Astrophysics of Galaxies
Extreme Kerr Newman Black Holes: Differential Geometry, Symmetry, and the Golden Ratio
Remo Ruffini and Giorgio Sonnino
We investigate the geometry of extreme Kerr-Newman black holes and its role in selecting distinct black hole states. Motivated by Smarr's question of what physical information is encoded in event-horizon
symmetries, we identify, besides the Smarr extreme family, a special family in which the mass, charge, angular momentum, and irreducible mass are constrained by a single irrational number. In the Christodoulou diagram, this family is selected by a discrete
symmetry of appropriately scaled charge and angular-momentum variables. The local differential geometry of the event horizon provides an additional selection principle, which, up to the discrete
symmetries (Q \rightarrow\pm Q) and (J \rightarrow\pm J), identifies a unique extreme Kerr-Newman black hole exhibiting the highest degree of local spherical
symmetry compatible with the rotating Kerr-Newman geometry. Remarkably, for this distinct extreme configuration, all relevant physical and geometrical quantities, including the energy, electric charge, angular momentum, and irreducible mass, are solely related through the golden ratio. We also examine reversible and irreversible transformations and the associated extractable energy. Intrinsic horizon geometry can therefore constrain the macroscopic parameters and single out distinct extreme Kerr-Newman configurations.
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High Energy Astrophysical Phenomena · Cross-listed from gr-qc
Survey of Novel Deep Learning Architectures for Denoising Gravitational-wave Signals
Rohan Raha and Prayush Kumar
Gravitational-wave denoising must handle the full diversity of spinning, precessing binaries, since the recovered waveform underpins parameter estimation, tests of general relativity, and population studies. Matched filtering achieves this at a cost that becomes prohibitive as next-generation detectors push event rates higher; deep learning offers real-time reconstruction, but current methods are developed on narrow parameter spaces, precluding principled comparison and reliable deployment. We present the first controlled comparison of five neural-network architectures for gravitational-wave denoising, trained identically across the full astrophysically-motivated spinning binary-black-hole parameter space. A unifying principle emerges: matching network structure to the spectral anatomy of a coalescence – inspiral, merger, ringdown – outperforms brute-force model scaling. Our Multi-Scale Frequency-Aware architecture embodies this via dedicated parallel branches per frequency regime, achieving the best fidelity while using fewer parameters than larger models. It generalizes from simulated training to real LIGO-Virgo-KAGRA data without retraining, recovering merger morphology across confirmed events spanning three observing runs and both detectors, despite training on a single detector's simulated noise. We construct population-level uncertainty bands from denoising residuals, validate their calibration, and stress-test the framework on extended mass ratios and a
spin population resembling hierarchical-merger remnants. Applied to real noise with no known signal, the network suppresses its output almost everywhere, with rare exceptions traced to noise transients rather than a general weakness – indicating the statistic discriminates signal from noise and motivating a future detection study. Released weights give a deployable, reproducible
benchmark for future extensions.
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Cosmology and Nongalactic Astrophysics · Cross-listed from gr-qc
Black Holes, Gravitational Waves and Space-Time Singularities Lemaitre Conference 2024
Massimo Bianchi, Sergio Luigi Cacciatori, Matteo Galaverni et al. (+2 more)
This editorial introduces the topical collection arising from the Lemaitre Conference 2024 - the second in a series of meetings dedicated to the scientific legacy of Georges Lemaitre - held at the Vatican Observatory in Castel Gandolfo, 17-20 June 2024, fifty-seven years after Lemaitre's death and on the eve of the centenary of his foundational 1927 paper on the expanding universe. The nineteen contributions collected here address the most pressing open problems at the interface of cosmology, gravitation, and
quantum theory: the Hubble tension and the future of ${\Lambda}$CDM in light of recent DESI data; inflationary cosmology and dark-energy model-building in string theory and supergravity, together with the Swampland constraints that bound them; the observer-dependence of the
quantum-cosmological wave function; the removal, or consistent crossing, of spacetime singularities - from the canonical quantization of Lemaitre's own 1933 dust model to string-theoretic pre-Big-Bang bounces and many-body constructions of singularity-free black-hole cores; primordial black holes and their gravitational-wave signatures; the search for a background-independent formulation of
quantum gravity and a first-principles account of horizon thermodynamics; and the foundational status of the
quantum-to-classical transition in gravitational contexts. A proposal for lunar-based cosmological observations, and a historical reconstruction of the genesis of Lemaitre's primeval-atom hypothesis, complete the collection. A recurring unifying thread was the legacy of Lemaitre himself - who first distinguished coordinate from physical singularities and coined the term "horizon" - whose pioneering
vision continues to guide research at the frontier of cosmology and fundamental physics.
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All authors Massimo Bianchi, Sergio Luigi Cacciatori, Matteo Galaverni, Gabriele Gionti, Fabio Scardigli
Solar and Stellar Astrophysics
Tidally perturbed pulsations in OO Dra
Niveditha Parthasarathy, Mikhail Kovalev and Randa Asa'd
We perform a pulsation analysis of OO Dra using Light Curve data from TESS and present the first identification of six dipole modes as doublets from the primary
star in OO Dra. The phases and amplitudes of these pulsation modes were analytically reconstructed. Among the six identified doublets, four are pulsating in $Y_{10x}$ mode with pulsation axis along the tidal axis, and two in $Y_{10y}$ with a pulsation axis orthogonal to tidal axis and the angular momentum axis. Our findings suggest that the primary
star in a non-synchronized, post mass-transfer OO Dra could be a tidally tilted $\delta$ Scuti pulsator.
