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Title: Gigahertz-peaked Spectra Pulsars and Thermal Absorption Model

Abstract

We present the results of our radio interferometric observations of pulsars at 325 and 610 MHz using the Giant Metrewave Radio Telescope. 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 constraints 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.

Authors:
; ; ;  [1];  [2]
  1. Janusz Gil Institute of Astronomy, University of Zielona Góra, ul. Z. Szafrana 2, PL-65-516 Zielona Góra (Poland)
  2. DLR Institute of Space Systems, Robert-Hooke-Str. 7 D-28359 Bremen (Germany)
Publication Date:
OSTI Identifier:
22663603
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 840; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; FLUX DENSITY; GHZ RANGE; LIMITING VALUES; LINEAR ABSORPTION MODELS; MHZ RANGE; NEUTRON STARS; PULSARS; RADIO TELESCOPES; RADIOWAVE RADIATION; SPECTRA; SUPERNOVA REMNANTS

Citation Formats

Kijak, J., Basu, R., Lewandowski, W., Rożko, K., and Dembska, M., E-mail: jkijak@astro.ia.uz.zgora.pl. Gigahertz-peaked Spectra Pulsars and Thermal Absorption Model. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA6FF2.
Kijak, J., Basu, R., Lewandowski, W., Rożko, K., & Dembska, M., E-mail: jkijak@astro.ia.uz.zgora.pl. Gigahertz-peaked Spectra Pulsars and Thermal Absorption Model. United States. doi:10.3847/1538-4357/AA6FF2.
Kijak, J., Basu, R., Lewandowski, W., Rożko, K., and Dembska, M., E-mail: jkijak@astro.ia.uz.zgora.pl. Wed . "Gigahertz-peaked Spectra Pulsars and Thermal Absorption Model". United States. doi:10.3847/1538-4357/AA6FF2.
@article{osti_22663603,
title = {Gigahertz-peaked Spectra Pulsars and Thermal Absorption Model},
author = {Kijak, J. and Basu, R. and Lewandowski, W. and Rożko, K. and Dembska, M., E-mail: jkijak@astro.ia.uz.zgora.pl},
abstractNote = {We present the results of our radio interferometric observations of pulsars at 325 and 610 MHz using the Giant Metrewave Radio Telescope. 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 constraints 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.},
doi = {10.3847/1538-4357/AA6FF2},
journal = {Astrophysical Journal},
number = 2,
volume = 840,
place = {United States},
year = {Wed May 10 00:00:00 EDT 2017},
month = {Wed May 10 00:00:00 EDT 2017}
}