from the or-is-it-inter-galactic-wifi? dept.
Fast radio bursts (FRBs) may be caused by neutron stars (pulsars) experiencing unusual conditions, such as proximity to a black hole or a highly magnetized wind nebula:
The first FRB was discovered in 2007, in archived data from the Parkes Radio Telescope in Australia. Astronomers were searching for new examples of magnetised neutron stars called pulsars, but found a new phenomenon - a radio burst from 2001. Since then, 18 FRBs - also referred to as "flashes" or "sizzles" - have been found in total.
The mystery surrounding their nature has spawned a variety of different possible explanations, from black holes to extra-terrestrial intelligence.
Only one of these sources of radio energy has erupted more than once - a so-called burster catalogued as FRB 121102. This FRB has sent out around 150 flashes since its discovery in 2012.
A chatty source of radio waves from deep space has a little more to say. Six more blasts of radio energy, each lasting just a few milliseconds, erupted from some phenomenon outside of our galaxy, researchers report in the Dec. 20 Astrophysical Journal. This detection follows 11 previously recorded outbursts of radio waves from the same location, the only known repeater in a class of enigmatic eruptions known as fast radio bursts.
The origins of these radio bursts, 18 of which have been reported since 2007, are an ongoing puzzle ( ScienceNews: 8/9/14, p. 22 [paywalled] ). The continuing barrage from this repeating source, roughly 3 billion light-years away in the constellation Auriga, implies that whatever is causing some radio bursts is not a one-time destructive event such as a collision or explosion. Flares from a young neutron star, the dense core left behind after a massive star explodes, are a promising candidate.
The latest volley was detected in late 2015, Paul Scholz, a graduate student at McGill University in Montreal, and colleagues report. Five blasts were recorded at the Green Bank Telescope in West Virginia and one at Arecibo Observatory in Puerto Rico. This object was first detected at Arecibo in 2012. Ten more blasts followed in May and June 2015 ( ScienceNews: 4/2/16, p. 12 ).
Breakthrough Listen, an initiative to find signs of intelligent life in the universe, has detected 15 brief but powerful radio pulses emanating from a mysterious and repeating source – FRB 121102 – far across the universe.
Fast radio bursts are brief, bright pulses of radio emission from distant but largely unknown sources, and FRB 121102 is the only one known to repeat: more than 150 high-energy bursts have been observed coming from the object, which was identified last year as a dwarf galaxy about 3 billion light years from Earth.