Astrophysics of Galaxies
Breaking the Blend: A multi-tracer kinematic decomposition method for IFS data applied to disentangling the AGN outflow and circumnuclear ring in NGC 5728 with JWST
Oscar Veenema, Niranjan Thatte, Dimitra Rigopoulou et al. (+26 more)
Integral field spectroscopy (IFS) of the central kiloparsecs of active galactic
nuclei (AGN) reveals a mixture of spatially coincident emission from
star-formation and AGN feedback exciting the interstellar medium. Disentangling these components remains a challenge, as most spectral tracers are affected by both processes, limiting robust interpretation of kinematics and energetics. We present a new framework for decomposing IFS data into distinct components on a spaxel-by-spaxel basis using a multi-tracer, stacked kinematics approach. This method combines kinematic modelling with imposed flux decomposition per spaxel, quantifying the contribution of each component across the field of view. We apply this method to JWST IFS observations of the Seyfert
galaxy NGC 5728 from the
Galaxy Activity,
Torus, and Outflow Survey (GATOS), analysing twelve mid-infrared fine-structure lines (4.49 < $\lambda$ < 25.89 $\mu$m, 7.9 < IP < 126.2 eV). We find that the circumnuclear emission can be decomposed into two dominant components: a
star-forming ring and an AGN-driven biconical outflow. Our method separates these structures and recovers their detailed spatial morphology. This framework provides a general and scalable method for physically motivated component separation in IFS data, applicable across many wavelength ranges and targets, enabling reliable interpretation of complex emission line structures (or morphologies) in active
galaxies and beyond.
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All authors Oscar Veenema, Niranjan Thatte, Dimitra Rigopoulou, Richard I. Davies, Miguel Pereira-Santaella, Ismael García-Bernete, Almudena Alonso-Herrero, Anelise Audibert, Enrica Bellocchi, Andrew J. Bunker, Françoise Combes, Tanio Díaz Santos, Fergus R. Donnan, Donaji Esparza-Arredondo, Federico Esposito, Santiago García-Burillo, Begoña García-Lorenzo, Omaira Gonzalez Martin, Laura Hermosa Muñoz, Erin K. S. Hicks, Sebastian F. Hönig, Masatoshi Imanishi, Alvaro Labiano, Nancy A. Levenson, Enrique Lopez-Rodriguez, Cristina Ramos Almeida, Claudio Ricci, Rogemar A. Riffel, Marko Stalevski
Solar and Stellar Astrophysics
Disc-mediated angular momentum transport resolves the mass-gain problem in rotating binaries
Sebastian Ljung, Avishai Gilkis and Sandro Tacchella
A large fraction of
stars interact with a close companion during their lifetime, in which the transfer of mass and angular momentum shapes their
evolution and final fate. Standard rotationally limited
accretion models predict that accretors reach critical rotation after gaining only a small fraction of their mass, severely suppressing further
accretion. This is in tension with observations of post-interaction systems that require substantial mass gain. We introduce a disc-mediated angular momentum transport prescription for mass-transfer onto stellar companions. This is based on a novel perturbative, analytic
star-disc boundary model that allows for continued mass inflow as the accretor approaches critical rotation. Furthermore, the model reproduces previous numerical results in which perturbations to super-critical rotation result in negative torques exerted by the disc, extracting excess angular momentum while allowing continued mass inflow. We implement this mechanism in detailed binary
evolution calculations with differential rotation using MESA, and compute grids spanning primary mass, orbital period, and mass ratio. Whereas rotationally limited models predict $\beta_{\rm eff}\lesssim 0.1$, the disc model yields sustained mass inflow near critical rotation, with effective mass-transfer efficiencies of $\beta_{\rm eff}\sim 0.4$-$1$ across much of the parameter space. The resulting accretor properties are broadly consistent with observed post-interaction sdOB+Be binaries. Disc-mediated angular momentum transport may therefore represent a key missing ingredient in standard binary
evolution models, with important implications for rapidly rotating
stars and compact-object progenitors.
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Instrumentation and Methods for Astrophysics
Differential Double Blind Fourier Holography (diff-DBFH)
Oren Pedatzur and David T. Chuss
High-performance optical systems, including space
telescopes, require wavefront-sensing and correction capabilities to achieve resolution near the diffraction limit. Existing wavefront-sensing approaches span a broad range of architectures, but many require dedicated interferometric hardware, rely on computationally intensive nonlinear or iterative reconstruction
algorithms or provide only limited wavefront information. Focal-plane wavefront-sensing methods are particularly attractive because they can operate without dedicated metrology hardware, and among these, Double Blind
Fourier Holography (DBFH) stands out as a robust and computationally light alternative to nonlinear and iterative solvers. Here we introduce differential Double Blind
Fourier Holography (diff-DBFH), a two-image variant of DBFH based on a small pupil-plane amplitude perturbation. Inspired by differential Optical Transfer Function (dOTF), diff-DBFH leverages the linear framework of DBFH to produce a more precise wavefront estimate. We derive the diff-DBFH formalism, compare its performance against dOTF using numerical simulations on a segmented aperture geometry inspired by the Habitable Worlds Observatory, analyze its sensitivity under noisy conditions, and demonstrate the method experimentally using an optical bench model of the same aperture.
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High Energy Astrophysical Phenomena · Cross-listed from gr-qc
The third law of black hole thermodynamics and the mass-to-charge ratio of scalar fields
Shahar Hod and Tsvi Piran
Kehle and Unger have recently shown that self-gravitating charged classical scalar fields can collapse to form extremal Reissner-Nordström (eRN) black holes in finite time, thus violating the third law of thermodynamics (TLT). Reall has subsequently proved that the formation of an eRN black hole in gravitational collapse is impossible if the mass-to-charge ratio of the field exceeds unity, $m/e\geq1$. In the present compact paper we
conjecture, using
quantum considerations, that the Reall bound is not sharp. In particular, we point out that the electric field of a charged system with charge $Q$ will spontaneously polarize the
vacuum in the regime $(eQ/\hbar)^2>(mQ/\hbar)^2+1/4$, thereby creating pairs of charged particles that discharge the black hole and ensure the
quantum validity of the TLT in this regime. Motivated by the TLT, we
conjecture that the classical Reall bound can be strengthened such that classical considerations would prevent eRN black holes from forming dynamically in the regime $m/e\geq\sqrt{1-\big({{\hbar}/{2eQ}}\big)^2}$, where
quantum polarization effects are unable to protect the TLT.
