Cosmological Backgrounds of
Neutrinos, Photons,
And Gravitational Waves
 Supernovae as neutrino and gravitational wave sources
Günter Sigl
GReCO, Institut d’Astrophysique de Paris, CNRS et
Fédération de Recherche Astroparticule et Cosmologie, Université Paris 7
http://www2.iap.fr/users/sigl/homepage.html
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
Onion structure of a supernova
Janka, Mueller
Convection, turbulence
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
Supernovae as Neutrino and Gravitational Wave Sources
Anisotropic mass motion and neutrino emission in massive star collapse leads
to gravitational wave emission. At low frequencies neutrino emission with
luminosity Lν(t) and anisotropy q(t) dominates and leads to
dimensionless strain at distance D:
2GN
h(t ) 
D
t D
 dt  L (t )q(t )
memory h(t)

fh( f ) 

f 0
L(t)
h(t  )
2
q(t)
A rotating core collapse model by Müller & Janka
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
≥100Msun PopIII
2x10-3 Msun in gw, <q>~3%
ordinary SN
10-8 Msun in gw, <q>~0.5%
gravitational wave spectra
neutrino spectra
Simulated individual signals
Individual supernovae (SN) in our Galaxy can give prominent signals
in neutrinos in Super-Kamiokande, Amanda, ICECUBE, Uno… and in
gravitational waves in Virgo/EGO, LIGO…, but are RARE events.
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
The background is then given by integration over all events
The Gaussianity of the signal is given by the “duty factor” which is proportional
to the event rate:
Where τ(f) is the time scale over which frequency f is emitted “coherently”
In a given event. For us: τ(f)~1/f
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
However, backgrounds from cosmological SN may soon be detectable
by gadolinium upgrade of Super-K in neutrinos and by gravitational wave
detectors such as the Big Bang Observatory (BBO).
SN rate
Ordinary SN ~ 1/sec
+ very massive PopIII stars
at z ≥ 15 with rate
~ 0.2 (fIII/10-3)/sec,
where fIII = baryon fraction
cycled thru PopIII stars.
future input from SWIFT…
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
=>
diffuse neutrino spectra from ordinary
SN close to current sensitivities
stochastic gravitational wave background
Ando and Sato, astro-ph/0410061
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Buonanno, Sigl, Raffelt, Janka, Mueller,
Phys.Rev.D 72 (2005) 084001
Günter Sigl, Astroparticules et Cosmologie, Paris
Pop III fraction of baryons fIII and infrared
background resulting from Lyα emission
Dwek et al., astro-ph/0508262
Madau, Silk., astro-ph/0502304
Diffuse infrared background can not be explained by
galaxies alone -> may need a Pop III contribution
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
Fate of a massive star as function of progenitor mass and metallicity
Heger et al., astro-ph/0211062
low metallicity: less cooling, larger progenitor masses,
less mass loss, more powerful explosions.
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
Fate of a massive star as function of progenitor mass and metallicity
Heger et al., astro-ph/0211062
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
Compare this with upper limits, sensitivities, and cosmological predictions
BBO
BBO correlated
SN and PopIII
Giovannini
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
Consequence:
Gravitational Wave Background from type II supernovae and PopIII stars
could mask inflationary background
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris
Conclusions
There is a deep connection between neutrino and gravitational
wave emission by collapsing massive stars. Both signals have
good chances to be seen by future experiments.
ILIAS/N5-N6 meeting, Paris, January 23-24, 2006
Günter Sigl, Astroparticules et Cosmologie, Paris