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Physics Astrophysics

astro-ph Watch Astrophysics

Tuesday 29 September

High Energy Astrophysical Phenomena

Science Using Single-Pulse Exploration with Combined Telescopes: II. Pulse profile evolution and single-pulse modulation

F. Jankowski, J.-M. Griessmeier, T. Roy et al. (+11 more)

Aims. We aim to illuminate how the pulsars' integrated pulse profiles and single-pulse modulation evolve with radio frequency, while separating intrinsic and propagation effects. Methods. We present integrated pulse profiles and phase-resolved modulation indices for 12 radio pulsars at up to five frequency bands. Our wideband dataset was systematically acquired with the Nancay Radio Observatory telescopes and the uGMRT, covering the frequency range 10 MHz to 2.8 GHz, including NenuFAR, LOFAR FR606, uGMRT, and NRT observations. We carefully measured the pulse widths and scattering times using multi-component profile fitting. We employed a profile width scaling model to separate the profile evolution into scattering and intrinsic contributions. We quantified the pulsars' single-pulse variability across frequency. Results. We describe the pulse profile evolution. Two pulsars have scattering indices compatible with Kolmogorov turbulence, while the majority have flatter scattering indices. This suggests complex scattering environments, dominated by localised turbulence. Complex scattering behaviour is seen in some pulsars, and most profiles are scattering-dominated below 200 MHz. The measured intrinsic power law indices are small, with absolute values between 0 and 0.3. Five pulsars exhibit decreasing intrinsic widths, two or three pulsars show flat behaviour, and four pulsars have increasing profile widths with frequency. Accounting for biases, most pulsar modulation parameters decrease with frequency, while three pulsars show flat behaviour. Conclusions. The pulse width evolution is explained by intrinsic radio beam narrowing, the emergence of profile components, and the balance between the two. Our modulation analysis indicates that the single-pulse emission from most of our pulsars becomes more erratic towards lower radio frequencies, consistent with increasing amplitude modulation.
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All authors F. Jankowski, J.-M. Griessmeier, T. Roy, M. Surnis, G. Theureau, L. Bondonneau, P. Noe, J. Petri, L. Guillemot, I. Cognard, M. Serylak, I. Kravtsov, V. Zakharenko, O. Ulyanov

Earth and Planetary Astrophysics

Radiation Hydrodynamics of Self-gravitating Protoplanetary Disks II. Accretion, Migration, Spin, and Internal Structure of GI Fragments

Yang Ni, Hongping Deng and Xue-Ning Bai

In the first paper of this series, we showed that gravitational instability (GI) in protoplanetary disks can produce fragments of planetary rather than brown-dwarf mass, leaving the subsequent evolution and ultimate fates of such fragments an open question. Here, we follow every bound object in a global three-dimensional radiation hydrodynamic simulation of a fragmenting $0.196\,M_\odot$ disk around a $1\,M_\odot$ star: seven surviving fragments, one disrupted clump, and one merged clump, followed for $1.2$\,kyr. The fragments form at $1.4$–$3.0\,M_\mathrm{J}$, consistent with the normalized initial-mass distribution of Paper~I. Mass growth follows a single Hill-limited scaling $\propto \Sigma \Omega R_\mathrm{H}^2$, regulated by the delivery of gas into draining feeding zones, while the latest-forming fragments experience supply starvation. Migration is bidirectional and governed by gravitational interactions with both the disk and neighboring clumps. Accretion supplies most of the fragments' spin, which aligns with their orbits and provides roughly a tenth of the support against gravity. The interiors are entropy-stratified, largely convectively stable, and accumulate mass far faster than they can radiatively cool: compression is quasi-adiabatic, and central entropies near $12\,k_\mathrm{B}$ per baryon favor hot-start initial conditions for fragments that evolve into gas giants. Integrating the measured growth law against the measured gas budget, we predict that the disk produces gas giants, brown dwarfs, and a possible low-mass stellar companion, while one scattered fragment may become a free-floating planet: the outcome of disk fragmentation is determined not merely at birth, but by the subsequent mass supply and dynamics.
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Earth and Planetary Astrophysics

Improved Constraints on the Surface of LHS 3844 b from its Mid-Infrared Spectrum

Kimberly Paragas, Heather A. Knutson, Renyu Hu et al. (+4 more)

The thermal emission spectra of terrestrial exoplanets provide a window into their surface compositions and corresponding geological processes. Close-in, rocky planets orbiting M dwarfs are ideal targets for these studies, as observations have shown that most have little to no atmosphere. LHS 3844 b is an ultra-short period super-Earth orbiting a nearby M dwarf, and is the most favorable target that does not have a dayside magma ocean. We present an updated JWST MIRI/LRS emission spectrum ($5-12$ $\mu$m) of this planet, derived from eight new and three archival eclipse observations. We combine these visits to obtain the highest SNR emission spectrum for any rocky exoplanet thus far, with a median SNR of 29 across 12 wavelength bins. Our data are sensitive to the predicted Si-O stretching feature (the strongest mid-infrared silicate feature) for a wide range of common materials and the transparency feature, which is relatively insensitive to composition and constrains the grain size and porosity of surface materials. We find that LHS 3844 b's emission spectrum resembles a blackbody shortward of 10 $\mu$m disfavoring the presence of a transparency feature, and identify a tentative feature ($1.9-3.5\sigma$) between $10-12$ $\mu$m. If this feature is astrophysical and not instrumental in nature, it can be matched by a fayalite (the iron end-member of olivine) surface, but might also be consistent with other candidate planet-forming materials like spinel or silicon carbide. We discuss possible biases introduced by the wavelength-dependent instrumental ramp, and outline several strategies to mitigate this effect in future observations of LHS 3844~b that would establish the surface composition of this rocky exoplanet.
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All authors Kimberly Paragas, Heather A. Knutson, Renyu Hu, Bethany L. Ehlmann, Aishwarya R. Iyer, Sebastian Zieba, Laura Kreidberg

Earth and Planetary Astrophysics

Constraining exoplanet population parameters with Kepler and simulation-based inference

Chloé Padois, Friedrich Anders and Daniel del Ser

In the context of the rapidly growing field of galactic exoplanet population studies, we present an exoplanet simulator capable of generating synthetic populations for millions of stars in a few seconds (Padois et al., 2025). Our framework combines observed exoplanet detections with the latest planetary formation models, incorporating dependencies between host star properties and planet occurrence rates, orbital period distributions, and other key demographic features. However, many model parameters remain uncertain and model-dependent. To constrain some of the most critical ones, we couple our simulator with simulation-based inference (SBI): we define a set of 44 free parameters describing the population of different planet types (occurrence rates, mass-period distribution, mass-radius relation, etc.), run millions of simulations sampling from broad prior distributions, simulate their detectability by Kepler, and train a machine-learning algorithm to learn the relationships between input parameters and the resulting "observed" synthetic populations. The best-fit parameters are then inferred by comparing model outputs to real observations, for which we adopt the Kepler confirmed planet catalogue as our reference dataset, since it provides the largest homogeneous sample from a single facility. We present preliminary results for the planet occurrence rate as a function of stellar mass and metallicity, across different planet types, along with constraints on several key simulation parameters such as the orbital period distribution and the inclination dispersion within planetary systems. These refined parameters enable us to refine our yield predictions for upcoming exoplanet detection missions, including PLATO, Roman, and HAYDN.
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Astrophysics of Galaxies

