AGC 226178 and NGVS 3543: Two deceptive dwarfs towards Virgo
  The two sources AGC 226178 and NGVS 3543, an extremely faint, clumpy, blue
stellar system and a low surface brightness dwarf spheroidal, are adjacent
systems in the direction of the Virgo cluster. Both have been studied in detail
previously, with it being suggested that they are unrelated normal dwarf
galaxies or that NGVS 3543 recently lost its gas through ram pressure
stripping, and that AGC 226178 formed from this stripped gas. However, with HST
ACS imaging we demonstrate that the stellar population of NGVS 3543 is
inconsistent with being at the distance of the Virgo cluster, and that it is
likely a foreground object at approximately 10 Mpc. Whereas the stellar
population of AGC 226178 is consistent with it being a very young (10-100 Myr)
object in the Virgo cluster. Through a re-analysis of the original ALFALFA HI
detection we show that AGC 226178 likely formed from gas stripped from the
nearby dwarf galaxy VCC 2034, a hypothesis strengthened by the high metallicity
measured with MUSE VLT observations. However, it is unclear whether ram
pressure or a tidal interaction is responsible for stripping the gas. AGC
226178 is one of at least five similar objects now known towards Virgo. These
objects are all young and unlikely to remain visible for over ~500 Myr,
suggesting that they are continually produced in the cluster.
