Galactic cosmic rays (GCR) and dark matter indirect detection - - PowerPoint PPT Presentation

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Galactic cosmic rays (GCR) and dark matter indirect detection - - PowerPoint PPT Presentation

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Galactic cosmic rays (GCR) and dark matter indirect detection Group: DARK (AMS-CREAM-LSST) Research activity: phenomenology 1. Introduction : GCRs, dark matter indirect detection 2. Recent results and interpretation 3. Research activities at

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Galactic cosmic rays (GCR) and dark matter indirect detection

CS LPSC 16 Dec. 2016

David Maurin (LPSC)

dmaurin@lpsc.in2p3.fr

  • 1. Introduction : GCRs, dark matter indirect detection
  • 2. Recent results and interpretation
  • 3. Research activities at LPSC and 2-year goals
  • Solar modulation
  • GCR interpretation
  • Dark matter indirect detection

Group: DARK (AMS-CREAM-LSST) Research activity: phenomenology

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SLIDE 2

R☼ ~ 8 kpc (nuclear physics) (plasma physics) (astrophysics + particle physics) Galactic wind

Tycho's SNR

  • 1. Introduction: GCR propagation and standard astrophysics

p, He, C p, d, e+, B

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R☼ ~ 8 kpc (nuclear physics) (plasma physics) (astrophysics + particle physics) Galactic wind

Tycho's SNR

Universe (after Planck)

  • 68.3 % dark energy
  • 26.8 % dark matter
  • 4.9 % ordinary matter

Milky-Way dark matter halo

  • ~ spherical halo
  • radius ~300 kpc
  • 1. Introduction: GCR propagation and dark matter

Dark matter Standard matter

Indirect detection

Production (colliders) Direct detection

p, d, e+ p, He, C p, d, e+, B

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SLIDE 4

~300 kpc 8 kpc ΔΩ

Galactic centre (diffuse emission) Dark micro-halos Dwarf spheroidal galaxies

Dense (~ ∫ ρ2) – Close (1/d2) – No astrophysical background Outside the Milky-Way In the Milky-Way

Galaxy clusters Extragalactic diffuse emission

  • 1. Introduction: dark matter indirect detection in γ-rays
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SLIDE 5
  • 1. Introduction: from lowest to highest energies

→ CR sources and transport? → Origin of spectral features, composition, anisotropy? → Transition galactic/extragalactic?

AMS ISS- CREAM

Impact of Solar modulation Extragalactic Galactic

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SLIDE 6
  • 1. Introduction: Galactic cosmic rays (~108-1015 eV)

→ Transport parameters → Dark matter indirect detection

Beringer et al., PRD 86, 010001 (2012)

p, He, diffuse γ-rays, antiprotons, e-, and e+

Beischer et al. (2009)

γ He e- _ p e+ p

→ Acceleration mechanisms: injection, efficiency, ... → Transport: diffusion, convection, energy gain and losses... → CR anisotropy δ<10-3 (≠ E and species)

Elemental composition

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SLIDE 7
  • 1. Introduction : GCRs, dark matter indirect detection
  • 2. Recent results and interpretation
  • 3. Research activities at LPSC and 2-year goals
  • Solar modulation
  • GCR interpretation
  • Dark matter indirect detection
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SLIDE 8
  • 2. Recent results: positron fraction and antiprotons

Solar modulation effect

Aguilar et al., PRL 110, 1102 (2013) Accardo et al., PRL 113, 121101 (2014)

Antiprotons → Seems consistent with astrophysics only

Kappl et al., JCAP 09, 023 (2015)

N.B.: see also e- and e+ in Aguilar et al., PRL 113, 121102 (2014)

Positron fraction, e-, e+ and e-+e+ spectra used to test astrophysical and/or dark matter hypothesis

  • Contribution from local SNRs/pulsars?

→ e.g., Delahaye et al., A&A 524, A51 (2010)

  • Dark matter hypothesis?

→ e.g., Boudaud et al., A&A 575, 67 (2015)

[N.B.: no boost, Lavalle et al., A&A 479, 427 (2008)]

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SLIDE 9

Aguilar et al., PRL 115, 211101 (2015)

  • 2. Recent results: p, He, and B/C

Spectral break at ~ 350 GV for p and He Different slopes γp−γHe>0.1

Aguilar et al., PRL 114, 171103 (2015)

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SLIDE 10

Aguilar et al., PRL 115, 211101 (2015)

  • 2. Recent results: p, He, and B/C

→ Need to explore slope for other primary (C, O) and secondary (Li, Be, B) species

Spectral break at ~ 350 GV for p and He Different slopes γp−γHe>0.1 Asymptotically Kolmogorov

Aguilar et al., PRL 117, 231102 (2016) Aguilar et al., PRL 114, 171103 (2015)

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SLIDE 11
  • 2. Recent results: possible interpretations

N.B.: Different diffusion coefficient in the disk and halo

[self-generated turbulence vs pre-existing turbulence,

  • r different damping mechanisms in different medium?]

