Multiwavelength Data Sonification: The Galactic Center

This reimagines combined x-ray, visible light, and infrared data from the Chandra X-Ray Observatory, the Hubble Space Telescope, and the Spitzer Space Telescope as sound rather than an image.

Video Credit: NASA

The Perseus Cluster

perseusCluster_cxc_cThe Perseus Cluster is a group of several thousand galaxies around 250 million light-years away. It’s one of the most massive objects in the Universe and the brightest galaxy cluster as seen in x-rays. Perseus A (NGC 1275), a giant cannibal galaxy, sits at the center of the cluster accreting matter as gas and whole galaxies fall into it. This Chandra Observatory x-ray image spans about 300,000 light-years across the galaxy cluster core showing remarkable details of the x-ray emission from the monster central galaxy and surrounding super hot (30 to 70 million °C) cluster gas. The bright central object is the supermassive black hole at the core of Perseus A. Low density regions are seen as dark bubbles or voids which are believed to be generated by cyclic outbursts of activity from the black hole. The activity creates pressure waves that move through the x-ray hot gas—sound waves on a cosmic scale. The blue-green wisps just above centre in this false-color view are probably x-ray shadows of the remains of a small galaxy being swallowed by Perseus A.

Image Credit: NASA

More Cosmic Leftovers

tycho_1Over four centuries after Tycho Brahe first observed the supernova that bears his name, the supernova remnant it created is still a bright source of X-rays. The supersonic expansion of the exploded star produced opposing shock waves, one moving outward into the surrounding interstellar gas and another moving back into the expanding stellar debris. This Chandra image of Tycho reveals the dynamics of the explosion’s interfering shock waves in detail. The outer shock has produced a rapidly moving shell of extremely high-energy electrons (blue), and the reverse shock has heated the expanding debris to millions of degrees (red and green). There is evidence from the Chandra data that the interference between these shock waves may be responsible for some of the ultra-energetic particles that pervade the Galaxy and constantly bombard the Earth as cosmic rays.

Image Credit: NASA

Sagittarius A* at the Center of Our Galaxy

A black hole called Sagittarius A* (pronounced A-star) lies at the center of our Milky Way Galaxy, only 27,000 light-years away. Its mass is roughly 4 million times the mass of the Sun. Our galaxy’s black hole is mild-mannered compared to the central black holes in some other galaxies, much more calmly consuming material around it. However, it does sometimes flare-up. An flareup lasting several hours is documented in this series of X-ray images from the orbiting Nuclear Spectroscopic Telescope Array (NuSTAR). NuSTAR is the first instrument to provide focused views of the area surrounding Sgr A* at X-ray energies higher than those accessible to the Chandra and XMM observatories. The flare sequence is shown in the panels on the right. The images cover a two-day span. X-rays are generated in material heated to over 100 million C and traveling at nearly the speed of light as it falls into the black hole. The center X-ray image spans about 100 light-years. Its bright white region is the hottest material closest to the black hole; the pinkish cloud probably belongs to the remnant of a nearby supernova. Click the picture to embiggen it.

Sgr A* is monitored on a daily basis by the X-ray telescope of the Swift satellite. I made contributions to the design of the power and thermal control systems of the Burst Alert Telescope instrument on Swift.

Image Credit: NASA

At the Core

SagA*quietThere’s a supermassive black hole at the center of our Milky Way galaxy. It’s known as Sagittarius A* and shown in the center of this infrared (red and yellow) and X-ray (blue) composite image. Data from observations taken in orbit by Chandra‘s X-ray telescope was used to create an image the diffuse emission surrounding the black hole. See the close-up inset. The inset’s field of view covers an area about 1/2 light-year across the galactic center some 26,000 light-years away. These X-ray emissions originate in hot gas drawn from the winds of massive young stars near the galactic center. The Chandra data indicate that only 1% or so of the gas within the black hole’s gravitational influence ever reaches the event horizon after losing enough heat and angular momentum to fall into the black hole. The rest of the gas escapes in an outflow. This explains why the Milky Way’s black hole is so quiet, much fainter than might be expected in energetic X-rays.

Note: All data is subject to future verification. Beowulf Shaeffer was unavailable for comment.

Image Credit: NASA