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Survey Science Group Workshop, 2013 High1 Resort. High Redshift Quasar Survey. Yiseul Jeon, Myungshin Im, W.-K. Park, J. H. Kim, M. Karouzos, J.-W. Kim, S.-K. Lee, H. Jun, C. Choi, D. Kim, D. Kim, J. Hong, M. Hyun, and Y. C. Taak
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Survey Science Group Workshop, 2013 High1 Resort High Redshift Quasar Survey Yiseul Jeon, Myungshin Im, W.-K. Park, J. H. Kim, M. Karouzos, J.-W. Kim, S.-K. Lee, H. Jun, C. Choi, D. Kim, D. Kim, J. Hong, M. Hyun, and Y. C. Taak Center for the Exploration of the Origin of the Universe (CEOU), Astronomy Program, Dept. of Physics & Astronomy, Seoul National University
Contents • Introduction • History of our Universe • High Redshift Quasars • Method of Study • Multi-wavelength Data • Color Selection • Current Status • Summary
History of our Universe BB Dark Age Reionization Galaxy Formation Robertson et al. 2010 Neutral Hydrogen Recombination First Star/First Galaxy/First SMBH z ~ 20 Reionization z ~ 10 Galaxy Formation
High Redshift Quasars • Quasar • - An energetic active galactic nucleus • - Powered by an accretion disc • High Redshift Quasar • - One of the brightest objects • - Useful for investigating the early universe • >50 quasars at z>5 discovered Artist's impression of quasar GB1508+5714 (z=4.3) • Intrinsic Properties of early SMBHs Mass Growth of SMBHs & Evolution of QLF • Environmental Effect due to Quasars Reionization of IGM
1. Growth of Super Massive Black Holes 1) SMBH at z~7 SMBH of 109M⊙ already exists age ~0.8 Gyr
1. Growth of Super Massive Black Holes 1) SMBH at z~7 First SMBH already exists age < 1 Gyr → must have formed at very early time. 2) Redshift Desert at 5<z<6 Due to limitations of current selection technique 109M⊙ z~6 1010M⊙ z~5 ←z=5.5 ←z=5.2 i-z x10 increase during 0.5Gyr Chiu et al. 2005 r-i
1. Growth of Super Massive Black Holes 1) SMBH at z~7 First SMBH already exists age < 1 Gyr → must have formed at very early 2) Redshift Desert at 5<z<6 Due to limitations of current selection Cause of SMBH Growth unknown More samples required
2. Reionization of Intergalactic Medium BB Dark Age Reionization Galaxy Formation Robertson et al. 2010 IGM attenuation (Madau 1996) ↓
2. Reionization of Intergalactic Medium Robertson et al. 2010 Gunn-Peterson trough z=6.13 Fan et al. 2006 Fan et al. 2006 z=5.93 z=5.83
3. Evolution of Quasar Luminosity Function ? Robertson et al. 2010 At z>10: First stars (e.g., Kashlinsky et al. 2005) At z<2.5: mostly by AGNs (e.g., Haardt & Madau 1996) Quasar Luminosity Function at z~6 Willott et al. 2010 At z~6: Star Forming Galaxy vs. Quasar ◇ SDSS main △ SDSS deep stripe ● CFHQS
SMBH Mass Growth HI Fraction in IGM QLF at z~6 Redshift Redshift M1450 • Limitations of Previous Studies • Redshift Desert at 5<z<6 and Discovery of z~7 Quasar • New selection technique • Various Luminosity Range • Deep Survey Data • Larger Sample Size • Wide Survey Data → New technique with New Deep/Wide survey data
Quasar candidate selection • e.g.) z~7 quasar (blue) • z Drop-out • Bluer Y-J than Brown Dwarf(green) • Power-law SED i z Y J H K 3.6 4.5 + Quasars Δ Model Brown Dwarfs + Star-forming galaxy + Passive Evolving Galaxy
Quasar candidate selection • Match multi-wavelength catalogues • Select quasar candidates using color-color diagram • Remove spurious objects by eyeball rejection • Do photometry on original images • Imaging follow-up • Spectroscopy of remaining candidates
Quasar candidate selection - Multi-wavelength catalogues (a) 3 mag deeper than SDSS z-band (b) available only for CEOU (c) only accessible to UKIDSS collaboration
Quasar Selection at 5<z<6 Redshift gap at 5<z<6: due to the limitations of current filter system
Quasar Selection at 5<z<6 <McDonald 2.1m> • Camera for QUasars in EArly uNiverse (CQUEAN) with custom designed Is and Iz filters at McDonald 2.1m ←CQUEAN • Spectroscopic Follow-up Observation • 2.5 nights at KP-4m (2012B) • 3 nights at KP-4m (2013A) • 3 nights at NTT (2013A)
Quasar Selection at 5<z<6 • 2.5 nights at KPNO 4-m telescope <KPNO 4-m Jan. 2013 >
Quasar Selection at z~7 Mauna Kea @May 2009
Quasar Selection at z~7 • The most distant known quasar at z=7.085 (Mortlock et al. 2011) • Ongoing & Future Optical/Near-IR Surveys Willott et al. 2010 Intermediate-widemedium-deep survey is needed. UKIRT NIR Survey !
Quasar Selection at z~6 (1) From SEGUE data confirmed by HET and follow-up NIR spec. at IRTF (2) From UKIDSS LAS dataconfirmed by Magellan Color-Color Diagram NIR spectrum by IRTF, SpeX
Quasar candidate selection - Spectroscopy of candidates • Confirm as Quasar! • Calculate redshift by identifying redshifted Lyman break and UV emission lines • Measure SMBH mass using UV emission lines such as CIV λ1549 • Investigate Lyman alpha forest to understand the ionization state of IGM
III. Summary • Limitations of Previous High-z Quasar Survey 1. Growth of SMBH 2. Reionization of IGM 3. Evolution of quasar LF • Deep/Wide Survey Data with New selection technique • SMBH evolution • IGM ionization process • CQUEAN/UKIRT • Thank you
On-going High-z Quasar Survey of CEOU *assuming continuous density evolution of the high-z quasar LF (Willott+10)
SMBH Mass Growth • < First SMBH > • Accretion from Seed BH • If BH mass increases by accretion with Eddington rate, • where tEdd = 0.45 Gyr and ε is the radiative effiency • From seed mass of 102M⊙, it takes 0.9 Gyr. • And From 105M⊙, 0.5 Gyr. (Volonteri10) • Not enough for 109M⊙ at z~7 • By Galaxy Merger • Possible from SAM in ΛCDM (Li+07) • < Vigorous growth at 5<z<6 > • Existence of the most massive SMBH Redshift
SMBH Mass Growth HI Fraction in IGM • Abrupt transition? • (Fan+06) • Continuous process? • (Becker+07) Redshift Redshift
SMBH Mass Growth HI Fraction in IGM QLF at z~6 Also, QLF of 5<z<6 and z~7 Redshift Redshift M1450 → Our research will contribute towards the understanding of the evolution of SMBHs and the IGM ionization state at the early Universe.