11 research outputs found
MeerTRAP: Twelve Galactic fast transients detected in a real-time, commensal MeerKAT survey
MeerTRAP is a real-time untargeted search project using the MeerKAT telescope
to find single pulses from fast radio transients and pulsars. It is performed
commensally with the MeerKAT large survey projects (LSPs), using data from up
to 64 of MeerKAT's 13.96~m dishes to form hundreds of coherent beams on sky,
each of which is processed in real time to search for millisecond-duration
pulses. We present the first twelve Galactic sources discovered by MeerTRAP,
with DMs in the range of 33--381~pc~cm. One source may be Galactic or
extragalactic depending on the Galactic electron density model assumed.
Follow-up observations performed with the MeerKAT, Lovell, and Parkes radio
telescopes have detected repeat pulses from seven of the twelve sources. Pulse
periods have been determined for four sources. Another four sources could be
localised to the arcsecond-level using a novel implementation of the tied-array
beam localisation method.Comment: 16 pages, 14 figure
FRB 20210405I: a nearby Fast Radio Burst localised to sub-arcsecond precision with MeerKAT
We present the first sub-arcsecond localised Fast Radio Burst (FRB) detected
using MeerKAT. FRB 20210405I was detected in the incoherent beam using the
MeerTRAP pipeline on 2021 April 05 with a signal to noise ratio of 140.8 and a
dispersion measure of 565.17 pc cm. It was detected while MeerTRAP was
observing commensally with the ThunderKAT large survey project, and was
sufficiently bright that we could use the ThunderKAT 8s images to localise the
FRB. Two different models of the dispersion measure in the Milky Way and halo
suggest that the source is either right at the edge of the Galaxy, or outside.
This highlights the uncertainty in the Milky Way dispersion measure models,
particularly in the Galactic Plane, and the uncertainty of Milky Way halo
models. Further investigation and modelling of these uncertainties will be
facilitated by future detections and localisations of nearby FRBs. We use the
combined localisation, dispersion measure, scattering, specific luminosity and
chance coincidence probability information to find that the origin is most
likely extra-galactic and identify the likely host galaxy of the FRB: 2MASS
J17012494932475. Using SALT spectroscopy and archival observations of the
field, we find that the host is a disk/spiral galaxy at a redshift of
.Comment: 15 pages, 4 tables, 10 figures. Accepted to MNRA
Real-time triggering capabilities for Fast Radio Bursts at the MeerKAT telescope:Proceedings of the ADASS XXX (2020) conference, to appear in ASP Conference Series
Schulverzeichnis. Berufsbildende Schulen Stand: 15.2.1984
SIGLEBibliothek Weltwirtschaft Kiel C124,699 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
First discoveries and localisations of Fast Radio Bursts with MeerTRAP: a real-time, commensal MeerKAT survey
The GMRT High Resolution Southern Sky Survey for pulsars and transients -II. New discoveries, timing and polarization properties
We have been conducting the GMRT High Resolution Southern Sky (GHRSS) survey
for the last four years and have discovered 18 pulsars to date. The GHRSS
survey is an off-Galactic-plane survey at 322 MHz in a region of the sky
(declination range -40 degrees to -54 degrees) complementary to other ongoing
low-frequency surveys. In this paper we report the discovery of three pulsars,
PSRs J1239-48, J1516-43 and J1726-52. We also present timing solutions for
three pulsars previously discovered with the GHRSS survey: PSR J2144-5237, a
millisecond pulsar with a period P=5 ms in a 10 day orbit around a < 0.18 Msun
companion; PSR J1516-43, a mildly recycled P=36 ms pulsar in a 228 day orbit
with a companion of mass ~0.4 Msun; and the P=320 ms PSR J0514-4408 which we
show is a source of pulsed -ray emission. We also report radio
polarimetric observations of three of the GHRSS discoveries, PSRs J0418-4154,
J0514-4408 and J2144-5237.Comment: 29 pages, 9 figures and 5 tables, Accepted for publication in Ap
Discovery of a radio emitting neutron star with an ultra-long spin period of 76 seconds
The radio-emitting neutron star population encompasses objects with spin
periods ranging from milliseconds to tens of seconds. As they age and spin more
slowly, their radio emission is expected to cease. We present the discovery of
an ultra-long period radio-emitting neutron star, J0901-4046, with spin
properties distinct from the known spin and magnetic-decay powered neutron
stars. With a spin-period of 75.88 s, a characteristic age of 5.3 Myr, and a
narrow pulse duty-cycle, it is uncertain how radio emission is generated and
challenges our current understanding of how these systems evolve. The radio
emission has unique spectro-temporal properties such as quasi-periodicity and
partial nulling that provide important clues to the emission mechanism.
Detecting similar sources is observationally challenging, which implies a
larger undetected population. Our discovery establishes the existence of
ultra-long period neutron stars, suggesting a possible connection to the
evolution of highly magnetized neutron stars, ultra-long period magnetars, and
fast radio burstsComment: Published in Nature Astronomy -
https://www.nature.com/articles/s41550-022-01688-