J1023+1952 is a cloud of neutral hydrogen located at the base of a tidal tail, associated with the interacting Seyfert system NGC 3227/6 that was discovered by Mundell et al. and identified as a candidate tidal dwarf galaxy. Here we report the discovery of active star formation concentrated in the southern half of this cloud. We suggest that the localized star formation and lack of detectable old stellar population imply a tidal origin for J1023+1954 and that its star formation is shock-triggered by collapsing gaseous tidal debris. Such shock-triggering may provide a possible formation mechanism for the recently-discovered population of young extragalactic H II regions.
|Title of host publication
|Astrophysics & Space Science Library
|Subtitle of host publication
|R. de Grijs, R. M. Gonzalez Delgado
|Place of Publication
|Published - 2005