Astrophysicists finally decipher weird beams emanating from Manatee Nebula

The Manatee Nebula is up to something strange, and astrophysicists with X-ray telescopes have finally figured it out.

If we could see it with our unaided eyes, the Manatee Nebula would take up a swath of sky four times wider than the full Moon. The expanding cloud of gas is what’s left of a massive star that exploded about 30,000 years ago.

Most of the time, the demise of a massive star leaves behind the star’s core in the form of a super-dense ball of neutrons called a neutron star. In the heart of the Manatee Nebula, however, what’s left is a black hole, blasting X-rays and charged particles into space at a quarter of the speed of light. And those relativistic jets, as astronomers call them, are doing something that, until very recently, experts couldn’t explain.

In this false-color image from XMM-Newton (which includes radio data from the Very Large Array radio telescope in New Mexico and optical data from the Skinakas Observatory in Greece), the red dot in the center is the black hole, officially known as SS 433.

• Yellow represents so-called “soft” X-rays with wavelengths of about 10 nanometers
• Magenta represents “medium” X-rays
• Cyan represents “hard” X-rays with wavelengths between 0.1 and 0.01 nanometers.
• Red represents radio wavelengths.
• Green represents optical wavelengths.

In 2018, a team of astronomers noticed that something in the Manatee Nebula was sending very high-energy particles zipping toward Earth. Each particle carried hundreds of teravolts of energy (a teravolt is a trillion volts or about as much energy as 1,000 bolts of lightning). And although they were clearly coming from somewhere in the Manatee Nebula, astronomers couldn’t pinpoint their exact source — or what was pumping so much energy into these particles.

The European Space Agency’s XMM-Newton space telescope and NASA’s Chandra and NuSTAR space telescopes — all of which specialize in detecting X-ray radiation from distant objects — recently teamed up to find the answer. It turns out that, if you can see the manatee shape that gives the nebula its name, the high-energy particles are coming from the manatee’s head.

Because the relativistic jets from the Manatee Nebula’s black hole move much faster than the expanding gas cloud, they quickly catch up with the leading edge of the gas and punch a hole through it on their way out into space. One of those jets seems to be hitting a shock wave in the gas cloud, and that interaction is ramping up the energy in the jet’s particles. Specifically, that happens about 100 light years away from the black hole and continues about 200 light years along the jet’s length.

That sheds a little more light on how different structures within a supernova remnant interact. Astrophysicists can apply that to other supernova remnants to better understand the life, violent end, and afterlife of the universe’s most massive stars.

Astrophysicist Samar Safi-Harb of the University of Manitoba and her colleagues published their findings in The Astrophysical Journal.