1 washington u. bob binns jay cummings louis geer georgia denolfo paul hink martin israel joseph...

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Washington U.Bob Binns Jay Cummings Louis Geer Georgia deNolfoPaul HinkMartin IsraelJoseph KlarmannKelly LaveDavid Lawrence

Caltech/JPLA.C. CummingsR.A. Leske R.A. MewaldtE.C. StoneM.E. Wiedenbeck

NASA/GoddardL. M BarbierT. BradtE.R. ChristianG.A. deNolfoT. HamsJ.T. LinkJ. W. MitchellK. SakaiM. SasakiT.T. Von Rosenvinge

U of MinnesotaC.J. Waddington

Constraints on the GCR Source Derived from Isotopic Abundance Measurements

Mike LijowskiJason Link Katharina Lodders Ryan MurphySusan NieburBrian Rauch Lauren ScottStephanie SposatoJohn E. Ward

ACE-CRIS (1997-Present) TIGER (2001-2003)Super-TIGER (2012)

Erice 2014-Bob Binns

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 Murphy’s talk)

First Ionization Potential or Refractory/Volatility nature of elements Constraints placed on the cosmic-ray sources by low-E cosmic rays

59NWhat is the time between nucleosynthesis and acceleration? Other important Isotopes (esp. 22Ne)Normal ISM (SS composition) or a mix of

material?

Talk 2—Elements 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

2Erice 2014-Bob Binns

Origin in our Galaxy.

30 GeV proton in B~6G 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 B~3G has gyro radius ~1 Mpc.

Andromeda galaxy is ~0.65 Mpc from Earth

Erice 2014-Bob Binns3

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.

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, Earth’s magnetic field (for Earth orbiting missions)

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

Credit: Gemini Observatory/AURAN44 Superbubble


UHCR Experiment

Ball/Sat Date Duration Area Ref. Detectors used

First detection of Z>30 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 y2/3rd 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.

Experiments aimed at measuring abundances of UHCRs

• 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

Techniques used for Low Energy, high-resolution GCR Composition Measurements (0.1-10GeV/nuc) (continued)

dE/dx = kZ2/β2

EKE = 0.5 mβ2

• Low energy elemental abundances Multiple dE/dx-Cherenkov

HEAO-3 HNE (C3)-Binns et al. 1989– dE/dx Ionization chambers

– Cherenkov n=1.5

– 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 (n=1.5, 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

dE/dx=kZ2/2

C1=k’Z2 [1-1/(n122)]

C0=a Z2 [1-1/(n0

22)]C1=b Z2 [1-1/(n1

22)]

Techniques used for Low Energy, high-resolution GCR Composition Measurements (0.1-10GeV/nuc)

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 ATIC—Panov et al. 2006 CREAM-Yoon et al. 2011 CALET-Torii et al. 2013

The ACE-CRIS Experiment: Isotope Measurements

The Cosmic Ray Isotope Spectrometer (CRIS) on ACE


CRIS

10 cm• 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

Instrument Cross-section

• Large geometrical factor of CRIS (~50 x previous instruments)

• Excellent mass resolution enables precise identification of abundances.

• Long time in orbit—nearly 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 <0.1º angle resolution)• Require “good hodoscope” three consistent x,y coordinate pairs• For best resolution, use events that are near vertical (e.g.<25º to

vertical); for Z>28, need all the particles we can get, so accept <60º

• 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

6 mm

Dead layers~500m thick

Crossplot of CRIS data


Histogram of CRIS data

What questions can we address with composition measurements of heavy nuclei (Z>26)?

• 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?


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 +

• 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????

GCR Nickel and Cobalt Histograms

• So GCR source is ambient interstellar matter accelerated >105 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)

Mass Ratio

0

0.2

0.4

0.6

0.8

1

10 12 14 16 18 20 22 24 26

59N

i/(59

Ni+

59C

o)

# Solar Masses for SN precursor star

Data taken from Woosley and Weaver, (1995) Ap.J. 101, 181.

Ratio of Ejected Mass• 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.


Other Isotopes measured by ACE-CRIS

22

-0.1 0.0 0.1 0.2 0.3 0.4 0.5

IDPs

Ne-E(L)>100Ne-E(H)~12

Ne-E

Ne-BNe-A

MeteoritesSolar WindSEPs

ACRsGCRS (CRIS)

22Ne/ 20Ne Ratio

Ne-C

Samples of the local interstellar medium (ISM) ~4.6 Gyr ago

Galactic Cosmic-RaySource

Sample of local ISM today

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 5.30.3

• 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)

• Evolution of surface abundances (mass fraction) with stellar mass for 60M⊙ star

(Meynet & Maeder, 2003)

Time evolution of WR abundancesNon-rotatingstar

RotatingStar300 km/sat equator •Top curve—total mass; Bottom

curve—convective core mass

Time evolution of mass

Non-rotatingStar

Rotating star

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

14N(,)18F(e+,)18O(,)22Ne

• Higdon and Lingenfelter (2003) GCR 22Ne/20Ne ratio

consistent with a source made of a mixture of ~82% SS composition and 18% wind outflow+ejecta 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 Z≤28 nuclei are consistent with ~20% massive star outflow (Meynet

& Maeder, 2003, 2005) mixed with ~80% normal ISM (SS composition). 24

ACE-CRIS isotope ratios for Z≤28

Ne

MgSi

Fe NiC/0

Isotopes for Z>26

25

Z>28 Nuclei

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• 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 isotope—lifetime 3.3d If real, they have to be

secondaries

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

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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.

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

Constraint #2

Summary of constraints imposed by isotope measurements

• Isotopes measured by ACE-CRIS have provided two constraints for the source of GCRsConstraint 1—The acceleration of GCRs must occur

more than ~105 years after nucleosynthesisConstraint 2—The 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)


1 washington u. bob binns jay cummings louis geer georgia denolfo paul hink martin israel joseph...

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