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Age and metallicity distribution of the Galactic bulge from extensive optical and near-IR stellar photometry
Rejkuba, M.; Greggio, L.; Zoccali, M. +7 more
We present a new determination of the metallicity distribution, age, and luminosity function of the Galactic bulge stellar population. By combining near-IR data from the 2MASS survey, from the SOFI imager at ESO NTT and the NICMOS camera on board HST we were able to construct color-magnitude diagrams (CMD) and luminosity functions (LF) with large …
Distances to nearby galaxies in Sculptor
Sarajedini, A.; Dolphin, A. E.; Grebel, E. K. +7 more
We present an analysis of Hubble Space Telescope/WFPC2 images of nine nearby galaxies in Sculptor. We derive their distances from the luminosity of the tip of the red giant branch stars with a typical accuracy of ~ 12%. Their distances are 4.21 Mpc (Sc 22), 4.92 Mpc (DDO 226), 3.94 Mpc (NGC 253), 3.40 Mpc (KDG 2), 3.34 Mpc (DDO 6), 3.42 Mpc (ESO 5…
The age, life expectancy, and space density of Post Common Envelope Binaries
Gänsicke, B. T.; Schreiber, M. R.
We present a sample of 30 well observed Post Common Envelope Binaries (PCEBs). Deriving the cooling age of the white dwarfs, we show that the PCEB population is dominated by young systems. Having calculated the orbital evolution of the systems under the assumption of two different prescriptions for the angular momentum loss, we find that most of t…
Formation of polar ring galaxies
Bournaud, F.; Combes, F.
Polar ring galaxies are peculiar systems in which a gas-rich, nearly polar ring surrounds an early-type or elliptical host galaxy. Two formation scenarios for these objects have been proposed: they are thought to form either in major galaxy mergers or by tidal accretion of the polar material from a gas rich donor galaxy. Both scenarios are studied…
Clusters in the inner spiral arms of M 51: The cluster IMF and the formation history
Panagia, N.; Bastian, N.; Bik, A. +2 more
We present the results of an analysis of the HST-WFPC2 observations of the interacting galaxy M 51. From the observations in 5 broadband filters (UBVRI) and two narrowband filters (Hα and [OIII]) we study the cluster population in a region of 3.2 x 3.2 kpc2 in the inner spiral arms of M 51, at a distance of about 1 to 3 kpc from the nuc…
On the Lyalpha emission from gamma-ray burst host galaxies: Evidence for low metallicities
Fruchter, A. S.; Wijers, R. A. M. J.; Pedersen, H. +11 more
We report on the results of a search for Lyalpha emission from the host galaxy of the z=2.140 GRB 011211 and other galaxies in its surrounding field. We detect Lyalpha emission from the host as well as from six other galaxies in the field. The restframe equivalent width of the Lyalpha line from the GRB 011211 host is about 21 Å. This is the fifth …
Local galaxy flows within 5 Mpc
Sarajedini, A.; Dolphin, A. E.; Grebel, E. K. +8 more
We present Hubble Space Telescope/WFPC2 images of sixteen dwarf galaxies as part of our snapshot survey of nearby galaxy candidates. We derive their distances from the luminosity of the tip of the red giant branch stars with a typical accuracy of ~ 12%. The resulting distances are 4.26 Mpc (KKH 5), 4.74 Mpc (KK 16), 4.72 Mpc (KK 17), 4.66 Mpc (ESO…
A radial mass profile analysis of the lensing cluster MS 2137.3-2353
Pelló, R.; Gavazzi, R.; Fort, B. +2 more
We reanalyze the strong lens modeling of the cluster of galaxies MS 2137.3-2353 using a new UBVRIJK data set obtained with the ESO Very Large Telescope. We infer the photometric redshifts of the two main arc systems which are both found to be at z=1.6+/- 0.1. After subtraction of the central cD star light in the previous F702/HST imaging we found …
Galaxy flow in the Canes Venatici I cloud
Sarajedini, A.; Dolphin, A. E.; Grebel, E. K. +7 more
We present an analysis of Hubble Space Telescope/WFPC2 images of eighteen galaxies in the Canes Venatici I cloud. We derive their distances from the luminosity of the tip of the red giant branch stars with a typical accuracy of ~ 12%. The resulting distances are 3.9 Mpc (UGC 6541), 4.9 Mpc (NGC 3738), 3.0 Mpc (NGC 3741), 4.5 Mpc (KK 109), >6.3 …
Molecular Gas in NUclei of GAlaxies (NUGA). I. The counter-rotating LINER NGC 4826
Tacconi, L. J.; Hunt, L. K.; Schinnerer, E. +8 more
We present new high-resolution observations of the nucleus of the counter-rotating LINER NGC 4826, made in the J=1-0 and J=2-1 lines of 12CO with the IRAM Plateau de Bure mm-interferometer(PdBI).The CO maps, which achieve 0.8arcsec (16 pc) resolution in the 2-1 line, fully resolve an inner molecular gas disk which is truncated at an out…