Related papers: Molecular hydrogen deficiency in HI-poor galaxies …
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…
[Abridged] Do some environments favor efficient conversion of molecular gas into stars? To answer this, we need to be able to estimate the H2 mass. Traditionally, this is done using CO and a few assumptions but the Herschel observations in…
The HI content of galaxies in the Eridanus group is studied using the GMRT observations and the HIPASS data. A significant HI deficiency up to a factor of 2-3 is observed in galaxies in the high galaxy density regions. The HI deficiency in…
The empirical studies of cold gas content serve as an essential aspect in comprehending the star formation activities and evolution in galaxies. However, it is not straightforward to understand these processes because they depend on various…
We perform a stacking analysis of the HI spectra from the Arecibo Legacy Fast ALFA (ALFALFA) survey for optically-selected local galaxies from the Sloan Digital Sky Survey (SDSS) to study the average gas fraction of galaxies at fixed…
Broadband B and R and H-alpha images have been obtained with the 4.1-m SOAR telescope atop Cerro Pachon, Chile for 29 spiral galaxies in the Pegasus I galaxy cluster and for 18 spirals in non-cluster environments. Pegasus I is a spiral-rich…
The latest observations of molecular gas and the atomic hydrogen content of local and high-redshift galaxies, coupled with how these correlate with star formation activity, have revolutionized our ideas about how to model star formation in…
We revisit the mass ratio Rmol between molecular hydrogen (H2) and atomic hydrogen (HI) in different galaxies from a phenomenological and theoretical viewpoint. First, the local H2-mass function (MF) is estimated from the local…
We have investigated the time scale for formation of molecular clouds by examining the conversion of HI to H2 using a time-dependent model. H2 formation on dust grains and cosmic ray and photo destruction are included in one-dimensional…
We describe a phenomenological model for molecular hydrogen formation suited for applications in galaxy formation simulations, which includes on-equilibrium formation of molecular hydrogen on dust and approximate treatment of both its…
(Abridged) We present a comprehensive analysis of the relationship between star formation rate surface density (SFR SD) and gas surface density (gas SD) at sub-kpc resolution in a sample of 18 nearby galaxies. We use high resolution HI data…
We show that gaseous \HI disks of primordial composition irradiated by an external radiation field can develop a multiphase medium with temperatures between 10^2 and 10^4 K due to the formation of molecular hydrogen. For a given \HI column…
The molecular-to-atomic gas ratio is crucial to the evolution of the interstellar medium in galaxies. We investigate the balance between the atomic ($\Sigma_{\rm HI}$) and molecular gas ($\Sigma_{\rm H2}$) surface densities in eight nearby…
The baryonic processes in galaxy evolution include gas infall onto galaxies to form neutral atomic hydrogen (HI), the conversion of HI to the molecular state (H$_2$), and, finally, the conversion of H$_2$ to stars. Understanding galaxy…
We examine the global HI properties of galaxies in quarter-billion particle cosmological simulations using Gadget-2, focusing on how galactic outflows impact HI content. We consider four outflow models, including a new one (ezw) motivated…
We present $^{12}$CO(1-0) and $^{12}$CO(2-1) observations of a sample of 20 star-forming dwarfs selected from the Herschel Virgo Cluster Survey, with oxygen abundances ranging from 12 + log(O/H) ~ 8.1 to 8.8. CO emission is observed in ten…
In this review, I discuss some highlights of recent research on molecular gas in galaxies; large-scale CO maps of nearby galaxies are being made, which extend our knowledge on global properties, radial gradients, and spiral structure of the…
Spatially resolved HI studies of dwarf galaxies have provided a wealth of precision data. However these high-quality, resolved observations are only possible for handful of dwarf galaxies in the Local Volume. Future HI surveys are unlikely…
We study the evolution of atomic and molecular gas in galaxies in semi-analytic models of galaxy formation that include new modeling of the partitioning of cold gas in galactic discs into atomic, molecular, and ionised phases. We adopt two…
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…