WALLABY pre-pilot survey: two dark clouds in the vicinity of NGC 1395

Abstract:

We present the Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pre-pilot observations of two ‘dark’ H i sources (with H i masses of a few times 108 and no known stellar counterpart) that reside within 363 kpc of NGC 1395, the most massive early-type galaxy in the Eridanus group of galaxies. We investigate whether these ‘dark’ H i sources have resulted from past tidal interactions or whether they are an extreme class of low surface brightness galaxies. Our results suggest that both scenarios are possible, and not mutually exclusive. The two ‘dark’ H i sources are compact, reside in relative isolation, and are more than 159 kpc away from their nearest H i-rich galaxy neighbour. Regardless of origin, the H i sizes and masses of both ‘dark’ H i sources are consistent with the H i size–mass relationship that is found in nearby low-mass galaxies, supporting the possibility that these H i …

Año de publicación:

2021

Keywords:

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