ma4: high-energy astrophysics critical situation of manpower : 1 person! only «free research»...
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MA4: HIGH-ENERGY ASTROPHYSICS
• Critical situation of manpower : 1 person!• Only «free research» based in OAT.• Big collaborations based elsewhere (Fermi, CTA,
MAGIC).• Competition/cooperation with INFN.• Collaborations: local: F. Longo (Trieste U.) A. De Angelis et al. (Udine U.) int’l: Y. Rephaeli (Tel Aviv, UCSD)
MAGIC, CTA,Fermi/LAT
NT particles, SF gal’s
Particle Acceleration
MacroArea 4: High Energy Astrophysics & AstroparticlesMassimo Persic
bremsstrahlungsynchrotron
Inverse Compton
Radiation Processes
4
rate of particles productionper unit volume of coord space
by definition:
energy lossfor particles of energy E
energygains / losses
diffusion
Diffusion-Loss Equation
Ne(g) = Ne,0 g-q g1 £g£g2
electron spectrum
synchro-Compton
MP, Rephaeli & Arieli 2008, A&A, 486, 143Rephaeli, Arieli & MP 2010, MNRAS, 401, 473MP & Rephaeli 2010, MNRAS, 403, 1569MP & Rephaeli 2013, A&A, to be submitted
Up from g-rays … directly from protons!
Cosmic Rays in Galaxies
Do electrons trace protons?
Coulomb
bremsstrahlung
p/e ratios
particle/field energy density equipartition
e.g., Schlickeiser 2002 MP & Rephaeli 2013
Up from electrons
Magnetic field
electrons trace protons
Equipartition + theor motivated p/e ratio ok
Energy gain timescale ~ ~ Energy loss timescale ~~ SF timescale
Application to high-z gal’s?
Ground Based γ-ray Astronomy
Current Status of VHE Ap
• The current generation of telescopes (H.E.S.S. / MAGIC / VERITAS) have detected >100 sources.
• Several more with HESS2 / MAGIC2 / upgraded VERITAS
Stellar WindsSupernova RemnantsPulsar Wind NebulaeBinary SystemsMolecular CloudsGalactic CentreNo Counterpart/Dark Sources AGN
Constraints on EBLConstraints on QGCR Electron Spectrum
Regular observations made between 70 GeV-20 TeV with few % Crab sensitivity
Science PotentialDistance kpc Mpc Gpc
Blazars (~60)SNR/PWN (~30)
Binaries (4)Radio Gals. (4)
Pulsed (1)
Starbursts (2)
ClustersCollidingWinds
Flux
Current
CTA
Sensitivity
DMGRBs
Current instruments have passed the critical sensitivity threshold and reveal a rich panorama, but this is clearly only the tip of the iceberg. What big science questions remain?
DM
Big Science Questions Left to Next-Generation Instruments
• Determining– Origin of galactic cosmic-rays– Whether γ-ray binaries emit via wind/jet
• Studying– Star formation regions– Pulsars and PWN – Studying Physics of AGN Jets– Galaxy clusters: the dark side of structure formation
• Constraining – Extragalactic Background Light – Quantum Gravity Energy Scale
• May detect WIMP annihilation• Dark sources / New source classes
CTA tech wish list
• Higher Sensitivity at TeV energies (x10)Deep Observations More Sources
• Higher Detection AreaGreater Detection Rates Transient Phenomena
• Better Angular ResolutionImproved morphology studies Structure of Extended Sources
• Lower Threshold (some 10 GeV)Pulsars, distant AGN, source mechanisms
• Higher Energy Reach (PeV and beyond)Cutoff region of galactic acceleratorsSources of UHECRs?
• Wide Field of ViewExtended Sources, Surveys
tyuujunas hjv
CTA sensitivity
Expected Design Study Results
• Detailed knowledge of characteristics, availability of a few good site candidates.
• Array layout which optimises physics performance for a given cost (and which is about 1 order of magnitude better than we have now).
• Detailed design and industrial cost estimates for telescopes and associated equipment
• Plan how to organise, produce, install commission, operate the facility; estimate for operating cost
• Model and prototype how to handle and analyse the data• Small prototype series of common components, to ensure
that production issues and costs are understood.
CTA Design started !
Possible CTA sites
CTA: In ContextSpace-based instruments only
UV | X-ray | g-ray | VHE g-rayoptical
10-11
10-12
10-13
10-14
10-15
10-16
nF n (
erg
cm-2
s-1)
1 eV 1 PeV1 TeV1 GeV1 MeV1 keV
Energy
Fermi GST
Integral
XMM
HST
Mor
e se
nsiti
ve
Current Instruments