1 / 98

The High-Redshift Universe

The High-Redshift Universe. Alberto Fernández-Soto Universitat de València. Plan of this talk. Definition and evolution of “high-redshift” “Objects” at high redshift Selection techniques for high-z objects Observations Towards galaxy evolution. How “high” is “high”?.

hilel-stanley
Télécharger la présentation

The High-Redshift Universe

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. The High-Redshift Universe Alberto Fernández-Soto Universitat de València

  2. Plan of this talk • Definition and evolution of “high-redshift” • “Objects” at high redshift • Selection techniques for high-z objects • Observations • Towards galaxy evolution BJ60 - Valencia

  3. How “high” is “high”? • Start with the discovery and identification of QSOs in the 60s (3C273 z=0.16) • For 30 years “monsters” dominated (z ~ 4) • Radiogalaxies -- Quasars • Colour selection drove towards “normal” galaxies • LBGs @ z ~ 3 -- Dropouts @ z ~ 3 – 5 • QSOs again pushed in (SDSS z ~ 6) • GRBs stand a chance (GRB050904 @ z=6.29) • …but not as high as z=1000! BJ60 - Valencia

  4. BJ60 - Valencia

  5. Data compiled by X. Fan BJ60 - Valencia

  6. Search for high-z objects • Identification of “peculiar” objects • X-ray sources  AGNs  Clusters of galaxies  Peculiar stars (or…) • Radio sources  Radio-loud QSOs • Important selection effects • Plagued QSO catalogues for years • Non-detectability of normal galaxies • By definition! BJ60 - Valencia

  7. Colour selection Use of hydrogen-imprinted features Peebles 1967, Partridge (1974), BVR selection (Piskunov y Kupka 2001) BJ60 - Valencia

  8. Intergalactic Absorption quasar Charlton & Churchill (2000) z = 1.3 Charlton & Churchill (2000) z = 3.6 z = 6.3 Becker et al. (2001) BJ60 - Valencia

  9. “The perfect QSO spectrum” BJ60 - Valencia

  10. (Steidel 1999) BJ60 - Valencia

  11. NOAODWFS(Jannuzzi et al) BJ60 - Valencia

  12. The importance of it all… • Neutral hydrogen is ubiquitous… • The features imprinted by HI are the same, for all types of objects, at a given redshift  Possibility of unbiased selection BJ60 - Valencia

  13. Colour-selected normal galaxiesin the HDF (Lanzetta et al 1996) BJ60 - Valencia

  14. (Giavalisco 2001) BJ60 - Valencia

  15. Expected colors of high z Lyman break galaxies are well defined. (Steidel et al 1999) BJ60 - Valencia

  16. (Steidel et al 1999) BJ60 - Valencia

  17. BJ60 - Valencia (Le Fevre et al 2005)

  18. BJ60 - Valencia (Le Fevre et al 2005)

  19. Quasars re-enter the stage • Colour selection can also be applied to QSOs • High-redshift QSOs much more luminous than galaxies, but much more scarce • Need for photometric, large-area surveys: • SDSS  ugriz colour images  10 000 square degrees  selection of QSOs up to z > 6 BJ60 - Valencia

  20. 17,000 Quasars from the SDSS Data Release One 5 Ly a 3 2 CIV CIII 1 MgII OIII Ha 0 4000 A 9000 A BJ60 - Valencia

  21. The Highest Redshift Quasars Today(SDSS, Fan et al) • z>4: ~700 known • z>5: ~30 • z>6: 7 • SDSS i-dropout Survey: • By Spring 2004: 6000 deg2 at zAB<20 • Fourteen luminous quasars at z>5.7 • 20 – 40 at z~6 expected in the whole survey Total Discoveries SDSS Discoveries BJ60 - Valencia

  22. BJ60 - Valencia

  23. Photometric redshifts • Originally in Baum (1963) • Koo (1985): “Poor man´s redshift machine” • Loh & Spillar (1986): Cosmology • Impulse with Hubble Deep Fields: • Deep, high quality, multi-colour images • High spatial resolution • Good spectral sample for calibration • Nowadays common tool of the trade BJ60 - Valencia

  24. Applications • “Poor man’s redshift machine” • Applications in (particularly): • Large volumes of data • Faint galaxy samples • Crowded fields • Proven accuracy: Dz/(1+z) ~ 0.05 (rms) • Catastrophic error rate < 5% • Already tested out to z ~ 6 BJ60 - Valencia

