High molecular gas fractions in normal massive star-forming galaxies in the young Universe

By L. Tacconi, R. Genzel, R. Neri, P. Cox, M. Cooper, K. Shapiro, A. Bolatto, N. Bouché, Frédéric Bournaud, A. Burkert and 12 more. Nature, 2010

811 citations recorded by the source corpus.

Stars form from cold molecular interstellar gas. As this is relatively rare in the local Universe, galaxies like the Milky Way form only a few new stars per year. Typical massive galaxies in the distant Universe formed stars an order of magnitude more rapidly. Unless star formation was significantly more efficient, this difference suggests that young galaxies were much more molecular-gas rich. Molecular gas observations in the distant Universe have so far largely been restricted to very luminous, rare objects, including mergers and quasars, and accordingly we do not yet have a clear idea about the gas content of more normal (albeit massive) galaxies. Here we report the results of a survey of molecular gas in samples of typical massive-star-forming galaxies at mean redshifts <z> of about 1.2 and 2.3, when the Universe was respectively 40% and 24% of its current age. Our measurements reveal that distant star forming galaxies were indeed gas rich, and that the star formation efficiency is not strongly dependent on cosmic epoch. The average fraction of cold gas relative to total galaxy baryonic mass at z = 2.3 and z = 1.2 is respectively about 44% and 34%, three to ten times higher than in today’s massive spiral galaxies. The slow decrease between z ≈ 2 and z ≈ 1 probably requires a mechanism of semi-continuous replenishment of fresh gas to the young galaxies.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/b96392a6bc2376cdd6d81276ea49ac92b0dfc207

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. L. Hernquist
3. R. Dav'e
4. R. Somerville
5. A. Dekel
6. T. Naab
7. Volker Springel
8. C. Conroy

