Astronomy and Astrophysics – Astrophysics
Scientific paper
1999-04-03
Astronomy and Astrophysics
Astrophysics
7 pages including 2 figures. Accepted by ApJ Letters
Scientific paper
10.1086/312048
Galaxies exhibit a sequence of various morphological types, i.e., the Hubble sequence, and they are basically composed of spheroidal components (elliptical galaxies and bulges in spiral galaxies) and disks. It is known that spheroidal components are found only in relatively massive galaxies with M=10^{10-12} M_sun, and all stellar populations in them are very old, but there is no clear explanation for these facts. Here we present a speculative scenario for the origin of the Hubble sequence, in which magnetic fields ubiquitously seen in galaxies have played a crucial role. We first start from a strange observational fact that magnetic field strengths observed in spiral galaxies sharply concentrate at a few microgauss, for a wide range of galaxy luminosity and types. We then argue that this fact and the observed correlation between star formation activity and magnetic field strength in spiral galaxies suggest that spheroidal galaxies have formed by starbursts induced by strong magnetic fields. Then we show that this idea naturally leads to the formation of spheroidal systems only in massive and high-redshift objects in hierarchically clustering universe, giving a simple explanation for various observations.
No associations
LandOfFree
Galaxy Formation by Galactic Magnetic Fields 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 Galaxy Formation by Galactic Magnetic Fields, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Galaxy Formation by Galactic Magnetic Fields will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-316654