Although numerous studies have focused on star formation enhancement and supression in the cluster and AGN environments, the exact mechanisms for star formation are still not clearly understood, even for isolated starburst galaxies. The use of radio emission as a star formation tracer is particularly useful as it is unaffected by extinction, unlike optical and UV tracers. To this end, we have used the Very Large Array (VLA) to image several nearby spiral galaxies with strong star formation activities: Maffei 2, IC 342, NGC 6946, and NGC 2903, in the 20 cm continuum emission. At 20 cm, the continuum is dominated by synchrotron emission which traces the integrated star formation history. In this experiment, we are sampling as much of the large scale structure as possible by observing the galaxies in the B-, C-, and D-configuration of the VLA, which yields a higher dynamic range ( 1000:1) than those of previous studies. The data were calibrated and mapped using the NRAO AIPS aperture synthesis software. In the cases of Maffei 2 and IC 342, we compare the 20 cm continuum emission to the atomic hydrogen (21 cm) images of these galaxies. We ask the questions as to whether star formation activities extend out into the disk of the galaxies as far as the atomic hydrogen, and whether star formation activities are well correlated with the gas distribution as traced by the atomic hydrogen.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1999