Millimeter-wave continuum observation of galaxies
Abstract
Millimeter-wave continuum observation of galaxies have been performed with the 45m telescope using Nobeyama Bolometer Array (NOBA) at 150GHz, SIS multi-beam receiver at 100GHz and 43GHz SIS receiver. The observation gave the first single dish image at either of the observing frequencies, and we got accurate total power spectrum of galaxies and their distributions. Their continuum spectra can be explained by combination of interstellar dust emission, synchrotron emission and free-free emission. Because the free-free emission from galaxies can be observed only at millimeter-wave freqnencies and their emission is optically thin, it can be the best indicator of star-formation activities in galaxies. The starburst galaxy, M82, shows extended structure at 150GHz and 100GHz. Both of the central compact component and diffuse component which extend above the galactic plane is observed. Their accurate total power spectrum is derived by integrating over the mapping region which show dominant contribution of free-free emission at millimeter-wave freqnencies. Star formation rate at central region is derived which seems to be higher than ever estimated.
- Publication:
-
The Central Regions of the Galaxy and Galaxies
- Pub Date:
- 1998
- Bibcode:
- 1998IAUS..184..143M