NOAO >   Observing Info >   Approved Programs >   2004A-0206

Small NOAO Logo

Proposal Information for 2004A-0206


PI: Ekaterina Verner, NASA Goddard Space Flight Center, kverner@fe2.gsfc.nasa.gov
Address: GSFC/NASA and CUA, Greenbelt, MD 27071, USA

CoI: Kimiaki Kawara, Institute of Astronomy, University of Tokyo
CoI: Yuzuru Yoshii, Institute of Astronomy,University of Tokyo
CoI: Bruce A. Peterson, Australian National University
CoI: Fred Bruhweiler, NASA Goddard Space Flight Center
CoI: Yumihiko Tsuzuki, Institute of Astronomy,University of Tokyo
CoI: Shinki Oyabu, Institute of Astronomy,University of Tokyo
CoI: Yoshiki Matsuoka, Institute of Astronomy,University of Tokyo

Title: Age Dating of Host Galaxies: Fe Abundance in Quasars at z = 2.4 - 3.6

Abstract: \quadA delay of ~ 1 - 2 Gyr in Fe enrichment, relative to (alpha) elements such as O and Mg, can be used as a chronometer for measuring the age of quasars, thus providing the information on the geometry of the Universe. Since many quasars exhibit prominent \ionFe2 emission features and the \ionMg2 resonance doublet near 2800 \AA in the UV, previous efforts were focused only on \ionFe2 (UV)/\ionMg2 measurements and no dependency on redshift has been found. Meanwhile, our model predicts that \ionFe2 emission in 4000 - 6000 \AA is sensitive to iron abundance. Therefore, to derive iron abundance we need to observe wide wavelength range and to measure both \ionFe2 (UV)/\ionMg2 and \ionFe2 (UV)/\ionFe2 (Optical) ratios, comparing them with the model. We will obtain optical and IR spectra of selected 7 quasars at z=2.4 - 3.6 by using the GoldCam on the KPNO 2.1m telescope, the FLMN on the KPNO 4m telescope, and the NIRI on the Gemini North. There is no explanation for large scatter of \ionFe2 (UV)/\ionMg2 ratios at this redshift. Yet there is already found one quasar with strong \ionFe2 (Optical) emission at z ~ 2.5. Applying our method in the wide wavelength spectra, we will derive the physical conditions in quasars and test the chemical evolution models.


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 >   2004A-0206

noaoprop-help@noao.edu

Small NOAO Logo