Aloisio et al., A&A 583, A95 (2015)

Many others explanations:

  • Secondary production at source (for positrons), single or multiple local sources, ...
  • Reacceleration, spiral arm structure, time and spatial discretness...
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SLIDE 12
  • 1. Introduction : GCRs, dark matter indirect detection
  • 2. Recent results and interpretation
  • 3. Research activities at LPSC and 2-year goals
  • Solar modulation
  • GCR interpretation
  • Dark matter indirect detection
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SLIDE 13

x 107

  • 3. Research activities at LSPC: GCR tools and studies

Galactic Cosmic Rays

1) Transport in the Galaxy

Time-dependent

size ~ 104 km ISS (h~400 km)

  • Atm. ~ 0 g cm-2

Balloon (h~40 km)

  • Atm. ~ 5 g cm-2

Neutron monitor (h<2 km)

  • Atm. ~ 600-1000 g cm-2

3) Earth magnetic shield 4) Top-of-Atmosphere to sea level

size ~ 30 kpc <t> ~ 20 Myr size ~ 100 AU <t> ~ few years

2) Transport in Solar cavity

Time-independent

x 105

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SLIDE 14

x 107

  • 3. Research activities at LSPC: CR database and φ (t)

Galactic Cosmic Rays

1) Transport in the Galaxy

Time-dependent

size ~ 104 km ISS (h~400 km)

  • Atm. ~ 0 g cm-2

Balloon (h~40 km)

  • Atm. ~ 5 g cm-2

Neutron monitor (h<2 km)

  • Atm. ~ 600-1000 g cm-2

3) Earth magnetic shield 4) Top-of-Atmosphere to sea level

size ~ 30 kpc <t> ~ 20 Myr size ~ 100 AU <t> ~ few years

2) Transport in Solar cavity

Time-independent

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CR database and φ time series (https://lpsc.in2p3.fr/crdb/): ~90000 requests from 90 countries Support F. Melot (service informatique)

  • A. Ghelfi (PhD thesis)
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SLIDE 15

x 107

  • 3. Research activities at LSPC: Cosmic-Ray DataBase

Galactic Cosmic Rays

1) Transport in the Galaxy

Time-dependent

size ~ 104 km ISS (h~400 km)

  • Atm. ~ 0 g cm-2

Balloon (h~40 km)

  • Atm. ~ 5 g cm-2

Neutron monitor (h<2 km)

  • Atm. ~ 600-1000 g cm-2

3) Earth magnetic shield 4) Top-of-Atmosphere to sea level

size ~ 30 kpc <t> ~ 20 Myr size ~ 100 AU <t> ~ few years

2) Transport in Solar cavity

Time-independent

x 105

  • A. Ghelfi, PhD thesis

Public codes

  • USINE, a propagation code
  • GreAT (http://lpsc.in2p3.fr/great),

an MCMC engine AMS-02 data interpretation

  • Origin of p/He anomaly
  • Two-halo propagation scenario
  • Impact of nuclear uncertainties
  • ...

Tomassetti (post-doc)

  • N. Tomassetti (post-doc)
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SLIDE 16

Angular resolution = 0.12° (HEALPix Nside=512) CLUMPY public code (http://lpsc.in2p3.fr/clumpy/)

  • V. Bonnivard (PhD thesis), C. Combet, M. Hütten (PhD student@DESY)

Triaxial dark matter halo Dark micro-halos Dwarf spheroidal galaxies

+

  • 3. Research activities at LSPC: γ-rays best targets and CTA

→ Best analysis for dwarf spheroidal ranking (crucial for Fermi-LAT constraints) → Ranking and stacking strategy for galaxy clusters (Fermi-LAT and CTA) → Dark clump sensitivity for CTA

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Stages M2 Theses Post-Docs Staff Pipex index

  • 3. Research activities at LPSC: evolution and goals

2017-2018

  • S. Aupetit (2015-18) : 50%
  • D. Maurin (CR) : 100%
  • C. Combet (CR) : 20%
  • J. Bregeon (visitor) : 10%

~2009-2012

  • A. Coulon (2011) : 50%
  • M. Vauthrin (2012) : 50%
  • A. Putze (2006-09) : 70%
  • B. Coste (2009-12) : 30%
  • D. Maurin (CR) : 100%
  • L. Derome (Prof.) : 20%

GCR: 5 pubs (260 citations) γ-rays: 6 pubs (166 citations) 2013-2016

  • V. Bonnivard (2013) : 50%
  • A. Ghelfi (2013) : 50%
  • V. Bonnivard (2013-16) : 70%
  • A. Ghelfi (2013-16) : 50%
  • S. Aupetit (2015-2018) : 50%
  • N. Tomassetti (2013-2016) : 50%
  • D. Maurin (CR) : 100%
  • C. Combet (CR) : 20%

