Browsing by Author "Irwin, M."

Now showing items 1-8 of 8

  • The Haunted Halos of Andromeda and Triangulum: A panorama of galaxy formation in action 

    Ibata, R.; Martin, N. F.; Irwin, M.; Chapman, S.; Ferguson, A. M. N.; Lewis, G. F.; McConnachie, A. W. (2007-12-20)
    We present a deep photometric survey of M31, conducted with the CFHT and INT, covering the inner 50 kpc of the galaxy, the Southern quadrant out to 150 kpc, and extending to M33. This is the first systematic panoramic study ...

  • The kinematic footprints of five stellar streams in Andromeda's halo 

    Chapman, S. C.; Ibata, R.; Irwin, M.; Koch, A.; Letarte, B.; Martin, N.; Collins, M.; Lewis, G. F.; McConnachie, A.; Penarrubia, J.; Rich, R. M.; Trethewey, D.; Ferguson, A. M. N.; Huxor, A.; Tanvir, N. (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 ...

  • A kinematically selected, metal-poor stellar halo in the outskirts of M31 

    Chapman, S. C.; Ibata, R.; Lewis, G. F.; Ferguson, A. M. N.; Irwin, M.; McConnachie, A.; Tanvir, N. (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 ...

  • On the accretion origin of a vast extended stellar disk around the Andromeda galaxy 

    Ibata, R.; Chapman, S.; Ferguson, A. M. N.; Lewis, G.; Irwin, M.; Tanvir, N. (2005-11-20)
    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 2800 stars with the Keck/DEIMOS spectrograph. ...

  • A spectroscopic survey of EC4, an Extended Cluster in Andromeda's halo 

    Collins, M. L. M.; Chapman, S. C.; Irwin, M.; Ibata, R.; Martin, N. F.; Ferguson, A. M. N.; Huxor, A.; Lewis, G. F.; Mackey, A. D.; McConnachie, A. W.; Tanvir, N. (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. ...

  • Strangers in the night: Discovery of a dwarf spheroidal galaxy on its first Local Group infall 

    Chapman, S. C.; Penarrubia, J.; Ibata, R.; McConnachie, A.; Martin, N.; Irwin, M.; Blain, A.; Lewis, G. F.; Letarte, B.; Lo, K.; Ludlow, A.; O'neil, K. (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 ...

  • Taking measure of the Andromeda halo: a kinematic analysis of the giant stream surrounding M31 

    Ibata, R.; Chapman, S.; Ferguson, A. M. N.; Irwin, M.; Lewis, G.; McConnachie, A. (2004-06)
    We present a spectroscopic survey of the giant stellar stream found in the halo of the Andromeda galaxy. Taken with the DEIMOS multi-object spectrograph on the Keck2 telescope, these data display a narrow velocity dispersion ...

  • The tidal trail of NGC205? 

    McConnachie, A.; Irwin, M.; Lewis, G.; Ibata, R.; Chapman, S.; Ferguson, A.; Tanvir, N. (2004-07)
    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 giant branch stars in the north-west quadrant ...