The<i>Chandra</i>High‐Energy Transmission Grating: Design, Fabrication, Ground Calibration, and 5 Years in Flight

Canizares, C. R.; Davis, John E.; Dewey, Daniel; Flanagan, Kathryn A.; Galton, Eugene B.; Huenemoerder, David P.; Ishibashi, Koji; Markert, T. H.; Marshall, Herman L.; McGuirk, Michael; Schattenburg, Mark L.; Schulz, Norbert S.; Smith, Henry I.; Wise, Michael

doi:10.1086/432898

Cited by 317 publications

(235 citation statements)

References 61 publications

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“…The gratings on board NASA's Chandra satellite (HETGS/LETGS, e.g. Brinkman et al 2000 andCanizares et al 2005) have the highest spectral resolution available in the X-ray band, but their effective area is smaller than that of RGS in the soft X-ray band where most ULX wind features are shown and where the flux is highest. HETGS and LETGS are clearly optimal to distinguish spectral features in the brightest objects, whilst the RGS has unique capabilities to detect lines in weak objects, which means that the continuation of the XMM-Newton and Chandra missions is crucial to study the ULXs and ULSs in detail.…”

Section: Xmm-newton In the Next Decadementioning

confidence: 99%

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

Pinto

Alston

Soria

et al. 2017

Monthly Notices of the Royal Astronomical Society

127

188

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In recent work with high-resolution grating spectrometers (RGS) aboard XMM-Newton Pinto et al. (2016) 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 disk X-ray photons almost entirely, making the source appear as a soft thermal emitter or ultraluminous supersoft Xray 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 disk. 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.

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Section: Xmm-newton In the Next Decadementioning

confidence: 99%

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

Pinto

Alston

Soria

et al. 2017

Monthly Notices of the Royal Astronomical Society

127

188

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“…To mitigate pileup, the first three observations were taken with the High Energy Transmission Grating (HETG; Canizares et al 2005) in place to act as a filter, for which we analyzed the zeroth order image. The final three observations were taken without the HETG, but with the chip read in 1/8 subarray mode to reduce the exposure frame time.…”

Section: Chandra Observations and Data Reductionmentioning

confidence: 99%

The 2015 Decay of the Black Hole X-Ray Binary V404 Cygni: Robust Disk-Jet Coupling and a Sharp Transition Into Quiescence

Plotkin

Miller-Jones

Gallo

et al. 2017

ApJ

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We present simultaneous X-ray and radio observations of the black hole X-ray binary V404 Cygni at the end of its 2015 outburst. From 2015 July 11-August 5, we monitored V404 Cygni with Chandra, Swift, and NuSTAR in the X-ray, and with the Karl G. Jansky Very Large Array and the Very Long Baseline Array in the radio, spanning a range of luminosities that were poorly covered during its previous outburst in 1989 (our 2015 campaign covers10 erg s 33 X 34 1 ). During our 2015 campaign, the X-ray spectrum evolved rapidly from a hard photon index of). We argue that V404 Cygni reaching G » 2 marks the beginning of the quiescent spectral state, which occurs at a factor of ≈3-4 higher X-ray luminosity than the average pre-outburst luminosity of »´-8 10 erg s 32 1. V404 Cygni falls along the same radio/X-ray luminosity correlation that it followed during its previous outburst in 1989, implying a robust disk-jet coupling. We exclude the possibility that a synchrotron-cooled jet dominates the X-ray emission in quiescence, leaving synchrotron self-Compton from either a hot accretion flow or from a radiatively cooled jet as the most likely sources of X-ray radiation, and/or particle acceleration along the jet becoming less efficient in quiescence. Finally, we present the first indications of correlated radio and X-ray variability on minute timescales in quiescence, tentatively measuring the radio emission to lag the X-ray by  15 4 minute, suggestive of X-ray variations propagating down a jet with alength of<3.0 au.

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“…This instrument contains two gratings: HEG and MEG with a resolution of 0.012 Å and 0.023 Å (full width at half maximum), respectively (Canizares et al 2005). The energy resolution of our models is therefore well within the resolution of the Chandra Space Telescope HETG detector.…”

Section: Data Analysis Of Gx 5-1mentioning

confidence: 99%

Absorption and scattering by interstellar dust in the silicon K-edge of GX 5-1

Zeegers

Costantini

Vries

et al. 2017

A&A

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Context. We study the absorption and scattering of X-ray radiation by interstellar dust particles, which allows us to access the physical and chemical properties of dust. The interstellar dust composition is not well understood, especially on the densest sight lines of the Galactic Plane. X-rays provide a powerful tool in this study. Aims. We present newly acquired laboratory measurements of silicate compounds taken at the Soleil synchrotron facility in Paris using the Lucia beamline. The dust absorption profiles resulting from this campaign were used in this pilot study to model the absorption by interstellar dust along the line of sight of the low-mass X-ray binary (LMXB) GX 5-1. Methods. The measured laboratory cross-sections were adapted for astrophysical data analysis and the resulting extinction profiles of the Si K-edge were implemented in the SPEX spectral fitting program. We derive the properties of the interstellar dust along the line of sight by fitting the Si K-edge seen in absorption in the spectrum of GX 5-1. Results. We measured the hydrogen column density towards GX 5-1 to be 3.40 ± 0.1 × 10 22 cm −2 . The best fit of the silicon edge in the spectrum of GX 5-1 is obtained by a mixture of olivine and pyroxene. In this study, our modeling is limited to Si absorption by silicates with different Mg:Fe ratios. We obtained an abundance of silicon in dust of 4.0 ± 0.3 × 10 −5 per H atom and a lower limit for total abundance, considering both gas and dust, of > 4.4 × 10 −5 per H atom, which leads to a gas to dust ratio of > 0.22. Furthermore, an enhanced scattering feature in the Si K-edge may suggest the presence of large particles along the line of sight.

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TheChandraHigh‐Energy Transmission Grating: Design, Fabrication, Ground Calibration, and 5 Years in Flight

Cited by 317 publications

References 61 publications

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

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

The 2015 Decay of the Black Hole X-Ray Binary V404 Cygni: Robust Disk-Jet Coupling and a Sharp Transition Into Quiescence

Absorption and scattering by interstellar dust in the silicon K-edge of GX 5-1

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