Elemental Abundances in the Cosmic Rays 26 = Z = 34

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Constraints on the GCR Source Derived from
Isotopic Abundance Measurements
Washington U. Bob Binns Jay Cummings Louis Geer
Georgia deNolfo Paul Hink Martin Israel Joseph
Klarmann Kelly Lave David Lawrence
Caltech/JPL A.C. Cummings R.A. Leske R.A.
Mewaldt E.C. Stone M.E. Wiedenbeck
NASA/Goddard L. M Barbier T. Bradt E.R.
Christian G.A. deNolfo T. Hams J.T. Link J. W.
Mitchell K. Sakai M. Sasaki T.T. Von Rosenvinge
Mike Lijowski Jason Link Katharina Lodders
Ryan Murphy Susan Niebur Brian Rauch Lauren
Scott Stephanie Sposato John E. Ward
U of Minnesota C.J. Waddington
TIGER (2001-2003)
ACE-CRIS (1997-Present)
Super-TIGER (2012)
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Outline

• Talk I--Isotopes
• Cosmic Ray Basics
• Sources of GCRs?
• Measurement Techniques and Instruments
• UH Isotope Measurements on ACE
• UH Element Measurements on TIGER, ACE,
  SuperTIGER (Ryan Murphys talk)
• First Ionization Potential or Refractory/Volatilit
  y nature of elements
• Constraints placed on the cosmic-ray sources by
  low-E cosmic rays
• 59N?What is the time between nucleosynthesis and
  acceleration?
• Other important Isotopes (esp. 22Ne)?Normal ISM
  (SS composition) or a mix of material?
• Talk 2Elements
• Element abundances--gas/dust components?
• Recent ?-ray measurements of distributed emission
• The OB association model of origin of GCRs
• Properties of massive stars OB associations
• Conclusions

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Origin in our Galaxy. 30 GeV proton in B6mG has
gyro radius 0.5x10-5 pc (1 au). Learn about
cosmic-ray sources from elemental and isotopic
composition.
Extragalactic origin. 3x1021 eV proton in B3mG
has gyro radius 1 Mpc. Andromeda galaxy is
0.65 Mpc from Earth
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Elemental Abundances in the Galactic Cosmic
Radiation

• Elements in the upper 2/3rds of the periodic
  table, are extremely rare compared to lighter
  elements.

• They contain unique information not obtainable
  from light cosmic rays.

• Measurement requires large instruments at the top
  of the atmosphere or in space for long exposure
  times.

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Objectives of Galactic Cosmic Ray Research

• Determine the source(s) of cosmic rays
• What material is accelerated?
• What are the nucleosynthesis sites of the
  accelerated nuclei?
• What are the accelerators?
• Measure the elemental, isotopic, and energy
  spectra so that the source abundances can be
  determined
• Determine what changes occur as the CRs propagate
  from their source to us at 1AU.
• Nuclear interactions, Leakage from galaxy, Solar
  Modulation, Earths magnetic field (for Earth
  orbiting missions)

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Cosmic Ray Source?

• Stellar atmosphere injection
• Low First-Ionization-Potential (FIP) elements
  enhanced (as in the solar corona, Solar Wind and
  SEPs).
• Casse Goret 1978 Meyer 1985
• Fractionation of particles from Sun probably
  results from a separation of ions and neutrals,
  which takes place between the photosphere and
  corona at temperatures of 6,000-10,000 K.
• Schmeltz et al 2012
• Interstellar gas/grains with enhanced grain
  source
• Many low-FIP elements are refractory and most
  high-FIP elements are volatile
• Refractory elements enhanced
• Mass dependence for volatile elements
• Epstein 1980 Bibring Cesarsky 1981 Ellison et
  al. 1997 Meyer et al. 1997
• Acceleration of material in OB associations and
  their superbubbles by SN shocks and stellar winds
• Wind material from massive stars
• Montmerle 1979 Cezarsky Montmerle 1981
  Streitmatter et al. 1985 Bykov 1999 Parizot, et
  al. 2004 Higdon Lingenfelter 2003, 2005, 2007
  Meli Biermann 2006 Prantzos 2012
• Supernova material

