Related papers: The size-velocity dispersion relationship of Galac…
Dealing numerically with the turbulent nature and non-linearity of the physical processes involved in the ISM requires the use of sophisticated numerical schemes coupled to HD and MHD mathematical models. SNe are the main drivers of the…
Within disk galaxies, the velocity dispersion, $\sigma$, of stars increases with age, $\tau$, as measured in the Milky Way (MW) and nearby galaxies. This relation provides a key window into galactic formation history, tracing both the…
A number of very small isolated HII regions have been discovered at projected distances up to 30 kpc from their nearest galaxy. These HII regions appear as tiny emission line objects in narrow band images obtained by the NOAO Survey for…
Understanding the history and the evolution of the Milky Way disc is one of the main goals of modern astrophysics. We study the velocity dispersion behaviour of Galactic disc stars as a function of the [Mg/Fe] ratio, which can be used as a…
We study a sample of 43 early-type galaxies, selected from the SDSS because they appeared to have velocity dispersion > 350 km/s. High-resolution photometry in the SDSS i passband using HRC-ACS on board the HST shows that just less than…
Most studies of correlations between X-ray and optical properties of galaxy clusters have used the largest samples of data available, regardless of the morphological types of clusters included. Given the increasing evidence that morphology…
We present an analysis of the residual velocities from a sample of 105 Galactic planetary nebulae (PNe), the largest done to date on this subject. The analysis has been carried out with long-slit, high dispersion echelle spectra. The data…
Most of the chemical evolution models are not very reliable for the last 5~Gyr of galactic evolution; this is mainly because abundance gradients found in the literature show a big dispersion for young objects; a big culprit of this is the…
We analyze 40 cosmological re-simulations of individual massive galaxies with present-day stellar masses of $M_{*} > 6.3 \times 10^{10} M_{\odot}$ in order to investigate the physical origin of the observed strong increase in galaxy sizes…
We infer the intrinsic ionised gas kinematics for 383 star-forming galaxies across a range of integrated star-formation rates (SFR $\in [10^{-3}, 10^2]$ M$_\odot$ yr$^{-1}$) at $z \lesssim 0.1$ using a consistent 3D forward-modelling…
We have obtained accurate CCD narrow band H_beta and H_alpha photometry of Giant HII Regions in M 33, NGC 6822 and M 101. Comparison with previous determinations of emission line fluxes show large discrepancies; their probable origins are…
We resolve the kinematic distance ambiguity for 266 inner Galaxy HII regions out of a sample of 291 using existing HI and 13CO sky surveys. Our sample contains all HII regions with measured radio recombination line (RRL) emission over the…
We study the role of environment in the evolution of central and satellite galaxies with the Sloan Digital Sky Survey. We begin by studying the size-mass relation, replicating previous studies, which showed no difference between the sizes…
We present a comprehensive study of the velocity dispersion of the atomic (HI) and molecular (H2) gas components in the disks (R < R25) of a sample of 12 nearby spiral galaxies with moderate inclinations. Our analysis is based on sensitive…
We examine the relation between stellar mass, velocity dispersion, size, S\'ersic index and $D_n4000$ for ~40,000 quiescent galaxies in the SDSS. At a fixed stellar mass, galaxies with higher $D_n4000$ have larger velocity dispersions and…
High-mass stars form in much richer environments than those associated with isolated low-mass stars, and once they reach a certain mass, produce ionised (HII) regions. The formation of these pockets of ionised gas are unique to the…
We present a study of the kinematic properties of the ionized gas in the dominant giant HII region of the well known HII galaxy: II Zw 40. High spatial and spectral resolution spectroscopy has been obtained using IFU mode on the GMOS…
We build, as far as theory will permit, self consistent model HII regions around central clusters of aging stars. These produce strong emission line diagnostics applicable to either individual HII regions in galaxies, or to the integrated…
Several measures of galaxy size and mass obtained from the neutral hydrogen mapping of 70 dwarf irregular galaxies presented in Paper I (Hoffman et al. 1996) are compared statistically to those for the set of all available HI-mapped dwarfs…
We analytically derive the observed size-mass relation of galaxies' atomic hydrogen (HI), including limits on its scatter, based on simple assumptions about the structure of HI discs. We trial three generic profiles for HI surface density…