1. Infrared Medium-deep Survey
Myungshin Im1, Jae-Woo Kim1, Seong-Kook J. Lee1, Yiseul Jeon1, Yongjung Kim1, Soojong Pak2, Yongmin Yoon1, Won-Kee Park1,3, Ji Hoon Kim1, Marios Karouzos1, Changsu Choi1, Hyunsung Jun1, Dohyeong Kim1, Jueun Hong1, Duho Kim1, Minhee Hyun1, Yoon Chan Taak1, Giseon Baek2, Hyeonju Jeong2, Juhee Lim2, Eunbin Kim2, Nahyun Choi2, Hye-In Lee2, K. M. Bae2, & Seunghyuk Chang4 & IMS Team
1CEOU/Astronomy Program, Dept. of Physics & Astronomy, Seoul National University, Seoul , KOREA, 2School of Space Research, Kyung Hee University, Suwon , KOREA, 3Korea Astronomy and Space Science Institute, Daejeon , KOREA, 4Samsung Electronics, Suwon, Gyeonggi-do , KOREA
The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea

2. Infrared Medium-deep Survey
Imaging survey at J(Y) < 23 AB mag, 130 deg2 of 7 fields
Follow-up NIR imaging of high redshift objects selected from deg2
~30 members from SNU, KHU, KASI, ASIAA, NCU, Subaru
Observation with UKIRT, McDonald 2.1m, since 2010
UKIRT 3.9-m (zYJHK)
McDonald 2.1-m with CQUEAN
(grizY, is/iz)
The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea

3. Key Scientific Questions
Massive clusters at z > 1!
(Foley et al many)
How did galaxies evolve?
LCDM universe OK?
Dark halo/galaxy relation?
Massive clusters at z > 1
Supermassive Black Holes
(109 – 1010 M⊙) at z < 7
(Fan et al. 2005; Mortlock et al. 2011)
When and how did they emerge?
Re-ionization State of IGM?
Quasars at 5 < z < 7.5
First stars at z ~ 11.5?
(Planck results +)
Death of massive stars?
GRBs and SNe
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4. High Redshift Objects Are Red
NIR imaging is
essential
QSO at z=7
Galaxy at z=2
Brown dwarf
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5. Survey Design : How Many, How Deep?
Quasars and galaxy clusters at high redshift
23 ABmag
1 .How faint?
2. How many?
3. What wavelength?
0.01 to 1 per 1 sq. degree
0.9 – 1 μm or longer: J or Y-band
QSO
(Willott et al. 2010)
The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea
Im et al. (2002)

6. IMS Fields: Total ~ 130 deg2 2016. 09. 29 Field RA Dec Area (deg2)
Optical Coverage (mag/deg2)
NIR Coverage
IR coverage
XMM-LSS
02:21:20
-04:30 5
CFHTLS-W1 (35 MegaPipe z-fields, z ~ 25AB/72deg2), NOAO DWS, Maidanak Y-band
UKIDSS DXS+UDS (2.6/8.75)
SWIRE (9.2)
CFHTLS-W2
08:54
-04:15 49
CFHLTLS-W2 (19 MegaPipe z-fields, z~25AB/49 deg2), COSMOS HST (1.8 deg2)
No NIR yet
Lockman Hole
10:45:00
58:00 15
CFHT MegaPipe Archive (15 fields), Subaru (~18 fields, I = 26 AB, B=27AB)
UKIDSS DXS (1/8.75)
SWIRE (11)
EGS
14:17
54:30
CFHTLS-W3 (44 MegaPipe z-fields, z~25ABmag/49 deg2)
IRAC GTO data, AKARI 15 micron
ELAIS-N1
16:11:00
55:00 9
CFHT MegaPipe (9 fields, z~25AB mag)
Subaru Deep I (18 fields (5 deg2)
UKIDSS DXS+UDS (1.7/8.75)
ELAIS-N2
16:36:48
41:01:45 6
CFHT MegaPipe (6 fields, z~25 AB mag), Subaru Deep I (18 fields (5 deg2)
SWIRE(4.8)
SA22
22:17
00:20 16
CFHLTLS-W4 (20 MegaPipe z-fields, z~25AB/16 deg2
UKIDSS DXS+UDS (3.5/8.75)
None

7. The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea
Science Highlights
High redshift quasars
High redshift galaxy clusters/galaxies
Transient objects (GRBs, TDE, SNe, etc)
The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea

8. SMBH Mass Evolution ? z ~ 5.5 z > 6.5 Fast growth from
AKARI points
(Jun, H., MI, et al.
2015) ?
Fast growth from
stellar mass BHs
Slow growth with
heavy BH seeds
1010 M⊙ at z ~ 5 (1.2 Gyr), and out to z ~ 6.4 (0.95 Gyr)
Lbol/LEdd ~ 1  Eddington-limited accretion (e.g., Willott et al. 2010)
What was happening at z ~ 5.5 and z > 7?

