massimo persic inaf/infn-trieste magic collaboration gev-tev prospects & results issues : ...
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Massimo PersicINAF/INFN-Trieste
MAGIC Collaboration
GeV-TeV prospects & resultsIssues:Origin & diffusion properties of Galactic CRs: Main accelerators: SNRs? Diffusion: measure it?
Galaxies: massive SFR
AGNs: variability, SED, EBL
GRBs: SED, emission
pulsars: emission region
Clusters of galaxies: NT side of structure formation
Galaxy halos: DM
Massimo PersicINAF-INFN TriesteMAGIC Collaboration
SNR shell particle accelerationResolved shell in VHE--rays -rays from leptonic or hadronic
channels?
SNR RX J1713.7-3946
Aharonian+ 2006
Berezhko & Völk 2006
H.E.S.S.
3EG J1714-3857
B=100Ghadronic channel favored
leptonic channel fav’d
Leptonic: Ee ~ 20 (E )1/2 TeV ~ 110 TeV … but KN sets on .. ~100 TeV Hadronic: Ep ~ E/ 0.15 ~ 30 / 0.15 TeV ~ ~ 200 TeV
... but: is SN statistics enough to fit CR energy density?
HESS J1813-178
Hadronic: 2M of target gas, exp-cutoff proton distrib: =2.1, E
c=100 TeV,
np=6cm -3, L(0.46 TeV)=2.5E+34erg/s
Leptonic: B=10mG, exp-cutoff electron distrib: =2.0, Ec=20TeV
D = 4 kpc
???MAGIC
AGILEFermi LAT
VHE -rays: hadronic or leptonic ?
Albert+ 2006
IACT
GeV data solve TeV spectral degeneracy CRp normalization
ABBA
index ~ (strong shock)little variation across SNR
Aharonian + 2006
GeV+TeV spatially resolved spectroscopy young SNRs (t<tcool (p,e)):CRp spectrum = 1+2 + b
measure (p) as a function of p
= p b … b~0.6 ?
from B/CNO ratiofrom VHE from radio
GalaxieGalaxiess
Arp 220
Integrated view of VHE em. from massive SF: acceleration, diffusion, energy loss
F(>0.1 TeV) ~~ 2 x10-12 cm-2s-1
F(>100 MeV) ~~ 10-8 cm-2s-1
MAGIC or VERITAS:hundreds of hours
Fermi LAT: first-year scan
M82: most promising candidate
MP, Rephaeli & Arieli 2008diffusion-loss eq. solved
Crab pulsar: detection First detection of pulsed emission at >25 GeV.Searches going on for ~35 years!!
EGRET + MAGIC: pl * exp [–E/16.3 GeV)] pl * exp [–(E/20.7 GeV)2]
at least for Crab pulsar,
polar cap scenario challengedMore psr obs’s: ms pulsars?
Active Galactic Nuclei
IACTFermi AGILE
Mrk 421Mrk 421
MAGIC MAGIC
3C454.3z=0.859
Jul/Aug & Nov/Dec 2007
AGILE trigger(S+E)SC modelGhisellini+ 2007
PG 1553+113(?)
AGILEMAGIC
Fermi
March/April 2008
First ever simultaneousHE+VHE -ray obs of a blazar!
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• Target-of-Opportunity (ToO) obs’s: high states
• trigger in other (AGILE, Fermi; x: Swift, Suzaku; optical: KVA)
• simultaneous mwl observations:
• evolution of emitting particle population– emergy-dependent evolution in time
• Monitoring obs’s: low states
• in several • check quiet emission of blazar
• properties of steady-state particle spectrum– emergy-dependent evolution in time
Limitless possibility for IACT follow-up?
Cross section (differ.):
Optical depth:
eeEBLHE TeV : Esoft : E ~ 1TeV
max for ~0.5 eV (~2m, K-band)
Heitler 1960
Stecker+ 2006
EBEBLL
IBL absorption
Slkkkàkàk-lknStecker 1999
Hauser & Dwek 2001
x=1+cos
Franceschiniet al. 2008
Measuring EBL(z).
Tools: sources with sound modeling & minimum number of parameters BLLacs!?(l.o.s. orientation, jet-only emission, single-zone SSC).
