NOAO >   Observing Info >   Approved Programs >   2017B-0200

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Program Information for 2017B-0200


PI: Letizia Stanghellini, NOAO, lstanghellini@noao.edu
Address: PO Box 26732, 950 NORTH CHERRY AVENUE, TUCSON, AZ 85726-6732 USA

CoI: Magda Arnaboldi, ESO
CoI: Laura Magrini, INAF-Osservatorio Astrofisico di Arcetri
CoI: Viviana Casasola, INAF-Osservatorio Astrofisico di Arcetri
CoI: Suryashree Aniyan, Australian National U.
CoI: Lodovico Coccato, ESO
CoI: Paola Di Matteo, Obs. Paris Meudon
CoI: Ken Freeman, Australian National U.
CoI: Ortwin Gerhard, Max-Planck-Institut für Extraterrestrische Physik
CoI: Misha Haywood, Obs. Paris Meudon
CoI: Silvia Torres-Peimbert, UNAM

Title: Time evolution of metallicity gradients: oxygen abundance measurements for young and old metallicity probes in NGC 628

Abstract: We propose to measure the time evolution of the metallicity gradients in the face-on spiral NGC 628, using tracers whose ages extend over a time window of 10 Gyr. This measurement is now possible because of the recent identification of distinct kinematically cold and hot planetary nebula (PN) populations over the galaxy disc, which have progenitor ages of < 2 Gyr and 5-10 Gyr, respectively. We will use auroral lines to measure the abundances of the gaseous remnants (the PNe envelopes) of these different populations, and thus construct independent radial abundance profiles for young, and old, PN progenitor stars. Including existing direct abundance measurements for the HII regions, we will have radial metallicity gradients for three different look-back times. This will allow us to constrain the processes that influence abundance gradients, such as gas infall, chemical evolution, feedback and radial migration, by comparing with cosmological models of galaxy evolution

Program Type: Standard/Galactic

Scheduled Nights:
Run 2 (2017B):  GEM-SQ/GMOSS -- 11hrs band 2 (GS-2017B-Q-59)


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2017B-0200

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