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The Cosmic Star Formation

The Cosmic Star Formation. and Metallicity History. Lisa Kewley Hubble Fellow U. Hawaii. with C. Kobulnicky (U.Wyoming), S. Ellison (U. Vic), M. Geller (CfA), R. Jansen (ASU). Summary. Motivation Star Formation Rates Cosmic Star Formation History Metallicity diagnostics

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The Cosmic Star Formation

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  1. The Cosmic Star Formation and Metallicity History Lisa Kewley Hubble Fellow U. Hawaii with C. Kobulnicky (U.Wyoming), S. Ellison (U. Vic), M. Geller (CfA), R. Jansen (ASU)

  2. Summary • Motivation • Star Formation Rates • Cosmic Star Formation History • Metallicity diagnostics • Cosmic Metallicity History • Conclusions & Future Directions

  3. Motivation Galaxy Evolution Image credit: R. Thompson, NASA Image credit: NASA

  4. Star Formation History Madau et al. (1996) Lilly et al. (1996)

  5. [OII] Optical Spectrum SFR measured in infrared, optical, radio, UV, X-rays

  6. Optical Spectrum disagreement SFR measured in infrared, optical, radio, UV, X-rays

  7. Star Formation Rate Discrepancies Teplitz et al. (2003) filled = [OII] unfilled = Ha

  8. Norman et al. (2003) 0 Teplitz et al. (2003) UV [OII] Ha IR radio comb -0.5 + + -1 + * * -1.5 x * log (MO / yr / Mpc3) . x -2 -2.5 0.2 0.8 0 0.4 0.6 Star Formation Rate Discrepancies SFR Density Redshift

  9. Towards SFR agreement Nearby Field Galaxy Survey (NFGS) • Jansen et al. (2000,2001) • 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 • integrated optical spectra

  10. Infrared Assumptions: young stars dominate emission large optical depth continuous burst model Salpeter IMF Measuring Star Formation Rates SFRIR = 4.5 x 10-44 x LIR e.g., Kennicutt (1998) NASA/JPL-Caltech/S. Willner (CfA)

  11. Optical : Ha Assumptions: no dust total re-emission of ionizing photons Salpeter IMF Measuring Star Formation Rates SFRHa = 7.9 x 10-42 x LHa e.g., Kennicutt (1998) Image credit: Fabio Bresolin (U. Hawaii)

  12. Ha vs. Infrared SFRs Kewley et al. (2002, AJ, 124, 3135) SFR(IR) SFR(Ha)

  13. Star Formation Rate Discrepancies Teplitz et al. (2003) filled = [OII] unfilled = Ha

  14. [OII] SFR SFR([OII]) = (1.4 +/- 0.4) x 10-41 x L([OII]) (Kennicutt 1998, 1992) Key Assumptions: Observed [OII]/Ha = 0.6 Observed [NII]/Ha = 0.5 (blended) No effect from ionization state of gas Independent of metallicity Salpeter IMF

  15. 100 rms = 0.11 1.0 Kewley, Geller, & Jansen (2004, AJ, 127, 2002) 0.01 0.01 1.0 100 SFR (Ha) 0.4 [OII] & Ha SFRs ratio -0.4 SFR [OII]

  16. [OII] SFR SFR([OII]) = (1.4 +/- 0.4) x 10-41 x L([OII]) (Kennicutt 1998, 1992) Key Assumptions: Observed [OII]/Ha = 0.6 Observed [NII]/Ha = 0.5 (blended) No effect from ionization state of gas Independent of metallicity Salpeter IMF

  17. Ionizing Radiation Field Starburst99 (Leitherer et al. 1999, Crowther et al. 2006) Instantaneous & Continuous Burst Models Extended Wolf-Rayet Atmospheres

  18. Photoionization Models Kewley et al. (2001) Mappings III- radiative transfer including dust Sutherland & Dopita 1993, Groves et al. 2003, 2006 Metallicity:0.05, 0.2, 0.4, 1.0, 2.0 x solar Ionization Parameter:1e7, 2e7, 4e7, 8e7, 1.5e8, 3e8 cm/s alternative: CLOUDY (Ferland et al. 1998)

  19. O ( ) log +12 H H ionizing photons/Area/s SH q = nH Ionization parameter: (cm/s) hydrogen density Definitions Metallicity = Gas-phase Oxygen Abundance = Solar ~ 8.7 (Allende Prieto et al. 2001)

  20. New [OII] calibration: Theoretical

  21. New [OII] calibration: Theoretical kHa L([OII]) SFR([OII],Z) = a+ bZ - cZ2 + dZ3 where Z = metallicity = log(O/H)+12 • Includes Metallicity & Ionization Parameter Correction Kewley, Geller, & Jansen (2004, AJ, 127, 2002)

  22. New [OII] calibration: Theoretical rms=0.04-0.05 (c.f. 0.11)

  23. Metallicity at High-z • Lilly, Carollo & Stockton 2003: M91 • 0.5 < z < 1.0 : log(O/H)+12~8.9 (c.f. 8.6 locally) • Hippelein et al. (2003): • 0.25 < z < 1.2 : [OII]/Ha = 0.9 (intrinsic) our [OII]/Ha - metallicity calibration • log(O/H)+12~8.77 Teplitz et al. (2003): • 0.4 < z < 1.4 : [OII]/Ha = 0.45 (observed) • = 0.83 (intrinsic) our [OII]/Ha - metallicity calibration • log(O/H)+12~8.81 Luminosity Selection Effect

