Do radio magnetars J1550-5418 and J1622-4950 have gigahertz-peaked spectra?

TL;DR

This study investigates the radio spectra of two magnetars, suggesting their gigahertz-peaked spectra are caused by environmental effects like free-free absorption, similar to typical pulsars, rather than different emission mechanisms.

Contribution

It demonstrates that radio magnetars can exhibit gigahertz-peaked spectra due to environmental factors, expanding the understanding of pulsar spectral behaviors.

Findings

Both magnetars show flux density decrease below 7 GHz.

The GPS feature is likely caused by surrounding ionized gas.

Magnetars with GPS are similar to typical pulsars in spectral origin.

Abstract

We study the radio spectra of two magnetars PSR J1550-5418 and J1622-4950. We argue that they are good candidates for the pulsars with gigahertz-peaked spectra as their observed flux density decreases at frequencies below 7 GHz. We suggest this behavior is due to the influence of pulsars' environments on the radio waves. Both of the magnetars are associated with supernova remnants, thus are surrounded by a hot, ionized gas, which can be responsible for the free-free absorption of radio-waves. We conclude that the GPS feature of both magnetars and typical pulsars are formed by similar processes in the surrounding media, rather than by different radio-emission mechanisms. Thus, the radio magnetars PSR J1550-5418 and J1622-4950 can be included in the class of the gigahertz-peaked spectra pulsars.