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相关论文: Fluorine variations in the globular cluster NGC 66…

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Fluorine is one of the most interesting elements for nuclear and stellar astrophysics. Fluorine abundance was first measured for stars other than the Sun in 1992, then for a handful metal-poor stars, which are likely to have formed in the…

We report the first high resolution, detailed abundances of 21 elements for giants in the Galactic bulge/bar within $1^\circ$ of the Galactic plane, where high extinction has rendered such studies challenging. Our high S/N and…

(shortened) The peculiar chemistry observed in the multiple populations of Galactic globular clusters is not generally found in other systems like dwarf galaxies and open clusters, and at the moment no model can fully explain its presence.…

太阳与恒星天体物理 · 物理学 2018-06-20 E. Pancino

We derive ages, metallicities and [alpha/Fe] ratios from the integrated spectra of 23 globular clusters in M31, by employing multivariate fits to two stellar population models. In parallel we analyze spectra of 21 Galactic globular clusters…

Large star-to-star variations of the abundances of proton-capture elements, such as Na and O, in globular clusters (GCs) are interpreted as the effect of internal pollution resulting from the presence of multiple stellar populations. To…

Although globular clusters are generally chemically homogeneous, substantial abundance variations are sometimes seen even among unevolved main sequence stars, especially for the CNO group of elements. Multi-object intermediate-dispersion…

天体物理学 · 物理学 2007-05-23 Russell Cannon , Gary Da Costa , John Norris , Laura Stanford , Barry Croke

The Fornax dwarf spheroidal galaxy has an anomalous number of globular clusters, five, for its stellar mass. There is a longstanding debate about a potential sixth globular cluster (Fornax~6) that has recently been `rediscovered' in DECam…

We present a comparison of high-resolution, integrated-light, detailed chemical abundances for Galactic and extragalactic globular clusters in both massive galaxies and dwarf galaxies. We include measurements of Fe, Ca, Si, Na, and Al for…

宇宙学与河外天体物理 · 物理学 2013-02-27 J. E. Colucci , R. A. Bernstein , A. McWilliam , J. G. Cohen

The [Sr/Ba] and [Y/Ba] scatter observed in some galactic halo stars that are very metal-poor stars and in a few individual stars of the oldest known Milky Way globular cluster NGC 6522,have been interpreted as evidence of early enrichment…

We derive the first detailed chemical abundances of three star clusters in the Large Magellanic Cloud (LMC), NGC1831 (436+/-22 Myr), NGC1856 (350+/-18 Myr) and [SL63]268 (1230+/-62 Myr) using integrated-light spectroscopic observations…

星系天体物理 · 物理学 2022-05-11 Randa Asa'd , S. Hernandez , A. M. As'ad , M. Molero , F. Matteucci , S. Larsen , Igor V. Chilingarian

We present chemical abundances for 17 elements in a sample of 11 red giant branch stars in NGC 6362 from UVES spectra. NGC 6362 is one of the least massive globulars where multiple populations have been detected, yet its detailed chemical…

太阳与恒星天体物理 · 物理学 2017-04-12 D. Massari , A. Mucciarelli , E. Dalessandro , M. Bellazzini , S. Cassisi , G. Fiorentino , R. A. Ibata , C. Lardo , M. Salaris

The prediction of the PLANCK-constrained primordial lithium abundance in the Universe is in discordance with the observed Li abundances in warm Population II dwarf and subgiant stars. Among the physically best motivated ideas, it has been…

The information on Galactic assembly time is imprinted on the chemodynamics of globular clusters. This makes them important probes that help us to understand the formation and evolution of the Milky Way. Discerning between in-situ and…

We present estimates of CN and Mg overabundances with respect to Fe for early-type galaxies in 8 clusters over a range of richness and morphology. Spectra were taken from the Sloan Digital Sky Survey (SDSS) DR1, and from WHT and CAHA…

天体物理学 · 物理学 2009-11-10 C. Carretero , A. Vazdekis , J. E. Beckman , P. Sanchez-Blazquez , J. Gorgas

We present the abundance analysis of 82 red giant branch stars in the dense, metal-poor globular cluster NGC 6093 (M 80), the largest sample of stars analyzed in this way for this cluster. From high resolution UVES spectra of 14 stars and…

星系天体物理 · 物理学 2015-03-12 E. Carretta , A. Bragaglia , R. G. Gratton , V. D'Orazi , S. Lucatello , A. Sollima , Y. Momany , G. Catanzaro , F. Leone

We present the Ca-CN-CH photometry of the metal-complex globular cluster (GC) M22 (NGC 6656). Our photometry clearly shows the discrete double CN-CH anticorrelations in M22 red giant branch (RGB) stars, due to the difference in the mean…

星系天体物理 · 物理学 2020-01-15 Jae-Woo Lee

We derive [K/Fe] abundance ratios for 119 stars in the globular cluster NGC 2808, all of them having O, Na, Mg and Al abundances homogeneously measured in previous works. We detect an intrinsic star-to-star spread in the Potassium…

太阳与恒星天体物理 · 物理学 2015-06-23 A. Mucciarelli , M. Bellazzini , T. Merle , B. Plez , E. Dalessandro , R. Ibata

We analyse the population of bright star clusters in the interacting galaxy pair NGC 4038/39 detected with HST WFPC1 by Whitmore & Schweizer (1995) using our spectrophotometric evolutionary synthesis models for various initial…

天体物理学 · 物理学 2007-05-23 Uta Fritze-v. Alvensleben

Phosphorus enhanced (P-rich; [P/Fe] > 0.8) giants have been found among mildly metal-poor fiels stars, but in only one star in a globular cluster (GC), M4 (NGC 6121). Also, in a sample of bulge spheroid stars, some of them showed a moderate…

Recent work has shown that most globular clusters have at least two chemically distinct components, as well as cluster-to-cluster differences in the mean [O/Fe], [Mg/Fe], and [Si/Fe] ratios at similar [Fe/H] values. In order to investigate…