Wednesday, January 24, 2018

Scientists Take Viewers to the Center of the Milky Way

via NASA

A new visualization provides an exceptional virtual trip – complete with a 360-degree view – to the center of our home galaxy, the Milky Way. This project, made using data from NASA’s Chandra X-ray Observatory and other telescopes, allows viewers to control their own exploration of the fascinating environment of volatile giant stars and powerful gravity around the monster black hole that lies in the center of the Milky Way.

The Earth is located about 26,000 light years, or about 150 trillion miles, from the center of the Galaxy.  While humans cannot physically travel there, scientists have been able to study this region by using data from powerful telescopes that can detect light in a variety of forms, including X-ray and infrared light.

This visualization builds on infrared data with the European Southern Observatory’s Very Large Telescope of 30 massive stellar giants called Wolf-Rayet stars that orbit within about 1.5 light years of the center of our Galaxy. Powerful winds of gas streaming from the surface of these stars are carrying some of their outer layers into interstellar space.

When the outflowing gas collides with previously ejected gas from other stars, the collisions produce shock waves, similar to sonic booms, which permeate the area. These shock waves heat the gas to millions of degrees, which causes it to glow in X-rays. Extensive observations with Chandra of the central regions of the Milky Way have provided critical data about the temperature and distribution of this multimillion-degree gas.

Astronomers are interested in better understanding what role these Wolf-Rayet stars play in the cosmic neighborhood at the Milky Way’s center. In particular, they would like to know how the stars interact with the Galactic center’s most dominant resident: the supermassive black hole known as Sagittarius A* (abbreviated Sgr A*). Pre-eminent yet invisible, Sgr A* has the mass equivalent to some four million Suns.

The Galactic Center visualization is a 360-degree movie that immerses a viewer into a simulation of the center of our Galaxy.  The viewer is at the location of Sgr A* and is able to see about 20 Wolf-Rayet stars (white, twinkling objects) orbiting Sgr A* as they continuously eject stellar winds (black to red to yellow color scale). These winds collide with each other, and then some of this material spirals towards Sgr A*. The movie, which starts 350 years in the past, spans 500 years.

See and learn more!

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