Neutrino and Gravitational Wave Signals from Cosmological Supernovae

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Neutrino and Gravitational Wave Signals from
Cosmological Supernovae

• Pearl Sandick
• University of Minnesota
• June 12, 2006

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Introduction

• Recent estimates SRNs and GWs detectable soon!
  
• Totani et al. (1995, 1996), Ando et al. (2003,
  2004), Strigari et al. (2004, 2005),
• Iocco et al. (2005)
• Ferrari et al. (1999), Araujo et al. (2002,
  2004), Buonanno et al. (2005)
• Estimates rely on supernova dynamics and
  structure formation history

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• Structure formation
• Daigne, Olive, Silk, Stoehr and Vangioni (2005)
• Relic Neutrino Background
• Daigne, Olive, Sandick and Vangioni, PRD 72
  103007 (2005)
• Olive and Sandick, arXivastro-ph/0603236
• Gravitational Waves
• Sandick, Olive, Daigne and Vangioni, PRD 73
  104024 (2006)

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The StoryDaigne, Olive, Silk, Stoehr and
Vangioni (2005)

• First stars formed in metal-free primordial
  structures with M 107 M?
• z 30
• Top-heavy initial mass function (massive mode)
• Critical metallicity normal mode star
  formation takes over
• Reproduces observed star formation for z lt 6 and
  low redshift SN rates (Types Ia and II)

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Star Formation History

• 1. Initial Mass Function (IMF) describes the
  mass distribution of stars in each model

Slope x1.3 in all models.
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Star Formation History

• 2. Star Formation Rate (SFR) describes the mass
  birthrate of stars per unit comoving volume

Data taken from Lanzetta et al. (2002) and
Hopkins (2004).
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Star Formation

• Bimodal star formation history
• Reionization at relatively high redshift
• Chemical enrichment of galaxies and IGM

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SF Modeling

• 3 baryon reservoirs
• MtotMstructMIGM
• MstructMISMMstars
• 4 exchange processes
• ab(t) baryon accretion
• ?(t) star formation
• e(t) ejection
• o(t) outflows

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SF Models

• Model 0 Normal Mode
• Neutron star remnant (m30 M?)
• Black hole remnant
• with mBHmHe core (mgt30 M?)
• SFR elliptical galaxies
• ? 2.8 Gyr for Mmin107 M?
• ?1 .2 Gyr-1 governs efficiency

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SF Models

• Massive Modes
• Zcrit10-4 Z?
• Model 1
• Black holes with mBHmHe core
• Model 2a
• PISNe total disruption, no remnant
• SFR reduced to avoid overproduction of metals
• Model 2b
• Total collapse to BH
• No heavy elements ejected

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(Except Model 2a ltE?gt1.2MeV)

• Note E'E(1z) is the neutrino energy at emission
  and

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Flux Calculation

• Differential SN Rate

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Single Mode Neutrino Fluxes
Normal
Massive
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Total Fluxes
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Note About Oscillations

• Results shown are for electron antineutrinos
  (easiest to detect at water Cerenkov detectors)
• Consider maximal mixing with
• Equipartition of total energy among neutrino
  species

Expect total flux neutrinos
with larger energies
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Model 1 w/ Oscillations
without oscillations
with oscillations
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Integrated fluxes at SK and SNO are given in
cm-2s-1 and models contain both the normal and
massive modes. Note that the entire observable
flux in each case comes from the normal mode.
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Sensitivity to ltE?gt
SK limit
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Summary

• Oscillations harden spectrum at higher
  (observable) energies
• SK bound saturated by all models (normal mode)
• See them soon?
• Despite large flux, neutrinos from massive mode
  unlikely to be observed soon due to redshifted
  spectrum

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Gravitational Waves

• Energy released in SN
• 99 neutrinos
• .01 visible light
• .00001-.001 gravitational waves
• Calculate stochastic background of GWs?
• Simulation Müller et al. (2004)
• Approximate source spectrum (fit) Buonanno et
  al. (2005)
• Apply star formation history PS et al. (2006)

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Simulation
Snapshots of entropy distribution for 15 M?
star after the core bounce (s15r from Müller et
al. 2004).
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Describing GWs

• Simulation provides source spectrum
• Differential closure density parameter
• Energy released in GWs

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Parameters
When collapse -gt NS E? 3?1053 ergs ltqgt.45 Buona
nno et al. (2005)
OR
When collapse -gt BH MrMHe core or
m e2?10-5 Fryer et al. (2001)

• Mr remnant mass
• e efficiency of GW production

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GW Signature
Normal Mode
Massive Modes
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Total GW Signal
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Detectors ground-based

• Currently Operating
• GEO600 (Germany)
• LIGO (US)
• VIRGO (Italy)
• TAMA (Japan)
• Laser Interferometers
• Sensitive to f 102-103Hz.
• Best Chance LIGO correlated detectors

http//www.ligo.caltech.edu
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Detectors space-based

• LISA planned launch 2012
• Sensitive to f ? 10-2 Hz.
• (low frequency tail).
• Merger signals
• BBO/DECIGO 2025?
• Proposed to cover frequency
• range between LIGO and LISA.
• Inflationary GWs and IMBH formation/mergers

http//universe.nasa.gov
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Detection
Note Inflationary background predicted to be
OGWh2 ? 10-15 Cooray (2005)
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Summary

• Spectrum features include redshift-dependent peak
  location and potential secondary peak due to an
  early massive mode of star formation.
• GW background from core collapse SNe large enough
  to be detected by BBO/DECIGO, and maybe even
  sooner by LIGO.
• Look forward to improved simulations ltqgt and/or
  e