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The MASSIVE Survey - III. Molecular gas and a broken Tully-Fisher relation in the most massive early-type galaxies
- Publication Year :
- 2015
- Publisher :
- arXiv, 2015.
-
Abstract
- In this work we present CO(1-0) and CO(2-1) observations of a pilot sample of 15 early-type galaxies (ETGs) drawn from the MASSIVE galaxy survey, a volume-limited integral-field spectroscopic study of the most massive ETGs ($M_* >10^{11.5}M_\odot$) within 108 Mpc. These objects were selected because they showed signs of an interstellar medium and/or star formation. A large amount of gas ($>$2$\times$10$^8$ M$_{\odot}$) is present in 10 out of 15 objects, and these galaxies have gas fractions higher than expected based on extrapolation from lower mass samples. We tentatively interpret this as evidence that stellar mass loss and hot halo cooling may be starting to play a role in fuelling the most massive galaxies. These MASSIVE ETGs seem to have lower star-formation efficiencies (SFE=SFR/M$_{\rm H2}$) than spiral galaxies, but the SFEs derived are consistent with being drawn from the same distribution found in other lower mass ETG samples. This suggests that the SFE is not simply a function of stellar mass, but that local, internal processes are more important for regulating star formation. Finally we used the CO line profiles to investigate the high-mass end of the Tully-Fisher relation (TFR). We find that there is a break in the slope of the TFR for ETGs at high masses (consistent with previous studies). The strength of this break correlates with the stellar velocity dispersion of the host galaxies, suggesting it is caused by additional baryonic mass being present in the centre of massive ETGs. We speculate on the root cause of this change and its implications for galaxy formation theories.<br />13 pages, 7 figures, accepted by MNRAS
- Subjects :
- Physics
Spiral galaxy
Stellar mass
010308 nuclear & particles physics
Star formation
Velocity dispersion
Astronomy
FOS: Physical sciences
Astronomy and Astrophysics
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Tully–Fisher relation
Astrophysics - Astrophysics of Galaxies
01 natural sciences
Galaxy
Interstellar medium
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
0103 physical sciences
Galaxy formation and evolution
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
QB
Subjects
Details
- ISSN :
- 00358711
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....059182e19e85d7b53a8e8fc257e99826
- Full Text :
- https://doi.org/10.48550/arxiv.1510.00729