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相关论文: Selecting Sagittarius: Identification and Chemical…

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The tidal disruption of the Sagittarius dwarf galaxy has generated a spectacular stream of stars wrapping around the entire Galaxy. We use data from $Gaia$ and the H3 Stellar Spectroscopic Survey to identify 823 high-quality Sagittarius…

We develop statistical methods for identifying star streams in the halo of the Milky Way galaxy that exploit observed spatial and radial velocity distributions. Within a great circle, departures of the observed spatial distribution from…

星系天体物理 · 物理学 2015-06-03 Charles King , Warren R. Brown , Margaret J. Geller , Scott J. Kenyon

Recent analyses of the stellar stream of the Sagittarius dwarf galaxy have claimed that the kinematics and three-dimensional location of the M-giant stars in this structure constrain the dark matter halo of our Galaxy to possess a triaxial…

星系天体物理 · 物理学 2015-06-12 Rodrigo Ibata , Geraint F. Lewis , Nicolas F. Martin , Michele Bellazzini , Matteo Correnti

We use Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) u,g,r,i,z photometry to study Milky Way halo substructure in the area around the North Galactic Cap. A simple color cut (g-r < 0.4) reveals the tidal stream of the Sagittarius…

The main aim of this paper is to report two new detections of tidal debris in the northern stream of the Sagittarius dwarf galaxy located at 45 arcdeg and 55 arcdeg from the center of galaxy. Our observational approach is based on deep…

天体物理学 · 物理学 2009-11-10 D. Martinez-Delgado , M. A. Gomez-Flechoso , A. Aparicio , R. Carrera

Observations of the lengthy tidal streams produced by the destruction of the Sagittarius dwarf spheroidal (Sgr dSph) are capable of providing strong constraints on the shape of the Galactic gravitational potential. However, previous work,…

星系天体物理 · 物理学 2015-05-14 David R. Law , Steven R. Majewski , Kathryn V. Johnston

We present observations obtained with the AAT's 2dF wide field spectrograph AAOmega of K-type stars located within a region of the sky which contains the Virgo Over-Density and the leading arm of the Sagittarius Stream. On the basis of the…

太阳与恒星天体物理 · 物理学 2015-06-04 A. R. Casey , S. C. Keller , G. Da Costa

The Sagittarius (Sgr) dwarf spheroidal galaxy is one of the most prominent satellites of the Milky Way (MW). It is currently undergoing tidal disruption, forming an extensive stellar stream that provides key insights into the assembly…

It has been recently claimed that the confined structure of the debris from the Sagittarius dwarf implies that the dark-matter halo of our Galaxy should be nearly spherical, in strong contrast with predictions from cold dark-matter (CDM)…

天体物理学 · 物理学 2009-11-10 Amina Helmi

The stellar stream connected to the Sagittarius (Sgr) dwarf galaxy is the most massive tidal stream that has been mapped in the Galaxy, and is the dominant contributor to the outer stellar halo of the Milky Way. We present metallicity maps…

We present a mass model for the Milky Way, which is fit to observations of the Sagittarius stream together with constraints derived from a wide range of photometric and kinematic data. The model comprises a S\'{e}rsic bulge, an exponential…

星系天体物理 · 物理学 2015-06-11 N. Deg , Lawrence Widrow

We analyze self-consistent N-body simulations of the Milky Way disk and the ongoing disruption of the Sagittarius dwarf satellite to study the effect of Sagittarius tidal debris on dark matter detection experiments. In agreement with…

星系天体物理 · 物理学 2012-08-24 Chris W. Purcell , Andrew R. Zentner , Mei-Yu Wang

This paper uses Gaussian mixture techniques to dissect the Milky Way (MW) stellar halo in angular momentum space. Application to a catalogue of 5389 stars near the plane of the Sagittarius (Sgr) stream with full 6D phase-space coordinates…

星系天体物理 · 物理学 2021-08-25 Jorge Peñarrubia , Michael S. Petersen

Recent maps of the halo using RR Lyrae from Pan-STARRS1 have clearly depicted the spatial structure of the Sagittarius stream. These maps show the leading and trailing stream apocenters differ in galactocentric radius by a factor of two,…

We propose a new model for the dark matter halo of the Milky Way that fits the properties of the stellar stream associated with the Sagittarius dwarf galaxy. Our dark halo is oblate with q_z = 0.9 for r < 10 kpc, and can be made to follow…

星系天体物理 · 物理学 2015-06-15 Carlos Vera-Ciro , Amina Helmi

The extensive span of the Sagittarius (Sgr) stream makes it a promising tool for studying the Milky Way gravitational potential. Characterizing its stellar kinematics can constrain halo properties and provide a benchmark for the Cold Dark…

星系天体物理 · 物理学 2017-03-08 Marion Dierickx , Abraham Loeb

Tidal streams of the Sagittarius dwarf spheroidal galaxy (Sgr) may be showering dark matter onto the solar system and contributing approx (0.3--23)% of the local density of our Galactic Halo. If the Sagittarius galaxy contains WIMP dark…

天体物理学 · 物理学 2009-11-10 Katherine Freese , Paolo Gondolo , Heidi Jo Newberg

Two studies have recently reported the discovery of pronounced Halo substructure in the Sloan Digital Sky Survey (SDSS) commissioning data. Here we show that this Halo substructure is almost in its entirety due to the expected tidal stream…

天体物理学 · 物理学 2009-05-29 Rodrigo Ibata , Michael Irwin , Geraint Lewis , Andrea Stolte

Standard cosmology predicts that dwarfs were the first galaxies to be formed in the Universe and that many of them merge afterwards to form bigger galaxies such as the Milky Way. This process would have left behind traces such as tidal…

天体物理学 · 物理学 2007-05-23 D. Martinez-Delgado , M. A. Gomez-Flechoso , A. Aparicio

The structure of the Sagittarius stream in the Southern Galactic hemisphere is analysed with the Sloan Digital Sky Survey Data Release 8. Parallel to the Sagittarius tidal track, but ~ 10deg away, there is another fainter and more…

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