ALMA Central Molecular Zone Exploration Survey (ACES) I: Overview
Abstract
The mass flows and energy cycles within the inner regions of galaxies exert a powerful influence on the evolution of the galaxy population. The centre of the Milky Way is the only galactic nucleus for which it is possible to resolve the physical mechanisms that drive these cycles, namely star formation and feedback, while also tracing global (>100 pc) processes which determine where and when star formation and feedback occur. We present an overview of ACES, the 'Atacama Large Millimeter/submillimeter Array (ALMA) CMZ Exploration Survey', a ~1.5" angular resolution, 0.2-3 km/s spectral resolution ALMA Band 3 (85-102 GHz), survey of the 'Central Molecular Zone' (CMZ) -- the inner-100 pc of the Galaxy (l = 359.4 deg to 0.8 deg). ACES spectral setup is tuned to observe optimal tracers of the physical, chemical, and kinematic conditions in over 70 spectral features (e.g. HCO+, HNCO, SiO, H40alpha, complex molecules) of the gas in the CMZ, to derive the properties of all potentially star-forming Galactic Centre gas, from global scales (100 pc) to dense ~0.05 pc structures that are expected to host individual star-forming cores, down to sub-sonic (<0.4 km/s) velocity resolution. In this overview paper, we provide the scientific justification for the ACES survey, explain the choice of observational setup, and describe the data legacy products. Finally, we show some of the initial ACES data which highlight the power of ACES' combination of high angular resolution, unprecedented spatial dynamic range, sensitivity, spectral resolution and spectral bandwidth as an illustration of how ACES aims to understand how global processes set the location, intensity, and timescales for star formation and feedback in the CMZ.
Keywords
Cite
@article{arxiv.2602.20340,
title = {ALMA Central Molecular Zone Exploration Survey (ACES) I: Overview},
author = {Steven N. Longmore and John Bally and Ashley T. Barnes and Cara Battersby and Laura Colzi and Adam Ginsburg and Jonathan D. Henshaw and Paul T. P. Ho and Izaskun Jiménez-Serra and J. M. Diederik Kruijssen and Elisabeth A. C. Mills and Maya A. Petkova and Mattia C. Sormani and Robin G. Tress and Daniel L. Walker and Jennifer Wallace and Emad Alkhuja and Lucia Armillotta and Nazar Budaiev and Rojita Buddhacharya and Alyssa Bulatek and Michael Burton and Natalie O. Butterfield and Laura A. Busch and Paola Caselli and Mélanie Chevance and Claire Cook and Samuel Crowe and Ana Karla Díaz-Rodríguez and Enrico DiTeodoro and Simon R. Dicker and Katarzyna M. Dutkowska and Adam Fairley and Christoph Federrath and Rubén Fedriani and Zi-Xuan Feng and Karl Fiteni and Gary Fuller and Pablo García and Javier Goicoechea and Philipp Girichidis and Simon C. O. Glover and Mark Gorski and Savannah R. Gramze and Qi-Lao Gu and H. Perry Hatchfield and Christian Henkel and Rebecca J. Houghton and Pei-Ying Hsieh and Yue Hu and Katharina Immer and Desmond Jeff and Janik Karoly and Jens Kauffmann and Ralf S. Klessen and Mark R. Krumholz and Alex Lazarian and Emily M. Levesque and Fu-Heng Liang and Dani Lipman and Xunchuan Liu and Xing Lu and Qiu-yi Luo and Alessandro Lupi and Laura McCafferty and S. Martín and Farideh Mazoochi and Mark R. Morris and Marie Nonhebel and Francisco Nogueras-Lara and Tomoharu Oka and Juergen Ott and Marco Padovani and Xing Pan and Jaime E. Pineda and Thushara G. S. Pillai and Marc W. Pound and Miguel Requena Torres and Denise Riquelme-Vásquez and Víctor M. Rivilla and Galaxy Salo and Álvaro Sánchez-Monge and Miriam G. Santa-Maria and Rainer Schoedel and Anika Schmiedeke and Matthias Schultheis and Howard A. Smith and Yoshiaki Sofue and Leonardo Testi and Grant R. Tremblay and Arianna Vasini and Gijs Vermariën and Alexey Vikhlinin and Serena Viti and Q. Daniel Wang and Fengwei Xu and Suinan Zhang and Qizhou Zhang},
journal= {arXiv preprint arXiv:2602.20340},
year = {2026}
}
Comments
Accepted to MNRAS. Website is https://sites.google.com/view/aces-cmz/home and data release is linked from there. Pipeline code is at https://github.com/ACES-CMZ/reduction_ACES/releases/tag/2026-02-18