SOFIA: Enabling IR High Resolution Spectroscopy from 2005...

1

Jackie Davidson Jackie Davidson

(USRA SOFIA Project Scientist)(USRA SOFIA Project Scientist)

http://sofia.arc.nasa.gov

SOFIAStratospheric Observatory for Infrared Astronomy

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SOFIA Characteristics• Wavelength range: UV - Radio (0.3µm - 1600µm) as defined by

the atmosphere above flight altitude.

Traub & Stier (1976)

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SOFIA Characteristics• Wavelength range: UV - Radio (0.3µm - 1600µm) as defined by the

atmosphere above flight altitude.

• Platform & Operating Altitude: Boeing 747SP; @ 37,000 - 45,000 ft

• Optical configuration: Bent Cassegrain with oscillating secondary mirror and flat folding tertiary mirror.

• Primary Mirror Ø: 2.7m (Aperture 2.5 m)

• Telecope emissivity: < 10% @ 10 µm (without dichroic tertiary)– Optical transmission: > 90% (without dichroic tertiary)

• Operating temperature: 240 K

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Observatory LayObservatory Lay--outout

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SOFIA Cavity - Waco January 2003

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Telescope in Aircraft

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Suspension Assembly (SUA) of

Telescope -Augsburg May 2002

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Installation of SUA - Waco February 2003

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Installing the Telescope Metering Structure-Waco May 2003

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Representative Chet Edwards - June 2003

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Primary Mirror Cell Installation - Waco July 2003

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Primary Mirror - France 2002

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Science Instrument Mounting Flange Installation - April 2003Cabling - ongoing; Photo ~ September 2003

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Clean SOFIA after Pressure Proof Test of the Aircraft Fuselage - Waco April 2004

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Cavity Door - Being assembled at Ames

Shear Layer Control

Flex Skirt

Cavity Door

Rigid ExternalDoor

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SOFIA Characteristics• Wavelength range: UV - Radio (0.3µm - 1600µm) as defined by the

atmosphere above flight altitude.

• Platform & Operating Altitude: Boeing 747SP; @ 37,000 - 45,000 ft

• Optical configuration: Bent Cassegrain with oscillating secondary mirror and flat folding tertiary mirror.

• Primary Mirror Ø: 2.7m (Aperture 2.5 m)

• Telecope emissivity: < 10% @ 10 µm (without dichroic tertiary)– Optical transmission: > 90% (without dichroic tertiary)

• Operating temperature: 240 K

• Visible image quality*: 80% energy within 5.3 arcseconds (first year)

80% energy within 1.6 arcseconds (by third year)

* Includes the effects of pointing jitter but not shear-layer seeing

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1

10

100

1 10 100 1000

Angular ResolutionD

iam

eter

(arc

sec)

Wavelength (µm)

SOFIA

KAO

ISO

IRAS

SIRTF

Herschel

SOFIA will open a new regime of FarSOFIA will open a new regime of Far--IR angular resolutionIR angular resolution

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Information on SOFIA Science Instruments:http://sofia.arc.nasa.gov

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SOFIA First-Light Science Instrumentshttp://sofia.arc.nasa.gov

10 0

10 1

10 2

10 3

10 4

10 5

10 6

10 7

10 8

1 10 100 1000Wavelength [µm]

Spec

tral

res

olut

ion

HIPO (

FLITECAM

FORCAST

EXES

HAWC

SAFIREFIFI LS

GREAT

CASIMIR

102410242225625622

12x3212x321024102422

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SOFIA Performance:

Herschel

10 -5

10 -4

10 -3

10 -2

10 -1

10 0

10 1

10 2

10 3

0. 1 10 100 1000

Photometric Sensitivity

Phot

omet

ric

Sens

itivi

ty1

Sigm

a, 1

hr,

Flu

x D

ensi

ty (m

Jy)

Wavelength (µm)

SOFIA

KAO SIRTF

ISO

IRAS

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SOFIA naturally complements Spitzer

• Spitzer observes faint sources only– Detectors too sensitive for bright sources

• SOFIA covers the bright sources– With good spatial resolution– With great spectral resolution

• i.e., matched to the object being observed

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HAWC

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Circumstellar Disks: Vega

Size of Solar System

SCUBA Beam Size

FORCAST Beam size

HAWC (60)

MIPS-70MIPS (24)

SCUBA 850 µm: rdisk~20" (160AU) ⇒ Tdust~ 80 K⇒ λpeak ~ 35 µm

ISO observed λpeak~35 µm ⇒little dust at r < 160 AU ⇒

hole in distribution

38 µm

Flux

(Jy)

Wavelength (µm)

Heinrichsen et al.1998 FORCAST: Resolve disk and hole ⇒ distribution of dust…

and planets?

