Research Articles (Physics)

Permanent URI for this collectionhttps://hdl.handle.net/10566/726

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Galaxy assembly bias in cosmological hydrodynamical simulations – a comparison between SIMBA and illustris TNG
(Oxford University Press, 2026) Davé, Romeel; Yang, Hong-Gang; Pellejero-Ibáñez, Marcos
Modelling of large-scale structure is increasingly concerned with galaxy assembly bias (GAB), the dependence of galaxy clustering on quantities other than halo mass. We investigate how baryonic physics affects the strength and redshift evolution of GAB using the largest runs of two state-of-the-art cosmological hydrodynamical simulations: SIMBA and illustris TNG. We quantify GAB by comparing the clustering of stellar-mass-selected galaxies to that of shuffled samples, where galaxies are randomly reassigned to haloes of similar mass. We find that GAB in both simulations increases from approximately zero at z = 5 to a ~ 5 per cent change in clustering amplitude at z = 2. After this epoch, the trends diverge: GAB in TNG continues to increase, reaching ~ 10 per cent at z = 0, while in SIMBA it decreases to nearly zero. By further shuffling galaxies within bins of halo mass and cosmic environment – characterized by smoothed matter overdensity (δ5) and tidal anisotropy (α5) – we show that most of the GAB in both simulations can be attributed to the overdensity, while tidal anisotropy contributes negligibly in both simulations. Exploring this effect from the point of view of the halo occupation distribution (HOD), we find that numbers of central and satellite galaxies vary with overdensity – but only near the respective turn-on masses for these two constituents: the galaxy contents of high-mass haloes are very nearly independent of environment. We present a simple parameterisation that allows the HOD modelling to be modified to reflect this form of density-dependent GAB.
Students’ experiences of teachers’ ways of unpacking visual representations in the context of intermolecular forces
(John Wiley and Sons Inc, 2026) Linder, Cedric; Patron, Emelie; Clark, Jonathan
This is the third article in a series, emanating from a project that used social semiotics and phenomenography to explore therole visual representations play in the teaching and learning of chemistry. Building on our earlier work that identified fivequalitatively different ways that teachers may use to unpack visual representations in their introductory classes at uppersecondary school when dealing with intermolecular forces, this article deals with how students describe their experience ofchemistry teachers’ unpacking of visual representations. The theoretical thematic analysis, grounded in phenomenography andsocial semiotics, foregrounds qualitative differences in students’ experiences of teachers’ representational work. The resultsshow that the ways of unpacking that we previously characterized as student‐centered were described by the students as beingparticularly valuable. Here, a key point from a student perspective is that the teacher reflects on how to verbally guide themthrough the unpacking process in ways that support them in their meaning‐making. We use these results to propose thatchemistry teacher practice and education can be modified to emphasize the importance of seeing the practice of unpackingfrom a semiotic perspective. Furthermore, based on our findings and previous research in the chemistry education field, weconclude by suggesting a strategy that can be used in teacher education and by in‐service teachers as a basis for planningchemistry lessons and reflecting on them, particularly with respect to the visual representations employed.
Crafts for H i cosmology. I. Data processing pipeline and validation tests
(American Astronomical Society, 2025) Hu, Wenkai; Yang, Wenxiu; Wolz, Laura
We present the calibration procedures and validation of source measurement with the data of the Commensal Radio Astronomy FAST Survey for H i intensity mapping by the Five-hundred-meter Aperture Spherical Radio Telescope. Using a 70 hr drift-scan observation with the L-band (1.05-1.45 GHz) 19 beam receiver, we obtain the data covering a 270 deg2 sky area. We employ both the pulsar backend and the spectrum backend to calibrate the spectral time-ordered data (TOD) before projecting them onto HEALPix maps. We produce calibrated TOD with a frequency resolution of 30 kHz and time resolution of 1 s and the map data cube with a frequency resolution of 30 kHz and spatial resolution of 2.95 arcmin2. We examine the pointing errors, noise overflow, radio-frequency interference (RFI) contamination, and their effect on the data quality. The resulting noise level is ∼5.7 mJy for the calibrated TOD and 1.6 mJy for the map, consistent with the theoretical predictions within 5% at RFI-free channels. We also validate the data by principal component analysis and find that the residual map looks thermal noise dominated after removing 30 modes. We identify 447 isolated bright continuum sources in our data matching the NRAO VLA Sky Survey catalog, with relative flux error of 8.3% for TOD and 6.6% for the map level. We also measure the H i emission of 90 galaxies with redshift z < 0.07 and compare them with H i-MaNGA spectra, yielding an overall relative H i integral flux error of 16.7%. These results provide an important first step in assessing the feasibility of conducting cosmological H i detection with CRAFTS.
