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

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

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

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

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

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

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

Indirect = Strong Probe Current Sensitivity LHC 8 TeV

Indirect = Strong Probe Current Sensitivity LHC 8 TeV 13

Indirect = Strong Probe Current Sensitivity LHC 8 TeV

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

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

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) 042001 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 Fit 2 (obs) l.o.s Classical: Well-determined Ultra-faint: Not well-determined. Prior dependence Phys.Rev. D89 (2014) 042001 Factor 1.6 ~ 2 unc. :Conservative? 19

Hidden Systematics of J-factor

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

Hidden Systematics of J-factor Prior Bias?/Cut? N < 100: > O(1) uncertainty Non Spherical? 0.2 0.4 uncertainty By K. Hayashi-san (Preliminary) Bonnivard et al., MNRAS, 446 (2015) 3002-3021

Hidden Systematics of J-factor Prior Bias?/Cut? N < 100: > O(1) uncertainty Non Spherical? 0.2 0.4 uncertainty Navarro et al., MNRAS, 402 (2010) 21 Etc (Velocity anisotropy, Halo truncation, stability)

Hidden Systematics of J-factor Prior Bias?/Cut? N < 100: > O(1) uncertainty 30 < NMem < 100 Non Spherical? 0.2 0.4 uncertainty Bonnivard et al., arxiv:1506.08209 Etc (Velocity anisotropy, Halo truncation, stability) Foreground Contamination? N < 100: O(1) uncertainty N 1000: < 0.4 Bonnivard et al., MNRAS, 453 (2015) 1, 849-867 Nmem 1000

Future Constraints 10 yrs Obs

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

Future Constraints 10 yrs Obs

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

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

Hidden Systematics Prior Bias?/Cut? N < 100: > O(1) uncertainty Non Spherical? 0.2 0.4 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?

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

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

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

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

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

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

Fit Results Contaminated (consider FG as Member star) 5% Contamination biases dlogj = ~0.3-0.5 Overestimates sensitivity line ~ 2-3 times stronger Our Fit Ursa Minor case LogJ dlogj Ref (input) 19.03 +0.27-0.19 (Geringer-Sameth et al.,arxiv:1408.0002) Contaminated 19.30 0.07 Out Fit 19.10 0.12 Reproduce Ref val. Obs Stars Sum FG Mem

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

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, 39 2016