Galaxy formation and evolution

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Herschel-SPIRE-Fourier Transform Spectroscopy of the nearby spiral galaxy IC342

Monthly Notices of the Royal Astronomical Society

Authors:

D Rigopoulou, PD Hurley, BM Swinyard, J Virdee, KV Croxall, RHB Hopwood, T Lim, GE Magdis, CP Pearson, E Pellegrini, E Polehampton, J-D Smith
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Large Synoptic Survey Telescope White Paper; The Case for Matching U-band on Deep Drilling Fields

Authors:

BW Holwerda, A Baker, S Blyth, S Kannappan, D Obreschkow, S Ravindranath, E Elson, M Vaccari, S Crawford, M Bershady, N Hathi, N Maddox, R Taylor, MATTHEW Jarvis, J Bridge

Abstract:

U-band observations with the LSST have yet to be fully optimized in cadence. The straw man survey design is a simple coverage of the medium-deep-fast survey. Here we argue that deep coverage of the four deep drilling fields (XMM-LSS, ECDFS, ELAIS-S1 and COSMOS) has a much higher scientific return, given that these are also the target of the Southern Hemisphere's Square Kilometer Array Pathfinder, the MeerKAT specifically, deep radio observations.
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MIGHTEE - HI: The relation between the HI gas in galaxies and the cosmic web

Monthly Notices of the Royal Astronomical Society, Volume 513, Issue 2, pp.2168-2177

Authors:

Tudorache, Madalina N. ; Jarvis, M. J. ; Heywood, I. ; Ponomareva, A. A. ; Maddox, N. ; Frank, B. S. ; Adams, N. J. ; Bowler, R. A. A. ; Whittam, I. H. ; Baes, M. ; Pan, H. ; Rajohnson, S. H. A. ; Sinigaglia, F. ; Spekkens, K.

Abstract:

We study the 3D axis of rotation (3D spin) of 77 H I galaxies from the MIGHTEE-H I Early Science observations, and its relation to the filaments of the cosmic web. For this HI-selected sample, the alignment between the spin axis and the closest filament (|cos ψ|) is higher for galaxies closer to the filaments, with ⟨|cos ψ|⟩ = 0.66 ± 0.04 for galaxies <5 Mpc from their closest filament compared to ⟨|cos ψ|⟩ = 0.37 ± 0.08 for galaxies at 5 < d < 10 Mpc. We find that galaxies with a low HI-to-stellar mass ratio (log10(MHI/M⋆) < 0.11) are more aligned with their closest filaments, with ⟨|cos ψ|⟩ = 0.58 ± 0.04; whilst galaxies with (log10(MHI/M⋆) > 0.11) tend to be mis-aligned, with ⟨|cos ψ|⟩ = 0.44 ± 0.04. We find tentative evidence that the spin axis of HI-selected galaxies tend to be aligned with associated filaments (d < 10 Mpc), but this depends on the gas fractions. Galaxies that have accumulated more stellar mass compared to their gas mass tend towards stronger alignment. Our results suggest that those galaxies that have accrued high gas fraction with respect to their stellar mass may have had their spin axis alignment with the filament disrupted by a recent gas-rich merger, whereas the spin vector for those galaxies in which the neutral gas has not been strongly replenished through a recent merger tend to orientate towards alignment with the filament. We also investigate the spin transition between galaxies with a high HI content and a low HI content at a threshold of MHI≈10^9.5M⊙ found in simulations; however, we find no evidence for such a transition with the current data.
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Magnetogenesis at Cosmic Dawn: Tracing the Origins of Cosmic Magnetic Fields

MNRAS

Authors:

Harley Katz, Sergio Martin-Alvarez, Julien Devriendt, Adrianne Slyz, Taysun Kimm

Abstract:

Despite their ubiquity, the origin of cosmic magnetic fields remains unknown. Various mechanisms have been proposed for their existence including primordial fields generated by inflation, or amplification and injection by compact astrophysical objects. Separating the potential impact of each magnetogenesis scenario on the magnitude and orientation of the magnetic field and their impact on gas dynamics may give insight into the physics that magnetised our Universe. In this work, we demonstrate that because the induction equation and solenoidal constraint are linear with $B$, the contribution from different sources of magnetic field can be separated in cosmological magnetohydrodynamics simulations and their evolution and influence on the gas dynamics can be tracked. Exploiting this property, we develop a magnetic field tracer algorithm for cosmological simulations that can track the origin and evolution of different components of the magnetic field. We present a suite of cosmological magnetohydrodynamical RAMSES simulations that employ this algorithm where the primordial field strength is varied to determine the contributions of the primordial and supernovae-injected magnetic fields to the total magnetic energy as a function of time and spatial location. We find that, for our specific model, the supernova-injected fields rarely penetrate far from haloes, despite often dominating the total magnetic energy in the simulations. The magnetic energy density from the supernova-injected field scales with density with a power-law slope steeper than 4/3 and often dominates the total magnetic energy inside of haloes. However, the star formation rates in our simulations are not affected by the presence of magnetic fields, for the ranges of primordial field strengths examined. These simulations represent a first demonstration of the magnetic field tracer algorithm (abridged).
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Modelling baryonic feedback for survey cosmology

Authors:

NE Chisari, AJ Mead, S Joudaki, P Ferreira, A Schneider, J Mohr, T Tröster, D Alonso, IG McCarthy, S Martin-Alvarez, JULIEN Devriendt, A Slyz, MPV Daalen

Abstract:

Observational cosmology in the next decade will rely on probes of the distribution of matter in the redshift range between $0
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