The James Webb Space Telescope (JWST) hosts a non-redundant Aperture Masking Interferometer (AMI) in its Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument, providing the only dedicated interferometric facility aboard – magnitudes more precise than any interferometric experiment previously flown. However, the performance of AMI (and other high resolution approaches such as kernel phase) in recovery of structure at high contrasts has not met design expectations. A major contributing factor has been the presence of uncorrected detector systematics, notably charge migration effects in the H2RG sensor, and insufficiently accurate mask metrology. Here we present Amigo, a data-driven calibration framework and analysis pipeline that forward-models the full JWST AMI system – including its optics, detector physics, and readout electronics – using an end-to-end differentiable architecture implemented in the Jax framework and in particular exploiting the $\partial$Lux optical modelling package. Amigo directly models the generation of up-the-ramp detector reads, using an embedded neural sub-module to capture non-linear charge redistribution effects, enabling the optimal extraction of robust observables, for example kernel amplitudes and phases, while mitigating systematics such as the brighter-fatter effect. We demonstrate Amigo’s capabilities by recovering the AB Dor AC binary from commissioning data with high-precision astrometry, and detecting both HD 206893 B and the inner substellar companion HD 206893 c: a benchmark requiring contrasts approaching 10 mag at separations of only 100 mas. These results exceed outcomes from all published pipelines and re-establish AMI as a viable competitor for imaging at high contrast at the diffraction limit. Amigo is publicly available as open-source software community resource .

We report the design and functionality of the Murchison Widefield Array Particle Detector Array (MWA PDA), an array of eight particle scintillation detectors deployed to Inyarrimanha Ilgari Bundara, the Murchison Radio-astronomy Observatory (MRO). The purpose of the instrument is to identify cosmic ray extensive air showers (EAS) occurring over the core of the MWA radio telescope and generate a trigger to allow radio data on the event to be captured and analysed. The system also acts as a pathfinder for a much larger instrument to be deployed in the core of the low-frequency component of the Square Kilometre Array, SKA-Low, by the SKA’s ultra-high-energy particles science working group. Here, we describe the instrument and associated infrastructure, which has been verified to comply with the strict radio-frequency emissions requirements of the MRO, and was deployed in November 2024. We present calibration data, which demonstrates the ability of each detector to identify individual atmospheric muons at the expected rate, and we characterise the temperature dependence of the system. We describe a sample of 35 500 EAS identified using multi-detector coincidence over a 13-d period, and show how the detector data can be used to reconstruct the arrival directions and approximate energies of these events. We conclude that the particle detector array can reliably trigger on and reconstruct EAS contained within the $\sim$$103 \times 90$ m$^2$ core region, arriving within 20$^{\circ}$ of zenith, at primary cosmic ray energies above $\sim$4 PeV. We have also verified that the detector array can generate triggers, allowing the capture of radio data from the MWA correlator for offline analysis.

We present the discovery of two intersecting radio shells, likely radio relics, surrounding a compact galaxy group dominated by a massive elliptical galaxy. The shells present as partial, edge-brightened rings with diameters of $\sim$240″ ($\sim$720 kpc) each and resemble a pair of odd radio circles. The central galaxy, WISEA J184105.19–654753.8, which shows signs of interactions, is radio bright, has a stellar mass of $3.1 \times 10^{11}$ M$_{\odot}$ (for a redshift of $z_\mathrm{phot}$ $\sim 0.18$) and is located in the intersect region. The double radio shell system, which we refer to as ORC J1841–6547, also known as ORC 6, was detected in 944 MHz radio continuum images obtained with Phased Array Feeds on the Australian Square Kilometre Array Pathfinder (ASKAP). The more prominent, north-western shell may be associated with an X-ray detection, while the weaker, south-eastern shell has no counterpart at non-radio wavelength. We propose outwards moving shocks from galaxy mergers driving into the intragroup medium, re-energising relic radio lobes, as a possible formation scenario for the observed radio shells. We conclude that at least some ORCs are shock-energised relics in the outskirts of galaxy groups, which originate during the merger evolution of the brightest group galaxy.

