Feedback from protoclusters does not significantly change the kinematic properties of the embedded dense gas structures

¹ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
e-mail: jwzhou@mpifr-bonn.mpg.de
² Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany
³ Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, PR China
⁴ Department of Physics; University of Helsinki, PO Box 64, 00014 Finland
⁵ Kavli Institute for Astronomy and Astrophysics, Peking University, Haidian District, Beijing 100871, PR China
⁶ Department of Astronomy, School of Physics, Peking University, Beijing 100871, PR China
⁷ Department of Astronomy, Yunnan University, Kunming 650091, PR China
⁸ Department of Physics, Faculty of Science, Kunming University of Science and Technology, Kunming 650500, PR China
⁹ National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
¹⁰ Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile
¹¹ Satyendra Nath Bose National Centre for Basic Sciences, BlockJD, Sector-III, Salt Lake, Kolkata-700 106, India

Received: 28 September 2023
Accepted: 1 December 2023

Abstract

A total of 64 ATOMS sources at different evolutionary stages were selected to investigate the kinematics and dynamics of gas structures under feedback. We identified dense gas structures based on the integrated intensity map of H¹³CO⁺ J = 1−0 emission, and then extracted the average spectra of all the structures to investigate their velocity components and gas kinematics. For the scaling relations between the velocity dispersion, σ, the effective radius, R, and the column density, N, of all the structures, σ − N * R always has a stronger correlation compared to σ − N and σ − R. There are significant correlations between velocity dispersion and column density, which may imply that the velocity dispersion originates in gravitational collapse, also revealed by the velocity gradients. The measured velocity gradients for dense gas structures in early-stage sources and late-stage sources are comparable, indicating gravitational collapse through all evolutionary stages. Late-stage sources do not have large-scale hub-filament structures, but the embedded dense gas structures in late-stage sources show similar kinematic modes to those in early- and middle-stage sources. These results may be explained by the multi-scale hub-filament structures in the clouds. We quantitatively estimated the velocity dispersion generated by the outflows, inflows, ionized gas pressure, and radiation pressure, and found that the ionized gas feedback is stronger than other feedback mechanisms. However, although feedback from HII regions is the strongest, it does not significantly affect the physical properties of the embedded dense gas structures. Combined with the conclusions in our previous work on cloud-clump scales, we suggest that although feedback from cloud to core scales will break up the original cloud complex, the substructures of the original complex can be reorganized into new gravitationally governed configurations around new gravitational centers. This process is accompanied by structural destruction and generation, and changes in gravitational centers, but gravitational collapse is always ongoing.