black hole mass
Recently Published Documents


TOTAL DOCUMENTS

646
(FIVE YEARS 158)

H-INDEX

80
(FIVE YEARS 13)

Author(s):  
Alokananda Kar ◽  
Shouvik Sadhukhan ◽  
Ujjal Debnath

In this paper, we have used the reconstructed Dirac–Born–Infeld (DBI)-essence dark energy density to modify the mass accretions of black holes and wormholes. In general, the black hole mass accretion does not depend on the metric or local Einstein geometry. That is why we have used a generalized mechanism by reconstructing the DBI-essence dark energy reconstruction with [Formula: see text] gravity. We have used some particular forms of the scale factor to analyze the accretion phenomena. We have shown the effect of cosmic evolution in the proper time variation of black hole mass accretion. Finally, we have studied the validity of energy conditions and analyzed the Type I–IV singularities for our reconstructed model.


2021 ◽  
Vol 922 (2) ◽  
pp. 222
Author(s):  
Shifeng Huang ◽  
Hongxing Yin ◽  
Shaoming Hu ◽  
Xu Chen ◽  
Yunguo Jiang ◽  
...  

Abstract Blazar PG 1553+113 is thought to be a host of supermassive black hole binary system. A 2.2 yr quasi-periodicity in the γ-ray light curve was detected, possibly a result of jet precession. Motivated by the previous studies based on the γ-ray data, we analyzed the X-ray light curve and spectra observed during 2012–2020. The 2.2 yr quasi-periodicity might be consistent with the main-flare recurrence in the X-ray light curve. When a weak rebrightening in the γ-ray was observed, a corresponding relatively strong brightening in the X-ray light curve can be identified. The harder-when-brighter tendency in both X-ray main and weak flares was shown, as well as a weak softer-when-brighter behavior for the quiescent state. We explore the possibility that the variability in the X-ray band can be interpreted with two-jet precession scenario. Using the relation between jets and accretion disks, we derive the primary black hole mass ≃3.47 × 108 M ☉ and mass of the secondary one ≃1.40 × 108 M ☉, and their mass ratio ∼0.41.


2021 ◽  
Vol 921 (2) ◽  
pp. 107
Author(s):  
M. J. Bustamante-Rosell ◽  
Eva Noyola ◽  
Karl Gebhardt ◽  
Maximilian H. Fabricius ◽  
Ximena Mazzalay ◽  
...  

2021 ◽  
Vol 2021 (11) ◽  
pp. 054
Author(s):  
Heling Deng

Abstract In a variety of mechanisms generating primordial black holes, each black hole is expected to form along with a surrounding underdense region that roughly compensates the black hole mass. This region will propagate outwards and expand as a shell at the speed of sound in the homogeneous background. Dissipation of the shell due to Silk damping could lead to detectable μ-distortion in the CMB spectrum: if black holes are rare on the last scattering surface, the signal(s) would be pointlike; whereas if there are a sufficient number of them, we could have a uniform distortion in the CMB sky. While the current bound on the average μ-distortion is |μ̅| ≲ 10-4, the standard ΛCDM model predicts |μ̅| ∼ 10-8, which could possibly be detected in future missions. It is shown in this work that the non-observation of μ̅ beyond ΛCDM can place a new upper bound on the density of supermassive primordial black holes within the mass range 106 M ☉≲ M ≲ 1015 M ☉. Furthermore, black holes with initial mass M ≳ 1012 M ☉ could leave a pointlike distortion with μ ≳10-8 at an angular scale ∼ 1° in CMB, and its non-observation would impose an even more stringent bound on the population of these stupendously large primordial black holes.


2021 ◽  
Vol 921 (1) ◽  
pp. 36
Author(s):  
Vardha N. Bennert ◽  
Tommaso Treu ◽  
Xuheng Ding ◽  
Isak Stomberg ◽  
Simon Birrer ◽  
...  

Author(s):  
A. Melo ◽  
V. Motta ◽  
N. Godoy ◽  
J. Mejia-Restrepo ◽  
R. J. Assef ◽  
...  

Author(s):  
M Lakićević ◽  
J Kovačević-Dojčinović ◽  
L Č Popović

Abstract The differences between Narrow Line Seyfert 1 galaxies (NLS1s) and Broad Line AGNs (BLAGNs) are not completely understood; it is thought that they may have different inclinations and/or physical characteristics. The FWHM(Hβ)–luminosities correlations are found for NLS1s and their origin is the matter of debate. Here we investigated the spectroscopic parameters and their correlations considering a dusty, cone model of AGN. We apply a simple conical dust distribution (spreading out of broad line region, BLR), assuming that the observed surface of the model is in a good correlation with MIR emission. The dusty cone model in combination with a BLR provides the possibility to estimate luminosity dependence on the cone inclination. The FWHM(Hβ)–luminosities correlations obtained from model in comparison with observational data show similarities which may indicate the influence of AGN inclination and structure to this correlation. An alternative explanation for FWHM(Hβ)–luminosities correlations is the selection effect by the black hole mass. These FWHM(Hβ)–luminosities correlations may be related to the starburst in AGNs, as well. The distinction between spectral properties of the NLS1s and BLAGNs could be caused by multiple effects: beside physical differencies between NLS1s and BLAGNs (NLS1s have lighter black hole mass than BLAGNs), inclination of the conical AGN geometry may have important role as well, where NLS1s may be seen in lower inclination angles.


2021 ◽  
Vol 920 (1) ◽  
pp. 9
Author(s):  
Sha-Sha Li ◽  
Sen Yang ◽  
Zi-Xu Yang ◽  
Yong-Jie Chen ◽  
Yu-Yang Songsheng ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document