相关论文: Density Variations in the NW Star Stream of M31

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,…

We present wide and deep photometry of the northwest part of the halo of the Andromeda galaxy (M31) using Hyper Suprime-Cam on the Subaru Telescope. The survey covers 9.2 deg$^{2}$ field in the $g$, $i$, and $NB515$ bands and shows a clear…

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 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 Telescope Wide Field Camera currently maps out an area of…

We present the first results from our survey of stellar substructure in the outskirts of M31 using the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope. We discuss the stellar populations associated with five prominent…

This paper is the first in a series which studies interactions between M31 and its satellites, including the origin of the giant southern stream. We construct accurate yet simple analytic models for the potential of the M31 galaxy to…

We analyse the M31 halo and its substructure within a projected radius of 120 kpc using a combination of Subaru/HSC $\textit{NB515}$ and CFHT/MegaCam $\textit{g}$- \& $\textit{i}$-bands. We succeed in separating M31's halo stars from…

We examine the nature of the progenitor of the giant stellar stream in M31 using as constraints new radial velocity measurements of stream red giant stars (presented in the companion paper by Guhathakurta et al. 2005, astro-ph/0406145)…

We present results from a large spectroscopic survey of M31 red giants using the Keck telescope/DEIMOS. Photometric pre-screening, based on the 100A-wide DDO51 band centered on the Mgb/MgH feature, was used to select spectroscopic targets.…

We present the first measurements of [Fe/H] and [$\alpha$/Fe] abundances, obtained using spectral synthesis modeling, for red giant branch stars in M31's giant stellar stream. The spectroscopic observations, obtained at a projected distance…

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…

GD-1 is a long, thin, Milky Way star stream that has readily visible density variations along its length. We quantify the locations, sizes and statistical significance of the density structure, i.e. gaps, using a set of scaled filters. The…

We present a renewed look at M31's Giant Stellar Stream along with the nearby structures Stream C and Stream D, exploiting a new algorithm capable of fitting to the red giant branch (RGB) of a structure in both colour and magnitude space.…

We present a kinematic and spectroscopic analysis of 40 red giant branch stars, in 9 fields, exquisitely delineating the lower segment of the North West Stream (NW-K2), which extends for $\sim$80 kpc from the centre of the Andromeda galaxy.…

The GD-1 star stream is currently the best available for identifying density fluctuations, "gaps", along its length as a test of the LCDM prediction of large numbers of dark matter sub-halos orbiting in the halo. Density variations of some…

We present the velocity dispersion of red giant branch (RGB) stars in M31's halo, derived by modeling the line of sight velocity distribution of over 5000 stars in 50 fields spread throughout M31's stellar halo. The dataset was obtained as…

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…

Measurements of velocity and density perturbations along stellar streams in the Milky Way provide a time integrated measure of dark matter substructure at larger galactic radius than the complementary instantaneous inner halo strong lensing…

We present results of our dynamical stream modelling for the North West Stream in the outer halo of the Andromeda galaxy (M31). Comprising two main segments, the North West Stream was thought to be a single structured arching around M31.…

The wide-field CCD camera at the CFH telescope was used to survey the giant stellar stream in the Andromeda galaxy, resolving stars down the red giant branch in M31 to I ~ 25, a magnitude deeper than our previous INT survey of this galaxy…