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Related papers: The Outer Halo Globular Clusters of M31

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The outer halo regions of early-type galaxies carry key information about their past accretion history. However, spectroscopically probing the stellar component at such galactocentric radii is still challenging. Using Keck/DEIMOS, we have…

We present deep (V ~= 27) V- and I-band stellar photometry of G302 and G312, two globular star clusters in the halo of M31. These data were obtained using the Hubble Space Telescope's Wide Field/Planetary Camera 2. We find iron abundances…

Astrophysics · Physics 2009-10-30 Stephen Holland , Gregory G. Fahlman , Harvey B. Richer

We present deep V & I WFPC2 photometry in two fields in the M31 halo 32' and 50' from the center of M31 along the SE minor axis at the locations of the M31 GCs G302 and G312 respectively. The M31 halo LFs are not consistent with a single…

Astrophysics · Physics 2009-10-28 Stephen Holland , Gregory G. Fahlman , Harvey B. Richer

We have obtained Keck LRIS imaging and spectra for 29 globular clusters associated with the lenticular galaxy NGC 524. Using the empirical calibration of Brodie & Huchra we find that our spectroscopic sample spans a metallicity range of…

Astrophysics · Physics 2009-11-10 Michael A. Beasley , Duncan A. Forbes , Jean P. Brodie , Markus Kissler-Patig

We present velocities for 230 stars in the outer parts of the globular cluster M15 measured with the Hydra multi-object spectrograph on the WIYN telescope. A new Bayesian technique is used for analyzing the data. The mean velocity of the…

We present preliminary results of 2dF spectroscopy of globular clusters in The Sombrero (M104). We find 56 new clusters, and compile a total sample of 103 velocities combined with previous data. Our 2dF data extend out to 20 arcmin radius…

Astrophysics · Physics 2009-11-07 Terry Bridges , Ken Freeman , Katherine Rhode , Steve Zepf

We present precision radial velocities and stellar population parameters for 77 star clusters in the Local Group galaxy M33. Our GTC and WHT observations sample both young, massive clusters and known/candidate globular clusters, spanning…

Astrophysics of Galaxies · Physics 2015-04-24 Michael A. Beasley , Izaskun San Roman , Carme Gallart , Ata Sarajedini , Antonio Aparicio

We report the discovery of a new, low luminosity star cluster in the outer halo of the Milky Way. High quality $gr$ photometry is presented, from which a color-magnitude diagram is constructed, and estimates of age, [Fe/H], [$\alpha$/Fe],…

Astrophysics of Galaxies · Physics 2015-06-23 Dongwon Kim , Helmut Jerjen , Antonino P. Milone , Dougal Mackey , Gary S. Da Costa

We establish a framework for determing absolute ages of Galactic globular clusters and then use these ages to investigate the age-metallicity and age-Galactocentric distance relations for the 36 clusters with the most reliable age data. The…

We examine the dynamics of the stars and globular clusters in the nearby giant galaxy M87 and constrain the mass distribution, using all the available data over a large range of radii, including higher-order moments of the stellar…

Astrophysics · Physics 2009-10-31 Aaron J. Romanowsky , Christopher S. Kochanek

Nine presently known "young" Galactic globular clusters, which have ages / 3 Gyr smaller than the oldest clusters of similar metallicity, all have RGC > 15 kpc. Furthermore these young globulars are found to have below-average luminosities.…

Astrophysics · Physics 2009-10-30 Sidney van den Bergh

Globular clusters in the outer halo (R_gc > 15 kpc) are found to be systematically fainter than those at smaller Galactocentric distances. Within the outer halo the compact clusters with half-light radii R_h < 10 pc are only found at R_gc <…

Astrophysics · Physics 2009-09-17 Sidney van den Bergh , Dougal Mackey

We present new VI photometry for the halo globular cluster M30 (NGC 7099), and compute luminosity functions (LFs) in both bands for samples of about 15,000 hydrogen-burning stars from near the tip of the red giant branch (RGB) to over four…

HIRES on the Keck I telescope has been used to measure the first radial velocities for stars belonging to eleven, heavily-reddened globular clusters in the direction of the inner Galaxy. The question of kinematic substructuring among the…

Astrophysics · Physics 2011-03-28 Patrick Cote

We present central velocity dispersions, masses, mass to light ratios ($M/L$s), and rotation strengths for 25 Galactic globular clusters. We derive radial velocities of 1951 stars in 12 globular clusters from single order spectra taken with…

Astrophysics of Galaxies · Physics 2015-06-23 Brian Kimmig , Anil Seth , Inese I. Ivans , Jay Strader , Nelson Caldwell , Tim Anderton , Dylan Gregersen

Using high-dispersion spectra from the HIRES echelle spectrograph on the Keck I telescope, we measure velocity dispersions for 4 globular clusters in M33. Combining the velocity dispersions with integrated photometry and structural…

Astrophysics · Physics 2009-11-07 S. S. Larsen , J. P. Brodie , A. Sarajedini , J. P. Huchra

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 [Fe/H] and [$\alpha$/Fe] abundances, derived using spectral synthesis techniques, for stars in M31's outer stellar halo. The 21 [Fe/H] measurements and 7 [$\alpha$/Fe] measurements are drawn from fields ranging from 43 to 165 kpc…

We present high resolution FLAMES/VLT spectroscopy of intracluster planetary nebula (ICPN) candidates, targeting three new fields in the Virgo cluster core with surface brightness down to mu_B = 28.5. Based on the projected phase space…

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