Olivier Doré JPL/Caltech

SPHEREx

for the SPHEREx team

http://spherex.caltech.edu

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 1 SPHEREX HAS THREE CORE SCIENCE THEMES

NASA Goal: Probe the origin and destiny of the Universe

SPHEREx maps the large scale structure of galaxies to study the inflationary birth of the universe

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 2 SPHEREX HAS THREE CORE SCIENCE THEMES

NASA Goal: Probe the origin and destiny of the Universe

SPHEREx maps the large scale structure of galaxies to study the inflationary birth of the universe

NASA Goal: Explore whether planets around other stars could harbor life

SPHEREx determines the abundance of interstellar water and organic ices available to proto-planetary systems

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 2 SPHEREX HAS THREE CORE SCIENCE THEMES

NASA Goal: Probe the origin and destiny of the Universe

SPHEREx maps the large scale structure of galaxies to study the inflationary birth of the universe

NASA Goal: Explore whether planets around other stars could harbor life

SPHEREx determines the abundance of interstellar water and organic ices available to proto-planetary systems

NASA Objective: Explore the origin and evolution of galaxies

SPHEREx measures the total light produced by stars and galaxies over cosmic history

Also talk by Tzu-Ching

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 2 SPHEREx: An All-Sky Spectral Survey

Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer A high throughput, low-resolution near-infrared spectrometer.

Credit IPAC/2MASS

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 3 SPHEREx: An All-Sky Spectral Survey

Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer A high throughput, low-resolution near-infrared spectrometer.

Credit IPAC/2MASS

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 3 SPHEREX: AN ALL-SKY SPECTRAL SURVEY

Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer

A high throughput, low-resolution near-infrared spectrometer.

SPHEREx Dataset:

For every 6.2” pixel over the entire sky:

➡ R=40 spectra spanning (0.75 μm < λ < 4.18 μm). ➡ R=150 spectra (4.18 μm < λ < 5.0 μm).

O.D., Bock et al., arXiv:1412.4872

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 4 SPHEREX SURVEY DEPTH

Deep survey

Current Best Estimated Full-sky survey

Maximum Estimated Value

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 5 SPHEREX PROVIDES A RICH ALL-SKY SPECTRAL ARCHIVE

Detected Med. High Accuracy Clusters > 1 Accuracy z’s z’s 25,000 billion > 100 million 10 million

All-Sky surveys demonstrate high scientific returns with a Galaxies Main Seq. Dust-forming Brown lasting data legacy used Spectra Cataclysms 10,000 Dwarfs > 1,000 across astronomy > 100 million > 400

COBE Stars IRAS Quasars Quasars z >7 Asteroid Galactic Line GALEX > 1 million 2 – 300? Spectra Maps WMAP 10,000 PAH, HI, H 2 Planck WISE Other

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 6 SPHEREx DESIGN An Innovative Architecture Based on Mature Technologies

Compact spectrometer Wide ﬁeld telescope

Passive cooling system 185cm Parameter Value Telescope eff. diameter 20 cm Field of view 3.5 x 711.3 degree degree Pixel size 6.2 arcsec Wavelength range 0.75 – 5 µm Ball BCP 100 Spacecraft Bus Resolving power l/Dl 41 - 135

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 7 High-ThroughputHigh%Throughput,LVF,Spectrometer, LVF Spectrometer

Linear&Variable&Filter& 2.5 µm H2RG Arrays in

t t1 t3 t Band t1 Band t3 Band

Focal&Plane&Assembly&

λ = 0.75 – 1.11 λ = 1.11 – 1.64 λ = 1.64 – 2.42

t1 t3 t4

5 µm H2RG Arrays in

t t1 t3 t Band t1 Band t3 Band

Methane&on&Pluto& 1.0& 3.5 0.8&

0.6& λ = 2.42 – 3.68 λ = 3.68 – 4.45 λ = 4.45 – 5.01 I/F& 0.4& t1 t3 t4 0.2&

0.0& 11.3 1.6&&&&&&&&&&&&&1.8&&&&&&&&&&&&&2.0&&&&&&&&&&&&&2.2&&&&&&&&&&&&2.4& Infrared&Spectral&Image& Wavelength&(µm)& LVFs&used&on&ISOCAM,&HSTPWFPC2,& Spectra&obtained&by&stepping&source&over&the& New&Horizons&LEISA,&&&OSIRIXPRex&(2016&launch)& FOV&in&mul;ple&images:&&no,moving,parts,

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 8 High-ThroughputHigh%Throughput,LVF,Spectrometer, LVF Spectrometer

Linear&Variable&Filter& 2.5 µm H2RG Arrays in

t t1 t3 t Band t1 Band t3 Band

Focal&Plane&Assembly&

λ = 0.75 – 1.11 λ = 1.11 – 1.64 λ = 1.64 – 2.42

t1 t3 t4

5 µm H2RG Arrays in

t t1 t3 t Band t1 Band t3 Band

Methane&on&Pluto& 1.0& 3.5 0.8&

0.6& λ = 2.42 – 3.68 λ = 3.68 – 4.45 λ = 4.45 – 5.01 I/F& 0.4& t1 t3 t4 0.2&

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 8 Mapping the Sky with LVFs