Emission-line stacking of 21 cm intensity maps with MeerKLASS: inference pipeline and application to the L-band deep-field data
(American Astronomical Society, 2025) Spinelli, Marta; Wang, Jingying; Fonseca, José; Camera, Stefano; Wang, Jingying
We present a novel analysis of observational systematics through the emission-line stacking of the MeerKLASS L-band deep-field intensity maps, following the detection in MeerKLASS Collaboration et al. A stacking signal is obtained by stacking the 21 cm intensity map cubelets around the galaxy positions from the GAMA survey at 0.39 ≲ z ≲ 0.46. An extensive simulation framework is built to study the viability of the stacking detection, the covariance estimation, and the model inference, which are then applied to the data. The statistical significance of the detection is 8.66σ when averaged into an angular map, and 7.45σ when averaged into a spectrum. The stacked spectrum exhibits an oscillating component of systematics, and we provide evidence that these systematics are a convolutional effect on the map data. The oscillation frequency matches the diffraction from the secondary reflector into the primary beam of the MeerKAT telescope. Bayesian inference can be used to constrain the systematics and the average H i emission of the galaxies. The fitting of the parameters gives a constraint on the systematics frequency ν sys [ MHz ] = 17.9 0 − 4.27 + 6.53 . The posterior of the systematics amplitude reaches the wide prior and gives A sys = 0.5 0 − 0.33 + 0.33 . A tentative measurement of the average H i mass of the sources is achieved at log 10 [ 〈 M H I 〉 / M ⊙ ] = 9.8 4 − 0.59 + 0.48 , which is an underestimation limited by the narrow redshift bin, the strong degeneracy with the systematics, and the low-density galaxy sample. These shortfalls will be resolved for future MeerKLASS data to enable accurate measurements of the H i density through stacking of intensity maps.
Euclid preparation: LVI. Sensitivity to non-standard particle dark matter models
(EDP Sciences, 2025) Karagiannis, Dionysios; Lesgourgues, J; Schwagereit, J
The Euclid mission of the European Space Agency will provide weak gravitational lensing and galaxy clustering surveys that can be used to constrain the standard cosmological model and its extensions, with an opportunity to test the properties of dark matter beyond the minimal cold dark matter paradigm. We present forecasts from the combination of the Euclid weak lensing and photometric galaxy clustering data on the parameters describing four interesting and representative non-minimal dark matter models: a mixture of cold and warm dark matter relics; unstable dark matter decaying either into massless or massive relics; and dark matter undergoing feeble interactions with relativistic relics. We modelled these scenarios at the level of the non-linear matter power spectrum using emulators trained on dedicated N-body simulations. We used a mock Euclid likelihood and Monte Carlo Markov chains to fit mock data and infer error bars on dark matter parameters marginalised over other parameters. We find that the Euclid photometric probe (alone or in combination with cosmic microwave background data from the Planck satellite) will be sensitive to the effect of each of the four dark matter models considered here. The improvement will be particularly spectacular for decaying and interacting dark matter models. With Euclid, the bounds on some dark matter parameters can improve by up to two orders of magnitude compared to current limits. We discuss the dependence of predicted uncertainties on different assumptions: the inclusion of photometric galaxy clustering data, the minimum angular scale taken into account, and modelling of baryonic feedback effects. We conclude that the Euclid mission will be able to measure quantities related to the dark sector of particle physics with unprecedented sensitivity. This will provide important information for model building in high-energy physics. Any hint of a deviation from the minimal cold dark matter paradigm would have profound implications for cosmology and particle physics.
