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相关论文: Galactic abundance gradients from Cepheids: alpha …

200 篇论文

The Milky Way's neutral hydrogen (HI) disk is warped and flared. However, a dearth of accurate HI-based distances has thus far prevented the development of an accurate Galactic disk model. Moreover, the extent to which our Galaxy's stellar…

星系天体物理 · 物理学 2019-02-05 Xiaodian Chen , Shu Wang , Licai Deng , Richard de Grijs , Chao Liu , Hao Tian

With the increasing numbers of large stellar survey projects, the quality and quantity of excellent tracers to study the Milky Way is rapidly growing, one of which is the classical Cepheids. Classical Cepheids are high precision standard…

星系天体物理 · 物理学 2020-05-25 Iminhaji Ablimit , Gang Zhao , Chris Flynn , Sarah A. Bird

The Nuclear Stellar Disc (NSD) is a rotating, disc-like structure in the Galactic Center, believed to have a distinct star formation. However, its formation history and evolutionary links to other structures in the Galactic Center remain…

星系天体物理 · 物理学 2025-07-09 N. Ryde , G. Nandakumar , R. Albarracin , M. Schultheis , A. Rojas-Arriagada , M. Zoccali

We use an extended and homogeneous data set of Galactic planetary nebulae (PNe) to study the metallicity gradients and the Galactic structure and evolution. The most up-to-date abundances, distances (calibrated with Magellanic Cloud PNe)…

星系天体物理 · 物理学 2015-05-18 L. Stanghellini , M. Haywood

We have performed the detailed analysis of 174 high-resolution spectra of FGK dwarfs obtained with the ELODIE echelle spectrograph at the Observatoire de Haute-Provence. Abundances of Fe, Si and Ni have been determined from equivalent…

天体物理学 · 物理学 2009-11-10 T. V. Mishenina , C. Soubiran , V. V. Kovtyukh , S. A. Korotin

The diagram depicting the abundance ratios [Mg/Mn] vs. [Al/Fe] has gained attention in recent literature as a valuable tool for exploring fundamental aspects of the evolution of the Milky Way and the Local Group. In particular, this…

星系天体物理 · 物理学 2023-10-10 Arianna Vasini , Emanuele Spitoni , Francesca Matteucci

We have selected a sample of Galactic Cepheids for which accurate estimates of radii, distances, and photometric parameters are available. The comparison between their pulsation masses, based on new Period-Mass-Radius (PMR) relations, and…

天体物理学 · 物理学 2009-11-07 G. Bono , W. P. Gieren , M. Marconi , P. Fouque' , F. Caputo

The recent Gaia Third Data Release contains a homogeneous analysis of millions of high-quality Radial Velocity Spectrometer (RVS) stellar spectra by the GSP-Spec module. This led to the estimation of millions of individual chemical…

We present the abundance analysis of 97 nearby metal-poor (-3.3<[Fe/H]<-0.5) stars having kinematics characteristics of the Milky Way (MW) thick disk, inner, and outer stellar halos. The high-resolution, high-signal-to-noise optical spectra…

星系天体物理 · 物理学 2015-06-05 M. N. Ishigaki , M. Chiba , W. Aoki

We present deep optical spectroscopy of eight HII regions located in the anticentre of the Milky Way. The spectra were obtained at the 10.4m GTC and 8.2m VLT. We determined Te([NII]) for all objects and Te([OIII]) for six of them. We also…

星系天体物理 · 物理学 2017-08-16 C. Esteban , X. Fang , J. Garcia-Rojas , L. Toribio San Cipriano

We used the ugr magnitudes of 1,437,467 F-G type main-sequence stars with metal abundance -2<[Fe/H]<+0.2 dex and estimated radial and vertical metallicity gradients for high Galactic-latitude fields (b>50) of the Milky Way Galaxy. The…

星系天体物理 · 物理学 2019-01-16 S. Tuncel Guctekin , S. Bilir , S. Karaali , O. Plevne , S. Ak

Uncertainty in the metal abundance dependence of the Cepheid variable period- luminosity (PL) relation remains one of the outstanding sources of systematic error in the extragalactic distance scale and Hubble constant. To test for such a…

We present the iron abundance and abundance ratios for 18 elements with respect to Fe in a sample of stars with a wide range in luminosity from luminous giants to stars near the turnoff in the globular cluster M5. The analyzed spectra,…

天体物理学 · 物理学 2009-11-07 Solange V. Ramirez , Judith G. Cohen

Integral field spectroscopy has been obtained for the nuclear regions of 3 large, well-studied, early-type galaxies. From these spectra we have obtained line strength maps for about 20 absorption lines, mostly belonging to the Lick system.…

Spectra from MDM Observatory are used to assess Lick/IDS feature strength gradients inside the half-light radius of the compact Local Group elliptical galaxy M32. All but a few (of 24 measured) indices show a statistically significant…

天体物理学 · 物理学 2009-11-10 Guy Worthey

Elemental abundances in the Milky Way disc trace its star-formation and enrichment history, but predicting these abundances from theory is limited by uncertain nucleosynthetic yields and poorly constrained chemical evolution models. Large…

The far side of the Milky Way's disk is one of the most concealed parts of the known Universe due to extremely high interstellar extinction and point source density toward low Galactic latitudes. Large time-domain photometric surveys…

太阳与恒星天体物理 · 物理学 2019-10-02 István Dékány , Gergely Hajdu , Eva K. Grebel , Márcio Catelan

Using a sample of red giant stars from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) Data Release 16, we infer the conditional distribution $p([\alpha/\text{Fe}]\,|\,[\text{Fe/H}])$ in the Milky Way disk for the…

星系天体物理 · 物理学 2021-10-13 Fiorenzo Vincenzo , David H. Weinberg , Andrea Miglio , Richard R. Lane , Alexandre Roman-Lopes

We present a new set of weak-line abundances of HII regions in M81, based on Gemini Multi-Object Spectrograph (GMOS) observations. The aim is to derive plasma and abundance analysis for a sizable set of emission-line targets to study the…

星系天体物理 · 物理学 2014-09-05 Letizia Stanghellini , Laura Magrini , Viviana Casasola , Eva Villaver

Cepheid masses are particularly necessary to help solving the mass discrepancy, while independent distance determinations provide crucial test of the period-luminosity relation and Gaia parallaxes. We used CHARA/MIRC to measure the…