Ray S. Sharma
We examine the quenching characteristics of $328$ isolated dwarf galaxies $\left(10^{8} < M_{\rm star}/M_\odot < 10^{10} \right)$ within the \Rom{} cosmological hydrodynamic simulation. Using mock observation methods, we identify isolated dwarf galaxies with quenched star formation and make direct comparisons to the quenched fraction in the NASA Sloan Atlas (NSA). Similar to other cosmological simulations, we find a population of quenched, isolated dwarf galaxies below $M_{\rm star} < 10^{9} M_\odot$ not detected within the NSA.
S. A. Turakulov
Astrophysical S-factors at zero energy for the direct <span class="search-hit mathjax">nuclear</span> capture <span class="search-hit mathjax">reactions</span> $^{3}{\rm He}(α, γ)^{7}{\rm Be}$, $^{3}{\rm H}(α, γ)^{7}{\rm Li}$ and $^{7}{\rm Be}(p, γ)^{8}{\rm B}$ are estimated within the framework of two-body potential cluster model on the basis of extranuclear capture approximation of D. Baye and E. Brainis. The values of S(0)-factors have been calculated using two different potential models for each process, which were adjusted to the binding energies and empirical values of the asymptotical normalization coefficients from the literature.
Antti Rantala
We present BIFROST, an extended version of the GPU-accelerated hierarchical fourth-order forward symplectic integrator code FROST. BIFROST (BInaries in FROST) can efficiently evolve collisional stellar systems with arbitrary binary fractions up to fbin=100% by using secular and regularised integration for binaries, triples, multiple systems or small clusters around black holes within the fourth-order forward integrator framework. Post-Newtonian (PN) terms up to order PN3.5 are included in the equations of motion of compact subsystems with optional three-body and spin-dependent terms.
First author: S. Pourojaghi
Using mock data for the Hubble diagrams of type Ia supernovae (SNIa) and quasars (QSOs) generated based on the standard model of cosmology, and using the least-squares method based on the Markov-Chain-Monte-Carlo (MCMC) algorithm, we first put constraints on the cosmographic parameters in the context of the various model-independent cosmographic methods reconstructed from the Taylor $4^{th}$ and $5^{th}$ order expansions and the Pade (2,2) and (3,2) polynomials of the Hubble parameter, respectively.
Hanneke C. Woudenberg
Stellar streams are a promising tool to study the Milky Way’s dark matter subhalo population, as interactions with subhalos could produce substructure in streams. However, other possible causes for substructure first need to be well understood. Here we study the kinematics and the unusual morphology of the stellar stream Jhelum. Using a combination of ground-based photometry and Gaia EDR3 astrometry we characterize the morphology of Jhelum. We combine this new data with radial velocities from the literature to perform orbit integrations of the stream in static Galactic potentials.
First author: Sho Fujibayashi
We explore a possible scenario of the explosion as a result of core collapses of rotating massive stars that leave a black hole by performing a radiation-viscous-hydrodynamics simulation in numerical relativity. We take moderately and rapidly rotating compact pre-collapse stellar models derived in stellar evolution calculations as the initial conditions. We find that the viscous heating in the disk formed around the central black hole powers an outflow.
First author: A. Gkogkou
In the submm regime, spectral line scans and line intensity mapping (LIM) are new promising probes for the cold gas content and star formation rate of galaxies across cosmic time. However, both of these two measurements suffer from field-to-field variance. We study the effect of field-to-field variance on the predicted CO and CII power spectra from future LIM experiments such as CONCERTO, as well as on the line luminosity functions (LFs) and the cosmic molecular gas mass density that are currently derived from spectral line scans.
Cristian Joana
Cosmic inflation is arguably the most favoured paradigm of the very early Universe. It postulates an early phase of fast, nearly exponential, and accelerated expansion. Inflationary models are capable of explaining the overall flatness and homogeneity of today’s Universe at large scales. Despite being widely accepted by the physics community, these models are not absent from criticism. In scalar field inflation, a necessary condition to begin inflation is the requirement of a Universe dominated by the field’s potential, which implies a subdominant contribution from the scalar field dynamics.
First author: Sidney Lower
We present the Cosmic Sands suite of cosmological zoom-in simulations based on the Simba galaxy formation model in order to study the build up of the first massive and dusty galaxies in the early Universe. Residing in the most massive halos, we find that the compact proto-massive galaxies undergo nearly continuous mergers with smaller subhalos, boosting star formation rates (SFRs) and the build up of stellar mass.
First author: Sofia Contarini
We present the first cosmological constraints derived from the analysis of the void size function. This work relies on the final BOSS DR12 data set, a large spectroscopic galaxy catalog, ideal for the identification of cosmic voids. We extract a sample of voids from the distribution of galaxies and we apply a cleaning procedure aimed at reaching high levels of purity and completeness. We model the void size function by means of an extension of the popular volume-conserving model, based on two additional nuisance parameters.
