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An HST/ACS View of the Inhomogeneous Outer Halo of M31
(2009-03-19)
We present a high precision photometric view of the stellar populations in the outer halo of M31, using data taken with the Hubble Space Telescope Advanced Camera for Surveys (HST/ACS). We analyse the field populations ...
Strangers in the night: Discovery of a dwarf spheroidal galaxy on its first Local Group infall
(2007-06-20)
We present spectroscopic observations of the AndXII dwarf spheroidal galaxy using DEIMOS/Keck-II, showing it to be moving rapidly through the Local Group (-556 km/s heliocentric velocity, -281 km/s relative to Andromeda ...
Deep Gemini/GMOS imaging of an extremely isolated globular cluster in the Local Group
(2009-09-08)
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 ...
Further multiwavelength observations of the SSA22 Ly_alpha emitting `blob'
(2004-05)
We present new follow-up observations of the sub-mm luminous Ly_alpha-emitting object in the SSA22 z=3.09 galaxy overdensity, referred to as `Blob 1' by Steidel et al.(2000). In particular we discuss high resolution Hubble ...
The nucleus of the Sagittarius dSph galaxy and M54: a window on the process of galaxy nucleation
(2008-09-01)
We present the results of a thorough study of the nucleus of the Sgr dwarf spheroidal galaxy and of the bright globular cluster M54 that resides within the same nucleus (Sgr,N). We have obtained accurate radial velocities ...
Inside the whale: the structure and dynamics of the isolated Cetus dwarf spheroidal
(2007-02-05)
This paper presents a study of the Cetus dwarf, an isolated dwarf galaxy within the Local Group. A matched-filter analysis of the INT/WFC imaging of this system reveals no evidence for significant tidal debris that could ...
A kinematically selected, metal-poor stellar halo in the outskirts of M31
(2006-12-10)
We present evidence for a metal-poor, [Fe/H]$\sim-1.4$ $\sigma$=0.2 dex, stellar halo component detectable at radii from 10 kpc to 70 kpc, in our nearest giant spiral neighbor, the Andromeda galaxy. This metal-poor sample ...
The kinematic footprints of five stellar streams in Andromeda's halo
(2008-10)
(abridged) We present a spectroscopic analysis of five stellar streams (`A', `B', `Cr', `Cp' and `D') as well as the extended star cluster, EC4, which lies within streamC, all discovered in the halo of M31 from our ...
The Properties of Microjansky Radio Sources in the HDF-N, SSA13, and SSA22 Fields
(2003-03)
(abridged) We present multiwavelength observations for a large sample of microjansky radio sources detected in ultradeep 1.4GHz maps centered on the Hubble Deep Field-North (HDF-N) and the Hawaii Survey Fields SSA13 and ...
A spectroscopic survey of EC4, an Extended Cluster in Andromeda's halo
(2009-03-26)
We present a spectroscopic survey of candidate red giant branch stars in the extended star cluster, EC4, discovered in the halo of M31 from our CFHT/MegaCam survey, overlapping the tidal streams, Stream Cp and Stream Cr. ...