Dark matter constraints from dwarf spheroidals

Transcription

1 Dark constraints from dwarf spheroidals Savvas M. Koushiappas Based on

2 Based on

3 Constraints from Dwarf Galaxies: Usual approach problem 1. Construct a oretical model in principle characterizes background 2. Compute signal/noise ratio ( place bound) DEC (deg) his.tmp1_0 35 Coma Berenices Background at this source 30 Computed by how much one understs this Very difficult! RA (deg)

4 This work Main assumption: Whatever processes are give rise phon events nearby each dwarf, se same processes are also at work in direction dwarf.

5 This work Main assumption: Whatever processes are give rise phon events nearby each dwarf, se same processes are also at work in direction dwarf. DEC (deg) his.tmp1_0 35 Coma Berenices Background at this source Same as here RA (deg)

6 This work Main assumption: Whatever processes are give rise phon events nearby each dwarf, se same processes are also at work in direction dwarf. Berge et al., AA 466, 1219 (2007) Not new: - Particle physics - Cerenkov telescopes Fig. 4. Count map γ-ray-like events from 5 hours H.E.S.S. observations a 2005d). Note that data were taken in wobble mode around targetpositionwi Alex Geringer-Sameth & Koushiappas, PRL The 107, ring-(left)reflected-region-(right)backgroundmodelsareillustratedsche (2011) Signal Background Gamma MC 1

7 Data - 3 years FERMI public data - PASS 7 phon events - Energy range: [1-100] GeV (dictated by size PSF--more on this later) - 7 Dwarf galaxies (Bootes I, Draco, Fornax, Sculpr, Sextans, Ursa Minor & Segue 1)

8 Gamma-ray flux Total Number phons along direction a dwarf PP = h vi 8 M 2 N Quantity interest µ( PP ) Exp PP J + Background Derive empirically Dark distribution SYSTEMATIC Uncertainty (See Louie Strigari s talk)

9 Background determination Mask sources present in 2nd Fermi Catalogue x

10 Background determination 400 independent ROI x

11 Multi-dimensional Neyman Construction Prob(counts PP) Likelihood PP 95% Counts Counts cou

12 Multi-dimensional Neyman Construction Prob(counts PP) Likelihood PP 95% Upper limit 95% Counts Measurement Counts cou

13 Combining observations dwarfs ϕpp measurement ϕpp counts Dwarf B counts Dwarf B counts Dwarf A counts Dwarf A counts

14 Combining observations dwarfs ϕpp Belts ϕpp counts Dwarf B counts Dwarf B counts Belt Dwarf A counts Dwarf A counts

15 Combining observations dwarfs ϕpp Belts ϕpp counts Dwarf B counts w / J Dwarf B counts Belt Dwarf A counts Dwarf A counts See Sutn, Classical Quantum Gravity, 26, (2009)

16 Result True 95% upper bound PP = cm 3 s 1 GeV 2 h vi = 8 N PP M 2

17 Result True 95% upper bound PP = cm 3 s 1 GeV 2 h vi = 8 N PP M 2 f Choose channel f

18 Result For h vi = cm 3 /s See also Steigman et al. arxiv: b b M!b b > GeV + M! > GeV See also Ackermann et al. PRL 107, (2011), Manoj Kaplinghat s talk after this one.

