Alanna Connors, for the AstroStatistics Working Group at Harvard Smithsonian Center for Astrophysics

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Astronomy Instruments from the Quantum Age
Do New Instruments, or New Ideas, Drive New
Science?

• Alanna Connors, for the AstroStatistics Working
  Group at Harvard Smithsonian Center for
  Astrophysics
• Processing of some sophistication is needed,
  rather than being just a fixup at the end. Tim
  Cornwell

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OUTLINE

• All Optical
• Eye and Hand
• Telescope and Hand
• Photography
• New Science Equations for fun!
• Mathematics of Invariance Relativity QM
• Bohr Atom
• New Instruments Seeing the Invisible
• Below the Visible Radio, Infrared (skip)
• Above the visible Ionizing Radiation
• Background or signal Cosmic rays
• Old Instruments, New Instruments
• Chandra has it easy, but illustrates main
  principles
• Tougher Instruments still, Do It Right

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Early Observations Eye, HandCrab Supernova July
1054 AD

• Anasazi
• Japan
• Chinese guest star seen in the day like Venus

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Armillary Sphere
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Grand Sweep of Stars and PlanetsHow to Infer 3D
from meticulous 2D Ptolemy, Hypatia,
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Telescope Galileo and onwardsAllows more
meticulous precision
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Planetary Motions 3D from 2D Kepler, Brahe,
Hooke, Newton
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Statistics

• Least-Squares Fitting (LaPlace)
• Periodic Motion (Fourier)
• SKIPPING many interesting math techniques for
  orbits, etc.

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Quantum Mechanics Relativity Oh, Equations!
Fun!

• QUANTUM MECHANICS
• E h n ( Energy Planck constant frequency )
• n c / l (frequency light-speed / wavelength)
• Wave properties for light AND matter!
• Comes in lumps
• Particle properties for matter AND light!
• RELATIVITY
• E m c2
• Electron 0.5 MeV, Proton and neutron 1 GeV

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Potential Energy balanced by angular momentum
Angular momentum quantized nh Result
Constructive interference Integer ls in each
orbit Energy levels 1/n2
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Stellar Spectra Annie Jump Cannon Women of
Harvard College Observatory
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Cecelia Payne-Gaposchkin Old Astronomy New QM
for 1st Time

• Huge amount of careful observations of spectra
• QM tells ionization balance
• Startling thesis result Most of the visible
  universe made of Hydrogen!

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New Instruments Seeing the Invisible
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Jumping Over Whole Story of RadioG. Reber, 1932
backyard Present VLA(But
Interferometry - very intersting!)
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Ionizing Radiation from the Sky
Victor Hess flies with a gold-leaf electroscope
like one at left Measures decreasing discharge
time as altitude increases
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Radio-Chemistry Skill of Curie FamilySupply
Standards of Radioactive Materials
Radium, purified
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New Instruments

• Scintillators (right also reading)
• Cloud chamber DEMO
• (tracing tracks by hand from photographs!)
• Geiger Counter DEMO
• Photographic / emulsion
• Basics same as many modern ones

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Take a minute to think about Statistics, I

• Historical notes on watching for scintillations
  in a dark room
• Tracks tracing by hand (!) until very recently
  (some HEP still do!)
• Historical note for some reason, most
  technicians who do this are women -- Claudia
  Brevard and CGRO EGRET
• Any thoughts on statistics?

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Take a minute to think about Statistics, II

• Optical culture What can I see?
• Invisible light culture
• m e R i
  b
• ltcountsgtEff. AreaInst.Redist.Source intensity
  SkyInst. Bkg
• Measured counts Y Poisson (m)
• Poisson(m) Normal(m,sqrt(m))
• Least-squares, c2 minimization, CC w/ R

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Pre-1975 Early X-Ray Telescopes Bin
sizegtPSF Many counts/bin NO processing

• SKYLAB Solar very large bright source
• Copernicus, ANS sky, but only point sources

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Pre-1975 Early G-Ray TelescopesBin sizegtPSF
fewer counts Bin them up

• gt 100 MeV G-ray profile of Galactic plane

SAS-2 satellite charged particle shield covers
spark chamberS
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1975-1990's COS-B Gamma-Ray SatellitePreliminary
imaging Simple Gauss-Normal fix it up at the
end

• COS-B satellite (Aug '75 - Apr '82 2 keV
  5GeV) Cutaway of spark-chambers, shielding

• Galactic Anti-center region Crab and Geminga
  pulsars Diffuse emission

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1975-1990s Einstein X-Ray Observatory
(HEAO2) First medium energy X-ray point
sourcesdiffuse imaging G-N approximation fix
it up at the end

Einstein Observatory (Nov. '78-April '81 0.15-3
keV) Mirror assembly
Tycho Supernova Remnant (1572)
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1990's and Beyond Great Observatoriesneed to do
it right no longer can fix it up at the end
Compton Gamma-Ray Observatory (Apr '91 Jun '00
COMPTEL 0.8-30 MeV EGRET 20 MeV-100 GeV)
Chandra X-Ray Observatory Jul 1999 and beyond
0.1-10 keV)
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CGRO/EGRET All-Sky Map diffuse glow
significantly non-Gaussian statistics
Log Counts per time per 05 degree pixel Four
years of data (ranges from zero to thousands per
pixel)
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CGRO/EGRET All-Sky Map
Log Inferred flux per 0.5 degree pixel Four
years of data (known point and diffuse sources
modelled out) Haar wavelet basis Dixon, Hartman,
Kolaczyk et al
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CGRO/COMPTEL All-Sky 1.8MeV(Knödelseder, Dixon,
Diehl, Strong, et al 1998)very non-diagonal
instrument response horrid background
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Mkn 501 at TeV Whipple Observatory (Quinn et
al. for Whipple collaboration, 1996, ApJL, 456,
p83)1st AGN DISCOVERED at TeV horrid
background, response
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Chandra has it easy BUT illustrates main
principles
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CHANDRA Image of Tycho Supernova
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CHANDRA PSF on-axis varies with energy
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CHANDRA PSF spreads off-axis 5 arcmin off-axis
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CHANDRA PSF off- axis 10 arcmin
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CHANDRA ACIS BACKGROUND
BI CCD
FI CCD
Effect of a Charged Particle Event
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Higher Energy More Extreme! Dim, BKG,
Rate
Hurley et al GRB940210 The diffuse background
in this direction results in about one photon
above 30 MeV detected by EGRET in 7 minutes. On
the subsequent Compton Observatory orbit, 1.5
hours later, EGRET had 20 minutes of livetime,
and 10 gamma rays were detected from the region
around the annulus, one with energy 26 GeV.
ABOUT 2 DOZEN PAPERS on 1!
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Pathway for Future

• Other instruments Ground-based TeV
• GLAST, Swift,
• CON-X, etc

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Doing it right in one area helps many
overlapping areas