Neutrinos in Core Collapse Supernovae Evan O’Connor, Stockholm University Outline: • SN theory & status • Neutrino Signal
Supernovae have a broad connection to the Universe Neutrinos & Gravitational Waves Nucleosynthesis Stellar Evolution Extreme Nuclear Physics Wikimedia/Jennifer Johnson ESO Cosmology Neutron Star & Black Holes Galaxy Evolution Long gamma-ray burst Science/MacFadyen LIGO/VIRGO Hubble Evan O’Connor – TAUP 2019 2 of 24 High-Z & SCP
Supernova Types HST Thermonuclear Core Collapse HST Evan O’Connor – TAUP 2019 Volumetric Supernova Survey: Li et al. (2010) 3 of 24
Collapse Phase 1000 R sun • Most massive stars core collapse during the red supergiant phase • CCSNe are triggered by the collapse of the iron core (~1000km, or 1/10 6 of the star’s radius) • Collapse ensues because electron degeneracy HST pressure can no longer support the core against gravity Iron Core 1000 km M ~ 1.4M sun Protoneutron Star ~30km Evan O’Connor – TAUP 2019 4 of 24
CCSNe: The Stages t = ~100ms t = -5ms t = 0ms stalled shock sonic point shock n n n r ~10 12 g cm -3 r ~10 14 g cm -3 n n n n n |---200 km---| |---200 km---| |---20 km---| Iron core collapse shock stagnation bounce Evan O’Connor – TAUP 2019 5 of 24
CCSNe: The Stages t = -5ms t > ~200ms sonic point |---150 km---| t = 0ms • The prevailing mechanism is the t = ~100ms shock stalled shock turbulence-aided neutrino mechanism r ~10 12 g cm -3 n Neutrinos from core heat outer layers n n • r ~10 14 g cm -3 n n Drives convection n • n e n n n n n Turbulence pressure support aids heating • and drives explosion p e- |---200 km---| Iron core collapse • Very successful in 2D*, many |---20 km---| |---200 km---| bounce successful explosions shock stagnation • Success in 3D too: fewer simulations Require some mechanism Explosion to drive explosion Evan O’Connor – TAUP 2019 6 of 24
The Core-Collapse Supernova Problem Understanding the transition from an imploding iron core to an exploding star has been a persistent and difficult problem in astrophysics. Requires: 3D - (Magneto)hydrodynamics General Relativity Nuclear Reactions Nuclear Equation Progenitors of State Neutrino Transport & Computational Physics Interactions EO & Couch (2018b) Evan O’Connor – TAUP 2019 7 of 24
• Similar progenitors Explosion Successes in multiD – 3D • GR gravity • Non-rotating Burrows et al. (2019) Evan O’Connor – TAUP 2019 8 of 24
• Similar progenitors Explosion Successes in multiD – 3D • GR gravity • Non-rotating Burrows et al. (2019) Lentz et al. (2015) Evan O’Connor – TAUP 2019 9 of 24
• Similar progenitors Explosion Successes in multiD – 3D • GR gravity • Non-rotating Burrows et al. (2019) Lentz et al. (2015) Melson et al. (2015b) Evan O’Connor – TAUP 2019 10 of 24
• Similar progenitors Explosion Successes in multiD – 3D • GR gravity • Non-rotating Burrows et al. (2019) Lentz et al. (2015) Ott et al. (2018) Melson et al. (2015b) Evan O’Connor – TAUP 2019 11 of 24
n n e Neutronization Burst p e - from 3ms before bounce to 6 ms after • When the matter reaches nuclear density and the supernova shock forms, it liberates the nucleons (animation) from the nuclei • Recently freed and no longer suppressed, protons now rapidly capture electrons, producing a burst of n e Evan O’Connor – TAUP 2019 12 of 24
Iron core mass increasing -> Neutronization Burst Matter temperature increasing -> 6 • n e ’s take a bit of time (few ms) 5 Luminosity [10 53 erg/s] before the density at the shock is n e low enough for the n ’s to escape 4 • anti- n e and n x neutrinos luminosity is 3 low. anti- n e are suppressed because high electron degeneracy, n x 2 because T is low _ 1 • Little progenitor dependence, n e n x universal* nature of collapse 0 -2 0 2 4 6 8 10 12 14 16 18 20 t - t bounce [ms] Evan O’Connor – TAUP 2019 13 of 24
Accretion Phase 200 1D models from Couch et al. (2019) & Luminosity (10 51 erg/s) Warren et al. (in prep) x3-4 Compactness t – t bounce [s] Learn about progenitor structure from neutrino observation of galactic supernova Evan O’Connor – TAUP 2019 14 of 24