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Solar and Stellar Astrophysics
Investigating Potential Relationships Between Mass Transfer Indicators and $\delta$ Scuti Pulsations in oEA Systems
E. Çelik and F. Kahraman Aliçavuş
We explored potential associations between ongoing mass transfer and the pulsation properties of $\delta$ Scuti primaries in a sample of 17 oscillating eclipsing Algol systems. For this purpose, we combined binary modelling, updated O-C analyses, and frequency characterization based on TESS photometry. To ensure homogeneity, the $T_{\rm eff}$ of the components were derived using a consistent SED fitting approach. From the binary solutions and O-C diagrams, we determined the mass transfer indicators (Q, dP/dt, and dM/dt) and examined their relations with the dominant pulsation period and amplitude. For the full sample, the results indicate weak to moderate positive trends, with the strongest relation found between logdP/dt and logPpuls, while the relations involving dM/dt and pulsation amplitudes are weaker and statistically insignificant. After excluding the two prominent outliers, R CMa and BW Del, the correlations between logPpuls and the mass transfer indicators become statistically more significant, including relations with dP/dt, Q, and dM/dt under both conservative and non-conservative assumptions. These relationships may reflect the indirect effects of mass transfer on the structure of the accreting primary and on the orbital configuration, potentially reducing tidal constraints and allowing shifts toward longer pulsation periods. However, the large dispersion and limited sample size indicate that these relationships remain poorly constrained. Our results suggest that pulsation properties are primarily governed by intrinsic stellar parameters and the well established Porb-Ppuls relation, while ongoing mass transfer may contribute as a secondary factor. Although the present sample does not allow firm conclusions regarding the role of mass transfer, this study provides a homogeneous observational framework for future investigations based on larger samples and improved constraints.
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Solar and Stellar Astrophysics
The Association of Solar Radio Bursts with Eruptive and Confined Flares
Stephen M. White, Maria D. Kazachenko and Edward W. Cliver
We classify the metric
radio emission associated with eruptive (CME-associated) and confined
flares using the sample of events between 2010 and 2016 identified by Kazachenko (2023). We find striking differences in the occurrence of
radio bursts between the two classes of
flare: for soft X-ray
flare sizes above M1.4, confined
flares largely lack Type II (1% association rate) and Type IV (6%) emission. Approximately 15% of the sample of $\geq$M1.4 confined
flares are associated with impulsive-phase Type III bursts. On the other hand, eruptive
flares are associated with Type II, Type III (both impulsive and late phase), and Type IV bursts 45-60% of the time. The different types of
radio burst are associated with different drivers (IIIs with electron beams, IIs with shocks, IVs with post-
flare loops), so it is striking that the connection of all three burst types to eruptive
flares is so pronounced. These results can be interpreted in terms of the reconnection
topology of the principle candidate
flare types, viz., reconnection between closed field lines for confined
flares and X-point reconnection in a CSHKP model for eruptive
flares, with interchange reconnection for jet-type
flares and Type III bursts.
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Astrophysics of Galaxies
Origins of complex organic molecules in L1551 IRS 5: Interplay of thermal heating and accretion shocks
Ji-hyun Kang, Jeong-Eun Lee, Seokho Lee et al. (+1 more)
Complex organic molecules (COMs) are typically observed in the warm inner envelopes of Class 0 protostars. In more evolved Class I sources, COM emission is confined to the compact inner disk and obscured by high dust opacity, but the FU Orionis-type binary L1551 IRS 5 offers a valuable opportunity to probe disk chemistry, as its outburst luminosity thermally sublimates ices out to large radii. We sought to spatially resolve the origins of COMs in this system to distinguish between central radiative heating and shock-induced chemistry driven by heterogeneous
accretion pathways. We analyzed high-angular-resolution ALMA archival data, focusing on COMs (e.g., CH3OH, CH3OCHO) and the shock tracer SO, and compared their spatial morphologies and kinematics to diagnose the excitation conditions associated with different
accretion flows. We find that the COM emission in L1551 IRS 5 arises from both radiative heating and localized
accretion shocks. In the northern source, the widespread low-excitation COM emission is primarily consistent with thermal heating by the recent outburst. This source also exhibits dual-mode
accretion with distinct chemical signatures, with COMs along the spiral arm tracing steady equatorial circumbinary disk-to-circumstellar disk
accretion and high-excitation COMs with bright SO along the eastern disk surface tracing a vertical envelope-to-disk streamer impact. In the southern source, methanol is confined to the southeastern streamer impact site, whereas SO forms a ring-like structure at the tidal truncation radius. We attribute this difference to differential chemical survival timescales. L1551 IRS 5 thus serves as an ideal laboratory to investigate how shock chemistry and binary-regulated
accretion shape the chemical structure of protostellar disks.
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All authors Ji-hyun Kang, Jeong-Eun Lee, Seokho Lee, Shigehisa Takakuwa
Cosmology and Nongalactic Astrophysics
Interacting fluid cosmologies from the metric-affine framework
Fotios K. Anagnostopoulos and Damianos Iosifidis
Metric-affine
gravity provides a natural
geometric framework in which spacetime
curvature, torsion, and non-metricity are treated as independent degrees of freedom, leading to novel cosmological dynamics beyond General Relativity. A generic consequence of such theories is the emergence of effective interactions among the cosmological fluids, even in the absence of explicit phenomenological couplings. Interestingly, the above happens while the Standard Model of Particle physics remains unmodified. In this work, we investigate interacting cosmological models that arise from metric-affine
gravity and analyze their implications for the background
evolution of the Universe. We derive the modified continuity equations governing the matter, radiation, and dark-energy components, highlighting the
geometric origin of energy exchange in the dark sector. We discuss how these interactions modify the expansion history and can effectively mimic evolving dark-energy behavior. The resulting cosmological scenarios are confronted with the most recent observational data from Type Ia
Supernovae (Pantheon+),
Cosmic Chronometers, and Baryon Acoustic Oscillations (DESI DR2). Moreover, using model selection criteria, e.g., Akaike Information Criterion,
Bayesian Information Criterion and the
Bayesian Evidence, we compare the aforementioned models against the standard $\Lambda$CDM model. We find that the proposed framework performs slightly better than $\Lambda CDM$, in the light of the data sets considered here. Our analysis demonstrates that metric-affine-induced interactions constitute a viable and theoretically motivated alternative for the description of the Universe.
