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Revealing the baryon cycle in Galaxy Clusters: connecting galaxy dynamics and gas thermodynamics using (sub-)mm-wave and optical IFU surveys
No full textInternational audienceObservations in the visible and near infrared are transforming our view of the processes affecting galaxy evolution, much of which is dominated by interactions with the large scale environment. Yet a complete picture is missing, as no corresponding high resolution view of the warm/hot intracluster, circumgalactic, and intergalactic media exists over large areas and a comparably broad range of redshifts. Combined with wide-field optical IFU surveys such as CATARSIS, a large diameter sub-mm telescope with a degree-scale field of view would enable a joint view of galaxy dynamics and gas thermodynamics, transforming our understanding of environmental processes
Electron temperature relations and the direct N, O, Ne, S and Ar abundances of 49959 star-forming galaxies in DESI Data Release 2
No full textInternational audienceWe present the largest direct-method abundance catalogue of galaxies to date, containing measurements of 49959 star-forming galaxies at dex. We show that the S/O and Ar/O abundance ratios are strongly correlated, consistent with the expected additional Type Ia enrichment channel for S and Ar. In this work we present an initial survey of the key properties of the sample, with this dataset serving as a foundation for extensive future work on galaxy abundances at low redshift
Assessing stray neutron dose variability across Monte Carlo codes in a proton therapy scenario
No full textInternational audienceBackground and purposeMonte Carlo (MC) simulations are widely used in proton therapy dosimetry, but neutron dose estimates vary significantly across different MC codes, nuclear models, and cross-section libraries. This study provides an overview of the expected differences in neutron fluence and dose equivalent calculations across five MC codes (PHITS, MCNP, FLUKA, GATE, and TOPAS) for a clinically-relevant proton beam model in a reference phantom.MethodsA spread-out Bragg peak (SOBP) proton beam was simulated in a water phantom. Neutron fluence spectra and dose equivalents were evaluated at multiple out-of-field positions using each code’s default nuclear models and cross-section libraries. Additional simulations explored the impact of alternative cross-section libraries (JENDL-5, JEFF-3.3, TENDL-2021) and nuclear models.ResultsWhile proton dose distributions were consistent across codes (spatial variations < 2 mm), neutron fluences differed by up to 130 %, and dose equivalents varied by 88 % depending on nuclear data. Proton cross-sections had a greater influence on neutron spectra than neutron cross-sections. Codes using the same nuclear data libraries produced comparable results, highlighting cross-section selection as a key source of variability.ConclusionThese results provide MC users with a reference for expected differences in neutron dose calculations. While default MC settings offer reasonable internal consistency, the observed variability underscores the need for benchmarking against experimental data to ensure accurate neutron dose predictions in proton therapy
Commissioning and performance of IDATEN: A large fast-timing <math altimg="si33.svg" display="inline" id="d1e332"><mi>γ</mi></math>-ray detector array at the RIBF
No full textInternational audienceA large fast-timing γ-ray detector array has been newly developed under the International Detector Assembly for fast-Timing measurements of Exotic Nuclei (IDATEN) project. The full IDATEN array comprises 82 LaBr3(Ce) γ-ray detectors, of which 46 and 36 are provided by the KHALA and FATIMA collaborations, respectively. To assess the fast-timing performance of this large-scale system with stopped rare-isotope beams, a commissioning experiment was recently carried out at the Radioactive Isotope Beam Factory (RIBF) at RIKEN. Neutron-deficient rare isotopes near 100Sn were produced via in-flight fragmentation of a 124Xe primary beam. The fast-timing capability was evaluated using 96Pd as the reference nucleus by measuring the half-lives of the 21+, 41+ and 61+ levels, which were populated through the decay of the long-lived 81+ isomeric state. These results demonstrate the reliability of our experimental setup, including the readout electronics and data acquisition system, thereby validating its readiness for forthcoming physics experiments at the RIBF. Moreover, the measured half-life values are in agreement with previously reported literature values, with some determinations achieving improved precision
