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MUSYC E-HDFS UBR composite

Formation and Clustering of High-redshift Galaxies 2. Galaxy Formation. Eric Gawiser Rutgers University. MUSYC E-HDFS UBR composite. What Do We Know About Galaxy Formation?. Recently Solved Problems Integral Constraints Protogalaxy Demographics.

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MUSYC E-HDFS UBR composite

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  1. Formation and Clustering of High-redshift Galaxies2. Galaxy Formation Eric Gawiser Rutgers University MUSYC E-HDFS UBR composite

  2. What Do We Know About Galaxy Formation? Recently Solved Problems Integral Constraints Protogalaxy Demographics

  3. Recently Solved Problems in Galaxy Formation • Initial Conditions: WMAP cosmology CMB + galaxy P(k) + Type Ia SNe  =0.7, m=0.3, b=0.04, H0=70 km/s/Mpc

  4. Recently Solved Problems in Galaxy Formation • Initial Conditions: WMAP cosmology • Final Conditions: Low-z galaxies Well-studied in MW and nearby galaxies

  5. Recently Solved Problems in Galaxy Formation • Initial Conditions: WMAP cosmology • Final Conditions: Low-z galaxies • Integral Constraints: Cosmological quantities Baryon budget: Star Formation Rate Density (SFRD) is integral constraint over space at a given time (M/yr/Mpc3) Gas Density(gas(t)= gas,0 -0t d*/dt), Stellar Mass Density(*(t)=0t d*/dt), Metal Density(*(t)=1/42 0t d*/dt) are integral constraints on SFRD over time CIB + FIRB constrain integrated SFRD to z=0

  6. Recently Solved Problems in Galaxy Formation • Initial Conditions: WMAP cosmology • Final Conditions: Low-z galaxies • Integral Constraints: Cosmological quantities • Identified Galaxy Zoo at z=3 Lyman break galaxies, Lyman alpha emitters, Distant red galaxies, Active Galactic Nuclei, Damped Lyman alpha systems, Submillimeter galaxies However: Evolutionary sequence unclear, progenitors of typical galaxies like the Milky Way yet to be identified

  7. Monolithic Collapse Eggen, Lynden-Bell & Sandage 1962 Gravitational collapse of cloud of primordial gas Thus all parts of galaxy formed at the same time Happened very early in the lifetime of the Universe Hierarchical Formation (CDM) Small clumps of matter merge together to form larger galaxies Happens throughout the lifetime of the Universe Thus formation of galaxies is an ongoing process Galaxy Formation Models

  8. Hierarchical Structure Formation No preferred scales in DM but non-linear collapse gives distribution of halos where galaxies can form Small halos collapse first  “bottom-up” At z>2, galaxy-mass halos are rare so majority of halos collapsed recently Galaxies have Mmax and Mmin Scales come from “gastrophysics” of virialization and feedback from supernovae and supermassive black holes Dark energy produces cosmological “freeze-out” - structure stopped forming at zeq~0.3 Galaxy formation freeze-out occurred earlier in massive galaxies  “downsizing” (anti-hierarchical?)

  9. Why high redshift? Galaxy formation hard to study in local universe High-z = Jurassic Park of galaxies Nature Sep. 14, 2006

  10. AGN with Damped Lyman  Absorber (DLA) DLAs have N(HI)>2x1020cm-2, sufficient to self-shield against (re)ionization Provide unbiased sample of lines of sight through the cosmos out to quasar Lower column density systems are ionized  DLAs dominate neutral gas content

  11. Cosmic density of neutral gas gas (x10-3) HI (DLAs) HI (21cm) Wolfe, Gawiser & Prochaska 2005, ARAA Neutral gas reservoir traced by DLAs is depleted by z=0

  12. History of neutral gas Closed box: dgas/dt =-d*/dt

  13. Cosmic density of neutral gas gas (x10-3) HI (DLAs) HI (21cm) Wolfe, Gawiser & Prochaska 2005, ARAA Neutral gas reservoir traced by DLAs is depleted by z=0

  14. Cosmic density of neutral gas stars gas (x10-3) HI (DLAs) HI (21cm) Wolfe, Gawiser & Prochaska 2005, ARAA Neutral gas reservoir traced by DLAs is depleted by z=0, forming >~ half of the stars seen today

  15. History of neutral gas Closed box: dgas/dt =-d*/dt

  16. History of neutral gas Closed box: dgas/dt =-d*/dt Open box: dgas/dt =-d*/dt + infall + merging - winds

  17. Cosmic density of neutral gas stars gas (x10-3) HI (DLAs) HI (21cm) Wolfe, Gawiser & Prochaska 2005, ARAA Neutral gas reservoir traced by DLAs is depleted by z=0, forming >~ half of the stars seen today

  18. Cosmic star formation history 16% of cosmic age Giavalisco et al. 2004 z>3 points from Lyman break galaxies only Solid blue curve: semi-analytic model of Somerville et al. 2001

  19. Most stars formed at z<2 Pettini 2003

  20. Stellar mass density *(t)=0t d*/dt Dickinson et al 2003 Dust extinction less problematic, but need to know IMF and star formation history

  21. Cosmic metal enrichment history*(t)=1/42 0t d*/dt Cosmic metallicity traced by DLAs rises gradually Wolfe, Gawiser & Prochaska 2005, ARAA

  22. DLA metallicities in context Pettini 2003

  23. Evidence for dust depletion and alpha enhancement in DLAs

  24. DLA Kinematics: Disks or Clumps?

  25. Theoretical Advances • Semi-analytical models reproduce observations moderately well • Cosmological hydrodynamic simulations have advanced greatly - but use recipes for star formation and supernova feedback

