Bayesian Analysis of Cosmic Ray Propagation: Evidence Against Homogeneous Diffusion

Jóhannesson, G.; Austri, Roberto Ruiz de; Vincent, Aaron C.; Moskalenko, I. V.; Orlando, E.; Porter, T. A.; Strong, A. W.; Trotta, Roberto; Feroz, Farhan; Graff, P. B.; Hobson, M.

doi:10.3847/0004-637x/824/1/16

Cited by 169 publications

(205 citation statements)

References 95 publications

(104 reference statements)

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“…This model has typical parameter values which reproduce B/C in reacceleration models (see also Trotta et al (2011);Jóhannesson et al (2016)). …”

Section: Estimates Using Galpropmentioning

confidence: 99%

Power requirements for cosmic ray propagation models involving diffusive reacceleration; estimates and implications for the damping of interstellar turbulence

Drury

Strong

2017

A&A

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We make quantitative estimates of the power supplied to the Galactic cosmic ray population by second-order Fermi acceleration in the interstellar medium, or as it is usually termed in cosmic ray propagation studies, diffusive reacceleration. Using recent results on the local interstellar spectrum from the Voyager missions we show that for parameter values, in particular the Alfvén speed, typically used in propagation codes such as Galprop to fit the B/C ratio, the power contributed by diffusive reacceleration is significant and can be of order 50% of the total Galactic cosmic ray power. The implications for the damping of interstellar turbulence are briefly considered.

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“…This model has typical parameter values which reproduce B/C in reacceleration models (see also Trotta et al (2011);Jóhannesson et al (2016)). …”

Section: Estimates Using Galpropmentioning

confidence: 99%

Power requirements for cosmic ray propagation models involving diffusive reacceleration; estimates and implications for the damping of interstellar turbulence

Drury

Strong

2017

A&A

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“…Because changing the gas models requires re-tuning of the propagation parameters the method described in [3] is followed. The propagation model parameters determined for the 2D gas model case are typical as found in other studies [22]. Using the 3D gas models produces significant changes in the propagation parameters because the total gas mass in these models is larger: the diffusion coefficient and the Alfven velocity both being about a factor of 2 lower with the new gas model.…”

Section: Effects On Cr Propagationmentioning

confidence: 55%

“…Two models for the gas are employed: the standard 2D azimuthally symmetric distributions in GALPROP that have been used successfully many times to explain CR data [22], and where the gas models are replaced with the ones described in last section. The CR source distribution is in both cases 2D azimuthally symmetric following the radial distribution of pulsars [23].…”

Section: Effects On Cr Propagationmentioning

confidence: 99%

Interstellar gas in 3D, implications for CR propagation and gamma-ray emission.

Jóhannesson¹,

Porter²,

Москаленко³

2017

Proceedings of 35th International Cosmic Ray Conference — PoS(ICRC2017)

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Cosmic-ray (CR) particles propagating in the Galaxy interact in the interstellar medium with gas, losing energy and producing secondary particles via inelastic losses and fragmentation. Observations of the secondaries can be used to constrain the origin and propagation of the CRs, and may also provide signatures of new physics. To date CR propagation models have used the 2D Galactocentric cylindrical symmetry approximation for the spatial distribution of the interstellar gas. This is partly due to difficulties in uniquely determining its true 3D structure. In this contribution a method for determining the 3D spatial distribution of interstellar gas is described and first results using it to develop models that can be used in CR propagation codes like GALPROP are given. Implications for analysis of CR and γ-ray data using 3D spatial models for the interstellar gas are also discussed.35th International Cosmic Ray Conference

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“…As pointed out in [13], there could be a significant difference between the propagation parameters derived from the light isotopes (p,p, He), and nuclei (boron to silicon). Our study does not show any evident discrepancies between the light isotopes (p,p, He), and the B/C ratio (nuclei).…”

Section: Pos(icrc2017)278mentioning

confidence: 99%

“…The key idea behind GALPROP is that all CR-related data, including direct measurements, γ-rays, synchrotron radiation, etc., are subject to the same Galactic physics and must be modeled simultaneously. The GALPROP model for CR propagation is being continuously developed in order to provide a framework for studies of CR propagation in the Galaxy and interpretation of relevant observations [4][5][6][7][8][9][10][11][12][13][14][15][16]. The latest version and supplementary datasets are available through a WebRun interface at the dedicated website.…”

Section: Introductionmentioning

confidence: 99%

Inside out: unveiling local interstellar spectra of cosmic ray species

Boschini¹,

Torre²,

Gervasi³

et al. 2017

Proceedings of 35th International Cosmic Ray Conference — PoS(ICRC2017)

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Local interstellar spectra (LIS) for protons, helium and antiprotons are built using the most recent experimental results combined with state-of-the-art models for propagation in the Galaxy and Heliosphere. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of cosmic ray (CR) species at different modulation levels and at both polarities of the solar magnetic field. To do so in a selfconsistent way, an iterative procedure was developed, where the GALPROP LIS output is fed into HelMod that provides modulated spectra for specific time periods of selected experiments to compare with the data. The parameters were tuned with a maximum likelihood procedure using an extensive data set of proton spectra from 1997-2015. The proposed LIS accommodate both the low energy interstellar CR spectra measured by Voyager 1 and the high energy observations by BESS, PAMELA, AMS-01, and AMS-02 made from the balloons and near-Earth payloads. The proton LIS also accounts for Ulysses counting rate features measured out of the ecliptic plane. The obtained solution is in a good agreement with proton, helium, and antiproton data by AMS-02, BESS, and PAMELA in the whole energy range.

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Bayesian Analysis of Cosmic Ray Propagation: Evidence Against Homogeneous Diffusion

Cited by 169 publications

References 95 publications

Power requirements for cosmic ray propagation models involving diffusive reacceleration; estimates and implications for the damping of interstellar turbulence

Power requirements for cosmic ray propagation models involving diffusive reacceleration; estimates and implications for the damping of interstellar turbulence

Interstellar gas in 3D, implications for CR propagation and gamma-ray emission.

Inside out: unveiling local interstellar spectra of cosmic ray species

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