TY - JOUR
T1 - The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters - IV. Helium content and relative age of multiple stellar populations within NGC 6352
AU - Nardiello, D.
AU - Piotto, G.
AU - Milone, A. P.
AU - Marino, A. F.
AU - Bedin, L. R.
AU - Anderson, J.
AU - Aparicio, A.
AU - Bellini, A.
AU - Cassisi, S.
AU - D'Antona, F.
AU - Hidalgo, S.
AU - Ortolani, S.
AU - Pietrinferni, A.
AU - Renzini, A.
AU - Salaris, M.
AU - van der Marel, R. P.
AU - Vesperini, E.
N1 - Publisher Copyright:
© 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2015/5/1
Y1 - 2015/5/1
N2 - In this paper, we combine Wide Field Camera3/UVIS F275W, F336W, and F438W data from the 'UV Legacy Survey of Galactic Globular Clusters: Shedding Light on Their Populations and Formation' (GO 13297) Hubble Space Telescope Treasury programme with F606W, F625W, F658N, and F814WAdvanced Camera for Surveys archive data for a multiwavelength study of the globular cluster NGC 6352. In the colour-magnitude and two-colour diagrams obtained with appropriate combination of the photometry in the different bands, we separate two distinct stellar populations and trace them from the main sequence to the subgiant, red giant, horizontal and asymptotic giant branches. We infer that the two populations differ in He by ΔY = 0.029 ± 0.006. With a new method, we also estimate the age difference between the two sequences. Assuming no difference in [Fe/H] and [α/Fe], and the uncertainties on ΔY, we found a difference in age between the two populations of 10 ± 120 Myr. If we assume [Fe/H] and [α/Fe] differences of 0.02 dex (well within the uncertainties of spectroscopic measurements), the total uncertainty in the relative age rises to ~300 Myr.
AB - In this paper, we combine Wide Field Camera3/UVIS F275W, F336W, and F438W data from the 'UV Legacy Survey of Galactic Globular Clusters: Shedding Light on Their Populations and Formation' (GO 13297) Hubble Space Telescope Treasury programme with F606W, F625W, F658N, and F814WAdvanced Camera for Surveys archive data for a multiwavelength study of the globular cluster NGC 6352. In the colour-magnitude and two-colour diagrams obtained with appropriate combination of the photometry in the different bands, we separate two distinct stellar populations and trace them from the main sequence to the subgiant, red giant, horizontal and asymptotic giant branches. We infer that the two populations differ in He by ΔY = 0.029 ± 0.006. With a new method, we also estimate the age difference between the two sequences. Assuming no difference in [Fe/H] and [α/Fe], and the uncertainties on ΔY, we found a difference in age between the two populations of 10 ± 120 Myr. If we assume [Fe/H] and [α/Fe] differences of 0.02 dex (well within the uncertainties of spectroscopic measurements), the total uncertainty in the relative age rises to ~300 Myr.
KW - Globular clusters: individual: NGC 6352
KW - Stars: Population II
KW - Techniques: photometric
UR - http://www.scopus.com/inward/record.url?scp=84938239219&partnerID=8YFLogxK
U2 - 10.1093/mnras/stv971
DO - 10.1093/mnras/stv971
M3 - Article
SN - 0035-8711
VL - 451
SP - 312
EP - 322
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -