Document Type
Article
Publication Date
8-1-2019
Abstract
We report optical and infrared observations of theX-ray source CXOGBS J174623.5.310550. This Galactic object was identified as a potential quiescent low-mass X-ray binary accreting from anM-type donor on the basis of optical spectroscopy and the broadHα emission line. The analysis of X-shooter spectroscopy covering three consecutive nights supports an M2/3-type spectral classification. Neither radial velocity variations nor rotational broadening is detected in the photospheric lines. No periodic variability is found in I- and r-band light curves. We derive r = 20.8, I = 19.2, and Ks ≈ 16.6 for the optical and infrared counterparts with the M-type star contributing .90 per cent to the I-band light. We estimate its distance to be 1.3. 1.8 kpc. The lack of radial velocity variations implies that the M-type star is not the donor star in the X-ray binary. This could be an interloper or the outer body in a hierarchical triple. We constrain the accreting binary to be a ≲2.2 h orbital period eclipsing cataclysmic variable or a low-mass X-ray binary lying in the foreground of the Galactic bulge.
Publication Source (Journal or Book title)
Monthly Notices of the Royal Astronomical Society
First Page
2296
Last Page
2306
Recommended Citation
Torres, M., Repetto, S., Wevers, T., Heida, M., Jonker, P., Hynes, R., Nelemans, G., Kostrzewa-Rutkowska, Z., Wyrzykowski, L., Britt, C., Heinke, C., Casares, J., Johnson, C., Maccarone, T., & Steeghs, D. (2019). Constraining the nature of the accreting binary in CXOGBS J174623.5-310550. Monthly Notices of the Royal Astronomical Society, 487 (2), 2296-2306. https://doi.org/10.1093/mnras/stz1405