Primordial non-Gaussianity — the effects of relativistic and wide-angle corrections to the power spectrum
(Institute of Physics, 2025) Guedezounme, Sêcloka; Jolicoeur, Sheean; Maartens, Roy
Wide-angle and relativistic corrections to the Newtonian and flat-sky approximations are important for accurate modeling of the galaxy power spectrum of next-generation galaxy surveys. In addition to Doppler and Sachs-Wolfe relativistic corrections, we include the effects of lensing convergence, time delay and integrated Sachs-Wolfe. We investigate the impact of these corrections on measurements of the local primordial non-Gaussianity parameter fNL, using two futuristic spectroscopic galaxy surveys, planned for SKAO2 and MegaMapper. In addition to the monopole, we include the quadrupole of the galaxy Fourier power spectrum. The quadrupole is much more sensitive to the corrections than the monopole. The combination with the quadrupole improves the precision on fNL by ∼ 45% and ∼ 63% for SKAO2 and MegaMapper respectively. Neglecting the wide-angle and relativistic corrections produces a shift in fNL which is very sensitive to the magnification bias and the redshift evolution of the comoving number density. In the case of SKAO2, the shift in fNL is negligible — since the contributions to the shift from integrated and non-integrated effects nearly cancel. For MegaMapper, there is only partial cancellation of integrated and non-integrated effects and the shift is ∼ 0.6 σ. We point out that some of the approximations made in the wide-angle and relativistic corrections may artificially suppress the shift in fNL.
The LOFAR two-metre sky survey: vii. third data release
(EDP Sciences, 2026) Jarvis, MJ; Vaccari, Mattia; Shimwell, TW
We present the third data release of the LOFAR Two-metre Sky Survey (LoTSS-DR3). The survey images cover 88% of the northern sky and were created from 12 950 h of data (18.6 PB) accumulated over 10.5 years. Producing the images took 20 million core hours of processing through direction-independent and direction-dependent calibration pipelines that correct for instrumental effects as well as spatially and temporally varying ionospheric distortions. In our 120–168 MHz continuum mosaic images with an angular resolution of 600 (900 below declination 10◦) we catalogue 13 667 877 sources, formed from 16 943 656 Gaussian components. The scatter in the astrometric precision approximately follows the expected noise-like behaviour but with an additional systematic component of at least 0.2400 that is likely due to calibration imperfections. The random flux density scale error is 6%, while the systematic offset was previously shown to be within 2%. The median sensitivity of our mosaics is 92 µJy beam−1, improving to 68 µJy beam−1 at high observing elevations, but degrading to 183 µJy beam−1 at the celestial equator due to station area projection effects. Completeness simulations, accounting for realistic source models, time- and bandwidth-smearing effects, and astrometric errors, indicate that we detect more than 95% of compact sources with integrated flux densities exceeding 9 times the local root mean square (RMS) noise. However, the recovered source counts in a particular integrated flux density bin do not match the injected counts until flux densities exceed 45 times the local RMS noise. The Euclidean-normalised differential source counts derived from the survey constrain the radio source population over five orders of magnitude and are in good agreement with previous deep and wide-area surveys. All data products are publicly available, including catalogues, individual-field Stokes I, Q, U, and V images, mosaicked Stokes I images, and uv data with associated direction-dependent calibration solutions.
Knot reconstruction of the scalar primordial power spectrum with Planck, ACT, and SPT CMB data
(Institute of Physics, 2025) Ballardini, Mario; Raffaelli, Antonio
We investigate a non-parametric Bayesian method for reconstructing the primordial power spectrum (PPS) of scalar perturbations using temperature and polarisation data from the Planck, ACT, and SPT CMB experiments. This reconstruction method is based on linear splines for the PPS between nodes in k-space whose amplitudes and positions are allowed to vary. All three data sets consistently show no significant deviations from a power-law form in the range 0.005 ≲ k Mpc ≲ 0.16 independent of the number of knots adopted to perform the reconstruction. The addition of high-resolution CMB measurements from ACT and SPT slightly improves the range of scales of the scalar PPS which are well constrained around a power law up to k ≃ 0.25Mpc−1 and k ≃ 0.2Mpc−1, respectively. At large scales, a potential oscillatory feature in the primordial power spectrum appears when we consider six or more nodes. We test the robustness of the methodology and our results by varying the detailed number of knots from N = 2 to N = 10. We have used the reconstructed scalar PPS to derive several quantities related to inflationary dynamics, such as the effective scalar spectral index, which describes the dependence of the PPS on the scales and parameters associated with the effective field theory of inflation, to provide information on possible departures from the standard single-field canonical case. Finally, we investigate whether the excess of smoothing in the region of the acoustic peaks of the CMB anisotropy temperature power spectrum in the Planck PR3 data is degenerate with our reconstructions of the PPS, but find no significant correlation between them.
