NGC 3175 is a spiral galaxy located in the far eastern part of the southern constellation of Antlia[8] at an approximate distance of 54 million light-years.[5] NGC 3175 was discovered on March 30, 1835 by English astronomer John Herschel,[9] whose notes described it as, "considerably bright, large, much extended NE-SW, very gradually little brighter middle".[10] This galaxy is the namesake of the NGC 3175 group of galaxies,[6] which includes the spiral galaxy NGC 3137.[11]
A study of the galaxy using the Australia Telescope Compact Array found that the outer disk of this galaxy, beyond a radius of 3.5 kpc from the core, is free of neutral hydrogen emission. This is an indication that no star formation is occurring, which is peculiar for a spiral galaxy. In contrast, the central region is undergoing star formation and contains 5.8×108M☉ of neutral hydrogen. There are no nearby galaxies that could explain the stripping of hydrogen gas from the outer part of the galaxy.[6]
^ abcStreicher, Magda (June 2010). "Antlia, the Machine Pneumatique". Monthly Notes of the Astronomical Society of South Africa. 69 (5 and 6): 107–112. Bibcode:2010MNSSA..69..107S.