THE SOUTH POLE TELESCOPE DISCOVERY OF
NEW POPULATIONS OF STRONG LENSES
Yashar D. Hezaveh (McGill University)Institute of Astronomy, Cambridge, Nov 2011
SPT SMG COLLABORATORS
GIL HOLDER (MCGILL)
JOAQUIN VIEIRA (CALTECH)
DAN MARONNE (ARIZONA)
• J. AGUIRRE
• M. ASHBY
• M. BOTHWELL
• J. CARLSTROM
• S. CHAPMAN
• T. CRAWFORD
• C. DEBREUCK
• C. FASSNACHT
• A. GONZALES
• T. GREVE
• M. JOHNSON
• M. MALKAN
• E. MURPHY
• M. ROSENMAN
• K. SHARON
• B. STALDER
• T. STARK
• A. WEISS
OUTLINE
South Pole Telescope and the Detection of Extremely Bright Sources
Lensed Number Count Models
Size Bias and Differential Lensing
Future of Lensed Submm Sources
Summary
MOTIVATION
Submm sources are the most extreme star forming objects in the universe, giving us a chance to observe and understand galaxy formation and star formation.
Gravitational lensing of these sources acts as a natural telescope enabling us to observe what’s otherwise impossible to see.
In order to use a gravitational lensing as a telescope we need to understand our instrument (=lensing)
An experiment optimized for fine-scale anisotropy measurements of the CMB
• Dedicated 10-m telescope at the South Pole• Background-limited 960-element mm camera
mapping at 90, 150, and 220 GHz simultaneously
Science Goals:• Mass-limited SZ survey of galaxy clusters
– study growth of structure, dark energy equation of state
• Fine-scale CMB temperature anisotropies– tSZ power spectrum to measure σ8
– kSZ power spectrum to constrain reionization
• mm sources– strongly lensed dusty star forming galaxies – AGN– rare galactic objects
90 GHz WMAP CMB map covering one of our SPT fields
1 degree
225 deg2
Lightly filtered SPT map of same area at 90 GHz
1 degree
225 deg2
~15-sigma SZ cluster detection
All these “large-scale”fluctuations are primary CMB.
Lots of bright emissive sources
1' resolution
ZOOM IN ON 2 MM MAP
~ 4 DEG2 OF ACTUAL DATA
R = 90 GHz, 3.2 mmG = 150 GHz, 2.0 mmB = 220 GHz, 1.4 mm
R = 90 GHz, 3.2 mmG = 150 GHz, 2.0 mmB = 220 GHz, 1.4 mm
10−4 10−3 10−2 10−1 100 101 10210−4
10−2
100
102
104
106
108
N (>
S) [d
egï2
]
S1.4 mm[mJy]
Lacey et al. semi-analytic source model
Vieira et al. 20101.4 mm SPT
PREDICTIONS OF
THEORETICAL MODELS
PREDICTIONS OF
THEORETICAL MODELS
Model from Negrello et al.(2007)Data from:
Coppin et al.(2006) Vieira et al. (2010)
�tot
(µ, zs
, Rs
, e
) = 4⇡
✓c
H0
◆Zzs
0dz
d
ZdM
�(µ, zd
, zs
, M, Rs
, e
)nc
(zd
, M)(1 + zd
)2D2(Zd
)p⌦0M (1 + z
d
)3 + ⌦0⇤
LENSING PROBABILITY
P (µ, z) =�tot
(µ, z)
4⇡D2s
dn
dS=
Z Z1
µ0dP
dµ0 (µ0, z)
dn
dS(S = S/µ0, z)dzdµ,
