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Related papers: Galactic abundance gradients from Cepheids: alpha …

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We present a reassessment of the radial abundance gradients of C, N, O, Ne, S, Cl and Ar in the Milky Way using deep spectra of 33 H II regions gathered from the literature, covering Galactocentric distances from 6 to 17 kpc. The distances…

Astrophysics of Galaxies · Physics 2020-06-10 Karla. Z. Arellano-Córdova , César Esteban , Jorge García-Rojas , J. Eduardo Méndez-Delgado

The Cepheid period-luminosity (PL) relation is unquestionably one of the most powerful tools at our disposal for determining the extragalactic distance scale. While significant progress has been made in the past few years towards its…

We summarize a selection process to identify red giants in the direction of the southern warp of the Galactic disk, employing VI_C photometry and multi-object spectroscopy. We also present results from follow-up high-resolution, high-S/N…

Astrophysics · Physics 2008-11-26 Bruce W. Carney , David Yong , Luisa de Almeida , Patrick Seitzer

We have made the first attempt to derive the chemical properties of the Galactic disc at its very central part using high-resolution infrared spectroscopic observations of four classical Cepheids. Those stars are located at Galactocentric…

Astrophysics of Galaxies · Physics 2019-09-04 V. V. Kovtyukh , S. M. Andrievsky , R. P. Martin , S. A. Korotin , J. R. D. Lepine , W. J. Maciel , L. E Keir . , E. A. Panko

One of the outstanding problems in modern physics is the origin is of accelerated expansion of the universe. High-precision determinations of the Hubble parameter $\mbox{H}_0$ at different redshifts provide direct insight into the Universe…

Solar and Stellar Astrophysics · Physics 2020-01-17 Sara Mancino , Martino Romaniello , Richard I. Anderson , Rolf-Peter Kudritzki

Open clusters are distributed all across the disk and are convenient tracers of its properties. In particular, outer disk clusters bear a key role for the investigation of the chemical evolution of the Galactic disk. The goal of this study…

Astrophysics of Galaxies · Physics 2016-03-30 T. Cantat-Gaudin , P. Donati , A. Vallenari , R. Sordo , A. Bragaglia , L. Magrini

Classical Cepheids are primary distance indicators and a crucial stepping stone to determining the present-day Hubble constant Ho to the precision and accuracy required to constrain apparent deviations from the LCDM Concordance Cosmological…

We present radial velocities and chemical abundances for nine stars in the old, distant open clusters Be 18, Be 21, Be 22, Be 32, and PWM 4. For Be 18 and PWM 4, these are the first chemical abundance measurements. Combining our data with…

Astrophysics of Galaxies · Physics 2015-06-05 David Yong , Bruce W. Carney , Eileen D. Friel

The spatial distribution of elemental abundances in the disc of our Galaxy gives insights both on its assembly process and subsequent evolution, and on the stellar nucleogenesis of the different elements. Gradients can be traced using…

We present spectra obtained with the 10.4 m Gran Telescopio Canarias telescope of 13 Galactic HII regions, most of them of very low ionisation degree. The objects are located along the Galactic disc, with R_G from 5.7 to 16.1 kpc. We…

Astrophysics of Galaxies · Physics 2018-05-16 C. Esteban , J. Garcia-Rojas

We provide new constraints on the chemo-dynamical models of the Milky Way by measuring the radial and vertical chemical gradients for the elements Mg, Al, Si, Ti, and Fe in the Galactic disc and the gradient variations as a function of the…

Based on a simple model of the chemical evolution of the Milky Way disk, we investigate the disk oxygen abundance gradient and its time evolution. Two star formation rates (SFRs) are considered, one is the classical Kennicutt-Schmidt law ($…

Astrophysics of Galaxies · Physics 2011-02-11 J. Fu , J. L. Hou , J. Yin , R. X. Chang

We present Galactic mean metallicity maps derived from the first year of the SDSS-III APOGEE experiment. Mean abundances in different zones of Galactocentric radius (0 < R < 15 kpc) at a range of heights above the plane (0 < |z| < 3 kpc),…

We present a reassessment of the radial abundance gradients of He, C, N, O, Ne, S, Cl, and Ar in the Milky Way using the deep optical spectra of 42 HII regions presented in Arellano-C\'ordova et al. (2020, 2021) and M\'endez-Delgado et al.…

The Open Cluster Chemical Abundances and Mapping (OCCAM) survey seeks to curate a large, comprehensive, uniform dataset of open clusters and member stars to constrain key Galactic parameters. This eighth entry from the OCCAM survey, based…

We map the trends of elemental abundance ratios across the Galactic disk, spanning R = 3-15 kpc and midplane distance |Z|= 0-2 kpc, for 15 elements in a sample of 20,485 stars measured by the SDSS/APOGEE survey (O, Na, Mg, Al, Si, P, S, K,…

We analyse the chemical properties of a set of solar vicinity stars, and show that the small dispersion in abundances of \alpha-elements at all ages provides evidence that the SFH has been uniform throughout the thick disk. In the context…

Astrophysics of Galaxies · Physics 2015-04-13 M. Haywood , P. Di Matteo , O. Snaith , M. Lehnert

Recent work on abundance gradients have focussed not only on their magnitudes, but also on their spatial and temporal variations. In this work, we analyze the behaviour of radial abundance gradients in the galactic disk giving special…

Astrophysics · Physics 2008-06-23 W. J. Maciel , R. D. D. Costa

The relationship between abundances and orbital parameters for 235 F- and G-type intermediate- and low- mass stars in the Galaxy is analyzed. We found that there are abundance gradients in the thin disk in both radial and vertical…

Astrophysics of Galaxies · Physics 2015-05-30 Chenzhou Cui , Yuqin Chen , Gang Zhao , Yongheng Zhao

Many nucleosynthetic channels create the elements, but two-parameter models characterized by $\alpha$ and Fe nonetheless predict stellar abundances in the Galactic disk to accuracies of 0.02 to 0.05 dex for most measured elements, near the…