Observatories and Instruments

Bringing Black Holes Into Focus. Image credit: ESA/NASA/JPL-Caltech

While I was off doing other things in June, NASA successfully launched the Nuclear Spectroscopic Telescope Array (NuSTAR) from a carrier aircraft somewhere over the Pacific Ocean. I mention this now because earlier this week, JPL announced that NuSTAR passed its Post-Launch Assessment Review. This means that although it has been observing X-ray sources for the past few weeks, the instrument has been cleared officially to enter the “science operations phase” of its two-year mission.

Here’s mission description from the Cal Tech website:

“NuSTAR will open a new window on the Universe by being the first satellite to focus high-energy X-rays into sharp images. NuSTAR’s high-energy X-rays eyes will see with more than 100 times the sensitivity of previous missions that have operated in this part of the electromagnetic spectrum, and with 10 times better resolution. NuSTAR will shed light on some of the hottest, densest, and most energetic objects in the universe.”

Sounds cool, all that sharpness and sensitivity, but what does it all mean? What will those super sharp images tell us?

The magic words: black holes and stellar explosions.

NuSTAR’s super optics permit the observations of active galaxies with black holes at their core (much like the Fermi Large Area Telescope and the Chandra X-Ray Observatory). Some of this is just a more complex form of census taking, looking closely at the center of our own galaxy and surveying the black holes and collapsed stars.  On top of that is the added objective of mapping the composition of the youngest supernova. The hope is by identifying and locating all the materials in a supernova, we will come to a better understanding of the explosive process and how it creates the elements that make up our universe.

The third layer of the science objectives has to do with “relativistic jets.”[1] I find relativistic jets both easy and incredibly difficult to understand. On one hand, a relativistic jet is just a super intense steam of plasma (partially ionized gas) jetting out of the center of active galaxies/black holes/neutron stars. On the other hand, what the heck? You might remember the Internet buzz about this time last summer, when a black hole was observed “devouring” a star. Astronomers stumbled on that example by sheer luck: the Swift satellite was in the right place at the right time—in the path of the star’s remains in the form of a relativistic jet. It’s not so much that we don’t know these jets exist, but the theory of how they exist is still being polished by physicists. NuSTAR observations should help with that.

To keep track of NuSTAR’s discoveries, visit the News and Updates section of the mission site.

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[1] If you’re wondering why they use the word “relativistic,” it’s because the particles move at almost the speed of light (0.99995c!).