VLT observations of the Central Compact Object in the Vela Jr. supernova remnant

TL;DR

This study uses deep optical and IR observations with the VLT to identify and analyze the optical/IR counterpart of the Vela Jr. CCO and its associated nebula, providing insights into its nature and emission mechanisms.

Contribution

First high-resolution deep optical and IR imaging of the Vela Jr. CCO field, revealing the nebula's structure and potential neutron star counterpart.

Findings

Nebula's flux and structure are dominated by Halpha emission.

A faint IR point source consistent with the neutron star's position was detected.

The nebula is likely a bow-shock or photo-ionization nebula caused by the neutron star.

Abstract

X-ray observations have unveiled the existence of enigmatic point-like sources at the center of young (a few kyrs) supernova remnants. These sources, known as Central Compact Objects (CCOs), are thought to be neutron stars produced by the supernova explosion, although their X-ray phenomenology makes them markedly different from all the other young neutron stars discovered so far.The aim of this work is to search for the optical/IR counterpart of the Vela Junior CCO and to understand the nature of the associated Halpha nebula discovered by Pellizzoni et al. (2002).}{We have used deep optical (R band) and IR (J,H,Ks bands) observations recently performed by our group with the ESO VLT to obtain the first deep, high resolution images of the field with the goal of resolving the nebula structure and pinpointing a point-like source possibly associated with the neutron star.Our R-band image shows that both the nebula's flux and its structure are very similar to the Halpha ones, suggesting that the nebula spectrum is dominated by pure Halpha line emission. However, the nebula is not detected in our IR observations, whick makes it impossible to to constrain its spectrum. A faint point-like object (J>22.6, H~21.6, Ks ~ 21.4) compatible with the neutron star's Chandra X-ray position is detected in our IR images (H and Ks) but not in the optical one (R > 25.6), where it is buried by the nebula background. The nebula is most likely a bow-shock produced by the neutron star motion through the ISM or, alternatively, a photo-ionization nebula powered by UV radiation from a hot neutron star.