Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2011-04-05
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
7 pages, to appear in the proceedings of the 25th Texas Symposium on Relativistic Astrophysics, December 6-10, 2010. This pape
Scientific paper
All galaxies without a radio-loud AGN follow a tight correlation between their global FIR and radio synchrotron luminosities, which is believed to be ultimately the result of the formation of massive stars. Two face-on colliding pairs of galaxies, UGC12914/5 and UGC 813/6 deviate from this correlation and show an excess of radio emission which in both cases originates to a large extent in a gas bridge connecting the two galactic disks. The radio synchrotron emission expected from the bridge region is calculated, assuming that the kinetic energy liberated in the predominantly gas dynamic interaction of the respective interstellar media (ISM) has produced shock waves that efficiently accelerate nuclei and electrons to relativistic energies. A simple model for the acceleration of relativistic particles in these shocks is presented together with a calculation of the resulting radio emission, its spectral index and the expected high-energy gamma-ray emission. This process is not related to star formation. It is found that the nonthermal energy produced in the collision is large enough to explain the radio emission from the bridge between the two galaxies. The calculated spectral index at the present time also agrees with the observed value. The expected gamma-ray emission, on the other hand, is too low by a factor of several to be detectable even with foreseeable instruments like CTA.
Lisenfeld Ute
Voelk Heinrich J.
No associations
LandOfFree
Shock acceleration of relativistic particles in galaxy-galaxy collisions 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 Shock acceleration of relativistic particles in galaxy-galaxy collisions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Shock acceleration of relativistic particles in galaxy-galaxy collisions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-416629