Emergence of high-mass stars in complex fiber systems

Project Information

EMERGE

Grant agreement ID: 851435

DOI

10.3030/851435

Project closed

EC signature date 6 September 2019

Start date 1 September 2020

End date 30 April 2026

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 497 805,00

EU contribution

€ 1 497 805,00

Coordinated by

UNIVERSITAT WIEN
Austria

Periodic Reporting for period 3 - EMERGE (Emergence of high-mass stars in complex fiber systems)

Reporting period: 2023-09-01 to 2025-02-28

Summary of the context and overall objectives of the project

The evolution of the most massive stars drives physical and chemical evolution of the Universe, from the formation of entire galaxies to the origin of the first molecules in space. However, the origin of these high-mass stars, many times more massive than our Sun, remains under debate in the astronomy community. In particular, it is unclear how these high-mass stars obtain their masses and whether they are form in the same way as the better known origin of lower mass objects.

The new observations of the Atacama Large Millimeter Array (ALMA) allow to explore the early states on the evolution of these high-mass stars with unprecedented detail. Originated in compact clusters of young stars, ALMA reveals that high-mass stars are formed out of a highly organized gas creating small filamentary structures known as fibers. These fibers are associated into complex networks that fragment to form hundreds of sun-like stars. At the junctions and nodes of these networks the interactions between fibers give rise to the unique physical conditions for the formation of high-mass stars. The main goal of this EMERGE project is characterize for the first time the physical properties of these networks in order to create a new model for the formation of these key objects.

As part of this ERC-StG project, EMERGE is developing a novel state-of-the-art data processing and analysis framework. That includes the development of a new generation of ALMA analysis tools together with the massive ALMA data reduction at supercomputers. In combination with low-mass studies, EMERGE will provide a major step towards a comprehensive model of star formation under one filamentary paradigm.

In addition to its scientific output, EMERGE is expected to produce a number of outreach highlights and images. With a main focus on basic science, our goal is to make its results accessible to the general public and spark the curiosity for the astronomy research.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

EMERGE started on September 2020 after a change of the host institution to the University of Vienna. This first reporting period corresponds to the time from this starting data and the Summer of 2021. It therefore includes the first technical developments and analysis steps of the project in preparation for main data production phase expected for next year.

Two main technical milestones for this project have been achieved during this period. In collaboration with the Dutch ALMA ARC node, we created and published the new ALminer software (Ahmadi & Hacar 2021) for the exploitation of the ALMA archive. ALminer is an open source tool offered to the community in a public repository (https://github.com/emerge-erc/ALminer). With this state-of-the-art software we open the possibility to efficiently explore the vast content of the ALMA Scientific Archive. ALminer is an instrumental piece of software for EMERGE as it will be used to define the survey of targets to be explored in the next years. On the other hand, during this period we have successfully carried out the first large-scale ALMA data reduction using supercomputer facilities. That includes the first parallel and massive reduction at the SURFsara supercomputer in Amsterdam (NL). Also, it includes its transfer and portability to the Vienna Scientific Cluster in Austria. To our knowledge, EMERGE is the first project to carry out massive data reduction of more than 800 individual ALMA continuum observations in less than a day. This work has been recently submitted for publication in Astronomy & Astrophysics (van Terwisga, Hacar, et al 2021). The development of ALminer together with the parallel data processing carried out in supercomputers set the foundations for the EMEGER analysis which will make use of these tools in the next years.

During the last months, three researchers have joined the EMERGE team, namely, 2x PhDs and 1x postdoc, who will be joining the PI during the next years. With the full research team already in place, EMERGE is exploring three key aspects for the project. First, we are now developing he analysis tools for the extraction and characterization of dense fibers in molecular datasets. With it, we aim to create the framework for the uniform analysis of our ALMA observations. Second, we started the design and exploration of our data pipeline. In this step, our goal is to be able to process the data selected by ALminer (see above). For that, we are now exploring the extraction of metadata information from standard visibility files from ALMA. This extraction is required in order to automatically process these data in our supercomputers. Last, we are also carrying out the first ALMA simulations. Our goal here is to quantify the effects of the interferometers in the observed data, a key piece to assess the reliability of the gas properties extracted there. These developments are expected to be complete by the end of the next reporting period in order to start the scientific exploitation of the EMERGE survey.

The scientific research of this project is complemented with ta key review chapter for Protostars and Planets VII (PPVII) on the “Initial conditions for Star Formation: a physical description of the filamentary ISM”. The PI of the EMERGE project is leading and coordinating this project with contributions with another 6 top researchers in the field. The Protostars and Planets series is the largest conference in the field taking place every ~5-7 years. The goal of this conference is to summarize the main results in the star and planet formation communities during that period. The leading role of the PI in this project, with a particular emphasis on the study of the filament physics, highlights the relevance of the research carried out in this project.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Several high impact results are expected until the end of this project. On the technical side, EMERGE is expected to produce and end-to-end pipeline for the massive analysis of ALMA datasets. That includes the extraction, calibration, imaging, and analysis of ALMA data obtained from its Science Archive. The systematic use of these tools will enable EMEGER to revolutionize the field of star formation. The analysis of the EMERGE survey will provide with unique constrains of the initial conditions for the formation of massive stars. That includes the statistical analysis of the gas properties prior their formation in the densest regions of complex fiber arrangements. For that, EMERGE will create a new set of analysis techniques in order to statistically quantify the properties of 30+ fiber networks, their interactions, and their local dynamical evolution. These observational results will be tested against state-of-the-art simulations. The ultimate goal of this project is to statistically quantify how unique multi-scale phenomena generated in these filamentary systems, such as collisions, mergers, and self-gravity, determine the initial conditions for the formation of high-mass stars solving a 20-years dichotomy in star formation theory.

Data Combination in the ALMA era

ALminer: ALMA archive mining and visualization toolkit