White dwarfs and neutron stars in globular cluster X-ray sources

Nature ◽  
1983 ◽  
Vol 301 (5901) ◽  
pp. 587-589 ◽  
Author(s):  
Piet Hut ◽  
Frank Verbunt
Keyword(s):  
Neutron Stars ◽  
Globular Cluster ◽  
White Dwarfs ◽  
X Ray

scholarly journals ROSAT Observations of Globular Clusters in the Galaxy and in M31

1996 ◽  
Vol 165 ◽  
pp. 389-400
Author(s):  
Helen M. Johnston ◽  
Frank Verbunt ◽  
Günther Hasinger ◽  
Wolfram Bunk
Keyword(s):  
Neutron Stars ◽  
Globular Cluster ◽  
Spectral Properties ◽  
Globular Clusters ◽  
Luminosity Function ◽  
Binary Systems ◽  
X Ray ◽  
The Galaxy ◽  
Galactic Globular Clusters

X-ray sources in globular clusters fall into two categories: the “bright” sources, with LX ∼ 1036-1038 erg s−1, and the “dim” sources, with LX ≲ 1034.5 erg s−1. The bright sources are clearly associated with accreting neutron stars in binary systems. The nature of the dim sources, however, remains in doubt. We review recent observations of globular-cluster X-ray sources with the ROSAT satellite. ROSAT detected bright sources in M31 globular clusters and greatly increased the number of dim sources known in galactic globular clusters. We discuss what these new observations have taught us about the distribution and nature of such sources, their spectral properties, and their underlying luminosity function.

scholarly journals Multiwavelength Emission from Magnetically Arrested Disks around Isolated Black Holes

2021 ◽  
Vol 922 (1) ◽  
pp. L15
Author(s):  
Shigeo S. Kimura ◽  
Kazumi Kashiyama ◽  
Kenta Hotokezaka
Keyword(s):  
Black Holes ◽  
Synchrotron Radiation ◽  
Interstellar Medium ◽  
Neutron Stars ◽  
White Dwarfs ◽  
Gamma Ray ◽  
Optical Signals ◽  
X Ray ◽  
Nonthermal Electrons

Abstract We discuss the prospects for identifying the nearest isolated black holes (IBHs) in our Galaxy. IBHs accreting gas from the interstellar medium likely form magnetically arrested disks (MADs). We show that thermal electrons in the MADs emit optical signals through the thermal synchrotron process while nonthermal electrons accelerated via magnetic reconnections emit a flat-spectrum synchrotron radiation in the X-ray to MeV gamma-ray ranges. The Gaia catalog will include at most a thousand IBHs within ≲1 kpc that are distributed on and around the cooling sequence of white dwarfs (WDs) in the Hertzsprung–Russell diagram. These IBH candidates should also be detected by eROSITA, with which they can be distinguished from isolated WDs and neutron stars. Follow-up observations with hard X-ray and MeV gamma-ray satellites will be useful to unambiguously identify IBHs.

Transient X-ray Binaries in the Magellanic Clouds and Milky Way

2017 ◽  
Vol 14 (S339) ◽  
pp. 127-130
Author(s):  
P. C. Charles ◽  
D. Buckley ◽  
D. Mata Sánchez ◽  
P. Meintjes ◽  
A. Rajoelimanana ◽  
...  
Keyword(s):  
Neutron Stars ◽  
White Dwarfs ◽  
Milky Way ◽  
Field Monitoring ◽  
Magellanic Clouds ◽  
Wide Field ◽  
X Ray ◽  
X Ray Binaries

AbstractThis contribution gave three examples of X-ray transients in the Magellanic Clouds and the Milky Way that have been observed as part of the SALT Transients Large Programme. The transients (SMC X-3, MAXI J1957+032 and ASASSN-16oh) have been triggered from both space-based wide-field monitoring facilities (Swift/XRT, MAXI) and ground-based ones (ASASSN, the All Sky Automated Survey for SN), providing insights into the physics of super-Eddington accretion onto neutron stars and white dwarfs, and also into the long-term properties of accreting millisecond X-ray pulsars.

scholarly journals Halo/Thick Disk CVS and the Cosmic X-Ray Background

1996 ◽  
Vol 168 ◽  
pp. 543-548
Author(s):  
Jonathan E. Grindlay ◽  
Eyal Maoz
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
Globular Clusters ◽  
White Dwarfs ◽  
Thick Disk ◽  
X Ray ◽  
Diffuse Flux ◽  
The Galaxy ◽  
X Ray Background

In a recent study (Maoz and Grindlay 1995) we have found that a number of previously recognized anomalies in the diffuse x-ray background at soft energies (~0.5-2 keV) can be understood if about 20-30% of the diffuse flux arises from a population of low luminosity sources in a thick disk or flattened halo distribution in the Galaxy. Here we summarize our results and review the arguements that these objects are not accreting neutron stars or black holes but rather white dwarfs (i.e. CVs) which may have been produced in a primordial population of disrupted globular clusters.

scholarly journals XMM-Newton and Chandra Observations of Neutron Stars and Cataclysmic Variables in the Globular Cluster NGC 2808

2007 ◽  
Vol 3 (S246) ◽  
pp. 373-374
Author(s):  
M. Servillat ◽  
N. A. Webb ◽  
D. Barret ◽  
R. Cornelisse ◽  
A. Dieball ◽  
...  
Keyword(s):  
Neutron Stars ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Cataclysmic Variables ◽  
Cataclysmic Variable ◽  
Specific Nature ◽  
X Ray ◽  
The Core ◽  
Show Evidence ◽  
Low Mass

AbstractWe report on XMM-Newton and Chandra observations of the globular cluster NGC 2808. We detect one quiescent low mass X-ray binary of the 3±1 expected, if these systems are formed through encounters, and we show evidence for the presence of 20±10 bright cataclysmic variables in the core with a luminosity above 4×1031 erg s−1. We also review the specific nature of cataclysmic variables in globular clusters with reference to recent VLT/FORS1 observations of a cataclysmic variable in M 22.

scholarly journals On the Origin of Neutron Stars in Globular Clusters

1987 ◽  
Vol 125 ◽  
pp. 173-185
Author(s):  
Jonathan E. Grindlay
Keyword(s):  
Neutron Stars ◽  
Globular Clusters ◽  
White Dwarfs ◽  
Binary Systems ◽  
High Luminosity ◽  
X Ray ◽  
Origin And Evolution ◽  
Compact Binary ◽  
X Ray Binaries ◽  
Mass Functions

The formation of neutron stars in globular clusters is discussed in light of a number of recent results and, in particular, studies of the origin and evolution of the high luminosity x-ray binaries found in globular clusters. We argue that the neutron stars most probably arise from the accretion-induced collapse of white dwarfs in compact binary systems, themselves detectable as low luminosity cluster x-ray sources. The white dwarfs which can collapse are probably the remnants of relatively more massive stars than those presently found in globulars. This can account for the predominant occurrence of the high luminosity cluster sources in clusters of relatively high metallicity, since those clusters have recently been found to probably have flatter mass functions of their component stars.

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