ISMabs: A COMPREHENSIVE X-RAY ABSORPTION MODEL FOR THE INTERSTELLAR MEDIUM

Gatuzz, E.; García, Javier A.; Kallman, T. R.; Mendoza, C.; Gorczyca, T. W.

doi:10.1088/0004-637x/800/1/29

Cited by 50 publications

(82 citation statements)

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“…X-ray absorption line spectra provide an additional means for distinguishing between the gas and solid phase abundances of select refractory elements, and the composition of dust in the ISM (Lee et al 2009). Indeed, X-ray absorption line studies toward eight X-ray binaries, obtained with the Chandra High Energy Transmission Grating Spectrometer, provided evidence for the fact that most of the interstellar iron is locked up in dust (Gatuzz et al 2015). Figure 4 shows the observed soft X-ray spectrum around the location of the iron L2 and L3 absorption edges.…”

Section: Maximal Fraction Of Mg Si and Fe In Thermally Condensed Dustmentioning

confidence: 98%

Iron: A Key Element for Understanding the Origin and Evolution of Interstellar Dust

Dwek

2016

ApJ

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The origin and depletion of iron differ from all other abundant refractory elements that make up the composition of interstellar dust. Iron is primarily synthesized in Type Ia supernovae (SNe Ia) and in core collapse supernovae (CCSN), and is present in the outflows from AGB stars. Only the latter two are observed to be sources of interstellar dust since searches for dust in SN Ia have provided strong evidence for the absence of any significant mass of dust in their ejecta. Consequently, more than 65% of the iron is injected into the ISM in gaseous form. Yet ultraviolet and X-ray observations along many lines of sight in the ISM show that iron is severely depleted in the gas phase as compared to expected solar abundances. The missing iron, comprising about 90% of the total, is believed to be locked up in interstellar dust. This suggests that most of the missing iron must have precipitated from the ISM gas by a cold accretion onto preexisting silicate, carbon, or composite grains. Iron is thus the only element that requires most of its growth to occur outside the traditional stellar condensation sources. This is a robust statement that does not depend on our evolving understanding of the dust destruction efficiency in the ISM. Reconciling the physical, optical, and chemical properties of such composite grains with their many observational manifestations is a major challenge for understanding the nature and origin of interstellar dust.

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Section: Maximal Fraction Of Mg Si and Fe In Thermally Condensed Dustmentioning

confidence: 98%

Iron: A Key Element for Understanding the Origin and Evolution of Interstellar Dust

Dwek

2016

ApJ

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“…The data were rebinned and the x-axis was rescaled for plotting purposes. different assumptions about the interstellar medium, we applied ISMABS (Gatuzz et al 2014) with the same power-law continuum. The abundance of each element is left as a free parameter so that the photoelectric absorption edges in ISMABS have the greatest possible opportunity to model the data in a way that would remove line-like features.…”

Section: Rgsmentioning

confidence: 99%

Nustar and XMM-Newton Observations of the Neutron Star X-Ray Binary 1rxs J180408.9-34205

Ludlam

Miller

Cackett

et al. 2016

ApJ

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We report on observations of the neutron star (NS) residing in the low-mass X-ray binary 1RXS J180408.9-34205 taken 2015 March by NuSTAR and XMM-Newton while the source was in the hard spectral state. We find multiple reflection features (Fe a K detected with NuSTAR; N VII, O VII, and O VIII detected in the RGS) from different ionization zones. Through joint fits using the self-consistent relativistic reflection model RELXILL, we determine the inner radius to be 11.1 R g . For a 1.4  M NS with a spin of * = a 0, this is an inner disk radius of 22.2 km. We find the inclination of the system to be between 18°and 29°. If the disk is truncated at a radius greater than the NS radius, it could be truncated by a boundary layer on the NS surface. It is also possible that the disk is truncated at the magnetospheric radius; conservative estimates would then imply ( -) B 0.3 1.0 10 9 G at the magnetic poles, though coherent pulsations have not been detected and the source is not identified as a pulsar.

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“…The observed spectrum, I obs , and the source spectrum, I src , are then related by I obs,ν = I src,ν · e −τ ν . For the individual contribution to σ ν from different phases of the absorbing medium (e.g., gas or dust) and the different constituents (e.g., oxygen) see Wilms et al (2000) or Gatuzz et al (2015). Generally in the X-ray range, the optical depth is dominated by metals (Wilms et al 2000) and σ ν ∝ E −3 , i.e., the photoelectric absorption acts more strongly on the low energy photons.…”

Section: Data and Spectral Analysismentioning

confidence: 99%

Long term variability of Cygnus X-1

Grinberg

Leutenegger

Hell

et al. 2015

A&A

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Binary systems with an accreting compact object offer a unique opportunity to investigate the strong, clumpy, line-driven winds of early-type supergiants by using the compact object's X-rays to probe the wind structure. We analyze the two-component wind of HDE 226868, the O9.7Iab giant companion of the black hole Cyg X-1, using 4.77 Ms Rossi X-ray Timing Explorer (RXTE) observations of the system taken over the course of 16 years. Absorption changes strongly over the 5.6 d binary orbit, but also shows a large scatter at a given orbital phase, especially at superior conjunction. The orbital variability is most prominent when the black hole is in the hard X-ray state. Our data are poorer for the intermediate and soft state, but show signs for orbital variability of the absorption column in the intermediate state. We quantitatively compare the data in the hard state to a toy model of a focussed Castor-AbbottKlein wind: as it does not incorporate clumping, the model does not describe the observations well. A qualitative comparison to a simplified simulation of clumpy winds with spherical clumps shows good agreement in the distribution of the equivalent hydrogen column density for models with a porosity length on the order of the stellar radius at inferior conjunction; we conjecture that the deviations between data and model at superior conjunction could either be due to lack of a focussed wind component in the model or to a more complicated clump structure.

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ISMabs: A COMPREHENSIVE X-RAY ABSORPTION MODEL FOR THE INTERSTELLAR MEDIUM

Cited by 50 publications

References 50 publications

Iron: A Key Element for Understanding the Origin and Evolution of Interstellar Dust

Iron: A Key Element for Understanding the Origin and Evolution of Interstellar Dust

Nustar and XMM-Newton Observations of the Neutron Star X-Ray Binary 1rxs J180408.9-34205

Long term variability of Cygnus X-1

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