We present the characterisation, including a photometric redshift (photo-z) analysis, of the optical counterparts (CTPs) to over 45 000 bright ($S_{856\,\mathrm{MHz}} \geq$ 30 mJy) compact radio sources, identified across all ASKAP First Large Absorption Survey in H I (FLASH) fields observed up to April 2025. These sources constitute a large, homogeneous population of background continuum sightlines specifically selected to enable statistical studies of cold gas at intermediate redshifts of $0.42 \leq z \leq 1$. As spectroscopic redshift measurements are not available for the majority of these candidate absorbers, we estimate photo-zs for the CTPs of all FLASH continuum sources cross-matched to the tenth data release of the DESI Legacy Imaging Surveys (LS10). Using these estimates, we establish the redshift distribution and find that approximately 13% of continuum sources lie at $z\lt0.42$ (foreground), 35% within the detectability range of FLASH (‘in-band’), and 52% at $z\gt1$ (background). We examine the subset of FLASH continuum sources with CTPs in the eROSITA X-ray survey, providing additional insight into their AGN content, multiwavelength properties, and environments. Finally, we discuss how this information can be used as a statistical prior to aid in distinguishing between associated and intervening H I absorption systems and estimating the total comoving absorption path length of the survey, establishing a framework for incorporating redshift-based priors in future large radio absorption surveys. We release a catalogue of LS10 counterparts to FLASH continuum sources, providing photo-z estimates, associated uncertainties, and measures of redshift degeneracies.

Post-red and post-asymptotic giant stars in binary systems with main sequence companions have periods in the range $\sim$50–2 000 d and eccentricities as high as 0.6 and are surrounded by a circumbinary disc. Their orbital separations are small enough that the system must have gone through Roche lobe overflow when the primary was a full blown giant; Roche lobe overflow between a giant and a more compact companion tend to lead to a common envelope inspiral, leaving a circular orbit with periods much shorter than observed in these systems. In this first work in a series we explore to what extent a high mass ratio, $q \equiv M_2/M_1$, can lead to wider orbital separations, by carrying out a series of 3D, hydrodynamical CE binary interaction simulations with the smoothed particle hydrodynamics code Phantom. The giant is a 0.88 M$_{\odot}$, 90 R$_{\odot}$, red giant branch star and the companions have a range of masses such that $q = 0.68$–$1.5$. While larger q values result in wider post-CE separations, the upper limit we predict is only $\sim$50 R$_{\odot}$, smaller than the observed range. The pre-CE mass transfer phase is longer for larger companion masses and around $q\gtrsim 1$ the nature of the CE inspiral changes significantly, showing greater stability, as predicted by analytical theory. However, this phase is not converged with respect to simulation resolution, and it is expected that a higher resolution would lead to even more stability and a longer pre-inspiral phase. Despite more material flowing through the $L_2$ and $L_3$ Lagrange points for higher q values, with the potential for the formation of a circumbinary disc structure in this way, we conclude that, for our parameters, circumbinary discs are more likely to form from fall back of leftover bound envelope. Fall-back times are short (a few $\times 100$ yr) and fall-back discs extend between $0.5$ and 5 au (outside the binary orbit), at which point the discs are likely to spread farther on short timescales via viscous torques. These discs have characteristics in line with those observed.

Following long periods of quiescence, low-mass X-ray binaries (XRBs) can exhibit intense X-ray outbursts triggered by instabilities within the accretion disk. These outbursts can sometimes be detected in optical wavelengths before being detected in X-ray, acting as an early onset warning and enabling a deep study of accretion disk properties informed by the lag between optical and X-ray rise. We explore the potential of Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) to detect these outbursts early through optical observations. We evaluate the capabilities of LSST based on currently planned survey cadence, filter-specific depth, and other observational factors that affect early detection. We develop and apply an extended metric to assess outburst detectability and recovery fraction. We find that despite inherent potential for early detection of XRB outbursts, the currently planned survey strategy makes it challenging to detect early onset of XRBs. Lastly, we demonstrate how this estimate can be used to infer the wider low mass X-ray binary population in the Galaxy as the LSST progresses.

