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First Science with FORCAST and the SOFIA Observatory

Eric Becklin

SOFIA Chief Science Advisor

SSSC NASA Ames

May 11 2011

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With Support from

* Terry Herter and FORCAST Team

• Jim DeBuizer

• Bill Vacca

• Hans Zinnecker

• Mark Morris

• Ralph Shuping

• Pasquale Temi

• The entire SOFIA team

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Outline of Material

* Flying on SOFIA, a personal experience

• First Science with FORCAST on SOFIA

• Summary

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Flying on Science Flight #1

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My Experience on the First Science Flight

• After the 3 TACFL flights it was decided that senior people on the SOFIA program should fly on the plane, including Short Science Co-Investigators.

• I was the first one selected and flew on the 1st of 3 Short Science Flights with FORCAST.

• I was also working with the FORCAST team on the Science objectives, but that was not the reason for flying.

• Others that flew with FORCAST were Pam Marcum, Paul Harvey, Alois Himmes, and Pasquale Temi.

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Safety Briefing

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Looking at the Data

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Impressions from the Flight

• The Flight was very long 10 hours…..This is very good: more data, best data at the end, but we were ready.

• The environmental conditions were good. Noise a little high, and headsets were necessary except in 1st Class.

• I was completely absorbed for the entire flight. Wanted to make sure Orion data were calibrated, PSF, positions and fluxes.

• I was very please with the overall operation. As efficient on our first science flight as the KAO. Could see the problem areas.

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What were some problems

• Communication seemed difficult, probably because of the layout of the seats.

• The communication between the FORCAST Instrument and the MCCS was still being worked out.

• Starting in the restricted area south of San Diego made the flight plans non-optimum.

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First SOFIA Science with FORCAST

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Science with FORCAST

• There is very good science from the FORCAST 3 Science Flights and TAC#3.

• Two Regions where stars are forming: Orion (most detail), and W3

• An Infrared Galaxy, A comet and several other regions.

• Results were presented at the AAS 1st week of Jan and also a press release. At least eight papers are being worked on and expected to be published this year.

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BNKL REGION

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Orion Nebula at Mid IR with 3 arcsec Resolution

• Focus on the very bright and luminous BNKL region

• Total power out similar to the bright young trapezium stars

• But all of the radiation is in the IR.

• Major questions: - What is causing all the

radiation? -Still forming stars converting

gravity to luminosity. -Very young stars just starting

their nuclear burning. - An explosive event 500 yrs

ago.

* Most radiation at wavelengths longer than 30 microns. Best view ever!!

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3-color images of BNKL region

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19um, 31um, 37 um

This is made with the two data pairs on the left of the last slide. The two 19um images were Used to bootstrap the registration of the 31 and 36um images. Array distortion could affectThe relative appearance of the 37um image with respect to the 19/31um pair. The right image is with the natural pixel scale of FORCAST, the right is a reconstruction under the assumption that the data is Nyquist sampled.

E

N

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What new do we find?

• BN is the hottest source and is not seen at 37 microns.

• The source IRc2 (bright at 12 microns) and radio source “I” are not seen at 37 microns. This is a surprise.

• There is in fact a hole in the emission at IRc2/”I”

• The brightest source at 37 microns is IRc4. Does seem to be heated from within (no color gradients) Also one of the coldest. (T~100K)

• Need more data. Results from Herschel or HAWC on SOFIA. Also Spectra… EXES, ALMA

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TRAPEZIUM REGION AND A NEW SOURCE !!

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1919

We have two data pairs with 7/37um and 19/37um taken simultaneously with the dichroic so their relative source locations are well-registered. 37um image was used to bootstrapthe offsets between 7 and 19um, but are subject to some changes when new distortion algorithm is finished. On the right only the 19 and 37um images are deconvolved. New source isjust west of the western most trapezium star

3-color images of Trapezium region7um, 19um, 37 um

Natural Resolution DMRM Deconvolution

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What is the New Source?

• Could be related to Trapezium Stars like Ney-Allen, but seems quite different given the very cold temperature (T~100K)

• Could be a source in the background that is contracting and converting gravitational energy to luminosity (A star in formation)

• How do we tell which is correct?

- Closer look at our data.

- More data: Herschel data or HAWC data with SOFIA,

- Spectra with EXES, FiFi-LS and GREAT with SOFIA.

- Association with radio or x-ray data.

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W3 Main

• Star Forming Region

37 microns19.7 microns

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W3 Main

• Star Forming Region

6.6 microns, no PAH7.7 microns, PAH

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M82

Visible light image

SOFIA infrared image (19.7, 31.5, and 37.1 m)

Inset (visible light)

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Comet Hartley 2

• 31 and 37 Micron data of Comet that had a fly by in Nov.

31.4 microns

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Energy Distribution of Hartley 2 (Meech etal)

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Technical Results from First Science and Issues

• Image Stability was very good. Allowed near diffraction limited imaging at 37 microns. FWHM images ~3 arcsec. Limited primarily by image jitter at 1 to 90 Hz.

• Infrared Sensitivity is what was expected especially at 43K feet.

• However there is extra background from an unknown source of about 35%. Sensitivity was specified at high water vapor and some loss put in.

• Plate scale is not the same is both directions, but now fixed.

• Calibration, especially at 37 microns is still being worked out.

27FORCAST performance 27

38001 40001 42001 44001

50

100

150

200

altitude

resp

37 micron response37 m in-flight measurements

• Response for different calibrators vs altitude. • These have been update with calibration fluxes from WDV 2011-03-16.

Res

pons

e (e

-/s/

mJy

)

GPS Altitude (feet)

Key:Symbols represent different calibrators as indicated. Shaded region indicates data take with the dichroic.

Data from OCF3 & Short Science flights

UMi

Ori

Cep

Dra

And

Cet

CMa

Gem

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Summary

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Summary• Unique early science was obtained

on SOFIA with FORCAST.– Overall the SOFIA observatory is

as efficient and easy to use as I remember the KAO. 10 hour flights and 6.5 hours above 41,000ft make it better than the KAO.

– Problems with the observatory and the FORCAST instrument are being solved by everyone working together.

– The biggest remaining issue is the calibration at 37 microns. Calibration appears best with the dichroic in, but you lose a factor of 2.5 in signal. The FORCAST and SMO team are working the problem.

• SOFIA with FORCAST and GREAT is a fantastic observatory!!