Radio wavelength transients: Current and emerging prospects

Abstract

Known classes of radio wavelength transients range from the nearby-stellar flares and radio pulsars-to the distant Universe-γ-ray burst afterglows. Hypothesized classes of radio transients include analogs of known objects, e.g., extrasolar planets emitting Jovian-like radio bursts and giant-pulse emitting pulsars in other galaxies, to the exotic, prompt emission from γ-ray bursts, evaporating black holes, and transmitters from other civilizations. A number of instruments and facilities are either under construction or in early observational stages and are slated to become available in the next few years. With a combination of wide fields of view and wavelength agility, the detection and study of radio transients will improve immensely.

A first search of transients in the Galactic center from 230 GHz ALMA observations

“…4 shows the dispersion in the edges of the scan during the track. Some expected time duration for radio transient emissions are given in Lazio (2008), Chiti et al (2016) and We have thus set the detection threshold of transients to peak excursion of 7 times the instantaneous rms between consecutive images, which also gives a very low probability of false detection from thermal noise. Supposing that noise follows a normal distribution, we have computed the number of beams that form the image Fig.…”

“…Many astronomical compact radio sources manifest as transients (e.g., Cordes et al, 2004;Lazio, 2008;Lorimer, 2018;Murphy, 2021). Usually, such sources originate from explosive or dynamic events, for example, outbursting Xray binaries (Bower et al, 2005;Generozov et al, 2018).…”