H-ATLAS/GAMA: quantifying the morphological evolution of the galaxy population using cosmic calorimetry

Eales, Stephen, Fullard, Andrew, Allen, Matthew, Smith, M W L, Baldry, Ivan, Bourne, Nathan, Clark, C J R, Driver, Simon, Dunne, Loretta, Dye, Simon, Graham, Alister W, Ibar, Edo, Hopkins, Andrew, Ivison, Rob, Kelvin, Lee S, Maddox, Steve, Maraston, Claudia, Robotham, Aaron S G, Smith, Dan, Taylor, Edward N, Valiante, Elisabetta, Werf, Paul van der, Baes, Maarten, Brough, Sarah, Clements, David, Cooray, Asantha, Gomez, Haley, Loveday, Jon, Phillipps, Steven, Scott, Douglas and Serjeant, Steve (2015) H-ATLAS/GAMA: quantifying the morphological evolution of the galaxy population using cosmic calorimetry. Monthly Notices of the Royal Astronomical Society, 452 (4). pp. 3489-3507. ISSN 0035-8711

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Abstract

Using results from the Herschel Astrophysical Terrahertz Large-Area Survey (H-ATLAS) and the Galaxy and Mass Assembly (GAMA) project, we show that, for galaxy masses above ≃ 108 M⊙, 51 per cent of the stellar mass-density in the local Universe is in early-type galaxies (ETGs; Sérsic n > 2.5) while 89 per cent of the rate of production of stellar mass-density is occurring in late-type galaxies (LTGs; Sérsic n < 2.5). From this zero-redshift benchmark, we have used a calorimetric technique to quantify the importance of the morphological transformation of galaxies over the history of the Universe. The extragalactic background radiation contains all the energy generated by nuclear fusion in stars since the big bang. By resolving this background radiation into individual galaxies using the deepest far-infrared survey with the Herschel Space Observatory and a deep near-infrared/optical survey with the Hubble Space Telescope (HST), and using measurements of the Sérsic index of these galaxies derived from the HST images, we estimate that ≃83 per cent of the stellar mass-density formed over the history of the Universe occurred in LTGs. The difference between this value and the fraction of the stellar mass-density that is in LTGs today implies there must have been a major transformation of LTGs into ETGs after the formation of most of the stars.

Item Type: Article
Keywords: Galaxies: bulges, Galaxies: evolution, Galaxies: star formation
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QB Astronomy
Depositing User: Richard Chambers
Date Deposited: 19 May 2016 11:03
Last Modified: 07 Mar 2017 17:56
URI: http://sro.sussex.ac.uk/id/eprint/61073

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Project NameSussex Project NumberFunderFunder Ref
Astronomy rolling grantG0278STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCILST/I000976/1