NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-07-22 T07:59:24 PDT
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For refcode 2015ApJ...798L..45V:
Retrieve 48 NED objects in this reference.
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2015ApJ...798L..45V Forty-seven Milky Way-sized, Extremely Diffuse Galaxies in the Coma Cluster van Dokkum, Pieter G.; Abraham, Roberto; Merritt, Allison; Zhang, Jielai; Geha, Marla; Conroy, Charlie Abstract. We report the discovery of 47 low surface brightness objects in deep images of a 3^degree^ x 3^degree^ field centered on the Coma cluster, obtained with the Dragonfly Telephoto Array. The objects have central surface brightness mu(g, 0) ranging from 24-26 mag arcsec^-2^ and effective radii r_eff_ = 3"-10", as measured from archival Canada-France-Hawaii Telescope images. From their spatial distribution we infer that most or all of the objects are galaxies in the Coma cluster. This relatively large distance is surprising as it implies that the galaxies are very large: with r_eff_ = 1.5-4.6 kpc their sizes are similar to those of L_*_ galaxies even though their median stellar mass is only ~6 x 10^7^ M_&sun;_. The galaxies are relatively red and round, with langg - irang = 0.8 and langb/arang = 0.74. One of the 47 galaxies is fortuitously covered by a deep Hubble Space Telescope Advanced Camera for Surveys (ACS) observation. The ACS imaging shows a large spheroidal object with a central surface brightness mu_475_ = 25.8 mag arcsec^-2^, a Sersic index n = 0.6, and an effective radius of 7", corresponding to 3.4 kpc at the distance of Coma. The galaxy is not resolved into stars, consistent with expectations for a Coma cluster object. We speculate that these "ultra-diffuse galaxies" may have lost their gas supply at early times, possibly resulting in very high dark matter fractions. Key words: galaxies: clusters: individual: Coma, galaxies: evolution, galaxies: structure
Retrieve 48 NED objects in this reference.
Please click here for ADS abstract

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