J/ApJ/863/119 Cosmic-ray nuclei studies with Voyager, ACE & AMS-02 (Zhu+, 2018)
Studies on cosmic-ray nuclei with Voyager, ACE, and AMS-02.
I. Local interstellar spectra and solar modulation.
Zhu C.-R., Yuan Q., Wei D.-M.
<Astrophys. J., 863, 119 (2018)>
=2018ApJ...863..119Z 2018ApJ...863..119Z
ADC_Keywords: Interstellar medium; Atomic physics
Keywords: acceleration of particles ; cosmic rays ; ISM: supernova remnants
Abstract:
The acceleration of cosmic-ray particles and their propagation in the
Milky Way and the heliosphere tangle with each other, leading to
complexity and degeneracy of the modeling of Galactic cosmic rays
(GCRs). The recent measurements of the GCR spectra by Voyager-1 from
outside of the heliosphere gave the first direct observation of GCRs
in the local interstellar (LIS) environment. Together with the
high-precision data near the Earth taken by the Advanced Composition
Explorer (ACE) and AMS-02, we derive the LIS spectra of helium,
lithium, beryllium, boron, carbon, and oxygen nuclei from a few MeV/n
to TeV/n, using a non-parameterization method. These LIS spectra are
helpful in further studying the injection and propagation parameters
of GCRs. The nearly 20 years of data recorded by ACE are used to
determine the solar modulation parameters over solar cycles 23 and 24,
based on the force-field approximation. We find general agreements of
the modulation potential with the results inferred from neutron
monitors and other cosmic-ray data.
Description:
The Voyager-1 spacecraft, which traveled for about 140au from the
Earth in nearly 40 years after its launch in 1977 and crossed the
boundary of the heliosphere on 2012 August 25 (Stone+ 2013Sci...341..150S 2013Sci...341..150S),
provides us with a unique opportunity to observe Galactic cosmic rays
(GCRs) in the local interstellar space (LIS) for the first time.
Recently, the AMS-02 collaboration reported the measurements of energy
spectra of primary nuclei (He, C, and O) and secondary ones (Li, Be,
and B) to rigidities of a few TV with very high precision
(Aguilar+ 2017PhRvL.119y1101A 2017PhRvL.119y1101A & 2018PhRvL.120b1101A 2018PhRvL.120b1101A).
The data of Voyager-1 and AMS-02 (Alpha Magnetic Spectrometer-02)
together give a full description of spectral behaviors of various
nuclei from MeV to TeV energies.
The GCR data from AMS-02, Voyager-1 (Cummings+ 2016, J/ApJ/831/18),
and the Advanced Composition Explorer (ACE)-CRIS are adopted. For
AMS-02 and Voyager-1, the data for helium, lithium, beryllium, boron,
carbon, and oxygen nuclei are available, while for ACE-CRIS only the
boron, carbon, and oxygen data are available. The AMS-02 data were
taken between 2011 May 19 and 2016 May 26. We extract the ACE-CRIS
data of the same period from the ACE Science center to derive the LIS
spectra. The ACE data of the whole 20 years of operation are then used
to study the solar modulation.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 38 276 Time series of φBCO and the 1σ and
2σ lower(upper) limits
table4.dat 32 425 LIS fluxes of Helium, Lithium, Beryllium, Boron,
Carbon, and Oxygen nuclei based on ACE and
AMS-02 measurements
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See also:
J/A+A/562/L10 : Solar activity reconstructed for 3 millennia (Usoskin+, 2014)
J/ApJ/818/187 : The cosmic TeV gamma-ray background spectrum (Inoue+, 2016)
J/ApJ/831/18 : H -- Ni intensities in LISM from Voyager 1 (Cummings+, 2016)
J/ApJ/840/115 : LIS spectra of cosmic-ray species (Boschini+, 2017)
J/ApJ/858/61 : Carbon and Oxygen local interstellar spectra (Boschini+, 2018)
J/ApJS/237/34 : Magnetic wave activity with Voyager 1 + 2 (Hollick+, 2018)
http://www.srl.caltech.edu/ACE/ASC/ : ACE Science Center home page
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 F8.3 yr Year [1997.6/2018] Decimal year of the observation
10- 14 F5.3 GV phi [0.34/1.28] Solar modulation potential (1)
16- 20 F5.3 GV phi1LO [0.33/1.27] The 1σ lower limit on phi
22- 26 F5.3 GV phi1UP [0.35/1.3] The 1σ upper limit on phi
28- 32 F5.3 GV phi2LO [0.32/1.25] The 2σ lower limit on phi
34- 38 F5.3 GV phi2UP [0.36/1.32] The 2σ upper limit on phi
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Note (1): Via fitting to the Voyager-1, ACE and AMS-02 Boron, Carbon
and Oxygen data.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Ion Nuclei identifier (B, Be, C, He, Li or O)
4- 12 E9.3 --- Ek [0.38/1161] Energy in GeV/nucleon
14- 22 E9.3 --- Flux [2.8e-9/322.3] Flux
in m-2s-1sr-1(GeV/nucleon)-1 units
24- 32 E9.3 --- e_Flux [1.4e-9/7.6] The 1σ error in Flux
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Aug-2019