Future DM indirect detection in dwarf spheroidal galaxies and Foreground effect on the J-factor estimation Koji Ichikawa

Transcription

1 Future DM indirect detection in dwarf spheroidal galaxies and Foreground effect on the J-factor estimation Koji Ichikawa In collaboration with Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto and Hajime Sugai. BSM in Okinawa, OIST, March 3-7, 12016

2 Future DM indirect detection in dwarf spheroidal galaxies and Foreground effect on the J-factor estimation Koji Ichikawa In collaboration with Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto and Hajime Sugai. BSM in Okinawa, OIST, March 3-7, 22016

3 Future DM indirect detection in dwarf spheroidal galaxies and Foreground effect on the J-factor estimation Koji Ichikawa In collaboration with Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto and Hajime Sugai. BSM in Okinawa, OIST, March 3-7, 32016

4 Future DM indirect detection in dwarf spheroidal galaxies and Foreground effect on the J-factor estimation Koji Ichikawa In collaboration with Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto and Hajime Sugai. BSM in Okinawa, OIST, March 3-7, 42016

5 Future DM indirect detection in dwarf spheroidal galaxies and Foreground effect on the J-factor estimation Koji Ichikawa In collaboration with Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto and Hajime Sugai. BSM in Okinawa, OIST, March 3-7, 52016

6 Future DM indirect detection in Foreground dwarf spheroidal galaxies Stars Member and Foreground Stars effect on the J-factor estimation Koji Ichikawa In collaboration with Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto and Hajime Sugai. BSM in Okinawa, OIST, March 3-7, 62016

7 Thank You! Koji Ichikawa In collaboration with Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto and Hajime Sugai. BSM in Okinawa, OIST, March 3-7, 72016

8 Direct Detection Dark Matter Search Indirect Detection DM SM DM SM Collider Production 8

9 Indirect Detection Milky-Way Galaxy dsphs 100 kpc 10 Mpc Extra Galaxy/ Cluster 8.5 kpc Charged CRs 9

10 Dwarf spheroidal galaxies dsphs: 1. Satellite galaxies: d= 10~100kpc 2. Clean (no strong gamma-ray source) 3. DM rich dsph Type Ultra-faint Classical SDSS-II MNRAS, 406 (2010) 1220

11 Indirect = Strong Probe Current Sensitivity LHC 8 TeV

12 Indirect = Strong Probe Current Sensitivity LHC 8 TeV

13 Indirect = Strong Probe Current Sensitivity LHC 8 TeV 13

14 Indirect = Strong Probe Current Sensitivity LHC 8 TeV

15 Indirect = Strong Probe Current Sensitivity LHC 8 TeV

16 Signal Flux Dwarf galaxy γ-rays Observed γ-ray Flux DM Property Halo Profile (J-factor)

17 Astrophysical Factor (J-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., Astrophys.J. 801 (2015) 2 17

18 Astrophysical Factor (J-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 Phys.Rev. D89 (2014)

19 Astrophysical Factor (J-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 Classical: Well-determined Ultra-faint: Not well-determined. Prior dependence Phys.Rev. D89 (2014) Factor 1.6 ~ 2 unc. :Conservative? 19

20 Hidden Systematics of J-factor

21 Hidden Systematics of J-factor Prior Bias?/Cut? N < 100: > O(1) uncertainty Classical Ultra-faint Martinez et al., JCAP 0906 (2009) 014

22 Hidden Systematics of J-factor Prior Bias?/Cut? N < 100: > O(1) uncertainty Non Spherical? uncertainty By K. Hayashi-san (Preliminary) Bonnivard et al., MNRAS, 446 (2015)

23 Hidden Systematics of J-factor Prior Bias?/Cut? N < 100: > O(1) uncertainty Non Spherical? uncertainty Navarro et al., MNRAS, 402 (2010) 21 Etc (Velocity anisotropy, Halo truncation, stability)

24 Hidden Systematics of J-factor Prior Bias?/Cut? N < 100: > O(1) uncertainty 30 < NMem < 100 Non Spherical? uncertainty Bonnivard et al., arxiv: Etc (Velocity anisotropy, Halo truncation, stability) Foreground Contamination? N < 100: O(1) uncertainty N 1000: < 0.4 Bonnivard et al., MNRAS, 453 (2015) 1, Nmem 1000

25 Future Constraints 10 yrs Obs

26 Future Constraints 10 yrs Obs inc. UF /w dlogjuf = 0.5, 0.2?

27 Future Constraints 10 yrs Obs

28 Future Constraints 10 yrs Obs We Should Precisely Determine the dsph DM Halo

29 Future Constraints 10 yrs Obs How?-> Increase #Obs Stars!

30 Hidden Systematics Prior Bias?/Cut? N < 100: > O(1) uncertainty Non Spherical? uncertainty In the future Increasing #Obs Star can reduce these errors Etc (Velocity anisotropy, Halo truncation, stability) Foreground Contamination? N < 100: O(1) uncertainty N 1000: < 0.4 Remains! Q. How to treat this FG contamination?

31 Purpose Q. How many stars will be observed? Q. How can we obtain purer dsph member star data? Q. How can we include the FG contamination in the fit? 31

32 Prime Focus Spectrograph FoV 1.3 deg (diam) with 2394 Fiber MMFS (M. G. Walker et al,. (2007)) 32

33 Prime Focus Spectrograph FoV 1.3 deg (diam) with 2394 Fiber MMFS (M. G. Walker et al,. (2007)) 33

34 Set up 1. Mock Observable: dsph Stellar + Foreground dsph Stellar Mock Assign stellar information (Age, metalicity, luminosity, color, etc) Assign velocity and distance, (Boltzmann Equation under DM profile) FoV 1.3 deg (diam) Member Star with 2394 Fiber Mock Preliminary Foreground Mock Besancon Model (Robin+ (2003)) Foreground Mock Preliminary 2. Detector: Prime Focus Spectrograph Obs

35 Cut Strategy ROI Cut: 0.65 deg radius for 1 pointing velocity Cut vlower < v < vupper Surface Gravity Cut M/4πR 2 MT 4 /L (Luminosity)^(-1) Eliminate Darker Foreground Star Color Magnitude Cut Halo Star Thick Disk Thin Disk * Teff, Chemical Cut do not so efficient Current #Star Draco: 450 Ursa Minor: 300 Member Future Expectation Draco: 900 Ursa FG Minor: 1100 Chem. -> degenerate + 3-5% FG

36 Fit including FG model Member Fraction Prob. Dist. Of FG Member Parameter = halo information FG Parameter Can be considered to be Gaussian after several cuts. 36

37 Fit Results Contaminated (consider FG as Member star) 5% Contamination biases dlogj = ~ Overestimates sensitivity line ~ 2-3 times stronger Our Fit Ursa Minor case LogJ dlogj Ref (input) (Geringer-Sameth et al.,arxiv: ) Contaminated Out Fit Reproduce Ref val. Obs Stars Sum FG Mem

38 Summary Indirect detection is essential for O(1) TeV DM search. Gamma-ray observation of dsphs can give robust constraints ( 1TeV or More) if dlogj is small enough. Investigation of stellar kinematics (PFS) will play a crucial role. Reduction of foreground stars can be achieved by our cut and new likelihood. 38

39 Thank You! Koji Ichikawa In collaboration with Kohei Hayashi, Masahiro Ibe, Miho N. Ishigaki, Shigeki Matsumoto and Hajime Sugai. BSM in Okinawa, OIST, March 3-7,