One loop renormalization of 5D gauge-Yukawa theories
No full textInternational audienceThe common lore dictates that extra dimensional theories loose predictive power at energies just above the compatification scale, due to the power-law running of bulk coupling. We show that five-dimensional gauge-Yukawa theories can be valid up to arbitrarily high scales, provided: 1) A finite number of terms are required to absorb power-law divergences; 2) All power-law running couplings flow to UV fixed points. By explicitly computing bulk and localized divergences for a gauge-Yukawa theory on , we prove the one-loop renormalization properties of Lagrangians containing only interactions that would be renormalizable in four dimensions. The existence of UV fixed points imposes further constraints on the content of the model. Our results provide a consistency check for the high-energy behavior of any 5D theory, and provide a discrimination between UV consistent models and those that can describe only a handful of Kaluza-Klein modes. Hence, we offer the first concrete step towards an all-order proof of `renormalizability' for gauge-Yukawa theories in five dimensions
Model-independent ZH production cross section at FCC-ee
No full textInternational audienceThis paper presents prospects for a model-independent measurement of the production cross section at the FCC-ee using the recoil-mass technique at center-of-mass energies of and GeV. The analysis considers the muon, electron, and hadronic decay modes of the associated boson. Event selections rely primarily on the kinematic properties of the reconstructed decay products, ensuring maximal independence from specific Higgs boson decay modes, while multivariate techniques are employed to further enhance sensitivity. Statistical interpretations of the individual final states yield relative precisions of for the combined leptonic channels and for the hadronic channel at GeV with an integrated luminosity of ab. Their full statistical combination leads to total uncertainties of at GeV and at GeV with ab. Dedicated statistical tests demonstrate model independence at the level of the obtained precision. This study presents, for the first time, a consistent and combined analysis of the leptonic and hadronic final states, achieving the most precise projected determination of the production cross section at future lepton colliders, with model independence demonstrated within the statistical precision
Superfluid fraction in the crystal phase of the inner crust of neutron stars
No full textInternational audienceIn the most extended layer of the inner crust of neutron stars, nuclear matter is believed to form a crystal of clusters immersed in a superfluid neutron gas. Here we analyze this phase of matter within fully self-consistent Hartree-Fock-Bogoliubov calculations using Skyrme-type energy density functionals for the mean field and a separable interaction in the pairing channel. The periodicity of the lattice is taken into account using Bloch boundary conditions, in order to describe the interplay between band structure and superfluidity. A relative flow between the clusters and the surrounding neutron gas is introduced in a time-independent way. As a consequence, the complex order parameter develops a phase, and in the rest frame of the superfluid one finds a counterflow between neutrons inside and outside the clusters. The neutron superfluid fraction is computed from the resulting current. Our results indicate that at densities above 0.03 fm, more than 90% of the neutrons are effectively superfluid, independently of the detailed choice of the interaction, cluster charge, and lattice geometry. This fraction is only slightly lower than the one obtained recently within linear response theory on top of the Bardeen-Cooper-Schrieffer approximation, and it approaches the hydrodynamic limit for strong pairing. As a consequence, it is likely that the inner crust alone can provide a sufficient superfluid angular momentum reservoir to explain pulsar glitches
Measurements of quasar proximity zones with the Lyman- forest of DESI Y1 quasars
