2001/03/26 by S. S. Eikenberry, William J. Fischer, W. J. Fischer +3 · 2 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Gamma-ray bursts and supernovae #astro-ph
paper · pdf · doi:10.1086/321560
To appear in the Astrophysical Journal; 15 pages, including 4 figures
arxiv created 2001/03/26 · openalex publication_date 2001/07/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We present deep infrared (2.2 μm) imaging of the Galactic microquasars 1E 1740-2942 and GRS 1758-258 using the Keck I 10 m telescope in 1998 June. The observations were taken under excellent seeing conditions (~0 45 full width at half-maximum), making them exceptionally deep for these crowded fields. We used the USNO-A2.0 catalog to astrometrically calibrate the infrared images (along with an optical CCD image in the case of GRS 1758-258), providing independent frame ties to the known radio positions of the objects. For 1E 1740-2942, we confirm potential candidates for the microquasar previously identified by Martí et al. and show that none of the objects near the microquasar have varied significantly from 1998 to 1999. For GRS 1758-258, our astrometry indicates a position shifted from previous reports of candidates for the microquasar. We find no candidates inside our 90% confidence radius to a 2 σ limiting magnitude of K s = 20.3 mag. We discuss the implications of these results for the nature of the microquasar binary systems.