中文
相关论文

相关论文: On the fine structure of the Cepheid metallicity g…

200 篇论文

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

We present homogeneous and accurate iron abundances for almost four dozen (47) of Galactic Cepheids using high-spectral resolution (R$\sim$40,000) high signal-to-noise ratio (S/N $\ge$ 100) optical spectra collected with UVES at VLT. A…

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

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,…

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 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…

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 gathered more than 1130 high-resolution optical spectra for more than 250 Galactic classical Cepheids. The spectra were collected with different optical spectrographs: UVES at VLT, HARPS at 3.6m, FEROS at 2.2m MPG/ESO, and STELLA. To…

Classical Cepheids (DCEPs) are crucial for calibrating the extragalactic distance ladder, ultimately enabling the determination of the Hubble constant through the PL and PW relations they exhibit. Hence it's vital to understand how the PL…

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…

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…

Classical Cepheids (CCs) are solid distance indicators and tracers of young stellar populations. Our aim is to provide iron, oxygen, and sulfur abundances for the largest and most homogeneous sample of Galactic CCs ever analyzed. The…

Classical Cepheids (CCs) have long been considered excellent tracers of the chemical evolution of the Milky Way's young disk. We present a homogeneous, NLTE spectroscopic analysis of 401 Galactic CCs, based on 1,351 high-resolution optical…

A sample of 37 Galactic, 10 LMC and 6 SMC cepheids is compiled for which individual metallicity estimates exist and BVIK photometry in almost all cases. The Galactic cepheids all have an individual distance estimate available. For the MC…

天体物理学 · 物理学 2009-11-10 M. A. T. Groenewegen , M. Romaniello , F. Primas , M. Mottini

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

Classical Cepheids (DCEPs) are the first fundamental step in the calibration of the cosmological distance ladder. Furthermore, they represent powerful tracers in the context of Galactic studies. We have collected high-resolution…

星系天体物理 · 物理学 2023-01-11 E. Trentin , V. Ripepi , G. Catanzaro , J. Storm , M. Marconi , G. De Somma , V. Testa , I. Musella

Using an updated and significantly augmented sample of Cepheid and TRGB distances to 28 nearby spiral and irregular galaxies, covering a wide range of metallicities, we have searched for evidence of a correlation of the zero-point of the…

太阳与恒星天体物理 · 物理学 2023-09-21 Barry F. Madore , Wendy L. Freedman

Open clusters are known as excellent tools for various topics in Galactic research. For example, they allow accurately tracing the chemical structure of the Galactic disc. However, the metallicity is known only for a rather low percentage…

太阳与恒星天体物理 · 物理学 2016-01-13 M. Netopil , E. Paunzen , U. Heiter , C. Soubiran

Based on spectra obtained at the Anglo-Australian Observatory, we present a discussion of the metallicity of the galactic disc derived using Cepheids at galactocentric distances 4-6 kpc. Our new results together with previous gradient…

‹ 上一页 1 2 3 10 下一页 ›