N44 Superbubble
Credit Gemini Observatory/AURA
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Experiments aimed at measuring abundances of UHCRs
UHCR Experiment Ball/Sat Date Duration Area Ref. Detectors used
First detection of Zgt30 nuclei was in meteorite crystals Fleischer, Price, Walker, and Maurette (1967) JGR 72, 331 First detection of Zgt30 nuclei was in meteorite crystals Fleischer, Price, Walker, and Maurette (1967) JGR 72, 331 First detection of Zgt30 nuclei was in meteorite crystals Fleischer, Price, Walker, and Maurette (1967) JGR 72, 331 First detection of Zgt30 nuclei was in meteorite crystals Fleischer, Price, Walker, and Maurette (1967) JGR 72, 331 First detection of Zgt30 nuclei was in meteorite crystals Fleischer, Price, Walker, and Maurette (1967) JGR 72, 331 First detection of Zgt30 nuclei was in meteorite crystals Fleischer, Price, Walker, and Maurette (1967) JGR 72, 331 First detection of Zgt30 nuclei was in meteorite crystals Fleischer, Price, Walker, and Maurette (1967) JGR 72, 331
Texas Flights VHCRN Balloon Texas 1966 0.6 days 4.5 m 2 Fowler et al. 1967 Four layers of nuclear emulsions with absorber interleaved
Barndoor I,II, III Balloon Texas 1967-1970 2.8 days 15 m 2 Wefel 1971 Plastic track detectors and nuclear emulsions
Heavy Nuclei Experiment HEAO-3 Satellite 1979 1.7 years 2 m 2 Binns et al. 1989 Ionization chambers, Cherenkov counters, wire ionization hodo.
HCRE Areal-6 Satellite 1979 1 year equiv. 0.5 m 2 Fowler et al. 1987 Spherical gas scintillator and acrylic Cherenkov detector
UHCRE LDEF Satellite 1984 5.75 years 20 m 2 Donnelly et al.2012 Plastic track detectors (Lexan)
Trek Mir Satellite 1991 1/3rd 2.5 y 2/3rd 4.2 y 1.2 m 2 Westphal et al.1998 Glass track detectors-Barium Phosphate Glass (BP-1)
CRIS ACE Satellite 1997 17 years 0.03 m 2 Stone et al. 1998 Silicon detector stack scintillating optical fiber hodo.
TIGER Balloon-Antarctica 2001, 2003 50 days 1.3 m 2 Rauch et al. 2009 Plastic scint, acrylic aerogel Cherenkov, scint fiber hodo.
SuperTIGER Balloon-Antarctica 2012 44 days equiv. 5.6 m 2 Binns et al. 2014 Plastic scint, acrylic aerogel Cherenkov, scint fiber hodo.
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Techniques used for Low Energy, high-resolution
GCR Composition Measurements (0.1-10GeV/nuc)
(continued)

• Low energy isotopic abundances
• dE/dx-ETotal
• ACE-CRIS-Stone et al. 1998
• IMP-7-Garcia-Munoz et al. 1979
• ISEE-3-Wiedenbeck Greiner 1981 Mewaldt et al.
  1980
• Voyager-Lukasiak et al. 1994 Webber et al. 1997
• Ulysees-Connell Simpson 1997
• CRESS-DuVernois et al. 1996
• Multiple dE/dx measurement crucial for good
  resolution
• Reject interactions in detector
• Consistency requirement for funny events

dE/dx kZ2/ß2 EKE 0.5 mß2
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Techniques used for Low Energy, high-resolution
GCR Composition Measurements (0.1-10GeV/nuc)

