[논문 리뷰] The COLIBRE project: cosmological hydrodynamical simulations of galaxy formation and evolution

Joop Schaye, Evgenii Chaikin외 19명|arXiv (Cornell University)|2025. 08. 28.

Galaxies: Formation, Evolution, Phenomena인용 수 6

한 줄 요약

COLIBRE는 새로운 은하 형성 모델과 명시적 차가운 ISM, 먼지, 그리고 다양한 AGN 피드백을 갖춘 우주론적 수치유체 시뮬레이션 모음을 제시하며 z≈0 관측에 보정되어 데이터와 좋은 수렴성을 보인다.

ABSTRACT

We present the COLIBRE galaxy formation model and the COLIBRE suite of cosmological hydrodynamical simulations. COLIBRE includes new models for radiative cooling, dust grains, star formation, stellar mass loss, turbulent diffusion, pre-supernova stellar feedback, supernova feedback, supermassive black holes and active galactic nucleus (AGN) feedback. The multiphase interstellar medium is explicitly modelled without a pressure floor. Hydrogen and helium are tracked in non-equilibrium, with their contributions to the free electron density included in metal-line cooling calculations. The chemical network is coupled to a dust model that tracks three grain species and two grain sizes. In addition to the fiducial thermally-driven AGN feedback, a subset of simulations uses black hole spin-dependent hybrid jet/thermal AGN feedback. To suppress spurious transfer of energy from dark matter to stars, dark matter is supersampled by a factor 4, yielding similar dark matter and baryonic particle masses. The subgrid feedback model is calibrated to match the observed $z \approx 0$ galaxy stellar mass function, galaxy sizes, and black hole masses in massive galaxies. The COLIBRE suite includes three resolutions, with particle masses of $\sim 10^5$, $10^6$, and $10^7\, ext{M}_\odot$ in cubic volumes of up to 100, 200, and 400 cMpc on a side, respectively. The largest runs use 136 billion ($5 imes 3008^3$) particles. We describe the model, assess its strengths and limitations, and present both visual impressions and quantitative results. Comparisons with various low-redshift galaxy observations generally show very good numerical convergence and excellent agreement with the data.

연구 동기 및 목표

• physically motivated, high-resolution cosmological model of galaxy formation and evolution.
• Incorporate explicit cold interstellar medium, dust evolution, and non-equilibrium hydrogen/helium chemistry.
• Implement comprehensive stellar, supernova, and AGN feedback, including spin-dependent jet/thermal modes.
• Calibrate the subgrid physics to match z≈0 galaxy stellar mass function, sizes, and BH masses.
• Provide a suite of simulations across multiple resolutions and volumes to test convergence and predictive power.

제안 방법

• Use the Swift gravity+SPH code with four times more dark matter particles than baryonic particles to suppress spurious energy transfer.
• Model cooling down to T<10^4 K without a pressure floor and couple cooling to non-equilibrium H/He chemistry and dust chemistry.
• Track dust growth, self-shielding, and molecular cooling within a full chemical-dust network.
• Implement pre-SN stellar feedback, SNe (core-collapse and Ia), stellar mass loss, and AGN feedback (thermally-driven and hybrid jet/thermal with BH spin).
• Calibrate subgrid feedback to reproduce the z≈0 galaxy stellar mass function, half-mass radii, and massive BH masses; explore spin-dependent hybrid feedback variants.
• Employ fourfold DM to baryon particle ratio to suppress spurious energy transfer, and run multiple resolutions (m5, m6, m7) with up to 5×3008^3 particles in large volumes.

실험 결과

연구 질문

• RQ1 How does explicit modelling of a multi-phase ISM, dust, and non-equilibrium chemistry affect galaxy formation and evolution in cosmological volumes?
• RQ2 What is the impact of different AGN feedback modes (fiducial thermal vs spin-dependent hybrid jet/thermal) on galaxy properties and their agreement with observations?
• RQ3 How do COLIBRE predictions converge with increasing resolution and how do results compare to other large-volume simulations?
• RQ4 Can calibration to z≈0 observables reproduce a broad set of low-redshift galaxy and CGM properties without resorting to strong a priori tuning?
• RQ5 What predictions do COLIBRE runs make for gas, dust, metallicity, and star-formation histories across halo mass and cosmic time?

주요 결과

• The COLIBRE suite achieves very good numerical convergence and excellent agreement with a broad set of low-redshift observations.
• COLIBRE includes explicit cooling below 10^4 K, dust growth, self-shielding, and molecular cooling, enabling a realistic cold ISM phase.
• Two flagship runs follow 5×3008^3 particles in 200 and 400 cMpc boxes, with baryonic and DM particle masses near 10^6 and 10^7 Msun respectively.
• The subgrid feedback model is calibrated to match the z≈0 galaxy stellar mass function, galaxy sizes, and massive BH masses, with additional tests of hybrid AGN feedback.
• Comparisons with observations show good convergence and agreement across multiple galaxy properties, including gas, metals, and dust related observables.
• A comparison between fiducial thermally-driven and spin-dependent hybrid jet/thermal AGN feedback shows only small differences in the resulting galaxy properties.