Related papers: Bright-red stars in the dwarf irregular galaxy Leo…
Leo T ($M_V = -8.0$) is both the faintest and the least massive galaxy known to contain neutral gas and to display signs of recent star formation. We analyse photometry and stellar spectra to identify member stars and to better understand…
We present HST/WFPC2 observations (F555W, F814W) and ATCA high resolution HI maps of three gas-rich dwarf galaxies in the Centaurus A group discovered in two blind 21-cm surveys (HIPASS, HIDEEP). We compare their individual properties and…
Images recorded through broad (J, H, K), and narrow (CO, and 2.2micron continuum) band filters are used to investigate the photometric properties of bright (K < 13.5) stars in a 6 x 6 arcmin field centered on the SgrA complex. The giant…
We report on the succesful search for CO (2-1) and (3-2) emission associated with OH/IR stars in the Galactic Bulge. We observed a sample of eight extremely red AGB stars with the APEX telescope and detected seven. The sources were selected…
Deep submillimetre surveys have successfully detected distant, star-forming galaxies, enshrouded in vast quantities of dust and which emit most of their energy at far infrared wavelengths. These luminous galaxies are an important…
We present a search and analysis of variable stars in the recently discovered Crater~II dwarf galaxy. Based on $B$, $V$, $I$ data collected with the Isaac Newton Telescope (FoV$\sim$0.44 square degrees) we detected 37 variable stars, of…
The current theory predicts that hot subdwarf binaries are produced from evolved low-mass binaries that have undergone mass transfer and drastic mass loss during either a common envelope phase or a stable Roche lobe overflow while on the…
We present V and I photometry of a 9.4 arcmin X 9.4 arcmin field centered on the dwarf spheroidal galaxy Leo I. The I magnitude of the tip of the Red Giant Branch is robustly estimated from two different datasets (I^{TRGB}=17.97…
A faint dwarf irregular galaxy has been discovered in the HST/ACS field of LV J1157+5638. The galaxy is resolved into individual stars, including the brightest magnitude of the red giant branch. The dwarf is very likely a physical satellite…
We investigate the intermediate-age asymptotic giant branch stellar population of two Local Group dwarf irregular galaxies to characterize their carbon star population in near-infrared (IR). Our work is based on J and K-band SOFI near-IR…
(abridged) Variability is a key property of stars on the asymptotic giant branch (AGB). Their pulsation period is related to the luminosity and mass-loss rate (MLR) of the star. Long-period variables (LPVs) and Mira variables are the most…
We investigate the relationship between the spatial distributions of stellar populations and of neutral and ionized gas in the Local Group dwarf irregular galaxy Sextans A. This galaxy is currently experiencing a burst of localized star…
Recent advances from astronomical surveys have revealed spatial, chemical, and kinematical inhomogeneities in the inner region of the stellar halo of the Milky Way Galaxy. In particular, large spectroscopic surveys, combined with Gaia…
Stellar photometry obtained using the Hubble Space Telescope is used to study the distributions of the number densities of stars of various ages in 12 irregular and dwarf spiral galaxies viewed edge-on. Two subsystems can be distinguished…
We have measured the clustering of z<0.9 red galaxies and constrained models of the evolution of large-scale structure using the initial 1.2 sq. degree data release of the NOAO Deep Wide-Field Survey (NDWFS). The area and BwRI passbands of…
We present Lithium abundance determination for a sample of K giant stars in the galactic bulge. The stars presented here are the only 13 stars with detectable Lithium line (6767.18 A) among ~400 stars for which we have spectra in this…
We report metallicities and radial velocities derived from spectra at the near-infrared calcium triplet for 373 red giants in a 200 square arcminute area at the optical center of the LMC bar. These are the first spectroscopic abundance…
We have characterized the pulsation properties of 164 candidate RR Lyrae variables (RRLs) and 55 candidate Anomalous and/or short-period Cepheids in Leo I dwarf spheroidal galaxy. On the basis of its RRLs Leo I is confirmed to be an…
We have conducted a galaxy survey based on low-resolution slitless spectra taken from the automated CFHT-Laval survey. We present redshift distributions for 522 galaxies distributed in 4 distinct regions of the sky. Redshifts are determined…
We have obtained deep near-infrared $J$- (1.25 $\mu$m), $H$- (1.65$ \mu$m) and $K_s$-band (2.15 $\mu$m) imaging for a sample of six dwarf galaxies ($M_B\ga-17$ mag) in the Local Volume (LV, $D\la10$ Mpc). The sample consists mainly of…