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Cosmology and Nongalactic Astrophysics
Non-linear Pairwise Velocities as a Cosmological Probe
Mariana Jaber, Antonela Taverna, Rasmus Strid et al. (+1 more)
Peculiar velocities trace gravitational dynamics directly, complementing density-based clustering as wide-field spectroscopic surveys (DESI, Euclid, PFS) and kinetic Sunyaev-Zel'dovich (kSZ) measurements enter the precision era. Observational analyses of pairwise velocities and the pairwise kSZ signal remain largely restricted to linear and quasi-linear scales ($\gtrsim20-30$ $h^{-1}Mpc$), despite substantial cosmological information available at smaller separations. We present a simulation-calibrated likelihood for $v_{12}(r,a)$, built on the exact pair conservation equation and PyCAMB HMcode-2020 non-linear clustering, and validate it against the QUIJOTE and TNG300-3 suites across resolution, particle sampling, box size, and
redshift. Using QUIJOTE, we show that extending the fit to non-linear scales tightens the $1\sigma$ uncertainty on $\Omega_\mathrm{m}$ and $\sigma_8$ by $74\%$ and $81\%$ at $z=0.5$ ($r_{\rm min}=4$ $h^{-1}Mpc$), and by $70\%$ and $74\%$ at $z=0$ ($r_{\rm min}=8$ $h^{-1}Mpc$), relative to the linear-regime baseline ($r_{\rm min}=50$ $h^{-1}Mpc$) (all at fixed $r_{max}=140$ $h^{-1}Mpc$); $\sigma(f\sigma_8)$ tightens by up to $86\%$, and the joint $\Omega_\mathrm{m}$-$f\sigma_8$ Figure-of-Merit improves by up to $9.1\times$ relative to the same baseline. These constraints are conditional on $h$ fixed at its QUIJOTE fiducial value, due to a near-degenerate response with $\sigma_8$; jointly sampling $h$ shifts and widens them substantially. This framework provides a validated route to exploiting that information in upcoming direct peculiar-velocity,
redshift-space, and kSZ analyses.
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All authors Mariana Jaber, Antonela Taverna, Rasmus Strid, Wojciech A. Hellwing
Solar and Stellar Astrophysics
SN 2024afyu interpreted as a Pair Instability Supernova
P. J. Pessi, S. Barmentloo, Ł. Wyrzykowski et al. (+63 more)
Pair-instability
supernovae (PISNe) are the predicted explosions of very massive
stars triggered by electron-positron pair production. Numerous transients have been proposed as PISN candidates, yet none has provided unambiguous confirmation of this explosion mechanism. The predicted strengths of nebular emission lines offer a powerful means of testing the PISN scenario. We investigate the nature of SN 2024afyu, a nearby (z = 0.0085), long-lived (trise = 85 +- 11.7 days) SN with peculiar spectral
evolution, with the aim of identifying its powering mechanism. We analyse multi-band photometry and optical and near-infrared spectroscopy from shortly after explosion to the nebular phase (around 500 days past peak). Besides early appearance of [Ca II] features, we identify a number of sulfur and silicon emission lines, for which we estimate electron temperatures and elemental masses. SN 2024afyu has an inferred 56Ni mass of around 0.4 to 1.0 solar masses and an inferred sulfur mass of the order of 3 solar masses, substantially larger than expected for conventional core-collapse explosions. SN 2024afyu is photometrically similar (although fainter, M_Peak(r) = -18.9 +- 0.04 mag) but spectroscopically distinct to other proposed PISNe. Yet, existing PISN models broadly reproduce several key characteristics, including the overall spectral appearance and broad photometric
evolution. SN 2024afyu is a strong PISN candidate, since alternative scenarios would struggle to explain the combination of broad light curve, large intermediate-mass-element abundance, and general spectroscopic
evolution. The discrepancies between the observations and currently available theoretical models highlight the need for new PISN calculations spanning a wider range of progenitor masses,
metallicities, mixing prescriptions, and circumstellar environments.
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All authors P. J. Pessi, S. Barmentloo, Ł. Wyrzykowski, S. Schulze, J. Sollerman, A. Gangopadhyay, P. J. Mikołajczyk, S. Rose, K. Kotysz, C. Fremling, A. Jerkstrand, R. Lunnan, L. Yan, C. Fransson, J. L. Wise, M. Dubey, K. Misra, A. P. Cotter, D. Athanasopoulos, A. Bochenek, M. Bronikowski, U. Burgaz, W. Burzynski, J. M. Carrasco, E. Concepcion, C. Galdies, A. F. Gillan, A. Gkini, E. Gkiokas, E. Głowacki, F-J. Hambsch, J. Japelj, N. Karaman, P. King, S. Kurowski, C. Liu, M. Maskoliunas, Z. McGrath, M. Mihelčič, M. Nikolajuk, W. Ogloza, E. Pakštienė, U. Pylypenko, A. Pucek, N. Rehemtulla, R. M. Rich, A. O. Simon, A. Singh, C. Skoglund, E. Stonkute, Y. Stsefanenka, P. Szober, K. Tsalapatas, B. F. A. van Baal, C. Ventura, K. Vrontaki, A. Wozniak, J. Zdanavicius, S. Zola, E. C. Bellm, J. Castaneda Jaimes, M. J. Graham, G. Helou, F. J. Masci, J. N. Purdum, R. Riddle
High Energy Astrophysical Phenomena · Cross-listed from gr-qc
Nonradial oscillations of realistic anisotropic neutron stars: Polar modes
L. M. Becerra, José F. Rodríguez-Ruiz, E.A. Becerra-Vergara et al. (+1 more)
In this work, we study the polar perturbations of static, spherically symmetric
neutron stars with anisotropic pressure in full general relativity, including linear-order perturbations of both the metric and the fluid. We calculate the $f$-mode frequencies and the corresponding damping times using a consistent treatment of the perturbation of the radial vector $k^\alpha$. In particular, its Lagrangian perturbation $\Delta k^\alpha$ is determined by the metric perturbations and the fluid Lagrangian displacement and is constrained to the $(\tilde{u},\tilde{k})$ plane, where $\tilde{u}^\alpha$ is the normalized fluid four-velocity. This constraint introduces an additional dynamical degree of freedom into the perturbation equations. Considering three equations of state and the Horvat and Bowers-Liang prescriptions for pressure anisotropy, we find that the $f$-mode frequency increases with stellar mass, ranging from $1$ to $3$~kHz, while the damping time decreases, ranging from $0.5$ to $1.25$~s. Increasing anisotropy, in the sense of tangential pressure exceeding radial pressure, generally lowers the oscillation frequency, while its effect on the damping time depends on the anisotropy prescription: the damping time decreases with increasing anisotropy for the Horvat model but increases with increasing anisotropy for the Bowers-Liang model. We further find quasi-universal relations between the real and imaginary parts of the $f$-mode frequency, $M\omega_R$ and $M\omega_I$, and the stellar compactness $\mathcal{C}=M/R$, which are largely insensitive to the equation of state.
Polynomial fits to these relations achieve an accuracy better than $10\%$, providing a simple phenomenological framework for constraining
neutron-
star pressure anisotropy through future asteroseismology observations.
