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Characterization of molecular outflows at core-scale in the massive clump AGAL G345.0029-0.224

E. Cohen Arazi, M. E. Ortega, S. Paron, P. F. Velázquez, A. Rodríguez-González, E. Alquicira

Abstract

High-mass stars, with their powerful winds and intense radiation fields, are fundamental in regulating galactic dynamics and evolution; however, despite their great relevance, the mechanisms involved in their formation are still not fully understood. In this context, molecular outflows, which are essential for removing angular momentum and allowing accretion onto the central object, are a crucial phenomenon for characterizing their formation. Previous studies reveal a discrepancy in the masses of outflows associated with high-mass clumps between works conducted at the clump scale ($\sim$ pc) and those at the core scale ($\sim$ subpc). This suggests that the high-mass outflow activity observed at the clump scale might be the result of the contribution from several lower-mass outflows linked to individual molecular cores. This work presents a study of the molecular gas toward a high-mass clump associated with an Extended Green Object (EGO). EGOs are indicators of jets associated with high-mass protostars. Employing high angular resolution data from the Atacama Large Millimeter/submillimeter Array (ALMA), the presence of several hot cores with outflow activity was observed in the source. A characterization of the outflows at the core scale is presented within the context of the physical parameters of the molecular clumps.

Characterization of molecular outflows at core-scale in the massive clump AGAL G345.0029-0.224

Abstract

High-mass stars, with their powerful winds and intense radiation fields, are fundamental in regulating galactic dynamics and evolution; however, despite their great relevance, the mechanisms involved in their formation are still not fully understood. In this context, molecular outflows, which are essential for removing angular momentum and allowing accretion onto the central object, are a crucial phenomenon for characterizing their formation. Previous studies reveal a discrepancy in the masses of outflows associated with high-mass clumps between works conducted at the clump scale ( pc) and those at the core scale ( subpc). This suggests that the high-mass outflow activity observed at the clump scale might be the result of the contribution from several lower-mass outflows linked to individual molecular cores. This work presents a study of the molecular gas toward a high-mass clump associated with an Extended Green Object (EGO). EGOs are indicators of jets associated with high-mass protostars. Employing high angular resolution data from the Atacama Large Millimeter/submillimeter Array (ALMA), the presence of several hot cores with outflow activity was observed in the source. A characterization of the outflows at the core scale is presented within the context of the physical parameters of the molecular clumps.
Paper Structure (7 sections, 4 figures, 2 tables)

This paper contains 7 sections, 4 figures, 2 tables.

Table of Contents

  1. Introduction
  2. Data
  3. ALMA data
  4. Additional data
  5. Results
  6. Discussion
  7. Summary and conclusion

Figures (4)

  • Figure 1: The left panel shows a WISE three-colour composite image, with 3.4 $\mu$m in blue, 4.6 $\mu$m in green, and 12 $\mu$m in red. The white contours represent the 870 $\mu$m emission from ATLASGAL. Levels are at 300, 600, 900, 1300 mJy beam$^{-1}$. The right panel is a close-up view of the ATLASGAL source 345.0029$-$0.2241 in which EGO G345.00$-$0.22(a) is embedded (yellow area). The black contours represent the ALMA continuum emission at 340 GHz. Levels are at 50, 100, 300, 700 mJy beam$^{-1}$.
  • Figure 2: $^{12}$CO J=3--2 emission distribution integrated (moment 0) between $-60$ and $-10$ km s$^{-1}$(blue), and between $+5$ and $+65$ km s$^{-1}$(red) considering the $^{12}$CO J=3--2 transition at rest (0 km s$^{-1}$). The continuum emission at 340 GHz is represented in green contours with levels of 100 and 200 mJy beam$^{-1}$
  • Figure 3: $^{12}$CO J=3--2 spectra obtained towards the red- and blue-shifted lobes (red and blue curves respectively) related to core C1. Both lobes exhibit high and low velocity components, which are labeled in the red lobe. The green dashed line indicates the rest frequency of the $^{12}$CO J=3--2 transition.
  • Figure 4: High- and low-velocity molecular outflow towards the core C1. Left panel: High-velocity outflow at 59 km s$^{-1}$ of the $^{12}$CO J=3--2 transition. Right panel: Low-velocity outflow at 6.7 km s$^{-1}$ of the $^{12}$CO J=3--2 transition. Both velocity planes are highlighted in the $^{12}$CO J=3--2 spectrum of Fig. \ref{['fig:spectra']}. The green contours represent the ALMA continuum emission at 340 GHz. Levels are at 100 and 200 mJy beam$^{-1}$.