Fast infrared winds during the radio-loud and X-ray obscured stages of the black hole transient GRS 1915+105
Abstract
The black hole transient GRS 1915+105 entered a new phase of activity in 2018, generally characterised by low X-ray and radio fluxes. This phase has only been interrupted by episodes of strong and variable radio emission, where high levels of X-ray absorption local to the source were measured. We present 18 epochs of near-infrared spectroscopy (2018-2023) obtained with GTC/EMIR and VLT/X-shooter, spanning both radio-loud and radio-quiet periods. We demonstrate that radio-loud phases are characterised by strong P-Cygni line profiles, indicative of accretion disc winds with velocities of up to ∼3000 km s−1. This velocity is consistent with those measured in other black hole transients. It is also comparable to the velocity of the X-ray winds detected during the peak outburst phases in GRS 1915+105, reinforcing the idea that massive, multi-phase outflows are characteristic features of the largest and most powerful black hole accretion discs. Conversely, the evolution of the Brγ line profile during the radio-quiet phases follows the expected trend for accretion disc lines in a system that is gradually decreasing its intrinsic luminosity, exhibiting weaker intensities and more pronounced double-peaks.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- December 2023
- DOI:
- 10.1051/0004-6361/202348184
- arXiv:
- arXiv:2311.12933
- Bibcode:
- 2023A&A...680L..16S
- Keywords:
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- accretion;
- accretion disks;
- instrumentation: spectrographs;
- techniques: spectroscopic;
- stars: individual: GRS 1915+105;
- infrared: stars;
- X-rays: binaries;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Accepted for publication in A&