Hot accretion disks with pairs: Effects of magnetic field and thermal cyclocsynchrotron radiation

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

8

Accretion Disks, Astronomical Models, Cyclotron Radiation, Magnetic Fields, Mathematical Models, Thermal Radiation, Viscosity, Active Galactic Nuclei, Black Holes (Astronomy), Bremsstrahlung, X Ray Spectra

Scientific paper

We show the effects of thermal cyclosynchrotron radiation and magnetic viscosity on the structure of hot, two-temperature accretion disks. Magnetic field, B, is assumed to be randomly oriented and the ratio of magnetic pressure to either gas pressure, alpha = Pmag/Pgas, or the sum of the gas and radiation pressures, alpha = (Pmag/Pgas + Prad), is fixed. We find those effects do not change the qualitative properties of the disks, i.e., there are still two critical accretion rates related to production of e+/- pairs, (M dot)(Ucr) and (M dot)(Lcr), that affect the number of local and global disk solutions, as recently found by Bjoernsson and Svensson for the case with B = 0. However, a critical value of the alpha-viscosity parameter above which those critical accretion rates disappear becomes smaller than alphacr = 1 found in the case of B = 0, for Pmag = alpha(Pgas + Prad). If Pmag = alpha Pgas, on the other hand, alphacr is still about unity. Moreover, when Comptonized cyclosynchrotron radiation dominates Comptonized bremsstrahlung, radiation from the disk obeys a power law with the energy spectral index of approximately 0.5, in a qualitative agreement with X-ray observations of active galactic nuclei (AGNS) and Galactic black hole candidates. We also extend the hot disk solutions for Pmag = alpha(Pgas + Prad) to the effectively optically thick region, where they merge with the standard cold disk solutions. We find that the mapping method by Bjoernsson and Svensson gives a good approximation to the disk structure in the hot region and show where it breaks in the transition region. Finally, we find a region in the disk parameter space with no solutions due to the inability of Coulomb heating to supply enough energy to electrons.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Hot accretion disks with pairs: Effects of magnetic field and thermal cyclocsynchrotron radiation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Hot accretion disks with pairs: Effects of magnetic field and thermal cyclocsynchrotron radiation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hot accretion disks with pairs: Effects of magnetic field and thermal cyclocsynchrotron radiation will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1014474

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.