No abstract

We study star cluster formation at low metallicities of Z/Z⊙ = 10−4–10−1 using three-dimensional hydrodynamics simulations. Particular emphasis is put on how the stellar mass distribution is affected by the cosmic microwave background radiation (CMB), which sets the temperature floor to the gas. Starting from the collapse of a turbulent cloud, we follow the formation of a protostellar system resolving ∼au scale. In relatively metal-enriched cases of Z/Z⊙ ≳ 10−2, where the mass function resembles the present-day one in the absence of the CMB, high temperature CMB suppresses cloud fragmentation and reduces the number of low-mass stars, making the mass function more top-heavy than in the cases without CMB heating at z ≳ 10. In lower-metallicity cases with Z/Z⊙ ≲ 10−3, where the gas temperature is higher than the CMB value due to inefficient cooling, the CMB has only a minor impact on the mass distribution, which is top-heavy regardless of the redshift. In cases either with a low metallicity of Z/Z⊙ ≲ 10−2 or at a high redshift z ≳ 10, the mass spectrum consists of a low-mass Salpeter-like component, peaking at 0.1 M⊙, and a top-heavy component with 10–50 M⊙, with the fraction in the latter increasing with increasing redshift. In galaxies forming at z ≳ 10, the major targets of the future instruments including JWST, CMB heating makes the stellar mass function significantly top-heavy, enhancing the number of supernova explosions by a factor of 1.4 (2.8) at z = 10 (20, respectively) compared to the prediction by Chabrier initial mass function when Z/Z⊙ = 0.1.

Architecture and Planning (Transactions of AIJ). This paper is based on the translation of the Japanese version with some slight modifications.

No abstract

This study examined the effects of a group cognitive behavioral intervention on senior school students affected by the Hiroshima heavy rain disaster and investigated the effects of reducing depression by enhancing resilience. A total of 229 second‐grade senior school students affected by the Hiroshima heavy rain disaster participated in the study. The intervention was performed in the following order: psychological education on daily stress, problem‐solving training for daily stress, psychological education on traumatic reactions derived from traumatic experiences, and instruction on the merits of utilizing information acquired from the intervention in daily life. The results showed that the high‐depression group's depression score was reduced by the intervention. Resilience score was increased both in the high‐ and low‐depression groups as a result of the intervention. Therefore, the intervention program used in this study was proven effective in reducing depression and improving resilience. Prospectively, strategies for psychological support during and after large‐scale disasters should be established by applying the findings obtained in this research.