1 / 16

Metallicity Evolution in Galaxies 0<z<1: Past, Present, and Future

This study by Lisa Kewley and collaborators explores the metallicity history of galaxies, from local samples like NFGS Galaxy Pairs to intermediate-z GOODS survey data. Using metallicity diagnostics and spectroscopic analysis, the research sheds light on the evolution of star-forming galaxies. The findings suggest a wider metallicity range in galaxy pairs compared to the NFGS sample, hinting at dynamical mixing influences. The study sets the stage for future research directions, including investigating LBGs, integrating near-IR spectra to resolve degeneracies, and refining emission-line selection models. Comprehensive and insightful, this work paves the way for further exploration in the field of galactic metallicity.

orien
Download Presentation

Metallicity Evolution in Galaxies 0<z<1: Past, Present, and Future

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Metallicity History of Galaxies 0<z<1 Lisa Kewley (IfA, U.Hawaii) Collaborators: C. Kobulnicky (U.Wyoming), M. Geller (SAO), B. Barton (UC Irvine), R. Jansen (ASU)

  2. Summary • Motivation • Metallicity diagnostics • Local samples: NFGS Galaxy Pairs • Intermediate-z: GOODS • Metallicity History 0<z<1 • Future Directions

  3. Motivation 1. Metallicity history of star-forming galaxies still largely theoretical. Nagamine et al. (2001)

  4. Motivation 2. [OII] SF History K98 [OII] SFR filled = [OII] unfilled = Ha data from Teplitz et al. (2003) Our [OII] SFR log(O/H)+12~8.6 AV=1 also: Rosa-Gonzalez, Terlevich, & Terlevich (2002) Our [OII] SFR log(O/H)+12~8.8 AV=1 Kewley, Geller & Jansen (2004)

  5. Metallicity Diagnostics “R23” Kewley & Dopita (2002, ApJS, 142, 35)

  6. Metallicity Diagnostics - [NII]/Ha Kewley & Dopita (2002, ApJS, 142, 35) also: Denicolo, Terlevich & Terlevich (2002, MNRAS, 330, 69) R23 and [NII]/Ha re-parameterized Kobulnicky & Kewley (2004,ApJ, 617, 240)

  7. Local Sample: NFGS • 198 galaxies objectively selected from the CfA galaxy survey • (Davis & Peebles 1983, Huchra et al. 1983) • full range in Hubble type • full range of absolute magnitudes in CfA survey • See Jansen et al. (2000) • http://cfa-www.harvard.edu/~jansen/nfgs/nfgssample.html

  8. Local Sample: Galaxy Pairs • 502 galaxies objectively selected from the CfA • redshift catalog • (v < 2300 km/s, Dv < 1035 km/s, DD < 77 h-1 Mpc) • Nuclear spectra for ~200 galaxies in pairs • (Barton et al. 2000) • EWs + stellar population synthesis • “burst timescale’’ (Barton et al. 2003)

  9. Pairs NFGS NFGS & Galaxy Pairs Nuclear Spectra: Requires Aperture Correction

  10. Aperture Correction Correction ~ 0.13 dex but may vary between 0-0.4 dex Kewley, Geller, & Jansen 2005, PASP, 117, 227

  11. GOODS Survey: 0.3 < z< 1 • 204 galaxies with metallicity-quality spectra • Metallicities calculated using EWs • Upper R23 branch assumed • Av=1 assumed if no Ha See Kobulnicky & Kewley (2004, ApJ, 617, 240)

  12. GOODS Survey: 0.3 < z< 1 Kobulnicky & Kewley (2004, ApJ, 617, 240)

  13. GOODS Survey: 0.3 < z< 1 Kobulnicky & Kewley (2004, ApJ, 617,240)

  14. Conclusions • Galaxy pairs nuclei span larger metallicity range • than NFGS: • less enriched - dynamical mixing? • Preliminary Metallicity History • (for star-forming galaxies) • Metallicity evolution observed.... • but more work to do...

  15. Pairs GOODS assumes upper branch Future Directions: 0<z<3 LBGs: Pettini et al. (2001) Shapley et al. (2004) Kobulnicky & Koo (2000)

  16. Future Directions • Near-IR Spectra (R23 degeneracy, Av) • Modelling of emission-line selection effects • More galaxies!

More Related