19 Result Major Caveat J enters as a systematic Charbonnier et al. arxiv: Ackermann et al. arxiv:

20 Where do se limits fit in big picture? 7 Direct detection Indirect detection 3 7 tea II simulation favor a somewhat Via Lactea II simulation favor a somewhat ults Via simulation favor a somewhat slope 1.2) [26], while Aquarius nner ( Lactea while 1.2)II[26], Aquarius eper ainner slope 1.2) [26], while Aquarius what less steep( value varies nds somewhat less steep value varies yielding velocity-independent spin-independent scattering, but p-wave suppressed. An example 7 2 such an operar would+ be (1/M )X X q q, in case τ τ where is a fermion. Anor example sults avia Lactea IIless simulation favor a somewhat oject finds somewhat steep value varies Relicbe abundance would (1/M 2 X q µ q, if ]. bb is a eeper inner slope ( 1.2) [26], while Aquarius th r [27]. complex scalar. Dark coupling through se oproject finds a somewhat less steep value invaries considering distribution he distribution in erars could potentially explain low-mass data When considering Way, ith r [27]. loparsecs Milky it isdistribution importantin DAMA, CoGeNT XENON10/100, but would be unntral kiloparsecs Milky Way, itare isimportant Milky Way, it is important he effects stars gas, not taken When considering distribution in constrained by Fermi-LAT dwarf spheroidal search. lude effects stars gas, are not taken stars gas, are not taken entral kiloparsecs Milky Way, it issuch important unt by -only simulations as Via As with gamma-ray bounds, bounds from o account by simulations such as Via -only clude effects stars gas, are not taken Aquarius, but gravita dominate -only simulations such as Via anti-pron flux can also be weakened eir by but dominate gravitactea II Aquarius, account by -only simulations such as Via p-wave suppressed, or by light mediaential Inner Galaxy. Generally speaking, us, but dominate gravitanal potential Inner Galaxy. Generally speaking, actea II Aquarius, but dominate gravitars. Such models matching CoGeNT, DAMA t dissipating baryons, density Inner Galaxy. Generally speaking, a result dissipating baryons, density onal potential Galaxy. Generally speaking, XENON10/100 data would be unconstrained by bounds re expected be Inner adiabatically contracted, resting a result dissipating baryons, density iles are expected be adiabatically contracted, from BESS-Polar II. baryons, density steepening ir inner priles [28]. Thereriles expected be adiabatically contracted, rethe -pron scattering cross-section ting inare steepening manifest ir inner priles [28]. The be adiabatically contracted, re this effect is depends on ulting in steepening ir inner priles [28]. The needed match low-mass direct detection data can be gree baryons this is manifest depends on f thateffect dissipate slowlythe by radiative ing ir inner priles [28]. egree this effect is manifest depends on shifted by or particle Massphysics (GeV)or astrophysics uncerction baryons that dissipate slowly by radiative FIG. 6: The range annihilatio action baryons that dissipate slowly by radiative tainties, such as uncertainties in masses nuclear m facr effect is manifest depends on Galactic FIG. oling. center 6: The range masses cross sections s can accoun ooling. FIG. 2: Favored regions exclusion conurs in FIG. The range distribution masses near or 6: in velocity earth. rodynamical simulations model Hooper proation Neyman confidence belt construcsas that dissipate slowly by radiative cross sections s can account Linden arxiv: (mhydrodynamical with fn /f 0.7. The solidproblack& simulations model majority 95% observed residual emission betwee X, p ) plane IVDM p = cross sections s FIG. 2: Derived limit on can v account as funct To normalize with all upper observations, here we ahave A As hydrodynamical simulations model proaxy mation have improved, efts predict Isospin Violeting DM generate upper limits on. Each axis reppp majority observed residual emission between + chan line is bound from this analysis at 95% CL, assuming cen used majority halo observed residual emission MeV GeV, three s galaxy mation have improved, efts predict6: 300 FIG. The range 10 masses mass in bb between ve. stard model choices calculate WIMP ess galaxy mation have improved, efts predict Kumar, Sand & Strigari, arxiv: Galaxy Clusters smber baryons have begun converge. In partic events that could be observed from a + + tral values satellite density prile. 300 MeV 10 GeV, three choices chan300 MeV 10 GeV, three choices channels ( lepns denotes equal fractions ethis, systemat µ µ an locity distribution (e.g. [32]); variations from model eral effects baryons have begun converge. converge. In partic-sections shaded area 95-percentile ecan cross reflects s account + he effects baryons begun In partic+ e+ + Han et al. arxiv: groups (using different codes) havedwarf consis+ ere, Dwarf A has ahave larger J value than B nels ( lepns denotes equal fractions e, µ µ simulations model pronels ( lepns denotes equal fractions e e, µ µ certainty may ). a ect Also shown comparison is cro results presented, especially mass ar, groups (using different codes) have consisconsisinshown distribution high dwarfs ar,several several groups (using codes) have ++ majority observed residual emission between ). Also shown comparison is cross nd that Milky Way sized halos are adiabatically ). Also comparison is cross aded area, bordered by solid line, represents section predicted a simple rmal relic ( v = 326WIMP 10 on have improved, efts halos predict targets [33]. 26 ntly found that Milky Milky are adiabatically canonical cross section a rmal ntly found that Way sized halos are adiabatically Alex Geringer-Sameth & Koushiappas, PRL 107, (2011) section predicted a simple rmal relic ( v = section predicted a simple rmal relic ( v = MeV 10 GeV, three choices chano, bounds would be tighter by a facr 2). Also d,belt increasing density PP ir value. The in dashed R a particular cm Note thabserved researches. is a facr There a few uncertainty in th are interesting 3 /s). 3 Complementary ontracted, increasing in ir have begun converge. In particing up tal abundance is sho ntracted, increasing density in ir + + cm /s). Note that re is a facr a few uncertainty in cm /s). Note that re is a facr a few uncertainty in shown are confidence DAMA [1] (3values, assumorders belts di erent umes relative signal thatregions predicted by nels ( lepns denotes fractions low-mass e e, µ µoverall dar cross section, corresponding constraints on equal mat- CDMS-Si (SUF) CDMS-Ge (SUF) CDMS-Ge (Soudan) XENON100 (2011) XENON10 (2011) SIMPLE (2011) CRESST (2011) DAMA (Savage et al.) CoGeNT (2010) CoGeNT (2011) Monday, May 7, 12 ner volumes relative that that predicted ner volumes relative predicted by by - corresponding detail overall dashed cross line.section, The inset figure shows lower m

21 Phon energy distribution spatial inmation Spectrum dn de PSF P ( )d Alex Geringer-Sameth & Koushiappas, In Preparation (2012)

22 Conclusion Current indirect detection constraint from dwarf galaxies: Stay tuned results at high-energy regime from joint analysis dwarfs using VERITAS.