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Solar and Stellar Astrophysics
Coronal Green-Line Emission During a Solar Prominence Eruption: Spectroscopic Evidence of Its Correspondence with the EUV Late Phase
P. Vemareddy, R. Ramesh and V. Muttu Priyal
We report spectroscopic observations during a prominence eruption on 9 October 2025 from the Sun's west limb, associated with an M2.0
flare that commenced at 12:11 UT. The event was captured in sit-and-stare mode by the Visible Emission Line Coronagraph (VELC) onboard Aditya-L1, providing continuous observations of the Fe XIV 5303 Åcoronal greenline. The spatially averaged green-line emission exhibits a clear correspondence with the EUV late-phase (ELP) emission observed in multiple SDO/AIA channels. In particular, an enhanced 5303 Åemission peak at 15:24 UT coincides with secondary peaks in the AIA 211, 171, 193, and 335 Åpassbands, occurring $\sim173$ minutes after the X-ray peak. The 5303 Åline-width information provides important constraints on the mechanism responsible for the ELP. The line-width decreases progressively by about 28% toward the ELP peak, broadly consistent with the cooling of post-
flare coronal loops. This behavior suggests that the ELP is predominantly associated with
plasma cooling, with relatively weak additional energy input from
magnetic reconnection, which does not produce a significant enhancement in line-widths. The estimated non-thermal velocity decreases from $\sim$36 km s$^{-1}$ during the impulsive phase to $\sim$21 km s$^{-1}$ during the gradual phase, indicating a reduction in turbulent
plasma motions. And doppler velocities evolve from predominantly positive values during the eruptive rise phase to negative values during the later gradual phase, implying upward and subsequent downward
plasma motions. To our knowledge, this study provides the first space-based spectroscopic evidence linking coronal green-line emission with the ELP and its origin during a solar
flare.
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Astrophysics of Galaxies
CERIDWEN: Fast and Flexible GPU-Accelerated Stellar Population Inference
Amanda Stoffers, Sandro Tacchella and Benjamin D. Johnson
JWST has increased both the number of high-
redshift galaxies with high-quality spectral energy distributions (SEDs) and their information content. In parallel, wide-area surveys from Euclid, Rubin's LSST, and Roman will increase
galaxy samples by orders of magnitude. Analysing these
datasets requires stellar-population models that are both flexible and computationally efficient. We present CERIDWEN, a GPU-native SED fitting framework written in JAX, with an end-to-end differentiable forward model spanning stellar populations, nebular emission, dust attenuation and emission, and projection into the observer frame. Its vectorised, compiled architecture lets nested sampling replace a batch of live points in parallel on the GPU, which makes flexible stellar-population models tractable under full
Bayesian inference. Automatic differentiation also provides exact gradients for the gradient-based samplers in the package. We jointly infer time-dependent chemical-enrichment histories instead of a single stellar
metallicity, and demonstrate non-parametric
star-formation histories (SFHs) with $\sim$120 age bins. Using $\alpha$-enhanced stellar libraries from FSPS, CERIDWEN can sample stellar [$\alpha$/Fe] jointly with [Fe/H], mass, and SFH, so that the joint posterior represents the [Fe/H]-[$\alpha$/Fe] degeneracy explicitly. In controlled mocks, CERIDWEN recovers parameters with well-calibrated posterior uncertainties, while fits to real JWST observations reproduce posteriors from the established Prospector framework: on a single GPU, CERIDWEN completes a fit in a median sampling time of $\sim$4 min, $\sim$134$\times$ faster per fit than equivalent CPU-based Prospector runs. CERIDWEN therefore makes full
Bayesian inference practical for larger
galaxy samples and more flexible stellar-population models, reducing computational constraints on the physical complexity explored in SED fitting.
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High Energy Astrophysical Phenomena · Cross-listed from gr-qc
Stiffness corrections for f-mode neutron star universal relations
Isaac G. Chu and Carolyn A. Raithel
Excitations of the
neutron star (NS) fundamental mode (f-mode) during a binary NS inspiral or from a glitching
pulsar can produce gravitational waves (GWs) that will be detectable with the next generation of detectors, opening the door to GW asteroseismology of
neutron stars. There exist approximately equation-of-state (EOS)-insensitive, or "universal," relations that relate the f-mode to other NS properties. These universal relations have typically been identified with relatively small, selective EOS samples. To more thoroughly explore the parameter space, we examine the f-modes for a large sample of piecewise-parametric EOSs by solving the linearized fluid perturbation equations for the f-mode frequency and damping time in full general relativity. We utilize our sample to evaluate the EOS-sensitivity of previously-proposed universal relations (URs) for both the f-mode frequency and damping time. We find that URs that depend on combinations of only NS mass and radius have significant residuals, as previously reported; but that these residuals are strongly correlated with the overall stiffness of the EOS. We account for this residual dependence on the EOS by introducing linear correction terms that depend on the characteristic radius predicted by the EOS and the slope of the mass-radius curve at intermediate masses. To assess the impact of our new correction terms on observables, we consider the case of GW emission due to a glitch in a Vela-like
pulsar and demonstrate that the predicted signal-to-noise ratio for such an event is over/under-estimated by up to ~10% when using an existing, single-parameter UR, but is recovered nearly exactly with our improved 3-parameter UR. In contrast, we find that URs between the f-mode and tidal deformability exhibit only minimal EOS-dependent correlations in their residuals and overall remain highly EOS-insensitive.
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Solar and Stellar Astrophysics
Formation of adducts of C$_6$H with Na$^+$, Mg$^+$ and Al$^+$ metal cations by radiative association
Niyazi Bulut, Octavio Roncero, Maria Mallo et al. (+6 more)
The Mg-bearing cations MgC$_4$H$^+$, MgC$_6$H$^+$, MgC$_3$N$^+$, and MgC$_5$N$^+$ have been recently observed in the carbon-rich envelope IRC\,+10216. These species are thought to form upon radiative association between Mg$^+$ and the corresponding neutral radical. This work aims to determine the radiative association rate coefficients for the cations Al$^+$, Mg$^+$, and Na$^+$ reacting with carbon chain radicals to estimate the relative importance of metal-bearing carbon cations for each of these metals. For this purpose we use statistical methods in combination with highly accurate ab initio calculations to obtain the radiative association rate coefficient. Moreover, anisotropic effects beyond mono-dimensional capture model are considered, providing a more reliable description of the simulated processes.} The radiative association rate coefficients to form Mg-, Al- and Na-C$_6$H$^+$, as well as MgC$_4$H$^+$, MgC$_3$N$^+$, and MgC$_5$N$^+$, are calculated with the new restrictions considered in this work. These new rate coefficients are included in a chemical model of the C-rich AGB envelope IRC\,+10216. The abundances of MgC$_4$H$^+$, MgC$_6$H$^+$, and MgC$_5$N$^+$ are consistent with observations, with differences no greater than one order of magnitude, corroborating radiative association as a plausible formation mechanism for these adducts. However, the calculated abundance of MgC$_3$N$^+$ is about two orders of magnitude lower than observed, which indicates that either the chemistry of this species is significantly different from the others or the calculated rate coefficient is too low. The abundances obtained for Na-C$_6$H$^+$ and Al-C$_6$H$^+$ are around two orders of magnitude lower than for Mg, making very difficult to detect the analogous metal-bearing cations in IRC\,+10216.
