| 15th of February 2021 |
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| A blind ATCA HI survey of the Fornax galaxy cluster |
| by Loni et al. |
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Loni et al. present the first interferometric blind HI survey covering
an area of 15 square degrees, of the Fornax galaxy cluster. The
Fornax cluster is a low mass cluster (~7×10^13 solar masses), located
in the southern sky at a distance of 20 Mpc (160 million light years),
making it the second closest galaxy cluster to us after the Virgo
cluster. Loni et al. detected neutral hydrogen emission from 16
galaxies out of 200 spectroscopically confirmed Fornax cluster
members. The detections cover ~3 orders of magnitude in HI mass, from
8x10^6 to 1.5x10^10 solar masses. The galaxies detected in neutral
hydrogen avoid the central region of the cluster, showing that they
are recent arrivals into the cluster and that, in Fornax, HI is lost
within a crossing time, ~2 Gyr.
The image above shows the layout and detections of the ATCA HI survey. The green outline marks the 15 square degree region of the survey. The red contours represent the lowest reliable HI column density of the 16 detections. The grey dashed circle is the virial radias of the cluster. The background optical image comes from the Digital Sky Survey (blue band). The yellow contours show the X-ray emission in the Fornax cluster detected with XMM-Newton and convolved with a 3 arcmin FWHM gaussian. The results are presented in a paper submitted to Astronomy & Astrophysics. |