Hydrogen Neutron Capture

Neutron star smash-ups may forge gold

Where did all the money come from? Violent collisions between the dense old stars may be why gold, lead, thorium and other heavy elements are in such abundance.

Only hydrogen, helium and lithium are present after the Big Bang. Stars regular elements then fused to the mass of iron. All things were created when the heavier atoms small neutron capture, some of which then decayed into protons.

A slow version of this process could occur in massive stars, but could only account for about half of the remaining heavy elements.Capture of fast neutrons are needed to explain the other half, including gold and lead, says Hans-Thomas Janka Max Planck Institute for Astrophysics in Garching, Germany.

Now new simulations show that his team mergers of neutron stars can do the trick.

These remnants of exploded stars contain a soup of particles ultradense, perfect conditions for rapid tightening the neutrons in the nuclei to form heavier elements. And when neutron stars collide mergers, the material element of decision is discarded.

In the simulations of the team, neutron star mergers produced the heavy elements necessary in the proportions think it exists in our galaxy. The absolute amounts of elements produced by fusion were also consistent with existing data and models.

Next the team will simulate mergers between neutron stars and black holes, which can also create favorable conditions for the capture of fast neutrons: although in some cases, nothing escapes such a smash in mergers the other neutron star becomes tense and some of the case near the far end escapes the gravitational pull of the black hole.

A mystery that remains is how traces of heavier atoms came to be in the old stars present at the dawn of the Milky Way. Neutron star mergers are probably not responsible, as the stars tend to take 100 million years to the spiral to the other. "We need another source to produce super-elements in old stars," said Janka.

09/29/11 Colloquium « Society of Physics Students at Florida State ...

Hello everyone,

I wanted to send everyone a reminder about the conference tomorrow, and the information I was given Dr. Tabor. Here are details on the department website:

President: Rebecca Surman, Union College (Host: Samuel Tabor)

Title: Synthesis of heavy elements in astrophysical environments, extreme

Summary: Although the astrophysical origins of light (hydrogen, helium) and intermediate mass (carbon through iron) components are fairly well established, our understanding of the synthesis of heavier elements is incomplete.One of the largest of these open questions is to identify the site of the Astrophysics of the formation of about half the elements heavier than iron, in the process of nucleosynthesis r. The abundance of the solar system model of these nuclei, one can say they have been synthesized by neutron capture in conditions of high temperature and density of free neutrons. However, when these extreme conditions are found to be permanently stuck even astrophysics.Here we will discuss aspects of nucleosynthesis process r in two potential sites for astrophysical neutrino-driven supernovae winds and outflows of hot neutron star black hole mergers and describe the role of data in nuclear physics simulations of the synthesis of elements in each site.

Dr. Tabor recommend you visit the website of the speaker (http://minerva.union.edu/surmanr/) and read some of his previous papers for some background.

Hydrogen, the essential element

The Capture

Hydrogen

Hydrogen

The hype about hydrogen, fact and fiction in the race to save the climate