Related papers: The Progenitors of Calcium-Strong Transients
A key tool astronomers have to investigate the nature of extragalactic transients is their position on their host galaxies. Galactocentric offsets, enclosed fluxes and the fraction of light statistic are widely used at different wavelengths…
Atomic diffusion in stars can create systematic trends of surface abundances with evolutionary stage. Globular clusters offer useful laboratories to put observational constraints on this theory as one needs to compare abundances in…
Blue straggler stars (BSSs) are stars observed to be hotter and bluer than other stars with the same luminosity in their environment. As such they appear to be much younger than the rest of the stellar population. Two main channels have…
In open star clusters, where all members formed at about the same time, blue straggler stars are typically observed to be brighter and bluer than hydrogen-burning main-sequence stars, and therefore should already have evolved into giant…
Rotating Radio Transients (RRATs) are a new class of neutron stars discovered through the emission of radio bursts. Eleven sources are known up to now, but population studies predict these objects to be more numerous than the normal radio…
Early-type dwarf galaxies are not simply featureless, old objects, but were found to be much more diverse, hosting substructures and a variety of stellar population properties. To explore the stellar content of faint early-type galaxies,…
We present a study of the hierarchical clustering of the young stellar clusters in six local (3--15 Mpc) star-forming galaxies using Hubble Space Telescope broad band WFC3/UVIS UV and optical images from the Treasury Program LEGUS (Legacy…
The recently discovered C-19 stellar stream is a collection of kinematically associated metal-poor stars in the halo of the Milky Way lacking an obvious progenitor. The stream spans an arc of ~15 degrees in the sky, and orbit-fitting…
Blue straggler stars (BSS) are abundantly observed in all Galactic globular clusters (GGC) where data exist. However, observations alone cannot reveal the relative importance of various formation channels or the typical formation times for…
[abridged] Protoplanetary disks with AU-scale inner clearings, often referred to as transitional disks, provide a unique sample for understanding disk dissipation mechanisms and possible connections to planet formation. Observations of…
We present a brief summary of our current results on the stellar distribution and population gradients of the resolved stars in the surroundings of ~50 nearby disk galaxies, observed with space- (Hubble & Spitzer) and ground-based…
Fast Radio Bursts (FRBs) are new transient radio sources discovered recently. Because of the angular resolution restriction in radio surveys, no optical counter part has been identified yet so it is hard to determine the progenitor of FRBs.…
We use GOODS and CANDELS images to identify progenitors of massive (log M > 10 Msun) compact "early-type" galaxies (ETGs) at z~1.6. Since merging and accretion increase the size of the stellar component of galaxies, if the progenitors are…
I assess the similarities and differences between the star-formation modes in quiescent spiral galaxies versus those in violent starburst regions, including galactic nuclei. As opposed to the quiescent star-formation mode, current empirical…
We propose the model describing the observed multiple fast radio bursts due to the close encounters and collisions of neutron stars in the central clusters of the evolved galactic nuclei. The subsystem of neutron star cluster may originate…
Fast Radio Bursts (FRBs) are intense, millisecond-duration broadband radio transients, the emission mechanisms of which are not understood. Masui et al. recently presented Green Bank Telescope observations of FRB 110523, which displayed…
Unveiling the nature of progenitors is crucial for understanding the origin and the mechanism of core-collapse and thermonuclear supernovae (SNe). While several methods have been developed to derive stellar properties so far, many questions…
In the last decade star clusters have been found in the centers of spiral galaxies across all Hubble types. We here present a spectroscopic study of the exceptionally bright (10^6 - 10^8 Lsun) but compact (Re ~ 5 pc) nuclear star clusters…
Young alpha-rich (YAR) stars have been detected in the past as outliers to the local age $\rm-$ [$\alpha$/Fe] relation. These objects are enhanced in $\alpha$-elements but apparently younger than typical thick disc stars. We study the…
We have investigated the metallicity distributions of mono-age stellar populations across the disc of $6 \lesssim R \lesssim 12$\,kpc and $|Z| \lesssim 2$\,kpc using samples selected from the main-sequence turn-off and sub-giant (MSTO-SG)…