Strategic Planning for 21cm Cosmology Albert Stebbins - PowerPoint PPT Presentation

Strategic Planning for 21cm Cosmology Albert Stebbins Fermilab, Batavia, USA Astrophysics Mini-Retreat B 20 April 2018

3D Cosmology Landscape circa 2026 Observable Universe • parameter accuracy ~ n mode-1/2 1000 • n mode ~ volume 100 10 CHIME 1 Dark 2D : CMB [CMB-3G/S4] dark CMB reionization DESI galaxies energy Ages galaxy imaging HIRAX HERA HERA 2D : single band imaging [APM] 2D + : + multi-band photo-z’s [DES/LSST] area ∝ volume 3D - : + lo-res spectroscopy [PAU/MKIDS] 3D : + hi-res spectroscopy [DESI]

21 cm Intensity Mapping Landscape GBT CHIME Tianlai PF OWFA HIRAX SKA-MID

DOE21: 21cm Roadmap stage 1 stage 2 stage 3 context post reionization post reionization dark ages 0 < z < 2 2 < z < 6 30 < z < 150 data taking LSST/DESI ongoing 2018-2020 construction community building stage 1 first results decadal survey submission 1st results LSST / DESI / stage 1 R&D based on stage 1 P5 submission 2020-2025 stage 1 results simulations Decadal Survey results P5 results firm up science case SKA online optimize design LSST/DESI ending 2025-2030 continuation? collaboration forming SKA results CD0/CD1 construction feasibility study 2030-2035 ? start of data taking preliminary design data taking construction 2035-2040 ? analysis start of data taking data taking 2040-2045 ? analysis DOE21 “ Cosmic Visions Dark Energy: 21-cm Roadmap” Slosar & co.

Target of Opportunity: “21cm Stage 2” 2 < z < 6 (200-500 MHz) bandwidth smaller than CHIME/HIRAX 256 x 256 array 6m dishes 64 x HIRAX dual polarization feeds close packed ~ 1.5 km 2 (very different design than SKA) highly redundant baseline correlator FFT (n log n) or direct summation (n 3/2 ) learn from HIRAX Total S/N in the power spectrum radial resolution ~3kHZ DESI limited by the number density of sources LSST by the precision of photometric redshifts. 21cm-S2 looses sensitivity at low-k due to foreground contamination ~ HIRAX but has most volume and most accurate sampling . DOE21 “ Cosmic Visions Dark Energy: 21-cm Roadmap” Slosar & co.

Foreground Removal? de Oliveira-Costa et al. 2008 versus ~10 2 μ K! prediction: this will be worked out by 2020

BAO Sensitivity current generation angular 40 DESI EUCLID WFIRST 21-cm 30 √ z distance /r d 20 10 D M ( z ) /r d √ z radial D V ( z ) /r d √ z √ z zD H ( z ) /r d 0 0 1 2 3 4 5 6 7 z DOE21 “ Cosmic Visions Dark Energy: 21-cm Roadmap” Slosar & co.

Dark Energy Density DOE21 “ Cosmic Visions Dark Energy: 21-cm Roadmap” Slosar & co.

“Realtime” Cosmology? 5 year redshift drift Sandage Effect: Could we directly detect cosmic (de)acceleration? DOE21 “ Cosmic Visions Dark Energy: 21-cm Roadmap” Slosar & co.

End Game: Stage 3 Dark Ages Tensor/Scalar 10 - 1 10 - 2 From curl lensing Min. r detectable at 3 s 10 - 3 From tidal fossils Moon 10 - 4 diameter 10 - 5 Floor set by scalar - induced vector modes 10 - 6 Floor set by scalar - induced tensor modes 10 - 7 10 20 50 100 200 500 1000 2000 5000 b @ km D DOE21 “ Cosmic Visions Dark Energy: 21-cm Roadmap” Slosar & co.

DOE Laboratory Strengths • Industrialization : • 21cm Stage 2 is an “industrial scale” radio telescope • Large arrays of identical, precision detectors • RF techniques related to accelerator cavities • RF instrumentation, fast digitization • Handling / processing high-volume data rates • Storage / analysis of large data sets DOE21 “ Cosmic Visions Dark Energy: 21-cm Roadmap” Slosar & co.

HEP Techniques Helps 21cm Interferometry : Example NEBuLA NumEriseur à Bande Large pour l’Astronomie Wide band digitizer for radioastronomy uses CERN Daniel Charlet 1 ,Cedric Viou 2 1 : Laboratoire de l'Accélérateur Linéaire White Rabbit Université Paris XI, 91898 Orsay 2 : Station de Radioastronomie de Nançay, timing Observatoire de Paris, PSL Research University, CNRS, Université d’Orléans, 18330 Nançay, France system TWEPP 2017 1 Daniel Charlet TWEPP-2017 digitize near antenna: time-stamped packets NOT analog cables

DOE21: 21cm Roadmap stage 1 stage 2 stage 3 context post reionization post reionization dark ages 0 < z < 2 2 < z < 6 30 < z < 150 data taking LSST/DESI ongoing 2018-2020 construction community building stage 1 first results decadal survey submission 1st results LSST/DESI/Stage 1 R&D based on stage 1 P5 submission stage 1 results 2020-2025 simulations Decadal Survey results continuation? P5 results firm up science case SKA online optimize design LSST/DESI ending 2025-2030 collaboration forming SKA results CD0/CD1 construction feasibility study 2030-2035 ? start of data taking preliminary design data taking construction 2035-2040 ? analysis start of data taking data taking 2040-2045 ? analysis DOE21 “ Cosmic Visions Dark Energy: 21-cm Roadmap” Slosar & co.