SPHEREx. Olivier Doré JPL/Caltech. for the SPHEREx team.

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1 SPHEREx Olivier Doré JPL/Caltech for the SPHEREx team Olivier Doré Aspen - Cosmological Signals from Cosmic Dawn to Present - January

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

3 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

4 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

5 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 3

6 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. λ Credit IPAC/2MASS 3

7 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:

8 SPHEREX SURVEY DEPTH Deep survey Current Best Estimated Full-sky survey Maximum Estimated Value 5

9 SPHEREX PROVIDES A RICH ALL-SKY SPECTRAL ARCHIVE Galaxies Stars Other Detected > 1 billion Main Seq. Spectra > 100 million Quasars > 1 million Med. Accuracy z s > 100 million Dust-forming 10,000 Quasars z > ? High Accuracy z s 10 million Brown Dwarfs > 400 Asteroid Spectra 10,000 Clusters 25,000 Cataclysms > 1,000 Galactic Line Maps PAH, HI, H 2 All-Sky surveys demonstrate high scientific returns with a lasting data legacy used across astronomy COBE IRAS GALEX WMAP Planck WISE 6

10 SPHEREx DESIGN An Innovative Architecture Based on Mature Technologies Wide field telescope Compact spectrometer 185 cm Passive cooling system Ball BCP 100 Spacecraft Bus Olivier Doré Parameter Telescope eff. diameter Field of view Pixel size Wavelength range Resolving power l/dl Aspen - Cosmological Signals from Cosmic Dawn to Present - January 2018 Value 20 cm 3.5 x degree degree 6.2 arcsec µm

11 High-Throughput LVF Spectrometer High%Throughput,LVF,Spectrometer, Linear&Variable&Filter& 2.5 µm H2RG Arrays in t t Focal&Plane&Assembly& λ = λ = λ = t4 5 µm H2RG Arrays in t t Methane&on&Pluto& 1.0& & I/F& 0.6& λ = & λ = λ = t4 0.2& 0.0& Infrared&Spectral&Image& 1.6&&&&&&&&&&&&&1.8&&&&&&&&&&&&&2.0&&&&&&&&&&&&&2.2&&&&&&&&&&&&2.4& Wavelength&(µm)& LVFs&used&on&ISOCAM,&HSTPWFPC2,& New&Horizons&LEISA,&&&OSIRIXPRex&(2016&launch)& Olivier Doré 11.3 Spectra&obtained&by&stepping&source&over&the& FOV&in&mul;ple&images:&&no,moving,parts, Aspen - Cosmological Signals from Cosmic Dawn to Present - January

12 High-Throughput LVF Spectrometer High%Throughput,LVF,Spectrometer, Linear&Variable&Filter& 2.5 µm H2RG Arrays in t t Focal&Plane&Assembly& λ = λ = λ = t4 5 µm H2RG Arrays in t t Methane&on&Pluto& 1.0& & I/F& 0.6& λ = & λ = λ = t4 0.2& 0.0& Infrared&Spectral&Image& 1.6&&&&&&&&&&&&&1.8&&&&&&&&&&&&&2.0&&&&&&&&&&&&&2.2&&&&&&&&&&&&2.4& Wavelength&(µm)& LVFs&used&on&ISOCAM,&HSTPWFPC2,& New&Horizons&LEISA,&&&OSIRIXPRex&(2016&launch)& Olivier Doré 11.3 Spectra&obtained&by&stepping&source&over&the& FOV&in&mul;ple&images:&&no,moving,parts, Aspen - Cosmological Signals from Cosmic Dawn to Present - January

13 Mapping the Sky with LVFs 1 orbit Spectral image 2 orbits N orbits A complete spectrum is made from a series of images SPHEREx maps the sky over multiple orbits with large and small slews 9

14 ASTRONOMY IN THE INTENSITY MAPPING REGIME 10

15 Probing the EBL with Spatial Fluctuations in NIR or mm Instead:))Probe)EBL)by)Studying)Spa$al&Varia$ons& Spitzer) Herschel)(FIR)wavelengths)) W Amblard*et*al.*2011* Kashlinsky*et*al.*2005* Cooray*et*al.*2012* Viero*et*al.*2013* min* c r a * 6 12*x* Planck CIB map Planck)(Lensing)map)) Akari) 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 ** Olivier Doré 2.4*um* 3.2*um* Aspen - Cosmological Signals from Cosmic Dawn to Present - January

16 PROBING THE EPOCH OF REIONIZATION Fluctuations in Continuum s SPHEREx orbits enable deep/frequent observations of about 200 sq. deg near the ecliptic poles (great for systematics!) SPHEREx wavelength coverage and resolution will enable large-scale measurement of spatial fluctuations in the Extragalactic Background Light (EBL). Current Measurements 1 σ 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 12

17 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 13

18 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. Olivier Doré SPHEREx Second Community Workshop - CfA, January

19 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? Sensitivity. The photo signal goes down as θpix 2 and the integration time goes down as θpix 2 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. 15

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