Accretion Phase 200 1D models from Couch et al. (2019) & Warren et al. (in prep) Luminosity (10 51 erg/s) Compactness t – t bounce [s] Learn about neutron star mass from neutrino observation of galactic supernova Evan O’Connor – TAUP 2019 15 of 24
Global effort towards agreement • Want to demonstrate the community’s ability to simulate SN • Comparison of 6 core-collapse supernova codes • Very carefully control input physics and initial conditions to ensure fair comparison Journal of Physics: G 45 10 2018 Evan O’Connor – TAUP 2019 16 of 24
Excellent Agreement in 1D Si/O interface Si/O interface EO+ 2018 Evan O’Connor – TAUP 2019 17 of 24
Systematic Effects Malmenbeck, O’Sullivan (2019) PoS- ICRC2019-975; arXiv:1909.00886 Implementation of detailed IceCube detector into SNOwGLoBES https://github.com/SNOwGLoBES/ Energy-dependent effective volume, • detector efficiency, deadtime, … Sensitive dependence on energy spectrum shows areas where improvements are needed *Normal Hierarchy: only adiabatic MSW Evan O’Connor – TAUP 2019 18 of 24
Accretion Phase - SASI Neutrinos can reveal important dynamics of the • Standing Accretion Shock Instability (SASI) can impact supernova engine signal. Observable in Hyper-K or IceCube at 10kpc data: Tamborra et al. (2013) Hyper-K design report (arXiv:1805.04163) see also TAUP talk by T. Takiwaki EO & Couch (2018b) Evan O’Connor – TAUP 2019 19 of 24
Rotation in Core-Collapse Supernovae Westernacher-Schneider, O’Connor, O’Sullivan+ (arXiv:1907.01138) Rotation impacts neutrinos • and excites the newly formed protoneutron star Correlated signal in GWs • and neutrinos see also TAUP talk by T. Takiwaki Use SNOwGLoBES + IceCube • to generate rates and realizations Evan O’Connor – TAUP 2019 20 of 24
Rotation in Core-Collapse Supernovae Westernacher-Schneider, O’Connor, O’Sullivan+ (arXiv:1907.01138) Rotation impacts neutrinos • and excites the newly formed protoneutron star Correlated signal in GWs • and neutrinos see also TAUP talk by T. Takiwaki Use SNOwGLoBES + IceCube • to generate rates and realizations Evan O’Connor – TAUP 2019 21 of 24
Rotation-induced Oscillations in neutrinos Neutrinos can reveal • Must be close to see such small important dynamics of the signal. In IceCube: ~1kpc supernova engine Westernacher-Schneider, O’Connor, O’Sullivan+ (arXiv:1907.01138) (animation) (animation) (animation) *Realizations take into account statistical noise and detector background noise Evan O’Connor – TAUP 2019 22 of 24
Transition from Accretion to Cooling Phase Vartanyan et al. (2019) 3D explosions by the Princeton group • (but also others) shows simultaneous accretion & ejection Luminosity 10 52 erg/s post bounce time [s] Evan O’Connor – TAUP 2019 23 of 24
Cooling Phase *Here x characterizes additional opacity due to nuclear pasta formation • How the protoneutron star cools relays info about the EOS • Also the neutron star mass (see TAUP x = talkby Y. Suwa) • <E> differences between n e and anti- n e is x =5 important and can impact nucleosynthesis x = Neutrinos from the cooling Super-K like phase shed light on key x =5 properties of PNS x = Horowitz et al. (2016) Evan O’Connor – TAUP 2019 24 of 24
Not all core collapses will succeed LIGO Evan O’Connor – TAUP 2019 25 of 24
Black Hole Formation O’Connor (2015) MSW only L n ~ 400 B/s! 10kpc with SNOwGLoBES Evan O’Connor – TAUP 2019 26 of 24
Summary • Core Collapse simulations in multiD explode via the turbulence-aided neutrino mechanism, across codes and progenitors • Models predict several interesting neutrino-signal-related phenomena Neutronization Burst (Universal) • Neutrino mass ordering likely discernible from signal • Accretion Luminosity (probes progenitor/PNS mass) • SASI predicts large time variations in signal • Rotation predicts correlated neutrino and GW signals • Equation of State and PNS mass sets cooling curve over ~5-100s • Failed supernovae predict sharp cutoff on neutrinos • Many more…. • • Caveats: Models, Neutrino Oscillations, reversing detected signal, … TAUP talks by: A. Harada, K. Nakazato, S. Abbar, N. Yamamoto, M. Mori, Y. Suwa, C. Kato, J. Migenda, M. Zaizen, T. Takiwaki Evan O’Connor – TAUP 2019 27 of 24
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