A Search for Transient Events at 843 MHz

Abstract

The Molonglo Observatory Synthesis Telescope is equipped with a transient event monitoring system which operates during normal synthesis observations. The device is designed to respond to impulsive signals which occur within the passband (843.0 ± 1.5 MHz) with time scales between 0.001 ms and 800 ms. The multiple beam facility of the telescope provides some discrimination against local interference. An upper limit of 1.7 × 10−2 events s−1 sr−1 has been placed on celestial events with durations between 1 ms and 25 ms and energy density ≥ 10−28 J m−2 Hz−1. The monitoring system has been recently reconfigured to improve the recognition and rejection of impulsive signals of non-celestial origin.

The MOST and Other Radio Telescopes

“…Other special modes are used for tasks such as the calibration of beam gains. • A transient event recorder (Amy et al 1989) looks for impulsive events in whatever field the telescope is observing.…”

Surveying the Dynamic Radio Sky With the Long Wavelength Demonstrator Array

“…Cortiglioni et al (1981), Inzani et al (1982), and Amy et al (1989) all detected some dispersed radio pulses, but found no convincing associations with GRBs. Balsano (1999) found a dispersed radio pulse apparently coincident with GRB 980329, but it was narrowband, which has led to it being interpreted as due to terrestrial interference.…”

“…Our focus is on comparison with MOTOR (Amy et al 1989) and STARE (Katz et al 2003), as both represent nearly all-sky surveys at frequencies below 1 GHz.…”

Radio wavelength transients: Current and emerging prospects

“…Radio Supernovae: Colgate & Noerdlinger (1971) predicted that a supernova explosion should produce a large, broadband radio pulse (< 1 s), though no such pulses have yet been detected (Huguenin & Moore 1974, Kardashev et al 1977). γ-ray Bursts: Cortiglioni et al (1981), Inzani et al (1982), and Amy et al (1989) detected dispersed radio pulses but found no convincing associations with gamma-ray burst sources. Various searches for radio pulses associated with gamma-ray bursts (including precursor pulses) have been conducted (Koranyi et al 1995;.…”