The Open Cluster Chemical Abundances and Mapping Survey. VII. APOGEE DR17 [C/N]–Age Calibration

Journal Article · Fri Apr 22 04:00:00 EDT 2022 · The Astronomical Journal

DOI:https://doi.org/10.3847/1538-3881/ac5d53· OSTI ID:1983161

Spoo, Taylor ^[1]; Tayar, Jamie ^[2]; Frinchaboy, Peter M. ^[1]; Cunha, Katia ^[3]; Myers, Natalie ^[1]; Donor, John ^[1]; Majewski, Steven R. ^[4]; Bizyaev, Dmitry ^[5]; García-Hernández, Domingo Aníbal ^[6]; Jönsson, Henrik ^[7]; Lane, Richard R. ^[8]; Pan, Kaike ^[9]; Longa-Peña, Penélope ^[10]; Roman-Lopes, Alexandre ^[11]

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1. Texas Christian University, Fort Worth, TX (United States)
2. University of Hawaii at Manoa, Honolulu, HI (United States); University of Florida, Gainesville, FL (United States)
3. Observatório Nacional, Rio de Janeiro (Brazil); University of Arizona, Tucson, AZ (United States)
4. University of Virginia, Charlottesville, VA (United States)
5. Apache Point Observatory and New Mexico State University, Sunspot, NM (United States); Moscow State University, Moscow (Russian Federation)
6. Instituto de Astrofísica de Canarias, San Cristobal de La Laguna (Spain); University of La Laguna, San Cristobal de La Laguna (Spain)
7. Malmö University (Sweden)
8. Universidad Bernardo O'Higgins, Santiago (Chile)
9. Apache Point Observatory and New Mexico State University, Sunspot, NM (United States)
10. University of Antofagasta (Chile)
11. Universidad La Serena (Chile)

Large-scale surveys open the possibility to investigate Galactic evolution both chemically and kinematically; however, reliable stellar ages remain a major challenge. Detailed chemical information provided by high-resolution spectroscopic surveys of the stars in clusters can be used as a means to calibrate recently developed chemical tools for age-dating field stars. Using data from the Open Cluster Abundances and Mapping survey, based on the Sloan Digital Sky Survey/Apache Point Observatory Galactic Evolution Experiment 2 survey, we derive a new empirical relationship between open cluster stellar ages and the carbon-to-nitrogen ([C/N]) abundance ratios for evolved stars, primarily those on the red giant branch. With this calibration, [C/N] can be used as a chemical clock for evolved field stars to investigate the formation and evolution of different parts of our Galaxy. We explore how mixing effects at different stellar evolutionary phases, like the red clump, affect the derived calibration. We have established the [C/N]–age calibration for APOGEE Data Release 17 (DR17) giant star abundances to be $$\mathrm{log}{[\mathrm{Age}(\mathrm{yr})]}_{\mathrm{DR}17}=10.14\,(\pm 0.08)+2.23(\pm 0.19)\,[{\rm{C}}/{\rm{N}}]$$, usable for $$8.62\leqslant \mathrm{log}(\mathrm{Age}[\mathrm{yr}])\leqslant 9.82$$, derived from a uniform sample of 49 clusters observed as part of APOGEE DR17 applicable primarily to metal-rich, thin- and thick-disk giant stars. This measured [C/N]–age APOGEE DR17 calibration is also shown to be consistent with asteroseismic ages derived from Kepler photometry.

• Research Organization: US Department of Energy (USDOE), Washington, DC (United States). Office of Science, Sloan Digital Sky Survey (SDSS); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC); National Science Foundation (NSF)
• OSTI ID: 1983161
• Journal Information: The Astronomical Journal, Journal Name: The Astronomical Journal Journal Issue: 5 Vol. 163; ISSN 0004-6256
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
abundance ratios
chemical abundances
galactic abundances
open star clusters