WorldWideScience

Sample records for bright ultraluminous x-ray

  1. Jets from ultraluminous X-ray sources

    Science.gov (United States)

    Urquhart, Ryan

    2017-08-01

    An important set of unsolved problems in accretion physics is whether super-Eddington accretion flows produce jets, what the jet power is (compared with the accretion power), and what the large-scale effect of the jet is on the surrounding gas. Most ultraluminous X-ray sources (ULXs) are super-Eddington stellar-mass compact objects: they provide the best local-Universe test of MHD accretion flow simulations. Observational evidence of collimated jets and fast outflows in ULXs may come in different forms: steady synchrotron radio emission from an unresolved, persistent core; radio flaring associated with discrete ejecta; internal shocks along the jet; hotspots from the jet/ISM interaction; hundred-parsec scale wind/jet-inflated nebulae. We discuss examples of the various cases, use them as proxies to measure the jet power, and compare them with (sub-Eddington) AGN and X-ray binary jets.

  2. Ultrafast outflows in ultraluminous X-ray sources

    CERN Document Server

    Pinto, Ciro; Middleton, Matthew; Walton, Dom

    2016-01-01

    Ultraluminous X-ray sources (ULXs) are bright extragalactic sources with X-ray luminosities above 10^39 erg/s powered by accretion onto compact objects. According to the first studies performed with XMM-Newton ULXs seemed to be excellent candidates to host intermediate-mass black holes (10^2-4 solar masses). However, in the last years the interpretation of super-Eddington accretion onto stellar-mass black holes or neutron stars for most ULXs has gained a strong consensus. One critical missing piece to confirm the super-Eddington scenario was the direct detection of the massive, radiatively-driven winds expected as atomic emission/absorption lines in ULX spectra. The first evidence for winds was found as residuals in the soft X-ray spectra of ULXs. Most recently we have been able to resolve these residuals into rest-frame emission and blueshifted (~0.2c) absorption lines arising from highly ionized gas in the deep high-resolution XMM-Newton spectra of two ultraluminous X-ray sources. The compact object is ther...

  3. A radio monitoring survey of ultra-luminous X-ray sources

    NARCIS (Netherlands)

    Körding, E.; Colbert, E.; Falcke, H.D.E.

    2005-01-01

    We present the results of a radio monitoring campaign to search for radio emission from nearby ultra-luminous X-ray sources (ULXs). These sources are bright off-nuclear X-ray point sources with luminosities exceeding LX > 1039 erg s-1. A well-defined sample of the 9

  4. From ultraluminous X-ray sources to ultraluminous supersoft sources: NGC 55 ULX, the missing link

    Science.gov (United States)

    Pinto, C.; Alston, W.; Soria, R.; Middleton, M. J.; Walton, D. J.; Sutton, A. D.; Fabian, A. C.; Earnshaw, H.; Urquhart, R.; Kara, E.; Roberts, T. P.

    2017-07-01

    In recent work with high-resolution reflection grating spectrometers (RGS) aboard XMM-Newton, Pinto et al. have discovered that two bright and archetypal ultraluminous X-ray sources (ULXs) have strong relativistic winds in agreement with theoretical predictions of high accretion rates. It has been proposed that such winds can become optically thick enough to block and reprocess the disc X-ray photons almost entirely, making the source appear as a soft thermal emitter or ultraluminous supersoft X-ray source (ULS). To test this hypothesis, we have studied a ULX where the wind is strong enough to cause significant absorption of the hard X-ray continuum: NGC 55 ULX. The RGS spectrum of NGC 55 ULX shows a wealth of emission and absorption lines blueshifted by significant fractions of the light speed (0.01-0.20)c indicating the presence of a powerful wind. The wind has a complex dynamical structure with the ionization state increasing with the outflow velocity, which may indicate launching from different regions of the accretion disc. The comparison with other ULXs such as NGC 1313 X-1 and NGC 5408 X-1 suggests that NGC 55 ULX is being observed at higher inclination. The wind partly absorbs the source flux above 1 keV, generating a spectral drop similar to that observed in ULSs. The softening of the spectrum at lower (˜ Eddington) luminosities and the detection of a soft lag agree with the scenario of wind clumps crossing the line of sight, partly absorbing and reprocessing the hard X-rays from the innermost region.

  5. Compact Optical Counterparts of Ultraluminous X-ray Sources

    CERN Document Server

    Tao, Lian; Grise, Fabien; Kaaret, Philip

    2011-01-01

    Using archival Hubble Space Telescope (HST) imaging data, we report the multiband photometric properties of 13 ultraluminous X-ray sources (ULXs) that have a unique compact optical counterpart. Both magnitude and color variation are detected at time scales of days to years. The optical color, variability, and X-ray to optical flux ratio indicate that the optical emission of most ULXs is dominated by X-ray reprocessing on the disk, similar to that of low mass X-ray binaries. For most sources, the optical spectrum is a power-law, $F_{\

  6. Gravitational waves from remnants of ultraluminous X-ray sources

    CERN Document Server

    Hopman, C; Hopman, Clovis; Zwart, Simon Portegies

    2005-01-01

    Ultraluminous X-ray sources (ULXs) with X-ray luminosities larger than the Eddington luminosity of stellar mass objects may be powered by intermediate mass black holes (IBHs) of masses Mbh~10^3Msun. If IBHs form in young dense stellar clusters, they can be fed by Roche lobe overflow from a tidally captured massive (Ms>10Msun) stellar companion. After the donor leaves the main sequence it forms a compact remnant, which spirals in due to gravitational wave (GW) emission. We show that space based detectors such as the Light Interferometer Space Antenna are likely to detect several of these sources. GW sources stemming from this scenario have small eccentricities which give distinct GW signals. Detection of such a GW signal will unambiguously prove the existence of IBHs, and support the hypothesis that some ULXs are powered by IBHs with captured companions.

  7. NuSTAR, XMM-Newton and Suzaku Observations of the Ultraluminous X-Ray Source Holmberg II X-1

    DEFF Research Database (Denmark)

    Walton, D. J.; Middleton, M. J.; Rana, V.;

    2015-01-01

    We present the first broadband 0.3-25.0 keV X-ray observations of the bright ultraluminous X-ray source (ULX) Holmberg II X-1, performed by NuSTAR, XMM-Newton, and Suzaku in 2013 September. The NuSTAR data provide the first observations of Holmberg II X-1 above 10 keV and reveal a very steep high...

  8. The Antennae Ultraluminous X-Ray Source, X-37, Is A Background Quasar

    CERN Document Server

    Clark, D M; Eikenberry, S S; Brandl, B R; Wilson, J C; Carson, J C; Henderson, C P; Hayward, T L; Barry, J; Ptak, A F; Colbert, E J M

    2005-01-01

    In this paper we report that a bright, X-ray source in the Antennae galaxies (NGC 4038/9), previously identified as an ultra-luminous X-ray source, is in fact a background quasar. We identify an isolated infrared and optical counterpart within 0.3+/-0.5 arcseconds the X-ray source X-37. After acquiring an optical spectrum of its counterpart, we use the narrow [OIII] and broad H_alpha emission lines to identify X-37 as a quasar at a redshift of z=0.26. Through a U, V, and K_s photometric analysis, we demonstrate that most of the observable light along this line of sight is from the quasar. We discuss the implications of this discovery and the importance of acquiring spectra for optical and IR counterparts to ULXs.

  9. Two eclipsing ultraluminous X-ray sources in M 51

    CERN Document Server

    Urquhart, Ryan

    2016-01-01

    We present the discovery, from archival Chandra and XMM-Newton data, of X-ray eclipses in two ultraluminous X-ray sources (ULXs), located in the same region of the galaxy M 51: CXOM51 J132940.0$+$471237 (ULX-1, for simplicity) and CXOM51 J132939.5$+$471244 (ULX-2). Three eclipses were detected for ULX-1, two for ULX-2. The presence of eclipses puts strong constraints on the viewing angle, suggesting that both ULXs are seen almost edge-on and are certainly not beamed towards us. Despite the similar viewing angles and luminosities ($L_{\\rm X} \\approx 2 \\times 10^{39}$ erg s$^{-1}$ in the $0.3$-$8$ keV band for both sources), their X-ray properties are different. ULX-1 has a soft spectrum, well fitted by Comptonization emission from a medium with electron temperature $kT_e \\approx 1$ keV. ULX-2 is harder, well fitted by a slim disk with $kT_{\\rm in} \\approx 1.5$-$1.8$ keV and normalization consistent with a $\\sim 10 M_{\\odot}$ black hole. ULX-1 has a significant contribution from multi-temperature thermal plasma...

  10. An Observational Diagnostic for Ultraluminous X-Ray Sources

    CERN Document Server

    Kalogera, V; Ivanova, N; King, A R

    2004-01-01

    We consider observational tests for the nature of Ultraluminous X-ray sources (ULXs). These must distinguish between thermal-timescale mass transfer on to stellar-mass black holes leading to anisotropic X-ray emission, and accretion on to intermediate-mass black holes. We suggest that long-term transient behavior via the thermal-viscous disk instability could discriminate between these two possibilities for ULXs in regions of young stellar populations. Thermal-timescale mass transfer generally produces stable disks and persistent X-ray emission. In contrast, mass transfer from massive stars to black holes produces unstable disks and thus transient behavior, provided that the black hole mass exceeds some minimum value. This minimum mass depends primarily on the donor mass and evolutionary state. We show that it exceeds 50 solar masses for a large fraction (greater than 90%) of the mass-transfer lifetime for the most likely donors in young clusters. Thus if long-term monitoring reveals a large transient fractio...

  11. The scaling of X-ray variability with luminosity in Ultra-luminous X-ray sources

    CERN Document Server

    Gonzalez-Martin, O; Reig, P; Zezas, A

    2010-01-01

    We investigated the relationship between the X-ray variability amplitude and X-ray luminosity for a sample of 14 bright Ultra-luminous X-ray sources (ULXs) with XMM-Newton/EPIC data, and compare it with the well established similar relationship for Active Galactic Nuclei (AGN). We computed the normalised excess variance in the 2-10 keV light curves of these objects and their 2-10 keV band intrinsic luminosity. We also determined model "variability-luminosity" relationships for AGN, under several assumptions regarding their power-spectral shape. We compared these model predictions at low luminosities with the ULX data. The variability amplitude of the ULXs is significantly smaller than that expected from a simple extrapolation of the AGN "variability-luminosity" relationship at low luminosities. We also find evidence for an anti-correlation between the variability amplitude and L(2-10 keV) for ULXs. The shape of this relationship is consistent with the AGN data but only if the ULXs data are shifted by four ord...

  12. Patchy Accretion Disks in Ultraluminous X-ray Sources

    CERN Document Server

    Miller, J M; Barret, D; Harrison, F A; Fabian, A C; Webb, N A; Walton, D J; Rana, V

    2014-01-01

    The X-ray spectra of the most extreme ultra-luminous X-ray sources -- those with L > 1 E+40 erg/s -- remain something of a mystery. Spectral roll-over in the 5-10 keV band was originally detected in in the deepest XMM-Newton observations of the brightest sources; this is confirmed in subsequent NuSTAR spectra. This emission can be modeled via Comptonization, but with low electron temperatures (kT_e ~ 2 keV) and high optical depths (tau ~ 10) that pose numerous difficulties. Moreover, evidence of cooler thermal emission that can be fit with thin disk models persists, even in fits to joint XMM-Newton and NuSTAR observations. Using NGC 1313 X-1 as a test case, we show that a patchy disk with a multiple temperature profile may provide an excellent description of such spectra. In principle, a number of patches within a cool disk might emit over a range of temperatures, but the data only require a two-temperature profile plus standard Comptonization, or three distinct blackbody components. A mechanism such as the p...

  13. Chilled disks in ultraluminous X-ray sources

    Science.gov (United States)

    Soria, Roberto; Kuncic, Zdenka; Gonçalves, Anabela C.

    2007-04-01

    The "soft-excess" component fitted to the X-ray spectra of many ultraluminous X-ray sources (ULXs) remains a controversial finding, which may reveal fundamental information either on the black hole (BH) mass or on the state of the accretion flow. In the simplest model, it was explained as thermal emission from a cool accretion disk around an intermediate-mass BH (about 1000 solar masses). We argue that this scenario is highly implausible, and discuss and compare the two most likely alternatives. 1) The soft-excess does come from a cool disk; however, the temperature is low not because of a high BH mass but because most of the accretion power is drained from the inner disk via magnetic torques, and channelled into jets and outflows ("chilled disk" scenario). Using a phenomenological model, we infer that ULXs contain BHs of about 50 solar masses accreting gas at about 10 times their Eddington rate. 2) The soft excess is in fact a soft deficit, if the power-law continuum is properly fitted. Such broad absorption features are caused by smeared absorption lines in fast, highly ionized outflows. This scenario has already been successfully applied to the soft excess in AGN. If so, this spectral feature reveals details of disk outflows,but is unrelated to the BH mass.

  14. An Ultraluminous X-ray Source Powered by An Accreting Neutron Star

    CERN Document Server

    Bachetti, M; Walton, D J; Grefenstette, B W; Chakrabarty, D; Fürst, F; Barret, D; Beloborodov, A; Boggs, S E; Christensen, F E; Craig, W W; Fabian, A C; Hailey, C J; Hornschemeier, A; Kaspi, V; Kulkarni, S R; Maccarone, T; Miller, J M; Rana, V; Stern, D; Tendulkar, S P; Tomsick, J; Webb, N A; Zhang, W W

    2014-01-01

    Ultraluminous X-ray sources (ULX) are off-nuclear point sources in nearby galaxies whose X-ray luminosity exceeds the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes. Their luminosity ranges from $10^{40}$ erg s$^{-1} $10^{40}$ erg s$^{-1}$), which require black hole masses MBH >50 solar masses and/or significant departures from the standard thin disk accretion that powers bright Galactic X-ray binaries. Here we report broadband X-ray observations of the nuclear region of the galaxy M82, which contains two bright ULXs. The observations reveal pulsations of average period 1.37 s with a 2.5-day sinusoidal modulation. The pulsations result from the rotation of a magnetized neutron star, and the modulation arises from its binary orbit. The pulsed flux alone corresponds to $L_X$(3 - 30 keV) = $4.9 \\times 10^{39}$ erg s$^{-1}$. The pulsating source is spatially coincident with a variable ULX which can reach $L_X$ (0.3 - 10 keV) = $1.8 \\times 10^{40}$ erg s$^{-1}$. This ...

  15. 2XMM Ultraluminous X-Ray Source Candidates in Nearby Galaxies

    CERN Document Server

    Walton, D J; Mateos, S; Heard, V

    2011-01-01

    Ultraluminous X-ray sources (ULXs) are some of the most enigmatic X-ray bright sources known to date. It is generally accepted that they cannot host black holes as large as those associated with active galaxies, but they appear to be significantly more luminous than their better understood Galactic X-ray binary (XRB) cousins, while displaying an intriguing combination of differences and similarities with them. Through studying large, representative samples of these sources we may hope to enhance our understanding of them. To this end, we derive a large catalogue of 650 X-ray detections of 470 ULX candidates, located in 238 nearby galaxies, by cross correlating the 2XMM Serendipitous Survey with the Third Reference Catalogue of Bright Galaxies. The presented dedicated catalogue offers a significant improvement over those previously published both in terms of number and the contribution of background contaminants, e.g. distant quasars, which we estimate to be at most 24 per cent, but more likely ~17 per cent. T...

  16. Soft X-ray Properties of Ultraluminous IRAS Galaxies

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We report on the results of cross-correlation of a sample of 903 Ultra luminous IRAS galaxies (ULIRGs) with the ROSAT-All Sky Survey Bright Source Catalogue and the ROSAT archived pointing observations. The sample of ULIRGs has been compiled from the recently released PSCz redshift survey. In total, 35 ULIRGs are securely detected by the ROSAT All-Sky Survey and pointing observa tions, five of which are blazars. The statistical properties of these sources in the soft X-ray band are determined and compared with their properties in other wavebands. We find that the ratio of the soft X-ray to the far-infrared flux spans about five orders of magnitude and reaches values of about unity. This ratio is a good indi cator of the main energy source of ULIRGs. Those with soft X-ray to far-infrared flux exceeding 0.01 are probably powered by accretion onto central supermassive black holes while those with ratios smaller than 0.001 are probably powered by starbursts or other heating processes, or are Compton thick sources. Some ULIRGs have energy contributions from both. This ratio is low for most ULIRGs and hy perluminous infrared galaxies, which explains their low detection rate by ROSAT and ASCA. We also find that some ULIRGs have a similar soft X-ray luminosity vs. temperature relation to that for groups of galaxies and elliptical galaxies, suggest ing a common origin of these systems. Our study also reveals a tight correlation between the hardness ratio and the soft X-ray luminosity for Seyfert ls/QSOs.

  17. Spectral variability of ultraluminous X-ray sources

    CERN Document Server

    Kajava, Jari J E

    2008-01-01

    We study spectral variability of 11 ultraluminous X-ray sources (ULX) using archived XMM-Newton and Chandra observations. We use three models to describe the observed spectra; a power-law, a multi-colour disk (MCD) and a combination of these two models. We find that out of the 11 ULXs in our sample, 7 ULXs show a correlation between the luminosity and the photon index Gamma (hereafter L-Gamma correlation). Furthermore, out of the 7 ULXs that have the L-Gamma correlation, 4 ULXs also show spectral pivoting in the observed energy band. We also find that two ULXs show an L-Gamma anti-correlation. The spectra of 4 ULXs in the sample can be adequately fitted with a MCD model. We compare these sources to known black hole binaries (BHB) and find that they follow similar paths in their luminosity-temperature (hereafter L-T) diagrams. Finally we show that the 'soft excess' reported for many of these ULXs at 0.2 keV seem to follow a trend L \\propto T^{-4} when modeled with a power-law plus a 'cool' MCD model. This is c...

  18. Spectral variability of ultraluminous X-ray sources

    CERN Document Server

    Kajava, Jari J E

    2009-01-01

    We study spectral variability of 11 ultraluminous X-ray sources (ULX) using archived XMM-Newton and Chandra observations. We use three models to describe the observed spectra: a power-law, a multi-colour disc (MCD) and a combination of these two models. We find that 7 ULXs show a correlation between the luminosity Lx and the photon index Gamma. Furthermore, 4 out of these 7 ULXs also show spectral pivoting in the observed energy band. We also find that two ULXs show an Lx-Gamma anti-correlation. The spectra of 4 ULXs in the sample can be adequately fitted with a MCD model. We compare these sources to known black hole binaries (BHB) and find that they follow similar paths in their luminosity-temperature diagrams. Finally we show that the `soft excess' reported for many of these ULXs at about 0.2 keV seems to roughly follow a trend Lsoft \\propto T^{-3.5} when modelled with a power-law plus a `cool' MCD model. This is contrary to the L \\propto T^4 relation that is expected from theory and what is seen for many a...

  19. Pulsator-like Spectra from Ultraluminous X-Ray Sources and the Search for More Ultraluminous Pulsars

    Science.gov (United States)

    Pintore, F.; Zampieri, L.; Stella, L.; Wolter, A.; Mereghetti, S.; Israel, G. L.

    2017-02-01

    Ultraluminous X-ray sources (ULXs) are a population of extragalactic objects whose luminosity exceeds the Eddington limit for a 10 M ⊙ black hole (BH). Their properties have been widely interpreted in terms of accreting stellar-mass or intermediate-mass BHs. However at least three neutron stars (NSs) have been recently identified in ULXs through the discovery of periodic pulsations. Motivated by these findings we studied the spectral properties of a sample of bright ULXs using a simple continuum model which was extensively used to fit the X-ray spectra of accreting magnetic NSs in the Galaxy. We found that such a model, consisting of a power-law with a high-energy exponential cut-off, fits most of the ULX spectra analyzed here very well, at a level comparable to that of models involving an accreting BH. On these grounds alone we suggest that other non-pulsating ULXs may host NSs. We also found that above 2 keV the spectrum of known pulsating ULXs is harder than that of the majority of the other ULXs of the sample, with only IC 342 X-1 and Ho IX X-1 displaying spectra of comparable hardness. We thus suggest that these two ULXs may host an accreting NS and encourage searches for periodic pulsations in the flux.

  20. Stability of mass transfer from massive giants: double black hole binary formation and ultraluminous X-ray sources

    Science.gov (United States)

    Pavlovskii, K.; Ivanova, N.; Belczynski, K.; Van, K. X.

    2017-02-01

    Mass transfer in binaries with massive donors and compact companions, when the donors rapidly evolve after their main sequence, determines the formation rates of merging double stellar-mass black hole (BH) binaries formed outside clusters. This mass transfer was previously postulated to be unstable and was expected to lead to a common envelope event. The common envelope event then ends with either the merger of the two stars or formation of a binary that eventually may become a merging double BH. We revisit the stability of this mass transfer and find an unanticipated third outcome: for a large range of binary orbital separations, this mass transfer is stable. This newly found stability allows us to reconcile the empirical rate obtained by LIGO, 9-240 Gpc-3 yr-1, with the theoretical rate for double BH binary mergers predicted by population synthesis studies by excluding a channel that predicts a merger rate above 1000 Gpc-3 yr-1. Furthermore, the stability of the mass transfer leads to the formation of ultraluminous X-ray sources. The theoretically predicted formation rates of bright ultraluminous X-ray sources powered by a stellar-mass BH are high enough to explain the number of observed bright ultraluminous X-ray sources.

  1. Exploring the overabundance of ultraluminous X-ray sources in metal- and dust-poor local Lyman break analogs

    Science.gov (United States)

    Basu-Zych, Antara; Lehmer, Bret; Fragos, Tassos; Hornschemeier, Ann E.; Zezas, Andreas; Yukita, Mihoko; Ptak, Andrew

    2016-01-01

    We have studied high mass X-ray binary (HMXB) populations within two low-metallicity, starburst galaxies, Haro 11 and VV 114. These galaxies serve as analogs to high-redshift (z > 2) Lyman break galaxies, and within the larger sample of Lyman break analogs (LBAs) are sufficiently nearby (1039 erg s-1 ultraluminous X-ray sources, ULXs) in these low-metallicity galaxies, based on 8 detected ULXs. Comparing with the star-forming galaxy X-ray luminosity function (XLF), Haro 11 and VV 114 host ~4 times more LX>1040 erg s-1 sources than expected given their SFRs. We simulate the effects of source blending from crowded lower luminosity HMXBs using the star-forming galaxy XLF and then vary the XLF normalizations and bright-end slopes until we reproduce the observed point source luminosity distributions. Based on this analysis, we find that these LBAs have a shallower bright end slope than the standard XLF.

  2. A Radio Monitoring Survey of Ultra-Luminous X-Ray Sources

    CERN Document Server

    Koerding, E; Falcke, H

    2005-01-01

    We present the results of a radio monitoring campaign to search for radio emission from nearby ultra-luminous X-ray sources (ULXs). These sources are bright off-nuclear X-ray point sources with luminosities exceeding L_X > 10^39 erg/sec. A well-defined sample of the 9 nearest ULXs has been monitored eight times during 5 months with the Very Large Array in A and B configuration. Our limiting sensitivity is approximately 0.15 mJy (4 sigma) for radio flares and around 60 uJy for continuous emission. In M82 two ULXs seem to have coincident compact radio sources, which are probably supernova remnants. No continuous or flaring radio emission has been detected from any other ULX. Thus, ULXs do not generally emit steady-state radio emission above radio powers of 1.5 10^17 W/Hz. The non-detections of the continuous emission are consistent with beamed or unbeamed radio emission from accreting black holes of <= 10^3 Msol based on the radio/X-ray correlation. Other published radio detections (M82, NGC 5408) are also d...

  3. First Search for an X-ray -- Optical Reverberation Signal in an Ultraluminous X-ray Source

    CERN Document Server

    Pasham, Dheeraj R; Cenko, S Bradley; Trippe, Margaret L; Mushotzky, Richard F; Gandhi, Poshak

    2016-01-01

    Using simultaneous optical (VLT/FORS2) and X-ray (XMM-Newton) data of NGC 5408, we present the first ever attempt to search for a reverberation signal in an ultraluminous X-ray source (NGC 5408 X-1). The idea is similar to AGN broad line reverberation mapping where a lag measurement between the X-ray and the optical flux combined with a Keplerian velocity estimate should enable us to weigh the central compact object. We find that although NGC 5408 X-1's X-rays are variable on a timescale of a few hundred seconds (RMS of 9.0$\\pm$0.5%), the optical emission does not show any statistically significant variations. We set a 3$\\sigma$ upper limit on the RMS optical variability of 3.3%. The ratio of the X-ray to the optical variability is an indicator of X-ray reprocessing efficiency. In X-ray binaries, this ratio is roughly 5. Assuming a similar ratio for NGC 5408 X-1, the expected RMS optical variability is $\\approx$2% which is still a factor of roughly two lower than what was possible with the VLT observations in...

  4. A variable ultra-luminous X-ray source in the colliding galaxy NGC 7714

    CERN Document Server

    Soria, R; Soria, Roberto; Motch, Christian

    2004-01-01

    We studied the colliding galaxy NGC 7714 with two XMM-Newton observations, six months apart. The galaxy contains two bright X-ray sources: we show that they have different physical nature. The off-nuclear source is an accreting compact object, one of the brightest ultraluminous X-ray sources (ULXs) found to date. It showed spectral and luminosity changes between the two observations, from a low/soft to a high/hard state; in the high state, it reached L_x ~ 6 x 10^{40} erg/s. Its lightcurve in the high state suggests variability on a ~ 2-hr timescale. Its peculiar location, where the tidal bridge between NGC 7714 and NGC 7715 joins the outer stellar ring of NGC 7714, makes it an interesting example of the connection between gas flows in colliding galaxies and ULX formation. The nuclear source (L_x ~ 10^{41} erg/s) coincides with a starburst region, and is the combination of thin thermal plasma emission and a point-source contribution (with a power-law spectrum). Variability in the power-law component between t...

  5. Observational Evidence for Intermediate-Mass Black Holes in Ultra-luminous X-ray Sources

    CERN Document Server

    Colbert, E J M

    2004-01-01

    Evidence is mounting that some Ultra-luminous X-ray sources (ULXs) may contain accreting intermediate-mass black holes (IMBHs). We review the current observational evidence for IMBH-ULXs. While low-luminosity ULXs with L_X ~ 10^40 ergs, we suggest that this class of ULXs is generally powered by accreting IMBHs.

  6. An ultraluminous X-ray source powered by an accreting neutron star

    DEFF Research Database (Denmark)

    Bachetti, M.; Harrison, F. A.; Walton, D. J.;

    2014-01-01

    the Eddington limit for a 1.4-solar-mass object, or more than ten times brighter than any known accreting pulsar. This implies that neutron stars may not be rare in the ultraluminous X-ray population, and it challenges physical models for the accretion of matter onto magnetized compact objects....

  7. 2XMM ultraluminous X-ray source candidates in nearby galaxies

    Science.gov (United States)

    Walton, D. J.; Roberts, T. P.; Mateos, S.; Heard, V.

    2011-09-01

    Ultraluminous X-ray sources (ULXs) are some of the most enigmatic X-ray bright sources known to date. It is generally accepted that they cannot host black holes as large as those associated with active galaxies, but they appear to be significantly more luminous than their better understood Galactic X-ray binary (XRB) cousins, while displaying an intriguing combination of differences and similarities with them. Through studying large, representative samples of these sources we may hope to enhance our understanding of them. To this end, we derive a large catalogue of 650 X-ray detections of 470 ULX candidates, located in 238 nearby galaxies, by cross-correlating the 2XMM Serendipitous Survey with the Third Reference Catalogue of Bright Galaxies. The presented dedicated catalogue offers a significant improvement over those previously published in terms of both the number and the contribution of background contaminants, e.g. distant quasars, which we estimate to be at most 24 per cent, but more likely ˜17 per cent. To undertake population studies, we define a 'complete' sub-sample of sources compiled from observations of galaxies with sensitivity limits below 1039 erg s-1. The luminosity function of this sample is consistent with a simple power law of form N(>LX) ∝ L-0.96 ± 0.11X. Although we do not find any statistical requirement for a cut-off luminosity of Lc˜ 1040 erg s-1, as has been reported previously, we are not able to rule out its presence. Also, we find that the number of ULXs per unit galaxy mass, Su, decreases with increasing galaxy mass for ULXs associated with spiral galaxies, and is well modelled with a power law of form Su ∝ M-0.64 ± 0.07. This is in broad agreement with previous results, and is likely to be a consequence of the decrease in specific star formation and increase in metallicity with increasing spiral galaxy mass. Su is consistent with being constant with galaxy mass for sources associated with elliptical galaxies, implying this

  8. Ultraluminous X-ray Sources in Interacting Galaxies

    CERN Document Server

    Swartz, Douglas A

    2009-01-01

    I give a brief review of how X-rays from nearby galaxies are used as direct tracers of recent star formation. This leads to the conclusion that it is the most luminous point-like sources that are associated with star formation and that the majority of these are high-mass X-ray binaries.I then discuss a recent study that shows that ULXs are preferentially found in regions as young as or younger than typical HII regions in their host galaxies. Finally, I describe a new study that attempts to determine the maximum luminosity of ULXs in the local universe by searching for them in interacting galaxies where the star formation rate is high.

  9. Broadband X-ray spectra of the ultraluminous x-ray source Holmberg IX X-1 observed with NuSTAR, XMM-Newton, and Suzaku

    DEFF Research Database (Denmark)

    Walton, D. J.; Harrison, F. A.; Grefenstette, B. W.;

    2014-01-01

    We present results from the coordinated broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 performed by NuSTAR, XMM-Newton, and Suzaku in late 2012. These observations provide the first high-quality spectra of Holmberg IX X-1 above 10 keV to date, extending the X...

  10. A hard X-ray study of the ultraluminous X-ray source NGC 5204 X-1 with NuSTAR and XMM-Newton

    DEFF Research Database (Denmark)

    Mukherjee, E. S.; Walton, D. J.; Bachetti, M.;

    2015-01-01

    We present the results from coordinated X-ray observations of the ultraluminous X-ray source NGC 5204 X-1 performed by the Nuclear Spectroscopic Telescope Array and XMM-Newton in early 2013. These observations provide the first detection of NGC 5204 X-1 above 10 keV, extending the broadband...

  11. On the black hole masses in ultra-luminous X-ray sources

    Science.gov (United States)

    Zhou, Xin-Lin

    2015-05-01

    Ultra-luminous X-ray sources (ULXs) are off-nuclear X-ray sources in nearby galaxies with X-ray luminosities ⩾ 1039 erg s-1. The measurement of the black hole (BH) masses of ULXs is a long-standing problem. Here we estimate BH masses in a sample of ULXs with XMM-Newton observations using two different mass indicators, the X-ray photon index and X-ray variability amplitude based on the correlations established for active galactic nuclei (AGNs). The BH masses estimated from the two methods are compared and discussed. We find that some extreme high-luminosity (LX > 5 ×1040 erg s-1) ULXs contain the BH of 104-105 M⊙ . The results from X-ray variability amplitude are in conflict with those from X-ray photon indices for ULXs with lower luminosities. This suggests that these ULXs generally accrete at rates different from those of X-ray luminous AGNs, or they have different power spectral densities of X-ray variability. We conclude that most of ULXs accrete at super-Eddington rate, thus harbor stellar-mass BH.

  12. A systematic search for near-infrared counterparts of nearby ultraluminous X-ray sources (II)

    Science.gov (United States)

    López, K. M.; Heida, M.; Jonker, P. G.; Torres, M. A. P.; Roberts, T. P.; Walton, D. J.; Moon, D.-S.; Harrison, F. A.

    2017-07-01

    We present the results of our continued systematic search for near-infrared (NIR) candidate counterparts to ultraluminous X-ray sources (ULXs) within 10 Mpc. We observed 42 ULXs in 24 nearby galaxies and detected NIR candidate counterparts to 15 ULXs. Fourteen of these ULXs appear to have a single candidate counterpart in our images and the remaining ULX has two candidate counterparts. Seven ULXs have candidate counterparts with absolute magnitudes in the range between -9.26 and -11.18 mag, consistent with them being red supergiants (RSGs). The other eight ULXs have candidate counterparts with absolute magnitudes too bright to be a single stellar source. Some of these NIR sources show extended morphology or colours expected for active galactic nuclei (AGNs), strongly suggesting that they are likely stellar clusters or background galaxies. The RSG candidate counterparts form a valuable sample for follow-up spectroscopic observations to confirm their nature, with the ultimate goal of directly measuring the mass of the compact accretor that powers the ULX using binary Doppler shifts.

  13. Ultraluminous X-ray Sources forming in low metallicity natal environments

    CERN Document Server

    Zampieri, L; Mapelli, M; Patruno, A; Roberts, T P

    2010-01-01

    In the last few years multiwavelength observations have boosted our understanding of Ultraluminous X-ray Sources (ULXs). Yet, the most fundamental questions on ULXs still remain to be definitively answered: do they contain stellar or intermediate mass black holes? How do they form? We investigate the possibility that the black holes hosted in ULXs originate from massive (40-120 $M_\\odot$) stars in low metallicity natal environments. Such black holes have a typical mass in the range $\\sim 30-90 M_\\odot$ and may account for the properties of bright (above $\\sim 10^{40}$ erg s$^{-1}$) ULXs. More than $\\sim 10^5$ massive black holes might have been generated in this way in the metal poor Cartwheel galaxy during the last $10^7$ years and might power most of the ULXs observed in it. Support to our interpretation comes from NGC 1313 X-2, the first ULX with a tentative identification of the orbital period in the optical band, for which binary evolution calculations show that the system is most likely made by a massiv...

  14. Ultraluminous X-ray Source Correlations with Star-Forming Regions

    CERN Document Server

    Swartz, Douglas A; Soria, Roberto

    2009-01-01

    Maps of low-inclination nearby galaxies in Sloan Digitized Sky Survey u-g, g-r and r-i colors are used to determine whether Ultraluminous X-ray sources (ULXs) are predominantly associated with star-forming regions of their host galaxies. An empirical selection criterion is derived from colors of HII regions in M81 and M101 that differentiates between the young, blue stellar component and the older disk and bulge population. This criterion is applied to a sample of 58 galaxies of Hubble type S0 and later and verified through an application of Fisher's linear discriminant analysis. It is found that 60% (49%) of ULXs in optically-bright environments are within regions blueward of their host galaxy's HII regions compared to only 27% (0%) of a control sample according to the empirical (Fisher) criterion. This is an excess of 3-sigma above the 32% (27%) expected if the ULXs were randomly distributed within their galactic hosts. This indicates a ULX preference for young, approximately <10 Myr, OB associations. Ho...

  15. Time series analysis of bright galactic X-ray sources

    DEFF Research Database (Denmark)

    Priedhorsky, W. C.; Brandt, Søren; Lund, Niels

    1995-01-01

    We analyze 70 to 110 day data sets from eight bright galactic X-ray binaries observed by WATCH/Eureca, in search of periodic variations. We obtain new epochs for the orbital variation of Cyg X-3 and 4U 1700-37, and confirmation of a dip in Cyg X-1 at superior conjunction of the X-ray star. No evi...

  16. Hard X-Rays from a Complete Sample of the Brightest Ultraluminous Infrared Galaxies

    Science.gov (United States)

    Sanders, David B.

    2003-01-01

    We were awarded 70kS of XMM-Newton spacecraft time using the Epic pn camera to observe three ultraluminous infrared galaxies (ULIGs) in order to measure the spectral shape of their hard X-Ray emission, and to use this information to search for the presence of an highly obscured active galactic nucleus (AGN), and to separate out the contributions from a putative starburst. By observing three objects we hope to be able to better assess the role of AGN in the complete class of ULIGs and therefore to better constrain their contribution to the X-ray background. XMM-Newton was deemed to be better suited to our proposed measurements of ULIGs than the Chandra X-ray observatory due to its larger aperture and better sensitivity to hard (2-10 keV) X-rays.

  17. Swift J1644+57: An Ultra-Luminous X-ray Event

    CERN Document Server

    Socrates, Aristotle

    2011-01-01

    The photon spectral energy distribution of the powerful transient Sw J1644+57 resembles those of the brightest Ultra-Luminous X-ray sources (ULXs). The transient nature of Sw J1644+57 is likely the result of a tidal disruption of a star by a super-massive black hole. The stellar disk generates accretion power at super-Eddington rates and the observational properties of Sw J1644+57 indicate -- in analogy with ULXs -- that the accretion flow maintains a high level of radiative efficiency with a corresponding super-Eddington luminosity. Due to its similarity to ULXs, this powerful transient may be thought of as an Ultra-Luminous X-ray event (ULX-E). Observational tests for this ULX-E model are proposed as well.

  18. The missing link between ultraluminous X-ray sources and metallicity

    CERN Document Server

    Mapelli, M

    2013-01-01

    The nature of ultraluminous X-ray sources (ULXs) is still debated. Recent studies show that metal-poor massive stars can collapse into massive stellar black holes (MSBHs), that is black holes with mass > 25 Msun. Such MSBHs are sufficiently massive to explain most ULXs without requiring substantial violations of the Eddington limit. The recent finding of an anti-correlation between metallicity of the environment and number of ULXs per galaxy supports this hypothesis. We present the results of recent N-body simulations, including metallicity dependent stellar evolution, and we discuss the main pathways to produce X-ray binaries powered by MSBHs.

  19. Stellar-mass black holes and ultraluminous x-ray sources.

    Science.gov (United States)

    Fender, Rob; Belloni, Tomaso

    2012-08-03

    We review the likely population, observational properties, and broad implications of stellar-mass black holes and ultraluminous x-ray sources. We focus on the clear empirical rules connecting accretion and outflow that have been established for stellar-mass black holes in binary systems in the past decade and a half. These patterns of behavior are probably the keys that will allow us to understand black hole feedback on the largest scales over cosmological time scales.

  20. CXOM31 J004253.1+411422: The first ultra-luminous X-ray transient in M 31

    CERN Document Server

    Kaur, A; Haberl, F; Pietsch, W; Greiner, J; Rau, A; Hartmann, D H; Sala, G; Hernanz, M

    2011-01-01

    We seek clarification of the nature of X-ray sources detected in M 31. Here we focus on CXOM31 J004253.1+411422, the brightness of which suggests that it belongs to the class of ultraluminous X-ray sources. We determine the X-ray properties of sources detected in the XMM-Newton Chandra monitoring program. We investigate spectral properties and search for periodic or quasi-periodic oscillations. A multi-component model is applied to the spectra obtained from XMM-Newton data to evaluate the relative contributions from thermal and non-thermal emission. The time dependence of this ratio is evaluated over a period of forty days. We simultaneously fit data from XMM-Newton EPIC-pn, MOS1 and MOS2 detectors with (non-thermal) powerlaw and (thermal) multicolored blackbody. The X-ray spectrum is best fit by the combination of a thermal component with kT ~ 1 keV and a powerlaw component with photon index approximately 2.6. From combined analysis of Chandra, Swift and XMM-Newton data, the unabsorbed total luminosity of th...

  1. Nature of the Extreme Ultraluminous X-ray Sources

    CERN Document Server

    Wiktorowicz, Grzegorz; Sadowski, Aleksander; Belczynski, Krzysztof

    2015-01-01

    In this proof-of-concept study we demonstrate how a binary system can easily form an extreme ULX source with the X-ray luminosity of L_x > 10^42 erg/s. Formation efficiencies and lifetimes of such objects are high enough to potentially explain all observed extreme ULXs. These systems are not only limited to binaries with stellar-origin black hole accretors. Noteworthy, we have also identified such objects with neutron stars. Typically, a 10 Msun black hole is fed by a massive (~10 Msun) Hertzsprung gap donor with Roche lobe overflow rate of ~10^-3 Msun/yr (~2600 Mdot_Edd). For neutron star systems the typical donors are evolved low-mass (~2 Msun) helium stars with Roche lobe overflow rate of ~10^-2 Msun/yr. We base our study purely on the available Roche lobe overflow rate in a binary system and show that if only even a small fraction (>10^-3) of the overflow reaches the BH, the source will be super-Eddington. Our study does not prove that any particular extreme ULX (e.g., HLX-1) is a regular binary system wi...

  2. Chandra ACIS Survey of X-ray Point Sources in Nearby Galaxies. II. X-ray Luminosity Functions and Ultraluminous X-ray Sources

    CERN Document Server

    Wang, Song; Liu, Jifeng; Bregman, Joel N

    2016-01-01

    Based on the recently completed {\\it Chandra}/ACIS survey of X-ray point sources in nearby galaxies, we study the X-ray luminosity functions (XLFs) for X-ray point sources in different types of galaxies and the statistical properties of ultraluminous X-ray sources (ULXs). Uniform procedures are developed to compute the detection threshold, to estimate the foreground/background contamination, and to calculate the XLFs for individual galaxies and groups of galaxies, resulting in an XLF library for 343 galaxies of different types. With the large number of surveyed galaxies, we have studied the XLFs and ULX properties across different host galaxy types, and confirm with good statistics that the XLF slope flattens from lenticular ($\\alpha\\sim1.50\\pm0.07$) to elliptical ($\\sim1.21\\pm0.02$), to spirals ($\\sim0.80\\pm0.02$), to peculiars ($\\sim0.55\\pm0.30$), and to irregulars ($\\sim0.26\\pm0.10$). The XLF break dividing the neutron star and black hole binaries is also confirmed, albeit at quite different break luminosi...

  3. Resolved atomic lines reveal outflows in two ultraluminous X-ray sources

    CERN Document Server

    Pinto, Ciro; Fabian, Andrew C

    2016-01-01

    Ultraluminous X-ray sources are extragalactic, off-nucleus, point sources in galaxies with an X-ray luminosity above 3x10^39 erg/s, thought to be powered by accretion onto a compact object. Possible explanations include accretion onto neutron stars with strong magnetic fields, stellar-mass black holes ( 5 sigma, and blueshifted (~0.2c) absorption lines (5 sigma) in the high-resolution X-ray spectrum of the ultraluminous X-ray source NGC 1313 X-1. In a similar source, NGC 5408 X-1, we also detect emission lines at rest and blueshifted absorption. The blueshifted absorption lines must occur in a fast outflowing gas, whereas the emission lines originate in slow-moving gas around the source. We conclude that the compact object is surrounded by powerful winds with an outflow velocity of about 0.2c as predicted by models of accreting supermassive black holes and hyper-accreting stellar mass black holes.

  4. The Lack of Very Ultraluminous X-ray Sources in Early-type Galaxies

    CERN Document Server

    Irwin, J A; Athey, A E; Irwin, Jimmy A.; Bregman, Joel N.; Athey, Alex E.

    2004-01-01

    We have searched for ultraluminous X-ray sources (ULXs) in a sample of 28 elliptical and S0 galaxies observed with Chandra. We find that the number of X-ray sources detected at a flux level that would correspond to a 0.3-10 keV X-ray luminosity of ~2 x 10^39 ergs/s or greater (for which we have used the designation very ultraluminous X-ray sources; VULXs) at the distance of each galaxy is equal to the number of expected foreground/background objects. In addition, the VULXs are uniformly distributed over the Chandra field of view rather than distributed like the optical light of the galaxies, strengthening the argument that the high flux sources are unassociated with the galaxies. We have also taken the VULX candidate list of Colbert and Ptak and determined the spatial distribution of VULXs in early-type galaxies and late-type galaxies separately. While the spiral galaxy VULXs are clearly concentrated toward the centers of the galaxies, the early-type galaxy VULXs are distributed randomly over the ROSAT HRI fi...

  5. On Physical Nature of the Source of Ultraluminous X-ray Pulsations

    CERN Document Server

    Ter-Kazarian, G

    2015-01-01

    To reconcile the observed unusual high luminosity of periodic source M82X-2 of the first NuSTAR ultraluminous X-ray pulsations with the most extreme violation of the Eddington limit, and in view that a persistent X-ray radiation from M82X-2 ultimately precludes the possibility of typical pulsars, we tackle the problem by the implications of "microscopic theory of black hole", the preceding developments of which are of vital interest for the physics of ultra-high energy (UHE) cosmic-rays. Replacing a central singularity by the infrastructures inside event horizon, subject to certain rules, MTBH explains the origin of ZeV-neutrinos which are of vital interest for the source of UHE- particles. Withal, M82X-2 is assumed to be a spinning intermediate mass black hole resided in final stage of growth. Then the thermal blackbody X-ray emission, arisen due to the rotational kinetic energy of black hole, escapes from event horizon through the vista to outside world that detected as ultraluminous X-ray pulsations. The M...

  6. Ultraluminous X-ray sources as super-Eddington accretion disks

    CERN Document Server

    Fabrika, Sergei; Atapin, Kirill

    2016-01-01

    The origin of Ultraluminous X-ray sources (ULXs) in external galaxies whose X-ray luminosities exceed those of the brightest black holes in our Galaxy by hundreds and thousands of times is mysterious. The most popular models for the ULXs involve either intermediate mass black holes (IMBHs) or stellar-mass black holes accreting at super-Eddington rates. Here we review the ULX properties, their X-ray spectra indicate a presence of hot winds in their accretion disks supposing the supercritical accretion. However, the strongest evidences come from optical spectroscopy. The spectra of the ULX counterparts are very similar to that of SS 433, the only known supercritical accretor in our Galaxy.

  7. A POPULATION OF ULTRALUMINOUS X-RAY SOURCES WITH AN ACCRETING NEUTRON STAR

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yong; Li, Xiang-Dong, E-mail: lixd@nju.edu.cn [Department of Astronomy, Nanjing University, Nanjing 210046 (China)

    2015-04-01

    Most ultraluminous X-ray sources (ULXs) are believed to be X-ray binary systems, but previous observational and theoretical studies tend to prefer a black hole rather than a neutron star (NS) accretor. The recent discovery of 1.37 s pulsations from the ULX M82 X-2 has established its nature as a magnetized NS. In this work we model the formation history of NS ULXs in an M82- or Milky Way (MW)-like Galaxy, by use of both binary population synthesis and detailed binary evolution calculations. We find that the birth rate is around 10{sup −4} yr{sup −1} for the incipient X-ray binaries in both cases. We demonstrate the distribution of the ULX population in the donor mass–orbital period plane. Our results suggest that, compared with black hole X-ray binaries, NS X-ray binaries may significantly contribute to the ULX population, and high-mass and intermediate-mass X-ray binaries dominate the NS ULX population in M82- and MW-like Galaxies, respectively.

  8. The X-ray spectral evolution of the ultraluminous X-ray source Holmberg IX X-1

    CERN Document Server

    Luangtip, W; Done, C

    2016-01-01

    We present a new analysis of X-ray spectra of the archetypal ultraluminous X-ray source (ULX) Holmberg IX X-1 obtained by the Swift, XMM-Newton and NuSTAR observatories. This ULX is a persistent source, with a typical luminosity of ~10^40 erg s^-1, that varied by a factor of 4 - 5 over eight years. We find that its spectra tend to evolve from relatively flat or two-component spectra in the medium energy band (1-6 keV), at lower luminosities, to a spectrum that is distinctly curved and disc-like at the highest luminosities, with the peak energy in the curved spectrum tending to decrease with increased luminosity. We argue that the spectral evolution of the ULX can be explained by super-Eddington accretion models, where in this case we view the ULX down the evacuated funnel along its rotation axis, bounded by its massive radiatively driven wind. The spectral changes then originate in enhanced geometric beaming as the accretion rate increases and wind funnel narrows, causing the scattered flux from the central r...

  9. Discovery of coherent pulsations from the Ultraluminous X-ray Source NGC 7793 P13

    CERN Document Server

    Fuerst, F; Harrison, F A; Stern, D; Barret, D; Brightman, M; Fabian, A C; Madsen, K K; Middleton, M J; Miller, J M; Pottschmidt, K; Ptak, A; Rana, V

    2016-01-01

    We report the detection of coherent pulsations from the ultraluminous X-ray source NGC 7793 P13. The ~0.42s nearly sinusoidal pulsations were initially discovered in broadband X-ray observations using XMM-Newton and NuSTAR taken in 2016. We subsequently also found pulsations in archival XMM-Newton data taken in 2013 and 2014. The significant (>>5 sigma) detection of coherent pulsations demonstrates that the compact object in P13 is a neutron star with an observed peak luminosity of ~1e40 erg/s, well above the Eddington limit for a 1.4 M_sun accretor. This makes P13 the second ultraluminous X-ray source known to be powered by an accreting neutron star. The pulse period varies between epochs, with a slow but persistent spin up over the 2013-2016 period. This spin-up indicates a magnetic field of B ~ 1.5e12 G, typical of many accreting pulsars. The most likely explanation for the extreme luminosity is a high degree of beaming, however this is difficult to reconcile with the sinusoidal pulse profile.

  10. Integral field spectroscopy of the ultraluminous X-ray source Holmberg II X-1

    CERN Document Server

    Lehmann, I; Fabrika, S; Roth, M; Miyaji, T; Afanasiev, V; Sholukhova, O; Sánchez, S F; Greiner, J; Hasinger, G; Costantini, E; Surkov, A; Burenkov, A

    2004-01-01

    We present optical integral field observations of the H II region containing the ultraluminous X-ray source Holmberg II X-1. We confirm the existence of an X-ray ionized nebula as the counterpart of the source due to the detection of an extended He II (4686A) region (21 x 47 pc) at the Chandra ACIS-S position. An extended blue objects with a size of 11 x 14 pc is coincident with the X-ray/He II region, which could indicate either a young stellar complex or a cluster. We have derived an X-ray to optical luminosity ratio of Lx/Lb>170, and presumable it is Lx/Lb~300-400 using the recent HST ACS data. We find a complex velocity dispersion at the position of the ULX. In addition, there is a radial velocity variation in the X-ray ionized region found in the He II emission of +-50 km/s on spatial scales of 2-3 arcsec. We believe that the putative black hole not only ionizes the surrounding HII gas, but also perturbs it dynamically (via jets or the accretion disk wind). The spatial analysis of the public Chandra ACIS...

  11. Non-Nuclear Hyper/Ultraluminous X-Ray Sources in the Starbursting Cartwheel Ring Galaxy

    CERN Document Server

    Gao, Y; Appleton, P N; Lucas, R A; Gao, Yu; Lucas, Ray A.

    2003-01-01

    We report the Chandra/ACIS-S detection of more than 20 ultraluminous X-ray sources (ULXs, L_{0.5-10 keV} >~ 3 x 10^{39} ergs/sec) in the Cartwheel collisional ring galaxy system, of which over a dozen are located in the outer active star-forming ring. A remarkable hyperluminous X-ray source (HLX, L_{0.5-10 keV} >~ 10^{41} ergs/sec assuming isotropic radiation), which dominates the X-ray emission from the Cartwheel ring, is located in the same segment of the ring as most ULXs. These powerful H/ULXs appear to be coincident with giant HII region complexes, young star clusters, and radio and mid-infrared hot-spots: all strong indicators of recent massive star formation. The X-ray spectra show that H/ULXs have similar properties as those of the {\\it most luminous} ULXs found in the nearest starbursts and galaxy mergers such as the Antennae galaxies and M82. The close association between the X-ray sources and the starbursting ring strongly suggests that the H/ULXs are intimately associated with the production and r...

  12. Irradiated, colour-temperature-corrected accretion discs in ultraluminous X-ray sources

    CERN Document Server

    Sutton, Andrew D; Roberts, Timothy P

    2014-01-01

    Although attempts have been made to constrain the stellar types of optical counterparts to ULXs, the detection of optical variability instead suggests that they may be dominated by reprocessed emission from X-rays which irradiate the outer accretion disc. Here, we report results from a combined X-ray and optical spectral study of a sample of ULXs, which were selected for having broadened disc-like X-ray spectra, and known optical counterparts. We simultaneously fit optical and X-ray data from ULXs with a new spectral model of emission from an irradiated, colour-temperature-corrected accretion disc around a black hole, with a central Comptonising corona. We find that the ULXs require reprocessing fractions of $\\sim 10^{-3}$, which is similar to sub-Eddington thermal dominant state BHBs, but less than has been reported for ULXs with soft ultraluminous X-ray spectra. We suggest that the reprocessing fraction may be due to the opposing effects of self-shielding in a geometrically thick super-critical accretion di...

  13. An extremely luminous and variable ultraluminous x-ray source in the outskirts of circinus observed with NuSTAR

    DEFF Research Database (Denmark)

    Walton, D. J.; Fuerst, F.; Harrison, F.;

    2013-01-01

    Following a serendipitous detection with the Nuclear Spectroscopic Telescope Array (NuSTAR), we present a multi-epoch spectral and temporal analysis of an extreme ultraluminous X-ray source (ULX) located in the outskirts of the Circinus galaxy, hereafter Circinus ULX5, including coordinated XMM-Newton+NuSTAR...... follow-up observations. The NuSTAR data presented here represent one of the first instances of a ULX reliably detected at hard (E > 10 keV) X-rays. Circinus ULX5 is variable on long time scales by at least a factor of similar to 5 in flux, and was caught in a historically bright state during our 2013...... observations (0.3-30.0 keV luminosity of 1.6 x 10(40) erg s(-1)). During this epoch, the source displayed a curved 3-10 keV spectrum, broadly similar to other bright ULXs. Although pure thermal models result in a high energy excess in the NuSTAR data, this excess is too weak to be modeled with the disk...

  14. X-ray bright groups and their galaxies

    CERN Document Server

    Helsdon, S F; Helsdon, Stephen F.; Ponman, Trevor J.

    2002-01-01

    Combining X-ray data from the ROSAT PSPC and optical data drawn from the literature, we examine in detail the relationship between the X-ray and optical properties of X-ray bright galaxy groups. We find a relationship between optical luminosity and X-ray temperature consistent with that expected from self-similar scaling of galaxy systems, L_B \\propto T^{1.6 +/- 0.2}. The self-similar form and continuity of the L_B : T relation from clusters to groups and the limited scatter seen in this relation, implies that the star formation efficiency is rather similar in all these systems. We find that the bright extended X-ray components associated with many central galaxies in groups appear to be more closely related to the group than the galaxy itself, and we suggest that these are group cooling flows rather than galaxy halos. In addition we find that the optical light in these groups appears to be more centrally concentrated than the light in clusters. We also use the optical and X-ray data to investigate whether ea...

  15. Chandra reveals a black-hole X-ray binary within the ultraluminous supernova remnant MF 16

    CERN Document Server

    Roberts, T P

    2003-01-01

    We present evidence, based on Chandra ACIS-S observations of the nearby spiral galaxy NGC 6946, that the extraodinary X-ray luminosity of the MF 16 supernova remnant actually arises in a black-hole X-ray binary. This conclusion is drawn from the point-like nature of the X-ray source, its X-ray spectrum closely resembling the spectrum of other ultraluminous X-ray sources thought to be black-hole X-ray binary systems, and the detection of rapid hard X-ray variability from the source. We briefly discuss the nature of the hard X-ray variability, and the origin of the extreme radio and optical luminosity of MF 16 in light of this identification.

  16. Optical studies of the ultraluminous X-ray source NGC1313 X-2

    CERN Document Server

    Liu, J; Miller, J; Kaaret, Philip; Liu, Jifeng; Bregman, Joel; Miller, Jon; Kaaret, Philip

    2007-01-01

    NGC1313 X-2 was among the first ultraluminous X-ray sources discovered, and has been a frequent target of X-ray and optical observations. Using the HST/ACS multi-band observations, this source is identified with a unique counterpart within an error circle of $0\\farcs2$. The counterpart is a blue star on the edge of a young cluster of $\\le10^7$ years amid a dominant old stellar population. Its spectral energy distribution is consistent with that for a Z=0.004 star with 8.5 $M_\\odot$ about $5\\times10^6$ years old, or for an O7 V star at solar metallicity. The counterpart exhibited significant variability of $\\Delta m = 0.153\\pm0.033$ mag between two F555W observations separated by three months, reminiscent of the ellipsoidal variability due to the orbital motion of this ULX binary.

  17. XMM-Newton EPIC observations of the ultraluminous X-ray source NGC 5204 X-1

    CERN Document Server

    Roberts, T P; Ward, M J; Goad, M R; Jenkins, L P

    2004-01-01

    We present the results of two XMM-Newton observations of the ultraluminous X-ray source (ULX) NGC 5204 X-1. The EPIC spectra are well-fit by the standard spectral model of a black-hole X-ray binary, comprising a soft multi-colour disc blackbody component plus a harder power-law continuum. The cool (kT_in ~ 0.2 keV) inner-disc temperature required by this model favours the presence of an intermediate-mass black hole (IMBH) in this system, though we highlight a possible anomaly in the slope of the power-law continuum in such fits. We discuss the interpretation of this and other, non-standard spectral modelling of the data.

  18. The X-ray spectral evolution of the ultraluminous X-ray source Holmberg IX X-1

    Science.gov (United States)

    Luangtip, Wasutep; Roberts, Timothy P.; Done, Chris

    2016-08-01

    We present a new analysis of X-ray spectra of the archetypal ultraluminous X-ray source (ULX) Holmberg IX X-1 obtained by the Swift, XMM-Newton and NuSTAR observatories. This ULX is a persistent source, with a typical luminosity of ˜1040 erg s-1, that varied by a factor of 4-5 over eight years. We find that its spectra tend to evolve from relatively flat or two-component spectra in the medium energy band (1-6 keV), at lower luminosities, to a spectrum that is distinctly curved and disc-like at the highest luminosities, with the peak energy in the curved spectrum tending to decrease with increased luminosity. We argue that the spectral evolution of the ULX can be explained by super-Eddington accretion models, where in this case we view the ULX down the evacuated funnel along its rotation axis, bounded by its massive radiatively driven wind. The spectral changes then originate in enhanced geometric beaming as the accretion rate increases and wind funnel narrows, causing the scattered flux from the central regions of the supercritical flow to brighten faster than the isotropic thermal emission from the wind, and so the curved hard spectral component to dominate at the highest luminosities. The wind also Compton down-scatters photons at the edge of the funnel, resulting in the peak energy of the spectrum decreasing. We also confirm that Holmberg IX X-1 displays spectral degeneracy with luminosity, and suggest that the observed differences are naturally explained by precession of the black hole rotation axis for the suggested wind geometry.

