Indirect detection of Dark Matter with gamma-rays - status & outlook

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Indirect detection of Dark Matter with gamma-rays - status & outlook

Jan Conrad

Oskar Klein Centre

Stockholm University

[email protected]

09-08-07 Jan Conrad, Stockholm Universitet

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Intro

2

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EYvPPP

W-/Z/q

W+/Z /q

0

Will consider generic WIMP, no specific models (except otherwise stated), no axions, for example

Indirect detection rate = (particle physics part) × (astrophysical part)

PPP APP

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Signatures I

Z,

Ullio et al. Phys.Rev.D66:123502,2002

Bringmann et al. JHEP 0801:049,2008. Birkedal et al.,

...


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What happened since the last IDM?

From Johann Cohen-Tanugi IDM 2008 GLAST -talk

”A wealth of exciting science from GLAST very soon!”

… not true …. Fermi did allright though ……


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... what else happened ?

+

+ =

PAMELA, Nature 458:607-609,2009Fermi-LAT, Phys.Rev.Lett.102:181101,2009

PAMELA, Phys.Rev.Lett.102:051101,2009

” leptophilic models”

Bergström et al.,Phys.Rev.Lett.103:031103,2009

see Lavalle’s talk yesterday


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Signatures II: the come-back kid: IC

• Motivated by PAMELA/Fermi light lepton results.

• Interaction/backreaction of light lepons on surrounding radiation gives rise to broad-band spectrum – in particular IC gamma-rays.

Profumo & Jeltema, JCAP 0907:020,2009Colafrancesco et al, Astron.Astroph.455:21,2006

No time to talk about spatial signatures: see J. Siegal-Gaskins talk


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Census of relevant gamma-ray experiments

HESS

MAGIC

CANGAROO

VERITAS

MILAGRO

AMS

AGILE

Fermi

AGIS

CTA

HAWC

future exp.


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Gamma-rays: sensitvitiy overview

%10~)(E

%15~)(E

Large FOV

AGIS

Fermi:

ACTs:

Water Cherenkov

%100~)(E

ACT/Fermi: angular resolution (0.10) at high energies

(WC: ~0.5)

CTA/CTA-US 2018


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Targets + Fermi publications

Fermi-LAT: TeVPA 2009, arXiv:0912.3828 Goodenough & Hooper, arXiv:0910.2998 Dobler et al., arXiv:0910.4583

Fermi-LAT: Astrophys.J.712:147-158,2010Fermi-LAT: JCAP 1005:025,2010 Scott et al.: JCAP 1001:031,2010 Buckley & Hooper, arXiv:1004.1644

Fermi-LAT: Phys.Rev.Lett.104:091302,2010

Fermi-LAT: JCAP 1004:014,2010 Akorvazian et. al. arXiv:1002.3820 Huetsi et. al. arXiv:1004.2036

Cirelli et. al. arXIv: 0912.0663


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The Galactic Center


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• H.E.S.S: updated position, energy spectrum and DM constraints (see Daniil Nekrassov’s talk).

• Fermi:– LAT 1 FGL J1745.6-2900 consistent with

H.E.S.S. source (i.e. Sgr A* and PWN 359.9)– (does not exclude SNR Sgr A east).

The GC in >GeV gamma-rays

e.g. J. Cohen-Tanugi (Fermi-LAT), Fermi Symposium 2009

~ 0.4 deg


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Fermi Galactic Centre

• Analysis:– Unbinned likelihood– 11 month (front converting)– 7x7 deg ROI– Model

• Gal. Diffuse (GALPROP)• Isotropic• Point sources (1 FGL)

Residuals under investigation

- Galactic diffuse emission?

- effective area systematics?

- NB: DM seems unlikely

e.g. V. Vitale (Fermi-LAT), RICAP 2009


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Dwarfs, Dark Matter satellites and Galaxy Clusters.


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Fermi-LAT: Search for Dark Matter satellites

• Search for DM clumps– Steady– Extended– Non-power-law (DM)– No counterparts.

• Fermi –Search– b > 10o

– No counterpart– Spatially extended– Spectrum consistent with DM spectrum– Constant emission– Threshold 5σ

No detection in 10 month of data (consistent with expectations)

e.g. P. Wang, TeVPA 2009

See also D. Hoopers talk


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Dwarfs probed in gamma-raysH.E.S.S. MAGICFermi Veritas

H.E.S.S. in prep.


