Detecting Dark Matter in the X-ray

Transcription

1 Detecting Dark Matter in the X-ray Kev Abazajian University of Maryland Quantum 2 Cosmos 3: Airlie Center, July 8, 2008

2 The CDM Ansatz

3 Problems in Cold Dark Matter? Halo Substructure: satellite galaxies and sub-halos (Klypin et al 1999; Moore et al 1999) Halo Cores and Densities: (Moore 1994; Gilmore et al 2006) Void Galaxy abundances (Peebles 2001) Angular Momentum Problem (Navarro & Benz 1991; Sommer-Larsen & Dolgov 2001) Disk Dominated Galaxy Formation (Governato et al 2002)

4 Problems in Cold Dark Matter? Halo Substructure: satellite galaxies and sub-halos (Klypin et al 1999; Moore et al 1999) Halo Cores and Densities: (Moore 1994; Gilmore et al 2006) Void Galaxy abundances (Peebles 2001) Angular Momentum Problem (Navarro & Benz 1991; Sommer-Larsen & Dolgov 2001) Disk Dominated Galaxy Formation (Governato et al 2002) Is the Dark Matter slightly Warm?

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6 Dwarf Spheroidal Density Profiles from Radial Stellar Velocity Dispersion Dwarf spheroidals studied are consistent with NFW and cored profiles, except for UMi, only consistent with cored profile [Gilmore et al.,astro-ph/ ] Constant mass halo consistent with M/L-Luminosity relation CDM

7 Sterile Neutrinos Beyond the Standard Model of Particle Physics ν s Phenomenological Insertion of Majorana & Dirac Mass Terms of Comparable Magnitude (atmos. & solar) (e.g. Asaka et al 2006) νmsm ν s Left-Right Symmetric Models (Pati & Salam 1974; Mohapatra & Pati 1975) ν s ν s ν s Higher Dimensional Operators in String-Inspired models (Langacker 1998) Bulk Fermions in Large Extra Dimensions (ADD; Dvali & Smirnov 2000) Axino in R-parity Violating Minimal Supersymmetric Models (Chun & Kim 1999)

8 Sterile Neutrino Dark Matter Production t f s(p, t) Hp p f s(p, t) Γ(ν α ν s ; p, t)[f α (p, t) f s (p, t)] Γ/H T (MeV) Dodelson & Widrow (1994) Abazajian et al (2001) Abazajian (2006) Asaka et al (2006)

9 Sterile Neutrino Dark Matter Production Abazajian (2006) t f s(p, t) Hp p f s(p, t) Γ(ν α ν s ; p, t)[f α (p, t) f s (p, t)] Asaka et al (2006) Γ/H T (MeV) Dodelson & Widrow (1994) Abazajian et al (2001) Abazajian (2006) Asaka et al (2006)

10 Detecting the Dark Matter: Laboratory Limits Pion Decay in Flight Beta Decay

11 Detecting the Dark Matter: Laboratory Limits Pion Decay in Flight Beta Decay

12 Radiative Decay in the X-ray l - l - 2 W + 1 ν i ν j + γ E γ = m s 2 1 kev Pal & Wolfenstein 1981 Γ γ (m s, sin 2 2θ) = s 1 ( sin 2 2θ 10 7 ) ( ms 1 kev ) 5

13 Radiative Decay in the X-ray l - l - 2 W + 1 ν i ν j + γ E γ = m s 2 1 kev Pal & Wolfenstein 1981 Γ γ (m s, sin 2 2θ) = s 1 ( sin 2 2θ 10 7 ) ( ms 1 kev ) 5

14 Dark Matter Halos as Particle Reservoirs: Detecting Decaying Dark Matter particles

15 Dark Matter Halos as Particle Reservoirs: Detecting Decaying Dark Matter particles Signal: F dω [ DM density/distance 2] J[ Ω(θ)] 2π J [ Ω(θ)] = ρ s dφ 0 θ 0 [ xmax(θ ) sin θ x min (θ ) I[ r(x)] dx ] dθ I NFW [ r(x)] = I BUR [ r(x)] = 1 r(x) [1 + r(x)] 2 1 [1 + r(x)] [1 + r 2 (x)]

16 Dark Matter Halos as Particle Reservoirs: Detecting Decaying Dark Matter particles Background: X-ray continuum Compact Objects Instrumental Signal: F dω [ DM density/distance 2] J[ Ω(θ)] J [ Ω(θ)] = ρ s 2π 0 dφ θ 0 [ xmax(θ ) sin θ x min (θ ) I[ r(x)] dx ] dθ I NFW [ r(x)] = I BUR [ r(x)] = 1 r(x) [1 + r(x)] 2 1 [1 + r(x)] [1 + r 2 (x)]

