Transcript SOFIA Stratospheric Observatory For Infrared Astronomy

1
SOFIA
Stratospheric Observatory
For Infrared Astronomy
E. E. Becklin
SOFIA Chief Scientist
October, 2007
2
Outline
•
•
•
•
3
Overview of SOFIA
Progress to Date
Science
Schedule
OVERVIEW
4
Overview of SOFIA
• SOFIA is 2.5 m telescope in a modified B747SP aircraft
– Optical-mm performance
– The obscured IR (30-300 m) is most important
• Joint Program between the US (80%) and Germany (20%)
• First Science 2009 (NASA, DLR, USRA, DSI)
• Designed for 20 year lifetime
5
Overview of SOFIA (continued)
• Operating altitude
– 39,000 to 45,000 feet (12 to 14 km)
– Above > 99% of obscuring water vapor
• World Wide Deployments
• Ramp up to ~1000 science hours per year
• Build on KAO Heritage with improvements (Facility Inst.,
Science Support)
• Science flights to originate from NASA Dryden Flight
Research Center (DFRC)
• Science Center is located at NASA Ames Research Center
6
SOFIA — The Observatory
open cavity
(door not shown)
Educators work station
pressure bulkhead
scientist stations, telescope and
instrument control, etc.
TELESCOPE
scientific instrument (1 of 9)
Why SOFIA?
• Infrared transmission in the
Stratosphere very good:
>80% from 1 to 1000
microns
• Instrumentation: wide
complement, rapidly
interchangeable, state-of-the
art
• Mobility: anywhere, anytime
• Long lifetime
8
PROGRESS TO DATE
9
Major Physical Installations Completed
Main Deck, Looking Aft at Instrument Interface
Telescope Installed
10
Rotation Isolation Subsystem
Spherical Bearing
The Bearing Sphere on the Nasmyth Tube
“First Oil“
11
Primary Mirror (uncoated)
12
Telescope in Action
QuickTime™ and a
Motion JPEG OpenDML decompressor
are needed to see this picture.
13
SOFIA rms Tracking of <0.8 arcsec
Tracker in centroid inertial tracking mode
550
540
530
Series1
520
510
500
550
14
560
570
580
590
600
SOFIA Makes Its First Flight!
15
SOFIA Arrival at NASA DFRC, May 31, 2007
16
SOFIA’s Instrument Complement
As an airborne mission, SOFIA
supports a unique, expandable
instrument suite
• SOFIA covers the full IR range with
imagers and low to high resolution
spectrographs
• 4 instruments at Initial Operations; 9
instruments at Full Operations.
• SOFIA will take fully advantage of
improvements in instrument technology.
There will be one new instrument or
major upgrade each year.
17
Four First Light Instruments
Working/complete
HIPO instrument
in Waco on SOFIA
during Aug 2004
Working/complete
FLITECAM
instrument at
Lick in 2004/5
Working FORCAST
instrument at
Palomar in 2005
Successful lab
demonstration of
GREAT in July 2005
18
SCIENCE
19
Science Capabilities
• Because of large aperture and better detectors, sensitivity for
imaging and spectroscopy similar to the space observatory
ISO
• 8x8 arcmin Field of View allows use of very large detector
arrays
• Image size is diffraction-limited beyond 25 µm, making it 3
times sharper than the space observatory Spitzer at these
wavelengths
20
Astrochemistry
SOFIA is an outstanding
observatory to study
chemistry in space
• Most ground state molecular lines
in IR or submillimeter
• Need high spectral resolution
throughout which SOFIA has.
• As sensitive as CSO, but much
larger wavelength range is
accessible
• Light molecules: Molecular
hydrogen, HD, water, other
hydrides in IR and submillimeter
• The fullerene, C60, has 4 IR lines
in SOFIA’s bands
21
CSO FTS Spectrum of ORION OMC1
Serabyn and Weisstein 1995
Occultation astronomy with SOFIA
SOFIA will determine
the properties of
Dwarf Planets in and
beyond the Kuiper
Belt
Pluto occultation lightcurve observed on
the KAO (1988) probes the atmosphere
•SOFIA can fly anywhere on the Earth, allowing it to position itself under the
shadow of an occulting object.
•Occultation studies with SOFIA will probe the sizes, atmospheres, and
possible satellites of newly discovered planet-like objects in the outer Solar
system.
•The unique mobility of SOFIA opens up some hundred events per year for
study compared to a handful for fixed observatories.
22
Planetary Atmospheres
SOFIA will determine
the Methane on Mars
The ground-based infrared spectrum of Mars is dominated by broad lines in
the Earth atmosphere. A weak feature on the wing of the strong terrestrial
methane line may be the Doppler-shifted methane line in the Mars
atmosphere.
