Related papers: Rescuing the Initial Mass Function for Arp 78
We review our current knowledge on the IMF in nearby environments, massive star forming regions, super star clusters, starbursts and alike objects from studies of integrated light, and discuss the various techniques used to constrain the…
A method is presented here for investigating variations in the upper end of the stellar Initial Mass Function (IMF) by probing the production rate of ionizing photons in unresolved, compact star clusters with ages<10 Myr and covering a…
We have examined the stellar structure of 10 nearby, low stellar mass (10^6 to 6 x 10^7 Msolar) dwarf irregular galaxies by fitting ellipses as a function of surface brightness on ultra-deep V images. These are compared to far ultraviolet…
We present a sample of 115 very low optical surface brightness, highly extended, HI-rich galaxies carefully selected from the ALFALFA survey that have similar optical absolute magnitudes, surface brightnesses, and radii to recently…
About 20 percent of all nearby early-type galaxies ($M_{\star} \gtrsim 6 \times 10^{9}$ M$_{\odot}$) outside the Virgo cluster are surrounded by a disc or ring of low-column-density neutral hydrogen (HI) gas with typical radii of tens of…
Using Hubble Space Telescope (HST) ACS/WFC data we present the photometry and spatial distribution of resolved stellar populations in the outskirts of NGC 2915, a blue compact dwarf with an extended HI disc. These observations reveal an…
Understanding the processes that determine the stellar Initial Mass Function (IMF) is a critical unsolved problem, with profound implications for many areas of astrophysics. In molecular clouds, stars are formed in cores, gas condensations…
The HI in galaxies often extends past their conventionally defined optical extent. I report results from our team which has been probing low intensity star formation in outer disks using imaging in H-alpha and ultraviolet. Using a sample of…
We study the recent star formation histories (SFHs) of 575 intermediate-mass galaxies (IMGs, $10^{9} \leq M/M_{\odot} \leq 10^{10}$) in COSMOS at $0.3<z<0.4$ by comparing their H$\alpha$ and UV luminosities. These two measurements trace…
A determination of the initial mass function (IMF) of the current, incomplete census of the 10 Myr-old TW Hya association (TWA) is presented. This census is built from a literature compilation supplemented with new spectra and 17 new radial…
The initial mass function (IMF) of the Arches cluster, which was formed a few million years ago in the harsh environment of the Galactic center (GC), has long been a target of interest to those who study the GC and the theory of star…
We present an ultra-violet (UV) study of the galaxy NGC~300 using GALEX far-UV (FUV) and near-UV (NUV) observations. We studied the nature of UV emission in the galaxy and correlated it with optical, H~I and mid-infrared (3.6 $\mu$m)…
We present the results of a 42-orbit HST/WFC3 survey of the rest-frame optical morphologies of star forming galaxies with spectroscopic redshifts in the range z=1.5-3.6. The survey consists of 42 orbits of F160W imaging covering ~65…
We explore how the estimated star formation rate (SFR) of a sample of isolated, massive dusty star-forming galaxies at early cosmic epochs ($1.5 < z < 3.5$) changes when their ultraviolet (UV) to near-infrared (NIR) spectral energy…
W51A is the most active star formation region of the Giant \ion{H}{2} region W51. It harbors the two massive proto-clusters W51e and W51\,IRS2, which are very rare in the Galaxy. We aim to identify the new born massive stars and UCHII…
We present the results of an Halpha near-infrared narrow-band survey searching for star-forming galaxies at redshift z=0.84. This work is an extension of our previous narrow-band studies in the optical at lower redshifts. After removal of…
[Abridged] We investigate the average physical properties and star formation histories of the most UV-luminous star-forming galaxies at z~3.7. Our results are derived from analyses of the average spectral energy distributions (SEDs),…
We used three indicators of massive star formation: $H_{\alpha}$, FIR and non-thermal radio luminosities, to compare estimations of Star Formation Rate (SFR) for the sample of 34 spiral galaxies. To adjust SFR values, obtained from…
The universality or non-universality of the initial mass function (IMF) has significant implications for determining star formation rates and star formation histories from photometric properties of stellar populations. We reexamine whether…
We use HST NICMOS continuum and Pa-alpha observations to study the near-infrared and star-formation properties of a representative sample of 30 local (d ~ 35-75Mpc) luminous infrared galaxies (LIRGs, infrared 8-1000um luminosities of…