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All authors Niyazi Bulut, Octavio Roncero, Maria Mallo, German Molpeceres, Marcelino Agundez, Maysa Yusef-Buey, Jose Cernicharo, Carlos Cabezas, Piotr Zuchowski
High Energy Astrophysical Phenomena · Cross-listed from nucl-th
Extending multi-messenger constraints on neutron star matter through the inclusion of direct Urca cooling
M. Dio Danarianto, Guilherme Grams, Thibeau Wouters et al. (+1 more)
The properties and behavior of strongly interacting matter at extreme densities can not only be determined through terrestrial experiments or through theoretical considerations, but also astrophysical observations of
neutron stars (NSs) and binary
neutron star systems become increasingly important to obtain complementary information. In light of these findings, we perform a
Bayesian study inferring the NS equation of state (EoS) by incorporating constraints from the direct Urca (dUrca) process, thereby including information on matter composition in addition to traditionally used macroscopic observables. We implement a self-consistent treatment of $\beta$-
equilibrium and charge neutrality in the jester framework, including the calculation of the
proton fraction and the onset of nucleonic dUrca in the presence of electrons and
muons. We combine constraints from chiral effective field theory, astrophysical measurements of NS masses, radii, and tidal deformabilities, and observations of rapidly and slowly cooling
neutron stars. The dUrca constraint seems to be in favor of stiffer EoSs, but –at the current stage– has only a minor impact on macroscopic NS properties once we include other nuclear and astrophysical constraints. In contrast, the dUrca information provides a constraint on the composition of canonical-mass NSs favoring a higher
proton fraction inside the
star, illustrating the complementary information carried by cooling observations. Our results demonstrate the potential of incorporating composition-sensitive observables into multimessenger inference and provide a step toward a more comprehensive treatment of dUrca constraints with microscopically motivated EoS models.
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All authors M. Dio Danarianto, Guilherme Grams, Thibeau Wouters, Tim Dietrich
Earth and Planetary Astrophysics
Deep HST/STIS Coronagraphic Imaging of the $\beta$ Pictoris Debris Disk: On the Scattered Light Component of the Cat's Tail
Arin M. Avsar, Kevin Wagner, Daniel Apai et al. (+6 more)
The $\beta$ Pictoris debris disk is a unique system where mid-infrared coronagraphic imaging with JWST/MIRI revealed a new spatially resolved substructure known as the Cat's Tail. We present deep HST/STIS coronagraphic imaging of $\beta$ Pic in scattered light, combining six epochs of observations between 2012 and 2025, in search of the scattered light component of the Cat's Tail. We detect the disk out to a projected separation of 500 au for the first time with HST/STIS, achieving SNR > 100 across much of the midplane between 50 and 200 au. We report the detection of the visible/near-infrared scattered light component of the Cat's Tail substructure. We find through injection-recovery analysis that the scattered light component of the Cat's Tail has a total flux of $0.1-0.4\%$ of the MIRI F1550C flux. Using the measured STIS-to-MIRI flux ratio, we model the Cat's Tail grain properties and find that the grains are highly porous and almost entirely composed of organic refractory material, which is in agreement with findings with JWST/MIRI. We use the organics content of Solar System dwarf
planets and dust in the local ISM as a proxy to estimate the size of the colliding progenitors that can produce enough organic refractory material seen in the Cat's Tail. We find that each colliding progenitor must have a mass of at least $1-3\times 10^{21}$ kg, comparable to Charon and Makemake in our Kuiper Belt. Additionally, we find a prominent warped morphology and surface brightness asymmetry in the outer dust
halo of $\beta$ Pic. We compare the observed
halo morphology and asymmetry to predicted vertical structures, which may arise from
planet–disk interactions.
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All authors Arin M. Avsar, Kevin Wagner, Daniel Apai, Isabel Rebollido, Antranik A. Sefilian, Marshall D. Perrin, Christopher C. Stark, Gabriel Weible, Andras Gaspar
Cosmology and Nongalactic Astrophysics
The Optical Expansion Scalar in Cosmological Perturbation Theory
Alexander Oestreicher and Sofie Marie Koksbang
Within the
geometric optics approximation, the optical expansion scalar describes the local rate of change in the amplitude of a wave or the area of a light bundle propagating through the Universe. As such, it is fundamental for describing almost all the observations we make in cosmology. It was recently pointed out that this quantity can, in principle, be reconstructed from measurements of the angular diameter distance $D_A$ and the effective observed expansion rate $\mathfrak{H}$. Motivated by this possibility, we introduce the observable $\vartheta \equiv \theta/\omega_o$, where $\theta$ is Sachs' optical expansion scalar, and $\omega_o$ the observed
photon frequency. We then derive the linear perturbative expression and angular power spectrum for $\vartheta$ in a flat FLRW universe with scalar perturbations. Comparing the power spectra with those of the fluctuations in $D_A$ and with power spectra from relativistic N-body simulations reveals no immediate striking advantage of studying the fluctuations of $\vartheta$ to those of $D_A$. However, the anisotropies of $\vartheta$ do exhibit several unique qualities such as an enhanced sensitivity to the peculiar velocity and relativistic potentials. We suggest that our results may hint at $\vartheta$ being useful for developing consistency tests of cosmological observations and possibly probing departures from FLRW cosmology and modified
gravity theories. The formalism developed and presented here provides the foundation for future studies into these possibilities.
