Identifying rotation in SASI-dominated core-collapse supernovae with a neutrino gyroscope

TY - JOUR

T1 - Identifying rotation in SASI-dominated core-collapse supernovae with a neutrino gyroscope

AU - Walk, Laurie

AU - Tamborra, Irene

AU - Janka, Hans-Thomas

AU - Summa, Alexander

PY - 2018/12/15

Y1 - 2018/12/15

N2 - Measuring the rotation of core-collapse supernovae (SN) and of their progenitor stars is extremely challenging. Here, it is demonstrated that neutrinos may potentially be employed as stellar gyroscopes, if phases of activity by the standing accretion-shock instability (SASI) affect the neutrino emission prior to the onset of the SN explosion. This is shown by comparing the neutrino emission properties of self-consistent, three-dimensional SN simulations of a 15 M progenitor without rotation as well as slow and fast rotation compatible with observational constraints. The explosion of the fast rotating model gives rise to long-lasting, massive polar accretion downflows with stochastic time variability, detectable, e.g., by the IceCube Neutrino Observatory for any observer direction. While spectrograms of the neutrino event rate of nonrotating SNe feature a well-known sharp peak due to SASI for observers located in the proximity of the SASI plane, the corresponding spectrograms of rotating models show activity over a wide range of frequencies, most notably above 200 Hz for rapid rotation. In addition, the Fourier power spectra of the event rate for rotating models exhibit a SASI peak with lower power than in nonrotating models. The spectra for the rotating models also show secondary peaks at higher frequencies with greater relative heights compared to the main SASI peak than for nonrotating cases. These rotational imprints will be detectable for SNe at 10 kpc or closer.

AB - Measuring the rotation of core-collapse supernovae (SN) and of their progenitor stars is extremely challenging. Here, it is demonstrated that neutrinos may potentially be employed as stellar gyroscopes, if phases of activity by the standing accretion-shock instability (SASI) affect the neutrino emission prior to the onset of the SN explosion. This is shown by comparing the neutrino emission properties of self-consistent, three-dimensional SN simulations of a 15 M progenitor without rotation as well as slow and fast rotation compatible with observational constraints. The explosion of the fast rotating model gives rise to long-lasting, massive polar accretion downflows with stochastic time variability, detectable, e.g., by the IceCube Neutrino Observatory for any observer direction. While spectrograms of the neutrino event rate of nonrotating SNe feature a well-known sharp peak due to SASI for observers located in the proximity of the SASI plane, the corresponding spectrograms of rotating models show activity over a wide range of frequencies, most notably above 200 Hz for rapid rotation. In addition, the Fourier power spectra of the event rate for rotating models exhibit a SASI peak with lower power than in nonrotating models. The spectra for the rotating models also show secondary peaks at higher frequencies with greater relative heights compared to the main SASI peak than for nonrotating cases. These rotational imprints will be detectable for SNe at 10 kpc or closer.

U2 - 10.1103/PhysRevD.98.123001

DO - 10.1103/PhysRevD.98.123001

M3 - Journal article

SN - 2470-0010

VL - 98

JO - Physical Review D

JF - Physical Review D

IS - 12

M1 - 123001

ER -