相关论文: A spectroscopic survey of Andromeda's Western Shel…

The giant southern stream (GSS) is the most prominent tidal debris feature in M31's stellar halo. The GSS is composed of a relatively metal-rich, high surface-brightness "core" and a lower metallicity, lower surface brightness "envelope."…

We focus on the evidence of a past minor merger discovered in the halo of the Andromeda galaxy (M31). Previous N-body studies have enjoyed moderate success in producing the observed giant stellar stream (GSS) and stellar shells in M31's…

Tidal streams and stellar shells are naturally formed in galaxy interactions and mergers. The Giant Stellar Stream (GSS), the North-East (NE), and Western (W) stellar shelves observed in Andromeda galaxy (M31) are examples of these…

Published maps of red giant stars in the halo region of M31 exhibit a giant stellar stream to the south of this galaxy, as well as a giant "shelf" to the northeast of M31's center. Using these maps, we find that there is a fainter shelf of…

The Giant Stellar Stream (GSS) is a prominent tidal feature in the halo of the Andromeda Galaxy (M31), representing the ongoing destruction of a satellite galaxy. In this paper, we investigate the formation of the GSS through detailed…

We obtained Keck/DEIMOS spectra of 556 individual red giant branch stars in 4 spectroscopic fields spanning $13-31$ projected kpc along the Northeast (NE) shelf of M31. We present the first detection of a complete wedge pattern in the space…

M31 has a giant stream of stars extending far to the south and a great deal of other tidal debris in its halo, much of which is thought to be directly associated with the southern stream. We model this structure by means of Bayesian…

We examine the nature, possible orbits and physical properties of the progenitor of the North-western stellar stream (NWS) in the halo of the Andromeda galaxy (M31). The progenitor is assumed to be an accreting dwarf galaxy with globular…

The halo region of M31 exhibits a startling level of stellar inhomogeneities, the most prominent of which is the "giant southern stream". Our previous analysis indicates that this stream, as well as several other observed features, are…

As part of the Z-PAndAS Keck II DEIMOS survey of resolved stars in our neighboring galaxy, Andromeda (M31), we have built up a unique data set of measured velocities and chemistries for thousands of stars in the Andromeda stellar halo,…

Detailed studies of stellar populations in the halos of the Milky Way and the Andromeda (M 31) galaxies have shown increasing numbers of tidal streams and dwarf galaxies, attesting to a complicated and on-going process of hierarchical…

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 of 11+/-3 km/s,…

Extensive photometric and spectroscopic surveys of the Andromeda galaxy (M31) have discovered tidal debris features throughout M31's stellar halo. We present stellar kinematics and metallicities in fields with identified substructure from…

We investigate a minor merger event in M31 that simultaneously forms the Andromeda Giant Southern Stream (AGSS), Eastern Extent (EE), North-Eastern Shelf (NES), and Western Shel (WS), offering a unified model for these substructures. By…

We present spectroscopic observations of red giant branch (RGB) stars in the Andromeda spiral galaxy (M31), acquired with the DEIMOS instrument on the Keck II 10-m telescope. The three fields targeted in this study are in the M31 spheroid,…

We present the discovery of a kinematically-cold stellar population along the SE minor axis of the Andromeda galaxy (M31) that is likely the forward continuation of M31's giant southern stream. This discovery was made in the course of an…

The nearest giant spiral, M31, exhibits a kinematically hot stellar disc, a global star formation episode ~2-4 Gyr ago, and conspicuous substructures in its stellar halo that are suggestive of a recent accretion event. Recent chemodynamical…

The combination of large size, high stellar density, high metallicity, and Sersic surface brightness profile of the spheroidal component of the Andromeda galaxy (M31) within R_proj ~ 20 kpc suggest that it is unlike any subcomponent of the…

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 underlies the…

Tidal streams from existing and destroyed satellite galaxies populate the outer regions of the Andromeda galaxy (M31). This inhomogeneous debris can be studied without many of the obstacles that plague Milky Way research. We review the…