Globular cluster and halo field abundances: similarities and a few differences
نویسندگان
چکیده
منابع مشابه
Nitrogen Overabundance: Globular Cluster and Halo Formation
Halo globular clusters pose four succinct issues that must be solved in any scenario of their formation: single-age, single metallicity stellar populations; a lower limit ([Fe/H]∼-2.3) to their average metallicity; comprising only 1% of the stellar halo mass, and being among the oldest stars in our Galaxy. New spectra are presented of Galactic stars and integrated spectra of Galactic globular c...
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Context. Globular clusters (GCs) in the outer halo are important probes of the composition and origin of the Galactic stellar halo. Aims. We derive chemical element abundance ratios in red giants belonging to the remote (R ∼90 kpc) GC Pal 3 and compare our measurements to those for red giant stars in both inner and outer halo GCs. Methods. From high-resolution spectroscopy of four red giants, o...
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The behaviour of the ∆ν=2 CO bands around 2.3 μm was examined by comparing observed and synthetic spectra in stars in globular clusters of different metallicity. Changes in the C/C isotopic ratio and the carbon abundances were investigated in stars from 3500–4900 K in the galactic globular clusters M71, M5, M3 and M13, covering the metallicity range from –0.7 to –1.6. We found relatively low ca...
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Main sequence turno magnitudes from the recent set of Yale isochrones (Chaboyer et al. 1995) have been combined with a variety of relations for the absolute magnitude of RR Lyr stars (Mv(RR)) to calibrate age as a function of the di erence in magnitude between the main sequence turn-o and the horizontal branch ( V HB). A best estimate for the calibration of Mv(RR) is derived from a survey of th...
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ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2005
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921305005934