Torsionally excited methanol in massive young stellar objects: The role of the mid-IR radiation field

C. Sanna, S. Leurini, A. Giannetti et al. (+9 more)

Observing the earliest stages of high-mass star formation in the mid-infrared (mid-IR) is challenging because the extinction is high and the resolution limited. Millimeter vibrationally and torsionally excited transitions of several molecules have been proposed as indirect probes of local mid-IR radiation fields around young stellar objects (YSOs). We investigate the excitation and spatial distribution of torsionally excited methanol ($\mathrm{CH_3OH}$) in 12 high-mass star-forming clumps in different evolutionary stages, assessing their potential as tracers of the mid-IR luminosity of embedded protostars. We analyzed rotational transitions of methanol within the same torsionally excited states $v_\mathrm{t}$$\geq$1 in the Atacama Large Millimeter/submillimeter Array (ALMA) 890 $\mathrm{\mu m}$ observations and compared them with Spitzer 24 $\mathrm{\mu m}$ data by plotting line luminosities normalized by methanol abundance against mid-IR luminosities. The torsionally excited methanol emission is generally compact and systematically coincident with ALMA dust continuum peaks and 24 $\mathrm{\mu m}$ emission, even in faint sources. The only clump without an IR counterpart also shows no $v_\mathrm{t}$$\geq$1 emission, supporting radiative pumping as the dominant excitation mechanism. We found a promising power-law trend between $v_\mathrm{t}$$\geq$1 methanol lines and 24 $\mathrm{\mu m}$ luminosities, largely independent of the methanol abundance. $\mathrm{CH_3OH}$ $v_\mathrm{t}$$\geq$1 transitions appear to be promising tracers of local mid-IR radiation fields of embedded protostars, providing core-scale information even in highly extincted regions. As a pilot study, our results suggest that extending our study to a larger statistical sample is crucial for testing and improving this method.
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All authors C. Sanna, S. Leurini, A. Giannetti, E. Schisano, L. Testi, S. Molinari, J. S. Urquhart, T. Pillai, F. Massi, K. Immer, E. Molinari, S. Casu

High Energy Astrophysical Phenomena

Joint Mass-Radius and Magnetic-Geometry Inference of PSR J0740+6620

Chun Huang, Tuomo Salmi and Alexander Y. Chen

X-ray pulse-profile modeling can measure neutron-star radii, but its physical interpretation remains limited by the largely phenomenological description of the surface hotspots. Here we connect the X-ray hotspots directly to the pulsar magnetospheric structure and jointly infer the mass, radius, and magnetic geometry of the massive millisecond pulsar PSR J0740+6620 from NICER and XMM-Newton observations. Using a GPU-accelerated implementation, we compare two low-dimensional magnetic configurations that can produce non-antipodal emission: a centered axisymmetric dipole–quadrupole and a shifted dipole. The shifted-dipole model is decisively favored under the adopted priors, with $\Delta\ln Z=5.65$ (Bayes factor $\sim285$), and yields $M=2.059^{+0.068}_{-0.069}\,M_{\odot}$ and $R=13.28^{+1.47}_{-1.07}\,\mathrm{km}$, broadly consistent with previous phenomenological analyses, while requiring nearly symmetric heating of the two polar caps. Both the marginalized shifted-dipole posterior and the timing-compatible representative require an effective X-ray-emitting footprint much smaller than the nominal force-free polar cap calibrated for a centered dipole. This compact footprint is not reproduced by our exploratory photon-conversion estimates and instead points to missing physics in the mapping from magnetospheric currents to observable X-ray emission. Our results show that physically motivated hotspots can preserve the mass–radius inference while turning hotspot morphology into a probe of pulsar magnetospheric structure and emission physics.
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Solar and Stellar Astrophysics

Detection of fine-structured radio bursts during a superflare on EQ Peg

Zhanhao Zhao, Xin Cheng, Yuankun Kou et al. (+6 more)

Superflares are frequently observed on magnetically active stars, particularly on active M-dwarfs, thereby influencing the habitability of nearby exoplanets. However, the causes of superflares remain unclear. Here, combining FAST and TESS, we detected a finely structured decimetric radio burst appearing as groups of spikes during a white-light superflare (total bolometric energy $\sim 10^{33} \ \mathrm{erg}$) on the M-dwarf binary EQ Peg on September 8th, 2022. The most significant ones appeared near the peak time of the optical flare and lasted for about $100 \ \mathrm{s}$. The radio spikes present extremely high brightness temperatures ($\gtrsim 10^{13} \ \mathrm{K}$) and high degrees of circular polarization ($\sim 0.84 \pm 0.16$), indicating the origin of a coherent emission process, most likely the electron cyclotron maser. Based on Zeeman-Doppler Imaging measurements of EQ Peg, we further locate the sources of the radio spikes, including their heights and latitudes, under the assumption of a large-scale dipolar magnetic field configuration. The results provide strong evidence for finely structured decimetric radio bursts generated by stellar flares and shed light on the origin of superflares.
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All authors Zhanhao Zhao, Xin Cheng, Yuankun Kou, Guoyin Chen, Hao Ning, Yao Chen, Baolin Tan, Keping Qiu, Mingde Ding

Astrophysics of Galaxies

A Full-Sky SPHEREx Map of Integrated 3.3 and 3.4 {\mu}m PAH Emission

Roke Cepeda-Arroita, Clive Dickinson, J. Alberto Rubiño-Martín et al. (+4 more)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the interstellar medium and are among its smallest carbonaceous grains. Their infrared emission bands trace this small-grain population together with the interstellar radiation field that excites it, and are widely used to diagnose photodissociation regions, dust processing and star formation. We present full-sky maps of the integrated radiance of the 3.3 $\mu$m aromatic C-H stretch and the adjacent 3.4-3.5 $\mu$m aliphatic complex, from SPHEREx QR2 Level-2 data. Existing all-sky PAH tracers are broadband, so the band emission can only be inferred as an excess over stellar and continuum emission; SPHEREx samples the spectrum finely enough for the bands to be fitted directly. We mask flagged detector pixels, subtract the per-pixel zodiacal-light model, subtract point sources with an empirically derived PSF, and coadd the results into inverse-variance-weighted HEALPix maps at 2.6' FWHM and Nside=4096 in 102 narrowband channels across Detector 4 (2.42-3.82 $\mu$m). At every sky pixel we fit a continuum and the two bands. The combined band radiance is the primary product; its decomposition into the aromatic and aliphatic components is released alongside it as an estimate, with its modelling systematic stated. These are the first full-sky maps of PAH band emission, resolving the 3.3 and 3.4-3.5 $\mu$m bands spectrally, and the first full-sky PAH maps from SPHEREx to be released. Because the 3.3 $\mu$m band is emitted preferentially by the smallest PAHs, the maps trace directly a grain population, including the candidate carriers of anomalous microwave emission, that broadband PAH proxies reach only indirectly. The maps and their associated products, including a reliability mask, are publicly available with an explanatory supplement at https://research.iac.es/proyecto/radioforegroundsplus/pages/data-products/spherex-pahs.php.
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All authors Roke Cepeda-Arroita, Clive Dickinson, J. Alberto Rubiño-Martín, Ricardo T. Génova-Santos, Gabriel A. Hoerning, Stuart E. Harper, Debabrata Adak

Instrumentation and Methods for Astrophysics

An End-to-End Numerical Framework for Tidal Disruption Events with AthenaK

Hong-Xuan Jiang, Mengqi Yang, David A. Velasco-Romero et al. (+4 more)

In a tidal disruption event (TDE), a black hole (BH) tears apart a star, whose bound debris returns over many orbits to form an accretion disk. We present a framework built on the GPU-accelerated finite-volume code AthenaK that follows these stages in a single simulation with self-gravity throughout. We extend AthenaK with a moving frame, restart remapping between domains, an adaptive-mesh multigrid Poisson solver, a tabulated hydrogen–helium equation of state including recombination, a dual-energy update for the cold supersonic debris stream, a moving BH potential with excision, and localized adaptive time stepping (LAT), which speeds up the production run more than threefold. Each component is validated separately and in combination: the gravity solver maintains an isolated Lane–Emden sphere to a density error of $2.0\times10^{-3}$ over 16.3 dynamical times, and dual-energy recovery reduces the pressure error of a Mach $7.75\times10^7$ entropy wave from 15.7 to $4.0\times10^{-12}$. We demonstrate the framework with a Newtonian $\beta=1$ disruption of a $1\,M_\odot$, $1\,R_\odot$ star by a $10^3\,M_\odot$ BH. The debris has the expected energy spread, insensitive to the self-gravity update interval, splits evenly into bound and unbound material, and yields a fallback rate approaching $t^{-5/3}$ at late times. At the pericenter nozzle, the thermal energy gained in the high-resolution run matches the vertical kinetic energy lost to within 6%, whereas the fiducial run, with 4–8 times coarser cells, overheats the thinnest early stream through numerical dissipation. Their heating agrees to 10% once the returning stream thickens. Multifrequency LTE post-processing produces synthetic images and luminosities.
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All authors Hong-Xuan Jiang, Mengqi Yang, David A. Velasco-Romero, Fangyuan Yu, Jing-Ze Xia, Xinyu Li, Yosuke Mizuno

Solar and Stellar Astrophysics · Cross-listed from physics.plasm-ph

Effects of Alfvénicity on the Compressible Energy Cascade in Magnetohydrodynamic Solar Wind Turbulence: Evidence from Parker Solar Probe, Solar Orbiter, and WIND observations

Nahuel Andrés, Carlos A. Gonzalez and Norberto Romanelli

The compressible MHD energy cascade in the solar wind is shaped by Alfvénicity, plasma fluctuations, and proton temperature, yet how these factors regulate the relative weight of compressible and incompressible energy transfer across heliocentric distances remains poorly understood. We apply compressible and incompressible exact relations to a large sample of 2-hour intervals from WIND (1~au), Parker Solar Probe ($<0.25$~au), and Solar Orbiter (0.3–1~au), classifying intervals as Alfvénic ($|\sigma_c|>0.75$) or non-Alfvénic ($|\sigma_c|<0.25$) and by wind speed, and examine the Yaglom-like and purely compressible components of the compressible cascade. Velocity fluctuation amplitude is the strongest predictor of the compressible cascade rate $\langle|\varepsilon_c|\rangle$, followed by density and magnetic field fluctuations. $\langle|\varepsilon_c|\rangle$ and $\langle|\varepsilon_i|\rangle$ are tightly correlated in all regimes, with their ratio organized by Alfvénicity and wind speed: non-Alfvénic and Alfvénic fast winds cluster along $\langle|\varepsilon_c|\rangle=\langle|\varepsilon_i|\rangle$, while Alfvénic slow wind shows a systematic excess consistent with internal energy contributions. The largest $\langle|\varepsilon_c|\rangle$ systematically occur in hotter intervals, with a two-decade increase from cool to hot events in Alfvénic slow and non-Alfvénic wind, a trend carried mainly by the purely compressible term, while the dominant Yaglom-like term controls the overall cascade magnitude. Alfvénicity and wind speed thus govern the efficiency of turbulent energy transfer across heliocentric distances, and the tight coupling between compressible and incompressible rates points to the need for compressible, multi-fluid descriptions of the solar wind dissipation budget.
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Solar and Stellar Astrophysics

Solar spicule population properties inferred from IRIS Mg II k off-limb spectra using likelihood-free Bayesian inference

Jiri Stepan, Stanislav Gunar, Akiko Tei et al. (+1 more)

Solar spicules are ubiquitous and strongly overlapping in off-limb observations, which complicates the interpretation of individual events. We aim to infer population-level properties of spicules from IRIS Mg~II~k off-limb spectra using a forward model that explicitly accounts for line-of-sight superposition and instrumental effects. We construct a stochastic three-dimensional spicule-population model and synthesize Mg II k spectra with radiative transfer, including instrumental degradation and photon noise. We then constrain the hyperparameters that describe the underlying spicule population with likelihood-free Bayesian inference based on approximate Bayesian computation and an adaptive population Monte Carlo sampler, comparing observed and simulated datasets through principal-component summary statistics at five heights above the limb. The inferred posterior constrains effective population-level properties of the spicules that dominate the observed Mg II k variability and height dependence. These constraints provide a route to connect off-limb spectroscopy with forthcoming spectropolarimetric diagnostics of the chromosphere-corona interface.
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All authors Jiri Stepan, Stanislav Gunar, Akiko Tei, Petr Heinzel

High Energy Astrophysical Phenomena

ALMA - CTAO synergies

Paola Andreani and Maria Diaz-Trigo

This article aims to raise awareness within the ESO astronomical community of the scientific opportunities offered by the upcoming Cherenkov Telescope Array, CTAO, highlighting cases where combining millimetre/submillimetre capabilities of the Atacama Large Millimeter / submillimeter Array, ALMA with the CTAO's very high energy, TeV, observations enables new avenues for discovery. Many astrophysical sources and environments exhibit emission processes detectable in both regimes; however, the synergies extend beyond shared emission mechanisms and include broader physical processes and observational connections linking millimetre, submillimetre and TeV energies.
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Solar and Stellar Astrophysics

Near-infrared periodicity in the SPICY catalog. True young stellar objects versus contaminants

