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

Abstract

We present 0.9 mm continuum and CO(3–2) line emission observations retrieved from the Atacama Large Millimeter/submillimeter Array archive toward the high-mass star formation region IRAS 16076-5134. We identify 14 dense cores with masses between 0.3 and 22 M ☉. 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 velocities of several filaments follow a linear velocity gradient, increasing from a common origin. Considering the whole ensemble of filaments, we estimate the total mass to be 138 and 216 M ☉, from its CO emission, for 70 K and 140 K, respectively. Also, assuming a constant velocity expansion for the filaments (of 83 km s−1), we estimate the dynamical age of the outflowing material (3500 yr), its momentum (∼104 M ☉ km s−1), and its kinetic energy (∼1048–49 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 yr), considering a constant star formation rate and efficiency, with respect to the galactocentric radius of the galaxy. This may imply a comparable rate between dispersal outflows and supernovae (approximately one every 50 yr), which may be important for the energy budget of the and the link between dispersal outflows and high-mass star formation.

One, Two, Three ... An Explosive Outflow in IRAS 12326-6245 Revealed by ALMA

“…With all of this, we estimate an updated rate of events of one every 90 yr. This value is comparable to that reported by Zapata et al (2020) andGuzmán Ccolque et al (2022). Our rough estimate will be refined once more explosive outflows will be detected.…”

“…Each of the streamers traces the position of one sequence of the CO condensations mapped at different radial velocities obtained from the velocity spectral cube. This procedure has been used already in many other studies; see, for example, Zapata et al (2009Zapata et al ( , 2013Zapata et al ( , 2020 and Guzmán Ccolque et al (2022). In order to get a better view of this procedure, we have made additionally Figure 2.…”

“…In each filament the shaded or blurry blue and red colors represent the error area that is about 0 1 for the on-the-sky distance. Zapata et al (2009) and Guzmán Ccolque et al (2022. The physical deviations from straight lines are likely due to internal motions or substructure of the expansive streamers.…”

“…The explosive flows are impulsive, and possibly created by a single energetic and brief event (Bally & Zinnecker 2005). These flows consist of dozens of collimated CO streamers, [Fe II] "fingertips," and H 2 wakes pointing back approximately to a central position (see for instance the cases of Orion BN/KL, G5.89−0.39, and IRAS16076−5134; Allen & Burton 1993;Zapata et al 2009;Bally 2016;Zapata et al 2020;Guzmán Ccolque et al 2022), reminiscent of an explosive dispersal event (e.g., Loiseau et al 2018). The CO streamers, tracing these outflows, are radially distributed, and appear nearly isotropic on the sky, presenting well-defined Hubble-Lemaitre-like velocity gradient along their length.…”

“…The disruption of the stellar cluster is clearly traced by the proper motions of at least four stellar objects that recede from the same central position as the molecular gas (Rodríguez et al 2020). Orion BN/KL is the only case with data from the originating protostellar system, searches for which have so far been elusive in the rest of the cases for now (DR21, G5.89−0.39, S106−IR, IRAS16076 −5134: Zapata et al 2013;Bally et al 2017;Zapata et al 2020;Guzmán Ccolque et al 2022), where the evidence comes form the kinematics of molecular gas.…”