  25. Sbc z=0.66 BJ60 - Valencia

  26. Sbc z=1.29 BJ60 - Valencia

  27. Irr z=2.51 BJ60 - Valencia

  28. SB1 z=4.36 BJ60 - Valencia

  29. SB1 z=7.96 BJ60 - Valencia

  30. Z(phot) vs Z(spec) (Fernandez-Soto et al 2001) BJ60 - Valencia

  31. Colour selection + grism spectra z=5.83 Selected inside HUDF via BVizJH photometry (Malhotra et al 2005) BJ60 - Valencia

  32. Emission-line searches • Emission line searches for high redshift galaxies (tuned to Lyman-a) existed for many years, with very low success rates • Only over the last few years narrow-band searches tuned at z~6 have offered results • Particular mention to • LALA • Keck • Subaru BJ60 - Valencia

  33. Subaru emission-line searches • NB711 @ z=4.86 (Masami et al 2003) • NB816 @ z=5.75 (Ajiki et al 2003) • NB921 @ z=6.55 (Kodaira et al 2003) BJ60 - Valencia

  34. Subaru emission-line search Narrow-band filter tuned to Lyman a @ z=6.55 (Kodaira et al 2004) BJ60 - Valencia

  35. Keck emission-line survey(Hu et al 2005) BJ60 - Valencia

  36. The Large Area Lyman Alpha Survey BJ60 - Valencia

  37. Candidate z=6.5 LALA galaxies Ic(NDWFS) z’SDSSNB918 All data from NOAO 4m telescopes; NB918 stack is 24 hours’ integration. BJ60 - Valencia

  38. z’ 9180 A Gemini image of z=6.535 galaxy (Rhoads et al. 2004) BJ60 - Valencia

  39. LALA J142442.24+353400.2 @ z=6.535 Gemini spectrum shows asymmetric line, no continuum. (Rhoads et al. 2004) BJ60 - Valencia

  40. Observing the Distant Universe with clusters Gravitational Telescopes: Lensed Galaxies are much brighter Use a BIG telescope! 1021m primary with an 8m secondary! The Cosmic Telescope! NOTE: magnification x25  from z=6 to z=1.5  from z=10 to z=2.5 1021m (M~1014Mo) BJ60 - Valencia

  41. z=1.034 z=2.515 z=5.6 A2218 (zcl=0.17) A2218 3 spectroscopic confirmed multiply imaged systems. BJ60 - Valencia

  42. A z=10 galaxy (Pello et al 2004) BJ60 - Valencia

  43. Some large ongoing surveys BJ60 - Valencia

  44. DEEP2 • DEEP • Keck + LRIS • 1000 galaxies to I=24.5 • DEEP2 • Keck + Deimos, R=5000 • 50000 galaxies 0.7 < z < 1.4 (BRI selected) BJ60 - Valencia

  45. VVDS • VLT + VIMOS • Imaging with CFHT (BVRI), NTT (K), ESO2.2 (U) • Shallow: • 100 000 galaxies to AB(I)=22.5, R=250 • Subsample observed at R=2500 • Deep: • 50 000 galaxies to AB(I)=24 • Ultra-Deep: • 1000 galaxies to AB(I)=26 observed with IFU BJ60 - Valencia

  46. GOODS • 300 sq. arcmins., HDFN and CDFS • Spitzer (Dickinson) • Ultradeep IRAC, deep IRAC and MIPS • Hubble (Giavalisco) • BViz deep images • Extra data from • KP+CTIO (U), • VLT (NIR), • VLT+ Gemini+Keck (spectroscopy), • XMM+Chandra (X rays) BJ60 - Valencia

  47. ALHAMBRA • Aim: 8 x ½ square degree fields • Calar Alto 3.5m, LAICA + W2000 • AB(BVRI) = 25, AB(JHK) ~ 22 • Designed with photometric redshifts in mind: • Optical coverage from 3500 to 9500 A • 20 non-overlapping 300 A-wide filters • Redshift accuracy Dz / (1+z) ~ 0.02 • 800 000 galaxies to AB(I)=24 • ~2000 galaxies at z>5 BJ60 - Valencia

  48. Filter system and survey depth (Moles et al 2006) (Benitez et al 2006) BJ60 - Valencia

  49. BJ60 - Valencia

  50. What have we learned about the high-redshift universe? BJ60 - Valencia

More Related