Broadband ‘spectro-temporal’ features of extragalactic black hole binaries LMC X-1 and LMC X-3: An AstroSat perspective

Abstract We present the first results of extragalactic black hole X-ray binaries LMC X-1 and LMC X-3 using all the archival and legacy observations by AstroSat during the period of 2016 − 2020. Broadband energy spectra (0.5 − 20 keV) of both sources obtained from the SXT and LAXPC on-board AstroSat are characterized by strong thermal disc blackbody component (kTin ∼ 1keV, $f_{disc}>79\%$) along with a steep power-law (Γ ∼ 2.4 − 3.2). Bolometric luminosity of LMC X-1 varies from $7-10\%$ of Eddington luminosity (LEdd) and for LMC X-3 is in the range $7-13\%$ of LEdd. We study the long-term variation of light curve using MAXI data and find the fractional variance to be $\sim 25\%$ for LMC X-1 and $\sim 53\%$ for LMC X-3. We examine the temporal properties of both sources and obtain fractional rms variability of PDS in the frequency range 0.002 − 10 Hz to be $\sim 9\%-17\%$ for LMC X-1, and $\sim 7\%-11\%$ for LMC X-3. The ‘spectro-temporal’ properties indicate both sources are in thermally dominated soft state. By modelling the spectra with relativistic accretion disc model, we determine the mass of LMC X-1 and LMC X-3 in the range 7.64 − 10.00 M⊙ and 5.35 − 6.22 M⊙ respectively. We also constrain the spin of LMC X-1 to be in the range 0.82 − 0.92 and that of LMC X-3 in 0.22 − 0.41 with 90% confidence. We discuss the implications of our results in the context of accretion dynamics around the black hole binaries and compare it with the previous findings of both sources.

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GRS 1758–258: RXTE Monitoring of a Rare Persistent Hard State Black Hole

Acta Polytechnica ◽

10.14311/1480 ◽

2011 ◽

Vol 51 (6) ◽

Author(s):

M. Obst ◽

K. Pottschmidt ◽

A. Lohfink ◽

J. Wilms ◽

M. Böck ◽

...

Keyword(s):

Black Hole ◽

State Transitions ◽

Spectral Evolution ◽

X Ray ◽

Soft State ◽

Hard State ◽

Long Term Behavior ◽

X Ray Binaries ◽

Black Hole Candidates

GRS 1758–258 is the least studied of the three persistent black hole X-ray binaries in our Galaxy. It is also one of only two known black hole candidates, including all black hole transients, which shows a decrease of its 3-10 keV flux when entering the thermally dominated soft state, rather than an increase.We present the spectral evolution of GRS 1758–258 from RXTE-PCA observations spanning a time of about 11 years from 1996 to 2007. During this time, seven dim soft states are detected. We also consider INTEGRAL monitoring observations of the source and compare the long-term behavior to that of the bright persistent black hole X-ray binary Cygnus X-1. We discuss the observed state transitions in the light of physical scenarios for black hole transitions.

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X-ray spectral and flux variability of the microquasar GRS 1758−258 on timescales from weeks to years

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834647 ◽

2020 ◽

Vol 636 ◽

pp. A51 ◽

Cited By ~ 1

Author(s):

Maria Hirsch ◽

Katja Pottschmidt ◽

David M. Smith ◽

Arash Bodaghee ◽

Marion Cadolle Bel ◽

...

Keyword(s):

Black Hole ◽

Power Spectra ◽

State Transitions ◽

X Ray ◽

Soft State ◽

Term Variation ◽

Transient Sources ◽

Hard State ◽

Proportional Counter Array

We present the spectral and timing evolution of the persistent black hole X-ray binary GRS 1758−258 based on almost 12 years of observations using the Rossi X-ray Timing Explorer Proportional Counter Array. While the source was predominantly found in the hard state during this time, it entered the thermally dominated soft state seven times. In the soft state GRS 1758−258 shows a strong decline in flux above 3 keV rather than the pivoting flux around 10 keV more commonly shown by black hole transients. In its 3–20 keV hardness intensity diagram, GRS 1758−258 shows a hysteresis of hard and soft state fluxes typical for transient sources in outburst. The RXTE-PCA and RXTE-ASM long-term light curves do not show any orbital modulations in the range of 2–30 d. However, in the dynamic power spectra significant peaks drift between 18.47 and 18.04 d for the PCA data, while less significant signatures between 19 d and 20 d are seen for the ASM data as well as for the Swift/BAT data. We discuss different models for the hysteresis behavior during state transitions as well as possibilities for the origin of the long term variation in the context of a warped accretion disk.