If true, the methane abundance is high and may reflect biogenic activity.
EXES working at 7.6 microns in the Stratosphere will be able to see directly
the Doppler-shifted methane lines on Mars
How much methane is on Mars?
Does it show biogenic activity? What are the spatial and seasonal
variability?
23
Extrasolar Planet Transits
SOFIA will determine
the properties of new
extrasolar planets by
use of transits with
HIPO and FLITECAM
working together
Artist concept of planetary transit and the lightcurve of HD
209458b measured by HST revealing the transit signature
Today over 200 extrasolar planets are known, and over 15 transit their
primary star
SOFIA will fly above the scintillating component of the atmosphere and will
provide the most sensitive freely pointing observatory for extrasolar
planetary transits after HST and before JWST.
SOFIA’s HIPO and FLITECAM instruments can observe with high signal-tonoise the small variations in stellar flux due to a planet transit and
– Provide good estimates for the mass, size and density of the planet
– May reveal the presence of, satellites, and/or planetary rings
24
Star Formation in the Center of the Galaxy in the Presence
of a Massive Black Hole
SOFIA will help determine how
stars form in the presence of
a Massive Black Hole
Astronomers at ESO and Keck have detected
fast moving stars revealing a 4 x 106 solar
mass black hole at the Galactic Center
One of the major discoveries of the KAO
was a ring of dust and gas orbiting
the very center of the Galaxy at r=1pc
Young newly formed stars have also been
found orbiting the black hole within 1000au
•
•
•
•
25
Did these young massive stars form in the ring of dust and gas?
If so, how do they get so close to the black hole?
Are there other ways that the massive stars could form?
SOFIA with its high angular and spectral resolution is well placed to
help answer these questions over the next 20 years
Resolving Star Formation: Spitzer & SOFIA
NASA/JPL-Caltech/Z. Wang
Antennae Galaxies
IRAC @ 8 microns (red; 160s, 4’ x 4’)
FORCAST @ 24 microns
26
NASA/JPL-Caltech/V. Gorjian
Henize 206- LMC high mass star formation
MIPS @ 24 microns (80s, 20’ x 20’)
HAWC @ 53 / 89 microns (mosaic)
Cold Molecular Hydrogen using HD
SOFIA will study deuterium in the
galaxy using the ground state HD line
at 112 microns. This will allow
determination the cold molecular
hydrogen abundance.
Atmospheric transmission around the HD line at 40,000 feet
Deuterium in the universe is created in the Big Bang.
Measuring the amount of cold HD (T<50K) can best be done with the ground state
rotational line at 112 microns.
Detections with ISO means a GREAT high resolution spectrometer study possible.
As pointed out by Bergin and Hollenbach, HD gives the cold molecular hydrogen.
HD has a much lower excitation temperature and a dipole pole moment that almost
compensates for the higher abundance of molecular hydrogen.
In the future could be used much like the HI 21cm maps but for cold molecular gas.
27
SOFIA: Science For the Whole Community
10 8
10 7
Planetary Atmospheres
Chemistry of the cold ISM
10 6
Dynamics of collapsing protostars
Comet Molecules
Spectral resolution
10 5
Dynamics of the Galactic Center
Velocity structure and gas composition in
disks and outflows of YSOs
10 4
PAH & organic molecules
10 3
Composition/dynamics/physics of the
ISM in external galaxies
Nuclear synthesis in supernovae in nearby galaxies
Composition of interstellar grains
10 2
Debris Disk Structure
10 1
KBOs, Planet Transits
Luminosity and Morphology of Star Formation Galactic and
Extra-Galactic Regions
10 0
1
10
Wavelength [µm]
28
100
1000
SCHEDULE
29
SOFIA Schedule (Major Milestones)
•
•
•
•
•
30
First Re-Flight
Door Drive Delivered
Open Door Flights at DFRC
First Science
Next Instrument call
Occurred April ‘07
Winter ‘07
Fall ‘08
‘09
‘10
US General Observer Opportunities
•
•
•
First call for science proposals in ‘09
Future calls every 12 months
First General Observers 2010
– Expect ~ 20 General Observer science flights
– Shared risk with Instrument PI’s
• Open Observatory with Facility Instruments
31
Next Call for New Instruments
•
•
•
•
32
The next call for instruments will be at first Science ~FY10
There will be additional calls every 3 years
There will be one new instrument or upgrade per year
Approximate funding for new instruments $8 M/yr
Preparations for Science Operations and
Community Task Force Activities
•
NASA Ames and USRA are ramping up for Observatory operations.
