Mapping jet-ISM interactions in X-ray binaries with ALMA: A GRS 1915+105 case study

Abstract

We present Atacama Large Millimetre/Sub-Millimetre Array (ALMA) observations of IRAS 19132+1035, a candidate jet-interstellar medium (ISM) interaction zone near the black hole X-ray binary (BHXB) GRS 1915+105.With these ALMA observations (combining data from the 12 m array and the Atacama Compact Array), we map the molecular line emission across the IRAS 19132+1035 region. We detect emission from the 12 CO [J = 2 - 1], 13 CO [v = 0, J = 2 - 1], C 18 O [J = 2 - 1], H 2 CO [J = 3 0, 3 - 2 0, 2 ], H 2 CO [J = 3 2, 2 - 2 2, 1 ], H 2 CO [J = 3 2, 1 - 2 2, 0 ], SiO [v = 0, J = 5 - 4] , CH 3 OH [J = 4 2, 2 - 3 1, 2 ], and CS [v = 0, J = 5 - 4] transitions. Given the morphological, spectral, and kinematic properties of this molecular emission, we present several lines of evidence that support the presence of a jet- ISM interaction at this site, including a jet-blown cavity in the molecular gas. This compelling new evidence identifies this site as a jet-ISM interaction zone, making GRS 1915+105, the third Galactic BHXB with at least one conclusive jet-ISM interaction zone. However, we find that this interaction occurs on much smaller scales than was postulated by previous work, where the BHXB jet does not appear to be dominantly powering the entire IRAS 19132+1035 region. Using estimates of the ISM conditions in the region, we utilize the detected cavity as a calorimeter to estimate the time-averaged power carried in the GRS 1915+105 jets of (8.4 +7.7 -8.1 ) × 10 32 erg s -1 . Overall, our analysis demonstrates that molecular lines are excellent diagnostic tools to identify and probe jet-ISM interaction zones near Galactic BHXBs.