相关论文: NGC 5128: The Giant Beneath

We present the results of a deep photometric study of the outer halo of NGC 1275, the highly active cD galaxy at the center of the Perseus cluster. We find a modest excess of faint ($R > 22.5$) starlike objects in its halo, indicating a…

We present multiband photometric observations of three spiral galaxies selected in a sample suited for the study of young stellar groupings and their relationship with the parent galaxy and the galactic environment. Star forming regions…

We present a CCD investigation of the galactic globular M5 aimed to increase the statistical relevance of the available sample of evolving bright stars. Previous investigations, limited to the outer cluster region, have been extended toward…

We present a study of compact star clusters in the nearby pair of interacting galaxies NGC 5194/95 (M51), based on multifilter Hubble Space Telescope WFPC2 archival images. We have detected ~400 isolated clusters. Our requirement that…

We have conducted a wide-field CCD-mosaic study of the resolved red-giant branch (RGB) stars of M31, in a field located 20 kpc from the nucleus along the SE minor axis. In our (I, V-I) color-magnitude diagram, RGB stars in the top three…

We describe a population of compact objects in the centre of the Fornax Cluster which were discovered as part of our 2dF Fornax Spectroscopic Survey. These objects have spectra typical of old stellar systems, but are unresolved on…

We perform a detailed abundance analysis on integrated-light spectra of 20 globular clusters (GCs) in the early-type galaxy NGC 5128 (Centaurus A). The GCs were observed with X-Shooter on the VLT. The cluster sample spans a metallicity…

Galactic open clusters do not survive long in the high density regions of the inner Galactic disc. Inside the solar ring only 11 open clusters are known with ages older than one Gyr. We show here, basing on deep, high-quality photometry,…

We show initial results from our ongoing HST GHOSTS survey of the resolved stellar envelopes of 14 nearby, massive disk galaxies. In hierarchical galaxy formation the stellar halos and thick disks of galaxies are formed by accretion of…

Stellar streams provide unique probes of galactic potentials, with the longer streams normally providing the cleaner measurements. In this paper, we show an example of a short tidal stream that is particularly sensitive to the shape of the…

We present results derived from VLT-FORS2 spectra of 17 globular clusters associated with the nearby lenticular galaxy NGC3115. Comparing line-strength indices to new stellar population models by Thomas et al. we determine ages,…

Dalessandro et al. observed a similar distribution for blue straggler stars and main-sequence turn-off stars in the Galactic globular cluster NGC 6101, and interpreted this feature as an indication that this cluster is not mass-segregated.…

We report the discovery of two new globular clusters in the remote halos of M81 and M82 in the M81 Group based on Hubble Space Telescope archive images. They are brighter than typical globular clusters (MV = -9.34 mag for GC-1 and M_V =…

We report a discovery of an extended globular-like star cluster, M33-EC1, at the outer edge of the spiral galaxy M33. The distance to the cluster is 890 kpc, and it lies at a 12.5 kpc projected distance from the center of M33. Old age (>~7…

Most Globular Clusters so far examined host (at least) two stellar populations. This feature requires a two--step process, in which the nuclearly processed matter from a first generation (FG) of stars gives birth to a second generation (SG)…

The properties of globular cluster systems (GCSs) in the core of the nearby galaxy clusters Fornax and Hydra I are presented. In the Fornax cluster we have gathered the largest radial velocity sample of a GCS system so far, which enables us…

Updated data of the 153 Galactic globular clusters are used to readdress fundamental parameters of the Milky Way. We build a reduced sample, decontaminated of the clusters younger than 10Gyr, those with retrograde orbits and/or evidence of…

This paper presents Gemini-$gri'$ high quality photometry for cluster candidates in the field of NGC 1316 (Fornax A) as part of a study that also includes GMOS spectroscopy. A preliminary discussion of the photometric data indicates the…

We present a new photometric catalog of 326 candidate globular clusters (GCs) in the nearby spiral galaxy M101, selected from B, V, and I Hubble Space Telescope Advanced Camera for Surveys images. The luminosity function (LF) of these…

In earlier work, we showed for the first time that the resolved stellar disk of NGC 300 is very extended with no evidence for truncation, a phenomenon that has since been observed in other disk galaxies. We revisit the outer disk of NGC 300…