398 research outputs found
The AARTFAAC 60 MHz transients survey
We report the experimental setup and overall results of the AARTFAAC
wide-field radio survey, which consists of observing the sky within 50
of Zenith, with a bandwidth of 3.2MHz, at a cadence of 1s, for
545h. This yielded nearly 4 million snapshots, two per second, of on
average 4800 square degrees and a sensitivity of around 60Jy. We find two
populations of transient events, one originating from PSRB095008 and one
from strong ionospheric lensing events, as well as a single strong candidate
for an extragalactic transient, with a peak flux density of Jy and
a dispersion measure of , We also set a strong
upper limit of 1.1 all-sky per day to the rate of any other populations of
fast, bright transients. Lastly, we constrain some previously detected types of
transient sources by comparing our detections and limits with other
low-frequency radio transient surveys.Comment: 10 pages, 8 figures. Published by MNRA
SCUBA Observations of the Host Galaxies of Gamma-Ray Bursts
In recent years, a population of galaxies with huge infrared luminosities and dust masses has been discovered in the submillimetre. Observations suggest that the AGN contribution to the luminosities of these submillimetre-selected galaxies is low; instead their luminosities are thought to be mainly due to strong episodes of star formation following merger events. Our current understanding of GRBs as the endpoints in the life of massive stars suggest that they will be located in such galaxies.We have observed a sample of well-located GRB host galaxies in the submillimetre. Comparing the results with the general submillimetre-selected galaxy population, we find that at low fluxes (S850 ≤ 4 mJy), the two agree well. However, there is a lack of bright GRB hosts in the submillimetre. This finding is reinforced when the results of other groups are included. Possible explanations are discussed. These results help us assess the roles of both GRB host galaxies and submillimetre-selected galaxies in the evolution of the Universe
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