Statistics of Hotspots in Radio Galaxies

TL;DR

This study analyzes the spatial distribution, sizes, and luminosities of hotspots in radio galaxies and quasars using FIRST survey data, revealing asymmetries and bending characteristics related to host type.

Contribution

It provides a comprehensive catalog of hotspots and investigates their geometric properties, highlighting differences between galaxy and quasar hosts.

Findings

Hotspot positions and properties were systematically cataloged.

Confirmed the tendency for brighter hotspots to be closer to the host.

Median bending angle of radio sources is 4.8 degrees, with differences between quasars and galaxies.

Abstract

Based on images from the FIRST survey of the radio sky at 1.4 GHz, the positions of $\sim$5200 hotspots in $\sim$2870 radio galaxies and quasars were compiled, and linear sizes and radio luminosities were derived from the hosts redshifts. For a subsample of $\sim$2100 radio sources with exactly one hotspot in each of the two opposite lobes, their geometry in terms of asymmetry and bending was studied. The known (weak) tendency for the brighter lobe (here hotspot) to lie closer to the host than the fainter one, is confirmed. The median bending angle between the two arms of radio sources is 4.8$^{\circ}$ with a significant difference in the distribution between the 627 quasar hosts and the 1501 galaxies.