probing the opposite ends of time with the cosmic ... · fridge mhz biased bolometers +...
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Cosmic Microwave Cosmic Microwave Background RadiationBackground Radiation
Matt DobbsMatt Dobbs
October 27, 13 700 002 006 ABB
Probing the opposite ends of time with the
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Spiral Galaxy
From our perspective as From our perspective as optical observers, the optical observers, the universe is a rich universe is a rich place full of structure, place full of structure, detail and beauty.detail and beauty.
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“Photograph” of the universe in the Microwave band.Real Experimental DATA from the COBE satellite, 1992.
Q: Where are we in the universe?
A: Nowhere special(on cosmological scales)
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What is cosmology?What is cosmology?Step back to larger scales, and Step back to larger scales, and the universe that surrounds us the universe that surrounds us is extremely uniformis extremely uniform––on large (Cosmological) scales, on large (Cosmological) scales, the universe isthe universe is
homogenous (the same homogenous (the same everywhere)everywhere)isotrophicisotrophic (looks the same in (looks the same in every direction)every direction)
Loosely put, Loosely put, cosmology is the cosmology is the study of our universe on study of our universe on these scalesthese scales..
This infinite cylinder is a 2d homogeneous surface, but it is not isotrophic.
The 2d surface of this sphereis isotrophic, and thereforealso homogeneous.
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EM SpectrumEM Spectrum
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different information is encoded in different bands.different information is encoded in different bands.
radiowavesradiowaves: i.e. radar: i.e. radar
visible: this is how we see the world around us.visible: this is how we see the world around us.
xx--rays: i.e. dentist/doctor.rays: i.e. dentist/doctor.
gammagamma--rays: highest energy particles we know of…rays: highest energy particles we know of…
hot
cold
cm km10-2-103 m
mm cm10-3-10-2 m
μm10-6-10-4 m
100s nm10-7-10-6 m
1-102 eV
102-105 eV
>105 eV
CMB Photons now.
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cold
cm km10-2-103 m
mm cm10-3-10-2 m
μm10-6-10-4 m
100s nm10-7-10-6 m
1-102 eV
102-105 eV
>105 eV
CMBPhotonsNow
as the universeexpands & cools, the Cosmic BackgroundRadiation photonsare stretched,and evolve throughthe EM spectrum.
“CMB” photonsa long time ago.
“CMB” photonsin the future.
All these “diffe
rent” photons t
ravel
at the sam
e speed, c = 3
x 108 m/s.
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The HorizonThe Horizonlight light –– and indeed any information and indeed any information –– cannot be transmitted cannot be transmitted faster than the faster than the speed of light, cspeed of light, c..
For a universe that is L=13.7 billion years old, information For a universe that is L=13.7 billion years old, information could be exchanged over a maximum distance could be exchanged over a maximum distance LcLc..
This defines “This defines “our horizonour horizon”.”.As time moves forward, our horizon increases!.As time moves forward, our horizon increases!.The Horizon problemThe Horizon problem: we see structures (e.g. the universe!!) : we see structures (e.g. the universe!!) that are uniform on superthat are uniform on super--horizon scales.horizon scales.
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Since light coming from further away takes Since light coming from further away takes longer to get here, the objects that emit the longer to get here, the objects that emit the light are from an earlier time, because the light light are from an earlier time, because the light was emitted a long time ago.was emitted a long time ago.
observations of distant objects are observations of our universe
at a younger age.
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1021
10-10
1
106
>= Galaxies
Size (m) Object Force Expert
Stars &planets
Living Things
Atoms
10-9 Molecules
10-15 Neutrons/protons
Gravit
y
InstinctRomanceBiology
PsychologistsTaxi Drivers
Biologists
Electr
omagneti
sm ChemistsPharmacists
Weak ForceStrong Nuclear Force
Nuclear & ParticlePhysicists
Cosmologists
Astronomers
Thanks to A. De Rujula for this slide idea. [email protected] – Oct 27, 2006
on different length scales, different forces are on different length scales, different forces are relevantrelevant–– and so we use different theories and and so we use different theories and equations.equations.
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Physics TheoriesPhysics Theories
Bigg
er M
ass
faste
r Speed
smaller size
Newtonian Gravity
Quantum Mechanics
Special Relativity
Particle PhysicsEW, QCD
?????String Thy?
General Relativity
We need this Grand Unified Theory to calculate anything near the big bang!
