Detalles de publicación

PP 023101

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

J. Sánchez-Sierras, T. Muñoz-Darias, S. E. Motta, R. P. Fender, A. Bahramian, C. Martínez-Sebastián, J. A. Fernández-Ontiveros, J. Casares, M. Armas Padilla, D. A. Green, D. Mata Sánchez, J. Strader, M. A. P. Torres
IAC, ULL, INAF-Brera, Oxford University, Cape Town University, Curtin university, CEFCA-Teruel and Cambridge University.
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 been only interrupted by episodes of strong and variable radio emission, during which 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 $\mathrm{\sim 3000~km~s^{-1}}$. 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 Br$\gamma$ 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.

 
Aceptado para publicación en A&A Letters | Enviado el 2023-12-11 | Proyecto P/309710