Ionized Carbon in Virgo Cluster Dwarf Galaxies

We use archival Herschel data to examine the ionized carbon ([CII]) content and infrared continuum of 14 dwarf galaxies in the Virgo cluster. We compare this to other samples, including the Herschel Dwarf Galaxy Survey (DGS) sample of dwarf galaxies in the field, to determine whether the line to continuum ratio is different in the dwarf galaxies in the Virgo cluster. We use SED fits to five Herschel continuum bands to determine the total infrared continuum (TIR) for the dwarf galaxies in our sample. Our initial analysis indicates that our sample of Virgo dwarfs has higher values of [CII]/TIR than the DGS sample. We also see possible indications of environmental effects on the [CII]/TIR ratio, with the highest ratios being found in dwarf galaxies between 2.5 and 4.5 degrees from either M87 or M49. As both [CII] and TIR trace the star formation rate this is unlikely to be due to enhanced star formation, thus it may indicate that [CII] is being created by other processes injecting energy into the ISM such as interactions with other galaxies or with the ICM.

Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

SOFIA is jointly operated by the Universities Space Research Association, Inc. (USRA), under NASA contract NNA17BF53C, and the Deutsches SOFIA Institut (DSI) under DLR contract 50 OK 0901 to the University of Stuttgart.