Spherex: New NASA MIDEX All-Sky 1-5 Um Spectral Survey
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SPHEREx: New NASA MIDEX All-Sky 1-5 um Spectral Survey Designed to Explore ▪ The Origin of the Universe ▪ The Origin and History of Galaxies ▪ The Origin of Water in Planetary Systems ▪ PI Jamie Bock, CalTech The First All-Sky Near-IR Spectral Survey A Rich Legacy Archive for the Astronomy Community with 100s of Millions of Stars and Galaxies Low-Risk Implementation ▪ 2022 NASA MIDEX Launch ▪ Single Observing Mode ▪ Large Design Margins Co-I Carey Lisse, SES/SRE ▪ No Moving Optics NASA SBAG Jun 25, 2019 Copyright 2017 California Institute of Technology. U.S. Government sponsorship acknowledged. New MIDEX SPHEREx (2022-2025): All-Sky 0.8 – 5.0 µm Spectral Legacy Archives Medium- High- Accuracy Accuracy Detected Spectra Spectra Clusters > 1 billion > 100 million 10 million 25,000 All-Sky surveys demonstrate high Galaxies scientiFic returns with a lasting Main data legacy used across astronomy Sequence Brown Spectra Dust-forming Dwarfs Cataclysms For example: > 100 million 10,000 > 400 > 1,000 COBE J IRAS J Stars GALEX Asteroid WMAP & Comet Galactic Quasars Quasars z >7 Spectra Line Maps Planck > 1.5 million 1 – 300? > 100,000 PAH, HI, H2 WISE J Other More than 400,000 total citations! SPHEREx Data Products & Tools: A spectrum (0.8 to 5 micron) for every 6″ pixel on the sky Planned Data Releases Survey Data Date (Launch +) Associated Products Survey 1 1 – 8 mo S1 spectral images Survey 2 8 – 14 mo S1/2 spectral images Early release catalog Survey 3 14 – 20 mo S1/2/3 spectral images Survey 4 20 – 26 mo S1/2/3/4 spectral images Final Release Legacy catalogs and maps Available Data Tools: Served through IRSA at IPAC Analysis Tool Function Image lookup Find image at location and time SED estimator Find spectrum of a known source Data cube viewer View spectrum of any sky region On-the-fly mosaic Images within specified time Variable sources Spectra over all 4 surveys Spectral image Moving sources SEDs for known moving objects Legacy Catalogs and Maps Catalog # Function Core science > 450 M Galaxy types & redshift catalogs > 20,000 Ice sources Deep field maps Image mosaics Stars > 100 M SEDs of known stars Galaxies 1.4 B SEDs of known galaxies Clusters 25,000 SEDs of cluster members Asteroids 10,000 SEDs of known objects Galaxy maps Image and line mosaics more releases, tools and catalogs under consideration SPHEREx Overview Passively cooled telescope (80K 30cm diameter primary) and near-infrared detectors (55K) in Low-earth Orbit Linear Wide-field telescope with Variable High-Throughput Linear Filter Variable Filter (LVF) Focal Spectrometer Plane Assembly Spectrum obtained by stepping source over astigmat FOV in multiple images: no moving parts mirror - Three PSF undersampled: 6 arcsecond resolution set by pixel plate scale in all bands Mapping the Sky with LVFs 1 orbit Spectral image 2 orbits LVF 1/6 LVF 1/6 LVF 1/6 N orbits A complete spectrum is made from a series of images SPHEREx maps the sky over multiple orbits with large and small slews SPHEREx Creates an All-Sky Legacy Archive at High Sensitivity R=135 Deep field (100 sq deg) R=41 R=41 R=41 R=35 All-sky R=110 Overarching SPHEREx Solar System Science Goal: The Local Cosmology (i.e Origin & Evolution of the Nearest Exosystem) [Besides, we need to remove the foreground objects to study the background properly.] Motivation: Besides the usual (M,R,P) for the host star + planets, we have: • Crater Counts • Detailed Orbital Dynamical Info • Meteorite Minerological & Isotopic info • Geomorphology rperihelion = 0.25 AU rperigee = 0.20 AU eccentricity = 1.19 SPHEREx would have provided Spectrophotometric st APO 3.5M DDT Time Imaging of 1 29 Oct 2017 UT g’ Meech et al. Detected 2017 Interstellar Object Point Source, 0.1 km < Radius < 0.2km in the Solar System: 1I/’Oumuamua Football Shaped Spheroid r’ Colors Consistent [Sept-Nov 2017 w/ Solar System Asteroids asteroid passage] r’ Double-Peaked See: Bolin, Weaver, Prot ~ 8.1 hrs Fernandez, Lisse+ 2017 Triaxial Ratio ApJ Lett 853, L8 4 < a:b < 7 (!!) KBO Science: What are These Bodies Made of, And Does This Vary Across the Kuiper Belt? We Know Densities Vary from 0.5 g/cm3 up to 2.5 g/cm3. Many Evince Strong Organic Ices Lines, Others Mainly Water. Why? Size? Evolution? How Do Binary KBO Partners Compare Spectrally? Pluto KBO NIR Spectroscopy The Heart Comet Science: Solar System Reservoirs of Astrophysical Ices; proxy measurement of abundances in the Proto-planetary Disk X – CH, PAHs AKARI Comet Spectroscopy of H2O/CO/CO2 : SPHEREx Will Return 100’s of Spectra Like These 18 AKARI R~100 Measurements CO2 sublimation CO2, not CO could be powers comet fundamental activity outside 2.5 comet/PPD molecule AU water ice line Follow the (Icy) Water! Schematic of a protoplanetary disk r apo e • Gas and dust in molecular er V n Wat i ne r of L o clouds are the reservoirs for new Laye ow Z ace Sn ce stars and planets Surf I - In molecular clouds, water is 100- Formation of icy Planetesimals 1000x more abundant in ice than Star in gas Diffusive Transport - Herschel observations of the TW of Water? 