The initial physical conditions of the Orion BN/KL fingers

TL;DR

This paper investigates the initial physical conditions of the Orion BN/KL fingers, explaining their age and structure through an analytic model of clump-environment interaction, shedding light on star formation phenomena.

Contribution

It introduces a new analytic model that accounts for the interaction of explosion debris with the surrounding medium to explain the Orion fingers' ages and structures.

Findings

The widespread ages of Orion fingers result from environmental interactions.

The model infers initial explosion conditions and lifetime.

It explains why some CO streamers lack associated H$_2$ fingers.

Abstract

Orion BN/KL is an example of a poorly understood phenomena in star forming regions involving the close encounter of young stellar objects. The explosive structure, the great variety of molecules observed, the energy involved in the event and the mass of the region suggest a contribution in the {chemical diversity} of the local interstellar medium. Nevertheless, the frequency and duration of other events like this have not been determined. In this paper, we explore a recent analytic model that takes into account the interaction of a clump with its molecular environment. We show that the widespread kinematic ages of the Orion fingers -- 500 to 4000 years -- is a consequence of the interaction of the explosion debris with the surrounding medium. This model explains satisfactorily the age discrepancy of the Orion fingers, and infers the initial conditions together with the lifetime of the explosion. Moreover, our model can explain why some CO streamers do not have a H$_2$ finger associated.