mostly high-excitation PNe within ~1.5 kpc of Earth, yielding 3 detections of diffuse X-ray emission and 9 detections of X-ray-luminous point sources at the central stars (CSPNe) of these objects. Combining these results with those obtained from Chandra archival data for all (14) other PNe within ~1.5 kpc that have been observed to date, we find an overall X-ray detection rate of 68%. Roughly 50% of the PNe observed by Chandra harbor X-ray-luminous CSPNe, while soft, diffuse X-ray emission tracing shocks formed by energetic wind collisions is detected in ~30%; five objects display both diffuse and point-like emission components. The presence of X-ray sources appears correlated with PN density structure, in that molecule-poor, elliptical nebulae are...

  4. Innovations in the Analysis of Chandra-ACIS Observations

    CERN Document Server

    Broos, Patrick S; Feigelson, Eric D; Getman, Konstantin V; Bauer, Franz E; Garmire, Gordon P

    2010-01-01

    As members of the instrument team for the Advanced CCD Imaging Spectrometer (ACIS) on NASA's Chandra X-ray Observatory and as Chandra General Observers, we have developed a wide variety of data analysis methods that we believe are useful to the Chandra community, and have constructed a significant body of publicly-available software (the ACIS Extract package) addressing important ACIS data and science analysis tasks. This paper seeks to describe these data analysis methods for two purposes: to document the data analysis work performed in our own science projects, and to help other ACIS observers judge whether these methods may be useful in their own projects (regardless of what tools and procedures they choose to implement those methods). The ACIS data analysis recommendations we offer here address much of the workflow in a typical ACIS project, including data preparation, point source detection via both wavelet decomposition and image reconstruction, masking point sources, identification of diffuse structure...

  5. The Norma arm region Chandra survey catalog: X-ray populations in the spiral arms

    Energy Technology Data Exchange (ETDEWEB)

    Fornasini, Francesca M. [Astronomy Department, University of California, 601 Campbell Hall, Berkeley, CA 94720 (United States); Tomsick, John A.; Bodaghee, Arash; Krivonos, Roman A. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720 (United States); An, Hongjun [Department of Physics, McGill University, Rutherford Physics Building, 3600 University Street, Montreal, QC H3A 2T8 (Canada); Rahoui, Farid [European Southern Observatory, Karl Schwarzschild-Strasse 2, D-85748 Garching bei München (Germany); Gotthelf, Eric V. [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Bauer, Franz E. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, 306, Santiago 22 (Chile); Stern, Daniel, E-mail: f.fornasini@berkeley.edu [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, MS 169-506, Pasadena, CA 91109 (United States)

    2014-12-01

    We present a catalog of 1415 X-ray sources identified in the Norma Arm Region Chandra Survey (NARCS), which covers a 2° × 0.°8 region in the direction of the Norma spiral arm to a depth of ≈20 ks. Of these sources, 1130 are point-like sources detected with ≥3σ confidence in at least one of three energy bands (0.5-10, 0.5-2, and 2-10 keV), five have extended emission, and the remainder are detected at low significance. Since most sources have too few counts to permit individual classification, they are divided into five spectral groups defined by their quantile properties. We analyze stacked spectra of X-ray sources within each group, in conjunction with their fluxes, variability, and infrared counterparts, to identify the dominant populations in our survey. We find that ∼50% of our sources are foreground sources located within 1-2 kpc, which is consistent with expectations from previous surveys. Approximately 20% of sources are likely located in the proximity of the Scutum-Crux and near Norma arm, while 30% are more distant, in the proximity of the far Norma arm or beyond. We argue that a mixture of magnetic and nonmagnetic cataclysmic variables dominates the Scutum-Crux and near Norma arms, while intermediate polars and high-mass stars (isolated or in binaries) dominate the far Norma arm. We also present the cumulative number count distribution for sources in our survey that are detected in the hard energy band. A population of very hard sources in the vicinity of the far Norma arm and active galactic nuclei dominate the hard X-ray emission down to f{sub X} ≈ 10{sup –14} erg cm{sup –2} s{sup –1}, but the distribution curve flattens at fainter fluxes. We find good agreement between the observed distribution and predictions based on other surveys.

  6. The Norma arm region Chandra survey catalog: X-ray populations in the spiral arms

    International Nuclear Information System (INIS)

    We present a catalog of 1415 X-ray sources identified in the Norma Arm Region Chandra Survey (NARCS), which covers a 2° × 0.°8 region in the direction of the Norma spiral arm to a depth of ≈20 ks. Of these sources, 1130 are point-like sources detected with ≥3σ confidence in at least one of three energy bands (0.5-10, 0.5-2, and 2-10 keV), five have extended emission, and the remainder are detected at low significance. Since most sources have too few counts to permit individual classification, they are divided into five spectral groups defined by their quantile properties. We analyze stacked spectra of X-ray sources within each group, in conjunction with their fluxes, variability, and infrared counterparts, to identify the dominant populations in our survey. We find that ∼50% of our sources are foreground sources located within 1-2 kpc, which is consistent with expectations from previous surveys. Approximately 20% of sources are likely located in the proximity of the Scutum-Crux and near Norma arm, while 30% are more distant, in the proximity of the far Norma arm or beyond. We argue that a mixture of magnetic and nonmagnetic cataclysmic variables dominates the Scutum-Crux and near Norma arms, while intermediate polars and high-mass stars (isolated or in binaries) dominate the far Norma arm. We also present the cumulative number count distribution for sources in our survey that are detected in the hard energy band. A population of very hard sources in the vicinity of the far Norma arm and active galactic nuclei dominate the hard X-ray emission down to fX ≈ 10–14 erg cm–2 s–1, but the distribution curve flattens at fainter fluxes. We find good agreement between the observed distribution and predictions based on other surveys.

  7. High Energy Processes in Pulsar Wind Nebulae

    CERN Document Server

    Bednarek, W

    2006-01-01

    Young pulsars produce relativistic winds which interact with matter ejected during the supernova explosion and the surrounding interstellar gas. Particles are accelerated to very high energies somewhere in the pulsar winds or at the shocks produced in collisions of the winds with the surrounding medium. As a result of interactions of relativistic leptons with the magnetic field and low energy radiation (of synchrotron origin, thermal, or microwave background), the non-thermal radiation is produced with the lowest possible energies up to $\\sim$100 TeV. The high energy (TeV) gamma-ray emission has been originally observed from the Crab Nebula and recently from several other objects. Recent observations by the HESS Cherenkov telescopes allow to study for the first time morphology of the sources of high energy emission, showing unexpected spectral features. They might be also interpreted as due to acceleration of hadrons. However, theory of particle acceleration in the PWNe and models for production of radiation ...

  8. Modeling Contamination Migration on the Chandra X-ray Observatory - II

    Science.gov (United States)

    O'Dell, Stephen L.; Swartz, Douglas A.; Tice, Neil W.; Plucinsky, Paul P.; Grant, Catherine E.; Marshall, Herman L.; Vikhlinin, Alexey A.; Tennant, Allyn F.

    2013-01-01

    During its first 14 years of operation, the cold (about -60C) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X-ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low-energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition have changed. This evolution has motivated further analysis of contamination migration within and near the ACIS cavity. To this end, the current study employs a higher-fidelity geometric model of the ACIS cavity, detailed thermal modeling based upon temperature data, and a refined model of the molecular transport.

  9. Simultaneous Chandra and VLA Observations of Young Stars and Protostars in rho Ophiuchus Cloud Core A

    OpenAIRE

    Gagne, Marc; Skinner, Stephen L.; Daniel, Kathryne J.

    2004-01-01

    A 96-ks Chandra X-ray observation of rho Ophiuchus cloud core A detected 87 sources, of which 60 were identified with counterparts at other wavelengths. The X-ray detections include 12 of 14 known classical T Tauri stars in the field, 15 of 17 known weak-lined TTS, and 4 of 15 brown dwarf candidates. The X-ray detections are characterized by hard, heavily absorbed emission. The mean photon energy of a typical source is 3 keV, and more than half of the detections are variable. Prominent X-ray ...

  10. The Soft X-ray Spectrum from NGC 1068 Observed with LETGS on Chandra

    OpenAIRE

    Brinkman, A. C.; Kaastra, J.S.; Van Der Meer, R.L.J.; Kinkhabwala, A.; Behar, E; Kahn, S. M.; Paerels, F. B. S.; Sako, M.

    2002-01-01

    Using the combined spectral and spatial resolving power of the Low Energy Transmission Grating (LETGS) on board Chandra, we obtain separate spectra from the bright central source of NGC 1068 (Primary region), and from a fainter bright spot 4" to the NE (Secondary region). Both spectra are dominated by line emission from H- and He-like ions of C through S, and from Fe L-shell ions, but also include narrow radiative recombination continua, indicating that most of the soft X-ray emission arises ...

  11. Modeling Contamination Migration on the Chandra X-Ray Observatory - III

    Science.gov (United States)

    O'Dell, Stephen L.; Swartz, Douglas A.; Tice, Neil W.; Plucinsky, Paul P.; Grant, Catherine E.; Marshall, Herman L.; Vikhlinin, Alexy A.; Tennant, Allyn F.; Dahmer, Matthew T.

    2015-01-01

    During its first 16 years of operation, the cold (about -60 C) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X-ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low-energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition have changed. This evolution has motivated further analysis of contamination migration within and near the ACIS cavity, in part to evaluate potential bake-out scenarios intended to reduce the level of contamination. Keywords: X-ray astronomy, CCDs, contamination, modeling and simulation, spacecraft operations

  12. The O VII X-Ray Forest Toward Markarian 421: Consistency between XMM-Newton and Chandra

    Energy Technology Data Exchange (ETDEWEB)

    Kaastra, J.S.; Werner, N.; Herder, J.W.A.den; /SRON, Utrecht; Paerels, F.B.S.; /Columbia U., Astron. Astrophys.; de Plaa, J.; /SRON, Utrecht; Rasmussen, A.P.; /KIPAC, Menlo; de Vries, C.P.; /SRON, Utrecht

    2006-04-28

    Recently the first detections of highly ionized gas associated with two Warm-Hot Intergalactic Medium (WHIM) filaments have been reported. The evidence is based on X-ray absorption lines due to O VII and other ions observed by Chandra towards the bright blazar Mrk 421. We investigate the robustness of this detection by a re-analysis of the original Chandra LETGS spectra, the analysis of a large set of XMM-Newton RGS spectra of Mrk 421, and additional Chandra observations. We address the reliability of individual spectral features belonging to the absorption components, and assess the significance of the detection of these components. We also use Monte Carlo simulations of spectra. We confirm the apparent strength of several features in the Chandra spectra, but demonstrate that they are statistically not significant. This decreased significance is due to the number of redshift trials that are made and that are not taken into account in the original discovery paper. Therefore these features must be attributed to statistical fluctuations. This is confirmed by the RGS spectra, which have a higher signal to noise ratio than the Chandra spectra, but do not show features at the same wavelengths. Finally, we show that the possible association with a Ly{alpha} absorption system also lacks sufficient statistical evidence. We conclude that there is insufficient observational proof for the existence of the two proposed WHIM filaments towards Mrk 421, the brightest X-ray blazar on the sky. Therefore, the highly ionized component of the WHIM still remains to be discovered.

  13. Neutrino physics at very high energies

    Energy Technology Data Exchange (ETDEWEB)

    Sciulli, F.; Barish, B.; Ford, W.; Oddone, P.; Peck, C.; /Caltech; Maschke, A.; /Fermilab; Barish, B.; /Caltech

    1970-06-01

    NAL presents the opportunity to expand our knowledge of neutrino interactions from energies of less than 10 GeV up to more than 300 GeV. We propose an exploratory experiment which is designed to emphasize the physics of very high energy interactions ({approx}300 GeV).

  14. Deep underground intensities of high energy muons

    International Nuclear Information System (INIS)

    The experiment of the deep underground emulsion chamber has been started in order to measure the energy spectra of muons deep underground at high energies. Preliminary results based on the emulsion chamber with 0.9 ton of lead are presented. This test exposure has been performed at the vertical depth of 850 hg/cm2 underground in the road tunnel. (orig.)

  15. Physics at high energy photon photon colliders

    International Nuclear Information System (INIS)

    I review the physic prospects for high energy photon photon colliders, emphasizing results presented at the LBL Gamma Gamma Collider Workshop. Advantages and difficulties are reported for studies of QCD, the electroweak gauge sector, supersymmetry, and electroweak symmetry breaking

  16. The evolution of high energy accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Courant, E.D.

    1989-10-01

    In this lecture I would like to trace how high energy particle accelerators have grown from tools used for esoteric small-scale experiments to gigantic projects being hotly debated in Congress as well as in the scientific community.

  17. 1570 nm High Energy Fiber Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase I project proposes a single frequency high energy fiber laser for remote sensing. Current state-of-art technologies can not provide all features of...

  18. Parton distributions with high energy proton beams

    International Nuclear Information System (INIS)

    The opportunities for using high energy proton beams to advance our current knowledge in parton distributions are discussed. Highlights from some Fermilab dimuon production experiments with 800 GeV proton beams are presented. Possible future directions are discussed

  19. The evolution of high energy accelerators

    International Nuclear Information System (INIS)

    In this lecture I would like to trace how high energy particle accelerators have grown from tools used for esoteric small-scale experiments to gigantic projects being hotly debated in Congress as well as in the scientific community

  20. High Energy Single Frequency Resonant Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase I project proposes a single frequency high energy resonant amplifier for remote sensing. Current state-of-art technologies can not provide all...

  1. High-energy black hole production

    OpenAIRE

    Giddings, Steven B.

    2007-01-01

    Black hole production in high-energy collisions is briefly surveyed. Included is a summary of recent developments and open problems relevant to collider (LHC) production, as well as of some theoretical issues pointing towards fundamental principles of quantum gravity.

  2. Research in High Energy Physics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Conway, John S.

    2013-08-09

    This final report details the work done from January 2010 until April 2013 in the area of experimental and theoretical high energy particle physics and cosmology at the University of California, Davis.