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High Energy Astrophysical Phenomena
A Helical Trajectory Interpretation of a Multi-wavelength Event in a Blazar S5 0716+714
Zhihao Ouyang, Jingyu Wu, Hubing Xiao et al. (+9 more)
Relativistic jets in blazars exhibit strong variability across multiple timescales, but the connection between temporal variability and the
evolution of jet structures remains poorly understood. In this work, we investigate the $\gamma$-ray variability of the BL Lac object S5 0716+714 from July 2014 to June 2015 and explore its possible connection with the parsec-scale jet
evolution. We identify an escalating periodic oscillation (EPO) in the $\gamma$-ray light curve, characterized by a sequence of successive flux enhancements with progressively increasing temporal separations. Combining Fermi-LAT data with contemporaneous 43 GHz Very Long Baseline Array (VLBA) observations, we find a temporal association between the EPO and the downstream propagation of a superluminal
knot. A helical trajectory model simultaneously fitting the $\gamma$-ray variability and the two-dimensional VLBA component positions reproduces the observed flux modulation and component motion. These results suggest that
geometric Doppler modulation caused by the changing viewing angle of a moving jet component provides a possible explanation for the observed EPO. This work provides a framework of connecting blazar variability to the
knot evolution of relativistic jets.
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All authors Zhihao Ouyang, Jingyu Wu, Hubing Xiao, Zhijian Luo, Zhu Chen, Shaohua Zhang, Liang Chen, Jianzhen Chen, Marina Manganaro, Luis C. Ho, Junhui Fan, Chenggang Shu
Solar and Stellar Astrophysics
DKIST unveils MHD-predicted sub-50 km photospheric vortices
S. Vargas Dominguez, O. A. Calvo Rebellon, J. S. Castellanos Duran et al. (+4 more)
Solar
vortices are rotating
plasma structures that play a key role in the transport of energy and
magnetic helicity from the photosphere to the chromosphere and corona. While numerical simulations predict the existence of small-scale photospheric
vortices with diameters of $50$–$100$ km, no direct observational evidence has been reported to date, primarily because of the limited spatial resolution of previous instrumentation. Here, we analyze high-resolution observations obtained with the 4-meter Daniel K. Inouye Solar
Telescope (DKIST) at 416 nm, with a spatial resolution of 12.3 km. Using
Fourier local correlation tracking and the swirling strength criterion ($\lambda_{\rm ci}$), we identify 201
vortex detections across a sequence of 143 reconstructed frames, spanning approximately 3.2 minutes, within a field of view of $4.92 \times 4.13$ Mm. The observations cover a photospheric plage region containing pore-like
magnetic concentrations. The detected
vortices have a median equivalent diameter of 38.6 km and a mean diameter of $39.5 \pm 3.3$ km. Virtually all detections are smaller than 50 km and therefore fall within the subgranular regime predicted by magnetohydrodynamic simulations but never previously observed. The median swirling period, $\tau_{\rm ci}=37.3$ s, satisfies the $\tau_{\rm ci}<100$ s criterion established by MURaM simulations. No statistically significant preference is found for prograde rotation (53.7%) over retrograde rotation (46.3%), consistent with the negligible influence of the Coriolis force at subgranular scales. These results demonstrate the unique capability of DKIST to resolve the population of photospheric convective
vortices predicted by state-of-the-art magnetoconvection simulations, opening a new observational window into small-scale solar convective dynamics.
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All authors S. Vargas Dominguez, O. A. Calvo Rebellon, J. S. Castellanos Duran, M. van Noort, F. Wöger, D. A. Rodriguez Torres, C. G. Bernal
Earth and Planetary Astrophysics
The GAPS programme at TNG LXXIX. New mass constraints for the infant planets in the V1298 Tau system through a long-term radial velocity monitoring with HARPS-N
M. Damasso, P. Leonardi, L. Borsato et al. (+26 more)
We aim to constrain the dynamical masses of the four confirmed transiting
planets orbiting the infant ($20\pm10$ Myr)
star V1298,Tau (orbital periods $P_b\sim$24.1 d, $P_c\sim$8.2 d, $P_d\sim$12.4 d, and $P_e\sim$48.7 d), through a new analysis of a homogeneous radial velocity
dataset. This system is a key
benchmark for testing formation and early-stage evolutionary models of
planets. We analysed more than 380 high-resolution spectra collected with the HARPS-N spectrograph over a time span of 4.5,yr. To account for dominant stellar activity and transit-timing-derived
planet-
planet interactions, we analysed radial velocities extracted using two different approaches, and combined N-body simulations with multi-dimensional Gaussian process regression. We tested a set of spectroscopic and photometric activity diagnostics to mitigate the variability due to the stellar
magnetic activity in the radial velocity time series. The mass determinations are sensitive to the choice of the radial velocity extraction method and activity diagnostics. For some specific models, we measured masses with a significance of 3.5–4$\sigma$ for
planets b ($0.52^{+0.12}{-0.14}$, $0.65^{+0.21}{-0.18}$, $0.67\pm0.16$, and $0.78^{+0.19}{-0.20}$ $M_{\rm Jup}$) and e (0.40$^{+0.14}{-0.13}$, 0.66$^{+0.17}{-0.18}$, and $0.71\pm0.20$ $M_{\rm Jup}$). These values are compatible with masses of giant
planets, and are notably higher than those recently derived from transit timing variations alone, which indicate that these are low-density “super-puffy”
planets. Injection-and-recovery simulations moderately support this conclusion for
planet b. For
planets c and d, we primarily provide updated mass upper limits. Our analysis represents an exploratory study to address the complex issue of mass measurement in a multi-planetary system characterised by high levels of stellar activity.