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All authors L. M. Becerra, José F. Rodríguez-Ruiz, E.A. Becerra-Vergara, F. D. Lora-Clavijo
Solar and Stellar Astrophysics
Precise physical and kinematical parameters of massive eclipsing binaries in the Small Magellanic Cloud
M. Kaya, Ö. Çak{\i}rl{\i}, B. Hoyman et al. (+3 more)
The formation of massive
stars serves an important field of study, requiring research into whether these
stars need to form together within clusters of low-mass
stars or if they are able to form independently. Currently, there has been an increase in the number of massive
stars found far from clusters in the Milky Way (MW) and Small Magellanic Cloud (SMC). The existence of isolation and composition in binary systems is an uncommon phenomenon among massive
stars, and their rare occurrence presents valuable insights that are regarded as evidence in this field. This research looks for ways to increase the catalogue of identified massive
stars in eclipsing binaries, particularly those that show significant indications of isolation. For the definition of the first step, we are analysing the eight double-lined spectroscopic binaries in the SMC, as detailed in the OGLE variable
star catalogues, with the goal of identifying their astrophysical properties. Later, we examine the expected locations and characteristics of binary
stars thought to be part of a cluster, using absolute parameters and a cross-validation approach to determine the connection between kinematic analysis and these parameters. If the kinematic connection with the cluster and the physical parameters match precisely with the cluster's isochrone, such
stars could act as reliable standard candles for determining the cluster's distance and age.
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All authors M. Kaya, Ö. Çak{\i}rl{\i}, B. Hoyman, O. Özdarcan, T. Yontan, R. Canbay
Astrophysics of Galaxies
The Role of Dark Matter in Driving Disk Perturbations: Application to LMC-SMC Like Galaxy Interactions
Himansh Rathore, Hayden R. Foote, Gurtina Besla et al. (+6 more)
Dark-matter (DM) models predict that satellite
galaxies distort their host's DM
halo. As such, both the satellite and the distorted
halo can perturb the host's stellar disk. The LMC-SMC system is a nearby $\sim1:10$~mass-ratio binary with a well-constrained orbit and well-characterized LMC disk perturbations. Hence, the system offers unique opportunities to test DM theory, provided the impact of
halo torques on the LMC's disk can be characterized along with the SMC's torques. We use
halo Basis Function Expansions (BFEs) of an N-body simulation of an isolated LMC-SMC-like interaction to quantify the time-dependent torques exerted on the LMC's disk by the SMC and the LMC's DM
halo. We find that the
halo torques arise from the quadrupole
halo distortion, and the inner (R$<6$ kpc) LMC disk warps are the most promising probe of this quadrupole. For the first time, we construct a BFE to quantify the LMC's disk perturbations resulting from the SMC and
halo torques. We find that the LMC's disk is significantly perturbed prior to the Clouds' Milky Way infall, possessing warps with a mean vertical extent of $\sim1$ kpc. Finally, we apply multi-channel singular spectral analysis (mSSA) to the time-series of the disk BFE coefficients,
halo quadrupole, and the LMC-SMC orbit. mSSA successfully separates the temporal
evolution of the LMC warps into components correlated with the
halo versus the SMC. Our framework identifies correlated
evolution between the LMC's
halo distortions and the LMC's disk perturbations, enabling the Clouds to be a precision laboratory for DM physics.
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All authors Himansh Rathore, Hayden R. Foote, Gurtina Besla, Silvio Varela-Lavin, Nicolas Garavito-Camargo, Martin D. Weinberg, Facundo A. Gomez, Kathryne J. Daniel, Chervin F.P. Laporte
Astrophysics of Galaxies
A pilot submillimeter search for IceCube neutrino counterparts: JCMT follow-up and dusty-galaxy catalog associations
Yuji Urata and Kuiyun Huang
The submillimeter band offers a complementary route to identifying electromagnetic counterparts of high-energy
neutrinos, tracing relativistic transients and persistent dust-obscured
galaxies. We present a pilot search combining JCMT/SCUBA-2 follow-up of IceCube events with catalog searches for bright high-
redshift dusty systems. Among nine rapidly observed IceCube fields, sources of particular interest were found in three: JCMT0402-0424 ("Shadow Blaster") in IC 210922A, a transient-like source following IC 220115A, and two known blazars in IC 240105A. ALMA resolved the Shadow Blaster into a strongly lensed dusty
star-forming
galaxy at z=2.988 with a compact gas-rich starburst core. Motivated by this result, we cross-matched IceCube localizations with the Herschel Bright Sources (HerBS) and Planck High-
Redshift Source Candidate (PHZ) catalogs. Among 51 historical IceCube events with A_bbox,90 <= pi deg^2, four fields contain at least one HerBS source, compared with 0.723 expected from right-ascension scrambling (fixed-cut p=4.18e-3). Scanning the localization-area threshold gives p_global,A=0.0135. Applying the same IceCube selection to PHZ gives four associated fields versus 3.544 expected (p=0.478). Because the focused HerBS selection followed a broader exploratory analysis with trials-corrected p_global=0.130, the focused result is suggestive rather than definitive. The four well-localized HerBS fields contain six high-
redshift DSFGs with apparent L_IR~10^13 L_sun. ALMA imaging and published spectroscopy reveal compact or multiple-component morphologies, extreme molecular-gas kinematics, and possible obscured nuclear activity. These results support a hierarchical strategy: identify luminous submillimeter candidates through wide-field imaging and catalogs, then characterize them at high angular resolution to test for compact gas-rich calorimetric conditions and obscured AGN activity.
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Solar and Stellar Astrophysics
An Approximate Bayesian Deep Learning Approach for Uncertainty-aware Differential Emission Measure Estimates in the Solar Corona from the SDO
N. Balodhi and R. J. Morton
Accurately estimating the temperature distribution of solar coronal
plasma, known as the Differential Emission Measure (DEM), is vital for understanding the thermodynamics of the corona and associated heating. However, recovering the DEM from multispectral observations like those from the Atmospheric Imaging Assembly (AIA) on board NASA's Solar Dynamics Observatory (SDO) is a mathematically ill-posed, underdetermined problem, and traditional regularization-based inversion methods are computationally intensive and provide limited uncertainty quantification. We present a deep learning framework for DEM reconstruction that incorporates Monte Carlo Dropout to perform approximate
Bayesian inference, yielding per-pixel empirical distributions over the DEM that characterize epistemic or systematic model uncertainty in the learned inversion. The network is trained with a dual-head architecture supervising both AIA image reconstruction and DEM fidelity, with non-negativity enforced by construction. The network is trained directly on real SDO/AIA observations along with the associated DEM solutions from regularized inversion. We validate performance against both synthetic thermal distributions and real coronal data, demonstrating accurate recovery of thermal structure across a range of
plasma conditions, while maintaining significant computational efficiency over traditional inversion techniques. This method ensures physically legitimate, non-negative solutions and provides per-pixel uncertainties, making it a reliable, high-speed, and uncertainty-aware tool for large-scale solar data analysis.
