Abstract
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 H i source associated
with the optical counterpart (AGC 226067), a smaller H i-only component
(AGC 229490), a second optical component (AGC 229491), and extended
low-surface brightness H i. Only ~1/4 of the single-dish H i emission is
associated with AGC 226067; as a result, we find
MHI/Lg ~ 6M⊙/L⊙
which is lower than previous work. At D = 17 Mpc, AGC 226067 has an H i
mass of 1.5 × 107M⊙ and Lg =
2.4 × 106L⊙, AGC 229490 (the H i-only
component) has MHI = 3.6 ×
106M⊙, and AGC 229491 (the second optical
component) has Lg = 3.6 ×
105L⊙. The nature of this system of three
sources is uncertain: AGC 226067 and AGC 229490 may be connected by an H
i bridge, and AGC 229490 and AGC 229491 are separated by only 0.5'. The
current data do not resolve the H i 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.
Original language | English |
---|---|
Article number | A134 |
Number of pages | 6 |
Journal | Astronomy and astrophysics |
Volume | 580 |
DOIs | |
Publication status | Published - Aug-2015 |
Externally published | Yes |
Keywords
- galaxies: dwarf
- galaxies: ISM
- radio lines: ISM