First author: Uri Keshet
A joint hadronic model is shown to quantitatively explain the observations of diffuse radio emission from galaxy clusters in the form of minihalos, giant halos, relics, and their hybrid, transitional stages. Cosmic-ray diffusion of order $D\sim 10^{31\text{–}32}\text{ cm}^2\text{ s}^{-1}$, inferred independently from relic energies, the spatial variability of giant-halo spectra, and the spectral evolution of relics, reproduces the observed spatio-spectral distributions, explains the recently discovered mega-halos as enhanced peripheral magnetisation, and quenches electron (re)acceleration by weak shocks or turbulence.
First author: A. Kuruvanthodi
Supermassive stars (SMS) with masses $M \gtrsim 10^3-10^4 M_{\odot}$, formed by runaway collisions in young, massive, and dense star clusters have been invoked as a possible solution to the puzzles raised by the presence of multiple stellar populations and peculiar abundance patterns observed in globular clusters. However, such objects have not been observed so far. We developed observational strategies to search for SMS hosted within young massive clusters (thought to be the precursors of globular clusters, GCs), which could be applicable in a relatively general fashion, using both photometric and spectroscopic observations.
First author: Haowen Zhang
Using recent empirical constraints on the dark matter halo–galaxy–supermassive black hole (SMBH) connection from $z=0-7$, we infer how undermassive, typical, and overmassive SMBHs contribute to the quasar luminosity function (QLF) at $z=6$. We find that beyond $L_\mathrm{bol} = 5 \times 10^{46}$ erg/s, the $z=6$ QLF is dominated by SMBHs that are at least 0.3 dex above the $z=6$ median $M_\bullet-M_$ relation. The QLF is dominated by typical SMBHs (i.
First author: Adam B. Watts
The quenching of cluster satellite galaxies is inextricably linked to the suppression of their cold interstellar medium (ISM) by environmental mechanisms. While the removal of neutral atomic hydrogen (HI) at large radii is well studied, how the environment impacts the remaining gas in the centres of galaxies, which are dominated by molecular gas, is less clear. Using new observations from the Virgo Environment traced in CO survey (VERTICO) and archival HI data, we study the HI and molecular gas within the optical discs of Virgo cluster galaxies on 1.
First author: Richard Lieu
With tantalizing evidence of the recent e-Rosita mission, re-discovering very soft X-rays and EUV radiation from a cluster of galaxies or its environment, the question of the origin of cluster EUV excess is revisited in this work. It will be shown that the gas temperature, density, and frozen-in magnetic field of the intracluster medium, collectively support the emission and propagation of coherent \u{C}erenkov radiation, which is low frequency and large amplitude radiation capable of accelerating charged particles to relativistic speeds.
First author: Simon J. Mutch
The fraction of ionizing photons that escape their host galaxies to ionize hydrogen in the inter-galactic medium (IGM) is a critical parameter in analyses of the reionization era. In this paper we use the Meraxes semi-analytic galaxy formation model to infer the mean ionizing photon escape fraction and its dependence on galaxy properties through joint modelling of the observed high redshift galaxy population and existing constraints on the reionization history.
First author: A. J. Barger
We use JWST NIRCam observations from 1.5 to 4.44 micron of the massive lensing cluster field A2744 to show that extreme red selected galaxies (f(F444W) > 1 uJy and f(F444W)/f(F150W) > 3.5) pick out all 9 >4.5-sigma ALMA 1.1 or 1.2 mm sources and 17 of the 19 >5-sigma SCUBA-2 850 micron sources in the covered areas. Next, we use the red selected galaxies as priors to probe deeper in the SCUBA-2 850 micron image, identifying a sample of 44 >3-sigma SCUBA-2 850 micron sources with accurate positions, photometric redshifts, and magnifications.
First author: Fangxia An
By combining high-sensitivity LOFAR 150MHz, uGMRT 400MHz, GMRT 610MHz, and JVLA 5GHz data in the ELAIS-N1 field, we study the radio spectral properties of radio-detected star-forming galaxies (SFGs) at observer-frame frequencies of 150-5000MHz. We select ~3,500 SFGs that have both LOFAR 150MHz and GMRT 610MHz detections by removing AGN from the two radio samples, and obtain a median spectral index of $\alpha_{150}^{610}=-0.51\pm0.01$ with a scatter of $\sigma=0.
First author: Yoshinobu Fudamoto
We present results of $[CII]$$,158,\rm{\mu m}$ emission line observations, and report the spectroscopic redshift confirmation of a strongly lensed ($\mu\sim20$) star-forming galaxy, MACS0308-zD1 at $z=6.2078\pm0.0002$. The $[CII]$ emission line is detected with a signal-to-noise ratio $>6$ within the rest-frame UV bright clump of the lensed galaxy (zD1.1) and exhibits multiple velocity components; the narrow $[CII]$ has a velocity full-width-half-maximum (FWHM) of $110\pm20,\rm{km/s}$, while broader $[CII]$ is seen with an FWHM of $230\pm20,\rm{km/s}$.
First author: Tyler Houston
In this letter, we explore the quiescent lives of central galaxies using the SAGE galaxy model and Uchuu dark matter simulation. We ask three questions: (1) How much of a galaxy’s life is spent in quiescence? (2) How often do galaxies transition off the main sequence? (3) What is the typical duration of a quiescent phase? We find low and high-mass galaxies spend the highest fraction of their lives in quiescence: 45 \pm 19% for log10(Mstar) < 9.