17 X-ray Limits: Virgo and M31 (XMM-Newton) Watson et al (2006) Abazajian et al (2001)

18 X-ray Constraint Summary for DW Model XMM Newton: The Virgo Cluster Andromeda Galaxy: Watson et al 2006 ms < 3.5 kev Milky Way in CXB: Abazajian et al 2006 ms < 5.7 kev Coma + Virgo Clusters: Boyarsky et al 2006 ms < 6.3 kev Virgo Cluster: Abazajian et al 2001 ms < 8.2 kev X-Ray Background: Boyarsky et al 2006 ms < 8.9 kev

19 Chandra Deep Field: Milky Way Halo Limits from the Unresoved X-ray Background CDF-South Source Removal Hickox & Markevitch 2006, 2007

20 Milky Way Line Flux limits from the Chandra Deep Field of the CXB High DM mass MW: m s < 2.95 kev 3σ Low DM mass MW: m s < 5.74 kev 2σ (2σ) Abazajian, Markevitch, Koushiappas & Hickox 2007

21 The Soft X-ray Background sec X-ray calorimeter exposure on sounding rocket flight from White Sands, NM Using modern X-ray quantum calorimeters Resolution ~9 ev FWHM (McCammon et al., 2002)

22 The Soft X-ray Background: Spectrum Sterile Neutrino Line (60x MW Predicted) McCammon et al. (2002) Abazajian et al (2006)

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24 Constellation-X Observatory - Beyond Einstein

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27 How warm is too warm? Or, where does the CDM ansatz fail? Abazajian 2006 SDSS 3D P(k) Main Galaxies (Tegmark et al 2003) SDSS Lyman-alpha forest (McDonald et al 2005) High-Resolution Lyman-alpha forest (Viel, Haehnelt & Springel 2004) CMB: WMAP, ACBAR, CBI, VSA, BooMERANG-2K2

28 How warm is too warm? Or, where does the CDM ansatz fail? SDSS galaxy P g (k) Abazajian 2006 SDSS 3D P(k) Main Galaxies (Tegmark et al 2003) SDSS Lyman-alpha forest (McDonald et al 2005) High-Resolution Lyman-alpha forest (Viel, Haehnelt & Springel 2004) CMB: WMAP, ACBAR, CBI, VSA, BooMERANG-2K2

29 How warm is too warm? Or, where does the CDM ansatz fail? SDSS galaxy P g (k) SDSS Ly-α forest P F (k) Abazajian 2006 SDSS 3D P(k) Main Galaxies (Tegmark et al 2003) SDSS Lyman-alpha forest (McDonald et al 2005) High-Resolution Lyman-alpha forest (Viel, Haehnelt & Springel 2004) CMB: WMAP, ACBAR, CBI, VSA, BooMERANG-2K2

30 How warm is too warm? Or, where does the CDM ansatz fail? SDSS galaxy P g (k) SDSS Ly-α forest P F (k) LUQAS (VLT) Ly-α forest P F (k) Abazajian 2006 SDSS 3D P(k) Main Galaxies (Tegmark et al 2003) SDSS Lyman-alpha forest (McDonald et al 2005) High-Resolution Lyman-alpha forest (Viel, Haehnelt & Springel 2004) CMB: WMAP, ACBAR, CBI, VSA, BooMERANG-2K2

31 How warm is too warm? Or, where does the CDM ansatz fail? SDSS galaxy P g (k) SDSS Ly-α forest P F (k) LUQAS (VLT) Ly-α forest P F (k) Keck Ly-α forest P F (k) Abazajian 2006 SDSS 3D P(k) Main Galaxies (Tegmark et al 2003) SDSS Lyman-alpha forest (McDonald et al 2005) High-Resolution Lyman-alpha forest (Viel, Haehnelt & Springel 2004) CMB: WMAP, ACBAR, CBI, VSA, BooMERANG-2K2

32 The Lyman-alpha Forest (Croft et al 1999)

33 The Lyman-alpha Forest (Croft et al 1999)

34 Stringent Lyman-alpha Forest Constraints? m s > 14 kev m s > 9 kev Seljak et al 2006: WMAP1 + SDSS Pg(k) + Lya + HR Viel et al 2006: WMAP3 + CMB + 2dFGRS + SDSS Lya Both depend on the McDonald et al. (2006) SDSS PF(k) Measurement

35 Lyman-α Dependence on Thermal History CDM with a warmer thermal history can mimic WDM (and vice-versa) Thermal broadening of the line and a larger jeans smoothing scale Abazajian, Lidz & Dalal (in preparation) Keck HIRES data CDM WDM

36 Sterile Neutrino Dark Matter Summary Warm Dark Matter has become the standard alternate cosmological structure formation scenario, as it may resolve many problems in structure formation Sterile Neutrino Dark Matter is a natural, minimal WDM and CDM candidate Lower-limits mass from the Lyman-alpha Forest are dependent on the thermal history of the universe and uncertain Sterile Neutrino Dark Matter, in the standard production scenarios, is detectable or potentially excludable with Constellation-X satellite