Citations in the corpus

• CANDELS: THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY (2011, positive): “Many star-forming galaxies at z ≈ 2 have compact sizes, high surface densities and high gas fractions (Tacconi et al. 2010), and exhibit star-forming clumps more massive than local star clusters (Elmegreen et al. 2009).”
• VALIDATION OF THE EQUILIBRIUM MODEL FOR GALAXY EVOLUTION TO z ∼ 3 THROUGH MOLECULAR GAS AND DUST OBSERVATIONS OF LENSED STAR-FORMING GALAXIES (2013, methodology): “The absolute flux calibration was done using observation of reference bright quasars, and is typically accurate to better than 20% (Tacconi et al. 2010).”
• xCOLD GASS: The Complete IRAM 30 m Legacy Survey of Molecular Gas for Galaxy Evolution Studies (2017, background): “Improvement in instrument sensitivities and bandwidth have also made possible the investigation of the molecular gas contents of galaxies far beyond the local Universe (Tacconi et al. 2010; Daddi et al. 2010; Geach et al. 2011; Magdis et al. 2012; Magnelli et al. 2012; Bauermeister et al. 2013).”
• REGULARITY UNDERLYING COMPLEXITY: A REDSHIFT-INDEPENDENT DESCRIPTION OF THE CONTINUOUS VARIATION OF GALAXY-SCALE MOLECULAR GAS PROPERTIES IN THE MASS-STAR FORMATION RATE PLANE (2013, positive): “…of SFGs have generally explicitly targeted either strong SBs (e.g., Solomon et al. 1997, Greve et al. 2005, Riechers et al. 2006, Ivison et al. 2011) or MS galaxies (e.g., Leroy et al. 2008, Daddi et al. 2010a, Tacconi et al. 2010, Geach et al. 2011, Magdis et al. 2012a, Tacconi et al. 2013).”
• The properties of the star-forming interstellar medium at z = 0.84-2.23 from HiZELS : mapping the internal dynamics and metallicity gradients in high-redshift disc galaxies. (2012, background): “…compared to the thin discs C© 2012 The Authors Monthly Notices of the Royal Astronomical Society C© 2012 RAS at R oyal O bservatory L ibrary on N ovem ber 20, 2014 http://m nras.oxfordjournals.org/ of local spirals (Daddi et al. 2010; Tacconi et al. 2010; Geach et al. 2011; Swinbank et al. 2011).”
• GRAVITATIONAL LENS MODELS BASED ON SUBMILLIMETER ARRAY IMAGING OF HERSCHEL-SELECTED STRONGLY LENSED SUB-MILLIMETER GALAXIES AT z > 1.5 (2013, background): “…based primarily on radio observations (Chapman et al. 2004; Muxlow et al. 2005; Biggs & Ivison 2008; Casey et al. 2009), but also includes a handful of with mm size measurements (Tacconi et al. 2006, 2010; Daddi et al. 2010) and the assumption that the radio and far-IR sizes are correlated.”
• Galaxy evolution in cosmological simulations with outflows ― I. Stellar masses and star formation rates (2011, background): “Furthermore, galaxies appear to be consuming their gas rapidly enough that fuel must be constantly replenished (Tacconi et al. 2010; Papovich et al. 2010), but merger-induced starbursts do not appears to be driving global star formation (Brinchmann et al. 2004; Noeske et al. 2007; Jogee et al.…”
• ISM MASSES AND THE STAR FORMATION LAW AT Z = 1 TO 6: ALMA OBSERVATIONS OF DUST CONTINUUM IN 145 GALAXIES IN THE COSMOS SURVEY FIELD (2015, background): “Tacconi et al. (2010) obtained a range of 0.2 - 0.5 at z ∼ 1.1 and 0.3 -0.8 at z ∼ 2.3.”
• The age structure of stellar populations in the solar vicinity Clues of a two-phase formation history of the Milky Way disk (2013, background): “…high redshift are known to be both gas rich, have high gas mass surface densities (Daddi et al. 2010; Aravena et al. 2010; Dannerbauer et al. 2009; Tacconi et al. 2010; Combes et al. 2011), have high velocity dispersions in their gas and intense star formation (Lehnert et al. 2009, 2013; Swinbank…”
• MOST SUBMILLIMETER GALAXIES ARE MAJOR MERGERS (2010, methodology): “…should be comparable (similar black hole masses), but the stellar luminosities are factors of several larger in high-z galaxies (due to the larger gas fractions, Tacconi et al. 2010; Daddi et al. 2010), and we therefore expect significantly smaller relative AGN contributions in high-z galaxies.”
• KILOPARSEC-SCALE DUST DISKS IN HIGH-REDSHIFT LUMINOUS SUBMILLIMETER GALAXIES (2016, background): “…or molecular line emission (CO), which traces the gas reservoirs required to fuel star formation, at sub-arcsecond resolution (&0.2′′; e.g., Tacconi et al. 2010; Engel et al. 2010; Bothwell et al. 2010; Hodge et al. 2012, 2013a; Tacconi et al. 2013; Genzel et al. 2013; Aravena et al.…”
• Evolution of the dust emission of massive galaxies up to z=4 and constraints on their dominant mode of star formation (2014, background): “Large gas reservoirs have been found in massive galaxies at high redshift (e.g., Daddi et al. 2008, 2010a; Tacconi et al. 2010, 2013; Aravena et al. 2013), which could Appendices are available in electronic form at http://www.aanda.org imply high SFRs with SFE similar to that of normal star-forming…”
• THE LESSER ROLE OF STARBURSTS IN STAR FORMATION AT z = 2 (2011, background): “Observations of the CO molecular gas content of MS galaxies indicate that their star formation efficiency does not depend strongly on cosmic epoch to z ∼ 2, with the SFR increase being due to higher molecular gas fractions (Daddi et al. 2008; 2010a; Tacconi et al. 2010; Geach et al. 2011).”
• HYDRODYNAMICS OF HIGH-REDSHIFT GALAXY COLLISIONS: FROM GAS-RICH DISKS TO DISPERSION-DOMINATED MERGERS AND COMPACT SPHEROIDS (2010, background): “The spectrum is more complex than the usual double-horn profile observed for rotating gas disks (including clumpy high-redshift disks, Daddi et al. 2010), and is best fitted by a combination of four main emitting components.”
• A survey of molecular gas in luminous sub-millimetre galaxies (2012, methodology): “We include in this plot the mean value for SMGs in the local Universe (Bothwell et al. 2009) as well measurements of UV-selected SMGs at z 1 from Tacconi et al. (2010) and Daddi et al. (2010), and mid-IR-selected z ∼ 0.4 LIRGs from Geach et al. (2011).”
• Enhanced star formation rates in AGN hosts with respect to inactive galaxies from PEP-Herschel observations (2012, background): “…long duty cycles (e.g. Dekel et al. 2009),outliers are believed to undergo short and intense starbursts occurring typically during mergers1 or in dense nuclear star forming regions, which increase their SF efficiency (Daddi et al. 2010; Tacconi et al. 2010; Genzel et al. 2010; Wuyts et al. 2011).”
• GALAXY STRUCTURE AND MODE OF STAR FORMATION IN THE SFR–MASS PLANE FROM z ∼ 2.5 TO z ∼ 0.1 (2011, background): “Complementing the observational results on the locus of SFGs in SFR-Mass space, direct measurements of the CO molecular line emission from galaxies residing on the MS have revealed molecular gas mass fractions as high as 35 (45) % at z ∼ 1 (2) (Tacconi et al. 2010).”
• What drives the growth of black holes (2011, result): “This result is found despite the large increase in SFR for AGNs over z ≈ 0–3 and the global increase in the coldgas mass fraction in massive galaxies with redshift (e.g., Daddi et al., 2010; Tacconi et al., 2010; Geach et al., 2011).”
• THE MAJOR AND MINOR GALAXY MERGER RATES AT z < 1.5 (2011, methodology): “The cold gas fractions measured for small numbers of disk galaxies at z ∼ 1− 1.5 are ∼ 40%, three times higher than today’s ∼ 10% (Tacconi et al. 2010; Daddi et al. 2010; McGaugh 2005).”
• Metallicity evolution, metallicity gradients, and gas fractions at z ~ 3.4 (2013, background): “Although with large dispersion, the average gas fraction in massive galaxies shows a rapid increase, by over an order of magnitude, from z=0 to z∼2, which was already known by previous studies (Tacconi et al. 2010; Daddi et al. 2010; Tacconi et al. 2013).”