  19. Chandra observation of an ultraluminous X-ray source from the Galaxy NGC 12911

    CERN Document Server

    Luna, Juan C

    2009-01-01

    I report the analysis of an ultraluminous X-ray source (ULX) located in the galaxy NGC 1291. This X-ray point source is denominated IXO6 in the Catalog of Candidate IXO (Colbert & Ptak). An Intermediate-luminosity X-ray Object (IXO) is defined as an off-nuclear, compact object with luminosity Lx [2-10keV] >= 1039 erg s-1. The cutoff Lx is defined as a value greater than the Eddington luminosity of a 1.4 Mo black hole (10 38.3 erg s-1). IXO is an early denomination of what is call now a ULX point source. The Catalog was derived from a ROSAT survey and represents 87 IXOS in 54 galaxies. IXO6 was selected because of being positioned in the outer disk of the galaxy, with no near X-ray source neighbors. The study of this ULX pretends to confirm certain assumptions related to this class of objects (Roberts et al.)

  20. Ultra-Luminous X-Ray Sources in the Most Metal Poor Galaxies

    CERN Document Server

    Prestwich, A H; Zezas, A; Jackson, F E; Roberts, T P; Foltz, R; Linden, T; Kalogera, V

    2013-01-01

    Ultra-Luminous X-ray sources (ULX) are X-ray binaries with Lx>1E^39 ergs/s. The most spectacular examples of ULX occur in starburst galaxies and are now understood to be young, luminous High Mass X-ray Binaries. The conditions under which ULX form are poorly understood, but recent evidence suggests they may be more common in low metallicity systems. Here we investigate the hypothesis that ULX form preferentially in low metallicity galaxies by searching for ULX in a sample of Extremely Metal Poor Galaxies (XMPG) observed with the Chandra X-ray Observatory. XMPG are defined as galaxies with log(O/H)+12<7.65, or less than 5% solar. These are the most metal-deficient galaxies known, and a logical place to find ULX if they favor metal poor systems. We compare the number of ULX (corrected for background contamination) per unit of star formation (Nulx) in the XMPG sample with Nulx in a comparison sample of galaxies with higher metallicities taken from the Spitzer Infrared Galaxy Sample (SINGS). We find that ULX o...

  1. New flaring of an ultraluminous X-ray source in NGC 1365

    CERN Document Server

    Soria, R; Risaliti, G; Fabbiano, G; King, A R; La Parola, V; Zezas, A

    2007-01-01

    We have studied a highly variable ultraluminous X-ray source (ULX) in the Fornax galaxy NGC 1365, with a series of 12 Chandra and XMM-Newton observations between 2002 and 2006. In 2006 April, the source peaked at a luminosity ~ 3 x 10^{40} erg/s in the 0.3-10 keV band (similar to the maximum luminosity found by ASCA in 1995), and declined on an e-folding timescale ~ 3 days. The X-ray spectrum is always dominated by a broad power-law-like component. When the source is seen at X-ray luminosities ~ 10^{40} erg/s, an additional soft thermal component (which we interpret as emission from the accretion disk) contributes ~ 1/4 of the X-ray flux; when the luminosity is higher, ~ 3 x 10^{40} erg/s, the thermal component is not detected and must contribute < 10% of the flux. At the beginning of the decline, ionized absorption is detected around 0.5-2 keV; it is a possible signature of a massive outflow. The power-law is always hard, with a photon index Gamma ~ 1.7 (and even flatter at times), as is generally the cas...

  2. Study of correlation between ultraluminous X-ray sources and their host galaxies

    Science.gov (United States)

    Priajana, I. G. P. M.; Wulandari, H. R. T.

    2016-11-01

    Ultraluminous X-ray sources (ULXs) are defined as non-nuclear point-source objects with apparent X-ray luminosities, Lx > 2×1039 erg s-1, in the 0.3-8 keV band. ULXs are often explained using two different scenarios, (1) ULXs as intermediate mass black hole (IMBH) with sub-Eddington accretion and (2) ULXs as stellar mass black hole with super-Eddington accretion. There are two methods that commonly used to study the characteristics of ULXs. One method is to study the X-ray spectra of ULXs, to determine the characteristics of their accretion flows from fitting their spectra using available spectral models. The other method is to investigate how population of ULXs correlate with their environment, in this case their host galaxies. Our goal is to find correlation between ULXs and the properties of its host galaxies, for example with Star Formation Rate (SFR), mass and morphology. From this study we found a positive correlation between ULXs number and SFR. From X-ray luminosity function, we found upper limit of black holes mass that power ULXs is about 100 M⊙.

  3. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism

    Science.gov (United States)

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D.; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J.; Mancuso, Christopher A.; Hogle, Craig W.; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L.; Dorney, Kevin M.; Chen, Cong; Shpyrko, Oleg G.; Fullerton, Eric E.; Cohen, Oren; Oppeneer, Peter M.; Milošević, Dejan B.; Becker, Andreas; Jaroń-Becker, Agnieszka A.; Popmintchev, Tenio; Murnane, Margaret M.; Kapteyn, Henry C.

    2015-01-01

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform. PMID:26534992

  4. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism.

    Science.gov (United States)

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J; Mancuso, Christopher A; Hogle, Craig W; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L; Dorney, Kevin M; Chen, Cong; Shpyrko, Oleg G; Fullerton, Eric E; Cohen, Oren; Oppeneer, Peter M; Milošević, Dejan B; Becker, Andreas; Jaroń-Becker, Agnieszka A; Popmintchev, Tenio; Murnane, Margaret M; Kapteyn, Henry C

    2015-11-17

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform.

  5. On the physical nature of the source of ultraluminous X-ray pulsations

    Science.gov (United States)

    Ter-Kazarian, G.

    2016-01-01

    To reconcile the observed unusual high luminosity of NuSTAR X-ray pulsations from M82X-2 with the most extreme violation of the Eddington limit, and in view that the persistent X-ray radiation from M82X-2 almost precludes the possibility of common pulsars, we tackle the problem by the implications of microscopic theory of black hole (MTBH). The preceding developments of MTBH are proved to be quite fruitful for the physics of ultra-high energy (UHE) cosmic-rays. Namely, replacing a central singularity by the infrastructures inside event horizon, subject to certain rules, MTBH explains the origin of ZeV-neutrinos which are of vital interest for the source of UHE-particles. The M82X-2 is assumed to be a spinning intermediate mass black hole resided in final stage of growth. Then, the thermal blackbody X-ray emission, arisen due to the rotational kinetic energy of black hole, escapes from event horizon through the vista to outside world, which is detected as ultraluminous X-ray pulsations. The M82X-2 indeed releases ˜99.6 % of its pulsed radiative energy predominantly in the X-ray bandpass 0.3-30 keV. We derive a pulse profile and give a quantitative account of energetics and orbital parameters of the semi-detached X-ray binary containing a primary accretor M82X-2 of inferred mass M≃138.5-226 M_{⊙} and secondary massive, M2> 48.3-64.9 M_{⊙}, O/B-type donor star with radius of R> 22.1-25.7 R_{⊙}, respectively. We compute the torque added to M82X-2 per unit mass of accreted matter which yields the measured spin-up rate.

  6. Toward a Clean Sample of Ultra-Luminous X-ray Sources

    CERN Document Server

    López-Corredoira, M

    2006-01-01

    CONTEXT. Observational follow-up programmes for the characterization of ultra-luminous X-ray sources (ULXs) require the construction of clean samples of such sources in which the contamination by foreground/background sources is minimum. AIMS. In this article we calculate the degree of foreground/background contaminants among the ULX sample candidates in the Colbert & Ptak (2002) catalogue and compare these computations with available spectroscopical identifications. METHODS. We use statistics based on known densities of X-ray sources and AGN/QSOs selected in the optical. The analysis is done individually for each parent galaxy. The existing identifications of the optical counterparts are compiled from the literature. RESULTS. More than a half of the ULXs, within twice the distance of the major axis of the 25 mag/arcsec$^2$ isophote from RC3 nearby galaxies and with X-ray luminosities $L_X$[2-10 keV] $\\ge 10^{39}$ erg/s, are expected to be high redshift background QSOs. A list of 25 objects (clean sample)...

  7. Supercritical Accretion Discs in Ultraluminous X-ray Sources and SS 433

    CERN Document Server

    Fabrika, Sergei; Vinokurov, Alexander; Sholukhova, Olga; Shidatsu, Megumi

    2015-01-01

    The black hole mass and accretion rate in Ultraluminous X-ray sources (ULXs) in external galaxies, whose X-ray luminosities exceed those of the brightest black holes in our Galaxy by hundreds and thousands of times$^{1,2}$, is an unsolved problem. Here we report that all ULXs ever spectroscopically observed have about the same optical spectra apparently of WNL type (late nitrogen Wolf-Rayet stars) or LBV (luminous blue variables) in their hot state, which are very scarce stellar objects. We show that the spectra do not originate from WNL/LBV type donors but from very hot winds from the accretion discs with nearly normal hydrogen content, which have similar physical conditions as the stellar winds from these stars. The optical spectra are similar to that of SS 433, the only known supercritical accretor in our Galaxy$^{3}$, although the ULX spectra indicate a higher wind temperature. Our results suggest that ULXs with X-ray luminosities of $\\sim 10^{40}$ erg s$^{-1}$ must constitute a homogeneous class of objec...

  8. The Ultraluminous X-ray Sources near the Center of M82

    CERN Document Server

    Kong, A K H; Hsieh, P -Y; Mak, D S Y; Pun, C S J

    2007-01-01

    We report the discovery of a recurrent ultraluminous X-ray source(ULX), a background AGN, and a young supernova remnant near the center of the starburst galaxy M82. From a series of Chandra observations taken from 1999 to 2005, we found that the ULX first appeared in 1999 October. The source turned off in 2000 January, but later reappeared and has been active since then. The X-ray luminosity of this source varies from below the detection level (~ 2.5e38 erg/s) to its active state in between ~8e39 erg/s and 1.3e40 erg/s (in the 0.5-10 keV energy band) and shows unusual spectral changes. The X-ray spectra are best fitted with an absorbed power-law model with photon index ranging from 1.3 to 1.7. The spectra are similar to those Galactic black hole binary candidates seen in the low/hard state except that a very hard spectrum was seen in one of the observations. By comparing with near infrared images taken with the Hubble Space Telescope, the ULX is found to be located within a young star cluster. Radio imaging i...

  9. An extremely luminous and variable ultraluminous x-ray source in the outskirts of circinus observed with NuSTAR

    DEFF Research Database (Denmark)

    Walton, D. J.; Fuerst, F.; Harrison, F.;

    2013-01-01

    Following a serendipitous detection with the Nuclear Spectroscopic Telescope Array (NuSTAR), we present a multi-epoch spectral and temporal analysis of an extreme ultraluminous X-ray source (ULX) located in the outskirts of the Circinus galaxy, hereafter Circinus ULX5, including coordinated XMM-N...

  10. Bifurcation timescales in power spectra of black hole binaries and ultraluminous X-ray sources

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    For black hole binaries(BHBs) and active galactic nuclei(AGNs),bifurcation timescales(BTs) Δtb exist,below which time-domain power is significantly higher than the corresponding Fourier power.Quasi-periodic oscillations(QPOs) are removed from the Fourier spectra of BHBs.A relationship between BT,black hole mass and bolometric luminosity is derived.Strong anti-correlation between BT and luminosity of Cyg X-1 is found.After removing the QPOs,BTs are also obtained for two ultraluminous X-ray sources(ULXs),M82 X-1 and NGC5408 X-1.The results support that they harbor intermediate mass black holes(IMBHs).

  11. New Hubble Space Telescope imaging of the counterparts to six ultraluminous X-ray sources

    CERN Document Server

    Roberts, T P; Goad, M R

    2008-01-01

    We report the results of new Hubble Space Telescope imaging of the positions of six ultraluminous X-ray sources (ULXs). Using images in three ACS filters we detect good candidate counterparts to four out of six ULXs, with one more possible detection, and observed magnitudes in the range m ~ 22 - 26 in the F606W filter. The extinction-corrected colours and absolute magnitudes vary from source to source, even after correcting for additional extinction in the host galaxy, and only one counterpart is readily explained as an OB star. Nevertheless, these counterparts are decent candidates for future follow-up in pursuit of dynamical mass constraints on the likely black holes powering these sources.

  12. PROFFIT: Analysis of X-ray surface-brightness profiles

    Science.gov (United States)

    Eckert, Dominique

    2016-08-01

    PROFFIT analyzes X-ray surface-brightness profiles for data from any X-ray instrument. It can extract surface-brightness profiles in circular or elliptical annuli, using constant or logarithmic bin size, from the image centroid, the surface-brightness peak, or any user-given center, and provides surface-brightness profiles in any circular or elliptical sectors. It offers background map support to extract background profiles, can excise areas using SAO DS9-compatible (ascl:0003.002) region files to exclude point sources, provides fitting with a number of built-in models, including the popular beta model, double beta, cusp beta, power law, and projected broken power law, uses chi-squared or C statistic, and can fit on the surface-brightness or counts data. It has a command-line interface similar to HEASOFT’s XSPEC (ascl:9910.005) package, provides interactive help with a description of all the commands, and results can be saved in FITS, ROOT or TXT format.

  13. Evidence for Quasi-periodic X-Ray Dips from an Ultraluminous X-Ray Source: Implications for the Binary Motion

    CERN Document Server

    Pasham, Dheeraj R

    2013-01-01

    We report results from long-term (approximately 1240 days) X-ray (0.3-8.0 keV) monitoring of the ultraluminous X-ray source NGC 5408 X-1 with the Swift/X-Ray Telescope. Here we expand on earlier work by Strohmayer (2009) who used only a part of the present data set. Our primary results are: (1) the discovery of sharp, quasi-periodic, energy-independent dips in the X-ray intensity that recur on average every 243 days, (2) the detection of an energy-dependent (variability amplitude decreases with increasing energy), quasi-sinusoidal X-ray modulation with a period of 112.6+-4 days the amplitude of which weakens during the second half of the light curve and (3) spectral evidence for an increase in photoelectric absorption during the last continuous segment of the data. We interpret the X-ray modulations within the context of binary motion in analogy to that seen in high-inclination accreting X-ray binaries. If correct, this implies that NGC 5408 X-1 is in a binary with an orbital period of 243+-23 days, in contra...

  14. A Possible 55-day X-ray Period of the Ultraluminous Accreting Pulsar M82 X-2

    CERN Document Server

    Kong, A K H; Lin, L C -C; Li, K L; Jin, R; Liu, C Y; Yen, D C -C

    2016-01-01

    We report a possible detection of a 55-day X-ray modulation for the ultraluminous accreting pulsar M82 X-2 from archival Chandra observations. Because M82 X-2 is known to have a 2.5-day orbital period, if the 55-day period is real, it will be the superorbital period of the system. We also investigated variabilities of other three nearby ultraluminous X-ray sources in the central region of M82 with the Chandra data and did not find any evidence of periodicities. Furthermore, we re-examined the previously reported 62-day periodicity near the central region of M82 by performing a systematic timing study with all the archival Rossi X-Ray Timing Explorer and Swift data. Using various dynamic timing analysis methods, we confirmed that the 62-day period is not stable, suggesting that it is not the orbital period of M82 X-1 in agreement with previous work.

  15. A Radio Nebula Surrounding the Ultra-luminous X-ray Source in NGC 5408

    CERN Document Server

    Lang, Cornelia C; Corbel, Stephane; Mercer, Allison

    2007-01-01

    New radio observations of the counterpart of the ultraluminous X-ray source in NGC 5408 show for the first time that the radio emission is resolved with an angular size of 1.5 to 2.0 arcseconds. This corresponds to a physical size of 35-46 pc, and rules out interpretation of the radio emission as beamed emission from a relativistic jet. In addition, the radio spectral index of the counterpart is well determined from three frequencies and found to be alpha=-0.8 pm 0.2. The radio emission is likely to be optically-thin synchrotron emission from a nebula surrounding the X-ray source. The radio luminosity of the counterpart is 3.8 x 10^34 erg/s and the minimum energy required to power the nebula is ~1 x 10^49 erg. These values are two orders of magnitude larger than in any Galactic nebula powered by an accreting compact object.

  16. Relativistic baryonic jets from an ultraluminous supersoft X-ray source

    CERN Document Server

    Liu, Ji-Feng; Wang, Song; Justham, Stephen; Lu, You-Jun; Gu, Wei-Min; Liu, Qing-Zhong; Di Stefano, Rosanne; Guo, Jin-Cheng; Cabrera-Lavers, Antonio; Alvarez, Pedro; Cao, Yi; Kulkarni, Shri

    2015-01-01

    The formation of relativistic jets by an accreting compact object is one of the fundamental mysteries of astrophysics. While the theory is poorly understood, observations of relativistic jets from systems known as microquasars\\cite{Mirabel98,Paredes03} have led to a well-established phenomenology\\cite{Fender04,Migliari06}. Relativistic jets are not expected from sources with soft or supersoft X-ray spectra, although two such systems are known to produce relatively low-velocity bipolar outflows\\cite{Southwell96,Becker98}. Here we report optical spectra of an ultraluminous supersoft X-ray source (ULS\\cite{DiStefano03,Swartz02}) in the nearby galaxy M81 (M81 ULS-1\\cite{Liu08a,Liu08b}) showing blueshifted broad H\\alpha\\ emission lines, characteristic of baryonic jets with relativistic speeds. The time variable jets have projected velocities ~17 per cent of the speed of light, and seem similar to those in the prototype microquasar SS 433\\cite{Margon84,Blundell07}. Such relativistic jets are not expected to be laun...

  17. The ultraluminous X-ray source NGC 1313 X-2 - Its optical counterpart and environment

    CERN Document Server

    Grisé, F; Soria, R; Motch, C; Smith, I A; Ryder, S D; Böttcher, M

    2008-01-01

    NGC 1313 X-2 is one of the brightest ultraluminous X-ray sources in the sky, at both X-ray and optical wavelengths; therefore, quite a few studies of available ESO VLT and HST data have appeared in the literature. Here, we present our analysis of VLT/FORS1 and HST/ACS photometric data, confirming the identification of the B ~ 23 mag blue optical counterpart. We show that the system is part of a poor cluster with an age of 20 Myr, leading to an upper mass limit of some 12 M_sun for the mass donor. We attribute the different results with respect to earlier studies to the use of isochrones in the F435W and F555W HST/ACS photometric system that appear to be incompatible with the corresponding Johnson B and V isochrones. The counterpart exhibits significant photometric variability of about 0.2 mag amplitude, both between the two HST observations and during the one month of monitoring with the VLT. This includes variability within one night and suggests that the light is dominated by the accretion disk in the syste...

  18. A mass of less than 15 solar masses for the black hole in an ultraluminous X-ray source.

    Science.gov (United States)

    Motch, C; Pakull, M W; Soria, R; Grisé, F; Pietrzyński, G

    2014-10-01

    Most ultraluminous X-ray sources have a typical set of properties not seen in Galactic stellar-mass black holes. They have luminosities of more than 3 × 10(39) ergs per second, unusually soft X-ray components (with a typical temperature of less than about 0.3 kiloelectronvolts) and a characteristic downturn in their spectra above about 5 kiloelectronvolts. Such puzzling properties have been interpreted either as evidence of intermediate-mass black holes or as emission from stellar-mass black holes accreting above their Eddington limit, analogous to some Galactic black holes at peak luminosity. Recently, a very soft X-ray spectrum was observed in a rare and transient stellar-mass black hole. Here we report that the X-ray source P13 in the galaxy NGC 7793 is in a binary system with a period of about 64 days and exhibits all three canonical properties of ultraluminous sources. By modelling the strong optical and ultraviolet modulations arising from X-ray heating of the B9Ia donor star, we constrain the black hole mass to be less than 15 solar masses. Our results demonstrate that in P13, soft thermal emission and spectral curvature are indeed signatures of supercritical accretion. By analogy, ultraluminous X-ray sources with similar X-ray spectra and luminosities of up to a few times 10(40) ergs per second can be explained by supercritical accretion onto massive stellar-mass black holes.

  19. Bright radio emission from an ultraluminous stellar-mass microquasar in M31

    CERN Document Server

    Middleton, Matthew J; Markoff, Sera; Fender, Rob; Henze, Martin; Hurley-Walker, Natasha; Scaife, Anna M M; Roberts, Timothy P; Walton, Dominic; Carpenter, John; Macquart, Jean-Pierre; Bower, Geoffrey C; Gurwell, Mark; Pietsch, Wolfgang; Haberl, Frank; Harris, Jonathan; Daniel, Michael; Miah, Junayd; Done, Chris; Morgan, John; Dickinson, Hugh; Charles, Phil; Burwitz, Vadim; Della Valle, Massimo; Freyberg, Michael; Greiner, Jochen; Hernanz, Margarita; Hartmann, Dieter H; Hatzidimitriou, Despina; Riffeser, Arno; Sala, Gloria; Seitz, Stella; Reig, Pablo; Rau, Arne; Orio, Marina; Titterington, David; Grainge, Keith

    2012-01-01

    A subset of ultraluminous X-ray sources (those with luminosities < 10^40 erg/s) are thought to be powered by the accretion of gas onto black holes with masses of ~5-20 M_solar, probably via an accretion disc. The X-ray and radio emission are coupled in such Galactic sources, with the radio emission originating in a relativistic jet thought to be launched from the innermost regions near the black hole, with the most powerful emission occurring when the rate of infalling matter approaches a theoretical maximum (the Eddington limit). Only four such maximal sources are known in the Milky Way, and the absorption of soft X-rays in the interstellar medium precludes determining the causal sequence of events that leads to the ejection of the jet. Here we report radio and X-ray observations of a bright new X-ray source whose peak luminosity can exceed 10^39 erg/s in the nearby galaxy, M31. The radio luminosity is extremely high and shows variability on a timescale of tens of minutes, arguing that the source is highl...

  20. Spectroscopic comparison between ultraluminous X-ray sources and magnetar bursts

    CERN Document Server

    Kajava, J J E

    2016-01-01

    Nearby galaxies host ultra-luminous X-ray sources (ULXs), whose nature remains largely unknown. Until the discovery of the first ULX pulsar, M82 X-2, the mechanism powering the large luminosities of most ULXs was thought to be super-Eddington accretion onto black holes. The ULX pulsar clearly indicates that this hypothesis is not universal, and the question arises if other ULXs are as well powered by accretion onto neutron stars. One possibility to have highly super-Eddington luminosity is by reducing the opacity by strong magnetic fields as in magnetars, as proposed for M82 X-2. To study the link between ULXs and magnetar bursts/flares, we have performed a comparative spectral study between these classes, which both emit at similar super-Eddington luminosities at around $L \\sim 10^{40}$ erg s$^{-1}$. We find that, when their spectra are fitted with dual thermal models, the long term spectral variations of ULXs are similar to short term spectral variability seen during magnetar flares. In both classes of sour...

  1. The ultraluminous X-ray source population of NGC 4485/4490

    CERN Document Server

    Gladstone, J C

    2009-01-01

    We report the results of spectral and temporal variability studies of the ultraluminous X-ray sources (ULXs) contained within the interacting pair of galaxies NGC 4485/4490, combining Chandra and XMM-Newton observations. Each of the four separate observations provide at least modest quality spectra and light curves for each of the six previously identified ULXs in this system; we also note the presence of a new transient ULX in the most recent observation. No short-term variability was observed for any ULX within our sample, but three out of five sources show correlated flux/spectral changes over longer timescales, with two others remaining stable in spectrum and luminosity over a period of at least five years. We model the spectra with simple power-law and multi-colour disc black body models. Although the data is insufficient to statistically distinguish models in each epoch, those better modelled (in terms of their chi^2 fit) by a multi-colour disc black body appear to show a disc-like correlation between l...

  2. THE SLIM-DISK STATE OF THE ULTRALUMINOUS X-RAY SOURCE IN M83

    Energy Technology Data Exchange (ETDEWEB)

    Soria, Roberto [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, WA 6845 (Australia); Kuntz, K. D.; Blair, William P. [The Henry A. Rowland Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Long, Knox S. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Plucinsky, Paul P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Winkler, P. Frank, E-mail: roberto.soria@curtin.edu.au [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States)

    2015-02-01

    The transient ULX in M83 that went into outburst in, or shortly before, 2010 is still active. Our new XMM-Newton spectra show that it has a curved spectrum typical of the upper end of the high/soft state or slim-disk state. It appears to be spanning the gap between Galactic stellar-mass black holes (BHs) and the ultraluminous state, at X-ray luminosities of ≈1-3 × 10{sup 39} erg s{sup –1} (a factor of two lower than in the 2010 and 2011 Chandra observations). From its broadened disk-like spectral shape at that luminosity, and from the fitted inner-disk radius and temperature, we argue that the accreting object is an ordinary stellar-mass BH with M ∼ 10-20 M {sub ☉}. We suggest that in the 2010 and 2011 Chandra observations, the source was seen at a higher accretion rate, resulting in a power-law-dominated spectrum with a soft excess at large radii.

  3. The Binary Black Hole Merger Rate from Ultraluminous X-ray Source Progenitors

    Science.gov (United States)

    Finke, Justin; Razzaque, Soebur

    2017-01-01

    Ultraluminous X-ray sources (ULXs) exceed the Eddington luminosity for an approximately 10 solar mass black hole. The recent detection of a black hole merger event GW 150914 by the gravitational wave detector ALIGO indicates that black holes with mass greater than 10 do indeed exist. Motivated by this, we explore a scenario where ULXs consist of black holes formed by the collapse of high-mass, low-metallicity stars, and that these ULXs become binary black holes (BBHs) that eventually merge. We use empirical relations between the number of ULXs and the star formation rate and host galaxy metallicity to estimate the ULX formation rate and the BBH merger rate at all redshifts. This assumes the ULX rate is directly proportional to the star formation rate for a given metallicity, and that the black hole accretion rate is distributed as a log-normal distribution. We include an enhancement in the ULX formation rate at earlier epochs due to lower mean metallicities. Our model is able to reproduce both the rate and mass distribution of BBH mergers in the nearby universe inferred from the detection of GW 150914, LVT 151012, and GW 151226 by LIGO if the median accretion rate of ULXs is a factor 1 to 30 greater than the Eddington rate. Our predictions of the BBH merger rate, mass distribution.

  4. A radiation-hydrodynamic model of accretion columns for ultra-luminous X-ray pulsars

    CERN Document Server

    Kawashima, Tomohisa; Ohsuga, Ken; Ogawa, Takumi

    2016-01-01

    Prompted by the recent discovery of pulsed emission from an ultra-luminous X-ray source, M82 X-2 ("ULX-pulsar"), we perform a two-dimensional radiation-hydrodynamic simulation of a super-critical accretion flow onto a neutron star through a narrow accretion column. We set an accretion column with a cone shape filled with tenuous gas with density of $10^{-4} {\\rm g}~ {\\rm cm}^{-3}$ above a neutron star and solve the two dimensional gas motion and radiative transfer within the column. The side boundaries are set such that radiation can freely escape, while gas cannot. Since the initial gas layer is not in a hydrostatic balance, the column gas falls onto the neutron-star surface, thereby a shock being generated. As a result, the accretion column is composed of two regions: an upper, nearly free-fall region and a lower settling region, as was noted by Basko \\& Sunyaev (1976). The average accretion rate is very high; ${\\dot M}\\sim 10^{2-3} L_{\\rm E}/c^2$ (with $L_{\\rm E}$ being the Eddington luminosity), and s...

  5. Ultraluminous X-ray Sources as Intermediate Mass Black Holes Fed by Tidally Captured Stars

    CERN Document Server

    Hopman, C; Alexander, T; Hopman, Clovis; Zwart, Simon F. Portegies; Alexander, Tal

    2004-01-01

    The nature of ultraluminous X-ray sources (ULXs) is presently unknown. A possible explanation is that they are accreting intermediate mass black holes (IBHs) that are fed by Roche lobe overflow from a tidally captured stellar companion. We show that a star can circularize around an IBH without being destroyed by tidal heating (in contrast to the case of M_bh> 10^6 M_sun massive black holes in galactic centers, where survival is unlikely). We find that the capture and circularization rate is of the order of 5 \\times 10^-8 yr^-1, almost independently of the cluster's relaxation time. We follow the luminosity evolution of the binary system during the main sequence Roche lobe overflow phase and show it can maintain ULX-like luminosities for >10 Myr. In particular, we show that the ULX in the young cluster MGG-11 in star-burst galaxy M82, which possibly harbors an IBH, is well explained by this mechanism, and we predict that \\gtrsim 10% of similar clusters with IBHs have a tidally captured circularized star. The c...

  6. The Local Environment of Ultraluminous X-ray Sources Viewed by XMM Newton's Optical Monitor

    CERN Document Server

    Berghea, Ciprian T

    2014-01-01

    We have used XMM-Newton's Optical Monitor (OM) images to study the local environment of a sample of 27 Ultraluminous X-ray Sources (ULXs) in nearby galaxies. UVW1 fluxes were extracted from 100 pc regions centered on the ULX positions. We find that at least 4 ULXs (out of 10 published) have spectral types that are consistent with previous literature values. In addition the colors are similar to those of young stars. For the highest-luminosity ULXs, the UVW1 fluxes may have an important contribution from the accretion disk. We find that the majority of ULXs are associated with recent star-formation. Many of the ULXs in our sample are located inside young OB associations or star-forming regions (SFRs). Based on their colors, we estimated ages and masses for star-forming regions located within 1 kpc from the ULXs in our sample. The resolution of the OM was insufficient to detect young dense super-clusters, but some of these star-forming regions are massive enough to contain such clusters. Only three ULXs have no...

  7. Revealing a Cool Accretion Disk in the Ultraluminous X-ray Source M81 X-9 (Holmberg IX X-1): Evidence for an Intermediate Mass Black Hole

    CERN Document Server

    Miller, J M; Miller, M C

    2003-01-01

    We report the results of an analysis of two XMM-Newton/EPIC-pn spectra of the bright ultraluminous X-ray source M81 X-9 (Holmberg IX X-1), obtained in snapshot observations. Soft thermal emission is clearly revealed in spectra dominated by hard power-law components. Depending on the model used, M81 X-9 was observed at a luminosity of L_X = 1.0-1.6 E+40 erg/s (0.3-10.0 keV). The variability previously observed in this source signals that it is an accreting source which likely harbors a black hole. Remarkably, accretion disk models for the soft thermal emission yield very low inner disk temperatures (kT = 0.17-0.29 keV, including 90 per cent confidence errors and variations between observations and disk models), and improve the fit statistic over any single-component continuum model at the 6 sigma level of confidence. This represents much stronger evidence for a cool disk than prior evidence which combined spectra from different observatories, and the strongest evidence of a cool disk in an ultraluminous X-ray ...

  8. A radiation-hydrodynamics model of accretion columns for ultra-luminous X-ray pulsars

    Science.gov (United States)

    Kawashima, Tomohisa; Mineshige, Shin; Ohsuga, Ken; Ogawa, Takumi

    2016-10-01

    Prompted by the recent discovery of pulsed emission from an ultra-luminous X-ray source, M 82 X-2 ("ULX-pulsar"), we perform a two-dimensional radiation-hydrodynamics simulation of a supercritical accretion flow onto a neutron star through a narrow accretion column. We set an accretion column with a cone shape filled with tenuous gas with the density of 10-4 g cm-3 above a neutron star and solve the two-dimensional gas motion and radiative transfer within the column. The side boundaries are set such that radiation can freely escape, but gas cannot. Since the initial gas layer is not in a hydrostatic balance, the column gas falls onto the neutron-star surface, and thereby a shock is generated. As a result, the accretion column is composed of two regions: an upper, nearly free-fall region and a lower settling region, as noted by Basko and Sunyaev (1976, MNRAS, 175, 395). The average accretion rate is very high; dot{M}˜ 10^{2{-}3} L_E/c2 (with LE being the Eddington luminosity), and so radiation energy dominates over gas internal energy entirely within the column. Despite the high accretion rate, the radiation flux in the laboratory frame is kept barely below LE/(4πr2) at a distance r in the settling region so that matter can slowly accrete. This adjustment is made possible, since a large amount of photons produced via dissipation of kinetic energy of matter can escape through the side boundaries. The total luminosity can greatly exceed LE by several orders of magnitude, whereas the apparent luminosity observed from the top of the column is much less. Due to such highly anisotropic radiation fields, the observed flux should exhibit periodic variations with the rotation period, provided that the rotation and magnetic axes are misaligned.

  9. Discovery of a Large Population of Ultraluminous X-ray Sources in the Bulge-less Galaxies NGC 337 and ESO 501-23

    CERN Document Server

    Somers, Garrett; Martini, Paul; Watson, Linda; Grier, Catherine J; Ferrarese, Laura

    2013-01-01

    We have used Chandra observations of eight bulge-less disk galaxies to identify new ultraluminous X-ray source (ULX) candidates, study their high mass X-ray binary (HMXB) population, and search for low-luminosity active galactic nuclei (AGN). We report the discovery of 16 new ULX candidates in our sample of galaxies. Eight of these are found in the star forming galaxy NGC 337, none of which are expected to be background contaminants. The HMXB luminosity function of NGC 337 implies a star formation rate (SFR) of 6.8$^{+4.4}_{-3.5}$ \\msun\\ yr$^{-1}$, consistent at 1.5$\\sigma$ with a recent state of the art SFR determination. We also report the discovery of a bright ULX candidate (X-1) in ESO 501-23. X-1's spectrum is well fit by an absorbed power law with $\\Gamma = 1.18^{+0.19}_{-0.11}$ and N$\\rm{_H}$ = 1.13$^{+7.07}_{-1.13} \\times 10^{20}$ cm$^{-2}$, implying a 0.3-8 keV flux of $1.08^{+0.05}_{-0.07} \\times 10^{-12}$ \\esc. Its X-ray luminosity (L$_X$) is poorly constrained due to uncertainties in the host gala...

  10. The Broadband XMM-Newton and NuSTAR X-ray Spectra of Two Ultraluminous X-ray Sources in the Galaxy IC 342

    DEFF Research Database (Denmark)

    Rana, Vikram; Harrison, Fiona A.; Bachetti, Matteo

    2015-01-01

    We present results for two Ultraluminous X-ray Sources (ULXs), IC 342 X-1 and IC 342 X-2, using two epochs of XMM-Newton and NuSTAR observations separated by ∼7 days. We observe little spectral or flux variability above 1 keV between epochs, with unabsorbed 0.3-30 keV luminosities being $1.......04+0.08/-0.06 x 1040 erg s-1 for IC 342 X-1 and 7.40±0.20 x 1039 erg s-1for IC 342 X-2, so that both were observed in a similar, luminous state. Both sources have a high absorbing column in excess of the Galactic value. Neither source has a spectrum consistent with a black hole binary in low/hard state, and both...... ULXs exhibit strong curvature in their broadband X-ray spectra. This curvature rules out models that invoke a simple reflection-dominated spectrum with a broadened iron line and no cutoff in the illuminating power-law continuum. X-ray spectrum of IC 342 X-1 can be characterized by a soft disk...

  11. FIRST SEARCH FOR AN X-RAY–OPTICAL REVERBERATION SIGNAL IN AN ULTRALUMINOUS X-RAY SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Pasham, Dheeraj R.; Strohmayer, Tod E.; Cenko, S. Bradley [Code 661, Astrophysics Science Division, NASA’s Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Trippe, Margaret L. [Johns Hopkins University Applied Physics Laboratory, Laurel, MD (United States); Mushotzky, Richard F. [Joint Space-Science Institute, University of Maryland, College Park, MD 20742 (United States); Gandhi, Poshak, E-mail: dheerajrangareddy.pasham@nasa.gov [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2016-02-10

    Using simultaneous optical (VLT/FORS2) and X-ray (XMM-Newton) data of NGC 5408, we present the first ever attempt to search for a reverberation signal in an ultraluminous X-ray source (NGC 5408 X-1). The idea is similar to active galactic nucleus broad line reverberation mapping where a lag measurement between the X-ray and the optical flux combined with a Keplerian velocity estimate should enable us to weigh the central compact object. We find that although NGC 5408 X-1's X-rays are variable on a timescale of a few hundred seconds (rms of 9.0 ± 0.5%), the optical emission does not show any statistically significant variations. We set a 3σ upper limit on the rms optical variability of 3.3%. The ratio of the X-ray to the optical variability is an indicator of X-ray reprocessing efficiency. In X-ray binaries, this ratio is roughly 5. Assuming a similar ratio for NGC 5408 X-1, the expected rms optical variability is ≈2%, which is still a factor of roughly two lower than what was possible with the VLT observations in this study. We find marginal evidence (3σ) for optical variability on a ∼24 hr timescale. Our results demonstrate that such measurements can be made, but photometric conditions, low sky background levels, and longer simultaneous observations will be required to reach optical variability levels similar to those of X-ray binaries.

  12. Swift Detection of a 65 Day X-Ray Period from the Ultraluminous Pulsar NGC 7793 P13

    Science.gov (United States)

    Hu, Chin-Ping; Li, K. L.; Kong, Albert K. H.; Ng, C.-Y.; Chun-Che Lin, Lupin

    2017-01-01

    NGC 7793 P13 is an ultraluminous X-ray source harboring an accreting pulsar. We report on the detection of a ∼65 day period X-ray modulation with Swift observations in this system. The modulation period found in the X-ray band is P = 65.05 ± 0.10 days and the profile is asymmetric with a fast rise and a slower decay. On the other hand, the u-band light curve collected by Swift UVOT confirmed an optical modulation with a period of P = 64.24 ± 0.13 days. We explored the phase evolution of the X-ray and optical periodicities and propose two solutions. A superorbital modulation with a period of ∼2700–4700 days probably caused by the precession of a warped accretion disk is necessary to interpret the phase drift of the optical data. We further discuss the implication if this ∼65 day periodicity is caused by the superorbital modulation. Estimated from the relationship between the spin-orbital and orbital-superorbital periods of known disk-fed high-mass X-ray binaries, the orbital period of P13 is roughly estimated as 3–7 days. In this case, an unknown mechanism with a much longer timescale is needed to interpret the phase drift. Further studies on the stability of these two periodicities with a long-term monitoring could help us to probe their physical origins.

  13. On the association of the ultraluminous X-ray sources in the Antennae galaxies with young stellar clusters

    CERN Document Server

    Poutanen, Juri; Valeev, Azamat F; Sholukhova, Olga; Greiner, Jochen

    2013-01-01

    The nature of the ultra-luminous X-ray sources (ULXs) in the nearby galaxies is a matter of debates. One of the popular hypothesis associates them with accretion at a sub-Eddington rate on to intermediate mass black holes. Another possibility is a stellar-mass black hole in a high-mass X-ray binary accreting at super-Eddington rates. In this paper we find a highly significant association between brightest X-ray sources in the Antennae galaxies and stellar clusters. On the other hand, we show that most of the X-ray sources are located outside of these clusters. We study clusters associated with the ULXs using the ESO Very Large Telescope spectra and the Hubble Space Telescope data together with the theoretical evolutionary tracks and determine their ages to be below 5 Myr. This implies that the ULX progenitor masses certainly exceed 40 and for some objects are closer to 100 solar masses. We also estimate the ages of clusters situated close to the less luminous X-ray sources (with luminosity in the range 3x10^3...

  14. The Broadband XMM-Newton and NuSTAR X-Ray Spectra of Two Ultraluminous X-Ray Sources in the Galaxy IC 342

    Science.gov (United States)

    Rana, Vikram; Harrison, Fiona A.; Bachetti, Matteo; Walton, Dominic J.; Furst, Felix; Barret, Didier; Miller, Jon M.; Fabian, Andrew C.; Boggs, Steven E.; Christensen, Finn C.; Craig, William W.; Grefenstette, Brian W.; Hailey, Charles J.; Madsen, Kristin K.; Ptak, Andrew F.; Stern, Daniel; Webb, Natalie A.; Zhang, William W.

    2015-02-01

    We present results for two ultraluminous X-ray sources (ULXs), IC 342 X-1 and IC 342 X-2, using two epochs of XMM-Newton and NuSTAR observations separated by ~7 days. We observe little spectral or flux variability above 1 keV between epochs, with unabsorbed 0.3-30 keV luminosities being 1.04+0.08-0.06 × 1040 erg s-1 for IC 342 X-1 and 7.40 ± 0.20 × 1039 erg s-1 for IC 342 X-2, so that both were observed in a similar, luminous state. Both sources have a high absorbing column in excess of the Galactic value. Neither source has a spectrum consistent with a black hole binary in low/hard state, and both ULXs exhibit strong curvature in their broadband X-ray spectra. This curvature rules out models that invoke a simple reflection-dominated spectrum with a broadened iron line and no cutoff in the illuminating power-law continuum. X-ray spectrum of IC 342 X-1 can be characterized by a soft disk-like blackbody component at low energies and a cool, optically thick Comptonization continuum at high energies, but unique physical interpretation of the spectral components remains challenging. The broadband spectrum of IC 342 X-2 can be fit by either a hot (3.8 keV) accretion disk or a Comptonized continuum with no indication of a seed photon population. Although the seed photon component may be masked by soft excess emission unlikely to be associated with the binary system, combined with the high absorption column, it is more plausible that the broadband X-ray emission arises from a simple thin blackbody disk component. Secure identification of the origin of the spectral components in these sources will likely require broadband spectral variability studies.

  15. External Compton emission from relativistic jets in Galactic black hole candidates and ultraluminous X-ray sources

    CERN Document Server

    Georganopoulos, M; Kirk, J G

    2002-01-01

    Galactic binary systems that contain a black hole candidate emit hard X-rays in their low luminosity mode. We show that this emission can be understood as due to the Compton scattering of photons from the companion star and/or the accretion disk by relativistic electrons in a jet. The same electrons are also responsible for the radio emission. Two sources -- XTE J1118+480 and Cygnus X-1 -- are modelled as representatives of black holes with low and high luminosity companion stars respectively. We further show that the ultraluminous compact X-ray sources observed in nearby galaxies have the properties expected of stellar mass black holes with high luminosity companions in which the jet is oriented close to our line of sight.

  16. A Hard X-Ray Study of Ultraluminous X-ray Source NGC 5204 X-1 with NuSTAR and XMM-Newton

    CERN Document Server

    Mukherjee, E S; Bachetti, M; Harrison, F A; Barret, D; Bellm, E; Boggs, S E; Christensen, F E; Craig, W W; Fabian, A C; Fuerst, F; Grefenstette, B W; Hailey, C J; Madsen, K K; Middleton, M J; Miller, J M; Rana, V; Stern, D; Zhang, W

    2015-01-01

    We present the results from coordinated X-ray observations of the ultraluminous X-ray source NGC 5204 X-1 performed by NuSTAR and XMM-Newton in early 2013. These observations provide the first detection of NGC 5204 X-1 above 10 keV, extending the broadband coverage to 0.3-20 keV. The observations were carried out in two epochs separated by approximately 10 days, and showed little spectral variation, with an observed luminosity of Lx = (4.95+/-0.11)e39 erg/s. The broadband spectrum confirms the presence of a clear spectral downturn above 10 keV, only hinted at by previous observations. This cutoff is inconsistent with the standard low/hard state seen in Galactic black hole binaries, as would be expected from an intermediate mass black hole accreting at significantly sub-Eddington rates given the observed luminosity. The continuum is apparently dominated by two optically thick thermal-like components, potentially accompanied by a faint non-thermal tail at high energies. The broadband spectrum is likely associat...

  17. Discovery of a Large Population of Ultraluminous X-Ray Sources in the Bulgeless Galaxies NGC 337 and ESO 501-23

    Science.gov (United States)

    Somers, Garrett; Mathur, Smita; Martini, Paul; Watson, Linda; Grier, Catherine J.; Ferrarese, Laura

    2013-11-01

    We have used Chandra observations of eight bulgeless disk galaxies to identify new ultraluminous X-ray source (ULX) candidates, study their high-mass X-ray binary (HMXB) population, and search for low-luminosity active galactic nuclei (AGNs). We report the discovery of 16 new ULX candidates in our sample of galaxies. Eight of these are found in the star forming galaxy NGC 337, none of which are expected to be background contaminants. The HMXB luminosity function of NGC 337 implies a star formation rate (SFR) of 6.8^{+4.4}_{-3.5} M ⊙ yr-1, consistent at 1.5σ with a recent state of the art SFR determination. We also report the discovery of a bright ULX candidate (X-1) in ESO 501-23. X-1's spectrum is well fit by an absorbed power law with \\Gamma = 1.18^{+0.19}_{-0.11} and N H = 1.13^{+7.07}_{-1.13} \\times 10^{20} cm-2, implying a 0.3-8 keV flux of 1.08^{+0.05}_{-0.07} \\times 10^{-12} erg s-1 cm-2. Its X-ray luminosity (LX ) is poorly constrained due to uncertainties in the host galaxy's distance, but we argue that its spectrum implies LX > 1040 erg s-1. An optical counterpart to this object may be present in an Hubble Space Telescope image. We also identify ULX candidates in IC 1291, PGC 3853, NGC 5964, and NGC 2805. We find no evidence of nuclear activity in the galaxies in our sample, placing a flux upper limit of 4 × 10-15 erg s-1 cm-2 on putative AGN. Additionally, the Type II-P supernova SN 2011DQ in NGC 337, which exploded two months before our X-ray observation, is undetected.

  18. Nustar Reveals an Intrinsically X-ray Weak Broad Absorption Line Quasar in the Ultraluminous Infrared Galaxy Markarian 231

    Science.gov (United States)

    Teng, Stacy H.; Brandt. W. N.; Harrison, F. A.; Luo, B.; Alexander, D. M.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W.; Fabian, A. C.; Farrah, D.; Fiore, F.; Gandhi, P.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R. C.; Madsen, K. K.; Ptak, A. F.; Rigby, Jane Rebecca; Risaliti, G.; Saz, C.; Stern, D.; Veilleux, S.; Walton, D. J.; Wik, D. R.; Zhang, W. W.

    2014-01-01

    We present high-energy (3-30 keV) NuSTAR observations of the nearest quasar, the ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5-8 keV) data from Chandra. The source was detected, though at much fainter levels than previously reported, likely due to contamination in the large apertures of previous non-focusing hard X-ray telescopes. The full band (0.5-30 keV) X-ray spectrum suggests the active galactic nucleus (AGN) in Mrk 231 is absorbed by a patchy and Compton-thin N(sub H) approx. 1.2(sup +0.3) sub-0.3) x 10(exp 23) / sq cm) column. The intrinsic X-ray luminosity L(sub 0.5-30 Kev) approx. 1.0 x 10(exp 43) erg /s) is extremely weak relative to the bolometric luminosity where the 2-10 keV to bolometric luminosity ratio is approx. 0.03% compared to the typical values of 2-15%. Additionally, Mrk 231 has a low X-ray-to-optical power law slope alpha(sub 0X) approx. -1.7. It is a local example of a low-ionization broad absorption line (LoBAL) quasar that is intrinsically X-ray weak. The weak ionizing continuum may explain the lack of mid-infrared [O IV], [Ne V], and [Ne VI] fine-structure emission lines which are present in sources with otherwise similar AGN properties. We argue that the intrinsic X-ray weakness may be a result of the super-Eddington accretion occurring in the nucleus of this ULIRG, and may also be naturally related to the powerful wind event seen in Mrk 231, a merger remnant escaping from its dusty cocoon.

  19. The Highly Perturbed X-ray Bright Group NGC 5044

    Science.gov (United States)

    David, Laurence

    2014-09-01

    The NGC 5044 group is the X-ray brightest group in the sky and hosts many small X-ray cavities that were inflated by weak AGN outbursts. The cumulative effect of many weak AGN outbursts may be the dominant reheating mechanism in cooling flows. While AGN feedback probably prevents the bulk of gas from cooling in NGC 5044, the presence of molecular structures, Halpha filaments, [CII] emission and star formation indicates that at least some gas is able to condense out of the hot phase. The near by 5044 group is the best target for detecting small X-ray cavities with Chandra and investigating the cumulative effect of repeated weak AGN outbursts. The wealth of multi-frequency data also makes NGC 5044 an ideal target for studying gas over a broad range of temperatures in a cooling flow.

  20. Testing the Paradigm that Ultra-Luminous X-Ray Sources as a Class Represent Accreting Intermediate

    Science.gov (United States)

    Berghea, C. T.; Weaver, K. A.; Colbert, E. J. M.; Roberts, T. P.

    2008-01-01

    To test the idea that ultraluminous X-ray sources (ULXs) in external galaxies represent a class of accreting Intermediate-Mass Black Holes (IMBHs), we have undertaken a program to identify ULXs and a lower luminosity X-ray comparison sample with the highest quality data in the Chandra archive. We establish a general property of ULXs that the most X-ray luminous objects possess the fattest X-ray spectra (in the Chandra band pass). No prior sample studies have established the general hardening of ULX spectra with luminosity. This hardening occurs at the highest luminosities (absorbed luminosity > or equals 5x10(exp 39) ergs/s) and is in line with recent models arguing that ULXs are actually stellar-mass black holes. From spectral modeling, we show that the evidence originally taken to mean that ULXs are IMBHs - i.e., the "simple IMBH model" - is nowhere near as compelling when a large sample of ULXs is looked at properly. During the last couple of years, XMM-Newton spectroscopy of ULXs has to some large extent begun to negate the simple IMBH model based on fewer objects. We confirm and expand these results, which validates the XMM-Newton work in a broader sense with independent X-ray data. We find (1) that cool disk components are present with roughly equal probability and total flux fraction for any given ULX, regardless of luminosity, and (2) that cool disk components extend below the standard ULX luminosity cutoff of 10(exp 39) ergs/s, down to our sample limit of 10(exp 38:3) ergs/s. The fact that cool disk components are not correlated with luminosity damages the argument that cool disks indicate IMBHs in ULXs, for which a strong statistical support was never made.

  1. THE BROADBAND XMM-NEWTON AND NuSTAR X-RAY SPECTRA OF TWO ULTRALUMINOUS X-RAY SOURCES IN THE GALAXY IC 342

    Energy Technology Data Exchange (ETDEWEB)

    Rana, Vikram; Harrison, Fiona A.; Walton, Dominic J.; Furst, Felix; Grefenstette, Brian W.; Madsen, Kristin K. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Bachetti, Matteo; Barret, Didier; Webb, Natalie A. [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Miller, Jon M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Fabian, Andrew C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, Finn C. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Ptak, Andrew F.; Zhang, William W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2015-02-01

    We present results for two ultraluminous X-ray sources (ULXs), IC 342 X-1 and IC 342 X-2, using two epochs of XMM-Newton and NuSTAR observations separated by ∼7 days. We observe little spectral or flux variability above 1 keV between epochs, with unabsorbed 0.3-30 keV luminosities being 1.04{sub −0.06}{sup +0.08}×10{sup 40} erg s{sup –1} for IC 342 X-1 and 7.40 ± 0.20 × 10{sup 39} erg s{sup –1} for IC 342 X-2, so that both were observed in a similar, luminous state. Both sources have a high absorbing column in excess of the Galactic value. Neither source has a spectrum consistent with a black hole binary in low/hard state, and both ULXs exhibit strong curvature in their broadband X-ray spectra. This curvature rules out models that invoke a simple reflection-dominated spectrum with a broadened iron line and no cutoff in the illuminating power-law continuum. X-ray spectrum of IC 342 X-1 can be characterized by a soft disk-like blackbody component at low energies and a cool, optically thick Comptonization continuum at high energies, but unique physical interpretation of the spectral components remains challenging. The broadband spectrum of IC 342 X-2 can be fit by either a hot (3.8 keV) accretion disk or a Comptonized continuum with no indication of a seed photon population. Although the seed photon component may be masked by soft excess emission unlikely to be associated with the binary system, combined with the high absorption column, it is more plausible that the broadband X-ray emission arises from a simple thin blackbody disk component. Secure identification of the origin of the spectral components in these sources will likely require broadband spectral variability studies.

  2. NuSTAR, XMM-Newton and Suzaku Observations of the Ultraluminous X-ray Source Holmberg II X-1

    CERN Document Server

    Walton, D J; Rana, V; Miller, J M; Harrison, F A; Fabian, A C; Bachetti, M; Barret, D; Boggs, S E; Christensen, F E; Craig, W W; Fuerst, F; Grefenstette, B W; Hailey, C J; Madsen, K K; Stern, D; Zhang, W

    2015-01-01

    We present the first broadband 0.3-25.0 kev X-ray observations of the extreme ultraluminous X-ray source (ULX) Holmberg II X-1, performed by NuSTAR, XMM-Newton and Suzaku in September 2013. The NuSTAR data provide the first observations of Holmberg II X-1 above 10 keV, and reveal a very steep high-energy spectrum, similar to other ULXs observed by NuSTAR to date. This implies that Holmberg II X-1 accretes at a high fraction of its Eddington accretion rate, and possibly exceeds it. The soft X-ray spectrum (E<10 keV) appears to be dominated by two blackbody-like emission components, the hotter of which may be associated with an accretion disk. However, all such models under-predict the NuSTAR data above ~10 keV, implying the presence of an additional emission component at the highest energies probed. We investigate plausible physical origins for this component, and favor a scenario in which the excess arises from Compton scattering in a hot corona of electrons with some properties similar to the very-high st...

  3. Suzaku investigation into the nature of the nearest ultraluminous X-ray source, M33 X-8

    CERN Document Server

    Isobe, Naoki; Sato, Hiroshi; Mizuno, Tsunefumi

    2012-01-01

    The X-ray spectrum of the nearest ultraluminous X-ray source, M33 X-8, obtained by Suzaku during 2010 January 11 -- 13, was closely analyzed to examine its nature. It is, by far, the only data with the highest signal statistic in 0.4 -- 10 keV range. Despite being able to reproduce the X-ray spectrum, Comptonization of the disk photons failed to give a physically meaningful solution. A modified version of the multi-color disk model, in which the dependence of the disk temperature on the radius is described as r^(-p) with p being a free parameter, can also approximate the spectrum. From this model, the innermost disk temperature and bolometric luminosity were obtained as T_in = 2.00-0.05+0.06 keV and L_disk = 1.36 x 10^39 (cos i)^(-1) ergs/s, respectively, where i is the disk inclination. A small temperature gradient of p = 0.535-0.005+0.004, together with the high disk temperature, is regarded as the signatures of the slim accretion disk model, suggesting that M33 X-8 was accreting at high mass accretion rate...

  4. Is SS 433 a misaligned ultraluminous X-ray source? Constraints from its reflected signal in the Galactic plane

    CERN Document Server

    Khabibullin, Ildar

    2015-01-01

    We evaluate the emission that must arise due to reflection of the putative collimated X-ray radiation of SS 433 by atomic gas and molecular clouds in the Galactic plane and compare the predicted signal with existing RXTE and ASCA data for the region of interest. Assuming that the intrinsic X-ray spectrum of SS 433 is similar to that of ultraluminous X-ray sources (ULXs), we obtain an upper limit of $\\sim 4\\times 10^{39}$ erg s$^{-1}$ on its total (angular-integrated) luminosity in the 2--10 keV energy band, which is only weakly dependent on the half-opening angle, $\\Theta_r$, of the emission cone. In contrast, the upper limit on the apparent luminosity of SS 433 (that would be perceived by an observer looking at its supercritical accretion disk face-on) decreases with increasing $\\Theta_r$ and is $\\sim 3\\times 10^{40}$ erg s$^{-1}$ for $\\Theta_r\\gtrsim\\Theta_p=21\\deg$, where $\\Theta_p$ is the precession angle of the baryonic jets (assuming that the emission cones precess in the same manner as the jets). This ...

  5. Optical counterparts of two ultraluminous X-ray sources NGC4559 X-10 and NGC4395 ULX-1

    CERN Document Server

    Vinokurov, A; Atapin, K

    2016-01-01

    We study the optical counterparts of ultraluminous X-ray sources NGC4559 X-10 and NGC4395 ULX-1. Their absolute magnitudes, after taking the reddening into account, are $M_V \\approx -5.3$ and $M_V \\approx -6.2$, respectively. The spectral energy distribution of the NGC4559 X-10 counterpart is well fitted by a spectrum of an F-type star, whereas NGC4395 ULX-1 has a blue power-law spectrum. Optical spectroscopy of NGC4395 ULX-1 has shown a broad and variable HeII~$\\lambda$4686 emission, which puts this object in line with all the other spectrally-studied ULXs. Using the Swift archival X-ray data for NGC4395 ULX-1, we have found a period of $62.8\\pm 2.3$ days. The X-ray phase curve of the source is very similar to the precession curve of SS433. The optical variation of the counterpart (between two accurate measurements) amounts to 0.10 mag. Analyzing the absolute magnitudes of 16 well-studied ULX counterparts one may suggest that as the original accretion rate decreases (but nevertheless remains supercritical), ...

  6. On the Nature of the mHz X-ray Quasi-Periodic Oscillations from Ultraluminous X-ray source M82 X-1: Search for Timing-Spectral Correlations

    Science.gov (United States)

    Pasham, Dheeraj R.; Strohmayer, Tod E.

