Fast infrared winds during the radio-loud and X-ray obscured stages of the black hole transient GRS 1915+105

Journal article

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

Authors: Sánchez-Sierras, J; Muñoz-Darias, T; Motta, SE; Fender, RP; Bahramian, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: EDP Sciences
• Journal: Astronomy & Astrophysics
• Volume: 680
• Pages: L16-L16
• Publication date: 2023-12-19
• Acceptance date: 2023-11-20
• DOI: 10.1051/0004-6361/202348184
• EISSN: 1432-0746
• ISSN: 0004-6361
• Language: English
• Keywords: Luminosity; QUIET; X-ray transient; Line (geometry); Astrophysics; Galaxy; Accretion (finance); Infrared; Physics; Accretion disc; Black hole (networking); Astronomy