The dwarf galaxy population as revealed by ALFALFA

• DOI: 10.1017/s174392131800710x
• Publication Date: 2019-10-30T05:58:08Z
• Authors: Elizabeth A. K. A...; Catherine Ball; John M. Cannon; Martha P. Haynes; Alec Hirschauer; Riccardo Giovanelli; William Janesh; Steven Janowiecki; Luke Leisman; Kristen B. W. McQ...; Katherine L. Rhode; John J. Salzer
• Keywords: Dwarf spheroidal galaxy; Dwarf galaxy problem; Dark galaxy

Abstract The combination of sensitivity and large sky coverage the ALFALFA HI survey has enabled detection difficult to observe low mass galaxies in numbers, including dwarf overlooked optical surveys. Three different, but connected, studies from are particular interest: SHIELD (Survey Extremely Low-mass Dwarfs), candidate gas-rich ultra-faint galaxies, (Almost) Dark population. is a systematic multiwavelength study all with M < 10 7.2 ⊙ clear counterparts. Candidate extend galaxy population even lower masses. These identified as isolated clouds no discernible counterpart subsequent observations reveal that some extremely faint, gas-dominated galaxies. Leo P, discovered first an detection, then found be actively star-forming galaxy, bridges gap between these sample. sample consists whose counterparts current surveys which detections ALFALFA. This includes field ultra-diffuse Coma peak surface brightness only ∼26.4 mag arcsec −2 g’, demonstrates sort extreme can survey.