Optical sky image of the area in the constellation Auriga where the fast radio burst FRB 121102 has been detected. The position of the burst, between the old supernova remnant S147 (left) and the star formation region IC 410 (right) is marked with a green circle. The burst appears to originate from much deeper in space, far beyond our galaxy.
© Rogelio Bernal Andreo (DeepSkyColors.com)
Arecibo 305 m radio telescope, located in a natural valley in Puerto Rico. © NAIC
Newly detected short radio pulse appears to come from far beyond our galaxy
The discovery of a split-second burst of radio waves using the Arecibo radio telescope in Puerto Rico provides important new evidence of mysterious pulses that appear to come from deep in outer space.
The findings by an international team of astronomers led by Laura Spitler from the Max Planck Institute for Radio Astronomy in Bonn, Germany are published on July 10 in the online issue of The Astrophysical Journal. They mark the first time that a so-called "fast radio burst" has been detected in the Northern hemisphere of the sky
Fast radio bursts (FRBs) are bright flashes of radio waves that last
only a few thousandths of a second. Scientists using the Parkes
Observatory in Australia have recorded such events for the first time,
but the lack of any similar findings by other facilities led to
speculation that the Australian instrument might have been picking up
signals originating from sources on or near Earth. The discovery at
Arecibo is the first detection of a fast radio burst using an instrument
other than the Parkes radio telescope. The position of the radio burst
is in the direction of the constellation Auriga in the Northern sky.
"There are only seven bursts every minute somewhere in the sky on
average, so you have to be pretty lucky to have your telescope pointed
in the right place at the right time", says Laura Spitler from Max
Planck Institute for Radio Astronomy (MPIfR) in Bonn, the lead author of
the paper. "The characteristics of the burst seen by the Arecibo
telescope, as well as how often we expect to catch one, are consistent
with the characteristics of the previously observed bursts from Parkes."
"Our result is important because it eliminates any doubt that these
radio bursts are truly of cosmic origin," continues Victoria Kaspi, an
astrophysics professor at McGill University in Montreal and Principal
Investigator for the pulsar-survey project that detected this fast radio
burst. "The radio waves show every sign of having come from far outside
our galaxy – a really exciting prospect."
Exactly what may be causing such radio bursts represents a major new
enigma for astrophysicists. Possibilities include a range of exotic
astrophysical objects, such as evaporating black holes, mergers of
neutron stars, or flares from magnetars — a type of neutron star with
extremely powerful magnetic fields.
"Another possibility is that they are bursts much brighter than the
giant pulses seen from some pulsars," notes James Cordes, a professor of
astronomy at Cornell University and co-author of the new study.
The unusual pulse was detected on November 02, 2012, at the Arecibo
Observatory with the world’s largest and most sensitive single-dish
radio telescope, with a radio-mirror spanning 305 metres and covering
about 20 acres.
While fast radio bursts last just a few thousandths of a second and
have rarely been detected, the new result confirms previous estimates
that these strange cosmic bursts occur roughly 10,000 times a day over
the whole sky. This astonishingly large number is inferred by
calculating how much sky was observed, and for how long, in order to
make the few detections that have so far been reported.
The bursts appear to be coming from beyond the Milky Way galaxy based
on measurements of an effect known as plasma dispersion. Pulses that
travel through the cosmos are distinguished from man-made interference
by the effect of interstellar electrons, which cause radio waves to
travel more slowly at lower radio frequencies. The burst detected by the
Arecibo telescope has three times the maximum dispersion measurement
that would be expected from a source within the galaxy, the scientists
report.
The discovery was made as part of the Pulsar Arecibo L-Band Feed
Array (PALFA) survey, which aims to find a large sample of pulsars and
to discover rare objects useful for probing fundamental aspects of
neutron star physics and testing theories of gravitational physics.
The research was supported by grants from the European Research
Council, the National Science Foundation, the Natural Sciences and
Engineering Research Council of Canada, the Fonds de recherche du Québec
- Nature et technologies, and the Canadian Institute for Advanced
Research, among others.
The Arecibo Observatory is operated by SRI International in alliance
with Ana G. Méndez-Universidad Metropolitana and the Universities Space
Research Association, under a cooperative agreement with the National
Science Foundation (AST-1100968).
The data were processed on the ATLAS cluster of the Max Planck
Institute for Gravitational Physics/Albert Einstein Institute, Hannover,
Germany.
Local Contacts
Dr. Laura Spitler
Phone:+48 228 525-108
Email: lspitler@mpifr-bonn.mpg.de
Max-Planck-Institut für Radioastronomie, Bonn
Dr. Paulo Freire
Phone:+49 228 525-396
Email: pfreire@mpifr-bonn.mpg.de
Max-Planck-Institut für Radioastronomie, Bonn
Dr. Norbert Junkes
Presse- und Öffentlichkeitsarbeit
Phone:+49 228 525-399
Max-Planck-Institut für Radioastronomie, Bonn