Deformation of the 01,2+ states in 110Cd from low-energy coulomb excitation
(Elsevier BV, 2026) Garrett, PE; Wrzosek-Lipska, K; Piętka, IZ
Electromagnetic properties of 110Cd were studied via low-energy Coulomb excitation with 32S and 14N beams. Magnitudes and relative signs of eight E 2 matrix elements, including quadrupole moments of the 21+ and 22+ states, were determined using the least-squares code GOSIA. From those, quadrupole deformation parameters of the 01,2,3+ states were inferred, providing for the first time conclusive evidence for the non-axial character of the ground state in 110Cd. The experimental results were compared with new calculations using the general quadrupole collective Bohr Hamiltonian model with SLy4 and UNEDF0 interactions. The non-axiality of the ground state is reproduced by the present calculations, independently of the interaction used.
Physics graduate preparedness: a human capabilities perspective
(University of the Western Cape, 2025) Audu, Bako; Conana, Honjiswa; Marshall, Delia
In South Africa and globally, the preparedness of physics graduates for the workplace and societal challenges is increasingly prioritised. This study, framed by a human capabilities approach, explores physics students’ and graduates’ perceptions of the development of their graduate preparedness. Findings revealed various interconnected conversion factors that are seen to differently enable or hinder students’ ability to transform educational resources and opportunities into desired capabilities and functionings. These included personal factors such as motivation and computational skills; social factors such as teaching approach, opportunities for peer engagement inside and outside the classroom, and career guidance; and environmental factors related to the urban setting of the university. The study highlights implications for teaching and institutional arrangements, including more explicit focus on fostering desired graduate attributes, developing student voice, and enhancing career exposure. The study explores how universities could better equip physics graduates as critical citizens to advance individual and societal well-being.
A spatially resolved spectral analysis of giant radio galaxies with Meerkat
(Oxford University Press, 2025) Jarvis, Matthew J.; An, Fangxia; Whittam, Imogen Helen
In this study we report the spatially resolved, wideband spectral properties of three giant radio galaxies (GRGs) in the COSMOS field: MGTC J095959.63+024608.6, MGTC J100016.84+015133.0, and MGTC J100022.85+031520.4. One of these galaxies, MGTC J100022.85+031520.4, is reported here for the first time, with a projected linear size of 1.29 Mpc at a redshift of 0.1034. Unlike the other two, it is associated with a brightest cluster galaxy (BCG), making it one of the few GRGs known to inhabit cluster environments. We examine the spectral age distributions of the three GRGs using new MeerKAT UHF-band (544–1088 MHz) observations, and L-band (900–1670 MHz) data from the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) survey. We test two models of spectral ageing, the Jaffe–Perola and Tribble models, using the Broadband Radio Astronomy Tools (brats) software, and find that they agree well with each other. We estimate the Tribble spectral age for MGTC J095959.63+024608.6 as 68 Myr, for MGTC J100016.84+015133.0 as 47 Myr, and for MGTC J100022.85+031520.4 as 67 Myr. We find significant disagreements between these spectral age estimates and the estimates of the dynamical ages of these GRGs, modelled in cluster and group environments. Our results highlight the need for additional processes that are not accounted for in either the dynamic age or the spectral age estimations. © 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.
