scholarly journals Central X-Ray Point Sources Found to Be Abundant in Low-mass, Late-type Galaxies Predicted to Contain an Intermediate-mass Black Hole

2021 ◽  
Vol 923 (2) ◽  
pp. 246
Author(s):  
Alister W. Graham ◽  
Roberto Soria ◽  
Benjamin L. Davis ◽  
Mari Kolehmainen ◽  
Thomas Maccarone ◽  
...  
Keyword(s):  
Black Hole ◽  
Spectral Energy Distribution ◽  
Star Clusters ◽  
Virgo Cluster ◽  
Point Sources ◽  
Spectral Energy ◽  
Late Type ◽  
Intermediate Mass ◽  
X Ray ◽  
X Ray Binaries

Abstract Building upon three late-type galaxies in the Virgo cluster with both a predicted black hole mass of less than ∼105 M ⊙ and a centrally located X-ray point source, we reveal 11 more such galaxies, more than tripling the number of active intermediate-mass black hole candidates among this population. Moreover, this amounts to a ∼36 ± 8% X-ray detection rate (despite the sometimes high, X-ray-absorbing, H i column densities), compared to just 10 ± 5% for (the largely H i-free) dwarf early-type galaxies in the Virgo cluster. The expected contribution of X-ray binaries from the galaxies’ inner field stars is negligible. Moreover, given that both the spiral and dwarf galaxies contain nuclear star clusters, the above inequality appears to disfavor X-ray binaries in nuclear star clusters. The higher occupation, or rather detection, fraction among the spiral galaxies may instead reflect an enhanced cool gas/fuel supply and Eddington ratio. Indeed, four of the 11 new X-ray detections are associated with known LINERs or LINER/H ii composites. For all (four) of the new detections for which the X-ray flux was strong enough to establish the spectral energy distribution in the Chandra band, it is consistent with power-law spectra. Furthermore, the X-ray emission from the source with the highest flux (NGC 4197: L X ≈ 1040 erg s−1) suggests a non-stellar-mass black hole if the X-ray spectrum corresponds to the “low/hard state”. Follow-up observations to further probe the black hole masses, and prospects for spatially resolving the gravitational spheres of influence around intermediate-mass black holes, are reviewed in some detail.

scholarly journals Multiwavelength analysis as a probe of accretion and radiative processes in LINERs

2012 ◽  
Vol 8 (S290) ◽  
pp. 355-356
Author(s):  
George Younes ◽  
Delphine Porquet
Keyword(s):  
Black Hole ◽  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Characteristics ◽  
Spectral Energy ◽  
X Ray ◽  
Radiative Processes ◽  
Central Engine ◽  
Galactic Black Hole ◽  
X Ray Binaries

AbstractWe study the multiwavelength properties of an optically selected sample of Low Ionization Nuclear Emission-line Regions (LINERs), in an attempt to determine the accretion mechanism powering their central engine. We show how their X-ray spectral characteristics, and their spectral energy distribution compare to luminous AGN, and briefly discuss their connection to their less massive counter-parts galactic black-hole X-ray binaries.

scholarly journals The Spectral Energy Distribution of Quiescent Black Hole X‐Ray Binaries: New Constraints fromSpitzer

2007 ◽  
Vol 670 (1) ◽  
pp. 600-609 ◽  
Author(s):  
Elena Gallo ◽  
Simone Migliari ◽  
Sera Markoff ◽  
John A. Tomsick ◽  
Charles D. Bailyn ◽  
...  
Keyword(s):  
Black Hole ◽  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
X Ray ◽  
X Ray Binaries

scholarly journals Thermal stability of winds driven by radiation pressure in super-Eddington accretion discs

