skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Role of nucleon strangeness in supernova explosions

Authors:
; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1254218
Grant/Contract Number:
FG02-97ER-41014
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 93; Journal Issue: 5; Related Information: CHORUS Timestamp: 2016-05-24 16:23:28; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Hobbs, T. J., Alberg, Mary, and Miller, Gerald A.. Role of nucleon strangeness in supernova explosions. United States: N. p., 2016. Web. doi:10.1103/PhysRevC.93.052801.
Hobbs, T. J., Alberg, Mary, & Miller, Gerald A.. Role of nucleon strangeness in supernova explosions. United States. doi:10.1103/PhysRevC.93.052801.
Hobbs, T. J., Alberg, Mary, and Miller, Gerald A.. Mon . "Role of nucleon strangeness in supernova explosions". United States. doi:10.1103/PhysRevC.93.052801.
@article{osti_1254218,
title = {Role of nucleon strangeness in supernova explosions},
author = {Hobbs, T. J. and Alberg, Mary and Miller, Gerald A.},
abstractNote = {},
doi = {10.1103/PhysRevC.93.052801},
journal = {Physical Review C},
number = 5,
volume = 93,
place = {United States},
year = {Mon May 23 00:00:00 EDT 2016},
month = {Mon May 23 00:00:00 EDT 2016}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevC.93.052801

Citation Metrics:
Cited by: 8works
Citation information provided by
Web of Science

Save / Share:
  • The neutrino-heated ''gain layer'' immediately behind the stalled shock in a core-collapse supernova is unstable to high-Reynolds-number turbulent convection. We carry out and analyze a new set of 19 high-resolution three-dimensional (3D) simulations with a three-species neutrino leakage/heating scheme and compare with spherically symmetric (one-dimensional, 1D) and axisymmetric (two-dimensional, 2D) simulations carried out with the same methods. We study the postbounce supernova evolution in a 15 M {sub ☉} progenitor star and vary the local neutrino heating rate, the magnitude and spatial dependence of asphericity from convective burning in the Si/O shell, and spatial resolution. Our simulations suggest that theremore » is a direct correlation between the strength of turbulence in the gain layer and the susceptibility to explosion. 2D and 3D simulations explode at much lower neutrino heating rates than 1D simulations. This is commonly explained by the fact that nonradial dynamics allows accreting material to stay longer in the gain layer. We show that this explanation is incomplete. Our results indicate that the effective turbulent ram pressure exerted on the shock plays a crucial role by allowing multi-dimensional models to explode at a lower postshock thermal pressure and thus with less neutrino heating than 1D models. We connect the turbulent ram pressure with turbulent energy at large scales and in this way explain why 2D simulations are erroneously exploding more easily than 3D simulations.« less
  • Violent eruptions, and consequently major mass loss, are a common feature of the so–called Luminous Blue Variable (LBV) stars. During major eruptive episodes LBVs mimic the behavior of real type IIn supernovae (SNe), showing comparable radiated energy and similar spectroscopic properties. For this reason these events are frequently labelled as SN impostors. Type IIn SN spectra are characterized by the presence of prominent narrow Balmer lines in emission. In most cases, SNe IIn arise from massive stars (M>8{sub ⊙}) exploding in a dense H–rich circumstellar medium (CSM), produced by progenitor’s mass loss prior to the SN explosion. Although the mechanismsmore » triggering these eruptions are still unknown, recently we had direct proofs of the connection between very massive stars, their eruptions and ejecta-CSM interacting SNe. SNe 2006jc, 2010mc, 2011ht and the controversial SN 2009ip are famous cases in which we observed the explosion of the star months to years after major outbursts. In this context, the case of a recent transient event, LSQ13zm, is extremely interesting since we observed an outburst just ∼3 weeks before the terminal SN explosion. All of this may suggest that SN impostors occasionally herald true SN explosions. Nonetheless, there are several cases where major eruptions are followed by a quiescent phase in the LBV life. The impostor SN 2007sv is one of these cases, since it showed a single outburst event. Its photometric (a relatively faint absolute magnitude at the maximum) and spectroscopic properties (low velocity and temperature of the ejecta, and the absence of the typical elements produced in the explosive nucleosynthesis) strongly suggest that SN 2007sv was the giant eruption of an LBV, which has then returned in a quiescent stage.« less
  • Until now the only way to study the strangeness changing baryon-baryon interaction has been through the decays of lambda hypernuclei. It would clearly be preferable to be able to study reactions such as {ital pn}{r_arrow}{ital p}{Lambda} in free space. In order to provide some guidance concerning the feasibility of such a measurement, we investigate the energy dependence, parity violating asymmetry, and shape of the cross section for this reaction.
  • We calculate the nucleon strangeness y{sub N} in the chiral quark model and the meson cloud model. With the internal relation between the sigma term of {pi}N ({sigma}{sub {pi}}{sub N}) and y{sub N}, we present the results of {sigma}{sub {pi}}{sub N} in these two models. Our calculations show that y{sub N} from the chiral quark model is significantly larger than that from the meson cloud model, whereas the difference of {sigma}{sub {pi}}{sub N} between the two models is relatively small. We also present the results of {sigma}{sub KN} and {sigma}{sub {eta}}{sub N}, which could be determined by {sigma}{sub {pi}}{sub N}more » and y{sub N} from their definition in the current algebra, and find that these two physical parameters are quite sensitive to y{sub N}. The results indicate the necessity to restrict the parameters of the two models from more precision measurements.« less