August 10, 2020

Video Credit: NASA/CXC/Pontificia Universidad Católica de Chile/C. Russell et al.

Imagine exploring the center of our galaxy 26,000 light years away from the comfort of your home. 

Thanks to a supercomputer simulation and data collected from telescopes at NASA, we now can experience the supermassive black hole at the center of the Milky Way with "Galactic Center VR." It was created by a team at the Instituto de Astrofísica VR Lab at Pontificia Universidad Católica de Chile, led by Christopher Russell, who is now a postdoctoral researcher of the Institute for Astrophysics and Computational Sciences at Catholic University, who works at NASA Goddard Space Flight Center's X-ray Astrophysics Laboratory.

Russell and his colleagues started the Galactic Center VR project in January 2019 as a way to improve upon his 360-degree videos of the Galactic-Center simulations. “We wanted to be able to move and look wherever we wanted, '' said Russell. “To achieve this complete immersion, we started working on getting the simulations into VR.”

They used NASA's Chandra X-ray Observatory. “Chandra is the only X-ray telescope with good enough vision to resolve this region of the sky, so we use the Chandra observations of the Galactic Center as the observational anchor of our simulations,” said Russell. 

“Our NASA supercomputer simulations are of our galaxy's central parsec, spanning about three light years. At the heart of the Milky Way is a super massive black hole (SMBH) weighing in at 4-million suns known as Sagittarius A*. In orbit around the SMBH are 25 massive stars called Wolf-Rayet stars,” said Russell.   

“The stars are spewing their outer layers into outer space at supersonic speeds, called stellar winds. The stellar winds collide with the winds from neighboring stars, which creates gas that is 10s of millions of degrees Kelvin and glows in X-ray light.”

In the simulation, different colors can be seen. The density of the winds is colored red-yellow, and X-ray emission is colored blue-cyan. The colors end up mixing, creating a lot of purple in the visualizations. 

“Our goal for the VR experience is to explore these simulations in a completely immersive fashion,” said Russell. “We take the output of our supercomputer simulations — position, density, and X-ray emission of every stellar-wind element, the star positions, and the SMBH location — and load all of it directly into a virtual environment. The output is not pared down or simplified in any way; everything in the virtual environment comes directly from the simulation.”

After 14 months of work, Russell and the team publicly released their work as a VR experience on Steam and Viveport VR platforms. In June, Russell presented Galactic Center VR at the American Astronomical Society Meeting that was held virtually, which added 500 years of animation to the VR experience.

Russell and his colleagues hope to add simulations of other astronomical objects, and partner with interested researchers to see their simulations in VR. 

“I hope folks can get a better appreciation and understanding of what is in outer space by exploring it in their living room with VR,” said Russell. “This offers so much more exploratory capability than any other media that we have created from these Galactic-center simulations.”