相关论文: ACS photometry of the globular cluster B514

We report the first results from deep ACS imaging of ten classical globular clusters in the far outer regions (15 < R_p < 100 kpc) of M31. Eight of the clusters, including two of the most remote M31 globular clusters presently known, are…

A new population of extended, luminous globular clusters has recently been discovered in the outskirts of M31. These objects have luminosities typical of classical globular clusters, but much larger half-light radii. We report the first…

We report on the identification of a new cluster in the far halo of the M31 galaxy. The cluster, named Bologna 514 (B514) has an integrated magnitude M_V=-8.5 +- 0.6, and a radial velocity, as estimated from two independent low-resolution…

We present the first results of a large spectroscopic survey of candidate globular clusters located in the extreme outskirts of the nearby M31 galaxy. We obtained low resolution spectra of 48 targets selected from the XSC of 2MASS, as in…

B514 is a remote M31 globular cluster which locating at a projected distance of R_p~55 kpc. Deep observations with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST) are used to provide the accurate integrated light…

We present a study of the density profile of the remote M31 globular cluster B514, obtained from HST/ACS observations. Coupling the analysis of the distribution of the integrated light with star counts we can reliably follow the profile of…

This paper describes the results of an HST WFPC2 search for star clusters in active star-formation regions of M31. Nine of the clusters were previously cataloged and 77 are new. Our 23 fields cover key areas of the galaxy's recent star…

We report the discovery of an extended globular cluster in a halo field in Centaurus A (NGC 5128), situated $\sim 38\kpc$ from the centre of that galaxy, imaged with the Advanced Camera for Surveys on board the Hubble Space Telescope. At…

The Hubble Space Telescope has been used to obtain WFPC2 (V,I) photometry for a large sample of stars in the outer halo of the giant elliptical NGC 5128 (d = 4 Mpc). The globular cluster N5128-C44, at the center of the Planetary Camera…

With the aim of increasing the sample of M31 clusters for which a colour magnitude diagram is available, we searched the HST archive for ACS images containing objects included in the Revised Bologna Catalogue of M31 globular clusters.…

We analyse the photometric, chemical, star formation history and structural properties of the brightest globular cluster (GC) in M81, referred as GC1 in this work, with the intention of establishing its nature and origin. We find that it is…

We report new, as yet unpublished HST/WFPC2 V, I photometry of 9 globular clusters in M31. These are part of a total sample of 19 clusters on M31 with well observed CMDs from HST. The clusters have the full range of horizontal branch…

We report new HST/WFPC2 photometry for 10 globular clusters (GC) in M31 observed in F5555W(V) and F814W(I). Additionally we have reanalyzed HST archival data of comparable quality for 2 more GCs. Extraordinary care is taken to account for…

We present photometry from Hubble Space Telescope (HST)/Wide Field Planetary Camera 2 parallel imagery of a remote M31 field at a projected distance of about 34 kpc from the nucleus near the SW major axis. This field is near the globular…

We report on deep imaging of a remote M31 globular cluster, MGC1, obtained with Gemini/GMOS. Our colour-magnitude diagram for this object extends ~5 magnitudes below the tip of the red giant branch and exhibits features consistent with an…

We recently found the globular cluster (GC) EXT8 in M31 to have an extremely low metallicity of [Fe/H]=-2.91+/-0.04 using high-resolution spectroscopy. Here we present a colour-magnitude diagram (CMD) for EXT8, obtained with the Wide Field…

Globular clusters at the distance of M31 have apparent angular sizes of a few arcseconds. While many M31 GCs have been detected and studied from ground-based images, the high spatial resolution of HST allows much more robust detection and…

We present a multiwavelength photometric analysis of the globular cluster M2. The data-set has been obtained by combining high-resolution (HST/WFPC2 and ACS) and wide-field (GALEX) space observations and ground based (MEGACAM-CFHT,…

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 present deep (V ~ 28.0) BV photometry obtained with the wide field channel of the Advanced Camera for Surveys on board HST for four M31 globular clusters that were identified as candidate intermediate-age (age ~ 1-9 Gyr) by various…