Angular correlation functions of bright Lyman-break galaxies at 3 ≲ z ≲ 5
Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (2025) staf1651
Abstract:
The Clustering of Active Galactic Nuclei and Star Forming Galaxies in the LoTSS Deep Fields
Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (2025) staf1626
Abstract:
Abstract Using deep observations across three of the LOFAR Two-metre Sky Survey Deep Fields, this work measures the angular clustering of star forming galaxies (SFGs) and low-excitation radio galaxies (LERGs) to z ≲1.5 for faint sources, S144 MHz ≥200 μJy. We measure the angular auto-correlation of LOFAR sources in redshift bins and their cross-correlation with multi-wavelength sources to measure the evolving galaxy bias for SFGs and LERGs. Our work shows the bias of the radio-selected SFGs increases from $b=0.90^{+0.11}_{-0.10}$ at z ∼0.2 to $b=2.94^{+0.36}_{-0.36}$ at z ∼1.2; faster than the assumed b($z$)∝1/D($z$) models adopted in previous LOFAR cosmology studies (at sensitivities where AGN dominate), but in broad agreement with previous work. We further study the luminosity dependence of bias for SFGs and find little evidence for any luminosity dependence at fixed redshift, although uncertainties remain large for the sample sizes available. The LERG population instead shows a weaker redshift evolution with $b=2.33^{+0.28}_{-0.27}$ at z ∼0.7 to $b=2.65^{+0.57}_{-0.55}$ at z ∼1.2, though it is also consistent with the assumed bias evolution model (b($z$)∝1/D($z$)) within the measured uncertainties. For those LERGs which reside in quiescent galaxies (QLERGs), there is weak evidence that they are more biased than the general LERG population and evolve from b=$2.62^{+0.33}_{-0.33}$ at z ∼0.7 to $b=3.08^{+0.85}_{-0.84}$ at z ∼1.2. This suggests the halo environment of radio sources may be related to their properties. These measurements can help constrain models for the bias evolution of these source populations, and can help inform multi-tracer analyses.The connection between the fastest astrophysical jets and the spin axis of their black hole
Nature Astronomy Springer Science and Business Media LLC (2025)
Abstract:
The dependence of the Type Ia Supernova colour–luminosity relation on their host galaxy properties
Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (2025) staf1570
Abstract:
Abstract Using the Dark Energy Survey 5-year sample, we determine the properties of type Ia supernova (SN Ia) host galaxies across a wide multi-wavelength range – from the optical to far-infrared – including data from the Herschel and Spitzer space telescopes. We categorise the SNe Ia into three distinct groups according to the distribution of their host galaxies on the star-formation rate (SFR) – stellar mass (M⋆) plane. Each region comprises host galaxies at distinct stages in their evolutionary pathways: Region 1 – low-mass hosts; Region 2 – high-mass, star-forming hosts and Region 3 – high-mass, passive hosts. We find SNe Ia in host galaxies located in Region 1 have the steepest slope (quantified by β) between their colours and luminosities, with $\beta _{\mathrm{R_1}} = 3.51 \pm 0.16$. This differs at the ∼6σ significance level to SNe Ia in Region 3, which have the shallowest colour–luminosity slope with $\beta _{\mathrm{R_3}} = 2.12 \pm 0.16$. After correcting SNe Ia in each subsample by their respective β, events in Region 3 (high-mass, passive hosts) are 0.07 − 0.12 mag (>3σ) brighter, post-standardisation. We conclude that future cosmological analyses should apply standardisation relations to SNe Ia based upon the region in which the SN host galaxy lies in the SFR–M⋆ plane. Alternatively, cosmological analyses should restrict the SN Ia sample to events whose host galaxies occupy a single region of this plane.Evidence for inverse Compton scattering in high-redshift Lyman-break galaxies
Monthly Notices of the Royal Astronomical Society (2025) staf1505