Speaker
Rodrigo Herrera-Camus
(Max Planck Institute for Extraterrestrial Physics)
Description
The [CII] 158 um and [NII] 122 and 205 um far-infrared
transitions are powerful tracers of the neutral and ionized
gas in the interstellar medium of local and high-z galaxies.
In this talk I will discuss the ability of these lines to
trace the star formation activity in a wide range of
environments that include low metallicity, normal,
star-forming galaxies, AGN, LIRGS and high-z galaxies. Our
work is based on a sample of resolved regions from nearby
galaxies observed by Herschel as part of the KINGFISH,
"Beyond the Peak" and SHINING surveys. For the [CII]
transition, we conclude that it can be used for measurements
of star formation rates (SFRs) on both, global and
kiloparsec scales, in normal star-forming galaxies in the
absence of strong AGNs. The main source of scatter in the
correlation is associated with regions that exhibit warm IR
colors. For the [NII] transitions, we find nearly linear
correlations between the [NII] emission and SFR. The scatter
in the correlation can be understood as a property of the
electron density distribution. For regions with electron
densities close to or higher than the [NII] line critical
densities, the [NII] based SFR calibration systematically
underestimates the SFR since the [NII] emission is
collisionally quenched. Finally, I will review how the [CII]
line can be used to measure the thermal pressure of the
diffuse, neutral gas and discuss its connection to the star
formation activity in the context of a galactic disk that
evolves into a state of dynamical, thermal, and star
formation equilibrium (e.g. Ostriker et al. 2010, Kim et al.
2013). As predicted by this model, the ratio between the
thermal pressure and the vertical weight of the overlying
ISM is about 0.3 and has a weak dependence with star
formation activity.
Primary author
Rodrigo Herrera-Camus
(Max Planck Institute for Extraterrestrial Physics)
Co-authors
Adam Leroy
(The Ohio State University)
Alberto Bolatto
(University of Maryland)
Bruce Draine
(Princeton University)
Daniela Calzetti
(University of Massachusetts)
Dieter Lutz
(Max Planck Institute for Extraterrestrial Physics)
Eckhard Sturm
(Max Planck Institute for Extraterrestrial Physics)
Eric Pellegrini
(Zentrum fur Astronomie der Universitat Heidelberg)
Eve Ostriker
(Princeton University)
Fabian Walter
(Max-Planck-Institut fur Astronomie)
Ilse de Looze
(University of Cambridge)
JD Smith
(University of Toledo)
Karin Sandstrom
(University of San Diego)
Kevin Croxall
(The Ohio State University)
Mark Wolfire
(University of Maryland)
Rob Kennicutt
(University of Cambridge)
