Hα3: an Hα imaging survey of HI selected galaxies from ALFALFA - I. Catalogue in the Local Supercluster

摘要

Context. We present Hα3 (acronym for Hα???αα), an?Hα narrow-band imaging survey of??~400?galaxies selected from the?HI?Arecibo Legacy Fast ALFA Survey (ALFALFA) in the Local Supercluster, including the Virgo cluster. Aims. By using hydrogen recombination lines as a tracer of recent star formation, we aim to investigate the relationships between atomic neutral gas and newly formed stars in different environments (cluster and field), morphological types (spirals and dwarfs), and over a wide range of stellar masses (~107.5???1011.5 M⊙). Methods. We image in Hα+[NII] all the galaxies that contain more than?107 M⊙ of neutral atomic hydrogen in the sky region 11h?