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Analysis details

Exposure

(hours)

Background

DM distribution

Fermi 11 month

(~ 1500 h)

Diffuse/

Point sources

Empirical NFW

H.E.S.S. 11 (SgrD)

10 (Canis M.)

wobble Empirical NFW

Theo. NFW

VERITAS ~15 (Willman, Bootes)

~19 (Draco, Ursa Min)

wobble Empirical NFW

MAGIC 16 (Willman I)

8 (Draco)

wobble Empir. NFW

Empir. core/cusp Kazantzidis

see Viana’s talk.

see Wagner’s talk


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Dwarfs

HESS Sag (cusped)

HESS Canis M

MAGIC Draco, Willman

See M. Llena -Gardestalk (Friday).

VERITAS Willman

Stacked Fermi dwarf

(more robust!) (Doesn’t include Segue

10-26


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Also dwarfs can be used to say something about Leptophilics

Fermi-LAT: Astrophys.J.712:147-158,2010

10-2510-2510-24


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B-field

Galactic diffuse emission

Radiation field

Gas

e

p

Gas

π0 γγ π± e±

B-field

p-bar,

brems

π± e±

sync

h IC

Li, B

Diffusion

reacceleration

convection

energy loss

spallation

decay

CNO

π0 γγDM

To some: To us:


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Fermi halo emission• Use spatial and spectral features in an

multicomponent likelihood fit work in progress

Cirelli et. al. arXIv: 0912.0663

conservative (no background)

caveat.: no e+/e- diffusion

Decaying DM exlcuded for all but muonic decays

See Andersson, Cuoco, Zaharijastalks

10-24


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Halo: H.E.S.S.• Approach 1: Slightly off- GC center

observation (b~2o), with an off source (b ~8o) away from GC.

• Approach 2: Drift scan mode

• Would be the most sensitive analysis if systematics can be controlled.

see Nekrassovs talk

uses Aquarius

boost factor


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The Fermi isotropic gamma-ray background

• Infer the isotropic gamma-ray emission by multi-component fit.

• Consistent with powerlaw (-2.41)

• Estimates:– EGB– Cosmic rays– Quasi-isotropic

galactic contributions.



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Cosmological WIMPs

N.B. Considerable quasi-isotropic contribution from halo substructure is possible.

Fermi-LAT: JCAP 1004:014,2010

see Zaharijas talk


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Fermi-LAT: constraints for cosmological WIMPs

Only resolved

Extrapolated to 1e-6 sol. M


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Spectral features


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Fermi line analysis

• Unbinned profile likelihood with background model from data, signal model is energy dispersion of the LAT.

• ROI: b>10 and 20x20 around GC

• Sources removed for b > 10.


T. Ylinen, PhD thesis, StockholmNon public energy reco

10-27


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Summary of line emission constraints

EGRET: Pullen at al, Phys.Rev.D76:063006,2007 H.E.S.S: Ripken, PhD thesis, Hamburg U.

EGRET

GC (binned)

Fermi

HESS

GC (binned)

100 h

UX1 lines

IDM lines

Mambrini, JCAP 0912:005,2009 Gustafsson et al, PRL,99:041301,2007

MSSM


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What does it look like next-to-next IDM?

Fermi 5 yr combined dwarfs

Fermi 5 yr halo, no substructure

Grey: indicating diffuse bg range.

H.E.S.S. 50 h halo, (Aquarius substructure) or Dwarf stacking?

10-27 …. with some work and ideas ….+ energy range, event selection

(Fermi) + news from othe exps. AMS,LHC(?)

Fermi 1 yr dwarfs


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TeVE 1@%10~)(

%5~)(E

Cherenkov Telescope Array (CTA)

22-24 m10-12 m ~7m

%105~)( E

03.0~)(

2018


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What can CTA do - conservatively

CTA halo (~100h)

(if halo sensitivity improvment comparable to Sag dwarf improvement)

Aquarius

CTA Sag, NFW, 20 h (based on CTA Design study simulations). NB: 5 σ

PRELIMINARY!


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Lines

CTA preliminary

(based on HESS type analysis of CTA simulation of the GC)


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Conclusions & Final remarks.

• Who ordered the Galactic Centre?

• Strongest constraints to be expected from the halo if systematics can be controlled. Dwarf stacking might be preferable: similar constraints, less systematics?

• Keep an eye on Fermi UNIDs.

• Fermi is going strong and there are some interesting results in the pipeline.

• MAGIC II operational, H.E.S.S II coming up, too.

• Pamela/Fermi CR excess: DM origin essentially ruled out by gamma-rays.

• For next-to-next IDM: going to cut ”deep” into annihilation cross-section space.

• Further down the road: CTA


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….. or ….

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Indirect detection of Dark Matter with gamma-rays - status & outlook