Spitzer Observations of Environmental Effects on Virgo Cluster Galaxies

TL;DR

This study uses Spitzer observations to investigate how the environment within the Virgo galaxy cluster affects the evolution and morphology of its member galaxies, revealing signs of ram pressure effects.

Contribution

It provides the first detailed infrared analysis of Virgo cluster galaxies, highlighting environmental impacts like ram pressure stripping and their observable signatures.

Findings

Detection of ram pressure-induced disturbances in radio morphologies

Identification of extraplanar gas tails from dust and optical data

Observation of unobscured star-forming regions with high H-alpha to 24um ratios

Abstract

We present the initial results from SPITSOV, the Spitzer Survey of Virgo, which includes MIPS and IRAC observations for a carefully selected sample of 44 Virgo cluster spiral and peculiar galaxies. SPITSOV is part of a multiwavelength campaign to understand the effects of the cluster environment on galaxy evolution. These Virgo galaxies are different from galaxies outside of clusters, since most of them have been significantly modified by their environment. The SPITSOV data can serve the community as the Spitzer sample of nearby cluster spiral galaxies, a complement to the SINGS data for nearby non-cluster galaxies. In this paper we describe the sample, the goals of the study, and present preliminary results in 3 areas: 1) Evidence for ram pressure-induced disturbances in radio morphologies based on changes in the FIR-radio (70um-20cm) correlation; 2) Evidence for ram-pressure stripped extraplanar gas tails from comparisons of dust/PAH (8um) emission and optical dust extinction; 3) Evidence for unobscured star-forming regions with large ratios of H-alpha to 24um emission in some galaxies due to ram pressure stripping of dust.