THE IMPACT OF ACCURATE EXTINCTION MEASUREMENTS FOR X-RAY SPECTRAL MODELS

Journal Article · Sat Feb 20 04:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/818/2/143· OSTI ID:22521523

Smith, Randall K. ^[1]; Valencic, Lynne A. ^[2]; Corrales, Lia ^[3]

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1. Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)
2. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
3. MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, 37-241, Cambridge, MA 02139 (United States)

Interstellar extinction includes both absorption and scattering of photons from interstellar gas and dust grains, and it has the effect of altering a source's spectrum and its total observed intensity. However, while multiple absorption models exist, there are no useful scattering models in standard X-ray spectrum fitting tools, such as XSPEC. Nonetheless, X-ray halos, created by scattering from dust grains, are detected around even moderately absorbed sources, and the impact on an observed source spectrum can be significant, if modest, compared to direct absorption. By convolving the scattering cross section with dust models, we have created a spectral model as a function of energy, type of dust, and extraction region that can be used with models of direct absorption. This will ensure that the extinction model is consistent and enable direct connections to be made between a source's X-ray spectral fits and its UV/optical extinction.

• OSTI ID: 22521523
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 818; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION SPECTRA
COMPARATIVE EVALUATIONS
COSMIC DUST
CROSS SECTIONS
DATA ANALYSIS
ENERGY DEPENDENCE
INTERSTELLAR GRAINS
INTERSTELLAR SPACE
LINEAR ABSORPTION MODELS
SCATTERING
X RADIATION
X-RAY SPECTRA