We used deep wide-field photometric observations to derive the fraction of binary systems in a sample of five high-latitude Galactic open clusters. By analysing the colour distribution of main-sequence stars, we derived the minimum fraction of binary systems required to reproduce the observed colour-magnitude diagram morphologies. We found that all

In this article we demonstrate that PKS J1037-2705 has a weak accretion flow luminosity, well below the Seyfert 1/QSO dividing line, weak broad emission lines (BELs), and moderately powerful FR II extended radio emission. It is one of the few documented examples of a broad-line object in which the time-averaged jet kinetic luminosity, Q, is larger

We used an N-body smoothed particle hydrodynamics algorithm, with a detailed treatment of star formation, supernovae feedback and chemical enrichment, to perform eight simulations of mergers between gas-rich disc galaxies. We vary the mass ratio of the progenitors, their rotation axes and their orbital parameters and analyse the kinematic

This paper is part of a series devoted to the study of the stellar populations in brightest cluster galaxies (BCGs), aimed at setting constraints on the formation and evolution of these objects. We have obtained high signal-to-noise ratio, long-slit spectra of 49 BCGs in the nearby Universe. Here, we derive single stellar population (SSP)

We present new observational results on the kinematical, morphological, and stellar population properties of a sample of 21 dEs located both in the Virgo Cluster and in the field, which show that 52% of the dEs (1) are rotationally supported, (2) exhibit structural signs of typical rotating systems such as disks, bars, or spiral arms, (3) are

We test the modified Newtonian dynamics (MOND) theory with the velocity dispersion profiles of Galactic globular clusters populating the outermost region of the Milky Way halo, where the Galactic acceleration is lower than the characteristic MOND acceleration a0. For this purpose, we constructed self-consistent, spherical models of stellar systems

We report evidence for dynamically significant rotation in the globular cluster systems of two luminous Virgo dwarf ellipticals, VCC1261 and VCC1528. Including previous results for VCC1087, the globular cluster systems of all three Virgo dwarf ellipticals studied in detail to date exhibit v rot/σlos>1. Taking the rotation seen in the globular

Aims: We present the main results of an imaging survey of possible young massive clusters (YMC) in M 31 performed with the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space Telescope (HST), with the aim of estimating their age and their mass. We obtained shallow (to B ˜ 25) photometry of individual stars in 19 clusters (of the 20

We present new B, V and I CCD time-series photometry for 177 variable stars in a 13 × 13arcmin2 field centred on the globular cluster M54 (lying at the centre of the Sagittarius dwarf spheroidal galaxy), 94 of which are newly identified variables. The total sample is composed of two anomalous Cepheids, 144 RR Lyrae stars (108 RR0 and 36 RR1), three

We find a significant number of massive and compact galaxies in clusters from the ESO Distant Clusters Survey (EDisCS) at 0.4 < z < 1. They have similar stellar masses, ages, sizes, and axial ratios to local z ~ 0.04 compact galaxies in WIde field Nearby Galaxy clusters Survey (WINGS) clusters, and to z = 1.4-2 massive and passive galaxies found in

Context. NGC 404 is a nearly face-on, nearby low-luminosity lenticular galaxy. Probing its characteristics provides a wealth of information on the details of the possible evolution processes of dS0 galaxies, which may not be possible in other, more distant objects. Aims: We study the internal kinematics and the spatial distribution of the star

A study of two dE/dSph members of the nearby M81 group of galaxies, KDG61 and UGC5442 = KDG64, has been made. Direct Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) images and integrated-light spectra of 6-m telescope of Special Astrophysical Observatory of Russian Academy of Sciences have been used for quantitative star formation

Aims: We present a new semi-analytical model of galaxy formation, GECO (Galaxy Evolution COde), designed to improve our understanding of when and how the processes of both star formation and galaxy assembly took place, by comparison with a wide variety of data about galaxy mass-function evolution and star-formation histories. Methods: Our model is

Context. The optical ring-like structure detected by Arp (1965) around M 81 (commonly referenced as “Arp's loop”) represents one of the most spectacular features observed in nearby galaxies. Arp's loop is commonly interpreted as a tail resulting from the tidal interaction between M 81 and M 82. However, since its discovery the nature of this

We study the impact of the environment on the evolution of galaxies in the zCOSMOS 10 k sample in the redshift range 0.1 ≤ z ≤ 1.0 over an area of ~1.5 deg2. The considered sample of secure spectroscopic redshifts contains about 8500 galaxies, with their stellar masses estimated by SED fitting of the multiwavelength optical to near-infrared (NIR)

Context. Empirical libraries of stellar spectra are used to classify stars and synthetize stellar populations. MILES is a medium spectral-resolution library in the optical domain covering a wide range of temperatures, surface gravities and metallicities. Aims: We redetermine the atmospheric parameters of these stars in order to improve the

Context. NGC 4486A is a low-luminosity elliptical galaxy harbouring an edge-on nuclear disk of stars and dust. It is known to host a super-massive black hole. Aims: We study its large-scale kinematics and stellar population along the major axis to investigate the link between the nuclear and global properties. Methods: We use long-slit medium

We report the detection of a pair of degree-long tidal tails associated with the globular cluster Palomar 14, using images obtained at the Canada-France-Hawaii Telescope. We reveal a power-law departure from a King profile at large distances to the cluster center. The density map constructed with the optimal matched filter technique shows a nearly

Context. Empirical libraries of stellar spectra play an important role in different fields. For example, they are used as reference for the automatic determination of atmospheric parameters, or for building synthetic stellar populations to study galaxies. The CFLIB (Coudé-feed library, Indo-US) database is at present one of the most complete

This paper presents further results from our spectroscopic study of the globular cluster (GC) system of the group elliptical NGC 3923. From observations made with the GMOS instrument on the Gemini South Telescope, an additional 50 GC and ultra-compact dwarf (UCD) candidates have been spectroscopically confirmed as members of the NGC 3923 system