Molecular and atomic gas along and across the main sequence of star-forming galaxies

By A. Saintonge, B. Catinella, L. Cortese, R. Genzel, R. Giovanelli, M. Haynes, S. Janowiecki, C. Kramer, K. Lutz, David Schiminovich and 3 more. 2016

168 citations recorded by the source corpus.

We use spectra from the ALFALFA, GASS and COLD GASS surveys to quantify variations in the mean atomic and molecular gas mass fractions throughout the SFR-M* plane and along the main sequence (MS) of star-forming galaxies. Although galaxies well below the MS tend to be undetected in the Arecibo and IRAM observations, reliable mean atomic and molecular gas fractions can be obtained through a spectral stacking technique. We find that the position of galaxies in the SFR-M* plane can be explained mostly by their global cold gas reservoirs as observed in the H I line, with in addition systematic variations in the molecular-to-atomic ratio and star formation efficiency. When looking at galaxies within ±0.4 dex of the MS, we find that as stellar mass increases, both atomic and molecular gas mass fractions decrease, stellar bulges become more prominent, and the mean stellar ages increase. Both star formation efficiency and molecular-to-atomic ratios vary little for massive MS galaxies, indicating that the flattening of the MS is due to the global decrease of the cold gas reservoirs of galaxies rather than to bottlenecks in the process of converting cold atomic gas to stars.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/b36342f1f13c9ab99c405606b0166d52d94b3114

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. P. Hopkins
2. A. Dekel
3. L. Hernquist
4. R. Dav'e
5. R. Somerville
6. R. Genzel
7. T. Naab
8. F. Walter

In Instrumentation

1. P. Hopkins
2. A. Dekel
3. R. Dav'e
4. T. Naab
5. L. Hernquist
6. R. Genzel
7. R. Somerville
8. S. Wuyts

Citations in the corpus

• xCOLD GASS: The Complete IRAM 30 m Legacy Survey of Molecular Gas for Galaxy Evolution Studies (2017, methodology): “The COLD GASS-low sample allows us here to extend the conclusions of Saintonge et al. (2016) that, on average, the SSFR of galaxies is set by both the molecular gas fraction and the star formation efficiency.”
• The Arecibo Legacy Fast ALFA Survey: The ALFALFA Extragalactic H i Source Catalog (2018, background): “Star formation is linked more closely to the molecular H2 gas (e.g. Kennicutt & Evans 2012; Saintonge et al. 2016; Catinella et al. 2018).”
• xGASS: total cold gas scaling relations and molecular-to-atomic gas ratios of galaxies in the local Universe (2018, background): “…the similarity between atomic and total gas scaling relations is not surprising, as galaxies in this stellar mass regime in the local Universe typically have cold gas reservoirs that are H Idominated (Saintonge et al. 2011; Boselli et al. 2014a; Saintonge et al. 2016, see also next section).”
• PHIBSS: Unified Scaling Relations of Gas Depletion Time and Molecular Gas Fractions (2017, methodology): “The xCOLD GASS sample is mass-selected from the SDSS (Saintonge et al. 2011a, b, Saintonge et al. 2016, 2017).”