Related papers: Rescuing the Initial Mass Function for Arp 78
During the initial data reduction of the Wisconsin H-Alpha Mapper (WHAM) H-Alpha Sky Survey, we have discovered several very long (~30--80 deg) filaments superimposed on the diffuse H-Alpha background. These features have no clear…
We present a study of star forming regions and its demographics in the nearby dwarf irregular galaxy WLM using the Ultra-Violet Imaging Telescope (UVIT) multi band observations in three filters F148W, N245M and N263M. We find that the UV…
We have carried out a deep imaging survey for H$\alpha$ emitting galaxies at $z\approx$0.24 using a narrowband filter tuned with the redshifted line. The total sky area covered is 706 arcmin$^2$ within a redshift range from 0.234 to 0.252…
Ultraviolet imaging with the Galaxy Evolution Explorer (GALEX) has revealed an extensive sample of UV-bright stellar complexes in the extreme outer disk of M83, extending to about four times the radius where the majority of HII regions are…
We present Multiband Imaging Photometer for Spitzer (MIPS) observations of M81 at 24, 70, and 160 micron. The grand design nature of M81 is clearly seen, showing two well resolved spiral arms containing numerous bright star forming regions.…
I present infrared spectroscopy of 37 brown dwarf candidates in the Upper Sco association, 35 of which are classified as young and cool, making them likely members. This sample includes many of the faintest spectroscopically confirmed…
Due to the recent dramatic technological advances, infrared interferometry can now be applied to new classes of objects, resulting in exciting new science prospects, for instance, in the area of high-mass star formation. Although…
We present results from ground-based optical imaging of a low-mass dwarf galaxy discovered by the ALFALFA 21-cm HI survey. Broadband (BVR) data obtained with the WIYN 3.5-m telescope at Kitt Peak National Observatory (KPNO) are used to…
We analyse new observations with the International Low Frequency Array (LOFAR) telescope, and archival data from the Multi-Element Radio Linked Interferometer Network (MERLIN) and the Karl G. Jansky Very Large Array (VLA). We model the…
We explore the possibility of using UV spectroscopy in combination with broad-band photometry as diagnostic tools for understanding the shape of the Initial Mass Function (IMF) in unresolved stellar populations. Building on our previous…
We investigate the build-up of galaxies at z~1 using maps of Halpha and stellar continuum emission for a sample of 57 galaxies with rest-frame Halpha equivalent widths >100 Angstroms in the 3D-HST grism survey. We find that the Halpha…
We present observations of Arp 147, a galaxy system comprising a collisionally-created ring galaxy and an early-type galaxy, using the Oxford SWIFT integral field spectrograph (IFS) at the 200-inch Hale telescope. We derive spatially…
The stellar initial mass function (IMF) describes the mass distribution of stars at the time of their formation and is of fundamental importance for many areas of astrophysics. The IMF is reasonably well constrained in the disk of the Milky…
Integral field unit (IFU) spectra of face-on star-forming galaxies from the MaNGA survey are stacked in radial bins so as to reach a S/N high enough to measure emission lines and Lick indices out to 2.5-3 R_e. Two thirds of galaxies have…
We systematically study the X-ray and ultraviolet emission of a subsample of M dwarfs from a recent proper-motion survey, selecting all M dwarfs within 10pc to obtain a nearly volume-limited sample (~90% completeness). Archival ROSAT,…
We present first results of the study of a set of exceptional HI sources identified in the 40% ALFALFA extragalactic HI survey catalog alpha.40 as being both HI massive (M_HI > 10^10 Msun) and having high gas fractions for their stellar…
A great deal of our understanding of star formation in the local universe has been built upon an extensive foundation of H-alpha observational studies. However, recent work in the ultraviolet (UV) with GALEX has shown that star formation…
We construct UV/optical/IR spectral energy distributions for 29 star forming regions in the interacting galaxy Arp 107, using GALEX UV, Sloan Digitized Sky Survey optical, and Spitzer infrared images. In an earlier study utilizing only the…
LIRGs and ULIRGs are much more numerous at higher redshifts than locally, dominating the star-formation rate density at redshifts ~1 - 2. Therefore, they are important objects in order to understand how galaxies form and evolve through…
The James Webb Space Telescope (JWST) has uncovered an abundance of $z>10$ galaxies bright in the ultraviolet (UV) that has challenged traditional theoretical models at high redshifts. Recently, various new models have emerged to address…