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Protostellar/Stellar Detectability with FORCAST

0.0001

0.001

0.01

0.1

1

10 100 1000 10000

Temperature (K)

L/L_

sun

5.6127.68819.5330.6837.65 - 928 - 38

Wavelength

d = 140 pcS/N = 5 in 3600 sec0.63" image quality

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SOFIA First-Light Science Instruments

10 0

10 1

10 2

10 3

10 4

10 5

10 6

10 7

10 8


Spec

tral

res

olut

ion

HIPO

FLITECAM

FORCAST

EXES

HAWC

SAFIREFIFI LS

GREAT

CASIMIR

For R=1000, at 100 um, 1For R=1000, at 100 um, 1--sigma, sigma, 1 hr limit is ~ 3x101 hr limit is ~ 3x10--1818 W/mW/m22

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SOFIA First-Light Science Instruments

10 0

10 1

10 2

10 3

10 4

10 5

10 6

10 7

10 8


Spec

tral

res

olut

ion

HIPO

FLITECAM

FORCAST

EXES

HAWC

SAFIREFIFI LS

GREAT

CASIMIR

Planetary AtmospheresPlanetary Atmospheres

Planetary AtmospheresPlanetary AtmospheresChemistry of the cold ISMChemistry of the cold ISM

Comet MoleculesComet Molecules Dynamics of the Galactic CenterDynamics of the Galactic Center

Dynamics of collapsing Dynamics of collapsing protostarsprotostars

Velocity structure and gas composition in Velocity structure and gas composition in disks and outflows ofdisks and outflows of YSOsYSOs

Composition/dynamics/physics of the Composition/dynamics/physics of the ISM in external galaxiesISM in external galaxiesPAH & organic moleculesPAH & organic molecules

Nuclear synthesis in supernovae in nearby galaxiesNuclear synthesis in supernovae in nearby galaxies

Composition of interstellar grainsComposition of interstellar grains

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Low-Mass Star Formation

SOFIA farSOFIA far--IRIRbeam diameterbeam diameter

for Taurus for Taurus

Hollenbach, Ceccarelli, Neufeld, and Teilens (1995)

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GREAT - CO(J>13) lines in inner most regions of circumstellar envelopes

(R=λ/∆λ ~ 104) Mrate =10-5 Mo /yr

OH OH (accretion shock)(accretion shock)

High-J CO lines -> measure acceleration ofinfalling gas

Hollenbach, Ceccarelli, Neufeld, and Teilens (1995)

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Spectroscopic Capabilities, 2003 - 2025

10 0

10 1

10 2

10 3

10 4

10 5

10 6

10 7

10 8


Spec

tral

res

olut

ion

HIPO

FLITECAM

EXES

SAFIREFIFI LS

GREAT

CASIMIR

SOFIA SOFIA -- 2006, 20072006, 2007

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10 2

10 3

10 4

Spec

tral

res

olut

ion

HIPO

FLITECAM

EXES

SAFIREFIFI LS

GREAT

CASIMIR

SpitzerSpitzer

SOFIA SOFIA -- 2006, 20072006, 2007Spitzer Spitzer -- 2003 to 20082003 to 2008

10 8

10 7

10 6

10 5

10 1

10 0

1 100 100010Wavelength [µm]

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10 2

10 3

10 4

Spec

tral

res

olut

ion

HIPO

FLITECAM

EXES

SAFIREFIFI LS

GREAT

CASIMIR

SpitzerSpitzerAstroAstro--FF

SOFIA SOFIA -- 2006, 20072006, 2007Spitzer Spitzer -- 2003 to 20082003 to 2008AstroAstro_F _F -- 2004 to 20062004 to 2006

10 8

10 7

10 6

10 5

10 1

10 0


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10 2

10 3

10 4

Spec

tral

res

olut

ion

HIPO

FLITECAM

EXES

SAFIREFIFI LS

GREAT

CASIMIR

HerschelHerschel

SpitzerSpitzerAstroAstro--FF

SOFIA SOFIA -- 2006, 20072006, 2007Spitzer Spitzer -- 2003 to 20082003 to 2008AstroAstro_F _F -- 2004 to 20062004 to 2006Herschel Herschel -- 2007 to 20102007 to 2010

HerschelHerschel

10 8

10 7

10 6

10 5

HerschelHerschel

10 1

10 0


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10 2

10 3

10 4

Spec

tral

res

olut

ion

HIPO

FLITECAM

EXES

SAFIREFIFI LS

GREAT

CASIMIR

HerschelHerschel

SpitzerSpitzer

JWSTJWST

AstroAstro--FF

SOFIA SOFIA -- 2006, 20072006, 2007Spitzer Spitzer -- 2003 to 20082003 to 2008AstroAstro_F _F -- 2004 to 20062004 to 2006Herschel Herschel -- 2007 to 20102007 to 2010JWST(JWST(NGSTNGST) ) -- >2010>2010

HerschelHerschel

10 8

10 7

10 6

10 5

HerschelHerschel

10 1

10 0


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SOFIA complements Herschel

• Herschel can’t do the whole sky in three years!– Must be selective

• Herschel is a natural for surveys– especially of faint sources (e.g., distant galaxy)

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Blank Field Surveys

100≤160Spitzer (2004)100170-500Herschel (2007)

3200HAWC/SOFIA (2005)0.1350SHARC II/CSO0.31300MAMBO/IRAM0.2850SCUBA/JCMT

galaxies/hour (5σ)λ (µm)Facility

A. Blain

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• Herschel is a natural for lines obscured by Earth’s atmosphere above the tropopause

