Merger induced clump formation in distant infrared luminous starburst galaxies

Autor: Emanuele Daddi, Shuowen Jin, Ivan Delvecchio, Annagrazia Puglisi, Chiara D'Eugenio, A. Calabrò, Jeremy Fensch, Anna Cibinel, Frédéric Bournaud
Přispěvatelé: Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), European Southern Observatory (ESO), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astronomy Centre, University of Sussex, Instituto de Astrofisica de Canarias (IAC), Universidad de La Laguna [Tenerife - SP] (ULL), Support by the European Union’sHorizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 788679., Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL)
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Astronomy and Astrophysics-A&A
Astronomy and Astrophysics-A&A, EDP Sciences, 2019, 632, pp.A98. ⟨10.1051/0004-6361/201935778⟩
Astronomy and Astrophysics-A&A, 2019, 632, pp.A98. ⟨10.1051/0004-6361/201935778⟩
Astronomy & Astrophysics
ISSN: 0004-6361
DOI: 10.1051/0004-6361/201935778⟩
Popis: While the formation of stellar clumps in distant galaxies is usually attributed to gravitational violent disk instabilities, we show here that major mergers also represent a competitive mechanism to form bright clumps. Using ~0.1'' resolution ACS F814W images in the entire COSMOS field, we measure the fraction of clumpy emission in 109 main sequence (MS) and 79 Herschel-detected starbursts (off-MS) galaxies at 0.5 < z < 0.9, representative of normal versus merger induced star-forming activity, respectively. We additionally identify merger samples from visual inspection and from Gini-M20 morphological parameters. Regardless of the merger criteria adopted, the clumpiness distribution of merging systems is different from that of normal isolated disks at > 99.5 % confidence level, with the former reaching higher clumpiness values, up to 20 % of the total galaxy emission. We confirm the merger induced clumpiness enhancement with novel hydrodynamical simulations of colliding galaxies with gas fractions typical of z ~ 0.7. Multi-wavelength images of three starbursts in the CANDELS field support the young nature of clumps, which are likely merger products rather than older pre-existing structures. Finally, for a subset of 19 starbursts with existing near-IR rest frame spectroscopy, we find that the clumpiness is mildly anti-correlated with the merger phase, decreasing towards final coalescence. Our result can explain recent ALMA detections of clumps in hyperluminous high-z starbursts, while normal objects are smooth. This work raises a question on the role of mergers on the origin of clumps in high redshift galaxies in general.
24 pages, 19 figures and 1 table ; Accepted for publication in Astronomy & Astrophysics
Databáze: OpenAIRE
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