The increasing field of view of radio telescopes and improved data processing capabilities have led to a surge in the detection of Fast Radio Bursts (FRBs). The discovery rate of FRBs is already a few per day and is expected to increase rapidly with new surveys coming online. The growing number of events necessitates prioritised follow-up due to limited multi-wavelength resources, requiring rapid and automated classification. In this study, we introduce Frabjous, a deep learning framework for an automated morphology classifier with an aim towards enabling the prompt follow-up of anomalous and intriguing FRBs, and a comprehensive statistical analysis of FRB morphologies. Deep learning models require a large training set of each FRB archetype; however, publicly available data lack sufficient samples for most FRB types. In this paper, we build a simulation framework for generating realistic examples of FRBs and train a network based on a combination of simulated and real data starting with the CHIME/FRB catalog. Applying our framework to the first CHIME/FRB catalog, we achieve an overall classification accuracy of approximately 55%, well over a random multiclass classification rate of 20% with five balanced classes during training. While this falls short of desirable performance, we critically discuss the limitations of our approach and propose potential avenues for improvement. Future work should explore strategies to augment training datasets and broaden the scope of FRB morphological studies, aiming for more accurate and reliable classification results.

The discovery of the galaxy ring known as the Council of Giants (CoG) highlights the need to explain such structures in the Local Universe. In the first paper of this series, we presented HINORA – a code to locate (ring-like) structures in 3D point sets – and used it to identify the CoG in the most complete observations of the Local Volume. Here, in Part II, we apply the same method to cosmological simulations to quantify the possible existence of such objects in the $\rm \Lambda$CDM model of structure formation. We analyse DM-only simulations with random and constrained initial conditions, selecting regions that reproduce the properties of the Local Group and Volume, respectively. In order to use the same selection criteria as previously done for observations, we relate K-band luminosities to halo masses through semi-empirical relations. After confirming that the selected regions from the simulations match the observed mass function and density of the Local Universe, we use HINORA to search for ring-like structures in them. We find that the existence of CoGs in $\rm \Lambda$CDM simulations is a rather unusual phenomenon. The observed CoG represents an anomaly of more than 2.7$\sigma$ from what is expected in the distribution of massive galaxies in $\rm \Lambda$CDM. These results hint that the CoG could either be a rare chance configuration or the imprint of physical processes at intermediate scales that standard DM-only simulations fail to capture.

Eccentric millisecond pulsar + helium white dwarf (MSP + He WD) systems have attracted increasing attention, with the rotationally delayed accretion-induced collapse (RD-AIC) scenario proposed as a possible formation channel. Given the similarity between the formation channels of He WDs and subdwarf B (sdB) stars, eccentric MSP + sdB binaries could also exist in the Galaxy, though none have been detected so far. Theoretical predictions of their properties would greatly aid in their discovery. Here, within the RD-AIC framework, I present predictions for their orbital parameters, including MSP mass, secondary mass, eccentricity, and orbital period. Based on two detailed binary population synthesis calculations, I estimate their Galactic birth rate to be $(0.67$–$1.5)\times10^\mathrm{-4}\mathrm{yr^\mathrm{-1}}$. Then, a very conservative upper limit for their total number in the Galaxy is 15 000, implying that the most optimistic fraction of eccentric MSP + sdB systems among all MSP + sdB populations could reach up to 55%. These systems are relatively young, with ages on the order of a few hundred Myr, and should therefore be found in relatively young environments. Furthermore, most MSPs in such eccentric binaries have masses below 1.5 M$_{\odot}$. I also briefly discuss their potential future applications in various astrophysical contexts.

