778 citations · 11.7k across the 152 of their papers we have counts for
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The mass content of the Sculptor dwarf spheroidal galaxy
G. Battaglia, A. Helmi, E. Tolstoy +1
We present a new determination of the mass content of the Sculptor dwarf spheroidal galaxy, based on a novel approach which takes into account the two distinct stellar populations…
The ACS LCID Project: RR Lyrae stars as tracers of old population gradients in the isolated dwarf spheroidal galaxy Tucana
Edouard J. Bernard, Carme Gallart, Matteo Monelli +9
We present a study of the radial distribution of RR Lyrae variables, which present a range of photometric and pulsational properties, in the dwarf spheroidal galaxy Tucana. We find…
The kinematic status and mass content of the Sculptor dwarf spheroidal galaxy
G. Battaglia, A. Helmi, E. Tolstoy +3
We present VLT/FLAMES spectroscopic observations (R~6500) in the CaII triplet region for 470 probable kinematic members of the Sculptor (Scl) dwarf spheroidal galaxy. The accurate…
Analysis and calibration of CaII triplet spectroscopy of Red Giant Branch stars from VLT/FLAMES observations
G. Battaglia, M. Irwin, E. Tolstoy +4
We demonstrate that low resolution CaII triplet (CaT) spectroscopic estimates of the overall metallicity ([Fe/H]) of individual Red Giant Branch (RGB) stars in two nearby dwarf sph…
Blue straggler stars in dwarf spheroidal galaxies
M. Mapelli, E. Ripamonti, E. Tolstoy +3
Blue straggler star (BSS) candidates have been observed in all old dwarf spheroidal galaxies (dSphs), however whether or not they are authentic BSSs or young stars has been a point…
Leo A: A Late-Blooming Survivor of the Epoch of Reionization in the Local Group
A. A. Cole, E. D. Skillman, E. Tolstoy +8
As part of a major program to use isolated Local Group dwarf galaxies as near-field probes of cosmology, we have obtained deep images of the dwarf irregular galaxy Leo A with the A…
Short-Period Variables in the Local Group Dwarf Galaxies Tucana and LGS3
E. J. Bernard, M. Monelli, C. Gallart +16
We present preliminary results concerning the search for short-period variable stars in Tucana and LGS3 based on very deep HST/ACS imaging. In the fraction of the observed field we…
Inside the whale: the structure and dynamics of the isolated Cetus dwarf spheroidal
G. F. Lewis, R. A. Ibata, S. C. Chapman +4
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…
Numerical simulations of the metallicity distribution in dwarf spheroidal galaxies
E. Ripamonti, E. Tolstoy, A. Helmi +2
Recent observations show that the number of stars with very low metallicities in the dwarf spheroidal satellites of the Milky Way is low, despite the low average metallicities of s…
A new view of the dwarf spheroidal satellites of the Milky Way from VLT/FLAMES: Where are the very metal poor stars?
Amina Helmi, M. J. Irwin, E. Tolstoy +13
As part of the Dwarf galaxies Abundances and Radial-velocities Team (DART) program, we have measured the metallicities of a large sample of stars in four nearby dwarf spheroidal ga…
The stellar content of the isolated transition dwarf galaxy DDO210
Alan W. McConnachie, Nobuo Arimoto, Mike Irwin +1
We use Subaru Suprime-Cam and VLT FORS1 photometry of the dwarf galaxy DDO210 to study the global stellar content and structural properties of a transition-type galaxy (with proper…
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…
Resolved Stellar Populations at the Distance of Virgo
Eline Tolstoy
Top of the wish list of any astronomer who wants to understand galaxy formation and evolution is to resolve the stellar populations of a sample of giant elliptical galaxies: to tak…
VLT/UVES Spectroscopy of Individual Stars in Three Globular Clusters in the Fornax Dwarf Spheroidal Galaxy
Bruno Letarte, Vanessa Hill, Pascale Jablonka +3
We present a high resolution (R ~ 43000) abundance analysis of a total of nine stars in three of the five globular clusters associated with the nearby Fornax dwarf spheroidal galax…
The Chemical Composition of Local Group Dwarf Spheroidals
Eline Tolstoy
I will review the progress of VLT spectroscopy of large numbers of individual stars in nearby dwarf spheroidal galaxies. This spectroscopy has allowed us to obtain detailed insight…
Spectroscopy of Red Giants in the LMC Bar: Abundances, Kinematics, and the Age-Metallicity Relation
Andrew A. Cole, E. Tolstoy, J. S. Gallagher +1
We report metallicities and radial velocities derived from spectra at the near-infrared calcium triplet for 373 red giants in a 200 square arcminute area at the optical center of t…
Abundances as Tracers of the Formation and Evolution of (Dwarf) Galaxies
Eline Tolstoy
This aims to be an overview of what detailed observations of individual stars in nearby dwarf galaxies may teach us about galaxy evolution. This includes some early results from th…
Two distinct ancient components in the Sculptor Dwarf Spheroidal Galaxy: First Results from DART
Eline Tolstoy, M. J. Irwin, A. Helmi +14
We have found evidence for the presence of two distinct ancient stellar components (both geq 10 Gyr old) in the Sculptor dwarf spheroidal galaxy. We used the ESO Wide Field Imager…
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…
First Stellar Abundances in the Dwarf Irregular Galaxy Sextans A
Andreas Kaufer, Kim A. Venn, Eline Tolstoy +2
We present the abundance analyses of three isolated A-type supergiant stars in the dwarf irregular galaxy Sextans A from high-resolution spectra the UVES spectrograph at the VLT. D…
The Effects of Age on Red Giant Metallicities Derived from the Near-Infrared Ca II Triplet
A. A. Cole, T. A. Smecker-Hane, E. Tolstoy +2
We have obtained spectra with resolution 2.5 Angstroms in the region 7500-9500 Angstroms for 116 red giants in 5 Galactic globular clusters and 6 old open clusters (5 with publishe…
Anomalous Evolution of the Dwarf Galaxy HIPASS J1321-31
Barton J. Pritzl, Patricia M. Knezek, John S. Gallagher +6
We present HST/WFPC2 observations of the dwarf galaxy HIPASS J1321-31. This unusual galaxy lies in the direction of the Centaurus A group of galaxies, and has a color-magnitude dia…
Deep Hubble Space Telescope Imaging of IC 1613 II. The Star Formation History
Evan D. Skillman, Eline Tolstoy, Andrew A. Cole +5
We present deep HST WFPC2 imaging of the Local Group dwarf irregular galaxy IC 1613. The photometry is the deepest to date for an isolated dwarf irregular galaxy. The resulting col…
The Chemical Composition of Two Supergiants in the Dwarf Irregular Galaxy WLM
K. A. Venn, E. Tolstoy, A. Kaufer +5
[Abridged] The chemical composition of two stars in WLM has been determined from high quality UVES data obtained at the VLT UT2 (program 65.N-0375). The model atmospheres analysis…