scholarly journals Detecting gravitational self-lensing from stellar-mass binaries composed of black holes or neutron stars

2019 ◽  
Vol 491 (1) ◽  
pp. 1506-1517 ◽  
Author(s):  
Daniel J D’Orazio ◽  
Rosanne Di Stefano
Keyword(s):  
Black Holes ◽  
Gravitational Lensing ◽  
Compact Object ◽  
Stellar Mass ◽  
The Other ◽  
Light Emitting ◽  
X Ray ◽  
Wave Emission ◽  
Orbital Periods ◽  
Electromagnetic Signature

ABSTRACT We explore a unique electromagnetic signature of stellar-mass compact-object binaries long before they are detectable in gravitational waves. We show that gravitational lensing of light emitting components of a compact-object binary, by the other binary component, could be detectable in the nearby Universe. This periodic lensing signature could be detected from present and future X-ray observations, identifying the progenitors of binaries that merge in the LIGO band, and also unveiling populations that do not merge, thus providing a tracer of the compact-object binary population in an enigmatic portion of its life. We argue that periodically repeating lensing flares could be observed for ≲100 ks orbital-period binaries with the future Lynx X-ray mission, possibly concurrent with gravitational wave emission in the LISA band. Binaries with longer orbital periods could be more common and be detectable as single lensing flares, though with reliance on a model for the flare that can be tested by observations of succeeding flares. Non-detection of such events, even with existing X-ray observations, will help to constrain the population of EM bright compact-object binaries.

scholarly journals Accretion onto Relativistic Objects

1974 ◽  
Vol 64 ◽  
pp. 194-212
Author(s):  
M. J. Rees
Keyword(s):  
Black Holes ◽  
Interstellar Medium ◽  
Neutron Stars ◽  
Binary Systems ◽  
Compact Object ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
Compact Objects ◽  
X Ray ◽  
Intergalactic Space

The physics of spherically symmetrical accretion onto a compact object is briefly reviewed. Neither neutron stars nor stellar-mass black holes are likely to be readily detectable if they are isolated and accreting from the interstellar medium. Supermassive black holes in intergalactic space may however be detectable. The effects of accretion onto compact objects in binary systems are then discussed, with reference to the phenomena observed in variable X-ray sources.

scholarly journals The missing link in gravitational-wave astronomy

2021 ◽  
Author(s):  
Manuel Arca Sedda ◽  
Christopher P. L. Berry ◽  
Karan Jani ◽  
Pau Amaro-Seoane ◽  
Pierre Auclair ◽  
...  
Keyword(s):  
Black Holes ◽  
Gravitational Wave ◽  
Particle Physics ◽  
Cosmic Time ◽  
Compact Object ◽  
Stellar Mass ◽  
Wave Band ◽  
Binary Black Holes ◽  
Tests Of General Relativity ◽  
Binary Neutron Star

AbstractSince 2015 the gravitational-wave observations of LIGO and Virgo have transformed our understanding of compact-object binaries. In the years to come, ground-based gravitational-wave observatories such as LIGO, Virgo, and their successors will increase in sensitivity, discovering thousands of stellar-mass binaries. In the 2030s, the space-based LISA will provide gravitational-wave observations of massive black holes binaries. Between the $\sim 10$ ∼ 10 –103 Hz band of ground-based observatories and the $\sim 10^{-4}$ ∼ 1 0 − 4 –10− 1 Hz band of LISA lies the uncharted decihertz gravitational-wave band. We propose a Decihertz Observatory to study this frequency range, and to complement observations made by other detectors. Decihertz observatories are well suited to observation of intermediate-mass ($\sim 10^{2}$ ∼ 1 0 2 –104M⊙) black holes; they will be able to detect stellar-mass binaries days to years before they merge, providing early warning of nearby binary neutron star mergers and measurements of the eccentricity of binary black holes, and they will enable new tests of general relativity and the Standard Model of particle physics. Here we summarise how a Decihertz Observatory could provide unique insights into how black holes form and evolve across cosmic time, improve prospects for both multimessenger astronomy and multiband gravitational-wave astronomy, and enable new probes of gravity, particle physics and cosmology.

