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Mid-‐IR and Far-‐IR Astrophysics: Antarc5ca vs. SOFIA
Hans Zinnecker SOFIA SMO Deputy Director German SOFIA Ins5tute
NASA-‐Ames Research Center USA
2
SOFIA
Stratospheric Observatory for Infrared Astronomy
2.7-‐meter
• Interna5onal partnership: 80% -‐-‐ NASA (US) 20% -‐-‐ DLR (Germany)
• Global deployments, incl. southern hemisphere • ~1000 research hours per year in full opera5on (2015) • ~ 20 year projected life5me
Boeing 747SP
h"p://www.sofia.usra.edu
Eric Becklin (SOFIA chief scien5st) + HZ
Why SOFIA? • Infrared transmission in the
Stratosphere very good: • >80% from 1 to 1000 microns
• Instrumenta5on: wide complement, rapidly interchangeable, state-‐of-‐the art
• Mobility: anywhere, any5me
• Long life5me (ca. 20 years)
• Outstanding pla`orm to train future instrumentalists
• Near Space Observatory that comes home aaer every flight
Atmospheric Transmission Cerro Chajnantor (5,600 m)
ALMA (courtesy NRAO, AUI, and ESO)
Time 3% 25% 72%
6
Tremblin et al. 2011, AA 535
Advantages of SOFIA over Dome C
• Water vapor overburden: 10mu vs. 100-‐200mu • mid-‐IR and far-‐IR (30-‐300 mu) atm transmission allows imaging of warm/cold dust emission with FORCAST and HAWC-‐POL, impossible at Dome C
• SOFIA allows far-‐IR heterodyne spectroscopy, eg. 158mu [CII] (1.9 THz) or 112mu [HD] (2.7 THz), impossible from Antarc5ca (unless by balloons)
• SOFIA enables follow-‐up of Herschel HIFI/PACS
Science examples
• mid-‐IR imaging (FORCAST): Orion TC and BNKL • Far-‐IR / THz heterodyne spectroscopy (GREAT): -‐embedded molecular ou`low from HII region -‐molecular infall towards embedded protostar
Background Image:Spitzer
KAO 38 um
(Stacey et al. 1995)
Ney-‐Allen Region Blue=7um Green=19um Red=37um
OMC1S-‐IRS1
Trapezium
OMC1S-‐IRS2
LV1
Shuping et al. (2012)
SOFIA Ney-‐Allen
θ1 D
KAO 38 um
(Stacey et al. 1995)
BN/KL Region Blue=19um Green=31um Red=37um
De Buizer et al. (2012)
SOFIA
Background Image:Spitzer
BN
IRc3
IRc4
IRc2
Source I
The Galac5c Center with FORCAST
• At right are mulitcolor infrared images of two regions of the center of the Milky Way made from SOFIA.
SOFIA/FORCAST images at 19.7 (blue), 31.5 (green), 37.1 (red) µm
Radio image of Sgr A, Pistol, Sickle, filaments and Arches
38 pc
Herter et al. 2012, in prep.
GREAT dips into cradle of star forma5on
CO J=11-‐10
Image: Spitzer/GLIMPSE 8 µm
G5.89 : a cluster of massive stars in the making
Cloud collapse is associated with energe5c ou`lows that can be studied with GREAT/SOFIA
λ
-‐-‐ case study: UCHIIR G34.3 red-‐shiaed absorp5on detected -‐-‐ modeled with infalling envelope
Vsys
G34.26+0.15 VLA 3.6cm
F.Wyrowski -‐ AAS SOFIA Splinter 09.01.2012
Science Results: probing infall
ATRAN plots of [CII] and HD
• While easily detectable at PWV=10mu (SOFIA), it is really (exponen5ally) out of reach for PWV=50-‐100mu, the best PWV at ANTARCTICA
• Other key ISM lines: OH (2.5 THz), [OI] (4.7 THz) these lines are way beyond reach for Herschel, OD (1.39 THz) and SH (1.38 THz) in Herschel gap
10micron WVO, C[II] line at 157.68 micron
7micron WVO, HD line at 112.07 micron
• OH absorp5on towards W49N saturated
• discovery of 18OH towards W49N core
First >2 THz spectroscopy from SOFIA
-‐ OH ground-‐state absorp5on against W49N
-‐ spectral features of Sagiqarius spiral arm
Science Results: 2.5 THz OH absorption
H. Wiesemeyer -‐ AAS SOFIA Splinter 09.01.2012
WEBSITE: www.sofia.usra.edu (incl. science vision) Recent review: Gehrz et al. 2011 (Adv. Space Res.)
SOFIA early science results published in 30 papers: -‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐ Astrophys. Journal Leqers 749, L17-‐L24 (FORCAST) Astronomy & Astrophys. Vol. 542, L1-‐L22 (GREAT)
see also GREAT webpage: hqp://www.mpifr-‐bonn.mpg.de/div/submmtech/great.html Click on “science results”
Recent Results
• SOFIA has just published two special issues that highlight the science accomplished during the Early Science period
Advantages of Antarc5ca (Dome C)
• NIR KLM-‐band wide field surveys (background) at high spa5al (sub-‐arcsec) resolu5on possible, eg. Magellanic Clouds (very deep imaging)
• Medium-‐size 10-‐25m submm telescopes possible, with good angular resolu5on: ~ 2-‐5”. Beqer than SOFIA (2.5m aperture telescope)
• Long nights: con5nuous darkness for 6 months
• Running costs (CONCORDIA) lower than SOFIA
Conclusion
• SOFIA can do many star forma5on studies that 2.5m telescope cannot not do from Antarc5ca
• SOFIA can observe Galaxy at lambda < 200mu, both imaging and heterodyne spectroscopy
• SOFIA only faces compe55on in one respect: a large submm (200-‐350mu) telescope (25m) which can beat SOFIA in spa5al resolu5on
• Antarc5ca wins in NIR (beqer seeing, lower sky background): winter-‐over darkness survey
Supplementary slides
• Flight path for a southern deployment to NZ to observe Galac5c Center and LMC/SMC
• Water vapor map as a func5on of season over the northern Pacific (similar for the southern)
• German MPIfR instrumental development (1.9-‐2.5 THz, 4.7 THz 7-‐pixel arrays, funded)
• Future long-‐dura5on balloon facili5es: e.g. GUSSTO (1.1m telescope, 1.9 THz surveys)
Page 25 ISOR Nov. 3-‐4, 2004
12.3h flight, 7h on Sgr A*
German Instrument Developments • upGREAT an enhancement of the GREAT heterodyne instrument is under development by Rolf Güsten (MPIfR) and collaborators.
• Compact heterodyne arrays – 7 pixels x 2 polariza5ons @ 1.9 to 2.5 THz
– 7 pixels @ 4.7 THz [O I]
Future balloon-‐borne telescopes from Antarc5ca
BLAST-‐POL GUSSTO