Long-term eclipse time variations in white dwarf binaries
(Oxford University Press, 2026) Kilkenny, D; Yates, Amalie; Parsons, S G
The overwhelming majority of eclipsing white dwarf (WD) binary systems show quasi-periodic variations in eclipse timings on many year time-scales. Currently, the mechanism behind these eclipse time variations (ETVs) is not known, with the main competing theories being the planetary hypothesis and the Applegate/Lanza mechanisms. Here, we present a comprehensive study of 43 WD binary systems, the vast majority of which have more than a decade of eclipse timing measurements, analysing their global properties to determine which driving force is the likely origin of the observed ETVs. Long-term, high-speed photometry data obtained with ULTRACAM, ULTRASPEC, and HiPERCAM have allowed us to track the evolution of the ETVs in these systems, and analyse any previously unseen trends. From this analysis, we find a clear difference in the level of observed ETVs past the fully convective boundary, where systems with partially radiative companion stars consistently showing high levels of variation. While some systems may be affected by the presence of an unknown planet, the results from this study strongly indicates that an Applegate- or Lanza-like mechanism is the most likely driving force for the timing variations seen in the majority of systems in this sample. However, as found in previous studies, the Applegate/Lanza mechanisms are still not able to reproduce the large and rapid timing variations seen in the vast majority of systems, with the companion star to the WD unable to provide sufficient energy on these short time-scales.
Optimisation of acoustic emission sensor- waveguide assembly for soil slope instability measurement
(Taylor & Francis Ltd, 2025) Mahapatro, Ajit; Kumar, Deepak; Singh, Sushi
Acoustic emission technology (AET) based soil slope monitoring is one of the most innovative and economically viable method that exhibits immense potential in the framework of a landslide early warning system (LEWS). Essential components of AET are AE sensor for soil originated AE signal detection and capturing, active wave-guide to tackle with high AE signal attenuation of soil media, and data acquisition and analysis system (DAAS) for AE parameter extraction, signal conditioning and data storage. AE signal parameters can be exploited to assess and evaluate the soil slope instability. The magnitude, rate, and acceleration of soil slope deformation are direct measures of slope instability. Research articles oriented around AET based soil slope monitoring are prominently focussed on the correlation between slope deformations and its AE behaviour, leaving the AE sensor and waveguide assembly effects unattended. The sensitivity of AET based LEWS is reliant on the performance of the AE sensor and active waveguide, since these are the components responsible solely for collecting relevant AE data from the slope. We have experimented with variety of active waveguide materials and designs, and optimised it for better performance with respect to soil slope deformation parameters. In the studies, two kinds of AE sensors are utilised: one resonant AE sensor and one broadband AE sensor. Steel and aluminium are used as waveguide material. Different grades of high-density polyethylene pipes are used as flexible membrane of the active waveguide. The experimental design and results are described in this article. For simulating real-time landslide slope conditions, a tilt trolley set-up is used for testing the optimised AE sensor-waveguide set-up. Futuristic aspects of the set-up in context of design and development of a LEWS are also discussed.
Phase evolution of electrodeposited manganese oxide for supercapacitor applications
(Springer Science and Business Media Deutschland GmbH, 2025) Iwuoha, Emmanuel Iheanyichukwu; Nwanya, Assumpta Chinwe; Iheme, Chidozie W.
Energy is of paramount importance in our everyday lives and energy storage technologies are needed to solve the global energy problems largely. In this work, manganese oxide (MnxOy) films were electrodeposited chronoamperometrically on stainless steel (ss) and fluorine doped tin oxide (FTO) substrates at different step potentials. The effect of the deposition potential and temperature treatment on the phase and supercapacitive properties of the MnxOy were studied. At a step potential of less than 1.2 V no deposition was achieved while at 1.2 V, the as deposited oxide showed a bit of amorphousness with vestiges of Mn(OH)2 as evident from the x-ray diffraction (XRD) studies. At higher potentials (1.4 and 1.6 V), the as-deposited oxide appeared as the MnO2 phase. However, higher temperature treatment (600 °C) of all the deposits obtained at the various potentials resulted to Mn2O3 phase. The scanning electron microscopy (SEM) of the films showed that the as-deposited and the 400 °C annealed electrodes are porous while they become more compact and cemented at 600 °C. The obtained bandgap energies ranged from 1.26–2.65 eV for the films deposited at differing potentials and heat treatments. The electrochemical analysis shows the highest specific capacitance of 455 F g−1 for the 1.2 V@400 °C electrode while the Mn2O3 electrodes are more stable. The electrodes exhibited good potentials for supercapacitor application. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.