  26. M=1010 M Cosmological hydro simulationsNagamine et al. 2003

  27. Hydro simulation of SFR history as a function of mass using “recipes” Nagamine et al. 2003

  28. Demographics of Protogalaxies • Searching for the progenitors of typical galaxies like the Milky Way - are they found amongst the zoo of objects at z=3? • Cosmological quantities (SFR, stellar mass buildup) should be summed over all high-redshift objects, not just DLAs, which trace the low-dust neutral gas, or LBGs, which trace the bright end of the luminosity function

  29. MUSYC(Multiwavelength Survey by Yale-Chile) Eric Gawiser (Yale, P.I.) Pieter van Dokkum (Yale, P.I.) Paulina Lira (U. Chile) Meg Urry (Yale) Martin Altmann (U. Chile) Felipe Barrientos (P.U. Catolica) Francisco Castander (IEEC-Barcelona) Daniel Christlein (U. Chile/Yale) Paolo Coppi (Yale) Marijn Franx (Leiden) Gaspar Galaz (P.U. Catolica) David Herrera (Yale) Leopoldo Infante (P.U. Catolica) Sheila Kannappan (U.T. Austin) Charles Liu (CUNY/AMNH) Sebastian Lopez (U. Chile) Danilo Marchesini (Yale) José Maza (U. Chile) Rene Méndez (U. Chile) Nelson Padilla (P.U. Catolica) Ezequiel Treister (ESO) Bill van Altena (Yale) Sukyoung Yi (Yonsei) www.astro.yale.edu/MUSYC Gawiser et al 2006a, ApJS 162, 1

  30. MUSYC (Multiwavelength Survey by Yale-Chile) • Square degree comprised of four 30'x30' fields (E-CDFS, E-HDFS, SDSS1030+05, Castander’s Window 1255+01) • Deep UBVRIzJHK + NB5000Å imaging (to 5 depths of U,B,V,RAB=26, KAB=23, NB5000=25) • Spitzer-MIPS+IRAC/HST-ACS/GALEX/XMM/Chandra coverage in 3/4 fields • Spectroscopic follow-up with VLT+VIMOS, Magellan+IMACS, Gemini+GNIRS

  31. MUSYC:A Square-degree Survey of the Formation and Evolution of Galaxies and their Central Black HolesScience Projects: • Census of galaxies at z=3 (Gawiser) • Evolved galaxies at 2<z<3 (van Dokkum) • AGN demographics at 0<z<6 (Urry) • Properties of K-selected galaxies at z<2 (Lira, Barrientos, Infante) • Proper motion + color survey for white and brown dwarfs (Mendez) • Groups and clusters at z<1 (Christlein, Lin) • Recent star formation in ellipticals (Yi) • Public outreach at Hayden Planetarium (Liu)

  32. Students giving MUSYC posters Paula Aguirre (PUC) "Clustering of K-selected galaxies" Harold Francke (U. Chile) "Clustering of AGN at z=3"

  33. 75% of the baryons are hydrogen • At z=3, Lyman series falls in observed-frame optical • Ionizing photons (>13.6eV= <912Å) do not escape  “Lyman Break” • Ly  photons (10.2eV=1216Å) from recombination if stars have formed recently enough that little dust exists

  34. Protogalaxies at z=3: TLAs • LBG=Lyman Break Galaxy selected via Lyman break, blue continuum (starburst) • LAE=Lyman Alpha Emitter selected via strong emission line (early stage of star formation) • DRG=Distant Red Galaxy selected via Balmer break in observed NIR • SMG=Sub-Millimeter Galaxy selected in sub-mm, use radio to get position • DLA=Damped Lyman  Absorption system selected in absorption, N(HI)>1020 cm-2

  35. Origin of the Lyman break Steidel & Hamilton 1992

  36. Origin of the Lyman break U V R Steidel & Hamilton 1992

  37. Lyman Break Galaxy (LBG) Steidel & Hamilton 1992

  38. LBG in E-CDFS, R=22.8, z=3.38strong Ly emission (EW=60Å, SFRUV ≥350 M/yr) numerous chemical absorption features (6 hr IMACS exposure) OI/SiII SiII SiII FeII CIV SiIV CII MUSYC Ly 

  39. LBGs: age, stellar mass,dust, SFR Pettini 2003

  40. Stellar winds in LBGs Pettini 2003

  41. Lyman  Emitter (LAE) V R NB5000 B U Gawiser et al 2006b, ApJ 642, L13, astro-ph/0603244 (MUSYC plus Caryl Gronwall, Robin Ciardullo, John Feldmeier)

  42. BV - NB5000 selection of LAEs

  43. LAE in E-CDFS, R=25.7, z=3.085 Ly EW=200Å, SFR≥30 M/yr (6 hr IMACS exposure) MUSYC Gawiser et al 2005

  44. # obj LBG Rest-frame UV continuum flux of spectroscopically confirmed samples LAE MUSYC

  45. UVR colors of confirmed objects Confirmed LAE Confirmed LBG

  46. Images from HST-ACS: irregular morphology at z=3 AGN z=3.60 R=22.4 LBG z=3.37 R=24.3 LBG z=3.24 R=23.8 LAE z=3.10 R=26.1

  47. NIR selects rest-frame Balmer break at 2<z<4 Reddy et al 2005

  48. Distant Red Galaxies (DRG) MUSYC van Dokkum et al 2005 van Dokkum et al 2005, in prep.

  49. Redshift distributions of 1.5<z<3.5 samples Reddy et al 2005

  50. SMG contribution to SFRD Chapman et al 2005

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