ALMA resolves giant molecular clouds in a tidal dwarf galaxy
| Autor: | Cinthya N. Herrera, Dario Colombo, Frank Bigiel, Annie Hughes, M. Querejeta, Andrew Rigby, Santiago García-Burillo, Eva Schinnerer, Sharon Meidt, Toby J. T. Moore, C. G. Mundell, Ute Lisenfeld, Federico Lelli, J. M. D. Kruijssen, Jérôme Pety |
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| Přispěvatelé: | Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
II
PROPAGATING STAR-FORMATION Milky Way FOS: Physical sciences PHYSICAL-PROPERTIES Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics interactions [Galaxies] 01 natural sciences star formation [Galaxies] Virial theorem 0103 physical sciences ISM [Galaxies] galaxies: interactions SCHMIDT 010303 astronomy & astrophysics galaxies: kinematics and dynamics Astrophysics::Galaxy Astrophysics Dwarf galaxy [PHYS]Physics [physics] Physics [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] INTERSTELLAR-MEDIUM 010308 nuclear & particles physics Star formation kinematics and dynamics [Galaxies] Molecular cloud Velocity dispersion Astronomy and Astrophysics galaxies: dwarf Astrophysics - Astrophysics of Galaxies Galaxy dwarf [Galaxies] Stars Physics and Astronomy GAS 13. Climate action Space and Planetary Science galaxies: star formation Astrophysics of Galaxies (astro-ph.GA) LUMINOSITY LARGE-MAGELLANIC-CLOUD [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] CLUSTERS galaxies: ISM UNCERTAINTY PRINCIPLE |
| Zdroj: | Digibug. Repositorio Institucional de la Universidad de Granada instname Digibug: Repositorio Institucional de la Universidad de Granada Universidad de Granada (UGR) Astronomy & Astrophysics ASTRONOMY & ASTROPHYSICS Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2021, 645, pp.A97. ⟨10.1051/0004-6361/202038955⟩ |
| ISSN: | 0004-6361 1432-0746 |
| DOI: | 10.1051/0004-6361/202038955⟩ |
| Popis: | Tidal dwarf galaxies (TDGs) are gravitationally bound condensations of gas and stars that formed during galaxy interactions. Here we present multi-configuration ALMA observations of J1023+1952, a TDG in the interacting system Arp 94, where we resolved CO(2–1) emission down to giant molecular clouds (GMCs) at 0.6400 ∼ 45 pc resolution. We find a remarkably high fraction of extended molecular emission (∼80−90%), which is filtered out by the interferometer and likely traces diffuse gas. We detect 111 GMCs that give a similar mass spectrum as those in the Milky Way and other nearby galaxies (a truncated power law with a slope of −1.76±0.13). We also study Larson’s laws over the available dynamic range of GMC properties (∼2 dex in mass and ∼1 dex in size): GMCs follow the sizemass relation of the Milky Way, but their velocity dispersion is higher such that the size-linewidth and virial relations appear superlinear, deviating from the canonical values. The global molecular-to-atomic gas ratio is very high (∼1) while the CO(2–1)/CO(1–0) ratio is quite low (∼0.5), and both quantities vary from north to south. Star formation predominantly takes place in the south of the TDG, where we observe projected offsets between GMCs and young stellar clusters ranging from ∼50 pc to ∼200 pc; the largest offsets correspond to the oldest knots, as seen in other galaxies. In the quiescent north, we find more molecular clouds and a higher molecular-to-atomic gas ratio (∼1.5); atomic and diffuse molecular gas also have a higher velocity dispersion there. Overall, the organisation of the molecular interstellar medium in this TDG is quite different from other types of galaxies on large scales, but the properties of GMCs seem fairly similar, pointing to near universality of the star-formation process on small scales. Instituto de Salud Carlos III Spanish Government PID2019-106027GA-C44 Spanish Ministerio de Economia y Competitividad AYA2017-84897-P European Commission Junta de Andalucia European Commission FQM108 European Research Council (ERC) 726384/EMPIRE 714907 MCIU/AEI/FEDER,UE PGC2018-094671-B-I00 AYA2016-76682-C3-2-P German Research Foundation (DFG) KR4801/1-1 German Research Foundation (DFG) KR4801/2-1 |
| Databáze: | OpenAIRE |
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