Spatial Variations and Breaks in the Optical-NIR spectra of the Pulsar and PWN in SNR 0540-69.3

• The supernova remnant SNR 0540-69.3 offer an excellent opportunity to study the continuum emission from a young pulsar and pulsar-wind nebula (PWN). We study the continuum emission from the pulsar and PWN of SNR 0540-69.3 with the VLT instruments MUSE and X-shooter in the wavelength range 3000–25,000 Å, which provides the possibility to study spatial variations of the optical spectra along with the first near-infrared (NIR) spectrum of SNR 0540-69.3. We model the optical spectra with a power law (PL) Fν ∝ ν−α and find clear spatial variations (including a torus-jet structure) in the spectral index across the PWN, the general trend being a spectral hardening toward the outer parts, from α ~ 1.7 to ~ 0.5. The full optical-NIR spectrum of the PWN is best described by a broken power law with the break frequency at log10 (νb) = 14.61 ± 0.04 Hz and spectral indices of α1 = 0.88 ± 0.04 and α2 = 1.27 ± 0.05. These results confirm that several breaks are needed to model the full spectral energy distribution of the PWN. Finally, we subtract the PWN contribution from the pulsar spectrum in MUSE and find that a spectral break at log10 (νb) = 14.622 ± 0.002 Hz and spectral indices of α1 = 1.02 ± 0.07 and α2 = 2.010 ± 0.007 describe the pulsar spectrum. 

Subject headings

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Keyword

Core-collapse Supernovae – Supernova remnants – Pulsar-Wind Nebulae – Pulsars

Atomic, Subatomic and Astrophysics

Atomär fysik, subatomär fysik och astrofysik

Publication and Content Type

vet (subject category)

ovr (subject category)