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Related papers: Does SEGUE/SDSS indicate a dual Galactic halo?

200 papers

We study the metal abundances of F and G type stars in the Galactic disk and halo using the Canada-France-Hawaii Telescope Legacy Survey D4 field. For a sample of stars within 7 kpc of the Galactic plane, we derive mean abundance values of…

Astrophysics · Physics 2009-11-13 Y. Karatas , M. Kilic , O. Gunes , F. Limboz

Correlations between stellar kinematics and chemical abundances are fossil evidence for evolutionary connections between Galactic structural components. Extensive stellar surveys show that the only tolerably clear distinction between…

Astrophysics · Physics 2009-10-22 Gerard Gilmore

We use the hydrodynamical EAGLE simulation to study the magnitude and origin of the scatter in the stellar mass - halo mass relation for central galaxies. We separate cause and effect by correlating stellar masses in the baryonic simulation…

Astrophysics of Galaxies · Physics 2017-01-18 Jorryt Matthee , Joop Schaye , Robert A. Crain , Matthieu Schaller , Richard Bower , Tom Theuns

We present an updated sample of blue horizontal-branch (BHB) stars selected from the photometric and spectroscopic data from Sloan Digital Sky Survey and its associated project Sloan Extension for Galactic Understanding and Exploration…

HIRES/Keck spectra of Mg II (2796) absorption arising in the "halos" of 15 identified 0.4 < z < 0.9 galaxies are presented. Comparison of the galaxy and absorbing gas properties reveal that the spatial distribution of galactic/halo gas does…

Astrophysics · Physics 2007-05-23 Christopher W. Churchill

We isolate samples of 733 bright (g < 18) and 437 faint (g > 18) high-Galactic latitude blue horizontal branch stars with photometry and spectroscopy in the Sloan Digital Sky Survey (SDSS). Comparison of independent photometric and…

Recent observations of the stellar halo have uncovered the debris of an ancient merger, Gaia-Sausage-Enceladus, estimated to have occurred ~8 Gyr ago. Follow-up studies have associated GSE with a large-scale tilt in the stellar halo that…

We present new constraints on the density profiles of dark matter (DM) halos in seven nearby dwarf galaxies from measurements of their integrated stellar light and gas kinematics. The gas kinematics of low mass galaxies frequently suggest…

Comparisons between observational surveys and galaxy formation models find that the mass of dark matter haloes can largely explain galaxies' stellar mass. However, it remains uncertain whether additional environmental variables, generally…

Correlations between the star formation rates (SFRs) of nearby galaxies (so-called galactic conformity) have been observed for projected separations up to 4 Mpc, an effect not predicted by current semi-analytic models. We investigate…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-27 Andrew P. Hearin , Peter S. Behroozi , Frank C. van den Bosch

Due to gravitational instability, an initially Gaussian density field develops non-Gaussian features as the Universe evolves. The most prominent non-Gaussian features are massive haloes, visible as clusters of galaxies. The distortion of…

Astrophysics · Physics 2015-06-24 Guido Kruse , Peter Schneider

Constraints on dark matter halo masses from weak gravitational lensing can be improved significantly by using additional information about the morphology of their density distribution, leading to tighter cosmological constraints derived…

We construct a new sample of ~1700 solar neighbourhood halo subdwarfs from the Sloan Digital Sky Survey, selected using a reduced proper motion diagram. Radial velocities come from the SDSS spectra and proper motions from the light-motion…

Astrophysics of Galaxies · Physics 2009-11-19 M. C. Smith , N. W. Evans , V. Belokurov , P. C. Hewett , D. M. Bramich , G. Gilmore , M. J. Irwin , S. Vidrih , D. B. Zucker

An observer that is moving towards a high-density region sees, on average, a higher matter density and more foreground-emitting sources ahead than behind themself. Consequently, the average abundance and luminosity of objects producing…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-11 Selim C. Hotinli , Elena Pierpaoli , Simone Ferraro , Kendrick Smith

A method to diagnose the gas distribution in the Galactic halo using a shock wave from the Galactic Centre (GC) is presented. Propagation of a shock wave caused by central explosion with released energy $\sim 10^{55}$ erg is calculated for…

Astrophysics of Galaxies · Physics 2019-01-23 Yoshiaki Sofue

Recent studies have presented evidence that the Milky Way global potential may be nonspherical. In this case, the assembling process of the Galaxy may have left long lasting stellar halo kinematic fossils due to the shape of the dark matter…

Astrophysics of Galaxies · Physics 2015-05-27 Armando Rojas-Niño , Luis A. Martínez-Medina , Barbara Pichardo , Octavio Valenzuela

Over the past two decades observations have revealed that the vertical density distribution of stars in galaxies near the mid-plane is substantially steeper than the sech^2 function that is expected from an isothermal approximation.…

Astrophysics · Physics 2011-02-11 Arunima Banerjee , Chanda J. Jog

We address the problem of identifying remnants of satellite galaxies in the halo of our galaxy with Gaia data. The remnants have to be extracted from a very large data set (of order 10^9 stars) in the presence of observational errors and…

Astrophysics · Physics 2009-11-11 Anthony Brown , Hector Velazquez , Luis Aguilar , ;

Using G dwarfs from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) survey, we have determined a vertical metallicity gradient over a large volume of the Milky Way's disk, and examined how this gradient varies for…

We explore halo assembly bias on cluster scales using large samples of superclusters. Leveraging the largest-ever X-ray galaxy cluster and supercluster samples obtained from the first SRG/eROSITA all-sky survey, we construct two subsamples…