The rest-frame ultraviolet (UV) spectra of star-forming galaxies are increasingly important as they become one of the primary windows to probe the physical properties of cosmic dawn ($z\gt8$) galaxies with the James Webb Space Telescope. However, the systematic discrepancies between UV and optical gas-phase metallicity measurements remain poorly understood in the local universe, partly due to challenges in achieving precise comparisons between UV and optical spectra for the same objects. In this work, we introduce a novel method that leverages the He II ${\lambda 1640}$ and He II ${\lambda 4686}$ nebular emission lines to achieve accurate aperture and reddening corrections between UV and optical spectra. Here we apply this method to three nearby Blue Compact Dwarf (BCD) galaxies. Our results demonstrate that this approach enables precise measurements, with electron temperatures ($T_e$) derived from UV and optical spectra exhibiting closer agreement compared to previous studies, and O/H abundance agreeing within 0.1 dex. However, two BCDs appear to have lower UV-based electron temperatures $T_{e\,1666}$ $\lt$ $T_{e\,4363}$, in contrast to expectations from the temperature fluctuation model. We consider a variety of possible explanations for these unphysical temperatures – differential dust attenuation, aperture differences, and spatial extent of emission lines – but no suitable cause is identified. These findings suggest a complex gaseous environment associated with star formation, and underscore the need for additional observations to further investigate the nature of He II nebular emission and address the systematic issues between UV and optical nebular properties. Nonetheless, the close empirical agreement of these results indicates that UV- and optical-based nebular temperature and abundance measurements can be reliably compared within 0.1 dex, providing a solid foundation for evolutionary studies from the local Universe to cosmic dawn.

We report the discovery of an intervening 21 cm absorption line at $z=0.882$ towards the $z=1.284$ quasar PKS 0405-385, identified in the First Large Absorption Survey in H i (FLASH). This quasar once displayed the most rapid known intraday variability at radio frequencies, from which it earned the title of ‘the smallest radio quasar’. Although its size was revised upwards soon after based on updated scattering theory, PKS 0405-385 remains an important probe of Galactic plasma, and now also of intervening gas discovered through H i absorption. We present new long-slit spectroscopy spanning both PKS 0405-385 and the candidate host of the intervening H i gas. We identify Mg ii and Fe ii absorption lines in this spectrum consistent with the redshift of the intervening H i, as well as two additional, independent metal-line systems at $z= 0.907$ and $z=0.966$, but we cannot accurately pinpoint the host(s) of this intervening gas in current data. We revisit the radio variability of PKS 0405-385 in light of advances in scintillation theory, as well as extended monitoring with the Australia Telescope Compact Array and the Australian SKA Pathfinder, and find a revised linear size $\geq0.3\,$pc, but no new evidence of repeating intraday variability.

Spectral-line results from a new cryogenic phased array feed (cryoPAF) on the Murriyang telescope at Parkes are presented. This array offers a significant improvement in field of view, aperture efficiency, bandwidth, chromaticity, and survey speed compared with conventional horn-fed receivers. We demonstrate this with measurements of sky calibrators and observations of 21-cm neutral hydrogen (HI) in the Large Magellanic Cloud (LMC) and the nearby galaxy NGC 6744. Within 0.3 deg of the optical axis, the ratio of system temperature to dish aperture efficiency ($T_\mathrm{sys}/\eta_{d}$) is 25 K, and the ratio with beam efficiency ($T_\mathrm{sys}/\eta_\mathrm{mb}$) is 21 K (at 1.4 GHz). For the previously measured $T_\mathrm{sys} = 17$ K, respective efficiency values $\eta_{d} \approx 0.7$ and $\eta_\mathrm{mb} \approx 0.8$ are derived. Our HI observational results are in good agreement with previous results, although detailed comparison with multibeam observations of the LMC suggests that the earlier observations may have missed an extended component of low-column-density gas ($\sim$$8\times 10^{18}$ cm$^{-2}$). We use the cryoPAF zoom-band and wideband data to make a preliminary investigation of whether the large number of simultaneous beams (72) permits the use of novel data reduction methods to reduce the effects of foreground/background continuum contamination and radio-frequency interference (RFI). We also investigate if these methods can better protect against signal loss for the detection of faint, extended cosmological signals such as HI intensity maps. Using robust higher-order singular value decomposition (SVD) techniques, we find encouraging results for the detection of both compact and extended sources, including challenging conditions with high RFI occupancy and significant sky continuum structure. Examples are shown that demonstrate that 3D SVD techniques offer a significant improvement in noise reduction and signal capture compared with more traditional layered 2D techniques.