Electronic conduction in hot-pressed calcium manganese oxide ceramics
(Elsevier Ltd, 2025) Mahapatro, Ajit; Pant, Megha
The basic concepts of electronic charge transport in materials are crucial for understanding and improving device performances. The electronic conduction is investigated through perfectly dense calcium manganese oxide (CaMnO3) ceramics prepared with simultaneous application of pressure (64 MPa) and temperature (1073 K) using hot-press technique. A proposed model, comprising of grain boundary assisted hopping and trap assisted transport mechanisms agrees well with the acquired current – voltage characteristics in the temperature range of 133–373 K. The estimated decrease in trap charge density with increasing temperature from 1015 cm 3 at 133 K to 109 cm􀀀 3 at 373 K is attributed to the temperature assisted detrapping of the highly localized trap charge carriers, resulting in lesser availability of trapped charges with increasing temperature. An energy band diagram is demonstrated by implementing the broadening and shifting of energetic trap distribution towards deep into the energy gap with increasing temperature observed in the capacitance-frequency measurements and leads to merging of trap states with the conduction band
Stabilizing metal halide perovskite films via chemical vapor deposition and cryogenic electron beam patterning
(John Wiley and Sons Inc, 2025) Arendse, Christopher Joseph; Burns, Randy; Chiaro, Dylan
Halide perovskites are hailed as semiconductors of the 21st century. Chemical vapor deposition (CVD), a solvent-free method, allows versatility in the growth of thin films of 3- and 2D organic–inorganic halide perovskites. Using CVD grown methylammonium lead iodide (MAPbI3) films as a prototype, the impact of electron beam dosage under cryogenic conditions is evaluated. With 5 kV accelerating voltage, the dosage is varied between 50 and 50000 µC cm−2. An optimum dosage of 35 000 µC cm−2 results in a significant blue shift and enhancement of the photoluminescence peak. Concomitantly, a strong increase in the photocurrent is observed. A similar electron beam treatment on chlorine incorporated MAPbI3, where chlorine is known to passivate defects, shows a blue shift in the photoluminescence without improving the photocurrent properties. Low electron beam dosage under cryogenic conditions is found to damage CVD grown 2D phenylethlyammoinum lead iodide films. Monte Carlo simulations reveal differences in electron beam interaction with 3- and 2D halide perovskite films. © 2024 Wiley-VCH GmbH.
Giant dielectric constant in calcium manganese oxide ceramics
(Elsevier Ltd, 2025) Mahapatro,, Ajit; Pant, Megha
Giant dielectric constant (GDC) materials have been promising for their potential utilization in multifunctional devices, including high-performance energy storage and development of efficient electronic elements. The preliminary charge transport study of ceramics possessing GDC would provide insight for utilization in world-wide applications. GDC of ~106 is realized in the temperature range of 133–593 K through perfectly dense calcium manganese oxide (CaMnO3) ceramics prepared using hot-press technique. The dc-conductivity and dielectric relaxation spectra exhibit Mott-variable range hopping in the temperature range of 133–393 K and small polaron hopping above 493 K. The Nyquist plot provides an equivalent model with series combination of two sets of parallelly connected circuits comprising of resistance and constant phase element, attributed to the contributions from grains and grain boundaries. The ac-conductivity suggests the presence of non-overlapping small polaron tunneling in temperature range of 133–333 K and overlapping large polaron tunneling above 333 K. An electronpolaron band located at 0.27 eV below the conduction band edge is demonstrated with consideration of polaron hopping and band gap energy. Scaling procedure employed to the ac-conductivity universality evidences the corrected Summerfield model and presence of Coulomb interaction between the charge carriers. The in-depth study of the frequency and temperature dependent electric and dielectric properties demonstrates GDC over a wide frequency range of 1 Hz ̶10 MHz, and low loss tangent above 10 kHz in the currently prepared perfectly dense CaMnO3 ceramics and suggests its suitability for engineering charge storage devices in the radio frequency region.
