Related papers: Old stellar systems in UV: resolved and integrated…
We present ultraviolet (UV) integrated colors of 44 Galactic globular clusters (GGCs) observed with the Galaxy Evolution Explorer (GALEX) in both FUV and NUV bands. This data-base is the largest homogeneous catalog of UV colors ever…
Globular clusters (GCs) are fundamental for understanding the integrated light of old stellar populations and galaxy assembly processes. However, the role of hot, evolved stars, such as horizontal branch (HB), extreme HB, and blue…
This paper is part of a series devoted to the investigation of a large sample of brightest cluster galaxies (BCGs), their properties and the relationships between these and the properties of the host clusters. In this paper, we compare the…
We present GALEX data for 44 Galactic globular clusters obtained during 3 GALEX observing cycles between 2004 and 2008. This is the largest homogeneous data set on the UV photometric properties of Galactic globular clusters ever collected.…
Ultraviolet observations are the best tool to study hot stellar populations which emit most of their light at short wavelengths. As part of a large project devoted to the characterization of the UV properties of Galactic globular clusters…
We have performed a census of the UV-bright population in 78 globular clusters using wide-field UV telescopes. This population includes a variety of phases of post-horizontal branch (HB) evolution, including hot post-asymptotic giant branch…
This paper explores if, and to what an extent, the stellar populations of early type galaxies can be traced through the colour distribution of their globular cluster systems. The analysis, based on a galaxy sample from the Virgo ACS data,…
Using GALEX, UVOT and optical photometry, we explore the prevalence and strength of the UV-upturn in the spectra of quiescent early type galaxies in several nearby clusters. Even for galaxies with completely passive optical colours, there…
We use high-precision photometry of red-giant-branch (RGB) stars in 57 Galactic globular clusters (GCs), mostly from the `Hubble Space Telescope (HST) UV Legacy Survey of Galactic globular clusters', to identify and characterize their…
The puzzling origin of the ``UV-upturn'' phenomenon, observed in some elliptical galaxies, has recently been settled by identifying hot HB stars as main contributors to galaxy ultraviolet luminosity excess. While a blue HB morphology seems…
We consider the general theoretical problem of ultraviolet light from old stellar populations (t > 2 Gyr), and the interpretation of galaxy spectra at short wavelengths (lamda < 3200A) The sources believed to be responsible for the observed…
Globular clusters (GCs) are among the oldest and most luminous stellar systems in the Universe, offering unique insights into galaxy formation and evolution. While the physical processes behind their origin have long remained elusive, major…
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters is providing a major breakthrough in our knowledge of Globular Clusters (GCs) and their stellar populations. Among the main results, we discovered that all the…
Recent observations and modeling of globular clusters with multiple populations strongly indicate the presence of super helium-rich subpopulations in old stellar systems. Motivated by this, we have constructed new population synthesis…
The UV upturn phenomenon observed in elliptical galaxies is attractive for its potential value as an age indicator of old stellar systems. We present our most recent population models for the UV evolution of elliptical galaxies. We confirm…
The connection between AGB evolution of stellar populations and infrared vs. ultraviolet properties of the parent galaxies is reviewed relying on the updated lookout provided by population-synthesis theory. In particular, planetary-nebula…
Star formation plays a central role in the evolution of galaxies and of the Universe as a whole. Studies of star-forming regions in the local universe have shown that star formation typically occurs in a clustered fashion. Building a…
In this study, we identified and characterized the hot and luminous UV-bright stars in the globular cluster NGC 2808. We combined data from the Ultra Violet Imaging Telescope (UVIT) on-board the Indian space satellite, AstroSat, with the…
The UV upturn refers to the increase in UV flux at wavelengths shorter than 3000 {\AA} observed in quiescent early-type galaxies (ETGs), which still remains a puzzle. In this study, we aim to identify ETGs showing the UV upturn phenomenon…
We present models of the late stages of stellar evolution intended to explain the UV upturn phenomenon in elliptical galaxies. Such models are sensitive to values of a number of poorly-constrained physical parameters, including metallicity,…