Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-05-04
Astrophys.J. 593 (2003) 733-759; Erratum-ibid. 601 (2004) 1160
Astronomy and Astrophysics
Astrophysics
accepted for publication in ApJ -- 38 pages of text, 8 tables, 12 figures (fig. 1, 7 and 10 degraded)
Scientific paper
10.1086/379247
Three nearby galaxies which have abnormally high infrared to radio continuum ratios, NGC 1377, IC 1953 and NGC 4491, are investigated with a view to understanding the physical origin of their peculiarity. We review the existing data and present new radio continuum measurements along with near-infrared integral-field spectroscopy and molecular gas observations. The three galaxies have low luminosities but starburst-like infrared colors; in NGC 1377, no synchrotron emission is detected at any wavelength; in IC 1953, the observed synchrotron component is attributable to the spiral disk alone, and is lacking in the central regions; the radio spectrum of NGC 4491 is unusually flat. We also compare and contrast them with NGC 4418, a heavily extinguished galaxy which shares some attributes with them. After examining various scenarios, we conclude that these galaxies are most likely observed within a few Myr of the onset of an intense star formation episode after being quiescent for at least ~ 100 Myr. This starburst, while heating the dust, has not produced optical signatures nor a normal amount of cosmic rays yet. We briefly discuss the statistics of such galaxies and what they imply for star formation surveys.
Beck Rainer
Bosma Albert
Condon James J.
Helou George
Jarrett Thomas H.
No associations
LandOfFree
Nascent starbursts in synchrotron-deficient galaxies with hot dust 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 Nascent starbursts in synchrotron-deficient galaxies with hot dust, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nascent starbursts in synchrotron-deficient galaxies with hot dust will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-329753