Limit Of Black Hole Mass Research Articles

An upper observable black hole mass scale for tidal destruction events with thermal X-ray spectra

ABSTRACT We comprehensively model the X-ray luminosity emergent from time-dependent relativistic accretion discs, developing analytical models of the X-ray luminosity of thermal disc systems as a function of black hole mass M, disc mass Md, and disc α-parameter. The X-ray properties of these solutions will be directly relevant for understanding tidal disruption event (TDE) observations. We demonstrate an extremely strong suppression of thermal X-ray luminosity from large mass black holes, LX ∼ exp (− m7/6), where m is a dimensionless mass, roughly the black hole mass in unity of 106M⊙. This strong suppression results in upper observable black hole mass limits, which we demonstrate to be of order Mlim ≃ 3 × 107M⊙, above which thermal X-ray emission will not be observable. This upper observable black hole mass limit is a function of the remaining disc parameters, and the full dependence can be described analytically (equation 82). We demonstrate that the current population of observed X-ray TDEs is indeed consistent with an upper black hole mass limit of order M ∼ 107M⊙, consistent with our analysis.

Six new supermassive black hole mass determinations from adaptive-optics assisted SINFONI observations

Different massive black hole mass – host galaxy scaling relations suggest that the growth of massive black holes is entangled with the evolution of their host galaxies. The number of measured black hole masses is still limited and additional measurements are necessary to understand the underlying physics of this apparent coevolution. We add six new black hole mass (MBH) measurements of nearby fast rotating early-type galaxies to the known black hole mass sample, namely NGC 584, NGC 2784, NGC 3640, NGC 4570, NGC 4281, and NGC 7049. Our target galaxies have effective velocity dispersions (σe) between 170 and 245 km s−1, and thus this work provides additional insight into the black hole properties of intermediate-mass early-type galaxies. We combined high-resolution adaptive-optics SINFONI data with large-scale MUSE, VIMOS and SAURON data from ATLAS3D to derive two-dimensional stellar kinematics maps. We then built both Jeans Anisotropic Models and axisymmetric Schwarzschild models to measure the central black hole masses. Our Schwarzschild models provide black hole masses of (1.3 ± 0.5) × 108 M⊙ for NGC 584, (1.0 ± 0.6) × 108 M⊙ for NGC 2784, (7.7 ± 5) × 107 M⊙ for NGC 3640, (5.4 ± 0.8) × 108 M⊙ for NGC 4281, (6.8 ± 2.0) × 107 M⊙ for NGC 4570, and (3.2 ± 0.8) × 108 M⊙ for NGC 7049 at 3σ confidence level, which are consistent with recent MBH−σe scaling relations. NGC 3640 has a velocity dispersion dip and NGC 7049 a constant velocity dispersion in the center, but we can clearly constrain their lower black hole mass limit. We conclude our analysis with a test on NGC 4570 taking into account a variable mass-to-light ratio (M/L) when constructing dynamical models. When considering M/L variations linked mostly to radial changes in the stellar metallicity, we find that the dynamically determined black hole mass from NGC 4570 decreases by 30%. Further investigations are needed in the future to account for the impact of radial M/L gradients on dynamical modeling.

Skyrmions around Kerr black holes and spinning BHs with Skyrme hair

We study solutions of the Einstein-Skyrme model. Firstly we consider test field Skyrmions on the Kerr background. These configurations — hereafter dubbed Skerrmions — can be in equilibrium with a Kerr black hole (BH) by virtue of a synchronisation condition. We consider two sectors for Skerrmions. In the sector with non-zero baryon charge, Skerrmions are akin to the known Skyrme solutions on the Schwarzschild background. These “topological” configurations reduce to flat spacetime Skyrmions in a vanishing BH mass limit; moreoever, they never become “small” perturbations on the Kerr background: the non-linearities of the Skyrme model are crucial for all such Skerrmions. In the non-topological sector, on the other hand, Skerrmions have no analogue on the Schwarzschild background. Non-topological Skerrmions carry not baryon charge and bifurcate from a subset of Kerr solutions defining an existence line. Therein the appropriate truncation of the Skyrme model yield a linear scalar field theory containing a complex plus a real field, both massive and decoupled, and the Skerrmions reduce to the known stationary scalar clouds around Kerr BHs. Moreover, non-topological Skerrmions trivialise in the vanishing BH mass limit. We then discuss the backreaction of these Skerrmions, that yield rotating BHs with synchronised Skyrme hair, which continously connect to the Kerr solution (self-gravitating Skyrmions) in the non-topological (topological) sector. In particular, the non-topological hairy BHs provide a non-linear realisation, within the Skyrme model, of the synchronous stationary scalar clouds around Kerr.

