Dynamical Equilibrium in the Molecular ISM in 28 Nearby Star-Forming Galaxies

Autor: Daniel A. Dale, Kathryn Grasha, Sharon Meidt, Jiayi Sun, Eve C. Ostriker, Alberto D. Bolatto, I-Da Chiang, Karin Sandstrom, Janice C. Lee, Eric Emsellem, Toshiki Saito, Jonathan D. Henshaw, Dyas Utomo, Cinthya N. Herrera, Antonio Usero, Erik Rosolowsky, Simon C. O. Glover, Frank Bigiel, Jérôme Pety, Annie Hughes, Andreas Schruba, María J. Jiménez-Donaire, Christopher Faesi, Miguel Querejeta, Guillermo A. Blanc, Mélanie Chevance, J. M. Diederik Kruijssen, Adam K. Leroy, Eva Schinnerer
Přispěvatelé: Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de 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)
Jazyk: angličtina
Rok vydání: 2020
Předmět:
010504 meteorology & atmospheric sciences
Interstellar dynamics
Funding grant
FOS: Physical sciences
Library science
Astrophysics::Cosmology and Extragalactic Astrophysics
PRESSURE
MASS
01 natural sciences
MAGNETIC-FIELDS
Atomic energy commission
German
3-DIMENSIONAL DISTRIBUTION
0103 physical sciences
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
0105 earth and related environmental sciences
Physics
INTERSTELLAR-MEDIUM
European research
Star formation
CLOUDS
GAS CONTENT
Astronomy and Astrophysics
Interstellar molecules
Astrophysics - Astrophysics of Galaxies
language.human_language
Physics and Astronomy
[SDU]Sciences of the Universe [physics]
13. Climate action
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
SUPERNOVA FEEDBACK
language
MILKY-WAY
TURBULENCE
Zdroj: ASTROPHYSICAL JOURNAL
The Astrophysical Journal
The Astrophysical Journal, 2020, 892, ⟨10.3847/1538-4357/ab781c⟩
ISSN: 0004-637X
1538-4357
1538-3881
1538-3873
0067-0049
0004-6361
DOI: 10.3847/1538-4357/ab781c⟩
Popis: We compare the observed turbulent pressure in molecular gas, $P_\mathrm{turb}$, to the required pressure for the interstellar gas to stay in equilibrium in the gravitational potential of a galaxy, $P_\mathrm{DE}$. To do this, we combine arcsecond resolution CO data from PHANGS-ALMA with multi-wavelength data that traces the atomic gas, stellar structure, and star formation rate (SFR) for 28 nearby star-forming galaxies. We find that $P_\mathrm{turb}$ correlates with, but almost always exceeds the estimated $P_\mathrm{DE}$ on kiloparsec scales. This indicates that the molecular gas is over-pressurized relative to the large-scale environment. We show that this over-pressurization can be explained by the clumpy nature of molecular gas; a revised estimate of $P_\mathrm{DE}$ on cloud scales, which accounts for molecular gas self-gravity, external gravity, and ambient pressure, agrees well with the observed $P_\mathrm{turb}$ in galaxy disks. We also find that molecular gas with cloud-scale ${P_\mathrm{turb}}\approx{P_\mathrm{DE}}\gtrsim{10^5\,k_\mathrm{B}\,\mathrm{K\,cm^{-3}}}$ in our sample is more likely to be self-gravitating, whereas gas at lower pressure appears more influenced by ambient pressure and/or external gravity. Furthermore, we show that the ratio between $P_\mathrm{turb}$ and the observed SFR surface density, $\Sigma_\mathrm{SFR}$, is compatible with stellar feedback-driven momentum injection in most cases, while a subset of the regions may show evidence of turbulence driven by additional sources. The correlation between $\Sigma_\mathrm{SFR}$ and kpc-scale $P_\mathrm{DE}$ in galaxy disks is consistent with the expectation from self-regulated star formation models. Finally, we confirm the empirical correlation between molecular-to-atomic gas ratio and kpc-scale $P_\mathrm{DE}$ reported in previous works.
Comment: 28 pages + 3 appendices, ApJ in press. See https://www.youtube.com/watch?v=qxkd-RXB0Ek for a short video describing the main results. Data tables available at https://www.canfar.net/storage/list/phangs/RELEASES/Sun_etal_2020 prior to publication
Databáze: OpenAIRE
Externí odkaz: