Astrophysics of Galaxies
Radial Distributions of Star Formation and Gas-phase Metallicity in Spiral-Elliptical Galaxy Pairs
Cailu Shi, Shuai Feng, Shiyin Shen et al. (+3 more)
Using integral field spectroscopy from SDSS-IV MaNGA, we investigate the radial distributions of
star formation rate (SFR) and gas-phase
metallicity in spiral
galaxies that reside in spiral-elliptical (S+E) pairs. Spirals in S+E pairs show suppressed central
star formation and elevated
metallicities, whereas spirals in spiral-spiral pairs exhibit centrally enhanced
star formation and reduced
metallicities. The degree of SFR suppression and
metallicity enhancement in S+E pairs depends on the masses of the pair members. Spirals with more massive elliptical companions experience stronger
star-formation suppression and larger increases in
metallicity, while lower-mass spirals show more pronounced
metallicity enhancement. In addition, within S+E systems,
galaxies with asymmetric gas velocity fields display enhanced SFR and higher
metallicities, whereas those with symmetric velocity fields exhibit clear central suppression. Based on these results, we infer that in S+E pairs, the spiral
galaxy experiences suppressed gas
accretion once it enters the hot circumgalactic medium of its early-type companion, which leads to the observed decline in
star-formation activity. When a close encounter takes place,
tidal perturbations can compress the remaining cold gas and trigger enhanced
star formation, producing rapid chemical enrichment and the associated increase in
metallicity.
Read the full abstract ▾
All authors Cailu Shi, Shuai Feng, Shiyin Shen, Linlin Li, Wenyuan Cui, Guozhen Hu
Cosmology and Nongalactic Astrophysics
BROOM: a python package for model-independent analysis of microwave astronomical data
Alessandro Carones, Sijil Jose, Aliza Mustafa et al. (+2 more)
We present BROOM, a new python package for the application of blind, minimum-variance component-separation techniques to microwave observations. The package enables the reconstruction of signals with known spectral energy distributions, such as the
Cosmic Microwave Background (CMB), Sunyaev–Zeldovich distortions, or foreground moments, in both temperature and polarization through a suite of Internal Linear Combination (ILC) implementations, in the presence of astrophysical and instrumental contaminants. In addition, BROOM supports the blind reconstruction of coherent emission components with unknown covariance properties via a Generalized ILC (GILC) framework. Beyond component separation, the package provides tools to diagnose foreground complexity and to estimate residual contamination leaking into reconstructed maps across angular scales and sky regions. It also includes utilities to generate realistic microwave simulations for arbitrary CMB experiments and to compute angular power spectra of the resulting products. We present a comprehensive description and validation of the implemented pipelines in two representative experimental configurations: a full-sky satellite mission and a ground-based experiment. BROOM is publicly available, fully documented, and easily installable at https://github.com/alecarones/broom
Read the full abstract ▾
All authors Alessandro Carones, Sijil Jose, Aliza Mustafa, Nicoletta Krachmalnicoff, Carlo Baccigalupi
Solar and Stellar Astrophysics
Analysis of Eruptive Prominence Plasma Parameters' Effects on the \ion{He}{2} 304~Å\ Line with Solar Orbiter EUI Observations
Yong Zhang, Nicolas Labrosse and Sargam M. Mulay
An observation of a large prominence on the
solar limb took place on February 15, 2022, by the Extreme Ultraviolet Imager (EUI) on board
Solar Orbiter. We aim to determine the range of physical parameters of this prominence, such as temperature, radial velocity, and altitude, and examine how these parameters affect the formation of the 304~Å\ line of \ion{He}{2}, especially how collisional excitation and radiative processes contribute to line formation. After constraining these parameters, we generate 200 random models and compute the \ion{He}{2} 304~Å\ line profile. We present these results using parallel coordinate plots to explore how these parameters affect the results. This allows us to infer the key physical parameters that impact the formation of the \ion{He}{2} 304~Å\ line. This study demonstrates that column mass and the steepness of the temperature profile are key factors in the formation of the \ion{He}{2} 304~Å\ line during the
solar prominence eruption on February 15, 2022. Radiative processes remain dominant in the formation of the \ion{He}{2} 304~Å\ line. These insights provide a foundation for future research and comparative studies.
Read the full abstract ▾
Solar and Stellar Astrophysics
Prominence Plasma Parameters Maps Inferred From Lyman $\beta$ and Lyman $\gamma$ Observations and Non-LTE Modelling
Y. Zhang, N. Labrosse, T. A. Kucera et al. (+1 more)
The first dedicated observation of an off-limb prominence by the Spectral Imaging of the Coronal Environment (SPICE) instrument took place on April 15, 2023. We aim to create parameter maps on the prominence region, including temperature, pressure, and column mass, by studying the integrated intensity of the Lyman $\beta$ and Lyman $\gamma$ lines from SPICE data. After constraining the altitude and radial velocity in the prominence, we use a 1D non-LTE radiative transfer code to generate 1000 random models and compute the Lyman $\beta$ and Lyman $\gamma$ line profiles. The computed intensities are compared with observed integrated intensities from SPICE. Then, we create models which simultaneously give a reasonable match with the observed intensities in both lines. Unlike previous approaches, our method uses contribution functions to guide the optimisation of temperature and pressure profiles. Our approach enables a physically constrained and consistent match to both spectral lines. The method in this paper enables us to generate models from pixels on the prominence region and use this information to generate parameter maps. The results obtained have potential for future research.
Read the full abstract ▾
All authors Y. Zhang, N. Labrosse, T. A. Kucera, S. Parenti
Solar and Stellar Astrophysics
Non-LTE Analysis of Pre-eruptive Prominence Plasma Parameters Effects on the Lyman-beta and Lyman-gamma Lines with Solar Orbiter SPICE Observations
Yong Zhang, Nicolas Labrosse, Susanna Parenti et al. (+1 more)
The first dedicated observation of an off-limb prominence by
Solar Orbiter took place on April 15, 2023. Our aim is to determine the range of different physical parameters of this prominence and to examine how these parameters affect the formation of the Lyman $\beta$ and Lyman $\gamma$ lines of hydrogen. We have found a way to refine key physical parameters by observational data. We will test the method by this prominence observation. We generate 200 random non-LTE models using these observational constraints and compute the Lyman $\beta$ line and the Lyman $\gamma$ line profiles. We use the Spectral Imaging of the Coronal Environment (SPICE) full-disk mosaic from November 13, 2023 to constrain the incident radiation. We present the parameters and results of 200 random models using parallel coordinate plots to explore how different parameters affect the results. This allows us to infer the key physical parameters (e.g., central pressure, column mass and temperature gradient) that impact the formation of the Lyman $\beta$ line and the Lyman $\gamma$ line in this observation.
Read the full abstract ▾
All authors Yong Zhang, Nicolas Labrosse, Susanna Parenti, Therese A. Kucera
Solar and Stellar Astrophysics
Analysis of Lyman-beta and Lyman-gamma Lines in a Pre-Eruptive and Eruptive Prominence with Solar Orbiter SPICE Observations
Yong Zhang, Nicolas Labrosse, Susanna Parenti et al. (+1 more)
The first dedicated observation of an off-limb prominence by the Spectral Imaging of the Coronal Environment (SPICE) instrument on board
Solar Orbiter took place on April 15, 2023. Our aim is to provide an overview of the potentiality of the diagnostics using these data. We show that we can derive the changes in the physical parameters of the pre-eruptive and eruptive prominence using the Lyman lines. We investigate the integrated intensity and line widths of the Lyman $\beta$ and Lyman $\gamma$ lines, finding variations between the prominence, disk, and coronal regions. The results reflect dynamic changes in density, temperature, and optical thickness. We analyze the spatial and temporal
evolution of the Lyman $\beta$ and Lyman $\gamma$ line profiles. Using a simple
geometric model, we obtain the radial velocity of this prominence at the early phase of its eruption with GONG H$\alpha$ images. This offers a way of calculating the radial velocity of an eruptive filament from a pair of 2D images. The result helps us understand the potential Doppler effect in line profiles. Overall, the spectral profiles indicate that the eruption enhances spatial and temporal variations in line intensity, reflecting dynamic changes in
plasma conditions within the prominence. These findings highlight the diagnostic potential of SPICE observations, and future Non-LTE radiative transfer modeling will help to further constrain prominence
plasma parameters.
