First high-resolution radio study of the Supernova Remnant G338.3-0.0 associated with the gamma-ray source HESS J1640-465

Abstract

We report on a multifrequency radio study of the supernova remnant (SNR) G338.3-0.0, in positional coincidence with the TeV source HESS J1640-465. To carry out this research we observed the SNR G338.3-0.0 using the Giant Metrewave Radio Telescope (GMRT) at 235, 610, and 1280 MHz. We also reprocessed archival data from the Australia Telescope Compact Array (ATCA) at 1290 and 2300 MHz. Also we conducted a search for radio pulsations towards a central point-like source, using the GMRT antennas at 610 and 1280 MHz. The molecular material in the region of the SNR was investigated based on observations made with the NANTEN telescope in the 12^CO (J=1-0) emission line. The new radio observations revealed a remnant with a bilateral morphology, which at 235 MHz has the western wing completely attenuated because of absorption due to foreground ionized gas. The quality of the new images allows us to provide accurate estimates for the total radio flux density of the whole SNR at different radio frequencies. From the new and existing flux density estimates between 235 and 5000 MHz we derived for the whole remnant a spectral index alpha=-0.51 +/-0.06 with a local free-free continuum optical depth at 235 MHz tau_{235}=0.9+/-0.3. No radio pulsations were detected towards the only radio point-like source within the HESS error circle. We derived upper limits of 2.0 and 1.0 mJy at 610 and 1280 MHz, respectively, for the pulsed flux towards this source. No radio counterpart was found for the pulsar wind nebula discovered in X-rays. The inspection of the interstellar molecular gas towards G338.3-0.0 and surroundings revealed that there is not any associated dense cloud that might explain a hadronic origin for the TeV detection.

7 pages, 4 figures. Accepted for publication in A&A

References in corpus (4)

• Fermi Detection of the Pulsar Wind Nebula HESS J1640-465
• Deep 610-MHz GMRT observations of the Spitzer extragalactic First Look Survey field - I. Observations, data analysis and source catalogue
• XMM-Newton observations reveal the X-ray counterpart of the very-high-energy gamma-ray source HESSJ1640-465
• High Resolution X-ray Observations of the Pulsar Wind Nebula Associated with the Gamma-ray Source HESSJ1640-465

Cited by in corpus (13)

• Radio emission from Supernova Remnants
• The Dipole Magnetic Field and Spin-down Evolutions of The High Braking Index Pulsar PSR J1640-4631
• The soft gamma-ray pulsar population: an high-energy overview
• The radio surface brightness to diameter relation for galactic supernova remnants: sample selection and robust analysis with various fitting offsets
• NuSTAR Discovery of a Young, Energetic Pulsar Associated with the Luminous Gamma-ray Source HESS J1640-465
• HESS J1640-465 - an exceptionally luminous TeV gamma-ray supernova remnant
• Interstellar gas towards the TeV gamma-ray sources HESS J1640-465 and HESS J1641-463
• Neutron Star Physics in the Square Kilometer Array Era : An Indian Perspective
• HESS J1640-465 -- a Gamma-ray emitting pulsar wind nebula ?
• The environment of the gamma-ray emitting SNR G338.3-0.0: a hadronic interpretation for HESS J1640-465
• Constraining the origin of the puzzling source HESS J1640-465 and the PeVatron candidate HESS J1641-463 using Fermi-LAT observations
• A Self-Consistent Explanation of TeV Emissions from HESS J1640-465 and HESS J1641-463
• Broadband X-ray Spectroscopy of the Pulsar Wind Nebula in HESS J1640-465