  3. Physics at High Energy Photon Photon Colliders

    OpenAIRE

    Chanowitz, Michael S.

    1994-01-01

    I review the physics prospects for high energy photon photon colliders, emphasizing results presented at the LBL Gamma Gamma Collider Workshop. Advantages and difficulties are reported for studies of QCD, the electroweak gauge sector, supersymmetry, and electroweak symmetry breaking.

  4. The Chandra X-Ray Observatory: Observations of Neutron Stars

    OpenAIRE

    Weisskopf, Martin C.

    2004-01-01

    We present here an overview of the status of the Chandra X-ray Observatory which has now been operating for five years. The Observatory is running smoothly, and the scientific return continues to be outstanding. We provide some details on the molecular contamination of the ACIS filters and its impact on observations. We review the observations with Chandra of the pulsar in the Crab Nebula and add some general comments as to the analysis of X-ray spectra. We conclude with comments about the fu...

  5. Lessons We Learned Designing and Building the Chandra Telescope

    Science.gov (United States)

    Arenberg, Jonathan; Matthews, Gary; Atkinson, C.; Cohen, L.; Golisano, C.; Havey, K.; Hefner, K.; Jones, C.; Kegley, J.; Knollenberg, P.; Lavoie, T.; Oliver, J.; Plucinsky, P.; Tananbaun, H.; Texter, S.; Weisskopf, M.

    2014-01-01

    2014 marks the crystal (15th) anniversary of the launch of the Chandra X-ray Observatory. This paper offers some of the major lessons learned by some of the key members of the Chandra Telescope team. We offer some of the lessons gleaned from our experiences developing, designing, building and testing the telescope and its subsystems, with 15 years of hindsight. Among the topics to be discussed are the early developmental tests, known as VETA-I and VETA-II, requirements derivation, the impact of late requirements and reflection on the conservatism in the design process.

  6. Chandra x-ray results on v426 ophiuchi

    Directory of Open Access Journals (Sweden)

    Lee Homer

    2004-01-01

    Full Text Available De las observaciones de 45 ks de Chandra de V426 Oph hemos obtenido espectros de rayos X de alta resoluci on con relaci on se~nal-a-ruido moderada, y una curva de luz no interrumpida de buena calidad. Los espectros se adaptan razonablemente a un modelo de ujo de enfriamiento, similar a EX Hya y U Gem. Nuestro an alisis de las curvas de luz de Chandra y las adicionales de rayos X/ optico revela una modulaci on persistente a 4.2 hr desde 1988 hasta 2003, probablemente el per odo de giro de la enana blanca, indicando una naturaleza polar intermedia para V426 Oph.

  7. Energy efficiency of high pressure pneumatic systems

    OpenAIRE

    Trujillo, José A.

    2015-01-01

    The energy efficiency assessment of high-pressure pneumatic circuits is the aim of this dissertation. From a historical perspective the past and cur- rent activities with regards to the energy saving conservation in pneumatic technology were examined, and it could be concluded that high pressure pneumatic circuits have been repeatedly used for years in several industrial applications but to date no studies on that specific field are known. After a systematic review of studies concerning e...

  8. Elementary particle physics and high energy phenomena

    International Nuclear Information System (INIS)

    This report discusses the following research in high energy physics: the properties of the z neutral boson with the SLD detector; the research and development program for the SDC muon detector; the fixed-target k-decay experiments; the Rocky Mountain Consortium for HEP; high energy photoproduction of states containing heavy quarks; and electron-positron physics with the CLEO II and Mark II detectors. (LSP)

  9. Elementary particle physics and high energy phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Barker, A.R.; Cumalat, J.P.; de Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.

    1992-06-01

    This report discusses the following research in high energy physics: the properties of the z neutral boson with the SLD detector; the research and development program for the SDC muon detector; the fixed-target k-decay experiments; the Rocky Mountain Consortium for HEP; high energy photoproduction of states containing heavy quarks; and electron-positron physics with the CLEO II and Mark II detectors. (LSP).

  10. A unified treatment of high energy interactions

    Energy Technology Data Exchange (ETDEWEB)

    Drescher, H.J.; Werner, K. [Centre National de la Recherche Scientifique, 44 - Nantes (France). Lab. de Physique Subatomique et des Technologies Associees; Hladik, M. [Centre National de la Recherche Scientifique, 44 - Nantes (France). Lab. de Physique Subatomique et des Technologies Associees]|[SAP AG, Berlin (Germany); Ostapchenko, S. [Moscow State Univ. (Russian Federation). Inst. of Nuclear Physics]|[Centre National de la Recherche Scientifique, 44 - Nantes (France). Lab. de Physique Subatomique et des Technologies Associees

    1999-11-01

    It is well known that high energy interactions as different as electron-positron annihilation, deep inelastic lepton-nucleon scattering, proton-proton interactions, and nucleus-nucleus collisions have many features in common. Based upon this observation, a model for all these interactions is constructed which relies on the fundamental hypothesis that the behavior of high energy interactions is universal. (author) 19 refs.

  11. High energy physics advisory panel's subpanel on vision for the future of high-energy physics

    International Nuclear Information System (INIS)

    This report was requested by the Secretary of Energy to (1) define a long-term program for pursuing the most important high-energy physics goals since the termination of the Superconducting Super Collider (SSC) project, (2) assess the current US high-energy physics program, and (3) make recommendations regarding the future of the field. Subjects on which recommendations were sought and which the report addresses were: high-energy physics funding priorities; facilitating international collaboration for future construction of large high-energy physics facilities; optimizing uses of the investment made in the SSC; how to encourage displaced scientists and engineers to remain in high-energy physics and to attract young scientists to enter the field in the future. The report includes a description of the state of high-energy physics research in the context of history, a summary of the SSC project, and documentation of the report's own origins and development

  12. Integral test for JENDL high energy file

    International Nuclear Information System (INIS)

    As activities of the Intermediate and High Energy Nuclear Data Integral Test Working Group in the Japanese Nuclear Data Committee, integral tests of JENDL High Energy File (JENDL-HE) have started. Processing method of JENDL-HE with the NJOY code has been established. As a result of benchmark tests for the 56Fe data in JENDL-HE with the two neutron incident experiments conducted at TIARA and RCNP, calculations with JENDL-HE agreed excellently with the experimental data. The data were found to be adequate for nuclear design calculations as far as the energy range tested, below 68-MeV, was concerned. (author)

  13. Looking for High Energy Peaked Blazars

    OpenAIRE

    Costamante, L.; Ghisellini, G.; Celotti, A.; Giommi, P.; Padovani, P.; Tagliaferri, G.; Wolter, A.; Chiaberge, M.; Fossati, G; Pian, E.; L. Maraschi(INAF National Institute for Astrophysics, I-00136 Rome, Italy); Tavecchio, F.; Treves, A.

    2000-01-01

    Blazars can be classified on the basis of their overall Spectral Energy Distribution (SED). BL Lac objects are usually divided in LBL or HBL (Low or High energy peaked BL Lacs), according to the peak frequency of the synchrotron emission, if in the optical or UV-soft-X band respectively. FSRQs instead are characterized by synchrotron peaks mainly at IR-optical frequencies, similarly to LBLs. Here we report on recent BeppoSAX observations which are unveiling the high energy branch of the range...

  14. Identifying the nature of high energy Astroparticles

    CERN Document Server

    Mora, Karen Salomé Caballero

    2016-01-01

    High energy Astroparticles include Cosmic Ray, gamma ray and neutrinos, all of them coming from the universe. The origin and production, acceleration and propagation mechanisms of ultrahigh-energy CR (up to $10^{20}$ eV) are still unknown. Knowledge on particle interactions taking place at those energies, useful for studying current theories on particle physics, can be obtained only from measurements of high energy astroparticles. In the present document some techniques on data analysis of mass composition of UHECR with the Pierre Auger Observatory are described. The relevance of the muon component of air showers produced by the primary CR, as well as some low energy simulations of that component, are explained.

  15. Ultra-High-Energy Cosmic Rays

    CERN Document Server

    Dova, M T

    2015-01-01

    The origin of the ultra high energy cosmic rays (UHECR) with energies above E > 10 17 eV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. This is a written version of a series of lectures devoted to UHECR at the 2013 CERN-Latin-American School of High-Energy Physics. We present anintroduction to acceleration mechanisms of charged particles to the highest energies in astrophysical objects, their propagation from the sources to Earth, and the experimental techniques for their detection. We also discuss some of the relevant observational results from Telescope Array and Pierre Auger Observatory. These experiments deal with particle interactions at energies orders of magnitude higher than achieved in terrestrial accelerators.

  16. High Energy Particles in the Solar Corona

    CERN Document Server

    Widom, A; Larsen, L

    2008-01-01

    Collective Ampere law interactions producing magnetic flux tubes piercing through sunspots into and then out of the solar corona allow for low energy nuclear reactions in a steady state and high energy particle reactions if a magnetic flux tube explodes in a violent event such as a solar flare. Filamentous flux tubes themselves are vortices of Ampere currents circulating around in a tornado fashion in a roughly cylindrical geometry. The magnetic field lines are parallel to and largely confined within the core of the vortex. The vortices may thereby be viewed as long current carrying coils surrounding magnetic flux and subject to inductive Faraday and Ampere laws. These laws set the energy scales of (i) low energy solar nuclear reactions which may regularly occur and (ii) high energy electro-weak interactions which occur when magnetic flux coils explode into violent episodic events such as solar flares or coronal mass ejections.

  17. Indiana University High Energy Physics, Task A

    International Nuclear Information System (INIS)

    This report discusses research at Indians University on the following high energy physics experiments: A search for mesons with unusual quantum numbers; hadronic states produced in association with high-mass dimuons; FNAL E740 (D0); superconducting super collider; and OPAL experiment at CERN

  18. Electrostatic energy analyzers for high energy charged particle beams

    International Nuclear Information System (INIS)

    The electrostatic energy analyzers for high energy charged particle beams emitted from extended large-size objects as well as from remote point sources are proposed. Results of the analytical trajectory solutions in ideal cylindrical field provide focusing characteristics for both configurations. The instruments possess of simple compact design, based on an ideal cylindrical field with entrance window arranged in the end-boundary between electrodes and can be used for measurements in space technologies, plasma and nuclear physics

  19. High energy physics. Ultimate structure of matter and energy

    International Nuclear Information System (INIS)

    Some of the principle discoveries and insights and their development up to today are sketched. It is shown how one layer after another was discovered by penetrating farther into the structure of matter. Covered are the mounting energy scale, discoveries at high energy frontier, the families of quarks and leptons, the four forces of nature, some achievements of the past few years, particle accelerators and experimental apparatus. A glossary of terms is included

  20. High energy experimental physics: Progress report

    International Nuclear Information System (INIS)

    This report contains papers of high energy physics experiments and detector equipment design. Proposals are also given for future experiments. Some of the topics covered in this report are: high energy predictions for /bar char/pp and pp elastic scattering and total cross sections; D0 forward drift chambers; polarized beam facility; analyzing power measurment in inclusive pion production at high transverse momentum; Skyrme model for baryons; string models for color flux tubes; hadronic decays for the /tau/ lepton; and meson form factors in perturbative QCD

  1. High energy hadron-hadron collisions

    International Nuclear Information System (INIS)

    Results of a study on high energy collisions with the geometrical model are summarized in three parts: (1) the elastic hadron-hadron collision, (2) the inelastic hadron-hadron collision, and (3) e+e- annihilation. For elastic scattering, a modified form for the hadronic matter form factor of the proton was proposed which is still dipole in form but contains an energy--dependent range parameter. This new expression of the opacity function fits the elastic bar pp scattering very well from the ISR to S bar ppS energies. Extrapolation of this theory also yielded results bar pp in good agreement with the bar pp differential cross section measured at the Tevatron. For inelastic hadron-hadron collisions, we have made a systematic investigation of the single-particle momentum spectra in the entire S bar ppS energy region. Results are useful for the extrapolation of angular distribution to the higher SSC energies. In e+e- annihilation, a detailed analysis of all available experimental multiplicity data from PETRA to LEP energies has been performed. The cluster size of emitted hadrons increases gradually with energy. Aside from high-energy collisions, the giant fullerene molecules were studied and precise algebraic eigenvalue expressions of the Hueckel problem for carbon-240 were obtained

  2. Extra galactic sources of high energy neutrinos

    CERN Document Server

    Waxman, E

    2005-01-01

    The main goal of the construction of large volume, high energy neutrino telescopes is the detection of extra-Galactic neutrino sources. The existence of such sources is implied by observations of ultra-high energy, >10^{19} eV, cosmic-rays (UHECRs), the origin of which is a mystery. The observed UHECR flux sets an upper bound to the extra-Galactic high energy neutrino intensity, which implies that the detector size required to detect the signal in the energy range of 1 TeV to 1 PeV is >=1 giga-ton, and much larger at higher energy. Optical Cerenkov neutrino detectors, currently being constructed under ice and water, are expected to achieve 1 giga-ton effective volume for 1 TeV to 1 PeV neutrinos. Coherent radio Cerenkov detectors (and possibly large air-shower detectors) will provide the >> 1 giga-ton effective volume required for detection at ~10^{19} eV. Detection of high energy neutrinos associated with electromagnetically identified sources will allow to identify the sources of UHECRs, will provide a uniq...

  3. The Chandra X-Ray Observatory: Five Years of Operation

    OpenAIRE

    Weisskopf, Martin C.

    2005-01-01

    The Chandra X-ray Observatory is the X-ray component of NASA's Great Observatory Program and has been operating successfully for over five years. We present here brief overview of the technical performance and some of the remarkable discoveries.

