Abstract
We present revised infrared (2.2 μm) astrometry of the field containing the Galactic microquasar GRS 1758-258, using observations at the Keck I10 m telescope. We find three candidates for the microquasar within a 3 σ error circle but none within 2 σ. We show that if the 18.4 day X-ray period of GRS 1758-258 is due to a binary orbit, then only one of the three candidates, an early K-type giant, is large enough to power the microquasar via Roche lobe overflow. We therefore identify this star as the infrared counterpart of GRS 1758-258, which we classify as a low-mass X-ray binary. Long-term infrared monitoring of this source should provide further information about the microquasar system, including a confirmation of the X-ray period and an estimate of the compact object's mass.
Original language | English (US) |
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Pages (from-to) | L61-L63 |
Journal | Astrophysical Journal |
Volume | 580 |
Issue number | 1 II |
DOIs | |
State | Published - Nov 20 2002 |
Keywords
- Black hole physics
- Infrared: stars
- Stars: individual (GRS 1758-258)
- X-rays: stars
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science