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We investigate the inner regions of the Milky Way with a sample of unprecedented size and coverage thanks to APOGEE DR16 and Gaia EDR3 data. Our inner Galactic sample has more than 26,000 stars within $|X_{\rm Gal}| <5$ kpc, $|Y_{\rm Gal}|…

Numerical simulations of double-barred galaxies predict the build-up of different structural components (e.g., bulges, inner discs) in the central regions of disc galaxies. In those simulations, inner bars have a prominent role in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 A. de Lorenzo-Cáceres , J. Falcón-Barroso , A. Vazdekis

We present a study of the connection between the galactic spin parameter $\lambda_{d}$ and the bar fraction in a volume-limited sample of 10,674 disk galaxies drawn from the Sloan Digital Sky Survey Data Release 7. The galaxies in our…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Bernardo Cervantes-Sodi , Cheng Li , Changbom Park , Lixin Wang

Barium stars conserve important information on the s-process and the third dredge-up in intermediate mass stars. Their discovery in various environments is therefore of great help to test nucleosynthesis and mixing models. Our aim is to…

Solar and Stellar Astrophysics · Physics 2015-06-15 Thomas Lebzelter , Stefan Uttenthaler , Oscar Straniero , Bernhard Aringer

We report the detection of a large sample of high-$\alpha$-metal-rich stars on the low giant branch with $2.6<logg<3.3$ dex in the LAMOST-MRS survey. This special group corresponds to an intermediate-age population of $5-9$ Gyr based on the…

Astrophysics of Galaxies · Physics 2021-08-18 Haopeng Zhang , Yuqin Chen , Gang Zhao , Jingkun Zhao , Xilong Liang , Haining Li , Yaqian Wu , Ali Luo , Rui Wang

Numerous studies of integrated starlight, stellar counts, and kinematics have confirmed that the Milky Way is a barred galaxy. However, far fewer studies have investigated the bar's stellar population properties, which carry valuable…

While it is incontrovertible that the inner Galaxy contains a bar, its structure near the Galactic plane has remained uncertain, where extinction from intervening dust is greatest. We investigate here the Galactic bar outside the bulge, the…

Astrophysics of Galaxies · Physics 2015-06-17 Christopher Wegg , Ortwin Gerhard , Matthieu Portail

We combine radial velocities, proper motions, and low resolution abundances for a sample of 315 K and M giants in the Baade's Window (l,b)=(0.9,-4) Galactic bulge field. The velocity ellipsoid of stars with [Fe/H]>-0.5 dex shows a vertex…

Astrophysics · Physics 2009-11-11 Mario Soto , R. Michael Rich , Konrad Kuijken

We present a novel interpretation of the previously puzzling different behaviours of stellar populations of the Milky Way's bulge. We first show, by means of pure N-body simulations, that initially co-spatial stellar populations with…

Astrophysics of Galaxies · Physics 2017-06-08 Victor P. Debattista , Melissa Ness , Oscar A. Gonzalez , K. Freeman , Manuela Zoccali , Dante Minniti

From an analysis of the stars remaining in central regions of the Galaxy after subtracting those belonging to the disc and the bulge, we deduce that the inner bulge must have an extra young population with respect the rest of the bulge. It…

Astrophysics · Physics 2009-10-31 M. Lopez-Corredoira , F. Garzon , P. L. Hammersley

This work reports the discovery of three new globular clusters (GCs) towards the Galactic bulge - Camargo 1107, 1108, and 1109. The discovery was made using the WISE, 2MASS, VVV, and Gaia-DR2 photometry. The new findings are old (12.0-13.5…

Astrophysics of Galaxies · Physics 2019-01-25 Denilso Camargo , Dante Minniti

We have measured the radial light profiles and global shapes of bars using two-dimensional 3.6 $\mu m $ image decompositions for 144 face-on barred galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S4G). The bar surface…

Red clump giant stars can be used as distance indicators to trace the mass distribution of the Galactic bar. We use RCG stars from 44 bulge fields from the OGLE-II microlensing collaboration database to constrain analytic tri-axial models…

Astrophysics · Physics 2009-06-23 Nicholas J. Rattenbury , Shude Mao , Takahiro Sumi , Martin C. Smith

The inner Galactic Bulge has, until recently, been avoided in chemical evolution studies due to extreme extinction and stellar crowding. Large, near-IR spectroscopic surveys, such as APOGEE, allow for the first time the measurement of…

We present the initial results of a census of 684 barred galaxies in the MaNGA galaxy survey. This large sample contains galaxies with a wide range of physical properties, and we attempt to link bar properties to key observables for the…

Astrophysics of Galaxies · Physics 2020-05-20 A. Fraser-McKelvie , M. Merrifield , A. Aragón-Salamanca , K. Masters , the MaNGA Survey Team

We re-analyse photometric near-infrared data in order to investigate why it is so hard to get a consensus for the shape and density law of the bulge, as seen from the literature. To solve the problem we use the Besancon Galaxy Model to…

Astrophysics of Galaxies · Physics 2015-06-03 Annie C. Robin , Douglas J. Marshall , Mathias Schultheis , Celine Reyle

We combine stellar metallicity and stellar mass estimates for a large sample of galaxies drawn from the SDSS DR2 spanning wide ranges in physical properties, in order to derive an inventory of the total mass of metals and baryons locked up…

Astrophysics · Physics 2011-11-10 Anna Gallazzi , Jarle Brinchmann , Stephane Charlot , Simon D. M. White

Cosmological models predict the oldest stars in the Galaxy should be found closest to the centre of the potential well, in the bulge. The EMBLA Survey successfully searched for these old, metal-poor stars by making use of the distinctive…

We present stellar age distributions of the Milky Way (MW) bulge region using ages for $\sim$6,000 high-luminosity ($\log(g) < 2.0$), metal-rich ($\rm [Fe/H] \ge -0.5$) bulge stars observed by the Apache Point Observatory Galactic Evolution…

We report the first abundance analysis of 17 M giant stars in the inner Galactic bulge at $(l,b)=(0\deg,-1\deg)$, based on $R=25,000$ infrared spectroscopy $(1.5-1.8 ~\mu \rm m)$ using NIRSPEC at the Keck telescope. Based on their…

Astrophysics · Physics 2009-11-13 R. Michael Rich , Livia Origlia , Elena Valenti
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