Star formation in a high-pressure environment: An SMA view of the Galactic centre dust ridge

Abstract

The star formation rate in the Central Molecular Zone (CMZ) is an order of magnitude lower than predicted according to star formation relations that have been calibrated in the disc of our own and nearby galaxies. Understanding how and why star formation appears to be different in this region is crucial if we are to understand the environmental dependence of the star formation process. Here, we present the detection of a sample of high-mass cores in the CMZ's "dust ridge" that have been discovered with the Submillimeter Array as part of the CMZoom survey. These cores range in mass from ~ 50 - 2150 Msun within radii of 0.1 - 0.25 pc. All appear to be young (pre-UCHII), meaning that they are prime candidates for representing the initial conditions of high-mass stars and sub-clusters. We report that at least two of these cores ('c1' and 'e1') contain young, high-mass protostars. We compare all of the detected cores with high-mass cores in the Galactic disc and find that they are broadly similar in terms of their masses and sizes, despite being subjected to external pressures that are several orders of magnitude greater - ~ 10^8 K/cm^3, as opposed to ~ 10^5 K/cm^3. The fact that > 80% of these cores do not show any signs of star-forming activity in such a high-pressure environment leads us to conclude that this is further evidence for an increased critical density threshold for star formation in the CMZ due to turbulence.

19 pages, 10 figures, 3 tables. Accepted for publication in MNRAS

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Cited by in corpus (31)

• Dynamical Equilibrium in the Molecular ISM in 28 Nearby Star-Forming Galaxies
• 'The Brick' is not a brick: A comprehensive study of the structure and dynamics of the Central Molecular Zone cloud G0.253+0.016
• The dynamical evolution of molecular clouds near the Galactic Centre - II. Spatial structure and kinematics of simulated clouds
• Ubiquitous velocity fluctuations throughout the molecular interstellar medium
• Which feedback mechanisms dominate in the high-pressure environment of the Central Molecular Zone?
• CMZoom: Survey Overview and First Data Release
• Star Formation Rates of Massive Molecular Clouds in the Central Molecular Zone
• ALMA Observations of Massive Clouds in the Central Molecular Zone: Jeans Fragmentation and Cluster Formation
• CHIMPS2: Survey description and ${}^{12}$CO emission in the Galactic Centre
• Young massive star cluster formation in the Galactic Centre is driven by global gravitational collapse of high-mass molecular clouds
• Star formation in 'the Brick': ALMA reveals an active proto-cluster in the Galactic centre cloud G0.253+0.016
• ALMA Observations of Massive Clouds in the Central Molecular Zone: Ubiquitous Protostellar Outflows
• New Insights into the Physical Conditions and Internal Structure of a Candidate Proto-Globular Cluster
• CMZoom II: Catalog of Compact Submillimeter Dust Continuum Sources in the Milky Way's Central Molecular Zone
• The centres of M83 and the Milky Way: opposite extremes of a common star formation cycle
• Fiery Cores: Bursty and Smooth Star Formation Distributions across Galaxy Centers in Cosmological Zoom-in Simulations
• Virial Clumps in Central Molecular Zone Clouds
• Galactic center gamma-ray production by cosmic rays from stellar winds and Sgr A East
• A Turbulent-Entropic Instability and the Fragmentation of Star-Forming Clouds
• Kinematics of Galactic Centre clouds shaped by shear-seeded solenoidal turbulence
• Gravitationally Bound Gas Determines Star Formation in the Galaxy
• The initial conditions for young massive cluster formation in the Galactic Centre: convergence of large-scale gas flows
• Star Formation in Extreme Environments: A 200 pc High Velocity Gas Stream in the Galactic Centre
• CMZoom III: Spectral Line Data Release
• Probing the Global Dust Properties and Cluster Formation Potential of the Giant Molecular Cloud G148.24+00.41
• Does the HCN/CO ratio trace the star-forming fraction of gas? I. A comparison with analytical models of star formation
• Star burst in W49N presumably induced by cloud-cloud collision
• Hot Molecular Core Candidates in the Galactic Center 50 km/s Molecular Cloud
• Does the HCN/CO ratio trace the star-forming fraction of gas? II. Variations in CO and HCN Emissivity
• Backlighting young stellar objects in the Central Molecular Zone: an ensemble-averaged abundance structure of methanol ices
• Mass Segregation in the CMZoom Survey