The Atacama Cosmology Telescope: ACTPol Suzanne Staggs CMB2013 - - PowerPoint PPT Presentation

The Atacama Cosmology Telescope: ACTPol

Suzanne Staggs CMB2013 Okinawa, 11 June

The Atacama Cosmology Telescope

• 6m off-axis Gregorian telescope
• 2m primary
• Located at 5200 m (0.5 mm PWV)
• Latitude -23o

The Atacama Cosmology Telescope

• 6m off-axis Gregorian telescope
• 2m primary
• Located at 5200 m (0.5 mm PWV)
• Latitude -23o

Reflector Secondary Reflector

ACT ground screens: large co- moving screen and 13 m

• uter screen.
• 72 panels
• 25-30 µm rms
• All aluminum

ACTPol – Next Generation Receiver

• 16x mapping speed of

MBAC

• 150 GHz and 100 GHz
• Polarization-sensitive

detectors Funded 2011-2016; first array in the field now, first light imminent.

Staggs; Okinawa 2013

ACTPol Science Goals in Brief

2000 4000 0.01 0.1 1 10 BB EE ACT Wide ACT Deep Planck

Statistical Noise Curves

Wide survey (~4000 deg2); Deep survey (5 fields, each 25 deg2) Details in Niemack et al, arXiv:1006.5049

Cluster Catalog -

• Overlap with existing surveys
• Complementary to SPT/Planck

Improved power spectra –

• (TT)
• TE
• E-modes
• B-modes
• Deflection field

Maps –

• CMB
• Deflection field

Staggs; Okinawa 2013

ACTPol Science Goals in Brief

EE Power Spectrum

• Smaller than TT but cleaner!
• At l ~ 3000, CMB is 20%

polarized; dust is 1-2% polarized.

• Forecast factor of ~2

improvements over forecasts for Planck (TT and EE) on:

• Σmν (.06 eV)
• YHe (0.005)
• Ωbh2 (1.3 x 10-4)
• Neff (CMB alone, 0.5)

Recall YHe impacts the high-l spectrum because those modes enter the horizon while He is not yet fully ionized.

Forecasts relatively simple so far.

Staggs; Okinawa 2013

• Lensing peak smearing more

evident for polarization

• SHO – x & v out-of-phase
• TT is a ~3:1 combo of x & v
• Polzn peaks are sharper!
• BB modes directly generated by

lensing

Polarization & Lensing (Reminder)

From Zaldarriaga & Seljak, 1998 Note also enhancement at high l

EE and BB and Deflection Field Maps

ACTPol BB errors Planck BB errors

Staggs; Okinawa 2013

CMB Lensing

Deflection Field Power Spectrum and Maps

CMB Lensing is going to explode as a field in the next few years

25 50 75 100

4 6 7 20 50 70 100

ACT

• I

ACT Full SPT

• 1

SPT Full Planck +ACTpol/SPTPol ACTpol Large Sky

S i g n a l

• t
• N
• i

s e

Pre-Planck figure from S. Das Planck

Staggs; Okinawa 2013

ACTPol Lensing Goals in Brief

Deflection Field Power Spectrum and Maps

• Lensing kernel at intermediate z (<5)
• Breaks degeneracies
• Makes cross-correlation studies rich

Plot from Smith, Cooray, Das, Dore et al, 2009 White Paper.

Sherwin et al, 2011

Dark Energy from the CMB Alone!

Staggs; Okinawa 2013

ACTPol Lensing Goals in Brief

Deflection Field Power Spectrum and Maps

• Lensing kernel at intermediate z (<5)
• Breaks degeneracies
• Makes cross-correlation studies rich

Dark Energy from the CMB Alone – Updated!

Planck Collaboration, XVII, 2013

Plot from Smith, Cooray, Das, Dore et al, 2009 White Paper.

Staggs; Okinawa 2013

ACTPOL Lensing Forecasts

Assuming no systematics other than instrumental noise, these plots show the signal and noise power spectra for the Deep and Wide configurations.

ACTPOL-DEEP: 150 sq-deg @ 3 µK-arcmin (temp) and 5 µK-arcmin (pol)

ACTPOL-WIDE: 4000 sq-deg @ 20 µK-arcmin (temp) and 28 µK-arcmin (pol)

Signal

Optimal Noise

Signal

Optimal Noise

Primordial B-modes

Staggs; Okinawa 2013

Temperature E-mode B-mode primordial lensing 10 100 1000 104 102 100 10

• 2

BICEP DASI CAPMAP QUAD MAXIPOL BOOMERANG WMAP ACBAR SPT ACT QUIET

dashed horizontal lines- limits on B-modes solid vertical lines - measurements of T and E

measurements

CBI

Primordial B- modes peak at even larger angles than TT! (c > c/31/2)

Primordial B-modes

Staggs; Okinawa 2013

ACT has great dynamic range (cross-linking, ML maps  little filtering) ... but ACTPol’s guaranteed capability in the GW quest is delensing because large angles are hard with large telescopes.

