Radio and infrared study of the supernova remnant candidate HESS J1912+101

¹ CONICET-Universidad de Buenos Aires, Instituto de Astronomía y Física del Espacio (IAFE), Intendente Guiraldes 2160, Ciudad Universitaria, (C1428EGA) Buenos Aires, Argentina
e-mail: duvidovich@iafe.uba.ar
² Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Intendente Guiraldes 2160, Ciudad Universitaria, (C1428EGA) Buenos Aires, Argentina
³ Universidad de Buenos Aires, Ciclo Básico Común, Ramos Mejía 841, (C1405CAE) Buenos Aires, Argentina
e-mail: apetriella@iafe.uba.ar

Received: 29 December 2022
Accepted: 23 February 2023

Abstract

Aims. We provide new insights into the γ-ray emission from HESS J1912+101, a TeV supernova remnant candidate probably associated with the radio pulsar PSR J1913+1011.

Methods. We obtained new observations at 1.5 GHz using the VLA in the D configuration, with the purpose of detecting the radio shell of the putative remnant. In addition, we observed a single pointing at 6.0 GHz toward PSR J1913+1011 to look for a radio pulsar wind nebula. We also studied the properties of the surrounding interstellar medium using data of the ¹³CO, HI, and infrared emissions, obtained from public surveys.

Results. We do not find evidence of a radio shell down to the sensitivity of the new image at 1.5 GHz. We detect faint diffuse emission around PSR J1913+1011 at 6.0 GHz, which could represent a radio pulsar wind nebula powered by the pulsar. We find dense ambient gas at ~60 km s⁻¹, which shows a good spatial correspondence with the TeV emission only in the western and eastern directions. There is also dense gas near the center of HESS J1912+101, where the TeV emission is weak. Using infrared data, we identify an active star-forming region in the western part of the shell.

Conclusions. Based on the poor spatial match between the ambient gas and the TeV emission (which shows a good correlation in the western and eastern directions and an anticorrelation in the other directions), we conclude that the hadronic mechanism alone does not give a satisfactory explanation of the γ rays from HESS J1912+101. Additional contributions may come from leptonic processes in the shell of the supernova remnant, together with contributions from PSR J1913+1011 and its pulsar wind nebula and/or from the star-forming region. A confident determination of the distance to the putative remnant is necessary to determine whether these sources are associated or just appear superimposed in the line of sight.