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arXiv · 2212.03478

Peekaboo: the extremely metal poor dwarf galaxy HIPASS J1131-31

I. D. Karachentsev·L. N. Makarova·B. S. Koribalski·G. S. Anand·R. B. Tully·A. Y. Kniazev
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Abstract

The dwarf irregular galaxy HIPASS J1131-31 was discovered as a source of HI emission at low redshift in such close proximity of a bright star that we call it Peekaboo. The galaxy resolves into stars in images with Hubble Space Telescope, leading to a distance estimate of 6.8+-0.7 Mpc. Spectral optical observations with the Southern African Large Telescope reveal HIPASS J1131-31 to be one of the most extremely metal-poor galaxies known with the gas-phase oxygen abundance 12+log(O/H) = 6.99+-0.16 dex via the direct [OIII] 4363 line method and 6.87+-0.07 dex from the two strong line empirical methods. The red giant branch of the system is tenuous compared with the prominence of the features of young populations in the color-magnitude diagram, inviting speculation that star formation in the galaxy only began in the last few Gyr.

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I. D. Karachentsev, L. N. Makarova, B. S. Koribalski, G. S. Anand, R. B. Tully, A. Y. Kniazev. 2022-12-07. Peekaboo: the extremely metal poor dwarf galaxy HIPASS J1131-31. https://doi.org/10.1093/mnras%2Fstac3284

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