Crafoord Symposium, Sept Quasars and Galaxies at the Highest Redshifts Richard McMahon Institute of Astronomy University of Cambridge, UK Crafoord Symposium, Stockholm, Sep 2005

Crafoord Symposium, Sept Some Background Information Main motivation is that objects at high redshift are ‘young’ due to the light travel time. e.g. we can ‘see’ objects that existed in the Universe before the Earth formed. Quasars are the most luminous members of the Active Galactic Nuclei (AGN) family. –M B < -23 ; AGN light exceeds energy from host galaxy stellar light. Quasars are intrinsically luminous bright beacons that are easier to observe that ‘normal’ galaxies like the Milky Way. Also ‘illuminate’ intervening material. i.e. IGM Energy source is accretion of matter onto a super-massive black hole (10 7 to 10 9 M sol ) –Rees, 1984, ARA&A, 22, 471, ‘Black Hole Models for Active Galactic Nuclei’ Recent observations have shown that most massive galaxies in the local Universe host super-massive black holes. The BH mass is correlated with the stellar bulge mass implies that the formation and evolution of BH and the stellar component in galaxies related (Magorrian et al, 1998; Ferrarese & Merrit, 2000; Gebhardt etal, 2000) –Rees, 1989, RvMA, 2, 1, ‘Is There a Massive Black Hole in Every Galaxy?’ Radiative feedback from quasars may play a major role in formation and evolution of galaxies.

Crafoord Symposium, Sept Formation of Solar System: ~5 Billion year ago (5Gyr) Look Back Time Redshift Look back Time (Gyr) Age of Universe Gyr Gyr Gyr Myr Myr Myr Myr Myr Myr  matter,  , H 0 = 0.3, 0.7, 70

Crafoord Symposium, Sept Highest Redshift History Galaxies Quasars

Crafoord Symposium, Sept Highest Redshift History Galaxies Quasars “Gunn”

Crafoord Symposium, Sept The Observational Challenges in surveys for surveys for high redshift objects Experimentally difficult because: –Distant objects are very faint. –Rest frame UV radiation is red-shifted to regions of observed sky spectrum where night-time sky is bright. –Foreground objects are much more numerous so the experimental selection technique has to be very efficient. –May be undetectable, in a ‘reasonable’ amount of time using current technology; i.e. may need to wait or develop the technological solution.

Crafoord Symposium, Sept Basic observational principles in optical surveys for higher redshift quasars and galaxies UV ‘drop-out’ due to: –Intrinsic or Intervening Neutral Hyrogen ‘Lyman limit’ at 912Å. –Intervening Lyman-a forest ( <1216Å) Emission line searches based on Lyman-  ( rest =1216Å) emission from ionized Hydrogen.

Crafoord Symposium, Sept C273 and z=3.62 comparison Evolution of HI: 3C273 spectrum from HST/FOC z=0; z=3.6 QSO HIRES/Keck spectrum from M. Rauch

Crafoord Symposium, Sept z=4 Model Quasar +SDSS filter set

Crafoord Symposium, Sept Multi-colour Selection and discovery of z>4 Quasars (pre-SDSS) Cambridge-APM Surveys See Storrie-Lombardi, Irwin, McMahon and Hook, n=49; z>4 quasars 15, 000 deg 2 Only two wavebands are needed. In practice this results in some(50%) contamination by M-stars

Crafoord Symposium, Sept z = 4.90, Schneider, Schmidt, Gunn, 1991, AJ, 98, 1951 z = 5.0, Fan with Guun, Lupton et al (SDSS collaboration) Quasars at z  5 Lyman-  Forest C,N,O,Si. Lyman-  ( rest =1216Å)

Crafoord Symposium, Sept z=5 quasar with SDSS filters

Crafoord Symposium, Sept z=6 quasar with SDSS filter set

Crafoord Symposium, Sept SDSS Surveys for z>5 Quasars Color selection of i-drop out quasars –At z>5.5, Lyα enters z-band  quasars have red i-z colour Technical Challenges: –Rarest objects One z~6 quasar every 500 deg 2 Key: contaminant elimination –Major contaminants are L and T type Brown Dwarfs  additional IR photometry Fan, et al.