[eein]
[eei
n]
−1 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1
−1
−0.8
−0.6
−0.4
−0.2
0
0.2
0.4
0.6
0.8
1
5
10
15
20
25
30
35
40
45
MAGNIFICATION CROSS-SECTION I
[eein]
[eei
n]
−1 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1
−1
−0.8
−0.6
−0.4
−0.2
0
0.2
0.4
0.6
0.8
1
5
10
15
20
25
30
35
40
45
MAGNIFICATION CROSS-SECTION II
[eein]
[eei
n]
−1 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1
−1
−0.8
−0.6
−0.4
−0.2
0
0.2
0.4
0.6
0.8
1
5
10
15
20
25
30
35
40
45
MAGNIFICATION CROSS-SECTION III
LENSED NUMBER COUNTS
1 10 100
10ï4
10ï3
10ï2
10ï1
100
101
102
103
S1.4 mm [ mJy ]
N (>
S) [d
egï2
]
Unlensed SourcesTotalLensed SourcesLensed z>3.0Lensed z>5.0SPT 1.4 mm
HEZAVEH & HOLDER 2010
EFFECTS OF UNCERTAINTIES ON LENSED NUMBER COUNTS
−2 −1.5 −1−2.5
−2
−1.5
−1
−0.5
0
N (>S) [deg−
2 ]
fm=1
fm=1.1
−2 −1.5 −1−2.5
−2
−1.5
−1
−0.5
0
m8=0.801
m8=0.831
−2 −1.5 −1−2.5
−2
−1.5
−1
−0.5
0
Log(S) [ Jy ]
N (>S) [deg−
2 ]
Rs=1 kpcRs=4 kpcRs=11 kpc
−2 −1.5 −1−2.5
−2
−1.5
−1
−0.5
0
Log(S) [ Jy ]
e = 0.15e = 0.25e = 0.35
HEZAVEH & HOLDER 2010
FOLLOW-UP OBSERVATIONS...
LENSING
CONFIR
MED
LENSING
CONFIR
MED
GREVE ET AL. (IN PREP)
SABOCA 350 UMLABOCA 870 UMSPT 1.4 MM
REDSHIFT DISTRIBUTION OF LENSED SOURCES
GREVE ET AL. (IN PREP) HEZAVEH & HOLDER 2010
SIZE BIAS IN LENSED SAMPLES
100 101
10−2
10−1
100
101
102
N (>
S) [d
egï2
]
Total UnlensedTotal LensedRs<1 kpc
Rs=1 kpc
Rs=3 kpc
Rs=8 kpc
100 1010
0.5
1
N(R
s)/NTO
TAL
S1.4 mm[mJy]
HEZAVEH, HOLDER, MARONNE (IN PREP)
DIFFERENTIAL MAGNIFICATIONOF COMPLEX SOURCES
HEZAVEH, HOLDER, MARONNE (IN PREP)
ï0.6 ï0.4 ï0.2 0 0.2 0.4 0.6
ï0.5
ï0.4
ï0.3
ï0.2
ï0.1
0
0.1
0.2
0.3
0.4
0.5
[arcsec]
[arcsec]
µ=26.05µ=63.36µ=9.76
−0.08 −0.06 −0.04 −0.02 0
0.02
0.04
0.06
DIFFERENTIAL MAGNIFICATIONOF COMPLEX SOURCES
12
12
12
50
5050
5022.5
622
22.5622
12
12
12
50
5050
50
22.5622
22.5622
12
12
12
50
5050
5022.5622
22.5622
12
12
1212
121212
12.4654
12.4654
12.4654
12.4654
12.4654
12.4654
12.465410
10
10
10
10
10
1010
2020
20
20
20
2020
20
12.4654
12.4654
12.4654
12.4654
12.4654
12.4654
12.465410
10
10
10
10
20
202020
22.5622
22.5622
22.562212
12
12
12
12
50
5050
5022.5622
22.5622
22.562212
12
12
12
12
40
40
40
40
40
22.5622
22.5622
22.562212
12
12
12
12
45
45
454545
22.5622
22.5622
22.562212
12
12
12
12
45
45
454545
22.5622
22.5622
22.5622
10
10
10
10
10
10
1010
2020
20
20
20
20
20
20
12.4654
12.4654 12.4
65412.4654
12.4654
12.4654
12.4654
−0.4
−0.3
−0.2
−0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
DIFFERENTIAL LENSING OF A TWO-COMPONENT SOURCE