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Sub-mm on SOFIA

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• SOFIA is a natural for in-depth studies of particular targets– With increased spectral coverage– With increased science instrument capabilities

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Spectroscopic Capabilities

10 2

10 3

10 4

Spec

tral

res

olut

ion

HIPO

FLITECAM

EXES

SAFIREFIFI LS

GREAT

CASIMIR

HerschelHerschel

SOFIA SOFIA -- 2006, 20072006, 2007Herschel Herschel -- 2007 to 20102007 to 2010

HerschelHerschel

10 8

10 7

10 6

10 5

HerschelHerschel

10 1

10 0


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Nearby Face-on Spiral Galaxies: M83

6” Resolution CO (1-0) Map overlayed on false-color HI (Rand,

Lord, & Higdon 1999)

SOFIA (& Herschel) will resolve Far-IR Lines and Far-IR continuum Emission from Spiral Arms ⇔ Star Formation and Spiral Density Waves

SOFIA

Visible Image of M83

FORCAST 38 µm beam: 75 pc

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Far-IR Spectral Lines • A host of Far-IR fine-structure and molecular-transition lines, accessible to

SOFIA at optimum spectral resolutions, can probe the physical properties of the ISM of the Milky Way and other galaxies:

• [OI]*, [SiII] lines probe the physical conditions of gas in PDRs.• [NIII], [SIII], and [OIII]* line pairs are excellent probes of HII region

densities.• [NII]* lines trace the warm ionized medium.• [CII]* line traces PDRs, atomic clouds, and warm ionized medium. • [NII]*/[NIII], [SIII]/[OIII]*, [NeIII]/[OIV]/[NeV] ratios give the effective

temperature of stellar or AGN UV radiation fields.• [SI], [SiI]*, [SiII] and [FeI] lines indicate the presence of dissociative J-

shocks.• High J CO* rotational lines trace shocked gas found in warm dense gas of

PDRs.• OH* lines trace shocked gas in cool dense gas.• H2 rotational lines probe the mass of warm molecular clouds.• OH*, CH*, and NH3* together constrain molecular cloud chemistry.

• Lines with “*” are observable from Herschel as well. Herschel cannot observe all of the SOFIA lines. Stacey Stacey

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Watson 1985Watson 1985

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10 2

10 3

10 4

Spec

tral

res

olut

ion

HIPO

FLITECAM

EXES

SAFIREFIFI LS

GREAT

CASIMIR

HerschelHerschel

SOFIA SOFIA -- 2006, 20072006, 2007Herschel Herschel -- 2007 to 20102007 to 2010

HerschelHerschel

10 8

10 7

10 6

10 5

HerschelHerschel

10 1

10 0


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10 2

10 3

10 4

Spec

tral

res

olut

ion

HIPO

FLITECAM

EXES

SAFIREFIFI LS

GREAT

CASIMIR

HerschelHerschel

SOFIA SOFIA -- 2006, 20072006, 2007Herschel Herschel -- 2007 to 20102007 to 2010SOFIA SOFIA -- 2008 to 20252008 to 2025 HerschelHerschel

FORCASTFORCAST

10 8

10 7

10 6

10 5

HerschelHerschel

10 1

10 0


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Increasing High Resolution Spectral Capabilities on SOFIA

• Finish SAFIRE (TES array, Fabry-Perot Spectrometer)

• EXES (Echelon Spectrometer)– Increase detector array size from 2562to 10242 Si:As array

• FORCAST (mid-IR camera)– Add Grism to allow for R=2,000 spectroscopy

• GREAT & CASIMIR (heterodyne spectrometers)– HEB mixers and new type of LOs for coverage <200 um– Heterodyne arrays

• Develop R~104 -105 spectral resolving capability spanning from 40 um to 200 um in one spectrometer.

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Increasing other Capabilities on SOFIA

• Use Occultation Cameras (HIPO & FLITECAM)• Add Polarimeters• Expand Wide Field FIR Cameras

– At 100 um, an 8’x 8’ fully sampled array is an 128x128 array

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Detector Array Capabilities

Wolf 2002Wolf 2002

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SOFIA supports the larger IR/SMM Technology Development Community

http://www.sofia.usra.edu/det_workshop/

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Beyond Spitzer & Herschel….• Hopefully new IR/SMM space missions

• BUT also, until the mid- 2020s, a vibrant IR/SMM airborne program (SOFIA) providing– Easy access to the IR/SMM Universe – State-of-the-art IR/SMM science instruments– A source of resources for new IR/SMM technology development– An advocate for the IR/SMM community

• SOFIA is the far-IR community’s “ground-based” observatory with many space-based type capabilities

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So how & when can the community use SOFIA?

• SOFIA will have an annual observing cycle– Call for Proposals will be issued by USRA annually

• Observing will start in January 2006

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Jackie Davidson Jackie Davidson

(USRA SOFIA Project Scientist)(USRA SOFIA Project Scientist)

http://sofia.arc.nasa.gov

SOFIAStratospheric Observatory for Infrared Astronomy

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SOFIA: Enabling IR High Resolution Spectroscopy from 2005...

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