Résumé (très partiel) des confs d’été « astro »

IRFU/SPP27 septembre 2010

Résumé (très partiel) des confs d’été « astro »

IRFU/SPP27 septembre 2010

• Ondes gravitationnelles : non couvertes• Cosmo : pas de nouveaux faits marquants, cf. Moriond Cosmo 2010

Rayons cosmiques

3

Fermi electron spectrum: low energy part• 1 year of data• Spectrum from 7 GeV up to 1 TeV• Compatible wit a power law of index -3.08 +/- 0.05

4

Significance of deviations from the

mean rate.• No significant anisotropy is

observed in the CR electron flux.• The results can rule out

dominance of a very bright nearby source.

• Analyse en coursJohnson, ICHEP 2010

Arrival directions of ~TeV protons

5

• Hot spots observed in both Milagro and ARGO with high significance• Harder spectrum (flattering)• Nearby CR accelerator … with non-standard

diffusion parameters!• No compelling explanation found yet Open issue!

Talk Omodei ICHEP 2010

water Cherenkov detector

MILAGRO

Single layer of resistive plate counters

ARGO-YBJ

Two regions of excess 15.0 and 12.7(7 yr data taking)

584 days

Auger’s sky (E>5x1019 eV)Evolution of degree of correlation

• After publication in 11/2007, correlation degree dropped from 69% to 38%• 0.3% probability to find such a correlation from an isotropic distribution

6Kampert, ICHEP 2010

UHECR composition

• Compositions between HiRes and Auger do not seem to agree…Compositions between HiRes and Auger do not seem to agree…• HIRES and AUGER are seeing different sky?• Modifications of cross sections at highest energies? Increasing p-Air X-section could

bring down Xmax• RMS of Xmax large..

7Farrar, ICHEP 2010

Matière Noire

8

Résultats de Xenon 100et WIMP “basse masse” (1)

• Xe double phase• Run préliminaire : 11 jours, volume actif 40kg • Pas d’indication en faveur des événements CoGeNT? tout dépend de la calibration de L_eff …

9

Talk Sadoulet Blois 2010

Résultats de Xenon 100et WIMP “basse masse” (2)

• Normalisation de Leff: +/- 30%• CoGeNT pourrait ne pas être exclu• Xe coll. prend une moyenne ponderee pour Leff

10

t Systematique importanteà basse energie

Talk Sachuman IDM 2010

CRESST : evts à basse energie

• For small WIMP mass, only O recoils above threshold• 32 events in the O band• Expected bck ~9 (neutrons+alpha+gamma leakage)• Compatible with a ~10 GeV WIMP• Waiting for details on background rejection…

11Talk Seidel IDM 2010

• CaWO4 crystals: scintillation/heat • threshold 10 keV• ~400 kgd

Comment abaisser le seuil pour Xenon ?

• Donnees de Xenon 10

• Seuil limité par le premier signal de scintillation

Utilisation de S2 seulement : seuil~1keVr

~pas de pouvoir de rejet

12

Talk Sorensen IDM 2010

PRELIMIN

ARY

Limites d’exclusion été 2010:spin-independent cross section

• Edelweiss II 2009: 144 kg.day

• Edelweiss II prel. : ~300 kg.day (Apr 09 – May 10) - 3 evts pres du seuil

- ~ 5 x 10-8 pb

• New prototype FIDs now working at LSM

13Talk Armengaud IDM 2010

x 2

Limites d’exclusion été 2010:spin-dependent cross section

• DM searches towards the Sun

• IceCube DeepCore (6 additional lines) 20 GeV energy threshold

• Competitive SD limits wrt direct detection

14Talk Danninger TeVPA 2010

Fermi : search for DM spectral lines• 11 months of data• ROI: b>10 and 20x20 around GC• Galactic plane and point sources excluded• Sources removed for b > 10No line detection

• NO line

15Talk Conrad IDM 2010

Energy resolution : 10% at 100 GeV

Example fit for a 40 GeV line

signalbck

95% CL upper limits

Galactic Halo Dark Matter Limits (|b|>10) from Fermi

• The diffuse flux from the Galactic halo can be used to set limits on dark matter annihilation.

