Astroparticle physics

3. Supernovae, neutrinos and high energy cosmic-rays

in the local Universe

Alberto CarramiñanaInstituto Nacional de Astrofísica, Óptica y Electrónica

Tonantzintla, Puebla, México

Xalapa, 9 August 2004

Iben (1967)

Post main sequence

M 8 M

• Hydrogen burning He core + H burning shell + envelope

• Helium burning:

– Explosive He core burning (previous He flash) CO white dwarf (M < 2.25 M)

– Stable He burning CO core + He burning shell + He layer + H burning shell + envelope (M > 2.25 M)

Post Main Seq. M > 8 M

• Nuclear processes:– He burning (108 K)

together with

– neutrino cooling (dominant from 5108 K)

– carbon burning (6108 K)

– oxygen burning (109 K)

• CO flash ignition SN (I½ probably! and Ia by accretion) for not so massive stars

The path to the Iron catastrophe• Above 8 M: onion structure

degenerate iron core• Succesive reactions (Si, S, Ar, ...):

less energy per nucleon.• Enhanced emission:

• Photodisintegration

• Electron capture:

Arnett, Bahcall, Kirschner & Woosley (1989)

Arnett, Bahcall, Kirschner & Woosley (1989)

Core collapse

• For an isothermal star supported by a non relativistic degenerated gas:– electron degeneracy – neutron degeneracy

• Electron absorption loss of e-degeneracy pressure core collapse in free-fall time (v 70,000 km/s)

• Infall halts at 81014 g cm–3 nucleus rebound.

Supernova explosion

• Bounce creates an upward prompt shock (stalled by inward shock! ).

provide required energy to continue (delayed shock)

• Initial shock temperature explosive Fe peak nucleosynthesis

0.08-0.40 M of 56Ni

SN 1987A

SN 1987A• Feb 23.316, 1987• The brightest in 383 yrs• In LMC (D 50 kpc).

• Intrinsically faint M=-15.5 (“only” 109 L)

• Blue giant precursor Sk–69 202, M 1622 M, core 5 7 M

0.07 M of 56Ni 56Co

Neutrinos from SN1987A

• First observational evidence of neutron star formation

• Observed by at least two experiments.

• Neutrinos from bounce (1% in 20 ms) and from cooling (99% in few s)

Arnett, Bahcall, Kirschner & Woosley (1989)

Neutrino properties from SN1987A

• Neutrino mass 16 eV• Neutrino charge

• Lifetime

• Same speed and geodesics for neutrinos and photons (within 10-8)

The local group of Galaxies

Cosmic-ray all energy spectrum

• Power-law:

• Secondaries (B) have steeper spectra than primaries (C,O).

k = 2.7

k = 3.0

k = 2.8

15/27

Cosmic-rays: propagation• Cosmic-rays do not propagate in straight lines:

trapped by Galactic magnetic field (average 3G)

• Transport equation:– Leaky box model:

• CR travel path:

• Proton injection spectrum:

– 10Be (mean life 3.9 Myrs) analysis: (Garcia-Muñoz, Mason & Simpson 1977)

Cosmic-rays below

the knee

• Knee: 1015 eV when:– a h(disc)– Theoretical

sources loose efficiency

• Directional information?

Cosmic-ray sources: limits

• Few sources with enough energetics

Waxman, astro-ph/0310079

GZK limit

Greisen-Zatsepin –Kuzmin (1966)

Or no GZK limit?

20/27

The local Universe

• Normal and radio galaxies.

Nearby cosmic rays?

Galactic halo? Concentrations of galaxies in the nearby Universe (red) and voids (yellow); if the cosmic rays were coming from radio galaxies or quasars we would expect some bias towards these directions. Hillas (1998)

4% anisotropy above 1e18 eV (AGASA experiment)

Extragalactic -ray sources

• Blazars (“radio loud flat spectrum AGNs”)

• Typically at high redshifts (z2).

Active Galaxies

• AGN zoo:– Starburst– Seyferts & radio galaxies– Quasars, BL Lacs

• AGN standard model:– accreting supermassive black hole

(106 to 109 M)

– AGN type depends on orientation

-ray blazars

• Over 50 extragalactic EGRET sources:– BL Lacs & FSRQ (z=0.03 to 2.3)

• Closest: Mk 421 (@120 Mpc), 2230+114 (@ 280 Mpc),

– Radiogalaxy Cen A (@ 6 Mpc)

– Spectra cannot show 0 bumps (GLAST?)

• Synchrotron Self-Compton models: hadronic & leptonic

25/27

TeV detections

• Mk 421: the nearest EGRET FSRQ (@120 Mpc)

• Mk 501: nearby FSRQ, undetected by EGRET

• Both up to 10 TeV

• GZK-like limit? FIR background...

The GZK problem

• High energy cosmic-rays must be extragalactic.• High energy cosmic-rays must come from

nearby (less than 50 Mpc).• No obvious sources within GZK distance

– unless all HECRs come from Cen A (and simils...)– unclear anisotropy / point source situation...

• Top-down scenario?

The Pierre Auger ObservatoryThe Pierre Auger Observatory