Related papers: The Arecibo Legacy Fast ALFA Survey VII: A Neutral…
We report the discovery of a ~500 kpc HI extension southwest of the Virgo Cluster HI-rich pair NGC 4532/DDO 137, detected as part of the Arecibo Legacy Fast ALFA (ALFALFA) Survey. The feature is the longest and most massive HI tail…
We have carried out a fully sampled large area ($4^{\circ} \times 8^{\circ}$) 21cm \HI line survey of part of the Virgo cluster using the Jodrell Bank multi-beam instrument. The survey has a sensitivity some 3 times better than the standard…
We present a fourth catalog of HI sources from the Arecibo Legacy Fast ALFA (ALFALFA) Survey. We report 541 detections over 136 deg2, within the region of the sky having 22h < R.A. < 03h and 24 deg < Dec. < 26 deg . This complements a…
We present in this paper the deepest Arecibo HI observations of Virgo cluster dwarf ellipticals (dEs) taken to date. Based on this data we argue that a significant fraction of Virgo cluster dEs recently underwent evolution. Our new…
Most detected neutral atomic hydrogen (HI) at low redshift is associated with optically bright galaxies. However, a handful of HI clouds are known which appear to be optically dark and have no nearby potential progenitor galaxies, making…
Using data from the ALFALFA Arecibo HI survey of galaxies and the Virgo cluster X-ray pressure profiles from XMM-Newton, we investigate the possibility that starless dark HI clumps, also known as "dark galaxies", are supported by external…
The discovery of a previously unknown 21cm HI line source identified as an ultra-compact high velocity cloud in the ALFALFA survey is reported. The HI detection is barely resolved by the Arecibo 305m telescope ~4' beam and has a narrow HI…
High sensitivity (rms noise $\sim 0.5$ mJy) 21-cm HI line observations were made of 33 galaxies in the Virgo cluster, using the refurbished Arecibo telescope, which resulted in the detection of 12 objects. These data, combined with the…
HI observations of the Virgo Cluster pair NGC 4532/DDO 137, conducted as part of the Arecibo Legacy Fast ALFA Survey (ALFALFA), reveal an HI feature extending ~500 kpc to the southwest. The structure has a total mass of up to 7 x 10^8 solar…
VIRGOHI21 is an HI source detected in the Virgo Cluster survey of Davies et al. (2004) which has a neutral hydrogen mass of 10^8 M_solar and a velocity width of Delta V_20 = 220 km/s. From the Tully-Fisher relation, a galaxy with this…
The ALFALFA (Arecibo Legacy Fast ALFA) blind survey is providing a census of HI in galaxies of all types in a range of environments. Here we report on ALFALFA results for Virgo Cluster early-type dwarfs between declinations of 4 and 16…
The Arecibo HI Strip Survey probed the halos of ~300 cataloged galaxies and the environments of ~14 groups with sensitivity to neutral hydrogen masses > 10^7 M_sun. The survey detected no objects with properties resembling the High Velocity…
Five galaxy groups with properties similar to those of the Local Group have been surveyed for HI clouds with the Arecibo Telescope. In total 300 pointings have been observed on grids of approximately 2.5 x 1.5 Mpc centred on the groups. The…
Using data from the Arecibo Galaxy Environment Survey, we report the discovery of five HI clouds in the Leo I group without detected optical counterparts. Three of the clouds are found midway between M96 and M95, one is only 10$^{\prime}$…
The Arecibo Galaxy Environment Survey (AGES) has detected a nearby HI source at a heliocentric velocity of +363 km/s . The object was detected through its neutral hydrogen emission and has an obvious possible optical counterpart in Sloan…
We investigate the distribution and velocity field of galaxies situated in a band of 100 by 20 degrees centered on M87 and oriented along the Local supercluster plane. Our sample amounts 2158 galaxies with radial velocities less than 2000…
We investigate the dwarf (M_B> -16) galaxies in the Virgo cluster in the radio, optical, and ultraviolet regimes. Of the 365 galaxies in this sample, 80 have been detected in HI by the Arecibo Legacy Fast ALFA survey. These detections…
We present an HI map constructed from the Arecibo Legacy Fast ALFA (ALFALFA) survey of the surroundings of the strongly asymmetric Virgo cluster Sc galaxy NGC 4254. Noted previously for its lopsided appearance, rich interstellar medium, and…
The Arecibo Legacy Fast ALFA (ALFALFA) Survey is a program aimed at obtaining a census of HI-bearing objects over a cosmologically significant volume of the local Universe. It will cover 7074 square degrees of the high latitude sky…
We present the analysis of Halpha3, an Halpha imaging survey of 409 galaxies selected from the HI Arecibo ALFALFA Survey in the Local Supercluster, including the Virgo cluster. We explore the relations between the stellar mass, the HI mass…