On Its Way to the Neutron Star-White Dwarf Binary Graveyard, IGR J16194−2810, A First Ascent M Giant X-Ray Binary
- Author(s)
- Kenneth H. Hinkle, Francis C. Fekel, Oscar Straniero, Zachary G. Maas, Richard R. Joyce, Thomas Lebzelter, Matthew W. Muterspaugh, James R. Sowell
- Abstract
A single-lined spectroscopic orbit for the M giant in the X-ray binary IGR J16194−2810 is determined from a time series of optical spectra. The spectroscopic orbital period of 192.5 days is twice that of the photometric period, confirming that the M giant in the system is an ellipsoidal variable. The giant is identified as a first ascent giant approaching the red giant tip. The primary is a neutron star (NS) with its M giant companion filling its Roche lobe, verifying the system classification as a low-mass X-ray binary (LMXB). Stellar C, N, O, and Fe abundances are derived for the M giant with the C, N, and O values typical for a field giant with [Fe/H] = −0.14. The system does not have a large kick velocity. Models for the evolution of the system into a binary NS-white dwarf are presented. The X-ray properties are discussed in the context of this model. This binary is a rare example of a luminous, long orbital period LMXB early in the transient ellipsoidal phase.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Gemini Observatory Northern Operations Center, Tennessee State University, INAF - Osservatorio Astronomico d'Abruzzo, INAF-Osservatorio Astrofisico di Torino, Istituto Nazionale di Fisica Nucleare (INFN), Roma, Indiana University Bloomington, Columbia State Community College, Georgia Institute of Technology
- Journal
- Astrophysical Journal
- Volume
- 969
- No. of pages
- 22
- ISSN
- 0004-637X
- DOI
- https://doi.org/10.3847/1538-4357/ad4641
- Publication date
- 07-2024
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/453b5e6f-6de5-4644-98d8-0059aa70f8c0