Crafoord Symposium, Sept z>5.7 quasars Separating z~6 quasars and Brown Dwarfs –Follow-up IR photometry –quasar: z-J ~ 1 –L to T dwarf stars z-J > 2 Fan, Narayanan, Lutpon, Strauss et al. Z>5.7 quasar

Crafoord Symposium, Sept SDSS compilation z>5.7 quasars

Crafoord Symposium, Sept ‘Edited’ Quasar compilation (pre-SDSS)

Crafoord Symposium, Sept ? Quasar compilation (now with SDSS) DR3QSO 50, 000 quasars

Crafoord Symposium, Sept Higher Redshift Quasar Surveys Need to work in Infra-Red –Different detector technology –Sky ‘brightness’ problem Two relevant projects –UK Infra Red Deep Sky Survey (UKIDSS) WFCAM on UKIRT Survey started in May 2005 Pipeline Data processing centre(Cambridge+Edinburgh) –VISTA (will be an ESO telescope) (Surveys will start in early 2007?)

Crafoord Symposium, Sept The Night Sky Problem Waveband Central Wavelength (Angstroms) ‘Dark’ Sky Brightness Redshift Lyman-  (1216Å) B V R I Z Y 10, J 12, H 16, K 22, Broad band sky gets brighter as you go to redder wavelengths

Crafoord Symposium, Sept z=6 quasar (SDSS filter set)

Crafoord Symposium, Sept z=7 quasar (SDSS filter set)

Crafoord Symposium, Sept z=8 quasar (SDSS filter set)

Crafoord Symposium, Sept z=6 quasar (SDSS filter set + WFCAM)

Crafoord Symposium, Sept z=7 UKIDSS/VISTA Filters

Crafoord Symposium, Sept z=8 UKIDSS/VISTA Filters

Crafoord Symposium, Sept z=9 UKIDSS/VISTA Filters

Crafoord Symposium, Sept z=10 UKIDSS/VISTA Filters

Crafoord Symposium, Sept UK Infra Red Telescope (UKIRT) Wide Field Camera (WFCAM) 3.6m telescope Mauna Kea, Hawaii 4x2048x2048 Hawaii II arrays 0.4 arcsec pixels 0.21 sq. degs / exposure Not contiguous Filters: Z,Y,J,H,K,H 2 -S(1),Br-g

Crafoord Symposium, Sept UKIRT Wide Field Camera on Telescope Simulator Asembled WFCAM cryostat WFCAM cryostat

Crafoord Symposium, Sept UKIDSS overview 5 elements of UKIDSS(5-7 year duration) Sub-SurveyBandsLimit (K) Area deg 2 night s Large Area SurveyLASYJHK Deep Extragalactic SurveyDXSJK Ultra Deep SurveyUDSJHK Galactic Plane SurveyGPSJHK Galactic Clusters SurveyGCSJHK

Crafoord Symposium, Sept UKIDSS Science goals Cool Universe - Y brown dwarfs Obscured Universe - Galactic plane - reddened AGN, starbursts, EROs High-redshift Universe A break z>1; high redshift galaxy clusters - Quasars at z>6.5

Crafoord Symposium, Sept Current Status of WFCAM+UKIDSS Instrument started commissioning on-sky phase in Nov, 2004 Science Verification started in April 2005 UKIDSS Survey started in May, 2005 Instrument taken off telecope in June, 2005 –As planned Survey restarted end of Aug, 2005 Should have 100deg 2 of data by end of 2005

Crafoord Symposium, Sept Visible and Infrared Survey Telescope for Astronomy 4-m wide field survey telescope at European Southern Observatory (ESO), Paranal near the VLT site. Initially Infra Red camera only. (i.e. an IR SDSS) 75% time for “large surveys”. (e.g. Southern SDSS) UK project (consortium of 18 Universities; funded in 1999) –Principal Investigator Jim Emerson (QMUL, London) Now part of UK ESO ‘late joining fee’. Will become ESO facility on completion of construction and commissioning in late 2006.

