The common envelope origins of the fast jet in the planetary nebula M 3-38

TL;DR

This study reveals a highly collimated, fast jet in planetary nebula M 3-38, likely formed through a common envelope binary interaction, supported by high-resolution spectroscopy and central star variability analysis.

Contribution

It provides the first detailed spectroscopic analysis of a fast jet in M 3-38 and links its origin to a binary system formed via common envelope evolution.

Findings

Fast jet velocity up to ~320 km/s

Presence of a close binary central star with 17.7-day period

Jet morphology suggests a common envelope formation scenario

Abstract

We present the analysis of Multi-Espectr\'ografo en GTC de Alta Resoluci\'on para Astronom\'ia (MEGARA) high-dispersion integral field spectroscopic observations of the bipolar planetary nebula (PN) M 3-38. These observations unveil the presence of a fast outflow aligned with the symmetry axis of M 3-38 that expands with a velocity up to $\pm$225 km s$^{-1}$. The deprojected space velocity of this feature can be estimated to be $\approx$320$^{+130}_{-60}$ km s$^{-1}$, which together with its highly collimated morphology suggests that it is one of the fastest jet detected in a PN. We have also used Kepler observations of the central star of M 3-38 to unveil variability associated with a dominant period of 17.7 days. We attribute this to the presence of a low-mass star with an orbital separation of $\approx$0.12-0.16 au. The fast and collimated ejection and the close binary system point towards a common envelope formation scenario for M 3-38.