0au 0.1au 1.0au Hydrae disk imply the presence 10au of 1000s of Earth oceans in ice (Hogerheijde et al. 2011) ISO absorption spectrum - Models suggest water and 30 biogenic molecules reside in ice in W33A XCN CO the disk mid-plane and beyond CO2 13CO the snow line 20 CH3OH 2 • Ideal ls to study ices: 2.5 - 5 µm H2O - Includes spectral features from 10 6 H2O, CO and CO2 in ~10 objects - Plus chemically important minor 0 constituents NH3, CH3OH, X-CN, 13 2.5 3.0 3.5 4.0 4.5 5.0 and CO2 Wavelength (microns) Jupiter Trojan Science : Were the Trojans Formed in Place, or Accreted During the LHB? (Lucy Discovery Mission Context) Ceres Moon Mercury Mars Wherever we look in the Solar System, we see massive cratering. Trojan Asteroid NIR Spectroscopy Outer Solar System Object NIR Reflectance Spectra Compared to HR4796A Ring 67P/C-G COMET NUCLEI 124P/Mrkos Quirico et al. 2015 C/LONEOS 2001 OG108 67P/C-G 2.39 um Absorption? KUIPER 19P/Borrelly Small End BELT 5145 Pholus H2O Ice? H2O Ice 5145 67P/C-G Pholus CENTAURS & TROJANS 624 Hektor 10199 Chariklo 2060 Chiron H2O Ice Jewitt & Luu 2004 Asteroid Science : Were Asteroids Formed From a Chemically Segregated Solar PPD and Then Mixed? (Dawn, Psyche Mission Context) DeMeo+ 2014 NIR Asteroid Spectral Characterization Know What You’re About to Mine (NASA PSD) or Get Whacked By (NASA NEO Office): Iron Metal (M-type), Rock (S-type), or Organic Mush (C-type) Inner Zody (Dust Debris) Cloud We Sense From Earth is a Mix of Asteroidal & Cometary Dust Inner Cloud is ~90% Cometary SPHEREx vs LSST, NeoCAM, JWST; Dawn, Lucy, Psyche • SPHEREx will get down to AB magnitude ~ 19 (5s) in the W1 passband, which => V ~ 20.5 for solar colored (i.e., neutral/grey objects), V~ 21-22 for reddish objects. • LSST has a limiting sensitivity of ~24.5 at V, or about 3 mags fainter than SPHEREx’s 3s limit for a neutral grey object. Therefore everything SPHEREx detects will be in the LSST survey, but not vice-versa. • JWST: SPHEREx’s all-sky survey will find the most interesting and high-value targets for NASA’s slowly slewing premier telescope of the 2020’s. • NEOCam is a 50 cm space telescope with a single imaging instrument operating at ~35K in two wavelength ranges: 4 - 5 μm and 6 - 10 μm. NeoCAM will have a limiting sensitivity about 2 mags more sensitive than SPHEREx at 4-5 um. Therefore everything SPHEREx detects will be in the NEOCam survey, but not vice-versa, but SPHEREx will provide unique spectra for ~ 105 of NEOCam’s 0.1 – 100 km radius targets, allowing detailed spectral characterization for future hazard and resource utilization applications. • Dawn, Lucy, Psyche: all these missions require an absolutely calibrated 1-3.5 um NIR reference spectrum of the mission target, WHICH has yet to be produced. Ground based spectra cannot cover the entire wavelength range, especially in the 2.7 – 3.1 um water bands. Dawn ASSUMED that Vesta was a water-poor, rocky body with a simple spectrum, and used this as the reference calibration spectrum for Ceres. SPHEREx will provide this spectrum, for 16 Psyche and all of Lucy’s Trojan targets, assuming they are not confused. Sample SPHEREx Solar System Projects • Spectral studies & lightcurves of the largest KBOs – e.g. the CO/CH4 peaks of Pluto’s lightcurve [K ~ 13], coordinated with the ice-rich Sputnik Plenum glacier • Chemical abundances of Comets as tracers of the PPD. E.g CO2 in Comets – the Fundamental Carbon Bearing Molecule in the PPD? And by extension in all molecular clouds and hot cores? • Monitor world (Planets + Giant Moons) atmospheric weather: CH4, H2O clouds & hazes • Icy Moon water, CO2, CO, CH4 trends w/time, parent body, rh + • Giant Planet H3 aurorae • Spectral classification of the Trojan Asteroids • Spectral survey of >106 of Asteroids – better reckoning of the origin and dynamical evolution of their types – formed in zones of the PPD then scattered E.g: Hydrated minerals vs Ammoniated Phyllosilicates from the Outer Solar System on Ceres • Solar System Wide Survey of Astrobiologically Important Molecules H2O, CO, CO2, CH4, C2H6, CN, CH3OH, H2CO, NH3, PAHs • Follow the Water throughout the Solar System: Search for episodic water emission from Ceres, Europa Study water temporal, spatial patterns on the Moon – implantation followed by sublimation under daylight? • Zodiacal (Debris) Cloud Measurement • Hb, Paschen a, Brackett a/b/g solar system albedos New MIDEX SPHEREx (2022-2025): All-Sky 0.8 – 5.0 µm Spectral Legacy Archives Medium- High- Accuracy Accuracy Detected Spectra Spectra