The ‘Heart of VISTA’; the IR focal plane: 16 IR arrays, each 2048 x 2048; sparse filled mosaic; 0.60 deg 2 covered by detectors 0.34 arcsec/pix. - 6 consecutive ‘offset’ pointings give a continuous region - 1.5deg by 1.0deg i.e. 1.5deg 2 - every pixel covered by 2 pointings.

Crafoord Symposium, Sept Comparison of IR camera field sizes Moon!

Crafoord Symposium, Sept Dome – May 05

Crafoord Symposium, Sept Summer 2005

Crafoord Symposium, Sept Design Reference Programme (epoch 2001; ~ 400 clear nights) used for Project Planning ESO Survey Call for Proposal is being planned Z filter now included Survey name Area (deg 2 ) YJHKsKs Clear nights (ex overheads) (Vega, 5  ) Very deep Deep Wide (high-gal lat) Galactic Plane + Magellanic Clouds * Sky Atlas

Crafoord Symposium, Sept Highest Redshift Galaxies

Crafoord Symposium, Sept Searches for higher redshift quasars and galaxies UV ‘drop-out’ technique survey technique due to: –Intrinsic or Intervening ‘Lyman limit’ 912Å. –Intervening Lyman-a forest ( <1216Å) Emission line searches based on Lyman-  emission from ionized Hydrogen.

Crafoord Symposium, Sept Highest Redshift History Galaxies Quasars

Crafoord Symposium, Sept High Redshift Lyman-  emission lines surveys: Astrophysical principles for Success Partridge and Peebles, 1967, Are Young Galaxies visible? Minimum Flux limit Previous surveysin the early 1990’s were based on the simple paradigm of a monolithic collapse. –expected star formation rates of M sol yr -1 –i.e. the SCUBA/FIR Population? Assume SFR detection limits more appropriate to a slowly forming disc or sub-galactic units in a halo –i.e. 1-3 M sol yr -1   erg s -1 cm -2 at z=4 Minimum Volume search a comoving volume within which you expect to find the progenitors of around 10 L* galaxies. (.i.e.~ Milky Way mass) –Local density 1.4±0.2  h 50 Mpc -3 (e.g. Loveday etal, 1992)  minimum is 1000 Mpc 3

Crafoord Symposium, Sept Potential Narrow band filter locations

Crafoord Symposium, Sept z=5.7 for Lyman-  z=6.6 for Lyman- 

Crafoord Symposium, Sept Basic experimental principle Basic principle is to survey regions where the sky sky spectrum is darkest in between the intense airglow. –“Gaps in the OH airglow picket fence” Lyman-alpha redshifts of gaps in “Optical-Silicon” CCD regime –7400 Å; z=5.3 –8120 Å; z=5.7; used extensively –9200 Å; z=6.6; used extensively –9600 Å; z=6.9; no results yet CCDs have poor QE and sky relatively bright

Crafoord Symposium, Sept Summary of known spectroscopically confirmed z>6.0 galaxies Narrow Band Surveys z>6.0; n=13 –from Hu et al. 2002(1), Kodeira et al. 2003(2), Rhoads et al 2004(1), Taniguchi et al. 2005(9) –z(max)=6.6 Other Surveys 2 other z>6 emission line selected galaxies –Kurk et al, 2004(1); Stern etal, 2005(1) Ellis etal, lensed search z=7 candidate (no line emission; photo-z) i-drops Nagao et al, 2004(1); Stanway etal, 2004(1) Quasars; SDSS n=5 (6.0< z<6.5)

Crafoord Symposium, Sept (observed; Lyman-  )=9190Å (rest; Lyman-  )=1216Å Redshift=6.558 Hu, etal, 2002

Crafoord Symposium, Sept z=6.597 galaxy (Taniguchi et al, PASJ, 2005) 9235Ang redshift6.597 z AB i-z>1.72 Survey: Subaru 8.2m Suprimecam 34’ x 27’; 0.2”/pixel 132Å filter centred at 9196Å Exposure time; 54,000 secs (15hrs) Results 58 candidates 9 spectroscpoically confirmed with z=6.6