– Relies on differences in the angular and spectral distributions of the diffuse production from cosmic rays versus dark matter.

– Still very preliminary. The constraints are very sensitive to the choice of the Galactic diffuse model. Investigations are still in progress of the dependence of the result on our astrophysical models of the Galaxy (e.g the CR source distribution, halo height, diffusion coef. etc.). R.P. Johnson

16

unpublished

CR source distributionfrom Case&Battacharya 98

Halo size

PRELIMINARY

Canis Major

o

Observed by FermiObserved by HESS

Dwarf galaxies

Fermi limit

Excluded (95% CL)

Glicenstein’s talkJohnson’s talk

7/28/1017

Talk Omodei ICHEP 2010

Sculptor dwarf (Preliminary)FERMI HESS

Fermi : Cosmological Dark Matter

3/15/2010 R.P. Johnson18

The isotropic extragalactic contribution have be interpreted in terms of limits on cosmological dark matter [Dark matter annihilation in all halos at all red-shifts should contribute]

Assuming a power-law model for astrophysical background

DM could supply all the photons in a given bin

DM structure evolution scenarios Models of absorption by EBL

JCAP04 (2010) 014

Astro neutrinos: diffuse flux • Energy estimator= Repetition (R) of

integration gate on the same Optical Module

• Rejection of downward going atmospheric muons (using measured zenith angle, track quality parameter, number of hits)

• Separation of the atmospheric background from signal using the energy estimator R

19

E2(E)90%= 4.7×10-8 GeV cm-2 s-1 sr-1

20 TeV<E<2.5 PeV

Upper limits on diffuse neutrino emission

Talk Spurio ICHEP 2010

Gamma-rays

20

Galactic Diffuse Emission

• The first Fermi-LAT publication on the galactic diffuse spectrum is in disagreement with the EGRET spectrum.

• In particular, there is no obvious “GeV excess” with respect to standard models of the diffuse production from cosmic rays.

ICHEP 2010 R.P. Johnson21

Fermi isotropic gamma-ray background• 1 year Femi LAT data, |b|> 10deg. • Derivation of the isotropic gamma-ray

flux (believed to be primarly extragalactic)

by reducing and understanding the residual CR background.• Guaranteed contribution: unresolved

extragalactic sources: blazars, star forming and star burst galaxies,...

• Spectrum featureless• Consistent with powerlaw : -2.41

22

• Some inconsistency with previous measurements by EGRET.

• Higher energy reach.

Fermi gamma-ray haze

23Talk Dobler TeVPA 2010

• Gamma-ray overdensity in the inner Galaxy

• Spectrum consistent with a the IC emission of a hard population of electrons on interstellar radiation• Morphology : elongated in b with respect to l• DM? It doesn’t look like..• Local source of electrons?

Fermi gamma-ray haze

24

Recap: after known foregrounds are subtracted, an excess appears in the residual maps within the inner ~20 around the Galactic Center

[GeV-TeV electrons emit hard synchrotron in the frequency range of WMAP]

Talk Dobler TeVPA 2010

• Gamma-ray overdensity in the inner Galaxy

• May be the IC counterpart to the WMAP haze

• Similar spatial morphology to the WMAP haze supporting the synchrotron interpretation of the microwave signal

22 GHz

“WMAP haze”

Fermi AGN stacking• 170 AGN (>4.1s) stacked (improved statistics!)• Expected photon maps from P6_v3 IRF (pre-launched estimate)• Excess! But…

25

• Official Fermi statement : PSF broader than expected at high energy• Corrections underway to fix the MC issue• “in-flight” PSF released soon Talk Ando TeVPA 2010