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The History of the UniverseThe History of the Universea photon’s journey from the a photon’s journey from the
opposite ends of timeopposite ends of time
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History of the universeHistory of the universe You are hereNOW (13.7 Billion years)
Surface of Last Scattering
Inflation? <10-35 seconds, 1016 GeVGravity waves produced
Plasma Epoch
Large Scale Structure
LHC probes this scale (TeV, 10-14s)
TIM
E
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History of the UniverseHistory of the Universe
The Big Bang The Big Bang
1920s & 30s: Hubble observed the universe is expanding.1920s & 30s: Hubble observed the universe is expanding. time=0Big Bang
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History of the UniverseHistory of the UniverseInflation Inflation
at t~10at t~10--3535 s ABB, the universe undergoes a phase s ABB, the universe undergoes a phase transition causing an explosive 10transition causing an explosive 103030 exponential exponential expansionexpansion
Inflation explains the horizon problem: why Inflation explains the horizon problem: why CMB is isotropicCMB is isotropic
10-38 sinflation10-45 10-35 10-5
TIME
UN
IVER
SE S
IZE
1
10-60
INFL
ATI
ON
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History of the UniverseHistory of the Universe
Plasma Epoch, Plasma Epoch, t <~ 400 000 yearst <~ 400 000 years
the universe is opaque to lightthe universe is opaque to light
matter and radiation are tightly coupled matter and radiation are tightly coupled in in thermal equilibrium thermal equilibrium
plasmaepoch
10-38 sinflation
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History of the UniverseHistory of the Universe
Recombination Recombination t~379 000 years ABB, T=3000K
protons combined with electrons to form neutral protons combined with electrons to form neutral hydrogenhydrogen
recombination is sudden.recombination is sudden.
this is the “surface of last scattering”
0 Big Bang
10-38 sinflation
plasmaepoch
379 000yearsrecombination
plasmaepoch
400 000yrrecombination
10-38 sinflation
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History of the UniverseHistory of the UniverseLarge Scale Structure Formation EpochLarge Scale Structure Formation Epoch
Matter collapses under gravity to form the rich Matter collapses under gravity to form the rich structure (including us!) of the universe.structure (including us!) of the universe.photons are (almost!) unaffectedphotons are (almost!) unaffected
Why the difference between Matter & Radiation now??Why the difference between Matter & Radiation now??radiation pressureradiation pressure resists the pull of gravity.resists the pull of gravity.
plasmaepoch
400 000yrrecombination
LSSepoch
10-38 sinflation
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History of the UniverseHistory of the Universe
NOW NOW t~13 700 002 006 years ABBt~13 700 002 006 years ABB
T=2.7 K (T=2.7 K (--27027000 C)C)
plasmaepoch
400 000yrrecombination
LSSepoch
13.7 GyearsNOW
End of the line for a preciousfew of the photons, as we trapthem in our detectors and glean a little information about the universe in which we live.
10-38 sinflation
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The Cosmic Microwave The Cosmic Microwave Background RadiationBackground Radiation
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Cosmic Microwave BackgroundCosmic Microwave Background
Cobe
1992
Cobe
1992
Cobe
1992
WM
AP
2003
Dipole Anisotropy 10-3
Large Scale Temp Anisotropy, 10-5
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from: Feb’03APS News
S. Coutu
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The TeamThe Team
Kevin
EricTrevor
James
Rajat
Claire
Big Blue
( Kareem )
John
Yoshi
( Robert )
the APEXthe APEX--SZ ExperimentSZ ExperimentU.C. Berkeley / LBNLU.C. Berkeley / LBNLHsiaoHsiao--Mei ChoMei ChoBill HolzapfelBill HolzapfelZigmundZigmund KermishKermishRuedigerRuediger KneisslKneisslAdrian LeeAdrian LeeMartin LuekerMartin LuekerJared Jared MehlMehlTom Tom PlaggePlaggePaul RichardsPaul RichardsDan Dan SchwanSchwanHelmuth Helmuth SpielerSpielerMartin WhiteMartin White
C.U. BoulderC.U. BoulderNils HalversonNils Halverson
McGill UniversityMcGill UniversityMatt DobbsMatt DobbsTrevor LantingTrevor Lanting
Max Planck Max Planck IfRIfR, Bonn, BonnKaustuvKaustuv BasuBasu
Frank BertoldiFrank BertoldiRolf GuestenRolf GuestenErnst KreysaErnst KreysaKarl MentenKarl MentenDirk MudersDirk MudersPeter Peter SchilkeSchilke
Cardiff Cardiff Peter AdePeter Ade
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CMB photons are used to backlight structure in the universe.CMB photons are used to backlight structure in the universe.