GCR: 13 pubs (105 citations) γ-rays: 7 pubs (95 citations)

N.B.: co-supervised theses (within the group) analysis/phenomenology

+ UK/US/Germany/France collaborations

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SLIDE 18

Stages M2 Theses Post-Docs Staff Pipex index

  • 3. Research activities at LPSC: evolution and goals

2017-2018

  • S. Aupetit (2015-18) : 50%
  • D. Maurin (CR) : 100%
  • C. Combet (CR) : 20%
  • J. Bregeon (visitor) : 10%

~2009-2012

  • A. Coulon (2011) : 50%
  • M. Vauthrin (2012) : 50%
  • A. Putze (2006-09) : 70%
  • B. Coste (2009-12) : 30%
  • D. Maurin (CR) : 100%
  • L. Derome (Prof.) : 20%

GCR: 5 pubs (260 citations) γ-rays: 6 pubs (166 citations) 2013-2016

  • V. Bonnivard (2013) : 50%
  • A. Ghelfi (2013) : 50%
  • V. Bonnivard (2013-16) : 70%
  • A. Ghelfi (2013-16) : 50%
  • S. Aupetit (2015-2018) : 50%
  • N. Tomassetti (2013-2016) : 50%
  • D. Maurin (CR) : 100%
  • C. Combet (CR) : 20%

GCR: 13 pubs (105 citations) γ-rays: 7 pubs (95 citations)

N.B.: co-supervised theses (within the group) analysis/phenomenology

+ UK/US/Germany/France collaborations

Solar modulation → Better Solar modulation model + time-dependent AMS data GCR interpretation → B/C, Li, pbar, etc.: collaboration with LAPTh DM and γ-rays → Extragalactic contribution (M. Hütten 3 months visit)

  • S. Aupetit (PhD student)
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  • Physics problem: motion in a turbulent field
  • Ansatz: diffusion equation

Unknown vx,y, unknown position in δBx,y Pitch angle µ=cos(v,B0) Taylor-Green-Kubo formula

→ Can only be solved in ideal situations

  • Quasi-Linear Theory (δB ≪B): QLT
  • 2nd order QLT: SOQLT
  • Non-linear guiding centre: NLGC

Numerical simulations Analytical calculation

  • Mean free path
  • Fokker-Planck coefficient
  • Equation of motion (Lorentz)

Reality: resonant wave-particle interaction with stochastic motion... turbulence model requires:

  • Energy spectrum (diff.eq. for wave!): W k-s
  • Geometry
  • Dynamical behaviour
  • Instabilities
  • Damped waved
  • Intermittency

Diffusion in MHD turbulence

[Adapted from R. Tautz (CRISM 2014)]

GCR propagation: from microphysics to diffusion

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SLIDE 21

B amplification, compression ratios... (concave spectra, γ-ray emission... ?) Amato, IJMD 23, 130013 (2013) But so far, in almost all propagation models

  • Power-law or broken power-law (with cut-off at high energy)
  • No time-dependence in fluxes (except for highest energies)

GCR propagation: source description

Hybrid simulations (fluid e-, kinetic p) of collisionless shocks [from Damiano Caprioli, ICRC 2015]

Dhybrid code (Gargaté et al. 2007, DC & Spitkovsky 2014)

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SLIDE 22

Escape

GCR time scales and consequences

Leptons Nuclear component

Taillet & Maurin, A&A 402, 971 (2003) Maurin & Taillet, A&A 404, 949 (2003)

→ CR leptons at high energy are very local (few hundreds of pc) → Time-dependent/single source effects expected

Syrovatskii, Soviet Astronomy 3 (1959) 22 Shen, ApJ 162 (1970) 181 Boulares, ApJ 342, 807 (1989) Atoyan, Aharonian &Völk, PRD 52 (1995) 3265

[separate continuum from point-like contributions at 1 kpc]

Strong & Moskalenko, ApJ 509, 212(1998) wind escape

Atoyan, Aharonian &Völk, PRD 52 (1995) 3265

Primaries (e.g., 1H, 4He, C) µ source/diffusion µ R-(α+δ) Secondaries (e.g., 2H, 3He, B) µ primary/diffusion µ R-(α+2δ) → Secondary to primary ratio (e.g., B/C) µ R-δ Need to produce α>2! [see, e.g., Amato's review, IJMD 23, 130013 (2013)] Theory: α~2 (DSA), δ~1/3 or 0.5 (turbulence cascade) Observation: α+δ~2.8 → CR nuclei originate from a large volume (for sources) → Below a few GeV/n, heavy CRs depleted/closer w.r.t. light ones

β-decay (e.g. 10Be)