  4. An Introduction to the Chandra Carina Complex Project

    CERN Document Server

    Townsley, Leisa K; Corcoran, Michael F; Feigelson, Eric D; Gagné, Marc; Montmerle, Thierry; Oey, M S; Smith, Nathan; Garmire, Gordon P; Getman, Konstantin V; Povich, Matthew S; Evans, Nancy Remage; Nazé, Yaël; Parkin, E R; Preibisch, Thomas; Wang, Junfeng; Wolk, Scott J; Chu, You-Hua; Cohen, David H; Gruendl, Robert A; Hamaguchi, Kenji; King, Robert R; Mac Low, Mordecai-Mark; McCaughrean, Mark J; Moffat, Anthony F J; Oskinova, L M; Pittard, Julian M; Stassun, Keivan G; ud-Doula, Asif; Walborn, Nolan R; Waldron, Wayne L; Churchwell, Ed; Nichols, J S; Owocki, Stanley P; Schulz, N S

    2011-01-01

    The Great Nebula in Carina provides an exceptional view into the violent massive star formation and feedback that typifies giant HII regions and starburst galaxies. We have mapped the Carina star-forming complex in X-rays, using archival Chandra data and a mosaic of 20 new 60ks pointings using the Chandra X-ray Observatory's Advanced CCD Imaging Spectrometer, as a testbed for understanding recent and ongoing star formation and to probe Carina's regions of bright diffuse X-ray emission. This study has yielded a catalog of properties of >14,000 X-ray point sources; >9800 of them have multiwavelength counterparts. Using Chandra's unsurpassed X-ray spatial resolution, we have separated these point sources from the extensive, spatially-complex diffuse emission that pervades the region; X-ray properties of this diffuse emission suggest that it traces feedback from Carina's massive stars. In this introductory paper, we motivate the survey design, describe the Chandra observations, and present some simple results, pr...

  5. Romanticism or Reality? An Exploration of Frances Mary Hendry's "Chandra."

    Science.gov (United States)

    Johnson, Jilaine

    This paper singles out a novel written for children about India, "Chandra" (1995) by Frances Mary Hendry, as a powerful and useful novel to present to today's 11 to 14 year old students. The paper contends that the novel allows students to explore and consider different value systems, challenges them to become aware of prejudice and the making of…

  6. INNOVATIONS IN THE ANALYSIS OF CHANDRA-ACIS OBSERVATIONS

    International Nuclear Information System (INIS)

    As members of the instrument team for the Advanced CCD Imaging Spectrometer (ACIS) on NASA's Chandra X-ray Observatory and as Chandra General Observers, we have developed a wide variety of data analysis methods that we believe are useful to the Chandra community, and have constructed a significant body of publicly available software (the ACIS Extract package) addressing important ACIS data and science analysis tasks. This paper seeks to describe these data analysis methods for two purposes: to document the data analysis work performed in our own science projects and to help other ACIS observers judge whether these methods may be useful in their own projects (regardless of what tools and procedures they choose to implement those methods). The ACIS data analysis recommendations we offer here address much of the workflow in a typical ACIS project, including data preparation, point source detection via both wavelet decomposition and image reconstruction, masking point sources, identification of diffuse structures, event extraction for both point and diffuse sources, merging extractions from multiple observations, nonparametric broadband photometry, analysis of low-count spectra, and automation of these tasks. Many of the innovations presented here arise from several, often interwoven, complications that are found in many Chandra projects: large numbers of point sources (hundreds to several thousand), faint point sources, misaligned multiple observations of an astronomical field, point source crowding, and scientifically relevant diffuse emission.

  7. A systematic Chandra study of Sgr A⋆ - I. X-ray flare detection

    Science.gov (United States)

    Yuan, Qiang; Wang, Q. Daniel

    2016-02-01

    Daily X-ray flaring represents an enigmatic phenomenon of Sagittarius A⋆ (Sgr A⋆) - the supermassive black hole at the centre of our Galaxy. We report initial results from a systematic X-ray study of this phenomenon, based on extensive Chandra observations obtained from 1999 to 2012, totalling about 4.5 Ms. We detect flares, using a combination of the maximum likelihood and Markov Chain Monte Carlo methods, which allow for a direct accounting for the pileup effect in the modelling of the flare light curves and an optimal use of the data, as well as the measurements of flare parameters, including their uncertainties. A total of 82 flares are detected. About one third of them are relatively faint, which were not detected previously. The observation-to-observation variation of the quiescent emission has an average root-mean-square of 6-14 per cent, including the Poisson statistical fluctuation of faint flares below our detection limits. We find no significant long-term variation in the quiescent emission and the flare rate over the 14 years. In particular, we see no evidence of changing quiescent emission and flare rate around the pericentre passage of the S2 star around 2002. We show clear evidence of a short-term clustering for the Advanced CCD Imaging Spectrometer - Spectroscopy array/high energy transmission gratings 0th-order flares on time-scale of 20-70 ks. We further conduct detailed simulations to characterize the detection incompleteness and bias, which is critical to a comprehensive follow-up statistical analysis of flare properties. These studies together will help to establish Sgr A⋆ as a unique laboratory to understand the astrophysics of prevailing low-luminosity black holes in the Universe.

  8. Chandra and Swift X-ray Observations of the X-ray Pulsar SMC X-2 During the Outburst of 2015

    OpenAIRE

    Li, K L; Hu, C. -P; Lin, L. C. C.; Kong, Albert K. H.

    2016-01-01

    We report the Chandra/HRC-S and Swift/XRT observations for the 2015 outburst of the high-mass X-ray binary (HMXB) pulsar in the Small Magellanic Cloud, SMC X-2. While previous studies suggested that either an O star or a Be star in the field is the high-mass companion of SMC X-2, our Chandra/HRC-S image unambiguously confirms the O-type star as the true optical counterpart. Using the Swift/XRT observations, we extracted accurate orbital parameters of the pulsar binary through a time of arriva...

  9. Opportunities for high wind energy penetration

    DEFF Research Database (Denmark)

    Tande, J.O.; Hansen, J.C.

    1997-01-01

    Wind power is today a mature technology, which at windy locations, is economically competitive to conventional power generation technologies. This and growing global environmental concerns have led governments to encourage and plan for wind energy development, a typical aim being 10% of electricity...... consumption. The successful operation of the three major power systems of Cape Verde, with a total wind energy penetration of about 15% since December 1994, demonstrates that power systems can be operated with high penetration of wind energy by adding simple control and monitoring systems only. Thorough...... analyses conclude that expanding to even above 15% wind energy penetration in the Cape Verde power systems is economical. Worldwide, numerous locations with favorable wind conditions and power systems similar to the Capeverdean provide good opportunities for installing wind farms and achieving high wind...

  10. High Energy Radiation from $\\gamma$ Ray Bursts

    CERN Document Server

    Dermer, C D; Dermer, Charles D.; Chiang, James

    1999-01-01

    Gamma-ray burst (GRB) engines are probed most intimately during the prompt gamma-ray luminous phase when the expanding blast wave is closest to the explosion center. Using GRBs 990123 and 940217 as guides, we briefly review observations of high-energy emission from GRBs and summarize some problems in GRB physics. \\gamma\\gamma transparency arguments imply relativistic beaming. The parameters that go into the external shock model are stated, and we show numerical simulation results of gamma-ray light curves from relativistic blast waves with different amounts of baryon loading. A distinct component due to the synchrotron self-Compton process produces significant emission at GeV and TeV energies. Predictions for spectral and temporal evolution at these energies are presented for a blast wave expanding into uniform surroundings. Observations of the slow decay of GeV-TeV radiation provide evidence for ultra-high energy cosmic ray acceleration in GRBs.

  11. Solar flares and solar high energy particles

    International Nuclear Information System (INIS)

    Generally, the solar high energy particles in the flares are believed to be accelerated in two stages: acceleration by abrupt release of magnetic energy in the first stage and coronal diffusive shock wave or stochastic acceleration in the second stage. We consider the diffusive shock wave acceleration in gradual solar flare associated with fast coronal shock wave. The results indicate: (1) the characteristics of the particle distribution with time depends on the momentum and with the increasing of transition time, the distribution increases to maximum quickly and turns to decrease then; the higher energy, the more time of moving to maximum; (2) the corresponding time integral spectrum is proportional to the power of the particle momentum. The possibility of accelerating particles to high energy range is also discussed

  12. A high energy photon polarimeter for astrophysics

    CERN Document Server

    Eingorn, Maxim; Vlahovic, Branislav; Wojtsekhowski, Bogdan; Urciuoli, Guido Maria; De Persio, Fulvio; Meddi, Franco

    2015-01-01

    A high-energy photon polarimeter for astrophysics studies in the energy range from 20 MeV to 1000 MeV is considered. The proposed concept uses a stack of silicon micro-strip detectors where they play the roles of both a converter and a tracker. The purpose of this paper is to outline the parameters of such a polarimeter and to estimate the productivity of measurements. Our study supported by a Monte Carlo simulation shows that with a one-year observation period the polarimeter will provide 5.5 % accuracy of the polarization degree for a photon energy of 100 MeV, which would be a significant advance relative to the currently explored energy range of a few MeV. The proposed polarimeter design could easily be adjusted to the specific photon energy range to maximize efficiency if needed.

  13. Meson-proton scattering at high energies

    International Nuclear Information System (INIS)

    We use a model in which the energy dependence of hadronic scattering is driven at high energies primarily by semihard scattering of constituent gluons and quarks to calculate the elastic differential and total cross sections for πp and Kp scattering. Our model predicts that, as a direct consequence of the dominance of gluon and sea-quark interactions at small x, the total cross sections for all the meson-proton processes should approach equality in the TeV energy regime. The cross sections are strikingly large for energies in the upper range of cosmic-ray energies, and the expected evolution of hadronic air showers may be changed as a result

  14. Alternative Approaches to High Energy Density Fusion

    Science.gov (United States)

    Hammer, J.

    2016-03-01

    This paper explores selected approaches to High Energy Density (HED) fusion, beginning with discussion of ignition requirements at the National Ignition Facility (NIF). The needed improvements to achieve ignition are closely tied to the ability to concentrate energy in the implosion, manifested in the stagnation pressure, Pstag . The energy that must be assembled in the imploded state to ignite varies roughly as Pstag -2, so among other requirements, there is a premium on reaching higher Pstag to achieve ignition with the available laser energy. The U.S. inertial confinement fusion program (ICF) is pursuing higher Pstag on NIF through improvements to capsule stability and symmetry. One can argue that recent experiments place an approximate upper bound on the ultimate ignition energy requirement. Scaling the implosions consistently in spatial, temporal and energy scales shows that implosions of the demonstrated quality ignite robustly at 9-15 times the current energy of NIF. While lasers are unlikely to reach that bounding energy, it appears that pulsed-power sources could plausibly do so, giving a range of paths forward for ICF depending on success in improving energy concentration. In this paper, I show the scaling arguments then discuss topics from my own involvement in HED fusion. The recent Viewfactor experiments at NIF have shed light on both the observed capsule drive deficit and errors in the detailed modelling of hohlraums. The latter could be important factors in the inability to achieve the needed symmetry and energy concentration. The paper then recounts earlier work in Fast Ignition and the uses of pulsed- power for HED and fusion applications. It concludes with a description of a method for improving pulsed-power driven hohlraums that could potentially provide a factor of 10 in energy at NIF-like drive conditions and reach the energy bound for indirect drive ICF.

  15. High Energy Photon-Photon Collisions -

    OpenAIRE

    Brodsky, Stanley J.; SLAC; Zerwas, Peter M.; DESY

    1994-01-01

    The collisions of high energy photons produced at an electron-positron collider provide a comprehensive laboratory for testing QCD, electroweak interactions, and extensions of the Standard Model. The luminosity and energy of the colliding photons produced by back-scattering laser beams is expected to be comparable to that of the primary $e^+e^-$ collisions. In this overview, we shall focus on tests of electroweak theory in photon-photon annihilation, particularly $\\gamma\\gamma \\rightarrow W^+...

  16. Measuring high energy excitations - the future

    International Nuclear Information System (INIS)

    The performance of the main neutron techniques for measuring high energy excitations: the reactor triple axis, and the pulsed source rotor spectrometers, crystal analyzer methods, and resonance detector and absorption methods, will be reviewed in turn. The possibilities opened up the order of magnitude increased in source fluxes now in sight will be explored having in mind in particular the measurement of single crystal excitations to higher energies

  17. High energy interactions and extensive air showers

    International Nuclear Information System (INIS)

    We report on papers presented in the high energy sessions of the conference that do not deal with the theory and observations of muons and neutrinos. We concentrate on the development and testing of hadronic interaction models, their extension to ultrahigh energy and their importance for the analysis and interpretation of air shower data. We also summarize data on the cosmic ray spectrum and composition obtained with air showers

  18. Galactic Ultra-High-Energy Cosmic Rays

    OpenAIRE

    Olinto, A. V.; Epstein, R. I.; P. Blasi(INAF Arcetri)

    1999-01-01

    The absence of the expected GZK cutoff strongly challenges the notion that the highest-energy cosmic rays are of distant extragalactic origin. We discuss the possibility that these ultra-high-energy events originate in our Galaxy and propose that they may be due to iron nuclei accelerated from young, strongly magnetic neutron stars. Newly formed pulsars accelerate ions from their surface through relativistic MHD winds. We find that pulsars whose initial spin periods are shorter than $\\sim 4 (...

  19. High Energy Phenomena in Clusters of Galaxies

    OpenAIRE

    P. Blasi(INAF Arcetri); Colafrancesco, S.

    1998-01-01

    Several phenomena in high energy astrophysics have been recently related to clusters of galaxies and to cosmic ray interactions occurring inside these structures. In many of these phenomena the observable effects depend on the energy density of cosmic rays confined in the Intra Cluster (IC) medium, which is a poorly known quantity. We propose here that useful indications about this quantity can be obtained from present and future observations of galaxy clusters in the radio and hard X-ray fre...

  20. Balance Function in High-Energy Collisions

    OpenAIRE

    Tawfik, A.; Shalaby, Asmaa G.

