SNEC -- The SuperNova Explosion Code

Submitted by cott on Fri, 07/25/2014 - 04:20
Folks at Caltech have been working on a new open-source 1D Lagragian radiation-hydrodynamics for supernova explosions called SNEC -- The SuperNova Explosion Code. We are not quite ready to release the full code yet, but its hydro portion is already available on stellarcollapse.org: http://stellarcollapse.org/SNEC and has been used in Piro & Morozova, Transparent Helium in Stripped Envelope Supernovae, submitted to ApJL, arXiv:1407.5992.

What is the role of thermal pressure in hypermassive neutron star merger remants?

Submitted by cott on Wed, 06/19/2013 - 00:18
The merger of two neutron star creates a hypermassive, extremely rapidly and differentially spinning object (frequently called a hypermassive neutron star [HMNS]). While the premerger neutron stars can be treated as essentially being cold, the impact of the two NSs leads to very strong shocks that leave the HMNS with temperatures in the range of ~5-40 MeV (1 MeV corresponds to about 1.16 x 10^{10} K). For progenitor NSs in the typical NS mass range (1.3-1.4 solar masses), the HMNS will have more baryonic mass than can be supported by the nuclear equations of state and is believed to be supported by rapid differential rotation and, possibly, thermal pressure. Kaplan et al. have investigated the role of thermal pressure support in HMNS and found something surprising and counter-intuitive: thermal pressure contributions do not appear to enhance the maximum HMNS mass; they do increase the baryonic mass supported by sub-critical configurations (i.e. not peak density, not critically rotating), but do not appear to give a significant boost to the overall maximum. Read more in Kaplan et al. 2014, which has been submitted to the Astrophysical Journal. It's available on stellarcollapse.org/kaplanetal2014.

Ott et al. 2013: Gravitational wave signals and source code available!

Submitted by cott on Thu, 10/25/2012 - 22:10

Ott et al. have submitted a new paper on 3D general-relativistic simulations of core-collapse supernovae. The gravitational-wave signals predicted from these simulations and the source code used for the leakage/heating scheme employed by the simulations are available for download at https://sntheory.org/ottetal2013.

Details in Ott et al. 2013

New Microphysics

Submitted by evanoc on Mon, 11/07/2011 - 08:08
We have recently added several new microphysics tools and routines. The first is EOSmaker, this set of routines is what we use to construct our .h5 tables from the data tables provided from nuclear theorists. Along with this we have updated the H. Shen et al. table, which now uses the updated table from Shen, H. et al. (2011). The second tool is NuLib, a preliminary set of open-source neutrino interaction routines.

New Version of the H. Shen et al. EOS

Submitted by cott on Wed, 09/01/2010 - 17:21

Hong Shen of Nankai University and her collaborators K. Sumiyoshi (Numazu College of Technology, Japan) and H. Toki (RIKEN, Osaka, Japan) have updated their relativistic-mean field EOS tables (Shen et al. 1998a, 1998b) and are providing new tables in ASCII format that are equally spaced, have a greater range and a finer temperature mesh. The tables can be obtained from their Shen et al. EOS web page.

New: Observed Neutron Star Masses

Submitted by cott on Sun, 05/09/2010 - 19:27

Jim Lattimer has been so kind to agree to allow stellarcollapse.org to host his collection of observed neutron star masses. You can find it at http://www.stellarcollapse.org/nsmasses. Updates will be posted at the same location. We have also updated the public release of the GR1D code to version 1.02, including updated radiation source terms and a number of small bug fixes.

 

Major update: Public release of the GR1D code and new EOS tables

Submitted by cott on Tue, 12/15/2009 - 03:45
We have had a busy and productive fall and have updated stellarcollapse.org today. The two major things are:
  • GR1D -- GR1D is a new spherically-symmetric open-source code for simulations of stellar collapse to neutron stars and black holes. The paper describing this code is O'Connor and Ott, arXiv:0912.2393. We have just submitted this paper to the special issue of Classical and Quantum Gravity for the MICRA2009 workshop. GR1D is available for download in the Codes section.
  • Equation of State Tables: We are making available for the first time full EOS tables for the EOS of Lattimer & Swesty (1990) with values of the nuclear incompressibility K of 180 MeV, 220 MeV, and 375 MeV. In addition, we have updated our existing EOS table for the EOS of Shen et al. (1998), including a more consistent treatment of neutron and proton chemical potentials at densities below 10^7 g/cm^3. You can find and download these tables in the Microphysics section.