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Astrophysics of Galaxies
LEGGOS: Direct abundances of N, O, Ne, S, and Ar in five lensed galaxies at Cosmic Noon
Brian Welch, Gourav Khullar, Taylor A. Hutchison et al. (+14 more)
We present direct $T_e$ chemical abundances in five strongly lensed
galaxies at
Cosmic Noon ($2.481 \leq z \leq 3.625$) using JWST/NIRSpec data from the LEGGOS survey. We measure gas-phase abundances of N, O, S, and Ar in all five
galaxies, and Ne in two
galaxies. Three
galaxies have electron temperature constraints from multiple different ionization zones, and we find that these are broadly consistent with temperature scaling relations observed in both local and high-$z$
galaxies. We find a range of oxygen abundances $8.04 \leq 12+\log(\text{O/H}) \leq 8.79$ (22 – 126% $Z_{\odot}$). The ratios of N/O and Ne/O are consistent with trends observed in local
galaxies. We do not observe any evidence for significant N enhancement in our sample, though the youngest
galaxy in our sample (SGAS-J1050) has a mildly elevated $\log(\text{N/O}) = 1.20 \pm 0.08$, which we suggest may be driven by a population of young massive
stars. The ratios of S/O and Ar/O are generally sub-solar, similar to trends observed in other high-$z$
galaxies. We find that the S/O and Ar/O abundances are sub-solar, consistent with enrichment from core-collapse
supernovae (CCSNe). Modeling of the
star formation histories of the LEGGOS
galaxies supports CCSNe enrichment, as each
galaxy shows a recent period of
star formation lasting $\lesssim 100$ Myr, indicating that type Ia
supernovae would not yet have had enough time to contribute significantly to the gas-phase abundances of these
galaxies.
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All authors Brian Welch, Gourav Khullar, Taylor A. Hutchison, Keren Sharon, Pedram Abedi, Matthew B. Bayliss, Michael Florian, Dylan Berry, Jacqueline Antwi-Danso, Nikko J. Cleri, Håkon Dahle, Aleena Ebey Panzer, Michael D. Gladders, Rion Oh, Cole Panzer, Jane R. Rigby, T. Emil Rivera-Thorsen
Astrophysics of Galaxies
LEGGOS: A Shocking Lack of Evidence for Shocks at sub-kiloparsec Scales at 2 < z < 4
Nikko J. Cleri, Taylor A. Hutchison, Brian Welch et al. (+11 more)
Here we present the first systematic search for shocks in six gravitationally lensed
galaxies at 2.37 < z < 3.625 with JWST/NIRSpec integral field spectroscopy from the
LEnsing and
Galaxy Growth: Observing Substructures (LEGGOS) survey. We employ diagnostics that utilize the fluxes and kinematics of shock-sensitive rest-frame optical emission lines He̱ta}, [O iii] {\lambda}5008, [O i] {\lambda}6302, H{\alpha}, [N ii] {\lambda}6585, and [S ii] {\lambda}{\lambda}6718, 6733. We find that, on pixel, clump, and
galaxy-integrated scales, the LEGGOS spectra show minimal if any evidence for shocks. The image plane pixels are < 8% within the shock regions of the rest-frame optical line ratio diagnostics for any individual
galaxy, and the shock-identified pixels do not show a coherent spatial structure. We also leverage MAPPINGS V shock models to infer shock velocities from the observed emission lines, and find that the distributions of inferred shock velocities are inconsistent with those expected for shock-dominated gas. Altogether, none of these methods provide significant evidence for shocks in the six LEGGOS sources. We conclude by discussing the implications of the lack of evidence for shocks in the broader context of
galaxy evolution at
cosmic noon and earlier epochs.
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All authors Nikko J. Cleri, Taylor A. Hutchison, Brian Welch, Gourav Khullar, Matthew B. Bayliss, Håkon Dahle, Michael Florian, Michael D. Gladders, Connor Luettgenau, Rion Oh, Jane R. Rigby, T. Emil Rivera-Thorsen, Julissa Sarmiento, Keren Sharon
High Energy Astrophysical Phenomena · Cross-listed from nucl-th
An EOS-Driven Extension of NSCool for Compact Star Cooling with Hadronic and Quark Degrees of Freedom
Federico Nola and Fernando Arias-Aragón
We present an EOS-driven extension of the NSCool thermal
evolution code that enables complete tabulated equations of state to be treated within a single composition-based input structure. The generalized NEW interface includes additional baryonic fractions, a bosonic composition variable, the hadronic volume fraction, and
quark fractions, allowing nucleonic, hyperonic, resonant-baryonic and hybrid
hadron-
quark configurations to be handled within the same workflow. The
neutrino sector is extended accordingly, including updated nucleonic modified Urca and bremsstrahlung rates, additional baryonic direct Urca channels, hyperonic processes, baryonic pair breaking and formation and
quark direct Urca, modified Urca, bremsstrahlung and PBF contributions. In mixed phases, emissivities and the corresponding core heat capacity contributions are evaluated from phase-local quantities and combined using the hadronic volume fraction. The implementation is validated against the original NSCool calculation for a controlled nucleonic
benchmark and demonstrated with representative hadronic and
quark-containing EOSs. These calculations are intended as software validation tests of the generalized workflow rather than as observational fits or statistical EOS inference.