Gravitational memory charges of supertranslation and superrotation on Rindler horizons

In a Rindler-type coordinate system spanned in a region outside of a black hole horizon, we have nonvanishing classical holographic charges as soft hairs on the horizon for stationary black holes. Taking a large black hole mass limit, the spacetimes with the charges are described by asymptotic Rindler metrics. We construct a general theory of gravitational holographic charges for a (1+3)-dimensional linearized gravity field in the Minkowski background with Rindler horizons. Although matter crossing a Rindler horizon causes horizon deformation and a time-dependent coordinate shift, that is, gravitational memory, the supertranslation and superrotation charges on the horizon can be defined during and after its passage through the horizon. It is generally proven that holographic states on the horizon cannot store any information about absorbed perturbative gravitational waves. However, matter crossing the horizon really excites holographic states. By using gravitational memory operators, which consist of the holographic charge operators, we suggest a resolution of the no-cloning paradox of quantum information between matter falling into the horizon and holographic charges on the horizon from the viewpoint of the contextuality of quantum measurement.

The basic parameters ofγ-ray-loud blazars

We determined the basic parameters, such as the central black hole mass (M), the boosting factor (or Doppler factor) (δ), the propagation angle (Φ) and the distance along the axis to the site of γ-ray production (d) for 23 γ-ray-loud blazars using their available variability timescales. In this method, the absorption effect depends on the γ-ray energy, emission size and property of the accretion disk. Using the intrinsic γ-ray luminosity as a fraction λ of the Eddington luminosity, and the optical depth equal to unity, we can determine the upper limit of the central black hole masses. We found that the black hole masses range between and when and 1.0 are adopted. Since this method is based on gamma-ray emissions and the short time-scale of the sources, it can also be used for central black hole mass determination of high redshift gamma-ray sources. In the case of the upper limit of black hole mass there is no clear difference between BLs and FSRQs, which suggests that the central black hole masses do not play an important role in the evolutionary sequence of blazars.

Multiwavelength Monitoring of the Narrow‐Line Seyfert 1 Galaxy Arakelian 564. II. Ultraviolet Continuum and Emission‐Line Variability

We present results of an intensive 2 month campaign of approximately daily spectrophotometric monitoring of the narrow-line Seyfert 1 galaxy (NLS1) Ark 564 with the Hubble Space Telescope. The fractional variability amplitude of the continuum variations between 1365 and 3000 is D6%, about a Ae factor of 3 less than that found in typical Seyfert 1 galaxies over a similar period of time. However, large-amplitude, short timescale —aring behavior is evident, with trough-to-peak —ux changes of about 18% in approximately 3 days. We present evidence for wavelength-dependent continuum time delays, with the variations at 3000 lagging behind those at 1365 by about 1 day. These delays may be Ae Ae interpreted as evidence for a strati—ed continuum reprocessing region, possibly an accretion disk structure. The Ly aj 1216 emission line exhibits —ux variations of about 1% amplitude. These variations lag those at 1365 by days, and combining this with the line width yields a virial black hole mass limit Ae [3 of . We caution that the low-amplitude Ly aj 1216 variations may indicate the bulk of [ 8 ] 106 M _ the emission region is at larger radii. This scenario aUects the veracity of our black hole mass upper limit in an uncertain manner owing to the unknown nature of the gas velocity —eld. Our mass estimate is thus unreliable; however, it is consistent with the independent estimate M D 1 ] 107 of Pounds et al. M _ based on a —uctuation power spectrum analysis of X-ray variability in Ark 564. The black hole mass and 5100 luminosity of Ark 564 are consistent with the hypothesis that, relative to Seyfert 1 galaxies, Ae NLS1s have lower black hole masses and higher accretion rates. Other strong emission lines (e.g., C IV j1549 and He II j1640) are constrained to vary with amplitudes of less than 5%. This low level of emission-line variability is diUerent from most Seyfert 1 galaxies, which characteristically display variations of D10% on similar timescales.