We report diffuse extended radio-continuum emission spatially coinciding with the IR source, WISEA J094409.17$-$751012.8, and a semi-variable star, V687 Carinae. We use 944 MHz radio data from the large-scale Evolutionary Map of the Universe (EMU) survey to analyse this diffuse emission (EMU J094412$-$751016), which we nickname ‘Anglerfish’. We investigate if the spatially correlated infrared (IR) source, WISEA J094409.17$-$751012.8, is physically related to Anglerfish. The IR colours of WISEA J094409.17$-$751012.8 are indicative of an elliptical galaxy, raising the possibility that Anglerfish may belong to the newly discovered class of extragalactic radio sources known as Odd Radio Circles (ORCs) with WISEA J094409.17$-$751012.8 as the host galaxy. We also investigate the possibility that Anglerfish is physically related to the star, V687 Carinae, and whether it may be a remnant from a previous epoch of stellar mass-loss. We determine that a physical association between the radio emission and the star is unlikely due to the star’s weak stellar winds compared to the theoretical expansion velocity of the ‘shell’. It is possible that Anglerfish may be a Galactic high-latitude supernova remnant; however, we find that the observed size and luminosity are not consistent with this scenario. We also investigate the ORC scenario, which we deem the most likely scenario based on the Anglerfish’s observed properties such as size, brightness, lack of other frequency detections, and possible host galaxy identification. We therefore propose Anglerfish as an ORC candidate, but note that additional radio and optical observations are vital to further constrain the properties and confirm this classification.

Flying on board the James Webb Space Telescope (JWST) above Earth’s turbulent atmosphere, the Aperture Masking Interferometer (AMI) on the NIRISS instrument is the highest-resolution infrared interferometer ever placed in space. However, its performance was found to be limited by non-linear detector systematics, particularly charge migration – or the Brighter-Fatter Effect. Conventional interferometric Fourier observables are degraded by non-linear transformations in the image plane, with the consequence that the inner working angle and contrast limits of AMI were seriously compromised. Building on the end-to-end differentiable model & calibration code , we here present a regularised maximum-likelihood image reconstruction framework , which can deconvolve AMI images either in the image plane or from calibrated Fourier observables, achieving high angular resolution and contrast over a wider field of view than conventional interferometric limits. This modular code by default includes regularisation by maximum entropy, and total variation defined with $l_1$ or $l_2$ metrics. We present imaging results from dorito for three benchmark imaging datasets: the volcanoes of Jupiter’s moon Io, the colliding-wind binary dust nebula WR 137 and the archetypal Seyfert 2 active galactic nucleus NGC 1068. In all three cases, we recover images consistent with the literature at diffraction-limited resolutions. The performance, limitations, and future opportunities enabled by amigo for AMI imaging (and beyond) are discussed.

Extended radio sources present unique challenges for automated detection and classification in wide-field radio surveys. With current surveys such as the Evolutionary Map of the Universe (EMU), robust and scalable methods are essential to identify and catalogue these complex sources. We apply three automatic approaches to detect complex radio emission in EMU observations of the Galaxy And Mass Assembly (GAMA) 09 field (EMU-G09) in order to evaluate their relative strengths and limitations in preparation for large-scale application across future EMU data releases. These include DRAGNhunter, designed to detect likely DRAGNs (Double Radio sources associated with Active Galactic Nuclei) from a component catalogue; coarse-grained complexity, a metric designed to highlight regions of complex emission; and RG-CAT, a machine learning pipeline trained on radio sources identified in the EMU pilot survey. We find that together, the three methods recover nearly all extended sources in EMU-G09 but identify largely distinct, partially overlapping subsets, with only 375 sources identified by all finders. This demonstrates that a combination of complementary techniques will be required to achieve a complete census of extended radio sources in future large-scale surveys.

