Chemical Abundances Of Open Clusters From High-Resolution Infrared Spectra. II. NGC 752

Abstract

We present a detailed near-infrared chemical abundance analysis of 10 red giant members of the Galactic open cluster NGC 752. High-resolution (R$\simeq$45000) near-infrared spectral data were gathered with the Immersion Grating Infrared Spectrograph (IGRINS), providing simultaneous coverage of the complete H and K bands. We derived the abundances of H-burning (C, N, O), $\alpha$ (Mg, Si, S, Ca), light odd-Z (Na, Al, P, K), Fe-group (Sc, Ti, Cr, Fe, Co, Ni) and neutron-capture (Ce, Nd, Yb) elements. We report the abundances of S, P, K, Ce, and Yb in NGC 752 for the first time. Our analysis yields solar metallicity and solar abundance ratios for almost all of the elements heavier than the CNO group in NGC 752. O and N abundances were measured from a number of OH and CN features in the $H$ band, and C abundances were determined mainly from CO molecular lines in the K band. High excitation \ion{C}{i} lines present in both near-infrared and optical spectra were also included in the C abundance determinations. Carbon isotopic ratios were derived from the R-branch band heads of first overtone (2-0) and (3$-$1) ${}^{12}$CO and (2-0) ${}^{13}$CO lines near 23440 Åand (3-1) ${}^{13}$CO lines at about 23730 Å. The CNO abundances and ${}^{12}$C/${}^{13}$C ratios are all consistent with our giants having completed "first dredge-up" envelope mixing of CN-cyle products. We independently assessed NGC 752 stellar membership from Gaia astrometry, leading to a new color-magnitude diagram for this cluster. Applications of Victoria isochrones and MESA models to these data yield an updated NGC 752 cluster age (1.52 Gyr) and evolutionary stage indications for the program stars. The photometric evidence and spectroscopic light element abundances all suggest that the most, perhaps all of the program stars are members of the helium-burning red clump in this cluster.

16 pages, 11 figures

References in corpus (8)

• The Gaia mission
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The Chemical Compositions and Evolutionary Status of Red Giants in the Open Cluster NGC 752
• Sulfur and zinc abundances of red giant stars
• Deriving temperature, mass and age of evolved stars from high-resolution spectra. Application to field stars and the open cluster IC 4651
• Chemical Abundances Of Open Clusters From High-Resolution Infrared Spectra. I. NGC 6940
• The chemical compositions and evolutionary status of red giants in the open cluster NGC 6940
• A Comparison of the Chemical Composition of Main Sequence and Giant Stars in the Open Cluster NCC 752

Cited by in corpus (11)

• The GALAH survey: effective temperature calibration from the InfraRed Flux Method in the Gaia system
• The Galactic Chemical Evolution of phosphorus observed with IGRINS
• Chemical Evolution of Ytterbium in the Galactic Disk
• Effective Temperature Estimations from Line Depth Ratios in the \H\ and \K-band Spectra of IGRINS
• High-resolution near-infrared spectroscopy of globular cluster and field stars toward the Galactic bulge
• UOCS. XIV. Uncovering extremely low mass white dwarfs and blue lurkers in NGC 752
• Evolved Eclipsing Binaries and the Age of the Open Cluster NGC 752
• A uvbyCaHbeta CCD Analysis of the Open Cluster Standard, M67,and its Relation to NGC 752
• M giants with IGRINS IV. Identification and characterization of a near-IR line of the s-element Barium
• $H$-band Temperature and Metallicity Indicators for Cool Giants: Empirical Relations in Bayesian Framework
• A Near-Infrared and Optical Study of NGC 5822: An Open Cluster Hosting Barium-stars and Lithium-Enriched Giant Stars