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All authors M. Damasso, P. Leonardi, L. Borsato, S. Benatti, A. Suárez Mascareño, A. Bonfanti, C. Di Maio, M. Mallorquín, L. Fossati, F. Marzari, D. Nardiello, S. Desidera, L. Naponiello, A. Sozzetti, G. Andreuzzi, M. Basilicata, A. Bignamini, A. S. Bonomo, M. Brogi, P. Giacobbe, G. Guilluy, A. F. Lanza, M. Lodi, L. Malavolta, L. Mancini, S. Messina, G. Micela, V. Nascimbeni, T. Zingales
Astrophysics of Galaxies
The JWST and ALMA view of local dwarf Pox 186: Evidence of stripped binaries driving a hard radiation field and little cold molecular gas resulting in high star-formation efficiency
Nimisha Kumari, Renske Smit, Claus Leitherer et al. (+5 more)
We present a JWST mid-infrared (MIR) view of Pox 186, one of the best local analogs of reionization-era
galaxies based on its extreme properties in the ultraviolet, optical, and far-infrared (FIR). We extracted a high signal-to-noise spectrum of Pox 186 from the spatially resolved MIR data taken with the Medium Resolution Spectrometer (MRS) on the MIR Instrument (MIRI), and compared its MIR properties with those of the other dwarf
galaxies in the Herschel Dwarf
Galaxy Survey. We probe the radiation hardness of Pox 186 using the so-called softness diagram, based on the MIR line ratios [NeIII]/[NeII] and [SIV]/[SIII], which suggest that Pox 186 hosts ionization sources with a hard radiation field. We probe the dominant ionization source in Pox 186 using diagnostic diagrams based on MIR line ratios. Our photoionization models provide evidence that stripped binary
stars are the main cause of the extreme MIR line ratios. Similarly, a young starburst is needed to reproduce the MIR dust continuum. We probe the warm and cold molecular gas content using the MIR H$_2$ rotational lines (S(1)-S(7)) from JWST, and the archival sub-mm CO(2-1) line from ALMA, which indicate a high
star-formation efficiency (SFE; $>$ 15 $\times$ 10$^{-9}$ yr$^{-1}$) and low gas depletion time comparable to that of the reionization-era
galaxies. This analysis strongly suggests that
star formation rather than active galactic
nuclei drives the hard radiation field observed in Pox 186, and cautions against relying solely on the UV diagnostics to establish the nature of high-z
galaxies.
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All authors Nimisha Kumari, Renske Smit, Claus Leitherer, J. Álvarez-Márquez, Katherine Ormerod, Joris Witstok, Suzanne Madden, Matthew Hayes
Cosmology and Nongalactic Astrophysics
Two-rung ladder: $H_0$ from Tip of the Red Giant Branch and geometric anchors alone
Richard Stiskalek, Harry Desmond and Guilhem Lavaux
We infer the Hubble constant $H_0$ from the ~400 Extragalactic Distance Database hosts with a tip of the red giant branch (TRGB) distance, calibrated on the
geometric anchors of the Large Magellanic Cloud and NGC 4258. We forward-model the tip magnitudes and host
redshifts including magnitude-limited selection, sky exposure, and density-dependent
galaxy bias, conditioning on each of the 80 Manticore-Local realisations of the local density and peculiar-velocity fields in turn. As most hosts lie at $cz_{\rm CMB} \lesssim 1000$ km/s, where peculiar velocities are important, the inference is limited by the variance of these fields rather than by the TRGB calibration. For a fixed realisation, the
redshift likelihood and density smoothing each move $H_0$ by less than 1 km/s/Mpc and a velocity monopole by $5.4 \pm 3.4$ km/s/Mpc, whereas the field-to-field scatter in $H_0$ is 5.2 km/s/Mpc. Weighting the posteriors from each realisation equally gives $H_0 = 68.4 \pm 5.9$ km/s/Mpc, while weighting each by its
Bayesian evidence gives $72.3 \pm 2.6$ km/s/Mpc. The latter value is set by a single particularly high-evidence realisation, making it sensitive to the finite sampling of the reconstruction posterior. This ladder therefore cannot yet arbitrate the Hubble tension. Extending the TRGB data beyond the present ~1000 km/s, together with improved reconstructions of the local Universe, would reduce the field-to-field scatter well below the 5.2 km/s/Mpc we find here.
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Cosmology and Nongalactic Astrophysics · Cross-listed from hep-th
Infrared Screening of the Cosmological Constant
Vincenzo Branchina, Riccardo Gandolfo and Arcangelo Pernace
The observed cosmological constant is set by the deepest infrared scale of the present universe rather than by the microscopic scales that contribute to the
vacuum energy. We show that this emerges as the
quantum fluctuations of the gravitational field are progressively taken into account. Considering the Einstein-
Hilbert+$R^2$ truncation of
gravity, we find that in a wide region of the parameter space the theory develops instabilities that give rise to large amplitude
quantum fluctuations which govern the renormalization group flow. Once the flow enters this region, it remains there all the way towards the infrared and progressively loses
memory of its boundary conditions. The running cosmological constant $\Lambda_k$ ($k$ is the running scale) is driven towards the universal infrared scaling $\Lambda_k\sim \lambda_{_{\rm IR}}\,k^2$, with $\lambda_{_{\rm IR}}= \frac{1}{2(\pi-2)}$. At the deepest infrared scale $k_{_{\rm IR}}\sim H_0$ (the current Hubble scale), the cosmological constant is then screened to its observed value $\Lambda_{_{\rm IR}}\sim H_0^2$.
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Astrophysics of Galaxies
PAHSPECS: JWST/MIRI Spectroscopy of PAHs at Cosmic Noon
Irene Shivaei, Tanio Díaz Santos, Leindert A. Boogaard et al. (+14 more)
The physical conditions of the interstellar medium (ISM) are thought to differ greatly at high
redshifts compared to local
galaxies. Polycyclic aromatic hydrocarbons (PAHs) are key ISM constituents, mediating the heating and cooling of gas in photo-dissociation regions. However, PAHs are unexplored in main-sequence (MS)
galaxies at z~1-2 (
cosmic noon), limiting our view of the ISM's thermal and chemical balance. We present the PAH Spectroscopic Survey (PAHSPECS) JWST program, the first MIRI/MRS survey of the 3.3, 6.2, 7.7, 8.6 and 11.3$\mu$m PAH features in MS
galaxies at z~1. The five targets come from the deep ALMA CO and continuum flux-limited sample in the HUDF. We detect the 6.2, 7.7 and 11.3$\mu$m PAHs in all
galaxies, and the 3.3$\mu$m feature in only two. Spectral energy distribution (SED) fitting to broad-band mid-IR photometry recovers the 6.2 and 7.7$\mu$m PAH luminosities derived from spectral decomposition of the MRS spectra to within ~25% accuracy. However, the 3.3 and 11.3$\mu$m features are overestimated by ~50% (up to 3-5x). Spatially resolved maps of ASPECS-6, the most extended source, show variations of the 7.7$\mu$m PAH contribution to the MIRI F1500W flux, suggesting that while photometry can infer PAH luminosity accurately, IFU spectroscopy is necessary to study variations in PAH ratios and characterize
galaxy dust properties. The PAH fraction of the total dust mass from photometric SED modeling roughly agrees with the $L_{\rm PAH}/L_{\rm IR}$ ratio measured from spectroscopy, but the correlation is not as tight as models predict. On average, PAHSPECS
galaxies show an excess in 6.2$\mu$m equivalent width relative to nearby dusty luminous systems, but lower 3.3$\mu$m equivalent widths than local systems, similar to higher-mass starbursts at z~1-3. This points to differential changes in the size distributions of neutral and ionized PAHs in
cosmic noon
galaxies.
