# Gigahertz-peaked spectra pulsars and thermal absorption model

## TL;DR

This study identifies five new gigahertz-peaked spectra pulsars through radio observations and models their spectra with thermal absorption, providing insights into interstellar medium properties and implications for future pulsar surveys.

## Contribution

The paper introduces a thermal free-free absorption model to explain GPS pulsar spectra and constrains the physical parameters of the absorbing medium.

## Key findings

- Identified five new GPS pulsars.
- Modeled spectra to estimate interstellar absorption parameters.
- Suggested optimal frequencies for future GPS pulsar searches.

## Abstract

We present the results of our radio interferometric observations of pulsars at 325 MHz and 610 MHz using the Giant Metrewave Radio Telescope (GMRT). We used the imaging method to estimate the flux densities of several pulsars at these radio frequencies. The analysis of the shapes of the pulsar spectra allowed us to identify five new gigahertz-peaked spectra (GPS) pulsars. Using the hypothesis that the spectral turnovers are caused by thermal free-free absorption in the interstellar medium, we modeled the spectra of all known objects of this kind. Using the model, we were able to put some observational constrains on the physical parameters of the absorbing matter, which allows us to distinguish between the possible sources of absorption. We also discuss the possible effects of the existence of GPS pulsars on future search surveys, showing that the optimal frequency range for finding such objects would be from a few GHz (for regular GPS sources) to possibly 10 GHz for pulsars and radio-magnetars exhibiting very strong absorption.