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This is stellarcollapse.org, a website aimed at providing resources supporting research in stellar collapse, core-collapse supernovae, neutron stars, and gamma-ray bursts.

Red Supergiant Radii and the Rise Times of SN IIP Light Curves

Submitted by cott on Wed, 03/30/2016 - 05:10

New paper by Viktoriya Morozova, Tony Piro, Mathieu Renzo, Christian Ott:

"Numerical Modeling of the Early Light Curves of Type IIP Supernovae", submitted to ApJ, arXiv:1603.08530.

We show, using SNEC, that there is a tight correlation between Type IIP (plateau) core-collapse supernova rise times (in g-band) and the radii of their progenitor red supergiant stars. See below figure! SNEC and all inputs to our models are available as part of our open-science initiative here on stellarcollapse.org: https://stellarcollapse.org/Morozova2016

SN IIP g-band rise times as a function of progenitor radius
Morozova et al. 2016, arXiv:1603.08530

 

stellarcollapse.org moved to new server

Submitted by cott on Thu, 03/03/2016 - 14:58

Welcome to the new stellarcollapse.org! We just completed the move to a new server with faster CPUs and more disk space. We have upgraded the content management system from Drupal 6 to Drupal 8. Stay tuned for more simulation results that will appear soon on stellarcollapse.org!

Please contact Christian Ott at cott #at# tapir.caltech.edu if you notice any problems with the site.

A large-scale dynamo and magnetoturbulence in rapidly rotating core-collapse supernovae, Nature Nov 30, 2015

Submitted by pmoesta on Thu, 12/03/2015 - 23:10

Mösta et al. recently published a break-through study on magnetoturbulence in rapidly rotating stellar collapse in Nature. They show that magnetohydrodynamic turbulence in the shear layer around a newly born proto-neutron star kicks off a highly efficient dynamo process that creates large-scale, ordered magnetar-strength (> 10^15 G) magnetic field. This field is strong enough to power hyperenergetic type Ic-bl explosions, a rare but extreme subclass of core-collapse supernovae, that are 10x more energetic than the average garden-variety supernovae and also make up all supernovae connected to long gamma-ray bursts. In addition, their simulations provide a first glimpse on a formation scenario for magnetars, very strongly magnetized neutron stars, that are left behind in these explosions.

The source code used to run the simulations and the initial data are available here. They have also created 3D visualizations of the magnetic field amplification in their simulations, embedded below.

 

Introducing SNEC: The SuperNova Explosion Code

Submitted by cott on Wed, 05/27/2015 - 03:27

Ever wanted to compute the light curve of a supernova explosion, but didn't have a code handy? Well, let us introduce SNEC, the SuperNova Explosion Code. SNEC is a new spherically-symmetric Lagrangian radiation-hydrodynamics code (in the flux-limited equilibrium diffusion approximation) that can explode stars and produce light curves (bolometric and various observational color bands). SNEC is open source and described in detail in Morozova et al. (2015), arXiv:1505.06746. All results shown in the Morozova et al. (2015) paper are fully reproducible.

Below plot shows light curves obtained from explosions of a 15-Msun star that has been systematically stripped (at a post-main-sequence stage) of hydrogen-rich envelope material in units of 1 Msun. See Morozova et al. (2015), arXiv:1505.06746 for further details.

You can download SNEC from stellarcollapse.org/SNEC and get simulation inputs and outputs from stellarcollapse.org/Morozova2015.

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.