Pre-supernova neutrino signal

Pre-supernova neutrino signal

10 years of progress in modelling

Andrzej Odrzywo lek

M. Smoluchowski Institute of Physics, Jagiellonian U. Cracov, Poland

Thursday 26 October

Early thouhts

I 60’s: ν detector on Pluto required to detect flux from stars, due to solar neutrino background [1]

I 80’s: Bahcal, Neutrino astrophysics: only 1 of 567 pages devoted to distant stars; renormalized CNO ν _e spectrum used to estimate detection [2]

I 90’s: A.O. noticed ν flux of 10 ¹² L  for Si burning stage; Presupernova at distance of

d =

√

10 ¹² = 10 ⁶ AU ' 5 parsecs could outshine the Sun in neutrinos. Unfortunately, no such a star exists!

I 2000: M. Misiaszek point out: half of the above flux is ¯ ν _e . Inverse β decay p + ¯ ν _e → n + e ⁺ . How to capture neutrons (Cl, ³ He, Cd . . . ) ?

I 2003: pair-annihilation e ⁻ + e ⁺ → ν _x + ¯ ν _x identified as main ¯ ν _e source; energy spectrum estimated via MonteCarlo simulation; enormous detector size required to get significant Galaxy coverage [3]

I A&A community: ,,absolutely undetectable” (S. E.

Woosley, priv. comm.) but experimental physicists excited: could we really forecast supernova?

I Beacom&Vagins: use Gd to capture neutrons;

essentially background-free detection channel [6]

Recent progress

1. better understanding of pair-annihilation neutrino spectra (MonteCarlo → moments/fit → 3D

integration → tabulation/interpolation → 2D integration) [3, 4, 16]

2. neutrino light curves and spectra for s15 model [5]

3. neutrino emission dependence on ZAMS mass (12, 15, 25 M  [11])

4. ν _e emission&detection channel (LS, LAr, coherent scattering detectors) [11]

5. how nuclear burning stages are reflected in ν signal?

6. other production channels (photo, plasma, deexcitation) [15, 18]

7. effects of neutrino oscillations [13, 14, 12]

8. hydrodynamics of O and Si burning [20, 21]

9. Betelgeuse explosion early warning, reactor background [13]

10. modern stellar evolution codes [12, 14, 16, 15, 17]

11. ONeMg vs Si-burning pre-supernovae [14, 16]

12. consistent post-processing of stellar models with β ^±

processes [15, 17]

Photon & neutrino HR diagram

Burning stages vs ν flux

Kippenhahn diagram + Neutrino light curve

SN Ia vs Pre-SN

Type Ia supernova explosion might be viewed as an extreme case of nuclear burning in stars.

Key similarities

I C/O → Si/Fe burning

I available fuel mass ∼ 1.5 M 

I identical ν production processes

I similar neutrino energies

Essential differences

I burning time: seconds vs days, hours

I energy lost to neutrinos 1% vs ∼100%

I event rate, minimal possible distance to Earth Overall, detection challenge comparable [7, 8, 9, 10].

Ν

 Ν

e

0 1 2 3 4 5

10

10

10

10

10

10

Czas od zaplonu @sD

L

@erg s D

¯

ν _e -HR diagram (α-network)

¯

ν _e -HR diagram (NSE/800 + FFN/189)

Neutrino oscillations

MSW effect in H envelope leads to flavor exhange:

F _ν ^osc _e = p F _{ν e} + (1 − p) F _{ν µ} F _ν ^osc _µ = (1 − p) F _{ν e} + p F _{ν µ} F _{ν ¯} ^osc _e = ¯ p F _{ν ¯ e} + (1 − ¯ p) F _{ν ¯ µ} F _{ν ¯} ^osc

µ = (1 − ¯ p) F _{ν ¯ e} + ¯ p F _{ν ¯ µ}

Depending on mass hierarchy of neutrinos coeeficients are: ^{p =}

( sin ² θ ₁₃ ' 0.02

sin ² θ ₁₂ cos ² θ ₁₃ ' 0.30 p = ¯

( cos ² θ ₁₂ cos ² θ ₁₃ ' 0.68 Normal

sin ² θ ₁₃ ' 0.02 Inverted

ν _e -HR diagram (α-network)

ν _e -HR diagram (NSE/800 + FFN/189)

Betelgeuse vs Galaxy

β Ori: Galactic longitude 200 ^◦

NASA/JPL-Caltech/R. Hurt (SSC/Caltech)

Neutron/β ⁻ decay controversy for ¯ ν _e flux

Contrary results (e.g [16] vs [17]) on importance of ¯ ν _e production process were obtained:

n + e ⁺ → p + ¯ ν _e

Is pair-annihilation or β ⁻ /postitron capture dominant ¯ ν _e production process in pre-supernova stars?

Observations:

I nuclear reaction network based results → pair dominates

I small NSE → pair/β similar

I massive NSE → β dominated

Possible explanation: neutron abundance as a function

of NSE network size (work in progress).

MESA & new approach to weak rates

I neutrino emission computed DIRECTLY [19] from nuclear data (mass, energy levels, matrix elements)

I 100% compatibility of nuclear kinetics and spectral neutrino emission now possible

I pathway to neutrino spectra computed directly

within stellar evolution code now open (vast area of research: N pocket, hot/explosive-CNO, 3α,

shell-burning neutrinos)

I 35 years of ,,FFN tables” era begins to end

I uncertainty factor of ∼2 or worse from interpolation procedure ALONE removed

I way open to include e.g. ν-accelerated H burning

Selected references

[1] Chiu,H.-Y. Cosmic neutrinos and their detection (1964) NASA-TM-X-51721 [2] J. Bahcall, Neutrino Astrophysics, §6.5 Fluxes from other stars

[3] OMK, Astroparticle Physics 21, 303 (2004)

[4] Misiaszek, Odrzywolek, Kutschera, PRD, 74, 043006 (2006)

[5] OMK, Future neutrino observations of nearby pre-supernova stars before core-collapse, In: J. R.Wilkes, editor, NNN06, Volume 944 of AIoP Conf.

Series, 109–118, (2007).

[6] John F. Beacom and Mark R. Vagins Phys. Rev. Lett. 93, 171101 (2004) [7] Kunugise&Iwamoto, Publications of the Astronomical Society of Japan,

Vol.59, No.6, L57 (2007)

[8] Odrzywolek&Plewa, A&A, 529, id.A156

[9] I. Seitenzahl et. al., Phys. Rev. D, Volume 92, Issue 12, id.124013 [10] Wright et. al., Phys. Rev. D, Volume 94, Issue 2, id.025026

[11] A. Odrzywolek, A. Heger, Neutrino Signatures of Dying Massive Stars, Acta Physica Polonica B, Vol. 41, No. 7, July 2010, page 1611.

[12] Yoshida et. al., Phys. Rev. D 93 123012 (2016) [13] The KamLAND Collaboration, ApJ 818:91 (2016) [14] Chinami Kato et. al. ApJ (2017) 808:2

[15] Kelly M. Patton et. al. ApJ (2017) 840:2

[16] Chinami Kato et. al. ApJ (2017) 848 48; arXiv:1704.05480 [17] Kelly M. Patton et. al. (2017); arXiv:1709.01877

[18] G. W. Misch, Y. Sun, G. M. Fuller, arXiv:1708:08792

[19] Paxton et al. 2011,2013,2015 http://mesa.sourceforge.net/

[20] Meakin & Arnett, ApJ, 667, 448 (2007)

[21] S. M. Couch, E. Chatzopoulos, W. David Arnett, and F. X. Timmes, ApJ

Letters, 808 Number 1, p. L21