Observations with the 8-meter Gemini North telescope, a program
of the NSF’s National Optical-Infrared Astronomy Research Laboratory,
have allowed astronomers to pinpoint the location of a Fast Radio Burst
in a nearby galaxy — making it the closest known example to Earth and
only the second repeating burst source to have its location pinpointed
in the sky. The source of this burst of radio waves is located in an
environment radically different from that seen in previous studies. This
discovery challenges researchers’ assumptions on the origin of these
already enigmatic extragalactic events.
An unsolved mystery in astronomy has become even more puzzling. The source of Fast Radio Bursts
(FRBs) — sudden bursts of radio waves lasting a few thousandths of a
second — has remained unknown since their discovery in 2007. Research published today in the scientific journal Nature,
and presented at the 235th meeting of the American Astronomical
Society, has pinpointed the origin of an FRB to an unexpected
environment in a nearby spiral galaxy. Observations with the Gemini North telescope of NSF’s Optical-Infrared Astronomy Research Laboratory (OIR Lab)
on Maunakea in Hawai‘i, played a vital role in this discovery, which
renders the nature of these extragalactic radio pulses even more
enigmatic.
The sources of FRBs and their nature are mysterious — many are
one-off bursts but very few of them emit repeated flashes. The recently
discovered FRB — identified by the unpoetic designation FRB
180916.J0158+65 — is one of only five sources with a precisely known
location and only the second such source that shows repeated bursts.
Such FRB’s are referred to as localized and can be associated with a
particular distant galaxy, allowing astronomers to make additional
observations that can provide insights into the origin of the radio
pulse.
“This object’s location is radically different from that of not only
the previously located repeating FRB, but also all previously studied
FRBs,” elaborates Kenzie Nimmo, PhD student at the University of
Amsterdam and a fellow lead author of this paper. “This blurs the
differences between repeating and non-repeating fast radio bursts. It
may be that FRBs are produced in a large zoo of locations across the
Universe and just require some specific conditions to be visible.”
Pinpointing the location of FRB 180916.J0158+65 required observations
at both radio and optical wavelengths. FRBs can only be detected with
radio telescopes, so radio observations are fundamentally necessary to
accurately determine the position of an FRB on the sky. This particular
FRB was first discovered by the Canadian CHIME radio telescope array in
2018[1]. The new research used the European VLBI Network (EVN)[2]
to precisely localize the source, but measuring the precise distance
and local environment of the radio source was only possible with
follow-up optical observations with the Gemini North telescope. The
international Gemini Observatory comprises telescopes in both the
northern and southern hemispheres, which together can access the entire
night sky.
“We used the cameras and spectrographs on the Gemini North telescope
to image the faint structures of the host galaxy where the FRB resides,
measure its distance, and analyze its chemical composition,” explains
Shriharsh Tendulkar, a postdoctoral fellow at McGill University in
Montreal, Canada who led the Gemini observations[3] and
subsequent data analysis. “These observations showed that the FRB
originates in a spiral arm of the galaxy, in a region which is rapidly
forming stars.”
However, the source of FRB 180916.J0158+65 — which lies roughly 500
million light-years from Earth — was unexpected and shows that FRB’s may
not be linked to a particular type of galaxy or environment, deepening
this astronomical mystery[4].
“This is the closest FRB to Earth ever localised,” explains Benito
Marcote, of the Joint Institute for VLBI European Research
Infrastructure Consortium and a lead author of the Nature paper.
“Surprisingly, it was found in an environment radically different from
that of the previous four localised FRBs — an environment that
challenges our ideas of what the source of these bursts could be.”
The researchers hope that further studies will reveal the conditions
that result in the production of these mysterious transient radio
pulses, and address some of the many unanswered questions they pose.
Corresponding author Jason Hessels of the Netherlands Institute for
Radio Astronomy (ASTRON) and the University of Amsterdam states that
“our aim is to precisely localize more FRBs and, ultimately, understand
their origin.”
“It’s a pleasure to see different observing facilities complement one
another during challenging high-priority investigations such as this,”
concludes Luc Simard, Gemini Board member and Director General of
NRC-Herzberg, which hosts CHIME, as well as the Canadian Gemini Office.
“We are particularly honored to have the opportunity to conduct
astronomical observations on Maunakea in Hawai’i. This site’s
exceptional observing conditions are vital to making astronomical
discoveries such as this.”
Chris Davis, National Science Foundation Program Officer for Gemini
adds, “understanding the origin of FRBs will undoubtedly be an exciting
challenge for astronomers in the 2020s; we’re confident that Gemini will
play an important role, and it seems fitting that Gemini has made these
important observations at the dawn of the new decade.”
Notes
[1] The Canadian Hydrogen Intensity Mapping Experiment (CHIME)
collaboration operates an innovative radio telescope at the Dominion
Radio Astrophysical Observatory in Canada. The CHIME telescope’s novel
construction makes it particularly adept at discovering FRBs such as FRB
180916.J0158+65.
[2] Radio observations were made using eight radio telescopes
of the European Very Long Baseline Interferometry Network (EVN)
following the discovery of FRB 180916.J0158+65 by the CHIME/FRB
Collaboration.
[3] The Gemini observations were made between July and
September of 2019 using the Gemini Multi-Object Spectrograph (GMOS) on
the Gemini North telescope on Hawaii’s Maunakea.
[4] Prior to the observations announced today, the evidence
hinted at the possibility that repeating and non-repeating FRBs were
formed in very different environments. The only repeating FRB apart from
FRB 180916.J0158+65 with a precisely determined location was found to
inhabit a region of massive star formation inside a dwarf galaxy.
Conversely, the three localized non-repeating FRBs were all found in
massive galaxies and appear not to be associated with star-forming
regions, leading to speculation that there were two separate types of
FRB.
More information
This research was presented in a paper in Nature entitled “A repeating fast radio burst source localized to a nearby spiral galaxy”.
NSF’s National Optical-Infrared Astronomy Research Laboratory, the US
center for ground-based optical-infrared astronomy, operates the Gemini
Observatory (a facility of NSF, NRC–Canada, CONICYT–Chile, MCTI–Brazil,
MCTIP–Argentina, and KASI–Republic of Korea), Kitt Peak National
Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the
Community Science and Data Center (CSDC), and the Large Synoptic Survey
Telescope (LSST, a facility that will be jointly operated by NSF and
DOE). It is managed by the Association of Universities for Research in
Astronomy (AURA) under a cooperative agreement with NSF and is
headquartered in Tucson, Arizona. The astronomical community is honored
to have the opportunity to conduct astronomical research on Iolkam Du’ag
(Kitt Peak) in Arizona, on Maunakea in Hawai’i, and on Cerro Tololo and
Cerro Pachón in Chile. We recognize and acknowledge the very
significant cultural role and reverence that these sites have to the
Tohono O’odham Nation, to the Native Hawaiian community, and to the
local Communities in Chile, respectively.
Contacts:
Peter Michaud
NewsTeam Manager
NSF’s National Optical-Infrared Astronomy Research Laboratory
Gemini Observatory, Hilo HI
Desk:: +1 808-974-2510
Cell: +1 808-936-6643
Email: pmichaud@gemini.edu
Jason Hessels
University of Amsterdam & ASTRON
Email: j.w.t.hessels@uva.nl
Phone: +31 610260062
Shriharsh Tendulkar
McGill University
Email: shriharsh@physics.mcgill.ca
Source: Gemini Observatory
