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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.

How loud are Neutron Star Mergers?

Submitted by cott on Sat, 08/06/2016 - 01:18

Our new paper led by Sebastiano Bernuzzi is out in Physical Review D! The paper is about a large set of neutron star merger simulations, using three different finite-temperature nuclear equation of state and binary parameters motivated by the galactic double neutron star population. Our focus was on how "loud" these mergers are in gravitational waves and what phase of their evolution is the "loudest".

Also exciting: We are providing open access to the gravitational waveforms extracted from our merger simulations. For details, see: https://stellarcollapse.org/Bernuzzi2016. Here is the money plot from the paper:

This figure shows that most of the gravitational wave energy in the entire history of a coalescing neutron star binary is actually emitted in the first ~10 ms after merger

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.