    2013-01-01

    Using all the archival XMM-Newton X-ray (3-10 keV) observations of the ultraluminous X-ray source (ULX) M82 X-1, we searched for a correlation between its variable mHz quasi-periodic oscillation (QPO) frequency and its hardness ratio (5-10 keV/3-5 keV), an indicator of the energy spectral power-law index. When stellar-mass black holes (StMBHs) exhibit type-C low-frequency QPOs (0.2-15 Hz), the centroid frequency of the QPO is known to correlate with the energy spectral index. The detection of such a correlation would strengthen the identification of M82 X-1's mHz QPOs as type-C and enable a more reliable mass estimate by scaling its QPO frequencies to those of type-C QPOs in StMBHs of known mass.We resolved the count rates and the hardness ratios of M82 X-1 and a nearby bright ULX (source 5/X42.3+59) through surface brightness modeling.We detected QPOs in the frequency range of 36-210 mHz during which M82 X-1's hardness ratio varied from 0.42 to 0.47. Our primary results are (1) that we do not detect any correlation between the mHz QPO frequency and the hardness ratio (a substitute for the energy spectral power-law index) and (2) similar to some accreting X-ray binaries, we find that M82 X-1's mHz QPO frequency increases with its X-ray count rate (Pearson's correlation coefficient = +0.97). The apparent lack of a correlation between the QPO centroid frequency and the hardness ratio poses a challenge to the earlier claims that the mHz QPOs of M82 X-1 are the analogs of the type-C low-frequency QPOs of StMBHs. On the other hand, it is possible that the observed relation between the hardness ratio and the QPO frequency represents the saturated portion of the correlation seen in type-C QPOs of StMBHs-in which case M82 X-1's mHz QPOs can still be analogous to type-C QPOs.

  7. NuSTAR Observations of the Compton-Thick Active Galactic Nucleus and Ultraluminous X-Ray Source Candidate in NGC 5643

    DEFF Research Database (Denmark)

    Annuar, A.; Gandhi, P.; Alexander, D. M.;

    2015-01-01

    We present two Nuclear Spectroscopic Telescope Array (NuSTAR) observations of the local Seyfert 2 active galactic nucleus (AGN) and an ultraluminous X-ray source (ULX) candidate in NGC 5643. Together with archival data from Chandra, XMM-Newton, and Swift-BAT, we perform a high-quality broadband s...

  8. The ultraluminous X-ray source HoII X-1: kinematic evidence of its escape from the cluster

    CERN Document Server

    Egorov, Oleg V; Moiseev, Alexei V

    2016-01-01

    We analyse the structure and kinematics of ionized gas in the vicinity of the ultraluminous X-ray source (ULX) HoII X-1 in the Holmberg II galaxy using observational data obtained with a scanning Fabry-Perot interferometer in the H$\\alpha$, [SII] and [OIII] emission lines at the Russian 6-m telescope. Decomposition of the line profiles allows us to identify the broad component of emission lines caused by the ULX action. We found evidence of an expanding superbubble around the young star cluster located in the studied region. We conclude that the blue-shifted 'arc' around the ULX observed in the line-of-sight velocity field may correspond to a bow shock caused by the ULX movement from that nearby young star cluster. If this interpretation is correct, it will be the first kinematic evidence of ULX's escape from their parent star clusters.

  9. The Broadband XMM-Newton and NuSTAR X-ray Spectra of Two Ultraluminous X-ray Sources in the Galaxy IC 342

    CERN Document Server

    Rana, Vikram; Bachetti, Matteo; Walton, Dominic J; Furst, Felix; Barret, Didier; Miller, Jon M; Fabian, Andrew C; Boggs, Steven E; Christensen, Finn C; Craig, William W; Grefenstette, Brian W; Hailey, Charles J; Madsen, Kristin K; Ptak, Andrew F; Stern, Daniel; Webb, Natalie A; Zhang, William W

    2014-01-01

    We present XMM-Newton and NuSTAR observations of two ultraluminous X-ray sources in the nearby galaxy IC 342. The observations were carried out in two epochs separated by ~7 days, with each having an approximate exposure time of ~40 ks (XMM-Newton) and ~100 ks (NuSTAR). We observe little spectral or flux variability above 1 keV between epochs, with unabsorbed 0.3--30 keV luminosities being $1.04^{+0.08}_{-0.06} \\times 10^{40}$ erg s$^{-1}$ for IC 342 X-1 and $7.40\\pm0.20 \\times 10^{39}$ erg s$^{-1}$ for IC 342 X-2. IC 342 X-2 shows a highly variable component prominent below 1 keV that cannot be explained by blackbody or thermal plasma emission. With the broad bandpass of these observations we can demonstrate conclusively for the first time that both objects have a clear spectral turnover above ~8 keV. Neither source is consistent with a black hole binary in a low/hard state, and a simple reflection-dominated spectrum with a broadened iron line and no cutoff in the illuminating power-law continuum can be rule...

  10. Puzzling accretion onto a black hole in the ultraluminous X-ray source M 101 ULX-1.

    Science.gov (United States)

    Liu, Ji-Feng; Bregman, Joel N; Bai, Yu; Justham, Stephen; Crowther, Paul

    2013-11-28

    There are two proposed explanations for ultraluminous X-ray sources (ULXs) with luminosities in excess of 10(39) erg s(-1). They could be intermediate-mass black holes (more than 100-1,000 solar masses, M sun symbol) radiating at sub-maximal (sub-Eddington) rates, as in Galactic black-hole X-ray binaries but with larger, cooler accretion disks. Alternatively, they could be stellar-mass black holes radiating at Eddington or super-Eddington rates. On its discovery, M 101 ULX-1 had a luminosity of 3 × 10(39) erg s(-1) and a supersoft thermal disk spectrum with an exceptionally low temperature--uncomplicated by photons energized by a corona of hot electrons--more consistent with the expected appearance of an accreting intermediate-mass black hole. Here we report optical spectroscopic monitoring of M 101 ULX-1. We confirm the previous suggestion that the system contains a Wolf-Rayet star, and reveal that the orbital period is 8.2 days. The black hole has a minimum mass of 5 M sun symbol, and more probably a mass of 20 M sun symbol-30 M sun symbol, but we argue that it is very unlikely to be an intermediate-mass black hole. Therefore, its exceptionally soft spectra at high Eddington ratios violate the expectations for accretion onto stellar-mass black holes. Accretion must occur from captured stellar wind, which has hitherto been thought to be so inefficient that it could not power an ultraluminous source.

  11. NuSTAR and XMM-Newton observations of the ultraluminous X-ray source NGC 5643 X-1

    CERN Document Server

    Krivonos, Roman

    2016-01-01

    We present a high-quality hard X-ray spectrum of the ultraluminous X-ray source (ULX) NGC 5643 X-1 measured with NuSTAR in May-June 2014. We have obtained this spectrum by carefully separating the signals from the ULX and from the active nucleus of its host galaxy NGC 5643 located 0.8 arcmin away. Together with long XMM-Newton observations performed in July 2009 and August 2014, the NuSTAR data confidently reveal a high-energy cutoff in the spectrum of NGC 5643 X-1 above ~10 keV, which is a characteristic signature of ULXs. The NuSTAR and XMM-Newton data are consistent with the source having a constant luminosity ~1.5E40 erg/s (0.2-12 keV) in all but the latest observation (August 2014) when it brightened to ~3E40 erg/s. This increase is associated with the dominant, hard spectral component (presumably collimated emission from the inner regions of a supercritical accretion disk), while an additional, soft component (with a temperature ~0.3 keV if described by multicolor disk emission), possibly associated wit...

  12. X-ray observations of the Ultraluminous infrared galaxy IRAS19254-7245 (The Superantennae)

    CERN Document Server

    Pappa, A; Stewart, G C

    1999-01-01

    We present ROSAT HRI and ASCA observations of the well known ULIRG IRAS19254-7245 (the Superantennae). The object is not detected by ROSAT yielding a 3\\sigma upper limit of L_x ~8x10^{41} erg/s in the 0.1-2 keV band. However, we obtain a clear detection by ASCA yielding a luminosity in the 2-10 keV band of 2 \\times 10^{42}erg/s. Its X-ray spectrum is very hard, equivalent to a photon index of Gamma=1.0+-0.35. We therefore, attempt to model the X-ray data with a "scatterer" model in which the intrinsic X-ray emission along our line of sight is obscured by an absorbing screen while some fraction, f, is scattered into our line of sight by an ionized medium; this is the standard model for the X-ray emission in obscured (but non Compton-thick) Seyfert galaxies. We obtain an absorbing column of 2x10^{23}cm^{-2} for a power-law photon index of Gamma=1.9, an order of magnitude above the column estimated on the basis of optical observations; the percentage of the scattered emission is high (~20%). Alternatively, a mod...

  13. Ultraluminous X-ray bursts in two ultracompact companions to nearby elliptical galaxies

    CERN Document Server

    Irwin, Jimmy A; Sivakoff, Gregory R; Romanowsky, Aaron J; Lin, Dacheng; Speegle, Tyler; Prado, Ian; Mildebrath, David; Strader, Jay; Liu, Jifeng; Miller, Jon M

    2016-01-01

    An X-ray flaring source was found near the galaxy NGC 4697. Two flares were seen, separated by four years. The flux increased by a factor of 90 on a timescale of about one minute. Both flares were very brief. There is no optical counterpart at the position of the flares, but if the source was at the distance of NGC 4697, the luminosities were 10^39 erg/s. Here we report the results of a search of archival X-ray data for 70 nearby galaxies looking for similar such flares. We found two flaring sources in globular clusters or ultra-compact dwarf companions of parent elliptical galaxies. One source flared once to a peak luminosity of 9 x 10^40 erg/s, while the other flared five times to 10^40 erg/s. All of the flare rise times were <1 minute, and they then decayed over about an hour. When not flaring, the sources appear to be normal accreting neutron star or black hole X-ray binaries, but they are located in old stellar populations, unlike the magnetars, anomalous X-ray pulsars or soft gamma repeaters that hav...

  14. Short Pulse High Brightness X-ray Production with the PLEIADES Thomson Scattering Source

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, S G; Barty, C P J; Betts, S M; Brown, W J; Crane, J K; Cross, R R; Fittinghoff, D N; Gibson, D J; Hartemann, F V; Kuba, J; LaSage, G P; Rosenzweig, J B; Slaughter, D R; Springer, P T; Tremaine, A M

    2003-07-01

    We describe PLEIADES, a compact, tunable, high-brightness, ultra-short pulse, Thomson x-ray source. The peak brightness of the source is expected to exceed 10{sup 20} photons/s/0.1% bandwidth/mm{sup 2}/mrad{sup 2}. Initial results are reported and compared to theoretical calculations.

  15. Binary black hole merger rates inferred from luminosity function of ultra-luminous X-ray sources

    Science.gov (United States)

    Inoue, Yoshiyuki; Tanaka, Yasuyuki T.; Isobe, Naoki

    2016-10-01

    The Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO) has detected direct signals of gravitational waves (GWs) from GW150914. The event was a merger of binary black holes whose masses are 36^{+5}_{-4} M_{{⊙}} and 29^{+4}_{-4} M_{{⊙}}. Such binary systems are expected to be directly evolved from stellar binary systems or formed by dynamical interactions of black holes in dense stellar environments. Here we derive the binary black hole merger rate based on the nearby ultra-luminous X-ray source (ULX) luminosity function (LF) under the assumption that binary black holes evolve through X-ray emitting phases. We obtain the binary black hole merger rate as 5.8(tULX/0.1 Myr)- 1λ- 0.6exp ( - 0.30λ) Gpc- 3 yr- 1, where tULX is the typical duration of the ULX phase and λ is the Eddington ratio in luminosity. This is coincident with the event rate inferred from the detection of GW150914 as well as the predictions based on binary population synthesis models. Although we are currently unable to constrain the Eddington ratio of ULXs in luminosity due to the uncertainties of our models and measured binary black hole merger event rates, further X-ray and GW data will allow us to narrow down the range of the Eddington ratios of ULXs. We also find the cumulative merger rate for the mass range of 5 M⊙ ≤ MBH ≤ 100 M⊙ inferred from the ULX LF is consistent with that estimated by the aLIGO collaboration considering various astrophysical conditions such as the mass function of black holes.

  16. First results from the high-brightness x-ray spectroscopy beamline at ALS

    Energy Technology Data Exchange (ETDEWEB)

    Perera, R.C.C.; Ng, W.; Jones, G. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Beamline 9.3.1 at the Advanced Light Source (ALS) is a windowless beamline, covering the 1-6 keV photon-energy range, designed to achieve the goal of high brightness at the sample for use in the X-ray Atomic and Molecular Spectroscopy (XAMS) science, surface and interface science, biology and x-ray optical development programs at ALS. X-ray absorption and time of flight photo emission measurements in 2 - 5 keV photon energy in argon along with the flux, resolution, spot size and stability of the beamline will be discussed. Prospects for future XAMS measurements will also be presented.

  17. Bright X-Ray Transients in M31: 2004 July XMM-Newton Observations

    Science.gov (United States)

    Trudolyubov, Sergey; Priedhorsky, William; Cordova, France

    2006-07-01

    We present the results of X-ray observations of four bright transients sources detected in the 2004 July XMM-Newton observations of the central bulge of M31. Two X-ray sources, XMMU J004315.5+412440 and XMMU J004144.7+411110, were discovered for the first time. Two other sources, CXOM31 J004309.9+412332 and CXOM31 J004241.8+411635, were previously detected by Chandra. The properties of the sources suggest their identification with accreting binary systems in M31. The X-ray spectra and variability of two sources, XMMU J004144.7+411110 and CXOM31 J004241.8+411635, are similar to that of the Galactic black hole transients. The X-ray source XMMU J004315.5+412440 demonstrates a dramatic decline of the X-ray flux on a timescale of three days and a remarkable flaring behavior on a timescale of tens of minutes. The X-ray data on XMMU J004315.5+412440 and CXOM31 J004309.9+412332 suggest that they can be either black hole or neutron star systems. Combining the results of 2000-2004 XMM-Newton observations of M31, we estimate the total rate of the bright transient outbursts in the central region of M31 to be 6-12 yr-1, in agreement with previous studies.

  18. The ultraluminous x-ray sources ngc 1313 x-1 and x-2: a broadband study with NuSTAR and XMM-Newton

    DEFF Research Database (Denmark)

    Bachetti, Matteo; Rana, Vikram; Walton, Dominic J.;

    2013-01-01

    We present the results of NuSTAR and XMM-Newton observations of the two ultraluminous X-ray sources: NGC 1313 X-1 and X-2. The combined spectral bandpass of the two satellites enables us to produce the first spectrum of X-1 between 0.3 and 30 keV, while X-2 is not significantly detected by NuSTAR...

  19. Optical Counterparts of Ultra-Luminous X-ray Sources identified from Archival Hubble Space Telescope/WFPC2

    CERN Document Server

    Ptak, A; Van der Marel, R; Roye, E; Heckman, T; Towne, B

    2006-01-01

    We present a systematic analysis of archival HST WFPC2 ``Association'' data sets that correlate with the Chandra positions of a set of 44 ultra-luminous X-ray sources (ULXs) of nearby galaxies. We have improved the Chandra-HST relative astrometry whenever possible. Disparate numbers of potential ULX counterparts are found, and in some cases none are found. The lack of or low number of counterparts in some cases may be due to insufficient depth in the WFPC2 images. Particularly in late-type galaxies, the HST image in the ULX region was often complex or crowded. We therefore address various scenarios for the nature of the ULX since it is not known which, if any, of the sources found are true counterparts. The optical luminosities of the sources are typically in the range 10^4-6 L_sun. In several cases color information is available, with the colors roughly tending to be more red in early-type galaxies. This suggests that, in general, the (potential) counterparts found in early-type galaxies are likely to be old...

  20. X-Ray bright active galactic nuclei in massive galaxy clusters - II. The fraction of galaxies hosting active nuclei

    DEFF Research Database (Denmark)

    Ehlert, S.; von der Linden, A.; Allen, S. W.

    2013-01-01

    We present a measurement of the fraction of cluster galaxies hosting X-ray bright active galactic nuclei (AGN) as a function of clustercentric distance scaled in units of r500. Our analysis employs high-quality Chandra X-ray and Subaru optical imaging for 42 massive X-ray-selected galaxy cluster...

  1. The outer regions of galaxy clusters: Chandra constraints on the X-ray surface brightness

    CERN Document Server

    Ettori, S

    2008-01-01

    (Abridged version) We study the properties of the X-ray surface brightness profiles in a sample of galaxy clusters that are observed with Chandra and have emission detectable with a signal-to-noise ratio larger than 2 at a radius beyond R500 ~ 0.7 R200. Our study aims at measuring the slopes of the X-ray surface brightness and of the gas density profiles in the outskirts of massive clusters. These constraints are then compared to similar results obtained from observations and numerical simulations of the temperature and dark matter density profiles with the intention to present a consistent picture of the outer regions of galaxy clusters. We extract the surface brightness profiles S_b(r) from X-ray exposures obtained with Chandra of 52 X-ray luminous galaxy clusters at z>0.3. We estimate R200 both using a beta-model to reproduce the surface brightness profile and scaling relations from the literature, showing that the two methods converge to comparable values. We evaluate then the radius, R_S2N, at which the ...

  2. Different types of ultraluminous X-ray sources in NGC 4631

    CERN Document Server

    Soria, Roberto

    2009-01-01

    We have re-examined the most luminous X-ray sources in the starburst galaxy NGC 4631, using XMM-Newton, Chandra and ROSAT data. The most interesting source is a highly variable supersoft ULX. We suggest that its bolometric luminosity ~ a few 10^{39} erg/s in the high/supersoft state: this is an order of magnitude lower than estimated in previous studies, thus reducing the need for extreme or exotic scenarios. Moreover, we find that this source was in a non-canonical low/soft (kT ~ 0.1-0.3 keV) state during the Chandra observation. By comparing the high and low state, we argue that the spectral properties may not be consistent with the expected behaviour of an accreting intermediate-mass black hole. We suggest that recurrent super-Eddington outbursts with photospheric expansion from a massive white dwarf (M_{wd} >~ 1.3 M_{sun}), powered by non-steady nuclear burning, may be a viable possibility, in alternative to the previously proposed scenario of a super-Eddington outflow from an accreting stellar-mass black...

  3. High-brightness beamline for x-ray spectroscopy at the ALS

    Energy Technology Data Exchange (ETDEWEB)

    Perera, R.C.C.; Jones, G. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States); Lindle, D.W. [Univ. of Nevada, Las Vegas, NV (United States)

    1997-04-01

    Beamline 9.3.1 at the Advanced Light Source (ALS) is a windowless beamline, covering the 1-6 keV photon-energy range, designed to achieve the goals of high energy resolution, high flux, and high brightness at the sample. When completed later this year, it will be the first ALS monochromatic hard x-ray beamline, and its brightness will be an order of magnitude higher than presently available in this energy range. In addition, it will provide flux and resolution comparable to any other beamline now in operation. To achieve these goals, two technical improvements, relative to existing x-ray beamlines, were incorporated. First, a somewhat novel optical design for x-rays, in which matched toroidal mirrors are positioned before and after the double-crystal monochromator, was adopted. This configuration allows for high resolution by passing a collimated beam through the monochromator, and for high brightness by focusing the ALS source on the sample with unit magnification. Second, a new {open_quotes}Cowan type{close_quotes} double-crystal monochromator based on the design used at NSLS beamline X-24A was developed. The measured mechanical precision of this new monochromator shows significant improvement over existing designs, without using positional feedback available with piezoelectric devices. Such precision is essential because of the high brightness of the radiation and the long distance (12 m) from the source (sample) to the collimating (focusing) mirror. This combination of features will provide a bright, high resolution, and stable x-ray beam for use in the x-ray spectroscopy program at the ALS.

  4. Populations of Bright X-ray Sources in the Starburst Galaxies NGC 4038/4039

    Institute of Scientific and Technical Information of China (English)

    Xi-Wei Liu; Xiang-Dong Li

    2007-01-01

    Assuming a naive star formation history,we construct synthetic X-ray source populations.using a population synthesis code,for comparison with the observed X-ray luminosity function (XLF) of the interacting galaxies NGC 4038/4039.We have included highand intermediate-mass X-ray binaries.young rotation-powered pulsars and fallback disk-fed black holes in modeling the bright X-ray sources detected.We find that the majority of the X-ray sources are likely to be intermediate-mass X-ray binaries.but for typical binary evolution parameters.the predicted XLF seems to be steeper than observed.We note that the shape of the XLFs depends critically on the existence of XLF break for young populations.and suggest super-Eddington accretion luminosities or the existence of intermediate-mass black holes to account for the high luminosity end and the slope of the XLF in NGC 4038/4039.

  5. Bright X-ray Transients in M31: 2004 July XMM-Newton Observations

    CERN Document Server

    Trudolyubov, S; Cordova, F; Trudolyubov, Sergey; Priedhorsky, William; Cordova, France

    2005-01-01

    We present the results of X-ray observations of four bright transients sources detected in the July 2004 XMM-Newton observations of the central bulge of M31. Two X-ray sources, XMMU J004315.5+412440 and XMMU J004144.7+411110, were discovered for the first time. Two other sources, CXOM31 J004309.9+412332 and CXOM31 J004241.8+411635, were previously detected by Chandra. The properties of the sources suggest their identification with accreting binary systems in M31. The X-ray spectra and variability of two sources, XMMU J004144.7+411110 and CXOM31 J004241.8+411635, are similar to that of the Galactic black hole transients, making them a good black hole candidates. The X-ray source XMMU J004315.5+412440 demonstrates a dramatic decline of the X-ray flux on a time scale of three days, and a remarkable flaring behavior on a short time scales. The X-ray data on XMMU J004315.5+412440 and CXOM31 J004309.9+412332 suggest that they can be either black hole or neutron star systems. Combining the results of 2000-2004 XMM o...

  6. On the Distribution of X-ray Surface Brightness from Diffuse Gas

    CERN Document Server

    Voit, G M; Bryan, Greg L.

    2001-01-01

    Hot intergalactic gas in clusters, groups, and filaments emanates a continuous background of 0.5-2.0 keV X-rays that ought to be detectable with the new generation of X-ray observatories. Here we present selected results from a program to simulate the surface-brightness distribution of this background with an adaptive-mesh cosmological hydrodynamics code. We show that the bright end of this distribution is well approximated by combining the cluster temperature function with a beta-model for surface brightness and appropriate luminosity-temperature and core radius-luminosity relations. Our simulations verify that the X-ray background from hot gas vastly exceeds observational limits if non-gravitational processes do not modify the intergalactic entropy distribution. An entropy floor of ~100 keV cm^2, which could be established by either heating or cooling, appears necessary to reconcile the simulated background with observations. Because the X-ray background distribution is so sensitive to the effects of non-gr...

  7. NUSTAR and Xmm-Newton Observations of the Extreme Ultraluminous X-Ray Source NGC 5907 UlX1: A Vanishing Act

    DEFF Research Database (Denmark)

    Walton, D. J.; Harrison, F. A.; Bachetti, M.;

    2015-01-01

    We present results obtained from two broadband X-ray observations of the extreme ultraluminous X-ray source (ULX) NGC 5907 ULX1, known to have a peak X-ray luminosity of ~5 × 1040 erg s–1. These XMM-Newton and NuSTAR observations, separated by only ~4 days, revealed an extreme level of short......-term flux variability. In the first epoch, NGC 5907 ULX1 was undetected by NuSTAR, and only weakly detected (if at all) with XMM-Newton, while in the second NGC 5907 ULX1 was clearly detected at high luminosity by both missions. This implies an increase in flux of ~2 orders of magnitude or more during...

  8. Suzaku observations of spectral variations of the ultra-luminous X-ray source Holmberg IX X-1

    Science.gov (United States)

    Kobayashi, Shogo B.; Nakazawa, Kazuhiro; Makishima, Kazuo

    2017-02-01

    Observations of the ultra-luminous X-ray source (ULX) Holmberg IX X-1 were carried out with Suzaku twice, once on 2012 April 13 and then on 2012 October 24, with exposures of 180 ks and 217 ks, respectively. The source showed a hard power-law shaped spectrum with a mild cutoff at ˜8 keV, which is typical of ULXs when they are relatively dim. On both occasions, the 0.6-11 keV spectrum was explained successfully in terms of a cool (˜0.2 keV) multi-color disk blackbody emission model and thermal Comptonization emission produced by an electron cloud with a relatively low temperature and high optical depth, assuming that a large fraction of the disk-blackbody photons are Comptonized whereas the rest are observed directly. The 0.5-10 keV luminosity was 1.2 × 1040 erg s-1 in April, and ˜14% higher in October. This brightening was accompanied by spectral softening in ≥2 keV, with little change in the ≤2 keV spectral shape. This behavior can be understood if the accretion disk remains unchanged while the electron cloud covers a variable fraction of the disk. The absorbing column density was consistent with the galactic line-of sight value, and did not vary by more than 1.6 × 1021 cm-2. Together with the featureless spectra, these properties may not be reconciled easily with the super-critical accretion scenario of this source.

  9. NuSTAR and XMM-Newton observations of the extreme ultraluminous X-ray source NGC 5907 ULX1: A Vanishing Act

    CERN Document Server

    Walton, D J; Bachetti, M; Barret, D; Boggs, S E; Christensen, F E; Craig, W W; Fuerst, F; Grefenstette, B W; Hailey, C J; Madsen, K K; Middleton, M J; Rana, V; Roberts, T P; Stern, D; Sutton, A D; Webb, N; Zhang, W

    2014-01-01

    We present results obtained from two broadband X-ray observations of the extreme ultraluminous X-ray source (ULX) NGC5907 ULX1, known to have a peak X-ray luminosity of ~5e40 erg/s. These XMM-Newton and NuSTAR observations, separated by only ~4 days, revealed an extreme level of short-term flux variability. In the first epoch, NGC5907 ULX1 was undetected by NuSTAR, and only weakly detected (if at all) with XMM-Newton, while in the second NGC5907 ULX1 was clearly detected at high luminosity by both missions. This implies an increase in flux of ~2 orders of magnitude or more during this ~4 day window. We argue that this is likely due to a rapid rise in the mass accretion rate, rather than to a transition from an extremely obscured to an unobscured state. During the second epoch we observed the broadband 0.3-20.0 keV X-ray luminosity to be (1.55+/-0.06)e40 erg/s, similar to the majority of the archival X-ray observations. The broadband X-ray spectrum obtained from the second epoch is inconsistent with the low/ha...

  10. A bright point source of ultrashort hard x-rays from laser bioplasmas

    CERN Document Server

    Krishnamurthy, M; Lad, Amit D; Ahmad, Saima; Narayanan, V; Rajeev, R; Kundu, M; Kumar, G Ravindra; Ray, Krishanu

    2010-01-01

    Micro and nano structures scatter light and amplify local electric fields very effectively. Energy incident as intense ultrashort laser pulses can be converted to x-rays and hot electrons more efficiently with a substrate that suitably modifies the local fields. Here we demonstrate that coating a plain glass surface with a few micron thick layer of an ubiquitous microbe, {\\it Escherichia coli}, catapults the brightness of hard x-ray bremsstrahlung emission (up to 300 keV) by more than two orders of magnitude at an incident laser intensity of 10$^{16}$ W cm$^{-2}$. This increased yield is attributed to the local enhancement of electric fields around individual {\\it E. coli} cells and is reproduced by detailed particle-in-cell (PIC) simulations. This combination of laser plasmas and biological targets can lead to turnkey, multi-kilohertz and environmentally safe sources of hard x-rays.

  11. The optical counterpart of the bright X-ray transient Swift J1745-26

    CERN Document Server

    Muñoz-Darias, T; Russell, D M; Guziy, S; Gorosabel, J; Casares, J; Padilla, M Armas; Charles, P A; Fender, R P; Belloni, T M; Lewis, F; Motta, S; Castro-Tirado, A; Mundell, C G; Sánchez-Ramírez, R; Thöne, C C

    2013-01-01

    We present a 30-day monitoring campaign of the optical counterpart of the bright X-ray transient Swift J1745-26, starting only 19 minutes after the discovery of the source. We observe the system peaking at i' ~17.6 on day 6 (MJD 56192) to then decay at a rate of ~0.04 mag/day. We show that the optical peak occurs at least 3 days later than the hard X-ray (15-50 keV) flux peak. Our measurements result in an outburst amplitude greater than 4.3 magnitudes, which favours an orbital period 250 km/s. The breadth of the line and the observed optical and X-ray fluxes suggest that Swift J1745-26 is a new black hole candidate located closer than ~7 kpc.

  12. Efficient Pumping Schemes for High Average Brightness Collisional X-ray Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Keenan, R; Dunn, J; Shlyaptsev, V N; Smith, R F; Patel, P K; Price, D F

    2003-10-07

    Advances in transient collisional x-ray lasers have been demonstrated over the last 5 years as a technique for achieving tabletop soft x-ray lasers using 2-10 J of laser pump energy. The high peak brightness of these sources operating in the high output saturation regime, in the range of 10{sup 24}-10{sup 25} ph. mm{sup -2} mrad{sup -2} s-1 (0.1% BW){sup -1}, is ideal for many applications requiring high photon fluence in a single short burst. However, the pump energy required for these x-ray lasers is still relatively high and limits the x-ray laser repetition rate to 1 shot every few minutes. Higher repetition rate collisional schemes have been reported and show some promise for high output in the future. We report a novel technique for enhancing the coupling efficiency of the laser pump into the gain medium that could lead to enhanced x-ray inversion with a factor of ten reduction in the drive energy. This has been applied to the collisional excitation scheme for Ni-like Mo at 18.9 nm and x-ray laser output has been demonstrated. Preliminary results show lasing on a single shot of the optical laser operating at 10 Hz and with 70 mJ in the short pulse. Such a proposed source would have higher average brightness, {approx}10{sup 14} ph. mm{sup -2} mrad{sup -2} s{sup -1} (0.1% BW){sup -1}, than present bending magnet 3rd generation synchrotron sources operating at the same spectral range.

  13. A Bright Spatially-Coherent Compact X-ray Synchrotron Source

    CERN Document Server

    Kneip, S; Martins, J L; Martins, S F; Bellei, C; Chvykov, V; Dollar, F; Fonseca, R; Huntington, C; Kalintchenko, G; Maksimchuk, A; Mangles, S P D; Matsuoka, T; Nagel, S R; Palmer, C; Schreiber, J; Phuoc, K Ta; Thomas, A G R; Yanovsky, V; Silva, L O; Krushelnick, K; Najmudin, Z

    2009-01-01

    Each successive generation of x-ray machines has opened up new frontiers in science, such as the first radiographs and the determination of the structure of DNA. State-of-the-art x-ray sources can now produce coherent high brightness keV x-rays and promise a new revolution in imaging complex systems on nanometre and femtosecond scales. Despite the demand, only a few dedicated synchrotron facilities exist worldwide, partially due the size and cost of conventional (accelerator) technology. Here we demonstrate the use of a recently developed compact laser-plasma accelerator to produce a well-collimated, spatially-coherent, intrinsically ultrafast source of hard x-rays. This method reduces the size of the synchrotron source from the tens of metres to centimetre scale, accelerating and wiggling a high electron charge simultaneously. This leads to a narrow-energy spread electron beam and x-ray source that is >1000 times brighter than previously reported plasma wiggler and thus has the potential to facilitate a myri...

  14. Generation of bright isolated attosecond soft X-ray pulses driven by multicycle midinfrared lasers.

    Science.gov (United States)

    Chen, Ming-Chang; Mancuso, Christopher; Hernández-García, Carlos; Dollar, Franklin; Galloway, Ben; Popmintchev, Dimitar; Huang, Pei-Chi; Walker, Barry; Plaja, Luis; Jaroń-Becker, Agnieszka A; Becker, Andreas; Murnane, Margaret M; Kapteyn, Henry C; Popmintchev, Tenio

    2014-06-10

    High harmonic generation driven by femtosecond lasers makes it possible to capture the fastest dynamics in molecules and materials. However, to date the shortest subfemtosecond (attosecond, 10(-18) s) pulses have been produced only in the extreme UV region of the spectrum below 100 eV, which limits the range of materials and molecular systems that can be explored. Here we experimentally demonstrate a remarkable convergence of physics: when midinfrared lasers are used to drive high harmonic generation, the conditions for optimal bright, soft X-ray generation naturally coincide with the generation of isolated attosecond pulses. The temporal window over which phase matching occurs shrinks rapidly with increasing driving laser wavelength, to the extent that bright isolated attosecond pulses are the norm for 2-µm driving lasers. Harnessing this realization, we experimentally demonstrate the generation of isolated soft X-ray attosecond pulses at photon energies up to 180 eV for the first time, to our knowledge, with a transform limit of 35 attoseconds (as), and a predicted linear chirp of 300 as. Most surprisingly, advanced theory shows that in contrast with as pulse generation in the extreme UV, long-duration, 10-cycle, driving laser pulses are required to generate isolated soft X-ray bursts efficiently, to mitigate group velocity walk-off between the laser and the X-ray fields that otherwise limit the conversion efficiency. Our work demonstrates a clear and straightforward approach for robustly generating bright isolated attosecond pulses of electromagnetic radiation throughout the soft X-ray region of the spectrum.

  15. High-energy Neutrino Flares from X-Ray Bright and Dark Tidal Disruption Events

    Science.gov (United States)

    Senno, Nicholas; Murase, Kohta; Mészáros, Peter

    2017-03-01

    X-ray and γ-ray observations by the Swift satellite revealed that a fraction of tidal disruption events (TDEs) have relativistic jets. Jetted TDEs have been considered to be potential sources of very-high-energy cosmic-rays and neutrinos. In this work, using semi-analytical methods, we calculate neutrino spectra of X-ray bright TDEs with powerful jets and dark TDEs with possible choked jets, respectively. We estimate their neutrino fluxes and find that non-detection would give us an upper limit on the baryon loading of the jet luminosity contained in cosmic-rays ξ cr ≲ 20–50 for Sw J1644+57. We show that X-ray bright TDEs make a sub-dominant (≲5%–10%) contribution to IceCube’s diffuse neutrino flux, and study possible contributions of X-ray dark TDEs given that particles are accelerated in choked jets or disk winds. We discuss future prospects for multi-messenger searches of the brightest TDEs.

  16. Detecting edges in the X-ray surface brightness of galaxy clusters

    CERN Document Server

    Sanders, J S; Russell, H R; Walker, S A; Blundell, K M

    2016-01-01

    The effects of many physical processes in the intracluster medium of galaxy clusters imprint themselves in X-ray surface brightness images. It is therefore important to choose optimal methods for extracting information from and enhancing the interpretability of such images. We describe in detail a gradient filtering edge detection method that we previously applied to images of the Centaurus cluster of galaxies. The Gaussian gradient filter measures the gradient in the surface brightness distribution on particular spatial scales. We apply this filter on different scales to Chandra X-ray observatory images of two clusters with AGN feedback, the Perseus cluster and M87, and a merging system, A3667. By combining filtered images on different scales using radial filters spectacular images of the edges in a cluster are produced. We describe how to assess the significance of features in filtered images. We find the gradient filtering technique to have significant advantages for detecting many kinds of features compar...

  17. Multiwavelength Observations and State Transitions of an Ultra-luminous Supersoft X-ray Source: Evidence for an Intermediate-Mass Black Hole

    CERN Document Server

    Kong, A K H; Sjouwerman, L O; Di Stefano, R

    2005-01-01

    We report the results of Chandra and XMM-Newton observations of an ultra-luminous supersoft X-ray source in M101. M101 ULX-1 underwent 2 outbursts in 2004 during which the peak bolometric luminosities reached 1e41 erg/s. The outburst spectra were very soft and can generally be fitted with a blackbody model with temperatures of 50-160 eV. In two of the observations, absorption edges at 0.33 keV, 0.56 keV, 0.66 keV, and 0.88 keV were found. A cool accretion disk was also found in the 2004 December outburst. During the low luminosity state, a power-law tail was seen up to 7 keV. It is clear the source changed from a low/hard state to a high/soft state. In addition, it showed at least 5 outbursts between 1996 and 2004. This is the first ultra-luminous X-ray source for which recurrent outbursts with state transitions similar to Galactic X-ray binaries have been observed. From the Hubble Space Telescope data, we found an optical counterpart to the source. During the 2004 outbursts, we also performed radio and groun...

  18. On the Nature of Ultraluminous X-Ray Sources, Or What a Black Hole Should Look Like

    Energy Technology Data Exchange (ETDEWEB)

    Poutanen, Juri; /Oulu U. /KIPAC, Menlo Park; Fabrika, Sergei; /Stavropol, Astrophys. Observ.; Butkevich, Alexey G.; /Oulu U. /Pulkovo Observ., St. Petersburg; Abolmasov,; /Stavropol, Astrophys. Observ.

    2006-09-18

    observed in the ultraluminous X-ray sources (ULX). The strong outflows combined with the large intrinsic X-ray luminosity of the central BH explain naturally the presence of the photoionized nebulae around ULX. An excellent agreement between the model and the observational data on ULX strongly argues in favour of ULX being super-critically accreting, stellar-mass BHs similar to SS 433, but viewed along the symmetry axis.

  19. NuSTAR reveals an intrinsically x-ray weak broad absorption line quasar in the ultraluminous infrared galaxy Markarian 231

    DEFF Research Database (Denmark)

    Teng, Stacy H.; Brandt, W. N.; Harrison, F. A.

    2014-01-01

    We present high-energy (3-30 keV) NuSTAR observations of the nearest quasar, the ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5-8 keV) data from Chandra. The source was detected, though at much fainter levels than previously......-ionization broad absorption line quasar that is intrinsically X-ray weak. The weak ionizing continuum may explain the lack of mid-infrared [O IV], [Ne V], and [Ne VI] fine-structure emission lines which are present in sources with otherwise similar AGN properties. We argue that the intrinsic X-ray weakness may...

  20. A study on materials of steels by high brightness X-ray

    CERN Document Server

    Tsuzaki, K; Umezawa, O; Hara, T; Takahashi, T; Omura, T; Hayakawa, M; Yamauchi, Y

    2001-01-01

    As the survey study on materials analysis of steels using high brightness X-ray, under aiming to clarify direct experimental facts on deformations, failure phenomena, and metal textures forming at interior portions of bulk materials, feasibility on materials research and development using SPring-8 was surveyed. Its concrete items were summarized to fields shown as follows: 1) acquirement of foundation on synchrotron X-ray, 2) visualization of cracks and artificial cracks in metal bulk samples by using refraction imaging (point light source topography), 3) visualization of the second phase in the metal bulk samples by using refraction imaging, and 4) speciation of carbon elements in steel cords by Moessbauer spectroscopy. Together with clarifying problems more and more by the survey and some experiments, subjects and understandings vacantly considered at standpoints of materials researchers could be arranged and defined. (G.K.)

  1. The Early X-ray Afterglows of Optically Bright and Dark Gamma-Ray Bursts

    Institute of Scientific and Technical Information of China (English)

    Yi-Qing Lin

    2006-01-01

    A systematic study on the early X-ray afterglows of both optically bright and dark gamma-ray bursts (B-GRBs and D-GRBs) observed by Swift is presented. Our sample includes 25 GRBs of which 13 are B-GRBs and 12 are D-GRBs. Our results show that the distributions of the X-ray afterglow fluxes (Fx), the gamma-ray fluxes (Sγ), and the ratio (Rγ,X) are similar for the two kinds of GRBs, that any observed differences should be simply statistical fluctuation. These results indicate that the progenitors of the two kinds of GRBs are of the same population with comparable total energies of explosion. The suppression of optical emission in the D-GRBs should result from circumburst but not from their central engine.

  2. Testing the Paradigm that Ultra-Luminous X-ray Sources as a Class Represent Accreting Intermediate-Mass Black Holes

    CERN Document Server

    Berghea, C T; Colbert, E J M; Roberts, T P

    2008-01-01

    To test the idea that ultraluminous X-ray sources (ULXs) in external galaxies represent a class of accreting Intermediate-Mass Black Holes (IMBHs), we have undertaken a program to identify ULXs and a lower luminosity X-ray comparison sample with the highest quality data in the {\\it Chandra} archive. We establish a general property of ULXs that the most X-ray luminous objects possess the flattest X-ray spectra (in the {\\it Chandra} band pass). No prior sample studies have established the general hardening of ULX spectra with luminosity. This hardening occurs at the highest luminosities (absorbed luminosity $\\geq5\\times10^{39}$ erg s$^{-1}$) and is in line with recent models arguing that ULXs are actually stellar-mass black holes. From spectral modeling, we show that the evidence originally taken to mean that ULXs are IMBHs - i.e., the ``simple IMBH model'' - is nowhere near as compelling when a large sample of ULXs is looked at properly. During the last couple of years, {\\it XMM-Newton} spectroscopy of ULXs ha...

  3. Transition of an X-ray binary to the hard ultraluminous state in the blue compact dwarf galaxy VII Zw 403

    CERN Document Server

    Brorby, Matthew; Feng, Hua

    2015-01-01

    We examine the X-ray spectra of VII Zw 403, a nearby low-metallicity blue compact dwarf (BCD) galaxy. The galaxy has been observed to contain an X-ray source, likely a high mass X-ray binary (HMXB), with a luminosity of 1.3-23x10^38 erg s^-1 in the 0.3-8 keV energy range. A new Suzaku observation shows a transition to a luminosity of 1.7x10^40 erg s^-1 [0.3-8 keV], higher by a factor of 7-130. The spectra from the high flux state are hard, best described by a disk plus Comptonization model, and exhibit curvature at energies above 5 keV. This is consistent with many high-quality ultraluminous X-ray source spectra which have been interpreted as stellar mass black holes (StMBH) accreting at super-Eddington rates. However, this lies in contrast to another HMXB in a low-metallicity BCD, I Zw 18, that exhibits a soft spectrum at high flux, similar to Galactic black hole binaries and has been interpreted as a possible intermediate mass black hole. Determining the spectral properties of HMXBs in BCDs has important im...

  4. {\\it NuSTAR} Reveals an Intrinsically X-ray Weak Broad Absorption Line Quasar in the Ultraluminous Infrared Galaxy Markarian 231

    CERN Document Server

    Teng, Stacy H; Harrison, F A; Luo, B; Alexander, D M; Bauer, F E; Boggs, S E; Christensen, F E; Comastri, A; Craig, W W; Fabian, A C; Farrah, D; Fiore, F; Gandhi, P; Grefenstette, B W; Hailey, C J; Hickox, R C; Madsen, K K; Ptak, A F; Rigby, J R; Risaliti, G; Saez, C; Stern, D; Veilleux, S; Walton, D J; Wik, D R; Zhang, W W

    2014-01-01

    We present high-energy (3--30 keV) {\\it NuSTAR} observations of the nearest quasar, the ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5--8 keV) data from {\\it Chandra}. The source was detected, though at much fainter levels than previously reported, likely due to contamination in the large apertures of previous non-focusing hard X-ray telescopes. The full band (0.5--30 keV) X-ray spectrum suggests the active galactic nucleus (AGN) in Mrk 231 is absorbed by a patchy and Compton-thin (N$_{\\rm H} \\sim1.2^{+0.3}_{-0.3}\\times10^{23}$ cm$^{-2}$) column. The intrinsic X-ray luminosity (L$_{\\rm 0.5-30 keV}\\sim1.0\\times10^{43}$ erg s$^{1}$) is extremely weak relative to the bolometric luminosity where the 2--10 keV to bolometric luminosity ratio is $\\sim$0.03% compared to the typical values of 2--15%. Additionally, Mrk 231 has a low X-ray-to-optical power law slope ($\\alpha_{\\rm OX}\\sim-1.7$). It is a local example of a low-ionization broad absorpti...

  5. X-Ray bright active galactic nuclei in massive galaxy clusters - II. The fraction of galaxies hosting active nuclei

    DEFF Research Database (Denmark)

    Ehlert, S.; von der Linden, A.; Allen, S. W.

    2013-01-01

    We present a measurement of the fraction of cluster galaxies hosting X-ray bright active galactic nuclei (AGN) as a function of clustercentric distance scaled in units of r500. Our analysis employs high-quality Chandra X-ray and Subaru optical imaging for 42 massive X-ray-selected galaxy cluster......, both of which are also suppressed near cluster centres to a comparable extent. These results strongly support the idea that X-ray AGN activity and strong star formation are linked through their common dependence on available reservoirs of cold gas....... fields spanning the redshift range 0.2 cluster galaxy AGN fraction in the central...

  6. Stability of mass transfer from massive giants: double black-hole binary formation and ultra-luminous X-ray sources

    CERN Document Server

    Pavlovskii, K; Belczynski, K; Van, K X

    2016-01-01

    The mass transfer in binaries with massive donors and compact companions, when the donors rapidly evolve after their main sequence, is one of the dominant formation channels of merging double stellar-mass black hole binaries. This mass transfer was previously postulated to be unstable and was expected to lead to a common envelope event. The common envelope event then would end with either double black hole formation, or with the merger of the two stars. We re-visit the stability of this mass transfer, and find that for a large range of the binary orbital separations this mass transfer is stable. This newly found stability allows us to reconcile the theoretical rate for double black hole binary mergers predicted by population synthesis studies, and the empirical rate obtained by LIGO. Futhermore, the stability of the mass transfer leads to the formation of ultra-luminous X-ray sources. The theoretically predicted formation rates of ultra-luminous X-ray sources powered by a stellar-mass BH, as well as the range...

  7. Relationship Between Solar Coronal X-Ray Brightness and Active Region Magnetic Fields: A Study Using High Resolution Observations

    CERN Document Server

    Hazra, Soumitra; Ravindra, B

    2014-01-01

    By utilizing high resolution observations of nearly co-temporal and co-spatial SOT spectropolarimeter and XRT coronal X-ray data onboard Hinode, we revisit the contentious issue of the relationship between global magnetic quantities and coronal X-ray intensity. Co-aligned vector magnetogram and X-ray data are used for this study. We find that there is no pixel-to-pixel correlation between the observed loop brightness and magnetic quantities. However, the X-ray brightness is well correlated with the integrated magnetic quantities such as total unsigned magnetic flux, total unsigned vertical current, area integrated square of the vertical magnetic field and horizontal magnetic fields. Comparing all these quantities we find that the total magnetic flux correlates well with the observed integrated X-ray brightness, though there is some differences in the strength of the correlation when we use the X-ray data from different filters. While we get a good correlation between X-ray brightness and total unsigned vertic...

  8. Bright X-ray source from a laser-driven micro-plasma-waveguide

    CERN Document Server

    Yi, Longqing

    2016-01-01

    Bright tunable x-ray sources have a number of applications in basic science, medicine and industry. The most powerful sources are synchrotrons, where relativistic electrons are circling in giant storage rings. In parallel, compact laser-plasma x-ray sources are being developed. Owing to the rapid progress in laser technology, very high-contrast femtosecond laser pulses of relativistic intensities become available. These pulses allow for interaction with micro-structured solid-density plasma without destroying the structure by parasitic pre-pulses. The high-contrast laser pulses as well as the manufacturing of materials at micro- and nano-scales open a new realm of possibilities for laser interaction with photonic materials at the relativistic intensities. Here we demonstrate, via numerical simulations, that when coupling with a readily available 1.8 Joule laser, a micro-plasma-waveguide (MPW) may serve as a novel compact x-ray source. Electrons are extracted from the walls by the laser field and form a dense ...

  9. H-alpha macrospicules - Identification with EUV macrospicules and with flares in X-ray bright points

    Science.gov (United States)

    Moore, R. L.; Tang, F.; Bohlin, J. D.; Golub, L.

    1977-01-01

    The paper presents observational evidence that two newly observed transient solar phenomena, EUV macrospicules and X-ray bright-point flares, are closely related. Time-lapse H-alpha filtergram observations of the limb in quiet regions show small surgelike eruptions called H-alpha macrospicules. From the similarity of H-alpha macrospicules and EUV macrospicules, and from comparison of simultaneous H-alpha and He II 304 A observations, we conclude that H-alpha macrospicules are EUV macrospicules viewed in H-alpha, although most EUV macrospicules are too faint in H-alpha to appear on H-alpha filtergrams of normal exposure. From comparison of simultaneous X-ray and H-alpha observations of flares in X-ray bright points situated on the limb, we show that flares in X-ray bright points often produce H-alpha macrospicules.

  10. NuSTAR Observations of the Compton-thick Active Galactic Nucleus and Ultraluminous X-ray Source Candidate in NGC 5643

    CERN Document Server

    Annuar, A; Alexander, D M; Lansbury, G B; Arévalo, P; Ballantyne, D R; Baloković, M; Bauer, F E; Boggs, S E; Brandt, W N; Brightman, M; Christensen, F E; Craig, W W; Del Moro, A; Hailey, C J; Harrison, F A; Hickox, R C; Matt, G; Puccetti, S; Ricci, C; Rigby, J R; Stern, D; Walton, D J; Zappacosta, L; Zhang, W

    2015-01-01

    We present two NuSTAR observations of the local Seyfert 2 active galactic nucleus (AGN) and an ultraluminous X-ray source (ULX) candidate in NGC 5643. Together with archival data from Chandra, XMM-Newton and Swift-BAT, we perform a high-quality broadband spectral analysis of the AGN over two decades in energy ($\\sim$0.5-100 keV). Previous X-ray observations suggested that the AGN is obscured by a Compton-thick (CT) column of obscuring gas along our line-of-sight. However, the lack of high-quality $\\gtrsim$ 10 keV observations, together with the presence of a nearby X-ray luminous source, NGC 5643 X-1, had left significant uncertainties in the characterization of the nuclear spectrum. NuSTAR now enables the AGN and NGC 5643 X-1 to be separately resolved above 10 keV for the first time and allows a direct measurement of the absorbing column density toward the nucleus. The new data show that the nucleus is indeed obscured by a CT column of $N_{\\rm{H}}$ $\\gtrsim$ 5 $\\times$ 10$^{24}$ cm$^{-2}$. The range of 2-10 ...

  11. A comprehensive analysis of the hard X-ray spectra of bright Seyfert galaxies

    Science.gov (United States)

    Lubiński, P.; Beckmann, V.; Gibaud, L.; Paltani, S.; Papadakis, I. E.; Ricci, C.; Soldi, S.; Türler, M.; Walter, R.; Zdziarski, A. A.

    2016-05-01

    Hard X-ray spectra of 28 bright Seyfert galaxies observed with INTEGRAL were analysed together with the X-ray spectra from XMM-Newton, Suzaku and RXTE. These broad-band data were fitted with a model assuming a thermal Comptonization as a primary continuum component. We tested several model options through a fitting of the Comptonized continuum accompanied by a complex absorption and a Compton reflection. Both the large data set used and the model space explored allowed us to accurately determine a mean temperature kTe of the electron plasma, the Compton parameter y and the Compton reflection strength R for the majority of objects in the sample. Our main finding is that a vast majority of the sample (20 objects) is characterized by kTe 200 keV. The median kTe for entire sample is 48_{-14}^{+57} keV. The distribution of the y parameter is bimodal, with a broad component centred at ≈0.8 and a narrow peak at ≈1.1. A complex, dual absorber model improved the fit for all data sets, compared to a simple absorption model, reducing the fitted strength of Compton reflection by a factor of about 2. Modest reflection (median R ≈ 0.32) together with a high ratio of Comptonized to seed photon fluxes point towards a geometry with a compact hard X-ray emitting region well separated from the accretion disc. Our results imply that the template Seyferts spectra used in the population synthesis models of active galactic nuclei (AGN) should be revised.

  12. The ultraluminous x-ray sources ngc 1313 x-1 and x-2: a broadband study with NuSTAR and XMM-Newton

    DEFF Research Database (Denmark)

    Bachetti, Matteo; Rana, Vikram; Walton, Dominic J.;

    2013-01-01

    We present the results of NuSTAR and XMM-Newton observations of the two ultraluminous X-ray sources: NGC 1313 X-1 and X-2. The combined spectral bandpass of the two satellites enables us to produce the first spectrum of X-1 between 0.3 and 30 keV, while X-2 is not significantly detected by Nu...... for the downturn of a broadened iron line in a reflection-dominated regime. The cutoff differs from the prediction of a single-temperature Comptonization model. Further, a cold disk-like blackbody component at similar to 0.3 keV is required by the data, confirming previous measurements by XMM-Newton only. We...

  13. ULTRA-BRIGHT X-RAY GENERATION USING INVERSE COMPTON SCATTERING OF PICOSECOND CO(2) LASER PLUSES.

    Energy Technology Data Exchange (ETDEWEB)

    TSUNEMI,A.; ENDO,A.; POGORELSKY,I.; BEN-ZVI,I.; KUSCHE,K.; SKARITKA,J.; YAKIMENKO,V.; HIROSE,T.; URAKAWA,J.; OMORI,T.; WASHIO,M.; LIU,Y.; HE,P.; CLINE,D.

    1999-03-01

    Laser-Compton scattering with picosecond CO{sub 2} laser pulses is proposed for generation of high-brightness x-rays. The interaction chamber has been developed and the experiment is scheduled for the generation of the x-rays of 4.7 keV, 10{sup 7} photons in 10-ps pulse width using 50-MeV, 0.5-nC relativistic electron bunches and 6 GW CO{sub 2} laser.

  14. Studying a kind of portable ultra-bright microfocus x-ray source

    Institute of Scientific and Technical Information of China (English)

    Wang Kai-Ge; Wang Lei; Niu Han-Ben

    2009-01-01

    This paper studies the properties of a kind of portable ultra-bright microfocus x-ray source with the Monte-Carlo method in detail. The new x-ray source consists of an electron-emission system, an electrostatic focusing system and a metal target. A crystal Lanthanum Hexaboride cathode, a Wehnelt grid and an extracted electrode compose the triode electrode electron-gun system. Two equal radius cylinder electrodes form the focusing system. The key factors determining the focus properties of the electron beam such as the ratio Dw/H, grid bias Vg, and the properties of the extracted electrode are numerically studied. The calculated results reveal that when Dw/H, Vg, the length of the extracted electrode, and the distance between the grid and the extracted electrode equals 5, -0.6 kV, 10 mm, and 8 mm respectively, the electron beam focal spot can be concentrated down to 9 μm in radius and a reasonable focal length about 72.5 mm can be achieved, at the same time, the cathode emission currents can be as high as 30 mA.

  15. A comprehensive analysis of the hard X-ray spectra of bright Seyfert galaxies

    CERN Document Server

    Lubinski, P; Gibaud, L; Paltani, S; Papadakis, I E; Ricci, C; Soldi, S; Türler, M; Walter, R; Zdziarski, A A

    2016-01-01

    Hard X-ray spectra of 28 bright Seyfert galaxies observed with INTEGRAL were analyzed together with the X-ray spectra from XMM-Newton, Suzaku and RXTE. These broad-band data were fitted with a model assuming a thermal Comptonization as a primary continuum component. We tested several model options through a fitting of the Comptonized continuum accompanied by a complex absorption and a Compton reflection. Both the large data set used and the model space explored allowed us to accurately determine a mean temperature kTe of the electron plasma, the Compton parameter y and the Compton reflection strength R for the majority of objects in the sample. Our main finding is that a vast majority of the sample (20 objects) is characterized by kTe 200 keV. The median kTe for entire sample is 48(-14,+57) keV. The distribution of the y parameter is bimodal, with a broad component centered at ~0.8 and a narrow peak at ~1.1. A complex, dual absorber model improved the fit for all data sets, compared to a simple absorption mo...

  16. Plasmon-enhanced photocathode for high brightness and high repetition rate x-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Polyakov, Aleksandr; Senft, Christoph; Thompson, K. F.; Feng, J.; Cabrini, S.; Schuck, P. J.; Padmore, Howard; Peppernick, Samuel J.; Hess, Wayne P.

    2013-02-11

    High brightness electron sources are at the heart of anew generation of x-ray sources based on the Free ElectronLaser (FEL) as well as in Energy Recovery Linac (ERL) and Inverse Compton Scattering (ICS) sources.The source of electrons consists of a photoinjector, comprised of a laser-driven photocathode in a high gradient electric field produced by an rf cavity. The function of the rf cavity is to provide a field sufficient for acceleration of electrons to relativistic velocity over a small distance, thus minimizing effects of the space-charge. Even so, the dense electron beam required for high brightness suffers from a space charge field that chirps and reshapes the electron pulse increasing beam emittance and thus reducing the overall brightness. This emittance growth can be avoided if the initial distribution of electrons is pancake shaped, with a semicircular transverse intensity profile. In this case, the electron distribution develops under its space charge field from a pancake into a uniformly filled ellipsoidal beam. This condition, referred to as the blowout regime, requires ultrashort pulses less than 100 fs long and has been successfully demonstrated recently in a high gradient photoinjector.

  17. Bright betatronlike x rays from radiation pressure acceleration of a mass-limited foil target.

    Science.gov (United States)

    Yu, Tong-Pu; Pukhov, Alexander; Sheng, Zheng-Ming; Liu, Feng; Shvets, Gennady

    2013-01-25

    By using multidimensional particle-in-cell simulations, we study the electromagnetic emission from radiation pressure acceleration of ultrathin mass-limited foils. When a circularly polarized laser pulse irradiates the foil, the laser radiation pressure pushes the foil forward as a whole. The outer wings of the pulse continue to propagate and act as a natural undulator. Electrons move together with ions longitudinally but oscillate around the latter transversely, forming a self-organized helical electron bunch. When the electron oscillation frequency coincides with the laser frequency as witnessed by the electron, betatronlike resonance occurs. The emitted x rays by the resonant electrons have high brightness, short durations, and broad band ranges which may have diverse applications.

  18. Rapidly Rotating, X-ray Bright Stars in the Kepler Field

    CERN Document Server

    Howell, Steve B; Boyd, Padi; Smith, Krista Lynne; Gelino, Dawn

    2016-01-01

    We present Kepler light curves and optical spectroscopy of twenty X-ray bright stars located in the Kepler field of view. The stars, spectral type FK, show evidence for rapid rotation including chromospheric activity 100 times or more above the Sun at maximum and flaring behavior in their light curves. Eighteen of our objects appear to be (sub)giants and may belong to the class of FK Com variables, that is evolved rapidly spinning single stars with no excretion disk and high levels of chromospheric activity. Such stars are rare and are likely the result of W UMa binary mergers, a process believed to produce the FK Com class of variable and their descendants. The FK Com stage, including the presence of an excretion disk, is short-lived but leads to longer-lived stages consisting of single, rapidly rotating evolved (sub)giants with high levels of stellar activity.

