Alan W. McConnachie

The remnants of galaxy formation from a panoramic survey of the region around M31 (2009)

McConnachie, Alan W., Irwin, Michael J., Ibata, Rodrigo A., Dubinski, John, Widrow, Lawrence M., Martin, Nicolas F., ...

In hierarchical cosmological models, galaxies grow in mass through the continual accretion of smaller ones. The tidal disruption of these systems is expected to result in loosely bound stars...

PAndAS' cubs: discovery of two new dwarf galaxies in the surroundings of the Andromeda and Triangulum galaxies (2009)

Martin, Nicolas F., McConnachie, Alan W., Irwin, Mike, Widrow, Lawrence M., Ferguson, Annette M. N., Ibata, Rodrigo A., ...

We present the discovery of two new dwarf galaxies, Andromeda XXI and Andromeda XXII, located in the surroundings of the Andromeda and Triangulum galaxies (M31 and M33). These discoveries stem from...

Stellar Metallicities and Kinematics in a Gas-Rich Dwarf Galaxy: First Calcium Triplet Spectroscopy of RGB Stars in WLM (2009)

Leaman, Ryan, Cole, Andrew A., Venn, Kim A., Tolstoy, Eline, Irwin, Mike J., Szeifert, Thomas, ...

We present the first determination of the radial velocities and metallicities of 78 red giant stars in the isolated dwarf irregular galaxy WLM. Observations of the calcium II triplet in these stars...

The mass-metallicity relation in galaxy clusters: the relative importance of cluster membership versus local environment (2009)

Ellison, Sara L., Simard, Luc, Cowan, Nicolas B., Baldry, Ivan K., Patton, David R., McConnachie, Alan W.

Using a large (14,857), homogenously selected sample of cluster galaxies identified in the Sloan Digital Sky Survey Data Release 4 (SDSS DR4), we investigate the impact of cluster membership and...

The Signature of Galactic Tides in Local Group Dwarf Spheroidals (2008)

Penarrubia, Jorge, Navarro, Julio F., McConnachie, Alan W., Martin, Nicolas F.

(Abridged) We use N-body simulations to explore the effects of tidal stripping on the structure of dwarf spheroidal galaxies (dSphs). We model dSphs as King spheres embedded in NFW dark halos that...

Compact groups in theory and practice - II. Comparing the observed and predicted nature of galaxies in compact groups (2008)

Brasseur, Crystal M., McConnachie, Alan W., Ellison, Sara L., Patton, David R.

We examine the properties of galaxies in compact groups identified in a mock galaxy catalogue based upon the Millennium Run simulation. The overall properties of groups identified in projection are...

Compact groups in theory and practice - I. The spatial properties of compact groups (2008)

McConnachie, Alan W., Ellison, Sara L., Patton, David R.

We use a mock galaxy catalogue based upon the Millennium Run simulation to investigate the intrinsic spatial properties of compact groups of galaxies. We find that approximately 30% of galaxy...

Galaxy Pairs in the Sloan Digital Sky Survey I: Star Formation, AGN Fraction, and the Luminosity/Mass-Metallicity Relation (2008)

Ellison, Sara L., Patton, David R., Simard, Luc, McConnachie, Alan W.

(Abridged). We present a sample of 1716 galaxies with companions within Delta v < 500 km/s, r_p < 80 kpc and stellar mass ratio 0.1 < M_1/M_2 < 10 from the Sloan Digital Sky Survey (SDSS) Data...

A trio of new local group galaxies with extreme properties (2008)

McConnachie, Alan W., Huxor, Avon, Martin, Nicolas F., Irwin, Mike J., Chapman, Scott C., Fahlman, Gregory, ...

We report on the discovery of three new dwarf galaxies in the Local Group. These galaxies are found in new CFHT/MegaPrime g,i imaging of the southwestern quadrant of M31, extending our extant survey...

Clues to the Origin of the Mass-Metallicity Relation: Dependence on Star Formation Rate and Galaxy Size (2007)

Ellison, Sara L., Patton, David R., Simard, Luc, McConnachie, Alan W.

We use a sample of 43,690 galaxies selected from the Sloan Digital Sky Survey Data Release 4 to study the systematic effects of specific star formation rate (SSFR) and galaxy size (as measured by the...

Ram pressure stripping of an isolated Local Group dwarf galaxy: evidence for an intra-group medium (2007)

McConnachie, Alan W., Venn, Kim A., Irwin, Mike J., Young, Lisa M., Geehan, Jonathan J.

We compare the stellar structure of the isolated, Local Group dwarf galaxy Pegasus (DDO216) with low resolution HI maps from Young et al. (2003). Our comparison reveals that Pegasus displays the...

The Tidal Evolution of Local Group Dwarf Spheroidals (2007)

Penarrubia, Jorge, Navarro, Julio F., McConnachie, Alan W.

(Abridged) We use N-body simulations to study the evolution of dwarf spheroidal galaxies (dSphs) driven by galactic tides. We adopt a cosmologically-motivated model where dSphs are approximated by a...

The stellar content of the isolated transition dwarf galaxy DDO210 (2006)

McConnachie, Alan W., Arimoto, Nobuo, Irwin, Mike, Tolstoy, Eline

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 properties intermediate...

Multiple dynamical components in Local Group dwarf spheroidals (2006)

McConnachie, Alan W., Penarrubia, Jorge, Navarro, Julio F.

The dwarf spheroidal (dSph) satellites of the Local Group have long been thought to be simple spheroids of stars embedded within extended dark matter halos. Recently, however, evidence for the...

The stellar halo and outer disk of M33 (2006)

McConnachie, Alan W., Chapman, Scott C., Ibata, Rodrigo A., Ferguson, Annette M. N., Irwin, Mike J., Lewis, Geraint F., ...

We present first results from a Keck/DEIMOS spectroscopic survey of red giant branch (RGB) stars in M33. The radial velocity distributions of the stars in our fields are well described by three...