Linking pre- and proto-stellar objects in the intermediate-/high-mass star forming region IRAS 05345+3157

TL;DR

This study uses high-resolution millimeter observations to analyze the morphology, kinematics, and interactions of cold condensations in the IRAS 05345+3157 high-mass star forming region, revealing complex dynamics and chemical similarities to low-mass cores.

Contribution

It provides a detailed analysis of the interactions and properties of multiple cores in a high-mass star forming region, highlighting the influence of outflows on core evolution.

Findings

Identification of three cores: C1-a, C1-b, and C2.

C1-b is associated with an early-B ZAMS star in a hot core.

Cores N and S show chemical properties similar to low-mass pre-stellar cores.

Abstract

To better understand the initial conditions of the high-mass star formation process, it is crucial to study at high-angular resolution the morphology, the kinematics, and eventually the interactions of the coldest condensations associated with intermediate-/high-mass star forming regions. The paper studies the cold condensations in the intermediate-/high-mass proto-cluster IRAS 05345+3157, focusing the attention on the interaction with the other objects in the cluster. We have performed millimeter high-angular resolution observations, both in the continuum and several molecular lines, with the PdBI and the SMA. In a recent paper, we have already published part of these data. The main finding of that work was the detection of two cold and dense gaseous condensations, called N and S (masses ~2 and ~9 M_sun), characterised by high values of the deuterium fractionation (~0.1 in both cores). In this paper, we present a full report of the observations, and a complete analysis of the data obtained. The millimeter maps reveal the presence of 3 cores inside the interferometers primary beam, called C1-a, C1-b and C2. None of them are associated with cores N and S. C1-b is very likely associated with a newly formed early-B ZAMS star embedded inside a hot-core, while C1-a is more likely associated with a class 0 intermediate-mass protostar. The nature of C2 is unclear. Both C1-a and C1-b are good candidates as driving sources of a powerful CO outflow, which strongly interacts with N and S, as demonstrated by the velocity gradient across both condensations. Our major conclusion is that the chemical properties of these pre-stellar cores are similar to those observed in low-mass isolated ones, while the kinematics is dominated by the turbulence triggered by the CO outflow and can influece their evolution.