  19. Thermometric- and Acoustic-Based Beam Power Monitor for Ultra-Bright X-Rays

    Energy Technology Data Exchange (ETDEWEB)

    Bentsen, Gregory; /Rochester U. /SLAC

    2010-08-25

    A design for an average beam power monitor for ultra-bright X-ray sources is proposed that makes simultaneous use of calorimetry and radiation acoustics. Radiation incident on a solid target will induce heating and ultrasonic vibrations, both of which may be measured to give a fairly precise value of the beam power. The monitor is intended for measuring ultra-bright Free-Electron Laser (FEL) X-ray beams, for which traditional monitoring technologies such as photo-diodes or scintillators are unsuitable. The monitor consists of a Boron Carbide (B{sub 4}C) target designed to absorb most of the incident beam's energy. Resistance temperature detectors (RTD) and piezoelectric actuators are mounted on the outward faces of the target to measure the temperature changes and ultrasonic vibrations induced by the incident beam. The design was tested using an optical pulsed beam (780 nm, 120 and 360 Hz) from a Ti:sapphire oscillator at several energies between 0.8 and 2.6 mJ. The RTDs measured an increase in temperature of about 10 K over a period of several minutes. The piezoelectric sensors recorded ringing acoustic oscillations at 580 {+-} 40 kHz. Most importantly, the amplitude of the acoustic signals was observed to scale linearly with beam power up to 2 mJ of pulse energy. Above this pulse energy, the vibrational signals became nonlinear. Several causes for this nonlinearity are discussed, including amplifier saturation and piezoelectric saturation. Despite this nonlinearity, these measurements demonstrate the feasibility of such a beam power measurement device. The advantage of two distinct measurements (acoustic and thermometric) provides a useful method of calibration that is unavailable to current LCLS diagnostics tools.

  20. A Chandra Observation of the Ultraluminous Infrared Galaxy IRAS 19254-7245 (The Superantennae): X-Ray Emission from the Compton-Thick Active Galactic Nucleus and the Diffuse Starburst

    Science.gov (United States)

    Jia, Jianjun; Ptak, Andrew; Heckman, Timothy M.; Braito, Valentina; Reeves, James

    2012-01-01

    We present a Chandra observation of IRAS 19254-7245, a nearby ultraluminous infrared galaxy also known as the Superantennae. The high spatial resolution of Chandra allows us to disentangle for the first time the diffuse starburst (SB) emission from the embedded Compton-thick active galactic nucleus (AGN) in the southern nucleus. No AGN activity is detected in the northern nucleus. The 2-10 keV spectrum of the AGN emission is fitted by a flat power law (TAU = 1.3) and an He-like Fe Kalpha line with equivalent width 1.5 keV, consistent with previous observations. The Fe K line profile could be resolved as a blend of a neutral 6.4 keV line and an ionized 6.7 keV (He-like) or 6.9 keV (H-like) line. Variability of the neutral line is detected compared with the previous XMM-Newton and Suzaku observations, demonstrating the compact size of the iron line emission. The spectrum of the galaxy-scale extended emission excluding the AGN and other bright point sources is fitted with a thermal component with a best-fit kT of approximately 0.8 keV. The 2-10 keV luminosity of the extended emission is about one order of magnitude lower than that of the AGN. The basic physical and structural properties of the extended emission are fully consistent with a galactic wind being driven by the SB. A candidate ultraluminous X-ray source is detected 8 south of the southern nucleus. The 0.3 - 10 keV luminosity of this off-nuclear point source is approximately 6 x 10(exp 40) erg per second if the emission is isotropic and the source is associated with the Superantennae.

  1. The ultraluminous X-ray sources NGC 1313 X-1 and X-2: A broadband study with NuSTAR and XMM-Newton

    Energy Technology Data Exchange (ETDEWEB)

    Bachetti, Matteo; Barret, Didier; Webb, Natalie A. [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Rana, Vikram; Walton, Dominic J.; Harrison, Fiona A.; Fürst, Felix; Grefenstette, Brian W.; Madsen, Kristin K. [Cahill Center for Astronomy and Astrophysics, Caltech, Pasadena, CA 91125 (United States); Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Fabian, Andrew C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Hornschemeier, Ann; Ptak, Andrew F.; Zhang, William W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Miller, Jon M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Stern, Daniel, E-mail: matteo.bachetti@irap.omp.eu [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2013-12-01

    We present the results of NuSTAR and XMM-Newton observations of the two ultraluminous X-ray sources: NGC 1313 X-1 and X-2. The combined spectral bandpass of the two satellites enables us to produce the first spectrum of X-1 between 0.3 and 30 keV, while X-2 is not significantly detected by NuSTAR above 10 keV. The NuSTAR data demonstrate that X-1 has a clear cutoff above 10 keV, whose presence was only marginally detectable with previous X-ray observations. This cutoff rules out the interpretation of X-1 as a black hole in a standard low/hard state, and it is deeper than predicted for the downturn of a broadened iron line in a reflection-dominated regime. The cutoff differs from the prediction of a single-temperature Comptonization model. Further, a cold disk-like blackbody component at ∼0.3 keV is required by the data, confirming previous measurements by XMM-Newton only. We observe a spectral transition in X-2, from a state with high luminosity and strong variability to a lower-luminosity state with no detectable variability, and we link this behavior to a transition from a super-Eddington to a sub-Eddington regime.

  2. Constraints on accretion in Ultraluminous X-ray Sources from Spitzer IRS observations of NGC 4485/90: Infrared diagnostic diagrams

    CERN Document Server

    Vázquez, G A; Colbert, E; Roberts, T P; Ward, M J; Malhotra, S; Vazquez, Gerardo A.; Hornschemeier, Ann E.; Colbert, Edward; Roberts, Tymothy P.; Ward, Martin J.

    2007-01-01

    Constraining the astrophysical nature of Ultra-Luminous X-ray (ULX) sources, which have X-ray luminosities exceeding 10^39 erg/s, has been elusive due to the optical faintness of any counterparts. With high spectral resolution observations in the ~10-30 microns wavelength range we have conducted an experiment to study six ULX sources in the NGC 4485/90 galaxy pair. We have found that five of the six ULXs, based on mid-infrared spectral diagnostics, show the characteristic higher ionization features that are found in AGN. The sixth source, ULX-1, is consistent with being a supernova remnant. The chief infrared spectral diagnostics used are the ratios of [S III]/[Si II] vs [Ne III}]/[Ne II]. In two instances fits to the continuum and poly aromatic hydrocarbons (PAH) features also indicate higher dust temperatures that are characteristic of accreting sources. Overall, however, we find the continuum is dominated by stellar processes, and the best diagnostic features are the emission lines. High spectral resolutio...

  3. The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1

    CERN Document Server

    Cseh, D; Jonker, P G; Grise, F; Paragi, Z; Corbel, S; Falcke, H; Frey, S; Kaaret, P; Koerding, E

    2015-01-01

    We present quasi-simultaneous, multi-epoch radio and X-ray measurements of Holmberg II X-1 using the European VLBI Network (EVN), the Karl G. Jansky Very Large Array (VLA), and the Chandra and Swift X-ray telescopes. The X-ray data show apparently hard spectra with steady X-ray luminosities 4 months apart from each other. In the high-resolution EVN radio observations, we have detected an extended milli-arcsecond scale source with unboosted radio emission. The source emits non-thermal, likely optically thin synchrotron emission and its morphology is consistent with a jet ejection. The 9-GHz VLA data show an arcsecond-scale triple structure of Holmberg II X-1 similar to that seen at lower frequencies. However, we find that the central ejection has faded by at least a factor of 7.3 over 1.5 years. We estimate the dynamical age of the ejection to be higher than 2.1 years. We show that such a rapid cooling can be explained with simple adiabatic expansion losses. These properties of Holmberg II X-1 imply that ULX r...

  4. SMC X-3: the closest ultraluminous X-ray source powered by a neutron star with non-dipole magnetic field

    Science.gov (United States)

    Tsygankov, S. S.; Doroshenko, V.; Lutovinov, A. A.; Mushtukov, A. A.; Poutanen, J.

    2017-09-01

    Aims: The magnetic field of accreting neutron stars determines their overall behavior including the maximum possible luminosity. Some models require an above-average magnetic field strength (≳1013 G) in order to explain super-Eddington mass accretion rate in the recently discovered class of pulsating ultraluminous X-ray sources (ULX). The peak luminosity of SMC X-3 during its major outburst in 2016-2017 reached 2.5 × 1039 erg s-1 comparable to that in ULXs thus making this source the nearest ULX-pulsar. Determination of the magnetic field of SMC X-3 is the main goal of this paper. Methods: SMC X-3 belongs to the class of transient X-ray pulsars with Be optical companions, and exhibited a giant outburst in July 2016-March 2017. The source has been observed over the entire outburst with the Swift/XRT and Fermi/GBM telescopes, as well as the NuSTAR observatory. Collected data allowed us to estimate the magnetic field strength of the neutron star in SMC X-3 using several independent methods. Results: Spin evolution of the source during and between the outbursts, and the luminosity of the transition to the so-called propeller regime in the range of (0.3-7) × 1035 erg s-1 imply a relatively weak dipole field of (1-5) × 1012 G. On the other hand, there is also evidence for a much stronger field in the immediate vicinity of the neutron star surface. In particular, transition from super- to sub-critical accretion regime associated with the cease of the accretion column and very high peak luminosity favor a field that is an order of magnitude stronger. This discrepancy makes SMC X-3 a good candidate for possessing significant non-dipolar components of the field, and an intermediate source between classical X-ray pulsars and accreting magnetars which may constitute an appreciable fraction of ULX population.

  5. Shedding Light on the Compton-thick Active Galactic Nucleus in the Ultraluminous Infrared Galaxy UGC 5101 with Broadband X-Ray Spectroscopy

    Science.gov (United States)

    Oda, Saeko; Tanimoto, Atsushi; Ueda, Yoshihiro; Imanishi, Masatoshi; Terashima, Yuichi; Ricci, Claudio

    2017-02-01

    We report the broadband X-ray spectra of the ultraluminous infrared galaxy (ULIRG) UGC 5101 in the 0.25–100 keV band observed with the Swift/Burst Alert Telescope (BAT), Nuclear Spectroscopic Telescope Array (NuSTAR), Suzaku, XMM-Newton, and Chandra. A Compton-thick active galactic nucleus (AGN) obscured with a hydrogen column density of ≈ 1.3× {10}24 cm‑2 is detected above 10 keV. A spectral fit with a numerical torus model favors a large half-opening angle of the torus, > 41°, suggesting that the covering fraction of material heavily obscuring the X-ray source is moderate. The intrinsic 2–10 keV luminosity is determined to be ≈ 1.4× {10}43 erg s‑1, which is ≈ 2.5 times larger than the previous estimate using only data below 10 keV with a simple spectral model. We find that UGC 5101 shows the ratio between the [O iv] 26 μm line and 2–10 keV luminosities similar to those of normal Seyfert galaxies, along with other ULIRGs observed with NuSTAR, indicating that a significant portion of local ULIRGs are not really “X-ray faint” with respect to the flux of forbidden lines originating from the narrow-line region. We propose a possible scenario that (1) the AGN in UGC 5101 is surrounded not only by Compton-thick matter located close to the equatorial plane but also by Compton-thin ({N}{{H}}∼ {10}21 cm‑2) matter in the torus-hole region and (2) it is accreting at a high Eddington rate with a steep UV to X-ray spectral energy distribution. Nevertheless, we argue that AGNs in many ULIRGs do not look extraordinary (i.e., extremely X-ray faint), as suggested by recent works, compared with normal Seyferts.

  6. Exploring the X-ray sky with the XMM-Newton bright serendipitous survey

    Science.gov (United States)

    Della Ceca, R.; Maccacaro, T.; Caccianiga, A.; Severgnini, P.; Braito, V.; Barcons, X.; Carrera, F. J.; Watson, M. G.; Tedds, J. A.; Brunner, H.; Lehmann, I.; Page, M. J.; Lamer, G.; Schwope, A.

    2004-12-01

    We present here ``The XMM-Newton Bright Serendipitous Survey'', composed of two flux-limited samples: the XMM-Newton Bright Source Sample (BSS, hereafter) and the XMM-Newton ``Hard'' Bright Source Sample (HBSS, hereafter) having a flux limit of f_x≃ 7 × 10-14 erg cm-2 s-1 in the 0.5-4.5 keV and 4.5-7.5 keV energy band, respectively. After discussing the main goals of this project and the survey strategy, we present the basic data on a complete sample of 400 X-ray sources (389 of them belong to the BSS, 67 to the HBSS with 56 X-ray sources in common) derived from the analysis of 237 suitable XMM-Newton fields (211 for the HBSS). At the flux limit of the survey we cover a survey area of 28.10 (25.17 for the HBSS) sq. deg. The extragalactic number-flux relationships (in the 0.5-4.5 keV and in the 4.5-7.5 keV energy bands) are in good agreement with previous and new results making us confident about the correctness of data selection and analysis. Up to now ˜ 71% (˜ 90%) of the sources have been spectroscopically identified making the BSS (HBSS) the sample with the highest number of identified XMM-Newton sources published so far. At the X-ray flux limits of the sources studied here we found that: a) the optical counterpart in the majority (˜ 90%) of cases has a magnitude brighter than the POSS II limit (R ˜ 21mag); b) the majority of the objects identified so far are broad line AGN both in the BSS and in the HBSS. No obvious trend of the source spectra (as deduced from the Hardness Ratios analysis) as a function of the count rate is measured and the average spectra of the ``extragalactic'' population corresponds to a (0.5-4.5 keV) energy spectral index of ˜ 0.8 (˜ 0.64) for the BSS (HBSS) sample. Based on the hardness ratios we infer that about 13% (40%) of the sources in the BSS (HBSS) sample are described by an energy spectral index flatter than that of the cosmic X-ray background. Based on previous X-ray spectral results on a small subsample of objects we

  7. Ultra-luminous X-ray sources and neutron-star-black-hole mergers from very massive close binaries at low metallicity

    Science.gov (United States)

    Marchant, Pablo; Langer, Norbert; Podsiadlowski, Philipp; Tauris, Thomas M.; de Mink, Selma; Mandel, Ilya; Moriya, Takashi J.

    2017-08-01

    The detection of gravitational waves from the binary black hole (BH) merger GW150914 may enlighten our understanding of ultra-luminous X-ray sources (ULXs), as BHs of masses >30 M⊙ can reach luminosities >4 × 1039 erg s-1 without exceeding their Eddington luminosities. It is then important to study variations of evolutionary channels for merging BHs, which might instead form accreting BHs and become ULXs. It was recently shown that very massive binaries with mass ratios close to unity and tight orbits can undergo efficient rotational mixing and evolve chemically homogeneously, resulting in a compact BH binary. We study similar systems by computing 120 000 detailed binary models with the MESA code covering a wide range of masses, orbital periods, mass ratios, and metallicities. For initial mass ratios q ≡ M2/M1 ≃ 0.1-0.4, primaries with masses above 40 M⊙ can evolve chemically homogeneously, remaining compact and forming a BH without experiencing Roche-lobe overflow. The secondary then expands and transfers mass to the BH, initiating a ULX phase. At a given metallicity this channel is expected to produce the most massive accreting stellar BHs and the brightest ULXs. We predict that 1 out of 104 massive stars evolves this way, and that in the local universe 0.13 ULXs per M⊙ yr-1 of star formation rate are observable, with a strong preference for low metallicities. An additional channel is still required to explain the less luminous ULXs and the full population of high-mass X-ray binaries. At metallicities log Z> -3, BH masses in ULXs are limited to 60 M⊙, due to the occurrence of pair-instability supernovae which leave no remnant, resulting in an X-ray luminosity cut-off for accreting BHs. At lower metallicities, very massive stars can avoid exploding as pair-instability supernovae and instead form BHs with masses above 130 M⊙, producing a gap in the ULX luminosity distribution. After the ULX phase, neutron star BH binaries that merge in less than a

  8. NuSTAR OBSERVATIONS OF THE COMPTON-THICK ACTIVE GALACTIC NUCLEUS AND ULTRALUMINOUS X-RAY SOURCE CANDIDATE IN NGC 5643

    Energy Technology Data Exchange (ETDEWEB)

    Annuar, A.; Gandhi, P.; Alexander, D. M.; Lansbury, G. B.; Moro, A. Del [Centre for Extragalactic Astronomy, Department of Physics, University of Durham, South Road, Durham, DH1 3LE (United Kingdom); Arévalo, P. [Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretana N 1111, Playa Ancha, Valparaíso (Chile); Ballantyne, D. R. [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Baloković, M.; Brightman, M.; Harrison, F. A. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Bauer, F. E. [EMBIGGEN Anillo, Concepción (Chile); Boggs, S. E.; Craig, W. W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Brandt, W. N. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (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); Hickox, R. C. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Matt, G. [Dipartimento di Matematica e Fisica, Universitá degli Studi Roma Tre, via della Vasca Navale 84, I-00146 Roma (Italy); Puccetti, S. [ASI Science Data Center, via Galileo Galilei, I-00044 Frascati (Italy); Ricci, C. [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); and others

    2015-12-10

    We present two Nuclear Spectroscopic Telescope Array (NuSTAR) observations of the local Seyfert 2 active galactic nucleus (AGN) and an ultraluminous X-ray source (ULX) candidate in NGC 5643. Together with archival data from Chandra, XMM-Newton, and Swift-BAT, we perform a high-quality broadband spectral analysis of the AGN over two decades in energy (∼0.5–100 keV). Previous X-ray observations suggested that the AGN is obscured by a Compton-thick (CT) column of obscuring gas along our line of sight. However, the lack of high-quality ≳10 keV observations, together with the presence of a nearby X-ray luminous source, NGC 5643 X–1, have left significant uncertainties in the characterization of the nuclear spectrum. NuSTAR now enables the AGN and NGC 5643 X–1 to be separately resolved above 10 keV for the first time and allows a direct measurement of the absorbing column density toward the nucleus. The new data show that the nucleus is indeed obscured by a CT column of N{sub H} ≳ 5 × 10{sup 24} cm{sup −2}. The range of 2–10 keV absorption-corrected luminosity inferred from the best-fitting models is L{sub 2–10,int} = (0.8–1.7) × 10{sup 42} erg s{sup −1}, consistent with that predicted from multiwavelength intrinsic luminosity indicators. In addition, we also study the NuSTAR data for NGC 5643 X–1 and show that it exhibits evidence of a spectral cutoff at energy E ∼ 10 keV, similar to that seen in other ULXs observed by NuSTAR. Along with the evidence for significant X-ray luminosity variations in the 3–8 keV band from 2003 to 2014, our results further strengthen the ULX classification of NGC 5643 X–1.

  9. Identification of the optical and quiescent counterparts to the bright X-ray transient in NGC 6440

    CERN Document Server

    in 't Zand, J J M; Pooley, D; Verbunt, F; Wijnands, R; Lewin, W H G

    2001-01-01

    After 3 years of quiescence, the globular cluster NGC 6440 exhibited a bright transient X-ray source turning on in August 2001, as noted with the RXTE All-Sky Monitor. We carried out a short target of opportunity observation with the Chandra X-ray Observatory and are able to associate the transient with the brightest of 24 X-ray sources detected during quiescence in July 2000 with Chandra. Furthermore, we securely identify the optical counterpart and determine that the 1998 X-ray outburst in NGC 6440 was from the same object. This is the first time that an optical counterpart to a transient in a globular cluster is securely identified. Since the transient is a type I X-ray burster, it is established that the compact accretor is a neutron star. Thus, this transient provides an ideal case to study the quiescent emission in the optical and X-ray of a transiently accreting neutron star while knowing the distance and reddening accurately. One model that fits the quiescent spectrum is an absorbed power law plus neu...

  10. X-Ray surface brightness and gas density fluctuations in the Coma cluster

    CERN Document Server

    Churazov, E; Zhuravleva, I; Schekochihin, A; Parrish, I; Sunyaev, R; Forman, W; Boehringer, H; Randall, S

    2011-01-01

    X-ray surface brightness fluctuations in the core ($650 \\times 650$ kpc) region of the Coma cluster observed with XMM-Newton and Chandra are analyzed using a 2D power spectrum approach. The resulting 2D spectra are converted to 3D power spectra of gas density fluctuations. The characteristic amplitude of the volume filling density fluctuations relative to the smooth underlying density distribution varies from 7-10% on scales of $\\sim$500 kpc down to $\\sim$5% at scales $\\sim$ 30 kpc. On smaller spatial scales, projection effects smear the density fluctuations by a large factor, precluding strong limits on the fluctuations in 3D. On the largest scales probed (hundreds of kpc), the dominant contributions to the observed fluctuations most likely arise from perturbations of the gravitational potential by the two most massive galaxies in Coma, NGC4874 and NGC4889, and the low entropy gas brought to the cluster by an infalling group. Other plausible sources of density fluctuations are discussed, including turbulence...

  11. C IV absorption line variability in X-ray bright BALQSOs

    CERN Document Server

    Joshi, Ravi; Srianand, Raghunathan; Majumdar, Jhilik

    2014-01-01

    We report kinematic shift and strength variability of C IV broad absorption line (BAL) trough in two high-ionization X-ray bright QSOs SDSS J085551+375752 (at zem ~ 1.936) and SDSS J091127+055054 (at zem ~ 2.793). Both these QSOs have shown combination of profile shift, appearance and disappearance of absorption components belonging to a single BAL trough, which we argue that they can be explained by combination of transverse and curved path motion of many small clouds. Our results supports the BAL outflow models involving many small self shielded clouds with low volume filling factor rather than a conventional single homogeneous continuous radial outflows. We found an average deceleration of ~ - 0.69 \\pm 0.09 cm/s^2, - 1.96 \\pm 0.09 cm/s^2 over a rest-frame time-span of 3.11 yr and 2.34 yr for SDSS J085551+375752 and SDSS J091127+055054, respectively. To our knowledge, these are largest kinematic shifts exceeding by factor 2.8, 7.8 than the highest deceleration reported in the literature; making both of them...

  12. Molecular Gas in the X-ray Bright Group NGC 5044 as Revealed by ALMA

    CERN Document Server

    David, Laurence P; Forman, William; Vrtilek, Jan; Combes, Francoise; Salome, Philippe; Edge, Alastair; Jones, Christine; Sun, Ming; O'Sullivan, Ewan; Gastaldello, Fabio; Temi, Pasquale; Schmitt, Henrique; Ohyama, Youichi; Hamer, Stephen; Mathews, William; Brighenti, Fabrizio; Giacintucci, Simona; Bardelli, Sandro; Trung, Dinh-V

    2014-01-01

    A short 30 minute ALMA observation of the early-type galaxy NGC 5044, which resides at the center of an X-ray bright group with a moderate cooling flow, has detected 24 molecular structures within the central 2.5 kpc. The masses of the molecular structures vary from 3e5 to 1e7 Mo3 and the CO(2-1) linewidths vary from 15 to 65 km/s. Given the large CO(2-1) linewidths, the observed structures are likely giant molecular associations (GMAs) and not individual molecular clouds (GMCs). Only a few of the GMAs are spatially resolved with the cycle 0 ALMA beam and the average density of these GMAs yields a GMC volume filling factor of about 15%. The observed masses of the resolved GMAs are insufficient for them to be gravitationally bound, however, the most massive GMA does contain a less massive component with a linewidth of 5.5 km/s (typical of an individual virialized GMC). We also show that the GMAs cannot be pressure confined by the hot gas. Given the observed CO(2-1) linewidths of the GMAs (i.e., the velocity di...

  13. The spectral and temporal properties of an Ultra-Luminous X-ray source in NGC 6946

    CERN Document Server

    Devi, A Senorita; Shanthi, K; Singh, K Y

    2008-01-01

    We report variability of the X-ray source, X-7, in NGC 6946, during a 60 ksec Chandra observation when the count rate decreased by a factor of ~1.5 in ~5000 secs. Spectral fitting of the high and low count rate segments of the light curve reveal that the simplest and most probable interpretation is that the X-ray spectra are due to disk black body emission with an absorbing hydrogen column density equal to the Galactic value of 2.1 X 10^{21} cm^{-2}. During the variation, the inner disk temperature decreased from ~0.29 to ~0.26 keV while the inner disk radius remained constant at ~6 X 10^8 cm. This translates into a luminosity variation from 3.8 to 2.8 X 10^{39} ergs cm^{-2} sec^{-1} and a black hole mass of ~400 solar masses. More complicated models like assuming intrinsic absorption and/or the addition of a power-law component imply a higher luminosity and a larger black hole mass. Even if the emission is beamed by a factor of ~5, the size of the emitting region would be > 2.7 X 10^8 cm implying a black hol...

  14. Ultraluminous X-ray Sources Powered by Radiatively Efficient Two-Phased Super-Eddington Accretion onto Stellar Mass Black holes

    CERN Document Server

    Socrates, A; Socrates, Aristotle; Davis, Shane W.

    2005-01-01

    The radiation spectra of many of the brightest ultraluminous X-ray sources (ULXs) are dominated by a hard power law component, likely powered by a hot, optically thin corona that Comptonizes soft seed photons emitted from a cool, optically thick black hole accretion disk. Before its dissipation and subsequent conversion into coronal photon power, the randomized gravitational binding energy responsible for powering ULX phenomena must separate from the mass of its origin by a means other than, and quicker than, electron scattering-mediated radiative diffusion. Therefore, the release of accretion power in ULXs is not necessarily subject to Eddington-limited photon trapping, as long as it occurs in a corona. Motivated by these basic considerations, we present a model of ULXs powered by geometrically thin accretion onto stellar mass black holes. We argue that the radiative efficiency of the flow remains high if the corona is magnetized or optically thin and the majority of the accretion power escapes in the form o...

  15. Binary Black Hole Merger Rates Inferred from Luminosity Function of Ultra-Luminous X-ray Sources: Implications to the Origin of GW150914

    CERN Document Server

    Inoue, Yoshiyuki; Isobe, Naoki

    2016-01-01

    The Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO) has detected direct signals of gravitational waves (GWs) from GW150914. The event was a merger of a binary black holes whose masses are $36^{+5}_{-4}M_{\\odot}$ and $29^{+4}_{-4}M_{\\odot}$. Such binary systems are expected to be formed in either isolated binary systems or dense stellar environments. Here we derived the binary black hole merger rate for isolated binary systems based on the nearby ultra-luminous X-ray source (ULX) luminosity function (LF). We obtained the binary black hole merger rate as $1.9 ({t}_{\\rm ULX}/{1 \\ \\rm Myr})^{-1} \\lambda^{-0.6} \\exp{(-0.30\\lambda)} \\ {\\rm Gpc^{-3}\\ yr^{-1}}$, where $t_{\\rm ULX}$ is the typical duration of the ULX phase and $\\lambda$ is the Eddington ratio. This is comparable to the event rate inferred from the detection of GW150914 as well as the predictions based on binary population synthesis models. Although we are currently unable to constrain $\\lambda$ due to the uncertainties of our mode...

  16. The Halo Occupation Distribution of X-ray-Bright Active Galactic Nuclei: A Comparison with Luminous Quasars

    CERN Document Server

    Richardson, Jonathan W; Zheng, Zheng; Myers, Adam; Hickox, Ryan C

    2013-01-01

    We perform halo occupation distribution (HOD) modeling of the projected two-point correlation function (2PCF) of high-redshift (z~1.2) X-ray-bright active galactic nuclei (AGN) in the XMM-COSMOS field measured by Allevato et al. The HOD parameterization is based on low-luminosity AGN in cosmological simulations. At the median redshift of z~1.2, we derive a median mass of (1.02+0.21/-0.23)x10^{13} Msun/h for halos hosting central AGN and an upper limit of ~10% on the AGN satellite fraction. Our modeling results indicate (at the 2.5-sigma level) that X-ray AGN reside in more massive halos compared to more bolometrically luminous, optically-selected quasars at similar redshift. The modeling also yields constraints on the duty cycle of the X-ray AGN, and we find that at z~1.2 the average duration of the X-ray AGN phase is two orders of magnitude longer than that of the quasar phase. Our inferred mean occupation function of X-ray AGN is similar to recent empirical measurements with a group catalog and suggests tha...

  17. RXTE/ASM and Swift / BAT observations of spectral transitions in bright X-ray binaries in 2005-2010

    Institute of Scientific and Technical Information of China (English)

    Jing Tang; Wen-Fei Yu; Zhen Yan

    2011-01-01

    We have studied X-ray spectral state transitions that can be seen in the longterm monitoring light curves of bright X-ray binaries from the All-Sky Monitor (ASM) onboard the Rossi X-ray Timing Explorer (RXTE) and the Burst Alert Telescope (BAT) onboard Swift during a period of five years from 2005 to 2010. We have applied a program to automatically identify the hard-to-soft (H-S) spectral state transitions in the bright X-ray binaries monitored by the ASM and the BAT. In total, we identified 128 hard-to-soft transitions, of which 59 occurred after 2008. We also determined the transition fluxes and the peak fluxes of the following soft states, updated the measurements of the luminosity corresponding to the H-S transition and the peak luminosity of the following soft state in about 30 bright persistent and transient black hole and neutron star binaries following Yu &Yan, and found the luminosity correlation and the luminosity range of spectral transitions in data between 2008-2010 are about the same as those derived from data before 2008. This further strengthens the idea that the luminosity at which the H-S spectral transition occurs in the Galactic X-ray binaries is determined by non-stationary accretion parameters such as the rate-of-change of the mass accretion rate rather than the mass accretion rate itself. The correlation is also found to hold in data of individual sources 4U 1608-52 and 4U 1636-53.

  18. Generation of bright attosecond x-ray pulse trains via Thomson scattering from laser-plasma accelerators.

    Science.gov (United States)

    Luo, W; Yu, T P; Chen, M; Song, Y M; Zhu, Z C; Ma, Y Y; Zhuo, H B

    2014-12-29

    Generation of attosecond x-ray pulse attracts more and more attention within the advanced light source user community due to its potentially wide applications. Here we propose an all-optical scheme to generate bright, attosecond hard x-ray pulse trains by Thomson backscattering of similarly structured electron beams produced in a vacuum channel by a tightly focused laser pulse. Design parameters for a proof-of-concept experiment are presented and demonstrated by using a particle-in-cell code and a four-dimensional laser-Compton scattering simulation code to model both the laser-based electron acceleration and Thomson scattering processes. Trains of 200 attosecond duration hard x-ray pulses holding stable longitudinal spacing with photon energies approaching 50 keV and maximum achievable peak brightness up to 1020 photons/s/mm2/mrad2/0.1%BW for each micro-bunch are observed. The suggested physical scheme for attosecond x-ray pulse trains generation may directly access the fastest time scales relevant to electron dynamics in atoms, molecules and materials.

  19. Testing the Universality of the TIS Model on Cluster Scales from the X-ray Surface Brightness Profiles

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The truncated isothermal sphere (TIS) model has been recently suggested as an alternative for virialized dark halos (Shapiro et al. 1999). Both its profound theoretical motivation and its successful explanations for the galactic rotation curves and the gravitational scaling laws of clusters indicate that the TIS model is a promising candidate among other prevailing models such as the NFW profile and the Burkert profile. This promotes us to re-examine the universality of the TIS model on cluster scales from a different angle. Using an ensemble of X-ray surface brightness profiles of 45 clusters, we test the goodness of fit of the TIS predicted gas distributions to the X-ray data under the assumption of isothermal, hydrostatic equilibrium. Unlike the conventional β model or the NFW/Burkert profile, for which about half of the clusters have the reduced x2v values smaller than 2,the TIS model fails in the fitting of the X-ray surface brightness profiles of clusters in the sense that 38 out of the 45 clusters show x2v > 2. This may constitute a challenge for the universality of the TIS model unless the present analysis is seriously contaminated by other uncertainties including the negligence of non-gravitational heating processes and the unconventional sampling of the X-ray data.

  20. THE HALO OCCUPATION DISTRIBUTION OF X-RAY-BRIGHT ACTIVE GALACTIC NUCLEI: A COMPARISON WITH LUMINOUS QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Jonathan [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60605 (United States); Chatterjee, Suchetana; Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82072 (United States); Zheng Zheng [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Hickox, Ryan, E-mail: jonathan.richardson@uchicago.edu, E-mail: schatte1@uwyo.edu [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)

    2013-09-10

    We perform halo occupation distribution (HOD) modeling of the projected two-point correlation function (2PCF) of high-redshift (z {approx} 1.2) X-ray-bright active galactic nuclei (AGNs) in the XMM-COSMOS field measured by Allevato et al. The HOD parameterization is based on low-luminosity AGNs in cosmological simulations. At the median redshift of z {approx} 1.2, we derive a median mass of 1.02{sub -0.23}{sup +0.21} Multiplication-Sign 10{sup 13} h{sup -1} M{sub sun} for halos hosting central AGNs and an upper limit of {approx}10% on the AGN satellite fraction. Our modeling results indicate (at the 2.5{sigma} level) that X-ray AGNs reside in more massive halos compared to more bolometrically luminous, optically selected quasars at similar redshift. The modeling also yields constraints on the duty cycle of the X-ray AGN, and we find that at z {approx} 1.2 the average duration of the X-ray AGN phase is two orders of magnitude longer than that of the quasar phase. Our inferred mean occupation function of X-ray AGNs is similar to recent empirical measurements with a group catalog and suggests that AGN halo occupancy increases with increasing halo mass. We project the XMM-COSMOS 2PCF measurements to forecast the required survey parameters needed in future AGN clustering studies to enable higher precision HOD constraints and determinations of key physical parameters like the satellite fraction and duty cycle. We find that N {sup 2}/A {approx} 5 Multiplication-Sign 10{sup 6} deg{sup -2} (with N the number of AGNs in a survey area of A deg{sup 2}) is sufficient to constrain the HOD parameters at the 10% level, which is easily achievable by upcoming and proposed X-ray surveys.

  1. Sleeping Giants? - X-ray search for low-luminosity AGN candidates in nearby optically bright galaxies

    CERN Document Server

    Kalcheva, Ivayla E

    2014-01-01

    In this Master's project, the X-ray nuclear properties of a sample of bright nearby galaxies are explored. This is done by matching their comprehensive optical spectroscopic classification to the latest available XMM-Newton catalogue - 3XMM-DR4. The good coverage (approx. 38 per cent) ensures that a statistically representative sample is investigated. All nuclear and morphological subsets found within the original sample of 486 galaxies are encompassed, but early-type galaxies and galaxies with optical features characteristic for active galactic nuclei (AGN) are favoured. The results from the investigation of the properties of our cross-matched sample are overall consistent with the presence of a large fraction of X-ray - detected low-luminosity AGN (LLAGN). The X-ray - detected galaxies within our HII and transition-LINER subsets are of particular interest, as they could harbour LLAGN missed by optical spectroscopic selection. The properties of these nuclei are explored by X-ray spectral fitting of available...

  2. A Multi-Epoch Timing and Spectral Study of the Ultraluminous X-Ray NGC 5408 X-1 with XMM-Newton

    Science.gov (United States)

    Dheeraj, Pasham; Strohmayer, Tod E.

    2012-01-01

    We present results of new XMM-Newton observations of the ultraluminous X-ray source (ULX) NGC 5408 X-1, one of the few ULXs to show quasi-periodic oscillations (QPOs). We detect QPOs in each of four new (approximately equal to 100 ks) pointings, expanding the range of frequencies observed from 10 to 40 mHz. We compare our results with the timing and spectral correlations seen in stellar-mass black hole systems, and find that the qualitative nature of the timing and spectral behavior of NGC 5408 X-1 is similar to systems in the steep power-law state exhibiting Type-C QPOs. However, in order for this analogy to quantitatively hold we must only be seeing the so-called saturated portion of the QPO frequency-photon index (or disk flux) relation. Assuming this to be the case, we place a lower limit on the mass of NGC 5408 X-1 of greater than or equal to 800 solar mass. Alternatively, the QPO frequency is largely independent of the spectral parameters, in which case a close analogy with the Type-C QPOs in stellar system is problematic. Measurement of the source's timing properties over a wider range of energy spectral index is needed to definitively resolve this ambiguity. We searched all the available data for both a broad Fe emission line as well as high-frequency QPO analogs (0.1- 1 Hz), but detected neither. We place upper limits on the equivalent width of any Fe emission feature in the 6-7 keV band and of the amplitude (rms) of a high-frequency QPO analog of approximately equal to 10 eV and approximately equal to 4%, respectively.

  3. High-brightness X-ray free-electron laser with an optical undulator by pulse shaping.

    Science.gov (United States)

    Chang, Chao; Liang, Jinyang; Hei, Dongwei; Becker, Michael F; Tang, Kelei; Feng, Yiping; Yakimenko, Vitaly; Pellegrini, Claudio; Wu, Juhao

    2013-12-30

    A normal-incident flattop laser with a tapered end is proposed as an optical undulator to achieve a high-gain and high-brightness X-ray free electron laser (FEL). The synchronic interaction of an electron bunch with the normal incident laser is realized by tilting the laser pulse front. The intensity of the flattop laser is kept constant during the interaction time of the electron bunch and the laser along the focal plane of a cylindrical lens. Optical shaping to generate the desired flattop pulse with a tapered end from an original Gaussian pulse distribution is designed and simulated. The flattop laser with a tapered end can enhance the X-ray FEL beyond the exponential growth saturation power by one order to reach 1 Gigawatt as compared to that without a tapered end. The peak brightness can reach 1030 photons/mm2/mrad2/s/0.1% bandwidth, more than 10 orders brighter than the conventional incoherent Thompson Scattering X-ray source.

  4. On the Lack of X-ray Bright Type IIP Supernovae

    CERN Document Server

    Dwarkadas, Vikram V

    2014-01-01

    Type IIP Supernovae (SNe) are expected to arise from Red Supergiant stars (RSGs). These stars have observed mass-loss rates that span more than two orders of magnitude, from $< 10^{-6}$ solar masses yr$^{-1}$ to almost $ 10^{-4} $ solar masses yr$^{-1}$. Thermal bremsstrahlung X-ray emission from at least some IIP's should reflect the larger end of the high mass-loss rates. Strangely, no IIP SNe are seen where the X-ray luminosity is large enough to suggest mass-loss rates greater than about $ 10^{-5} $ solar masses yr$^{-1}$. We investigate if this could be due to absorption of the X-ray emission. After carefully studying all the various aspects, we conclude that absorption would not be large enough to prevent us from having detected X-ray emission from high mass-loss rate IIP's. This leads us to the conclusion that there may be an upper limit of $\\sim 10^{-5} $ solar masses yr$^{-1}$ to the mass-loss rate of Type IIP progenitors, and therefore to the luminosity of RSGs that explode to form Type IIPs. Thi...

  5. The optical emission lines of type 1 X-ray bright Active Galactic Nuclei

    CERN Document Server

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

    2013-01-01

    A strong X-ray emission is one of the defining signatures of nuclear activity in galaxies. According to the Unified Model for Active Galactic Nuclei (AGN), both the X-ray radiation and the prominent broad emission lines, characterizing the optical and UV spectra of Type 1 AGNs, are originated in the innermost regions of the sources, close to the Super Massive Black Holes (SMBH), which power the central engine. Since the emission is concentrated in a very compact region (with typical size $r 2000 km/s) and narrow line (1000 km/s < FWHMH$_{\\rm H\\beta}\\, \\leq$ 2000 km/s) emitting objects, it has been observed that the kinematic and ionization properties of matter close to the SMBHs are related together, and, in particular, that ionization is higher in narrow line sources. Here we report on the study of the optical and X-ray spectra of a sample of Type 1 AGNs, selected from the Sloan Digital Sky Survey (SDSS) database, within an upper redshift limit of z = 0.35, and detected at X-ray energies. We present anal...

  6. High-Energy Density science with an ultra-bright x-ray laser

    Science.gov (United States)

    Glenzer, Siegfried

    2015-11-01

    This talk will review recent progress in high-energy density physics using the world's brightest x-ray source, the Linac Coherent Light Source, SLAC's free electron x-ray laser. These experiments investigate laser-driven matter in extreme conditions where powerful x-ray scattering and imaging techniques have been applied to resolve ionic interactions at atomic (Ångstrom) scale lengths and to visualize the formation of dense plasma states. Major research areas include dynamic compression experiments of solid targets to determine structural properties and to discover and characterize phase transitions at mega-bar pressures. A second area studies extreme fields produced by high-intensity radiation where fundamental questions of laboratory plasmas can be related to cosmological phenomena. Each of these areas takes advantage of the unique properties of the LCLS x-ray beam. They include small foci for achieving high intensity or high spatial resolution, high photon flux for dynamic structure factor measurements in single shots, and high spectral bandwidth to resolve plasmon (Langmuir) waves or ion acoustic waves in dense plasmas. We will further describe new developments of ultrafast pump-probe technique at high repetition rates. These include studies on dense cryogenic hydrogen that have begun providing fundamental insights into the physical properties of matter in extreme conditions that are important for astrophysics, fusion experiments and generation of radiation sources. This work was supported by DOE Office of Science, Fusion Energy Science under FWP 100182.

  7. SUZAKU OBSERVATIONS OF γ-RAY BRIGHT RADIO GALAXIES: ORIGIN OF THE X-RAY EMISSION AND BROADBAND MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Fukazawa, Yasushi; Itoh, Ryosuke; Tokuda, Shin' ya [Department of Physical Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Finke, Justin [U.S. Naval Research Laboratory, Code 7653, 4555 Overlook Avenue SW, Washington, DC 20375-5352 (United States); Stawarz, Łukasz [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Tanaka, Yasuyuki, E-mail: fukazawa@hep01.hepl.hiroshima-u.ac.jp [Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)

    2015-01-10

    We performed a systematic X-ray study of eight nearby γ-ray bright radio galaxies with Suzaku in order to understand the origins of their X-ray emissions. The Suzaku spectra for five of those have been presented previously, while the remaining three (M87, PKS 0625–354, and 3C 78) are presented here for the first time. Based on the Fe-K line strength, X-ray variability, and X-ray power-law photon indices, and using additional information on the [O III] line emission, we argue for a jet origin of the observed X-ray emission in these three sources. We also analyzed five years of Fermi Large Area Telescope (LAT) GeV gamma-ray data on PKS 0625–354 and 3C 78 to understand these sources within the blazar paradigm. We found significant γ-ray variability in the former object. Overall, we note that the Suzaku spectra for both PKS 0625–354 and 3C 78 are rather soft, while the LAT spectra are unusually hard when compared with other γ-ray detected low-power (FR I) radio galaxies. We demonstrate that the constructed broadband spectral energy distributions of PKS 0625–354 and 3C 78 are well described by a one-zone synchrotron/synchrotron self-Compton model. The results of the modeling indicate lower bulk Lorentz factors compared to those typically found in other BL Lacertae (BL Lac) objects, but consistent with the values inferred from modeling other LAT-detected FR I radio galaxies. Interestingly, the modeling also implies very high peak (∼10{sup 16} Hz) synchrotron frequencies in the two analyzed sources, contrary to previously suggested scenarios for Fanaroff-Riley (FR) type I/BL Lac unification. We discuss the implications of our findings in the context of the FR I/BL Lac unification schemes.

  8. Increasing X-Ray Brightness of HBL Source 1ES 1727+650

    Science.gov (United States)

    Kapanadze, Bidzina

    2017-02-01

    The nearby TeV-detected HBL object 1ES 1727+502 (1Zw 187, z=0.055) has been targeted 111 times by X-ray Telescope (XRT) onboard Swift since 2010 April 2. During this monitoring, the 0.3-10 keV count rate varied by a factor of 17.4 (see http://www.swift.psu.edu/monitoring/source.php?source=QSOB1727+502) and showed a prolonged X-ray flaring activity during 2015 March - 2016 February, revealed mainly via the Target of Opportunity observations performed in the framework of our request of different urgencies (Request Number 6571, 6606, 6717, 6809, 6927, 7322, 7355, 7379, 7390, 7404, 7430, 7441, 7516, 7565; see Kapanadze et al. 2015, Atel #8224, #7342).

  9. Joint Spectral Analysis for Early Bright X-ray Flares of -Ray Bursts with Swift BAT and XRT Data

    Indian Academy of Sciences (India)

    Fang-Kun Peng; You-Dong Hu; Xiang-Gao Wang; Rui-Jing Lu; En-Wei Liang

    2014-09-01

    A joint spectral analysis for early bright X-ray flares that were simultaneously observed with Swift BAT and XRT are present. Both BAT and XRT lightcurves of these flares are correlated. Our joint spectral analysis shows that the radiations in the two energy bands are from the same spectral component, which can be well fitted with a single power-law. Except for the flares in GRBs 060904B and 100906A, the photon spectral indices are < 2.0, indicating the peak energies (p) of the prompt -rays should be above the high energy end of the BAT band.

  10. A Flaring X-ray Source with an Halpha-bright Counterpart toward the SMC

    CERN Document Server

    Laycock, Silas

    2008-01-01

    We report the discovery of a flaring X-ray source with an optical counterpart with Halpha emission and red-excess, in the direction of the SMC. A 100 ksec X-ray observation with Chandra detected a flare lasting 6 ksec in the source CXO J005428.9-723107. The X-ray spectrum during the flare was consistent with a thermal plasma of temperature kT=2.5 keV. In quiescence following the flare the spectrum was softer (kT= 0.4 keV). Timing analysis did not reveal any significant periodicities or QPOs. Optical images taken with the Magellan-Baade 6.5m telescope show a single star in the (0.9") error circle. This star has apparent magnitude V=19.17, exhibits enhanced Halpha emission (Halpha - r = -0.88), and has a large proper motion. Alternative explanations are explored, leading to identification as a relatively nearby (Galactic) coronally active star of the BY Draconis class.

  11. The Origin of Bright X-Ray Sources in Multiple Stars

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, V V; Eggleton, P P

    2009-04-23

    Luminous X-ray stars are very often found in visual double or multiple stars. Binaries with periods of a few days possess the highest degree of coronal X-ray activity among regular, non-relativistic stars. But the orbital periods in visual double stars are too large for any direct interaction between the companions to take place. We suggest that most of the strongest X-ray components in resolved binaries are yet-undiscovered short-period binaries, and that a few are merged remnants of such binaries. The omnipresence of short-period active stars, e.g. of BY-Dra-type binaries, in multiple systems is explained via the dynamical evolution of triple stars with large mutual inclinations. The dynamical perturbation on the inner pair pumps up the eccentricity in a cyclic manner, a phenomenon known as Kozai cycling. At times of close periapsis, tidal friction reduces the angular momentum of the binary, causing it to shrink. When the orbital period of the inner pair drops to a few days, fast surface rotation of the companions is driven by tidal forces, boosting activity by a few orders of magnitude. If the period drops still further, a merger may take place leaving a rapidly-rotating active dwarf with only a distant companion.

  12. A re-consideration of the HEAO-1 A2 Measurements of the Cosmic X-ray Background Surface Brightness

    Science.gov (United States)

    Jahoda, K.

    2005-12-01

    The HEAO-1 A2 experiment was designed to make high precision and low systematics measurements of the Cosmic X-ray Background from 0.1 - 60 keV. No subsequent experiment has been capable of similarly clean separation of cosmic and instrumental background. Most more recent measurements of the 2-10 keV surface brightness are 20% higher than values derived from the spectral parameterization of the 3-50 keV spectrum given in the original A2 analysis of Marshall et al. (1980, ApJ 235, 4 (M80)). A recent analysis of archival A2 data by Revnivtsev et al. (astro-ph/0412304 (R05)) finds a surface brightness 15-20% higher than M80, an uncomfortably large discrepancy for data taken from a single experiment. We present a third analysis of the A2 data and identify two effects neglected in the comparison of previous A2 results: (a) the extrapolation of the M80 parameterization below 3 keV fails to describe the data; (b) R05 uses an unabsorbed, and high, value for the flux from the Crab nebula plus pulsar which results in a high value for the inferred count rate to CXB surface brightness conversion. Correcting for these effects, our best estimate of the 2-10 keV surface brightness is 1.84 × 10-11 ergs cm-2 s-1 deg-2 on a flux scale where the (absorbed) 2-10 Crab flux is 2.32 × 10-8 ergs cm-2 s-1. This value is only about 10% below the average compiled by Moretti et al. (2003, ApJ, 588, 696). We discuss how well the X-ray brightness of the Crab, to which this measurement is normalized, is known. This research made use of data from the High Energy Astrophysics Science Archive Research Center (HEASARC), provided by NASA's Goddard Space Flight Center.

  13. X-ray Surface Brightness Profiles of Active Galactic Nuclei in the Extended Groth Strip: Implications for AGN Feedback

    CERN Document Server

    Chatterjee, Suchetana; Jeltema, Tesla; Myers, Adam D; Aird, James; Coil, Alison L; Cooper, Michael; Finoguenov, Alexis; Laird, Elise; Montero-Dorta, Antonio; Nandra, Kripal; Willmer, Christopher; Yan, Renbin

    2013-01-01

    Using data from the All Wavelength Extended Groth Strip International Survey (AEGIS) we statistically detect the extended X-ray emission in the interstellar medium (ISM) in both active and normal galaxies at 0.3 < z < 1.3 at a scale of 40-60 kpc. We study the effect of feedback from active galactic nuclei (AGN) on the diffuse interstellar gas by comparing the stacked X-ray surface brightness profiles of active and normal galaxies in the same redshift range with identical properties in optical color--magnitude space. In accordance with theoretical studies we detect a slight deficit (< 1.5 \\sigma) of X-ray photons when averaged over a scale of 0-30 kpc in the profile of AGN host galaxies at 0.3 < z < 0.7. The equivalent flux deficit is (1.25 +/- 0.75) X 10^(-19) ergs/s/cm^(-2). When averaged over a scale of 30-60 kpc, beyond the PSF scales of our AGN sources, we observe a (~ 2 \\sigma) photon excess in the profile of the AGN host galaxies with an equivalent flux excess of (1.1 +/- 0.5) X 10^{-19} ...

  14. The VLT-FLAMES Tarantula survey XX. The nature of the X-ray bright emission line star VFTS 399

    CERN Document Server

    Clark, J S; Broos, P S; Townsley, L K; Taylor, W D; Walborn, N R; Bird, A J; Sana, H; de Mink, S E; Dufton, P L; Evans, C J; Langer, N; Apellániz, J Maíz; Schneider, F R N; Soszyński, I

    2015-01-01

    The stellar population of the 30 Doradus star-forming region in the Large Magellanic Cloud contains a subset of apparently single, rapidly rotating O-type stars. The physical processes leading to the formation of this cohort are currently uncertain. One member of this group, the late O-type star VFTS 399, is found to be unexpectedly X-ray bright for its bolometric luminosity - in this study we aim to determine its physical nature and the cause of this behaviour. We find VFTS 399 to be an aperiodic photometric variable with an apparent near-IR excess. Its optical spectrum demonstrates complex emission profiles in the lower Balmer series and select HeI lines - taken together these suggest an OeBe classification. The highly variable X-ray luminosity is too great to be produced by a single star, while the hard, non-thermal nature suggests the presence of an accreting relativistic companion. Finally, the detection of periodic modulation of the X-ray lightcurve is most naturally explained under the assumption that ...

  15. Generation of Bright Isolated Attosecond Soft X-Ray Pulses Driven by Multi-Cycle Mid-Infrared Lasers

    CERN Document Server

    Chen, M -C; Mancuso, C; Dollar, F; Galloway, B; Popmintchev, D; Huang, P -C; Walker, B; Plaja, L; Jaron-Becker, A; Becker, A; Popmintchev, T; Murnane, M M; Kapteyn, H C

    2014-01-01

    High harmonic generation driven by femtosecond lasers makes it possible to capture the fastest dynamics in molecules and materials. However, to date the shortest attosecond (as) pulses have been produced only in the extreme ultraviolet (EUV) region of the spectrum below 100 eV, which limits the range of materials and molecular systems that can be explored. Here we use advanced experiment and theory to demonstrate a remarkable convergence of physics: when mid-infrared lasers are used to drive the high harmonic generation process, the conditions for optimal bright soft X-ray generation naturally coincide with the generation of isolated attosecond pulses. The temporal window over which phase matching occurs shrinks rapidly with increasing driving laser wavelength, to the extent that bright isolated attosecond pulses are the norm for 2 \\mu m driving lasers. Harnessing this realization, we demonstrate the generation of isolated soft X-ray attosecond pulses at photon energies up to 180 eV for the first time, that e...

  16. Soft X-ray Variability of the Bright Quasar 3C273

    Indian Academy of Sciences (India)

    Chulhee Kim

    2001-12-01

    We present the results from ROSAT observations of 3C273 in the soft X-ray band. The light variation of 3C273 was investigated for three different energy bands of soft, medium, and hard. The maximum variability with a factor of 2 for 551 dayswas confirmed at all three different bands. This appears to be a periodic variation within the period of roughly 6 months. However, the short-term or micro variation was not so distinct and the light variation of each band did not show any correlation between them. The hardness ratio for hard and soft bands shows irregular variation but there was no correlation between them. There is no distinct variation of the photon index in the case of simple power law model fitting. For power law + free absorption model fitting, the average photon index () is 2.08.

  17. Hubble Space Telescope Imaging of Bright Galactic X-Ray Binaries in Crowded Fields

    Science.gov (United States)

    Deutsch, Eric W.; Margon, Bruce; Wachter, Stefanie; Anderson, Scott F.

    1996-01-01

    We report high spatial resolution HST imagery and photometry of three well-studied, intense Galactic X-ray binaries, X2129+470, CAL 87, and GX 17+2. All three sources exhibit important anomalies that are not readily interpreted by conventional models. Each source also lies in a severely crowded field, and in all cases the anomalies would be removed if much of the light observed from the ground in fact came from a nearby, thus far unresolved superposed companion. For V1727 Cyg (X2129+470), we find no such companion. We also present an HST FOS spectrum and broadband photometry which is consistent with a single, normal star. The supersoft LMC X-ray source CAL 87 was already known from ground-based work to have a companion separated by O.9 minutes from the optical counterpart; our HST images clearly resolve these objects and yield the discovery of an even closer, somewhat fainter additional companion. Our photometry indicates that contamination is not severe outside eclipse, where the companions only contribute 20% of the light in V, but during eclipse more than half of the V light comes from the companions. The previously determined spectral type of the CAL 87 secondary may need to be reevaluated due to this significant contamination, with consequences on inferences of the mass of the components. We find no companions to NP Ser (= X1813-14, = GX 17+2). However, for this object we point out a small but possibly significant astrometric discrepancy between the position of the optical object and that of the radio source which is the basis for the identification. This discrepancy needs to be clarified.

  18. High-brightness laser plasma soft X-ray source using a double-stream gas puff target irradiated with the Prague Asterix Laser System (PALS)

    Energy Technology Data Exchange (ETDEWEB)

    Fiedorowicz, H.; Bartnik, A.; Juha, L.; Jungwirth, K.; Kralikova, B.; Krasa, J.; Kubat, P.; Pfeifer, M.; Pina, L.; Prchal, P.; Rohlena, K.; Skala, J.; Ullschmied, J.; Horvath, M.; Wawer, J

    2004-01-14

    High brightness laser plasma soft X-ray source based on a recently developed double-stream gas puff target irradiated with 0.5 ns laser pulses with energies up to 700 J from the Prague Asterix Laser System (PALS) is presented. The gas puff target was created by pulsed injection of xenon into a hollow stream of helium using an electromagnetic valve system with the double-nozzle setup. Soft X-ray emission was measured using the transmission grating spectrograph coupled to a CCD camera and the calibrated silicon photodiodes. The absolute soft X-ray production was determined to be 160 J for 540 J of laser energy, giving the soft X-ray conversion efficiency of about 30%. The source has been used in initial experiments on soft X-ray ablation of organic polymers and elemental solids.

  19. Bright, water-soluble CeF{sub 3} photo-, cathodo-, and X-ray luminescent nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Clement, Sandhya; Deng, Wei; Drozdowicz-Tomsia, Krystyna; Liu, Deming [Macquarie University, Centre for Nanoscale BioPhotonics, Department of Physics and Astronomy (Australia); Zachreson, Cameron [University of Technology Sydney, School of Physics and Advanced Materials (Australia); Goldys, Ewa M., E-mail: ewa.goldys@mq.edu.au [Macquarie University, Centre for Nanoscale BioPhotonics, Department of Physics and Astronomy (Australia)

    2015-01-15

    Bright, water-soluble CeF{sub 3} nanoparticles with small size and narrow size distribution have been synthesized using a simple co-precipitation method without any ligands. Size control of nanoparticles from 13 ± 2 to 9 ± 2 nm was achieved by varying the reaction time. Colloidal properties have been found to vary with pH and, independently, with dilution. The photoluminescence of the as-synthesized nanoparticles shows a highly photostable UV/Visible fluorescence band due to allowed 5d–4f transitions, also observed in the X-ray luminescence spectrum. This band is suitable for X-ray excitation of a range of photosensitizers. The photoluminescence quantum yield of nanoparticles was also determined to be 31 %. Using the measured fluorescence decay time of 25 ns, the radiative lifetime of Ce in CeF{sub 3} was found to be 80.6 ns. Both photoluminescence and cathodoluminescence emission are affected by the reaction time and measurement temperature. Electron-beam-induced defect annealing is also observed.

  20. On the Nature of X-ray Surface Brightness Fluctuations in M87

    CERN Document Server

    Arévalo, P; Zhuravleva, I; Forman, W R; Jones, C

    2015-01-01

    X-ray images of galaxy clusters and gas-rich elliptical galaxies show a wealth of small-scale features which reflect fluctuations in density and/or temperature of the intra-cluster medium. In this paper we study these fluctuations in M87/Virgo, to establish whether sound waves/shocks, bubbles or uplifted cold gas dominate the structure. We exploit the strong dependence of the emissivity on density and temperature in different energy bands to distinguish between these processes. Using simulations we demonstrate that our analysis recovers the leading type of fluctuation even in the presence of projection effects and temperature gradients. We confirm the isobaric nature of cool filaments of gas entrained by buoyantly rising bubbles, extending to 7' to the east and south-west, and the adiabatic nature of the weak shocks at 40" and 3' from the center. For features of 5--10 kpc, we show that the central 4'x 4' region is dominated by cool structures in pressure equilibrium with the ambient hotter gas while up to 30 ...

