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Related papers: Box/peanut-shaped bulges in action space

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We report the statistical properties of stars and brown dwarfs obtained from four radiation hydrodynamical simulations of star cluster formation, the metallicities of which span a range from 1/100 to 3 times the solar value. Unlike previous…

Solar and Stellar Astrophysics · Physics 2019-01-15 Matthew R. Bate

Double bars are thought to be important features for secular evolution in the central regions of galaxies. However, observational evidence about their origin and evolution is still scarce. We report on the discovery of the first Box-Peanut…

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

Here we study the metallicity bias in the velocity dispersions, the derived quantity called anisotropy and the mean azimuthal velocity profiles of the Milky Way stellar halo using Blue Horizontal Branch (BHB) stars taken from SDSS/SEGUE…

Astrophysics of Galaxies · Physics 2013-02-18 P. R. Kafle , S. Sharma , G. F. Lewis , J. Bland-Hawthorn

The HST/WFC3 multiband photometry spanning from the UV to the near-IR of four fields in the Galactic bulge, together with that for six template globular and open clusters, are used to photometrically tag the metallicity [Fe/H] of stars in…

The distribution of metals within a galaxy traces the baryon cycle and the buildup of galactic disks, but the detailed gas phase metallicity distribution remains poorly sampled. We have determined the gas phase oxygen abundances for 7,138…

New observational facilities are probing astrophysical transients such as stellar explosions and gravitational wave (GW) sources at ever increasing redshifts, while also revealing new features in source property distributions. To interpret…

Astrophysics of Galaxies · Physics 2023-05-24 L. A. C. van Son , S. E. de Mink , M. Chruslinska , C. Conroy , R. Pakmor , L. Hernquist

A three-dimensional hydrodynamical N-body model for the formation of the Galaxy is presented with special attention to the formation of the bulge component. Starting with cosmologically motivated initial conditions, we obtain a…

Astrophysics · Physics 2009-11-07 Naohito Nakasato , Ken'ichi Nomoto

We obtained stellar ages and metallicities via spectrum fitting for a sample of 575 bulges with spectra available from the Sloan Digital Sky Survey. The structural properties of the galaxies have been studied in detail in Gadotti (2009b)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Paula Coelho , Dimitri A. Gadotti

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…

Astrophysics of Galaxies · Physics 2016-07-06 M. Zoccali , E. Valenti

We study the impact of different galaxy statistics and empirical metallicity scaling relations on the merging rates and on the properties of compact objects binaries. First, we analyze the similarities and differences of using the star…

Astrophysics of Galaxies · Physics 2021-02-17 Lumen Boco , Andrea Lapi , Martyna Chruslinska , Darko Donevski , Alex Sicilia , Luigi Danese

Studies of the red clump giant population in the inner Milky Way suggest the Galactic bulge/bar has a boxy/peanut/X-shaped structure as predicted by its formation via a disc buckling instability. We used a non-parametric method of…

Astrophysics of Galaxies · Physics 2023-08-10 Dylan Paterson , Brenna Coleman , Chris Gordon

Bar strengths are compared between active and non-active galaxies for a sample of 43 barred galaxies. The relative bar torques are determined using a new technique (Buta and Block 2001), where maximum tangential forces are calculated in the…

Astrophysics · Physics 2009-11-07 E. Laurikainen , H. Salo , P. Rautiainen

We used near-infrared integral field spectroscopic observations from the AMAZE and LSD programs to constrain the metallicity in a sample of 40 star forming galaxies at 3<z<5 (most of which at z~3.4). We measure metallicities by exploiting…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 P. Troncoso , R. Maiolino , V. Sommariva , G. Cresci , F. Mannucci , A. Marconi , M. Meneghetti , A. Grazian , A. Cimatti , A. Fontana , T. Nagao , L. Pentericci

We provide new insight on the origin of the cold high-V$_{\rm los}$ peaks ($\sim$200 kms$^{-1}$) in the Milky Way bulge discovered in the APOGEE commissioning data \citep{Nidever2012}. Here we show that such kinematic behaviour present in…

Astrophysics of Galaxies · Physics 2017-08-22 J. G. Fernández-Trincado , A. C. Robin , E. Moreno , A. Pérez-Villegas , B. Pichardo

We present a systematic study of the metallicity variations within the collisional ring galaxy NGC 922 based on long-slit optical spectroscopic observations. We find a metallicity difference between star-forming regions in the bulge and the…

We present key sample results of a systematic survey of the pulsation properties of models of hot B subdwarfs. We use equilibrium structures taken from detailed evolutionary sequences of solar metallicity (Z = 0.02) supplemented by grids of…

Astrophysics · Physics 2009-10-28 Stephane Charpinet , Gilles Fontaine , Pierre Brassard , Ben Dorman

We aim at reproducing the chemical evolution of the bulge of M31 by means of a detailed chemical evolution model, including radial gas flows coming from the disk. We study the impact of the initial mass function, the star formation rate and…

Astrophysics of Galaxies · Physics 2015-06-23 M. M. Marcon-Uchida , F. Matteucci , G. A. Lanfranchi , E. Spitoni , V. Grieco

We show for the first time, that a fully cosmological hydrodynamical simulation can reproduce key properties of the innermost region of the Milky Way. Our high resolution simulation matches the profile and kinematics of the Milky Way's…

Astrophysics of Galaxies · Physics 2018-07-25 Tobias Buck , Melissa K. Ness , Andrea V. Macciò , Aura Obreja , Aaron A. Dutton

Metallicity is one of the crucial factors that determine stellar evolution. To characterize the properties of stellar populations one needs to know the fraction of stars forming at different metallicities. Knowing how this fraction evolves…

Astrophysics of Galaxies · Physics 2019-07-29 Martyna Chruslinska , Gijs Nelemans