Canes Venatici I cloud of galaxies seen in the H-alpha line

TL;DR

This study provides H-alpha imaging data for 42 galaxies in the Canes Venatici I cloud, analyzing their star formation rates and gas content, and compares these properties with those in the M81 group, revealing no strong environmental influence on star formation.

Contribution

First comprehensive H-alpha imaging and star formation analysis for the Canes Venatici I galaxy cloud, including all known members and their comparison with a nearby virialized group.

Findings

No significant correlation between star formation activity and galaxy environment.

Most CVnI galaxies can produce their baryon mass at current SFRs within the Hubble time.

Galaxies in CVnI have sufficient gas to sustain current SFRs for a long period.

Abstract

We present results of H-alpha imaging for 42 galaxies in the nearby low-density cloud Canes Venatici I populated mainly by late-type objects. Estimates of the H-alpha flux and integrated star formation rate (SFR) are now available for all 78 known members of this scattered system, spanning a large range in luminosity, surface brightness, HI content and SFR. Distributions of the CVnI galaxies versus their SFR, blue absolute magnitude and total hydrogen mass are given in comparison with those for a population of the nearby virialized group around M81. We found no essential correlation between star formation activity in a galaxy and its density environment. A bulk of CVnI galaxies had enough time to generate their baryon mass with the observed SFR. Most of them possess also a supply of gas sufficient to maintain their observed SFR's during the next Hubble time.