Related papers: Threshold between Spontaneous and Cloud-Collisiona…
Different from Milky-Way-like galaxies, discs of gas-rich galaxies are clumpy. It is believed that the clumps form because of gravitational instability. However, a necessary condition for gravitational instability to develop is that the…
We review recent observations of molecular gas in nearby galaxies and their implications for the star formation law on large (>1 kpc) scales. High-resolution data provided by millimetre interferometers are now adding to the basic…
We test some ideas for star formation relations against data on local molecular clouds. On a cloud by cloud basis, the relation between the surface density of star formation rate and surface density of gas divided by a free-fall time,…
We explore the relation between the stellar mass surface density and the mass surface density of molecular hydrogen gas in twelve nearby molecular clouds that are located at $<$1.5 kpc distance. The sample clouds span an order of magnitude…
We compare the structure of molecular gas at $40$ pc resolution to the ability of gas to form stars across the disk of the spiral galaxy M51. We break the PAWS survey into $370$ pc and $1.1$ kpc resolution elements, and within each we…
A positive power-law trend between the local surface densities of molecular gas, $\Sigma_{gas}$, and young stellar objects, $\Sigma_{\star}$, in molecular clouds of the Solar Neighbourhood has been identified by Gutermuth et al. How it…
Observations of external galaxies and of local star-forming clouds in the Milky Way have suggested a variety of star formation laws, i.e., simple direct relations between the column density of star formation (Sigma_SFR: the amount of gas…
We consider the general problem of fitting a parametric density model to discrete observations, taken to follow a non-homogeneous Poisson point process. This class of models is very common, and can be used to describe many astrophysical…
We present an analysis of the large-scale molecular cloud structure and of the stability of clumpy structures in nearby molecular clouds. In our recent work, we identified a structural transition in molecular clouds by studying the…
The mass distribution of the Galactic disk is constructed from the terminal velocity curve and the mass discrepancy-acceleration relation. Mass models numerically quantifying the detailed surface density profiles are tabulated. For $R_0 =…
One of the most puzzling properties of observed galaxies is the universality of the empirical correlation between the star formation rate and average gas surface density on kiloparsec scales (the Schmidt law). In this study I present…
Using the PHANGS-ALMA CO (2-1) survey, we characterize molecular gas properties on ${\sim}$100 pc scales across 102,778 independent sightlines in 70 nearby galaxies. This yields the best synthetic view of molecular gas properties on cloud…
Observationally, it has been reported that the densest stellar system in the Universe does not exceed a maximum stellar surface density, $\Sigma^{\max}_{*}$ = $3\times10^5$M$_{\odot}$pc$^{-2}$, throughout a wide physical scale ranging from…
We use observed radial profiles of mass surface densities of total, $\Sigma_g$, & molecular, $\Sigma_{\rm H2}$, gas, rotation velocity & star formation rate (SFR) surface density, $\Sigma_{\rm sfr}$, of the molecular-rich ($\Sigma_{\rm…
We investigate Schmidt's conjecture (i.e., that the star formation rate scales in a power-law fashion with the gas density) for four well-studied local molecular clouds (GMCs). Using the Bayesian methodology we show that a local Schmidt…
We measure the velocity dispersion, $\sigma$, and surface density, $\Sigma$, of the molecular gas in nearby galaxies from CO spectral line cubes with spatial resolution $45$-$120$ pc, matched to the size of individual giant molecular…
We investigate the relation between star formation rate (SFR) and gas surface densities in Galactic star forming regions using a sample of YSOs and massive clumps. Our YSO sample consists of objects located in 20 molecular clouds from the…
Collisions between giant molecular clouds (GMCs) are one of the pathways for massive star formation, due to the high densities created. However the enhancement of the star formation rate (SFR) is not well constrained. In this study we…
We examine the hypothesis that hydrostatic pressure alone determines the ratio of atomic to molecular gas averaged over a particular radius in disk galaxies. The hypothesis implies that the transition radius, the location where the ratio is…
This study presents a catalog of 8107 molecular clouds that covers the entire Galactic plane and includes 98% of the $^{12}$CO emission observed within $b\pm5^\circ$. The catalog was produced using a hierarchical cluster identification…