scholarly journals Probing black hole accretion tracks, scaling relations, and radiative efficiencies from stacked X-ray active galactic nuclei

2019 ◽  
Vol 493 (1) ◽  
pp. 1500-1511 ◽  
Author(s):  
Francesco Shankar ◽  
David H Weinberg ◽  
Christopher Marsden ◽  
Philip J Grylls ◽  
Mariangela Bernardi ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Selection Bias ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
Independent Evidence ◽  
X Ray ◽  
Black Hole Accretion ◽  
Black Hole Masses ◽  
Hole Accretion

ABSTRACT The masses of supermassive black holes at the centres of local galaxies appear to be tightly correlated with the mass and velocity dispersions of their galactic hosts. However, the local Mbh–Mstar relation inferred from dynamically measured inactive black holes is up to an order-of-magnitude higher than some estimates from active black holes, and recent work suggests that this discrepancy arises from selection bias on the sample of dynamical black hole mass measurements. In this work, we combine X-ray measurements of the mean black hole accretion luminosity as a function of stellar mass and redshift with empirical models of galaxy stellar mass growth, integrating over time to predict the evolving Mbh–Mstar relation. The implied relation is nearly independent of redshift, indicating that stellar and black hole masses grow, on average, at similar rates. Matching the de-biased local Mbh–Mstar relation requires a mean radiative efficiency ε ≳ 0.15, in line with theoretical expectations for accretion on to spinning black holes. However, matching the ‘raw’ observed relation for inactive black holes requires ε ∼ 0.02, far below theoretical expectations. This result provides independent evidence for selection bias in dynamically estimated black hole masses, a conclusion that is robust to uncertainties in bolometric corrections, obscured active black hole fractions, and kinetic accretion efficiency. For our fiducial assumptions, they favour moderate-to-rapid spins of typical supermassive black holes, to achieve ε ∼ 0.12–0.20. Our approach has similarities to the classic Soltan analysis, but by using galaxy-based data instead of integrated quantities we are able to focus on regimes where observational uncertainties are minimized.

scholarly journals Effect of Compact Objects Near Be Stars

1987 ◽  
Vol 92 ◽  
pp. 516-518
Author(s):  
Krishna M.V. Apparao ◽  
S.P. Tarafdar
Keyword(s):  
Black Holes ◽  
Neutron Star ◽  
Rotation Period ◽  
Compact Object ◽  
Compact Objects ◽  
X Rays ◽  
Be Stars ◽  
Eccentric Orbit ◽  
X Ray ◽  
Be Star

Several Be stars are identified with bright X-ray sources. (Rappaport and Van den Heuvel, 1982). The bright X-ray emission and observed periodicities indicate the existence of compact objects (white dwarfs, neutron stars or black holes) near the Be stars. A prime example is the brightest X-ray source A0538-66 in LMC, which contains a neutron star with a rotation period of 59 ms. Apparao (1985) explained the X-ray emission, which occurs in periodic flares, by considering an inclined eccentric orbit for the neutron star around the assumed Be-star. The neutron star when it enters a gas ring (around the Be-star) accreting matter giving out X-rays.The X-ray emission from the compact objects, when the gas ring from the Be-star envelopes the objects, has interesting consequences. The X-ray emission produces an ionized region (compact object Stromgren sphere or COSS) in the gas surrounding the compact object (CO).

scholarly journals High-Mass X-ray Binaries: progenitors of double compact objects

2018 ◽  
Vol 14 (S346) ◽  
pp. 1-13
Author(s):  
Edward P. J. van den Heuvel
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Stars ◽  
Compact Objects ◽  
High Mass ◽  
X Ray ◽  
Future Evolution ◽  
Short Period ◽  
Orbital Periods ◽  
X Ray Binaries

