Jet–ISM interactions near the microquasars GRS 1758−258 and 1E 1740.7−2942

Abstract

ABSTRACT We present Atacama Large Millimeter/Sub-millimeter Array observations of the candidate jet–ISM interaction zones near the black hole X-ray binaries GRS 1758−258 and 1E 1740.7−2942. Using these data, we map the molecular line emission in the regions, detecting emission from the HCN [J = 1−0], HCO+ [J = 1−0], SiO [J = 2−1], CS [J = 2−1], 13CO [J = 1−0], C18O [J = 1−0], HNCO [J = 40,4−30,3], HNCO [J = 50,5−40,4], and CH3OH [J = 21,1−11,0] molecular transitions. Through examining the morphological, spectral, and kinematic properties of this emission, we identify molecular structures that may trace jet-driven cavities in the gas surrounding these systems. Our results from the GRS 1758−258 region in particular, are consistent with recent work, which postulated the presence of a jet-blown cocoon structure in deep radio continuum maps of the region. Using these newly discovered molecular structures as calorimeters, we estimate the time averaged jet power from these systems, finding $(1.1{\!-\!}5.7)\times 10^{36}{\rm erg\, s}^{-1}$ over 0.12−0.31 Myr for GRS 1758−258 and $(0.7{\!-\!}3.5)\times 10^{37}{\rm erg\, s}^{-1}$ over 0.10−0.26 Myr for 1E 1740.7−2942. Additionally, the spectral line characteristics of the detected emission place these molecular structures in the central molecular zone of our Galaxy, thereby constraining the distances to the black hole X-ray binaries to be 8.0 ± 1.0 kpc. Overall, our analysis solidifies the diagnostic capacity of molecular lines, and highlights how astro-chemistry can both identify jet–ISM interaction zones and probe jet feedback from Galactic X-ray binaries.