Study of nucleosynthesis in accretion disks around black holes was initiated by Chakrabarti et al. (1987). In the present work we do the similar analysis using the state-of-the-art disk model, namely, Advective Accretion Disks. During the infall, matter temperature and density are generally increased which are first computed. These quantities are used to obtain local changes in composition, amo...

On the basis of data from an energy-conserving 3D general relativistic MHD simulation, we predict the statistical character of variability in the coronal luminosity from accreting black holes. When the inner boundary of the corona is defined to be the electron scattering photosphere, its location depends only on the mass accretion rate in Eddington units ṁ. Nearly independent of viewing angle a...

We consider the effects of “photon bubble” shock trains on the vertical structure of radiation pressure-dominated accretion disks. These density inhomogeneities are expected to develop spontaneously in radiation-dominated accretion disks where magnetic pressure exceeds gas pressure, even in the presence of magnetorotational instability (MRI). They increase the rate at which radiation escapes fr...

The inferred black hole in the Galactic center spans the largest angle on the sky among all known black holes. Forthcoming observational programs plan to localize or potentially resolve the image of Sgr A* to an exquisite precision, comparable to the scale of the black hole horizon. Here we show that the location of the image centroid of Sgr A* should depend on observing frequency because of re...

The black hole candidate X-ray transient XTE J1817−330 was observed by the Swift satellite over 160 days of its 2006 outburst with the XRT and UVOT instruments. At the start of the observations, the XRT spectra show that the 0.6-10 keV emission is dominated by an optically thick, geometrically thin accretion disk with an inner disk temperature of ∼ 0.8 keV, indicating that the source was in a h...

Double-peaked emission lines are believed to be originated from accretion disks around supermassive black holes (SMBHs), and about 3% of z < 0.33 AGNs are found to be double-peaked emitters. The quasar SDSS J153636.22+044127.0 has recently been identified with peculiar broad-line emission systems exhibiting multiple redshifts. We decompose the Hα and Hβ profiles into a circular Keplerian disk l...

For the first time, all available pseudo-Schwarzschild potentials are exhaustively used to investigate the possibility of shock formation in hydrodynamic, invicid, black hole accretion discs. It is shown that a significant region of parameter space spanned by important accretion parameters allows shock formation for flow in all potentials used in this work. This leads to the conclusion that the...

Primordial Black Holes evaporate due to Hawking radiation. We find that the evaporation time of primordial black holes increase when accretion of radiation is included. Thus depending on accretion efficiency more and more number of primordial black holes are existing today, which strengthens the idea that the primordial black holes are the proper candidate for dark matter. PACS numbers : 98.80....

We present new equilibrium solutions of stationary models magnetized thick disks (or tori) around Kerr black holes with synchronised scalar hair. The reported here largely extend our previous results based on constant radial distributions the specific angular momentum along equatorial plane. introduce a way to prescribe distribution disk's combination two proposals and compute outside plane by ...