9. z~5.5 Quasars Stars Quasars Chiu et al. 2005 Identification of z ~ 5.5
Difficult due to photometric
properties of existing surveys

10. High Redshift Quasar Selection @z=5. 5 and z=6
High Redshift Quasar and z=6.5 NIR+WISE color  Follow-up with Special filters

11. CQUEAN, Camera for QUasars in EArly uNiverse
Kyungheee Univ.(S. Pak)/SNU
NIR sensitive (~1 micron)
Custom is and iz filters
- tailored for high-z QSO selection
Focal Reducer (3x, 5’ x 5’)
Auto-guiding system
Installed on the 2.1m at McDonald Observatory
~30 nights/year for high redshift quasar survey

12. Spectroscopic confirmation of Bright QSOs at z ~ 5.5 and z ~ 6
Spectroscopic identification of
8 QSOs at z = 5 – 6
(all with 3-4m class telescopes)
More spectroscopy to come
(BH mass, IGM study)
z = 6.0
Lyα
Jeon, Y., MI, et al. 2016, in prep.
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13. Magellan FIRE Spectroscopy
MgII  MBH
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14. Luminous z ~ 5 Quasars are at near maximal accretion
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15. Discovery of a Faint Quasar at z ~ 6 Gemini-S GMOS
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16. What are the main sources that illuminated the early universe?
Quasar LF
(Kim et al. 2015)
Many quasars:
Quasars
Few Quasars:
Galaxies
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17. The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea
The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea

18. High Redshift Clusters
> 100s clusters at z < 1: Good agreement with CDM universe
Clusters at z > 1 (Overzier et al. 2008, Kang & Im 2009; Matsuda et al. 2011; Capak et al. 2011,…; 1 < z < 5.3)  Not many, trouble with CDM universe?
~ 1??
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19. Search for High Redshift Clusters
Photometric redshift or color-color diagram 
Redshift bin 
Identify over-dense area
z - J
3.6 – 4.5 micron
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20. The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea
Cluster at z=1.1
1000 candidates identified
(See P4-17, 21, 42, 45 by Kim, Lee, Hyun, Karouzos et al.)
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21. IMACS Observation

22. Three clusters with 1014 > Msun
140 Mpc
35 Mpc
Discovery of =0.9 in SSA22 (Jae-Woo Kim, MI, et al. 2015)
See also, poster by Minhee Hyun (P4.1) for ELAIS-N1
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23. Simulation shows triple clusters are unlikely to be found at z=0.9
IMS SSA22 area
Red points: cluster > 1014 Msun
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24. The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea
IMACS
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25. Passive fraction (Npassive/Ntotal)
Fraction of Quiescent Galaxy At z > 1.4, mass dependent (not environment) At z < 1.4, environment becomes important
Seong-Kook Lee, MI, et al (Talk later)
log (M*/M⊙) ≥ 9.1
log (M*/M⊙) ≥ 10.0
Red: Cluster
Blue: Field
Passive fraction (Npassive/Ntotal)
– 8. 22
APRIM 2014, Daejon

26. The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea
GRB, Transients
Tidal disruption event: Swift J
(Burrows et al. .., MI, .., 2011, Nature)
Long-term (3 years) monitoring results
(Yoon, et al. 2015)
Christmas Burst, GRB A
(Thone, , MI,.. et al. 2011, Nature)
CQUEAN riz data helped determine
the black body radiation afterglow
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27. Swift J1644+57 Long-term Light Curve
Before host subtraction
∝ t-0.4
After host subtraction
∝ t-1.1
( c.f. TD ∝ t-5/3 )
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28. Black hole responsible for Swift J1644+54 (YM Yoon, MI, et al. 2015)
Yongmin Yoon
(P4.7)
Long-term monitoring data  host galaxy property  MBH ~ a few x 106 M⊙
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29. The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea
New CQUEAN filters
Medium-band filters on CQUEAN-II
From 0.6 – 1.0 micron, 0.5 micron width
Good for QSOs at 4 < z < 7, red galaxies at 0.5 < z < 1.5 (accurate photo-z) 1 2 3 4 5 6 7 8 9
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30. Faint z=5-6 quasar selection
z-band ~ AB mag
Gemini-S GMOS spectroscopy confirmation
BH mass, LF
Jeon, MI, et al. (2016)
The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea

31. The 10th East Asian Meeting on Astronomy, SNU, Seoul, Korea
Summary
Infrared Medium-deep Survey
- 130 deg2 imaging in J and Y (23 AB mag)
- CQUEAN imaging of high redshift objects (2000+ deg2)
- Transient follow-up
Bright quasars at z ~ 5 – 5.5
Faint quasars at z ~ 5 - 6
Superclusters/clusters at z ~ 1
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