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Related papers: Kinematics and Composition of the Galactic Bulge: …

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We selected Bulge stars from APOGEE DR17 cross-matched with astrometric data from \textit{Gaia} DR3. Bulge stars were divided into sub-samples with line-of-sight velocity dispersion analyzed and the peaks of MDF were detected by both…

Astrophysics of Galaxies · Physics 2025-10-29 Haoyang Liu , Cuihua Du , Zhongcheng Li , Jian Zhang , Mingji Deng

The structure, formation, and evolution of the Milky Way bulge is a matter of debate. Important diagnostics for discriminating between bulge models include alpha-abundance trends with metallicity, and spatial abundance and metallicity…

Astrophysics of Galaxies · Physics 2015-12-23 N. Ryde , M. Schultheis , V. Grieco , F. Matteucci , R. M. Rich , S. Uttenthaler

The correlation between the maximum rotational velocity of the disk (v_m) and the central stellar velocity dispersion of the bulge (sigma) offers insights into the relationship between the halo and the bulge. We have assembled integrated H…

Astrophysics · Physics 2009-11-13 Luis C. Ho

Recent spectroscopic and photometric surveys are providing a comprehensive view of the MW bulge stellar population properties with unprecedented accuracy. This in turn allows us to explore the correlation between kinematics and stellar…

We obtained FLAMES-GIRAFFE spectra (R=22,500) at the ESO Very Large Telescope for 650 bulge red giant branch (RGB) stars and performed spectral synthesis to measure Mg, Ca, Ti, and Si abundances. This sample is composed of 474 giant stars…

It has recently been discovered that the Galactic bulge is X-shaped, with the two southern arms of the X both crossing the lines of sight at l=0 and |b|>4, hence producing a double red clump (RC) in the bulge CMD. Dynamical models predict…

(Abridged) We analyzed the stellar parameters and radial velocities of ~1200 stars in five bulge fields as determined from the Gaia-ESO survey data (iDR1). We use VISTA Variables in The Via Lactea (VVV) photometry to obtain reddening values…

In this paper, we aim to derive high-precision alpha-element abundances using CRIRES high-resolution IR spectra of 72 cool M giants of the inner Galactic bulge. Silicon, magnesium, and calcium abundances were determined by fitting a…

Astrophysics of Galaxies · Physics 2023-03-08 N. Nieuwmunster , G. Nandakumar , E. Spitoni , N. Ryde , M. Schultheis , R. M. Rich , P. S. Barklem , O. Agertz , F. Renaud , F. Matteucci

The first and second moments of stellar velocities encode important information about the formation history of the Galactic halo. However, due to the lack of tangential motion and inaccurate distances of the halo stars, the velocity moments…

This paper investigates the peculiar behaviour of the light even (alpha-elements) and odd atomic number elements in red giants in the galactic bulge, both in terms of the chemical evolution of the bulge, and in terms of possible deep-mixing…

Astrophysics · Physics 2009-11-11 A. Lecureur , V. Hill , M. Zoccali , B. Barbuy , A. Gomez , D. Minniti , S. Ortolani , A. Renzini

The presence of two stellar populations in the Milky Way bulge has been reported recently. We aim at studying the abundances and kinematics of stars in the outer bulge, thereby providing additional constraints on models of its formation.…

Astrophysics of Galaxies · Physics 2015-06-05 Stefan Uttenthaler , Mathias Schultheis , David. M. Nataf , Annie C. Robin , Thomas Lebzelter , B. Chen

We present the metallicity results from the ARGOS spectroscopic survey of the Galactic bulge. Our aim is to understand the formation of the Galactic bulge: did it form via mergers, as expected from Lambda CDM theory, or from disk…

Astrophysics of Galaxies · Physics 2015-06-12 M. Ness , K. Freeman , E. Athanassoula , E. Wylie de Boer , J. Bland Hawthorn , M. Asplund , G. F. Lewis , D. Yong , R. R. Lane , L. L. Kiss

We have used N-body simulations for the Milky Way to investigate the kinematic and structural properties of the old metal-poor stellar halo in the barred inner region of the Galaxy. We find that the extrapolation of the density distribution…

Astrophysics of Galaxies · Physics 2016-10-26 Angeles Pérez-Villegas , Matthieu Portail , Ortwin Gerhard

Visual, NIR, and H_alpha surface photometry of the oval disk galaxy M94 (NGC 4736) was performed to study the distribution of mass in old stars and the distribution of the warm emission line gas. The radial profile of the inner stellar disk…

Astrophysics · Physics 2016-08-30 C. Moellenhoff , M. Matthias , O. E. Gerhard

We propose a new way to search for hypervelocity stars in the Galactic bulge, by using red clump (RC) giants, that are good distance indicators. The 2nd Gaia Data Release and the near-IR data from the VISTA Variables in the Via Lactea (VVV)…

Astrophysics of Galaxies · Physics 2020-01-08 Alonso Luna , Dante Minniti , Javier Alonso-García

We take advantage of the Gaia-ESO Survey iDR4 bulge data to search for abundance anomalies that could shed light on the composite nature of the Milky Way bulge. The alpha-elements (Mg, Si, and whenever available, Ca) abundances, and their…

We analyze the structure and chemo-dynamical properties of the Galactic bulge using ab-type RR Lyrae stars (RRabs) from OGLE-IV and giant stars from APOGEE and Gaia. Orbital integration of 1,879 RRab variables reveals three populations:…

Astrophysics of Galaxies · Physics 2026-03-18 Hai-Feng Wang , Xiao Han , Giovanni Carraro , Martin Lopez-Corredoira , Yuan-Sen Ting , Guan-Yu Wang

The Blanco DECam Bulge Survey (BDBS) provides near-ultraviolet to near-infrared photometry for ~250 million unique stars. By combining BDBS photometry with the latest Gaia astrometry, we characterize the chemo-dynamics of red clump stars…

We have studied a sample containing about 6000 OB stars with proper motions and trigonometric parallaxes from the Gaia DR2 catalogue. The following parameters of the angular velocity of Galactic rotation have been found:…

Astrophysics of Galaxies · Physics 2019-06-26 V. V. Bobylev , A. T. Bajkova

Two main scenarios for the formation of the Galactic bulge are invoked, the first one through gravitational collapse or hierarchical merging of subclumps, the second through secular evolution of the Galactic disc. We aim to constrain the…

Astrophysics of Galaxies · Physics 2015-05-19 C. Babusiaux , A. Gomez , V. Hill , F. Royer , M. Zoccali , F. Arenou , R. Fux , A. Lecureur , M. Schultheis , B. Barbuy , D. Minniti , S. Ortolani