Related papers: A Maximum Stellar Surface Density in Dense Stellar…
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…
A maximum stellar surface density $\Sigma_{max} \sim 3 \times 10^5\,{\rm M_\odot\,pc^{-2}}$ is observed across all classes of dense stellar systems (e.g. star clusters, galactic nuclei, etc.), spanning $\sim 8$ orders of magnitude in mass.…
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 =…
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…
We present a global study of low mass, young stellar object (YSO) surface densities (Sigma) in nearby (< 500 pc) star forming regions based on a comprehensive collection of Spitzer Space Telescope surveys. We show that the distribution of…
Studies by Lada (2010) and Heiderman (2010) have suggested that star formation mostly occurs above a threshold in gas surface density Sigma of Sigma_c = 120 Msun pc^{-2} (A_K = 0.8). Heiderman infer a threshold by combining low-mass…
We analyze the relationship between maximum cluster mass, and surface densities of total gas (Sigma_gas), molecular gas (Sigma_H_2), neutral gas (Sigma_HI) and star formation rate (Sigma_SFR) in the grand design galaxy M51, using published…
We analyze the relationship between maximum cluster mass, M_max, and surface densities of total gas (Sigma_gas), molecular gas (Sigma_H2) and star formation rate (Sigma_SFR) in the flocculent galaxy M33, using published gas data and a…
In this paper we investigate the level of star formation activity within nearby molecular clouds. We employ a uniform set of infrared extinction maps to provide accurate assessments of cloud mass and structure and compare these with…
Newborn stars form within the localized, high density regions of molecular clouds. The sequence and rate at which stars form in dense clumps and the dependence on local and global environments are key factors in developing descriptions of…
The central regions of galaxies show the presence of massive black holes and/or dense stellar systems. The question about their modes of formation is still under debate. A likely explanation of the formation of the central dense stellar…
We present a global study of low mass, young stellar object (YSO) surface densities in nearby (< 500 pc) star forming regions based on a comprehensive collection of Spitzer Space Telescope surveys. We show that the distribution of YSO…
We present stellar mass surface density profiles of a mass-selected sample of 177 galaxies at 0.5 < z < 2.5, obtained using very deep HST optical and near-infrared data over the GOODS-South field, including recent CANDELS data. Accurate…
The large columns of dusty gas enshrouding and fuelling star-formation in young, massive stellar clusters may render such systems optically thick to radiation well into the infrared. This raises the prospect that both "direct" radiation…
We use a robust sample of 11 z~7 galaxies (z-dropouts) to estimate the stellar mass density of the universe when it was only ~750 Myr old. We combine the very deep optical to near-Infrared photometry from the HST ACS and NICMOS cameras with…
Galaxy star formation rates (SFRs) are sensitive to the local environment; for example, the high-density regions at the cores of dense clusters are known to suppress star formation. It has been suggested that galaxy transformation occurs…
The stellar surface mass density profiles at the centers of typical ~L* and lower-mass spheroids exhibit power law 'cusps' with $\Sigma \propto R^(-n)$, where 0.5<n<1 for radii ~1-100 pc. Observations and theory support models in which…
We use a complete sample of galaxies drawn from the SDSS to study how structure, star formation and nuclear activity depend on local density and on stellar mass. Local density is estimated by counting galaxies above a fixed absolute…
We investigate the relationship between the star formation rate per unit area and the surface density of the ISM (the local Kennicutt-Schmitt law) using a simplified model of the ISM and a simple estimate of the star formation rate based on…
We present a suite of 3D multi-physics MHD simulations following star formation in isolated turbulent molecular gas disks ranging from 5 to 500 parsecs in radius. These simulations are designed to survey the range of surface densities…