First author: Aritra Ghosh
We use the Galaxy Morphology Posterior Estimation Network (GaMPEN) to estimate morphological parameters and associated uncertainties for $\sim 8$ million galaxies in the Hyper Suprime-Cam (HSC) Wide survey with $z \leq 0.75$ and $m \leq 23$. GaMPEN is a machine learning framework that estimates Bayesian posteriors for a galaxy’s bulge-to-total light ratio ($L_B/L_T$), effective radius ($R_e$), and flux ($F$). By first training on simulations of galaxies and then applying transfer learning using real data, we trained GaMPEN with $<1%$ of our dataset.
First author: Daniel A. Dale
We present a comparison of theoretical predictions of dust continuum and polycyclic aromatic hydrocarbon (PAH) emission with new JWST observations in three nearby galaxies: NGC 628, NGC 1365, and NGC 7496. Our analysis focuses on a total of 1063 compact stellar clusters and 2654 stellar associations previously characterized by HST in the three galaxies. We find that the distributions and trends in the observed PAH-focused infrared colors generally agree with theoretical expectations, and that the bulk of the observations is more aligned with models of larger, ionized PAHs.
First author: Byeonghee Yu
We present growth of structure constraints from the cosmological analysis of the power spectrum multipoles of SDSS-III BOSS DR12 galaxies. We use the galaxy power spectrum model of Hand et al. (2017), which decomposes the galaxies into halo mass bins, each of which is modeled separately using the relations between halo biases and halo mass. The model combines Eulerian perturbation theory and halo model calibrated on $N$-body simulations to model the halo clustering.
First author: Anton V. Afanasiev
(Abridged) We study the galaxy mass-size relation in CARLA spectroscopically confirmed clusters at $1.4<z<2.8$, which span a total stellar mass $11.3<\mathrm{log}(M^c_*/M_{\odot})<12.6$ (halo mass $13.5 \lesssim \mathrm{log}(M^c_h/M_{\odot}) \lesssim 14.5$). Our main finding is that cluster passive ETG at $z \gtrsim 1.5$ with ${\rm log}(M/M_{\odot})>10.5$ are systematically $\gtrsim 0.2-0.3~{\rm dex}$ larger than field ETGs. The passive ETG average size evolution is slower at $1<z<2$ when compared to the field.
First author: Gautam Nagaraj
Euclid and the Roman Space Telescope (Roman) will soon use grism spectroscopy to detect millions of galaxies via H$\alpha$ and [O III] $\lambda 5007$ emission. To better constrain the expected galaxy counts from these instruments, we use a vetted sample of 4,239 emission-line galaxies from the 3D-HST survey to measure the H$\alpha$ and [O III] $\lambda 5007$ luminosity functions between $1.16<z<1.90$; this sample is $\sim 4$ times larger than previous studies at this redshift.
First author: Guido D’Amico
We derive the kernels and the Effective Field Theory of Large-Scale Structure counterterms for the one-loop bispectrum of dark matter and of biased tracers in real and redshift space. This requires the expansion of biased tracers up to fourth order in fluctuations. In the process, we encounter several subtleties related to renormalization. One is the fact that, in renormalizing the momentum, a local counterterm contributes non-locally.
First author: Xi Shao
The $\gamma$-ray narrow-line Seyfert 1 galaxies (NLS1s) can be considered to be the third class of $\gamma$-ray active galactic nuclei possessing relativistic jets. In this paper, we present multi-band high resolution Very Long Baseline Array (VLBA) images of the $\gamma$-ray NLS1, SDSS J211852.96$-$073227.5 (J2118$-$0732, $z=0.26$). We find a core-jet radio morphology and significant flux density variations in the radio core. The high brightness temperature estimated from VLBA images and core variability demonstrate that it exhibits substantial relativistic beaming effects.
First author: Yongseok Jo
In a novel approach employing implicit likelihood inference (ILI), also known as likelihood-free inference, we calibrate the parameters of cosmological hydrodynamic simulations against observations, which has previously been unfeasible due to the high computational cost of these simulations. For computational efficiency, we train neural networks as emulators on ~1000 cosmological simulations from the CAMELS project to estimate simulated observables, taking as input the cosmological and astrophysical parameters, and use these emulators as surrogates to the cosmological simulations.
First author: A. Saccardi
The study of the properties of galaxies in the first billion years after the Big Bang is one of the major topic of current astrophysics. Optical/near-infrared spectroscopy of the afterglows of long Gamma-ray bursts (GRBs) provide a powerful diagnostic tool to probe the interstellar medium (ISM) of their host galaxies and foreground absorbers, even up to the highest redshifts. We analyze the VLT/X-shooter afterglow spectrum of GRB 210905A, triggered by the Swift Neil Gehrels Observatory, and detect neutral-hydrogen, low-ionization, high-ionization, and fine-structure absorption lines from a complex system at z=6.
First author: Ekta Patel
We present new mass estimates for Andromeda (M31) using the orbital angular momenta of four satellite galaxies (M33, NGC 185, NGC 147, IC 10) derived from existing proper motions, distances, and line-of-sight velocities. We infer two masses for M31: $M_{\rm vir}= 2.81^{+1.48}{-0.75}\times10^{12}, M{\odot}$ using satellite galaxy phase space information derived with HST-based M31 proper motions and $M_{\rm vir}=2.99^{+1.32}{-0.68}\times10^{12}, M{\odot}$ using phase space information derived with the weighted average of HST+Gaia-based M31 proper motions.