    2015-01-01

    Aspects and implications of the balance functions (BF) in high-energy physics are reviewed. The various calculations and measurements depending on different quantities, for example, system size, collisions centrality, and beam energy, are discussed. First, the different definitions including advantages and even short-comings are highlighted. It is found that BF, which are mainly presented in terms of relative rapidity, and relative azimuthal and invariant relative momentum, are se...

  1. Infrared Faint Radio Sources in the Extended Chandra Deep Field South

    Science.gov (United States)

    Huynh, Minh T.

    2009-01-01

    Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey (ATLAS) which have no observable counterpart in the Spitzer Wide-area Infrared Extragalactic Survey (SWIRE). The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6 to 70 micron) 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 SED of these objects shows that they are consistent with high redshift AGN (z > 2).

  2. Updated phase coherent timing solution of the isolated neutron star RX J0720.4-3125 using recent XMM-Newton and Chandra observations

    NARCIS (Netherlands)

    Hohle, M. M.; Haberl, F.; Vink, J.; Turolla, R.; Zane, S.; de Vries, C. P.; Mendez, M.

    2010-01-01

    Aims. Since the last phase coherent timing solution of the nearby radio-quiet isolated neutron star RX J0720.4-3125 six new XMM-Newton and three Chandra observations were carried out. The phase coherent timing solutions from previous authors were performed without restricting to a fixed energy band.

  3. Strongly Interacting Matter at High Energy Density

    Energy Technology Data Exchange (ETDEWEB)

    McLerran,L.

    2008-09-07

    This lecture concerns the properties of strongly interacting matter (which is described by Quantum Chromodynamics) at very high energy density. I review the properties of matter at high temperature, discussing the deconfinement phase transition. At high baryon density and low temperature, large N{sub c} arguments are developed which suggest that high baryonic density matter is a third form of matter, Quarkyonic Matter, that is distinct from confined hadronic matter and deconfined matter. I finally discuss the Color Glass Condensate which controls the high energy limit of QCD, and forms the low x part of a hadron wavefunction. The Glasma is introduced as matter formed by the Color Glass Condensate which eventually thermalizes into a Quark Gluon Plasma.

  4. Experimental and theoretical high energy physics research

    International Nuclear Information System (INIS)

    Progress in the various components of the UCLA High-Energy Physics Research program is summarized, including some representative figures and lists of resulting presentations and published papers. Principal efforts were directed at the following: (I) UCLA hadronization model, PEP4/9 e+e- analysis, bar P decay; (II) ICARUS and astroparticle physics (physics goals, technical progress on electronics, data acquisition, and detector performance, long baseline neutrino beam from CERN to the Gran Sasso and ICARUS, future ICARUS program, and WIMP experiment with xenon), B physics with hadron beams and colliders, high-energy collider physics, and the φ factory project; (III) theoretical high-energy physics; (IV) H dibaryon search, search for KL0 → π0γγ and π0ν bar ν, and detector design and construction for the FNAL-KTeV project; (V) UCLA participation in the experiment CDF at Fermilab; and (VI) VLPC/scintillating fiber R ampersand D

  5. Why is High Energy Physics Lorentz Invariant?

    CERN Document Server

    Afshordi, Niayesh

    2015-01-01

    Despite the tremendous empirical success of equivalence principle, there are several theoretical motivations for existence of a preferred reference frame (or aether) in a consistent theory of quantum gravity. However, if quantum gravity had a preferred reference frame, why would high energy processes enjoy such a high degree of Lorentz symmetry? While this is often considered as an argument against aether, here I provide three independent arguments for why perturbative unitarity (or weak coupling) of the Lorentz-violating effective field theories put stringent constraints on possible observable violations of Lorentz symmetry at high energies. In particular, the interaction with the scalar graviton in a consistent low-energy theory of gravity and a (radiatively and dynamically) stable cosmological framework, leads to these constraints. The violation (quantified by the relative difference in maximum speed of propagation) is limited to $\\lesssim 10^{-10} E({\\rm eV})^{-4}$ (superseding all current empirical bound...

  6. Scientific applications for high-energy lasers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, R.W. [comp.

    1994-03-01

    The convergence of numerous factors makes the time ripe for the development of a community of researchers to use the high-energy laser for scientific investigations. This document attempts to outline the steps necessary to access high-energy laser systems and create a realistic plan to implement usage. Since an academic/scientific user community does not exist in the USA to any viable extent, we include information on present capabilities at the Nova laser. This will briefly cover laser performance and diagnostics and a sampling of some current experimental projects. Further, to make the future possibilities clearer, we will describe the proposed next- generation high-energy laser, named for its inertial fusion confinement (ICF) goal, the multi-megaJoule, 500-teraWatt National Facility, or NIF.

  7. IC model of pulsar high energy emission

    CERN Document Server

    Lyutikov, Maxim

    2012-01-01

    We discuss growing evidence that pulsar high energy is emission is generated via Inverse Compton mechanism. We reproduce the broadband spectrum of Crab pulsar, from UV to very high energy gamma-rays - nearly ten decades in energy, within the framework of the cyclotron-self-Compton model. Emission is produced by two counter-streaming beams within the outer gaps, at distances above ~ 20 NS radii. The outward moving beam produces UV-X-ray photons via Doppler-booster cyclotron emission, and GeV photons by Compton scattering the cyclotron photons produced by the inward going beam. The scattering occurs in the deep Klein-Nishina regime, whereby the IC component provides a direct measurement of particle distribution within the magnetosphere. The required plasma multiplicity is high, ~ 10^6-10^7, but is consistent with the average particle flux injected into the pulsar wind nebula.

  8. Future high energy colliders symposium. Summary report

    International Nuclear Information System (INIS)

    A 'Future High Energy Colliders' Symposium was held October 21-25, 1996 at the Institute for Theoretical Physics (ITP) in Santa Barbara. This was one of the 3 symposia hosted by the ITP and supported by its sponsor, the National Science Foundation, as part of a 5 month program on 'New Ideas for Particle Accelerators'. The long term program and symposia were organized and coordinated by Dr. Zohreh Parsa of Brookhaven National Laboratory/ITP. The purpose of the symposium was to discuss the future direction of high energy physics by bringing together leaders from the theoretical, experimental and accelerator physics communities. Their talks provided personal perspectives on the physics objectives and the technology demands of future high energy colliders. Collectively, they formed a vision for where the field should be heading and how it might best reach its objectives

  9. Energy recovery in high energy neutral beam injectors

    International Nuclear Information System (INIS)

    One way to heat the plasma of thermonuclear fusion experiments, is to inject high energy (50 to 100 KeV per nucleon), neutral particles (hydrogen or deuterium). Neutral beam elaboration consists in ion production and acceleration, neutralisation by charge exchange on gas target, disposal of unneutralized ions. But, in the case of positive ion based neutral beam injection, the neutralisation efficiency is limited to 50% at 100 KeV, and decreases rapidly with energy. The energy recovery is a new method for disposing of the unneutralized ions: these are electrostatically decelerated and collected on electrodes which are polarized at low voltage, close to the ion source potential. An energy recovery system was studied and experimented with positive ion beams of 50 and 100 KeV. In the framework of a french-japanese collaboration, we measured a relative power reduction of about 20%, with 100 KeV, 1,5 MW deuterium beams. We have also studied theoretically an energy recovery system for negative ion beams, which will be utilized at high energy (1 MeV). A relative power reduction of 20% can be expected in the best conditions

  10. Detector for high-energy photon backscatter

    Science.gov (United States)

    Silver, Michael D.; Erker, Joseph W.; Duncan, Michael Z.; Hartford, Thomas J.; Sivers, E. A.; Hopkinson, James F.

    1993-12-01

    High energy photon backscatter uses pair production to probe deep beneath surfaces with single side accessibility or to image thick, radiographically opaque objects. At the higher photon energies needed to penetrate thick and/or highly attenuating objects, Compton backscatter becomes strongly forward peaked with relatively little backscatter flux. Furthermore, the downward energy shift of the backscattered photon makes it more susceptible to attenuation on its outbound path. Above 1.022 MeV, pair production is possible; at about 10 MeV, pari production crosses over Compton scatter as the dominant x-ray interaction mechanism. The backscattered photons can be hard x rays from the bremsstrahlung of the electrons and positrons or 0.511 MeV photons from the annihilation of the positron. Monte Carlo computer simulations of such a backscatter system were done to characterize the output signals and to optimize a high energy detector design. This paper touches on the physics of high energy backscatter imaging and describes at some length the detector design for tomographic and radiographic imaging.

  11. CHANDRA OBSERVATIONS OF SGR 1627-41 NEAR QUIESCENCE

    Energy Technology Data Exchange (ETDEWEB)

    An, Hongjun; Kaspi, Victoria M.; Cumming, Andrew [Department of Physics, McGill University, Rutherford Physics Building, 3600 University Street, Montreal, QC H3A 2T8 (Canada); Tomsick, John A.; Bodaghee, Arash [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Gotthelf, E. V. [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Rahoui, Farid [Department of Astronomy and Harvard-Smithsonian Center for Astrophysics, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States)

    2012-09-20

    We report on an observation of SGR 1627-41 made with the Chandra X-Ray Observatory on 2011 June 16. Approximately three years after its outburst activity in 2008, the source's flux has been declining, as it approaches its quiescent state. For an assumed power-law spectrum, we find that the absorbed 2-10 keV flux for the source is 1.0{sup +0.3}{sub -0.2} Multiplication-Sign 10{sup -13} erg cm{sup -2} s{sup -1} with a photon index of 2.9 {+-} 0.8 (N{sub H} = 1.0 Multiplication-Sign 10{sup 23} cm{sup -2}). This flux is approximately consistent with that measured at the same time after the source's outburst in 1998. With measurements spanning three years after the 2008 outburst, we analyze the long-term flux and spectral evolution of the source. The flux evolution is well described by a double exponential with decay times of 0.5 {+-} 0.1 and 59 {+-} 6 days, and a thermal cooling model fit suggests that SGR 1627-41 may have a hot core (T{sub c} {approx} 2 Multiplication-Sign 10{sup 8} K). We find no clear correlation between flux and spectral hardness as found in other magnetars. We consider the quiescent X-ray luminosities of magnetars and the subset of rotation-powered pulsars with high magnetic fields (B {approx}> 10{sup 13} G) in relation to their spin-inferred surface magnetic field strength and find a possible trend between the two quantities.

  12. Chandra Observations of Dying Radio Sources in Galaxy Clusters

    Science.gov (United States)

    Murgia, M.; Markevitch, M.; Govoni, F.; Parma, P.; Fanti, R.; de Ruiter, H. R.; Mack, K.-H.

    2012-01-01

    Context. The dying radio sources represent a very interesting and largely unexplored stage of the active galactic nucleus (AGN) evolution. They are considered to be very rare, and almost all of the few known ones were found in galaxy clusters. However, considering the small number detected so far, it has not been possible to draw any firm conclusions about their X-ray environment. Aims. We present X-ray observations performed with the Chandra satellite of the three galaxy clusters Abell 2276, ZwCl 1829.3+6912, and RX J1852.1+5711, which harbor at their center a dying radio source with an ultra-steep spectrum that we recently discovered. Methods. We analyzed the physical properties of the X-ray emitting gas surrounding these elusive radio sources. We determined the global X-ray properties of the clusters, derived the azimuthally averaged profiles of metal abundance, gas temperature, density, and pressure. Furthermore, we estimated the total mass profiles. Results. The large-scale X-ray emission is regular and spherical, suggesting a relaxed state for these systems. Indeed, we found that the three clusters are also characterized by significant enhancements in the metal abundance and declining temperature profiles toward the central region. For all these reasons, we classified RX J1852.1+5711, Abell 2276, and ZwCl 1829.3+6912 as cool-core galaxy clusters. Conclusions. We calculated the non-thermal pressure of the radio lobes assuming that the radio sources are in the minimum energy condition. For all dying sources we found that this is on average about one to two orders of magnitude lower than that of the external gas, as found for many other radio sources at the center of galaxy groups and clusters. We found marginal evidence for the presence of X-ray surface brightness depressions coincident with the fossil radio lobes of the dying sources in A2276 and ZwCl 1829.3+691. We estimated the outburst age and energy output for these two dying sources. The energy power from

  13. High energy radiography for detecting details in highly complex packings

    International Nuclear Information System (INIS)

    For the radiographic investigation of large containers the energies of conventional X-ray tubes are inadequate for certain layer thicknesses. In that case, high energy X-ray radiation sources like electron accelerators and gamma radiators like 60Co are adequate for the non-destructive inspection of large containers because of the high penetration through thick materials, sensitivity and ability to distinguish low and high Z materials. So it is to be expected that objects of organic substances are hard to recognize behind thick walls of heavy metal or bore holes in metalblocks. In contrast to gamma emitters like 60Co with its spectral lines about 1.3 MeV the bremsstrahlung from an accelerator has an essential ratio of low energy radiation with a smooth transition to higher energies. The primary aim here is to investigate the detectability of dangerous materials (light objects) in cargo containers with a complex packing. Experiments are conducted on a miniature container model with 3 mm wall thickness using a betatron (JME X-ray 2-7.5 MeV) as a high energy X-ray source and a high resolution matrix detector (Perkin Elmer XRD1621) for digital X-ray imaging. It was investigated with different energies how material discrimination is possible behind different kinds of shielding. By using the aRTist (analytical RT Inspection Simulation Tool) software the experimental results were compared with simulations for modeling radiographic procedures. On the one hand the results of the experimental investigations can be used for detecting suspect objects within machines for example but on the other hand for the detection and recognition of dangerous materials in cargo container for public security or for customs. (orig.)

