First author: Yuer Jiang
Cross-correlating the data of neutral hydrogen (HI) 21cm intensity mapping with galaxy surveys is an effective method to extract astrophysical and cosmological information. In this work, we investigate the cross-correlation of MeerKAT single-dish mode HI intensity mapping and China Space Station Telescope (CSST) spectroscopic galaxy surveys. We simulate a survey area of $\sim 300$ $\mathrm{deg}^2$ of MeerKAT and CSST surveys at $z=0.5$ using Multi-Dark N-body simulation.
First author: Alex McDaniel
Many star-forming galaxies and those hosting active galactic nuclei (AGN) show evidence of massive outflows of material in a variety of phases including ionized, neutral atomic, and molecular. Molecular outflows in particular have been the focus of recent interest as they may be responsible for removing gas from the galaxy, thereby suppressing star formation. As material is ejected from the cores of galaxies, interactions of the outflowing material with the interstellar medium can accelerate cosmic rays and produce high-energy gamma rays.
First author: Alexandra Le Reste
Around 400 million years after the big bang, ultraviolet emission (Lyman Continuum, LyC) from star-forming galaxies drove the reionization of the Universe. How this radiation escapes the cold neutral gas (HI) of galaxies with sufficiently little absorption to reionize the intergalactic medium is poorly understood. HI has never been mapped in confirmed LyC-emitters, leaving major uncertainties on how LyC photons escape galaxies and ionize the intergalactic medium.
First author: Alisson Pellissier
We present the Rhapsody-C simulations that extend the Rhapsody-G suite of massive galaxy clusters at the $M_{\rm vir}\sim10^{15}\thinspace{\rm M}_{\odot}$ scale with cosmological magneto-hydrodynamic zoom-in simulations that include anisotropic thermal conduction, modified supermassive black hole (SMBH) feedback, new SMBH seeding and SMBH orbital decay model. These modelling improvements have a dramatic effect on the SMBH growth, star formation and gas depletion in the proto-clusters. We explore the parameter space of the models and report their effect on both star formation and the thermodynamics of the intra-cluster medium (ICM) as observed in X-ray and SZ observations.
First author: Anowar J. Shajib
Strong-lensing time delays enable measurement of the Hubble constant ($H_{0}$) independently of other traditional methods. The main limitation to the precision of time-delay cosmography is mass-sheet degeneracy (MSD). Some of the previous TDCOSMO analyses broke the MSD by making standard assumptions about the mass density profile of the lens galaxy, reaching 2% precision from seven lenses. However, this approach could potentially bias the $H_0$ measurement or underestimate the errors.
First author: John R. Weaver
In November 2022, the James Webb Space Telescope (JWST) returned deep near-infrared images of Abell~2744 – a powerful lensing cluster capable of magnifying distant, incipient galaxies beyond it. Together with the existing Hubble Space Telescope (HST) imaging, this publicly available dataset opens a fundamentally new discovery space to understand the remaining mysteries of the formation and evolution of galaxies across cosmic time. In this work, we detect and measure some 50,000 objects across the 45 arcmin$^2$ JWST footprint down to a $5,\sigma$ limiting magnitude of $\sim$29.
First author: Alexander Johnson
Studying coupling between different galactic components is a challenging problem in galactic dynamics. Using basis function expansions (BFEs) and multichannel singular spectrum analysis (mSSA) as a means of dynamical data mining, we discover evidence for two multi-component disc-halo dipole modes in a Milky-Way-like simulated galaxy. One of the modes grows throughout the simulation, while the other decays throughout the simulation. The multi-component disc-halo modes are driven primarily by the halo, and have implications for the structural evolution of galaxies, including observations of lopsidedness and other non-axisymmetric structure.
First author: Rongjun Huang
Previous studies have shown that the normalization and scatter of the galaxy ‘main sequence’ (MS), the relation between star formation rate (SFR) and stellar mass ($M_$), evolves over cosmic time. However, such studies often rely on photometric redshifts and/or only rest-frame UV to near-IR data, which may underestimate the SFR and $M_$ uncertainties. We use MAGPHYS+photo-z to fit the UV to radio spectral energy distributions of 12,380 galaxies in the COSMOS field at $0.
First author: Jacques P Vallée
We compare the observed radial velocity of different arm tracers, taken near the tangent to a spiral arm. A slight difference is predicted by the density wave theory, given the shock predicted at the entrance to the inner spiral arm. In many of these spiral arms, the observed velocity offset confirms the prediction of the density wave theory (with a separation between the maser velocity and the CO gas peak velocity, of about 20 km/s) - when the observed offset is bigger than the error estimates.
First author: A. Feltre
Line ratio diagnostics provide valuable clues on the source of ionizing radiation in galaxies with intense black hole accretion and starbursting events, like local Seyfert or galaxies at the peak of the star-formation history. We aim at providing a reference joint optical and mid-IR analysis for studying AGN identification via line ratios and test predictions from photoionization models. We obtained homogenous optical spectra with the Southern Africa Large Telescope for 42 Seyfert galaxies with IRS/Spitzer spectroscopy and X-ray to mid-IR multi-band data available.
