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相关论文: The anticenter old open cluster NGC 1883: radial v…

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We present new high signal-to-noise spectroscopic data on the M31 globular cluster system, obtained with the Hectospec multifiber spectrograph on the 6.5m MMT. More than 300 clusters have been observed at a resolution of 5A. The primary…

星系天体物理 · 物理学 2015-05-27 Nelson Caldwell , Ricardo Schiavon , Heather Morrison , James A. Rose , Paul Harding

We present a chemical abundance study of three inner old halo clusters NGC 6287, NGC 6293, and NGC 6541, finding [Fe/H] = -2.01 +/- 0.05, -1.99 +/- 0.02, and -1.76 +/- 0.02, respectively, and our metallicity measurements are in good…

天体物理学 · 物理学 2009-11-07 Jae-Woo Lee , Bruce W. Carney

We present spectroscopic ages, metallicities, and [alpha/Fe] ratios for 70 globular clusters in M31 that were derived from Lick line-index measurements. In addition to a population of old (>10 Gyr) globular clusters with a wide range of…

天体物理学 · 物理学 2009-11-10 Thomas H. Puzia , Kathy M. Perrett , Terry J. Bridges

We study the metallicity distribution and evolution in the Galactic disk based on the largest sample of open star clusters in the Galaxy. From the catalogue of 1879 open clusters in the range of Galactocentric distance (R_GC) from 4 to 20…

星系天体物理 · 物理学 2024-03-29 Yogesh C. Joshi , Deepak , Sagar Malhotra

The problem of the chemical composition gradient in the galactic disk is studied based on a sample of metallicity estimates of open star clusters, using Gaia DR2-improved distance estimates. A clearly non-monotonic variation was observed in…

太阳与恒星天体物理 · 物理学 2020-05-06 A. V. Loktin , M. E. Popova

We have carried out a big FLAMES survey of 10 Galactic open clusters aiming at different goals. One of them is the determination of chemical abundances, in order to put constraints on the radial metallicity gradient in the disk and its…

天体物理学 · 物理学 2009-11-13 P. Sestito , S. Randich , A. Bragaglia

The radial metallicity distribution in the Galactic thin disc represents a crucial constraint for modelling disc formation and evolution. Open clusters allow us to derive both the radial metallicity distribution and its evolution over time.…

We summarize radial velocity studies of selected stars in the old, distant clusters Berkeley 20, Berkeley 21, NGC 2141, Berkeley 29, and Berkeley 31. Three members of M67 were observed similarly, and those velocities compare extremely well…

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

We present new high resolution spectroscopic observations of the intermediate age (~2 Gyr) open cluster NGC 752. We investigate the Li vs. Teff distribution and we obtain a new accurate determination of the cluster metallicity. We compare…

天体物理学 · 物理学 2009-11-10 P. Sestito , S. Randich , R. Pallavicini

We present JHKs near-infrared CCD photometric study for the Galactic open clusters NGC 1641 and NGC 2394. These clusters have never been studied before, and we provide, for the first time, the cluster parameters; reddening, distance,…

天体物理学 · 物理学 2015-06-24 Sang Chul Kim

We present results derived from VLT-FORS2 spectra of 17 globular clusters associated with the nearby lenticular galaxy NGC3115. Comparing line-strength indices to new stellar population models by Thomas et al. we determine ages,…

天体物理学 · 物理学 2007-05-23 Harald Kuntschner , Bodo L. Ziegler , R. M. Sharples , Guy Worthey , Klaus J. Fricke

We present a detailed abundance analysis of giant stars in NGC 1978, a massive, intermediate-age stellar cluster in the Large Magellanic Cloud, characterized by a high ellipticity and suspected to have a metallicity spread. We analyzed 11…

天体物理学 · 物理学 2009-11-11 Francesco R. Ferraro , Alessio Mucciarelli , Eugenio Carretta , Livia Origlia

Open clusters have long been used to illuminate both stellar evolution and Galactic evolution. The oldest clusters, though rather rare, can reveal the chemical and nucleosynthetic processes early in the history of the Galaxy. We have…

星系天体物理 · 物理学 2015-05-13 Ann Merchant Boesgaard , Elizabeth E. C. Jensen , Constantine P. Deliyannis

In this paper, we make use of data collected for open cluster members by high-resolution spectroscopic surveys and programmes (i.e., APOGEE, Gaia-ESO, GALAH, OCCASO, and SPA). These data have been homogenised and then analysed as a whole.…

星系天体物理 · 物理学 2022-02-02 Lorenzo Spina , Laura Magrini , Katia Cunha

We report the first high spectral resolution study of 17 M giants kinematically confirmed to lie within a few parsecs of the Galactic Center, using R=24,000 spectroscopy from Keck/NIRSPEC and a new linelist for the infrared K band. We…

星系天体物理 · 物理学 2017-11-29 R. M. Rich , N. Ryde , B. Thorsbro , T. K. Fritz , M. Schultheis , L. Origlia , H. Jönsson

(Abridged for arXiv) The history of the mass assembly of brightest cluster galaxies may be studied by the mapping the stellar populations at large radial distances from the galaxy centre. We provide extended and robust measurements of the…

We analyse CCD broad band (UBV(RI)c) photometric data obtained in the fields of the poorly studied open clusters NGC 2425 and NGC 2635. Both clusters are found to be of intermediate age thus increasing the population of open clusters known…

天体物理学 · 物理学 2009-11-11 A. Moitinho , G. Carraro , G. Baume , R. A. Vazquez

We present results derived from VLT-FORS2 spectra of 24 different globular clusters associated with the lenticular galaxy NGC3115. A subsample of 17 globular clusters have sufficiently high signal-to-noise to allow precision measurements of…

天体物理学 · 物理学 2009-11-07 Harald Kuntschner , Bodo L. Ziegler , R. M. Sharples , Guy Worthey , Klaus J. Fricke

We report metallicities for three $\sim$Gyr-old stars in the Milky Way nuclear star cluster (NSC) using high-resolution near-infrared spectroscopy. We derive effective temperatures from a calibration with Sc line strength, which yields…

Open clusters are a useful tool when investigating several topics connected with stellar evolution; for example the age or distance can be more accurately determined than for field stars. However, one important parameter, the metallicity,…

太阳与恒星天体物理 · 物理学 2015-06-16 M. Netopil , E. Paunzen