WISE - the Wide-field Infrared Survey Explorer

National Aeronautics and Space AdministrationJet Propulsion LaboratoryCalifornia Institute of Technology

Wide-field Infrared Survey Explorer (WISE)

ELW - 113 Jun 11

WISE - the Wide-field Infrared Survey Explorer

Ned Wright (UCLA)



ELW - 213 Jun 11



ELW - 313 Jun 11

Salient Features• 4 imaging channels covering 3 - 25 microns

wavelength• 40 cm telescope operating at <17K• Two stage solid hydrogen cryostat• Delta launch from WTR: 14 Dec 2009 • Sun-synchronous 6am 530km orbit• Scan mirror provides efficient mapping• Expected life: 10 months, actual 7.7-9.5• 4 TDRSS tracks per day

Wide Field Infrared Survey ExplorerScience• Sensitive all sky survey with 8X redundancy

– Find the most luminous galaxies in the universe

– Find the closest stars to the sun– Provide an important catalog for

JWST– Provide lasting research legacy

Project Overview



ELW - 413 Jun 11

Infrared

• Optical Near-IR Thermal-IR• Reflected light different colors emitted radiation



ELW - 513 Jun 11

Space vs Ground

• Space hardware costs 1000x more than ground-based.

• A huge advantage over ground-based instruments is needed to get funded.

• The 1600:1 background ratio was not enough to sell NIRAS in 1988

• 2.7 million to one ratio was sufficient to sell Spitzer and WISE



ELW - 613 Jun 11

NIRAS in 1988

• NIRAS SMEX proposal in 1988. Fazio as PI. CJL & ELW as co-I’s.

• “Big” Arrays: 58x62

• Constant inertial rate

• Scan mirror to freeze images on arrays

• All-sky survey at 1.9 and 3.5 μm

• Review panel suggested ground-based survey.– NIRAS was not funded!

– But this suggestion led to 2MASS

• Bottom Line: near-IR only in space will not be an easy sell!

• Mid-IR like WISE is sellable.



ELW - 713 Jun 11

Animated Scan Mirror Icon



ELW - 813 Jun 11

WISE Survey Strategy Provides Minimum of 8 Exposures Per Position

• Scan mirror enables efficient surveying

– 8.8-s exposure/11-s duty cycle

• 10% frame to frame overlap

• 90% orbit to orbit overlap

• Sky covered in 6 months observing

1 Orbit 2 Consecutive Orbits 2 Orbits 20 Days Apart

• Single observing mode

• Minimum 8, median 14 exposures/position after losses to Moon and SAA



ELW - 913 Jun 11



ELW - 1013 Jun 11

JGC 4/30/2009

Focusing WISE at SDL

WISE Instrument(LHe cooled)

Blue Tube(LN2 cooled)

Fused silica window

Fold mirror

Mylar sheet (ND filter)

CollimatorPinhole

Blackbody



ELW - 1113 Jun 11

Final assembly & test at Ball



ELW - 1213 Jun 11

WISE is tiny (in the PPF)!



ELW - 1313 Jun 11

WISE is tiny in the fairing



ELW - 1413 Jun 11

Launch! 14 Dec 2009 @ 06:09 PST

• g



ELW - 1513 Jun 11

On to Survey Mode

• 33 seconds in the life of WISE, 3 of >7000 frames/day



ELW - 1613 Jun 11

Asteroids Observed by WISE

• Four frames of data taken on 2010 Jan. 8 during in-orbit checkout.

• Blue = 3.6um; green = 4.6um; red = 12um

• Circled asteroids are (L to R in the first frame, diameters in km):17818 MBA D~12.4153204 MBA D~2.822006 MBA D~11.587355 MBA D~4.380590 MBA D~4.1

Field of view = 34 x 25 arcmin (whole WISE FOV is 47 x 47 arcmin)



ELW - 2113 Jun 11

Thus WISE has

• Discovered many new Aten class and potentially hazardous asteroids, has determined give radiometric diameters for more than 150,000 objects.

• Nearly 4 million asteroid observations, the most of any observatory in 2010 up to 13 Sep 2010.



ELW - 2213 Jun 11

WISE and Brown Dwarfs

• Brown Dwarfs are stars with too little mass to fuse Hydrogen into Helium.

• WISE two short wavelength filters are tuned to methane dominated brown dwarf spectra.

• WISE could identify brown dwarfs as cool as 200 Kelvin (-100 Fahrenheit) out to 4 light years, the distance to the nearest known star.



ELW - 2313 Jun 11

Inhabitants of WISE Color Space

SDSS Classifications:

• Galaxies

• z ~ 0.4 LIRGs

• Local LIRGs

• Local ULIRGs

• QSOs



ELW - 2413 Jun 11

First Spectroscopically Confirmed WISE Brown Dwarf

• WISE 0458+64 spectrum from LUCIFER on LBT.• At the time, was as cool or cooler than any known BD• Mainzer et al 2010 (ApJ in press).

