First author: Francois Hammer
Halo inhabitants are individual stars, stellar streams, star and globular clusters, and dwarf galaxies. Here we compare the two last categories that include objects of similar stellar mass, which are often studied as self-dynamical equilibrium systems. We discover that the half-light radius of globular clusters depends on their orbital pericenter and total energy, and that Milky Way (MW) tides may explain the observed correlation. We also suggest that the accretion epoch of stellar systems in the MW halo can be calibrated by the total orbital energy, and that such a relation is due to both the mass growth of the MW and dynamical friction affecting mostly satellites with numerous orbits.
First author: Wolfram Kollatschny
IRAS23226-3843 has previously been classified as a changing-look AGN based on X-ray and optical spectral variations. In 2019, Swift observations revealed a strong rebrightening in X-ray and UV fluxes in comparison to observations in 2017. We took follow-up Swift, XMM-Newton, and NuSTAR observations together with optical spectra (SALT and SAAO 1.9m telescope) from 2019 until 2021. IRAS23226-3843 showed a strong X-ray and optical outburst in 2019.
First author: Sofia Contarini
We investigate the main tensions within the current standard model of cosmology from the perspective of the void size function in BOSS DR12 data. For this purpose, we present the first cosmological constraints on the parameters $S_8\equiv \sigma_8\sqrt{\Omega_{\rm m}/0.3}$ and $H_0$ obtained from voids as a stand-alone probe. We rely on an extension of the popular volume-conserving model for the void size function, tailored to the application on data, including geometric and dynamic distortions.
First author: Marco Castellano
We report the detection of a high density of redshift $z\approx 10$ galaxies behind the foreground cluster Abell 2744, selected from imaging data obtained recently with NIRCam onboard JWST by three programs – GLASS-JWST, UNCOVER, and DDT-2756. To ensure robust estimates of the lensing magnification $\mu$, we use an improved version of our model that exploits the first epoch of NIRCam images and newly obtained MUSE spectra, and avoids regions with $\mu>5$ where the uncertainty may be higher.
First author: Duncan Farrah
The assembly of stellar and supermassive black hole (SMBH) mass in elliptical galaxies since $z\sim1$ can help to diagnose the origins of locally-observed correlations between SMBH mass and stellar mass. We therefore construct three samples of elliptical galaxies, one at $z\sim0$ and two at $0.7\lesssim z \lesssim2.5$, and quantify their relative positions in the $M_{BH}-M_*$ plane. Using a Bayesian analysis framework, we find evidence for translational offsets in both stellar mass and SMBH mass between the local sample and both higher redshift samples.
First author: Kazuharu G. Himoto
We present morphological analyses of Post-starburst galaxies (PSBs) at $0.7<z<0.9$ in the COSMOS field. We fitted ultraviolet to mid-infrared multi-band photometry of objects with $i<24$ from COSMOS2020 catalogue with population synthesis models assuming non-parametric, piece-wise constant function of star formation history, and selected 94 those galaxies that have high specific star formation rates (SSFRs) of more than $10^{-9.5}$ yr$^{-1}$ in 321–1000 Myr before observation and an order of magnitude lower SSFRs within recent 321 Myr.
First author: Yunchong Zhang
We report the discovery of five bright strong gravitationally-lensed galaxies at $3 < z < 4$: COOL J0101$+$2055 ($z = 3.459$), COOL J0104$-$0757 ($z = 3.480$), COOL J0145$+$1018 ($z = 3.310$), COOL J0516$-$2208 ($z = 3.549$), and COOL J1356$+$0339 ($z = 3.753$). These galaxies have magnitudes of $r_{\rm AB}, z_{\rm AB} < 21.81$ mag and are lensed by galaxy clusters at $0.26 < z < 1$.
First author: Tony Bonnaire
Degeneracies among parameters of the cosmological model are known to drastically limit the information contained in the matter distribution. In the first paper of this series, we shown that the cosmic web environments; namely the voids, walls, filaments and nodes; can be used as a leverage to improve the real-space constraints on a set of six cosmological parameters, including the summed neutrino mass. Following-upon these results, we propose to study the achievable constraints of environment-dependent power spectra in redshift space where the velocities add up information to the standard two-point statistics by breaking the isotropy of the matter density field.
First author: V. Strazzullo
We investigate structural properties of massive galaxy populations in the central regions of five very massive galaxy clusters at z~1.4-1.7 from the South Pole Telescope Sunyaev Zel’dovich effect survey. We probe the connection between galaxy structure and broad stellar population properties, at stellar masses log(M/Msun)>10.85. We find that quiescent and star-forming cluster galaxy populations are largely dominated by bulge- and disk-dominated sources, respectively, with relative contributions consistent with those of field counterparts.
First author: Dante J. Paz
We present a new definition of cosmic void and a publicly available code with the algorithm that implements it. In this void finder, underdense regions are defined as free-form objects, called popcorn voids, made from the union of spheres of maximum volume with a given joint integrated underdensity contrast. This provides, for the first time, a definition of a void in the matter field whose abundance can be faithfully reproduced by excursion set theory, in particular using the Vdn model without any adjustment or cleaning process.