C. Ordenes-Huanca, A. Bayo, M. Zoccali et al. (+2 more)

Infrared (IR) large-sky surveys allow study of how localized star formation is, enabling searches for young stellar objects (YSOs) not only at the centers of known stellar nurseries but also across the Galactic plane. However, these spatially unbiased searches suffer from contamination, most notably from dusty asymptotic giant branch (AGB) stars characterized by long-period variability. Using time-series analysis, and taking advantage of the different variability timescales of YSOs against long-period variables (LPVs), we assess the level of contamination of one of the most spatially unbiased YSO catalogs (Spitzer/IRAC Candidate YSO, SPICY). Distinguishing between these two groups lets us draw more robust conclusions about the frequency of isolated YSOs in our Galaxy and their implications. We cross-match the SPICY and VIRAC2 catalogs (VVV/VVVX Survey), build near-IR light curves for common sources, and compute their periods and amplitudes. Contaminants are identified as sources with periodic flux variations with periods $P\geq 80\,d$ and amplitudes $\Delta K_{\rm s}\geq0.35\,\rm{mag}$. From $58\,737$ common sources, we identify $742$ SPICY objects as LPV contaminants based on their long-period variability, and identify $307$ high-confidence periodic YSO candidates exhibiting short-period flux changes consistent with cool spots. Near- and mid-IR amplitudes are correlated only among LPVs, suggesting a common pulsation origin. In addition, the spatial distribution of the identified populations further supports our classification, with LPVs preferentially associated with the bulge and YSOs at the lowest galactic latitudes.
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All authors C. Ordenes-Huanca, A. Bayo, M. Zoccali, V. Guzmán, A. Rojas-Arriagada

High Energy Astrophysical Phenomena

Shaping binary black hole merger efficiency with gravitational wave observations

Michele Bosi, Lumen Boco, Stefano Torniamenti et al. (+5 more)

Gravitational wave (GW) astronomy offers unprecedented insights into binary black hole (BBH) coalescence. However, many of the key quantities involved remain inaccessible to direct observations. The BBH merger rate density is deeply linked to both the merger efficiency and the distribution of delay time between binary formation and merger, neither of which is directly constrained by observations. Disentangling their impact on the merger rate represents a highly non-trivial endeavour. Here we present a semi-parametric BBH population model, based on population synthesis simulations of both isolated and dynamically-formed BBHs, anchored on an observation-driven, metallicity-dependent star formation history. We parametrise the merger efficiency of these two formation channels, fitting the model to GW events from the Gravitational-Wave Transient Catalog 5.0 within a hierarchical Bayesian framework. Our analysis suggests that the isolated BBH merger efficiency should be lowered by a factor $\mathcal{O}(10)$ relative to standard population synthesis results. The dynamical channel requires an efficiency more than an order of magnitude larger than the isolated one to reproduce current GW observations. Nevertheless, we find that the two channels provide comparable contributions to the observed number of events. Finally, we introduce a parametrisation for the delay time distribution of the isolated BBHs. We derive a distribution consistent with the observed local merger rate and show its degeneracy with the merger efficiency.
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All authors Michele Bosi, Lumen Boco, Stefano Torniamenti, Stefano Rinaldi, Cecilia Sgalletta, Michela Mapelli, Carlo Baccigalupi, Andrea Lapi

Instrumentation and Methods for Astrophysics

On-sky commissioning and technical performance of Proto-NUX at Pic du Midi

Rasjied Sloot, Rudy Wijnands, Steven Bloemen et al. (+3 more)

The Near-Ultraviolet eXplorer (NUX) is a proposed ground-based observing facility designed to expand near-ultraviolet (NUV) astronomy by enabling observations in the 300–350 nm range from Earth. The full system is intended to consist of four modified 36 cm Celestron RASA telescopes with custom NUV-optimized optics and UV-sensitive CMOS detectors, providing a total field of view of about 67 square degrees for high-cadence searches for fast, hot transients. To validate this concept, a single-telescope prototype, Proto-NUX, was constructed. Its optical design and development are described in previous work. Initial sea-level tests in the Netherlands showed that the instrument could be operated successfully and that the main technical requirements were met. In March 2026, Proto-NUX was deployed at the Pic du Midi Observatory in the French Pyrenees, at an altitude of 2877 m, for its first high-altitude on-sky commissioning campaign. The campaign tested the full system under realistic observing conditions, including deployment, remote operation, calibration procedures, detector behaviour, image quality, tracking, ghosting, and simultaneous optical monitoring. The observations demonstrate that Proto-NUX is a viable platform for ground-based NUV observations, but also show that the system was not yet operating at its expected optical limit. In particular, the delivered NUV point-spread function was broader than expected, with likely contributions from residual collimation error, defocus, chromatic effects, and internal reflections. The detector dark current was also found to be a significant contributor to the noise budget. We discuss these limitations and identify the main improvements needed for future Proto-NUX campaigns and for scaling the concept to the full NUX facility.
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All authors Rasjied Sloot, Rudy Wijnands, Steven Bloemen, Hans Ellermeijer, Alexander Hoogerbrug, Rik ter Horst

Earth and Planetary Astrophysics

Detecting atmospheres in the presence of stellar contamination: an empirically calibrated framework applied to four JWST/NIRSpec PRISM transits of TRAPPIST-1c

Alexander D. Rathcke and Lars A. Buchhave

Transmission spectroscopy of rocky exoplanets orbiting late M dwarfs is limited by stellar contamination rather than photon noise. We present a framework for this contamination-dominated regime, fitting all transit epochs jointly with a Gaussian process per epoch for the time-varying stellar contamination and a single atmospheric model shared across epochs. We use pure CO$_2$, H$_2$O, and CH$_4$ models scaled by their peak-to-trough amplitude, allowing us to measure how large a signal must be to be recovered. We calibrate this framework using injection-recovery tests and 17 archival JWST/PRISM transits of the airless sibling TRAPPIST-1 b to quantify the spurious signals that stellar contamination alone produces. Applied to four JWST/NIRSpec PRISM transits of TRAPPIST-1 c, our framework recovers injected CO$_2$ signals without bias and reaches detection thresholds of 146 (171) ppm for moderate (strong) evidence, compared with 96 ppm if there were no stellar contamination. CO$_2$ and CH$_4$ produce no spurious signals on the airless control planet, whereas H$_2$O shows a persistent stellar floor of $+55 \pm 34$ ppm. TRAPPIST-1 c is consistent with a featureless, airless baseline for all three molecules. Our 95 per cent upper limit of 90 ppm for CO$_2$-shaped signals effectively rules out clear, isothermal pure-CO$_2$ atmospheres ($\geq$0.1 bar) and N$_2$-dominated atmospheres with 1 per cent CO$_2$ ($\geq$1 bar) at the equilibrium temperature. An empirical scaling study using 2 to 10 transits of TRAPPIST-1 b shows the CO$_2$ detection threshold decreasing with the number of transits $k$ as $k^{-0.6}$, reaching 80 ppm at ten transits, while water searches become limited by the stellar floor beyond about six transits. CO$_2$ atmospheres, by contrast, are detectable when we utilize our framework to account for stellar activity at the cost of roughly 1.5 to 2 times as many transits.
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High Energy Astrophysical Phenomena

Fast and furious – High-velocity features of Ca and Si in the spectra of Type Ia supernovae

Zsófia Bora, József Vinkó, J. Craig Wheeler et al. (+2 more)

High velocity absorption lines of Ca II and Si II (high-velocity features, HVFs) are common in the early spectra of Type Ia supernovae (SNe Ia), but their physical origin is still poorly understood. We used 181 optical spectra of 56 SNe Ia that show HVFs in at least the Ca II NIR triplet to better understand the nature of HVFs. To model the profiles of HVFs we applied Gaussian fitting as well as spectrum synthesis modeling with the SYNOW code. We found that Gaussian fitting usually underestimates the velocity of HVFs compared to SYNOW, and derived a linear formula for correction. In accord with many previous studies, the observed properties of HVFs (velocity, strength, duration) were found to correlate with the general observables of SNe Ia (decline rate, spectral subtype). Brighter, slow-declining SNe usually exhibit stronger, higher velocity HVFs, while fainter objects typically show weak, low velocity HVFs. SNe Ia in early-type galaxies showed weaker and slower HVFs compared to events in late-type galaxies in our sample. Comparing these observational findings with theoretical predictions, we conclude that the overall physical picture of HVFs is quite complex, and could be explained by multiple models. A double detonation explosion model is promising as it is inherently capable of explaining the creation of high-velocity shells that may produce HVFs, but an asymmetric delayed detonation model or interaction with circumstellar material cannot be ruled out.
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All authors Zsófia Bora, József Vinkó, J. Craig Wheeler, Réka Könyves-Tóth, G.H. Marion

Solar and Stellar Astrophysics

Common Envelope Evolution: Too stochastic to be deterministic

Noam Soker

I argue for significant stochastic behavior in the common envelope evolution (CEE) of cool giants and main-sequence companions to the degree that it is almost impossible to know the exact CEE outcome of an individual binary system from the average properties of the stars and their initial orbit. I start with two observational properties of post-CEE planetary nebulae: many have jet-shaped morphologies, and they show a wide variety of morphologies. The first suggests that the standard CEE model should include jets, and the second shows that the CEE has a wide variety of evolutionary routes; for example, jets can be launched before, during, and/or after the main CEE phase. I show that the properties of the disk with which the main-sequence companion enters the CEE depend sensitively and stochastically on the pulsations and convection of the giant star. Pulsations and giant-envelope convection stochastically determine the evolution of the accretion disk inside the envelope. The stochastic nature of the accretion disk properties implies that jet power is also stochastic. Adopting the view that jets play a major role in CEE outcomes, I conclude that the CEE outcome is stochastic. I conclude that the CEE efficiency parameter alpha(CE) has little merit for individual systems, although it still has meaning in population synthesis and other studies of large populations.
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Astrophysics of Galaxies

Thermally irreversible sulfur chemisorption on silicate grains as a major sulfur reservoir in molecular clouds

Ni-En Sie, Masashi Tsuge, Yasuhiro Oba et al. (+3 more)

Sulfur (S) chemistry in the interstellar medium remains poorly constrained due to the longstanding "missing sulfur" problem, where a significant fraction of cosmic sulfur in molecular clouds remains unidentified. To gain a comprehensive understanding of S chemistry in the interstellar medium, its behavior on interstellar dust grains must be clarified. Here, we experimentally investigated the surface elementary processes of S atoms under conditions mimicking interstellar molecular clouds. Our in-situ laser-based detection method enabled the direct tracking of S atoms adsorbed on astrophysically relevant silicate substrates and amorphous solid water (ASW). We found that sulfur atoms strongly chemisorbs onto silicate surfaces and remains bound even after ASW sublimation, rendering it observationally invisible. An astrochemical model coupled with these results suggests that at least 10 percent of the total sulfur budget in molecular clouds must be locked onto silicate dust grains. Our results identify sulfur chemisorption on silicate as a key mechanism driving sulfur depletion and provide a physical explanation for the missing sulfur problem.
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All authors Ni-En Sie, Masashi Tsuge, Yasuhiro Oba, Germán Molpeceres, Kenji Furuya, Naoki Watanabe

High Energy Astrophysical Phenomena

X-ray measurements of the elemental abundances for the diffuse emission in the nuclear starburst galaxy NGC 3079

Jiejia Liu, Junjie Mao, Shuinai Zhang et al. (+3 more)

Outflows driven by feedback leave imprints on a galaxy's diffuse X-ray emission. Elemental abundances provide key diagnostics of feedback-driven chemical enrichment. We present a spectroscopic study of the diffuse X-ray emission in NGC 3079 using XMM-Newton RGS and EPIC, focusing on the nuclear region and the extended galactic-scale superbubble (GSB). We analyzed the high-resolution RGS spectrum of the central $\sim4~\rm kpc$ region, encompassing the $\sim1~\rm kpc$ nuclear superbubble (NSB), and the EPIC spectrum of the GSB out to $5'~(\sim25~\rm kpc)$. The nuclear spectrum is best described by a multi-temperature thermal-plasma model plus a charge-exchange (CX) component, which contributes approximately $13\%$ of the total observed energy flux in the $0.2-2~\rm keV$ band. The best-fit O/Fe and Ne/Fe ratios are $0.47$ and $0.77$ in solar units. Comparing these ratios with IMF-weighted core-collapse supernova (SNcc) yields gives an upper progenitor-mass cutoff of $M_{\rm u}\simeq13-15~M_{\odot}$ for pure SNcc enrichment. For the best-fit spectral model, including an SNIa contribution increases the inferred cutoff, but its $1\sigma$ upper limit remains below $25~M_\odot$ for SNIa fractions up to $10\%$ within the adopted yield models. The characteristic ages of the NSB and GSB are $0.92^{+0.39}_{-0.46}~\rm Myr$ and $29.6^{+1.6}_{-2.9}~\rm Myr$, respectively, suggesting episodic feedback in NGC 3079.
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All authors Jiejia Liu, Junjie Mao, Shuinai Zhang, Guan-Fu Liu, Rui Huang, Wei Cui

Astrophysics of Galaxies

GA-NIFS: sRMS, a new method for disentangling resolved and unresolved emission in integral field spectroscopy. Application to distant quasars

Michele Perna, Santiago Arribas, Carlota Prieto-Jiménez et al. (+28 more)

The interpretation of AGN emission-line profiles in type1 AGN is often complicated by the dominance of bright, spatially unresolved nuclear continuum and broad-line region (BLR) emission over narrower and blended components from the narrow-line region (NLR) and the host galaxy. This remains challenging even with integral-field spectroscopy (IFS), as the relevant spatial variations can occur on scales smaller than the angular resolution, particularly in the compact host of distant AGN. We introduce the spatial root-mean-square (sRMS) technique, a new approach to analyse single-epoch IFS that uses the spatial variance of spectra extracted from partially overlapping apertures to isolate off-nuclear emission of high-z BL-AGN, and investigate whether the resulting kinematic information can improve the decomposition of their integrated spectra. We construct sRMS spectra from ensembles of overlapping apertures centred on the unresolved nucleus. Emission that is spatially invariant on the scales probed by the apertures is consequently suppressed, whereas spatially varying emission is retained. We apply the procedure to JWST/NIRSpec data of two z~6.5 QSOs. We model the resulting sRMS spectra with multiple Gaussian components to determine the kinematics of the spatially varying emission, and use these kinematic constraints to model the integrated spectra. The sRMS technique identifies spatially varying narrow-line emission on scales up to ~5x smaller than the NIRSpec PSF and provides robust constraints on the kinematics of individual kinematic components. Imposing these kinematic constraints on the integrated-spectrum fit reduces significantly the degeneracy of multi-component decompositions. Simulations further demonstrate the potential of the method to detect spatially offset BLR emission from close dual BL-AGN, down to projected separations of ~200 pc at z~6.5 for a BLR flux ratio of ~10.
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All authors Michele Perna, Santiago Arribas, Carlota Prieto-Jiménez, Isabella Lamperti, Lorenzo Ulivi, Hannah Übler, Giovanni Cresci, Bruno Rodríguez Del Pino, Torsten Böker, Andrew J. Bunker, Stéphane Charlot, Roberto Maiolino, Chris J. Willott, Ivan Delvecchio, Elena Bertola, Madeline A. Marshall, Eleonora Parlanti, Pablo G. Pérez-González, Giacomo Venturi, Sandra Zamora, Filippo Mannucci, Quirino D'Amato, Alessandra De Rosa, Ismael García-Bernete, Alessandro Marconi, Miguel Pereira-Santaella, Fabio Rigamonti, Martina Scialpi, Paola Severgnini, Cristian Vignali, Maria Vittoria Zanchettin

Solar and Stellar Astrophysics

Abundance analysis of three new extremely metal-poor stars, including one CEMP-s star

P. François, T. Suda, S. Wanajo et al. (+5 more)

We report a detailed abundance analysis of three extremely metal-poor (EMP) stars thanks to spectra obtained with the high-dispersion spectrograph (HDS) at the Subaru telescope. The aim is to observe a sample of EMP candidate stars selected from the Sloan Digital Sky Survey (SDSS) and determine their detailed chemical composition. High-resolution spectra of three faint turn-off stars using HDS on the Subaru telescope were acquired.We used standard 1D models to compute the abundances of several elements (Li, C, Mg, Ca, Sr, and Ba). The stars we analysed have a metallicity [Fe/H] of between -3.02 and -3.57 dex. We also measured accurate radial velocities that, coupled with the Gaia astrometric data, allowed us to compute actions and Galactic orbits for the stars. Our analysis confirms that the stars are genuine EMP stars. One of them (SDSS J074238.68 +470537.0) can be classified as a CEMP-s star with the highest [Mg/Fe] ratio ever measured in a turn-off CEMP-s star with [Mg/Fe] = 1.85 dex. For the star SDSS J012630.30+073029.3 ([Fe/H]= -3.02 dex), we have a clear detection of lithium with A(Li) = 2.05. Kinematically, SDSS J214340.08-002835.5 is a thick-disc star, while the other two belong to the halo and are candidate members of the Gaia- Sausage-Enceladus.
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All authors P. François, T. Suda, S. Wanajo, E. Caffau, P. Bonifacio, W. Aoki, S. Yamada, M. Y. Fujimoto

Astrophysics of Galaxies

Fooled by mass? Recovering the $\Gamma-\lambda_{Edd}$ relation of quasars from their X-ray variability

Matilde Signorini, Andrea Sacchi, Bartolomeo Trefoloni et al. (+7 more)

We measure the relation between the X-ray photon index $\Gamma$ and the Eddington ratio $\lambda_{Edd}$ in unobscured type-1 quasars, using as parent sample the cross-match of the SDSS DR16Q catalogue with the 4XMM-DR14 serendipitous catalogue. After cleaning the sample of potential observational biases, we obtain 7835 objects, one order of magnitude larger than most previous analyses in the literature. A single regression of $\Gamma$ against $\log\lambda_{Edd}$, with single-epoch virial black-hole masses, returns slopes that depend on the mass indicator (H$\beta$, MgII, CIV) and on the bolometric correction, and that are generally flat. We interpret this as regression dilution: the systematic uncertainty on virial masses is much larger than the intrinsic spread of $\lambda_{Edd}$ in SDSS quasars. We therefore introduce a different approach, which removes the black-hole mass from the problem. For quasars observed by XMM-Newton at multiple epochs, the mass of each object is fixed, and changes in its X-ray luminosity trace changes in its accretion state. We fit the $\Gamma$-$\log(L_{2keV})$ relation of each object (for a sample of N=893) and combine the per-object posteriors. This recovers the mean response of the population $a_X = 0.35\pm0.03$, which steepens to $\approx0.43$ when only epochs with precisely measured photon indices are used. Translated to the Eddington ratio, this corresponds to $a_\lambda\approx0.20$-0.25, depending on the choice of bolometric correction and on the LX-LUV slope. The $\Gamma$–$\lambda_{Edd}$ relation therefore exists, but it can be uncovered only by exploiting the variability of individual sources, which removes the black-hole mass from the problem. Moreover, its shallowness implies that the differences in Eddington ratio, as currently measured, cannot by themselves account for the variety of photon indices observed among unobscured quasars.
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All authors Matilde Signorini, Andrea Sacchi, Bartolomeo Trefoloni, Matteo Guainazzi, Elisabeta Lusso, Emanuele Nardini, Chiara Niccolai, Federica Ricci, Anastasia Shlentsova, Mateusz Rałowski

Earth and Planetary Astrophysics

TOI-6981 b: a transiting sub-Neptune at the water ice line

Madison G. Scott, Amaury H.M.J Triaud, Emily K. Pass et al. (+42 more)

We present TOI-6981 b, a cold (Teq= 170.0 +/-4.5 K, assuming an Earth-like albedo) sub-Neptune (Rb=2.40+/-0.10 R_oplus) on a 60.8 day orbit around around its M4-type host star (R*=0.304 +/- 0.012 R_odot, M*=0.296 +/- 0.026 M_odot, Teff = 3215+/-58K), part of the SPECULOOS TEMPOS program. We validate the planetary nature of TOI-6981 b using ground-based follow-up photometry, statistical validation and high-resolution spectroscopy. At such cold temperatures, TOI-6981 b sits roughly at the location of the water ice line (approx 170 K). Given its orbital period and high transmission spectroscopy metric (TSM=51 +/- 9), it is one of the only planets in the sparsely populated cold planet regime amenable for atmospheric studies with JWST. Therefore, TOI-6981 b could. possibly become a crucial benchmark in cold chemistry studies, tests of Hycean world hypotheses, and drawling parallels to the Solar System's ice giants. Additionally, given its current orbit, it may provide insight into planetary formation and migration at or beyond the water ice line.
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All authors Madison G. Scott, Amaury H.M.J Triaud, Emily K. Pass, Aleyna Adamson, Karen A. Collins, Khalid Barkaoui, Allyson Bieryla, Adam J. Burgasser, Mark E. Everett, Steve B. Howell, David W. Latham, Benjamin V. Rackham, Boris S. Safonov, Miquel Serra-Ricart, Abderahmane Soubkiou, Georgina Dransfield, Katharine Hesse, Pipa Fernandez de Diego, Emma Softich, Gregor Srdoc, Mathilde Timmermans, Jeroen Audenaert, Roi Alonso, Artem Y. Burdanov, Yasmin T. Davis, Fatemeh Davoudi, Julien de Wit, Shishir Dholakia, Elsa Ducrot, Michaël Gillon, Yilen Gomez Maqueo Chew, Matthew J. Hooton, Clàudia Janó-Muñoz, Emmanuel Jehin, Akanksha Khandelwal, Thomas R. Marriott, Peter P. Pedersen, Manuel Pichardo Marcano, Francisco J. Pozuelos, Rafael Rebolo-López, Manu Stalport, Alexander Venner, Selçuk Yalçinkaya, Francis Zong Lang, Sebastián Zúñiga-Fernández

Cosmology and Nongalactic Astrophysics

Carving out the Multifield Cosmological Collider Landscape

Denis Werth

We show that inflation with a large number of fields, as predicted by concrete ultraviolet embeddings, generically produces almost-local cosmological collider signals in the bispectrum squeezed limit. We construct the most general boost-breaking mixings between the curvature perturbation and $N_{\rm f}$ additional fields, and extract the late-time scaling dimensions that dictate the soft limits of cosmological correlators. For a handful of fields, an enhanced squeezed limit (with potential oscillations) is a fine-tuned signal. At large $N_{\rm f}\sim100$, however, mixings generically drive the scaling dimensions toward the unitarity boundary. We show that this is a direct consequence of extreme value statistics and random-matrix universality, turning an almost-local bispectrum shape into a generic prediction for almost any masses and mixings.
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Earth and Planetary Astrophysics

The Occurrence Rate of Planets Around Subgiant Stars from TESS Photometric Survey

Arkaprova Dutta and Priyanka Chaturvedi

Subgiant stars represent a critical phase in stellar evolution, offering an opportunity to investigate how planetary systems respond to the early stages of post-main-sequence expansion. Despite their importance, systematic occurrence-rate studies of this population remain sparse compared with those of main-sequence and red-giant hosts. In this work, we present a uniform analysis of planet occurrence around a sample of 282,904 subgiant stars selected from the Gaia DR3 catalogue. We perform an independent reanalysis of TESS light curves for transit-signal detection and refinement, followed by multi-stage vetting including visual inspection and statistical false-positive assessment. We quantify the detection sensitivity of the survey through injection-and-recovery experiments, with 565,808 synthetic transit signals injected across the stellar sample. Over the period range of 1–10 days and the planet-radius range for which the detection completeness is well characterised, we measure a completeness-corrected planet occurrence rate of 0.644^{+0.048}_{-0.041}. The occurrence rate is strongly dependent on planet radius, with the highest occurrence contributed by planets in the 1-4 R_earth range and a secondary enhancement at 12-15 R_earth. These results provide a demographic baseline for studying the population of close-in planets around stars undergoing early post-main-sequence evolution.
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Astrophysics of Galaxies

Caught in the act: diffuse stellar and Ly$\alpha$ emission around a halo-less quasar in the assembling cluster CARLA J0800+4029 at z=2

Sofia G. Gallego, Simona Mei, Emanuele Daddi et al. (+3 more)

Extended Ly$\alpha$ emission is commonly detected around luminous quasars at $z\sim2$-3 and traces cold gas in the circumgalactic environment of the AGN. Together with the spatial distribution of galaxies, Ly$\alpha$ probes gas and galaxy assembly in high-redshift overdensities. We use deep KCWI wide-field spectroscopy and HST/F140W imaging to investigate the assembling cluster CARLA J0800+4029 at $z=1.986\pm0.014$. No robust extended Ly$\alpha$ emission is detected at the radio-loud quasar position. Instead, the dominant Ly$\alpha$ emission is offset from the AGN and coincides with a disturbed structure composed of galaxies, tidal features, and diffuse intra-halo light (IHL). The detected structure has $L_{\rm Ly\alpha}=1.42\times10^{43}$ erg/s and reaches surface-brightness levels of $\sim10^{-17}$ erg/s/cm$^2$/arcsec$^2$. At the quasar position, a matched $3\sigma$ limit gives $L_{\rm Ly\alpha}<4.20\times10^{42}$ erg/s, a factor of $\sim3.4$ below the detected offset emission and among the most stringent constraints at similar redshift. The Ly$\alpha$ emission is dominated by one extended region near systemic velocity, with FWHM $\sim300$-500 km/s. The associated tidal structure has an IHL fraction of 18.8%, and contains a spatially coherent absorption-like decrement at $\sim+1000$ km/s. The offset and alignment between Ly$\alpha$ emission and IHL suggest that gas and stars have been redistributed together during assembly. The lack of a comparable Ly$\alpha$ halo around the quasar further suggests that gas in the immediate AGN environment is ionized, depleted, or suppressed, while the offset region remains favorable for Ly$\alpha$ emission. CARLA J0800+4029 reveals baryon redistribution during cluster assembly, with the dominant observable Ly$\alpha$ reservoir decoupled from the central AGN and linked to ongoing tidal assembly.
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All authors Sofia G. Gallego, Simona Mei, Emanuele Daddi, Gaël Noirot, Dominika Wylezalek, R. Michael Rich

