Spectral evolution and polarization of variable structures in the pulsar wind nebula of PSR B0540-69.3

Abstract

We present high spatial resolution optical imaging and polarization observations of the PSR B0540-69.3 and its highly dynamical pulsar wind nebula (PWN) performed with HST, and compare them with X-ray data obtained with the Chandra X-ray Observatory. We have studied the bright region southwest of the pulsar where a bright "blob" is seen in 1999. We show that it may be a result of local energy deposition around 1999, and that the emission from this then faded away. Polarization data from 2007 show that the polarization properties show dramatic spatial variations at the 1999 blob position arguing for a local process. Several other positions along the pulsar-"blob" orientation show similar changes in polarization, indicating previous recent local energy depositions. In X-rays, the spectrum steepens away from the "blob" position, faster orthogonal to the pulsar-"blob" direction than along this axis of orientation. This could indicate that the pulsar-"blob" orientation is an axis along where energy in the PWN is mainly injected, and that this is then mediated to the filaments in the PWN by shocks. We highlight this by constructing an [S II]-to-[O III]-ratio map. We argue, through modeling, that the high [S II]/[O III] ratio is not due to time-dependent photoionization caused by possible rapid Xray emission variations in the "blob" region. We have also created a multiwavelength energy spectrum for the "blob" position showing that one can, to within 2sigma, connect the optical and X-ray emission by a single power law. We obtain best power-law fits for the X-ray spectrum if we include "extra" oxygen, in addition to the oxygen column density in the interstellar gas of the Large Magellanic Cloud and the Milky Way. This oxygen is most naturally explained by the oxygen-rich ejecta of the supernova remnant. The oxygen needed likely places the progenitor mass in the 20 - 25 Msun range.

Accepted by MNRAS on December 6th 2010, 18 pages, 15 figures. The article with full resolution figures is available here ftp://ftp.astro.su.se/pub/peter/papers/pwn0540_2010_corrected.pdf

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Cited by in corpus (16)

• A multi-wavelength look at the young plerionic supernova remnant 0540-69.3
• The near-infrared detection of PSR B0540-69 and its nebula
• Imprints of the jittering jets explosion mechanism in the morphology of the supernova remnant SNR 0540-69.3
• Clumps and rings of ejecta in SNR 0540-69.3 as seen in 3D
• From young to old: the evolutionary path of Pulsar Wind Nebulae
• Optical linear polarization of 74 white dwarfs with the RoboPol polarimeter
• The PSR J1124-5916 wind nebula in the near-infrared
• Atacama Compact Array Observations of the Pulsar-Wind Nebula of SNR 0540-69.3
• Properties of the three-dimensional structure in the central region of the supernova remnant SNR 0540-69.3
• The first ultraviolet detection of the Large Magellanic Cloud pulsar PSR B0540-69 and its multi-wavelength properties
• On the new braking index of PSR B0540-69: further support for magnetic field growth of neutron stars following submergence by fallback accretion
• VLT polarimetry observations of PSR B0656+14
• Kinematics, structure and abundances of supernova remnant 0540-69.3
• Pulsar Wind Nebulae
• Spatial Variations and Breaks in the Optical-NIR spectra of the Pulsar and PWN in SNR 0540-69.3
• A Spectroscopic Study of Supernova Remnants with the Infrared Space Observatory