Related papers: H2 MAGIE: H2 as a Major Agent to Galaxy Interactio…
The build-up of galaxies is regulated by a complex interplay between gravitational collapse, galaxy merging and feedback related to AGN and star formation. The energy released by these processes has to dissipate for gas to cool, condense,…
Galaxy formation depends on a complex interplay between gravitational collapse, gas accretion, merging, and feedback processes. Yet, after many decades of investigation, these concepts are poorly understood. This paper presents the argument…
Spitzer space telescope observations led to the surprising detection of a diverse set of extragalactic sources whose infrared spectra are dominated by line emission of molecular hydrogen (H2). The absence or relative weakness of typical…
Observations show that star formation in galaxies is closely correlated with the abundance of molecular hydrogen. Modeling this empirical relation from first principles proves challenging, however, and many questions regarding its…
We use time-varying models of the coupled evolution of the HI, H_2 gas phases and stars in galaxy-sized numerical simulations to: a) test for the emergence of the Kennicutt-Schmidt (K-S) and the H_2-pressure relation, b) explore a realistic…
We study the kinematics and excitation mechanisms of H2 and [Fe II] lines in a sample of 67 emission-line galaxies with Infrared Telescope Facility SpeX near-infrared (NIR, 0.8-2.4 micrometers) spectroscopy together with new photoionisation…
Molecular hydrogen (H$_2$) and hydrogen deuteride (HD) are key coolants in primordial gas and regulate the formation of the first stars and proto-galaxies. Recent results from the James Webb Space Telescope provide striking insights into…
Ultra-luminous infrared galaxies are among the most luminous objects in the local universe and are thought to be powered by intense star formation. It has been shown that in these objects the rotational spectral lines of molecular hydrogen…
We introduce a sub-grid model for the non-equilibrium abundance of molecular hydrogen in cosmological simulations of galaxy formation. We improve upon previous work by accounting for the unresolved structure of molecular clouds in a…
The collision of gas-rich galaxies is believed to produce strong shocks between their gas clouds which cause the onset of the observed bursts of extended star formation. However, the so far observed shock signatures in colliding galaxies…
We study the connection of star formation to atomic (HI) and molecular hydrogen (H$_2$) in isolated, low metallicity dwarf galaxies with high-resolution ($m_{\rm gas}$ = 4 M$_\odot$, $N_{\rm ngb}$ = 100) SPH simulations. The model includes…
We investigate the physical properties of molecular hydrogen (H2) in isolated and interacting disk galaxies with different masses and Hubble types by using chemodynamical simulations with H2 formation on dust grains and dust growth and…
Interstellar dust plays decisive roles in the conversion of neutral to molecular hydrogen (H_2), the thermodynamical evolution of interstellar medium (ISM), and the modification of spectral energy distributions (SEDs) of galaxies. These…
Observations and interpretation of extragalactic rotational and rovibrational H2 emission are reviewed. Direct observations of H2 lines do not trace bulk H2 mass, but excitation rate. As such, the H2 lines are unique diagnostics, if the…
We use a pressure-based model for splitting cold hydrogen into its atomic (HI) and molecular (H2)components to tackle the co-evolution of HI, H2, and star formation rates (SFR) in ~3e7 simulated galaxies in the Millennium simulation. The…
Stars form out of molecular gas and supply dust grains during their last evolutionary stages; in turn hydrogen molecules (H2) are produced more efficiently on dust grains. Therefore, dust can drastically accelerate H2 formation, leading to…
The bulk of the molecular gas in spiral galaxies is under the form of cold H2, that does not radiate and is only suspected through tracer molecules, such as CO. All tracers are biased, and in particular H2 could be highly underestimated in…
Context: Molecular hydrogen ($\rm{H_2}$) is crucial in galaxy formation and evolution, serving as the main fuel for star formation (SF). In metal-enriched environments, $\rm{H_2}$ primarily forms on interstellar dust grain surfaces.…
We have obtained CO(1-0) observations for a sample of 37 interacting galaxy systems, chosen from a parent sample of optically-selected interacting galaxies. The sample observed here spans a large range of interaction strengths and star…
We investigate the abundance of galactic molecular hydrogen (H$_2$) in the "Evolution and Assembly of GaLaxies and their Environments" (EAGLE) cosmological hydrodynamic simulations. We assign H$_2$ masses to gas particles in the simulations…