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Title: Another brick in understanding chemical and kinematical properties of BSSs: NGC 6752

We used high-resolution spectra acquired with the multifiber facility FLAMES at the Very Large Telescope of the European Southern Observatory to investigate the chemical and kinematical properties of a sample of 22 blue straggler stars (BSSs) and 26 red giant branch stars in the nearby globular cluster NGC 6752. We measured radial and rotational velocities and Fe, O, and C abundances. According to radial velocities, metallicity, and proper motions, we identified 18 BSSs as likely cluster members. We found that all the BSSs rotate slowly (less than 40 km s{sup –1}), similar to the findings in 47 Tucanae, NGC 6397, and M30. The Fe abundance analysis reveals the presence of three BSSs affected by radiative levitation (showing [Fe/H] significantly higher than that measured in 'normal' cluster stars), confirming that element transport mechanisms occur in the photosphere of BSSs hotter than ≅8000 K. Finally, BSS C and O abundances are consistent with those measured in dwarf stars. No C and O depletion ascribable to mass transfer processes has been found on the atmospheres of the studied BSSs (at odds with previous results for 47 Tucanae and M30), suggesting the collisional origin for BSSs in NGC 6752 or that the CO depletionmore » is a transient phenomenon.« less
Authors:
; ; ; ;  [1]
  1. Dipartimento di Fisica and Astronomia, Università degli Studi di Bologna, viale Berti Pichat 6/2, I-40127 Bologna (Italy)
Publication Date:
OSTI Identifier:
22341986
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 778; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; BRICKS; CARBON MONOXIDE; DWARF STARS; FLAMES; LEVITATION; MASS TRANSFER; METALLICITY; PHOTOSPHERE; PROPER MOTION; RADIAL VELOCITY; RESOLUTION; SPECTRA; STAR CLUSTERS; STAR EVOLUTION; TELESCOPES; TRANSIENTS