TUNA Lunch Talk:

Karen Knierman

Arizona State University

Tidal Tales of Minor Mergers: Star Formation in the Tidal Debris

July 16

12:10PM, Note unusual location: ER Auditorium

Abstract:

While the spectacular displays of major mergers are famous (e.g., NGC 4039/9 ''The Antennae"), equal mass galaxy mergers are relatively rare compared to minor mergers (mass ratio <0.3). Minor mergers are less energetic than major mergers, but more common in the observable universe, and thus likely played a pivotal role in the formation of most large galaxies. Centers of mergers host vigorous star formation from high gas density and turbulence and are surveyed over cosmological distances. However, the tidal debris resulting from these mergers has not been well studied. Such regions have lower gas density, but also have large reservoirs of gaseous material that can be used as fuel for subsequent star formation. Tracers of star formation at local and global scales have been examined for three tidal tails in two minor merger systems. These tracers include young star cluster populations, H-alpha and [CII] emission. The rate of apparent star formation derived from these tracers is compared to the gas available to estimate the star formation efficiency (SFE).