e+ + e-(atic, FERMI, HESS, PAMELA) e-, p drown in cosmic rays?

Transcription

1 Indirect Dark Matter Signatures for Dark Matter Annihilation Annihilation products from dark matter annihilation: Gamma rays (FERMI -> arxiv: v1) Positrons (PAMELA, arxiv: ) Antiprotons (PAMELA) Neutrinos (Icecube, no results yet) e+ + e-(atic, FERMI, HESS, PAMELA) e-, p drown in cosmic rays? Wim de Boer, Karlsruhe ERICE International School, September

2 Expansion rate of universe determines thermal relic annihilation cross section Thermal equilibrium abundance Comoving number density I G. Steigman Actual abundance II III T=M/22 x=m/t I: T>>M: f+f->m+m; M+M->f+f II: T<M: M+M->f+f III:T=M/22 M decoupled, stable density (wenn annihilation rate expansion rate, i.e. =< v>n (x fr ) H(x fr )!) WMAP -> h 2 = /< v>-> < v>= cm 3 /s DM increases in Galaxies: GeV WIMP/coffee cup 10 5 <ρ>. DMA ( ρ 2 ) restarts again.. Only assumption: WIMP = STABLE THERMAL RELIC! Note: annihilation cross section 10 orders of magnitude larger than upper limit on scattering x-section on nuclci, AS PREDICTED BY SUPERSYMMETRY Wim de Boer, Karlsruhe ERICE International School, September

3 PAMELA Positron excess confirmed with new data and new analysis Pamela, arxiv: v1 Wim de Boer, Karlsruhe ERICE International School, September

4 Origin? Depends on whom you ask! My assumption: Data>= a p-> 0 Background> + a DMA DMA> + a sec SNR> + a local SNR(x)> + a pulsar Pulsar> Unitarity must be fulfilled. However, each component has enough uncertainty to saturate observations For details: WdB, AIP Conf.Proc.1200: ,2010. arxiv: [astro-ph.co] Wim de Boer, Karlsruhe ERICE International School, September

5 AMS: large magn. spectrometer with redundant particle ID Wim de Boer, Karlsruhe ERICE International School, September

6 AMS to be installed on ISS Schedule: Transport with ST-134 Space Shuttle Flight in Feb Testflight 1998 Wim de Boer, Karlsruhe ERICE International School, September

7 AMS-02 from CERN to Cape Canaveral on Loading the 7.5 tons at Geneva airport Wim de Boer, Karlsruhe ERICE International School, September

8 Antiprotons GALPROP Antiprotons Donata et al. [ ] Gebauer and WdB B,arXiv: Pamela GALPROP (with and without) convection has deficit of antiprotons. Darksusy and others (which only look into charged particles, no gamma rays) can saturate data. Wim de Boer, Karlsruhe ERICE International School, September

9 FERMI measures GeV gamma rays + electrons e + e Wim de Boer, Karlsruhe ERICE International School, September

10 EGRET (predecessor from FERMI) excess disappeared? Only latitudes between 10 and 20 degrees considered Egret excess DM? WdB et al., A&A 444:51,2005. astro-ph/ FERMI-LAT Coll., arxiv: v1, 8 Feb 2010 Wim de Boer, Karlsruhe ERICE International School, September

11 FERMI Coll. Wim de Boer, Karlsruhe ERICE International School, September

12 Data driven analysis of FERMI gamma ray data (publicly available from NASA archive) Idea: Fit known shapes of 3 main components: Inverse Compton:(IC) CR electron density x ISRF Bremstrahlung:(BR) CR electron density x gas density P CR P Gas scattering:( 0 ) CR proton density x gas density Main unknowns: CR electron density CR proton density (both measured locally, i.e. at a single point in Galaxy) Alternative to data driven analysis: compare data with Galactic Propagation Model Best publicly available model: GALPROP (Moskalenko,Strong Wim de Boer, Karlsruhe ERICE International School, September

13 Fitted background in broad agreement with GALPROP Proto on CR density scale Longitude Wim de Boer, Karlsruhe ERICE International School, September

14 Fitted background in broad agreement with GALPROP Elect tron CR density scale Longitude Wim de Boer, Karlsruhe ERICE International School, September

15 2 much improved by adding DM 2/d.o.f. Longitude Wim de Boer, Karlsruhe ERICE International School, September

16 FERMI diffuse spectra from Galactic centre without DMA with DMA 0+IC+BR DMA 60 GeV neutralino Wim de Boer, Karlsruhe ERICE International School, September