  1. A bright thermonuclear X-ray burst simultaneously observed with Chandra and RXTE

    CERN Document Server

    Zand, J J M in t; Marshall, H L; Ballantyne, D R; Jonker, P G; Paerels, F B S; Palmer, D M; Patruno, A; Weinberg, N N

    2013-01-01

    The prototypical accretion-powered millisecond pulsar SAX J1808.4-3658 was observed simultaneously with Chandra-LETGS and RXTE-PCA near the peak of a transient outburst in November 2011. A single thermonuclear (type-I) burst was detected, the brightest yet observed by Chandra from any source, and the second-brightest observed by RXTE. We found no evidence for discrete spectral features during the burst; absorption edges have been predicted to be present in such bursts, but may require a greater degree of photospheric expansion than the rather moderate expansion seen in this event (a factor of a few). These observations provide a unique data set to study an X-ray burst over a broad bandpass and at high spectral resolution (lambda/delta-lambda=200-400). We find a significant excess of photons at high and low energies compared to the standard black body spectrum. This excess is well described by a 20-fold increase of the persistent flux during the burst. We speculate that this results from burst photons being sc...

  2. Observation of spatial and temporal variations in X-ray bright point emergence patterns. [at solar surface

    Science.gov (United States)

    Golub, L.; Krieger, A. S.; Vaiana, G. S.

    1976-01-01

    Observations of X-ray bright points (XBP) over a six-month interval in 1973 show significant variations in both the number density of XBP as a function of heliographic longitude and in the full-sun average number of XBP from one rotation to the next. The observed increases in XBP emergence are estimated to be equivalent to several large active regions emerging per day for several months. The number of XBP emerging at high latitudes varies in phase with the low-latitude variation and reaches a maximum approximately simultaneous with a major outbreak of active regions. The quantity of magnetic flux emerging in the form of XBP at high latitudes alone is estimated to be as large as the contribution from all active regions.

  3. ON THE NATURE OF X-RAY SURFACE BRIGHTNESS FLUCTUATIONS IN M87

    Energy Technology Data Exchange (ETDEWEB)

    Arévalo, P. [Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretana N 1111, Playa Ancha, Valparaíso (Chile); Churazov, E. [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Strasse 1, D-85741 Garching (Germany); Zhuravleva, I. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305-4085 (United States); Forman, W. R.; Jones, C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

    2016-02-10

    X-ray images of galaxy clusters and gas-rich elliptical galaxies show a wealth of small-scale features that reflect fluctuations in density and/or temperature of the intracluster medium. In this paper we study these fluctuations in M87/Virgo to establish whether sound waves/shocks, bubbles, or uplifted cold gas dominate the structure. We exploit the strong dependence of the emissivity on density and temperature in different energy bands to distinguish between these processes. Using simulations we demonstrate that our analysis recovers the leading type of fluctuation even in the presence of projection effects and temperature gradients. We confirm the isobaric nature of cool filaments of gas entrained by buoyantly rising bubbles, extending to 7′ to the east and southwest, and the adiabatic nature of the weak shocks at 40″ and 3′ from the center. For features of ∼5–10 kpc, we show that the central 4′ × 4′ region is dominated by cool structures in pressure equilibrium with the ambient hotter gas while up to 30% of the variance in this region can be ascribed to adiabatic fluctuations. The remaining part of the central 14′ × 14′ region, excluding the arms and shocks described above, is dominated by apparently isothermal fluctuations (bubbles) with a possible admixture (at the level of ∼30%) of adiabatic (sound waves) and by isobaric structures. Larger features, of about 30 kpc, show a stronger contribution from isobaric fluctuations. The results broadly agree with a model based on feedback from an active galactic nucleus mediated by bubbles of relativistic plasma.

  4. New insights into the X-ray properties of the nearby barred spiral galaxy NGC 1672

    CERN Document Server

    Jenkins, L P; Colbert, E J M; Levan, A J; Roberts, T P; Ward, M J; Zezas, A

    2008-01-01

    We present some preliminary results from new Chandra and XMM-Newton X-ray observations of the nearby barred spiral galaxy NGC1672. It shows dramatic nuclear and extra-nuclear star formation activity, including starburst regions located near each end of its strong bar, both of which host ultraluminous X-ray sources (ULXs). With the new high-spatial-resolution Chandra imaging, we show for the first time that NGC1672 possesses a faint ($L(X)~10^39 erg/s), hard central X-ray source surrounded by an X-ray bright circumnuclear starburst ring that dominates the X-ray emission in the region. The central source may represent low-level AGN activity, or alternatively the emission from X-ray binaries associated with star-formation in the nucleus.

  5. Can AGN and galaxy clusters explain the surface brightness fluctuations of the cosmic X-ray background?

    Science.gov (United States)

    Kolodzig, Alexander; Gilfanov, Marat; Hütsi, Gert; Sunyaev, Rashid

    2017-04-01

    Fluctuations of the surface brightness of cosmic X-ray background (CXB) carry unique information about faint and low-luminosity source populations, which is inaccessible for conventional large-scale structure (LSS) studies based on resolved sources. We used XBOOTES (5ks deep Chandra X-ray Observatory ACIS-I maps of the ˜ 9 deg2 Bootes field of the NOAO Deep Wide-Field Survey) to conduct the most accurate measurement to date of the power spectrum of fluctuations of the unresolved CXB on the angular scales of 3 arcsec-17 arcmin. We find that at sub-arcmin angular scales, the power spectrum is consistent with the active galactic nucleus (AGN) shot noise, without much need for any significant contribution from their one-halo term. This is consistent with the theoretical expectation that low-luminosity AGN reside alone in their dark matter haloes. However, at larger angular scales, we detect a significant LSS signal above the AGN shot noise. Its power spectrum, obtained after subtracting the AGN shot noise, follows a power law with the slope of -0.8 ± 0.1 and its amplitude is much larger than what can be plausibly explained by the two-halo term of AGN. We demonstrate that the detected LSS signal is produced by unresolved clusters and groups of galaxies. For the flux limit of the XBOOTES survey, their flux-weighted mean redshift equals ˜ 0.3, and the mean temperature of their intracluster medium (ICM), ≈ 1.4 keV, corresponds to the mass of M500 ˜ 1013.5 M⊙. The power spectrum of CXB fluctuations carries information about the redshift distribution of these objects and the spatial structure of their ICM on the linear scales of up to ˜Mpc, i.e. of the order of the virial radius.

  6. Can AGN and galaxy clusters explain the surface brightness fluctuations of the cosmic X-ray background?

    CERN Document Server

    Kolodzig, Alexander; Hütsi, Gert; Sunyaev, Rashid

    2016-01-01

    Fluctuations of the surface brightness of cosmic X-ray background (CXB) carry unique information about faint and low luminosity source populations, which is inaccessible for conventional large-scale structure (LSS) studies based on resolved sources. We used Chandra data of the XBOOTES field ($\\sim9\\,\\mathrm{deg^2}$) to conduct the most accurate measurement to date of the power spectrum of fluctuations of the unresolved CXB on the angular scales of $\\sim3\\,$arcsec $-$ $\\sim17\\,$arcmin. We find that at sub-arcmin angular scales, the power spectrum is consistent with the AGN shot noise, without much need for any significant contribution from their one-halo term. This is consistent with the theoretical expectation that low-luminosity AGN reside alone in their dark matter halos. However, at larger angular scales we detect a significant LSS signal above the AGN shot noise. Its power spectrum, obtained after subtracting the AGN shot noise, follows a power law with the slope of $-0.8\\pm0.1$ and its amplitude is much ...

  7. Systematic search for VHE gamma-ray emission from X-ray bright high-frequency BL Lac objects

    CERN Document Server

    Albert, J

    2007-01-01

    Motivated by the fact that all but two (M87, BL Lac) extragalactic sources detected so far at VHE energies belong to the so-called HBL class of high-frequency peaked BL Lac objects, a systematic scan of the compilation of X-ray blazars by Donato et al. (2001) has been performed using the MAGIC telescope. The observations took place from December 2004 to March 2006 and cover sources on the northern sky visible under small zenith distances zd 2uJy) sources emitting at least the same energy flux at 200GeV as at 1keV. In order to avoid strong gamma-ray attenuation close to the energy threshold, the redshift of the sources was constrained to values z < 0.3. Of the 14 sources observed, 1ES 1218+30.4 (for the first time at very high energies) and 1ES 2344+51.4 (strong detection in a low flux state) have been detected in addition to the known bright TeV blazars Mrk 421 and Mrk 501. For the remaining sources, we present here the 99% confidence level upper limits on the integral flux above ~200GeV. A marginal exces...

  8. The European X-ray Free-Electron Laser: toward an ultra-bright, high repetition-rate x-ray source

    Institute of Scientific and Technical Information of China (English)

    M.Altarelli

    2015-01-01

    The status of the European X-ray Free-Electron Laser(European XFEL), under construction near Hamburg, Germany, is described. The start of operations of the LCLS at SLAC and of SACLA in Japan has already produced impressive scientific results. The European XFEL facility is powered by a 17.5 Ge V superconducting linear accelerator that,compared to these two operating facilities, will generate two orders of magnitude more pulses per second, up to 27 000.It can therefore support modes of operation switching the beam up to 30 times per second among three different experiments, providing each of them with thousands of pulses per second. The scientific possibilities opened up by these capabilities are briefly described, together with the current instrumental developments(in optics, detectors, lasers,etc.) that are necessary to implement this program.

  9. Developing a bright 17 keV x-ray source for probing high-energy-density states of matter at high spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Huntington, C. M.; Park, H.-S.; Maddox, B. R.; Barrios, M. A.; Benedetti, R.; Braun, D. G.; Landen, O. L.; Wehrenberg, C. E.; Remington, B. A. [Lawrence Livermore National Laboratory, Livermore, California, 94551 (United States); Hohenberger, M.; Regan, S. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2015-04-15

    A set of experiments were performed on the National Ignition Facility (NIF) to develop and optimize a bright, 17 keV x-ray backlighter probe using laser-irradiated Nb foils. High-resolution one-dimensional imaging was achieved using a 15 μm wide slit in a Ta substrate to aperture the Nb He{sub α} x-rays onto an open-aperture, time integrated camera. To optimize the x-ray source for imaging applications, the effect of laser pulse shape and spatial profile on the target was investigated. Two laser pulse shapes were used—a “prepulse” shape that included a 3 ns, low-intensity laser foot preceding the high-energy 2 ns square main laser drive, and a pulse without the laser foot. The laser spatial profile was varied by the use of continuous phase plates (CPPs) on a pair of shots compared to beams at best focus, without CPPs. A comprehensive set of common diagnostics allowed for a direct comparison of imaging resolution, total x-ray conversion efficiency, and x-ray spectrum between shots. The use of CPPs was seen to reduce the high-energy tail of the x-ray spectrum, whereas the laser pulse shape had little effect on the high-energy tail. The measured imaging resolution was comparably high for all combinations of laser parameters, but a higher x-ray flux was achieved without phase plates. This increased flux was the result of smaller laser spot sizes, which allowed us to arrange the laser focal spots from multiple beams and produce an x-ray source which was more localized behind the slit aperture. Our experiments are a first demonstration of point-projection geometry imaging at NIF at the energies (>10 keV) necessary for imaging denser, higher-Z targets than have previously been investigated.

  10. RXTE/ASM and Swift/BAT Observations of Spectral Transitions in Bright X-ray Binaries in 2005-2010

    CERN Document Server

    Tang, Jing; Yan, Zhen

    2010-01-01

    We have studied X-ray spectral state transitions that can be seen in the long- term monitoring light curves of bright X-ray binaries from the All-Sky Monitor (ASM) on board the Rossi X-ray Timing Explorer (RXTE) and the Burst Alert Telescope (BAT) on board Swift during a period of five years from 2005 to 2010. We have applied a program to automatically identify the hard-to-soft (H-S) spectral state transitions in the bright X- ray binaries monitored by the ASM and the BAT. In total we identified 128 hard-to-soft transitions, of which 59 occurred after 2008. We also determined the transition fluxes and the peak fluxes of the following soft states, updated the measurements of the luminosity corresponding to the H-S transition and the peak luminosity of the following soft state in about 30 bright persistent and transient black hole and neutron star binaries following Yu & Yan (2009), and found the luminosity correlation and the luminosity range of spectral transitions in data between 2008-2010 are about the ...

  11. VizieR Online Data Catalog: Intermediate-luminosity X-ray objects catalog (Colbert+, 2002)

    Science.gov (United States)

    Colbert, E. J. M.; Ptak, A. F.

    2002-11-01

    ROSAT, and now Chandra, X-ray images allow studies of extranuclear X-ray point sources in galaxies other than our own. X-ray observations of normal galaxies with ROSAT and Chandra have revealed that off-nuclear, compact, intermediate-luminosity (LX[2-10keV]>=1039erg/s) X-ray objects (IXOs, a.k.a. ULXs [ultraluminous X-ray sources]) are quite common. Here we present a catalog and finding charts for 87 IXOs in 54 galaxies, derived from all of the ROSAT HRI imaging data for galaxies with cz<=5000km/s from the Third Reference Catalog of Bright Galaxies. (2 data files).

  12. Exploratory Chandra observation of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.30

    CERN Document Server

    Ai, Yanli; Fan, Xiaohui; Wang, Feige; Wu, Xue-Bing; Bian, Fuyan

    2016-01-01

    We report exploratory \\chandra\\ observation of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.30. The quasar is clearly detected by \\chandra\\ with a possible component of extended emission. The rest-frame 2-10 keV luminosity is 9.0$^{+9.1}_{-4.5}$ $\\times$ 10$^{45}$ erg s$^{-1}$ with inferred photon index of $\\Gamma$ = 3.03$^{+0.78}_{-0.70}$. This quasar is X-ray bright, with inferred X-ray-to-optical flux ratio \\aox\\ $=-1.22^{+0.07}_{-0.05}$, higher than the values found in other quasars of comparable ultraviolet luminosity. The properties inferred from this exploratory observation indicate that this ultraluminous quasar might be growing with super-Eddington accretion and probably viewed with small inclination angle. Deep X-ray observation will help to probe the plausible extended emission and better constraint the spectral features for this ultraluminous quasar.

  13. On the artificial nature of aperiodic variability in XMM-Newton observations of M31 X-ray sources and the ultraluminous X-ray source NGC 4559 ULX-7

    CERN Document Server

    Barnard, R; Kolb, U C; Haswell, C A; Osborne, J P; Priedhorsky, W C

    2007-01-01

    Context: Power density spectra (PDS) that are characteristic of low mass X-ray binaries (LMXBs) have been previously reported for M31 X-ray sources, observed by XMM-Newton. However, we have recently discovered that these PDS result from the improper addition/subtraction of non-simultaneous lightcurves. Aims: To understand the properties and origins of the artefact. Methods: We re-analysed our XMM-Newton observations of M31 with non-simultaneous and simultaneous lightcurves, then combined simulated lightcurves at various intensities with various offsets and found that the artefact is more dependent on the offset than the intensity. Results: The lightcurves produced by the XMM-Newton Science Analysis Software (SAS) are non-synchronised by default. This affects not only the combination of lightcurves from the three EPIC detectors (MOS1, MOS2 and pn), but also background subtraction in the same CCD. It is therefore imperative that all SAS-generated lightcurves are synchronised by time filtering, even if the whole...

  14. Real-Time Observation of Laser Heated Metals with High Brightness Monochromatic X-Ray Techniques at Present and Their Future Prospects

    Science.gov (United States)

    Daido, H.; Shobu, T.; Yamada, T.; Yamashita, S.; Sugihara, K.; Nishimura, A.; Muramatsu, T.

    We present the x-ray techniques for characterizing laser heated metals for welding and cutting techniques. At present, with an undulator (70 keV) as well as bending magnet (30 keV) sources at SPring-8 as a probe source, CW 300 W Ytterbium fiber laser irradiates an Aluminum slab as a sample. Simultaneously the x-ray beam probes the sample for real time observation of a molten pool. We observe the convection indicated by the motion of tungsten based particles as a tracer in the molten pool. During the cooling phase, the molten metal is solidified with residual stresses which are affected by the heating and convection processes. In this experiment the time and space resolution are ˜milli-second and several tens of μm, respectively. On the other hand, microscopic short transient phenomena also play a significant role for the quality of a solidified material. For this purpose, we need high energy short pulse x-ray sources. We try to discuss on the capability and limitation of present x-ray sources and the prospect of an ultra high brightness x-ray source as a complementary source for full characterization of the laser heated and cooling processes of metals.

  15. RXTE/ASM and Swift/BAT observations of spectral transitions in bright X-ray binaries in 2005-2010

    Science.gov (United States)

    Tang, Jing; Yu, Wen-Fei; Yan, Zhen

    2011-04-01

    We have studied X-ray spectral state transitions that can be seen in the long-term monitoring light curves of bright X-ray binaries from the All-Sky Monitor (ASM) onboard the Rossi X-ray Timing Explorer (RXTE) and the Burst Alert Telescope (BAT) onboard Swift during a period of five years from 2005 to 2010. We have applied a program to automatically identify the hard-to-soft (H-S) spectral state transitions in the bright X-ray binaries monitored by the ASM and the BAT. In total, we identified 128 hard-to-soft transitions, of which 59 occurred after 2008. We also determined the transition fluxes and the peak fluxes of the following soft states, updated the measurements of the luminosity corresponding to the H-S transition and the peak luminosity of the following soft state in about 30 bright persistent and transient black hole and neutron star binaries following Yu & Yan, and found the luminosity correlation and the luminosity range of spectral transitions in data between 2008-2010 are about the same as those derived from data before 2008. This further strengthens the idea that the luminosity at which the H-S spectral transition occurs in the Galactic X-ray binaries is determined by non-stationary accretion parameters such as the rate-of-change of the mass accretion rate rather than the mass accretion rate itself. The correlation is also found to hold in data of individual sources 4U 1608-52 and 4U 1636-53.

  16. Transform-Limited X-Ray Pulse Generation from a High Brightness Self-Amplified Spontaneous Emission Free-Electron Laser

    CERN Document Server

    McNeil, B W J; Dunning, D J

    2012-01-01

    A method to achieve High-Brightness Self-Amplified Spontaneous Emission (HB-SASE) in the Free Electron Laser (FEL) is described. The method uses repeated non-equal electron beam delays to de-localise the collective FEL interaction and break the radiation coherence length dependence on the FEL cooperation length. The method requires no external seeding or photon optics and so is applicable at any wavelength or repetition rate. It is demonstrated using linear theory and numerical simulations that the radiation coherence length can be increased by approximately two orders of magnitude over SASE with a corresponding increase in spectral brightness. Examples are shown of HB-SASE generating transform-limited FEL pulses in the soft X-ray and near transform-limited pulses in the hard X-ray. Such pulses may greatly benefit existing applications and may also open up new areas of scientific research.

  17. V723 Cassiopeia still on in X-rays: A bright Super Soft Source 12 years after outburst

    CERN Document Server

    Ness, J U-; Starrfield, S; Osborne, J P; Page, K L; Beardmore, A P; Wagner, R M; Woodward, C E

    2008-01-01

    We find that the classical nova V723 Cas (1995) is still an active X-ray source more than 12 years after outburst and analyze seven X-ray observations carried out with Swift between 2006 January 31 and 2007 December 3. The average count rate is 0.022+/-0.01 cts s^{-1} but the source is variable within a factor of two of the mean and does not show any signs of turning off. We present supporting optical observations which show that between 2001 and 2006 an underlying hot source was present with steadily increasing temperature. In order to confirm that the X-ray emission is from V723 Cas, we extract a ROSAT observation taken in 1990 and find that there was no X-ray source at the position of the nova. The Swift XRT spectra resemble those of the Super Soft X-ray binary Sources (SSS) which is confirmed by RXTE survey data which show no X-ray emission above 2 keV between 1996 and 2007. Using blackbody fits we constrain the effective temperature to between T_eff=(2.6-4.6)x10^5 K and a bolometric luminosity >5x10^35 e...

  18. XID II: Statistical Cross-Association of ROSAT Bright Source Catalog X-ray Sources with 2MASS Point Source Catalog Near-Infrared Sources

    CERN Document Server

    Haakonsen, Christian Bernt; 10.1088/0067-0049/184/1/138

    2009-01-01

    The 18806 ROSAT All Sky Survey Bright Source Catalog (RASS/BSC) X-ray sources are quantitatively cross-associated with near-infrared (NIR) sources from the Two Micron All Sky Survey Point Source Catalog (2MASS/PSC). An association catalog is presented, listing the most likely counterpart for each RASS/BSC source, the probability Pid that the NIR source and X-ray source are uniquely associated, and the probability Pnoid that none of the 2MASS/PSC sources are associated with the X-ray source. The catalog includes 3853 high quality (Pid>0.98) X-ray--NIR matches, 2280 medium quality (0.98>Pid>0.9) matches, and 4153 low quality (0.9>Pid>0.5) matches. Of the high quality matches, 1418 are associations that are not listed in the SIMBAD database, and for which no high quality match with a USNO-A2 optical source was presented for the RASS/BSC source in previous work. The present work offers a significant number of new associations with RASS/BSC objects that will require optical/NIR spectroscopy for classification. For...

  19. The Hamburg/RASS Catalogue of optical identifications. Northern high-galactic latitude ROSAT Bright Source Catalogue X-ray sources

    CERN Document Server

    Zickgraf, F J; Hagen, H J; Reimers, D; Voges, W

    2003-01-01

    We present the Hamburg/RASS Catalogue (HRC) of optical identifications of X-ray sources at high-galactic latitude. The HRC includes all X-ray sources from the ROSAT Bright Source Catalogue (RASS-BSC) with galactic latitude |b| >= 30 degr and declination delta >= 0 degr. In this part of the sky covering ~10 000 deg^2 the RASS-BSC contains 5341 X-ray sources. For the optical identification we used blue Schmidt prism and direct plates taken for the northern hemisphere Hamburg Quasar Survey (HQS) which are now available in digitized form. The limiting magnitudes are 18.5 and 20, respectively. For 82% of the selected RASS-BSC an identification could be given. For the rest either no counterpart was visible in the error circle or a plausible identification was not possible. With ~42% AGN represent the largest group of X-ray emitters, \\~31% have a stellar counterpart, whereas galaxies and cluster of galaxies comprise only ~4% and ~5%, respectively. In ~3% of the RASS-BSC sources no object was visible on our blue dire...

  20. X-ray and radio bright type Ic SN2002ap -- a hypernova without an associated GRB

    CERN Document Server

    Sutaria, F K; Chandra, P

    2002-01-01

    Combined X-ray (0.3 -10 keV) and Radio (0.61 and 1.42 GHz) observations of the type Ic SN 2002ap are used here, to determine the origins of the prompt X-ray and Radio emission from this source.Our analysis of the XMM-Newton observations suggests that the prompt X-ray emission originates from inverse Compton scattering of photospheric thermal emission by energetic electrons. We also compare the early radiospheric properties of SN 2002ap with those of SN 1998bw (type Ic) and SN 1993J (type IIb), to contrast the prompt emission from a GRB associated SN with other supernovae without GRB counterparts.

  1. Comprehensive Monitoring of Gamma-ray Bright Blazars. I. Statistical Study of Optical, X-ray, and Gamma-ray Spectral Slopes

    CERN Document Server

    Williamson, Karen E; Marscher, Alan P; Larionov, Valeri M; Smith, Paul S; Agudo, Iván; Arkharov, Arkady A; Blinov, Dmitry A; Casadio, Carolina; Efimova, Natalia V; Gómez, José L; Hagen-Thorn, Vladimir A; Joshi, Manasvita; Konstantinova, Tatiana S; Kopatskaya, Evgenia N; Larionova, Elena G; Larionova, Liudmilla V; Malmrose, Michael P; McHardy, Ian M; Molina, Sol N; Morozova, Daria A; Schmidt, Gary D; Taylor, Brian W; Troitsky, Ivan S

    2014-01-01

    We present $\\gamma$-ray, X-ray, ultraviolet, optical, and near-infrared light curves of 33 $\\gamma$-ray bright blazars over four years that we have been monitoring since 2008 August with multiple optical, ground-based telescopes and the Swift satellite, and augmented by data from the Fermi Gamma-ray Space Telescope and other publicly available data from Swift. The sample consists of 21 flat-spectrum radio quasars (FSRQs) and 12 BL Lac objects (BL Lacs). We identify quiescent and active states of the sources based on their $\\gamma$-ray behavior. We derive $\\gamma$-ray, X-ray, and optical spectral indices, $\\alpha_\\gamma$, $\\alpha_X$, and $\\alpha_o$, respectively ($F_\

  2. Observations of Ultraluminous Infrared Galaxies with the Infrared Spectrograph on the Spitzer Space Telescope II: The IRAS Bright Galaxy Sample

    CERN Document Server

    Armus, L; Bernard-Salas, J; Spoon, H W W; Marshall, J A; Higdon, S J U; Desai, V; Teplitz, H I; Hao, L; Devost, D; Brandl, B R; Wu, Y; Sloan, G C; Soifer, B T; Houck, J R; Herter, T L

    2006-01-01

    We present spectra taken with the Infrared Spectrograph on Spitzer covering the 5-38 micron region of the ten Ultraluminous Infrared Galaxies (ULIRGs) found in the IRAS Bright Galaxy Sample. Among the BGS ULIRGs, we find a factor of 50 spread in the rest-frame mid to far-infrared spectral slope. The 9.7 micron silicate optical depths range from less than 0.4 more than 4.2, implying line of sight extinctions of A(V) ~ 8 - 78 mag. There is evidence for water ice and hydrocarbon absorption and C2H2 and HCN absorption features in four and possibly six of the 10 BGS ULIRGs, indicating shielded molecular clouds and a warm, dense ISM. We have detected [NeV] emission in three of the ten BGS ULIRGs, at flux levels of 5-18E-14 erg/cm^2/sec and [NeV] 14.3/[NeII] 12.8 line flux ratios of 0.12-0.85. The remaining BGS ULIRGs have limits on their [NeV]/[NeII] line flux ratios which range from less than 0.15 to less than 0.01. Among the BGS ULIRGs, the AGN fractions implied by either the [NeV]/[NeII] or [OIV]/[NeII] line flu...

  3. A Search for Discrete X-Ray Spectral Features in a Sample of Bright Gamma-Ray Burst Afterglows

    Energy Technology Data Exchange (ETDEWEB)

    Sako, M

    2004-09-09

    We present uniform, detailed spectral analyses of gamma-ray burst (GRB) X-ray afterglows observed with ASCA, Beppo-SAX, Chandra, and XMM-Newton, and critically evaluate the statistical significances of X-ray emission and absorption features in these spectra. The sample consists of 21 X-ray afterglow observations up to and including that of GRB040106 with spectra of sufficient statistical quality to allow meaningful line searches, chosen here somewhat arbitrarily to be detections with more than 100 total (source plus background) counts. This sample includes all nine X-ray afterglows with published claims of line detections. Moderate resolution spectra are available for 16 of the 21 sources, and for the remaining five the Chandra transmission grating spectrometers obtained high-resolution data. All of the data are available from the public archive. We test a simple hypothesis in which the observed spectra are produced by a power-law continuum model modified by photoelectric absorption by neutral material both in our Galaxy and possibly also local to the burst. As a sample, these afterglow spectra are consistent with this relatively simple model. However, since the {chi}{sup 2} statistic is not sensitive to weak and/or localized fluctuations, we have performed Monte Carlo simulations to search for discrete features and to estimate their significances. Our analysis shows that there are four afterglows (GRB011211, GRB030227, GRB021004, and GRB040106) with line-like features that are significant at the 3 {sigma} level. We cautiously note that, in two cases, the features are associated with an unusual background feature; in the other two, the fractional magnitudes of the lines are small, and comparable to the expected level of systematic uncertainty in the spectral response. In addition, none of the statistically significant features are seen in more than one detector or spectral order where available. We conclude that, to date, no credible X-ray line feature has been

  4. SU Lyncis, a hard X-ray bright M giant: Clues point to a large hidden population of symbiotic stars

    CERN Document Server

    Mukai, K; Cusumano, G; Segreto, A; Munari, U; Sokoloski, J L; Lucy, A B; Nelson, T; Nunez, N E

    2016-01-01

    Symbiotic star surveys have traditionally relied almost exclusively on low resolution optical spectroscopy. However, we can obtain a more reliable estimate of their total Galactic population by using all available signatures of the symbiotic phenomenon. Here we report the discovery of a hard X-ray source, 4PBC J0642.9+5528, in the Swift hard X-ray all-sky survey, and identify it with a poorly studied red giant, SU Lyn, using pointed Swift observations and ground-based optical spectroscopy. The X-ray spectrum, the optical to UV spectrum, and the rapid UV variability of SU Lyn are all consistent with our interpretation that it is a symbiotic star containing an accreting white dwarf. The symbiotic nature of SU Lyn went unnoticed until now, because it does not exhibit emission lines strong enough to be obvious in low resolution spectra. We argue that symbiotic stars without shell-burning have weak emission lines, and that the current lists of symbiotic stars are biased in favor of shell-burning systems. We conclu...

  5. SU Lyncis, a Hard X-Ray Bright M Giant: Clues Point to a Large Hidden Population of Symbiotic Stars

    Science.gov (United States)

    Mukai, K.; Luna, G. J. M.; Cusumano, G.; Segreto, A.; Munari, U.; Sokoloski, J. L.; Lucy, A. B.; Nelson, T.; Nunez, N. E.

    2016-01-01

    Symbiotic star surveys have traditionally relied almost exclusively on low resolution optical spectroscopy. However, we can obtain amore reliable estimate of their total Galactic population by using all available signatures of the symbiotic phenomenon. Here we report the discovery of a hard X-ray source, 4PBC J0642.9+5528, in the Swift hard X-ray all-sky survey, and identify it with a poorly studied red giant, SU Lyn, using pointed Swift observations and ground-based optical spectroscopy. The X-ray spectrum, the optical to UV spectrum, and the rapid UV variability of SU Lyn are all consistent with our interpretation that it is a symbiotic star containing an accreting white dwarf. The symbiotic nature of SU Lyn went unnoticed until now, because it does not exhibit emission lines strong enough to be obvious in low resolution spectra. We argue that symbiotic stars without shell-burning have weak emission lines, and that the current lists of symbiotic stars are biased in favour of shell-burning systems. We conclude that the true population of symbiotic stars has been underestimated, potentially by a large factor.

  6. Comprehensive monitoring of gamma-ray bright blazars. I. Statistical study of optical, X-ray, and gamma-ray spectral slopes

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, Karen E.; Jorstad, Svetlana G.; Marscher, Alan P.; Agudo, Iván; Joshi, Manasvita; Malmrose, Michael P. [Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Larionov, Valeri M.; Blinov, Dmitry A.; Efimova, Natalia V.; Hagen-Thorn, Vladimir A.; Konstantinova, Tatiana S.; Kopatskaya, Evgenia N.; Larionova, Elena G.; Larionova, Liudmilla V. [Astronomical Institute, St. Petersburg State University, Universitetskij Pr. 28, Petrodvorets, 198504 St. Petersburg (Russian Federation); Smith, Paul S. [Steward Observatory, University of Arizona, Tucson, AZ 85721-0065 (United States); Arkharov, Arkady A. [Main (Pulkovo) Astronomical Observatory of RAS, Pulkovskoye shosse 60, 196140 St. Petersburg (Russian Federation); Casadio, Carolina; Gómez, José L.; Molina, Sol N. [Instituto de Astrofísica de Andalucía, CSIC, Apartado 3004, E-18080 Granada (Spain); McHardy, Ian M., E-mail: kwilliam@bu.edu [Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); and others

    2014-07-10

    We present γ-ray, X-ray, ultraviolet, optical, and near-infrared light curves of 33 γ-ray bright blazars over 4 years that we have been monitoring since 2008 August with multiple optical, ground-based telescopes and the Swift satellite, and augmented by data from the Fermi Gamma-ray Space Telescope and other publicly available data from Swift. The sample consists of 21 flat-spectrum radio quasars (FSRQs) and 12 BL Lac objects (BL Lacs). We identify quiescent and active states of the sources based on their γ-ray behavior. We derive γ-ray, X-ray, and optical spectral indices, α{sub γ}, α{sub X}, and α{sub o}, respectively (F{sub ν}∝ν{sup α}), and construct spectral energy distributions during quiescent and active states. We analyze the relationships between different spectral indices, blazar classes, and activity states. We find (1) significantly steeper γ-ray spectra of FSRQs than for BL Lacs during quiescent states, but a flattening of the spectra for FSRQs during active states while the BL Lacs show no significant change; (2) a small difference of α{sub X} within each class between states, with BL Lac X-ray spectra significantly steeper than in FSRQs; (3) a highly peaked distribution of X-ray spectral slopes of FSRQs at ∼ –0.60, but a very broad distribution of α{sub X} of BL Lacs during active states; (4) flattening of the optical spectra of FSRQs during quiescent states, but no statistically significant change of α{sub o} of BL Lacs between states; and (5) a positive correlation between optical and γ-ray spectral slopes of BL Lacs, with similar values of the slopes. We discuss the findings with respect to the relative prominence of different components of high-energy and optical emission as the flux state changes.

  7. Impact of Supernova and Cosmic-Ray Driving on the Surface Brightness of the Galactic Halo in Soft X-Rays

    Science.gov (United States)

    Peters, Thomas; Girichidis, Philipp; Gatto, Andrea; Naab, Thorsten; Walch, Stefanie; Wünsch, Richard; Glover, Simon C. O.; Clark, Paul C.; Klessen, Ralf S.; Baczynski, Christian

    2015-11-01

    The halo of the Milky Way contains a hot plasma with a surface brightness in soft X-rays of the order 10-12 erg cm-2 s-1 deg-2. The origin of this gas is unclear, but so far numerical models of galactic star formation have failed to reproduce such a large surface brightness by several orders of magnitude. In this paper, we analyze simulations of the turbulent, magnetized, multi-phase interstellar medium including thermal feedback by supernova explosions as well as cosmic-ray feedback. We include a time-dependent chemical network, self-shielding by gas and dust, and self-gravity. Pure thermal feedback alone is sufficient to produce the observed surface brightness, although it is very sensitive to the supernova rate. Cosmic rays suppress this sensitivity and reduce the surface brightness because they drive cooler outflows. Self-gravity has by far the largest effect because it accumulates the diffuse gas in the disk in dense clumps and filaments, so that supernovae exploding in voids can eject a large amount of hot gas into the halo. This can boost the surface brightness by several orders of magnitude. Although our simulations do not reach a steady state, all simulations produce surface brightness values of the same order of magnitude as the observations, with the exact value depending sensitively on the simulation parameters. We conclude that star formation feedback alone is sufficient to explain the origin of the hot halo gas, but measurements of the surface brightness alone do not provide useful diagnostics for the study of galactic star formation.

  8. IMPACT OF SUPERNOVA AND COSMIC-RAY DRIVING ON THE SURFACE BRIGHTNESS OF THE GALACTIC HALO IN SOFT X-RAYS

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Thomas; Girichidis, Philipp; Gatto, Andrea; Naab, Thorsten [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Walch, Stefanie [Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln (Germany); Wünsch, Richard [Astronomical Institute, Academy of Sciences of the Czech Republic, Bocni II 1401, 141 31 Prague (Czech Republic); Glover, Simon C. O.; Klessen, Ralf S.; Baczynski, Christian [Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Clark, Paul C., E-mail: tpeters@mpa-garching.mpg.de [School of Physics and Astronomy, Cardiff University, 5 The Parade, Cardiff CF24 3AA, Wales (United Kingdom)

    2015-11-10

    The halo of the Milky Way contains a hot plasma with a surface brightness in soft X-rays of the order 10{sup −12} erg cm{sup −2} s{sup −1} deg{sup −2}. The origin of this gas is unclear, but so far numerical models of galactic star formation have failed to reproduce such a large surface brightness by several orders of magnitude. In this paper, we analyze simulations of the turbulent, magnetized, multi-phase interstellar medium including thermal feedback by supernova explosions as well as cosmic-ray feedback. We include a time-dependent chemical network, self-shielding by gas and dust, and self-gravity. Pure thermal feedback alone is sufficient to produce the observed surface brightness, although it is very sensitive to the supernova rate. Cosmic rays suppress this sensitivity and reduce the surface brightness because they drive cooler outflows. Self-gravity has by far the largest effect because it accumulates the diffuse gas in the disk in dense clumps and filaments, so that supernovae exploding in voids can eject a large amount of hot gas into the halo. This can boost the surface brightness by several orders of magnitude. Although our simulations do not reach a steady state, all simulations produce surface brightness values of the same order of magnitude as the observations, with the exact value depending sensitively on the simulation parameters. We conclude that star formation feedback alone is sufficient to explain the origin of the hot halo gas, but measurements of the surface brightness alone do not provide useful diagnostics for the study of galactic star formation.

  9. 人类首次在黑洞超软谱态下发现相对论性喷流%Relativistic baryonic jets from an ultraluminous supersoft X-ray source

    Institute of Scientific and Technical Information of China (English)

    白宇; 王松; 刘继峰

    2016-01-01

    The formation of relativistic jets by an accreting compact object is one of the fundamental mysteries of astrophysics. While the theory is poorly understood, the observations of relativistic jets from systems known as microquasars have led to a well-established phenomenology. Relativistic jets are not expected from sources with soft or supersoft X-ray spectra, although two such systems are known to produce relatively low-velocity bipolar outflows. Here we report the optical spectra of an ultraluminous supersoft X-ray source (ULS) in the nearby galaxy M81 (M81 ULS-1) showing blueshifted broad Hα emission lines, the characteristics of baryonic jets with relativistic speeds. The time variable jets have projected velocities ~17 percent of the speed of light, which seems similar to those in the prototype microquasar SS433. Such relativistic jets are not expected to be launched from white dwarfs, but an origin from a black hole or neutron star in M81 ULS-1 is hard to reconcile with its constant soft X-rays. The completely unexpected presence of relativistic jets in a ULS challenges the canonical theories for jet formation, which is possibly explained by a long speculated super-critically accreting black hole with optically thick outflows.%致密天体吸积过程中相对论喷流的形成机制,是天体物理学的基础问题之一.理论上虽然很难回答这个问题,但对于微类星体相对论喷流的观测,在现象上给出了规律:对于辐射出超软X射线的天体,相对论喷流是无法产生的.对于河外星系M81中超软极亮X射线源(M81 ULS1)的光谱观测表明,蓝移的宽Hα发射线,是重子物质相对论喷流的证据.喷流的进动导致发射线随时间变化,其投影速度约为光速的17%,这与微类星体的原型SS433极为相似.这种相对论喷流不可能起源于白矮星,而是起源于中子星或黑洞,这与M81 ULS1的超软X射线光谱相矛盾.X射线超软源中相对论喷流的发现,打破以往对喷

  10. Impact of supernova and cosmic-ray driving on the surface brightness of the galactic halo in soft X-rays

    CERN Document Server

    Peters, Thomas; Gatto, Andrea; Naab, Thorsten; Walch, Stefanie; Wünsch, Richard; Glover, Simon C O; Clark, Paul C; Klessen, Ralf S; Baczynski, Christian

    2015-01-01

    The halo of the Milky Way contains a hot plasma with a surface brightness in soft X-rays of the order $10^{-12}$erg cm$^{-2}$ s$^{-1}$ deg$^{-2}$. The origin of this gas is unclear, but so far numerical models of galactic star formation have failed to reproduce such a large surface brightness by several orders of magnitude. In this paper, we analyze simulations of the turbulent, magnetized, multi-phase interstellar medium including thermal feedback by supernova explosions as well as cosmic-ray feedback. We include a time-dependent chemical network, self-shielding by gas and dust, and self-gravity. Pure thermal feedback alone is sufficient to produce the observed surface brightness, although it is very sensitive to the supernova rate. Cosmic rays suppress this sensitivity and reduce the surface brightness because they drive cooler outflows. Self-gravity has by far the largest effect because it accumulates the diffuse gas in the disk in dense clumps and filaments, so that supernovae exploding in voids can eject...

  11. Bright X-Ray Flares from the BL Lac Object Markarian 421, Detected with MAXI in 2010 January and February

    Science.gov (United States)

    Isobe, Naoki; Sugimori, Kousuke; Kawai, Nobuyuki; Ueda, Yoshihiro; Negoro, Hitoshi; Sugizaki, Mutsumi; Matsuoka, Masaru; Daikyuji, Arata; Eguchi, Satoshi; Hiroi, Kazuo; Ishikawa, Masaki; Ishiwata, Ryoji; Kawasaki, Kazuyoshi; Kimura, Masashi; Kohama, Mitsuhiro; Mihara, Tatehiro; Miyoshi, Sho; Morii, Mikio; Nakagawa, Yujin E.; Nakahira, Satoshi; Nakajima, Motoki; Ozawa, Hiroshi; Sootome, Tetsuya; Suzuki, Motoko; Tomida, Hiroshi; Tsunemi, Hiroshi; Ueno, Shiro; Yamamoto, Takayuki; Yamaoka, Kazutaka; Yoshida, Atsumasa; MAXI Team

    2010-12-01

    Strong X-ray flares from the blazar Mrk 421 were detected in 2010 January and February through 7-month monitoring with the MAXI GSC. The maximum 2-10 keV flux in the January and February flares was measured to be 120±10 mCrab and 164±17 mCrab, respectively; the latter is the highest among those reported from the object. A comparison of the MAXI and Swift BAT data suggests a convex X-ray spectrum with an approximated photon index of Γ ≳ 2. This spectrum is consistent with a picture that MAXI is observing near the synchrotron peak frequency. The source exhibited a spectral variation during these flares, slightly different from those in previous observations, in which the positive correlation between the flux and hardness was widely reported. By equating the halving decay timescale in the January flare, td ˜ 2.5 × 104 s, to the synchrotron cooling time, the magnetic field was evaluated to be B ˜ 4.5 × 10-2G (δ/10)-1/3, where δ is the jet beaming factor. Assuming that the light crossing time of the emission region is shorter than the doubling rise time, tr ≲ 2 × 104 s, the region size was roughly estimated as R < 6 × 1015 cm (δ/10). These results are consistent with values previously reported. For the February flare, the rise time, tr < 1.3 × 105 s, gives a loose upper limit on the size as R < 4 × 1016 cm (δ/10), although the longer decay time, td ˜ 1.4 × 105s, indicates B ˜ 1.5 × 10-2G (δ/10)-1/3, which is weaker than the previous results. This could be reconciled by invoking a scenario that this flare is a superposition of unresolved events with a shorter timescale.

  12. X-ray selected BALQSOs

    CERN Document Server

    Page, M J; Ceballos, M; Corral, A; Ebrero, J; Esquej, P; Krumpe, M; Mateos, S; Rosen, S; Schwope, A; Streblyanska, A; Symeonidis, M; Tedds, J A; Watson, M G

    2016-01-01

    We study a sample of six X-ray selected broad absorption line (BAL) quasi-stellar objects (QSOs) from the XMM-Newton Wide Angle Survey. All six objects are classified as BALQSOs using the classic balnicity index, and together they form the largest sample of X-ray selected BALQSOs. We find evidence for absorption in the X-ray spectra of all six objects. An ionized absorption model applied to an X-ray spectral shape that would be typical for non-BAL QSOs (a power law with energy index alpha=0.98) provides acceptable fits to the X-ray spectra of all six objects. The optical to X-ray spectral indices, alpha_OX, of the X-ray selected BALQSOs, have a mean value of 1.69 +- 0.05, which is similar to that found for X-ray selected and optically selected non-BAL QSOs of similar ultraviolet luminosity. In contrast, optically-selected BALQSOs typically have much larger alpha_OX and so are characterised as being X-ray weak. The results imply that X-ray selection yields intrinsically X-ray bright BALQSOs, but their X-ray sp...

  13. Formation and evolution of X-ray binaries

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We review recent progress in theoretical understanding of X-ray binaries,which has largely been driven by new observations.We select several topics including formation of compact low-mass X-ray binaries,the evolutionary connection between low-mass X-ray binaries and binary and millisecond radio pulsars,and ultraluminous X-ray sources,to illustrate the interplay between theories and observations.

  14. Using GRO J1655-40 to test Swift/BAT as a monitor for bright hard X-ray sources

    CERN Document Server

    Senziani, F; De Luca, A; Caraveo, P A; Belloni, T; Bignami, Giovanni Fabrizio

    2007-01-01

    While waiting for new gamma-ray burst detections, the Burst Alert Telescope (BAT) on board Swift covers each day ~50% of the sky in the hard X-ray band (``Survey data''). The large field of view (FOV), high sensitivity and good angular resolution make BAT a potentially powerful all-sky hard X-ray monitor, provided that mask--related systematics can be properly accounted for. We have developed and tested a complete procedure entirely based on public Swift/BAT software tools to analyse BAT Survey data, aimed at assessing the flux and spectral variability of bright sources in the 15-150 keV energy range. Detailed tests of the capabilities of our procedure were performed focusing, in particular, on the reliability of spectral measurements over the entire BAT FOV. First, we analyzed a large set of Crab observations, spread over ~7 months. Next, we studied the case of GRO J1655-40, a strongly variable source, which experienced a 9-month long outburst, beginning on February 2005. Such an outburst was systematically ...

  15. An unexpected drop in the magnetic field of the X-ray pulsar V0332+53 after the bright outburst occurred in 2015

    CERN Document Server

    Cusumano, G; D'Ai, A; Segreto, A; Tagliaferri, G; Barthelmy, S D; Gehrels, N

    2016-01-01

    How the accreted mass settling on the surface of a neutron star affects the topology of the magnetic field and how the secular evolution of the binary system depends on the magnetic field change is still an open issue. We report evidence for a clear drop in the observed magnetic field in the accreting pulsar V0332+53 after undergoing a bright 3-month long X-ray outburst. We determine the field from the position of the fundamental cyclotron line in its X-ray spectrum and relate it to the luminosity. For equal levels of luminosity, in the declining phase we measure a systematically lower value of the cyclotron line energy with respect to the rising phase. This results in a drop of ~1.7 x 10^11 G of the observed field between the onset and the end of the outburst. The settling of the accreted plasma onto the polar cap seems to induce a distortion of the magnetic field lines weakening their intensity along the accretion columns. Therefore the dissipation rate of the magnetic field could be much faster than previo...

  16. XID Cross-Association of ROSAT/Bright Source Catalog X-ray Sources with USNO A2 Optical Point Sources

    CERN Document Server

    Rutledge, R E; Prince, T A; Lonsdale, C; Rutledge, Robert E.; Brunner, Robert J.; Prince, Thomas A.; Lonsdale, Carol

    2000-01-01

    We quantitatively cross-associate the 18811 ROSAT Bright Source Catalog (RASS/BSC) X-ray sources with optical sources in the USNO-A2 catalog, calculating the the probability of unique association (Pid) between each candidate within 75 arcsec of the X-ray source position, on the basis of optical magnitude and proximity. We present catalogs of RASS/BSC sources for which the probability of association is >98%, >90%, and >50%, which contain 2705, 5492, and 11301 unique USNO-A2 optical counterparts respectively down to the stated level of significance. We include in this catalog a list of objects in the SIMBAD database within 10 arcsec of the USNO position, as an aid to identification and source classification. The catalog is more useful than previous catalogs which either rely on plausibility arguments for association, or do not aid in selecting a counterpart between multiple off-band sources in the field. We find that a fraction ~65.8% of RASS/BSC sources have an identifiable optical counterpart, down to the mag...

  17. Understanding Bright 13 keV Kr K-shell X-ray Sources at the NIF

    Science.gov (United States)

    May, M. J.; Colvin, J. D.; Kemp, G. E.; Fournier, K. B.; Scott, H.; Patel, M.; Barrios, Widmann; Widmann, K.

    2015-11-01

    High x-ray conversion efficiency (CE) K-shell Kr sources are being investigated for High Energy Density experiments. These sources are 4.1 mm in diameter 4.4 mm tall hollow epoxy tubes having a 40 μm thick wall holding either 1.2 or 1.5 atm of Kr gas. The CE of K-shell Kr is dependent upon the peak electron temperature in the radiating plasma. In the NIF experiments, the available energy heats the source to Te = 6-7 keV, well below the temperature of Te ~25 keV needed to optimize the Kr CE. The CE is a steep function of the peak electron temperature. A spatially averaged electron temperature can be estimated from measured He(α) and Ly(α) line ratios. Some disagreement has been observed in the simulated and measured line ratios for some of these K-shell sources. Disagreements have been observed between the simulated and measured line ratios for some of these K-shell sources. To help understand this issue, Kr gas pipes have been shot with 3 ω light at ?750 kJ at ~210, ~140 TW and ~120 TW power levels with 3.7, 5.2 and 6.7 ns pulses, respectively. The power and pulse length scaling of the measured CE and K-shell line ratios and their comparison to simulations will be discussed. This work was performed under the auspic

  18. Generating coherent soft x-ray pulses in the water window with a high-brightness seeded free-electron laser

    CERN Document Server

    Zhou, Kaishang; Deng, Haixiao; Wang, Dong

    2016-01-01

    We propose a new scheme to generate high-brightness and temporal coherent soft x-ray radiation in a seeded free-electron laser. The proposed scheme is based the coherent harmonic generation (CHG) and superradiant principles. A CHG scheme is first used to generate coherent signal at ultra-high harmonics of the seed. This coherent signal is then amplified by a series of chicane-undulator modules via the fresh bunch and superradiant processes in the following radiator. Using a representative of realistic set of parameters, three-dimensional simulations have been carried out and the simulations results demonstrated that 10 GW-level ultra-short coherent radiation pulses in the water window can be achieved by using the proposed technique.

  19. Generating high-brightness and coherent soft x-ray pulses in the water window with a seeded free-electron laser

    Directory of Open Access Journals (Sweden)

    Kaishang Zhou

    2017-01-01

    Full Text Available We propose a new scheme to generate high-brightness and temporal coherent soft x-ray radiation in a seeded free-electron laser. The proposed scheme is based on the coherent harmonic generation (CHG and superradiant principles. A CHG scheme is first used to generate a coherent signal at ultrahigh harmonics of the seed. This coherent signal is then amplified by a series of chicane-undulator modules via the fresh bunch and superradiant processes in the following radiator. Using a representative of a realistic set of parameters, three-dimensional simulations have been carried out and the simulations results demonstrated that 10 GW-level ultrashort (∼20  fs coherent radiation pulses in the water window can be achieved by using a 1.6 GeV electron beam based on the proposed technique.

  20. Conceptual design of a high-brightness linac for soft X-ray SASE-FEL source

    Energy Technology Data Exchange (ETDEWEB)

    Alesini, D.; Bertolucci, S.; Biagini, M.E.; Biscari, C.; Boni, R.; Boscolo, M.; Castellano, M.; Clozza, A.; Pirro, G.D.G. Di; Drago, A.; Esposito, A.; Ferrario, M. E-mail: massimo.ferrario@lnf.infn.it; Fusco, V.; Gallo, A.; Ghigo, A.; Guiducci, S.; Incurvati, M.; Laurelli, P.; Ligi, C.; Marcellini, F.; Migliorati, M.; Milardi, C.; Palumbo, L.; Pellegrino, L.; Preger, M.; Raimondi, P.; Ricci, R.; Sanelli, C.; Sgamma, F.; Spataro, B.; Serio, M.; Stecchi, A.; Stella, A.; Tazzioli, F.; Vaccarezza, C.; Vescovi, M.; Vicario, C.; Zobov, M.; Acerbi, E.; Alessandria, F.; Barni, D.; Bellomo, G.; Birattari, C.; Bonardi, M.; Boscolo, I.; Bosotti, A.; Broggi, F.; Cialdi, S.; DeMartinis, C.; Giove, D.; Maroli, C.; Michelato, P.; Monaco, L.; Pagani, C.; Petrillo, V.; Pierini, P.; Serafini, L.; Sertore, D.; Volpini, G.; Chiadroni, E.; Felici, G.; Levi, D.; Mastrucci, M.; Mattioli, M.; Medici, G.; Petrarca, G.S.; Catani, L.; Cianchi, A.; D' Angelo, A.; Salvo, R.D.R. Di; Fantini, A.; Moricciani, D.; Schaerf, C.; Bartolini, R.; Ciocci, F.; Dattoli, G.; Doria, A.; Flora, F.; Gallerano, G.P.; Giannessi, L.; Giovenale, E.; Messina, G.; Mezi, L.; Ottaviani, P.L.; Picardi, L.; Quattromini, M.; Renieri, A.; Ronsivalle, C.; Avaldi, L.; Carbone, C.; Cricenti, A.; Pifferi, A.; Perfetti, P.; Prosperi, T.; Albertini, V.R.V. Rossi; Quaresima, C.; Zema, N

    2003-07-11

    FELs based on SASE are believed to be powerful tools to explore the frontiers of basic sciences, from physics to chemistry to biology. Intense R and D programs have started in the USA and Europe in order to understand the SASE physics and to prove the feasibility of these sources. The allocation of considerable resources in the Italian National Research Plan (PNR) brought about the formation of a CNR-ENEA-INFN-University of Roma 'Tor Vergata' study group. A conceptual design study has been developed and possible schemes for linac sources have been investigated, leading to the SPARX proposal. We report in this paper the results of a preliminary start to end simulation concerning one option we are considering based on an S-band normal conducting linac with high-brightness photoinjector integrated in an RF compressor.

  1. Galaxies in X-ray Selected Clusters and Groups in Dark Energy Survey Data: Stellar Mass Growth of Bright Central Galaxies Since z~1.2

    CERN Document Server

    Zhang, Y; Mckay, T; Rooney, P; Evrard, A E; Romer, A K; Perfecto, R; Song, J; Desai, S; Mohr, J; Wilcox, H; Bermeo, A; Jeltema, T; Hollowood, D; Bacon, D; Capozzi, D; Collins, C; Das, R; Gerdes, D; Hennig, C; Hilton, M; Hoyle, B; Kay, S; Liddle, A; Mann, R G; Mehrtens, N; Nichol, R C; Papovich, C; Sahlén, M; Soares-Santos, M; Stott, J; Viana, P T; Abbott, T; Abdalla, F B; Banerji, M; Bauer, A H; Benoit-Lévy, A; Bertin, E; Brooks, D; Buckley-Geer, E; Burke, D L; Rosell, A Carnero; Castander, F J; Diehl, H T; Doel, P; Cunha, C E; Eifler, T F; Neto, A Fausti; Fernandez, E; Flaugher, B; Fosalba, P; Frieman, J; Gaztanaga, E; Gruen, D; Gruendl, R A; Honscheid, K; James, D; Kuehn, K; Kuropatkin, N; Lahav, O; Maia, M A G; Makler, M; Marshall, J L; Martini, Paul; Miquel, R; Ogando, R; Plazas, A A; Roodman, A; Rykoff, E S; Sako, M; Sanchez, E; Scarpine, V; Schubnell, M; Sevilla, I; Smith, R C; Sobreira, F; Suchyta, E; Swanson, M E C; Tarle, G; Thaler, J; Tucker, D; Vikram, V; Da Costa, L N

    2015-01-01

    Using the science verification data of the Dark Energy Survey (DES) for a new sample of 106 X-Ray selected clusters and groups, we study the stellar mass growth of Bright Central Galaxies (BCGs) since redshift 1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into analysis of a redshift-dependent BCG-cluster mass relation, $m_{*}\\propto(\\frac{M_{200}}{1.5\\times 10^{14}M_{\\odot}})^{0.24\\pm 0.08}(1+z)^{-0.19\\pm0.34}$, and compare the observed relation to the simulation prediction. We estimate the average growth rate since z = 1.0 for BCGs hosted by clusters of $M_{200, z}=10^{13.8}M_{\\odot}$, at $z=1.0$: $m_{*, BCG}$ appears to have grown by $0.13\\pm0.11$ dex, in tension at $\\sim 2.5 \\sigma$ significance level with the 0.4 dex growth rate expected in the simulation. We show that...

  2. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  3. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  4. Final Report on DTRA Basic Research Project #BRCALL08-Per3-C-2-0006 "High-Z Non-Equilibrium Physics and Bright X-ray Sources with New Laser Targets"

    Energy Technology Data Exchange (ETDEWEB)

    Colvin, Jeffrey D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-06-01

    This project had two major goals. Final Goal: obtain spectrally resolved, absolutely calibrated x-ray emission data from uniquely uniform mm-scale near-critical-density high-Z plasmas not in local thermodynamic equilibrium (LTE) to benchmark modern detailed atomic physics models. Scientific significance: advance understanding of non-LTE atomic physics. Intermediate Goal: develop new nano-fabrication techniques to make suitable laser targets that form the required highly uniform non-LTE plasmas when illuminated by high-intensity laser light. Scientific significance: advance understanding of nano-science. The new knowledge will allow us to make x-ray sources that are bright at the photon energies of most interest for testing radiation hardening technologies, the spectral energy range where current x-ray sources are weak. All project goals were met.

  5. Quasi Periodic Oscillations and Strongly Comptonized X-ray emission from Holmberg IX X-1

    CERN Document Server

    Dewangan, G C; Rao, A R

    2006-01-01

    We report the discovery of a 200mHz quasi-periodic oscillation (QPO) in the X-ray emission from a bright ultra-luminous X-ray source (ULX) Holmberg IX X-1 using a long XMM-Newton observation. The QPO has a centroid at 202.5_{-3.8}^{+4.9}mHz, a coherence Q ~9.3 and an amplitude (rms) of 6% in the 0.2-10keV band. This is only the second detection of a QPO from an ULX, after M82 X-1, and provides strong evidence against beaming. The power spectrum is well fitted by a power law with an index of ~0.7. The total integrated power (rms) is ~9.4% in the 0.001-1Hz range. The X-ray spectrum shows clear evidence for a soft X-ray excess component that is well described by a multicolor disk blackbody (kT_in ~ 0.3keV) and a high energy curvature that can be modeled either by a cut-off power law (Gamma ~ 1; E_cutoff ~9keV) or as a strongly Comptonized continuum in an optically thick (tau ~7.3) and cool (kT_e ~3keV) plasma. Both the presence of the QPO and the shape of the X-ray spectrum strongly suggest that the ULX is not i...

