Koji Ichikawa. (In preparation) TAUP, Torino, Sep. 7-11, 2015

Transcription

1 Koji Ichikawa (In preparation) In collaboration with Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto and Hajime Sugai. 1 TAUP, Torino, Sep. 7-11, 2015

2 Direct Detection Dark Matter Search Indirect Detection DM SM DM SM Collider Production 2

3 Signal Target Milky-Way Galaxy dsphs 100 kpc 10 Mpc Extra Galaxy/ Cluster 8.5 kpc Charged CRs 3

4 Current(slightly old) observational limit Wino DM annihilation cross section 4

5 Current(slightly old) observational limit Wino DM annihilation cross section 5

6 Current observational limit 6

7 Dwarf spheroidal galaxies dsphs: 1. Neighbor galaxies: 10~100kpc 2. Large Mass to Luminosity ratio = DM rich 3. Fewer gas containment Ultra-faint Classical SDSS-II arxiv: v6 [astro-ph.co] 7

8 Current observational limit 8

9 Current observational limit 9

10 Signal Flux Particle Physics Factor f WW, ZZ,, Z Error: 1-10 % level Astrophysics Factor (J-factor) Large uncertainty: Next Slide Hryczuk and Iengo (2012) arxiv: v4 [hep-ph] Cirelli et al. (2012) arxiv: [hep-ph] 10

11 Astrophysical Factor DM Density profile ( r / r s s ) (1 r / r s 1 s (1 r / r ) 1 s ) (1 r / r 2 s ) 2 Cusp Cored Stellar Density Profile: ν(r) Jeans equation for stars 2 (Theory) l.o.s Fit 2 (obs) l.o.s Geringer-Sameth et al., arxiv:

12 Astrophysical Factor DM Density profile ( r / r s s ) (1 r / r s 1 s (1 r / r ) 1 s ) (1 r / r 2 s ) 2 Cusp Cored Stellar Density Profile: ν(r) Jeans equation for stars 2 (Theory) l.o.s 2 (obs) l.o.s Fit Classical: Well-determined Ultra-faint: Not well-determined. Prior dependence Conservative? 12

13 Hidden Systematics Prior Bias?/Cut? Draco Segue1 ex: Martinez et al., arxiv: Non Spherical? => uncertainty Foreground Contamination? Member Star Sampling Bias? Bonnivard et al., arxiv: Geringer-Sameth et al., arxiv:

14 Hidden Systematics Prior Bias?/Cut? Draco Segue1 ex: Non Spherical? => uncertainty Martinez et al., arxiv: Axisymmetric Hayasi and Chiba., arxiv: Foreground Contamination? Member Star Sampling Bias? Bonnivard et al., arxiv:

15 Prime Focus Spectroscopy FoV 1.3 deg (diam) with 2394 Fiber MMFS (M. G. Walker et al,. (2007)) 15

16 Prime Focus Spectroscopy FoV 1.3 deg (diam) with 2394 Fiber MMFS (M. G. Walker et al,. (2007)) 16

17 #Obs Star (<V) #Obs Star (<V) by M. Ishigaki Prime Focus Spectroscopy More accurate DM profile estimation More Robust constraints

18 Strategy 1. Mock Observable: (R, v, Metalicity, Luminosity) = dsph Stellar + Foreground dsph Stellar Mock Boltzmann Equation under DM profile Foreground Mock Besancon Model (Robin+ (2003)) 2. Detector Convolution: 1. fix: dv = 3.0km/s 3. Fit: (DM profile, anisotropy, dsph stellar profile, dsph v, foreground norm + metalicity) Fit to (v, r) probability density. 18 Walker+, AJ 137 (2009)

19 Strategy 1. Mock Samples ρdm(r), νstar(r) => f(r,v) Cuddeford (1991) 1. Mock Observable: (R, v, Metalicity, Luminosity) = dsph Stellar + Foreground dsph Stellar Mock Boltzmann Equation under DM profile Foreground Mock Besancon Model (Robin+ (2003)) 2. Detector Convolution: 1. fix: dv = 3.0km/s 3. Fit: (DM profile, anisotropy, dsph stellar profile, dsph v, foreground norm + metalicity) Fit to (v, r) probability density. 19 Walker+, AJ 137 (2009)

20 Strategy Fit without Foreground 1. Mock Observable: (R, v, Metalicity, Luminosity) = dsph Stellar + Foreground dsph Stellar Mock Boltzmann Equation under DM profile Foreground Mock Besancon Model (Robin+ (2003)) 2. Detector Convolution: 1. fix: dv = 3.0km/s 3. Fit: (DM profile, anisotropy, dsph stellar profile, dsph v, foreground norm + metalicity) Fit to (v, r) probability density. 20 Walker+, AJ 137 (2009)

21 Prob. Density Strategy 2. Foreground Besancon Model 1. Mock Observable: Robin+ (2003) (R, v, Metalicity, Luminosity) = dsph Stellar + Foreground dsph Stellar Mock 3. Fit Boltzmann Equation under DM profile Foreground Mock Besancon Model (Robin+ (2003)) 2. Detector Convolution: 1. fix: dv = 3.0km/s 3. Fit: (DM profile, anisotropy, dsph stellar profile, dsph v, foreground norm + metalicity) Fit to (v, r) probability density. Obs 21 Walker+, AJ 137 (2009)

22 Prob. Density Strategy 2. Foreground Besancon Model 1. Mock Observable: Robin+ (2003) (R, v, Metalicity, Luminosity) = dsph Stellar + Foreground dsph Stellar Mock 3. Fit Boltzmann Equation under DM profile Foreground Mock Besancon Model (Robin+ (2003)) 2. Detector Convolution: 1. fix: dv = 3.0km/s 3. Fit: (DM profile, anisotropy, dsph stellar profile, dsph v, foreground norm + metalicity) Fit to (v, r) probability density. Ursa Minor Like 700 w FG Obs N = True 22 Walker+, AJ 137 (2009)

23 Foreground Contamination Outer Region = FG dominant How to Reduce FG stars? ~ 10 % Contamination Cut: 1. Velocity The most effective 2. Color Not Bad 3. Chemical Component Degenerate 4. Others? 23

24 Foreground Contamination Outer Region = FG dominant How to Reduce FG stars? ~ 10 % Contamination Cut: 1. Velocity The most effective 2. Color Not Bad 3. Chemical Component Degenerate 4. Others? 24

25 Foreground Contamination Outer Region = FG dominant How to Reduce FG stars? ~ 10 % Contamination Cut: 1. Velocity The most effective 2. Color Not Bad 3. Chemical Component Degenerate 4. Others? 25

26 Foreground Contamination Outer Region = FG dominant How to Reduce FG stars? ~ 10 % Contamination Cut: 1. Velocity The most effective 2. Color Not Bad 3. Chemical Component Degenerate 4. Others? 26

27 Foreground Contamination Outer Region = FG dominant How to Reduce FG stars? ~ 10 % Contamination Cut: 1. Velocity The most effective 2. Color Not Bad 3. Chemical Component Degenerate 4. Others? 27

28 Summary Indirect detection is essential for DM search. Gamma-ray observation of dsph can give robust constraints on the DM annihilation cross section. Investigation of stellar kinematics is important. PFS will play a crucial role. 28

29 Thank You! Koji Ichikawa In collaboration with Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto and Hajime Sugai. 29 TAUP, Torino, Sep. 7-11, 2015

30 Back up 30

31 V V-I M. G. Walker et al,. (2007) J. D. Simon et al., (2011) 31

32 32