  24. High-z Galaxies 0.8 < z < 1.6 Hicks et al. (2002) 0.5 < z < 1.1 Tresse et al. (2002)

  25. Star Formation History K98 [OII] SFR inconsistent reddening correction filled = [OII] unfilled = Ha data from Teplitz et al. (2003) Our [OII] SFR log(O/H)+12~8.6, consistent reddening correction also: Rosa-Gonzalez, Terlevich, & Terlevich (2002) Our [OII] SFR log(O/H)+12~8.8 consistent reddening and metallicity correction Kewley, Geller, & Jansen (2004)

  26. Metallicity History Metallicity history of star-forming galaxies still largely theoretical. Nagamine et al. (2001)

  27. Metallicity History Galactic Winds Image credit: FOCAS, Subaru 8.2-m Telescope, NAOJ.

  28. TheoreticalMetallicity History Predicted for: • Star-forming gas • Stars • Neutral gas e.g., Dave & Oppenheimer (2007)

  29. TheoreticalMetallicity History Predicted for: • Star-forming gas • Stars • Neutral gas e.g., Dave & Oppenheimer (2007)

  30. Metallicity Diagnostics “R23” Kewley & Dopita (2002, ApJS, 142, 35) Also: Pagel (1979), McCall et al. (1985), ..., Skillman et al. (1989), McGaugh (1991),..., Zaritsky et al. (1994), Charlot (2001), ...

  31. Metallicity Diagnostics - [NII]/Ha Kewley & Dopita (2002) also: Denicolo, Terlevich & Terlevich (2002) Pettini & Pagel (2004) R23 and [NII]/Ha re-parameterized Kobulnicky & Kewley (2004)

  32. H ionizing photons/Area/s SH q = nH (cm/s) hydrogen density Ionization Parameter - O32 Kewley & Dopita (2002)

  33. Local Samples: NFGS + SDSS Kewley, Jansen & Geller (2005) • 45,086 SDSS • star-forming galaxies • g-band covering • fraction > 20%

  34. GOODS+ : 0.3 < z< 1 ~450 galaxies from: GOODS + Lilly et al. (2003) Kobulnicky et al. (2003) Maier et al. (2004,05,06) Liang et al. (2004) Lamareille et al. (2005) Savaglio et al. (2005)

  35. GOODS+ : 0.3 < z< 1 ~450 galaxies from: GOODS + Lilly et al. (2003) Kobulnicky et al. (2003) Maier et al. (2004,05,06) Liang et al. (2004) Lamareille et al. (2005) Savaglio et al. (2005)

  36. High-z sample • 5 galaxies: 1<z<1.5 (Shapley et al. 2005) • [OII], [OIII], Hb, [NII] • 7 galaxies: 2 < z < 2.5 (Shapley et al. 2004) • [NII], Ha • 2 galaxies: z=2.3, 2.9 (Kobulnicky & Koo 2000) • [OII], [OIII], Hb • 5 galaxies: 2.7<z<3.4 (Pettini et al. 2001) • [OII], [OIII], Hb

  37. Metallicity Diagnostic Discrepancies Kewley & Ellison (2007) SDSS mass-metallicity relation Tremonti et al. (2004)

  38. Metallicity Diagnostic Discrepancies Kewley & Ellison (2007)

  39. Metallicity Diagnostic Discrepancies Before: After: Kewley & Ellison (2007)

  40. Metallicity History 0<z<3 NFGS Lyman Break Galaxies SDSS 0.15 dex/z GOODS+ assumes upper branch Kewley & Kobulnicky (2006, in prep)

  41. Metallicity History 0<z<3 Models: Dave & Oppenheimer (2006) Kewley & Kobulnicky (2006, in prep)

  42. Metallicity History Bias: 0.4 < z < 1 Assumptions: R23 upper branch AV = 1 Kewley & Kobulnicky (2006, in prep)

  43. Solution: 0.4 < z < 1 NIR multi-object spectroscopy Subaru - MOIRCS observations ongoing Soon to come: VLT - NIRMOS (2008/2009) Gemini-S - Flamingos-II (2008) Magellan - MMIRS (2008)

  44. Metallicity History Bias: z > 1 Color selection BzK Lyman Break

  45. High-z Metallicity Bias? Try alternative selection: • Lensed galaxies • GRB Hosts • [OII], [OIII] emitters • Luminous red star-forming galaxies

  46. Alternative selection: Lensed Galaxies Lemoine-Busserolle et al. (2003) z=1.9 log(O/H)+12 ~ 7.6 +/- 0.2 log(O/H)+12 ~ 9.0 +/- 0.1

  47. Metallicity History 0<z<3 Models: Dave & Oppenheimer (2006) Kewley & Kobulnicky (2006, in prep)

  48. Alternative selection: GRB Hosts Local GRB hosts may favor low metallicity galaxies GRB Hosts Kewley et al. (2006)

  49. SFR Conclusions • Agreement between SFRIR and SFRHa • Discrepancy between SFR[OII] and SFRHa: • reddening and metallicity • New theoretical SFR[OII] calibration removes • this discrepancy • ... but what if metallicity changes with redshift?

  50. Metallicity Conclusions • Metallicity History for star-forming galaxies • Metallicity evolution observed • First comparison with appropriate metallicities • from cosmological hydrodynamic simulations • Steeper Metallicity evolution predicted • More work needed for robust metallicity history...

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