Crafoord Symposium, Sept Composite spectrum of z=5.7 candidate galaxies z=5.7; note asymmetry z=1.2; note resolved doublet z=0.6; unresolved and 4959 line [OIII]4959 Lyman-  (1216Å) [OII](3727Å) [OIII](5007Å) n=18 galaxies Hu, Cowie, Capak, McMahon, Hayashino, Komiyama, 2004, AJ, 127, 563

Crafoord Symposium, Sept z~5.7 Lyman-  (1216Å) emitters Observed wavelength (Angstroms)

Crafoord Symposium, Sept z~1.2 [OII]3727 doublet emitters Observed wavelength (Angstroms)

Crafoord Symposium, Sept The Night Sky Problem Waveband Central Wavelength (Angstroms) ‘Dark’ Sky Brightness Redshift Lyman-  (1216Å) B V R I Z J 12, H 16, K 21, Broad band sky gets brighter as you go to redder wavelengths

Crafoord Symposium, Sept Narrow band searches in the near Infrared OH lines contribute 95% of sky background in  m range; – i.e. 20 times the continuum emission. Filters need to have widths of 10Å or 0.1% to avoid OH lines. – c.f. 100Å in the optical NB. Narrower band means you solve a smaller redshift range i.e. volume so wide field is needed. Some of the technical issues –Filter design and manufacture –Field angle shift of central wavelength –Out of band blocking;

Crafoord Symposium, Sept Infrared OH Sky Observations: Mahaira etal, 1993, PASP GOOD NEWS The 1.0 to 1.8 micron IR sky is very dark between the OH lines which contain 95% of broad band background. THE NOT SO GOOD NEWS The narrowest gaps are narrower than in the optical; filter widths of 0.1 per cent are needed compared with 1% filters in optical. THIS IS A TECHNICAL CHALLENGE WE HAVE SOLVED; see Ian Parry’s talk

Crafoord Symposium, Sept Sky emission and absorption spectrum around 1.06 and 1.33 microns showing DAZLE filter pairs for Lyman  at z=7.7, 9.9; other gaps are at 8.8, 9.2 DAZLE – Dark Age Z Lyman Explorer McMahon, Parry, Bland-Hawthorn(AAO), Horton et al IR narrow band imager with OH discrimination at R=1000 i.e. 0.1% filter FOV 6.9  6.9 arcmin 2048 Rockwell Hawaii-II 0.2”/pixel Sensitivity: erg cm -2 sec -1 (5  ), 10hrs on VLT i.e. ~1 M  yr -1 at z=8;

Crafoord Symposium, Sept DAZLE: Digital state 3D CAD drawing of DAZLE Final Design on VLT UT3(Melipal) Visitor Focus Nasmyth Platform. UT3 optical axis is 2.5m above the platform floor grey shading shows the DAZLE cold room(-40C)which is 2.5m(l) x 1.75m(w) x 3m(h). Blue Dewar at top contains the 2048 x 2048 pixel IR detector

Crafoord Symposium, Sept Dazle in Cambridge Laboratory(Aug 2005) Refridgeration ‘Box’

Crafoord Symposium, Sept Highest Redshift History Galaxies Quasars

Crafoord Symposium, Sept ? Quasar compilation (now with SDSS) DR3QSO 50, 000 quasars

Crafoord Symposium, Sept Some Future ground based surveys for higher redshift Galaxies and Quasars z>7 galaxies Dark Ages ‘Z’ Lyman-  Explorer (DAZLE) on the VLT (to start Jan 2006) z>7 quasars UKIDSS: UK Intra-Red Deep Sky Survey (started May 2005; 5 year survey project) –UKIRT (Hawaii) + WFCAM –ESO members; Public Access from late 2005); Worldwide +18month VISTA Surveys (to start early 2007)

Crafoord Symposium, Sept FINAL SLIDE