The dynamics and star-forming potential of the massive Galactic centre cloud G0.253+0.016

Abstract

The massive infrared dark cloud G0.253+0.016 projected 45pc from the Galactic centre contains ~10^5Msun of dense gas whilst being mostly devoid of observed star-formation tracers. To scrutinise the physical properties, dynamics and structure of this cloud with reference to its star-forming potential, we have carried out a concerted SMA and IRAM 30m study of this cloud in dust continuum, CO isotopologues, shock tracing molecules, as well as H${}_2$CO to trace the gas temperature. We detect and characterise the dust cores within G0.253+0.016 at ~1.3 mm and find that the kinetic temperature of the gas is >320K on size-scales of ~0.15 pc. Analysis of the position-velocity diagrams of our observed lines show broad linewidths and strong shock emission in the south of the cloud, indicating that G0.253+0.016 is colliding with another cloud at v(LSR)~70 km/s. We confirm via an analysis of the observed dynamics in the CMZ that it is an elongated structure, orientated with Sgr B2 closer to the Sun than Sgr A*, however our results suggest that the actual geometry may be more complex than an elliptical ring. We find that the column density PDF of G0.253+0.016 is log-normal with no discernible power-law tail, consistent with little star formation, and that its width can be explained in the framework of theory predicting the density structure of clouds created by supersonic, magnetised turbulence. We also present the delta-variance spectrum of this region, and show it is consistent with that expected for clouds with no star formation. Using G0.253+0.016 as a test-bed of the conditions required for star formation in a different physical environment to that of nearby clouds, we also conclude that there is not one column density threshold for star formation, but instead this value is dependant on the local physical conditions. [Abbrv.]

Published in Astronomy and Astrophysics. 19 pages, 18 figures

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• Turbulence sets the initial conditions for star formation in high-pressure environments
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• Tracing the Conversion of Gas into Stars in Young Massive Cluster Progenitors
• CMZoom: Survey Overview and First Data Release
• Abundant Methanol Masers but no New Evidence for Star Formation in GCM0.253+0.016
• Star Formation Rates of Massive Molecular Clouds in the Central Molecular Zone
• Star formation in a high-pressure environment: An SMA view of the Galactic centre dust ridge
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• Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde. III. The Orion Molecular Cloud 1
• Kinetic temperature of massive star forming molecular clumps measured with formaldehyde. II. The Large Magellanic Cloud
• Clustered star formation at early evolutionary stages. Physical and chemical analysis of the young star-forming regions ISOSS J22478+6357 and ISOSS J23053+5953
• The CARMA 3mm Survey of the Inner $0.7^{\circ }\times 0.4^{\circ }$ of the Central Molecular Zone
• A wind-blown bubble in the Central Molecular Zone cloud G0.253+0.016
• A Turbulent-Entropic Instability and the Fragmentation of Star-Forming Clouds
• JWST reveals widespread CO ice and gas absorption in the Galactic Center cloud G0.253+0.016
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• Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde V. The massive filament DR21
• The initial conditions for young massive cluster formation in the Galactic Centre: convergence of large-scale gas flows
• Prospects for Detection of Synchrotron Emission from Secondary Electrons and Positrons in Starless Cores: Application to G0.216+0.016
• Star Formation in the Galactic Center
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