Please visit the SOFIA web site (http://www.sofia.usra.edu/) for Job
opportunities.
• There will be community involvement in the Early Science Program.
• We will hold a “SOFIA’s 2020 Vision” Workshop at Caltech, December
6-8, 2007 – long term science
•
33
We will hold a “SOFIA Early Science” Workshop at the January AAS
meeting in Austin, TX, January 8, 2008
Summary
• Program making progress!
– Aircraft structural modifications
complete
– Telescope installed, several
instruments tested on ground
observatories
– Completed first flight and ferry flight
to NASA Dryden
– Full envelope flight testing (closed
door) has started.
– Several subsystems will be
installed spring/summer 08 (Door
motor drive, coated primary mirror)
– First science in ’09
• SOFIA will be one of the primary
facilities for far-IR and submillimeter astronomy for many
years
34
BACK-UP
35
OPERATIONS PLANS
36
SOFIA Operations Drivers
• Frequent Flights: 960 science hours/year (2x KAO)
• World wide deployments especially to the Southern Hemisphere will
be scheduled as required by science
• Both Facility and PI Instruments
• Facility Instruments: Good tools, Data Pipelines and Archive - easy
for non-IR astronomer to obtain good data (New for Airborne
Astronomy with SOFIA)
• PI Instruments: State of the art and innovative
• General Investigator program for both FSI and PI, with funded
research
• Robust Instrument program to allow Observatory to “reinvent itself”
every few years
• Unique Education and Public Outreach program
37
SOFIA Science Operations
• SOFIA will be operated as an observatory open to the whole science
community through peer review
• 3 flights a week for ~40 weeks per year
• Flights will be primarily out of Dryden (Edwards AFB) with occasional
deployments to the southern hemisphere and other sites as needed
– Continuous access of science and mission staff to airplane
– Preflight instrument simulator facilities (testing and alignment) for
mission preparation
– Instrument laboratories including cryogen facilities
– Rapid instrument exchange
• Science center will be at Ames
–
–
–
–
–
–
38
Telescope time peer review
Observing time schedule
Flight planning
Management of Instruments (Operations and Development)
Science Data Archive(Facility Instruments Reduced data, PI raw data)
Observing Support
SOFIA and Spitzer
• SOFIA will become operational near the time that Spitzer runs
out of cryogens. The science impact of not being
contemporary is small: Spitzer is a high sensitivity imaging
and low resolution spectroscopy mission. SOFIA is a high
spectral and high angular resolution mission
• As it now stands, the two observatories are very
complementary and when Spitzer runs out of cryogens in
early FY09, SOFIA will be the only observatory working in the
25 to 60 micron region for over 10 years: Comets,
Supernovae, Variable AGN, other discoveries.
39
SOFIA and Herschel
• Herschel and SOFIA will now start at about the same time
• Joint calibration work is on going
• For the years of overlap, SOFIA will be only program
– with 25 to 60 micron capability
– with high resolution spectroscopy in the 60 to 150 micron region
• When cryogens run out in Herschel in ~2011 SOFIA will be
only NASA mission in 25 to 600 micron region for many years
– Important follow-up
– Advanced instrumentation will give unique capabilities to SOFIA:
Polarization, Heterodyne Arrays, Heterodyne Spectroscopy at
28 microns (ground state of molecular hydrogen), and other
interesting astrophysics lines
• Both missions are critically important and complementary
40
SOFIA and JWST
• SOFIA is very complementary to JWST
• Before JWST is deployed and after Spitzer cryogens run out ,
SOFIA is only mission with 5 to 8 micron capabilities
– important organic signatures
• After JWST is launched SOFIA is the only mission to give
complementary observation beyond 28 microns and high
resolution spectroscopy in 5 to 28 micron region
41
SOFIA and WISE
• WISE is a very sensitive all sky survey in the 3.3 to 23 micron
region. It is expect to launch just as SOFIA begins operations.
• SOFIA can provide a number of important follow up observations.
– Very red sources seen only at 23 microns can be followed up at 38
microns with FORCAST on SOFIA and spectra can be obtained with
EXES on SOFIA for the brightest 23 micron sources not seen by IRAS.
– Nearby cold Brown Dwarfs discovered by WISE can be followed up
with the FLITECAM GRISM and EXES.
42
100
SPITZER
SAFIR
0.3
Herschel
Wavelength (µm)
1000
SOFIA
?
3
JWST
10
30
1
2005
Ground-based
Observatories
43
2010
2015
2020
2025
SOFIA provides temporal continuity and wide spectral
coverage, complementing other infrared observatories.
Frequency (THz)
Infrared Space Observatories