Vales

Abstract

Context. Spatially resolved observations of the ionized and molecular gas are critical for understanding the physical processes that govern the interstellar medium (ISM) in galaxies. The observation of starburst systems is also important as they present extreme gas conditions that may help to test different ISM models. However, matched resolution imaging at ∼kpc scales for both ISM gas phases are usually scarce, and the ISM properties of starbursts still remain poorly understood. Aims. We aim to study the morpho-kinematic properties of the ionized and molecular gas in three dusty starburst galaxies at z = 0.12−0.17 to explore the relation between molecular ISM gas phase dynamics and the star-formation activity. Methods. We employ two-dimensional dynamical modelling to analyse Atacama Large Millimeter/submillimiter Array CO(1–0) and seeing-limited Spectrograph for INtegral Field Observations in the Near Infrared Paschen-α (Paα) observations, tracing the molecular and ionized gas morpho-kinematics at ∼kpc-scales. We use a dynamical mass model, which accounts for beam-smearing effects, to constrain the CO-to-H2 conversion factor and estimate the molecular gas mass content. Results. One starburst galaxy shows irregular morphology, which may indicate a major merger, while the other two systems show disc-like morpho-kinematics. The two disc-like starbursts show molecular gas velocity dispersion values comparable with those seen in local luminous and ultra luminous infrared galaxies but in an ISM with molecular gas fraction and surface density values in the range of the estimates reported for local star-forming galaxies. We find that these molecular gas velocity dispersion values can be explained by assuming vertical pressure equilibrium. We also find that the star-formation activity, traced by the Paα emission line, is well correlated with the molecular gas content, suggesting an enhanced star-formation efficiency and depletion times of the order of ∼0.1−1 Gyr. We find that the star-formation rate surface density (ΣSFR) correlates with the ISM pressure set by self-gravity (Pgrav) following a power law with an exponent close to 0.8. Conclusions. In dusty disc-like starburst galaxies, our data support the scenario in which the molecular gas velocity dispersion values are driven by the ISM pressure set by self-gravity and are responsible for maintaining the vertical pressure balance. The correlation between ΣSFR and Pgrav suggests that, in these dusty starbursts galaxies, the star-formation activity arises as a consequence of the ISM pressure balance.

MUSE-ALMA Halos VI: Coupling Atomic, Ionised & Molecular Gas Kinematics of Galaxies

“…Recent observations of the ionised and molecular gas phases in galaxies between redshifts 𝑧 ∼ 0.1 − 1.4 have found that both phases mostly align well directionally (e.g. Übler et al 2018;Møller et al 2017;Klitsch et al 2018;Loiacono et al 2019;Péroux et al 2019;Molina et al 2019Molina et al , 2020. Similarly, we find that Q2131-G1 is well constrained by a disk model and that the ionised and molecular gas phase are aligned well directionally with similar inclinations and position angles.…”

“…Kinematic studies have revealed that the two phases mostly align well spatially (e.g. Übler et al 2018;Møller et al 2017;Klitsch et al 2018;Loiacono et al 2019;Péroux et al 2019;Molina et al 2019Molina et al , 2020. Further kinematic studies by the EDGE-CALIFA survey (Levy et al 2018) have shown that 75% of the galaxies in their sample have higher maximum rotational velocities for the molecular gas while the remaining 25% have similar maximum rotational velocities to the ionised gas.…”

From giant clumps to clouds – III. The connection between star formation and turbulence in the ISM

“…Ho we ver, some studies have suggested that galactic turbulence in ionized and molecular gas are similar (e.g. Übler et al 2018 ;Molina et al 2019Molina et al , 2020. This discrepancy might be due to the observations tracing outflows, rather than the turbulent motions within the ISM, or beam smearing.…”

Physics of ULIRGs with MUSE and ALMA: The PUMA project

“…Molina et al (2020),Cochrane et al (2021), and KMOS 3D individual targets; stellar masses of LIRGs and ULIRGs from this study, fromBellocchi et al (2013), Pereira-Santaella et al (2019 andCrespo et al (2021), are instead derived from the dynamical mass estimates, assuming M * = (1− f gas )×(1− f DM )× M dyn , where f gas and f DM are the gas and dark matter fractions 4 , respectively, and M dyn is the dynamical mass within 2R e (see next section). For the gas fraction, we considered a conservative f gas = 0.1(Isbell et al 2018; higher f gas values would further increase their δMS).…”