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Cosmology and Nongalactic Astrophysics
Observation-driven simulations of strong lensing galaxy clusters
L. Leuzzi, M. Meneghetti, A. Adam et al. (+9 more)
Galaxy clusters are the most powerful strong lenses: they greatly magnify the flux of distant and faint sources. Strong
lensing also allows for the reconstruction of their mass distribution with-1% level accuracy and enables investigating cosmological parameters. The number of known systems of this type is bound to increase in the next years thanks to wide imaging surveys. Using simulations in this context is crucial to validate the analysis methods before they are applied to real data, and to train machine learning
algorithms that can handle large volumes of images. In this work, we present a simulated set of one hundred images of
galaxy clusters that we have produced with a novel code for simulating cluster-scale strong lenses. One of the main novelties of our approach, distinguishing it from other existing codes, is the use of empirical relations, derived from state-of-the-art observations, for modelling the characteristics, such as morphology, color, and spatial distribution of the cluster member population. This allows us to reliably reproduce the complexity of real observations. The simulations are partly carried out with the latest version of SkyLens, a code that creates mock observations of strong
lensing events in different systems and observational setups. The main improvements we introduce are the use of the message passage interface (MPI) paradigm, a standard for parallel programming that leverages the use of several processors to perform some given task, and the implementation of score-based
diffusion models to augment the images of the background sources. Together, they lead to more efficient and realistic image simulations. We also present the validation of the code and simulations by comparing the properties of the mock clusters to those of real ones. [Abridged]
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All authors L. Leuzzi, M. Meneghetti, A. Adam, L. Moscardini, C. Giocoli, P. Bergamini, Y. Hezaveh, M. Maturi, A. Mercurio, A. Moretti, Andrés A. Plazas Malagón, P. Rosati
Solar and Stellar Astrophysics
Global 3D simulations of convection and dynamos in Red Giants
Carolina Ortiz-Rodríguez, Petri Käpylä, Juan Pablo Hidalgo et al. (+2 more)
Understanding the internal dynamics of red giants is essential for studying angular momentum transport and
magnetic field generation during stellar
evolution. We present three-dimensional magnetohydrodynamic simulations of a $1M_{\odot}$ red giant at the bottom of the red giant branch using a
star-in-a-box setup with the Pencil Code, together with ongoing efforts to refine the numerical model. By varying the rotation rate, we explore different Rossby numbers and identify systematic changes in the convective dynamics and large-scale flows. As the rotation increases, convective motions become more anisotropic, showing clear signatures of rotational constraint and a shift in the dominant convective scales. These changes are accompanied by variations in the differential rotation profile, reflecting the redistribution of angular momentum within the convective envelope. The impact of rotation is also evident in the growth rate and saturation level of the
magnetic field, indicating a strong dependence of dynamo efficiency on the underlying flow structure. Together, these results highlight the interplay between convection, rotation, and large-scale flows in shaping
magnetic activity in red giant
stars.
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All authors Carolina Ortiz-Rodríguez, Petri Käpylä, Juan Pablo Hidalgo, Dominik Schleicher, Robi Banerjee
High Energy Astrophysical Phenomena
Abundance Stratification in Type Ia Supernovae – VIII. The 03fg-like SN\,2012dn: a double-degenerate merger interpretation
Charles J. Aouad, Paolo A. Mazzali, Stephan Hachinger et al. (+1 more)
A detailed study using abundance
tomography of SN 2012dn, a peculiar Type Ia
supernova, is presented. Despite exhibiting a normal peak luminosity, it retains early-phase super-Chandrasekhar (03fg-like) characteristics: weak Fe III, narrow intermediate-mass element (IME), persistent carbon, and the absence of high-velocity Ca II features. Its nebular spectrum is unusually faint due to grey dimming beginning $\sim$60 days after maximum and shows [O I] emission, rare in SNe Ia. While a Chandrasekhar-mass density profile reproduces the photospheric phase, it fails at late times. The [O I] emission requires additional low-velocity mass, implying a total ejecta mass of $1.66$ $M_\odot$, including $0.33$ $M_\odot$ of oxygen (with $0.1$ $M_\odot$ in the core). The $^{56}$Ni mass is estimated to be $0.45$–$0.49$ $M_\odot$, a range set by uncertainties in the grey-extinction correction applied at the nebular phase, and is insufficient on its own to account for the peak luminosity. Stable iron is confined to intermediate layers and absent from both the core and outer ejecta, the latter indicating sub-solar progenitor
metallicity. Silicon and sulfur span the full ejecta, while carbon extends down to $v \sim 6000$ ${\rm km,s^{-1}}$. These properties favour a double-degenerate CO–CO white dwarf merger scenario. The remaining luminosity deficit may be explained by additional energy input from a weak interaction with a low-mass, carbon-rich circumstellar shell.
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All authors Charles J. Aouad, Paolo A. Mazzali, Stephan Hachinger, Chris Ashall
Astrophysics of Galaxies
A New Sample of $\sim$ 100 Intermediate-mass Black Holes Reaching $z \approx 1$
Wen-Juan Liu, Luis C. Ho, Su Yao et al. (+2 more)
We present a systematic search for intermediate-mass black hole (IMBH) active galactic
nuclei (AGNs) at $0.5 < z \lesssim 1$ using DESI DR1 spectroscopy.We identify 98 broad-line IMBH AGNs with black hole masses $M_\mathrm{BH}<10^6$ $M_{\odot}$ through quantitative spectral decomposition and broad-H$\beta$ selection. This sample spans $M_\mathrm{BH}=10^{5.5}-10^{6.0}$ $M_{\odot}$ and Eddington ratios from 1.2 to 9.0 extending systematic IMBH AGN searches to intermediate
redshift. Compared with a consistently selected $z<0.6$ IMBH sample, the $0.5<z<1$ sources reach higher broad-H$\beta$ luminosities and substantially higher Eddington ratios, indicating more extreme
accretion states at earlier
cosmic times. They also show broader [O III] profiles and stronger blueshifted wing components, with these kinematic differences persisting after matching in black hole mass and Eddington ratio. These results reveal two distinct signatures of
evolution among IMBH AGNs at $z<1$: ability of IMBHs to reach increasingly extreme
accretion states toward higher
redshift, and systematic changes in their ionized-gas kinematics. The former demonstrates that rapid, including super-Eddington, growth of IMBHs can persist to relatively late
cosmic times, while the latter may indicate
evolution in the ionized-gas environment and associated outflow activity of actively growing IMBHs. Together, these findings provide new constraints on the evolutionary pathways of IMBHs at $z<1$, and show that seed-mass black holes can continue to undergo rapid growth well after the
cosmic dawn.
