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Neutral atomic hydrogen in Hickson Compact Group 44

Submitter: Sahba Yahya
Description: This image is a slide from my presentation at ASTRON lunch talk in August, and shows one of the main scientific results from my visit to ASTRON/JIVE during the summer of 2015. The image shows a preliminary map of the total neutral atomic hydrogen (HI) in Hickson Compact Group 44 (HCG 44). HCG 44 is a group of galaxies consist of three spiral galaxies NGC 3190, NGC 3187, NGC 3185 and background galaxy, SDSS J1017.

On the left, previous observations of HCG 44 with WSRT and HIPASS from Serra et al. (2013) suggest the possibility that NGC3162 flew by the group and caused gas stripping, creating the long HI tail. Another possibility is an HI bridge between the group, the tail and NCG 3126.

KAT-7 is a 7 dish array, and a testbed for the 64-dish Meerkat. Meerkat is the South African pathfinder for the SKA. With a 1 degree field of view, and angular resolution = 4 arcmin, KAT-7 is a compact array, with low system temperature, good for measuring low surface brightness emission on large angular scales. These specifications make KAT7 ideal for investigating HI abundance in and around HCG44.

During my visit to ASTRON, I met great people, had so much fun, and learned a lot about radio astronomy. Thanks to Dr. Kelley Hess' guidance, I successfully reduced the HCG 44 data from the KAT-7 telescope and produced a cube showing HI abundance on HCG 44 compact group. Understanding the gas content and the impact of the group environment on galaxies is important for understanding their overall evolution. We detected that the tail is even more massive and more extended than the previously reported observations. We also found more large scale gas within and between the three compact group galaxies that make up HCG 44.
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