First author: Liang Li
Gamma-ray bursts (GRBs) are the most powerful explosions in the universe. The standard model invokes a relativistic fireball with a bright photosphere emission component. How efficiently the jet converts its energy to radiation is a long-standing problem and it is poorly constrained. A definitive diagnosis of GRB radiation components and measurement of GRB radiative efficiency requires prompt emission and afterglow data with high-resolution and wide-band coverage in time and energy.
First author: Kasper E. Heintz
Galaxies throughout the last 12 Gyr of cosmic time follow a single, universal fundamental plane that relates their star-formation rates (SFRs), stellar masses ($M_\star$) and chemical abundances. Deviation from these fundamental scaling relations would imply a drastic change in the processes that regulate galaxy evolution. Observations have hinted at the possibility that this relation may be broken in the very early universe. However, until recently, chemical abundances of galaxies could be only measured reliably as far back as redshift $z = 3.
First author: Tianqing Zhang
Cosmological weak lensing measurements rely on a precise measurement of the shear two-point correlation function (2PCF) along with a deep understanding of systematics that affect it. In this work, we demonstrate a general framework for describing the impact of PSF systematics on the cosmic shear 2PCF, and mitigating its impact on cosmological analysis. Our framework can describe leakage and modeling error from all spin-2 quantities contributed by the PSF second and higher moments, rather than just the second moments.
First author: Lior Shamir
The discrepancy between the mass of galaxies and their rotational velocity is one of the most puzzling scientific phenomena. Despite over a century of research, this phenomenon is not fully understood. Common explanations include dark matter and MOND, among other theories. Here we report on another observation that shows tension between the physics of galaxy rotation and its rotational velocity. We compare the brightness of galaxies, and find that galaxies that spin in the same direction as the Milky Way have different brightness than galaxies that spin in the opposite direction.
Kensuke Akita
We review the distortions of spectra of relic neutrinos due to the interactions with electrons, positrons, and neutrinos in the early universe. We solve integro-differential kinetic equations for the neutrino density matrix, including vacuum three-flavor neutrino oscillations, oscillations in electron and positron background, a collision term and finite temperature corrections to electron mass and electromagnetic plasma up to the next-to-leading order $\mathcal{O}(e^3)$. After that, we estimate the effects of the spectral distortions in neutrino decoupling on the number density and energy density of the Cosmic Neutrino Background (C$ν$B) in the current universe, and discuss the implications of these effects on the capture rates in direct detection of the C$ν$B on tritium, with emphasis on the PTOLEMY-type experiment.
First author: Laila Linke
Third-order weak lensing statistics are a promising tool for cosmological analyses since they extract cosmological information in the non-Gaussianity of the cosmic large-scale structure. However, such analyses require precise and accurate models for the covariance. In this second paper of a series on third-order weak lensing statistics, we derive and validate an analytic model for the covariance of the third-order aperture statistics $\langle M_\mathrm{ap}^3\rangle$. We derive the covariance model from a real-space estimator for $\langle M_\mathrm{ap}^3\rangle$.
First author: Varenya Upadhyaya
We search for a linearity in the ratio of dark matter to baryonic matter as a function of radius for galaxy clusters, motivated by a recent result by Lovas (arXiv:2206.11431), who has discovered such a linearity for a diverse suite of galaxies in the SPARC sample. For our analysis, we used a sample of 54 non-cool core clusters from the HIFLUGCS sample. We do not find any evidence for a linear trend in the aforementioned ratio as a function of radius for individual clusters.
First author: W. Zhang
We study the Fourier time-lags due to the Comptonization of disc-emitted photons in a spherical, uniform, and stationary X-ray corona, which located on the rotational axis of the black hole. We use Monk, a general relativistic Monte-Carlo radiative transfer code, to calculate Compton scattering of photons emitted by a thin disc with a Novikov-Thorne temperature profile. We find that the model time-lags due to Comptonization remain constant up to a characteristic frequency and then rapidly decrease to zero at higher frequencies.
First author: Caleb Lammers
Despite the importance of feedback from active galactic nuclei (AGN) in models of galaxy evolution, observational constraints on the influence of AGN feedback on star formation remain weak. To this end, we have compared the star formation trends of 279 low-redshift AGN galaxies with 558 non-active control galaxies using integral field unit spectroscopy from the SDSS-IV MaNGA survey. With a Gaussian process-based methodology, we reconstruct non-parametric star formation histories in spatially-resolved spaxels covering the face of each galaxy.
Roark Habegger
In galactic disks, the Parker instability results when non-thermal pressure support exceeds a certain threshold. The non-thermal pressures considered in the Parker instability are cosmic ray pressure and magnetic pressure. This instability takes a long time to saturate $(>500 , \mathrm{Myr})$ and assumes a background with fixed cosmic ray pressure to gas pressure ratio. In reality, galactic cosmic rays are injected into localized regions $(< 100 ,\mathrm{pc})$ by events like supernovae, increasing the cosmic ray pressure to gas pressure ratio.