17 Wim de Boer, Karlsruhe ERICE International School, September

18 What is DM haloprofile? Given DM contribution in 960 directions, can one determine haloprofile? Procedure: i) assume haloprofile ii)normalize to rotation curve iii) calculate l.o.s. of gamma rays in 960 directions iv) find optimum haloprofile parameters by minimum 2 Result: 1) NFW haloprofile for diffuse DM (>90% of mass) with boostfactor 1 and signal 2 + 2) clumpy halo profile with Einasto profile ( 5% of mass and signal + 3) two doughnut like ring structures with few % of mass Wim de Boer, Karlsruhe ERICE International School, September

19 FERMI provides DM contribution in all directions-> HALO PROFILE = NFW (diffuse)+ Einasto (clumps) (expected from N-body simulations) inner ring outer ring Motivation for outer ring : Monocerus ring of stars (SDSS, 2002), discussed as tidal disruption of Canis Major dwarf AND gas flaring Motivation for inner ring : dust ring Wim de Boer, Karlsruhe ERICE International School, September

20 Halo density on scale of 300 kpc Sideview Topview Cored isothermal profile with scale 4 kpc fits FERMI data (as EGRET, but 6x smaller boost factor) Wim de Boer, Karlsruhe ERICE International School, September

21 Halo density on scale of 30 kpc Sideview Topview FERMI data best fitted with 2 doughnut-like rings at 4 and 14 kpc. Mass in inner (outer) ring 0.3 (3)% of total DM Wim de Boer, Karlsruhe ERICE International School, September

22 Rotation curve Milky Way Weber, The esis, KIT Weber, db, arxiv: VLBI point Oort limit on local density prevents larger DM contr. (Hipparcos data Wim de Boer, Karlsruhe ERICE International School, September

23 VERA: VLBI Exploration of Radio Astrometry Japan VLBI = Very Large Baseline Interferometry allows very precise parallax measurements. Maser light from Molecular Clouds allows large distance interferometry Measured parallax of as at distance of >5 kpc over 1 yr-> rotation velocity A. Honma et al, PASJ 2007, Astrometry of Galactic Star-Forming Region Sharpless 269 with VERA:Parallax Measurements and Constraint on Outer Rotation Curve at 13 kpc Wim de Boer, Karlsruhe ERICE International School, September

24 Inner Ring coincides with ring of dust and H 2 -> gravitational potential well! H 2 Dust ring at 4 kpc 4 kpc coincides with ring of neutral hydrogen molecules! H+H->H 2 in presence of dust-> grav. potential well at 4-5 kpc. Wim de Boer, Karlsruhe ERICE International School, September

25 The Milky Way and its satellite galaxies Canis Major Tidal force ΔF G 1/r 3 Wim de Boer, Karlsruhe ERICE International School, September

26 Tidal streams of dark matter from CM and Sgt CM Sun Sgt From David Law, Caltech Wim de Boer, Karlsruhe ERICE International School, September

27 N-body simulation from Canis-Major dwarf galaxy Obs served stars R=13 kpc prograde Canis Major (b=-15 0 ) retrograde Wim de Boer, Karlsruhe ERICE International School, September

28 Canis Major Dwarf orbits from N-body simulations to fit visible ring of stars at 13 and 18 kpc Movie from Nicolas Martin, Rodrigo Ibata Canis Major leaves at 13 kpc tidal stream of gas(10 6 M from 21 cm line), stars (10 8 M,visible), dark matter (10 10 M, Fermi data) Wim de Boer, Karlsruhe ERICE International School, September

29 Gas flaring in the Milky Way P M W Kalberla, L Dedes, J Kerp and U Haud, arxiv: no ring with outer ring Mass in ring few % of total Gas flaring needs also outer ring with mass of M! Wim de Boer, Karlsruhe ERICE International School, September

30 Summary Indirect search for DM annihilation in interesting era: PAMELA shows excess for positrons (but conventional sources can explain) Fermi shows excess of gamma rays w.r.t GALPROP (consistent with DMA) HOWEVER, FERMI DATA PREL. WAIT FOR NEXT REPROCESSING WITH BETTER BG REJECTION FOR ANY CONCLUSION AMS expected to start data taking next year for ALL charged particles up to TeV range AND gamma rays simultaneously-> expect better understanding of Galaxy However, indirect DM searches indirect, hope to find signal with confirmation from LHC or direct DM searches Wim de Boer, Karlsruhe ERICE International School, September