English

Variations of the Radio Synchrotron Spectral Index in M33

Astrophysics 2008-02-06 v1

Abstract

We determine the variation in the nonthermal radio spectral index in the nearby spiral galaxy M33. We separate the thermal and nonthermal components of the radio continuum emission without the assumption of a constant nonthermal spectral index. Using the Spitzer FIR data at 70 and 160 μ\mum and a standard dust model, we de-redden the Hα\alpha emission. The extinction-corrected Hα\alpha emission serves as a template for the thermal free-free radio emission. Subtracting from the observed 3.6 and 20cm emission (Effelsberg and the VLA) this free-free emission, we obtain maps of the nonthermal intensity and spectral index.

Keywords

Cite

@article{arxiv.0802.0642,
  title  = {Variations of the Radio Synchrotron Spectral Index in M33},
  author = {F. S. Tabatabaei and R. Beck and E. Krügel and M. Krause and E. M. Berkhuijsen and K. D. Gordon and K. M. Menten},
  journal= {arXiv preprint arXiv:0802.0642},
  year   = {2008}
}

Comments

2 pages, 1 figure, to appear in the Proceeding "Formation and Evolution of Galaxy Disks", eds: Jose G. Funes, S.J. & Enrico M. Corsini (ASP conference series)