  6. A New X-ray Bright Point Catalog From Honode XRT images As An Application of Feature Recognition Methods and Emerging Heliophysics Knowledge Base Systems

    Science.gov (United States)

    Slater, Gregory L.; Freeland, S. L.; Weber, M. A.

    2007-05-01

    A new effort is underway to process the rapidly growing volume of solar observational data by using automated feature recognition and cataloguing software (c.f., Schrijver et al SPD 2007 or Hurlburt et al, SPD 2007). We apply a particular set of feature recognition tools called FINDSTUFF, available within the SolarSoft IDL framework, to the problem of automatically extracting X-Ray Bright Point (XBP) features from images recorded by the XRT instrument aboard the recently launched Japanese Hinode satellite. The extracted events are automatically catalogued by the FINDSTUFF software. The events are converted into standardized XML format as VOEvents, and these XML event files in turn are automatically deposited in the Heliophysics Knowledge Base (HKB) being developed at Lockheed Martin in collaboration with other institutions (c.f., Hurlburt et al, SPD 2007). In addition to providing a very useful end-to-end test of the Heliophysics Knowledge Base Project (Schrijver et al), the catalogue yields a valuable scientific database of XBPs extracted from high resolution XRT images. We discuss the aspects of our processing pipeline which are generally applicable to many feature archiving projects; we demonstrate how the final Heliophysics Knowledge Base may be queried to explore the XBP archive; we compare our catalogue of XBPs with previously generated ones; and we provide examples of discoveries made with massively autonomous feature extraction (MAFE). The U.S. XRT team is supported by NASA contracts from NASA to SAO (XRT), while the SOT team is supported by NASA contract number NNM07AA01C. Hinode is an international project supported by JAXA, NASA, PPARC and ESA. We are grateful to the Hinode team for all their efforts in the design, development and operation of the mission.

  7. Chest X Ray?

    Science.gov (United States)

    ... this page from the NHLBI on Twitter. Chest X Ray A chest x ray is a fast and painless imaging test ... tissue scarring, called fibrosis. Doctors may use chest x rays to see how well certain treatments are ...

  8. X-Rays

    Science.gov (United States)

    X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat ...

  9. Medical X-Rays

    Science.gov (United States)

    ... Benefits The discovery of X-rays and the invention of CT represented major advances in medicine. X- ... in X-ray and CT Examinations — X-ray definition, dose measurement, safety precautions, risk, and consideration with ...

  10. Applications of soft x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.H.

    1993-08-01

    The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x-ray lasers from the perspective of applications, and present an overview of the applications currently being developed.

  11. A Correlation between the Intrinsic Brightness and Average Decay Rate of Gamma-Ray Burst X-Ray Afterglow Light Curves

    Science.gov (United States)

    Racusin, J. L.; Oates, S. R.; de Pasquale, M.; Kocevski, D.

    2016-07-01

    We present a correlation between the average temporal decay ({α }{{X},{avg},\\gt 200{{s}}}) and early-time luminosity ({L}{{X},200{{s}}}) of X-ray afterglows of gamma-ray bursts as observed by the Swift X-ray Telescope. Both quantities are measured relative to a rest-frame time of 200 s after the γ-ray trigger. The luminosity-average decay correlation does not depend on specific temporal behavior and contains one scale-independent quantity minimizing the role of selection effects. This is a complementary correlation to that discovered by Oates et al. in the optical light curves observed by the Swift Ultraviolet Optical Telescope. The correlation indicates that, on average, more luminous X-ray afterglows decay faster than less luminous ones, indicating some relative mechanism for energy dissipation. The X-ray and optical correlations are entirely consistent once corrections are applied and contamination is removed. We explore the possible biases introduced by different light-curve morphologies and observational selection effects, and how either geometrical effects or intrinsic properties of the central engine and jet could explain the observed correlation.

  12. Optically Levitated Targets as a Source for High Brightness X-rays and a Platform for Mass-Limited Laser-interaction Experiments

    Science.gov (United States)

    Giltrap, Samuel; Stuart, Nick; Robinson, Tim; Armstrong, Chris; Hicks, George; Eardley, Sam; Gumbrell, Ed; Smith, Roland

    2016-10-01

    Here we report on the development of an optical levitation based x-ray and proton source, motivated by the requirement for a debris free, high spatial resolution, and low EMP source for x-ray radiography and proton production. Research at Imperial College has led to the development of a feedback controlled optical levitation trap which is capable of holding both solid (Glass beads) and liquid (silicon based oil) micro-targets ( 3-10um). The optical levitation trap has been successfully fielded in a high-intensity laser interaction experiment at Imperial College London and at the Vulcan Petawatt Laser system at the Rutherford Appleton Laboratory (RAL). Here we report on the results from that RAL run including; an x-ray source size of 10-15um with very good spherical symmetry when compared to wire targets, secondly very low EMP signal from isolated levitated targets (9 times less RF signal than a comparable wire target). At Imperial College we were also able to record an x-ray energy spectrum which produced an electron temperature of 0.48KeV, and performed interferometry of a shock evolving into a blast wave off an optically levitated droplet which allowed us to infer the electron density within the shock front.

  13. Spectral Variability in Hard X-rays and the Evidence for a 13.5 Years Period in the Bright Quasar 3C273

    Indian Academy of Sciences (India)

    R. K. Manchanda

    2002-09-01

    We report the observation of nearest quasar 3C273 made with LASE instrument on November 20th, 1998 as a part of our continuing programme of balloon borne hard X-ray observations in the 20–200 keV band using high sensitivity Large Area Scintillation counter Experiment. Our data clearly show a steep spectrum in the 20–200 keV with power law spectral index = 226 ± 0.07. This is in complete contrast to the reported data from OSSE and BeppoSAX which suggest the value of 1.3 to 1.6 for the power law index in the X-ray energy band, but is quite consistent with the value derived for the high energy gamma ray data. A single power law fit in the X-ray and gamma ray energy bands points to a common origin of these photons and the absence of spectral break around 1 MeV as suggested in literature. We have reanalyzed the available data to study the temporal variability of the spectrum in the hard X-ray band. Our analysis reveals that 50 keV flux from the source, shows a strong modulation with a period of about 13.5 years. The analysis of the optical light curve of the source also supports the 5000 day period.We discuss the emission mechanism and the possible sites for X-ray photons along with the implications of the long term periodicity with respect to source geometry.

  14. X-ray lasers: Multicolour emission

    Science.gov (United States)

    Feng, Chao; Deng, Haixiao

    2016-11-01

    The X-ray free-electron laser at the SLAC National Accelerator Laboratory in the US can now generate multicolour X-ray pulses with unprecedented brightness using the fresh-slice technique. The development opens the way to new forms of spectroscopy.

  15. X-ray bright active galactic nuclei in massive galaxy clusters III: New insights into the triggering mechanisms of cluster AGN

    CERN Document Server

    Ehlert, S; Brandt, W N; Canning, R E A; Luo, B; Mantz, A; Morris, R G; von der Linden, A; Xue, Y Q

    2014-01-01

    We present the results of a new analysis of the X-ray selected Active Galactic Nuclei (AGN) population in the vicinity of 135 of the most massive galaxy clusters in the redshift range of 0.2 < z < 0.9 observed with Chandra. With a sample of more than 11,000 X-ray point sources, we are able to measure, for the first time, evidence for evolution in the cluster AGN population beyond the expected evolution of field AGN. Our analysis shows that overall number density of cluster AGN scales with the cluster mass as $\\sim M_{500}^{-1.2}$. There is no evidence for the overall number density of cluster member X-ray AGN depending on the cluster redshift in a manner different than field AGN, nor there is any evidence that the spatial distribution of cluster AGN (given in units of the cluster overdensity radius r_500) strongly depends on the cluster mass or redshift. The $M^{-1.2 \\pm 0.7}$ scaling relation we measure is consistent with theoretical predictions of the galaxy merger rate in clusters, which is expected ...

  16. The ultraluminous GRB 110918A

    Energy Technology Data Exchange (ETDEWEB)

    Frederiks, D. D.; Svinkin, D. S.; Pal' shin, V. D.; Aptekar, R. L.; Golenetskii, S. V.; Mazets, E. P.; Oleynik, Ph. P.; Tsvetkova, A. E.; Ulanov, M. V.; Kokomov, A. A. [Ioffe Physical-Technical Institute, Politekhnicheskaya 26, St. Petersburg 194021 (Russian Federation); Hurley, K. [Space Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720-7450 (United States); Mangano, V.; Burrows, D. N.; Sbarufatti, B.; Siegel, M. H. [Pennsylvania State University, Department of Astronomy and Astrophysics, College Park, PA 16801 (United States); Oates, S. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); Cline, T. L.; Krimm, H. A. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Pagani, C. [University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Mitrofanov, I. G., E-mail: fred@mail.ioffe.ru [Space Research Institute, Profsoyuznaya 84/32, Moscow 117997 (Russian Federation); and others

    2013-12-20

    GRB 110918A is the brightest long gamma-ray burst (GRB) detected by Konus-WIND during its almost 19 yr of continuous observations and the most luminous GRB ever observed since the beginning of the cosmological era in 1997. We report on the final Interplanetary Network localization of this event and its detailed multiwavelength study with a number of space-based instruments. The prompt emission is characterized by a typical duration, a moderate peak energy of the time-integrated spectrum, and strong hard-to-soft evolution. The high observed energy fluence yields, at z = 0.984, a huge isotropic-equivalent energy release E {sub iso} = (2.1 ± 0.1) × 10{sup 54} erg. The record-breaking energy flux observed at the peak of the short, bright, hard initial pulse results in an unprecedented isotropic-equivalent luminosity L {sub iso} = (4.7 ± 0.2) × 10{sup 54} erg s{sup –1}. A tail of the soft γ-ray emission was detected with temporal and spectral behavior typical of that predicted by the synchrotron forward-shock model. The Swift/X-Ray Telescope and the Swift/Ultraviolet Optical Telescope observed the bright afterglow from 1.2 to 48 days after the burst and revealed no evidence of a jet break. The post-break scenario for the afterglow is preferred from our analysis, with a hard underlying electron spectrum and interstellar-medium-like circumburst environment implied. We conclude that, among the multiple reasons investigated, the tight collimation of the jet must have been a key ingredient to produce this unusually bright burst. The inferred jet opening angle of 1.°7-3.°4 results in reasonable values of the collimation-corrected radiated energy and the peak luminosity, which, however, are still at the top of their distributions for such tightly collimated events. We estimate a detection horizon for a similar ultraluminous GRB of z ∼ 7.5 for Konus-WIND and z ∼ 12 for the Swift/Burst Alert Telescope, which stresses the importance of GRBs as probes of the early

  17. Sixteen years of X-ray monitoring of Sagittarius A*: Evidence for a decay of the faint flaring rate from 2013 August, 13 months before a rise in the bright flaring rate

    Science.gov (United States)

    Mossoux, Enmanuelle; Grosso, Nicolas

    2017-08-01

    Context. X-ray flaring activity from the closest supermassive black hole Sagittarius A* (Sgr A*) located at the center of our Galaxy has been observed since 2000 October 26 thanks to the current generation of X-ray facilities. In a study of X-ray flaring activity from Sgr A* using Chandra and XMM-Newton public observations from 1999 to 2014 and Swift monitoring in 2014, it was argued that the "bright and very bright" flaring rate has increased from 2014 August 31. Aims: As a result of additional observations performed in 2015 with Chandra, XMM-Newton, and Swift (total exposure of 482 ks), we seek to test the significance and persistence of this increase of flaring rate and to determine the threshold of unabsorbed flare flux or fluence leading to any change of flaring rate. Methods: We reprocessed the Chandra, XMM-Newton, and Swift data from 1999 to 2015 November 2. From these data, we detected the X-ray flares via our two-step Bayesian blocks algorithm with a prior on the number of change points properly calibrated for each observation. We improved the Swift data analysis by correcting the effects of the target variable position on the detector and we detected the X-ray flares with a 3σ threshold on the binned light curves. The mean unabsorbed fluxes of the 107 detected flares were consistently computed from the extracted spectra and the corresponding calibration files, assuming the same spectral parameters. We constructed the observed distribution of flare fluxes and durations from the XMM-Newton and Chandra detections. We corrected this observed distribution from the detection biases to estimate the intrinsic distribution of flare fluxes and durations. From this intrinsic distribution, we determined the average flare detection efficiency for each XMM-Newton, Chandra, and Swift observation. We finally applied the Bayesian blocks algorithm on the arrival times of the flares corrected from the corresponding efficiency. Results: We confirm a constant overall flaring

  18. Submm-bright X-ray absorbed QSOs at z~2: insights into the co-evolution of AGN and star-formation

    CERN Document Server

    Khan-Ali, A; Page, M J; Stevens, J A; Mateos, S; Symeonidis, M; Orjales, J M Cao

    2015-01-01

    We have assembled a sample of 5 X-ray-absorbed and submm-luminous type 1 QSOs at $z \\sim 2$ which are simultaneously growing their central black holes through accretion and forming stars copiously. We present here the analysis of their rest-frame UV to submm Spectral Energy Distributions (SEDs), including new Herschel data. Both AGN (direct and reprocessed) and Star Formation (SF) emission are needed to model their SEDs. From the SEDs and their UV-optical spectra we have estimated the masses of their black holes $M_{BH}\\sim 10^{9}-10^{10}\\,M_{\\odot}$, their intrinsic AGN bolometric luminosities $L_{BOL}\\sim(0.8 - 20)\\times 10^{13} L_{\\odot}$, Eddington ratios $L_{BOL}/L_{Edd}\\sim 0.1 - 1.1$ and bolometric corrections $L_{BOL}/L_{X,2-10}\\sim 30 - 500$. These values are common among optically and X-ray-selected type 1 QSOs (except for RX~J1249), except for the bolometric corrections, which are higher. These objects show very high far-infrared luminosities $L_{FIR}\\sim$ (2 - 8)$\\times10^{12}\\,M_{\\odot}$ and Star...

  19. Extremity x-ray

    Science.gov (United States)

    ... degenerative) Bone tumor Broken bone (fracture) Dislocated bone Osteomyelitis (infection) Arthritis Other conditions for which the test ... Bone tumor Bone x-ray Broken bone Clubfoot Osteomyelitis X-ray Review Date 7/3/2016 Updated ...

  20. Abdominal x-ray

    Science.gov (United States)

    ... are, or may be, pregnant. Alternative Names Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also ...

  1. INTEGRAL observations of the GeV blazar PKS 1502+106 and the hard X-ray bright Seyfert galaxy Mkn 841

    Science.gov (United States)

    Pian, E.; Ubertini, P.; Bazzano, A.; Beckmann, V.; Eckert, D.; Ghisellini, G.; Pursimo, T.; Tagliaferri, G.; Tavecchio, F.; Türler, M.; Bianchi, S.; Bianchin, V.; Hudec, R.; Maraschi, L.; Raiteri, C. M.; Soldi, S.; Treves, A.; Villata, M.

    2011-02-01

    Context. Extragalactic nuclear activity is most effectively explored with observations at high energies, where the most extreme flux and spectral variations are expected to occur, because of changes in either the accretion flow or the kinematics of the plasma. In active galactic nuclei of blazar type, these variations are the most dramatic. Aims: By following blazar outbursts from their onset and correlating the observed variations at many different wavelengths, we can reconstruct the behavior of the plasma and map out the development of the flare within the jet. Methods: The advent of the Fermi satellite has allowed the start of a systematic and intensive monitoring program of blazars. Blazar outbursts are very effectively detected by the LAT instrument in the MeV-GeV domain, and these can be promptly followed up with other facilities. Based on a Fermi LAT detection of a high MeV-GeV state, we observed the blazar PKS 1502+106 with the INTEGRAL satellite between 9 and 11 August 2008. Simultaneous Swift observations were also accomplished, as well as optical follow-up at the Nordic Optical Telescope. Results: The IBIS instrument onboard INTEGRAL detected a source at a position inconsistent with the optical coordinates of PKS 1502+106, but consistent with those of the Seyfert 1 galaxy Mkn 841, located at 6.8 arcmin south-west of the blazar, which is therefore responsible for all the hard X-ray flux detected by IBIS. At the location of the blazar, IBIS sets an upper limit of ~ 10-11 erg s-1 cm-2 on the 15-60 keV flux, which is consistent with a model of inverse Compton scattering accounting for the soft X-ray and gamma-ray spectra measured by Swift XRT and Fermi LAT, respectively. The gamma-ray spectrum during the outburst indicates substantial variability in the characteristic energy of the inverse Compton component in this blazar. The hard X-ray state of the Seyfert appears to be nearly unchanged with respect to the past. On the other hand, its soft X-ray flux (0

  2. X-Ray Supernovae

    CERN Document Server

    Immler, S; Immler, Stefan; Lewin, Walter H.G.

    2002-01-01

    We present a review of X-ray observations of supernovae (SNe). By observing the (~0.1--100 keV) X-ray emission from young SNe, physical key parameters such as the circumstellar matter (CSM) density, mass-loss rate of the progenitor and temperature of the outgoing and reverse shock can be derived as a function of time. Despite intensive search over the last ~25 years, only 15 SNe have been detected in X-rays. We review the individual X-ray observations of these SNe and discuss their implications as to our understanding of the physical processes giving rise to the X-ray emission.

  3. X-ray backscatter imaging

    Science.gov (United States)

    Dinca, Dan-Cristian; Schubert, Jeffrey R.; Callerame, J.

    2008-04-01

    In contrast to transmission X-ray imaging systems where inspected objects must pass between source and detector, Compton backscatter imaging allows both the illuminating source as well as the X-ray detector to be on the same side of the target object, enabling the inspection to occur rapidly and in a wide variety of space-constrained situations. A Compton backscatter image is similar to a photograph of the contents of a closed container, taken through the container walls, and highlights low atomic number materials such as explosives, drugs, and alcohol, which appear as especially bright objects by virtue of their scattering characteristics. Techniques for producing X-ray images based on Compton scattering will be discussed, along with examples of how these systems are used for both novel security applications and for the detection of contraband materials at ports and borders. Differences between transmission and backscatter images will also be highlighted. In addition, tradeoffs between Compton backscatter image quality and scan speed, effective penetration, and X-ray source specifications will be discussed.

  4. Search for TeV Gamma-ray Emission from GRB 100621A, an extremely bright GRB in X-rays, with H.E.S.S

    CERN Document Server

    Abramowski, A; Benkhali, F Ait; Akhperjanian, A G; Angüner, E; Anton, G; Balenderan, S; Balzer, A; Barnacka, A; Becherini, Y; Tjus, J Becker; Bernlöhr, K; Birsin, E; Bissaldi, E; Biteau, J; Böttcher, M; Boisson, C; Bolmont, J; Bordas, P; Brucker, J; Brun, F; Brun, P; Bulik, T; Carrigan, S; Casanova, S; Cerruti, M; Chadwick, P M; Chalme-Calvet, R; Chaves, R C G; Cheesebrough, A; Chrétien, M; Colafrancesco, S; Cologna, G; Conrad, J; Couturier, C; Dalton, M; Daniel, M K; Davids, I D; Degrange, B; Deil, C; deWilt, P; Dickinson, H J; Djannati-Ataï, A; Domainko, W; Drury, L O'C; Dubus, G; Dutson, K; Dyks, J; Dyrda, M; Edwards, T; Egberts, K; Eger, P; Espigat, P; Farnier, C; Fegan, S; Feinstein, F; Fernandes, M V; Fernandez, D; Fiasson, A; Fontaine, G; Förster, A; Füßling, M; Gajdus, M; Gallant, Y A; Garrigoux, T; Giebels, B; Glicenstein, J F; Grondin, M -H; Grudzińska, M; Häffner, S; Hahn, J; Harris, J; Heinzelmann, G; Henri, G; Hermann, G; Hervet, O; Hillert, A; Hinton, J A; Hofmann, W; Hofverberg, P; Holler, M; Horns, D; Jacholkowska, A; Jahn, C; Jamrozy, M; Janiak, M; Jankowsky, F; Jung, I; Kastendieck, M A; Katarzyński, K; Katz, U; Kaufmann, S; Khélifi, B; Kieffer, M; Klepser, S; Klochkov, D; Kluźniak, W; Kneiske, T; Kolitzus, D; Komin, Nu; Kosack, K; Krakau, S; Krayzel, F; Krüger, P P; Laffon, H; Lamanna, G; Lefaucheur, J; Lemière, A; Lemoine-Goumard, M; Lenain, J -P; Lennarz, D; Lohse, T; Lopatin, A; Lu, C -C; Marandon, V; Marcowith, A; Marx, R; Maurin, G; Maxted, N; Mayer, M; McComb, T J L; Méhault, J; Menzler, U; Meyer, M; Moderski, R; Mohamed, M; Moulin, E; Murach, T; Naumann, C L; de Naurois, M; Niemiec, J; Nolan, S J; Oakes, L; O'Brien, P T; Ohm, S; Wilhelmi, E de Oña; Opitz, B; Ostrowski, M; Oya, I; Panter, M; Parsons, R D; Arribas, M Paz; Pekeur, N W; Pelletier, G; Perez, J; Petrucci, P -O; Peyaud, B; Pita, S; Poon, H; Pühlhofer, G; Punch, M; Quirrenbach, A; Raab, S; Raue, M; Reimer, A; Reimer, O; Renaud, M; Reyes, R de los; Rieger, F; Rob, L; Romoli, C; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Sahakian, V; Sanchez, D A; Santangelo, A; Schlickeiser, R; Schüssler, F; Schulz, A; Schwanke, U; Schwarzburg, S; Schwemmer, S; Sol, H; Spengler, G; Spies, F; Stawarz, Ł; Steenkamp, R; Stegmann, C; Stinzing, F; Stycz, K; Sushch, I; Szostek, A; Tam, P H T; Tavernet, J -P; Tavernier, T; Taylor, A M; Terrier, R; Tluczykont, M; Trichard, C; Valerius, K; van Eldik, C; Vasileiadis, G; Venter, C; Viana, A; Vincent, P; Völk, H J; Volpe, F; Vorster, M; Wagner, S J; Wagner, P; Ward, M; Weidinger, M; Weitzel, Q; White, R; Wierzcholska, A; Willmann, P; Wörnlein, A; Wouters, D; Zacharias, M; Zajczyk, A; Zdziarski, A A; Zech, A; Zechlin, H -S

    2014-01-01

    The long gamma-ray burst (GRB) 100621A, at the time the brightest X-ray transient ever detected by Swift-XRT in the $0.3\\textrm{--}10$ keV range, has been observed with the H.E.S.S. imaging air Cherenkov telescope array, sensitive to gamma radiation in the very-high-energy (VHE, $>100$ GeV) regime. Due to its relatively small redshift of $z\\sim0.5$, the favourable position in the southern sky and the relatively short follow-up time ($<700 \\rm{s}$ after the satellite trigger) of the H.E.S.S. observations, this GRB could be within the sensitivity reach of the H.E.S.S. instrument. The analysis of the H.E.S.S. data shows no indication of emission and yields an integral flux upper limit above $\\sim$380 GeV of $4.2\\times10^{-12} \\rm cm^{-2}s^{-1}$ (95 % confidence level), assuming a simple Band function extension model. A comparison to a spectral-temporal model, normalised to the prompt flux at sub-MeV energies, constraints the existence of a temporally extended and strong additional hard power law, as has been ...

  5. X-Ray Polarimetry

    CERN Document Server

    Kaaret, Philip

    2014-01-01

    We review the basic principles of X-ray polarimetry and current detector technologies based on the photoelectric effect, Bragg reflection, and Compton scattering. Recent technological advances in high-spatial-resolution gas-filled X-ray detectors have enabled efficient polarimeters exploiting the photoelectric effect that hold great scientific promise for X-ray polarimetry in the 2-10 keV band. Advances in the fabrication of multilayer optics have made feasible the construction of broad-band soft X-ray polarimeters based on Bragg reflection. Developments in scintillator and solid-state hard X-ray detectors facilitate construction of both modular, large area Compton scattering polarimeters and compact devices suitable for use with focusing X-ray telescopes.

  6. Symbiotic Stars in X-rays

    Science.gov (United States)

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.

    2014-01-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. Swift/XRT detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the alpha/beta/gamma classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new sigma classification for sources with

  7. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  8. X-ray Pulsation Searches with NICER

    Science.gov (United States)

    Ray, Paul S.; Arzoumanian, Zaven

    2016-04-01

    The Neutron Star Interior Composition Explorer (NICER) is an X-ray telescope with capabilities optimized for the study of the structure, dynamics, and energetics of neutron stars through high-precision timing of rotation- and accretion-powered pulsars in the 0.2-12 keV band. It has large collecting area (twice that of the XMM-Newton EPIC-pn camera), CCD-quality spectral resolution, and high-precision photon time tagging referenced to UTC through an onboard GPS receiver. NICER will begin its 18-month prime mission as an attached payload on the International Space Station around the end of 2016. I will describe the science planning for the pulsation search science working group, which is charged with searching for pulsations and studying flux modulation properties of pulsars and other neutron stars. A primary goal of our observations is to detect pulsations from new millisecond pulsars that will contribute to NICER’s studies of the neutron star equation of state through pulse profile modeling. Beyond that, our working group will search for pulsations in a range of source categories, including LMXBs, new X-ray transients that might be accreting millisecond pulsars, X-ray counterparts to unassociated Fermi LAT sources, gamma-ray binaries, isolated neutron stars, and ultra-luminous X-ray sources. I will survey our science plans and give an overview of our planned observations during NICER’s prime mission.

  9. X-Ray

    Science.gov (United States)

    ... You may be allowed to remain with your child during the test. If you remain in the room during the X-ray exposure, you'll likely be asked to wear a lead apron to shield you from unnecessary exposure. After the X-ray ...

  10. Dental x-rays

    Science.gov (United States)

    ... X-rays are a form of high energy electromagnetic radiation. The x-rays penetrate the body to form ... for detecting cavities, unless the decay is very advanced and deep. Many ... The amount of radiation given off during the procedure is less than ...

  11. X-Ray Surveys

    CERN Document Server

    Giommi, P; Perri, M

    1998-01-01

    A review of recent developments in the field of X-ray surveys, especially in the hard (2-10 and 5-10 keV) bands, is given. A new detailed comparison between the measurements in the hard band and extrapolations from ROSAT counts, that takes into proper account the observed distribution of spectral slopes, is presented. Direct comparisons between deep ROSAT and BeppoSAX images show that most hard X-ray sources are also detected at soft X-ray energies. This may indicate that heavily cutoff sources, that should not be detectable in the ROSAT band but are expected in large numbers from unified AGN schemes, are in fact detected because of the emerging of either non-nuclear components, or of reflected, or partially transmitted nuclear X-rays. These soft components may complicate the estimation of the soft X-ray luminosity function and cosmological evolution of AGN.

  12. X-ray Polarimetry

    Science.gov (United States)

    Kallman, T.

    In spite of the recent advances in X-ray instrumentation, polarimetry remains an area which has been virtually unexplored in the last 20 years. The scientific motivation to study polarization has increased during this time: emission models designed to repro- duce X-ray spectra can be tested using polarization, and polarization detected in other wavelength bands makes clear predictions as to the X-ray polarization. Polarization remains the only way to infer geometrical properties of sources which are too small to be spatially resolved. At the same time, there has been recent progress in instrumen- tation which is likely to allow searches for X-ray polarization at levels significantly below what was possible for early detectors. In this talk I will review the history of X-ray polarimetry, discuss some experimental techniques and the scientific problems which can be addressed by future experiments.

  13. X-ray crystallography

    Science.gov (United States)

    2001-01-01

    X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

  14. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

  16. Femtosecond X-ray magnetic circular dichroism absorption spectroscopy at an X-ray free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Higley, Daniel J., E-mail: dhigley@stanford.edu; Yuan, Edwin [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Hirsch, Konstantin; Dakovski, Georgi L.; Jal, Emmanuelle; Lutman, Alberto A.; Coslovich, Giacomo; Hart, Philip; Hoffmann, Matthias C.; Mitra, Ankush; Moeller, Stefan; Ohldag, Hendrik; Seaberg, Matthew; Stöhr, Joachim; Nuhn, Heinz-Dieter; Reid, Alex H.; Dürr, Hermann A.; Schlotter, William F. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Liu, Tianmin; MacArthur, James P. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Physics, Stanford University, Stanford, California 94305 (United States); and others

    2016-03-15

    X-ray magnetic circular dichroism spectroscopy using an X-ray free electron laser is demonstrated with spectra over the Fe L{sub 3,2}-edges. The high brightness of the X-ray free electron laser combined with high accuracy detection of incident and transmitted X-rays enables ultrafast X-ray magnetic circular dichroism studies of unprecedented sensitivity. This new capability is applied to a study of all-optical magnetic switching dynamics of Fe and Gd magnetic sublattices in a GdFeCo thin film above its magnetization compensation temperature.

  17. Bone x-ray

    Science.gov (United States)

    ... or broken bone Bone tumors Degenerative bone conditions Osteomyelitis (inflammation of the bone caused by an infection) ... Multiple myeloma Osgood-Schlatter disease Osteogenesis imperfecta Osteomalacia Osteomyelitis Paget disease of the bone Rickets X-ray ...

  18. Hand x-ray

    Science.gov (United States)

    ... include fractures, bone tumors , degenerative bone conditions, and osteomyelitis (inflammation of the bone caused by an infection). ... chap 46. Read More Bone tumor Broken bone Osteomyelitis X-ray Review Date 9/8/2014 Updated ...

  19. Pelvis x-ray

    Science.gov (United States)

    X-ray - pelvis ... Tumors Degenerative conditions of bones in the hips, pelvis, and upper legs ... hip joint Tumors of the bones of the pelvis Sacroiliitis (inflammation of the area where the sacrum ...

  20. Chest X-Ray

    Medline Plus

    Full Text Available ... and use a very small dose of ionizing radiation to produce pictures of the inside of the ... x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs ...

  1. Chest X-Ray

    Medline Plus

    Full Text Available ... Index A-Z Spotlight October is National Breast Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography ( ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  2. Chest X-Ray

    Medline Plus

    Full Text Available ... chest x-ray is used to evaluate the lungs, heart and chest wall and may be used ... diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A ...

  3. X-ray - skeleton

    Science.gov (United States)

    ... x-ray particles pass through the body. A computer or special film records the images. Structures that ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  4. X-Ray Diffraction.

    Science.gov (United States)

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  5. Chest X-Ray

    Medline Plus

    Full Text Available ... breath, persistent cough, fever, chest pain or injury. It may also be useful to help diagnose and ... have some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to ...

  6. X-Ray Diffraction.

    Science.gov (United States)

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  7. Chest X-Ray

    Medline Plus

    Full Text Available ... breath, persistent cough, fever, chest pain or injury. It may also be useful to help diagnose and ... have some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to ...

  8. Chest X-Ray

    Medline Plus

    Full Text Available ... CT Angiography Video: Myelography Video: CT of the Heart Video: Radioiodine I-131 Therapy Radiology and You ... x-ray is used to evaluate the lungs, heart and chest wall and may be used to ...

  9. X-Ray Detector Simulations - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Tina, Adrienne [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-20

    The free-electron laser at LCLS produces X-Rays that are used in several facilities. This light source is so bright and quick that we are capable of producing movies of objects like proteins. But making these movies would not be possible without a device that can detect the X-Rays and produce images. We need X-Ray cameras. The challenges LCLS faces include the X-Rays’ high repetition rate of 120 Hz, short pulses that can reach 200 femto-seconds, and extreme peak brightness. We need detectors that are compatible with this light source, but before they can be used in the facilities, they must first be characterized. My project was to do just that, by making a computer simulation program. My presentation discusses the individual detectors I simulated, the details of my program, and how my project will help determine which detector is most useful for a specific experiment.

  10. Ultraluminous x-ray sources: an observational review

    Directory of Open Access Journals (Sweden)

    G. Fabbiano

    2004-01-01

    Full Text Available Las fuentes ultraluminosas en rayos X (ULXs son, como su propio nombre indica, emisores extremadamente luminosos en rayos X, adem as de objetos relativamente poco frecuentes en galaxias. Debido a su luminosidad, se ha sugerido que pueden ser producidos por un fen omeno de acreci on a un agujero negro (BH de unos cientos de M , es decir, a un agujero negro m as masivo que el que se podr a originar a partir del proceso de evoluci on estelar normal. Hay modelos alternativos que incluyen remanentes j ovenes de supernovas (SNRs, emisi on dirigida en forma de haz desde un agujero negro normal perteneciente al sistema binario emisor en rayos X (XRB y con un alto ritmo de acreci on, o bien, sistemas binarios con emisi on en rayos X que emiten un haz con velocidades relativistas. La evidencia observacional sugiere que, aunque la mayor a de estos objetos parecen ser objetos acrecientes compactos, no hay una evidencia clara de si estamos ante un sistema binario emisor de un haz dirigido en rayos X, o bien, ante un agujero negro acreciente muy masivo. Es posible que lo que se denomina ULXs sea una familia heterog enea de fuentes de rayos X.

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... holds the x-ray film or image recording plate . Sometimes the x-ray is taken with the ... an x-ray film holder or image recording plate is placed beneath the patient. top of page ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) ... diagnosis and disease management. top of page How is the procedure performed? The technologist, an individual specially ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... holds the x-ray film or image recording plate . Sometimes the x-ray is taken with the ... an x-ray film holder or image recording plate is placed beneath the patient. top of page ...

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... that might interfere with the x-ray images. Women should always inform their physician and x-ray ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  16. Galaxies in x-ray selected clusters and groups in Dark Energy Survey Data I: Stellar mass growth of bright central galaxies since Z similar to 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Miller, C.; McKay, T.; Rooney, P.; Evrard, A. E.; Romer, A. K.; Perfecto, R.; Song, J; Desai, S.; Mohr, J. J.; Vikram, V.

    2016-01-10

    Using the science verification data of the Dark Energy Survey for a new sample of 106 X-ray selected clusters and groups, we study the stellar mass growth of bright central galaxies (BCGs) since redshift z similar to 1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into an analysis of a redshift-dependent BCG-cluster mass relation, m(*) proportional to (M-200/1.5 x 10(14)M(circle dot))(0.24 +/- 0.08)(1+z)(-0.19 +/- 0.34), and compare the observed relation to the model prediction. We estimate the average growth rate since z = 1.0 for BCGs hosted by clusters of M-200,M-z = 10(13.8)M(circle dot); at z = 1.0: m(*, BCG) appears to have grown by 0.13 +/- 0.11 dex, in tension at the similar to 2.5 sigma significance level with the 0.40 dex growth rate expected from the semi-analytic model. We show that the build-up of extended intracluster light after z = 1.0 may alleviate this tension in BCG growth rates.

  17. X-Rays from Saturn and its Rings

    Science.gov (United States)

    Bhardwaj, Anil; Elsner, Ron F.; Waite, J. Hunter; Gladstone, G. Randall; Cravens, Tom E.; Ford, Peter G.

    2005-01-01

    In January 2004 Saturn was observed by Chandra ACIS-S in two exposures, 00:06 to 11:00 UT on 20 January and 14:32 UT on 26 January to 01:13 UT on 27 January. Each continuous observation lasted for about one full Saturn rotation. These observations detected an X-ray flare from the Saturn's disk and indicate that the entire Saturnian X-ray emission is highly variable -- a factor of $\\sim$4 variability in brightness in a week time. The Saturn X-ray flare has a time and magnitude matching feature with the solar X-ray flare, which suggests that the disk X-ray emission of Saturn is governed by processes happening on the Sun. These observations also unambiguously detected X-rays from Saturn's rings. The X-ray emissions from rings are present mainly in the 0.45-0.6 keV band centered on the atomic OK$\\alpha$ fluorescence line at 525 eV: indicating the production of X-rays due to oxygen atoms in the water icy rings. The characteristics of X-rays from Saturn's polar region appear to be statistically consistent with those from its disk X-rays, suggesting that X-ray emission from the polar cap region might be an extension of the Saturn disk X-ray emission.

  18. Current Problems in X-Ray Emission Spectroscopy

    Science.gov (United States)

    Goldstein, Joseph I.; Williams, David B.; Lyman, Charles E.

    1989-01-01

    Various problems that limit X-ray analysis in the analytical electron microscope are reviewed. Major emphasis is given to the trade-off between minimum mass fraction and spatial resolution. New developments such as high-brightness electron guns, new X-ray spectrometers and clean high-vacuum analysis conditions will lead to major improvements in the accuracy and detectability limits of X-ray emission spectroscopy.

  19. X-Ray Absorption with Transmission X-Ray Microscopes

    NARCIS (Netherlands)

    de Groot, F.M.F.

    2016-01-01

    In this section we focus on the use of transmission X-ray microscopy (TXM) to measure the XAS spectra. In the last decade a range of soft X-ray and hard X-ray TXM microscopes have been developed, allowing the measurement of XAS spectra with 10–100 nm resolution. In the hard X-ray range the TXM

  20. X-ray Pulsars

    CERN Document Server

    Walter, Roland

    2016-01-01

    X-ray pulsars shine thanks to the conversion of the gravitational energy of accreted material to X-ray radiation. The accretion rate is modulated by geometrical and hydrodynamical effects in the stellar wind of the pulsar companions and/or by instabilities in accretion discs. Wind driven flows are highly unstable close to neutron stars and responsible for X-ray variability by factors $10^3$ on time scale of hours. Disk driven flows feature slower state transitions and quasi periodic oscillations related to orbital motion and precession or resonance. On shorter time scales, and closer to the surface of the neutron star, X-ray variability is dominated by the interactions of the accreting flow with the spinning magnetosphere. When the pulsar magnetic field is large, the flow is confined in a relatively narrow accretion column, whose geometrical properties drive the observed X-ray emission. In low magnetized systems, an increasing accretion rate allows the ignition of powerful explosive thermonuclear burning at t...

  1. The SAS-3 X-ray observatory

    Science.gov (United States)

    Mayer, W. F.

    1975-01-01

    The experiment section of the Small Astronomy Satellite-3 (SAS-3) launched in May 1975 is an X-ray observatory intended to determine the location of bright X-ray sources to an accuracy of 15 arc-seconds; to study a selected set of sources over a wide energy range, from 0.1 to 55 keV, while performing very specific measurements of the spectra and time variability of known X-ray sources; and to monitor the sky continuously for X-ray novae, flares, and unexpected phenomena. The improvements in SAS-3 spacecraft include a clock accurate to 1 part in 10 billion, rotatable solar panels, a programmable data format, and improved nutation damper, a delayed command system, improved magnetic trim and azimuth control systems. These improvements enable SAS-3 to perform three-axis stabilized observations of any point on the celestial sphere at any time of the year. The description of the experiment section and the SAS-3 operation is followed by a synopsis of scientific results obtained from the observations of X-ray sources, such as Vela X-1 (supposed to be an accreting neutron star), a transient source of hard X-ray (less than 36 min in duration) detected by SAS-3, the Crab Nebula pulsar, the Perseus cluster of galaxies, and the Vela supernova remnant.

  2. X-Ray Protection

    Science.gov (United States)

    1955-01-01

    15,000. • When developed In Kodak liquid X-ray developer for 5 min at a temperature of 200 C. b Film sensitivities vary with photon energy by the...for example temporomandibular -joint exposures where a skin dose of 25 r or more may be obtained during a single exposure with 65 kvp, 1.5 mm aluminum...communication. W. J. Updegrave, Temporomandibular articulation-X-ray examina- tion, Dental Radiography and Photography 26, No. 3, 41 (1953). H. 0. Wyckoff, R. J

  3. X-ray Reflection

    Science.gov (United States)

    Fabian, A. C.; Ross, R. R.

    2010-12-01

    Material irradiated by X-rays produces backscattered radiation which is commonly known as the Reflection Spectrum. It consists of a structured continuum, due at high energies to the competition between photoelectric absorption and electron scattering enhanced at low energies by emission from the material itself, together with a complex line spectrum. We briefly review the history of X-ray reflection in astronomy and discuss various methods for computing the reflection spectrum from cold and ionized gas, illustrated with results from our own work reflionx. We discuss how the reflection spectrum can be used to obtain the geometry of the accretion flow, particularly the inner regions around black holes and neutron stars.

  4. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a very small dose of ... x-ray , is a two-dimensional (2-D) dental x-ray examination that captures the entire mouth ...

  5. Optical Counterparts of Ultra Luminous X-ray Sources

    CERN Document Server

    Gutíerrez, C M

    2006-01-01

    We present optical identification and characterization of counterparts of four objects previously catalogued as ultra-luminous X-ray sources. The objects were selected from the Colbert & Ptak (2002) catalogue. The optical counterparts are identified as point-like objects with magnitudes in the range \\~17-19. The optical spectra of three of the sources (IXO 32, 37 and 40) show the presence of emission lines typical of quasars. The position of these lines allows a precise estimation of their redshifts (2.769, 0.567 and 0.789 for IXO 32, 37 and 40 respectively). The fourth X-ray source, IXO35, is associated with a red object that has a spectrum typical of an M star in our Galaxy. These identifications are useful for building clean samples of ULX sources, selecting suitable targets for future observations and performing statistical studies on the different populations of X-ray sources.

  6. Chest X-Ray

    Medline Plus

    Full Text Available ... Therapy November 8 is the International Day of Radiology (IDoR) Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  7. Local Ultraluminous Infrared Galaxies and Quasars

    CERN Document Server

    Veilleux, S

    2006-01-01

    This paper reviews the recent results from a comprehensive investigation of the most luminous mergers in the local universe, the ultraluminous infrared galaxies (ULIRGs) and the quasars. First, the frequency of occurrence and importance of black hole driven nuclear activity in ULIRGs are discussed using the latest sets of optical, near-infrared, mid-infrared, and X-ray spectra on these objects. Obvious trends with luminosity, infrared color, and morphology are pointed out. Next, the host galaxy properties of ULIRGs are described in detail and then compared with local quasar hosts and inactive spheroids. By and large, these data are consistent with the scenario where ULIRGs are intermediate-mass elliptical galaxies in formation and in the process of becoming moderate-luminosity optical quasars. The powerful galactic winds detected in many ULIRGs may help shed any excess gas during this transformation. However, this evolutionary scenario does not seem to apply to all ULIRGs and quasars: Ultraluminous infrared m...

  8. Model Atmospheres for X-ray Bursting Neutron Stars

    CERN Document Server

    Medin, Zach; Calder, Alan C; Fontes, Christopher J; Fryer, Chris L; Hungerford, Aimee L

    2016-01-01

    The hydrogen and helium accreted by X-ray bursting neutron stars is periodically consumed in runaway thermonuclear reactions that cause the entire surface to glow brightly in X-rays for a few seconds. With models of the emission, the mass and radius of the neutron star can be inferred from the observations. By simultaneously probing neutron star masses and radii, X-ray bursts are one of the strongest diagnostics of the nature of matter at extremely high densities. Accurate determinations of these parameters are difficult, however, due to the highly non-ideal nature of the atmospheres where X-ray bursts occur. Observations from X-ray telescopes such as RXTE and NuStar can potentially place strong constraints on nuclear matter once uncertainties in atmosphere models have been reduced. Here we discuss current progress on modeling atmospheres of X-ray bursting neutron stars and some of the challenges still to be overcome.

  9. Nonlinear X-ray Compton Scattering

    CERN Document Server

    Fuchs, Matthias; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P H; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack; Hart, Philip; Kenney, Christopher; Guillet, Serge; Boutet, Sebastien; Williams, Garth; Messerschmidt, Marc; Seibert, Marvin; Moeller, Stefan; Hastings, Jerome B; Reis, David A

    2015-01-01

    X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrashort pulses. However, in the focus of an XFEL the assumption of a weak linear probe breaks down, and nonlinear light-matter interactions can become ubiquitous. The field can be sufficiently high that even non-resonant multiphoton interactions at hard X-rays wavelengths become relevant. Here we report the observation of one of the most fundamental nonlinear X-ray-matter interactions, the simultaneous Compton scattering of two identical photons producing a single photon at nearly twice the photon energy. We measure scattered...

  10. Supergiant Fast X-ray Transients

    CERN Document Server

    Sidoli, Lara

    2011-01-01

    The phenomenology of a subclass of High Mass X-ray Binaries hosting a blue supergiant companion, the so-called Supergiant Fast X-ray Transients (SFXTs), is reviewed. Their number is growing, mainly thanks to the discoveries performed by the INTEGRAL satellite, then followed by soft X-rays observations (both aimed at refining the source position and at monitoring the source behavior) leading to the optical identification of the blue supergiant nature of the donor star. Their defining properties are a transient X-ray activity consisting of sporadic, fast and bright flares, (each with a variable duration between a few minutes and a few hours), reaching 1E36-1E37 erg/s. The quiescence is at a luminosity of 1E32 erg/s, while their more frequent state consists of an intermediate X-ray emission of 1E33-1E34 erg/s (1-10 keV). Only the brightest flares are detected by INTEGRAL (>17 keV) during short pointings, with no detected persistent emission. The physical mechanism driving the short outbursts is still debated, al...

  11. Outbursts in ultracompact X-ray binaries

    CERN Document Server

    Hameury, J -M

    2016-01-01

    Very faint X-ray binaries appear to be transient in many cases with peak luminosities much fainter than that of usual soft X-ray transients, but their nature still remains elusive. We investigate the possibility that this transient behaviour is due to the same thermal/viscous instability which is responsible for outbursts of bright soft X-ray transients, occurring in ultracompact binaries for adequately low mass-transfer rates. More generally, we investigate the observational consequences of this instability when it occurs in ultracompact binaries. We use our code for modelling the thermal-viscous instability of the accretion disc, assumed here to be hydrogen poor. We also take into account the effects of disc X-ray irradiation, and consider the impact of the mass-transfer rate on the outburst brightness. We find that one can reproduce the observed properties of both the very faint and the brighter short transients (peak luminosity, duration, recurrence times), provided that the viscosity parameter in quiesce...

  12. Optical and X-ray observations of the low-mass X-ray binary EXO 0748-676

    Science.gov (United States)

    Thomas, Brian; Corbet, Robin; Augusteijn, Thomas; Callanan, Paul; Smale, Alan P.

    1993-01-01

    Optical and X-ray observations of EXO-676 in late March 1989 are presented. Our optical observations provide some support for the previously observed correlation between the mean optical brightness and light curve morphology. Unexpectedly, the mean X-ray and optical flux levels during this period do not reflect similar system states. The optical counterpart is found to be in an intermediate to low state, while X-ray data imply a bright (high) state. The changed relationship between optical and X-ray fluxes is evidence showing that EXO 0748-676 has possibly evolved. We fail to find correlated variability in simultaneous X-ray and optical observations. The lack of covariability is attributed to the limited simultaneous coverage of the source and/or significant geometric modulation in the optical light curve.

  13. X-Ray Astronomy

    Science.gov (United States)

    Wu, S. T.

    2000-01-01

    Dr. S. N. Zhang has lead a seven member group (Dr. Yuxin Feng, Mr. XuejunSun, Mr. Yongzhong Chen, Mr. Jun Lin, Mr. Yangsen Yao, and Ms. Xiaoling Zhang). This group has carried out the following activities: continued data analysis from space astrophysical missions CGRO, RXTE, ASCA and Chandra. Significant scientific results have been produced as results of their work. They discovered the three-layered accretion disk structure around black holes in X-ray binaries; their paper on this discovery is to appear in the prestigious Science magazine. They have also developed a new method for energy spectral analysis of black hole X-ray binaries; four papers on this topics were presented at the most recent Atlanta AAS meeting. They have also carried Monte-Carlo simulations of X-ray detectors, in support to the hardware development efforts at Marshall Space Flight Center (MSFC). These computation-intensive simulations have been carried out entirely on the computers at UAH. They have also carried out extensive simulations for astrophysical applications, taking advantage of the Monte-Carlo simulation codes developed previously at MSFC and further improved at UAH for detector simulations. One refereed paper and one contribution to conference proceedings have been resulted from this effort.

  14. X-ray lithography masking

    Science.gov (United States)

    Smith, Henry I. (Inventor); Lim, Michael (Inventor); Carter, James (Inventor); Schattenburg, Mark (Inventor)

    1998-01-01

    X-ray masking apparatus includes a frame having a supporting rim surrounding an x-ray transparent region, a thin membrane of hard inorganic x-ray transparent material attached at its periphery to the supporting rim covering the x-ray transparent region and a layer of x-ray opaque material on the thin membrane inside the x-ray transparent region arranged in a pattern to selectively transmit x-ray energy entering the x-ray transparent region through the membrane to a predetermined image plane separated from the layer by the thin membrane. A method of making the masking apparatus includes depositing back and front layers of hard inorganic x-ray transparent material on front and back surfaces of a substrate, depositing back and front layers of reinforcing material on the back and front layers, respectively, of the hard inorganic x-ray transparent material, removing the material including at least a portion of the substrate and the back layers of an inside region adjacent to the front layer of hard inorganic x-ray transparent material, removing a portion of the front layer of reinforcing material opposite the inside region to expose the surface of the front layer of hard inorganic x-ray transparent material separated from the inside region by the latter front layer, and depositing a layer of x-ray opaque material on the surface of the latter front layer adjacent to the inside region.

  15. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a ... Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your privacy. Information entered here ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body. X-rays are the oldest and most frequently used form of medical imaging. A bone ... bones. top of page How should I prepare? Most bone x-rays require no special preparation. You ...

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... tissue shows up in shades of gray and air appears black. Until recently, x-ray images were ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  18. Soft X-ray Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Seely, John

    1999-05-20

    The contents of this report cover the following: (1) design of the soft x-ray telescope; (2) fabrication and characterization of the soft x-ray telescope; and (3) experimental implementation at the OMEGA laser facility.

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? A bone x-ray is used to: ... and x-rays. top of page What does the equipment look like? The equipment typically used for ...

  20. Bone X-Ray (Radiography)

    Science.gov (United States)

    ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Us News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses ... assess trauma patients in emergency departments. A CT scan can image complicated fractures, subtle fractures or dislocations. ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that ...

  5. Abdomen X-Ray (Radiography)

    Science.gov (United States)

    ... Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very small dose ... to produce pictures of the inside of the abdominal cavity. It is used to evaluate the stomach, liver, ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... radiation like light or radio waves. X-rays pass through most objects, including the body. Once it ... organs, allow more of the x-rays to pass through them. As a result, bones appear white ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... and x-rays. A Word About Minimizing Radiation Exposure Special care is taken during x-ray examinations ... patient's body not being imaged receive minimal radiation exposure. top of page What are the limitations of ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement and fracture reductions. look for injury, ... and Media Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to X-ray ( ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? A bone x-ray is used to: ... and x-rays. top of page What does the equipment look like? The equipment typically used for ...

  11. X-Ray Exam: Hip

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Hip KidsHealth > For Parents > X-Ray Exam: Hip A A A What's in ... español Radiografía: cadera What It Is A hip X-ray is a safe and painless test that ...

  12. X-Ray Exam: Finger

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Finger KidsHealth > For Parents > X-Ray Exam: Finger A A A What's in ... español Radiografía: dedo What It Is A finger X-ray is a safe and painless test that ...

  13. X-Ray Exam: Foot

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Foot KidsHealth > For Parents > X-Ray Exam: Foot A A A What's in ... español Radiografía: pie What It Is A foot X-ray is a safe and painless test that ...

  14. X-Ray Exam: Wrist

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Wrist KidsHealth > For Parents > X-Ray Exam: Wrist A A A What's in ... español Radiografía: muñeca What It Is A wrist X-ray is a safe and painless test that ...

  15. X-Ray Exam: Ankle

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Ankle KidsHealth > For Parents > X-Ray Exam: Ankle A A A What's in ... español Radiografía: tobillo What It Is An ankle X-ray is a safe and painless test that ...

  16. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Pelvis KidsHealth > For Parents > X-Ray Exam: Pelvis A A A What's in ... español Radiografía: pelvis What It Is A pelvis X-ray is a safe and painless test that ...

  17. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Forearm KidsHealth > For Parents > X-Ray Exam: Forearm A A A What's in ... español Radiografía: brazo What It Is A forearm X-ray is a safe and painless test that ...

  18. X-ray Crystallography Facility

    Science.gov (United States)

    2000-01-01

    Edward Snell, a National Research Council research fellow at NASA's Marshall Space Flight Center (MSFC), prepares a protein crystal for analysis by x-ray crystallography as part of NASA's structural biology program. The small, individual crystals are bombarded with x-rays to produce diffraction patterns, a map of the intensity of the x-rays as they reflect through the crystal.

  19. Planetary X-ray studies: past, present and future

    Science.gov (United States)

    Branduardi-Raymont, Graziella

    2016-07-01

    Our solar system is a fascinating physics laboratory and X-ray observations are now firmly established as a powerful diagnostic tool of the multiple processes taking place in it. The science that X-rays reveal encompasses solar, space plasma and planetary physics, and the response of bodies in the solar system to the impact of the Sun's activity. This talk will review what we know from past observations and what we expect to learn in the short, medium and long term. Observations with Chandra and XMM-Newton have demonstrated that the origin of Jupiter's bright soft X-ray aurorae lies in the Charge eXchange (CX) process, likely to involve the interaction with atmospheric neutrals of local magnetospheric ions, as well as those carried in the solar wind. At higher energies electron bremsstrahlung is thought to be the X-ray emitting mechanism, while the whole planetary disk acts as a mirror for the solar X-ray flux via Thomson and fluorescent scattering. This 'X-ray mirror' phenomenon is all that is observed from Saturn's disk, which otherwise lacks X-ray auroral features. The Earth's X-ray aurora is bright and variable and mostly due to electron bremsstrahlung and line emission from atmospheric species. Un-magnetised planets, Venus and Mars, do not show X-ray aurorae but display the interesting combination of mirroring the solar X-ray flux and producing X-rays by Solar Wind Charge eXchange (SWCX) in their exospheres. These processes respond to different solar stimulation (photons and solar wind plasma respectively) hence their relative contributions are seen to vary according to the Sun's output. Present and future of planetary X-ray studies are very bright. We are preparing for the arrival of the Juno mission at Jupiter this summer and for coordinated observations with Chandra and XMM-Newton on the approach and later during Juno's orbital phase. These will allow direct correlation of the local plasma conditions with the X-ray emissions and the establishment of the

  20. SMM x ray polychromator

    Science.gov (United States)

    Saba, J. L. R.

    1993-01-01

    The objective of the X-ray Polychromator (XRP) experiment was to study the physical properties of solar flare plasma and its relation to the parent active region to understand better the flare mechanism and related solar activity. Observations were made to determine the temperature, density, and dynamic structure of the pre-flare and flare plasma as a function of wavelength, space and time, the extent to which the flare plasma departs from thermal equilibrium, and the variation of this departure with time. The experiment also determines the temperature and density structure of active regions and flare-induced changes in the regions.

  1. X-ray today

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, U. [Philips Medical Systems, Hamburg (Germany)

    2001-09-01

    The interest attracted by the new imaging modalities tends to overshadow the continuing importance of projection radiography and fluoroscopy. Nevertheless, projection techniques still represent by far the greatest proportion of diagnostic imaging examinations, and play an essential role in the growing number of advanced interventional procedures. This article describes some of the latest developments in X-ray imaging technology, using two products from the Philips range as examples: the Integris Allura cardiovascular system with 3D image reconstruction, and the BV Pulsera: a high-end, multi-functional mobile C-arm system with cardiac capabilities. (orig.)

  2. XMM-Newton observation of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.326

    Science.gov (United States)

    Ai, Yanli; Fabian, A. C.; Fan, Xiaohui; Walker, S. A.; Ghisellini, G.; Sbarrato, T.; Dou, Liming; Wang, Feige; Wu, Xue-Bing; Feng, Longlong

    2017-09-01

    A brief Chandra observation of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.326 showed it to be a relatively bright, soft X-ray source with a count rate of about 1 count ks-1. In this article, we present results for the quasar from a 65-ks XMM-Newton observation, which constrains its spectral shape well. The quasar is clearly detected with a total of ∼460 net counts in the 0.2-10 keV band. The spectrum is characterized by a simple power-law model with a photon index of Γ = 2.30^{+0.10}_{-0.10} and the intrinsic 2-10 keV luminosity is 3.14 × 1045 erg s-1. The 1σ upper limit to any intrinsic absorption column density is NH = 6.07 × 1022 cm-2. No significant iron emission lines were detected. We derive an X-ray-to-optical flux ratio αox of -1.74 ± 0.01, consistent with the values found in other quasars of comparable ultraviolet luminosity. We did not detect significant flux variations either in the XMM-Newton exposure or between XMM-Newton and Chandra observations, which are separated by ∼8 months. The X-ray observation enables the bolometric luminosity to be calculated after modelling the spectral energy distribution: the accretion rate is found to be sub-Eddington.

  3. X-ray lithography source

    Science.gov (United States)

    Piestrup, Melvin A.; Boyers, David G.; Pincus, Cary

    1991-01-01

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

  4. Optically thick outflows in ultraluminous supersoft sources

    CERN Document Server

    Urquhart, Ryan

    2015-01-01

    Ultraluminous supersoft sources (ULSs) are defined by a thermal spectrum with colour temperatures ~0.1 keV, bolometric luminosities ~ a few 10^39 erg/s, and almost no emission above 1 keV. It has never been clear how they fit into the general scheme of accreting compact objects. To address this problem, we studied a sample of seven ULSs with extensive Chandra and XMM-Newton coverage. We find an anticorrelation between fitted temperatures and radii of the thermal emitter, and no correlation between bolometric luminosity and radius or temperature. We compare the physical parameters of ULSs with those of classical supersoft sources, thought to be surface-nuclear-burning white dwarfs, and of ultraluminous X-ray sources (ULXs), thought to be super-Eddington stellar-mass black holes. We argue that ULSs are the sub-class of ULXs seen through the densest wind, perhaps an extension of the soft-ultraluminous regime. We suggest that in ULSs, the massive disk outflow becomes effectively optically thick and forms a large ...

