We report abundance analysis for six M giant members of the old open cluster NGC 6791, based on infrared spectroscopy (1.5-1.8 mum) at R=25,000, using the NIRSPEC spectrograph at the Keck II telescope. We find the iron abundance =+0.35+/-0.02, confirming the supersolar metallicity of this cluster as derived from optical medium-high resolution spectroscopy. We also measure C, O, and other alpha-element abundances, finding a roughly solar value of [alpha/Fe] and =-0.35. Our approach constrains [O/Fe] especially well, on the basis of the measurement of a number of OH lines near 1.6 mum we find [O/Fe]=-0.07+/-0.03. The solar value of [alpha/Fe] is in contrast to the composition of similar stars in the Galactic bulge. We also find a low value of 12C/13C~10, confirming the presence of extramixing processes during the red giant phase of evolution, up to supersolar metallicities.

Origlia L., Valenti E., Rich R. M., Ferraro F.R. (2006). High-Resolution Infrared Spectroscopy of the Old Open Cluster NGC 6791. THE ASTROPHYSICAL JOURNAL, 646, 499-504 [10.1086/504829].

High-Resolution Infrared Spectroscopy of the Old Open Cluster NGC 6791

VALENTI, ELENA;FERRARO, FRANCESCO ROSARIO
2006

Abstract

We report abundance analysis for six M giant members of the old open cluster NGC 6791, based on infrared spectroscopy (1.5-1.8 mum) at R=25,000, using the NIRSPEC spectrograph at the Keck II telescope. We find the iron abundance =+0.35+/-0.02, confirming the supersolar metallicity of this cluster as derived from optical medium-high resolution spectroscopy. We also measure C, O, and other alpha-element abundances, finding a roughly solar value of [alpha/Fe] and =-0.35. Our approach constrains [O/Fe] especially well, on the basis of the measurement of a number of OH lines near 1.6 mum we find [O/Fe]=-0.07+/-0.03. The solar value of [alpha/Fe] is in contrast to the composition of similar stars in the Galactic bulge. We also find a low value of 12C/13C~10, confirming the presence of extramixing processes during the red giant phase of evolution, up to supersolar metallicities.
2006
Origlia L., Valenti E., Rich R. M., Ferraro F.R. (2006). High-Resolution Infrared Spectroscopy of the Old Open Cluster NGC 6791. THE ASTROPHYSICAL JOURNAL, 646, 499-504 [10.1086/504829].
Origlia L.; Valenti E.; Rich R. M.; Ferraro F.R.
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/29632
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 75
  • ???jsp.display-item.citation.isi??? 81
social impact