HEZAVEH, HOLDER, MARONNE (IN PREP)
12
12
12
50
50
50
50
22.5622
22.5622
12
12
12
50
50
50
50
22.5622
22.5622
12
12
12
50
50
50
50
22.5622
22.5622
12
12
1212
121212
12.4654
12.4654
12.4654
12.4654
12.4654
12.4654
12.465410
10
10
10
10
10
1010
20
20
20
20
20
2020
20
12.4654
12.4654
12.4654
12.4654
12.4654
12.4654
12.4654
10
10
10
10
10
20
20
2020
22.5622
22.5622
22.562212
12
12
12
12
50
50
50
50
22.5622
22.5622
22.562212
12
12
12
12
40
40
40
40
40
22.5622
22.5622
22.562212
12
12
12
12
45
45
454545
22.5622
22.5622
22.562212
12
12
12
12
45
45
454545
22.5622
22.5622
22.5622
10
10
10
10
10
10
1010
20
20
20
20
20
20
20
20
12.4654
12.4654 12.4
65412.4654
12.4654
12.4654
12.4654
−0.4
−0.3
−0.2
−0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
10
10
10
20
20
20
12.1065
12.1065
12.1065
12.1065
12.1065
10
10
10
10
20
20
20
20
20
10.9757
10.9757 10.9
75710.9757
10.9757
10.9757
10.975710
10
10
10
20
20
20
20
12.1241
12.1241 12.1
241 12.1241
12.1241
12.1241
12.1241
−0.4
−0.3
−0.2
−0.1
0
0.1
0.2
0.3
0.4
12
12
12
50
50
50
50
22.5622
22.5622
12
12
12
50
50
50
50
22.5622
22.5622
12
12
12
50
50
50
50
22.5622
22.5622
12
12
1212
121212
12.4654
12.4654
12.4654
12.4654
12.4654
12.4654
12.465410
10
10
10
10
10
1010
20
20
20
20
20
2020
20
12.4654
12.4654
12.4654
12.4654
12.4654
12.4654
12.4654
10
10
10
10
10
20
20
2020
22.5622
22.5622
22.562212
12
12
12
12
50
50
50
50
22.5622
22.5622
22.562212
12
12
12
12
40
40
40
40
40
22.5622
22.5622
22.562212
12
12
12
12
45
45
454545
22.5622
22.5622
22.562212
12
12
12
12
45
45
454545
22.5622
22.5622
22.5622
−0.4
−0.3
−0.2
−0.1
0
0.1
0.2
0.3
0.4
0.5
10
10
10
20
20
20
12.1065
12.1065
12.1065
12.1065
12.1065
10
10
10
10
20
20
20
20
20
10.9757
10.9757 10.9
75710.9757
10.9757
10.9757
10.9757
−0.4
−0.3
−0.2
−0.1
0
0.1
0.2
0.3
0.4
0.5
FUTURE: ALMA, HST
SMG’S: GALAXY FORMATION IN ACTION
LENSING IS A POWERFUL TOOL TO OBSERVE HIGH REDSHIFT STAR FORMATION WITH UNMATCHED RESOLUTION
SPATIAL RESOLUTION AND LENS RECONSTRUCTION IS AN ESSENTIAL INGREDIENT TO INFER USEFUL INFORMATION ABOUT LENSED SMG’S
HST + ALMA = LENS MODELLING
= UNBIASED PROPERTIES OF A LARGE SAMPLE OF STARFORMING GALAXIES
SUMMARY
SPT has discovered a population of extremely bright strongly lensed sources
Lensed Number Counts can explain these sources and predict statistical distributions for them.
Strongly Lensed SMG’s can be affected by biases such as Differential Lensing which can be corrected by a correct lens model
ALMA will enable us to resolve these, Construct Lens Models and allow us to use them to study galaxy formation
THANK YOU