AbstractA summary is given of the present state of our knowledge of High-Mass X-ray Binaries (HMXBs), their formation and expected future evolution. Among the HMXB-systems that contain neutron stars, only those that have orbital periods upwards of one year will survive the Common-Envelope (CE) evolution that follows the HMXB phase. These systems may produce close double neutron stars with eccentric orbits. The HMXBs that contain black holes do not necessarily evolve into a CE phase. Systems with relatively short orbital periods will evolve by stable Roche-lobe overflow to short-period Wolf-Rayet (WR) X-ray binaries containing a black hole. Two other ways for the formation of WR X-ray binaries with black holes are identified: CE-evolution of wide HMXBs and homogeneous evolution of very close systems. In all three cases, the final product of the WR X-ray binary will be a double black hole or a black hole neutron star binary.

scholarly journals Wind Roche lobe overflow in high-mass X-ray binaries

2019 ◽  
Vol 622 ◽  
pp. L3 ◽  
Author(s):  
I. El Mellah ◽  
J. O. Sundqvist ◽  
R. Keppens
Keyword(s):  
Mass Transfer ◽  
Compact Object ◽  
Stellar Mass ◽  
Roche Lobe ◽  
High Mass ◽  
Transfer Rates ◽  
X Ray ◽  
Accretion Rates ◽  
Mass Outflow ◽  
X Ray Binaries

Ultraluminous X-ray sources (ULXs) have such high X-ray luminosities that they were long thought to be accreting intermediate-mass black holes. Yet, some ULXs have been shown to display periodic modulations and coherent pulsations suggestive of a neutron star in orbit around a stellar companion and accreting at super-Eddington rates. In this Letter, we propose that the mass transfer in ULXs could be qualitatively the same as in supergiant X-ray binaries (SgXBs), with a wind from the donor star highly beamed towards the compact object. Since the star does not fill its Roche lobe, this mass transfer mechanism known as “wind Roche lobe overflow” can remain stable even for large donor-star-to-accretor mass ratios. Based on realistic acceleration profiles derived from spectral observations and modeling of the stellar wind, we compute the bulk motion of the wind to evaluate the fraction of the stellar mass outflow entering the region of gravitational predominance of the compact object. The density enhancement towards the accretor leads to mass-transfer rates systematically much larger than the mass-accretion rates derived by the Bondi-Hoyle-Lyttleton formula. We identify orbital and stellar conditions for a SgXBs to transfer mass at rates necessary to reach the ULX luminosity level. These results indicate that Roche-lobe overflow is not the only way to funnel large quantities of material into the Roche lobe of the accretor. With the stellar mass-loss rates and parameters of M101 ULX-1 and NGC 7793 P13, wind Roche-lobe overflow can reproduce mass-transfer rates that qualify an object as an ULX.

scholarly journals Observational evidence for stellar-mass black holes

2006 ◽  
Vol 2 (S238) ◽  
pp. 3-12 ◽  
Author(s):  
Jorge Casares
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mass Spectrum ◽  
Radial Velocity ◽  
Stellar Mass ◽  
Observational Evidence ◽  
X Ray ◽  
History Of ◽  
X Ray Binaries ◽  
Dynamical Masses

AbstractRadial velocity studies of X-ray binaries provide the most solid evidence for the existence of stellar-mass black holes. We currently have 20 confirmed cases, with dynamical masses in excess of 3 M⊙. Accurate masses have been obtained for a subset of systems which gives us a hint at the mass spectrum of the black hole population. This review summarizes the history of black hole discoveries and presents the latest results in the field.

scholarly journals Supercritically accreting stellar mass black holes as ultraluminous X-ray sources

2007 ◽  
Vol 377 (3) ◽  
pp. 1187-1194 ◽  
Author(s):  
J. Poutanen ◽  
G. Lipunova ◽  
S. Fabrika ◽  
A. G. Butkevich ◽  
P. Abolmasov
Keyword(s):  
Black Holes ◽  
Stellar Mass ◽  
X Ray
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