• DOI:10.1051/0004-6361/201322489
• Corpus ID: 30594186

The applicability of far-infrared fine-structure lines as star formation rate tracers over wide ranges of metallicities and galaxy types

@article{Looze2014TheAO,
  title={The applicability of far-infrared fine-structure lines as star formation rate tracers over wide ranges of metallicities and galaxy types},
  author={Ilse de Looze and Diane Cormier and Vianney Lebouteiller and Suzanne C. Madden and Maarten Baes and George J Bendo and M{\'e}d{\'e}ric Boquien and Alessandro Boselli and David L. Clements and Luca Cortese and Asantha Cooray and Maud Galametz and Fr{\'e}d{\'e}ric Galliano and Javier Graci{\'a}-Carpio and Kate Gudrun Isaak and Oskar L. Karczewski and Tara J. Parkin and Eric W. Pellegrini and Aur{\'e}lie R{\'e}my-Ruyer and Luigi Spinoglio and Matthew W. L. Smith and Eckhard Sturm},
  journal={Astronomy and Astrophysics},
  year={2014},
  volume={568},
  pages={1-34}
}

• I. D. Looze, D. Cormier, +19 authors E. Sturm
• Published 17 February 2014
• Physics
• Astronomy and Astrophysics

Aims. We analyze the applicability of far-infrared fine-structure lines [Cii] 158 μm, [Oi] 63 μm, and [Oiii] 88 μm to reliably trace the star formation rate (SFR) in a sample of low-metallicity dwarf galaxies from the Herschel Dwarf Galaxy Survey and, furthermore, extend the analysis to a broad sample of galaxies of various types and metallicities in the literature.

Methods. We study the trends and scatter in the relation between the SFR (as traced by GALEX FUV and MIPS 24 μm) and far-infrared line emission, on spatially resolved and global galaxy scales, in dwarf galaxies. We assemble far-infrared line measurements from the literature and infer whether the far-infrared lines can probe the SFR (as traced by the total infrared luminosity) in a variety of galaxy populations.

Results. In metal-poor dwarfs, the [Oi]_(63) and [Oiii]_(88) lines show the strongest correlation with the SFR with an uncertainty on the SFR estimates better than a factor of 2, while the link between [Cii] emission and the SFR is more dispersed (uncertainty factor of 2.6). The increased scatter in the SFR–L_([CII]) relation toward low metal abundances, warm dust temperatures, and large filling factors of diffuse, highly ionized gas suggests that other cooling lines start to dominate depending on the density and ionization state of the gas. For the literature sample, we evaluate the correlations for a number of different galaxy populations. The [Cii] and [Oi]_(63) lines are considered to be reliable SFR tracers in starburst galaxies, recovering the star formation activity within an uncertainty of factor 2. For sources with composite and active galactic nucleus (AGN) classifications, all three FIR lines can recover the SFR with an uncertainty factor of 2.3. The SFR calibrations for ultra-luminous infrared galaxies (ULIRGs) are similar to starbursts/AGNs in terms of scatter but offset from the starburst/AGN SFR relations because of line deficits relative to their total infrared luminosity. While the number of detections of the FIR fine-structure lines is still very limited at high redshift for [Oi]_(63) and [Oiii]_(88), we provide an SFR calibration for [Cii].