504 citations · 5.2k across the 62 of their papers we have counts for
6 papers · 2 filters
Thin Disk Theory with a Non-Zero Torque Boundary Condition and Comparisons with Simulations
Robert F. Penna, Aleksander Sadowski, Jonathan C. McKinney
We present an analytical solution for thin disk accretion onto a Kerr black hole that extends the standard Novikov-Thorne alpha-disk in three ways: (i) it incorporates nonzero stre…
Slim accretion disks around black holes
A. Sadowski
In this thesis, I study hydrodynamical models of slim accretion disks --- advective, optically thick disks which generalize the standard models of radiatively efficient thin disks…
Stability of radiation-pressure dominated disks. I. The dispersion relation for a delayed heating alpha-viscosity prescription
Adam Ciesielski, Maciej Wielgus, Wlodek Kluzniak +4
We derive and investigate the dispersion relation for accretion disks with retarded or advanced heating. We follow the alpha-prescription but allow for a time offset (τ) between he…
Studies of Thermally Unstable Accretion Disks around Black Holes with Adaptive Pseudospectral Domain Decomposition Method. II. Limit-Cycle Behavior in accretion disks around Kerr black holes
Li Xue, Aleksander Sądowski, Marek A. Abramowicz +1
For the first time ever, we derive equations governing the time-evolution of fully relativistic slim accretion disks in the Kerr metric, and numerically construct their detailed no…
Spinning up black holes with super-critical accretion flows
Aleksander Sadowski, Michal Bursa, Marek Abramowicz +4
We study the process of spinning up black holes by accretion from slim disks in a wide range of accretion rates. We show that for super-Eddington accretion rates and low values of…
Measuring Black Hole Spin by the Continuum-Fitting Method: Effect of Deviations from the Novikov-Thorne Disc Model
Akshay K. Kulkarni, Robert F. Penna, Roman V. Shcherbakov +7
The X-ray spectra of accretion discs of eight stellar-mass black holes have been analyzed to date using the thermal continuum fitting method, and the spectral fits have been used t…