A complete radio study of SNR G15.4+0.1 from new GMRT observations

Aims. The supernova remnant (SNR) G15.4+0.1 is considered to be the possible counterpart of the γ-ray source HESS J1818-154. With the goal of getting a complete view of this remnant and understanding the nature of the γ-ray flux, we conducted a detailed radio study that includes the search for pulsa...

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Detalles Bibliográficos
Publicado:	2015
Materias:	Gamma rays: ISM ISM: individual objects: SNR G15.4+0.1 ISM: supernova remnants Radio continuum: ISM Astronomy Pulsars Radio telescopes Supernovae Far infrared wavelengths Galactic plane surveys Gamma rays: isms Giant metrewave radio telescopes ISM: individual objects Spectral energy distribution Gamma rays
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v576_n_p_Supan http://hdl.handle.net/20.500.12110/paper_00046361_v576_n_p_Supan
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00046361_v576_n_p_Supan
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spelling	paper:paper_00046361_v576_n_p_Supan2023-06-08T14:28:10Z A complete radio study of SNR G15.4+0.1 from new GMRT observations Gamma rays: ISM ISM: individual objects: SNR G15.4+0.1 ISM: supernova remnants Radio continuum: ISM Astronomy Pulsars Radio telescopes Supernovae Far infrared wavelengths Galactic plane surveys Gamma rays: isms Giant metrewave radio telescopes ISM: individual objects ISM: supernova remnants Radio continuum: ISM Spectral energy distribution Gamma rays Aims. The supernova remnant (SNR) G15.4+0.1 is considered to be the possible counterpart of the γ-ray source HESS J1818-154. With the goal of getting a complete view of this remnant and understanding the nature of the γ-ray flux, we conducted a detailed radio study that includes the search for pulsations and a model of the broadband emission for the SNR G15.4+0.1/HESS J1818-154 system. Methods. Low-frequency imaging at 624 MHz and pulsar observations at 624 and 1404 MHz towards G15.4+0.1 were carried out with the Giant Metrewave Radio Telescope (GMRT). We correlated the new radio data with observations of the source at X-ray and infrared wavelengths from XMM-Newton and Herschel observatories, respectively. To characterize the neutral hydrogen (HI) medium towards G15.4+0.1, we used data from the Southern Galactic Plane Survey. We modelled the spectral energy distribution (SED) using both hadronic and leptonic scenarios. Results. From the combination of the new GMRT observations with existing data, we derived a continuum spectral index α =-0.62 ± 0.03 for the whole remnant. The local synchrotron spectra of G15.4+0.1, calculated from the combination of the GMRT data with 330 MHz observations from the Very Large Array, tends to be flatter in the central part of the remnant, accompanying the region where the blast wave is impinging molecular gas. No spectral index trace was found indicating the radio counterpart to the pulsar wind nebula proposed from X-ray observations. In addition, the search for radio pulsations yielded negative results. Emission at far-infrared wavelengths is observed in the region where the SNR shock is interacting with dense molecular clumps. We also identified HI features forming a shell that wraps most of the outer border of G15.4+0.1. Characteristic parameters were estimated for the shocked HI gas. We found that either a purely hadronic or leptonic model is compatible with the broadband emission known so far. © 2015 ESO. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v576_n_p_Supan http://hdl.handle.net/20.500.12110/paper_00046361_v576_n_p_Supan
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Gamma rays: ISM ISM: individual objects: SNR G15.4+0.1 ISM: supernova remnants Radio continuum: ISM Astronomy Pulsars Radio telescopes Supernovae Far infrared wavelengths Galactic plane surveys Gamma rays: isms Giant metrewave radio telescopes ISM: individual objects ISM: supernova remnants Radio continuum: ISM Spectral energy distribution Gamma rays
spellingShingle	Gamma rays: ISM ISM: individual objects: SNR G15.4+0.1 ISM: supernova remnants Radio continuum: ISM Astronomy Pulsars Radio telescopes Supernovae Far infrared wavelengths Galactic plane surveys Gamma rays: isms Giant metrewave radio telescopes ISM: individual objects ISM: supernova remnants Radio continuum: ISM Spectral energy distribution Gamma rays A complete radio study of SNR G15.4+0.1 from new GMRT observations
topic_facet	Gamma rays: ISM ISM: individual objects: SNR G15.4+0.1 ISM: supernova remnants Radio continuum: ISM Astronomy Pulsars Radio telescopes Supernovae Far infrared wavelengths Galactic plane surveys Gamma rays: isms Giant metrewave radio telescopes ISM: individual objects ISM: supernova remnants Radio continuum: ISM Spectral energy distribution Gamma rays
description	Aims. The supernova remnant (SNR) G15.4+0.1 is considered to be the possible counterpart of the γ-ray source HESS J1818-154. With the goal of getting a complete view of this remnant and understanding the nature of the γ-ray flux, we conducted a detailed radio study that includes the search for pulsations and a model of the broadband emission for the SNR G15.4+0.1/HESS J1818-154 system. Methods. Low-frequency imaging at 624 MHz and pulsar observations at 624 and 1404 MHz towards G15.4+0.1 were carried out with the Giant Metrewave Radio Telescope (GMRT). We correlated the new radio data with observations of the source at X-ray and infrared wavelengths from XMM-Newton and Herschel observatories, respectively. To characterize the neutral hydrogen (HI) medium towards G15.4+0.1, we used data from the Southern Galactic Plane Survey. We modelled the spectral energy distribution (SED) using both hadronic and leptonic scenarios. Results. From the combination of the new GMRT observations with existing data, we derived a continuum spectral index α =-0.62 ± 0.03 for the whole remnant. The local synchrotron spectra of G15.4+0.1, calculated from the combination of the GMRT data with 330 MHz observations from the Very Large Array, tends to be flatter in the central part of the remnant, accompanying the region where the blast wave is impinging molecular gas. No spectral index trace was found indicating the radio counterpart to the pulsar wind nebula proposed from X-ray observations. In addition, the search for radio pulsations yielded negative results. Emission at far-infrared wavelengths is observed in the region where the SNR shock is interacting with dense molecular clumps. We also identified HI features forming a shell that wraps most of the outer border of G15.4+0.1. Characteristic parameters were estimated for the shocked HI gas. We found that either a purely hadronic or leptonic model is compatible with the broadband emission known so far. © 2015 ESO.
title	A complete radio study of SNR G15.4+0.1 from new GMRT observations
title_short	A complete radio study of SNR G15.4+0.1 from new GMRT observations
title_full	A complete radio study of SNR G15.4+0.1 from new GMRT observations
title_fullStr	A complete radio study of SNR G15.4+0.1 from new GMRT observations
title_full_unstemmed	A complete radio study of SNR G15.4+0.1 from new GMRT observations
title_sort	complete radio study of snr g15.4+0.1 from new gmrt observations
publishDate	2015
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v576_n_p_Supan http://hdl.handle.net/20.500.12110/paper_00046361_v576_n_p_Supan
_version_	1768542388681179136

A complete radio study of SNR G15.4+0.1 from new GMRT observations

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