No full textInternational audienceThe intergalactic medium (IGM) around quasars is shaped by their dense environments and by their excess ionizing radiation, forming a "quasar proximity zone" whose size and anisotropy depend on the quasar's halo mass, luminosity, age, and radiation geometry. Using over 10,000 quasar pairs from the Dark Energy Spectroscopic Instrument (DESI) Year 1 data, with projected comoving separations , we investigate how the proximity zone of foreground quasars at affects Lyman-alpha absorption in their background quasars. The large DESI sample enables unprecedented precision in measuring this "transverse proximity" effect, allowing a detailed investigation of the signal's dependence on the projected separation of quasar pairs and the luminosity of the foreground quasar. We find that enhanced gas clustering near quasars dominates over their ionizing effect, leading to stronger absorption on neighboring sightlines. Under the assumption that quasar ionizing luminosity is isotropic and steady, we infer the IGM overdensity profile in the vicinity of quasars, finding overdensities as high as at comoving distance from the most luminous systems. Surprisingly, however, we find no significant dependence of the proximity profile on the luminosity of the foreground quasar. This lack of luminosity dependence could reflect a cancellation between higher ionizing flux and higher gas overdensity, or it could indicate that quasar emission is highly time variable or anisotropic, so that the observed luminosity does not trace the ionizing flux on nearby sightlines
The Simons Observatory: forecasted constraints on primordial gravitational waves with the expanded array of Small Aperture Telescopes
No full textInternational audienceWe present updated forecasts for the scientific performance of the degree-scale (0.5 deg FWHM at 93 GHz), deep-field survey to be conducted by the Simons Observatory (SO). By 2027, the SO Small Aperture Telescope (SAT) complement will be doubled from three to six telescopes, including a doubling of the detector count in the 93 GHz and 145 GHz channels to 48,160 detectors. Combined with a planned extension of the survey duration to 2035, this expansion will significantly enhance SO's search for a -mode signal in the polarisation of the cosmic microwave background, a potential signature of gravitational waves produced in the very early Universe. Assuming a noise model with knee multipole and a moderately complex model for Galactic foregrounds, we forecast a (or 68% confidence level) constraint on the tensor-to-scalar ratio of , assuming no primordial -modes are present. This forecast assumes that 70% of the -mode lensing signal can ultimately be removed using high resolution observations from the SO Large Aperture Telescope (LAT) and overlapping large-scale structure surveys. For more optimistic assumptions regarding foregrounds and noise, and assuming the same level of delensing, this forecast constraint improves to . These forecasts represent a major improvement in SO's constraining power, being a factor of around 2.5 times better than what could be achieved with the originally planned campaign, which assumed the existing three SATs would conduct a five-year survey
Optical Follow-Up Strategies for the Next Neutrino-Detected Galactic Core-Collapse Supernova
No full textInternational audienceCore-collapse supernovae (CCSNe) are expected to produce intense bursts of neutrinos preceding the emergence of their electromagnetic (EM) counterparts. The prompt detection of such neutrino signals offers a unique opportunity to trigger early follow-up observations in the EM domain. We aim to assess the feasibility and efficiency of an optical-NIR follow-up strategy for CCSNe discovered via neutrino bursts, by modelling the spatial distribution of events and simulating realistic observational campaigns taking into account the size of the localization error box generated by triangulating the neutrino burst. We modelled the Galactic distribution of CCSNe, including the effects of interstellar extinction, and considered three main progenitor types: Wolf-Rayet stars, red and blue supergiants. We included the shock breakout in the EM signatures that could be detected following the neutrino burst. A population of CCSNe was generated and detected by different networks of neutrino observatories, including IceCube, KM3NeT, Super-Kamiokande, Hyper-Kamiokande, and JUNO. The resulting skymaps were used as input for GWEMOPT to produce optimized follow-up plans with two optical facilities: LSST and the TAROT robotic telescopes. Both LSST and TAROT exhibit comparable detection efficiencies for the simulated CCSN population. However, the TAROT network achieves similar success rates while requiring fewer pointings to cover the CCSN skymap. Our simulations demonstrate that neutrino follow-up campaigns can effectively CCSN optical counterparts using both large and small facilities. Depending on the neutrino network, the median number of pointings for the two tested optical facilities is of the order of 20 to 100 to find the EM emission. The number of images is larger for LSST than for TAROT by a factor of 2 to 4