If dark matter annihilates into standard model particles with a cross-section which is velocity dependent, then Local Group dwarf galaxies will not be the best place to search for the resulting gamma ray emission. A greater flux would be produced by more distant and massive halos, with larger velocity dispersions. We construct full-sky predictions for the gamma-ray emission from galaxy- and cluster-mass halos within $\sim 200 \, {\mathrm{Mpc}}$ using a suite of constrained $N$-body simulations (CSiBORG) based on the Bayesian Origin Reconstruction from Galaxies algorithm. Comparing to observations from the Fermi Large Area Telescope and marginalising over reconstruction uncertainties and other astrophysical contributions to the flux, we obtain constraints on the cross-section which are two (seven) orders of magnitude tighter than those obtained from dwarf spheroidals for $p$-wave ($d$-wave) annihilation. We find no evidence for either type of annihilation from dark matter particles with masses in the range $m_\chi = 2-500 \, {\mathrm{GeV}}/c^2$, for any channel. As an example, for annihilations producing bottom quarks with $m_\chi = 10 \, {\mathrm{GeV}}/c^2$, we find $a_{1}<2.4 \times 10^{-21} \, {\mathrm{cm^3 s^{-1}}}$ and $a_{2}<3.0 \times 10^{-18} \, {\mathrm{cm^3 s^{-1}}}$ at 95% confidence, where the product of the cross-section, $\sigma$, and relative particle velocity, $v$, is given by $\sigma v = a_\ell (v/c)^{2\ell}$ and $\ell=1, 2$ for $p$-, $d$-wave annihilation, respectively. Our bounds, although failing to exclude the thermal relic cross-section for velocity-dependent annihilation channels, are among the tightest to date.
We introduce a fast method to measure the conversion gain in complementary metal-oxide-semiconductor active pixel sensors, which accounts for nonlinearity and interpixel capacitance (IPC). The standard “mean-variance” method is biased because it assumes that pixel values depend linearly on the signal, and existing methods to correct for nonlinearity still introduce significant biases. While current IPC correction methods are prohibitively slow for a per-pixel application, our new method uses separate measurements of the IPC kernel to calculate the gain almost instantaneously. Using test data from a flight detector of the ESA Euclid mission, the IPC correction recovers the results of slower methods with 0.1% accuracy. The nonlinearity correction ensures that the estimated gain is independent of signal, correcting a bias of more than 2.5%.
The palm ruff (Seriolella violacea) is a marine fish species of high relevance to fisheries along the Pacific coast of South America, and in the last decade with great potential for aquaculture diversification in the South Pacific. This fish typically inhabits environments with temperatures ranging from 13 degrees C to 18 degrees C. However, the optimal temperature for its growth in the early stages of development is still unknown. This study assessed the effects of a temperature gradient on survival, oxygen consumption, oxidative stress, and tissue morphology in S. violacea larvae at 50-55 days post-hatching (dph). Mortality significantly increased above 21 degrees C, indicating greater sensitivity to elevated rather than reduced thermal conditions. Oxygen consumption significantly decreased at both low (5-7 degrees C) and high (23-25 degrees C) temperatures. Superoxide dismutase (SOD) activity rose above 11 degrees C, while oxidative stress biomarkers showed peak protein carbonylation at 7 degrees C and maximal lipid peroxidation at 25 degrees C. Enhanced expression of the HSP70 chaperone, as evaluated via immunohistochemistry, was noted in erythrocytes and mucosal tissue of fish kept at temperatures below 7 degrees C and above 23 degrees C. In addition, morphological alterations were most evident in skin and gills of fish maintained at temperatures outside the 7-21 degrees C range, including vascular changes and elevated goblet cell numbers. Overall, the results suggest that S. violacea employs compensatory responses to withstand acute thermal stress, including metabolic adjustments, enhanced mucus secretion, and increased blood flow. This study provides valuable insights into the thermal tolerance and physiological plasticity of S. violacea during larval culture. However, acute episodes of extreme temperatures can trigger oxidative damage and tissue dysfunction, ultimately decreasing larval survival.
Euclid is currently mapping the distribution of matter in the Universe in detail via the weak lensing signature of billions of distant galaxies. The weak lensing signal is most prominent around galaxy clusters and can extend up to distances well beyond their virial radius, thus constraining their total mass. Near the centre of clusters, where contamination by member galaxies is an issue, the weak lensing data can be complemented with strong lensing data. Strong lensing information can also diminish the uncertainty due to the mass-sheet degeneracy and provide high-resolution information about the distribution of matter in the centre of clusters. Here we present a joint strong and weak lensing analysis of the Euclid Early Release Observations of the cluster Abell 2390 at z = 0.228. Thanks to Euclid’s wide field of view of 0.5 deg2, combined with its angular resolution in the visible band of 0.″13 and sampling of 0.″1 per pixel, we constrained the density profile in a wide range of radii, 30 kpc < r< 2000 kpc, from the inner region near the brightest cluster galaxy to beyond the virial radius of the cluster. We find relatively good consistency with earlier X-ray results based on assumptions of hydrostatic equilibrium and thus indirectly confirm the nearly relaxed state of this cluster. We also find consistency with previous results based on weak lensing data and ground-based observations of this cluster. From the combined strong + weak lensing profile, we derive the values of the viral mass M200 = (1.48 ± 0.29) × 1015 M⊙, and virial radius r200 = (2.05 ± 0.13 Mpc), with error bars representing one standard deviation. The profile is well described by a Navarro-Frenk-White model with a concentration c = 6.5 and a small-scale radius of 230 kpc in the 30 kpc < r< 2000 kpc range that is best constrained by strong lensing and weak lensing data. Abell 2390 is the first of many examples where Euclid data will play a crucial role in providing masses for clusters. The large coverage provided by Euclid, combined with the depth of the observations and high angular resolution, will allow us to produce similar results in hundreds of other clusters with rich strong lensing data that is already available.
The geodetic facilities at Corsica, which were initially developed for the purpose of monitoring the performance of nadir satellite altimeters, have been adapted to calibrate successive satellite altimeters in an absolute sense. In anticipation of SWOT, a preliminary phase of extension of the reference surfaces of the Corsica site was executed in June 2021, followed by a subsequent phase in May 2022. To further refine the along-track resolution of the nadir altimetry satellites, additional surveys were conducted in 2023, 2024, and 2025, focusing on the ground tracks of historical satellites. The measurements were carried out using the instruments developed by DT-INSU (CalNaGeo and Cyclop & eacute;e), which demonstrated a centimeter level consistency. A thorough analysis of GNSS processing employing various methodologies has been conducted, including differential and Precise Point Positioning approaches with the use of the GPS and Galileo constellations. This analysis underscores the considerable potential of Precise Point Positioning. The subsequent sections present the various stages of processing the GNSS reference surface derived from the aforementioned surveys. It is demonstrated that the GNSS reference surface ultimately exhibits a precision of a few millimeters. Preliminary results demonstrate the high potential of the Corsica facilities to provide insight into the SWOT measurement precision.
