Related papers: Binary stars and the UVX in early type galaxies

The acquisition of deep Near-IR imaging with Wide Field Camera 3 on the Hubble Space Telescope has provided the opportunity to study the very-high redshift Universe. For galaxies up to $z\approx 7.7$ sufficient wavelength coverage exists to…

We derive the optical luminosity, colors, and ratios of the blue and red helium burning (HeB) stellar populations from archival Hubble Space Telescope observations of nineteen starburst dwarf galaxies and compare them with theoretical…

We investigate the nebular emission produced by young stellar populations using the new GALSEVN model based on the combination of the SEVN population-synthesis code including binary-star processes and the GALAXEV code for the spectral…

Using the Subaru very deep K'-band imaging and HST WFPC2/NICMOS archival data of the Hubble Deep Field North, we investigate the evolution of the stellar mass, color, morphology of galaxies to z ~ 3. We mainly examine the rest-frame U-V…

We present far-ultraviolet (far-UV) images of the rich galaxy cluster ZwCl1358.1+6245, taken with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope (HST). When combined with archival HST observations, our data…

We present the stellar population properties of 13 dwarf galaxies residing in poor groups (low-density environment, LDE) observed with VIMOS@VLT. Ages, metallicities, and [alpha/Fe] ratios were derived from the Lick indices Hbeta, Mgb,…

In this proceeding we present the results from a study of very high-redshift galaxies with the newly commissioned Wide Field Camera 3 on the Hubble Space Telescope. With the deepest near-infrared data ever taken, we discovered 31 galaxies…

We investigate the evolution of the properties of model populations of ultraluminous X-ray sources (ULXs) consisting of a black-hole accretor in a binary with a donor star. We have computed models corresponding to three different…

Using the Hyperz code (Bolzonella et al. 2000) we present photometric redshift estimates for a random sample of galaxies selected from the SDSS/DR7 and GALEX/DR4, for which spectroscopic redshifts are also available. We confirm that the…

With nearly a hundred gravitational wave detections, the origin of black hole mergers has become a key question. Here, we focus on understanding the typical galactic environment in which binary black hole mergers arise. To this end, we…

We present the results of the first spectroscopic follow-up of 132 optically blue UV-excess sources selected from the UV-excess survey of the Northern Galactic Plane (UVEX). The UV-excess spectra are classified into different populations…

We investigate the [3.6] - [4.5] Spitzer-IRAC colour behaviour of the early-type galaxies of the SAURON survey, a representative sample of 48 nearby ellipticals and lenticulars. We investigate how this colour, which is unaffected by dust…

We combine GALEX (ultra-violet; UV) and SDSS (optical) photometry to study the recent star formation histories of ~100 field galaxies on the optical red sequence, a large fraction of which exhibit widespread signs of disturbed morphologies…

Evolutionary population synthesis models for a wide range of metallicities, ages, star formation histories, and Horizontal Branch morphologies, including blue morphologies at high metallicity, are computed. The energetics of the post Main…

Hubble Space Telescope observations with Wide Field Camera 3/IR reveal that galaxies at z~7 have very blue ultraviolet (UV) colors, consistent with these systems being dominated by young stellar populations with moderate or little…

We present numerical models of the nebular emission from H II regions around young stellar populations over a range of compositions and ages. The synthetic stellar pop- ulations include both single stars and interacting binary stars. We…

Young, massive stars dominate the rest-frame ultraviolet spectra of star-forming galaxies. At high redshifts (z>2), these rest-UV features are shifted into the observed-frame optical and a combination of gravitational lensing, deep…

Since the discovery of the Ultraviolet Upturn Phenomenon (``UVX'') in early-type galaxies it has been clear that the stellar populations of such systems contain an unexpected hot component. Recent work has provided strong circumstantial…

We have constructed a model which describes the optical emission from ultraluminous X-ray sources (ULXs), and have used it to constrain the parameters of seven ULX systems. Our model assumes a binary nature for ULXs, and accounts for…

Subdwarf B stars (sdBs) can significantly change the ultraviolet spectra of populations at age t~1Gyr, and have been even included in the volutionary population synthesis (EPS) models by Han et al. (2007). In this study we present the…