Exploring the Neutron Star探索中子星

Jia Liu 刘佳Gesamtkunstwerk 1020

2012 - 04 - 20

Stellar Evolution

Kepler's Supernova, SN 1604

Credit: NASA/ESA/JHU/R.Sankrit & W.Blair

Kepler's Supernova, SN 1604

Credit: NASA/ESA/JHU/R.Sankrit & W.Blair

The Crab Nebula, SN 1054

Credit: NASA/ESA/ASU/J.Hester & A.Loll

《宋史·天文志-第九》对蟹状星云的记载

The Crab Nebula, SN 1054

Credit: Optical: NASA/ESA/ASU/J.Hester & A.Loll; X-ray: NASA/CXC/ASU/J.Hester et al.

Mass of a Neutron Star

Earth Mass6 × 1024 kg

Solar Mass2 × 1030 kg

Mass of Neutron Star~ 1.35 - 2 Solar mass

The Size of a Neutron Star

~ The size of Manhattan

Neutron Star is Very Very ... Dense!

The density of neutron star is equivalent to the mass of the entire

human population compressed to the size of a sugar cube.

7 Billion

Conservation of Angular Momentum

7 Billion

Similarly, changing from the size of the Sun to the size of Manhattan (while keeping its mass) makes neutron star spin very fast.

Neutron Star Spins Very Very ... Fast!

7 Billion

Earth Period1 day (86,400 seconds)

Neutron Star Period~ 0.01 seconds

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The Microscopic World

MoleculesAtoms

NucleusQuarks

Proton

Neutron

Fundamental physics question: How matter behaves in extremely dense environment?

Neutron Star as A Laboratory

How matter behaves in extremely dense environment (nuclei density)? We are unable to create such dense environment in any laboratories on Earth, so Neutron star, where we can observe the densest matters in our Universe, become our lab in the sky.

Neutron Star as One Giant Neutron

The key question to answer: What is the mass - radius relation for neutron star?

Mass - Radius Relation

But it's difficult to measure the mass and radius of a neutron star, because they're only as big as Manhattan, but hundreds of light years away. It's like to measure the size of an atom in California from New York!

My Research: Simulating Neutron Star Atmosphere

RXTE Space Telescope

My Research: Simulating Neutron Star Atmosphere

Simulation run11.75 layer 0

We are learning more and more about neutron stars, However," This is not the end. It is not even the beginning of the end. But it is, perhaps, The end of the beginning. "- Sir Winston Churchill

My Research: Simulating Neutron Star Atmosphere