First author: Jessica A. Cowell
The assumption of isotropy – that the Universe looks the same in all directions on large scales – is fundamental to the standard cosmological model. This model forms the building blocks of essentially all of our cosmological knowledge to date. It is therefore critical to empirically test in which regimes its core assumptions hold. Anisotropies in the cosmic expansion are expected on small scales due to nonlinear structures in the late Universe, however, the extent to which these anisotropies might impact our low-redshift observations remains to be fully tested.
First author: Aditya Manuwal
${\rm H}_2$ detections are usually biased towards star-forming galaxies, whose low number statistics in clusters has led to contradictory results in the literature regarding the impact of environment on their ${\rm H}_2$ content, across redshifts. In this work, we employ the EAGLE simulation to investigate the relationship between the ${\rm H}2$ content of star-forming galaxies and their environment for redshifts spanning $0\leq z\leq 1$. To do so, we divide the sample into those that are bound to clusters and those that are not.
First author: Keita Fukushima
We examine star formation and chemical enrichment in protoclusters (PCs) using cosmological zoom-in hydrodynamic simulations. We find that the total star formation rate (SFR) in all PC ($>10^{14.4},h^{-1}$~M$\odot$) reaches $>10^4,\mathrm{M}\odot \mathrm{yr}^{-1}$, at $z=3$, equivalent to the observed PCs. The SFR in the Core region accounts for about $30%$ of the total star formation in the PC at $z\gtrsim1$, suggesting the importance of the outer regions to reveal the evolution of galaxy clusters.
First author: Xiang-Cun Meng
Although type Ia supernovae are so important in many astrophysical field, e.g. in cosmology, their explosion mechanism and progenitor system are still unclear. In physics, the relative equivalent width (REW) of the Si II 635.5 nm absorption feature reflects the velocity interval of silicon in the supernova ejecta and then may provide constraints on the explosion mechanism of SNe Ia. In this paper, we divide the SNe Ia into broad line (BL) and normal line (NL) subsamples based on their REW of Si II 635.
First author: Antonio D. Montero-Dorta
Satellite galaxies undergo a variety of physical processes when they are accreted by groups and clusters, often resulting in the loss of baryonic and dark matter (DM) mass. In this work, we evaluate the predictions from the IllustrisTNG hydrodynamical simulation regarding the evolution of the matter content of satellites, focusing on a population that are accreted at $z>1$ and retain their identity as satellites down to $z=0$.
First author: Eleonora Di Valentino
We present strong model-marginalized limits on mixed hot dark matter scenarios, which consider both thermal neutrinos and thermal QCD axions. A novel aspect of our analyses is the inclusion of small-scale Cosmic Microwave Background (CMB) observations from the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT), together with those from the Planck satellite and Baryon Acoustic Oscillation (BAO) data. After marginalizing over a number of well-motivated non-minimal background cosmologies, the tightest $95%$ CL upper bound we obtain is $0.
First author: Themiya Nanayakkara
The confirmation of the presence of very massive quiescent galaxies at epochs only 1-2 Gyr after the Big Bang $[1-8]$ has challenged models of cosmology and galaxy formation $[9]$. Producing sufficient numbers of these requires abundant numbers of the host dark matter halos to have been assembled and sufficient time for star formation to proceed extremely quickly and then cease just as rapidly. Ground-based spectroscopy has suggested ages of 200-300 Myr$[3]$ at redshifts $3<z<4$.
First author: Ryan D. Boyden
The stellar cluster environment is expected to play a central role in the evolution of circumstellar disks. We use thermochemical modeling to constrain the dust and gas masses, disk sizes, UV and X-ray radiation fields, viewing geometries, and central stellar masses of 20 Class II disks in the Orion Nebula Cluster (ONC). We fit a large grid of disk models to $350$ GHz continuum, CO $J=3-2$, and HCO$^+$ $J=4-3$ ALMA observations of each target, and we introduce a procedure for modeling interferometric observations of gas disks detected in absorption against a bright molecular cloud background.
First author: Prabin Sherpaili
An increase in satellite application has skyrocketed the number of satellites, especially in the low earth orbit (LEO). The major concern today is that these satellites become debris after the end of life, negatively affecting the space environment. As per the International Guidelines of the European Space Agency, it is mandatory to deorbit the satellite within 25 years of its end of life. This paper is aimed to design the solid chemical propellant thruster to deorbit the StudSat II from its original orbit to the lower orbit.
First author: A. D. Supanitsky
Cosmic rays are relativistic particles that come to the Earth from outer space. Despite a great effort made in both experimental and theoretical research, their origin is still unknown. One of the main keys to understand their nature is the determination of its chemical composition as a function of primary energy. In this paper, we review the measurements of the mass composition above $10^{15}$ eV.
