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Related papers: LMC Bar: Evidence for a warped bar

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We present derivations of star formation histories based on color-magnitude diagrams of three fields in the LMC from HST/WFPC2 observations. A significant component of stars older than 4 Gyr is required to match the observed color-magnitude…

Astrophysics · Physics 2008-11-26 J. A. Holtzman , J. S. Gallagher , A. A. Cole , J. R. Mould , C. J. Grillmair , the WFPC2 Idt

I discuss observational evidence -- independent of the direct spectral diagnostics of stellar winds themselves -- suggesting that mass-loss rates for O stars need to be revised downward by roughly a factor of three or more, in line with…

Astrophysics · Physics 2007-10-19 Nathan Smith

We use a sample of 938 red clump giant stars located in the direction of the galactic long bar to study the chemistry of Milky Way bar stars. Kinematically separating stars on bar orbits from stars with inner disc orbits, we find that stars…

Astrophysics of Galaxies · Physics 2019-12-18 C. Wegg , A. Rojas-Arriagada , M. Schultheis , O. Gerhard

Aims: We investigate whether the cylindrical (galactocentric) radial velocity gradient of ~ -3 km/s/kpc, directed radially from the Galactic center and recently observed in the stars of the solar neighborhood with the RAVE survey, can be…

Astrophysics of Galaxies · Physics 2014-10-01 Giacomo Monari , Amina Helmi , Teresa Antoja , Matthias Steinmetz

We compare red clump stars with parallaxes known to better than 10% in the Hipparcos catalog and corrected for the interstellar extinction, with the OGLE red clump stars in Baade's Window also corrected for the interstellar extinction.…

Astrophysics · Physics 2009-10-30 Bohdan Paczynski , K. Z. Stanek

Approximately four thousand light curves of red variable stars in the LMC were selected from the 2.3-years duration MOA database by a period analysis using the Phase Dispersion Minimization method. Their optical features (amplitudes,…

Astrophysics · Physics 2016-01-27 Sachiyo Noda , Mine Takeuti

Recent observations on structural properties of the Large Magellanic Cloud (LMC) based on the Deep Near-Infrared Southern Sky Survey (DENIS) and Two Micron All-Sky Survey (2MASS) have revealed that the LMC has an off-center bar even in the…

Astrophysics · Physics 2009-11-13 Kenji Bekki

Outer rings are located at the greatest distance from the galaxy center of any feature resonant with a bar. Because of their large scale, their morphology is sensitive to the distribution of the dark matter in the galaxy. We introduce here…

Astrophysics · Physics 2016-08-30 A. C. Quillen , J. A. Frogel

For 2442 galaxies of the catalog, compiled based on the NED, SDSS, and CATS survey data with redshifts z, > 0.3 we conducted an analysis of the amplitude of temperature fluctuations in the cosmic microwave background (CMB) in the points,…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-23 O. V. Verkhodanov , M. L. Khabibullina

I review some of the work on bars which is closely linked to the bar/bulge system in our Galaxy. Several independent studies, using totally independent methods, come to the same results about the 3D structure of a bar, i.e., that a bar is…

Astrophysics of Galaxies · Physics 2015-06-04 E. Athanassoula

We present a comprehensive study of bar structures in the local Universe using data from the DESI Legacy Imaging Surveys. Through isophotal analysis of 232,142 galaxies, we identify bars and classify them into strong and weak categories…

Astrophysics of Galaxies · Physics 2025-03-31 Wenwen Wang , Zhimin Zhou

We performed R-band time series observations of the young, metal rich open cluster NGC 2301 for 12 nights in Feb. 2004. B images were also obtained and color magnitude diagrams, having limits of R=19.5 and B=21.5, were produced. Only asmall…

We analyzed the distribution of the RC stars throughout Galactic bulge using 2MASS data. We mapped the position of the red clump in 1 sq.deg. size fields within the area |l|<=8.5deg and $3.5deg<=|b|<=8.5deg, for a total of 170 sq.deg. The…

Astrophysics of Galaxies · Physics 2015-05-28 Roberto K. Saito , Manuela Zoccali , Andrew McWilliam , Dante Minniti , Oscar A. Gonzalez , Vanessa Hill

We report on the results of an I-band photometric variability survey of eighteen L dwarfs. We find that seven exhibit statistically significant variations above the 95.4% confidence level with root-mean-square scatter (including photometric…

We report metallicities and radial velocities derived from spectra at the near-infrared calcium triplet for 373 red giants in a 200 square arcminute area at the optical center of the LMC bar. These are the first spectroscopic abundance…

Astrophysics · Physics 2009-11-10 Andrew A. Cole , E. Tolstoy , J. S. Gallagher , T. A. Smecker-Hane

We derive the mean velocity components at various Galactocentric radii from 8 to 14 kpc using about 40,000 red clump stars observed in the LAMOST survey. We find that the vertical bulk motion for younger red clump stars are significantly…

Astrophysics of Galaxies · Physics 2017-03-29 Chao Liu , Hai-Jun Tian , Jun-Chen Wan

(Abridged) We analyze the UBVI color-magnitude diagrams towards the Galactic bulge in a relatively low-reddening region of Baade's Window. The dereddened red giant branch is very wide [~1.0 mag in (U-B)_0 and ~0.4 mag in (B-V)_0 and…

Astrophysics · Physics 2007-05-23 K. Z. Stanek , J. Kaluzny , A. Wysocka , I. Thompson

Observational data indicate that the Milky Way is a barred spiral galaxy. Computation facilities and availability of data from Galactic surveys stimulate the appearance of models of the Galactic structure. More efforts to build dynamical…

Astrophysics of Galaxies · Physics 2018-07-18 Tatiana A. Michtchenko , Jacques R. D. Lépine , Douglas A. Barros , Ronaldo S. S. Vieira

We analyse the positions of RR Lyrae stars in the central region of the Milky Way. In addition to the overall bar shape detected previously, we find evidence for a peanut shaped structure, in form of overdensities near $\ell=-2$ deg and $1$…

Astrophysics of Galaxies · Physics 2021-11-24 Marcin Semczuk , Walter Dehnen , Ralph Schoenrich , E. Athanassoula

We present simulations of bar-unstable stellar discs in which the bars thicken into box/peanut shapes. Detailed analysis of the evolution of each model revealed three different mechanisms for thickening the bars. The first mechanism is the…

Astrophysics of Galaxies · Physics 2020-05-27 J. A. Sellwood , Ortwin Gerhard