scholarly journals Be/X-Ray Binaries with Black Holes in the Galaxy and in the Magellanic Clouds

2014 ◽  
Vol 1 (1) ◽  
pp. 175-180 ◽  
Author(s):  
Janusz Ziolkowski
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Star ◽  
Magellanic Clouds ◽  
X Ray ◽  
The Galaxy ◽  
X Ray Binaries ◽  
Successful Candidate

I will start with the statistics indicating that the objects named in the title of my talk are either non-existing or very elusive to detect (not a single such object is known against 119 known Be/neutron star X-ray binaries). After brief reviewing of the properties of Be/X-ray binaries I discuss several objects that were proposed as the long sought for candidates for Be/black hole X-ray binaries. After three unsuccessful candidates (LS I +61° 303, LS 5039 and MAXI J1836-194), a successful candidate (AGL J2241+4454/MWC 656) was finally, very recently, announced.

scholarly journals On the apparent lack of Be X-ray binaries with black holes in the galaxy and in the Magellanic Clouds

2010 ◽  
Vol 6 (S275) ◽  
pp. 329-330
Author(s):  
Janusz Ziółkowski ◽  
Krzysztof Belczyński
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Star ◽  
Stellar Population ◽  
Magellanic Clouds ◽  
Population Synthesis ◽  
X Ray ◽  
Stellar Population Synthesis ◽  
The Galaxy ◽  
X Ray Binaries

AbstractIn the Galaxy there are 67 Be X-ray binaries known to-date. Out of those, 45 host a neutron star, and for the reminder the nature of a companion is not known. None, so far, is known to host a black hole. This disparity is referred to as a missing Be – black hole X-ray binary problem. The stellar population synthesis calculations following the formation of Be X-ray binaries (Belczyński & Ziółkowski 2009) predict that the ratio of the binaries with neutron stars to the ones with black holes is rather high FNS/BH ~ 30–50. A comparison of this ratio with the number of confirmed Be – neutron star X-ray binaries (45) indicates that the expected number of Be – black hole X-ray binaries is of the order of only ~0–2. This is entirely consistent with the observed Galactic sample. Therefore, there is no problem of the missing Be+BH X-Ray Binaries for the GalaxyIn the Magellanic Clouds there are 94 Be X-ray binaries known to-date. Out of those, 60 host a neutron star. Again, none hosts a black hole. The stellar population synthesis calculations carried out specifically for the Magellanic Clouds (Ziółkowski & Belczyński 2010) predict that the ratio of the Be X-ray binaries with neutron stars to the ones with black holes is only FNS/BH ~ 10. This value is rather too low, as it implies the expected number of Be+BH X-ray binaries of the order of ~6, while none is observed. We found, that to remove the discrepancy, one has to take into account a different history of the star formation rate in the Magellanic Clouds, with the respect to the Galaxy. New stellar population synthesis calculations are currently being carried out.

scholarly journals Spectroscopy of Stellar X-ray Sources in the Magellanic Clouds

1984 ◽  
Vol 108 ◽  
pp. 305-312
Author(s):  
J. B. Hutchings
Keyword(s):  
Black Hole ◽  
Magellanic Cloud ◽  
Active Galaxies ◽  
Magellanic Clouds ◽  
Dwarf Stars ◽  
X Ray ◽  
Preliminary Comparison ◽  
The Galaxy ◽  
Optical Identifications ◽  
X Ray Binaries

In the Magellanic Clouds, about 75 candidate stellar X-ray sources have been detected. Most of these positions have now been investigated and optical identifications made for ~ 50%. The majority of sources are foreground dwarf stars or background active galaxies. Detailed investigations exist for 3 SMC sources and 6 LMC sources. It is possible to make a preliminary comparison with the population of galactic X-ray sources. The Magellanic Cloud X-ray binaries have a number of unique or remarkable properties and the most important ones are presented and discussed. These include the most rapid pulsars (SMC X-1, 0538–66), the possible precessing disk in LMC X-4, and the black hole candidates LMC X-3, LMC X-1. The properties of these objects relate to the evolution of stars in the Magellanic Clouds and how it differs from the Galaxy.

scholarly journals Formation of Low-Mass Black Hole X-Ray Transients

1998 ◽  
Vol 11 (2) ◽  
pp. 775-778
Author(s):  
Simon Portegies Zwart ◽  
Frank Verbunt ◽  
Ene Ergma
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Star ◽  
Formation Rate ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

We study the formation of low-mass X-ray binaries with a black hole as accreting object. The performed semi-analytic analysis reveals that the formation rate of black holes in low-mass X-ray binaries is about two orders of magnitude smaller than that of systems with a neutron star as accretor. This is contradicted by the six observed systems, which are all transients, which suggest that the majority of these systems has not been seen jet. The birthrate for both type of objects are expected to be similar (for reviews see Cowley 1992, Tanaka & Lewin 1995).

scholarly journals The Formation and Evolution of Black-Hole Binaries

1996 ◽  
Vol 165 ◽  
pp. 93-103
Author(s):  
Roger W. Romani
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Star ◽  
High Mass ◽  
X Ray ◽  
Black Hole Binaries ◽  
Low Mass ◽  
Formation And Evolution ◽  
X Ray Binaries ◽  
Black Hole Candidates