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All authors Irene Shivaei, Tanio Díaz Santos, Leindert A. Boogaard, Karin Sandstrom, Cristina Lofaro, Fergus R. Donnan, Pablo G. Pérez González, Roman Fernández Aránda, Javier Álvarez Márquez, Manuel Aravena, Roberto Decarli, Frédéric Galliano, Hanae Inami, Göran Östlin, Gergö Popping, Fabian Walter, Paul van der Wer
Cosmology and Nongalactic Astrophysics · Cross-listed from hep-ph
Plasma Effects Suppress Mixing-Induced Collisional Freeze-In
Shao-Ping Li and Josef Pradler
Dark matter that is weakly mixed with particles in a thermal
plasma can be produced through both, oscillatory and collisional freeze-in. While
plasma effects have long been known to suppress the former, their role in collisional freeze-in remains less clear quantitatively, leading to conflicting results in sterile
neutrino dark matter production via collisional freeze-in. Using first-principles nonequilibrium Kadanoff-Baym equations in the flavour-covariant formulation, we establish the general result that
plasma effects also suppress collisional freeze-in: the
vacuum mixing angle in the collision rate is replaced by its
plasma-corrected counterpart. Applying this result, we conclude that sterile
neutrinos cannot be dark matter in the keV-MeV mass range when produced from the Standard Model
plasma.
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High Energy Astrophysical Phenomena
Exceptional Gamma-Ray Flaring Activity of the Blazar S4 0954+65 in Early 2025
Zhihao Ouyang, Jingyu Wu, Hubing Xiao et al. (+11 more)
S4 0954+65 (4FGL J0958.7+6534) is a TeV-detected blazar at a
redshift of $z = 0.3694 \pm 0.0011$, classified as an intermediate-synchrotron-peaked BL Lac object. In early 2025, it entered an exceptional $\gamma$-ray high state. We aim to investigate the origin and physical properties of the exceptional 2025
flare, and to constrain the emission processes responsible for this flaring activity. We performed a multi-wavelength analysis using $\gamma$-ray, X-ray, optical/UV,
radio, and 43 GHz Very Long Baseline Array (VLBA) observations. We examined multi-band correlations with the z-transformed discrete correlation function (zDCF), analyzed the spectral
evolution and parsec-scale jet kinematics, and modeled the broadband spectral energy distributions (SEDs). The $\gamma$-ray variations lead the optical and
radio emission by 3.22 days and possibly 18.26 days, respectively, while no significant correlation is found between the $\gamma$-ray and X-ray emission. The $\gamma$-ray spectra show a harder-when-brighter behavior, consistent with enhanced particle acceleration during the active state. A similar spectral trend is also observed in the X-ray band, where the
photon index is anti-correlated with flux. During the major $\gamma$-ray
flare, VLBA images reveal the emergence of a new superluminal
radio knot from the core, whose extrapolated ejection time is consistent with the peak of the $\gamma$-ray
flare. The temporal and structural
evolution during the 2025
flare is consistent with a shock-in-jet scenario, in which a newly emerging disturbance propagates downstream and drives the
flare. Broadband SED modeling shows that a leptonic synchrotron self-Compton plus external Compton model with dusty
torus seed
photons reproduces the multi-wavelength observations with physically plausible parameters. A lepto-hadronic interpretation remains possible but requires substantially higher jet power.
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All authors Zhihao Ouyang, Jingyu Wu, Hubing Xiao, Lili Yang, Shangchun Xie, Shaohua Zhang, Zhijian Luo, Jianzhen Chen, Jianguo Wang, Mingjun Liu, Qinyu Wu, Huaqing Cheng, Wenda Zhang, Junhui Fan
Instrumentation and Methods for Astrophysics
Simultaneous PSF Matching via Dual Kernel Optimization
Carter Lee Rhea, Pieter Van Dokkum, Roberto Abraham et al. (+6 more)
Standard point spread function (PSF) matching
algorithms consider one image as the reference and aim to find a convolution kernel such that, when applied to the reference image, the PSFs of the reference and non-reference images are matched. This method works well if one image is a degraded version of the other. However, this is not always the case: if the PSFs of the two images have different orientations or shapes, a simple convolution of one of the images does not lead to a satisfactory match. While this can be trivially solved by convolving the first PSF with the second and vice-versa, this results in unnecessarily large PSFs. In this paper, we present a new
algorithm, Dual Kernel Optimization (DKO), that simultaneously solves for two convolution kernels, one for each image, such that the PSFs match and the sizes of the kernels are minimized. This results in a minimally-degraded final set of PSFs. Since this problem is highly degenerate, we use
Stochastic Gradient Langevin Dynamics (SGLD) which rigorously explores the parameter space and converges on the globally-optimal solution.We discuss the algorithmic challenges for this problem and the modifications to standard SGLD used to constrain it. Finally, we include a discussion on the application of this methodology to real-world images, including cases where the PSF varies over the field of view.
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All authors Carter Lee Rhea, Pieter Van Dokkum, Roberto Abraham, Imad Pasha, Steven R. Janssens, William P. Bowman, Deborah Lokhorst, Seery Chen, Qing Lui
Astrophysics of Galaxies
Discovery of an isolated RELHIC Candidate: J1351+0039
Jin-Long Xu, Alejandro Benitez-Llambay, Ming Zhu et al. (+6 more)
We report the discovery of J1351+0039, a new isolated dark
galaxy candidate identified through a blind HI survey with the Five-hundred-meter Aperture Spherical
radio Telescope (FAST), combined with deep optical imaging from the DESI Legacy Survey. The object displays a compact HI structure with a systemic velocity of V_{LSR} = 429.0 \kms and an inferred HI mass of 4.8*10^5 Msun. No optical counterpart is detected in the DESI images, with a g-band surface brightness limit of 28.1 mag arcsec^{-2}, corresponding to a stellar mass limit of M_{
star} of 1.5*10^{5} Msun. The dynamical mass is estimated to be M_{dyn} of 1.3*10^{8} Msun, yielding a dark-to-baryonic mass ratio of 200, implying that J1351+0039 is overwhelmingly dominated by dark matter. While week rotation is detected in J1351+0039, the kinematics are dominated by internal velocity dispersion, confirming pressure support and reminiscent of Reionization-Limited HI Clouds (RELHICs). J1351+0039 stands out as one of the most promising isolated RELHIC candidates, offering a unique laboratory for studying baryonic physics and dark matter in the absence of
star formation.
