Indications of a Si-rich bilateral jet of ejecta in the Vela SNR observed with XMM-Newton

Abstract

The Vela supernova remnant displays several ejecta, which are fragment-like features protruding beyond the front of its primary blast shock wave. They appear to be "shrapnel", bowshock-shaped relics of the supernova explosion. One of these pieces of shrapnel (A), located in the northeastern edge of the remnant, is peculiar because its X-ray spectrum exhibits a high Si abundance, in contrast to the other observed ejecta fragments, which show enhanced O, Ne, and Mg abundances. We present the analysis of another fragment located opposite to shrapnel A with respect to the center of the shell, in the southwestern boundary of the remnant, named shrapnel G. We thoroughly analyzed a dedicated XMM-Newton observation of shrapnel G by producing background-subtracted and exposure-corrected maps in different energy ranges, which we complemented with a spatially resolved spectral analysis of the X-ray emission. The fragment presents a bowshock-like shape with its anti-apex pointing to the center of the remnant. Its X-ray spectrum is best fit by a thermal plasma out of equilibrium of ionization with low O and Fe, roughly solar Ne and Mg, and a significantly high Si abundance, which is required to fit a very clear Si line at ~1.85 keV. Its chemical composition and spectral properties are compatible with those of shrapnel A, which is located on the opposite side of the remnant. As a consequence of the nucleosynthesis, pieces of Si-rich shrapnel are expected to originate in deeper layers of the progenitor star compared to ejecta with lower-Z elements. A high velocity and density contrast with respect to the surrounding ejecta are necessary to make shrapnel A and G overtake the forward shock. The line connecting shrapnel A and G crosses almost exactly the expansion center of the remnant, strongly suggesting a Si-rich jet-counterjet structure, reminiscent of that observed in the young remnant Cas A.

5 pages, 4 figures. Accepted for publication in Astronomy & Astrophysics Letters

References in corpus (6)

• eROSITA Science Book: Mapping the Structure of the Energetic Universe
• The Polar Regions of Cassiopeia A: The Aftermath of a Gamma Ray Burst?
• Probing the Nature of the Vela X Cocoon
• Physical and chemical inhomogeneities inside the Vela SNR shell. Indications of ejecta shrapnels
• Spatially Resolved X-ray Spectroscopy of Vela Shrapnel A
• XMM-Newton observation of the supernova remnant Kes 78 (G32.8-0.1): Evidence for shock-cloud interaction

Cited by in corpus (14)

• The imprints of the last jets in core collapse supernovae
• The role of jets in exploding supernovae and in shaping their remnants
• Three-Dimensional Kinematic Reconstruction of the Optically-Emitting, High-Velocity, Oxygen-Rich Ejecta of Supernova Remnant N132D
• Imprints of the jittering jets explosion mechanism in the morphology of the supernova remnant SNR 0540-69.3
• A detailed look at the thermal and non-thermal X-ray emission from the Vela supernova remnant with SRG/eROSITA
• 3D modeling from the onset of the SN to the full-fledged SNR: Role of an initial ejecta anisotropy on matter mixing
• Jet-shaped geometrically modified light curves of core collapse supernovae
• Direct evidence of two-component ejecta in supernova 2016gkg from nebular spectroscopy
• Simulating the inflation of bubbles by late jets in core collapse supernova ejecta
• X-ray emitting structures in the Vela SNR: ejecta anisotropies and progenitor stellar wind residuals
• Modelling light curves of bipolar core collapse supernovae from the equatorial plane
• Transition Elements in Supernova Presolar Grains: Condensation vs. Implantation
• Spatially resolved X-ray spectra of the Galactic SNR G18.95-1.1: SRG/eROSITA view
• Mantle Degassing Lifetimes through Galactic Time and the Maximum Age Stagnant-lid Rocky Exoplanets can Support Temperate Climates