From Active Stars to Black Holes: A Discovery Tool for Galactic X-Ray Sources
Abstract
Galactic X-ray sources are diverse, ranging from active M dwarfs to compact object binaries, and everything in between. The X-ray landscape of today is rich, with point source catalogs such as those from XMM-Newton, Chandra, and Swift, each with ≳105 sources and growing. Furthermore, X-ray astronomy is on the verge of being transformed through data releases from the all-sky SRG/eROSITA survey. Many X-ray sources can be associated with an optical counterpart, which in the era of Gaia, can be determined to be Galactic or extragalactic through parallax and proper motion information. Here, I present a simple diagram—the "X-ray Main Sequence," which distinguishes between compact objects and active stars based on their optical color and X-ray-to-optical flux ratio (F X/F opt). As a proof of concept, I present optical spectroscopy of six exotic accreting WDs discovered using the X-ray Main Sequence as applied to the XMM-Newton catalog. Looking ahead to surveys of the near future, I additionally present SDSS-V optical spectroscopy of new systems discovered using the X-ray Main Sequence as applied to the SRG/eROSITA eFEDS catalog.
- Publication:
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Publications of the Astronomical Society of the Pacific
- Pub Date:
- May 2024
- DOI:
- 10.1088/1538-3873/ad357c
- arXiv:
- arXiv:2401.09537
- Bibcode:
- 2024PASP..136e4201R
- Keywords:
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- X-ray astronomy;
- Binary stars;
- Cataclysmic variable stars;
- RS Canum Venaticorum variable stars;
- Variable stars;
- Astronomy data visualization;
- X-ray stars;
- 1810;
- 154;
- 203;
- 1416;
- 1761;
- 1968;
- 1823;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Submitted to PASP