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Indirect detection of Dark Matter with gamma-rays - status & outlook
Jan Conrad
Oskar Klein Centre
Stockholm University
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)
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09-08-07 Jan Conrad, Stockholm Universitet
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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.,
...
09-08-07 Jan Conrad, Stockholm Universitet
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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 ……
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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Census of relevant gamma-ray experiments
HESS
MAGIC
CANGAROO
VERITAS
MILAGRO
AMS
AGILE
Fermi
AGIS
CTA
HAWC
future exp.
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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The Galactic Center
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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Dwarfs, Dark Matter satellites and Galaxy Clusters.
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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Dwarfs probed in gamma-raysH.E.S.S. MAGICFermi Veritas
H.E.S.S. in prep.
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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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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09-08-07 Jan Conrad, Stockholm Universitet
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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:
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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09-08-07 Jan Conrad, Stockholm Universitet
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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.
Fermi-LAT: Phys.Rev.Lett.104:101101,2010
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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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.
Fermi-LAT: Phys.Rev.Lett.104:091302,2010
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
09-08-07 Jan Conrad, Stockholm Universitet
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TeVE 1@%10~)(
%5~)(E
Cherenkov Telescope Array (CTA)
22-24 m10-12 m ~7m
%105~)( E
03.0~)(
2018
09-08-07 Jan Conrad, Stockholm Universitet
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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!
09-08-07 Jan Conrad, Stockholm Universitet
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Lines
CTA preliminary
(based on HESS type analysis of CTA simulation of the GC)
09-08-07 Jan Conrad, Stockholm Universitet
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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
09-08-07 Jan Conrad, Stockholm Universitet
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….. or ….
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