Galactic Star Formation with NIKA2 (GASTON): Evidence of mass accretion onto dense clumps

TL;DR

This study uses high-sensitivity millimeter continuum mapping of the Galactic plane to identify dense clumps and provides evidence that massive star-forming clumps gain mass from their surroundings early in their evolution, supporting clump-fed formation models.

Contribution

First large-scale millimeter continuum survey of the Galactic plane with NIKA2, revealing mass accretion onto dense clumps during early high-mass star formation stages.

Findings

Identified 1467 dense clumps in the Galactic plane.

Evidence of mass accretion onto clumps during early evolution.

Supports clump-fed models of high-mass star formation.

Abstract

High-mass stars ($m_* \gtrsim 8 \, M_\odot$) play a crucial role in the evolution of galaxies, and so it is imperative that we understand how they are formed. We have used the New IRAM KIDs Array 2 (NIKA2) camera on the Institut de Radio Astronomie Millim\'{e}trique (IRAM) 30-m telescope to conduct high-sensitivity continuum mapping of $\sim2$ deg$^2$ of the Galactic plane (GP) as part of the Galactic Star Formation with NIKA2 (GASTON) large program. We have identified a total of 1467 clumps within our deep 1.15 mm continuum maps and, by using overlapping continuum, molecular line, and maser parallax data, we have determined their distances and physical properties. By placing them upon an approximate evolutionary sequence based upon 8 $\mu$m $\textit{Spitzer}$ imaging, we find evidence that the most massive dense clumps accrete material from their surrounding environment during their early evolution, before dispersing as star formation advances, supporting clump-fed models of high-mass star formation.