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