Central Molecular Zone star formation campaign
Coordinated Observations of Nebulae in the Central Molecular Zone Exploring gas Recycling and Transformation
CONCERT connects the turbulent, magnetized cloud environment of the Galactic Center to the small-scale physics of filaments, dense cores, disks, streamers, and protostellar feedback.
Campaign Logic
Large programs such as CMZoom and ACES give the community the wide-area view. CONCERT deliberately goes deeper and finer on a small, carefully chosen sample so that the same clouds can be followed from parsec-scale gas flows down to dense cores and 100 AU-scale disk structures.
Measure fragmentation, pressure confinement, density structure, and cloud-wide source populations.
Identify shocks, absorption structures, HNCO fibers, and gas reservoirs feeding dense structures.
Connect core mass functions, outflows, magnetic fields, and local gravitational flows.
Resolve rotating disks, envelopes, spirals, and streamers around massive protostars.
Programs
CONCERT uses a music-inspired naming scheme for focused observing programs. The expanded names below show the role of each subcampaign: characterize the gas, find hidden reservoirs, measure magnetic forces, then follow gas into disks.
Quad-band ALMA mapping of CMZ cloud excitation and structure
Four ALMA bands toward selected CMZ clouds, with 12-m, 7-m, and TP data, are designed to sample gas density and temperature from cloud to core scales. This program connects physical conditions to N-PDFs and core mass functions.
Related publications
Molecular absorption and H I self-absorption kinematics with ALMA
CO and related absorption filaments reveal gas that can be missed in emission-only views. These structures test whether foreground reservoirs, self-absorption, and shocks reshape the apparent CMZ cloud structure.
Related publications
Polarization of cores and disks in the Central Molecular Zone
ALMA Band 7 polarization resolves magnetic fields around dense cores. The goal is to compare magnetic tension, gravity, and turbulent distortion where gas is actively moving into cores.
Related publications
Broadband ALMA long-baseline look-in at accretion disks
Long-baseline ALMA observations use line forests and continuum structure to separate disks, envelopes, spirals, and streamers around massive protostars in the CMZ.
Related publications
Dual-band Unified Exploration of Three CMZ Clouds
Matched 1.3 mm and 3 mm observations provide cloud-wide spectral indices and a source census, linking dust cores, free-free emission, and evolutionary stage across multiple CMZ clouds.
Related publications
Publication Map
The publication map is organized by the question each paper answers. It begins with foundation papers that define the CMZ star-formation problem, then follows the CONCERT sequence from cloud-scale structure to disk-scale accretion.
Deeply Embedded Protostellar Population in the 20 km s^-1 Cloud of the Central Molecular Zone
Establishes that deeply embedded high-mass star formation is already present in the 20 km/s cloud, motivating later high-resolution follow-up.
The Molecular Gas Environment in the 20 km s^-1 Cloud in the Central Molecular Zone
Characterizes the gas environment of the 20 km/s cloud, one of the anchors for connecting cloud conditions to later core and disk-scale work.
Star Formation Rates of Massive Molecular Clouds in the Central Molecular Zone
Sets the cloud-scale star formation rate problem that CONCERT later attacks with deeper views of fragmentation, feedback, and gas delivery.
A Census of Early-phase High-mass Star Formation in the Central Molecular Zone
Provides the census framework for identifying where massive star formation is beginning across the CMZ.
ALMA Observations of Massive Clouds in the Central Molecular Zone: Jeans Fragmentation and Cluster Formation
Establishes the ALMA cloud sample and asks how dense gas fragments under CMZ pressures.
ALMA Observations of Massive Clouds in the Central Molecular Zone: Ubiquitous Protostellar Outflows
Shows that embedded star formation is widespread once protostellar outflows are traced at high resolution.
A massive Keplerian protostellar disk with flyby-induced spirals in the Central Molecular Zone
Pushes to long baselines and asks whether massive protostellar disks in the CMZ resemble Galactic disk counterparts.
Magnetic Fields in the Central Molecular Zone Influenced by Feedback and Weakly Correlated with Star Formation
Places core-scale polarization work into the broader CMZ magnetic-field environment.
ALMA Observations of Massive Clouds in the Central Molecular Zone: External-pressure-confined Dense Cores and Salpeter-like Core Mass Functions
Links CMZ pressure confinement to core mass functions, setting the statistical baseline for star formation models.
ALMA observations of massive clouds in the central molecular zone: slim filaments tracing parsec-scale shocks
Shows how thin filamentary structures can record cloud-scale shocks and gas transport.
Subclustering and Star Formation Efficiency in Three Protoclusters in the Central Molecular Zone
Connects the dense-core census to the way protoclusters assemble in the CMZ environment.
Dual-band Unified Exploration of three CMZ Clouds (DUET): Cloud-wide census of continuum sources showing low spectral indices
Uses two bands to separate source populations and identify low spectral-index objects across three clouds.
ALMA Polarization Study of the Magnetic Fields in Two Massive Clumps in the 20 km s^-1 Cloud of the Central Molecular Zone
Tests whether magnetic tension can redirect gas flow into selected dense cores.
The Keplerian Disk, Envelope, and Streamers Surrounding an Early O-type Protostar in the Sagittarius C Cloud of the Central Molecular Zone
Dissects a disk, envelope, and streamer system around an early O-type protostar, closing the loop from cloud gas to stellar growth.
Reading the sequence: the 2015-2019 papers establish the 20 km/s cloud, CMZ star-formation rates, and the early-phase census. The CONCERT sequence then adds fragmentation, outflows, core statistics, filaments, continuum source populations, protocluster assembly, magnetic forces, and disk/envelope/streamer systems. The campaign is therefore a connected argument, not a set of isolated case studies.
Context
Wide-field surveys define the CMZ environment, identify filaments and source populations, and provide comparison samples.
Deep, matched-resolution, multi-band observations of selected clouds allow physical conditions, magnetic fields, and disk-scale structures to be studied in the same targets.
The emerging picture is that star-formation microphysics still works in the CMZ, but the extreme environment changes the boundary conditions and makes the same physics appear unusual.
Team
The visible team list below includes collaborators represented in the current CONCERT publication list, as well as researchers actively working on CONCERT papers. CONCERT remains open to anyone interested in the campaign; please contact xinglu@shao.ac.cn if you would like to get involved.