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Light curves of five type Ia supernovae at intermediate redshift
R. Amanullah, V. Stanishev, A. Goobar +14
We present multi-band light curves and distances for five type Ia supernovae at intermediate redshifts, 0.18<z<0.27. Three telescopes on the Canary Island of La Palma, INT, NOT and…
Strangers in the night: Discovery of a dwarf spheroidal galaxy on its first Local Group infall
S. C. Chapman, J. Penarrubia, R. Ibata +9
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 ve…
Galactic halo stellar structures in the Triangulum-Andromeda region
Nicolas F. Martin, Rodrigo A. Ibata, Mike Irwin
This letter reports on the Galactic stellar structures that appear in the foreground of our Canada-France-Hawaii-Telecopse/MegaCam survey of the halo of the Andromeda galaxy. We re…
ACS photometry of newly-discovered globular clusters in the outer halo of M31
A. D. Mackey, A. Huxor, A. M. N. Ferguson +6
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 t…
Draco, a flawless dwarf galaxy
Mathieu Segall, Rodrigo Ibata, Michael Irwin +2
The Draco dwarf spheroidal galaxy (dSph), with its apparent immense mass to light ratio and compact size, holds many clues to the nature of the enigmatic dark matter. Here we prese…
ACS photometry of extended, luminous globular clusters in the outskirts of M31
A. D. Mackey, A. Huxor, A. M. N. Ferguson +6
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 cluster…
The DART imaging and CaT survey of the Fornax Dwarf Spheroidal Galaxy
G. Battaglia, E. Tolstoy, A. Helmi +13
As part of the DART project we have used the ESO/2.2m Wide Field Imager in conjunction with the VLT/FLAMES GIRAFFE spectrograph to study the detailed properties of the resolved ste…
The VLT-FLAMES Survey of Massive Stars: Stellar parameters and rotational velocities in NGC3293, NGC4755 and NGC6611
P. L. Dufton, S. J. Smartt, J. K. Lee +8
An analysis is presented of VLT-FLAMES spectroscopy for three Galactic clusters, NGC3293, NGC4755 and NGC6611. Non-LTE model atmosphere calculations have been used to estimate effe…
The VLT-FLAMES Survey of Massive Stars: Observations in the Galactic Clusters NGC 3293, NGC 4755 and NGC 6611
C. J. Evans, S. J. Smartt, J. -K. Lee +23
We introduce a new survey of massive stars in the Galaxy and the Magellanic Clouds using the Fibre Large Array Multi-Element Spectrograph (FLAMES) instrument at the Very Large Tele…
On the accretion origin of a vast extended stellar disk around the Andromeda galaxy
R. Ibata, S. Chapman, A. M. N. Ferguson +3
We present the discovery of an inhomogenous, low-surface brightness, extended disk-like structure around the Andromeda galaxy (M31) based on a large kinematic survey of more than 2…
Stellar Chemical Signatures And Hierarchical Galaxy Formation
K. A. Venn, M. Irwin, M. D. Shetrone +3
ABRIDGED: To compare the chemistries of stars in the Milky Way dSph galaxies with stars in the Galaxy, we have compiled a large sample of Galactic stellar abundances from the liter…
The tidal trail of NGC205?
A. McConnachie, M. Irwin, G. Lewis +4
Using data taken as part of the Isaac Newton Telescope Wide Field Camera (INT WFC) survey of M31, we have identified an arc-like overdensity of blue, presumably metal-poor, red gia…
One Ring to Encompass them All: A giant stellar structure that surrounds the Galaxy
R. A. Ibata, M. J. Irwin, G. F. Lewis +2
We present evidence that the curious stellar population found by the Sloan Digital Sky Survey in the Galactic anticentre direction extends to other distant fields that skirt the pl…
Evidence for Stellar Substructure in the Halo and Outer Disk of M31
Annette Ferguson, Mike Irwin, Rodrigo Ibata +2
We report the discovery of significant stellar substructure in the halo and outer disk of our nearest large galactic neighbour, M31. Our deep panoramic survey with the Isaac Newton…
A giant stream of metal-rich stars in the halo of the galaxy M31
Rodrigo Ibata, Michael Irwin, Geraint Lewis +2
Recent observations have revealed streams of gas and stars in the halo of the Milky Way that are the debris from interactions between our Galaxy and some of its dwarf companion gal…
Absorption Systems in the Spectra of 66 z > 4 Quasars
Celine Peroux, Lisa J. Storrie-Lombardi, Richard G. McMahon +2
We present high signal-to-noise, 5 A resolution (FWHM) spectra of 66 z \ga 4 bright quasars obtained with the 4 m Cerro Tololo Inter-American Observatory and 4.2 m William Hershel…
Galactic Halo substructure in the Sloan Digital Sky Survey: the ancient tidal stream from the Sagittarius dwarf galaxy
Rodrigo Ibata, Michael Irwin, Geraint Lewis +1
Two studies have recently reported the discovery of pronounced Halo substructure in the Sloan Digital Sky Survey (SDSS) commissioning data. Here we show that this Halo substructure…
Great Circle tidal streams: evidence for a nearly spherical massive dark halo around the Milky Way
Rodrigo Ibata, Geraint F. Lewis, Michael Irwin +2
An all high-latitude sky survey for cool carbon giant stars in the Galactic halo has revealed 75 such stars, of which the majority are new detections. Of these, more than half are…
Magellanic Cloud Periphery Carbon Stars IV: The SMC
William Kunkel, Serge Demers, M. J. Irwin
The kinematics of 150 carbon stars observed at moderate dispersion on the periphery of the Small Magellanic Cloud are compared with the motions of neutral hydrogen and early type s…
Discovery of high proper motion ancient white dwarfs: nearby massive compact halo objects?
Rodrigo Ibata, Michael Irwin, Olivier Bienayme +2
We present the discovery and spectroscopic identification of two very high proper motion ancient white dwarf stars, found in a systematic proper motion survey. Their kinematics and…
Measurements of the Cosmological Parameters Omega and Lambda from the First 7 Supernovae at z >= 0.35
S. Perlmutter, S. Gabi, G. Goldhaber +21
We have developed a technique to systematically discover and study high-redshift supernovae that can be used to measure the cosmological parameters. We report here results based on…