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相关论文: Something about the structure of the Galaxy

200 篇论文

The evolution history of the Milky Way disk is imprinted in the ages, positions, and chemical compositions of individual stars. In this study, we derive the intrinsic density distribution of different stellar populations using the final…

The Triangulum Spiral Galaxy Messier 33 offers unique insights into the building of a galactic disk. We identify spectacular arcs of intermediate age (0.6 Gyr - 2 Gyr) stars in the low-metallicity outer disk. The northern arc spans approx.…

The Milky Way is a spiral galaxy comprising three main components: the Bulge, the Disk, and the Halo. Of particular interest is the Galactic disk, which holds a significant portion of the baryonic matter angular momentum and harbors at…

星系天体物理 · 物理学 2024-02-13 Maria Rah , Manolya Yatman , Ali Taani , Ahmad A. Abushattal , Mohammad K. Mardini

Based on VLT/FORS spectroscopy and HST/ACS imaging, we have constructed a sample of ~200 field spiral galaxies that cover redshifts up to z~1. Such a large data set allows to study the evolution of fundamental galaxy parameters like…

天体物理学 · 物理学 2007-05-23 Asmus Boehm , Bodo L. Ziegler

We attempt to study the characteristics of the different stellar populations present in the Galactic central region. A Monte Carlo method is used to simultaneously fit 11 thin disc and triaxial outer bulge density parameters on (Ks,J-Ks)…

天体物理学 · 物理学 2009-11-10 S. Picaud , A. C. Robin

We present a comprehensive statistical analysis of star-forming objects located in the vicinities of 1 360 bubble structures throughout the Galactic Plane and their local environments. The compilation of ~70 000 star-forming sources, found…

The formation of the extended thin disc is the most spectacular event of our Galaxy in the past $\sim8$\,Gyr. To unveil this process, obtaining precise and accurate stellar ages for a large sample of stars is essential although challenging.…

星系天体物理 · 物理学 2023-01-20 Wu Yaqian , Xiang Maosheng , Zhao Gang , Chen Yuqin , Bi Shaolan , Li Yaguang

We review the observational evidences concerning the three-dimensional structure of the Galactic bulge. Although the inner few kpc of our Galaxy are normally referred to as {\it the bulge}, all the observations demonstrate that this region…

星系天体物理 · 物理学 2016-07-06 M. Zoccali , E. Valenti

We present results of a study of the galactic open cluster population based on the all-sky catalogue ASCC-2.5 (I/280A) compiled from Tycho-2, Hipparcos and other catalogues. The sample of optical clusters from ASCC-2.5 is complete up to…

天体物理学 · 物理学 2009-11-11 A. E. Piskunov , N. V. Kharchenko , S. Röser , E. Schilbach , R. -D. Scholz

[Abridged] The environment where galaxies are found heavily influences their evolution. Close groupings, like the cores of galaxy clusters or compact groups, evolve in ways far more dramatic than their isolated counterparts. We have…

Ages have been derived for 55 globular clusters (GCs) from overlays of isochrones onto the turnoff photometry, assuming distances based on fits of zero-age horizontal branch (ZAHB) models to the lower bound of the observed distributions of…

星系天体物理 · 物理学 2013-10-14 Don A. Vandenberg , Karsten Brogaard , Ryan Leaman , Luca Casagrande

We have determined detailed elemental abundances and stellar ages for a sample of now 38 microlensed dwarf and subgiant stars in the Galactic bulge. Stars with sub-solar metallicities are all old and have enhanced alpha-element abundances…

We consider models of gas flow in spiral galaxies in which the spiral structure has been excited by various possible mechanisms: a global steady density wave, self-gravity of the stellar disc and an external tidal interaction, as well as…

星系天体物理 · 物理学 2015-05-19 C. L. Dobbs , J. E. Pringle

Within the distance of 1 pc from the Galactic center (GC), more than 100 young massive stars have been found. The massive stars at 0.1-1 pc from the GC are located in one or two disks, while those within 0.1 pc from the GC, S-stars, have an…

星系天体物理 · 物理学 2015-05-18 Michiko Fujii , Masaki Iwasawa , Yoko Funato , Junichiro Makino

We present a deep near-infrared wide-angle photometric analysis of the structure of the inner Galactic bar and central disk. The presence of a triaxial structure at the centre of the Galaxy is confirmed, consistent with a bar inclined at…

天体物理学 · 物理学 2009-11-10 C. Babusiaux , G. Gilmore

(Abridge) Bars are very common in the centre of the disc galaxies, and they drive the evolution of their structure. A volume-limited sample of 2106 disc galaxies extracted from the Sloan Digital Sky Survey Data Release 5 was studied to…

星系天体物理 · 物理学 2009-11-13 J. A. L. Aguerri , J. Mendez-Abreu , E. M. Corsini

We analysed the chemodynamical evolution of the Galactic disc using precise [Mg/Fe] abundances from a previous study and accurate Gaia data. For this purpose, we estimated ages and dynamical properties for 366 MSTO solar neighbourhood stars…

Our Galaxy is a barred spiral. Recent work based on the COBE NIR data implies a small bulge-bar and a disk with a short scale-length. The corotation radius of the bar is in the range 3-4.5 kpc. The stellar density distribution beyond the…

天体物理学 · 物理学 2007-05-23 Ortwin E. Gerhard

Since thin disc stars are younger than thick disc stars on average, the thin disc is predicted by some models to start forming after the thick disc had formed, around 10 Gyr ago. Accordingly, no significant old thin disc population should…