AGORA High-resolution Galaxy Simulations Comparison Project

□ In the AGORA Project (Assembling Galaxies Of Resolved Anatomy; formerly known as Santa Cruz High-resolution Galaxy Simulation Comparison Project), we aim to:

• Inaugurate a lasting infrastructure for comparing high-resolution galaxy formation simulations across different high-resolution numerical platforms

• Establish isolated and cosmological initial conditions so each participating group can run a suite of simulations in the coming years

• Invite (but not require) each of the participating code groups to perform two types of high-resolution galaxy formation simulations (isolated galaxy and cosmological zoom-in galaxy) with resolution of ~100 parsecs

• Analyze and compare the resulting simulations at several epochs and in multiple dimensions; at the end, go a step further to include comparisons with observational data

• Focus on science-based, multi-platform research, rather than merely an one-time code comparison; use this project as a springboard to launch many science-oriented comparison endeavors

• Raise the predictive power of the numeircal galaxy formation collectively

• Maintain healthy and vibrant collaboration through annual workshops, and online meetings between them

□ Early history and rationale:

• AGORA Project was launched during its 1st Workshop in 2012 at UC Santa Cruz. The initial project infrastructures were built and the proof-of-concept simulations were carried out in 2012-2013, which led us to achieve its first measurable objective in late 2013, the Project's "Flagship paper" (published in 2014).

• All the main simulation groups in the world were represented (in many cases by their leaders), and through extremely constructive discussion we were able to reach consensus on a wide variety of key issues. These include common initial conditions for cosmological zoom-in simulations and isolated disk simulations, common physics packages such as ultraviolet background and cooling functions, and common analysis tools including yt.

• People have signed up to be key contacts for all the simulation groups, titles and topics of the major papers to be produced by the Project were agreed upon with at least one person tentatively agreeing to take charge of each.

• It is remarkable that we have launched this project at the time when several key technologies have just become available including the simulation codes, the MUlti-Scale Initial Conditions generator (MUSIC) for simulation ICs, and the yt code for analyzing the outputs from many simulations. This project will be state-of-the-art in every respect, and in fact will advance the entire field of galaxy simulations.

□ Task-oriented Working Groups (I-IV): click the Groups tab to learn more

• Working Group I - Common Physics and Introduction to Project

• Working Group II - Common ICs: Isolated

• Working Group III - Common ICs: Cosmological

• Working Group IV - Common Analysis

□ Science-oriented Working Groups (V-XIII): click the Groups tab to learn more

• Working Group V - Isolated Galaxies and Subgrid Physics

• Working Group VI - Dwarf Galaxies in Cosmological Simulations

• Working Group VII - Dark Matter

• Working Group VIII - Satellite Galaxies

• Working Group IX - Characteristics of Cosmological Galaxies

• Working Group X - Outflows

• Working Group XI - High-redshift Galaxies

• Working Group XII - Interstellar Medium

• Working Group XIII - Black Hole Accretion and Feedback

□ Examples of Paper Groups: click the Groups tab to learn more

• Paper Group "Flagship"

• Paper Group "Disk"

• Paper Group "CosmoRun"

+ many more

□ AGORA Steering Committee

• Tom Abel (Stanford University)

• Piero Madau (University of California at Santa Cruz)

• Lucio Mayer (University of Zurich)

• Joel Primack (University of California at Santa Cruz)

• Romain Teyssier (University of Zurich)

• James Wadsley (McMaster University)

+ Ji-hoon Kim (Seoul National University, Project Coordinator)

□ AREPO: [to be confirmed]

□ ART-I (NMSU): Daniel Ceverino, Anatoly Klypin, Santi Roca-Fabrega, Sebastian Trujillo-Gomez

□ ART-II (Chicago): Robert Feldmann, Nick Gnedin, Sam Leitner

□ CHANGA: Johnny Powell, Tom Quinn, Hector Velazquez, Spencer Wallace

□ ENZO: Mike Butler, John Forbes, Ji-hoon Kim, Christine Simpson, John Wise

□ GADGET-2/3/4: Junhwan Choi, Ken Nagamine, Jose Onorbe, Miguel Rocha, Ikkoh Shimizu, Keita Todoroki

□ GADGET-SPHS: Alexander Hobbs, Justin Read

□ GASOLINE: Ben Keller, Sijing Shen, James Wadsley

□ GCD+: Daisuke Kawata

□ GEAR: Loic Hausammann, Yves Revaz

□ GIZMO/P-SPH: Philip Hopkins, Alessandro Lupi

□ NYX: Wolfram Schmidt (isolated runs only)

□ PKDGRAV-2: Javiera Guedes, Mike Kuhlen (cosmological runs only)

□ RAMSES: Oscar Agertz, Oliver Hahn, Santi Roca-Fabrega, Romain Teyssier

□ If you are looking for the AGORA common initial conditions (ICs), examples of common analysis yt scripts used in the Project, or the isolated galaxy simulation snapshots produced by AGORA, click the Tools+Data tab above.

□ Consider joining the Collaboration with no obligation, especially if you want to learn more about the AGORA common ICs and analysis scripts used in the Project. Simply send an email to the Project coordinator. Contact us if you have any other question, too!