  14. Elementary particle physics and high energy phenomena

    International Nuclear Information System (INIS)

    Experimental and theoretical high-energy physics programs at the University of Colorado are reported. Areas of concentration include the following: study of the properties of the Z0 with the SLD detector; fixed-target K-decay experiments; the R ampersand D program for the muon system: the SDC detector; high-energy photoproduction of states containing heavy quarks; electron--positron physics with the CLEO II detector at CESR; lattice QCD; and spin models and dynamically triangulated random surfaces. 24 figs., 2 tabs., 117 refs

  15. Beam dynamics in high energy particle accelerators

    CERN Document Server

    Wolski, Andrzej

    2014-01-01

    Particle accelerators are essential tools for scientific research in fields as diverse as high energy physics, materials science and structural biology. They are also widely used in industry and medicine. Producing the optimum design and achieving the best performance for an accelerator depends on a detailed understanding of many (often complex and sometimes subtle) effects that determine the properties and behavior of the particle beam. Beam Dynamics in High Energy Particle Accelerators provides an introduction to the concepts underlying accelerator beam line design and analysis, taking an approach that emphasizes the elegance of the subject and leads into the development of a range of powerful techniques for understanding and modeling charged particle beams.

  16. COMPILATION OF CURRENT HIGH ENERGY PHYSICS EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Wohl, C.G.; Kelly, R.L.; Armstrong, F.E.; Horne, C.P.; Hutchinson, M.S.; Rittenberg, A.; Trippe, T.G.; Yost, G.P.; Addis, L.; Ward, C.E.W.; Baggett, N.; Goldschmidt-Clermong, Y.; Joos, P.; Gelfand, N.; Oyanagi, Y.; Grudtsin, S.N.; Ryabov, Yu.G.

    1981-05-01

    This is the fourth edition of our compilation of current high energy physics experiments. It is a collaborative effort of the Berkeley Particle Data Group, the SLAC library, and nine participating laboratories: Argonne (ANL), Brookhaven (BNL), CERN, DESY, Fermilab (FNAL), the Institute for Nuclear Study, Tokyo (INS), KEK, Serpukhov (SERP), and SLAC. The compilation includes summaries of all high energy physics experiments at the above laboratories that (1) were approved (and not subsequently withdrawn) before about April 1981, and (2) had not completed taking of data by 1 January 1977. We emphasize that only approved experiments are included.

  17. Status of High-Energy Neutrino Astronomy

    CERN Document Server

    Kowalski, Marek

    2014-01-01

    With the recent discovery of high-energy neutrinos of extra-terrestrial origin by the IceCube neutrino observatory, neutrino-astronomy is entering a new era. This review will cover currently operating open water/ice neutrino telescopes, the latest evidence for a flux of extra-terrestrial neutrinos and current efforts in the search for steady and transient neutrino point sources. Generalised constraints on potential astrophysical sources are presented, allowing to focus the hunt for the sources of the observed high-energy neutrinos.

  18. A Chandra View Of Nonthermal Emission In The Northwestern Region Of Supernova Remnant RCW 86: Particle Acceleration And Magnetic Fields

    CERN Document Server

    Castro, Daniel; Slane, Patrick O; Yamaguchi, Hiroya; Ramirez-Ruiz, Enrico; Figueroa-Feliciano, Enectali

    2013-01-01

    The shocks of supernova remnants (SNRs) are believed to accelerate particles to cosmic ray (CR) energies. The amplification of the magnetic field due to CRs propagating in the shock region is expected to have an impact on both the emission from the accelerated particle population, as well as the acceleration process itself. Using a 95 ks observation with the Advanced CCD Imaging Spectrometer (ACIS) onboard the Chandra X-ray Observatory, we map and characterize the synchrotron emitting material in the northwestern region of RCW 86. We model spectra from several different regions, filamentary and diffuse alike, where emission appears dominated by synchrotron radiation. The fine spatial resolution of Chandra allows us to obtain accurate emission profiles across 3 different non-thermal rims in this region. The narrow width (l = 10''-30'') of these filaments constrains the minimum magnetic field strength at the post-shock region to be approximately 80 {\\mu}G.

  19. Observation of high current effects in high energy linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Seeman, J.T.

    1991-12-01

    The acceleration and transport of electron beams with high currents and low emittances are subjects studied very carefully for many operating accelerators and most future accelerators. For a example, several Free Electron Lasers (FEL) and the Stanford Linear Collider (SLC) presently operate with high energy intense beams. The next generation of synchrotron light sources and future linear colliders require a much higher degree of component precision and beam control. In this note the basic concepts governing the effects of high currents in accelerators are explored, including observations of high currents in present accelerators. The effects of longitudinal wakefields on acceleration and energy spreads are studied first. Then, the transverse equations of motion are developed including the technique of BNS damping to control wakefield growth. These wakefield effects are investigated to characterize their influence on the control and observation of beam oscillations. Finally, the reduction of transverse wakefield effects is important for maintaining the emittance of intense beams. 49 refs., 48 figs.

  20. Observation of high current effects in high energy linear accelerators

    International Nuclear Information System (INIS)

    The acceleration and transport of electron beams with high currents and low emittances are subjects studied very carefully for many operating accelerators and most future accelerators. For a example, several Free Electron Lasers (FEL) and the Stanford Linear Collider (SLC) presently operate with high energy intense beams. The next generation of synchrotron light sources and future linear colliders require a much higher degree of component precision and beam control. In this note the basic concepts governing the effects of high currents in accelerators are explored, including observations of high currents in present accelerators. The effects of longitudinal wakefields on acceleration and energy spreads are studied first. Then, the transverse equations of motion are developed including the technique of BNS damping to control wakefield growth. These wakefield effects are investigated to characterize their influence on the control and observation of beam oscillations. Finally, the reduction of transverse wakefield effects is important for maintaining the emittance of intense beams. 49 refs., 48 figs

  1. Chandra Detection of the First X-ray Forest along the Line of Sight To Mkn 421

    CERN Document Server

    Nicastro, F; Elvis, M; Drake, J; Fiore, F; Fang, T; Fruscione, A; Krongold, Y; Marshall, H; Williams, R; Nicastro, Fabrizio; Mathur, Smita; Elvis, Martin; Drake, Jeremy; Fiore, Fabrizio; Fang, Taotao; Fruscione, Antonella; Krongold, Yair; Marshall, Herman; Williams, Rik

    2005-01-01

    We present the first >=3.5 sigma (conservative) or >=5.8 sigma (sum of lines significance) detection of two Warm-Hot Intergalactic Medium (WHIM) filaments at z>0, which we find along the line of sight to the blazar Mkn 421. These systems are detected through highly ionized resonant metal absorption in high quality Chandra-ACIS and -HRC Low Energy Transmission Grating (LETG) spectra of Mkn 421, obtained following our two Target of Opportunity requests during two outburst phases. The two intervening WHIM systems that we detect, have OVII and NVII columns of N(OVII)=(1.0 +/- 0.3) x 1e15 cm-2} N(NVII)=(0.8 +/- 0.4) x 1e15 cm-2, and N(OVII)=(0.7 +/- 0.3) x 1e15 cm-2, N(NVII)=(1.4 +/- 0.5) x 1e15 cm-2 respectively. From the detected number of WHIM filaments along this line of sight we can estimate the number of OVII filaments per unit redshift with columns larger than 7e14 cm-2, dP(OVII)/dz(N(OVII)>=7e14) = 67^{+88}_{-43}, consistent, within the large 1-sigma errors, with the hydrodynamical simulation predictions o...

  2. High energy astrophysics and high-altitude laboratories

    International Nuclear Information System (INIS)

    These are some summary remarks given at the Chacaltaya meeting on cosmic ray physics, held in La Paz (Bolivia), July 23-27, 2000. The meeting covered a wide range of topics in cosmic ray physics and high energy astrophysics. This contribution briefly touches on some of the highlights of the meeting, and discusses the important role that high-altitude laboratories can have in the future of these fundamental fields

  3. Precision timing measurements for high energy photons

    Science.gov (United States)

    Anderson, Dustin; Apreysan, Artur; Bornheim, Adi; Duarte, Javier; Newman, Harvey; Pena, Cristian; Ronzhin, Anatoly; Spiropulu, Maria; Trevor, Jason; Xie, Si; Zhu, Ren-Yuan

    2015-07-01

    Particle colliders operating at high luminosities present challenging environments for high energy physics event reconstruction and analysis. We discuss how timing information, with a precision on the order of 10 ps, can aid in the reconstruction of physics events under such conditions. We present calorimeter based timing measurements from test beam experiments in which we explore the ultimate timing precision achievable for high energy photons or electrons of 10 GeV and above. Using a prototype calorimeter consisting of a 1.7×1.7×1.7 cm3 lutetium-yttrium oxyortho-silicate (LYSO) crystal cube, read out by micro-channel plate photomultipliers, we demonstrate a time resolution of 33.5±2.1 ps for an incoming beam energy of 32 GeV. In a second measurement, using a 2.5×2.5×20 cm3 LYSO crystal placed perpendicularly to the electron beam, we achieve a time resolution of 59±11 ps using a beam energy of 4 GeV. We also present timing measurements made using a shashlik-style calorimeter cell made of LYSO and tungsten plates, and demonstrate that the apparatus achieves a time resolution of 54±5 ps for an incoming beam energy of 32 GeV.

  4. Precision timing measurements for high energy photons

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Dustin, E-mail: djanders@caltech.edu [California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125 (United States); Apreysan, Artur; Bornheim, Adi; Duarte, Javier; Newman, Harvey; Pena, Cristian [California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125 (United States); Ronzhin, Anatoly [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Spiropulu, Maria; Trevor, Jason; Xie, Si; Zhu, Ren-Yuan [California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125 (United States)

    2015-07-01

    Particle colliders operating at high luminosities present challenging environments for high energy physics event reconstruction and analysis. We discuss how timing information, with a precision on the order of 10 ps, can aid in the reconstruction of physics events under such conditions. We present calorimeter based timing measurements from test beam experiments in which we explore the ultimate timing precision achievable for high energy photons or electrons of 10 GeV and above. Using a prototype calorimeter consisting of a 1.7×1.7×1.7 cm{sup 3} lutetium–yttrium oxyortho-silicate (LYSO) crystal cube, read out by micro-channel plate photomultipliers, we demonstrate a time resolution of 33.5±2.1 ps for an incoming beam energy of 32 GeV. In a second measurement, using a 2.5×2.5×20 cm{sup 3} LYSO crystal placed perpendicularly to the electron beam, we achieve a time resolution of 59±11 ps using a beam energy of 4 GeV. We also present timing measurements made using a shashlik-style calorimeter cell made of LYSO and tungsten plates, and demonstrate that the apparatus achieves a time resolution of 54±5 ps for an incoming beam energy of 32 GeV.

  5. Studies of Pulsar Wind Nebula in the Supernova Remnant IC443: Preliminary Observations from the Chandra Data

    Science.gov (United States)

    Ariyibi, E. A.

    2009-10-01

    Preliminary observations of the Chandra data were made in order to study the Pulsar Wind Nebula in the Supernova Remnant IC443. The Chandra X-ray observatory short observation on IC443 was centred on 13 chip ACIS. The CIAO analytical programme was used for the data analysis. The data were separated into point source, with an energy range of 2.1 to 10.0 keV, and diffuse source with energy less than 2.1 Kev. The resulting spectra were fitted to a power law. The observed density numbers and the normalised counts of both the point source and the diffuse source were used to describe the X-ray source. Afin d'étudier la "Pulsar wind Nebula" dans le reste de la Supernova IC 443, nous avons mené une exploitation préliminaire des observations provenant du satellite spatiale Chandra. L'observation brêve de IC 443, par Chandra fut centrée sur les composantes du spectromètre identifiées par la séquence 13. Le programme informatique CIAO fut utilisé pour l'analyse des données. Les données furent groupées en sources ponctuelles, chacune ayant des énergies allant de 2.1 a 10.0 kev ; et en sources diffuses chacune avec des énergies de moins de 2.1 kev. Les spectres obtenus furent interpolés à l'aide de fonction puissance. La densité de flux ainsi que le décompte des particules induites au détecteur par le rayonnement provenant des sources ponctuelles et diffuses furent utilisés pour décrire la source de rayon-X.

  6. High energy bosons do not propagate

    Energy Technology Data Exchange (ETDEWEB)

    Kurkov, M.A., E-mail: Kurkov@na.infn.it [Dipartimento di Fisica, Università di Napoli Federico II (Italy); INFN, Sezione di Napoli (Italy); Lizzi, Fedele, E-mail: fedele.lizzi@na.infn.it [Dipartimento di Fisica, Università di Napoli Federico II (Italy); INFN, Sezione di Napoli (Italy); Departament de Estructura i Constituents de la Matèria, Institut de Ciéncies del Cosmos, Universitat de Barcelona, Barcelona, Catalonia (Spain); Vassilevich, Dmitri, E-mail: dvassil@gmail.com [CMCC, Universidade Federal do ABC, Santo André, S.P. (Brazil)

    2014-04-04

    We discuss the propagation of bosons (scalars, gauge fields and gravitons) at high energy in the context of the spectral action. Using heat kernel techniques, we find that in the high-momentum limit the quadratic part of the action does not contain positive powers of the derivatives. We interpret this as the fact that the two-point Green functions vanish for nearby points, where the proximity scale is given by the inverse of the cutoff.

  7. Detection of High-Energy Particles

    OpenAIRE

    Lohse, Thomas

    2006-01-01

    In spite of quantum field theoretical and philosophical problems to define the concept of elementary particles and to understand their localizability, particles become intuitively apparent by the traces they leave in particle detectors. Today, experimental particle physicists have reached a high degree of perfection in measuring and visualizing particles up to highest energies using a variety of high technology detection devices and sophisticated, powerful particle accel...

