Related papers: Bimodal abundance pattern in M51: evidence for cor…
We present the I-band luminosity function of the differentially reddened globular cluster M10. We combine photometric analysis derived from wide-field (23' x 23') images that include the outer regions of the cluster and high-resolution…
M51 and NGC 5195 is an interacting system that can be explored in great details with ground-based telescopes. The H II regions in M51 were observed using the 2.16 m telescope of the National Astronomical Observatories of the Chinese Academy…
We study the relations between luminosity and chemical abundance profiles of spiral galaxies, using detailed models for the chemical and spectro-photometric evolution of galactic discs. The models are ``calibrated'' on the Milky Way disc…
Galactic disc chemical evolution models generally ignore azimuthal surface density variation that can introduce chemical abundance azimuthal gradients. Recent observations, however, have revealed chemical abundance changes with azimuth in…
We report the highest-fidelity observations of the spiral galaxy M51 in CO emission, revealing the evolution of giant molecular clouds (GMCs) vis-a-vis the large-scale galactic structure and dynamics. The most massive GMCs (so-called GMAs)…
We present an investigation of the relationships between the radio properties of a giant radio galaxy MRC B0319-454 and the surrounding galaxy distribution with the aim of examining the influence of intergalactic gas and gravity associated…
There is a growing body of evidence for the presence of multiple stellar populations in some globular clusters, including NGC 1851. For most of these peculiar globular clusters, however, the evidence for the multiple red giant-branches…
The Milky Way harbours two disks that appear distinct concerning scale-heights, kinematics, and elemental abundance patterns. Recent years have seen a surge of studies of the elemental abundance trends in the disks using high resolution…
We investigate the evolution of the galaxy population since redshift 2 with a focus on the colour bimodality and mass density of the red sequence. We obtain precise and reliable photometric redshifts up to z=2 by supplementing the optical…
In this paper we adopt a chemical evolution model, which is an improved version of the Chiappini, Matteucci and Gratton (1997) model, assuming two main accretion episodes for the formation of the Galaxy. The present model takes into account…
We show the variations of the CO J=2-1/1-0 line ratio (R21) across the barred spiral galaxy M83, using the 46 pc resolution data from ALMA. The R21 map clearly evidences the systematic large-scale variations as a function of galactic…
We present deep HST/ACS observations of the G1 clump, a distinct stellar overdensity lying at ~30 kpc along the south-western major axis of M31 close to the G1 globular cluster (Ferguson et al. 2002). Our well-populated colour-magnitude…
We present the sample for an abundance analysis of 25 members of M71 with luminosities ranging from the red giant branch tip to the upper main sequence. The spectra are of high dispersion and of high precision. We describe the observing…
The spatial distribution of oxygen in the interstellar medium of galaxies is the key to understanding how efficiently metals that are synthesized in massive stars can be redistributed across a galaxy. We present here a case study in the…
Transient spiral waves of moderate amplitude cause substantial changes to the angular momenta of many stars in a galaxy disk. Stars near to corotation are affected most strongly: for a wave of ~20% overdensity, the rms change for particles…
It is well established that the chemical structure of the Milky Way exhibits a bimodality with respect to the $\alpha$-enhancement of stars at a given [Fe/H]. This has been studied largely based on a bulk $\alpha$ abundance, computed as a…
Based on a simple, but fairly successful, model of the chemical evolution of the Milky Way disk, we study the evolution of the abundances of the elements He, C, N, O, Ne, Mg, Al, Si, S, Ar and Fe. We use metallicity dependent yields for…
We present hydrodynamical models of the grand design spiral M51 (NGC 5194), and its interaction with its companion NGC 5195. Despite the simplicity of our models, our simulations capture the present day spiral structure of M51 remarkably…
Using the B-I color index in the radial photometry of M51, applied to defined azimuthal sectors, we reveals asymmetries in the shape of the density pattern of the galactic arms. The anomalous shape is present only in the side close to the…
We exploit the superb resolution of the new HST/ACS mosaic image of M51 to select a large sample of young (< 1 Gyr) star clusters in the spiral disk, based on their sizes. The image covers the entire spiral disk in B, V, I and H_alpha, at a…