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All authors Wen-Juan Liu, Luis C. Ho, Su Yao, Xiao-Bo Dong, Yaqi Zhao
Cosmology and Nongalactic Astrophysics
The SRG/eROSITA All-Sky Survey: Early dark energy and Hubble constant from the cluster mass function
J. Strunk, E. Artis, E. Bulbul et al. (+23 more)
The
evolution of the mass function of massive
galaxy clusters is a well-established probe of cosmology. Using the eROSITA X-ray instrument on board the Spectrum Roentgen Gamma (SRG) mission, the western Galactic hemisphere of eROSITA's first All-Sky Survey (eRASS1) delivers a uniformly selected and securely confirmed sample of 5259
galaxy clusters spanning $0.1 < z < 0.8$. When combined with overlapping weak
lensing data from DES Year 3, KiDS, and HSC for mass calibration, this
dataset enables precise tests of the standard $\Lambda$CDM framework and beyond. In this work, we use the $0.1 < z < 0.45$ subsample of the eRASS1 cluster catalog to place constraints on an
axion-like Early Dark Energy (EDE) scenario. Such models have been proposed as a possible mechanism to alleviate the tension between early- and late-Universe measurements of the Hubble constant. In this framework, a scalar field temporarily enhances the
cosmic expansion rate around the epoch of recombination before rapidly diluting at later times, leaving distinct imprints on structure growth. We leverage these signatures to present the first constraints on EDE derived from
galaxy cluster number counts. Using eRASS1 number counts alone, we obtain an upper limit on the maximum EDE fraction of $f_{\rm EDE} < 0.3$, consistent with primary CMB analyses. Combining our cluster analysis with primary CMB measurements, baryon acoustic oscillations, and CMB
lensing, while notably excluding distance-ladder calibration data, yields results consistent with a nonzero EDE contribution and $H_0$ values compatible with late-Universe measurements. The most significant detection, at $\sim 3.2\sigma$, arises from the joint analysis of the eRASS1 sample with the full set of external
datasets, yielding $f_{\rm EDE} = 0.10^{+0.04}_{-0.03}$ and $H_0 = 71.4 \pm 1.4$ km/s/Mpc. [ABRIDGED]
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All authors J. Strunk, E. Artis, E. Bulbul, S. Grandis, N. Clerc, V. Ghirardini, M. Kluge, A. Liu, F. Balzer, J. Comparat, I. Chiu, Z. Ding, N. Malavasi, A. Merloni, T. Mistele, H. Miyatake, S. Miyazaki, K. Nandra, F. Kleinebreil, N. Okabe, M. E. Ramos-Ceja, J. S. Sanders, T. Schrabback, R. Seppi, S. Zelmer, X. Zhang
Instrumentation and Methods for Astrophysics
Neural Posterior Estimation for Tomographic Weak Lensing Mass Mapping
Tim White, Shreyas Chandrashekaran, Camille Avestruz et al. (+2 more)
Weak gravitational
lensing shear and convergence trace the distribution of baryonic and dark matter across space, making them a powerful probe of
cosmic structure. Inferring shear and convergence from images is a challenging inverse problem. The prevailing approach to this task estimates shear from weighted averages of
galaxy ellipticities, calibrates these estimates to account for systematic biases, and transforms them to reconstruct convergence, a multistage procedure that requires substantial computational resources and meticulous handling of statistical uncertainties. As an alternative, we propose a probabilistic approach to field-level weak
lensing inference in which we train a deep neural network to directly map a multiband image to a variational distribution over the underlying tomographic shear and convergence fields. This neural posterior estimation (NPE) procedure implicitly marginalizes over nuisance variables in the cosmological forward model and does not require evaluating the likelihood function. It is also amortized, so it enables rapid posterior inference for astronomical surveys once the neural network is trained. When evaluated on synthetic images from the LSST-DESC DC2 Simulated Sky Survey, NPE produces well-calibrated variational distributions for shear and convergence that are consistent with the ground truth. We describe how maps sampled from these variational distributions could be used in a subsequent simulation-based inference procedure to approximate the posterior distribution over cosmological parameters.
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All authors Tim White, Shreyas Chandrashekaran, Camille Avestruz, Jeffrey Regier, the LSST Dark Energy Science Collaboration
Astrophysics of Galaxies
A Dusty Quenching-candidate AGN host at z=5.7: massive quiescent galaxies may quench already during the dust-obscured phase
Francesco D'Eugenio, Matilde Brazzini, Roberto Maiolino et al. (+12 more)
We present a spectro-photometric analysis of RUBIES-EGS-9809, a broad-line AGN host at z=5.7 with a Balmer break and a dominant point source. The source is dust reddened ($A_V>$3 mag), shows hot- and cold-dust emission, and is X-ray Compton thick, with X-ray-to-bolometric ratio consistent with luminous AGN. The large $A_V$ agrees with strong NaI absorption (EW=17$\pm 2 \AA$), possibly from a neutral-gas outflow (3 $\sigma$), while broad [O III] traces an ionized outflow, suggesting AGN feedback may be affecting the host. We estimate a stellar mass log(M*/M$_\odot$)=10.7$\pm$0.3, Lbol$\sim4\times10^{46}$ erg s$^{-1}$ , and black-hole mass log(M$_{BH}/M_\odot)\sim8.1$ (subject to large systematics). The resolved Balmer break (0.1 arcsec, 0.6 kpc) is consistent with a stellar origin, implying the
galaxy is already old in
stars while still heavily obscured. This shows that massive
galaxies can host evolved stellar populations during their compact, dust-obscured phase, consistent with formation in an earlier dusty starburst. SED modelling suggests a declining SFR, but low-resolution spectroscopy alone cannot constrain the recent SFR, so we treat the source as a strong quenching candidate rather than a secure post-starburst system. Because quenching follows the decline in SFR,
star-formation-driven outflows are disfavoured, leaving AGN feedback as a plausible driver. We speculate that such rapid feedback ($\sim$100 Myr timescale) may precipitate quenching while the post-quenching phase stays dust-enshrouded, concealing the UV-bright quenched phase that would otherwise be easily detected, if dust free. By the time dust clears, the UV-luminous
stars may have already dwindled, leaving a classic dust-free quiescent
galaxy. This 'dusty path' to quiescence may explain the lack of intermediate-age quenched progenitors (ages 50-100 Myr) linking dusty starbursts to massive quiescent systems at z=3-7.