• Low energy elemental abundances
• Multiple dE/dx-Cherenkov
• HEAO-3 HNE (C3)-Binns et al. 1989
• dE/dx Ionization chambers
• Cherenkov n1.5
• Wire ionization hodoscope
• Multiple dE/dx-Double Cherenkov
• TIGER SuperTIGER-Rauch et al. 2009 Binns et
  al. 2014
• dE/dx (dL/dx) Plastic scintillator (dE/dx
  saturates)
• Double refractive index Cherenkov (n1.5, 1.04,
  1.025)
• Scintillating fiber hodoscope
• Multiple Cherenkov
• HEAO-3 (C2)-Engelmann et al. 1990
• Five Cherenkov counters (multiple refractive
  indices)
• Flash tube hodoscope

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Other composition experiments at higher energies

• Magnet Experiments (Elements Isotopes)
• ISOMAX-Hams et al. 2004
• HEAT-Beach et al. 2001
• PAMELA-Adriani et al. 2013
• BESS
• AMS-Aguilar et al. 2013
• Calorimeter experiments
• ATICPanov et al. 2006
• CREAM-Yoon et al. 2011
• CALET-Torii et al. 2013

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The ACE-CRIS Experiment Isotope Measurements
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The Cosmic Ray Isotope Spectrometer (CRIS) on ACE

• Advanced Composition Explorer (ACE) satellite
  launched in August, 1997.
• Still in orbit about the L1 Lagrange point
  between Earth and the Sun
• Still sending back good element and isotope data
  on GCRs
• No significant degradation in instrument
  performance

10 cm
CRIS
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Instrument Cross-section

• Large geometrical factor of CRIS (50 x previous
  instruments)
• Excellent mass resolution enables precise
  identification of abundances.
• Long time in orbitnearly 17 years

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How do we derive source abundances from data?

• CRIS concept is simple, but the DEVIL is in the
  details!!
• Mass resolution
• Angle Measurement
• Theta correction to signals (achieved lt0.1º angle
  resolution)
• Require good hodoscope? three consistent x,y
  coordinate pairs
• For best resolution, use events that are near
  vertical (e.g.lt25º to vertical) for Zgt28, need
  all the particles we can get, so accept lt60º
• Reject interactions
• Reject penetrating events--signal in the bottom
  anticoincidence detector
• Require charge estimate consistency using
  different combinations of detectors for estimate
• Require penetration to E3 or deeper so can apply
  consistency rqmt
• Reject dead layer events (particles stopping
  within 500 µm from surface on one side of wafer)
  correct for nonlinearities in signal from
  silicon detectors
• Reject particles exiting through the side of the
  stack using anticoincidence rings
• Map actual thickness of all silicon detectors
• Abundances at top-of-detector
• Interaction corrections
• Energy interval corrections
• Source abundances
• Propagate from instrument through heliosphere
• Propagate back to the source

Dead layers
500mm thick
6 mm
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Crossplot of CRIS data
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Histogram of CRIS data
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What questions can we address with composition
measurements of heavy nuclei (Zgt26)?

• What is the time between nucleosynthesis and
  acceleration?
• How do GCR isotope and element ratios compare
  with those from possible sources?
• Does the volatile (gas) or refractory (dust
  grains) nature of an element affect the
  composition of CRs?
• Do cosmic ray abundances depend on mass?

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What is the time between nucleosynthesis and
acceleration of GCRs?

• Does a SN shock accelerate nuclei synthesized in
  that same SN?
• Soutoul et al., 1978 ?radioactive isotopes that
  decay only by electron-capture can be used to
  measure the time between nucleosynthesis and
  acceleration.
• 59Ni decays only by electron-capture with
  half-life 76,000yr in lab.
• 59Ni e- ? 59Co n
• BUT, at cosmic-ray energies it is stripped of
  electrons, so is essentially stable.

• If GCR are accelerated by the same SN in which
  the nuclei are synthesized, expect to see 59Ni in
  the GCR.
• So what do we observe????

