Criss-cross mapping BD+30 3639: a new kinematic analysis technique

TL;DR

This paper introduces a novel 'criss-cross' mapping technique for analyzing kinematic data in planetary nebulae, revealing the nebula's center offset and non-homologous expansion patterns.

Contribution

The paper presents a new 'criss-cross' mapping method for kinematic analysis, applied to BD+30 3639, providing insights into its center offset and expansion dynamics.

Findings

Kinematic center offset of 0.5 arcsec SE from the star

Evidence of non-homologous expansion

Disturbance aligned with bipolar molecular bullets

Abstract

We present a new analysis of kinematic data of the young planetary nebula BD+30 3639. The data include spectroscopic long-slit and internal proper motion measurements. In this paper we also introduce a new type of mapping of kinematic proper motion data that we name "criss-cross" mapping. It basically consists of finding all points where extended proper motion vectors cross converge. From the crossing points a map is generated which helps to interpret the kinematic data. From the criss-cross mapping of BD+30 3639, we conclude that the kinematic center is approximately 0.5 arcsec offset to the South-East from the central star. The mapping does also show evidence for a non-homologous expansion of the nebula that is consistent with a disturbance aligned with the bipolar molecular bullets.