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All authors Francesco D'Eugenio, Matilde Brazzini, Roberto Maiolino, Elena Bertola, Stefano Carniani, Xihan Ji, Ignas Juodžbalis, Yixiao Liu, Minjung Park, Eleonora Parlanti, Robert G. Pascalau, Gabriele Pezzulli, Jan Scholtz, Sandro Tacchella, Stefano Zibetti
Astrophysics of Galaxies
The MICADO first light imager for the ELT: Simulated Observations of Star Forming Clumps at Cosmic Noon
Matteo Simioni, Carmelo Arcidiacono, Andrea Grazian et al. (+18 more)
Galaxies at
redshift z$\sim$2-6 exhibit prominent
star-forming regions (clumps). Characterisation of these galactic structures requires both high sensitivity and spatial resolution of $\sim$100 pc or less. Currently, these spatial scales are achievable only with the aid of strong gravitational
lensing. However,
lensing introduces model-dependent uncertainties and limits the sample to
galaxies behind massive clusters. The upcoming 40m-class
telescopes, such as the ESO Extremely Large
Telescope (ELT), will enable routine studies of clumps in ubiquitous, non-lensed z$\ge$2
galaxies. We assess the capability of MICADO, the first-light imager and spectrograph of the ELT, to characterise clumps in non-lensed z=2
galaxies. Specifically, we focus on two representative observing scenarios, providing the basis for an early scientific exploitation of the instrument. We modelled clumps in an idealised z=2
star-forming
galaxy and produced mock MICADO observations in both broad- and narrow-band imaging. The latter leverages the strong emission lines typical of clumps to improve detection and characterisation. Reaching UV rest-frame magnitudes of clumps as faint as M$_{UV} \sim -15$ in optimal observing conditions, MICADO will be able to efficiently characterise clumps in non-lensed z=2
galaxies down to R$_{e} \sim 20$ pc. Moreover, the full MICADO $\sim$1 arcmin$^2$ field of view enables efficient surveys of multiple targets. This study demonstrates MICADO's potential to fill a crucial observational gap, shedding new light on clump formation and
evolution at
cosmic noon. Accurate PSF reconstruction will be crucial to fully harness this capability as it significantly impacts clump detection and characterisation, especially at the smallest sizes ($<$40 pc).
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All authors Matteo Simioni, Carmelo Arcidiacono, Andrea Grazian, Marco Gullieuszik, Elisa Portaluri, Alvio Renzini, Benedetta Vulcani, Anita Zanella, Francesca Annibali, Michele Cirasuolo, Richard Davies, Natascha Förster Schreiber, Johanna Hartke, Hanindyo Kuncarayakti, Matteo Messa, Stefan Raffetseder, Letizia Scaloni, Elena Valenti, Eros Vanzella, Joël Vernet, Roland Wagner
Earth and Planetary Astrophysics
Sea Ice as an Origin of Life Location for Hycean and Ocean Worlds
Edouard F. L. Barrier, Nikku Madhusudhan and Frances E. Rigby
Water worlds with potential deep oceans are at the forefront of currently observable exoplanetary habitability. The standard requirements for habitability are the presence of an energy source, a source of nutrients, and a solvent, all of which can be met in
exoplanets with deep
liquid water oceans. Such
planets may be numerous, ranging from hycean worlds and ocean worlds to terrestrial-size
planets with enhanced water content. However, abiogenesis requires additional conditions, namely a mechanism to accumulate nutrients to the high concentrations required for prebiotic chemistry, and an energy source to drive the chemistry. A deep ocean, and in some cases the high-pressure ice layers underneath, has traditionally been thought to prevent the required concentrations. Here we outline a location where nutrients could be concentrated in sufficiently high quantities to make abiogenesis possible – at the interface between the open ocean and the surface ice shelf. Using a 3D General Circulation Model, we explore cases corresponding to several candidate habitable
exoplanets which might have dayside sea ice. We discuss how the
planet's
climate influences the nature and behaviour of the sea ice. We investigate the ability of small-scale ice formation and melting processes to concentrate nutrients to prebiotically useful levels, and also explore the potential for meteoritic impactor fragments to provide a platform for prebiotic chemistry. We find that both of these mechanisms may plausibly provide concentrated chemical feedstock for prebiotic chemistry, which adds an important new perspective when evaluating the prospects of habitability in
planets with deep oceans.
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Cosmology and Nongalactic Astrophysics · Cross-listed from hep-ph
Inelastic Singlet-Doublet Fermion Dark Matter in light of the 248 keV LZ event
Debasish Borah, Sujit Kumar Sahoo, Narendra Sahu et al. (+1 more)
Recently, the LUX-ZEPLIN (LZ) collaboration reported the observation of a single dark matter (DM)-
nucleus scattering event at a nuclear recoil energy of $248\pm23_{\rm stat}\pm23_{\rm sys}$ keV, corresponding to an exposure of 2.84 tonne-year. The absence of events at lower nuclear recoil energies in the predicted spectrum is naturally explained if the underlying process is inelastic DM-
nucleus scattering. Motivated by this, we investigate the singlet-doublet
fermion DM model, in which the DM consists of two pseudo-Dirac states: the Majorana nature of the lighter state forbids tree level $Z$-mediated elastic scattering identically, while the same states enable inelastic DM-
nucleus scattering via $Z$ exchange, with any residual elastic scattering proceeding only through a suppressed
Higgs-mediated channel. We further extend the model with a $Z_2$-even scalar triplet, which is responsible both for generating the pseudo-Dirac splitting and for realizing Majorana
neutrino masses via the Type-II seesaw mechanism.
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All authors Debasish Borah, Sujit Kumar Sahoo, Narendra Sahu, Shashwat Sharma
High Energy Astrophysical Phenomena
Two-Phase Structure of Synchrotron-Cooling-Unstable Relativistic Plasma
Agnieszka Wierzchucka, Pablo J. Bilbao, Robert J. Ewart et al. (+2 more)
Using analytic theory, radiative particle-in-
cell (PIC) simulations, and fluid simulations, we show that relativistic, synchrotron-cooling, collisionless, high-$\beta$ pair
plasmas filament into a two-phase medium. This process occurs through the interplay of the synchrotron cooling instability (SCI) with the synchrotron firehose instability (SFHI). One phase has high
plasma~$\beta$ and is infested with small-scale firehose fluctuations, which scatter particles and pin the pressure anisotropy to the firehose-marginal level. The other phase has much lower~$\beta$, causing the suppression of firehose modes and thus allowing large pressure anisotropies. We propose a fluid model for this two-phase
plasma, which we use to study the linear and nonlinear
evolution of the SCI and SFHI, and to predict the emergence time of the two-phase structure.
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All authors Agnieszka Wierzchucka, Pablo J. Bilbao, Robert J. Ewart, Dmitri A. Uzdensky, Alexander A. Schekochihin