This study presents a comprehensive analysis of the infrared (IR) luminosity functions (LF) of star-forming (SF) galaxies and active galactic nuclei (AGN) using data from the ZFOURGE survey. We employ CIGALE to decompose the spectral energy distribution of galaxies into SF and AGN components to investigate the co-evolution of these processes at higher redshifts and fainter luminosities. Our CIGALE-derived SF and AGN LFs are generally consistent with previous studies, with an enhancement at the faint end of the AGN LFs. We attribute this to CIGALE’s capability to recover low-luminosity AGN more accurately, which may be underrepresented in other works. We find evidence for a significant evolutionary epoch for AGN activity below $z \approx 2$, comparable to the peak of cosmic star formation at $z \approx 2$, which we also recover well. Based on our results, the gas supply in the early universe favoured the formation of brighter star-forming galaxies from high-redshift until $z=2$, below which the gas for SF becomes increasingly exhausted. In contrast, AGN activity peaked earlier and declined more gradually, suggesting a possible feedback scenario in which AGN positively influence SF.

Observations indicate that high-redshift galaxies undergo episodic star formation bursts, driving strong outflows that expel gas and suppress accretion. We investigate the consequences for metal and dust content of galaxies at $z\geq\!5$ using our semi-analytical model, Ashvini. We track gas-phase and stellar metallicities ($Z_{\textrm g}, Z_{\star}$) and dust mass ($M_{\textrm{d}}$) in dark matter haloes spanning $M_{\textrm{h}} = 10^6{-}10^{11}\,\text{M}_{\odot}$, comparing continuous and bursty star formation scenarios – which reflect underlying assumptions of instantaneous and delayed feedback – and we allow for metallicity-dependent feedback efficiency. Delayed feedback induces oscillations in $Z_{\textrm{g}}$ and $Z_{\star}$, with $Z_{\textrm{g}}$ declining sharply at low stellar and halo masses; the mass scale of this decline increases towards lower redshift. Reionisation introduces significant scatter in $Z_{\textrm{g}}$, producing an upturn followed by rapid decline. Metallicity-dependent feedback moderates this decline at $z=7{-}10$, flattening the $Z_{\textrm{g}}$–mass relation to $\simeq$$0.03$–$0.04\,\text{Z}_{\odot}$. Dust production tracks $Z_{\textrm{g}}$ but is sensitive to burst history, causing delayed enrichment. Our results show that burst-driven feedback decouples $Z_{\textrm{g}}$ and $Z_{star}$, imprints intrinsic scatter in mass–metallicity relations, and delays dust growth. These effects are strongest in low-mass halos ($M_{\textrm{h}}\sim 10^7\,\text{M}_{\odot}$), where shallow potentials amplify the impact of feedback. Our results are consistent with recent hydrodynamical and semi-analytical simulations and provide context for interpreting James Webb Space Telescope metallicity and dust measurements, highlighting the importance of episodic star formation in early galaxy chemical evolution.

