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arXiv · 1709.00780

A deep Parkes HI survey of the Sculptor group and filament: HI mass function and environment

T. Westmeier·D. Obreschkow·M. Calabretta·R. Jurek·B. S. Koribalski·M. Meyer·A. Musaeva·A. Popping·L. Staveley-Smith·O. I. Wong·A. Wright
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Abstract

We present the results of a deep survey of the nearby Sculptor group and the associated Sculptor filament taken with the Parkes 64-m radio telescope in the 21-cm emission line of neutral hydrogen. We detect 31 HI sources in the Sculptor group/filament, eight of which are new HI detections. We derive a slope of the HI mass function along the Sculptor filament of $\alpha = -1.10^{+0.20}_{-0.11}$, which is significantly flatter than the global mass function and consistent with the flat slopes previously found in other low-density group environments. Some physical process, such as star formation, photoionisation or ram-pressure stripping, must therefore be responsible for removing neutral gas predominantly from low-mass galaxies. All of our HI detections have a confirmed or tentative optical counterpart and are likely associated with luminous rather than 'dark' galaxies. Despite a column density sensitivity of about $4 \times 10^{17}~\mathrm{cm}^{-2}$, we do not find any traces of extragalactic gas or tidal streams, suggesting that the Sculptor filament is, at the current time, a relatively quiescent environment that has not seen any recent major interactions or mergers.

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T. Westmeier, D. Obreschkow, M. Calabretta, R. Jurek, B. S. Koribalski, M. Meyer, A. Musaeva, A. Popping, L. Staveley-Smith, O. I. Wong, A. Wright. 2017-09-04. A deep Parkes HI survey of the Sculptor group and filament: HI mass function and environment. https://doi.org/10.1093/mnras/stx2289

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