AGC 226067: A possible interacting low-mass system

作者：Adams E A K^*; Cannon J M; Rhode K L; Janesh W F; Janowiecki S; Leisman L; Giovanelli R; Haynes M P; Oosterloo T A; Salzer J J; Zaidi T

来源：Astronomy & Astrophysics, 2015, 580: A134.

DOI：10.1051/0004-6361/201526857

• galaxies: dwarf
• galaxies: ISM
• radio lines: ISM

We present Arecibo, GBT, VLA, and WIYN/pODI observations of the ALFALFA source AGC 226067. Originally identified as an ultra-compact high velocity cloud and candidate Local Group galaxy, AGC 226067 is spatially and kinematically coincident with the Virgo cluster, and the identification by multiple groups of an optical counterpart with no resolved stars supports the interpretation that this systems lies at the Virgo distance (D = 17 Mpc). The combined observations reveal that the system consists of multiple components: a central Hi source associated with the optical counterpart (AGC 226067), a smaller Hi-only component (AGC 229490), a second optical component (AGC 229491), and extended low-surface brightness Hi. Only similar to 1/4 of the single-dish Hi emission is associated with AGC 226067; as a result, we find M-HI/L-g similar to 6 M-circle dot/L-circle dot which is lower than previous work. At D = 17 Mpc, AGC 226067 has an Hi mass of 1.5x10(7) M-circle dot and L-g = 2.4x10(6) L-circle dot, AGC 229490 (the Hi-only component) has M-HI = 3.6x10(6) M-circle dot, and AGC 229491 (the second optical component) has L-g = 3.6 x 10(5) L-circle dot. The nature of this system of three sources is uncertain: AGC 226067 and AGC 229490 may be connected by an Hi bridge, and AGC 229490 and AGC 229491 are separated by only 0.5'. The current data do not resolve the Hi in AGC 229490 and its origin is unclear. We discuss possible scenarios for this system of objects: an interacting system of dwarf galaxies, accretion of material onto AGC 226067, or stripping of material from AGC 226067.

• 出版日期2015-8