TY - JOUR
T1 - Optically unseen H I detections toward the Virgo cluster detected in the Arecibo Legacy Fast ALFA survey
AU - Kent, Brian R.
AU - Giovanelli, Riccardo
AU - Haynes, Martha P.
AU - Saintonge, Amélie
AU - Stierwalt, Sabrina
AU - Balonek, Thomas
AU - Brosch, Noah
AU - Catinella, Barbara
AU - Koopmann, Rebecca A.
AU - Momjian, Emmanuel
AU - Spekkens, Kristine
PY - 2007
Y1 - 2007
N2 - We report the discovery by the Arecibo Legacy Fast ALFA (ALFALFA) survey of eight H i features not coincident with stellar counterparts in the Virgo Cluster region. All of the H i clouds have cz < 3000 km s-1 and, if at the Virgo distance, H i masses between 1.9 × 107 and 1.1 × 109 M⊙. Four of the eight objects were reported or hinted at by previous studies and "rediscovered" by ALFALFA. While some clouds appear to be associated with optical galaxies in their vicinity, others show no clear association with a stellar counterpart. Two of them are embedded in relatively dense regions of the cluster and are associated with M49 and M86; they were previously known. The others are mostly located in peripheral regions of the cluster. Especially notable are a concentration of objects toward the so-called M cloud, 3°-5° to the northwest of M87, and a complex of several clouds projected roughly halfway between M87 and M49. The object referred to as VIRGOHI 21 and proposed to be a "dark galaxy" is also detected and shown to be a tidal feature associated with NGC 4254.
AB - We report the discovery by the Arecibo Legacy Fast ALFA (ALFALFA) survey of eight H i features not coincident with stellar counterparts in the Virgo Cluster region. All of the H i clouds have cz < 3000 km s-1 and, if at the Virgo distance, H i masses between 1.9 × 107 and 1.1 × 109 M⊙. Four of the eight objects were reported or hinted at by previous studies and "rediscovered" by ALFALFA. While some clouds appear to be associated with optical galaxies in their vicinity, others show no clear association with a stellar counterpart. Two of them are embedded in relatively dense regions of the cluster and are associated with M49 and M86; they were previously known. The others are mostly located in peripheral regions of the cluster. Especially notable are a concentration of objects toward the so-called M cloud, 3°-5° to the northwest of M87, and a complex of several clouds projected roughly halfway between M87 and M49. The object referred to as VIRGOHI 21 and proposed to be a "dark galaxy" is also detected and shown to be a tidal feature associated with NGC 4254.
KW - Galaxies: clusters: general
KW - Galaxies: clusters: individual (Virgo cluster)
KW - Galaxies: halos
KW - Galaxies: interactions
KW - Intergalactic medium
KW - Radio lines: galaxies
UR - http://www.scopus.com/inward/record.url?scp=34548356723&partnerID=8YFLogxK
U2 - 10.1086/521100
DO - 10.1086/521100
M3 - Article
AN - SCOPUS:34548356723
VL - 665
JO - The Astrophysical Journal
JF - The Astrophysical Journal
SN - 0004-637X
IS - 1 PART 2
ER -