1) Based on GeV data, set up a list of BLLacs whose predicted VHE flux is detectable with IACTs. Populate redshift space (out to z ~ 1) as closely as possible.
2) For each BLLac source, obtain simultaneous well-sampled mwl SEDs (at optical, X-ray, HE, and VHE frequencies) corresponding to different source states (low, high). This amounts to having several SEDs at each given z. Since in such SEDs the Compton peak typically occurs in the EBL-unaffected region <100GeV, using HE data the SSC model can be closed with substantially no EBL-induced bias. Hence, the SSC model in the VHE region (>100 GeV) is known and can be assumed to represent the intrinsic VHE source spectrum. Contrasting it with data (measured between photon energies E1 and E2), we obtain nEBL(z) at redshift z and in the energy interval between, locally at redshift z, 0.5/[E2(1+z)] eV and 0.5/[E1(1+z)] eV.
3) Repeating procedure (2) with different SEDs (i.e.: different sources, or same source in different emission states) at the same z, in principle we should obtain consistent determinations of the EBL. In practice, we will reduce the statistic error affecting each determination of nEBL(z).
4) Selecting BLLac objects progressively farther away, we will measure EBL at different z. By repeating steps (2),(3) we will in principle obtain measures of nEBL(z) -- out to z ~1.
Gamma-Ray Bursts (GRBs)Most energetic explosions since Big Bang (1054 erg if isotropic)
Astrophysical setting unknown (hypernova?)
Emission mechanism unknown (hadronic vs leptonic, beaming, size of emitting region, role of environment, … … )
Cosmological distances (z >> 1) but ... missed naked-eye GRB 080319B (z=0.937)
Gggg
HE+VHE data crucial to constrain/unveil emission mechanism(s)
----------------------------
HESS
MAGIC
MAGIC ST
GRBs 080319B missed obs of “naked-eye” GRB
Intrinsically:Nearby: z=0.937Brightest ever observed in opticalExceedingly high isotropic-equivalent in soft -rays
Swift/BAT could have observed it out to z=4.91m-class telescope could observe out to z=17
Missed by both AGILE (Earth screening) and MAGIC (almost dawn)
next BIG ONE awaited !!
Galaxy Clusters
Targets: Draco, Willman-I, Segue gals.
2. DRACO dSph2. DRACO dSph
Milky Way surrounded by small, faint companion galaxies
- dSph’s very DM-dominated objects.- Distances, M/L ratios 16<D/kpc<250 kpc, 30<M/L<300
DRACO dSphhigh
M/L>200d~80 kpc
Northern source MAGIC ok !!
Draco dSph: modeling
cusped profile
cored profile
total DM annihil. rate
N: -rays / annihil.-ray flux
-ray flux
Av>, m: WIMP annihil. cross section, mass
d~80 kpc
rs = 7 – 0.2 kpc0 = 107 – 109 Mž kpc-3
02 rs
3 = 0.03 – 6 Mž2 kpc-3
Bergström & Hooper 2006
upper limit
MAGIC40-h exp.
Fermi1-yr exp.
IACT neutralino detection: <Av> 10-25 cm3s-1
Bergström & Hooper 2006
max. cusped
min. cored+-
W+W-
ZZ
bbt t
__
Stoehr + 2003unid’d GeV sky brightness fluct’sto be followed up a TeV energies
Draco dSph obs’d MAGIC arXiv:0711.2574
7.8 hrMay 2007
m0 > 2 TeV … < (DMDM)WMAP=0.113m0 > 2 TeV … < (DMDM)WMAP=
m0 2 TeV … < (DMDM)WMAP=0.113m0 2 TeV … (DMDM)WMAP=0.09751
Probing Quantum Gravity
Mrk 501: Jul 9, 2005
GeV+TeV: wide spectral coverage to observe Galactic-environment phenomena useful to solve long-standing issues about CRs.
SNRs, molecular clouds HE+VHE emission mechanism, energy-dependent diffusion.
GRBs, star-forming galaxies SFR(z)
Galaxy clusters NT side of structure formation
Pulsars measure magnetosph. emission cutoff
AGNs solve (S+E)SC model of AGNs measure EBL(z) probe short-time variability as function of E simultaneous mwl monitoring of low-state ToO obs’s of high states
DM halos depending on m, decay channels, central density, distance
Outlook
Thanks!