Star formation in 'the Brick': ALMA reveals an active proto-cluster in the Galactic centre cloud G0.253+0.016

Abstract

G0.253+0.016, aka 'the Brick', is one of the most massive (> 10^5 Msun) and dense (> 10^4 cm-3) molecular clouds in the Milky Way's Central Molecular Zone. Previous observations have detected tentative signs of active star formation, most notably a water maser that is associated with a dust continuum source. We present ALMA Band 6 observations with an angular resolution of 0.13" (1000 AU) towards this 'maser core', and report unambiguous evidence of active star formation within G0.253+0.016. We detect a population of eighteen continuum sources (median mass ~ 2 Msun), nine of which are driving bi-polar molecular outflows as seen via SiO (5-4) emission. At the location of the water maser, we find evidence for a protostellar binary/multiple with multi-directional outflow emission. Despite the high density of G0.253+0.016, we find no evidence for high-mass protostars in our ALMA field. The observed sources are instead consistent with a cluster of low-to-intermediate-mass protostars. However, the measured outflow properties are consistent with those expected for intermediate-to-high-mass star formation. We conclude that the sources are young and rapidly accreting, and may potentially form intermediate and high-mass stars in the future. The masses and projected spatial distribution of the cores are generally consistent with thermal fragmentation, suggesting that the large-scale turbulence and strong magnetic field in the cloud do not dominate on these scales, and that star formation on the scale of individual protostars is similar to that in Galactic disc environments.

arXiv commentAccepted for publication in MNRAS. 23 pages, 13 figures, 4 tables

References in corpus (90)

• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• A General Theory of Turbulence-Regulated Star Formation, From Spirals to ULIRGs
• A geometric distance measurement to the Galactic Center black hole with 0.3% uncertainty
• The Star Formation Rate of Turbulent Magnetized Clouds: Comparing Theory, Simulations, and Observations
• Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
• On the Star Formation Rates in Molecular Clouds
• MAMBO Mapping of Spitzer c2d Small Clouds and Cores
• Hi-GAL: the Herschel infrared Galactic Plane Survey
• The mass function of dense molecular cores and the origin of the IMF
• The Star Formation Rate of Supersonic MHD Turbulence
• Massive molecular outflows
• Variations in the Galactic star formation rate and density thresholds for star formation
• Massive Stars in the Quintuplet Cluster
• Massive Stars in the Arches Cluster
• Star Formation Rates in Molecular Clouds and the Nature of the Extragalactic Scaling Relations
• What controls star formation in the central 500 pc of the Galaxy?
• Hi-GAL, the Herschel infrared Galactic Plane Survey: photometric maps and compact source catalogues. First data release for Inner Milky Way: +68°> l > -70°
• Hierarchical fragmentation and differential star formation in the Galactic "Snake": infrared dark cloud G11.11-0.12
• The dynamical evolution of molecular clouds near the Galactic Centre - I. Orbital structure and evolutionary timeline
• The Nature of the Dense Core Population in the Pipe Nebula: Thermal Cores Under Pressure
• Dense gas in the Galactic central molecular zone is warm and heated by turbulence
• Molecular gas kinematics within the central 250 pc of the Milky Way
• Magnetic Fields in High-Mass Infrared Dark Clouds
• Fragmentation at the Earliest Phase of Massive Star Formation
• Chemistry in Infrared Dark Cloud Clumps: a Molecular Line Survey at 3 mm
• The link between turbulence, magnetic fields, filaments, and star formation in the Central Molecular Zone cloud G0.253+0.016
• Star formation rates and efficiencies in the Galactic Centre
• Fragmentation of Molecular Clumps and Formation of Protocluster
• MALT90: The Millimetre Astronomy Legacy Team 90 GHz Survey
• Accretion disks in luminous young stellar objects
• Characterizing Precursors to Stellar Clusters with Herschel
• The ages of young star clusters, massive blue stragglers and the upper mass limit of stars: analysing age dependent stellar mass functions
• SiO emission from the Galactic Center Molecular Clouds
• Multi-temperature mapping of dust structures throughout the Galactic Plane using the PPMAP tool with Herschel Hi-GAL data
• The massive star initial mass function of the Arches cluster
• G0.253+0.016: a molecular cloud progenitor of an Arches-like cluster
• A Dynamical Model for the Formation of Gas Rings and Episodic Starbursts Near Galactic Centres
• eXtended CASA Line Analysis Software Suite (XCLASS)
• The Galactic Center Molecular Cloud Survey. I. A Steep Linewidth-Size Relation & Suppression of Star Formation
• A cluster in the making: ALMA reveals the initial conditions for high-mass cluster formation
• Turbulence sets the initial conditions for star formation in high-pressure environments
• Analytical theory for the initial mass function: III time dependence and star formation rate
• A Dynamical Model for Gas Flows, Star Formation, and Nuclear Winds in Galactic Centres
• The Galactic Center Cloud G0.253+0.016: A Massive Dense Cloud with low Star Formation Potential
• 'The Brick' is not a brick: A comprehensive study of the structure and dynamics of the Central Molecular Zone cloud G0.253+0.016
• Distributed star formation throughout the Galactic Center cloud Sgr B2
• AUTO-MULTITHRESH: A General Purpose Automasking Algorithm
• G11.92-0.61 MM 1: A fragmented Keplerian disk surrounding a proto-O star
• The Survey of Water and Ammonia in the Galactic Center (SWAG): Molecular Cloud Evolution in the Central Molecular Zone
• The dynamical evolution of molecular clouds near the Galactic Centre - II. Spatial structure and kinematics of simulated clouds
• The Life Cycle of the Central Molecular Zone. I: Inflow, Star Formation, and Winds
• Galactocentric variation of the gas-to-dust ratio and its relation with metallicity
• G0.253+0.016: A centrally condensed, high-mass protocluster
• Evolution and excitation conditions of outflows in high-mass star-forming regions
• STATCONT: A statistical continuum level determination method for line-rich sources
• The Star Formation Rate of Molecular Clouds
• Ubiquitous velocity fluctuations throughout the molecular interstellar medium
• Multi-directional mass-accretion and collimated outflows in W51
• Tracing the Conversion of Gas into Stars in Young Massive Cluster Progenitors
• The dynamics and star-forming potential of the massive Galactic centre cloud G0.253+0.016
• On the temperature structure of the Galactic Centre cloud G0.253+0.016
• Chasing discs around O-type (proto)stars - ALMA evidence for an SiO disc and disc wind from G17.64+0.16
• The ALMA Survey of 70 $\mu \mathrm{m}$ Dark High-mass Clumps in Early Stages (ASHES). II: Molecular Outflows in the Extreme Early Stages of Protocluster Formation
• A multi-wavelength view of the Galactic center dust ridge reveals little star formation
• 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
• The Dense Gas Fraction in Galactic Center Clouds
• Star formation in a high-pressure environment: An SMA view of the Galactic centre dust ridge
• ALMA Observations of Massive Clouds in the Central Molecular Zone: Jeans Fragmentation and Cluster Formation
• The Galactic Center Molecular Cloud Survey. II. A Lack of Dense Gas & Cloud Evolution along Galactic Center Orbits
• A Census of Early Phase High-Mass Star Formation in the Central Molecular Zone
• Comparing Young Massive Clusters and their Progenitor Clouds in the Milky Way
• Fragmentation and disk formation in high-mass star formation: The ALMA view of G351.77-0.54 at 0.06" resolution
• Young massive star cluster formation in the Galactic Centre is driven by global gravitational collapse of high-mass molecular clouds
• The dynamical evolution of molecular clouds near the Galactic Centre -- III. Tidally--induced star formation in protocluster clouds
• A SiO J = 5 - 4 Survey Toward Massive Star Formation Regions
• Infall and Outflow of Molecular Gas in Sgr B2
• Temperature structures in Galactic Center clouds - Direct evidence for gas heating via turbulence
• Fragmentation and disk formation during high-mass star formation: The IRAM NOEMA (Northern Extended Millimeter Array) large program CORE
• ALMA view of G0.253+0.016: Can cloud-cloud collision form the cloud?
• Origins of Scatter in the Relationship Between HCN 1-0 and Dense Gas Mass in the Galactic Center
• Star formation in the massive "starless" infrared dark cloud G0.253$+$0.016
• SiO excitation from dense shocks in the earliest stages of massive star formation
• CMZoom II: Catalog of Compact Submillimeter Dust Continuum Sources in the Milky Way's Central Molecular Zone
• Sgr B2(N): A bipolar outflow and rotating hot core revealed by ALMA
• Evidence that widespread star formation may be underway in G0.253+016, "The Brick"
• Absorption Filaments Towards the Massive Clump G0.253+0.016
• A new distance to the Brick, the dense molecular cloud G0.253+0.016

