Bulgeless galaxies in the COSMOS field:environment and star formation evolution at z < 1

Grossi, Marco and Fernandes, Cristina and Sobral, David and Afonso, J. and Paulino-Afonso, Ana (2018) Bulgeless galaxies in the COSMOS field:environment and star formation evolution at z < 1. Monthly Notices of the Royal Astronomical Society, 475 (1). pp. 735-747. ISSN 0035-8711

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Abstract

Combining the catalogue of galaxy morphologies in the COSMOS field and the sample of Hα emitters at redshifts z = 0.4 and z = 0.84 of the HiZELS survey, we selected ∼ 220 star-forming bulgeless systems (S ́ersic index n ≤ 1.5) at both epochs. We present their star formation properties and we investigate their contribution to the star for- mation rate function (SFRF) and global star formation rate density (SFRD) at z < 1. For comparison, we also analyse Hα emitters with more structurally evolved mor- phologies that we split into two classes according to their S ́ersic index n: intermediate (1.5 < n ≤ 3) and bulge-dominated (n > 3). At both redshifts the SFRF is dominated by the contribution of bulgeless galaxies and we show that they account for more than 60% of the cosmic SFRD at z < 1. The decrease of the SFRD with redshift is common to the three morphological types but it is stronger for bulge-dominated systems. Star- forming bulgeless systems are mostly located in regions of low to intermediate galaxy densities (Σ ∼ 1 − 4 Mpc−2) typical of field-like and filament-like environments and their specific star formation rates (sSFRs) do not appear to vary strongly with local galaxy density. Only few bulgeless galaxies in our sample have high (sSFR > 10−9 yr−1) and these are mainly low-mass systems. Above M∗ ∼ 1010 M⊙ bulgeless are evolving at a “normal” rate (10−9 yr−1 < sSFR <10−10 yr−1) and in the absence of an external trigger (i.e. mergers/strong interactions) they might not be able to develop a central classical bulge.

Item Type:
Journal Article
Journal or Publication Title:
Monthly Notices of the Royal Astronomical Society
Additional Information:
This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version Marco Grossi, Cristina A C Fernandes, David Sobral, José Afonso, Eduardo Telles, Luca Bizzocchi, Ana Paulino-Afonso, Israel Matute; Bulgeless galaxies in the COSMOS field: environment and star formation evolution at z < 1, Monthly Notices of the Royal Astronomical Society, Volume 475, Issue 1, 21 March 2018, Pages 735–747, https://doi.org/10.1093/mnras/stx3165 is available online at: https://academic.oup.com/mnras/article/475/1/735/4712233
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1900/1912
Subjects:
ID Code:
89012
Deposited By:
Deposited On:
30 Nov 2017 11:28
Refereed?:
Yes
Published?:
Published
Last Modified:
27 Sep 2020 04:13