Related papers: Threshold between Spontaneous and Cloud-Collisiona…
We calculate the stellar surface mass density (Sigma_*) and two-component (gas+stars) disk stability (Q_RW) for 25 late-type galaxies from the DiskMass Survey. These calculations are based on fits of a dynamical model to our ionized-gas and…
The tight correlation between galaxy bulges and their central black hole masses likely emerges in a phase of rapid collapse and starburst at high redshift, due to the balance of gravity on gas with the feedback force from starbursts and the…
We performed a correlation analysis between the brightness temperature of the CO line and number density of HII regions in the longitude--velocity diagram (LVD) of the Milky Way in order to investigate the volumetric star-formation law. We…
Magnetic fields are ubiquitously observed in the interstellar medium (ISM) of present-day star-forming galaxies with dynamically relevant energy densities. Using three-dimensional magneto-hydrodynamic (MHD) simulations of the supernova (SN)…
We offer a simple parameterization of the rate of star formation in galaxies. In this new approach, we make explicit and decouple the timescales associated (a) with disruptive effects the star formation event itself, from (b) the timescales…
Observations indicate that massive stars form in regions of very high surface density, ~1 g cm^-2. Clusters containing massive stars and globular clusters have a comparable column density. The total pressure in clouds of such a column…
We study the response of the gaseous component of a galactic disc to the time dependent potential generated by N-body simulations of a spiral galaxy. The results show significant variation of the spiral structure of the gas which might be…
It is well-established that a gas density gradient inside molecular clouds and clumps raises their star formation rate compared to what they would experience from a gas reservoir of uniform density. This effect should be observed in the…
Stars in galaxies form in giant molecular clouds that coalesce when the atomic hydrogen is converted into molecules. There are currently two dominant models for what property of the galactic disk determines its molecular fraction: either…
We explore, through a simplified, semi-analytic model, the formation of dense clusters containing massive stars. The parent cloud spawning the cluster is represented as an isothermal sphere. This sphere is in near force balance between…
We measure empirical relationships between the local star formation rate (SFR) and properties of the star-forming molecular gas on 1.5 kpc scales across 80 nearby galaxies. These relationships, commonly referred to as "star formation laws,"…
Star formation laws are empirical relations between the cold gas (HI+H$_2$) content of a galaxy and its star formation rate (SFR), being crucial for any model of galaxy formation and evolution. A well known example of such laws is the…
We present the results from simulations of GMC formation in spiral galaxies. First we discuss cloud formation by cloud-cloud collisions, and gravitational instabilities, arguing that the former is prevalent at lower galactic surface…
The relationship between the star formation rate surface density and the molecular gas surface density in galaxies is key to understanding galaxy evolution. To investigate the molecular Kennicutt-Schmidt (K-S) relation and its dependence on…
Stars generally form in aggregates, some of which are bound ('clusters') while others are unbound and disperse on short ($\sim10$ Myr) timescales ('associations'). The fraction of stars forming in bound clusters ($\Gamma$) is a fundamental…
We revisit an alternate explanation for the turbulent nature of molecular clouds - namely, that velocity dispersions matching classical predictions of driven turbulence can be generated by the passage of clumpy material through a shock.…
On galactic scales, the surface density of star formation appears to be well correlated with the surface density of molecular gas. This has lead many authors to suggest that there exists a causal relationship between the chemical state of…
Using N-body/gasdynamic simulations of a Milky Way-like galaxy we analyse a Kennicutt-Schmidt relation, $\Sigma_{SFR} \propto \Sigma_{gas}^N$, at different spatial scales. We simulate synthetic observations in CO lines and UV band. We adopt…
We study the effects of passages of compact objects such as stars, star clusters, and black holes through molecular clouds, and propose that the gravitational interaction between the compact object and the ambient gas can lead to the…
What is the nature of a star forming clump? Observations reveal these to be chaotic environments being modified and influenced by many physical processes. However, numerical simulations often define these initial star forming clumps to be…