2019 ◽  
Vol 491 (4) ◽  
pp. 5702-5716 ◽  
Author(s):  
C Pinto ◽  
M Mehdipour ◽  
D J Walton ◽  
M J Middleton ◽  
T P Roberts ◽  
...  
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
Radiation Pressure ◽  
Spectral Energy Distribution ◽  
Accretion Disc ◽  
Spectral Energy ◽  
X Ray ◽  
Thermal Status ◽  
X Ray Binaries

ABSTRACT Ultraluminous X-ray sources (ULXs) are mainly powered by accretion in neutron stars or stellar-mass black holes. Accreting at rates exceeding the Eddington limit by factors of a few up to hundreds, radiation pressure is expected to inflate the accretion disc, and drive fast winds that have in fact been observed at significant fractions of the speed of light. Given the super-Eddington luminosity, the accretion disc will be thicker than in sub-Eddington accretors such as common active galactic nuclei and X-ray binaries, leading to a different spectral energy distribution and, possibly, a different thermal status of the wind. Here, we show the first attempt to calculate the photoionization balance of the winds driven by strong radiation pressure in thick discs with a focus on ULXs hosting black holes or non-magnetic neutron stars. We find that the winds are generally in thermally stable equilibrium, but long-term variations in the accretion rate and the inclination due to precession may have significant effects on the wind appearance and stability. Our model trends can explain the observed correlation between the spectral residuals around 1 keV and the ULX spectral state. We also find a possible correlation between the spectral hardness of the ULX, the wind velocity, and the ionization parameter in support of the general scenario.

scholarly journals Evolution of black-hole intermediate-mass X-ray binaries

2006 ◽  
Vol 2 (S238) ◽  
pp. 339-340
Author(s):  
Wen-Cong Chen ◽  
Xiang-Dong Li
Keyword(s):  
Black Hole ◽  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Intermediate Mass ◽  
X Ray ◽  
Angular Momentum Loss ◽  
Low Mass ◽  
Plausible Mechanism ◽  
X Ray Binaries ◽  
Mass Form

AbstractWe propose a plausible mechanism for orbital angular momentum loss in black-hole intermediate-mass X-ray binaries, assuming that a small fraction of the transferred mass form a circumbinary disc. The disc can effectively drain orbital angular momentum from the binary, leading to the formation of compact black-hole low-mass X-ray binaries. This scenario also suggests the possible existence of luminous, persistent black hole low-mass X-ray binaries.

scholarly journals X-ray and optical observations of the black hole candidate MAXI J1828−249

2019 ◽  
Vol 71 (5) ◽  
Author(s):  
Sonoe Oda ◽  
Megumi Shidatsu ◽  
Satoshi Nakahira ◽  
Toru Tamagawa ◽  
Yuki Moritani ◽  
...  
Keyword(s):  
Black Hole ◽  
Low Temperature ◽  
Power Law ◽  
Spectral Power ◽  
Spectral Energy Distribution ◽  
Disk Surface ◽  
Optical Observations ◽  
Spectral Energy ◽  
X Ray ◽  
Black Hole Candidate

Abstract We report results from X-ray and optical observations of the Galactic black hole candidate MAXI J1828−249 performed with Suzaku and the Kanata telescope around the X-ray flux peak in the 2013 outburst. The time-averaged X-ray spectrum covering 0.6–168 keV was approximately characterized by a strong multi-color disk blackbody component with an inner disk temperature of ∼0.6 keV, and a power-law tail with a photon index of ∼2.0. We detected an additional structure at 5–10 keV, which can be modeled neither with X-ray reflection on the disk nor relativistic broadening of the disk emission. Instead, it was successfully reproduced with a Comptonization of disk photons by thermal electrons with a relatively low temperature (≲10 keV). We infer that the source was in the intermediate state, considering its long-term trend in the hardness intensity diagram, the strength of the spectral power-law tail, and its variability properties. The low-temperature Comptonization component could be produced in a boundary region between the truncated standard disk and the hot inner flow, or a Comptonizing region that somehow developed above the disk surface. The multi-wavelength spectral energy distribution suggests that the optical and ultraviolet fluxes were dominated by irradiated outer disk emission.

