OrbitalHub

NASA dicit:

This is a sonification of X-ray light emitted by the Crab Nebula. The data was obtained by NASA’s NuSTAR and Chandra space observatories, whose teams turned the data into sound to enable people to audibly perceive different features of the Crab Nebula, making it more accessible for the visually impaired.

In this sonification, X-ray wavelengths from NuSTAR (represented as different colors) are mapped to different musical pitches and sounds. Red, yellow, purple, blue, and white are mapped to notes from low to high. For Chandra, brightness in the X-ray data corresponds with pitch and volume, and a bell sound indicates the position of the pulsar at the center of the nebula.

The Crab Nebula is what remains of a star that exploded as a supernova. The explosion that created the Crab Nebula was visible from Earth in the year 1054, when it was recorded by Chinese astronomers. Most of the star’s mass was pushed into space, creating a wide debris field that continues to expand.

The rest of the stellar material collapsed into a dense object called a pulsar. The pulsar’s rapid rotation and strong magnetic field accelerate particles and shoot them into space.The particles emit high-energy X-rays that NuSTAR can detect, but as they travel outward, they collide with the debris scattered by the supernova, causing them to slow down and lose their energy. This is why NuSTAR only sees light from a relatively small region close to the pulsar. Lower energy X-rays detected by Chandra can be seen farther out.

Video credit: NASA/JPL-Caltech/CXC/SAO

NASA dixit:

“A new study using data from NASA’s NuSTAR space telescope suggests that the most luminous and massive stellar system within 10,000 light-years, Eta Carinae, is accelerating particles to high energies — some of which may reach Earth as cosmic rays. Cosmic rays with energies greater than 1 billion electron volts (eV) come to us from beyond our solar system. But because these particles — electrons, protons and atomic nuclei — all carry an electrical charge, they veer off course whenever they encounter magnetic fields. This scrambles their paths and masks their origins. Eta Carinae, located about 7,500 light-years away in the southern constellation of Carina, contains a pair of massive stars whose eccentric orbits bring them unusually close every 5.5 years. The stars contain 90 and 30 times the mass of our Sun.

Both stars drive powerful outflows called stellar winds, which emit low-energy X-rays where they collide. NASA’s Fermi Gamma-ray Space Telescope observes gamma rays — light packing far more energy than X-rays — from a source in the direction of Eta Carinae. But Fermi’s vision isn’t as sharp as X-ray telescopes, so astronomers couldn’t confirm the connection. To bridge this gap, astronomers turned to NASA’s NuSTAR observatory. Launched in 2012, NuSTAR can focus X-rays of much greater energy than any previous telescope.

The team examined NuSTAR observations acquired between March 2014 and June 2016, along with lower-energy X-ray observations from the European Space Agency’s XMM-Newton satellite over the same period. NuSTAR detects a source emitting X-rays above 30,000 eV, some three times higher than can be explained by shock waves in the colliding winds. For comparison, the energy of visible light ranges from about 2 to 3 eV.

The researchers say both the X-ray emission seen by NuSTAR and the gamma-ray emission seen by Fermi is best explained by electrons accelerated in shock waves where the winds collide. The X-rays detected by NuSTAR and the gamma rays detected by Fermi arise from starlight given a huge energy boost by interactions with these electrons. Some of the superfast electrons, as well as other accelerated particles, must escape the system and perhaps some eventually wander to Earth, where they may be detected as cosmic rays. Zoom into Eta Carinae, where the outflows of two massive stars collide and shoot accelerated particles cosmic rays into space.”

Credits Music: “Expectant Aspect” from Killer Tracks

Credits Video: NASA’s Goddard Space Flight Center

Credits: NASA/CXC/J.Hester (ASU); NASA/ESA/J.Hester & A.Loll (ASU); NASA/JPL-Caltech/R.Gehrz (Univ. Minn.)

Carnival of Space #97 is hosted by Cheap Astronomy.

This week you can read about the Mars Express webcam, HiRISE images of a Martian avalanche, dark energy, high speed solar sails, and much more.

This week, OrbitalHub presents the Nuclear Spectroscopic Telescope Array (NuSTAR). NuSTAR is a high-energy X-ray space telescope that will expand our understanding of the origins and the development of stars and galaxies.

Credits: NASA/JPL

The Nuclear Spectroscopic Telescope Array (NuSTAR) is a high-energy X-ray space telescope that will expand our understanding of the origins and the development of stars and galaxies.

NuSTAR was proposed to NASA in May 2003. In 2006, while NuSTAR was undergoing an extended feasibility study, NASA cancelled the program due to budgetary constraints. However, in September 2007, the program was restarted.

In 2007, Orbital Sciences Corporation was selected by NASA to design, manufacture, and test the NuSTAR telescope.

The spacecraft is based on a proven design, used by Orbital for other NASA Small Explorer missions: SORGE, GALEX, AIM, and OCO. NuSTAR will have a launch mass of 360 kg, and will be powered by articulated solar arrays providing 600 W.

The spacecraft incorporates a ten-meter long extendable mast. The mast allows the telescope to fit into a small launch vehicle.

The technology used to build the telescope is not new. A team of researchers, led by Dr. Fiona Harrison, professor of physics and astronomy at Caltech, has been improving the NuSTAR technology for the last ten years. A previous high energy X-ray telescope (High Energy Focusing Telescope or HEFT) was developed as part of a high altitude balloon payload.

The currently operational X-ray telescopes, Chandra and XMM-Newton, observe the sky in the low energy X-ray spectrum (X-ray energies less than 10 keV). NuSTAR will make observations in a higher range, up to 79 keV. As much of the energy emitted by a black hole is absorbed by the surrounding gas and dust, observations in the high-energy X-ray spectrum can reveal in greater detail what is happening closer to the event horizon.

Credit: NASA/CXC/CfA/R.Kraft et al./MPIfR/ESO/APEX/A.Weiss et al./ESO/WFI

The NuSTAR telescope will have a sensitivity two orders of magnitude greater than any other instrument used to detect black holes. NuSTAR will help scientists understand how black holes are distributed throughout the universe, and what powers the most active galaxies.

The NuSTAR instrument consists of two co-aligned hard X-ray telescopes. The ten-meter mast mentioned above separates the mirrors and the imaging detectors. The detectors are Cadmium Zinc Telluride (CdZnTe) detectors and do not require cryogenic operation.

On February 9, 2009, NASA awarded Orbital the launch services contract for the NuSTAR mission. The telescope will be launched in 2011 aboard a Pegasus XL launch vehicle. Pegasus XL will be carried beneath a L-1011 aircraft and released over the Pacific Ocean. The air-launch system is very cost-effective, providing flexibility during operation and requiring minimal ground support.

NuSTAR will be deployed into a 525×525 km low Earth orbit (LEO) with a twenty-seven degree inclination.

For more details about the science of NuSTAR, you can visit the mission’s home page at Caltech. Orbital has also posted a NuSTAR fact sheet on their web site.