Cited by in corpus (20)

• The Atacama Cosmology Telescope: Microwave Intensity and Polarization Maps of the Galactic Center
• Disruption of Hierarchical Clustering in the Vela OB2 Complex and the Cluster Pair Collinder 135 and UBC7 with Gaia EDR3: Evidence of Supernova Quenching
• A massive Keplerian protostellar disk with flyby-induced spirals in the Central Molecular Zone
• A global view on star formation: The GLOSTAR Galactic plane survey IV. Radio continuum detections of young stellar objects in the Galactic Centre region
• A wind-blown bubble in the Central Molecular Zone cloud G0.253+0.016
• JWST reveals widespread CO ice and gas absorption in the Galactic Center cloud G0.253+0.016
• Kinematics of Galactic Centre clouds shaped by shear-seeded solenoidal turbulence
• On Far-Infrared and Submm Circular Polarization
• The initial conditions for young massive cluster formation in the Galactic Centre: convergence of large-scale gas flows
• Gravitationally Bound Gas Determines Star Formation in the Galaxy
• CMZoom III: Spectral Line Data Release
• Clustering of low mass stars around Herbig Be star IL Cep -- Evidence of "Rocket Effect" using Gaia EDR3 ?
• Modelling of ionising feedback with Smoothed Particle Hydrodynamics and Monte Carlo Radiative Transfer on a Voronoi grid
• Dual-band Unified Exploration of Three CMZ Clouds (DUET). Cloud-wide census of continuum sources showing low spectral indices
• The complex multi-scale structure in simulated and observed emission maps of the proto-cluster cloud G0.253+0.016 (`the Brick')
• ArTéMiS imaging of the filamentary infrared dark clouds G1.75-0.08 and G11.36+0.80: Dust-based physical properties of the clouds and their clumps
• Chemical templates of the Central Molecular Zone. Shock and protostellar object signatures under Galactic Center conditions
• Mass Segregation in the CMZoom Survey
• Investigating star formation scenarios in the Milky Way using YSO distributions -- A pilot study
• The 107 GHz methanol transition is a dasar in G0.253+0.016