RED SUPERGIANTS AS COSMIC ABUNDANCE PROBES: THE FIRST DIRECT METALLICITY DETERMINATION OF NGC 4038 IN THE ANTENNAE

Journal Article · Tue Oct 20 00:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/812/2/160· OSTI ID:22518757

Lardo, C.; Davies, B. ^[1]; Kudritzki, R-P.; Gazak, J. Z. ^[2]; Evans, C. J. ^[3]; Patrick, L. R. ^[4]; Bergemann, M. ^[5]; Plez, B. ^[6]

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1. Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom)
2. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
3. UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)
4. Institute for Astronomy, University of Edinburgh, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)
5. Max-Planck Institute for Astronomy, D-69117 Heidelberg (Germany)
6. Laboratoire Univers et Particules de Montpellier, Université de Montpellier, CNRS, F-34095 Montpellier (France)

We present a direct determination of the stellar metallicity in the close pair galaxy NGC 4038 (D = 20 Mpc) based on the quantitative analysis of moderate-resolution KMOS/Very Large Telescope spectra of three super star clusters. The method adopted in our analysis has been developed and optimized to measure accurate metallicities from atomic lines in the J-band of single red supergiant (RSG) or RSG-dominated star clusters. Hence, our metallicity measurements are not affected by the biases and poorly understood systematics inherent to strong line H ii methods, which are routinely applied to massive data sets of galaxies. We find [Z] = +0.07 ± 0.03 and compare our measurements to H ii strong line calibrations. Our abundances and literature data suggest the presence of a flat metallicity gradient, which can be explained as redistribution of metal-rich gas following the strong interaction.

• OSTI ID: 22518757
• Journal Information: Astrophysical Journal, Vol. 812, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ANTENNAS
CALIBRATION
COMPARATIVE EVALUATIONS
ELEMENT ABUNDANCE
GALAXIES
HYDROGEN
METALLICITY
PROBES
RED GIANT STARS
RESOLUTION
STAR CLUSTERS
TELESCOPES