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Thermal and radiation driving can produce observable disc winds in hard-state X-ray binaries

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa209 ◽

2020 ◽

Vol 492 (4) ◽

pp. 5271-5279 ◽

Cited By ~ 2

Author(s):

Nick Higginbottom ◽

Christian Knigge ◽

Stuart A Sim ◽

Knox S Long ◽

James H Matthews ◽

...

Keyword(s):

Black Hole ◽

Binary Systems ◽

Velocity Structure ◽

Spectral Energy ◽

X Ray ◽

Black Hole Binaries ◽

Soft State ◽

Before And After ◽

Hard State ◽

New Generation

ABSTRACT X-ray signatures of outflowing gas have been detected in several accreting black hole binaries, always in the soft state. A key question raised by these observations is whether these winds might also exist in the hard state. Here, we carry out the first full-frequency radiation hydrodynamic simulations of luminous (${L = 0.5 \, L_{\mathrm{\mathrm{ Edd}}}}$) black hole X-ray binary systems in both the hard and the soft state, with realistic spectral energy distributions (SEDs). Our simulations are designed to describe X-ray transients near the peak of their outburst, just before and after the hard-to-soft state transition. At these luminosities, it is essential to include radiation driving, and we include not only electron scattering, but also photoelectric and line interactions. We find powerful outflows with ${\dot{M}_{\mathrm{ wind}} \simeq 2 \, \dot{M}_{\mathrm{ acc}}}$ are driven by thermal and radiation pressure in both hard and soft states. The hard-state wind is significantly faster and carries approximately 20 times as much kinetic energy as the soft-state wind. However, in the hard state the wind is more ionized, and so weaker X-ray absorption lines are seen over a narrower range of viewing angles. Nevertheless, for inclinations ≳80°, blueshifted wind-formed Fe xxv and Fe xxvi features should be observable even in the hard state. Given that the data required to detect these lines currently exist for only a single system in a luminous hard state – the peculiar GRS 1915+105 – we urge the acquisition of new observations to test this prediction. The new generation of X-ray spectrometers should be able to resolve the velocity structure.

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Long‐Term Evolution of Massive Black Hole Binaries

The Astrophysical Journal ◽

10.1086/378086 ◽

2003 ◽

Vol 596 (2) ◽

pp. 860-878 ◽

Cited By ~ 170

Author(s):

Miloš Milosavljević ◽

David Merritt

Keyword(s):

Black Hole ◽

Long Term Evolution ◽

Massive Black Hole ◽

Black Hole Binaries ◽

Term Evolution

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Radiative Processes and Geometry of Spectral States of Black-hole Binaries

Symposium - International Astronomical Union ◽

10.1017/s0074180900162898 ◽

2000 ◽

Vol 195 ◽

pp. 153-170 ◽

Cited By ~ 2

Author(s):

A. A. Zdziarski

Keyword(s):

Black Hole ◽

High Energy ◽

Power Density Spectrum ◽

Main Process ◽

Density Spectrum ◽

Black Hole Binaries ◽

Nonthermal Electrons ◽

Radiative Processes ◽

Soft State ◽

Spectral States

I review radiative processes responsible for X-ray emission in the hard (low) and soft (high) spectral states of black-hole binaries. The main process in the hard state appears to be thermal Comptonization (in a hot plasma) of blackbody photons emitted by a cold disk. This is supported by correlations between the spectral index, the strength of Compton reflection, and the peak frequencies in the power-density spectrum, as well as by the frequency-dependence of Fourier-resolved spectra. Spectral variability may then be driven by the variable truncation radius of the disk. The soft state appears to correspond to the smallest truncation radii. However, the lack of high-energy cutoffs observed in the soft state implies that its main radiative process is Compton scattering of disk photons by nonthermal electrons. The bulk-motion Comptonization model for the soft state is shown to be ruled out by the data.