1 orbit

Spectral image

2 orbits

N orbits

SPHEREx maps the sky over multiple A complete spectrum is made from a series of images orbits with large and small slews

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 9 ASTRONOMY IN THE INTENSITY MAPPING REGIME

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 10 ProbingInstead:))Probe)EBL)by)Studying) the EBL with Spatial FluctuationsSpa$al&Varia$ons& in NIR or mm

•Herschel)(FIR)wavelengths))W Spitzer) Amblard*et*al.*2011* Kashlinsky*et*al.*2005* Viero*et*al.*2013* Cooray*et*al.*2012*

* Planck CIB map arcmin 12*x*6*

Akari) Planck)(Lensing)map)) Matsumoto*et*al.*2010* 10*arcmin* Planck*C.*et*al.*2014*

Successful)Applica=ons)at)Longer)Wavelengths) *****Herschel*EBL:**Viero*et*al.*2013* *****Planck*EBL:**Planck*C.*et*al.*2013* XXX *****Planck*EBL*x*CMB*Lensing:**Planck*C.*et*al.*2014* XVIII *****Herschel*EBL*x*CMB*Lensing:**Many ** 2.4*um* 3.2*um*

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 11 PROBING THE EPOCH OF REIONIZATION

Fluctuations in Continuum Bands • SPHEREx orbits enable deep/frequent observations of about 200 sq. deg near the ecliptic poles (great for systematics!) Current Measurements • SPHEREx wavelength coverage and 1 σ resolution will enable large-scale measurement of spatial fluctuations in the Extragalactic Background Light (EBL).

• In particular, SPHEREx will monitor/explain the Intra-Halo Light and its evolution (CIBER, Zemcov++14).

• SPHEREx has the raw sensitivity to probe the expected EOR signal (but separation with low z signal will be challenging).

• The sensitivity in this region will enable deep intensity mapping regimes using multiple lines at all redshift, and maybe Lyα at high redshift (see Croft++15) see Tzu-Ching’s talk tonight Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 12 SPHEREX TEAM Jamie Bock (PI) Caltech/JPL Roland de Putter JPL

Matt Ashby CfA Tim Eifler JPL

Peter Capak IPAC Rachel Akeson IPAC

Asantha Cooray UC Irvine Yan Gong UC Irvine

Brendan Crill JPL/Caltech Lindsey Bleem Argon

Olivier Doré (PS) JPL/Caltech Daniel Masters Caltech

Chris Hirata OSU Phil Mauskopf ASU

Woong-Seob Jeong KASI Tzu-Ching Chang JPL/Caltech

Minjim Kim KASI Hien Nguyen JPL

Phil Korngut (IS) Caltech Karin Öberg CfA

Elisabeth Krause Stanford Davy Kirkpatrick IPAC

Dae-Hee Lee KASI Harry Teplitz IPAC

Gary Melnick CfA Volker Tolls CfA

Roger Smith Caltech Salman Habib Argonne

Yong-Seon Song KASI Katrin Heitmann Argonne

Stephen Unwin JPL Karin Sandstrom UCSD

Michael Werner JPL Carey Lisse JHU

Michael Zemcov Caltech Rogier Windhorst ASU

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 13 SPHEREX WILL ENABLE ROBUST AND UNIQUE SCIENCE INVESTIGATIONS

•SPHEREx will create the first all sky near-infrared spectroscopic survey: ➡SPHEREx will create a dataset of lasting legacy. ➡High quality archival products are now fully part of the MIDEX mission.

•SPHEREx offers a simple and very robust design and modus operandi: ➡It naturally enables a high control of systematics thanks to multiple built-in redundancy.

•SPHEREx will also enable other original and powerful studies on EOR: ➡The extra-galactic background light from z=0 till the reionization era. ➡Relies on broadband fluctuation measurements or line intensity mapping.

•Community support is important! ➡If you want SPHEREx to happen, please mention it in your papers or talks.

http://spherex.caltech.edu

Olivier Doré SPHEREx Second Community Workshop - CfA, January 2018 14 FREQUENTLY ASKED QUESTIONS • The pixel size under samples the PSF, isn’t that bad? ➡ For sources for known positions, we know the PSF and pointing in each image and can do optimal forced photometry (a la Tractor). For unknown source positions yes there is some degradation of sensitivity for aperture photometry. Sensitivities quoted for sources with known positions.

• How can SPHEREx be more sensitive than WISE? ➡ We checked. SPHEREx has long integrations that are photon noise limited, and fewer effective pixels in the PSF. These more than compensate for 2x smaller mirror diameter.

• Isn’t SPHEREx confusion limited with 6” pixels? ➡ Confusion is minor in high-latitude sky at our sensitivity, and blended galaxies are flagged based on PS-DES and WISE images and removed from the cosmology survey. Confusion is definitely an issue in the Galactic plane and in the deep fields.

• Why not make the pixel size smaller? Or spectral resolution higher? 2 ➡ Sensitivity. The photo signal goes down as θpix and the integration time goes 2 down as θpix since more pointings are required to cover the sky. Photon noise = read noise with 5″ pixels. Similar arguments apply to spectral resolution. After extensive simulations, modest changes in pixel size do not substantially change the confusion limit.

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 15 FIN

Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 16