The XSTAR Atomic Database

• Main Authors: Claudio Mendoza, Manuel A. Bautista, Jérôme Deprince, Javier A. García, Efraín Gatuzz, Thomas W. Gorczyca, Timothy R. Kallman, Patrick Palmeri, Pascal Quinet, Michael C. Witthoeft
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Atoms
• Subjects: <span style="font-variant: small-caps">xstar</span>; atomic databases; atomic processes; line formation; X-rays; high-density plasmas
• Online Access: https://www.mdpi.com/2218-2004/9/1/12

We describe the atomic database of the <span style="font-variant: small-caps;">xstar</span> spectral modeling code, summarizing the systematic upgrades carried out in the past twenty years to enable the modeling of K-lines from chemical elements with atomic number <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Z</mi><mo>≤</mo><mn>30</mn></mrow></semantics></math></inline-formula> and recent extensions to handle high-density plasmas. Such plasma environments are found, for instance, in the inner region of accretion disks round compact objects (neutron stars and black holes), which emit rich information about the system’s physical properties. Our intention is to offer a reliable modeling tool to take advantage of the outstanding spectral capabilities of the new generation of X-ray space telescopes (e.g., <span style="font-variant: small-caps;">xrism</span> and <span style="font-variant: small-caps;">athena</span>) to be launched in the coming years. Data curatorial aspects are discussed and an updated list of reference sources is compiled to improve the database provenance metadata. Two <span style="font-variant: small-caps;">xstar</span> spin-offs—the ISMabs absorption model and the uaDB database—are also described.