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Accretion-outflow connection in the outliers of the “universal” radio/X-ray correlation

Proceedings of the International Astronomical Union ◽

10.1017/s174392131001611x ◽

2010 ◽

Vol 6 (S275) ◽

pp. 255-259

Author(s):

M. Coriat ◽

S. Corbel ◽

L. Prat ◽

J. C. A. Miller-Jones ◽

D. Cseh ◽

...

Keyword(s):

Black Hole ◽

Compact Objects ◽

X Rays ◽

X Ray ◽

Black Hole Candidate ◽

Long Term Study ◽

Hard State ◽

Universal Correlation ◽

X Ray Binaries

AbstractIn recent years, numerous efforts have been devoted to unravel the connection between accretion flow and jets in accreting compact objects. Here we report new constraints on these issues, through the long term study of the radio and X-ray behaviour of the black hole candidate H 1743–322. This source is known to be one of the “outliers” of the universal radio/X-ray correlation, i.e. a group of stellar mass accreting black holes displaying fainter radio emission for a given X-ray luminosity, than expected from the correlation. In this work we find, at high X-ray luminosity in the hard state, a tight radio/X-ray correlation with an unusual steep slope of b = 1.38 ± 0.03. This correlation then breaks below ~5 × 10−3LEdd (M/10M⊙)−1 in X-rays and becomes shallower. When compared with radio/X-ray data from other black hole X-ray binaries, we see that the deviant points of H 1743–322 join the universal correlation and seem to follow it at low luminosity. Based on these results, we investigate several hypotheses that could explain both the b ~ 1.4 slope and the transition toward the universal correlation.

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Long‐Term Evolution of Massive Black Hole Binaries. II. Binary Evolution in Low‐Density Galaxies

The Astrophysical Journal ◽

10.1086/491598 ◽

2005 ◽

Vol 633 (2) ◽

pp. 680-687 ◽

Cited By ~ 68

Author(s):

Peter Berczik ◽

David Merritt ◽

Rainer Spurzem

Keyword(s):

Black Hole ◽

Long Term Evolution ◽

Low Density ◽

Massive Black Hole ◽

Black Hole Binaries ◽

Term Evolution ◽

Binary Evolution

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NuSTAR and Swift Observations of the Extragalactic Black Hole X-ray Binaries

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab2448 ◽

2021 ◽

Author(s):

Arghajit Jana ◽

Sachindra Naik ◽

Debjit Chatterjee ◽

Gaurava K Jaisawal

Keyword(s):

Black Hole ◽

Thermal Emission ◽

Light Curves ◽

Telescope Array ◽

X Ray ◽

Soft State ◽

Galactic Black Hole ◽

Photon Index ◽

X Ray Binaries ◽

Emission Fraction

Abstract We present the results obtained from detailed spectral and timing studies of extra-galactic black hole X-ray binaries LMC X–1 and LMC X–3, using simultaneous observations with Nuclear Spectroscopic Telescope Array (NuSTAR) and Neil Gehrels Swift observatories. The combined spectra in the 0.5 − 30 keV energy range, obtained between 2014 and 2019, are investigated for both sources. We do not find any noticeable variability in 0.5 − 30 keV light curves, with 0.1 − 10 Hz fractional rms estimated to be <2 per cent. No evidence of quasi-periodic oscillations is found in the power density spectra. The sources are found to be in the high soft state during the observations with disc temperature Tin ∼ 1 keV, photon index, Γ > 2.5 and thermal emission fraction, fdisc > 80 per cent. An Fe Kα emission line is detected in the spectra of LMC X–1, though no such feature is observed in the spectra of LMC X–3. From the spectral modelling, the spins of the black holes in LMC X–1 and LMC X–3 are estimated to be in the range of 0.92 − 0.95 and 0.19 − 0.29, respectively. The accretion efficiency is found to be, η ∼ 0.13 and η ∼ 0.04 for LMC X–1 and LMC X–3, respectively.

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