NASA GSFC WFF PSL CSBF SWRI Balloon Workshop Jack Tueller 1 Gamma-Ray Astronomy From Balloons Jack...

SWRI Balloon Workshop Jack Tueller 1

NASAGSFCWFF

PSLCSBF

Gamma-Ray Astronomy From Balloons

Jack Tueller

Balloon Project Scientist


NASAGSFCWFF

PSLCSBFGamma Rays

• Gamma rays are the highest energy photons.• Gamma rays do not penetrate to the ground.• Balloons can provide access to all energies >20 keV

(Hard X-rays and Gamma Rays)


NASAGSFCWFF

PSLCSBFWhat makes suborbital different?

Different Risk Management Strategy

• the payload is recovered• re-flights are inexpensive

(<$1M for a balloon vs >$100M for a rocket)

Higher Risk is the Best Strategy• lower cost• faster migration of new

technology• smaller more focused efforts• training new workforce


NASAGSFCWFF

PSLCSBF

Gamma-Ray Astronomy from Balloons

• atmospheric cutoff is 20keV no soft x-rays

• To get a high sensitivity gamma-ray payloads must be big and heavy

• gamma-ray payloads work best at low latitudes

magnetic shielding low background

• gamma-ray payloads must be pointed

• real science is possible but we need LDB at low latitudes

Boggs NCT GRIS

ProtoEXIST

InFOCuS

GLAST

HEFT


NASAGSFCWFF

PSLCSBFSN1987A

• first nearby supernova in 400 years

• every instrument possible was used

• many new phenomena were discovered

• balloons can provide quick access to space for timely measurements

HST rings

beforeafter


NASAGSFCWFF

PSLCSBFHigh Resolution Spectroscopy

• In 1987 there were no high resolution germanium spectrometers in space like INTEGRAL

• Gamma-ray lines yield nuclear yields and velocity distribution that cannot be determined at other wavelengths

• Balloon experiments filled the gap GRIS, HEXAGONE, Lockheed Martin

• balloon's success leads to INTEGRAL

GRIS

INTEGRAL


NASAGSFCWFF

PSLCSBFSN1987A Lines

• Gamma ray line profiles are not distorted by complicated effects such as resonant scattering.

• Line profiles did not fit the standard models.Lines are red-shifted not blue-shifted.

• But, they validate the detailed IR line profiles.

• SN1987a was an asymmetric explosion!

• future: 44Ti lines?


NASAGSFCWFF

PSLCSBFNuclear Lines

• Nuclear lines are the unique signal of the production of new elements

Boggs ACT Concept Study


NASAGSFCWFF

PSLCSBFType Ia Supernovae

Much Cosmology rests on using Type Ia's as a standard candle but the physics are not understood!

Explosion is driven by radioactive decay.

Boggs ACT study


NASAGSFCWFF

PSLCSBFCompton Scattering

• GRIS worked with large detectors to capture all the energy and a thick collimator (800 lbs of NaI) to isolate the source.

• Compton scattering is the dominant cross section between 200 keV and 2 MeV where most of the interesting gamma ray lines occur.

• Localizing all the interactions allows accurate reconstruction of the source positions and spectra over a wide field


NASAGSFCWFF

PSLCSBFCompton Telescopes

Boggs NCTDevelopment of an Advanced Compton Telescope

• several technologies are possible– Si & Ge strip detectors– Si & CdZnTe strip detectors– thick Si– Liquid Xe– Gaseous Xe-LaBr3

– LaBr3

• All are now or are proposed balloon payloads

ACT Concept


NASAGSFCWFF

PSLCSBFHigh Energy Gamma Rays

• Technology for EGRET developed on HEBE balloon experiment

• Go-no go test of GLAST technology on balloonsWould the background rejection work?

EGRET All-Sky >100 MeV

GLAST

balloon test bed

detector

CGRO/EGRET


NASAGSFCWFF

PSLCSBF

absorbed (52)unabsorbed(49)

Understanding Supermassive Black Holes

• How do black holes form and grow?

• What stops the growth?

• How do black holes effect galaxy formation?

BATXMM

• Only in hard x-ray can you find all the sources and measure their luminosity.


NASAGSFCWFF

PSLCSBF

• A hard X-ray all-sky monitor can make great advances in variability studies of black holes.

• A sensitive hard X-ray all-sky survey is the only way to find all the obscured sources.

ProtoEXIST

EXIST

Swift/BAT Hard X-ray Survey >14 keV


NASAGSFCWFF

PSLCSBFHard X-ray Focusing Optics

• multilayer grazing incidence focusing optics

• long focal lengths are required (InFOCuS is 8m)

• CdZnTe focal plane is the other critical technology. (A Si focal plane would be 1 cm thick.)

• Balloons can accommodate long focal lengths without costly mechanisms.

LaunchSep 16,2004 Ft. SumnerNM

InFOCuS

9m

No mechanism was required to launch 9m truss.


NASAGSFCWFF

PSLCSBF3 Balloon Instruments

Three instruments are currently active:

• HEFT-CIT Columbia• InFOCuS-GSFC Nagoya• HERO-MSFC

Each of these instruments test alternative technology for hard x-ray focusing optics.

Proposed for Con-X enhancement and SMEX-NuSTAR

InFOCuS

HERO

HEFT


NASAGSFCWFF

PSLCSBF

The Black Hole at the Galactic Center• A supermassive black hole

lurks at the Galactic Center.• Like most black holes at the

center of galaxies it is a very weak source at all wavelengths.

• What is the accretion rate and why is it so low?

• The GC is a very crowded area.

• Only high resolution hard X-ray imaging can answer this question.

INTEGRAL

INTEGRAL imaging with >10 arcmin resolution is hopelessly confused. Soft X-ray imaging with Chandra sees 2000 sources <10 arcmin from the center.


NASAGSFCWFF

PSLCSBFWhat is the future?

How do we maintain strong balloon science in this field?

• long duration flights at low latitude

– super pressure balloon

– trajectory modification system

– long duration requires higher reliability - more cost and oversight

• advanced designs:bigger and heavier payloads

• secure and adequate funding


NASAGSFCWFF

PSLCSBFWorkforce Replenishment

How are future instrument builders recruited and trained? BALLOONS!

• fast enough for grad student to complete all phases of a project

• small enough for the university researcher

• open to hands-on student participation

• pushing newest technology• produces significant science

results

Mission/

Instrument

PI

CGRO

BATSE Fishman

EGRET Fichtel

INTEGRAL

SPI Teegarden

Matteson

HEAO-3 Jacobson

HEAO-1 Peterson


NASAGSFCWFF

PSLCSBFConclusions

• Gamma-ray astronomy could have a bright future in ballooning.

• Significant science can be achieved on balloons.

• Balloons are crucial to the development of new missions.

• Low cost ballooning can keep a field alive in hard times.

• Ballooning is the natural way to recruit and train a workforce.NASA and gamma-ray astronomy need a vigorous balloon program

NASA GSFC WFF PSL CSBF SWRI Balloon Workshop Jack Tueller 1 Gamma-Ray Astronomy From Balloons Jack...

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