  5. A mirror for lab-based quasi-monochromatic parallel x-rays.

    Science.gov (United States)

    Nguyen, Thanhhai; Lu, Xun; Lee, Chang Jun; Jung, Jin-Ho; Jin, Gye-Hwan; Kim, Sung Youb; Jeon, Insu

    2014-09-01

    A multilayered parabolic mirror with six W/Al bilayers was designed and fabricated to generate monochromatic parallel x-rays using a lab-based x-ray source. Using this mirror, curved bright bands were obtained in x-ray images as reflected x-rays. The parallelism of the reflected x-rays was investigated using the shape of the bands. The intensity and monochromatic characteristics of the reflected x-rays were evaluated through measurements of the x-ray spectra in the band. High intensity, nearly monochromatic, and parallel x-rays, which can be used for high resolution x-ray microscopes and local radiation therapy systems, were obtained.

  6. A mirror for lab-based quasi-monochromatic parallel x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thanhhai; Lu, Xun; Lee, Chang Jun; Jeon, Insu, E-mail: i-jeon@chonnam.ac.kr [School of Mechanical Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of); Jung, Jin-Ho [Pro-optics Co., Ltd., 475 Ami-ri, Bubal-eup, Icheon 467-866 (Korea, Republic of); Jin, Gye-Hwan [Department of Radiology, Nambu University, 76 Chumdan Jungang 1-ro, Gwangsan-gu, Gwangju 506-706 (Korea, Republic of); Kim, Sung Youb [School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology, 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of)

    2014-09-15

    A multilayered parabolic mirror with six W/Al bilayers was designed and fabricated to generate monochromatic parallel x-rays using a lab-based x-ray source. Using this mirror, curved bright bands were obtained in x-ray images as reflected x-rays. The parallelism of the reflected x-rays was investigated using the shape of the bands. The intensity and monochromatic characteristics of the reflected x-rays were evaluated through measurements of the x-ray spectra in the band. High intensity, nearly monochromatic, and parallel x-rays, which can be used for high resolution x-ray microscopes and local radiation therapy systems, were obtained.

  7. Multi-Kilovolt X-Ray Conversion Efficiencies

    Energy Technology Data Exchange (ETDEWEB)

    Back, C A; Davis, J L; Grun, J; Landen, O L; Miller, M C; Suter, L J

    2001-08-23

    X-ray sources in the 3-7 keV energy regime can be produced by laser-irradiating mid- and high-Z gas-filled targets with high-powered lasers. A series of experiments have been performed using underdense targets that are supersonically heated with {approx} 35 kJ of 0.35 {micro}m laser light. These targets were cylindrical Be enclosures that were filled with 1-2 atms of Xe or Ar gas. L-shell x-ray emission is emitted from the plasma and detected by Bragg crystal spectrometers and x-ray diodes. Absolute flux measurements show conversion efficiencies of {approx} 10% in the multi-kilovolt x-ray emission. These sources can be used as bright x-ray backlighters or for material testing.

  8. IPC two-color analysis of x ray galaxy clusters

    Science.gov (United States)

    White, Raymond E., III

    1990-01-01

    The mass distributions were determined of several clusters of galaxies by using X ray surface brightness data from the Einstein Observatory Imaging Proportional Counter (IPC). Determining cluster mass distributions is important for constraining the nature of the dark matter which dominates the mass of galaxies, galaxy clusters, and the Universe. Galaxy clusters are permeated with hot gas in hydrostatic equilibrium with the gravitational potentials of the clusters. Cluster mass distributions can be determined from x ray observations of cluster gas by using the equation of hydrostatic equilibrium and knowledge of the density and temperature structure of the gas. The x ray surface brightness at some distance from the cluster is the result of the volume x ray emissivity being integrated along the line of sight in the cluster.

  9. Preheating of the early universe by radiation from high-mass X-ray binaries

    Science.gov (United States)

    Sazonov, S. Yu.; Khabibullin, I. I.

    2017-04-01

    Using a reliablymeasured intrinsic (i.e., corrected for absorption effects) present-day luminosity function of high-mass X-ray binaries (HMXBs) in the 0.25-2 keV energy band per unit star formation rate, we estimate the preheating of the early Universe by soft X-rays from such systems. We find that X-ray irradiation, mainly executed by ultraluminous and supersoft ultraluminous X-ray sources with luminosity L X > 1039 erg s-1, could significantly heat ( T > T CMB, where T CMB is the temperature of the cosmic microwave background) the intergalactic medium by z 10 if the specific X-ray emissivity of the young stellar population in the early Universe was an order of magnitude higher than at the present epoch (which is possible due to the low metallicity of the first galaxies) and the soft X-ray emission from HMXBs did not suffer strong absorption within their galaxies. This makes it possible to observe the 21 cm line of neutral hydrogen in emission from redshifts z < 10.

  10. Optical and X-ray Outbursts of Be/X-ray binary system SAX J2103.5+4545

    CERN Document Server

    Kiziloglu, U; Kiziloglu, N; Baykal, A

    2009-01-01

    We present the relations between Halpha equivalent width, optical brightness and X-ray flux of Be/X-ray binary system SAX J2103.5+4545, by analyzing the optical photometric and spectroscopic observations together with the X-ray observations. In the photometric observations PSF photometry were applied using MIDAS and its DAOPHOT package. The reduction and analysis of spectra were done by using MIDAS and its suitable packages. The X-ray outburst of the system occurred just after the optical outburst. The nearly symmetric Halpha emission line profiles observed during the beginning of optical outburst turn into asymmetric profiles with increased EW values during the dissipation of Be disc. Halpha lines changed from emission to absorption during the observation period. The observed double peaked HeI emission lines might come from the accretion disc of neutron star which is temporarily formed at the time of X-ray outburst.

  11. Optical Identifications of X-ray Selected AGNs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    For investigating the statistical properties of X-ray selected Active Galactic Nuclei (AGNs), we have carried out a program of optical identification of a selection of X-ray sources from ROSAT All Sky Survey Bright Source Catalogue (RASS-BSC) using the 2.16 m telescope of Beijing Astronomical Observatory (BAO). In the preliminary observations, 23 new AGNs were discovered, of which 9 are quasars, and 14 are Seyfert galaxies.

  12. Topological X-Rays Revisited

    Science.gov (United States)

    Lynch, Mark

    2012-01-01

    We continue our study of topological X-rays begun in Lynch ["Topological X-rays and MRI's," iJMEST 33(3) (2002), pp. 389-392]. We modify our definition of a topological magnetic resonance imaging and give an affirmative answer to the question posed there: Can we identify a closed set in a box by defining X-rays to probe the interior and without…

  13. X-ray instrumentation for SR beamlines

    CERN Document Server

    Kovalchuk, M V; Zheludeva, S I; Aleshko-Ozhevsky, O P; Arutynyan, E H; Kheiker, D M; Kreines, A Y; Lider, V V; Pashaev, E M; Shilina, N Y; Shishkov, V A

    2000-01-01

    The main possibilities and parameters of experimental X-ray stations are presented: 'Protein crystallography', 'X-ray structure analysis', 'High-precision X-ray optics', 'X-ray crystallography and material science', 'X-ray topography', 'Photoelectron X-ray standing wave' that are being installed at Kurchatov SR source by A.V. Shubnikov Institute of Crystallography.

  14. X-ray Fluorescence Sectioning

    CERN Document Server

    Cong, Wenxiang

    2012-01-01

    In this paper, we propose an x-ray fluorescence imaging system for elemental analysis. The key idea is what we call "x-ray fluorescence sectioning". Specifically, a slit collimator in front of an x-ray tube is used to shape x-rays into a fan-beam to illuminate a planar section of an object. Then, relevant elements such as gold nanoparticles on the fan-beam plane are excited to generate x-ray fluorescence signals. One or more 2D spectral detectors are placed to face the fan-beam plane and directly measure x-ray fluorescence data. Detector elements are so collimated that each element only sees a unique area element on the fan-beam plane and records the x-ray fluorescence signal accordingly. The measured 2D x-ray fluorescence data can be refined in reference to the attenuation characteristics of the object and the divergence of the beam for accurate elemental mapping. This x-ray fluorescence sectioning system promises fast fluorescence tomographic imaging without a complex inverse procedure. The design can be ad...

  15. Soft X-ray optics

    CERN Document Server

    Spiller, Eberhard A

    1993-01-01

    This text describes optics mainly in the 10 to 500 angstrom wavelength region. These wavelengths are 50 to 100 times shorter than those for visible light and 50 to 100 times longer than the wavelengths of medical x rays or x-ray diffraction from natural crystals. There have been substantial advances during the last 20 years, which one can see as an extension of optical technology to shorter wavelengths or as an extension of x-ray diffraction to longer wavelengths. Artificial diffracting structures like zone plates and multilayer mirrors are replacing the natural crystals of x-ray diffraction.

  16. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

  17. Modeling X-ray Emission Around Galaxies

    CERN Document Server

    Anderson, Michael E

    2014-01-01

    Extended X-ray emission can be studied either spatially (through its surface brightness profile) or spectrally (by analyzing the spectrum at various locations in the field). Both techniques have advantages and disadvantages, and when the emission becomes particularly faint and/or extended, the two methods can disagree. We argue that an ideal approach would be to model the events file directly, and therefore to use both the spectral and spatial information which are simultaneously available for each event. In this work we propose a first step in this direction, introducing a method for spatial analysis which can be extended to leverage spectral information simultaneously. We construct a model for the entire X-ray image in a given energy band, and generate a likelihood function to compare the model to the data. A critical goal of this modeling is disentangling vignetted and unvignetted backgrounds through their different spatial distributions. Employing either maximum likelihood or Markov Chain Monte Carlo, we ...

  18. Optical-faint, Far-infrared-bright Herschel Sources in the CANDELS Fields: Ultra-Luminous Infrared Galaxies at z>1 and the Effect of Source Blending

    CERN Document Server

    Yan, Haojing; Ma, Zhiyuan; Willner, Steven; Somerville, Rachel; Ashby, Matthew; Dave, Romeel; Perez-Gonzalez, Pablo G; Cava, Antonio; Wiklind, Tommy; Kocevski, Dale; Rafelski, Marc; Kartaltepe, Jeyhan; Cooray, Asantha

    2013-01-01

    Optical counterpart identification is a critical link in maximizing the science returns of the Herschel very wide-field survey data. Currently, the Sloan Digital Sky Survey (SDSS) is the best resource for optical counterpart identifications over such wide areas. However a large number of very bright FIR sources are not detected in the SDSS, and their true nature remains to be determined. Using the public HerMES data, we studied seven such sources that are within the CANDELS fields. To deal with the source blending problem, we used the near-IR or the optical images directly for position priors and decomposed these FIR sources. This new appraoch is an improvement over the previous decomposition efforts where the position priors are derived from the mid-IR data that still suffer from the source blending problem in the first place, and can be applied to the regions where the mid-IR data are not available. We found that in most cases the single Herschel sources are made of multiple components that may or may not b...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more of the x-rays to pass through them. As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air ...

  1. Focusing X-Ray Telescopes

    Science.gov (United States)

    O'Dell, Stephen; Brissenden, Roger; Davis, William; Elsner, Ronald; Elvis, Martin; Freeman, Mark; Gaetz, Terrance; Gorenstein, Paul; Gubarev, Mikhall; Jerlus, Diab; Juda, Michael; Kolodziejczak, Jeffrey; Murray, Stephen; Petre, Robert; Podgorski, William; Ramsey, Brian; Reid, Paul; Saha, Timo; Wolk, Scott; Troller-McKinstry, Susan; Weisskopf, Martin; Wilke, Rudeger; Zhang, William

    2010-01-01

    During the half-century history of x-ray astronomy, focusing x-ray telescopes, through increased effective area and finer angular resolution, have improved sensitivity by 8 orders of magnitude. Here, we review previous and current x-ray-telescope missions. Next, we describe the planned next-generation x-ray-astronomy facility, the International X-ray Observatory (IXO). We conclude with an overview of a concept for the next next-generation facility, Generation X. Its scientific objectives will require very large areas (about 10,000 sq m) of highly-nested, lightweight grazing-incidence mirrors, with exceptional (about 0.1-arcsec) resolution. Achieving this angular resolution with lightweight mirrors will likely require on-orbit adjustment of alignment and figure.

  2. X-Ray Tomographic Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Bonnie Schmittberger

    2010-08-25

    Tomographic scans have revolutionized imaging techniques used in medical and biological research by resolving individual sample slices instead of several superimposed images that are obtained from regular x-ray scans. X-Ray fluorescence computed tomography, a more specific tomography technique, bombards the sample with synchrotron x-rays and detects the fluorescent photons emitted from the sample. However, since x-rays are attenuated as they pass through the sample, tomographic scans often produce images with erroneous low densities in areas where the x-rays have already passed through most of the sample. To correct for this and correctly reconstruct the data in order to obtain the most accurate images, a program employing iterative methods based on the inverse Radon transform was written. Applying this reconstruction method to a tomographic image recovered some of the lost densities, providing a more accurate image from which element concentrations and internal structure can be determined.

  3. X-Ray Diffraction Apparatus

    Science.gov (United States)

    Blake, David F. (Inventor); Bryson, Charles (Inventor); Freund, Friedmann (Inventor)

    1996-01-01

    An x-ray diffraction apparatus for use in analyzing the x-ray diffraction pattern of a sample is introduced. The apparatus includes a beam source for generating a collimated x-ray beam having one or more discrete x-ray energies, a holder for holding the sample to be analyzed in the path of the beam, and a charge-coupled device having an array of pixels for detecting, in one or more selected photon energy ranges, x-ray diffraction photons produced by irradiating such a sample with said beam. The CCD is coupled to an output unit which receives input information relating to the energies of photons striking each pixel in the CCD, and constructs the diffraction pattern of photons within a selected energy range striking the CCD.

  4. X-ray monitoring optical elements

    Energy Technology Data Exchange (ETDEWEB)

    Stoupin, Stanislav; Shvydko, Yury; Katsoudas, John; Blank, Vladimir D.; Terentyev, Sergey A.

    2016-12-27

    An X-ray article and method for analyzing hard X-rays which have interacted with a test system. The X-ray article is operative to diffract or otherwise process X-rays from an input X-ray beam which have interacted with the test system and at the same time provide an electrical circuit adapted to collect photoelectrons emitted from an X-ray optical element of the X-ray article to analyze features of the test system.

  5. X-ray diagnostics for TFTR

    Energy Technology Data Exchange (ETDEWEB)

    von Goeler, S.; Hill, K.W.; Bitter, M.

    1982-12-01

    A short description of the x-ray diagnostic preparation for the TFTR tokamak is given. The x-ray equipment consists of the limiter x-ray monitoring system, the soft x-ray pulse-height-analysis-system, the soft x-ray imaging system and the x-ray crystal spectrometer. Particular attention is given to the radiation protection of the x-ray systems from the neutron environment.

  6. X-ray Sources in the Hubble Deep Field Detected by Chandra

    CERN Document Server

    Hornschemeier, A E; Garmire, G P; Schneider, D P; Broos, P S; Townsley, L K; Bautz, M W; Burrows, D N; Chartas, G; Feigelson, E D; Griffiths, R; Lumb, D H; Nousek, J A; Sargent, W L W

    2000-01-01

    We present first results from an X-ray study of the Hubble Deep Field North (HDF-N) and its environs obtained using 166 ks of data collected by the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-ray Observatory. This is the deepest X-ray observation ever reported, and in the HDF-N itself we detect six X-ray sources down to a 0.5--8 keV flux limit of 4E-16 erg cm^-2 s^-1. Comparing these sources with objects seen in multiwavelength HDF-N studies shows positional coincidences with the extremely red object NICMOS J123651.74 +621221.4, an active galactic nucleus (AGN), three elliptical galaxies, and one nearby spiral galaxy. The X-ray emission from the ellipticals is consistent with that expected from a hot interstellar medium, and the spiral galaxy emission may arise from a `super-Eddington' X-ray binary or ultraluminous supernova remnant. Four of the X-ray sources have been detected at radio wavelengths. We also place X-ray upper limits on AGN candidates found in the HDF-N, and we present the t...

  7. X-ray Observations of Neutron Star Binaries: Evidence for Millisecond Spins

    OpenAIRE

    Strohmayer, Tod E.

    2001-01-01

    High amplitude X-ray brightness oscillations during thermonuclear X-ray bursts were discovered with the Rossi X-ray Timing Explorer (RXTE) in early 1996. Spectral and timing evidence strongly supports the conclusion that these oscillations are caused by rotational modulation of the burst emission and that they reveal the spin frequency of neutron stars in low mass X-ray binaries (LMXB), a long sought goal of X-ray astronomy. I briefly review the status of our knowledge of these oscillations. ...

  8. Short X-ray pulses from third-generation light sources.

    Science.gov (United States)

    Stepanov, A G; Hauri, C P

    2016-01-01

    High-brightness X-ray radiation produced by third-generation synchrotron light sources (TGLS) has been used for numerous time-resolved investigations in many different scientific fields. The typical time duration of X-ray pulses delivered by these large-scale machines is about 50-100 ps. A growing number of time-resolved studies would benefit from X-ray pulses with two or three orders of magnitude shorter duration. Here, techniques explored in the past for shorter X-ray pulse emission at TGLS are reviewed and the perspective towards the realisation of picosecond and sub-picosecond X-ray pulses are discussed.

  9. Single shot diffraction of picosecond 8.7-keV x-ray pulses

    OpenAIRE

    F. H. O’Shea; O. Williams; Andonian, G.; Barber, S; Sakai, Y.; Rosenzweig, J. B.; Pogorelsky, I.; Fedurin, M.; K. Kusche; Yakimenko, V.

    2012-01-01

    We demonstrate multiphoton, single shot diffraction images of x rays produced by inverse Compton scattering a high-power CO_{2} laser from a relativistic electron beam, creating a pulse of 8.7 keV x rays. The tightly focused, relatively high peak brightness electron beam and high photon density from the 2 J CO_{2} laser yielded 6×10^{7} x-ray photons over the full opening angle in a single shot. Single shot x-ray diffraction is performed by passing the x rays though a vertical slit and on to ...

  10. AGN variability at hard X-rays

    CERN Document Server

    Soldi, S; Beckmann, V; Lubinski, P

    2010-01-01

    We present preliminary results on the variability properties of AGN above 20 keV in order to show the potential of the INTEGRAL IBIS/ISGRI and Swift/BAT instruments for hard X-ray timing analysis of AGN. The 15-50 keV light curves of 36 AGN observed by BAT during 5 years show significantly larger variations when the blazar population is considered (average normalized excess variance = 0.25) with respect to the Seyfert one (average normalized excess variance = 0.09). The hard X-ray luminosity is found to be anti-correlated to the variability amplitude in Seyfert galaxies and correlated to the black hole mass, confirming previous findings obtained with different AGN hard X-ray samples. We also present results on the Seyfert 1 galaxy IC 4329A, as an example of spectral variability study with INTEGRAL/ISGRI data. The position of the high-energy cut-off of this source is found to have varied during the INTEGRAL observations, pointing to a change of temperature of the Comptonising medium. For several bright Seyfert...

  11. Extended X-ray emission from radio galaxy cocoons

    CERN Document Server

    Nath, Biman B

    2010-01-01

    We study the emission of X-rays from lobes of FR-II radio galaxies by inverse Compton scattering of microwave background photons. Using a simple model that takes into account injection of relativistic electrons, their energy losses through adiabatic expansion, synchrotron and inverse Compton emission, and also the stopping of the jet after a certain time, we study the evolution of the total X-ray power, the surface brightness, angular size of the X-ray bright region and the X-ray photon index, as functions of time and cocoon size, and compare the predictions with observations. We find that the radio power drops rapidly after the stopping of the jet, with a shorter time-scale than the X-ray power. The X-ray spectrum initially hardens until the jet stops because the steepening of electron spectrum is mitigated by the injection of fresh particles, for electrons with $\\gamma \\ge 10^3$. This happens because of the concurrence of two times scales, that of the typical jet lifetimes and cooling due to inverse Compton...

  12. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential. Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detect...

  13. X-ray shout echoing through space

    Science.gov (United States)

    2004-01-01

    , the team in Leicester have determined accurately the distance to the dust sheets by measuring the size of the expanding rings. The nearest dust sheet is located 2900 light years away and is probably part of the Gum nebula, a bubble of hot gas resulting from many supernova explosions. The other dust layer is about 4500 light years away. Understanding how dust is distributed in our Galaxy is important because dust favours the collapse of cool gas clouds, which can then form stars and planets. Knowing where dust is located helps astronomers to determine where star and planet formation is likely to occur. Expanding X-ray dust scattering rings, such as those around GRB 031203, have never been seen before. Slower-moving rings, caused by a similar effect, have been seen in visible light around a very few exploding stars, mostly supernovae. The expanding rings also provide much needed information on the gamma-ray burst itself. Gamma-ray bursts are the most powerful explosive events in the Universe, but astronomers are still trying to understand the mystery that surrounds their origin. Some occur with the supernova explosion of a massive star when it has used up all of its fuel, although only stars which have lost their outer layers and which collapse to make a black hole seem able to make a gamma-ray burst. The delayed X-rays from the echo of GRB 031203 are very useful because they tell astronomers how bright the burst was in the X-ray spectrum when it went off on 3 December. The only direct data available from that moment are those obtained by ESA's Integral observatory in the gamma-ray range. "XMM-Newton's measurements are thus crucial to better understand the nature of the burst," said Dr. Fred Jansen, XMM-Newton's project scientist. "The more details we gather of the burst, the more we can learn on how black holes are made." Today, ESA's Integral and XMM-Newton observatories provide astronomers with their most powerful facilities for studying gamma-ray bursts. In 2004 a

  14. Soft-X-Ray Projection Lithography Using a High-Repetition-Rate Laser-Induced X-Ray Source for Sub-100 Nanometer Lithography Processes

    NARCIS (Netherlands)

    E. Louis,; F. Bijkerk,; Shmaenok, L.; Voorma, H. J.; van der Wiel, M. J.; Schlatmann, R.; Verhoeven, J.; van der Drift, E. W. J. M.; Romijn, J.; Rousseeuw, B. A. C.; Voss, F.; Desor, R.; Nikolaus, B.

    1993-01-01

    In this paper we present the status of a joint development programme on soft x-ray projection lithography (SXPL) integrating work on high brightness laser plasma sources. fabrication of multilayer x-ray mirrors. and patterning of reflection masks. We are in the process of optimization of a laser-pla

  15. Experimental and theoretical characterisation of short pulse X ray lasers

    CERN Document Server

    Strati, F

    2002-01-01

    Since the demonstration in 1984 of x-ray laser action in Ne-like Se at 20.6 and 20.9 nm, much experimental and theoretical effort has been ongoing to investigate different lasing schemes. Aims in this research include improving pumping efficiency, beam quality and overall energy output of the demonstrated x-ray lasers and the production of lasing at shorter wavelengths. The envisaged and demonstrated applications of x-ray lasers utilise their short wavelength, high brightness and coherence. Examples of potential applications include x-ray imaging and holography of biological materials in the water window region (2.3 - 4.4 nm), x-ray photolithography for the fabrication of microcircuits and structures below the micron scale and x-ray interferometry, deflectometry and radiography of dense plasma environments of interest in inertial confinement fusion and astrophysics. Soft x-ray laser action has been demonstrated in various plasma active media with wavelengths ranging from 3.5 nm to 40.0 nm and above. However, ...

  16. Recent trends of projection X-ray microscopy in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yada, K. [Tohken CO., LTD. 2-27-7 Tamagawa Chofu, Tokyo 182-0025 (Japan)], E-mail: kyada@tohken.co.jp

    2009-08-15

    Recent activities of projection X-ray microscopy in Japan are reviewed. 1) By employing high brightness Schottky electron gun, resolution of 0.1 {mu}m is realized by Tohken CO. group and some application examples are shown. 2) Deblurring of Fresnel diffracted image formed by synchrotron orbital radiation (SOR) X-rays is successfully tried by Chiba University group. Remarkable Fresnel fringes appearing at HeLa cell are mostly reconstructed by an iteration method. 3) Element analysis is carried out by Meiji University group utilizing absorption-edge characteristics between two kinds of X-ray targets without X-ray spectrometer. Actually, Cu and Ni targets are used with an inter-changeable system for elemental analysis of Fe{sub 2}O{sub 3} particles and iron component in a mosquito larva.

  17. X-ray harmonic comb from relativistic electron spikes

    CERN Document Server

    Pirozhkov, Alexander S; Esirkepov, Timur Zh; Ragozin, Eugene N; Faenov, Anatoly Ya; Pikuz, Tatiana A; Kawachi, Tetsuya; Sagisaka, Akito; Mori, Michiaki; Kawase, Keigo; Koga, James K; Kameshima, Takashi; Fukuda, Yuji; Chen, Liming; Daito, Izuru; Ogura, Koichi; Hayashi, Yukio; Kotaki, Hideyuki; Kiriyama, Hiromitsu; Okada, Hajime; Nishimori, Nobuyuki; Kondo, Kiminori; Kimura, Toyoaki; Tajima, Toshiki; Daido, Hiroyuki; Kato, Yoshiaki; Bulanov, Sergei V

    2010-01-01

    X-ray devices are far superior to optical ones for providing nanometre spatial and attosecond temporal resolutions. Such resolution is indispensable in biology, medicine, physics, material sciences, and their applications. A bright ultrafast coherent X-ray source is highly desirable, for example, for the diffractive imaging of individual large molecules, viruses, or cells. Here we demonstrate experimentally a new compact X-ray source involving high-order harmonics produced by a relativistic-irradiance femtosecond laser in a gas target. In our first implementation using a 9 Terawatt laser, coherent soft X-rays are emitted with a comb-like spectrum reaching the 'water window' range. The generation mechanism is robust being based on phenomena inherent in relativistic laser plasmas: self-focusing, nonlinear wave generation accompanied by electron density singularities, and collective radiation by a compact electric charge. The formation of singularities (electron density spikes) is described by the elegant mathem...

  18. X-ray outbursts of low-mass X-ray binary transients observed in the RXTE era

    CERN Document Server

    Yan, Zhen

    2014-01-01

    We have performed a statistical study of the outburst properties of 110 bright X-ray outbursts in 36 low-mass X-ray binary transients (LMXBTs) seen with the All-Sky Monitor (ASM; 2--12 keV) on board the Rossi X-ray Timing Explorer ({\\it RXTE}) in 1996--2011. We have measured a number of outburst properties including peak X-ray luminosity, rate-of-change of luminosity on daily timescale, $e$-folding rise and decay timescales, outburst duration and total radiated energy. We found the average values of some properties such as peak X-ray luminosity, rise and decay timescales, outburst duration and total radiated energy of black hole LMXBTs are at least two times larger than those of neutron star LMXBTs, implying that these properties can be used to infer the nature of the central compact object of a newly discovered LMXBT. We also found the outburst peak X-ray luminosity is correlated with the rate-of-change of X-ray luminosity in both the rise and the decay phases, which is consistent with our previous studies. ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review ...

  20. Bone X-Ray (Radiography)

    Science.gov (United States)

    ... bony fragments following treatment of a fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement ... A portable x-ray machine is a compact apparatus that can be taken to the patient in ...

  1. Bone X-Ray (Radiography)

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    Full Text Available ... the oldest and most frequently used form of medical imaging. A bone x-ray makes images of any ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ...

  2. Bone X-Ray (Radiography)

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  3. Bone X-Ray (Radiography)

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ... in the typical diagnostic range for this exam. Risks There is always a slight chance of cancer ...

  4. CELESTIAL X-RAY SOURCES.

    Science.gov (United States)

    sources, (4) the physical conditions in the pulsating x-ray source in the Crab Nebula , and (5) miscellaneous related topics. A bibliography of all work performed under the contract is given. (Author)

  5. Bone X-Ray (Radiography)

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    Full Text Available ... asked to wait until the radiologist determines that all the necessary images have been obtained. A bone ... while it may be barely seen, if at all, on a hip x-ray. For suspected spine ...

  6. Bone X-Ray (Radiography)

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    Full Text Available ... patients and physicians. Because x-ray imaging is fast and easy, it is particularly useful in emergency ... diagnosis and treatment of the individual patient's condition. Ultrasound imaging, which uses sound waves instead of ionizing ...

  7. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  8. Bone X-Ray (Radiography)

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    Full Text Available ... a form of radiation like light or radio waves. X-rays pass through most objects, including the ... individual patient's condition. Ultrasound imaging, which uses sound waves instead of ionizing radiation to create diagnostic images, ...

  9. Bone X-Ray (Radiography)

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    Full Text Available ... pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to ... See the Safety page for more information about pregnancy and x-rays. top of page What does ...

  10. Bone X-Ray (Radiography)

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    Full Text Available ... are easily accessible and are frequently compared to current x-ray images for diagnosis and disease management. ... of North America, Inc. (RSNA). To help ensure current and accurate information, we do not permit copying ...

  11. Bone X-Ray (Radiography)

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    Full Text Available ... ionizing radiation to produce pictures of any bone in the body. It is commonly used to diagnose ... bone x-ray makes images of any bone in the body, including the hand, wrist, arm, elbow, ...

  12. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... examination may also be necessary so that any change in a known abnormality can be monitored over ...

  13. Bone X-Ray (Radiography)

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  14. Bone X-Ray (Radiography)

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  15. Bone X-Ray (Radiography)

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  16. Bone X-Ray (Radiography)

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  17. Bone X-Ray (Radiography)

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    Full Text Available ... x-ray machine is a compact apparatus that can be taken to the patient in a hospital ... so that any change in a known abnormality can be monitored over time. Follow-up examinations are ...

  18. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... in a known abnormality can be monitored over time. Follow-up examinations are sometimes the best way ...

  19. Bone X-Ray (Radiography)

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  20. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2017 Radiological ...

  1. Electromechanical x-ray generator

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Scott A; Platts, David; Sorensen, Eric B

    2016-05-03

    An electro-mechanical x-ray generator configured to obtain high-energy operation with favorable energy-weight scaling. The electro-mechanical x-ray generator may include a pair of capacitor plates. The capacitor plates may be charged to a predefined voltage and may be separated to generate higher voltages on the order of hundreds of kV in the AK gap. The high voltage may be generated in a vacuum tube.

  2. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

    This first book to cover in-depth the generation of x-rays in particle accelerators focuses on electron beams produced by means of the novel Energy Recovery Linac (ERL) technology. The resulting highly brilliant x-rays are at the centre of this monograph, which continues where other books on the market stop. Written primarily for general, high energy and radiation physicists, the systematic treatment adopted by the work makes it equally suitable as an advanced textbook for young researchers.

  3. X-ray fluorescence holography

    CERN Document Server

    Hayashi, K; Takahashi, Y

    2003-01-01

    X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

  4. X-ray Sensitive Material

    Science.gov (United States)

    2015-12-01

    these published reports. There were two main types of X-ray detection methods: “indirect,” which uses a scintillation material coupled to a light...Reference 3), inorganic semiconductors (silicon [Si], cadmium zinc telluride [CdZnTe]) (Reference 4) and selenium (References 5 and 6), Ne-Xe...metal-oxide semiconductor field-effect transistor (MOSFET) X-ray dosimeters (Reference 24). Electrets may be charged by a range of methods

  5. X-ray laser; Roentgenlaser

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsen, Emil J.; Breiby, Dag W.

    2009-07-01

    X-ray is among the most important research tools today, and has given priceless contributions to all disciplines within the natural sciences. State of the art in this field is called XFEL, X-ray Free Electron Laser, which may be 10 thousand million times stronger than the x-rays at the European Synchrotron Radiation Facility in Grenoble. In addition XFEL has properties that allow the study of processes which previously would have been impossible. Of special interest are depictions on atomic- and molecular level by the use of x-ray holographic methods, and being able to study chemical reactions in nature's own timescale, the femtosecond. Conclusion: The construction of x-ray lasers is a natural development in a scientific field which has an enormous influence on the surrounding society. While the discovery of x-ray was an important breakthrough in itself, new applications appear one after the other: Medical depiction, dissemination, diffraction, DNA and protein structures, synchrotron radiation and tomography. There is reason to believe that XFEL implies a technological leap as big as the synchrotrons some decades ago. As we are now talking about studies of femtosecond and direct depiction of chemical reactions, it is obvious that we are dealing with a revolution to come, with extensive consequences, both scientifically and culturally. (EW)

  6. X-Rays, Pregnancy and You

    Science.gov (United States)

    ... and Procedures Medical Imaging Medical X-ray Imaging X-Rays, Pregnancy and You Share Tweet Linkedin Pin ... the decision with your doctor. What Kind of X-Rays Can Affect the Unborn Child? During most ...

  7. Automatic classification of time-variable X-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Kitty K.; Farrell, Sean; Murphy, Tara; Gaensler, B. M. [Sydney Institute for Astronomy, School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia)

    2014-05-01

    To maximize the discovery potential of future synoptic surveys, especially in the field of transient science, it will be necessary to use automatic classification to identify some of the astronomical sources. The data mining technique of supervised classification is suitable for this problem. Here, we present a supervised learning method to automatically classify variable X-ray sources in the Second XMM-Newton Serendipitous Source Catalog (2XMMi-DR2). Random Forest is our classifier of choice since it is one of the most accurate learning algorithms available. Our training set consists of 873 variable sources and their features are derived from time series, spectra, and other multi-wavelength contextual information. The 10 fold cross validation accuracy of the training data is ∼97% on a 7 class data set. We applied the trained classification model to 411 unknown variable 2XMM sources to produce a probabilistically classified catalog. Using the classification margin and the Random Forest derived outlier measure, we identified 12 anomalous sources, of which 2XMM J180658.7–500250 appears to be the most unusual source in the sample. Its X-ray spectra is suggestive of a ultraluminous X-ray source but its variability makes it highly unusual. Machine-learned classification and anomaly detection will facilitate scientific discoveries in the era of all-sky surveys.

  8. X-ray scattering studies of lanthanides magnetism

    DEFF Research Database (Denmark)

    McMorrow, D.; Bohr, Jakob; Gibbs, D.

    1999-01-01

    Interest in the applications of X-ray synchrotron radiation has grown rapidly during the last decade. At the present time, intense, ultra-bright synchrotron radiation is available on a routine basis from third-generation sources located in Europe (ESRF), North America (APS) and Japan (Spring8). T...

  9. Phase-contrast imaging of a soft biological object using X-pinch as X-ray source

    Science.gov (United States)

    Liu, R.; Wang, X. X.; Zou, X. B.; Zeng, N. G.; He, L. Y.

    2008-07-01

    The X-ray emission from an X-pinch was measured with diamond photoconducting detectors and a pinhole camera, and the results show that the X-ray source of the X-pinch is extremely small in size and high in brightness. As such, the X-pinch could be considered as an X-ray point source having a high spatial coherence that is required by a simplified scheme of X-ray phase-contrast imaging. The X-pinch was used as X-ray source for the phase-contrast imaging of a weakly X-ray-absorbing mosquito and an image with high contrast was obtained.

  10. Tabletop Ultrabright Kiloelectronvolt X-Ray Sources from Xe and Kr Hollow Atom States

    Science.gov (United States)

    Sankar, Poopalasingam

    Albert Einstein, the father of relativity, once said, "Look deep into nature, and then you will understand everything better". Today available higher resolution tabletop tool to look deep into matters and living thing is an x-ray source. Although the available tabletop x-rays sources of the 20th century, such as the ones used for medical or dental x-rays are tremendously useful for medical diagnostics and industry, a major disadvantage is that they have low quality skillful brightness, which limits its resolution and accuracy. In the other hand, x-ray free-electrons laser (XFEL) and synchrotron radiation sources provided extreme bright x-rays. However, number of applications of XFEL and synchrotron such as medical and industrials, has been hampered by their size, complexity, and cost. This has set a goal of demonstrating x-ray source with enough brightness for potential applications in an often-called tabletop compact x-ray source that could be operated in university laboratory or hospitals. We have developed two tabletop ultrabright keV x-ray sources, one from a Xe hollow-atom states and the other one from Kr hollow-atom stares with a unique characteristic that makes them complementary to currently-available extreme-light sources; XFEL, and synchrotron x-ray source. Upgraded tabletop ultra-fast KrF* pump-laser interacts with target rare-gas clusters and produces hollow-atom states, which later coherently collapse to the empty inner-shell and thereby generate keV x-ray radiation. The KrF* pump-laser beam is self-focused and forms a self-channel to guide the generated x-ray radiation in the direction of the pump-laser beam to produce directed x-ray beam. Xe (M) x-ray source operates at 1.2-1.6 nm wavelength while the Kr(L) x-ray source operates in 600-800 pm wavelength. System is mounted upon 3 optical-tables (5´x12´) with two KrF amplifiers at a repetition rate of 0.1 Hz. A lower bound for brightness value for both Xe and Kr x-ray sources is 1026 photons s-1mm-2

  11. Discovery of Spatial and Spectral Structure in the X-Ray Emission from the Crab Nebula

    Science.gov (United States)

    Weisskopf, Martin C.; Hester, J. Jeff; Tennant, Allyn F.; Elsner, Ronald F.; Schulz, Norbert S.; Marshall, Herman L.; Karovska, Margarita; Nichols, Joy S.; Swartz, Douglas A.; Kolodziejczak, Jeffery J.

    2000-01-01

    The Chandra X-Ray Observatory observed the Crab Nebula and pulsar during orbital calibration. Zeroth-order images with the High-Energy Transmission Grating (HETG) readout by the Advanced Charge Coupled Devices (CCD) Imaging Spectrometer spectroscopy array (ACIS-S) show a striking richness of X-ray structure at a resolution comparable to that of the best ground-based visible-light observations. The HETG-ACIS-S images reveal, for the first time, an X-ray inner ring within the X-ray torus, the suggestion of a hollow-tube structure for the torus, and X-ray knots along the inner ring and (perhaps) along the inward extension of the X-ray jet. Although complicated by instrumental effects and the brightness of the Crab Nebula, the spectrometric analysis shows systematic variations of the X-ray spectrum throughout the nebula.

  12. RF Phase Stability and Electron Beam Characterization for the PLEIADES Thomson X-Ray Source

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W J; Hartemann, F V; Tremaine, A M; Springer, P T; Le Sage, G P; Barty, C P J; Rosenzweig, J B; Crane, J K; Cross, R R; Fittinghoff, D N; Gibson, D J; Slaughter, D R; Anderson, S

    2002-10-16

    We report on the performance of an S-band RF photocathode electron gun and accelerator for operation with the PLEIADES Thomson x-ray source at LLNL. To produce picosecond, high brightness x-ray pulses, picosecond timing, terahertz bandwidth diagnostics, and RF phase control are required. Planned optical, RF, x-ray and electron beam measurements to characterize the dependence of electron beam parameters and synchronization on RF phase stability are presented.

  13. Coherent methods in X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gorobtsov, Oleg

    2017-05-15

    X-ray radiation has been used to study structural properties of materials for more than a hundred years. Construction of extremely coherent and bright X-ray radiation sources such as free electron lasers (FELs) and latest generationstorage rings led to rapid development of experimental methods relying on high radiation coherence. These methods allow to perform revolutionary studies in a wide range of fields from solid state physics to biology. In this thesis I focus on several important problems connected with the coherent methods. The first part considers applications of dynamical diffraction theory on crystals to studies with coherent X-ray radiation. It presents the design of a high-resolution spectrometer for free electron lasers that should allow to resolve spectral structure of individual FEL pulses. The spectrometer is based on the principle of dynamical diffraction focusing. The knowledge of individual FEL pulse spectra is necessary for understanding FEL longitudinal coherence. In the same part I present quasi-kinematical approximation to dynamical theory which allows to treat analytically phase effects observed in X-ray coherent imaging on nanocrystals. These effects may play a big role when methods such as ptychography are used to study crystalline samples. The second part deals with measurements of FEL coherence properties using intensity - intensity interferometry. Results of several experiments performed at FELs FLASH and LCLS are revealed in this section. I have developed models and theories to explain the behavior observed in experiments on FLASH. These models allowed to extract information about external positional jitter of FEL pulses and secondary beams present in FEL radiation. In the LCLS experiment the Hanbury Brown and Twiss type interferometry was performed on Bragg peaks from colloidal crystal. This did not require additional measurements without the sample and information was extracted directly from diffraction patterns. Therefore intensity

  14. X-ray Optics for BES Light Source Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Dennis [Argonne National Lab. (ANL), Argonne, IL (United States); Padmore, Howard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lessner, Eliane [Dept. of Energy (DOE), Washington DC (United States). Office of Science

    2013-03-27

    Each new generation of synchrotron radiation sources has delivered an increase in average brightness 2 to 3 orders of magnitude over the previous generation. The next evolution toward diffraction-limited storage rings will deliver another 3 orders of magnitude increase. For ultrafast experiments, free electron lasers (FELs) deliver 10 orders of magnitude higher peak brightness than storage rings. Our ability to utilize these ultrabright sources, however, is limited by our ability to focus, monochromate, and manipulate these beams with X-ray optics. X-ray optics technology unfortunately lags behind source technology and limits our ability to maximally utilize even today’s X-ray sources. With ever more powerful X-ray sources on the horizon, a new generation of X-ray optics must be developed that will allow us to fully utilize these beams of unprecedented brightness. The increasing brightness of X-ray sources will enable a new generation of measurements that could have revolutionary impact across a broad area of science, if optical systems necessary for transporting and analyzing X-rays can be perfected. The high coherent flux will facilitate new science utilizing techniques in imaging, dynamics, and ultrahigh-resolution spectroscopy. For example, zone-plate-based hard X-ray microscopes are presently used to look deeply into materials, but today’s resolution and contrast are restricted by limitations of the current lithography used to manufacture nanodiffractive optics. The large penetration length, combined in principle with very high spatial resolution, is an ideal probe of hierarchically ordered mesoscale materials, if zone-plate focusing systems can be improved. Resonant inelastic X-ray scattering (RIXS) probes a wide range of excitations in materials, from charge-transfer processes to the very soft excitations that cause the collective phenomena in correlated electronic systems. However, although RIXS can probe high-energy excitations, the most exciting and

  15. X-ray Optics for BES Light Source Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Dennis [Argonne National Lab. (ANL), Argonne, IL (United States); Padmore, Howard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lessner, Eliane [Dept. of Energy (DOE), Washington DC (United States). Office of Science

    2013-03-27

    Each new generation of synchrotron radiation sources has delivered an increase in average brightness 2 to 3 orders of magnitude over the previous generation. The next evolution toward diffraction-limited storage rings will deliver another 3 orders of magnitude increase. For ultrafast experiments, free electron lasers (FELs) deliver 10 orders of magnitude higher peak brightness than storage rings. Our ability to utilize these ultrabright sources, however, is limited by our ability to focus, monochromate, and manipulate these beams with X-ray optics. X-ray optics technology unfortunately lags behind source technology and limits our ability to maximally utilize even today’s X-ray sources. With ever more powerful X-ray sources on the horizon, a new generation of X-ray optics must be developed that will allow us to fully utilize these beams of unprecedented brightness. The increasing brightness of X-ray sources will enable a new generation of measurements that could have revolutionary impact across a broad area of science, if optical systems necessary for transporting and analyzing X-rays can be perfected. The high coherent flux will facilitate new science utilizing techniques in imaging, dynamics, and ultrahigh-resolution spectroscopy. For example, zone-plate-based hard X-ray microscopes are presently used to look deeply into materials, but today’s resolution and contrast are restricted by limitations of the current lithography used to manufacture nanodiffractive optics. The large penetration length, combined in principle with very high spatial resolution, is an ideal probe of hierarchically ordered mesoscale materials, if zone-plate focusing systems can be improved. Resonant inelastic X-ray scattering (RIXS) probes a wide range of excitations in materials, from charge-transfer processes to the very soft excitations that cause the collective phenomena in correlated electronic systems. However, although RIXS can probe high-energy excitations, the most exciting and

  16. X-ray Echo Spectroscopy

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-01

    X-ray echo spectroscopy, a counterpart of neutron spin echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a pointlike x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02 meV ultrahigh-resolution IXS applications (resolving power >108 ) with broadband ≃5 - 13 meV dispersing systems are introduced featuring more than 103 signal enhancement. The technique is general, applicable in different photon frequency domains.

  17. X-ray echo spectroscopy

    CERN Document Server

    Shvyd'ko, Yuri

    2015-01-01

    X-ray echo spectroscopy, a counterpart of neutron spin-echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a point-like x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x-rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1--0.02-meV ultra-high-resolution IXS applications (resolving power $> 10^8$) with broadband $\\simeq$~5--13~meV dispersing systems are introduced featuring more than $10^3$ signal e...

  18. X-ray Echo Spectroscopy.

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-26

    X-ray echo spectroscopy, a counterpart of neutron spin echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a pointlike x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02 meV ultrahigh-resolution IXS applications (resolving power >10^{8}) with broadband ≃5-13  meV dispersing systems are introduced featuring more than 10^{3} signal enhancement. The technique is general, applicable in different photon frequency domains.

  19. A Catalog of Intermediate-luminosity X-ray Objects

    CERN Document Server

    Colbert, E

    2002-01-01

    ROSAT, and now Chandra, X-ray images allow studies of extranuclear X-ray point sources in galaxies other than our own. X-ray observations of normal galaxies with ROSAT and Chandra have revealed that off-nuclear, compact, Intermediate-luminosity (Lx 2-10 keV >= 1e39 erg/s) X-ray Objects (IXOs, a.k.a. ULXs) are quite common. Here we present a catalog and finding charts for 87 IXOs in 54 galaxies, derived from all of the ROSAT HRI imaging data for galaxies with cz <= 5000 km/s from the Third Reference Catalog of Bright Galaxies (RC3). We have defined the cutoff Lx for IXOs so that it is well above the Eddington luminosity of a 1.4 Msol black hole (10^{38.3} erg/s), so as not to confuse IXOs with ``normal'' black hole X-ray binaries. This catalog is intended to provide a baseline for follow-up work with Chandra, and with space- and ground-based survey work at wavelengths other than X-ray. We demonstrate that elliptical galaxies with IXOs have a larger number of IXOs per galaxy than non-elliptical galaxies with...

  20. On the Nature of the mHz X-Ray QPOs from ULX M82 X-1: Evidence for Timing-Spectral (anti) Correlation

    Science.gov (United States)

    Pasham, Dheeraj R.; Strohmayer, Tod E.

    2013-01-01

    Using all the archival XMM-Newton X-ray (3-10 keV) observations of the ultraluminous X-ray source (ULX) M82 X-1 we searched for a correlation between its variable mHz quasi-periodic oscillation (QPO) frequency and its energy spectral power-law index. These quantities are known to correlate in stellar mass black holes (StMBHs) exhibiting Type-C QPOs (approx 0.2-15 Hz). The detection of such a correlation would strengthen the identification of its mHz QPOs as Type-C and enable a more reliable mass estimate by scaling its QPO frequencies to those of Type-C QPOs in StMBHs of known mass. We resolved the count rates of M82 X-1 and a nearby bright ULX (source 5/X42.3+59) through surface brightness modeling and identify observations in which M82 X-1 was at least as bright as source 5. Using only those observations, we detect QPOs in the frequency range of 36-210 mHz during which the energy spectral power-law index varied from 1.7-2.2. Interestingly, we find evidence for an anti-correlation (Pearsons correlation coefficient = -0.95) between the power-law index and the QPO centroid frequency. While such an anti-correlation is observed in StMBHs at high Type-C QPO frequencies (approx 5-15 Hz), the frequency range over which it holds in StMBHs is significantly smaller (factor of approx 1.5-3) than the QPO range reported here from M82 X-1 (factor of 6). However, it remains possible that contamination from source 5 can bias our result. Joint Chandra/XMM-Newton observations in the future can resolve this problem and confirm the timing-spectral anti-correlation reported here.

  1. X-ray observations of the Sagittarius D HII region toward the Galactic center with Suzaku

    NARCIS (Netherlands)

    Sawada, M.; Tsujimoto, M.; Koyama, K.; Law, C.J.; Tsuru, T.G.; Hyodo, Y.

    2009-01-01

    We present a Suzaku X-ray study of the Sagittarius D (Sgr D) HII region in the Galactic center region. Two 18' × 18' images by the X-ray Imaging Spectrometer (XIS) encompass the entire Sgr D complex. Thanks to the low background, XIS discovered two diffuse sources with low surface brightness and obt

  2. X-ray phase contrast imaging of biological specimens with tabletop synchrotron radiation

    CERN Document Server

    Kneip, S; Dollar, F; Bloom, M S; Chvykov, V; Kalintchenko, G; Krushelnick, K; Maksimchuk, A; Mangles, S P D; Matsuoka, T; Najmudin, Z; Palmer, C A J; Schreiber, J; Schumaker, W; Thomas, A G R; Yanovsky, V

    2011-01-01

    Since their discovery in 1896, x-rays have had a profound impact on science, medicine and technology. Here we show that the x-rays from a novel tabletop source of bright coherent synchrotron radiation can be applied to phase contrast imaging of biological specimens, yielding superior image quality and avoiding the need for scarce or expensive conventional sources.

  3. X-ray imaging: Perovskites target X-ray detection

    Science.gov (United States)

    Heiss, Wolfgang; Brabec, Christoph

    2016-05-01

    Single crystals of perovskites are currently of interest to help fathom fundamental physical parameters limiting the performance of perovskite-based polycrystalline solar cells. Now, such perovskites offer a technology platform for optoelectronic devices, such as cheap and sensitive X-ray detectors.

  4. Portable X-Ray Device

    Science.gov (United States)

    1983-01-01

    Portable x-ray instrument developed by NASA now being produced commercially as an industrial tool may soon find further utility as a medical system. The instrument is Lixiscope - Low Intensity X-Ray Imaging Scope -- a self-contained, battery-powered fluoroscope that produces an instant image through use of a small amount of radioactive isotope. Originally developed by Goddard Space Flight Center, Lixiscope is now being produced by Lixi, Inc. which has an exclusive NASA license for one version of the device.

  5. A Hard X-ray Study of the Normal Star-Forming Galaxy M83 with NuSTAR

    CERN Document Server

    Yukita, M; Lehmer, B D; Ptak, A; Wik, D R; Zezas, A; Antoniou, V; Maccarone, T J; Replicon, V; Tyler, J B; Venters, T; Argo, M K; Bechtol, K; Boggs, S; Christensen, F E; Craig, W W; Hailey, C; Harrison, F; Krivonos, R; Kuntz, K; Stern, D; Zhang, W W

    2016-01-01

    We present results from sensitive, multi-epoch NuSTAR observations of the late-type star-forming galaxy M83 (d=4.6 Mpc), which is the first investigation to spatially resolve the hard (E>10 keV) X-ray emission of this galaxy. The nuclear region and ~ 20 off-nuclear point sources, including a previously discovered ultraluminous X-ray (ULX) source, are detected in our NuSTAR observations. The X-ray hardnesses and luminosities of the majority of the point sources are consistent with hard X-ray sources resolved in the starburst galaxy NGC 253. We infer that the hard X-ray emission is most likely dominated by intermediate accretion state black hole binaries and neutron star low-mass X-ray binaries (Z-sources). We construct the X-ray binary luminosity function (XLF) in the NuSTAR band for an extragalactic environment for the first time. The M83 XLF has a steeper XLF than the X-ray binary XLF in NGC 253, consistent with previous measurements by Chandra at softer X-ray energies. The NuSTAR integrated galaxy spectrum ...

  6. NuSTAR Hard X-ray Survey of the Galactic Center Region II: X-ray Point Sources

    CERN Document Server

    Hong, JaeSub; Hailey, Charles J; Nynka, Melania; Zhang, Shuo; Gotthelf, Eric; Fornasini, Francesca M; Krivonos, Roman; Bauer, Franz; Perez, Kerstin; Tomsick, John A; Bodaghee, Arash; Chiu, Jeng-Lun; Clavel, Maïca; Stern, Daniel; Grindlay, Jonathan E; Alexander, David M; Aramaki, Tsuguo; Baganoff, Frederick K; Barret, David; Barrière, Nicolas; Boggs, Steven E; Canipe, Alicia M; Christensen, Finn E; Craig, William W; Desai, Meera A; Forster, Karl; Giommi, Paolo; Grefenstette, Brian W; Harrison, Fiona A; Hong, Dooran; Hornstrup, Allan; Kitaguchi, Takao; Koglin, Jason E; Madsen, Kristen K; Mao, Peter H; Miyasaka, Hiromasa; Perri, Matteo; Pivovaroff, Michael J; Puccetti, Simonetta; Rana, Vikram; Westergaard, Niels J; Zhang, William W; Zoglauer, Andreas

    2016-01-01

    We present the first survey results of hard X-ray point sources in the Galactic Center (GC) region by NuSTAR. We have discovered 70 hard (3-79 keV) X-ray point sources in a 0.6 deg^2 region around Sgr A* with a total exposure of 1.7 Ms, and 7 sources in the Sgr B2 field with 300 ks. We identify clear Chandra counterparts for 58 NuSTAR sources and assign candidate counterparts for the remaining 19. The NuSTAR survey reaches X-ray luminosities of ~4 x and ~8 x 10^32 erg s^-1 at the GC (8 kpc) in the 3-10 and 10-40 keV bands, respectively. The source list includes three persistent luminous X-ray binaries and the likely run-away pulsar called the Cannonball. New source-detection significance maps reveal a cluster of hard (>10 keV) X-ray sources near the Sgr A diffuse complex with no clear soft X-ray counterparts. The severe extinction observed in the Chandra spectra indicates that all the NuSTAR sources are in the central bulge or are of extragalactic origin. Spectral analysis of relatively bright NuSTAR sources ...

  7. The NIF x-ray spectrometer calibration campaign at Omega.

    Science.gov (United States)

    Pérez, F; Kemp, G E; Regan, S P; Barrios, M A; Pino, J; Scott, H; Ayers, S; Chen, H; Emig, J; Colvin, J D; Bedzyk, M; Shoup, M J; Agliata, A; Yaakobi, B; Marshall, F J; Hamilton, R A; Jaquez, J; Farrell, M; Nikroo, A; Fournier, K B

    2014-11-01

    The calibration campaign of the National Ignition Facility X-ray Spectrometer (NXS) was carried out at the Omega laser facility. Spherically symmetric, laser-driven, millimeter-scale x-ray sources of K-shell and L-shell emission from various mid-Z elements were designed for the 2-18 keV energy range of the NXS. The absolute spectral brightness was measured by two calibrated spectrometers. We compare the measured performance of the target design to radiation hydrodynamics simulations.

  8. The NIF x-ray spectrometer calibration campaign at Omega

    Energy Technology Data Exchange (ETDEWEB)

    Pérez, F.; Kemp, G. E.; Barrios, M. A.; Pino, J.; Scott, H.; Ayers, S.; Chen, H.; Emig, J.; Colvin, J. D.; Fournier, K. B., E-mail: fournier2@llnl.gov [Lawrence Livermore National Laboratory, P. O. Box 808, Livermore, California 94551 (United States); Regan, S. P.; Bedzyk, M.; Shoup, M. J.; Agliata, A.; Yaakobi, B.; Marshall, F. J.; Hamilton, R. A. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Jaquez, J.; Farrell, M.; Nikroo, A. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)

    2014-11-15

    The calibration campaign of the National Ignition Facility X-ray Spectrometer (NXS) was carried out at the OMEGA laser facility. Spherically symmetric, laser-driven, millimeter-scale x-ray sources of K-shell and L-shell emission from various mid-Z elements were designed for the 2–18 keV energy range of the NXS. The absolute spectral brightness was measured by two calibrated spectrometers. We compare the measured performance of the target design to radiation hydrodynamics simulations.

  9. A 78 Day X-ray Period Detected from NGC 5907 ULX1 by Swift

    CERN Document Server

    Walton, D J; Bachetti, M; Barret, D; Brightman, M; Fabian, A C; Gehrels, N; Harrison, F A; Heida, M; Middleton, M J; Rana, V; Roberts, T P; Stern, D; Tao, L; Webb, N

    2016-01-01

    We report the detection of a $78.1\\pm0.5$ day period in the X-ray lightcurve of the extreme ultraluminous X-ray source NGC 5907 ULX1 ($L_{\\rm{X,peak}}\\sim5\\times10^{40}$ erg s$^{-1}$), discovered during an extensive monitoring program with Swift. These periodic variations are strong, with the observed flux changing by a factor of $\\sim$3-4 between the peaks and the troughs of the cycle; our simulations suggest that the observed periodicity is detected comfortably in excess of 3$\\sigma$ significance. We discuss possible origins for this X-ray period, but conclude that at the current time we cannot robustly distinguish between orbital and super-orbital variations.

  10. A 78 Day X-Ray Period Detected from NGC 5907 ULX1 by Swift

    Science.gov (United States)

    Walton, D. J.; Fürst, F.; Bachetti, M.; Barret, D.; Brightman, M.; Fabian, A. C.; Gehrels, N.; Harrison, F. A.; Heida, M.; Middleton, M. J.; Rana, V.; Roberts, T. P.; Stern, D.; Tao, L.; Webb, N.

    2016-08-01

    We report the detection of a 78.1 ± 0.5 day period in the X-ray light curve of the extreme ultraluminous X-ray source NGC 5907 ULX1 ({L}{{X,peak}}˜ 5× {10}40 erg s-1), discovered during an extensive monitoring program with Swift. These periodic variations are strong, with the observed flux changing by a factor of ˜3-4 between the peaks and the troughs of the cycle; our simulations suggest that the observed periodicity is detected comfortably in excess of 3σ significance. We discuss possible origins for this X-ray period, but conclude that at the current time we cannot robustly distinguish between orbital and super-orbital variations.

