Astronomers using the Chandra X-ray Observatory have detected an unusual mark left by collision between an “unidentified object” and a powerful cosmic jet, NASA has revealed.
The discovery was made during observations of a galaxy 12 million light-years from Earth called Centaurus A, an ongoing subject of investigation by astronomers due to the massive black hole at its center.
The galaxy’s black hole produces extremely strong jets of high-energy particles, a byproduct of the powerful gravitational fields and magnetic envelope surrounding Centaurus A.
Now, data obtained by the Chandra X-ray Observatory reveals that the supermassive black hole’s powerful jet was involved in a cosmic collision that led to it “striking an unidentified object in its path,” the space agency reported on Tuesday.
Imagery obtained by Chandra revealed X-rays ranging from pink to purple and blue, representing energy levels from those lowest to highest detectable, in what NASA characterizes as the deepest X-ray images ever obtained of Centaurus A.
Portions of the jet produced by the galaxy’s black hole are believed to be moving at a rate approaching light speed, revealing a V-shaped patch of emission associated with a previously undetected luminous source of X-rays astronomers have dubbed C4.
Centaurus A, C4’s X-rays and a “Mystery Object”
C4 is positioned near the path of the black hole’s jet, giving rise to 700-light-year-long “arms” extending from the point of the V-shaped emission source in the new images.
Each of the V’s arms comprises an astonishing cosmic length of nearly double the distance from Earth to our nearest neighboring star in the Milky Way.
However, arguably the most intriguing component of this distant galactic picture involves the object being blasted by the black hole’s jet, which will likely remain a mystery for some time to come, given that the unidentified object—whatever it is—is too far away to be discernible with even the strongest telescopes presently available to astronomers.
Theories Emerge About a Cosmic Collision
Presently, astronomers have several ideas about what the unseen object may be.
One possibility is that it could be a large star, or possibly even a pair of them. The gases ejected outward from these stars in the form of stellar winds could be colliding with particles in the jet, giving rise to the X-rays seen emanating from C4.
Astronomers have pointed out that one mechanism for the appearance of the X-ray emissions Chandra obtained could be their ignition, which is likely the result of turbulence created as the suspected stellar gases collide with the black hole jet’s highly charged particles.
However, there are other theories, too.
One problem with the stellar collision idea involves the V-shaped appearance of the bright source of X-rays, C4. While the “V” it produces is clearly discernible, what causes its shape presently remains unknown. One of the V’s arms is especially problematic for astronomers, due to its exceptional angle in relation to the black hole’s jet, which makes it difficult to explain.
Although the feature is unique, the recent observations of C4 are just one instance where a black hole jet appears to be colliding with celestial objects in Centaurus A. In fact, there are a few other known examples where stars and extremely large clouds of gas appear to intersect with the jet’s path.
A Unique Collision with a V-Shape
What makes C4 unique among these cosmic collisions is the distinctive V-shaped X-ray signature it generates, compared with the typically elliptical shapes other collisions produce.
Presently, additional corroboration with other space observatories is impossible, since Chandra is the only one with instruments capable of detecting such features. Still, additional observations with Chandra could eventually help determine what makes C4 so different in appearance from other black hole jet intersections with surrounding objects.
It remains unclear for the time being whether future observations by Chandra will be able to help identify the mystery object involved in the cosmic collision with Centaurus A’s jet, given its extreme distance from Earth.
The discovery was recently detailed in a new paper, “Superluminal proper motion in the X-ray jet of Centaurus A,” by D. Bogensberger, J. Miller, et al, which appeared in The Astrophysical Journal.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.