  8. High energy excitations in itinerant ferromagnets

    International Nuclear Information System (INIS)

    Itinerant magnets, those whose electrons move throughout the crystal, are described by band theory. Single particle excitations offer confirmation of band theory, but their description requires important corrections. The energetics of magnetism in iron and nickel is also described in band theory but requires complex bands. Magnetism above the critical temperature and the location of the critical temperature offer discriminants between the two major models of magnetism at high temperature and can be addressed by high energy excitations

  9. OER reduction with high-energy neutrons

    International Nuclear Information System (INIS)

    Further to work recently reported (Harrison et al Brit. J. Radiol.; 48:409 (1975)) that neutrons produced by 80 MeV deuterons bombarding a thick beryllium target have an OER = 1.3 +- 0.2 measured with Vicia seedlings, data are here presented of additional measurements with other high-energy neutron sources. Primary beams of 35 MeV deuterons, 66 MeV protons, 80 MeV deuterons and 101 MeV protons produced neutrons of 15, 22, 32 and 50 mean energy respectively. The neutron OER values, with standard errors, are shown as a function of mean neutron energy. The data suggest a significant reduction in OER as the mean energy is increased above 25 MeV. The implications of these results for cancer therapy are clear since the original rationale for clinical trials with neutrons was centred almost exclusively on reduced OER. (U.K.)

  10. Baryon number violation in high energy collisions

    International Nuclear Information System (INIS)

    We study the phenomenology of baryon number violation induced by electroweak instantons. We find that if the naive-instanton amplitudes were valid for arbitrarily high energies, the event rate at the SSC would be a few per hour, with a typical event consisting of 3 'primary' antileptons and 7 'primary' antiquark jets, accompanied by ≅ 85 electroweak gauge bosons, having a sharp threshold in the total sub-energy at about 17 TeV. We describe how to establish their electroweak-instanton-induced origin. The naive instanton approximation is known to overestimate the rate for these processes, so this work focusses attention on the need for more accurate calculations, and for a calculational method which is appropriate when the energy of the initial particles is above the sphaleron energy. (orig.)

  11. High Energy Studies of Pulsar Wind Nebulae

    CERN Document Server

    Slane, Patrick

    2008-01-01

    The extended nebulae formed as pulsar winds expand into their surroundings provide information about the composition of the winds, the injection history from the host pulsar, and the material into which the nebulae are expanding. Observations from across the electromagnetic spectrum provide constraints on the evolution of the nebulae, the density and composition of the surrounding ejecta, the geometry of the systems, the formation of jets, and the maximum energy of the particles in the nebulae. Here I provide a broad overview of the structure of pulsar wind nebulae, with specific examples that demonstrate our ability to constrain the above parameters. The association of pulsar wind nebulae with extended sources of very high energy gamma-ray emission are investigated, along with constraints on the nature of such high energy emission.

  12. ACCELERATING POLARIZED PROTONS TO HIGH ENERGY.

    Energy Technology Data Exchange (ETDEWEB)

    BAI, M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; BEEBE-WANG, J.; BLASKIEWICZ, M.; BRAVAR, A.; BRENNAN, J.M.; BRUNO, D.; BUNCE, G.; ET AL.

    2006-10-02

    The Relativistic Heavy Ion Collider (RHIC) is designed to provide collisions of high energy polarized protons for the quest of understanding the proton spin structure. Polarized proton collisions at a beam energy of 100 GeV have been achieved in RHIC since 2001. Recently, polarized proton beam was accelerated to 250 GeV in RHIC for the first time. Unlike accelerating unpolarized protons, the challenge for achieving high energy polarized protons is to fight the various mechanisms in an accelerator that can lead to partial or total polarization loss due to the interaction of the spin vector with the magnetic fields. We report on the progress of the RHIC polarized proton program. We also present the strategies of how to preserve the polarization through the entire acceleration chain, i.e. a 200 MeV linear accelerator, the Booster, the AGS and RHIC.

  13. Virtual compton scattering at high energy

    International Nuclear Information System (INIS)

    The virtual Compton scattering (VCS) reaction (ep→e'p' gamma) at high energy will provide new information on the proton structure. The invariant momentum transfer (t=(q-q')2) de pendence of high energy VCS is related to the flavor dependent vector and axial-vector form factors of the the proton. Thus VCS can provide information that is complementary to parity violating electron scattering measurements. For small t and large Q2, VCS generalizes the structure functions of deep inelastic lepton scattering. These generalized structure functions have a sum rule which yields the net contribution of quark spin and orbital angular momentum to the proton spin. A large acceptance detector such as the MEMUS design, capable of running at a luminosity 1035/cm2/sec at incident electron energies from 10 to 30 GeV can measure the VCS process in a broad and exciting kinematic range. (orig.)

  14. Ultra High Energy Cosmic Rays: Strangelets?

    Institute of Scientific and Technical Information of China (English)

    徐仁新; 吴飞

    2003-01-01

    The conjecture that ultra-high-energy cosmic rays (UHECRs) are actually strangelets is discussed. Besides the reason that strangelets can do as cosmic rays beyond the Greisen-Zatsepin-Kuzmin-cutoff, another argument to support the conjecture is addressed by the study of formation of Te V-scale microscopic black holes when UHECRs bombarding bare strange stars. It is proposed that the exotic quark surface of a bare strange star could be an effective astro-laboratory in the investigations of the extra dimensions and of the detection of ultra-high-energy neutrino fluxes. The flux of neutrinos (and other point-like particles) with energy larger than 2.3 × 1020 eV could be expected to be smaller than 10-26 cm-2 s-1 if there are two extra spatial dimensions.

  15. CHANDRA AND XMM OBSERVATIONS OF THE COMPOSITE SUPERNOVA REMNANT G327.1-1.1

    International Nuclear Information System (INIS)

    We present new X-ray imaging and spectroscopy of a composite supernova remnant G327.1-1.1 using the Chandra and XMM-Newton X-ray observatories. G327.1-1.1 has an unusual morphology consisting of a symmetric radio shell and an off center nonthermal component that indicates the presence of a pulsar wind nebula (PWN). Radio observations show a narrow finger of emission extending from the PWN structure toward the northwest. X-ray studies with ASCA, ROSAT, and BeppoSAX revealed elongated extended emission and a compact source at the tip of the finger that may be coincident with the actual pulsar. The high resolution Chandra observations provide new insight into the structure of the inner region of the remnant. The images show a compact source embedded in a cometary structure from which a trail of X-ray emission extends in the southeast direction. The Chandra images also reveal two prong-like structures that appear to originate from the vicinity of the compact source and extend into a large bubble that is oriented in the northwest direction, opposite from the bright radio PWN. The emission from the entire radio shell is detected in the XMM data and can be characterized by a thermal plasma model with a temperature of ∼ 0.3 keV, which we use to estimate the physical properties of the remnant. The peculiar morphology of G327.1-1.1 may be explained by the emission from a moving pulsar and a relic PWN that has been disrupted by the reverse shock.

  16. Astrophysics, cosmology and high energy physics

    International Nuclear Information System (INIS)

    A brief survey is given of some topics in astrophysics and cosmology, with special emphasis on the inter-relation between the properties of the early Universe and recent ideas in high energy physics, and on simple order-of-magnitude arguments showing how the scales and dimensions of cosmic phenomena are related to basic physical constants. (orig.)

  17. DOE is Funding Young High- Energy Physicists

    Science.gov (United States)

    Waff, Craig B.

    1978-01-01

    Reports on some recommendations made by a subpanel on High Energy Physics Manpower for the purpose of employing additional physicists through the transfer of some postdoctoral monies to produce long-term positions, and the creation of a five-year national fellowship program. (GA)

  18. Theoretical and experimental high energy physics

    International Nuclear Information System (INIS)

    This report discusses experimental and theoretical work in High Energy Physics. Some topics discussed are: quantum field theory; supersymmetry; cosmology; superstring model; relic photinos; inflationary universe; dark matter; standard model; supernovae; semileptonic decay; quantum Langevin equation; underground neutrino detection at Soudan; strange quark systems; cosmic ray detection; superconducting super collider detectors; and studies of direct photon production

  19. Wigner Functions in High Energy Physics

    CERN Document Server

    Csörgö, T

    2004-01-01

    Recent developments are (meta)reviewed in the applications of Wigner functions to describe the observed single particle spectra and two-particle Bose-Einstein (or Hanbury Brown -- Twiss) correlations in high energy particle and nuclear physics, with examples from hadron-proton and Pb + Pb collisions at CERN SPS.

  20. Indiana University High Energy Physics, Task A

    International Nuclear Information System (INIS)

    This report discusses research in High Energy Physics under the following experiments: Meson spectroscopy at BNL; dimuon production at FNAL; the DO collider experiment at FNAL; the Mark II experiment at SLC and PEP; the OPAL experiment at CERN; and the superconducting supercollider

  1. Phenomenology of extragalactic high energy sources

    International Nuclear Information System (INIS)

    The course is divided in two main bodies: Chapters 1 and 2 deal with some of the fundamental properties of the production of high energy radiation, while chapter 3 is devoted to the observations of active galaxies; chapter 4 presents the X-ray emission of clusters of galaxies and the sky background

  2. Quark deconfinement and high energy nuclear collisions

    International Nuclear Information System (INIS)

    Statistical QCD predicts that with increasing density, strongly interacting matter will undergo a transition to a plasma of deconfined quarks and gluons. High energy heavy ion collisions are expected to permit experimental studies of this transition and of the predicted new state of matter. 22 refs., 6 figs

  3. ACCELERATION FOR A HIGH ENERGY MUON COLLIDER

    International Nuclear Information System (INIS)

    The authors describe a method for designing the acceleration systems for a muon collider, with particular application and examples for a high energy muon collider. This paper primarily concentrates on design considerations coming from longitudinal motion, but some transverse issues are briefly discussed

  4. Density Estimation Trees in High Energy Physics

    CERN Document Server

    Anderlini, Lucio

    2015-01-01

    Density Estimation Trees can play an important role in exploratory data analysis for multidimensional, multi-modal data models of large samples. I briefly discuss the algorithm, a self-optimization technique based on kernel density estimation, and some applications in High Energy Physics.

  5. On high energy scattering inside gravitational backgrounds

    OpenAIRE

    Nastase, Horatiu

    2004-01-01

    We analyze the high energy scattering inside gravitational backgrounds using 't Hooft's formalism. The scattering is equivalent to geodesic shifts accross Aichelburg-Sexl waves inside the gravitational backgrounds. We find solutions for A-S waves inside various backgrounds and analyze them.

  6. SPACE: More high energy gamma sources

    International Nuclear Information System (INIS)

    Ultra high energy (TeV) gamma rays have been observed by an international team working at the Whipple observatory in Arizona. These also correlate with some of the signals seen by NASA's big Gamma Ray Observatory (GRO) satellite launched by the Space Shuttle Atlantis last year

  7. Ultra- and extremely high energy neutrino astronomy

    OpenAIRE

    I. SokalskiINFN, Bari

    2014-01-01

    Scientific motivations for ultra- and extremely high energy neutrino astronomy are considered. Sources and expected fluxes of EHE/UHE neutrinos are briefly discussed. Operating and planned experiments on astrophysical neutrino detection are reviewed focusing on deep underwater/ice Cherenkov neutrino telescopes.

  8. High-Energy Gamma and Neutrino Astronomy

    OpenAIRE

    Bergstrom, L.

    1997-01-01

    An overview is given of high-energy gamma-ray and neutrino astronomy, emphasizing the links between the two fields. With several new large detectors just becoming operational, the TeV gamma-ray and neutrino sky will soon be surveyed with unprecedented sensitivity.

  9. SU(5) at very high energies

    International Nuclear Information System (INIS)

    By exhibiting the relationship between the full SU(5) theory in the unitary gauge and the underlying Higgs-Goldstone system in the t'Hooft-Feynman gauge the high energy limits of amplitudes (involving gauge and Higgs bosons) can be calculated easily. As an application tree unitarity bounds on Higgs parameters and masses are discussed. (Author)

  10. Studies in theorectical high energy particles physics

    International Nuclear Information System (INIS)

    This paper discusses the research being done at the University of Illinois in theoretical high energy physics. Some areas discussed are string models, collider physics, symmetries in gauge theories, sigma model, radiative decay of mesons, supersymmetry, superconducting, and hydroproduction of charm

  11. Theoretical and experimental high energy physics

    International Nuclear Information System (INIS)

    This report discusses the following topics: The Soudan enterprise; study of strange quarks at Fermilab; direct photons at Fermilab; the Brookhaven programs; AMY and CLEO: studies of e+e- annihilations; cosmic ray studies with the DO muon chamber; progress report on HEP computer upgrade; muon triggering and reconstruction at SSC; and, theoretical high energy physics

  12. PC database for high energy preprint collections

    International Nuclear Information System (INIS)

    We describe a microcomputer database used by the high energy group to keep track of preprints in our collection. It is used as a supplement to the SLAC-SPIRES database to retrieve preprints on hand. This was designed as a low overhead system for a small group

  13. Wigner Functions in High Energy Physics

    OpenAIRE

    Csorgo, T.

    2003-01-01

    Recent developments are (meta)reviewed in the applications of Wigner functions to describe the observed single particle spectra and two-particle Bose-Einstein (or Hanbury Brown -- Twiss) correlations in high energy particle and nuclear physics, with examples from hadron-proton and Pb + Pb collisions at CERN SPS.

  14. Resume: networking in high energy physics

    International Nuclear Information System (INIS)

    Networking in High Energy Physics covers communications inside the experiment and internationally. Inside the experiment the need for agreed 'codes of practice' is now accepted. Within Europe it is accepted that a common infrastructure based on the use of the ISO OSI protocols should be used. In the USA a community initiative has been proposed. The background to these approaches is discussed. (author)

  15. Chandra and XMM-Newton study of the supernova remnant Kes 73 hosting the magnetar 1E 1841-045

    International Nuclear Information System (INIS)

    We present a Chandra and XMM-Newton study of the supernova remnant (SNR) Kes 73 hosting the anomalous X-ray pulsar 1E 1841–045. The Chandra image reveals clumpy structures across the remnant with enhanced emission along the western rim. The X-ray emission fills the radio shell and spatially correlates with the infrared image. The global X-ray spectrum is described by a two-component thermal model with a column density N H = 2.6−0.3+0.4×1022 cm–2 and a total luminosity of LX = 3.3−0.5+0.7×1037 erg s–1 (0.5-10 keV, at an assumed distance of 8.5 kpc). The soft component is characterized by a temperature kTs = 0.5−0.2+0.1 keV, a high ionization timescale, and enhanced Si and S abundances, suggesting emission that is dominated by shocked ejecta. The hard component has a temperature kTh = 1.6−0.7+0.8 keV, a relatively low ionization timescale, and mostly solar abundances suggesting emission that is dominated by interstellar/circumstellar shocked material. A spatially resolved spectroscopy study reveals no significant variations in the spectral properties. We infer an SNR age ranging between 750 yr and 2100 yr, an explosion energy of 3.0−1.8+2.8×1050 erg and a shock velocity of (1.2 ± 0.3)×103 km s–1 (under the Sedov phase assumption). We also discuss the possible scenario for Kes 73 expanding into the late red-supergiant wind phase of its massive progenitor. Comparing the inferred metal abundances to core-collapse nucleosynthesis model yields, we estimate a progenitor mass ≳20 M ☉, adding a candidate to the growing list of highly magnetized neutron stars proposed to be associated with very massive progenitors.

