Dynamics of stationary axisymmetric configuration of the viscous accreting fluids surrounding a non-rotating compact object in final stages of accretion flow is presented here. For the special case of thin disk approximation, the relativistic fluid equations ignoring self-gravity of the disk are derived in Schwarzschild geometry. For two different state equations, two sets of self-consistent an...

We propose to bring the power of NGST to bear on one of the most important problems in star formation { understanding protostellar formation from parent molecular cores and subsequent evolution towards becoming young stars. A few extremely young (10 < < 10 yr) protostars have nally been discovered with sub-millimeter telescopes in recent years, but the high extinctions (Av > 400 mag) towards th...

We show that the burning of a small mass fraction X12 of 12C in a neutron star ocean is thermally unstable at low accumulated masses when the ocean contains heavy ashes from the hydrogen burning rapid proton (rp) process. The key to early unstable ignition is the decreased thermal conductivity of a heavy element ocean. The instability requires accretion rates, Ṁ, in excess of one-tenth the Eddi...

We suggest a possible mechanism of efficient transport of the large-scale external magnetic flux inward through a turbulent accretion disk. The outward drift by turbulent diffusion which limits the effectiveness of this process is reduced if the external flux passes through the disk in concentrated patches. Angular momentum loss by a magnetocentrifugal wind from these patches of strong field ad...

It is now generally agreed that some process prevents the diffuse gas in galaxy clusters from cooling significantly, although there is less agreement about the nature of this process. I suggest that cluster gas may be heated by a natural extension of the mechanism establishing the MBH − σ and MBH −Mbulge relations in galaxies, namely outflows resulting from super–Eddington accretion on to the g...

We review the present knowledge of disk accretion in young low mass stars, and in particular, the mass accretion rate ˙ M and its evolution with time. The methods used to obtain mass accretion rates from ultraviolet excesses and emission lines are described, and the current best estimates of ˙ M for Classical T Tauri stars and for objects still surrounded by infalling envelopes are given. We ar...