Zanardo, G;
Staveley-Smith, L;
Indebetouw, R;
Chevalier, RA;
Matsuura, M;
Gaensler, BM;
Barlow, MJ;
... Van Loon, JT; + view all
(2014)
Spectral and morphological analysis of the remnant of Supernova 1987A with ALMA and ATCA.
The Astrophysical Journal
, 796
(2)
, Article 82. 10.1088/0004-637X/796/2/82.
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Abstract
We present a comprehensive spectral and morphological analysis of the remnant of supernova (SN) 1987A with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA). The non-thermal and thermal components of the radio emission are investigated in images from 94 to 672 GHz (λ 3.2 mm to 450 μm), with the assistance of a high-resolution 44 GHz synchrotron template from the ATCA, and a dust template from ALMA observations at 672 GHz. An analysis of the emission distribution over the equatorial ring in images from 44 to 345 GHz highlights a gradual decrease of the east-to-west asymmetry ratio with frequency. We attribute this to the shorter synchrotron lifetime at high frequencies. Across the transition from radio to far infrared, both the synchrotron/dust-subtracted images and the spectral energy distribution (SED) suggest additional emission beside the main synchrotron component (S ν∝ν–0.73) and the thermal component originating from dust grains at T ~ 22 K. This excess could be due to free-free flux or emission from grains of colder dust. However, a second flat-spectrum synchrotron component appears to better fit the SED, implying that the emission could be attributed to a pulsar wind nebula (PWN). The residual emission is mainly localized west of the SN site, as the spectral analysis yields –0.4 lesssim α lesssim –0.1 across the western regions, with α ~ 0 around the central region. If there is a PWN in the remnant interior, these data suggest that the pulsar may be offset westward from the SN position.
| Type: | Article |
|---|---|
| Title: | Spectral and morphological analysis of the remnant of Supernova 1987A with ALMA and ATCA |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1088/0004-637X/796/2/82 |
| Publisher version: | https://doi.org/10.1088/0004-637X/796/2/82 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | ISM: supernova remnants; radiation mechanisms: non-thermal; radiation mechanisms: thermal; radio continuum: general; stars: neutron; supernovae: individual (SN 1987A) |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10093771 |
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