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All authors Jin-Long Xu, Alejandro Benitez-Llambay, Ming Zhu, Chuan-Peng Zhang, Nai-Ping Yu, Xiao-Lan Liu, Mei Ai, Ruilei Zhou, Bin Liu
Earth and Planetary Astrophysics
Extracting Asteroid Physical Properties from Vera C. Rubin Observatory Science Validation Survey Data: Rotational Periods, Colors, and Taxonomies
V. Carruba, S. Greenstreet, M. Mastropietro et al. (+7 more)
The Vera C. Rubin Observatory will enable large-scale characterization of minor bodies through high-cadence, multi-band photometry. Early Science Validation (SV) observations from 2025-2026 provide one of the first extensive
datasets for Solar System studies, but typically with sparser and more heterogeneous coverage than the Rubin First Look data, where hundreds of observations were available for well-characterized objects. In this work, we build on the methodology developed for the Rubin First Look data to extract asteroid rotation periods, amplitudes, colors, and taxonomic classifications from early Rubin SV data using multi-band (griz) photometry. Rotation periods are determined through a combination of high-order
Fourier light-curve fitting and multi-band Lomb-Scargle analysis. A unified light-curve model is then used to derive rotation-corrected colors, which are converted into taxonomic classes using calibrated color indices and spectral slopes. We validate the method on objects with sufficient observational coverage and show that preliminary physical properties can be estimated from sparse and irregular
datasets, while robust determinations require improved temporal coverage. By simulating sparsely observed data, we identify the observational conditions required for period determinations. The inclusion of z-band photometry extends traditional color-based taxonomy and improves compositional discrimination relative to gri-only analyses.
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All authors V. Carruba, S. Greenstreet, M. Mastropietro, S. Aljbaae, G. Caritá, R. C. Domingos, M. Huaman, M. M. Bala, R. D. Z. Pedroso, E. M. D. S. Delfino
Solar and Stellar Astrophysics
A Multiwavelength View of $\rho$ Oph II: Disentangling the Variability of the Multi-Star Component C
Sean J. Gunderson, Walter W. Golay, Jackson Codd et al. (+8 more)
We present a multiwavelength analysis of the
star $\rho$ Oph C, covering X-ray, optical, near-infrared, and
radio observations to test for the presence of interferometrically-detected cool
star companions. The X-ray observations from Chandra, XMM-Newton, and NuSTAR show
flare-like events lasting minutes or days in time and spectral properties consistent with those of cooler
stars instead of the primary
magnetic B
star. The near-infrared data is also consistent with the proposed trinary system properties due to the presence of CO-band heads. After removing the primary B
star's rotation, the optical data from TESS shows a residual signal at the level of 0.8 mmags, matching the variations expected from cool
stars in orbit around a bright B
star. Finally, multi-epoch
radio data reveals that $\rho$ Oph C exhibits significant large scale flux variations that are atypical for a
magnetic massive
star. Taken as a whole, the multi-epoch and -wavelength data presents a consistent picture of $\rho$\,Oph\,C as a rare trinary system composed of a hot
star and two cool
stars.
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All authors Sean J. Gunderson, Walter W. Golay, Jackson Codd, David P. Huenemoerder, Felipe Navarete, Christiana Erba, Alexandrea Moreno, John M. Cannon, Richard Ignace, Pragati Pradhan, the MACRO consortium
High Energy Astrophysical Phenomena
Observational signatures of warped accretion flows in tidal disruption events
Andrew Mummery and Eliot Quataert
We analyze the possible observational signatures and
evolution of global warps in the
accretion flows produced in tidal disruption events. These warps are driven by Lense-Thirring torques resulting from the misalignment of the disk's rotation axis and the black hole's
spin axis. In a previous paper we argued that these global warps should be generically present in TDE
accretion flows as they enter a late-time thin disk phase of
evolution. We isolate three possible observational signatures of warps: (i) anomalous (reddened) late time optical colors, resulting from irradiative heating of the warped outer disk by the inner flow, (ii) delayed X-ray rises, resulting from the inner disk being slowly revealed to a distant observer as the warped flow gradually aligns with the
spin axis, and (iii) reverberation of turbulent X-ray
flares into optical/UV frequencies as the inner disk heats the outer disk during a flaring state. We present preliminary observational evidence that all three effects may have already been observed in TDE systems. Observations of TDEs may well offer the cleanest astronomical signatures of the strong-
gravity effects which cause disk warping, and provide unique constraints on the poorly understood
evolution of warped
accretion disks.
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Earth and Planetary Astrophysics
VLTI/MATISSE observations of the hot dust around $\beta$ Pictoris: Observing faint objects with MATISSE
P. Priolet, J.-C. Augereau, J. Milli et al. (+32 more)
Context: Hot exozodiacal dust has been detected around approximately 20% of nearby main-sequence
stars, indicating that it is a common feature of extrasolar planetary systems. However, its spatial distribution and grain properties remain poorly understood. Aims: We aim to show that the spatial distribution of hot dust around beta Pictoris, an iconic planetary system with two known
planets and a population of exocomets, can be constrained through a detailed analysis of optical long-baseline interferometry data. Methods: We obtained L-band observations at approximately 3.5 microns of beta Pictoris with MATISSE at the VLTI. We developed a method to assess correlations in the visibility measurements by estimating the full data covariance
matrix, and modeled the circumstellar emission with
geometric brightness distributions. Results: We detect circumstellar emission around beta Pictoris consistent with hot exozodiacal dust. Modeling the emission with and without accounting for data correlations demonstrates their significant impact on the inferred dust properties. The best-fit model reveals a compact (approximately 0.05 au), highly inclined dust structure near the sublimation radius, misaligned by approximately 60 degrees on the sky with respect to the extended edge-on outer disk. It contributes approximately 4%-7.5% of the total flux at 3.4 microns and is composed of submicron-sized grains. The data are also compatible with an additional dust component near 1 au. Conclusions: For beta Pictoris, the two-decade-old paradigm placing hot exozodiacal dust near the sublimation radius and consisting of submicron-sized grains finds observational support in the detailed analysis of MATISSE data. The misalignment with the known debris disk further supports a link to exocometary activity.
