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相关论文: On the metallicity distribution of classical Cephe…

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We present homogeneous and accurate iron abundances for 42 Galactic Cepheids based on high-spectral resolution (R~38,000) high signal-to-noise ratio (SNR>100) optical spectra collected with UVES at VLT (128 spectra). The above abundances…

We present iron abundance measurements, based on high resolution spectroscopy, and accurate distance determinations, based on near infrared photometry, for 34 Galactic Cepheids. The new data are used to constrain the Galactic iron abundance…

天体物理学 · 物理学 2007-11-27 B. Lemasle , A. Piersimoni , S. Pedicelli , G. Bono , P. Francois , F. Primas , M. Romaniello

Aims: The iron abundance gradient in the Galactic stellar disk provides fundamental constraints on the chemical evolution of this important Galaxy component. However the spread around the mean slope is, at fixed Galactocentric distance,…

Context: Classical Cepheids can be adopted to trace the chemical evolution of the Galactic disk since their distances can be estimated with very high accuracy. Aims: Homogeneous iron abundance measurements for 33 Galactic Cepheids located…

天体物理学 · 物理学 2009-11-13 B. Lemasle , P. Francois , A. Piersimoni , S. Pedicelli , G. Bono , C. D. Laney , F. Primas , M. Romaniello

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…

We report the discovery from our IRSF/SIRIUS Near-Infrared (NIR) variability survey of five new classical Cepheids located in the inner Galactic Disk, at longitude $l\simeq -40^{\circ}$. The new Cepheids are unique in probing the kinematics…

As a continuation of our previous work, which concerned the radial abundance distribution in the galactic disc over the distances 4-10 kpc this paper presents the first results on the metallicicty in the outer disc (RG > 10 kpc). Based on…

天体物理学 · 物理学 2009-11-07 S. M. Andrievsky , V. V. Kovtyukh , R. E. Luck , J. R. D. Lepine , W. J. Maciel , Yu. V. Beletsky

Metallicity gradients refer to the sloped radial profile of metallicities of gas and stars and are commonly seen in disk galaxies. A well-defined metallicity gradient of the Galactic disk is observed particularly well with classical…

The recent introduction of high resolution/large spectral range spectrographs provided the opportunity to investigate in detail the chemical composition of classical Cepheids. This paper is focussed on new abundance determinations for iron…

天体物理学 · 物理学 2009-11-13 B. Lemasle , P. Francois , G. Bono , M. Mottini , F. Primas , M. Romaniello

We derived elemental abundances in 27 Cepheids, the great majority situated within a zone of Galactocentric distances ranging from 5 to 7 kpc. One star of our sample, SU Sct, has a Galactocentric distance of about 3 kpc, and thus falls in a…

星系天体物理 · 物理学 2015-06-24 R. P. Martin , S. M. Andrievsky , V. V. Kovtyukh , S. A. Korotin , I. A. Yegorova , Ivo Saviane

Classical Cepheids are the most popular distance indicators and tracers of young stellar populations. The key advantage is that they are bright and they can be easily identified in Local Group and Local Volume galaxies. Their evolutionary…

We have measured the elemental abundances of 68 Galactic and Magellanic Cepheids from FEROS and UVES high-resolution and high signal-to-noise spectra in order to establish the influence of the chemical composition on the properties of these…

天体物理学 · 物理学 2010-12-09 M. Mottini , M. Romaniello , F. Primas , G. Bono , M. A. T. Groenewegen , P. Francois

While the number of stars in the Galactic bulge with detailed chemical abundance measurements is increasingly rapidly, the inner Galactic bulge ( |b| < 2$^\circ$) remains poorly studied, due to heavy interstellar absorption and photometric…

星系天体物理 · 物理学 2018-05-23 G. Nandakumar , N. Ryde , M. Schultheis , B. Thorsbro , H. Jönsson , P. S. Barklem , R. M. Rich , F. Fragkoudi

We present metallicities, [Fe/H], and elemental abundance ratios, [X/Fe], for a sample of 24 Cepheids in the outer Galactic disk. The sample have Galactocentric distances covering 12 < R_GC (kpc) < 17.2 making them the most distant Galactic…

天体物理学 · 物理学 2008-11-26 David Yong , Bruce W. Carney , Luisa de Almeida , Brian L. Pohl

We present new accurate abundances for five neutron-capture (Y, La, Ce, Nd, Eu) elements in 73 classical Cepheids located across the Galactic thin disk. Individual abundances are based on high spectral resolution (R ~ 38,000) and high…

Although there have been numerous studies of chemical abundances in the Galactic bulge, the central two degrees have been relatively unexplored due to the heavy and variable interstellar extinction, extreme stellar crowding, and the…

星系天体物理 · 物理学 2019-07-17 M. Schultheis , R. M. Rich , L. Origlia , N. Ryde , G. Nandakumar , B. Thorsbro , N. Neumayer

We present new homogeneous measurements of Na, Al and three alpha-elements (Mg, Si, Ca) for 75 Galactic Cepheids. The abundances are based on high spectral resolution (R ~ 38,000) and high signal-to-noise ratio (S/N ~ 50-300) spectra…

We present the study of the metallicity dependence of the Fourier amplitude ratios R_21 and R_31 for the light curves of short-period Galactic classical Cepheids in B, V, R_C and I_C bands. Based on the available photometric and…

太阳与恒星天体物理 · 物理学 2013-08-01 P. Klagyivik , L. Szabados , A. Szing , S. Leccia , N. Mowlavi

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…

Context: Galactic abundance gradients set strong constraints to chemo-dynamical evolutionary models of the Milky Way. Given the PL relations that provide accurate distances and the large number of spectral lines, Cepheids are excellent…

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