  11. Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction.

    Science.gov (United States)

    Maddox, B R; Akin, M C; Teruya, A; Hunt, D; Hahn, D; Cradick, J; Morgan, D V

    2016-08-01

    Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from the sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10(7) molybdenum Kα photons.

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ... This ensures that those parts of a patient's body not being imaged receive minimal radiation ... x-ray images are among the clearest, most detailed views of ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  14. X-rays and magnetism.

    Science.gov (United States)

    Fischer, Peter; Ohldag, Hendrik

    2015-09-01

    Magnetism is among the most active and attractive areas in modern solid state physics because of intriguing phenomena interesting to fundamental research and a manifold of technological applications. State-of-the-art synthesis of advanced magnetic materials, e.g. in hybrid structures paves the way to new functionalities. To characterize modern magnetic materials and the associated magnetic phenomena, polarized x-rays have emerged as unique probes due to their specific interaction with magnetic materials. A large variety of spectroscopic and microscopic techniques have been developed to quantify in an element, valence and site-sensitive way properties of ferro-, ferri-, and antiferromagnetic systems, such as spin and orbital moments, and to image nanoscale spin textures and their dynamics with sub-ns time and almost 10 nm spatial resolution. The enormous intensity of x-rays and their degree of coherence at next generation x-ray facilities will open the fsec time window to magnetic studies addressing fundamental time scales in magnetism with nanometer spatial resolution. This review will give an introduction into contemporary topics of nanoscale magnetic materials and provide an overview of analytical spectroscopy and microscopy tools based on x-ray dichroism effects. Selected examples of current research will demonstrate the potential and future directions of these techniques.

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z X-ray ( ... are the fastest and easiest way for your doctor to view and assess bone fractures, injuries and ...

  16. X-Ray Diffractive Optics

    Science.gov (United States)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

    X-ray optics were fabricated with the capability of imaging solar x-ray sources with better than 0.1 arcsecond angular resolution, over an order of magnitude finer than is currently possible. Such images would provide a new window into the little-understood energy release and particle acceleration regions in solar flares. They constitute one of the most promising ways to probe these regions in the solar atmosphere with the sensitivity and angular resolution needed to better understand the physical processes involved. A circular slit structure with widths as fine as 0.85 micron etched in a silicon wafer 8 microns thick forms a phase zone plate version of a Fresnel lens capable of focusing approx. =.6 keV x-rays. The focal length of the 3-cm diameter lenses is 100 microns, and the angular resolution capability is better than 0.1 arcsecond. Such phase zone plates were fabricated in Goddard fs Detector Development Lab. (DDL) and tested at the Goddard 600-microns x-ray test facility. The test data verified that the desired angular resolution and throughput efficiency were achieved.

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... and places the x-ray film holder or digital recording plate under the table in the area of the body being imaged. When necessary, sandbags, pillows or other positioning devices will be used to help you maintain the ...

  18. Alpha proton x ray spectrometer

    Science.gov (United States)

    Rieder, Rudi; Waeke, H.; Economou, T.

    1994-01-01

    Mars Pathfinder will carry an alpha-proton x ray spectrometer (APX) for the determination of the elemental chemical composition of Martian rocks and soils. The instrument will measure the concentration of all major and some minor elements, including C, N, and O at levels above typically 1 percent.

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... An x-ray (radiograph) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  1. Stellar X-Ray Polarimetry

    Science.gov (United States)

    Swank, J.

    2011-01-01

    Most of the stellar end-state black holes, pulsars, and white dwarfs that are X-ray sources should have polarized X-ray fluxes. The degree will depend on the relative contributions of the unresolved structures. Fluxes from accretion disks and accretion disk corona may be polarized by scattering. Beams and jets may have contributions of polarized emission in strong magnetic fields. The Gravity and Extreme Magnetism Small Explorer (GEMS) will study the effects on polarization of strong gravity of black holes and strong magnetism of neutron stars. Some part of the flux from compact stars accreting from companion stars has been reflected from the companion, its wind, or accretion streams. Polarization of this component is a potential tool for studying the structure of the gas in these binary systems. Polarization due to scattering can also be present in X-ray emission from white dwarf binaries and binary normal stars such as RS CVn stars and colliding wind sources like Eta Car. Normal late type stars may have polarized flux from coronal flares. But X-ray polarization sensitivity is not at the level needed for single early type stars.

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... dislocations. In elderly or patients with osteoporosis, a hip fracture may be clearly seen on a CT scan, while it may be barely seen, if at all, on a hip x-ray. For suspected spine injury or other ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... An x-ray (radiograph) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  4. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    OpenAIRE

    de Groot, F. M. F.

    2001-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption process. Section II discusses 1s X-ray absorption, i.e., the K edges, and section III deals with 2p X-ray absorption, the L edges. X-ray emission is discussed in, respectively, the L edges. X-ray emis...

  5. Preface: The 5th International Workshop on X-ray Mirror Design, Fabrication, and Metrology.

    Science.gov (United States)

    Assoufid, Lahsen; Goldberg, Kenneth; Yashchuk, Valeriy V

    2016-05-01

    Recent developments in synchrotron storage rings and free-electron laser-based x-ray sources with ever-increasing brightness and coherent flux have pushed x-ray optics requirements to new frontiers. This Special Topic gathers a set of articles derived from a subset of the key presentations of the International Workshop on X-ray Mirrors Fabrication (IWXM-2015) and Metrology held at Lawrence Berkley National Laboratory, Berkeley, California, USA, July 14-16, 2015. The workshop objective was to report on recent progress in x-ray synchrotron radiation mirrors fabrication as well as on new developments in related metrology tools and methods.

  6. Synchrotron X-Ray Diffraction Analysis of Meteorites in Thin Section: Preliminary Results

    Science.gov (United States)

    Treiman, A. H.; Lanzirotti, A.; Xirouchakis, D.

    2004-01-01

    X-ray diffraction is the pre-eminent technique for mineral identification and structure determination, but is difficult to apply to grains in thin section, the standard meteorite preparation. Bright focused X-ray beams from synchrotrons have been used extensively in mineralogy and have been applied to extraterrestrial particles. The intensity and small spot size achievable in synchrotron X-ray beams makes them useful for study of materials in thin sections. Here, we describe Synchrotron X-ray Diffraction (SXRD) in thin section as done at the National Synchrotron Light Source, and cite examples of its value for studies of meteorites in thin section.

  7. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    NARCIS (Netherlands)

    Groot, F.M.F. de

    2000-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption

  8. Emittance measurement at the NSLS x-ray ring

    Energy Technology Data Exchange (ETDEWEB)

    Safranek, J.; Stefan, P.M.

    1996-12-31

    A pinhole camera for imaging x-ray synchrotron radiation from a dipole magnet is now in operation at the NSLS X-Ray Ring. The pinhole camera detector is a 0.5 mm thick YAG phosphor screen viewed by a video camera. Both the theoretical pinhole diffraction pattern and the measured modulation transfer function (MTF) of the phosphor and camera have been deconvolved from the measured profile in order to derive the true transverse profile of the electron beam. This profile was then fit to a 2-dimensional Gaussian. The electron beam emittance as a function of the phase space acceptance of the pinhole camera has been derived, so the horizontal and vertical electron emittances can be deduced from the major and minor sigmas of the fit Gaussian. In the X-Ray Ring, the vertical emittance is kept small to maximize the synchrotron radiation brightness. The ratio of the measured vertical to horizontal emittance is 0.001.

  9. 11th International Conference on X-Ray Lasers

    CERN Document Server

    Lewis, Ciaran L. S; X-Ray Lasers 2008

    2009-01-01

    This book provides a thorough account of the current status of achievements made in the area of soft X-ray laser source development and of the increasingly diverse applications being demonstrated using such radiation sources. There is significant effort worldwide to develop very bright, short duration radiation sources in the X-ray spectral region – driven by the multitude of potential applications in all branches of science. This book contains updates on several different approaches for comparative purposes but concentrates on developments in the area of laser-produced plasmas, whereby transient population inversion and gain between ion states is pumped by optical lasers interacting with pre-formed plasmas. The most significant development here is the demonstrated increasing feasibility to produce useful soft X-ray laser beams with high repetition rates in a typical, small, university-class laboratory – as opposed to the requirement of access to a national facility some 20 years ago. Experimental progres...

  10. Compact x-ray lasers in the laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Barletta, W.A.

    1988-10-03

    Compact x-ray lasers in the laboratory can be produced with ultrahigh gradient rf linacs based on recent advances in linac technology by an SLAC-LLNL-LBL collaboration and on the development of bright, high current electron sources by BNL and LANL. The GeV electron beams generated with such accelerators can be converted to soft x rays in the range of 2--10 nm by passage through short period, high field strength wigglers. Alternatively, the beam can pump a low density dielectric to produce x rays via recombination. Such linear light sources can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitable for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 15 refs., 7 figs., 3 tabs.

  11. Imaging X-ray Thomson Scattering Spectrometer Design and Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Gamboa, E.J. [University of Michigan; Huntington, C.M. [University of Michigan; Trantham, M.R. [University of Michigan; Keiter, P.A [University of Michigan; Drake, R.P. [University of Michigan; Montgomery, David [Los Alamos National Laboratory; Benage, John F. [Los Alamos National Laboratory; Letzring, Samuel A. [Los Alamos National Laboratory

    2012-05-04

    In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally-curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam.

  12. Is Coronal X-ray Emission Energized By Electric Currents?

    Science.gov (United States)

    Ishibashi, Kazunori; Metcalf, T.; Lites, B.

    2007-05-01

    We examine the spatial correlation between coronal X-ray emission observed with the Hinode X-Ray Telescope and electric currents observed with the Hinode Solar Optical Telescope Spectro-polarimeter. We determine to what extent the X-ray brightness is correlated with electric current density and hence to what extent the hot corona is energized by electric currents which flow through the photosphere. We will also consider whether the currents reach the corona to heat the coronal plasma or whether they predominantly close below the corona. Hinode is an international project supported by JAXA, NASA, PPARC and ESA. We are grateful to the Hinode team for all their efforts in the design, development and operation of the mission.

  13. X-ray reprocessing in binaries

    Science.gov (United States)

    Paul, Biswajit

    2016-07-01

    We will discuss several aspects of X-ray reprocessing into X-rays or longer wavelength radiation in different kinds of binary systems. In high mass X-ray binaries, reprocessing of hard X-rays into emission lines or lower temperature black body emission is a useful tool to investigate the reprocessing media like the stellar wind, clumpy structures in the wind, accretion disk or accretion stream. In low mass X-ray binaries, reprocessing from the surface of the companion star, the accretion disk, warps and other structures in the accretion disk produce signatures in longer wavelength radiation. X-ray sources with temporal structures like the X-ray pulsars and thermonuclear burst sources are key in such studies. We will discuss results from several new investigations of X-ray reprocessing phenomena in X-ray binaries.

  14. Enhanced x-rays from resonant betatron oscillations in laser wakefield with external wigglers

    Science.gov (United States)

    Zhang, Z. M.; Zhang, B.; Hong, W.; Yu, M. Y.; Deng, Z. G.; Teng, J.; He, S. K.; Gu, Y. Q.

    2016-11-01

    Generation of ultra-short betatron x-rays by laser-accelerated electron beams is of great research interest as it has many applications. In this paper, we propose a scheme for obtaining bright betatron x-rays by applying external wiggler magnetic field in the laser wakefield to resonantly drive the betatron oscillations of the accelerated electrons therein. This results in a significant enhancement of the betatron oscillation amplitude and generation of bright x-rays with high photon energy. The scheme is demonstrated using two-dimensional particle-in-cell simulation and discussed using a simple analytical model.

  15. A simulation study of Tsinghua Thomson scattering X-ray source

    Institute of Scientific and Technical Information of China (English)

    TANG Chuan-Xiang; LI Ren-Kai; HUANG Wen-Hui; CHEN Huai-Bi; DU Ying-Chao; DU Qiang; DU Tai-Bin; HE Xiao-Zhong; HUA Jian-Fei; LIN Yu-Zhen; QIAN Hou-Jun; SHI Jia-Ru; XIANG Dao; YAN Li-Xin; Yu Pei-Cheng

    2009-01-01

    Thomson scattering X-ray sources are compact and afrordable facifities that produce short duration,high brightness X-ray pulses enabling new experimental capacities in ultra-fast science studies,and also medical and industrial applications.Such a facility has been built at the Accelerator Laboratory of Tsinghua University,and upgrade is in progress.In this paper,we present a proposed layout of the upgrade with design parameters by simulation,aiming at high X-ray pulses flux and brightness,and also enabling advanced dynamics studies and applications of the electron beam.Design and construction status of main subsystems are also presented.

  16. LIGHT SOURCE: A simulation study of Tsinghua Thomson scattering X-ray source

    Science.gov (United States)

    Tang, Chuan-Xiang; Li, Ren-Kai; Huang, Wen-Hui; Chen, Huai-Bi; Du, Ying-Chao; Du, Qiang; Du, Tai-Bin; He, Xiao-Zhong; Hua, Jian-Fei; Lin, Yu-Zhen; Qian, Hou-Jun; Shi, Jia-Ru; Xiang, Dao; Yan, Li-Xin; Yu, Pei-Cheng

    2009-06-01

    Thomson scattering X-ray sources are compact and affordable facilities that produce short duration, high brightness X-ray pulses enabling new experimental capacities in ultra-fast science studies, and also medical and industrial applications. Such a facility has been built at the Accelerator Laboratory of Tsinghua University, and upgrade is in progress. In this paper, we present a proposed layout of the upgrade with design parameters by simulation, aiming at high X-ray pulses flux and brightness, and also enabling advanced dynamics studies and applications of the electron beam. Design and construction status of main subsystems are also presented.

  17. LUX - A recirculating linac-based ultrafast X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N.; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Green, M.A.; Heimann, P.; Leone, S.R.; Lidia, S.; Li, D.; Parmigiani, F.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Zholents, A.

    2003-08-01

    We describe the design of a proposed source of ultra-fast synchrotron radiation x-ray pulses based on a recirculating superconducting linac, with an integrated array of ultrafast laser systems. The source produces x-ray pulses with duration of 10-50 fs at a 10 kHz repetition rate, with tunability from EUV to hard x-ray regimes, and optimized for the study of ultra-fast dynamics. A high-brightness rf photocathode provides electron bunches. An injector linac accelerates the beam to the 100 MeV range, and is followed by four passes through a 700 MeV recirculating linac. Ultrafast hard x-ray pulses are obtained by a combination of electron bunch manipulation, transverse temporal correlation of the electrons, and x-ray pulse compression. EUV and soft x-ray pulses as short as 10 fs are generated in a harmonic-cascade free electron laser scheme.

  18. X-RAY EMISSION FROM MAGNETIC MASSIVE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Nazé, Yaël [GAPHE, Département AGO, Université de Liège, Allée du 6 Août 17, Bat. B5C, B-4000 Liège (Belgium); Petit, Véronique [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States); Rinbrand, Melanie; Owocki, Stan [Department of Physics and Astronomy, University of Delaware, Bartol Research Institute, Newark, DE 19716 (United States); Cohen, David [Department of Physics and Astronomy, Swarthmore College, Swarthmore, PA 19081 (United States); Ud-Doula, Asif [Penn State Worthington Scranton, Dunmore, PA 18512 (United States); Wade, Gregg A., E-mail: naze@astro.ulg.ac.be [Department of Physics, Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, ON K7K 4B4 (Canada)

    2014-11-01

    Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM-Newton observations, corresponding to all available exposures of known massive magnetic stars (over 100 exposures covering ∼60% of stars compiled in the catalog of Petit et al.). We show that the X-ray luminosity is strongly correlated with the stellar wind mass-loss rate, with a power-law form that is slightly steeper than linear for the majority of the less luminous, lower- M-dot B stars and flattens for the more luminous, higher- M-dot O stars. As the winds are radiatively driven, these scalings can be equivalently written as relations with the bolometric luminosity. The observed X-ray luminosities, and their trend with mass-loss rates, are well reproduced by new MHD models, although a few overluminous stars (mostly rapidly rotating objects) exist. No relation is found between other X-ray properties (plasma temperature, absorption) and stellar or magnetic parameters, contrary to expectations (e.g., higher temperature for stronger mass-loss rate). This suggests that the main driver for the plasma properties is different from the main determinant of the X-ray luminosity. Finally, variations of the X-ray hardnesses and luminosities, in phase with the stellar rotation period, are detected for some objects and they suggest that some temperature stratification exists in massive stars' magnetospheres.

  19. Small-animal tomography with a liquid-metal-jet x-ray source

    Science.gov (United States)

    Larsson, D. H.; Lundström, U.; Westermark, U.; Takman, P. A. C.; Burvall, A.; Arsenian Henriksson, M.; Hertz, H. M.

    2012-03-01

    X-ray tomography of small animals is an important tool for medical research. For high-resolution x-ray imaging of few-cm-thick samples such as, e.g., mice, high-brightness x-ray sources with energies in the few-10-keV range are required. In this paper we perform the first small-animal imaging and tomography experiments using liquid-metal-jet-anode x-ray sources. This type of source shows promise to increase the brightness of microfocus x-ray systems, but present sources are typically optimized for an energy of 9 keV. Here we describe the details of a high-brightness 24-keV electron-impact laboratory microfocus x-ray source based on continuous operation of a heated liquid-In/Ga-jet anode. The source normally operates with 40 W of electron-beam power focused onto the metal jet, producing a 7×7 μm2 FWHM x-ray spot. The peak spectral brightness is 4 × 109 photons / ( s × mm2 × mrad2 × 0.1%BW) at the 24.2 keV In Kα line. We use the new In/Ga source and an existing Ga/In/Sn source for high-resolution imaging and tomography of mice.

  20. The History of X-ray Free-Electron Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrini, C.; /UCLA /SLAC

    2012-06-28

    The successful lasing at the SLAC National Accelerator Laboratory of the Linear Coherent Light Source (LCLS), the first X-ray free-electron laser (X-ray FEL), in the wavelength range 1.5 to 15 {angstrom}, pulse duration of 60 to few femtoseconds, number of coherent photons per pulse from 10{sup 13} to 10{sup 11}, is a landmark event in the development of coherent electromagnetic radiation sources. Until now electrons traversing an undulator magnet in a synchrotron radiation storage ring provided the best X-ray sources. The LCLS has set a new standard, with a peak X-ray brightness higher by ten orders of magnitudes and pulse duration shorter by three orders of magnitudes. LCLS opens a new window in the exploration of matter at the atomic and molecular scales of length and time. Taking a motion picture of chemical processes in a few femtoseconds or less, unraveling the structure and dynamics of complex molecular systems, like proteins, are some of the exciting experiments made possible by LCLS and the other X-ray FELs now being built in Europe and Asia. In this paper, we describe the history of the many theoretical, experimental and technological discoveries and innovations, starting from the 1960s and 1970s, leading to the development of LCLS.

  1. Employing Soft X-rays in Experimental Astrochemistry

    CERN Document Server

    Pilling, Sergio

    2011-01-01

    The presence of soft x-rays is very important for the chemical evolution of interstellar medium and other astrophysical environments close to young and bright stars. Soft X-rays can penetrate deep in molecular clouds and protostellar disks and trigger chemistry in regions in which UV stellar photons do not reach. The effects of soft X-rays in astrophysical ices are also remarkable because they release secondary electrons in and on the surface of the ices, which trigger a new set or chemical reactions. In this chapter we will discuss firstly about the origin and relevance of soft X-rays in astrophysics. Next we will move to the effect of ionizing radiation in organic molecules present in astrophysical environment. We will discuss the use soft X-rays in astrochemistry laboratory studies at both gas- and solid-phase (ice). We will make a review covering our publications in this field, in particular, about the experiments employing time-of-flight spectroscopy (TOF-MS), Fourier transform infrared (FTIR) spectrosco...

  2. Probing magnetar magnetosphere through X-ray polarization measurements

    Science.gov (United States)

    Taverna, R.; Muleri, F.; Turolla, R.; Soffitta, P.; Fabiani, S.; Nobili, L.

    2014-02-01

    The study of magnetars is of particular relevance since these objects are the only laboratories where the physics in ultra-strong magnetic fields can be directly tested. Until now, spectroscopic and timing measurements at X-ray energies in soft gamma repeaters and anomalous X-ray pulsars (AXPs) have been the main source of information about the physical properties of a magnetar and of its magnetosphere. Spectral fitting in the ˜0.5-10 keV range allowed us to validate the `twisted magnetosphere' model, probing the structure of the external field and estimating the density and velocity of the magnetospheric currents. Spectroscopy alone, however, may fail in disambiguating the two key parameters governing magnetospheric scattering (the charge velocity and the twist angle) and is quite insensitive to the source geometry. X-ray polarimetry, on the other hand, can provide a quantum leap in the field by adding two extra observables, the linear polarization degree and the polarization angle. Using the bright AXP 1RXS J170849.0-400910 as a template, we show that phase-resolved polarimetric measurements can unambiguously determine the model parameters, even with a small X-ray polarimetry mission carrying modern photoelectric detectors and existing X-ray optics. We also show that polarimetric measurements can pinpoint vacuum polarization effects and thus provide indirect evidence for ultra-strong magnetic fields.

  3. The XMM Cluster Survey: X-ray analysis methodology

    CERN Document Server

    Lloyd-Davies, E J; Hosmer, Mark; Mehrtens, Nicola; Davidson, Michael; Sabirli, Kivanc; Mann, Robert G; Hilton, Matt; Liddle, Andrew R; Viana, Pedro T P; Campbell, Heather C; Collins, Chris A; Dubois, E Naomi; Freeman, Peter; Hoyle, Ben; Kay, Scott T; Kuwertz, Emma; Miller, Christopher J; Nichol, Robert C; Sahlen, Martin; Stanford, S Adam; Stott, John P

    2010-01-01

    The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM- Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-ray scaling relations. In this paper we describe the data processing methodology applied to the 5776 XMM observations used to construct the current XCS source catalogue. A total of 3669 > 4-{\\sigma} cluster candidates with >50 background-subtracted X-ray counts are extracted from a total non-overlapping area suitable for cluster searching of 410 deg^2 . Of these, 1022 candidates are detected with >300 X-ray counts, and we demonstrate that robust temperature measurements can be obtained down to this count limit. We describe in detail the automated pipelines used to perform the spectral and surface brightness fitting for these sources, as well as to estimate redshifts from the X-ray data alone. A total of 517 (126) X-ray temperatures to a typical accuracy of <40 (<10) per cent have ...

  4. X-Ray Probes of Cosmic Star Formation History

    Science.gov (United States)

    Ghosh, Pranab; White, Nicholas E.

    2001-01-01

    We discuss the imprints left by a cosmological evolution of the star formation rate (SFR) on the evolution of X-ray luminosities Lx of normal galaxies, using the scheme earlier proposed by us, wherein the evolution of LX of a galaxy is driven by the evolution of its X-ray binary population. As indicated in our earlier work, the profile of Lx with redshift can both serve as a diagnostic probe of the SFR profile and constrain evolutionary models for X-ray binaries. We report here the first calculation of the expected evolution of X-ray luminosities of galaxies, updating our work by using a suite of more recently developed SFR profiles that span the currently plausible range. The first Chandra deep imaging results on Lx evolution are beginning to probe the SFR profile of bright spiral galaxies; the early results are consistent with predictions based on current SFR models. Using these new SFR profiles, the resolution of the "birthrate problem" of low-mass X-ray binaries and recycled, millisecond pulsars in terms of an evolving global SFR is more complete. We discuss the possible impact of the variations in the SFR profile of individual galaxies and galaxy types.

  5. A Hard X-Ray Study of the Normal Star-Forming Galaxy M83 with NuSTAR

    DEFF Research Database (Denmark)

    Yukita, M.; Hornschemeier, A. E.; Lehmer, B. D.

    2016-01-01

    likely dominated by intermediate accretion state black hole binaries and neutron star low-mass X-ray binaries (Z-sources). We construct the X-ray binary luminosity function (XLF) in the NuSTAR band for an extragalactic environment for the first time. The M83 XLF has a steeper XLF than the X-ray binary......We present the results from sensitive, multi-epoch NuSTAR observations of the late-type star-forming galaxy M83 (d = 4.6 Mpc). This is the first investigation to spatially resolve the hard (E > 10 keV) X-ray emission of this galaxy. The nuclear region and similar to 20 off-nuclear point sources......, including a previously discovered ultraluminous X-ray source, are detected in our NuSTAR observations. The X-ray hardnesses and luminosities of the majority of the point sources are consistent with hard X-ray sources resolved in the starburst galaxy NGC 253. We infer that the hard X-ray emission is most...

  6. A High Resolution X-ray Image of the Jet in M 87

    CERN Document Server

    Marshall, H L; Davis, D S; Perlman, E S; Wise, M; Canizares, C R; Harris, D E

    2001-01-01

    We present the first high resolution X-ray image of the jet in M 87 using the Chandra X-ray Observatory. There is clear structure in the jet and almost all of the optically bright knots are detected individually. The unresolved core is the brightest X-ray feature but is only 2-3 times brighter than knot A (12.3" from the core) and the inner knot HST-1 (1.0" from the core). The X-ray and optical positions of the knots are consistent at the 0.1" level but the X-ray emission from the brightest knot (A) is marginally upstream of the optical emission peak. Detailed Gaussian fits to the X-ray jet one-dimensional profile show distinct X-ray emission that is not associated with specific optical features. The X-ray/optical flux ratio decreases systematically from the core and X-ray emission is not clearly detected beyond 20" from the core. The X-ray spectra of the core and the two brightest knots, HST-1 and A1, are consistent with a simple power law with alpha = 1.46 +/- 0.05, practically ruling out inverse Compton mo...

  7. X-Ray-powered Macronovae

    Science.gov (United States)

    Kisaka, Shota; Ioka, Kunihito; Nakar, Ehud

    2016-02-01

    A macronova (or kilonova) was observed as an infrared excess several days after the short gamma-ray burst GRB 130603B. Although the r-process radioactivity is widely discussed as an energy source, it requires a huge mass of ejecta from a neutron star (NS) binary merger. We propose a new model in which the X-ray excess gives rise to the simultaneously observed infrared excess via thermal re-emission, and explore what constraints this would place on the mass and velocity of the ejecta. This X-ray-powered model explains both the X-ray and infrared excesses with a single energy source such as the central engine like a black hole, and allows for a broader parameter region than the previous models, in particular a smaller ejecta mass ˜ {10}-3{--}{10}-2{M}⊙ and higher iron abundance mixed as suggested by general relativistic simulations for typical NS-NS mergers. We also discuss the other macronova candidates in GRB 060614 and GRB 080503, and the implications for the search of electromagnetic counterparts to gravitational waves.

  8. Be/X-ray binaries

    CERN Document Server

    Reig, Pablo

    2011-01-01

    The purpose of this work is to review the observational properties of Be/X-ray binaries. The open questions in Be/X-ray binaries include those related to the Be star companion, that is, the so-called "Be phenomenon", such as, timescales associated to the formation and dissipation of the equatorial disc, mass-ejection mechanisms, V/R variability, and rotation rates; those related to the neutron star, such as, mass determination, accretion physics, and spin period evolution; but also, those that result from the interaction of the two constituents, such as, disc truncation and mass transfer. Until recently, it was thought that the Be stars' disc was not significantly affected by the neutron star. In this review, I present the observational evidence accumulated in recent years on the interaction between the circumstellar disc and the compact companion. The most obvious effect is the tidal truncation of the disc. As a result, the equatorial discs in Be/X-ray binaries are smaller and denser than those around isolat...

  9. X-Ray Crystallography Reagent

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2003-01-01

    Microcapsules prepared by encapsulating an aqueous solution of a protein, drug or other bioactive substance inside a semi-permeable membrane by are disclosed. The microcapsules are formed by interfacial coacervation under conditions where the shear forces are limited to 0-100 dynes per square centimeter at the interface. By placing the microcapsules in a high osmotic dewatering solution. the protein solution is gradually made saturated and then supersaturated. and the controlled nucleation and crystallization of the protein is achieved. The crystal-filled microcapsules prepared by this method can be conveniently harvested and stored while keeping the encapsulated crystals in essentially pristine condition due to the rugged. protective membrane. Because the membrane components themselves are x-ray transparent, large crystal-containing microcapsules can be individually selected, mounted in x-ray capillary tubes and subjected to high energy x-ray diffraction studies to determine the 3-D smucture of the protein molecules. Certain embodiments of the microcapsules of the invention have composite polymeric outer membranes which are somewhat elastic, water insoluble, permeable only to water, salts, and low molecular weight molecules and are structurally stable in fluid shear forces typically encountered in the human vascular system.

  10. X-ray induced chemical reaction revealed by in-situ X-ray diffraction and scanning X-ray microscopy in 15 nm resolution (Conference Presentation)

    Science.gov (United States)

    Ge, Mingyuan; Liu, Wenjun; Bock, David; De Andrade, Vincent; Yan, Hanfei; Huang, Xiaojing; Marschilok, Amy; Takeuchi, Esther; Xin, Huolin; Chu, Yong S.

    2016-09-01

    The detection sensitivity of synchrotron-based X-ray techniques has been largely improved due to the ever increasing source brightness, which have significantly advanced ex-situ and in-situ research for energy materials, such as lithium-ion batteries. However, the strong beam-matter interaction arisen from the high beam flux can significantly modify the material structure. The parasitic beam-induced effect inevitably interferes with the intrinsic material property, which brings difficulties in interpreting experimental results, and therefore requires comprehensive evaluation. Here we present a quantitative in-situ study of the beam-effect on one electrode material Ag2VO2PO4 using four different X-ray probes with different radiation dose rate. The material system we reported exhibits interesting and reversible radiation-induced thermal and chemical reactions, which was further evaluated under electron microscopy to illustrate the underlying mechanism. The work we presented here will provide a guideline in using synchrotron X-rays to distinguish the materials' intrinsic behavior from extrinsic structure changed induced by X-rays, especially in the case of in-situ and operando study where the materials are under external field of either temperature or electric field.

  11. Measurements of Si Hybrid CMOS X-Ray Detector Characteristics

    CERN Document Server

    Bongiorno, Stephen D; Burrows, David N; Cook, Robert; Bai, Yibin; Farris, Mark

    2009-01-01

    The development of Hybrid CMOS Detectors (HCDs) for X-Ray telescope focal planes will place them in con- tention with CCDs on future satellite missions due to their faster frame rates, flexible readout scenarios, lower power consumption, and inherent radiation hardness. CCDs have been used with great success on the current generation of X-Ray telescopes (e.g. Chandra, XMM, Suzaku, and Swift). However their bucket-brigade read-out architecture, which transfers charge across the chip with discrete component readout electronics, results in clockrate limited readout speeds that cause pileup (saturation) of bright sources and an inherent susceptibility to radiation induced displacement damage that limits mission lifetime. In contrast, HCDs read pixels with low power, on-chip multiplexer electronics in a random access fashion. Faster frame rates achieved with multi-output readout design will allow the next generation's larger effective area telescopes to observe bright sources free of pileup. Radiation damaged latt...

  12. High duty cycle inverse Compton scattering X-ray source

    Science.gov (United States)

    Ovodenko, A.; Agustsson, R.; Babzien, M.; Campese, T.; Fedurin, M.; Murokh, A.; Pogorelsky, I.; Polyanskiy, M.; Rosenzweig, J.; Sakai, Y.; Shaftan, T.; Swinson, C.

    2016-12-01

    Inverse Compton Scattering (ICS) is an emerging compact X-ray source technology, where the small source size and high spectral brightness are of interest for multitude of applications. However, to satisfy the practical flux requirements, a high-repetition-rate ICS system needs to be developed. To this end, this paper reports the experimental demonstration of a high peak brightness ICS source operating in a burst mode at 40 MHz. A pulse train interaction has been achieved by recirculating a picosecond CO2 laser pulse inside an active optical cavity synchronized to the electron beam. The pulse train ICS performance has been characterized at 5- and 15- pulses per train and compared to a single pulse operation under the same operating conditions. With the observed near-linear X-ray photon yield gain due to recirculation, as well as noticeably higher operational reliability, the burst-mode ICS offers a great potential for practical scalability towards high duty cycles.

  13. On the weakness of disc models in bright ULXs

    CERN Document Server

    Gonçalves, A C; Goncalves, Anabela C.; Soria, Roberto

    2006-01-01

    It is sometimes suggested that phenomenological power-law plus cool disc-blackbody models represent the simplest, most robust interpretation of the X-ray spectra of bright ultraluminous X-ray sources (ULXs); this has been taken as evidence for the presence of intermediate-mass black holes (BHs) (M ~ 10^3 Msun) in those sources. Here, we assess this claim by comparing the cool disc-blackbody model with a range of other models. For example, we show that the same ULX spectra can be fitted equally well by subtracting a disc-blackbody component from a dominant power-law component, thus turning a soft excess into a soft deficit. Then, we propose a more complex physical model, based on a power-law component slightly modified at various energies by smeared emission and absorption lines from highly-ionized, fast-moving gas. We use the XMM-Newton/EPIC spectra of two ULXs in Holmberg II and NGC 4559 as examples. Our main conclusion is that the presence of a soft excess or a soft deficit depends on the energy range over ...

  14. Chest X-Ray (Chest Radiography)

    Science.gov (United States)

    ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ...

  15. The X-ray Pulsar M82 X-2 on its Propeller Line

    CERN Document Server

    Christodoulou, D M; Laycock, S G T

    2016-01-01

    {\\it NuSTAR} has detected pulsations from the ultraluminous X-ray source X-2 in M82 and archival {\\it Chandra} observations have given us a good idea of its duty cycle. The newly discovered pulsar exhibited at least 4 super-Eddington outbursts in the past 15 years but, in its lowest-power state, it radiates just below the Eddington limit and its properties appear to be typical of high-mass X-ray binaries. M82 X-2 has been described as a common neutron star with a 1~TG magnetic field that occasionally accretes above the Eddington rate and as a magnetar-like pulsar with a 10-100~TG magnetic field that reaches above the quantum limit. We argue in favor of the former interpretation. Using standard accretion theory and the available observations, we calculate the stellar magnetic field of this pulsar in two independent ways and we show that it cannot exceed 3~TG in either case. We discuss the implications of our results for other ultraluminous X-ray sources that occasionally exhibit similar powerful outbursts.

  16. Empirical studies of solar flares: Comparison of X-ray and H alpha filtergrams and analysis of the energy balance of the X-ray plasma

    Science.gov (United States)

    Moore, R. L.

    1979-01-01

    The physics of solar flares was investigated through a combined analysis of X-ray filtergrams of the high temperature coronal component of flares and H alpha filtergrams of the low temperature chromospheric component. The data were used to study the magnetic field configuration and its changes in solar flares, and to examine the chromospheric location and structure of X-ray bright points (XPB) and XPB flares. Each topic and the germane data are discussed. The energy balance of the thermal X-ray plasma in flares, while not studied, is addressed.

  17. X-Ray Exam: Scoliosis (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Scoliosis KidsHealth > For Parents > X-Ray Exam: Scoliosis A A A What's in ... español Radiografía: escoliosis What It Is A scoliosis X-ray is a relatively safe and painless test ...

  18. X-Ray Exam: Neck (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Neck KidsHealth > For Parents > X-Ray Exam: Neck A A A What's in ... español Radiografía: cuello What It Is A neck X-ray is a safe and painless test that ...

  19. X-Ray Exam: Femur (Upper Leg)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Femur (Upper Leg) KidsHealth > For Parents > X-Ray Exam: Femur (Upper Leg) A A A ... español Radiografía: fémur What It Is A femur X-ray is a safe and painless test that ...

  20. Center for X-ray Optics, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1989-04-01

    This report briefly reviews the following topics: soft-x-ray imaging; reflective optics for hard x-rays; coherent XUV sources; spectroscopy with x-rays; detectors for coronary artery imaging; synchrotron-radiation optics; and support for the advanced light source.

  1. Cryotomography x-ray microscopy state

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-10-26

    An x-ray microscope stage enables alignment of a sample about a rotation axis to enable three dimensional tomographic imaging of the sample using an x-ray microscope. A heat exchanger assembly provides cooled gas to a sample during x-ray microscopic imaging.

  2. Internet hand x-rays: A comparison of joint space narrowing and erosion scores (Sharp/Genant of plain versus digitized x-rays in rheumatoid arthritis patients

    Directory of Open Access Journals (Sweden)

    Watson Margaret M

    2002-04-01

    Full Text Available Abstract Background The objective of the study is to examine the reliability of erosion and joint space narrowing scores derived from hand x-rays posted on the Internet compared to scores derived from original plain x-rays. Methods Left and right x-rays of the hands of 36 patients were first digitized and then posted in standard fashion to a secure Internet website. Both the plain and Internet x-rays were scored for erosions and joint space narrowing using the Sharp/Genant method. All scoring was completed in a blind and randomized manner. Agreement between plain and Internet x-ray scores was calculated using Lin's concordance correlations and Bland-Altman graphical representation. Results Erosion scores for plain x-rays showed almost perfect concordance with x-rays read on the Internet (concordance 0.887. However, joint space narrowing scores were only "fair" (concordance 0.365. Global scores demonstrated substantial concordance between plain and Internet readings (concordance 0.769. Hand x-rays with less disease involvement showed a tendency to be scored higher on the Internet versions than those with greater disease involvement. This was primarily evident in the joint space narrowing scores. Conclusions The Internet represents a valid medium for displaying and scoring hand x-rays of patients with RA. Higher scores from the Internet version may be related to better viewing conditions on the computer screen relative to the plain x-ray viewing, which did not include magnifying lens or bright light. The capability to view high quality x-rays on the Internet has the potential to facilitate information sharing, education, and encourage collaborative studies.

  3. The 300 Kpc Long X-Ray Jet in PKS 1127-145, Z=1.18 Quasar: Constraining X-Ray Emission Models

    Energy Technology Data Exchange (ETDEWEB)

    Siemiginowska, Aneta; /Harvard-Smithsonian Ctr. Astrophys.; Stawarz, Lukasz; /Heidelberg Observ. /Jagiellonian U., Astron. Observ. /KIPAC, Menlo Park; Cheung, C.C.; /KIPAC,; Harris, D.E.; /Harvard-Smithsonian Ctr. Astrophys.; Sikora, Marek; /Warsaw, Copernicus Astron. Ctr.; Aldcroft, Thomas L.; /Harvard-Smithsonian Ctr. Astrophys.; Bechtold,; /Arizona U., Astron. Dept. - Steward Observ.

    2006-11-20

    We present a {approx} 100 ksec Chandra X-ray observation and new VLA radio data of the large scale, 300 kpc long X-ray jet in PKS 1127-145, a radio loud quasar at redshift z=1.18. With this deep X-ray observation we now clearly discern the complex X-ray jet morphology and see substructure within the knots. The X-ray and radio jet intensity profiles are seen to be strikingly different with the radio emission peaking strongly at the two outer knots while the X-ray emission is strongest in the inner jet region. The jet X-ray surface brightness gradually decreases by an order of magnitude going out from the core. The new X-ray data contain sufficient counts to do spectral analysis of the key jet features. The X-ray energy index of the inner jet is relatively flat with {alpha}{sub x} = 0.66 {+-} 0.15 and steep in the outer jet with {alpha}{sub x} = 1.0 {+-} 0.2. We discuss the constraints implied by the new data on the X-ray emission models and conclude that ''one-zone'' models fail and at least a two component model is needed to explain the jet's broad-band emission. We propose that the X-ray emission originates in the jet proper while the bulk of the radio emission comes from a surrounding jet sheath. We also consider intermittent jet activity as a possible cause of the observed jet morphology.

  4. X-ray and optical observations of four polars

    Science.gov (United States)

    Worpel, H.; Schwope, A. D.; Granzer, T.; Reinsch, K.; Schwarz, R.; Traulsen, I.

    2016-08-01

    Aims: We investigate the temporal and spectral behaviour of four polar cataclysmic variables from the infrared to X-ray regimes, refine our knowledge of the physical parameters of these systems at different accretion rates, and search for a possible excess of soft X-ray photons. Methods: We obtained and analysed four XMM-Newton X-ray observations of three of the sources, two of them discovered with the SDSS and one in the RASS. The X-ray data were complemented by optical photometric and spectroscopic observations and, for two sources, archival Swift observations. Results: SDSSJ032855.00+052254.2 was X-ray bright in two XMM-Newton and two Swift observations, and shows transitions from high and low accretion states on a timescale of a few months. The source shows no significant soft excess. We measured the magnetic field strength at the main accreting pole to be 39 MG and the inclination to be 45° ≤ i ≤ 77°, and we refined the long-term ephemeris. SDSSJ133309.20+143706.9 was X-ray faint. We measured a faint phase X-ray flux and plasma temperature for this source, which seems to spend almost all of its time accreting at a low level. Its inclination is less than about 76°. 1RXSJ173006.4+033813 was X-ray bright in the XMM-Newton observation. Its spectrum contained a modest soft blackbody component, not luminous enough to be considered a significant soft excess. We inferred a magnetic field strength at the main accreting pole of 20 to 25 MG, and that the inclination is less than 77° and probably less than 63°. V808 Aur, also known as CSS081231:J071126+440405, was X-ray faint in the Swift observation, but there is nonetheless strong evidence for bright and faint phases in X-rays and perhaps in UV. Residual X-ray flux from the faint phase is difficult to explain by thermal emission from the white dwarf surface, or by accretion onto the second pole. We present a revised distance estimate of 250 pc. Conclusions: The three systems we were able to study in detail

  5. Old and Young X-ray Point Source Populations in Nearby Galaxies

    CERN Document Server

    Colbert, E; Ptak, A; Strickland, D K

    2004-01-01

    We analyzed 1441 Chandra X-ray point sources in 32 nearby galaxies. The total point-source X-ray luminosity L_XP is well correlated with B, K, and FIR+UV luminosities of spiral host galaxies, and with the B and K luminosities for ellipticals. This suggests an intimate connection between L_XP and both the old and young stellar populations, for which K and FIR+UV luminosities are proxies for the galaxy mass M and star-formation rate SFR. We derive proportionality constants 1.3E29 erg/s/Msol and 0.7E39 erg/s/(Msol/yr), which can be used to estimate the old and young components from M and SFR, respectively. The cumulative X-ray luminosity functions for the point sources have quite different slopes for the spirals (gamma ~= 0.5-0.8) and ellipticals (gamma ~= 1.4), implying *the most luminous point sources dominate L_XP* for the spirals. Most of the point sources have X-ray colors that are consistent with either LMXBs or Ultraluminous X-ray sources (ULXs a.k.a. IXOs) and we rule out classical HMXBs (e.g. neutron-st...

  6. Chandra Observation of the X-Ray Source Population of NGC 6946

    CERN Document Server

    Holt, S S; Hwang, U; Petre, R

    2003-01-01

    We present the results of a study of discrete X-ray sources in NGC 6946 using a deep Chandra ACIS observation. Based on the slope of the log N-log S distribution and the general correlation of sources with the spiral arms, we infer that the overall discrete source sample in NGC 6946 is dominated by high mass X-ray binaries, in contrast to the source distributions in M31 and the Milky Way. This is consistent with the higher star formation rate in NGC 6946 than in those galaxies. We find that the strong X-ray sources in the region of the galactic center do not correlate in detail with images of the region in the near-IR, although one of them may be coincident with the galactic center. The non-central ultra-luminous X-ray source in NGC 6946, previously identified with a supernova remnant, has an X-ray spectrum and luminosity that is inconsistent with either a traditional pulsar wind nebula or a blast wave remnant.

  7. Stereoscopic observations of a solar flare hard X-ray source in the high corona

    Science.gov (United States)

    Kane, S. R.; Mctiernan, J.; Loran, J.; Fenimore, E. E.; Klebesadel, R. W.; Laros, J. G.

    1992-01-01

    The vertical structure of the impulsive and gradual hard X-ray sources in high coronae and the characteristics of the impulsive soft X-ray emission are investigated on the basis of PVE, ICE, and GOES observations of the energetic flare on February 16, 1984. The average photon spectra observed by these instruments during the impulsive and gradual hard X-ray bursts are summarized. A comparison of these unocculted and partially occulted spectra shows that the sources of the impulsive hard X-ray (greater than about 25 keV) and impulsive soft X-ray (2-5 keV) emissions in this flare extended to coronal altitudes greater than about 200,000 km above the photosphere. At about 100 keV, the ratio of the coronal source brightness to the total source brightness was 0.001 during the impulsive phase and less than about 0.01 during the gradual hard X-ray burst. The sources of the gradual hard X-ray burst and gradual soft X-ray burst were almost completely occulted, indicating that these sources were located at heights less than 200,000 km above the photosphere.

  8. X-Ray Visions of SS Cygni

    Science.gov (United States)

    Young, D. L.

    2004-12-01

    The Chandra X-Ray Observatory is the most sophisticated X-ray observatory launched by NASA. Chandra is designed to observe X-rays from highenergy regions of the universe, such as X-ray binary stars. On September 14, 2000, triggered by alerts from amateur astronomers worldwide, Chandra observed the outburst of the brightest northern dwarf nova SS Cygni. The cooperation of hundreds of amateur variable star astronomers and the Chandra X-Ray scientists and spacecraft specialists provided proof that the collaboration of amateur and professional astronomers is a powerful tool to study cosmic phenomena.

  9. X-ray Spectroscopy of Cooling Cluster

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, J.R.; /SLAC; Fabian, A.C.; /Cambridge U., Inst. of Astron.

    2006-01-17

    We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from simple radiative cooling models. The same observations have provided compelling evidence that the gas in the cores is cooling below half the maximum temperature. We review these results, discuss physical models of cooling clusters, and describe the X-ray instrumentation and analysis techniques used to make these observations. We discuss several viable mechanisms designed to cancel or distort the expected process of X-ray cluster cooling.

  10. Comets: mechanisms of x-ray activity

    Science.gov (United States)

    Ibadov, Subhon

    2016-07-01

    Basic mechanisms of X-ray activity of comets are considered, including D-D mechanism corresponding to generation of X-rays due to production of hot short-living plasma clumps at high-velocity collisions between cometary and interplanetary dust particles as well as M-M one corresponding to production of X-rays due to recombination of multicharge ions of solar wind plasma via charge exchange process at their collisions with molecules/atoms of the cometary atmospheres. Peculiarities of the variation of the comet X-ray spectrum and X-ray luminosity with variation of its heliocentric distance are revealed.

  11. X-rays from solar system objects

    CERN Document Server

    Bhardwaj, Anil; Gladstone, G Randall; Cravens, Thomas E; Lisse, Carey M; Dennerl, Konrad; Branduardi-Raymont, Graziella; Wargelin, Bradford J; Waite, J Hunter; Robertson, Ina; Ostgaard, Nikolai; Beiersdorfer, Peter; Snowden, Steven L; Kharchenko, Vasili; 10.1016/j.pss.2006.11.009

    2010-01-01

    During the last few years our knowledge about the X-ray emission from bodies within the solar system has significantly improved. Several new solar system objects are now known to shine in X-rays at energies below 2 keV. Apart from the Sun, the known X-ray emitters now include planets (Venus, Earth, Mars, Jupiter, and Saturn), planetary satellites (Moon, Io, Europa, and Ganymede), all active comets, the Io plasma torus (IPT), the rings of Saturn, the coronae (exospheres) of Earth and Mars, and the heliosphere. The advent of higher-resolution X-ray spectroscopy with the Chandra and XMM-Newton X-ray observatories has been of great benefit in advancing the field of planetary X-ray astronomy. Progress in modeling X-ray emission, laboratory studies of X-ray production, and theoretical calculations of cross-sections, have all contributed to our understanding of processes that produce X-rays from the solar system bodies. At Jupiter and Earth, both auroral and non-auroral disk X-ray emissions have been observed. X-ray...

  12. Phase-contrast X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi [Hitachi Ltd., Hatoyama, Saitama (Japan). Advanced Research Lab.

    1996-08-01

    X-ray transmission imaging that creates image contrast from the distribution of the X-ray absorption coefficient is not sensitive to materials consisting of light elements such as hydrogen, carbon, nitrogen, and oxygen. On the other hand, the X-ray phase shift caused by the light elements is substantial enough to be detected even when absorption is almost zero. Hence, phase-contrast X-ray imaging is a promising technique for observing the structure inside biological soft tissues without the need for staining and without serious radiation exposure. Using fringe scanning X-ray interferometry, the X-ray phase shift caused by an object was measured. Three-dimensional image reconstruction of cancerous tissues using the measured phase shifts was enabled under tomographic configuration phase-contrast X-ray computed tomography (CT). (author)

  13. X-ray generation by inverse Compton scattering at the superconducting RF test facility

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Hirotaka, E-mail: hirotaka@post.kek.jp [KEK, 1-1 Oho, Tsukuba 305-0801, Ibaraki (Japan); Akemoto, Mitsuo; Arai, Yasuo; Araki, Sakae; Aryshev, Alexander; Fukuda, Masafumi; Fukuda, Shigeki; Haba, Junji; Hara, Kazufumi; Hayano, Hitoshi; Higashi, Yasuo; Honda, Yosuke; Honma, Teruya; Kako, Eiji; Kojima, Yuji; Kondo, Yoshinari; Lekomtsev, Konstantin; Matsumoto, Toshihiro; Michizono, Shinichiro; Miyoshi, Toshinobu [KEK, 1-1 Oho, Tsukuba 305-0801, Ibaraki (Japan); and others

    2015-02-01

    Quasi-monochromatic X-rays with high brightness have a broad range of applications in fields such as life sciences, bio-, medical applications, and microlithography. One method for generating such X-rays is via inverse Compton scattering (ICS). X-ray generation experiments using ICS were carried out at the superconducting RF test facility (STF) accelerator at KEK. A new beam line, newly developed four-mirror optical cavity system, and new X-ray detector system were prepared for experiments downstream section of the STF electron accelerator. Amplified pulsed photons were accumulated into a four-mirror optical cavity and collided with an incoming 40 MeV electron beam. The generated X-rays were detected using a microchannel plate (MCP) detector for X-ray yield measurements and a new silicon-on-insulator (SOI) detector system for energy measurements. The detected X-ray yield by the MCP detector was 1756.8±272.2 photons/(244 electron bunches). To extrapolate this result to 1 ms train length under 5 Hz operations, 4.60×10{sup 5} photons/1%-bandwidth were obtained. The peak X-ray energy, which was confirmed by the SOI detector, was 29 keV, and this is consistent with ICS X-rays.

  14. Single shot diffraction of picosecond 8.7-keV x-ray pulses

    Directory of Open Access Journals (Sweden)

    F. H. O’Shea

    2012-02-01

    Full Text Available We demonstrate multiphoton, single shot diffraction images of x rays produced by inverse Compton scattering a high-power CO_{2} laser from a relativistic electron beam, creating a pulse of 8.7 keV x rays. The tightly focused, relatively high peak brightness electron beam and high photon density from the 2 J CO_{2} laser yielded 6×10^{7} x-ray photons over the full opening angle in a single shot. Single shot x-ray diffraction is performed by passing the x rays though a vertical slit and on to a flat silicon (111 crystal. 10^{2} diffracted photons were detected. The spectrum of the detected x rays is compared to simulation. The diffraction and detection of 10^{2} x rays is a key step to a more efficient time resolved diagnostic in which the number of observed x rays might reach 10^{4}; enabling a unique, flexible x-ray source as a sub-ps resolution diagnostic for studying the evolution of chemical reactions, lattice deformation and melting, and magnetism.

  15. The Effect of Variability on X-Ray Binary Luminosity Functions

    Science.gov (United States)

    Binder, Breanna A.; Gross, Jacob; Williams, Benjamin F.; Eracleous, Michael; Gaetz, Terrance J.; Plucinsky, Paul P.; Skillman, Evan D.

    2017-08-01

    X-ray binaries are inherently variable X-ray sources, particularly at low luminosities (factor of ~2). The power-law index of ~1.2 and high fluxes suggest that the persistent sources intrinsic to NGC 300 are dominated by Roche-lobe-overflowing low-mass X-ray binaries. The variable X-ray sources are described by a broken power law, with a faint-end power-law index of ~1.7, a bright-end index of ~2.8-4.9, and a break luminosity of ~4 × 1036 erg s-1. This suggests that these variable sources are mostly outbursting, wind-fed high-mass X-ray binaries, although the logN-logS distribution of variable sources likely also contains low-mass X-ray binaries. We generate model logN-logS distributions for synthetic X-ray binaries and constrain the distribution of maximum X-ray fluxes attained during outburst. Our observations suggest that the majority of X-ray binaries outburst at sub-Eddington luminosities, where mass transfer likely occurs through direct wind accretion at ~1%-3% of the Eddington rate.

  16. Revealing the nature of the ULX and X-ray population of the spiral galaxy NGC 4088

    CERN Document Server

    Mezcua, M; Gladstone, J C; Farrell, S A; Soria, R

    2014-01-01

    We present the first \\textit{Chandra} and \\textit{Swift} X-ray study of the spiral galaxy NGC\\,4088 and its ultraluminous X-ray source (ULX N4088--X1). We also report very long baseline interferometry (VLBI) observations at 1.6 and 5 GHz performed quasi-simultaneously with the \\textit{Swift} and \\textit{Chandra} observations, respectively. Fifteen X-ray sources are detected by \\textit{Chandra} within the D25 ellipse of NGC\\,4088, from which we derive the X-ray luminosity function (XLF) of this galaxy. We find the XLF is very similar to those of star-forming galaxies and estimate a star-formation rate of 4.5 $M_{\\odot}$ yr$^{-1}$. The \\textit{Chandra} detection of the ULX yields its most accurate X-ray position, which is spatially coincident with compact radio emission at 1.6 GHz. The ULX \\textit{Chandra} X-ray luminosity, $L_\\mathrm{0.2-10.0 keV} = 3.4\\ \\times$ 10$^{39}$ erg s$^{-1}$, indicates that N4088--X1 could be located at the high-luminosity end of the high-mass X-ray binary (HMXB) population of NGC\\,4...

  17. Ultrafast atomic process in X-ray emission by using inner-shell ionization method for sodium and carbon atoms

    Energy Technology Data Exchange (ETDEWEB)

    Moribayashi, Kengo; Sasaki, Akira; Tajima, Toshiki [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment

    1998-07-01

    An ultrafast inner-shell ionization process with X-ray emission stimulated by high-intensity short-pulse X-ray is studied. Carbon and sodium atoms are treated as target matter. It is shown that atomic processes of the target determine the necessary X-ray intensity for X-ray laser emission as well as the features of X-ray laser such as wavelength and duration time. The intensity also depends on the density of initial atoms. Furthermore, we show that as the intensity of X-ray source becomes high, the multi-inner-shell ionization predominates, leading to the formation of hollow atoms. As the density of hollow atoms is increased by the pumping X-ray power, the emission of X-rays is not only of significance for high brightness X-ray measurement but also is good for X-ray lasing. New classes of experiments of pump X-ray probe and X-ray laser are suggested. (author)

  18. Full-field transmission x-ray imaging with confocal polycapillary x-ray optics.

    Science.gov (United States)

    Sun, Tianxi; Macdonald, C A

    2013-02-07

    A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens.

  19. Cumulative luminosity distributions of Supergiant Fast X-ray Transients in hard X-rays

    CERN Document Server

    Paizis, A

    2014-01-01

    We have analyzed in a systematic way about nine years of INTEGRAL data (17-100 keV) focusing on Supergiant Fast X-ray Transients (SFXTs) and three classical High Mass X-ray Binaries (HMXBs). Our approach has been twofold: image based analysis, sampled over a ~ks time frame to investigate the long-term properties of the sources, and lightcurve based analysis, sampled over a 100s time frame to seize the fast variability of each source during its ~ks activity. We find that while the prototypical SFXTs (IGR J17544-2619, XTE J1739-302 and SAX J1818.6-1703) are among the sources with the lowest ~ks based duty cycle ($<$1% activity over nine years of data), when studied at the 100s level, they are the ones with the highest detection percentage, meaning that, when active, they tend to have many bright short-term flares with respect to the other SFXTs. To investigate in a coherent and self consistent way all the available results within a physical scenario, we have extracted cumulative luminosity distributions for ...

  20. The origin of the hard X-ray tail in neutron-star X-ray binaries

    Science.gov (United States)

    Reig, P.; Kylafis, N.

    2016-06-01

    Context. Neutron star X-ray binaries emit a compact, optically thick, relativistic radio jet during low-luminosity, usually hard states, as Galactic black-hole X-ray binaries do. When radio emission is bright, a hard power-law tail without evidence for an exponential cutoff is observed in most systems. Aims: We have developed a jet model that explains many spectral and timing properties of black-hole binaries in the states where a jet is present. Our goal is to investigate whether our jet model can reproduce the hard tail, with the correct range of photon index and the absence of a high-energy cutoff, in neutron-star X-ray binaries. Methods: We performed Monte Carlo simulations of the Compton upscattering of soft, accretion-disk or boundary layer photons in the jet and computed the emergent energy spectra, as well as the time lag of hard photons with respect to softer ones as a function of Fourier frequency. We fit the energy spectra with a power law modified by an exponential cutoff at high energy. Results: We demonstrate that our jet model naturally explains the observed power-law distribution with photon index in the range 1.8-3. With an appropriate choice of the parameters, the cutoff expected from Comptonization is shifted to energies above ~300 keV, producing a pure power law without any evidence for a rollover, in agreement with the observations. Conclusions: Our results reinforce the idea that the link between the outflow (jet) and inflow (disk) in X-ray binaries does not depend on the nature of the compact object, but on the process of accretion. Furthermore, we address the differences between jets in black-hole and neutron-star X-ray binaries and predict that the break frequency in the spectral energy distribution of neutron-star X-ray binaries, as a class, will be lower than that of black-hole binaries.