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All authors P. Priolet, J.-C. Augereau, J. Milli, A. Matter, B. Lopez, H. Beust, J. Varga, P. Boley, W.-C. Danchi, L. Foteini, T. Henning, M. Houllé, M. Letessier, F. Millour, J. Scigliuto, G. Weigelt, S. Wolf, O. Absil, J.-P. Berger, Y.-I. Bouarour, G. Bourdarot, D. Defrère, C. Desgrange, J.-B. Le Bouquin, D. Iglesias, T. A. Stuber, P. Berio, F. Bettonvil, P. Cruzalèbes, M. Heininger, J. W. Isbell, S. Lagarde, A. Meilland, R. Petrov, S. Robbe-Dubois
Astrophysics of Galaxies
How Magnetic Fields Regulate Cooling and Mixing in Turbulent Radiative Mixing Layers
Rajsekhar Mohapatra, Lachlan Lancaster, Drummond Fielding et al. (+2 more)
Turbulent radiative mixing layers (TRMLs) are expected wherever hot and cold gas move past one another, including in the solar corona, galactic winds, and cold filaments in
galaxy clusters. These environments are often magnetized, but
magnetic effects on mixing and cooling remain less well understood than in the hydrodynamic (HD) case. We present magnetohydrodynamic (MHD) simulations of TRMLs at resolutions up to $1024 \times 2048^2$, spanning fields aligned with and transverse to the shear, and polarity-reversing configurations in which oppositely directed fields form current sheets at the interface. Even initially weak hot-phase fields, with $\mathcal{M}_{\rm A,shear}\equiv v_{\rm shear}/v_{\rm A}\sim14$, reduce the mass and enthalpy flux and radiative cooling rate by up to an order of magnitude relative to HD.
Magnetic tension weakens turbulent motions, reducing both the
diffusion of hot gas into the layer and the folding of the cooling surface. Transverse fields suppress cooling somewhat more strongly than shear-aligned ones, although a transverse field exerts no tension against the initial linear instability. Polarity reversal changes the morphology of the cooling gas without restoring HD-like mixing. The dependence on the Damköhler number is similar to the HD case, but the degree of suppression is dependent on the initial field orientation. The net cooling rate appears resolution-independent in HD but declines with resolution in MHD, and has not converged, so our suppression factors are lower limits.
Magnetic fields therefore strongly regulate cooling and mixing in multiphase gas, and quantitative predictions require careful treatment of transport processes.
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All authors Rajsekhar Mohapatra, Lachlan Lancaster, Drummond Fielding, Eliot Quataert, Greg L. Bryan
Solar and Stellar Astrophysics
Quantum Phase Transitions in Nuclei and the Origin of Rhodium
P. Agarwal, H. Schatz, A. Francis et al. (+3 more)
The astrophysical rapid
neutron capture process (r-process) is a major nucleosynthesis process responsible for the production of elements heavier than copper. Prominent features in the observationally inferred r-process abundance distributions provide critical clues for astrophysical conditions and possible r-process sites. The lack of clear features for the r-process elements lighter than tellurium has led to a broad range of proposed possible scenarios and alternative processes that may produce these elements. Here we show that the enhancement found in the solar system of rhodium and ruthenium isotopes compared to neighboring isotopes can serve as such a feature. The enhancement can be traced back to sudden changes in shape of unstable rare isotopes in the path of the light element r-process. Such shape changes have been described as
quantum phase transitions. This finding points to r-process scenarios with relatively high
neutron densities and temperatures for the origin of rhodium and ruthenium in the solar system. Rhodium and ruthenium abundances observed in r-process enhanced
stars can now be used as diagnostics for the r-process conditions that produce these lighter r-process elements. Observational data for these elements indicate that different types of r-processes may have operated in the early
Galaxy, and that the conditions do not necessarily align with the weak and main r-process classifications used in the past.
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All authors P. Agarwal, H. Schatz, A. Francis, F. Montes, B. Pol, L. Roberts
Astrophysics of Galaxies · Cross-listed from gr-qc
Environmental Imprints of Dark Matter and Accretion Disks on Eccentric EMRIs around Kerr Black Holes
Hai-Chao Yuan and Yong Tang
Extreme-mass-ratio inspirals (EMRIs), systems in which a stellar-mass compact object spirals into a supermassive black hole ($M_1$), are
prime targets for the space-based gravitational-wave interferometers and are acutely sensitive to their astrophysical environment. We quantify the joint imprint of a dark matter (DM) spike and an
accretion disk on the waveforms of eccentric, equatorial Kerr EMRIs, integrating four modular effects—DM dynamical friction, DM self-
gravity, Newtonian
accretion-disk torques, and disk self-
gravity—into a fifth post-Newtonian (5PN) augmented analytic kludge (AAK) waveform model, and assess their measurability via a Fisher-
matrix analysis. The DM dynamical-friction dephasing peaks at $M_1\sim 10^6\,M_\odot$, reaching $\sim 10^2$–$10^3\,\mathrm{rad}$; there the DM spike slope is measurable to sub-percent precision and both DM channels are unambiguously detectable, while omitting DM biases the intrinsic parameters significantly. At $M_1\gtrsim 10^8\,M_\odot$ the DM and disk self-
gravity channels dominate their dissipative counterparts. The disk parameters remain degenerate across the explored parameter space, since the supersonic regime dominates the inspiral and the subsonic-to-supersonic transition only mildly weakens this degeneracy without lifting it; a combined DM$+$disk analysis further reveals a cross-sector degeneracy between the DM slope and the disk parameters. This physical degeneracy, reflected in the near-singular Fisher
matrix, implies that independently measuring the disk parameters requires a relativistic torque model or an electromagnetic counterpart.
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High Energy Astrophysical Phenomena · Cross-listed from gr-qc
Multi-messenger and multi-band signal from first-order phase transitions in proto-neutron stars
Christian Ecker, Mauro Giliberti and Luciano Rezzolla
A first-order phase transition (PT) alters a compact
star on two scales: globally, via growth of a
quark-matter core, and microscopically, via collision of
quark bubbles, driving a simultaneous gravitational-wave (GW) emission in the kHz and MHz bands. Using a constrained ensemble of model-agnostic equations of state, we follow the
accretion-driven
evolution of proto-
neutron stars through the PT and compute the resulting multi-band GW signal. The correlations found between the kHz emission and the MHz burst could help constrain nuclear matter and the physics of the PT. A delayed
neutrino burst should accompany the signal, with the delay set by the details of the PT, thus providing a
prime multi-messenger source.
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