English
Related papers

Related papers: A Test for Radial Mixing Using Local Star Samples

200 papers

We studied the relationship between the average stellar abundance of several elements and the orbital evolution of stars in the neighbourhood of the Sun, using both observational data for 325 late-type dwarfs in a volume-complete sample and…

[Abridged] In this first paper of this series, we present a new approach for studying the chemo-dynamical evolution in disk galaxies, which consists of fusing disk chemical evolution models with compatible numerical simulations of galactic…

Astrophysics of Galaxies · Physics 2015-06-11 I. Minchev , C. Chiappini , M. Martig

We examine the origin of radial and vertical gradients in the age/metallicity of the stellar component of a galaxy disc formed in the APOSTLE cosmological hydrody- namical simulations. Some of these gradients resemble those in the Milky…

HST trigonometric distances, photometric metallicities, isochronic ages from the second revised version of the Geneva--Copenhagen survey, and uniform spectroscopic Fe and Mg abundances from our master catalog are used to construct and…

Astrophysics of Galaxies · Physics 2015-05-28 V. A. Marsakov , V. V. Koval' , T. V. Borkova , M. V. Shapovalov

We analyse the phase-space structure of simulated thick discs that are the result of a significant merger between a disc galaxy and a satellite. Our main goal is to establish what would be the characteristic imprints of a merger origin for…

Astrophysics of Galaxies · Physics 2015-05-13 Álvaro Villalobos , Amina Helmi

A recent observational study of haloes of nearby Milky Way-like galaxies shows that only half (four out of eight) of the current sample exhibits strong negative metallicity ([Fe/H]) gradients. This is at odds with predictions from…

We search for the existence of chemically-distinct stellar components in the solar neighbourhood using published data. Extending earlier work, we show that when the abundances of Fe, alpha elements, and the r-process element Eu are…

Astrophysics of Galaxies · Physics 2015-05-19 Julio F. Navarro , Mario G. Abadi , Kim A. Venn , Kenneth C. Freeman , Borja Anguiano

We study the radial dependence in stellar populations of 33 nearby early-type galaxies with central stellar velocity dispersions sigma* > 150 km/s. We measure stellar population properties in composite spectra, and use ratios of these…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Jenny E Greene , Jeremy D Murphy , Genevieve J Graves , James E Gunn , Sudhir Raskutti , Julia M Comerford , Karl Gebhardt

Radial migration is defined as the change in guiding centre radius of stars and gas caused by gains or losses of angular momentum that result from gravitational interaction with non-axisymmetric structure. This has been shown to have…

Astrophysics of Galaxies · Physics 2015-01-08 Robert J. J. Grand , Daisuke Kawata , Mark Cropper

Radial O/H abundance gradients derived from HII regions, hot stars and planetary nebulae are combined with [Fe/H] gradients from open cluster stars in order to derive an independent [O/Fe] x [Fe/H] relation for the galactic disk. A…

Astrophysics · Physics 2007-05-23 W. J. Maciel

Predicting the local flux of dark matter particles is vital for dark matter direct detection experiments. To date, such predictions have been based on simulations that model the dark matter alone. Here we include the influence of the…

Astrophysics of Galaxies · Physics 2015-05-13 J. I. Read , V. Debattista , O. Agertz , L. Mayer , A. M. Brooks , F. Governato , G. Lake

Using combined asteroseismic and spectroscopic observations of 418 red-giant stars close to the Galactic disc plane (6 kpc $<R_{\rm Gal}\lesssim13$ kpc, $|Z_{\rm Gal}|<0.3$ kpc), we measure the age dependence of the radial metallicity…

The temporal behaviour of the radial abundance gradients has important consequences on models for the chemical evolution of the Galaxy. We present a comparison of the time variation of the abundance gradients in the Milky Way disk as…

Astrophysics · Physics 2007-05-23 W. J. Maciel , R. D. D. Costa , P. A. L. Ferreira

A sample of 229 nearby thick disk stars has been used to investigate the existence of an age-metallicity relation (AMR) in the Galactic thick disk. The results indicate that that there is indeed an age-metallicity relation present in the…

Astrophysics · Physics 2009-11-10 T. Bensby , S. Feltzing , I. Lundstrom

The stellar metallicity and abundance ratio gradients from the fiducial late-type galaxy simulation of Stinson et al. (2010) are presented. Over 1-3 scalelengths, gradients are shown to flatten with time, consistent with empirical evidence…

Astrophysics of Galaxies · Physics 2012-02-15 K. Pilkington , B. K. Gibson

[Abridge] In the first paper of this series (paper I) we presented a new approach for studying the chemo-odynamical evolution in disk galaxies, focusing on the Milky Way. Here we extend these results to different distances from the Galactic…

Astrophysics of Galaxies · Physics 2014-12-03 Ivan Minchev , Cristina Chiappini , Marie Martig

We study the relationship between age, metallicity, and alpha-enhancement of FGK stars in the Galactic disk. The results are based upon the analysis of high-resolution UVES spectra from the Gaia-ESO large stellar survey. We explore the…

We show that spiral waves in galaxy discs churn the stars and gas in a manner that largely preserves the overall angular momentum distribution and leads to little increase in random motion. Changes in the angular momenta of individual stars…

Astrophysics · Physics 2011-05-05 J A Sellwood , J J Binney

The study of the Milky Way stellar discs in the context of galaxy formation is discussed. In particular we explore the properties of the Milky Way disc using a new sample of about 550 dwarf stars for which we have recently obtained…

Astrophysics · Physics 2009-11-13 S. Feltzing , T. Bensby

Recent low-redshift observations have attempted to determine the star formation histories of elliptical galaxies by tracking correlations between the stellar population parameters (age and metallicity) and the structural parameters that…

Astrophysics of Galaxies · Physics 2012-01-31 L. A. Porter , R. S. Somerville , D. J. Croton , M. D. Covington , G. J. Graves , S. M. Faber , J. R. Primack