Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-12-15
Astrophys.J.694:1435-1451,2009
Astronomy and Astrophysics
Astrophysics
19 pages, 10 figures; Astrophysical Journal
Scientific paper
10.1088/0004-637X/694/2/1435
(abridged) We present a study on the effects of the intracluster medium (ICM) on the interstellar medium (ISM) of 10 Virgo cluster spiral galaxies using {\it Spitzer} far-infrared (FIR) and VLA radio continuum imaging. Relying on the FIR-radio correlation within normal galaxies, we use our infrared data to create model radio maps which we compare to the observed radio images. For 6 of our sample galaxies we find regions along their outer edges that are highly deficient in the radio compared with our models. We believe these observations are the signatures of ICM ram pressure. For NGC 4522 we find the radio deficit region to lie just exterior to a region of high radio polarization and flat radio spectral index, although the total 20 cm radio continuum in this region does not appear strongly enhanced. These characteristics seem consistent for other galaxies with radio polarization data in the literature. The strength of the radio deficit is inversely correlated with the time since peak pressure as inferred from stellar population studies and gas stripping simulations, suggesting the strength of the radio deficit is good indicator of the strength of the current ram pressure. We also find that galaxies having {\it local} radio {\it deficits} appear to have {\it enhanced global} radio fluxes. Our preferred physical picture is that the observed radio deficit regions arise from the ICM wind sweeping away cosmic-ray (CR) electrons and the associated magnetic field, thereby creating synchrotron tails as observed for some of our galaxies. We propose that CR particles are also re-accelerated by ICM-driven shocklets behind the observed radio deficit regions which in turn enhances the remaining radio disk brightness.
Chung Aeree
Helou George
Howell Justin H.
Kenney Jeffrey D. P.
Murphy Eric J.
No associations
LandOfFree
Environmental Effects in Clusters: Modified Far-Infrared--Radio Relations within Virgo Cluster Galaxies 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 Environmental Effects in Clusters: Modified Far-Infrared--Radio Relations within Virgo Cluster Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Environmental Effects in Clusters: Modified Far-Infrared--Radio Relations within Virgo Cluster Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-226287