  16. Study of the energy response of high pressure ionization chamber for high energy gamma-ray

    Institute of Scientific and Technical Information of China (English)

    HUA Zheng-Dong; XU Xun-Jiang; WANG Jian-Hua; LIU Shu-Dong; LI Jian-Ping

    2008-01-01

    The energy response calibration of the commonly used high pressure ionization chamber is very difficult to obtain when the gamma-ray energy is more than 3 MeV.In order to get the calibration of the higher part of the high pressure ionization chamber,we use the Fluka Monte Carlo program to perfclrm the energy response in both the spherical and the cylindrical high pressure ionization chamber which are full of argon gas.The results compared with prior study when the gamma-ray energy is less than 1.25 MeV.Our result of Monte Carlo calculation shows agreement with those obtained by measurement within the uncertainty of the respective methods.The calculation of this study is significant for the high pressure ionization chamber to measure the high energy gamma-ray.

  17. Highly Compressed Ion Beam for High Energy Density Science

    International Nuclear Information System (INIS)

    The Heavy Ion Fusion Virtual National Laboratory is developing the intense ion beams needed to drive matter to the High Energy Density regimes required for Inertial Fusion Energy and other applications. An interim goal is a facility for Warm Dense Matter studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach they are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto thin target ''foils,'' which may in fact be foams with mean densities 1% to 10% of solid. This approach complements that being pursued at GSI Darmstadt, wherein high-energy ion beams deposit a small fraction of their energy in a cylindrically target. They present the beam requirements for Warm Dense Matter experiments. The authors discuss neutralized drift compression and final focus experiments and modeling. They describe suitable accelerator architectures based on Drift-Tube Linac, RF, single-gap, Ionization-Front Accelerator, and Pulse-Line Ion Accelerator concepts. The last of these is being pursued experimentally. Finally, they discuss plans toward a user facility for target experiments

  18. Highly Compressed Ion Beams for High Energy Density Science

    CERN Document Server

    Friedman, Alex; Briggs, Richard J; Callahan, Debra; Caporaso, George; Celata, C M; Davidson, Ronald C; Faltens, Andy; Grant-Logan, B; Grisham, Larry; Grote, D P; Henestroza, Enrique; Kaganovich, Igor D; Lee, Edward; Lee, Richard; Leitner, Matthaeus; Nelson, Scott D; Olson, Craig; Penn, Gregory; Reginato, Lou; Renk, Tim; Rose, David; Sessler, Andrew M; Staples, John W; Tabak, Max; Thoma, Carsten H; Waldron, William; Welch, Dale; Wurtele, Jonathan; Yu, Simon

    2005-01-01

    The Heavy Ion Fusion Virtual National Laboratory (HIF-VNL) is developing the intense ion beams needed to drive matter to the High Energy Density (HED) regimes required for Inertial Fusion Energy (IFE) and other applications. An interim goal is a facility for Warm Dense Matter (WDM) studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach we are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto thin target "foils," which may in fact be foams or "steel wool" with mean densities 1% to 100% of solid. This approach complements that being pursued at GSI, wherein high-energy ion beams deposit a small fraction of their energy in a cylindrical target. We present the requirements for warm dense matter experiments, and describe suitable accelerator concepts, including novel broadband traveling wave pulse-line, drift-tube linac, RF, and single-gap approa...

  19. Cross-calibration of the CCD Instruments onboard the Chandra, Suzaku, Swift, and XMM-Newton Observatories using 1E 0102.2-7219

    Science.gov (United States)

    Plucinsky, Paul P.; Beardmore, Andrew P.; Foster, Adam; Guainazzi, Matteo; Haberl, Frank; Miller, Eric; Pollock, Andrew; Sembay, Steve; Stuhlinger, Martin

    2016-04-01

    We report on our continuing efforts to compare the time-dependent calibrations of the current generation of CCD instruments onboard the Chandra, Suzaku, Swift, and XMM-Newton observatories using the brightest supernova remnant in the Small Magellanic Cloud, 1E 0102.2-7219 (hereafter E0102). This calibration is a function of time due to the effects of radiation damage on the CCDs and the accumulation of a contamination layer on the filters or CCDs. We desire a simple comparison of the absolute effective areas in the 0.5-1.0 keV bandpass. The spectrum of E0102 has been well-characterized using the RGS grating instrument on XMM-Newton and the HETG grating instrument on Chandra. We have developed an empirical model for E0102 that includes Gaussians for the identified lines, two absorption components, and two continuum components with different temperatures. In our fits, the model is highly constrained in that only the normalizations of the four brightest line complexes (the O VII triplet, the O VIII Ly-alpha line, the Ne IX triplet, and the Ne X Ly-alpha line) and an overall normalization are allowed to vary. In our previous study, we found that based on observations early in the missions, most of the fitted line normalizations agreed to within +/- 10%. We have now expanded this study to include more recent data from these missions using the latest calibration updates and we will report on the current level of agreement amongst these instruments. This work is based on the activities of the International Astronomical Consortium for High Energy Calibration (IACHEC).

  20. Pulse switching for high energy lasers

    Science.gov (United States)

    Laudenslager, J. B.; Pacala, T. J. (Inventor)

    1981-01-01

    A saturable inductor switch for compressing the width and sharpening the rise time of high voltage pulses from a relatively slow rise time, high voltage generator to an electric discharge gas laser (EDGL) also provides a capability for efficient energy transfer from a high impedance primary source to an intermediate low impedance laser discharge network. The switch is positioned with respect to a capacitive storage device, such as a coaxial cable, so that when a charge build-up in the storage device reaches a predetermined level, saturation of the switch inductor releases or switches energy stored in the capactive storage device to the EDGL. Cascaded saturable inductor switches for providing output pulses having rise times of less than ten nanoseconds and a technique for magnetically biasing the saturable inductor switch are disclosed.

  1. Intermediate/high energy nuclear physics

    International Nuclear Information System (INIS)

    Progress during the last year is reviewed under the following topics: relativistic hadron--nucleus and nucleus--nucleus collisions (heavy meson production, photon production and fragmentation functions--direct photon production with the QCM and photon fragmentation functions, Cronin efffect and multiple scattering, effective nuclear parton distributions); solving quantum field theories in nonperturbative regime; light-front dynamics and high-spin states (soft form factor of the pion and nucleon for transverse and longitudinal momentum transfers, light front spinors for high-spin objects); high-energy spin physics; relativistic wave equations, quarkonia, and e+e- resonances; associated production of Higgs boson at collider energies, and microscopic nuclear many-body theory and reactions. 135 refs

  2. Semiconductor High-Energy Radiation Scintillation Detector

    CERN Document Server

    Kastalsky, A; Spivak, B

    2006-01-01

    We propose a new scintillation-type detector in which high-energy radiation produces electron-hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The key issue is how to make the semiconductor essentially transparent to its own infrared light, so that photons generated deep inside the semiconductor could reach its surface without tangible attenuation. We discuss two ways to accomplish this, one based on doping the semiconductor with shallow impurities of one polarity type, preferably donors, the other by heterostructure bandgap engineering. The proposed semiconductor scintillator combines the best properties of currently existing radiation detectors and can be used for both simple radiation monitoring, like a Geiger counter, and for high-resolution spectrography of the high-energy radiation. The most important advantage of the proposed detector is its fast response time, about 1 ns, essentially limited only by the recombi...

  3. Non-critical strings at high energy

    International Nuclear Information System (INIS)

    We consider scattering amplitudes in non-critical string theory of N external states in the limit where the energy of all external states is large compared to the string tension. We argue that the amplitudes are naturally complex analytic in the matter central charge c and we propose to define the amplitudes for arbitrary value of c by analytic continuation. We show that the high energy limit is dominated by a saddle point that can be mapped onto an equilibrium electrostatic energy configuration of an assembly of N pointlike (Minkowskian) charges, together with a density of charges arising from the Liouville field. We argue that the Liouville charges accumulate on segments of curves, and produce quadratic branch cuts on the world-sheet. The electrostatics problem is solved for string tree level in terms of hyper-elliptic integrals and is given explicitly for three- and four-point functions. We show that the high energy limit should behave in a string-like fashion with exponential dependence on the energy scale for generic values of c. (orig.)

  4. Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy gamma-rays

    CERN Document Server

    Aleksić, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; de Almeida, U Barres; Barrio, J A; González, J Becerra; Bednarek, W; Berger, K; Bernardini, E; Biland, A; Blanch, O; Bock, R K; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Fidalgo, D Carreto; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Mendez, C Delgado; Doert, M; Domínguez, A; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Farina, E; Ferenc, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; López, R J García; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Giavitto, G; Godinović, N; Muñoz, A González; Gozzini, S R; Hadamek, A; Hadasch, D; Herrero, A; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Kadenius, V; Kellermann, H; Knoetig, M L; Krause, J; Kushida, J; La Barbera, A; Lelas, D; Lewandowska, N; Lindfors, E; Lombardi, S; López, M; López-Coto, R; López-Oramas, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martínez, M; Mazin, D; Menzel, U; Meucci, M; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Niedzwiecki, A; Nilsson, K; Nowak, N; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Partini, S; Persic, M; Prada, F; Moroni, P G Prada; Prandini, E; Preziuso, S; Puljak, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Garcia, J Rodriguez; Rügamer, S; Saggion, A; Saito, K; Salvati, M; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamatescu, V; Stamerra, A; Steinbring, T; Storz, J; Sun, S; Surić, T; Takalo, L; Tavecchio, F; Temnikov, P; Terzić, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Uellenbeck, M; Vogler, P; Wagner, R M; Zandanel, F; Zanin, R; Balmaverde, B; Kataoka, J; Rekola, R; Takahashi, Y; .,

    2013-01-01

    The radio galaxy NGC 1275, recently identified as a very high energy (VHE, >100 GeV) gamma-ray emitter by MAGIC, is one of the few non-blazar AGN detected in the VHE regime. In order to better understand the origin of the gamma-ray emission and locate it within the galaxy, we study contemporaneous multi-frequency observations of NGC 1275 and model the overall spectral energy distribution (SED). We analyze unpublished MAGIC observations carried out between Oct. 2009 and Feb. 2010, and the already published ones taken between Aug. 2010 and Feb. 2011. We study the multi-band variability and correlations analyzing data of Fermi-LAT (0.1 - 100 GeV), Chandra (X-ray), KVA (optical) and MOJAVE (radio) taken during the same period. Using custom Monte Carlo simulations corresponding to early MAGIC stereo data, we detect NGC 1275 also in the earlier MAGIC campaign. The flux level and energy spectra are similar to the results of the second campaign. The monthly light curve above 100 GeV shows a hint of variability at the...

  5. Proposal for a High Energy Nuclear Database

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D A; Vogt, R

    2005-03-31

    The authors propose to develop a high-energy heavy-ion experimental database and make it accessible to the scientific community through an on-line interface. This database will be searchable and cross-indexed with relevant publications, including published detector descriptions. Since this database will be a community resource, it requires the high-energy nuclear physics community's financial and manpower support. This database should eventually contain all published data from Bevalac, AGS and SPS to RHIC and CERN-LHC energies, proton-proton to nucleus-nucleus collisions as well as other relevant systems, and all measured observables. Such a database would have tremendous scientific payoff as it makes systematic studies easier and allows simpler benchmarking of theoretical models to a broad range of old and new experiments. Furthermore, there is a growing need for compilations of high-energy nuclear data for applications including stockpile stewardship, technology development for inertial confinement fusion and target and source development for upcoming facilities such as the Next Linear Collider. To enhance the utility of this database, they propose periodically performing evaluations of the data and summarizing the results in topical reviews.

  6. High-energy fluxes of atmospheric neutrinos

    CERN Document Server

    Sinegovskaya, T S; Sinegovsky, S I

    2013-01-01

    High-energy neutrinos from decays of mesons, produced in collisions of cosmic ray particles with air nuclei, form unavoidable background for detection of astrophysical neutrinos. More precise calculations of the high-energy neutrino spectrum are required since measurements in the IceCube experiment reach the intriguing energy region where a contribution of the prompt neutrinos and/or astrophysical ones should be discovered. Basing on the referent hadronic models QGSJET II-03, SIBYLL 2.1, we calculate high-energy spectra, both of the muon and electron atmospheric neutrinos, averaged over zenith-angles. The computation is made using three parameterizations of cosmic ray spectra which include the knee region. All calculations are compared with the atmospheric neutrino measurements by Frejus and IceCube. The prompt neutrino flux predictions obtained with thequark-gluon string model (QGSM) for the charm production by Kaidalov & Piskunova do not contradict to the IceCube measurements and upper limit on the astr...