The S4G-wise view of global star formation in the nearby universe
(Institute of Physics, 2025) Cluver, Michelle E.; Jarrett, Thomas H.; Dale, Daniel A.
In this work, we present source-tailored Wide-field Infrared Survey Explorer (WISE) mid-infrared photometry (at 3.4, 4.6, 12, and 23 μm) of 2812 galaxies in the extended Spitzer Survey of Stellar Structure in Galaxies sample, and characterize the mid-infrared colors and dust properties of this legacy nearby galaxy data set. Informed by the relative emission between W3 (12 μm) and W4 (23 μm), we rederive star formation rate (SFR) scaling relations calibrated to L TIR, which results in improved agreement between the two tracers. By inverse-variance weighting the W3 and W4-derived SFRs, we generate a combined mid-infrared SFR that is a broadly robust measure of star formation activity in dusty, star-forming galaxies in the nearby Universe. In addition, we investigate the use of a W3-derived dust density metric, Σ12 μm (L ⊙/kpc2), to estimate the SFR deficit of low mass, low dust galaxies. This is achieved by combining WISE with existing Galaxy Evolution Explorer ultraviolet (UV) photometry, which we further use to explore the relationship between dust and UV emission as a function of morphology. Finally, we use our derived SFR prescriptions to examine the location of galaxies in the log SFR-log M stellar plane, as a function of morphological type, which underscores the complexity of dust-derived properties seen in galaxies of progressively earlier type.
The radio spectral energy distribution and star formation calibration in MIGHTEECOSMOS highly star-forming galaxies at 1.5
(Institute of Physics, 2025) Jarvis, Matt; Taylor, Russ; Whittam, Imogen H; An, Fangxia; Vaccari, Mattia
Studying the radio spectral energy distribution (SED) of distant galaxies is essential for understanding their assembly and evolution over cosmic time. We present rest-frame radio SEDs of a sample of 160 star-forming galaxies at 1.5 < z < 3.5 in the Cosmic Evolution Survey field as part of the MeerKAT International GHz Tiered Extragalactic Exploration project. MeerKAT observations combined with archival Very Large Array and Giant Metrewave Radio Telescope data allow us to determine the integrated mid-radio (ν = 1–10 GHz) continuum (MRC) luminosity and magnetic field strength. A Bayesian method is used to model the SEDs and to separate the free–free and synchrotron emission. We also calibrate the star formation rate (SFR) in radio both directly through SED analysis and indirectly through the infrared–radio correlation (IRRC). With a mean value of αnt ≃ 0.7, the synchrotron spectral index flattens with both redshift and specific SFR, indicating that cosmic rays are more energetic in the early Universe due to higher star formation activity. The magnetic field strength increases with redshift, B ∝ (1 + z) (0.7±0.1) , and SFR as B ∝ SFR0.3, suggesting a small-scale dynamo acting as its main amplification mechanism. Taking into account the evolution of the SEDs, the IRRC is redshift invariant, and it does not change with stellar mass at 1.5 < z < 3.5, although the correlation deviates from linearity. Similarly, we show that the SFR traced using the integrated MRC luminosity is redshift invariant.
The study of 110Cd with the (n,n′γ) reaction revisited
(Springer, 2026) Garrett, Paul; Bangay J; Jolie, Jan
Data from a previous study of 110Cd with the (n,n′γ) reaction with monoenergetic neutrons have been reanalysed with the aim of identifying additional low-intensity γ-ray transitions. The data set included excitation functions measured with neutron energies between 1.94 and 3.34 MeV, and γ-ray angular distributions performed at neutron energies of 2.6, 2.9, and 3.2 MeV. A total of 162 γ rays were placed in a level scheme comprising 69 levels (of which 58 γ-ray assignments and 10 levels are newly established) up to 3.3 MeV in excitation energy. Lifetimes, or limits, were established for many levels using the Doppler-shift attenuation technique allowing for the determination of an extended set of transition rates.

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