Formation and evolution of intermediate mass black hole X-ray binaries

2007 ◽  
pp. 247-253
Author(s):  
Simon F. Portegies Zwart ◽  
Jasinta Dewi ◽  
Tom Maccarone
Keyword(s):  
Black Hole ◽  
Intermediate Mass ◽  
X Ray ◽  
Formation And Evolution ◽  
X Ray Binaries

scholarly journals Variability of ultraluminous X-ray sources in the Cartwheel Ring

2006 ◽  
Vol 2 (S238) ◽  
pp. 255-258
Author(s):  
Anna Wolter ◽  
Ginevra Trinchieri ◽  
Monica Colpi
Keyword(s):  
Black Hole ◽  
Star Formation ◽  
Luminosity Function ◽  
High Mass ◽  
High Luminosity ◽  
Intermediate Mass ◽  
X Ray ◽  
External Galaxies ◽  
X Ray Binaries

AbstractThe Cartwheel is one of the most outstanding examples of a dynamically perturbed galaxy where star formation is occurring inside the ring–like structure. In previous studies with Chandra, we detected 16 Ultra Luminous X-ray sources lying along the southern portion of the ring. Their Luminosity Function is consistent with them being in the high luminosity tail of the High Mass X-ray Binaries distribution, but with one exception: source N.10. This source, detected with Chandra at LX = 1 × 1041 erg s−1, is among the brightest non–nuclear sources ever seen in external galaxies. Recently, we have observed the Cartwheel with XMM-Newton in two epochs, six months apart. After having been at its brightest for at least 4 years, the source has dimmed by at least a factor of two between the two observations. This fact implies that the source is compact in nature. Given its extreme isotropic luminosity, there is the possibility that the source hosts an accreting intermediate–mass black hole. Other sources in the ring vary in flux between the different datasets. We discuss our findings in the context of ULX models.

scholarly journals On the nature of the soft γ-ray emission in the hard state of the black hole transient GRS 1716−249

2020 ◽  
Vol 494 (1) ◽  
pp. 571-583 ◽  
Author(s):  
T Bassi ◽  
J Malzac ◽  
M Del Santo ◽  
E Jourdain ◽  
J-P Roques ◽  
...  
Keyword(s):  
Black Hole ◽  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Component ◽  
Coronal Magnetic Field ◽  
Spectral Energy ◽  
Emission Model ◽  
X Ray ◽  
Hard State ◽  
Γ Ray

ABSTRACT The black hole transient GRS 1716−249 was monitored from the radio to the γ-ray band during its 2016–2017 outburst. This paper focuses on the spectral energy distribution (SED) obtained in 2017 February–March, when GRS 1716−249 was in a bright hard spectral state. The soft γ-ray data collected with the INTEGRAL/SPI telescope show the presence of a spectral component that is in excess of the thermal Comptonization emission. This component is usually interpreted as inverse Compton emission from a tiny fraction of non-thermal electrons in the X-ray corona. We find that hybrid thermal/non-thermal Comptonization models provide a good fit to the X-/γ-ray spectrum of GRS 1716−249. The best-fitting parameters are typical of the bright hard state spectra observed in other black hole X-ray binaries. Moreover, the magnetized hybrid Comptonization model belm provides an upper limit on the intensity of the coronal magnetic field of about 106 G. Alternatively, this soft γ-ray emission could originate from synchrotron emission in the radio jet. In order to test this hypothesis, we fit the SED with the irradiated disc plus Comptonization model combined with the jet internal shock emission model ishem. We found that a jet with an electron distribution of p ≃ 2.1 can reproduce the soft γ-ray emission of GRS 1716−249. However, if we introduce the expected cooling break around 10 keV, the jet model can no longer explain the observed soft γ-ray emission, unless the index of the electron energy distribution is significantly harder (p < 2).

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