High Energy Astrophysical Phenomena

Search for dark matter annihilation in the Sun using the full ANTARES dataset

A. Albert, S. Alves, M. André et al. (+133 more)

Weakly Interacting Massive Particles (WIMPs) are among the most popular candidates for particle dark matter. In certain scenarios, WIMPs could be gravitationally captured into massive celestial objects and then annihilate into Standard Model particles, possibly leading to the emission of neutrinos. The ANTARES neutrino telescope, located in the Mediterranean Sea, is sensitive to neutrinos with energies ranging from a few tens of GeV to the TeV scale, making it well suited to search for the annihilation of WIMPs with masses below a few TeV/c$^2$. One of the closest potential astrophysical sources of neutrinos from WIMP annihilations is the Sun. In this work, a search for high-energy neutrinos originating from the Sun, using the full dataset recorded by ANTARES from 2007 to 2022 was conducted. The analysis yielded no significant evidence for a neutrino excess over the expected background, and upper limits on the WIMP-proton interaction cross section have been obtained, for both spin-dependent and spin-independent processes. These limits are valid for dark matter masses ranging from 35 GeV/c$^2$ to 10 TeV/c$^2$ for the annihilation benchmark channels WIMP$+$WIMP $\longrightarrow$ $b\bar{b},\tau^+\tau^-, W^+W^-$, assuming a 100$\%$ branching ratio for each of these channels. These results improve on those previously obtained by the ANTARES Collaboration by a factor of two-three and are consistent with those reported by other experiments in direct and indirect searches for dark matter.
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All authors A. Albert, S. Alves, M. André, M. Ardid, S. Ardid, J.-J. Aubert, J. Aublin, B. Baret, S. Basa, Y. Becherini, B. Belhorma, F. Benfenati, V. Bertin, S. Biagi, J. Boumaaza, M. Bouta, M.C. Bouwhuis, H. Brânzaş, R. Bruijn, J. Brunner, J. Busto, B. Caiffi, D. Calvo, S. Campion, A. Capone, L. Caramete, F. Carenini, J. Carr, V. Carretero, T. Cartraud, S. Celli, M. Chabab, T. Chiarusi, M. Circella, J.A.B. Coelho, A. Coleiro, R. Coniglione, P. Coyle, A. Creusot, A. F. Díaz, B. De Martino, C. Distefano, I. Di Palma, C. Donzaud, D. Dornic, D. Drouhin, T. Eberl, A. Eddymaoui, T. van Eeden, D. van Eijk, S. El Hedri, A. Enzenhöfer, P. Fermani, G. Ferrara, F. Filippini, L.A. Fusco, S. Gagliardini, J. García-Méndez, C. Gatius Oliver, P. Gay, N. Geißelbrecht, H. Glotin, R. Gozzini, R. Gracia Ruiz, K. Graf, C. Guidi, L. Haegel, H. van Haren, A.J. Heijboer, Y. Hello, L. Hennig, J.J. Hernández-Rey, J. Hößl, F. Huang, G. Illuminati, B. Jisse-Jung, M. de Jong, P. de Jong, M. Kadler, O. Kalekin, U. Katz, A. Kouchner, I. Kreykenbohm, V. Kulikovskiy, R. Lahmann, M. Lamoureux, A. Lazo, D. Lefèvre, E. Leonora, G. Levi, S. Le Stum, S. Loucatos, J. Manczak, M. Marcelin, A. Margiotta, A. Marinelli, P. Migliozzi, A. Moussa, R. Muller, S. Navas, E. Nezri, B. Ó Fearraigh, E. Oukacha, A.M. Păun, G.E. Păvălaş, S. Peña-Martínez, M. Perrin-Terrin, P. Piattelli, C. Poirè, T. Pradier, N. Randazzo, D. Real, G. Riccobene, A. Romanov, A. Sánchez Losa, A. Saina, F. Salesa Greus, D. F. E. Samtleben, M. Sanguineti, P. Sapienza, F. Schüssler, J. Seneca, M. Spurio, Th. Stolarczyk, M. Taiuti, Y. Tayalati, B. Vallage, G. Vannoye, V. Van Elewyck, S. Viola, D. Vivolo, J. Wilms, S. Zavatarelli, A. Zegarelli, J.D. Zornoza, J. Zúñiga

Instrumentation and Methods for Astrophysics · Cross-listed from gr-qc

Scaling RIFT 1: Extending RIFT to third-generation gravitational-wave analyses

R. O'Shaughnessy, A. Jan, J. Lange et al. (+1 more)

Interpretation of compact binary signals observed by third-generation gravitational-wave detectors is complicated by their high signal-to-noise ratios, often reaching hundreds to thousands, and by time- and frequency-dependent detector responses arising from Earth's rotation and the detectors' large physical extent. Building on prior work for LISA, we implement generic, robust extensions of the RIFT parameter estimation pipeline that enable interpretation of these sources using any existing waveform model, without recourse to intermediate pretrained data products like reduced-order approximations or normalizing flows. We demonstrate end-to-end recovery of finite-size binary-neutron-star injections in a three-site next-generation network to $\mathrm{SNR}=1000$, localizing the source's extrinsic parameters to $0.8\times10^{-3}\,\mathrm{deg}^2$ in minutes on a single GPU.
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All authors R. O'Shaughnessy, A. Jan, J. Lange, R. Mechum

Astrophysics of Galaxies

The ALPINE-CRISTAL-JWST Survey: Investigating the role of interstellar dust, gas and stars in high-z galaxies at kpc-scales

F. Lopez, M. Relano, I. De Looze et al. (+37 more)

A comprehensive understanding of galaxy evolution requires a detailed analysis of gas and dust, their distribution, and evolution within galaxies. We analyse spatially resolved (~kpc) rest-frame [CII] and dust continuum ALMA observations together with JWST/NIRSpec IFU data of a sample of galaxies at z~4-5. We focus on deriving the spatial distributions of atomic and molecular gas masses, dust and stellar masses, star formation rates (SFR), and metallicity. The oxygen abundance maps have values in the range of 12+log(O/H)~8.1-8.3 with variations of the order of 1dex within the same galaxy. The calibration used in this study to estimate the atomic gas mass in our galaxies seems to overestimate the atomic gas mass surface densities up to 1-2 orders of magnitude. However, a calibration based on a spatially resolved [CII] conversion factor gives a more robust estimation of the total gas mass. Galaxies exhibiting signatures of strong outflows have lower dust-to-stellar surface mass density ratio and lower gas mass fractions than the galaxies with no outflow signatures. While the latter is consistent with these galaxies ejecting part of their gas reservoir to the circumgalactic medium, the low dust-to-stellar surface mass density ratios also suggest that part of the dust content is expelled outside the galaxy, which reinforces previous theoretical suggestions of dust removal by stellar feedback or radiation pressure to explain the high UV luminosities in galaxies at very high-redshifts. Some galaxies of our sample have almost an order of magnitude higher dust-to-gas and dust-to-stellar surface mass density ratio than galaxies in the local Universe, suggesting that a large dust reservoir has been built up already at time scales of ~1 Gyr in these galaxies.
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All authors F. Lopez, M. Relano, I. De Looze, A. L. Faisst, R. Herrera-Camus, R. A. Jorgenson, E. Pérez-Montero, M. Palla, C. Accard, R. O. Amorin, M. Aravena, R. J. Assef, A. J. Battisti, M. Boquien, E. da Cunha, P. Dam, R. L. Davies, M. Dessauges-Zavadsky, A. Ferrara, S. Fujimoto, M. Ginolfi, N. Gutierrez-Vera, A. Hadi, E. Ibar, H. Inami, A. M. Koekemoer, L. L. Lee, J. Li, J. Molina, A. Nanni, D. Narayanan, F. Pozzi, F. Rizzo, M. Romano, D. B. Sanders, P. Sawant, L. Vallini, S. A. van der Giessen, V. Villanueva, G. Zamorani