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arXiv · 1903.08840

A Cold Stellar Stream in Pegasus

H. D. Perottoni·C. Martin·H. J. Newberg·H. J. Rocha-Pinto·F. de Almeida-Fernandes·A. R. Gomes-Junior
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Abstract

We report the serendipitous discovery of a stellar stream in the constellation Pegasus in the south Galactic hemisphere. The stellar stream was detected using the SDSS Data Release 14 by means of a matched filter in the color--magnitude diagram that is optimised for a stellar population that is 8 Gyr old with [Fe/H] = $-$0.46 dex, and located at heliocentric distance of 18 kpc. The candidate stream is faint (turnoff point at $r_0 \sim$ 19.6), sparse and barely visible in SDSS photometry. It is also detected in the (shallower) Pan-STARRs data. The residual stellar density in the $(u-g)_0$, $(g-r)_0$ color--color diagram gives the same estimate for the age and [Fe/H] of this stellar population. The stream is located at a Galactic coordinates $(l,b) = (79.4,-24.6)$ and extends over 9$^\circ$ (2.5 kpc), with a width of 112 pc. The narrow width suggests a globular cluster progenitor.

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H. D. Perottoni, C. Martin, H. J. Newberg, H. J. Rocha-Pinto, F. de Almeida-Fernandes, A. R. Gomes-Junior. 2019-03-21. A Cold Stellar Stream in Pegasus. https://doi.org/10.1093/mnras%2Fstz869

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