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相关论文: An Old Cluster in NGC 6822

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We present a detailed analysis of the chemistry and kinematics of red giants in the dwarf irregular galaxy NGC 6822. Spectroscopy at 8500 Angstroms was acquired for 72 red giant stars across two fields using FORS2 at the VLT. Line of sight…

星系天体物理 · 物理学 2016-02-08 Jesse Swan , Andrew A. Cole , Eline Tolstoy , Mike J. Irwin

In the present work we analyzed seven globular clusters selected from their location in the Galactic bulge and with metallicity values in the range $-1.30\lesssim\rm{[Fe/H]}\lesssim-0.50$. The aim of this work is first to derive cluster…

The metallicity gradient and the stellar distribution within the Local Group dwarf galaxy NGC 6822 has been studied photometrically using asymptotic branch stars (AGB). In order to study the stellar and metallicity distribution, the carbon-…

太阳与恒星天体物理 · 物理学 2010-11-22 L. F. Sibbons , M. -R. L. Cioni , M. Irwin , M. Rejkuba

In this study, we report conclusive evidence for an ancient star cluster that has been accreted by the Large Magellanic Cloud (LMC). By leveraging observations from the Hubble Space Telescope (HST), we investigate the chrono-dynamical…

UV-to-visual spectra of eight young star clusters in the merger remnant and protoelliptical galaxy NGC 7252, obtained with the Blanco 4-m telescope on Cerro Tololo, are presented. These clusters lie at projected distances of 3-15 kpc from…

天体物理学 · 物理学 2009-10-30 Francois Schweizer , Patrick Seitzer

We present homogeneous age determinations for a large sample of 55 Galactic globular clusters, which constitute about 30% of the total Galactic population. A study of their age distribution reveals that all clusters from the most metal poor…

天体物理学 · 物理学 2008-11-26 M. Salaris , A. Weiss

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…

The Small Magellanic Cloud (SMC) is the only dwarf galaxy in the Local Group known to have formed and preserved populous star clusters continuously over the past 12 Gyr. These clusters provide a unique, closely spaced set of single-age,…

天体物理学 · 物理学 2007-05-23 A. Kayser , E. K. Grebel , D. R. Harbeck , A. A. Cole , A. Koch , J. S. Gallagher , G. S. Da Costa

We present the results of determination of the age, helium mass fraction (Y), metallicity ([Fe/H]), and abundances of the elements C, N, O, Na, Mg, Ca, Ti, C and Mn for the Galactic globular cluster NGC 6652. We use its medium-resolution…

星系天体物理 · 物理学 2020-09-02 M. E. Sharina , V. V. Shimansky

We present high-quality, Keck spectroscopic data for a sample of 20 globular clusters (GCs) in the massive E0 galaxy NGC1407. A subset of twenty line-strength indices of the Lick/IDS system have been measured for both the GC system and the…

天体物理学 · 物理学 2008-11-26 A. Javier Cenarro , Michael A. Beasley , Jay Strader , Jean P. Brodie , Duncan A. Forbes

We have obtained V and I images of the lone globular cluster that belongs to the dwarf Local Group irregular galaxy known as WLM. The color-magnitude diagram of the cluster shows that it is a normal old globular cluster with a well-defined…

天体物理学 · 物理学 2009-10-31 Paul W. Hodge , Andrew E. Dolphin , Toby R. Smith , Mario Mateo

HST (V,I) photometry has been obtained for the inner halo globular cluster NGC 6652. The photometry reaches approximately 4 mag below the turn-off and includes a well populated horizontal branch. This cluster is located close to the…

天体物理学 · 物理学 2009-10-31 Brian Chaboyer , Ata Sarajedini , Taft E. Armandroff

We present Spitzer imaging of the metal-deficient (Z ~30% Z_sun) Local Group dwarf galaxy NGC 6822. On spatial scales of ~130 pc, we study the nature of IR, H alpha, HI, and radio continuum emission. Nebular emission strength correlates…

I propose and apply a method for deriving ages of the metal-poor globular clusters (GCs) in a distance-independent way, which is based on age indicator related to the main sequence in the two-color diagrams with U-B index. Age of the…

天体物理学 · 物理学 2007-05-23 Valery V. Kravtsov

We present the age determination of 13 globular clusters dynamically associated with the Gaia-Sausage-Enceladus (GSE) merger event, as part of the CARMA project effort to trace the Milky Way assembly history. We used deep and homogeneous…

We present the abundances analysis for a sample of 11 red giant branch stars in the metal-poor globular cluster NGC 6809 based on high-resolution spectra. Our main goals are to characterize its chemical composition and analyze this…

太阳与恒星天体物理 · 物理学 2018-12-19 M. J. Rain , S. Villanova , C. Muñoz , C. Valenzuela-Calderon

Using two epochs of observations with HST/WFPC2 we obtain the stellar proper motions for all stars in the field. The proper motions are used to separate the bulge from the cluster stars. The stellar sequences in the resulting colour-…

天体物理学 · 物理学 2007-05-23 Sofia Feltzing , Rachel Johnson

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 the results of medium-resolution spectroscopy of 28 globular clusters (GCs) in six nearby galaxies of different luminosities and morphological types, situated in: M33 (15 objects), M31 (3), IC10 (4), UGCA86 (4), HolmbergIX (1),…

宇宙学与河外天体物理 · 物理学 2015-05-18 Margarita E. Sharina , Rupali Chandar , Thomas H. Puzia , Paul Goudfrooij , Emmanuel Davoust

We present moderate-resolution Keck spectra of nine candidate globular clusters in the possible merger-remnant elliptical galaxy NGC 3610. Eight of the objects appear to be bona fide globular clusters of NGC 3610. We find that two of the…

天体物理学 · 物理学 2009-11-07 Jay Strader , Jean P. Brodie , Francois Schweizer , Soeren S. Larsen , Patrick Seitzer