Journal article
The Evolution of Molecular Gas Fraction Traced by the CO Tully-Fisher Relation
Astrophysical journal. Letters, Vol.869(2), p.L37
12/20/2018
DOI: 10.3847/2041-8213/aaf872
Abstract
Carbon monoxide (CO) observations show a luminosity−line width correlation that evolves with redshift. We present a method to use CO measurements alone to infer the molecular gas fraction (fmol) and constrain the CO−H2 conversion factor ( CO). We compile from the literature spatially integrated low-J CO observations of six galaxy populations, including a total of 449 galaxies between 0.01 ≤ z ≤ 3.26. The CO data of each population provide an estimate of the -normalized mean molecular gas fraction (fmol/ CO). The redshift evolution of the luminosity−line width correlation thus indicates an evolution of fmol/ CO. We use a Bayesian-based Monte Carlo Markov Chain sampler to derive the posterior probability distribution functions of fmol/ CO for these galaxy populations, accounting for random inclination angles and measurement errors in the likelihood function. We find that the molecular gas fraction evolves rapidly with redshift, with β 2, for both normal star-forming and starburst galaxies. Furthermore, the evolution trend agrees well with that inferred from the Kennicutt-Schmidt relation and the star-forming main sequence. Finally, at z < 0.1 normal star-forming galaxies (SFGs) require a ∼5× larger CO than starburst galaxies to match their molecular gas fractions, but at z > 1 both star-forming types exhibit sub-Galactic CO values and normal SFGs appear more gas rich than starbursts. Future applications of this method include calibrating Tully-Fisher relations without inclination correction and inferring the evolution of the atomic gas fraction with H i observations.
Details
- Title: Subtitle
- The Evolution of Molecular Gas Fraction Traced by the CO Tully-Fisher Relation
- Creators
- Jacob W Isbell - University of IowaRui Xue - University of IowaHai Fu - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Astrophysical journal. Letters, Vol.869(2), p.L37
- DOI
- 10.3847/2041-8213/aaf872
- ISSN
- 2041-8205
- eISSN
- 2041-8213
- Publisher
- The American Astronomical Society
- Number of pages
- 8
- Language
- English
- Date published
- 12/20/2018
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199786802771
Metrics
16 Record Views