Relativistic X-Ray Reflection Models for Accreting Neutron Stars
We present new reflection models specifically tailored to model the X-ray radiation reprocessed in accretion disks around neutron stars, in which the primary continuum is characterized by a single-temperature blackbody spectrum, emitted either at the surface of the star or at the boundary layer. These models differ significantly from those with a standard power-law continuum, typically observed in most accreting black holes. We show comparisons with earlier reflection models and test their performance in the NuSTAR observation of the neutron star 4U 1705−44. Simulations of upcoming missions such as XRISM-Resolve and Athena X-IFU are shown to highlight the diagnostic potential of these models for high-resolution X-ray reflection spectroscopy. These new reflection models xillverNS, and their relativistic counterpart relxillNS, are made publicly available to the community as an additional flavor in the relxill suite of reflection models.
Additional Information© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 March 11; revised 2021 November 17; accepted 2021 November 22; published 2022 February 8. We thank the referee for thoughtful comments that greatly improved this paper. We also thank E. Kara, D. Barret, and E. Kammoun for clarifications regarding the simulations with XRISM and Athena instrumental responses. J.A.G. acknowledges support from NASA ATP grant 80NSSC20K0540 and from the Alexander von Humboldt Foundation. R.M.L. acknowledges the support of NASA through the Hubble Fellowship Program grant HST-HF2-51440.001. This work was partially supported under NASA contract No. NNG08FD60C and made use of data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the National Aeronautics and Space Administration. We thank the NuSTAR Operations, Software, and Calibration teams for support with the execution and analysis of these observations. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS), jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (USA). Facility: NuSTAR. - Software: xspec (v12.10.0c; Arnaud 1996), xillver (García & Kallman 2010; García et al. 2013), relxill (v1.5.0; García et al. 2014; Dauser et al. 2014).
Published - García_2022_ApJ_926_13.pdf
Accepted Version - 2111.12838.pdf