H-ATLAS: The Far-Infrared properties of galaxies in and around the Coma Cluster

TL;DR

This study uses Herschel far-infrared data to analyze the properties of galaxies in the Coma cluster and its filament, revealing differences in detection rates and dust temperatures among galaxy types, with implications for galaxy evolution.

Contribution

First comprehensive far-infrared survey of the Coma cluster and filament, providing new insights into galaxy dust properties and environmental effects.

Findings

13% of cluster galaxies detected at 250μm

44% of filament galaxies detected at 250μm

Early type galaxy dust temperatures are hotter in the cluster

Abstract

We describe a far infrared survey of the Coma cluster and the galaxy filament it resides within. Our survey covers an area of $\sim$150 deg$^2$ observed by $Herschel$ H-ATLAS in five bands at 100, 160, 250, 350 and 500$\mu$m. The SDSS spectroscopic survey ($m_{r} \le 17.8)$ is used to define an area (within the Virial radius) and redshift selected ($4268 < v < 9700$ km s$^{-1}$) sample of 744 Coma cluster galaxies - the Coma Cluster Catalogue (CCC). For comparison we also define a sample of 951 galaxies in the connecting filament - the Coma Filament Catalogue (CFC). The optical positions and parameters are used to define appropriate apertures to measure each galaxy's far infrared emission. We have detected 99 of 744 (13\%) and 422 of 951 (44\%) of the cluster and filament galaxies in the SPIRE 250$\mu$m band. We consider the relative detection rates of galaxies of different morphological types finding that it is only the S0/Sa population that shows clear differences between the cluster and filament. We find no differences between the dust masses and temperatures of cluster and filament galaxies with the exception of early type galaxy dust temperatures, which are significantly hotter in the cluster than in the filament (X-ray heating?). From a chemical evolution model we find no evidence for different evolutionary processes (gas loss or infall) between galaxies in the cluster and filament.