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GCR Nickel and Cobalt Histograms

• So GCR source is ambient interstellar matter
  accelerated gt105 years after nucleosynthesis
• Corolary Whatever the source of GCRs, there must
  be time between nucleosynthesis and acceleration
  for the 59Ni to decay
• Constraint 1

Wiedenbeck, et al., ApJL, 523, L51 (1999)
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Mass Ratio

• What fraction of mass-59 nuclei is expected to be
  synthesized as 59Ni in core-collapse SNe?
• Note that Type-1a Sne are also copious producers
  of 59Co and 59Ni (Iwamoto et al. 1999)
• However, Type 1a SNe
• 15 of total SN rate
• ejecta spreads throughout the galaxy over time
• Core-collapse SNe seed a high-metallicity
  superbubble environment, ready for acceleration
  by the relatively frequent, nearby SNe.

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Other Isotopes measured by ACE-CRIS
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The cosmic-ray source composition differs from
that of the Solar System.

• The CRIS experiment, finds a 22Ne/20Ne source
  ratio relative to SS of 5.3?0.3
• Earlier experiments also found substantial
  enhancements (e.g. Ulysses, Voyager, CRRES,
  ISEE-3)
• Best accepted explanation is that this might
  result from an admixture of WR wind material,
  rich in 22Ne, with normal ISM (with SS
  composition). (Montmerle, 1979 Cesarsky
  Montmerle, 1981 Higdon Lingenfelter 2003, 2005)

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Time evolution of WR abundances
Time evolution of mass
Non- rotating star

Rotating star
Non-rotating Star
Rotating Star 300 km/s at equator

• Top curvetotal mass Bottom curveconvective
  core mass

• 22Ne greatly enhanced during helium
• burning through the ?-capture
• reaction

• Evolution of surface abundances (mass fraction)
  with stellar mass for 60M? star (Meynet Maeder,
  2003)

14N(?,?)18F(e,?)18O(?,?)22Ne
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ACE-CRIS isotope ratios for Z28

• Higdon and Lingenfelter (2003)
• GCR 22Ne/20Ne ratio consistent with a source made
  of a mixture of 82 SS composition and 18 wind
  outflowejecta from massive stars.
• Superbubble/OB association origin of GCRs.
• But, used Schaller et al. 1992 for massive star
  wind yield. More recent calculations (Hirshi, et
  al. 2005) show reduced 22Ne production.
• Binns, et al (2005)
• GCR abundances of a range of isotope and element
  ratios for Z28 nuclei are consistent with 20
  massive star outflow (Meynet Maeder, 2003,
  2005) mixed with 80 normal ISM (SS composition).

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Isotopes for Zgt26
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Zgt28 Nuclei

• ACE-CRIS has provided the first, and only
  existing measurements of isotopic abundances of
  29Cu, 30Zn, 31Ga, 32Ge.
• We see well resolved isotope peaks from 29Cu
  through 32Ge with sufficient statistics for a
  meaningful measurement.
• Note possible 3-event peak at mass 67--
  Electron capture isotopelifetime 3.3d
• If real, they have to be secondaries

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Ultra-heavy isotopes in context of previous
lower-Z data

• Note that the isotopic ratio error bars for new
  UH isotopes are statistical only.

Constraint 2
New data are consistent with model, but also with
solar system abundances. ?CR source must be able
to produce isotope ratios that are equivalent
to that obtained by mixing 20 of MSO with 80
of normal ISM.
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Summary of constraints imposed by isotope
measurements

• Isotopes measured by ACE-CRIS have provided two
  constraints for the source of GCRs
• Constraint 1The acceleration of GCRs must occur
  more than 105 years after nucleosynthesis
• Constraint 2The abundances of the isotopic
  ratios measured must be equivalent to that
  obtained by mixing 20 of massive star outflow
  material with 80 of normal ISM (with SS
  abundances)