  7. Advances in High Energy Materials (Review Paper

    Directory of Open Access Journals (Sweden)

    U. R. Nair

    2010-03-01

    Full Text Available Research and development efforts for realizing higher performance levels of high energy materials (HEMs are continued unabated all over the globe. Of late, it is becoming increasingly necessary to ensure that such materials are also eco-friendly. This has provided thrust to research in the area of force multiplying HEMs and compounds free from pollution causing components. Enhancement of the performance necessitates introduction of strained structure or increase in oxygen balance to achieve near stoichiometry. The search for environment friendly molecules is focused on chlorine free propellant compositions and lead free primary explosives. Energetic polymers offer added advantage of partitioning of energy and thus not necessitating the concentration of only solid components (HEMs and metal fuels in the formulations, to achieve higher performance, thereby leading to improvement in energetics without adversely affecting the processability and mechanical properties. During recent times, research in the area of insensitive explosives has received impetus particularly with the signature of STANAG. This paper gives a review of the all-round advances in the areas of HEMs encompassing oxidizers, high-energy dense materials, insensitive high-energy materials, polymers and plasticizers. Selected formulations based on these materials are also included.Defence Science Journal, 2010, 60(2, pp.137-151, DOI:http://dx.doi.org/10.14429/dsj.60.327

  8. High energy neutral atoms from high intensity laser plasma interaction

    International Nuclear Information System (INIS)

    Interaction of a high intensity laser with solid targets leads to acceleration of ions from the surface of the target. Ion acceleration is governed by electron dynamics at the target vacuum interface setting up a charge separation. This electron cloud near the target interface can also provide a neutralizing background for ions that have been accelerated. The accelerated ions are thus detected as a high energy neutral atom on a detector. Further, due to the inherent contrast profile of high intensity lasers a pre-plasma is almost always formed and neutral atoms can be detected. The ion and neutral atom energies are measured by a Thomson parabola spectrometer coupled with a 'time of flight' measurement. The neutral atom energies are obtained from the time of flight. The TIFR 20TW laser with an intensity contrast 10-5 was used to carry out the experiment. Defocusing the target led to a 2 fold increase in the neutral atom yield suggesting the role of the pre-plasma. Using a high contrast laser we attempt to tune the recombination dynamics for efficient neutralization of ions by using a controlled pre-plasma. (author)

  9. High energy hadron-hadron collisions

    International Nuclear Information System (INIS)

    Results of a study on high energy collision with the geometrical model are summarized in three parts: (i) the elastic hadron-hadron collision, (ii) the inelastic hadron-hadron collision, and (iii) the e+e- annihilation. For elastic collisions, a simple expression for the proton matter distribution is proposed which fits well the elastic bar pp scattering from ISR to S bar ppS energies within the geometrical model. The proton form factor is of the dipole form with an energy-dependent range parameter. The bar pp elastic differential cross section at Tevatron energies obtained by extrapolation is in good agreement with experiments. For multiparticle emission processes a unified physical picture for hadron-hadron and e+e- collisions was proposed. A number of predictions were made, including the one that KNO-scaling does not obtain for e+e- two-jet events. An extension of the considerations within the geometrical model led to a theory of the momentum distributions of the outgoing particles which are found in good agreement with current experimental data. Extrapolations of results to higher energies have been made. The cluster size of hadrons produced in e+e- annihilation is found to increase slowly with energy

  10. Automatic Energy Schemes for High Performance Applications

    Energy Technology Data Exchange (ETDEWEB)

    Sundriyal, Vaibhav [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    Although high-performance computing traditionally focuses on the efficient execution of large-scale applications, both energy and power have become critical concerns when approaching exascale. Drastic increases in the power consumption of supercomputers affect significantly their operating costs and failure rates. In modern microprocessor architectures, equipped with dynamic voltage and frequency scaling (DVFS) and CPU clock modulation (throttling), the power consumption may be controlled in software. Additionally, network interconnect, such as Infiniband, may be exploited to maximize energy savings while the application performance loss and frequency switching overheads must be carefully balanced. This work first studies two important collective communication operations, all-to-all and allgather and proposes energy saving strategies on the per-call basis. Next, it targets point-to-point communications to group them into phases and apply frequency scaling to them to save energy by exploiting the architectural and communication stalls. Finally, it proposes an automatic runtime system which combines both collective and point-to-point communications into phases, and applies throttling to them apart from DVFS to maximize energy savings. The experimental results are presented for NAS parallel benchmark problems as well as for the realistic parallel electronic structure calculations performed by the widely used quantum chemistry package GAMESS. Close to the maximum energy savings were obtained with a substantially low performance loss on the given platform.

  11. Solar electric energy supply at high altitude

    Energy Technology Data Exchange (ETDEWEB)

    Knaupp, W.; Mundschau, E. [Zentrum fur Sonnenenergie- und Wasserstoff-Forschung (ZSW), Ulm (Germany)

    2004-04-01

    Solar-hydrogen systems were analyzed regarding their usability as energy supply system for high altitude platforms. In a first step for an assessment of solar and photovoltaic resources near-ground spectral transmittances of atmosphere were extended with simplified height correction functions to achieve spectral irradiance descriptions versus atmospheric height up to 25 km. The influence of atmospheric height to different solar cell technologies regarding electrical performance was quantified at some examples for the aspect of spectral distribution with the help of the introduced spectral height factor. The main attention during analysis of the whole solar-hydrogen energy system was directed to characteristics of current or near term available technology. Specific power weight of photovoltaic system, electrolyzer, fuel cell and gas tanks and their dependence on operation mode and power range were assessed. A pre-design of a solar-hydrogen energy system was carried out for an airship (volume 580,000 m3) withstanding continuous wind speeds up to {approx} 130 km/h. The calculated coverage ratio of photovoltaic and load share of energy system mark the frame of usability. Depending on the airship size, shape and other external boundary conditions the total electrical energy demand could be covered by a solar-hydrogen energy system of current or near term technology for full year operation. However further investigations are necessary regarding e.g. further mass reductions. (author)

  12. Updated phase coherent timing solution of the isolated neutron star RX J0720.4-3125 using recent XMM-Newton and Chandra observations

    OpenAIRE

    Hohle, M. M.; Haberl, F.; Vink, J.; Turolla, R.; Zane, S.; de Vries, C. P.; Méndez, M.

    2010-01-01

    Aims. Since the last phase coherent timing solution of the nearby radio-quiet isolated neutron star RXJ0720.4−3125 six new XMM-Newton and three Chandra observations were carried out. The phase coherent timing solutions from previous authors were performed without restricting to a fixed energy band. However, we recently showed that the phase residuals are energy dependent, and thus phase coherent solutions must be computed referring always to the same energy band. Methods. We updated the phase...

  13. High energy photons production in nuclear reactions

    International Nuclear Information System (INIS)

    Hard photon production, in nucleus-nucleus collisions, were studied at beam energies between 10 and 125 MeV. The main characteristics of the photon emission are deduced. They suggest that the neutron-proton collisions in the early stage of the reaction are the main source of high energy gamma-rays. An overview of the theoretical approaches is given and compared with experimental results. Theoretical attempts to include the contribution of charged pion exchange currents to photon production, in calculations of proton-nucleus-gamma and nucleus-nucleus-gamma reactions, showed suitable fitting with experimental data

  14. A high energy photon polarimeter for astrophysics

    OpenAIRE

    Eingorn, Maxim; Fernando, Lakma; Vlahovic, Branislav; Ilie, Cosmin; Wojtsekhowski, Bogdan; Urciuoli, Guido Maria; De Persio, Fulvio; Meddi, Franco

    2015-01-01

    A high-energy photon polarimeter for astrophysics studies in the energy range from 20 MeV to 1000 MeV is considered. The proposed concept uses a stack of silicon micro-strip detectors where they play the roles of both a converter and a tracker. The purpose of this paper is to outline the parameters of such a polarimeter and to estimate the productivity of measurements. Our study supported by a Monte Carlo simulation shows that with a one-year observation period the polarimeter will provide 6%...

  15. Opportunities for high wind energy penetration

    DEFF Research Database (Denmark)

    Tande, J.O.; Hansen, J.C.

    1997-01-01

    Wind power is today a mature technology, which at windy locations, is economically competitive to conventional power generation technologies. This and growing global environmental concerns have led governments to encourage and plan for wind energy development, a typical aim being 10% of electricity...... analyses conclude that expanding to even above 15% wind energy penetration in the Cape Verde power systems is economical. Worldwide, numerous locations with favorable wind conditions and power systems similar to the Capeverdean provide good opportunities for installing wind farms and achieving high wind...

  16. Stochastic aspects of QCD at high energy

    International Nuclear Information System (INIS)

    I present a pedagogical discussion of the influence of particle number fluctuations on the high energy evolution in QCD. I emphasize the event-by-event description and the correspondence with the problem of ''fluctuating pulled fronts'' in statistical physics. I explain that the correlations generated by fluctuations reduce the phase space for BFKL evolution up to saturation. Because of that, the evolution slows down, and the rate for the energy increase of the saturation momentum is considerably decreased. I discuss the diagrammatic interpretation of the particle number fluctuations in terms of pomeron loops. (orig.)

  17. Consistency of Hitomi, XMM-Newton and Chandra 3.5 keV data from Perseus

    CERN Document Server

    Conlon, Joseph P; Jennings, Nicholas; Krippendorf, Sven; Rummel, Markus

    2016-01-01

    Hitomi observations of Perseus with the Soft X-ray Spectrometer (SXS) provide a high-resolution look at the 3.5 keV feature reported by multiple groups in the Perseus cluster. The Hitomi spectrum -- which involves the sum of diffuse cluster emission and the point-like central Active Galactic Nucleus (AGN) -- does not show any excess at $E \\sim 3.5 {\\rm keV}$, giving an apparent inconsistency with previous observations of excess diffuse emission. We point out that 2009 Chandra data reveals a strong dip in the AGN spectrum at $E = (3.54 \\pm 0.02) {\\rm keV}$ (cluster frame) -- the identical energy to the diffuse excess observed by XMM-Newton. Scaling this dip to the 2016 AGN luminosity and adding it to the diffuse XMM-Newton excess, this predicts an overall dip in the SXS field of view of $(-7.7 \\pm 4.6) \\times 10^{-6} \\, {\\rm ph} \\, {\\rm cm}^{-2} \\, {\\rm s}^{-1}$ at $E= 3.54$ keV -- a precise match to the Hitomi data when broadened by the dark matter virial velocity. We describe models of Fluorescent Dark Matte...

  18. Corona, Jet, and Relativistic Line Models for Suzaku/RXTE/Chandra-HETG Observations of the Cygnus X-1 Hard State

    CERN Document Server

    Nowak, Michael A; Trowbridge, Sarah N; Markoff, Sera B; Wilms, Joern; Pottschmidt, Katja; Coppi, Paolo; Maitra, Dipankar; Davis, John E; Tramper, Frank

    2010-01-01

    Using Suzaku and the Rossi X-ray Timing Explorer, we have conducted a series of four simultaneous observations of the galactic black hole candidate Cyg X-1 in what were historically faint and spectrally hard low states. Additionally, all of these observations occurred near superior conjunction with our line of sight to the X-ray source passing through the dense phases of the focused wind from the mass donating secondary. One of our observations was also simultaneous with observations by the Chandra-High Energy Transmission Grating. These latter spectra are crucial for revealing the ionized absorption due to the secondary's focused wind. Such absorption is present and must be accounted for in all four spectra. These simultaneous data give an unprecedented view of the 0.8-300 keV spectrum of Cyg X-1, and hence bear upon both corona and X-ray emitting jet models of black hole hard states. Three models fit the spectra well: coronae with thermal or mixed thermal/non-thermal electron populations, and jets. All thre...

  19. X-ray spectroscopy of the ADC source X1822-371 with Chandra and XMM-Newton

    CERN Document Server

    Iaria, R; D'Aì, A; Burderi, L; Mineo, T; Riggio, A; Papitto, A; Robba, N R

    2012-01-01

    The eclipsing low-mass X-ray binary X1822-371 is the prototype of the accretion disc corona (ADC) sources. We analyse two Chandra observations and one XMM-Newton observation to study the discrete features and their variation as a function of the orbital phase, deriving constraints on the temperature, density, and location of the plasma responsible for emission lines. The HETGS and XMM/Epic-pn observed X1822-371 for 140 and 50 ks, respectively. We extracted an averaged spectrum and five spectra from five selected orbital-phase intervals that are 0.04-0.25, 0.25-0.50, 0.50-0.75, 0.75-0.95, and, finally, 0.95-1.04; the orbital phase zero corresponds to the eclipse time. All spectra cover the energy band between 0.35 and 12 keV. We confirm the presence of local neutral matter that partially covers the X-ray emitting region; the equivalent hydrogen column is $5 \\times 10^{22}$ cm$ ^{-2}$ and the covered fraction is about 60-65%. We identify emission lines from highly ionised elements, and a prominent fluorescence ...

  20. Anatomy of the AGN in NGC 5548: III. The high-energy view with NuSTAR and INTEGRAL

    CERN Document Server

    Ursini, F; Petrucci, P -O; Matt, G; Cappi, M; Bianchi, S; Kaastra, J; Harrison, F; Walton, D J; di Gesu, L; Costantini, E; De Marco, B; Kriss, G A; Mehdipour, M; Paltani, S; Peterson, B M; Ponti, G; Steenbrugge, K C

    2015-01-01

    We describe the analysis of the seven broad-band X-ray continuum observations of the archetypal Seyfert 1 galaxy NGC 5548 that were obtained with XMM-Newton or Chandra, simultaneously with high-energy (> 10 keV) observations with NuSTAR and INTEGRAL. These data were obtained as part of a multiwavelength campaign undertaken from the summer of 2013 till early 2014. We find evidence of a high-energy cut-off in at least one observation, which we attribute to thermal Comptonization, and a constant reflected component that is likely due to neutral material at least a few light months away from the continuum source. We confirm the presence of strong, partial covering X-ray absorption as the explanation for the sharp decrease in flux through the soft X-ray band. The obscurers appear to be variable in column density and covering fraction on time scales as short as weeks. A fit of the average spectrum over the range 0.3-400 keV with a realistic Comptonization model indicates the presence of a hot corona with a temperat...