11--2% of CMB photons 2% of CMB photons traversing galaxy traversing galaxy clusters are clusters are inverse Compton inverse Compton scattered to higher scattered to higher energyenergy–– the the Sunyaev Sunyaev Zeldovich EffectZeldovich Effect..
Tool for mapping expansion historyTool for mapping expansion history
Galaxy cluster searchesGalaxy cluster searches
BIMA
DiaboloSuZIE
FREQUENCY FREQUENCY
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Galaxy cluster searchesGalaxy cluster searches
optical / Xoptical / X--ray ray skysky clustersclusters fade away at high redshift.fade away at high redshift.
SZ observations do not fade away over large distances SZ observations do not fade away over large distances
Clusters can be seen at any distance.Clusters can be seen at any distance.
Carlstrom et al.
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Chile
N
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VolcanLicancabu
BOLIVIACHILE
APEX-SZ
LagoVerde
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LagoVerdeVolcan
Licancabu
APEX-SZ
BOLIVIA
CHILE
San Pedro de Atacama
N
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APEXAPEX--SZSZ320 element TES bolometer array320 element TES bolometer arraypulse tube cooler w/ pulse tube cooler w/ 33He sorption He sorption fridgefridgeMHz biased bolometers + MHz biased bolometers + multiplexingmultiplexingTelescope: 12m Telescope: 12m CassegrainCassegrain, ALMA , ALMA prototype built by Vertexprototype built by VertexChajnantorChajnantor site, 5100m site, 5100m Atacama Plateau, ChileAtacama Plateau, ChileFirst light, Dec 2005First light, Dec 20051’ resolution at 2mm1’ resolution at 2mm
(under(under--filled primary)filled primary)
0.4 degree FOV0.4 degree FOV
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Building a CMB TelescopeBuilding a CMB TelescopeThe Night Sky
Cold Electronics
Readou
t Syst
em
300 mK
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SZ Camera Installed Dec 13SZ Camera Installed Dec 13
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APEXAPEX--SZ Readout SystemSZ Readout System
Readout Create with Osc/Demod boards
SZ Camera with SQUID Controllers
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APEXAPEX--SZ Field TeamSZ Field Team
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Dec 24, 2005Several Minutes of APEX-SZ Data38 TES Bolometers biased with MHz carriers and cooled without expendable cryogens
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South Pole TelescopeSouth Pole Telescope10m off axis Gregory telescope10m off axis Gregory telescope1 deg 1 deg FoVFoV, 1 , 1 arcminarcmin beam at beam at 2mm2mm1000 element bolometer array1000 element bolometer array
frequency domain multiplexed frequency domain multiplexed readoutreadout
deploy to pole January 2007 deploy to pole January 2007 factor 10 faster mapping speed factor 10 faster mapping speed than APEXthan APEX
4000 deg4000 deg22 at 10 µK/pixelat 10 µK/pixel→→ ~10~1044 clustersclusters
U. Chicago, UC Berkeley, Case Western R., CU Boulder, U. Illinois, LBNL, McGill, Harvard SAO
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South Pole Telescope (SPT)South Pole Telescope (SPT)
Dec 11, 2005
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One of the primary challengesfor CMB observations is trying tosee the tiny 2.7 K sky temperaturewhile you’re looking through awarm (300 K) atmosphere, with cloudsand other changing conditions.
This has driven scientists to put theirtelescopes as high as possible—on board high altitude balloons, U2 spy airplanes, and on satellites.
BalloonBalloon--Borne InstrumentsBorne InstrumentsThe Maxima Balloon Payload.
The Boomerang Balloon at the South [email protected] – Oct 27, 2006
55 element wedge
4 mm
Spider web TES bolometer
Ti
Au
Al 54μm
54μm
64mm
TES Bolometer ArrayTES Bolometer Array
G ~ 400 pW/Kτ ~ 7-9 ms
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Readout SystemReadout System
fMUX Chip
DDS Oscillators
RB
R1
R2
-V2
V1
I
I1
RS
C1 C2 C3 Cn
L1 L2 L3 Ln
2
Σ Vn(fn)
Demodulator
RSRSRS
Rfb
ADCSQUID Controller
TES Bolometers
Series Array SQUIDs
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Special thanks to the staff that make things happen at McGill:• John and Robert, who have put together a first rate lab and made it happen fast.• Eddie and Steve, who always tell me it’s nearly impossible to build, then build it.• Diane (who’s fighting the overhead monster with me)• Sonia (who’s helping build our next electronics board)• Elizabeth, Louise, and Paula, who make everything happen.
• Nick and Eric (borrowed from UdM), who are building the next generation.