Exploring the accretion-ejection geometry of GRS 1915+105 in the obscured state with future X-ray spectro-polarimetry

Abstract

GRS 1915+105 has been in a bright flux state for more than 2 decades, but in 2018 a significant drop in flux was observed, partly due to changes in the central engine along with increased X-ray absorption. The aim of this work is to explore how X-ray spectro-polarimetry can be used to derive the basic geometrical properties of the absorbing and reflecting matter. In particular, the expected polarisation of the radiation reflected off the disc and the putative outflow is calculated. We use \textit{NuSTAR} data collected after the flux drop to derive the parameters of the system from hard X-ray spectroscopy. The spectroscopic parameters are then used to derive the expected polarimetric signal, using results from a MonteCarlo radiative transfer code both in the case of neutral and fully ionised matter. From the spectral analysis, we find that the continuum emission becomes softer with increasing flux, and that in all flux levels the obscuring matter is highly ionised. This analysis, on the other hand, confirms that spectroscopy alone is unable to put constraints on the geometry of the reflectors. Simulations show that X-ray polarimetric observations, like those that will be provided soon by the Imaging X-ray Polarimetry Explorer (IXPE), will help to determine the geometrical parameters which are left unconstrained by the spectroscopic analysis.

arXiv comment14 pages, 13 figures, Accepted for publication in Astronomy & Astrophysics

References in corpus (40)

• On the Absorption of X-rays in the Interstellar Medium
• Towards a unified model for black hole X-ray binary jets
• The MAXI Mission on the ISS: Science and Instruments for Monitoring All Sky X-Ray Images
• Broad-band gamma-ray and X-ray spectra of NGC 4151 and their implications for physical processes and geometry
• The May 1989 outburst of the Soft X-ray Transient GS 2023+338 (V404 Cyg)
• The Swift/BAT Hard X-ray Transient Monitor
• X-ray reflected spectra from accretion disk models. III. A complete grid of ionized reflection calculations
• MERLIN observations of relativistic ejections from GRS 1915+105
• Ubiquitous equatorial accretion disc winds in black hole soft states
• X-ray reflected spectra from accretion disk models. I. Constant density atmospheres
• An efficient photoelectric X-ray Polarimeter for the study of Black Holes and Neutron Stars
• The Contribution of the Obscuring Torus to the X--Ray Spectrum of Seyfert Galaxies: A Test for the Unification Model
• A Parallax Distance to the Microquasar GRS 1915+105 and a Revised Estimate of its Black Hole Mass
• The Chandra HETGS and RXTE view of GRS 1915+105
• High resolution Chandra HETG and RXTE observations of GRS 1915+105 : A hot disk atmosphere & cold gas enriched in Iron and Silicon
• X-ray Polarization from Accreting Black Holes: Coronal Emission
• Normalizing a Relativistic Model of X-ray Reflection: The Definition of the Reflection Fraction and its Implementation in relxill
• On why the Iron K-shell absorption in AGN is not a signature of the local Warm/Hot Intergalactic Medium
• Modeling optical and UV polarization of AGNs I. Imprints of individual scattering regions
• GRS 1915+105 in "Soft State": Nature of Accretion Disk Wind and Origin of X-Ray Emission
• X-ray reflected spectra from accretion disk models.II. Diagnostic tools for X-ray observations
• Clumped stellar winds in supergiant high-mass X-ray binaries: X-ray variability and photoionization
• Constraining the size of the corona with fully relativistic calculations of spectra of extended corona. I - the Monte Carlo radiative transfer code
• The Accretion Disk Wind in the Black Hole GRS 1915+105
• Swift observations of V404 Cyg during the 2015 outburst: X-ray outflows from super-Eddington accretion
• An Obscured, Seyfert-2-like State of the Stellar-mass Black Hole GRS 1915+105 Caused by Failed Disk Winds
• The obscured X-ray binaries V404 Cyg, Cyg X-3, V4641 Sgr, and GRS 1915+105
• NuSTAR reveals the hidden nature of SS433
• Spotting the misaligned outflows in NGC 1068 using X-ray polarimetry
• Variable iron-line emission near the black hole of Markarian 766
• Variable Nature of Magnetically-Driven Ultra-Fast Outflows
• A NICER View of a Highly-Absorbed Flare in GRS 1915+105
• Predicting the X-ray polarization of type-2 Seyfert galaxies
• MoCA: A Monte Carlo code for Comptonisation in Astrophysics. I. Description of the code and first results
• Disk-Wind Connection During the Heartbeats of GRS 1915+105
• The radio/X-ray correlation in Cyg X-3 and the nature of its hard spectral state
• The Novel Obscured State of Stellar-mass Black Hole GRS 1915+105
• Contribution of parsec-scale material onto the polarized X-ray spectrum of type-1 Seyfert galaxies
• Insight-HXMT observations of a possible fast transition from jet to wind dominated state during a huge flare of GRS~1915+105
• A variable magnetic disc wind in the black hole X-ray binary GRS 1915+105?

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