FROM HERSCHEL to ALMA: UNDERSTANDING NEARBY GALAXIES
by Alberto D. Bolatto (University of Maryland)
I will present and discuss the results of two ongoing projects based on Herschel and ALMA observations. In the first one, we systematically explore the [CII] 158 um emission from nearby galaxies in the KINGFISH sample to derive a calibration of star formation rate. [CII] emission is the main coolant of gas at intermediate densities, and thus in equilibrium it provides an excellent measure of the incident far- ultraviolet radiation field and a measure of the star formation activity. In the second one, we use ALMA to map molecular gas in the center of NGC 253, one of the nearest starburst galaxies and known to host a wind. We image extraplanar CO emission and use it to measure the mass outflow rate of the cool component of the wind, finding it similar or larger than the star formation activity. We also study the resolved molecular cloud properties in the starburst, and find very high densities for the GMCs. This is the first time such measurements have been possible.
