TY - JOUR
T1 - Spectral and morphological analysis of the remnant of supernova 1987A with alma and atca
AU - Zanardo, Giovanna
AU - Staveley-Smith, Lister
AU - Indebetouw, R.
AU - Chevalier, R.A.
AU - Matsuura, M.
AU - Gaensler, B.M.
AU - Barlow, M.J.
AU - Fransson, C.
AU - Manchester, R.N.
AU - Baes, M.
AU - Kamenetzky, J.R.
AU - Lakićević, M.
AU - Lundqvist, P.
AU - Márcaide, J.M.
AU - Martí-Vidal, I.
AU - Meixner, M.M.
AU - Chi Yung, N.
AU - Park, S.
AU - Sonneborn, G.
AU - Spyromilio, J.
AU - Van Loon, J.T.H.
PY - 2014
Y1 - 2014
N2 - © 2014. The American Astronomical Society. All rights reserved.. 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-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 ≲ α ≲ -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.
AB - © 2014. The American Astronomical Society. All rights reserved.. 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-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 ≲ α ≲ -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.
U2 - 10.1088/0004-637X/796/2/82
DO - 10.1088/0004-637X/796/2/82
M3 - Article
SN - 0004-637X
VL - 796
SP - 82
JO - The Astrophysical Journal
JF - The Astrophysical Journal
IS - 2
ER -