We have analysed photometric data from a sample of pulsating stars observed by the Transiting Exoplanet Survey Satellite. By applying Fourier and prewhitening techniques, we extracted the significant frequencies for each star. We investigated the presence of rotationally split multiplets and evaluated frequency spacings using the Kolmogorov–Smirnov test. These analyses allow us to estimate stellar parameters such as the large frequency spacing, which in turn provides insights into the stellar mean densities. However, identifying clear multiplets and frequency spacings in ${\unicode{x03B4}}$ Scuti stars remains challenging due to the complexity of their oscillation spectra. Our rotationally-split mode findings are yet to be confirmed, while the K–S test revealed no convincing large frequency spacings that could be used toward mass estimation. We derived orbital periods for stars we identified to be in binary systems. We provide spectral type classifications to confirm the ${\unicode{x03B4}}$ Sct and/or ${\unicode{x03B3}}$ Dor nature of the stars we found. Out of 43 stars presented in this paper, 18 are identified as ${\unicode{x03B4}}$ Sct/${\unicode{x03B3}}$ Dor hybrids (including five candidates), 20 as ${\unicode{x03B4}}$ Sct stars, one as a ${\unicode{x03B3}}$ Dor star and four as binary systems without any signature of pulsation.

AM CVn stars are ultra-compact semi-detached binaries consisting of a white dwarf primary and a hydrogen-depleted secondary. In this paper, we present spectroscopic and photometric results of 15 transient sources pre-classified as AM CVn candidates. Our analysis confirms 9 systems of the type AM CVn, 3 hydrogen-rich cataclysmic variables (accreting white dwarfs with near-main-sequence stars for donors), and 3 systems that could be evolved cataclysmic variables. Eight of the AM CVn stars are analysed spectroscopically for the first time, which increases the number of spectroscopically confirmed AM CVns by about 10%. TESS data revealed the orbital period of the AM CVn star ASASSN-20pv to be $P_{\mathrm{orb}}=27.282\,\mathrm{min}$, which helps to constrain the possible values of its mass ratio. TESS also helped to determine the superhump periods of one AM CVn star (ASASSN-19ct, $P_{\mathrm{sh}}=30.94\,\mathrm{min}$) and two cataclysmic variables we classify as WZ Sge stars ($P_{\mathrm{sh}}=90.77\,\mathrm{min}$ for ZTF18aaaasnn and $P_{\mathrm{sh}}=91.6\,\mathrm{min}$ for ASASSN-15na). We identified very different abundances in the spectra of the AM CVns binaries ASASSN-15kf and ASASSN-20pv (both $P_{\mathrm{orb}}\sim 27.5$ min), suggesting different type of donors. Six of the studied AM CVns are X-ray sources, which helped to determine their mass accretion rates. Photometry shows that the duration of all the superoutbursts detected in the AM CVns is consistent with expectations from the disc instability model. Finally, we provide refined criteria for the identification of new systems using all-sky surveys such as LSST.

We present a novel approach to correcting H${\unicode{x03B1}}$ luminosity functions for dust extinction by calibrating against radio-based star formation rates (SFRs), using data from the Evolutionary Map of the Universe (EMU) and Galaxy and Mass Assembly (GAMA) surveys. Accurate dust correction is essential for deriving SFRs from rest-frame UV-optical emission lines, particularly as the James Webb Space Telescope extends such measurements to galaxies at $z\gt5$. While a luminosity dependence of dust obscuration has long been recognised, our method exploits the empirical relationship between obscured (H${\unicode{x03B1}}$) and unobscured (radio) SFRs to provide a dust correction that can be applied where traditional spectroscopic techniques, for example, Balmer line based approaches, are unavailable. We apply the SFR based dust correction to 25 published H${\unicode{x03B1}}$ luminosity functions spanning $0\lt z\lt 8$ and derive corresponding star formation rate densities (SFRDs). Adopting the locally calibrated H${\unicode{x03B1}}$–radio relation ends up with an overestimate of the cosmic SFRD by more than two orders of magnitude at $z\gtrsim1$. Motivated by the luminosity dependent relation in the local Universe, we introduce a new model where the luminosity dependence of the dust obscuration decreases with increasing redshift. This approach can reproduce observed SFRDs across cosmic time. These results highlight the potential of a radio-based calibration for dust correction, where a luminosity dependent correction would need to decline in strength with increasing redshift. This implies that the dust content or distribution in galaxies at early epochs differs substantially from that in the local Universe.