Star Formation Rates from [CII] 158 um and Mid Infrared Emission Lines
  for Starbursts and AGN
  A summary is presented for 130 galaxies observed with the Herschel PACS
instrument to measure fluxes for the [CII] 158 um emission line. Sources cover
a wide range of active galactic nucleus to starburst classifications, as
derived from polycyclic aromatic hydrocarbon (PAH) strength measured with the
Spitzer Infrared Spectrograph. Redshifts from [CII] and line to continuum
strengths (equivalent width of [CII]) are given for the full sample, which
includes 18 new [CII] flux measures. Calibration of L([CII)]) as a star
formation rate (SFR) indicator is determined by comparing [CII] luminosities
with mid-infrared [NeII] and [NeIII] emission line luminosities; this gives the
same result as determining SFR using bolometric luminosities of reradiating
dust from starbursts: log SFR = log L([CII)]) - 7.0, for SFR in solar masses
per year and L([CII]) in solar luminosities. We conclude that L([CII]) can be
used to measure SFR in any source to a precision of ~ 50%, even if total source
luminosities are dominated by an AGN component. The line to continuum ratio at
158 um, EW([CII]), is not significantly greater for starbursts (median
EW([CII]) = 1.0 um) compared to composites and AGN (median EW([CII]) = 0.7 um),
showing that the far infrared continuum at 158 um scales with [CII] regardless
of classification. This indicates that the continuum at 158 um also arises
primarily from the starburst component within any source, giving log SFR = log
vLv(158 um) - 42.8 for SFR in solar masses per year and vLv(158 um) in erg per
sec.