The presence of accreting black holes (BH) among the X-ray binaries has been recognized for many years. Traditionally, Cyg X-1 and the handful of other candidates have been thought of as cousins of the HMXB neutron star systems. Recent studies of the soft X-ray transients such as A 0620-00 have, however, shown that the dynamical evidence makes these low-mass systems very strong black-hole candidates. Further, analysis of the eventual end-states of various high-mass X-ray binaries suggest that some could end as observable BH-pulsar binaries, although the first such system is yet to be discovered.

scholarly journals The Missing Population of Be+Black Hole X-Ray Binaries

2008 ◽  
Vol 4 (S252) ◽  
pp. 399-403
Author(s):  
Aleksander Sadowski ◽  
J. Ziółkowski ◽  
K. Belczyński ◽  
T. Bulik
Keyword(s):  
Black Hole ◽  
Stellar Population ◽  
Magellanic Clouds ◽  
Population Synthesis ◽  
Period Range ◽  
X Ray ◽  
Stellar Population Synthesis ◽  
The Galaxy ◽  
Orbital Periods ◽  
X Ray Binaries

AbstractAt present, 117 Be/neutron star (Be/NS) X-ray binaries (XRBs) are known in the Galaxy and the Magellanic Clouds, but not a single Be/black hole (Be/BH) binary was found so far. We carried out the calculations of stellar population synthesis to investigate the case of the apparently missing population of Be/BH XRBs. According to our calculations, the main reason of this disparity is the fact that within the orbital period range where Be XRBs are found (~10 to ~300 days), these systems are formed predominantly with a NS component. The systems with a BH component are formed predominantly with much longer orbital periods and they are not easy to detect.

scholarly journals Big Game Hunting in the Andromeda Galaxy: Identifying and Weighing Black Holes in Low Mass X-Ray Binaries

2004 ◽  
Vol 194 ◽  
pp. 71-72
Author(s):  
R. Barnard
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Star ◽  
Power Density ◽  
Accretion Rate ◽  
Power Density Spectrum ◽  
Density Spectrum ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractWe have devised a new technique for identifying stellar mass black holes in low mass X-ray binaries, and have applied it to XMM-Newton observations of two X-ray sources in M31. In particular we search for low accretion rate power density spectra; these are very similar for all LMXB, whether the primary is a black hole or a neutron star. Galactic neutron star LMXB exhibit these distinctive PDS at very low luminosities (~ 1036 erg s–1) while black hole LMXB can exhibit them at luminosities > 1038 erg s–1! Following the work of van der Klis (1994), we assume a maximum accretion rate (as a fraction of the Eddington limit) for low accretion rate PDS that is constant for all LMXB, and obtain an empirical value of ~10% Eddington. We have so far discovered two candidate black hole binaries in M31, exhibiting low accretion rate PDS at up to 3 x 1038 and 5 x 1037 erg s–1. If we assume that they are at <10% Eddington, they have minimum masses of 20 and 4 M⊙ respectively. Furthermore, any LMXB exhibiting a low accretion rate power density spectrum at a luminosity > 5 x 1037 erg s–1 is likely to have a black hole primary.

scholarly journals SS433 and the nature of ultra-luminous X-ray sources

2006 ◽  
Vol 2 (S238) ◽  
pp. 219-224
Author(s):  
P. A. Charles ◽  
A. D. Barnes ◽  
J. Casares ◽  
J. S. Clark ◽  
R. Cornelisse ◽  
...  
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
High Resolution ◽  
Binary System ◽  
Compact Object ◽  
High Mass ◽  
X Ray ◽  
New Class ◽  
The Galaxy ◽  
X Ray Binaries

AbstractThe prototypical micro-quasar, SS433, one of the most bizarre objects in the Galaxy, is a weak X-ray source, yet the kinetic energy of its relativistic, precessing jets is vastly greater. In spite of its importance as the nearest example of directly observable relativistic phenomena, we know remarkably little about the nature of this binary system. There are ongoing arguments not only about the mass of the compact object, but even as to whether it is a black hole or a neutron star, an argument that recent high resolution optical spectroscopy has contributed to.Combined with the INTEGRAL discovery of a new class of highly obscured galactic high-mass X-ray binaries, one of which has been found to precess on a similar timescale to SS433, we suggest that these would indeed be seen by external observers as ULXs, once additional effects such as beaming (either relativistic or geometrical) are included.

scholarly journals A minimal timescale for the continuum in 4U 1608-52 and Aql X-1

2021 ◽  
Vol 502 (1) ◽  
pp. L72-L78
Author(s):  
K Mohamed ◽  
E Sonbas ◽  
K S Dhuga ◽  
E Göğüş ◽  
A Tuncer ◽  
...  
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Power Spectra ◽  
Light Curves ◽  
State Transitions ◽  
Strong Positive Correlation ◽  
Present Evidence ◽  
X Ray ◽  
X Ray Binaries ◽  
The Continuum

ABSTRACT Similar to black hole X-ray binary transients, hysteresis-like state transitions are also seen in some neutron-star X-ray binaries. Using a method based on wavelets and light curves constructed from archival Rossi X-ray Timing Explorer observations, we extract a minimal timescale over the complete range of transitions for 4U 1608-52 during the 2002 and 2007 outbursts and the 1999 and 2000 outbursts for Aql X-1. We present evidence for a strong positive correlation between this minimal timescale and a similar timescale extracted from the corresponding power spectra of these sources.

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