Possible Explosive Dispersal Outflow in IRAS 16076-5134 revealed with ALMA

TL;DR

This study uses ALMA observations to identify filament-like CO ejections from a high-mass star formation region, revealing a possible explosive dispersal outflow with implications for galactic energy dynamics.

Contribution

It provides the first detailed analysis of filamentary explosive outflows in IRAS 16076-5134, estimating their properties and suggesting a high frequency of such events in the galaxy.

Findings

Identified 14 dense cores with masses 0.3-22 M$_{\ m\odot}$.

Estimated outflow mass between 138 and 216 M$_{\rm\odot}$.

Proposed a dispersal outflow with explosive characteristics and a galactic rate of one every 110 years.

Abstract

We present 0.9 mm continuum and CO (3-2) line emission observations retrieved from the Atacama Large Millimeter/submillimeter Array (ALMA) archive toward the high-mass star formation region IRAS 16076-5134. We identify fourteen dense cores with masses between 0.3 to 22 M$_{\odot}$. We find an ensemble of filament-like CO (3-2) ejections from -62 to +83 km s$^{-1}$ that appear to arise radially from a common central position, close to the dense core MM8. The ensemble of filaments, has a quasi-isotropic distribution in the plane of the sky. The radial velocity of several filaments follow a linear velocity gradient, incresing from a common origin. Considering the whole ensemble of filaments, we estimate its total mass to be 138 and 216 M$_{\odot}$ from its CO emission, for 70 K and 140 K respectively. Also, assuming a constant velocity expansion of the filaments (of 83 km s$^{-1}$) we estimate the dynamical age of the outflowing material (3500 years), its momentum (~10$^{4}$ M$_{\odot}$ km s$^{-1}$) and its kinetic energy (~10$^{48-49}$ erg). The morphology and kinematics presented by the filaments suggest the presence of a dispersal outflow with explosive characteristics in IRAS 16076-5134. In addition, we make a raw estimate of the lower limit of the frequency rate of the explosive dispersal outflows in the Galaxy (one every 110 years) considering constant star formation rate and efficiency with respect to the galactocentric radius of the Galaxy. This may imply a comparable rate of dispersal outflows and supernovae (approximately one every 50 years), which may be important for the energy budget of the Interstellar Medium and the link between dispersal outflows and high-mass star formation.