W0458+64

W2 = 13.02W1-W2 = 3.38J-W2 = 4.45



ELW - 2513 Jun 11

But wait there’s more

• Burgasser et al (in press): 5 WISE BDs

• Kirkpatrick et al (submitted) has ≈102 BDs

• Triples the number of known T8s

• 10× the number of known T9s



ELW - 2613 Jun 11

H-W2 vs. W1-W2



ELW - 2713 Jun 11

Who’s the Coolest Dwarf of all?

• Is it 1405+55?

• J = 20.2

• J-H = -1.5

• W2 = 14.1

• W1 > 18

• J-W2=6.1



ELW - 2813 Jun 11

Need HST WF3 IR Grism for spectrum

• Clearly see the 1.27 and 1.59 μm peaks of a CH4 dominated dwarf



ELW - 2913 Jun 11

Clear Ammonia Signature

• NH3 is cutting the short end of the 1.59 μm bump and narrowing the 1.27 μm bump

• A Y dwarf!

• Cushing etal submitted



ELW - 3013 Jun 11

Astrometry so far

• 2 WISE positions

• 1 Spitzer position

• 1 HST position

• Proper motion 2.14 ± 0.26 arc-sec/yr

• Parallax 0.11 ± 0.08 arc-sec

WISE data alone give a 6σ detection of motion. To do this all-sky will require coadding and cataloguing the 2 band data.



ELW - 3113 Jun 11

H-W2 vs. W1-W2



ELW - 3213 Jun 11

1828+2650

• The reddest source of all as seen by the HST

• W2 = 14.25, W1-W2>4, H-W2=8.5, J-H≈0.72±0.42



ELW - 3313 Jun 11

The far-off Universe

L* at z=0.33, z=6.4 QSO, z=3 ULIRG: FSC15307 x 3



ELW - 3413 Jun 11

WISE Band 1 and 2 Dropouts

• W1 > 17.4 and W2 > 15.9 and (W3 < 10.6 or W4 < 7.7)

• W1814+34 (Eisenhardt et al 2011, Bridge et al 2011)

• z=2.452

• Extended Lyman alpha emission (~40 kpc)



ELW - 3513 Jun 11

SED of W1814+34

• AGN with AV = 50

• Starburst

• Spiral Galaxy

• Warm Spitzer data to get 3.6 & 4.5 μm since WISE did not detect it at 3.4 & 4.6 μm.

• SHARC II (CSO) at 350 μm

• VLA radio data

• Peak νLν = 1013.38 L



ELW - 3613 Jun 11

Warm Spitzer Followup

• Objects not detected by WISE at 3.4 & 4.6 μm can be measured using warm Spitzer

– bigger mirror

– longer integration times

• Synergy between surveys and great observatories



ELW - 3713 Jun 11

Many W12 drops

• About 1000/sky

• High percentage with high z’s: see histogram

• Spitzer followup usually picks up 3.6 and 4.5 μm flux

• Herschel followup usually detects far-IR flux



ELW - 3813 Jun 11

AGN Selection

• Stern et al poster 333.15 at the Jan 2011 AAS meeting

• Density 70/sq.deg

• 60% have published z’s in COSMOS field



ELW - 3913 Jun 11

Z-distribution of WISE AGNs



ELW - 4013 Jun 11

W1 on z=1.132 SPT-CL 2106-58



ELW - 5313 Jun 11

Telescope Temperatures



ELW - 5413 Jun 11

4 Band Coverage to 5 Aug 2010



ELW - 5513 Jun 11

End of Cryo Coverage



ELW - 5613 Jun 11

Final 2 band coverage

Ten trillion pixels observed!



ELW - 5813 Jun 11

Thus WISE has

• Discovered many new NEOs and potentially hazardous asteroids and gave radiometric diameters for nearly 200,000 objects.

• Searched for the ½ to ⅔ of the stars in the solar neighborhood that have not yet been seen, including the closest stars to the Sun.

• Surveyed star formation in the Milky Way and in massive Ultra-Luminous Infrared Galaxies.

• Or at least we have the data now: 10 trillion pixels worth. We have lots of work left analyzing this treasure trove of information.



ELW - 5913 Jun 11

WISE Summary

• Launched 14 Dec 2009

• Band centers 3.4, 4.6, 12 & 22 microns

• Sensitivity should be better than 0.08, 0.11, 1 & 6 mJy

• Saturation at 0.3, 0.5, 0.7 & 10 Jy point sources

• Angular Resolution 6, 6, 6 & 12 arc-seconds

• Position accuracy about 0.15 arc-seconds 1σ 1-axis for high SNR

• Completed all-sky survey 17 July, big tank ran out hydrogen 5 Aug, little tank empty on 29 Sep, two-band survey for asteroids continued until 1 Feb 2011.

• Data release plans:

– Preliminary release of 57% of the sky on 14 April 2011

– Final release 17 months after survey ended

• Data products include image atlas and source catalog

http://wise.astro.ucla.edu



ELW - 6013 Jun 11

Preliminary Data Release

• Available at irsa.ipac.caltech.edu

WISE - the Wide-field Infrared Survey Explorer

Documents

Transcript of WISE - the Wide-field Infrared Survey Explorer