Primordial B- modes peak at even larger angles than TT! (c > c/31/2)

ACTPol Cross-correlations

25,000 deg2 available; wide survey will overlap with SDSS-III BOSS; deep surveys may

• verlap with XMM-LSS, CFHTLS, HerMES,UKIDSS, DES, GAMA, etc

ACTPol Cross-correlations

HyperSuprime Camera

• n Subaru
• Prime Focus Spectrograph
• IPMU/NAOJ/Princeton*/

Caltech/JHU/Sao Paolo/ Marseilles/Edinburgh

• First light this summer
• Galaxy cosmic shear in wide

and deep surveys; overlap to ACTPol with some of each *but not me

ACTPol Instrument (Deltas)

Old optical path

New optical path

30 cm 30 cm

New optical path

• Increased throughput
• ptical design (M.Niemack)
• Wideband silicon lenses (J.

McMahon)

• Feedhorn-coupled

polarization arrays of TES bolometers from NIST (TRUCE)

• 2 arrays at 150 GHz;
• 1 at 100/150 GHz
• 100 mK cryogenics with 24

hour operations

Wide Bandwidth Silicon Lenses

• Low loss material
• High n = 3.4

=> excellent image quality – Need good AR coating

• Developed 2-layer

simulated-dielectric AR coating

Smallest ACTPol lens

( Datta, Niemack, McMahon et al. in prep. )

ACT production developed at UMich in McMahon group

150 GHz ABS single detector

Polarization Sensitive Detectors

Truce Collaboration: ABS, SPTPol, and ACTPol

5mm ( ABS: Essinger-Hileman et al. LTD 2009, SPTPol: Bleem et al. JLTP 2012, ACTPol: Niemack et al. SPIE 2010 ) 1 mm

Old ACT detector

• Feedhorn Coupled TES Polarimeters
• Bulk absorption
• vs. Superconducting circuits
• 2D wafers (cf 1x32)

OMT couples to feedhorn TES bolometer

• Three arrays (~1000 TES each)
• 0.1K bath temperature (0.3K

previously) 150 GHz paths

Silicon Polarimeter Arrays

Better detectors + optics + cryogenics => ~ 4x increase in sensitivity (16x mapping speed)

Silicon feedhorn array Sub-array with 255 TES Polarimeter 90/150 GHz path

5mm

Detectors + TDM muxing SQUID Readout

Staggs : Okinawa 2013

0.3 meters Superconducting flexible cabling; double layer Multiplexing SQUIDs, shunt resistors, Nyquist

Detectors + TDM muxing SQUID Readout

Staggs : Okinawa 2013

Monolithic feedhorn array

First ACTPol Array!

Emily Grace, Laura Newburgh and Christine Pappas with the first completed ACTPol array. See Emily Grace’s poster!

ABSTRACT: ACTPol is a polarization-sensitive receiver upgrade to the Atacama Cosmology Telescope, located at an elevation of 5200 meters in the

Atacama Desert in Chile. With the new receiver, we will make millimeter wavelength measurements of the small-scale polarization anisotropies of the Cosmic Microwave Background (CMB) to explore structure formation, constrain the sum of the neutrino masses, probe early dark energy, and perform other cosmological tests. ACTPol will employ three arrays of transition edge sensor (TES) bolometer detectors. The detectors, with a target transition temperature of 150 mK, will be operated at a bath temperature of ~100 mK provided by a dilution refrigerator. One array operating at a central frequency of 150 GHz and consisting of 1020 TESes has recently been installed in the telescope at the ACT site.. We anticipate fielding a second identical array and a multi-chroic array that simultaneously measures 90 GHz and 150 GHz near the end of this observing season.

Characterization and Performance of a Kilo-TES Sub-Array for ACTPol

Emily Grace1 for the ACTPol Collaboration

1Department of Physics, Princeton University, Jadwin Hall, Princeton, NJ 08544 (Email:egrace@princeton.edu)

ACTPol Receiver Deployment

Staggs; Okinawa 2013

Observing the sky with the receiver at 17kft Putting the receiver into the telescope cabin ~ last week!

ACTPol Receiver Deployment

Staggs; Okinawa 2013

Special thanks to graduate students Ben Schmitt and Marius Lungu in the field with Pato Gallardo and Masao Uehara.

THE END

Many thanks to many collaborators for slides, figures & slide concepts.