相关论文: The Gaseous Trail of the Sagittarius Dwarf Galaxy
The possibility of a gaseous halo stream which was stripped from the Sagittarius dwarf galaxy is presented. The total mass of the neutral hydrogen along the orbit of the Sgr dwarf in the direction of the Galactic anticenter is 4-10 x 10^6…
We present a comparison of semi-analytic models of the phase-space structure of tidal debris with observations of stars associated with the Sagittarius dwarf galaxy (Sgr). We find that many features in the data can be explained by these…
The remarkable 1994 discovery of the Sagittarius dwarf galaxy (Sgr) revealed that, together with the Magellanic Clouds (MCs), there are at least three major dwarf galaxies, each with a total mass of order 10^10 - 10^11 solar masses, falling…
We use the astrometric and photometric data from Gaia Data Release 2 and line-of-sight velocities from various other surveys to study the 3d structure and kinematics of the Sagittarius dwarf galaxy. The combination of photometric and…
Recently, radial velocities have been measured for a large sample of M giants from the 2MASS catalog, selected to be part of the Sgr dwarf leading and trailing streams. Here we present a comparison of their kinematics to models of the Sgr…
What is the mass of the progenitor of the Sagittarius (Sgr) dwarf galaxy? Here, we reassemble the stellar debris using SDSS and 2MASS data to find the total luminosity and likely mass. We find that the luminosity is in the range 9.6-13.2…
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…
The main characteristics of a wide photometric survey of the Sgr dwarf spheroidal galaxy are shortly presented. V and I photometry has been obtained for ~ 90000 stars toward Sgr and for ~ 9000 stars in a region devoid of Sgr stars (for…
A new overdensity of A-colored stars in distant parts of the Milky Way's stellar halo, at a dereddened SDSS magnitude of g_0 = 20.3, is presented. Identification of associated variable RR Lyrae candidates supports the claim that these are…
We report on a 60 degree-long stream of stars, extending from Ursa Major to Sextans, in the Sloan Digital Sky Survey. The stream is approximately 2 degrees wide and is clearly distinct from the northern tidal arm of the Sagittarius dwarf…
We use N-body simulations to explore the possibility that the Sagittarius (Sgr) dwarf galaxy was originally a late-type, rotating disc galaxy, rather than a non-rotating, pressure-supported dwarf spheroidal galaxy, as previously thought. We…
The Sagittarius galaxy (Sgr), the closest satellite galaxy of the Milky Way, has survived for many orbits about the Galaxy. Extant numerical calculations modeled this galaxy as a system with a centrally-concentrated mass profile, following…
M giants recovered from the Two Micron All-Sky Survey (2MASS) have recently been used to map the position and velocity distributions of tidal debris from the Sagittarius (Sgr) dwarf spheroidal galaxy entirely around the Galaxy. We compare…
We present a new N-body model for the tidal disruption of the Sagittarius (Sgr) dwarf that is capable of simultaneously satisfying the majority of angular position, distance, and radial velocity constraints imposed by current wide-field…
Possible orbital histories of the Sgr dwarf galaxy are explored. A special-purpose N-body code is used to construct the first models of the Milky Way - Sgr Dwarf system in which both the Milky Way and the Sgr Dwarf are represented by full…
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…
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…
Numerical simulations of dwarf spheroidal galaxies undergoing several close encounters with the Milky Way are described. By comparing our models to observed properties of the recently discovered dwarf galaxy in Sagittarius (Sgr), we discuss…
We present the first all-sky view of the Sagittarius (Sgr) dwarf galaxy mapped by M giant star tracers detected in the complete Two Micron All-Sky Survey (2MASS). The main body is fit with a King profile of 30 deg limiting radius, but with…
We have discovered a new Galactic satellite galaxy in the constellation of Sagittarius. The Sagittarius dwarf galaxy is the nearest galaxy known, subtends an angle of $> 10$ degrees on the sky, lies at a distance of $24 \kpc$ from the Sun,…