Read the full abstract ▾
All authors Yong Zhang, Nicolas Labrosse, Susanna Parenti, Therese A. Kucera
Solar and Stellar Astrophysics
Radial Velocity Evidence for a Post-Mass-Transfer Massive Binary System NaSt1
Kittipong Wangnok, Samaporn Tinyanont, Ryan M. Lau et al. (+11 more)
We present multi-epoch high-resolution optical spectroscopy ($R \simeq 80{,}000$) of the emission-line object NaSt1 to test its proposed binary nature, along with long-term multiband photometry, mid-infrared spectroscopy, and spatially resolved integral field unit (IFU) spectroscopy to probe the circumstellar kinematics of the system. We detect two groups of 36 emission lines showing radial velocity (RV) variation with a mean period of 311 $\pm$ 5 d, but varying in opposite phase. We associate these two groups with the optically thick wind of the stripped primary
star and the wind-wind collision region with the companion
star, providing strong evidence for binarity. The RV and light curve (LC) periods are consistent within the uncertainties, ruling out ellipsoidal modulation, which would require an orbital period of about 620 d. The RV-LC phase relationship and high-ionization lines favor binary interaction over pulsations. We model the 1–5~$\mu$m spectrum of NaSt1 and find two optically thin
dust components: hot $T_{\rm h} \simeq 1230$ K, $M_{\rm h} \simeq 2 \times 10^{-10} M_{\odot}$ and warm $T_{\rm c} \simeq 660$ K, $M_{\rm c} \simeq 3 \times 10^{-8} M_{\odot}$. IFU spectroscopy spatially resolves the circumstellar medium in the [\ion{N}{2}] $\lambda6548$ and $\lambda6584$ emission lines, showing a deprojected expansion velocity of $\sim31$ km~s$^{-1}$, implying a dynamical age of $\sim40$ yr. This short timescale suggests that the nebula was produced by recent mass loss. The system may represent a
Galactic analog of a massive binary undergoing a mass-loss process to become a stripped-envelope
supernova progenitor.
Read the full abstract ▾
All authors Kittipong Wangnok, Samaporn Tinyanont, Ryan M. Lau, Ryan J. Foley, R. Paul Butler, Poemwai Chainakun, Kyle W. Davis, Kishalay De, Jared A. Goldberg, Bradford P. Holden, Adriana Kuehnel, Nathan Smith, Jonathan Swift, Steven S. Vogt
Solar and Stellar Astrophysics
Shock properties for solar energetic particle events with signatures of inverse velocity arrival
A. Kouloumvakos, D. Lario, G. M. Mason et al. (+20 more)
We present a detailed investigation of the shock properties associated with
solar energetic particle (SEP) events that exhibit a concave (“nose-like”) shape in their energy spectrogram, characterized by inverse velocity arrival (IVA) of the particles, where high-energy particles arrive later than mid-energy ones. Using measurements from
Solar Orbiter and Parker
Solar Probe between 2018 and 2025, we identify 26 such SEP events and reconstruct the observed shock fronts in three dimensions. We derive shock parameters along the
magnetic field lines connected to each spacecraft using kinematic modeling and coronal magnetohydrodynamic simulations. Our analysis indicates that IVA-SEP events arise due to the spatial and temporal
evolution of the shock properties and
magnetic connectivity. In most cases analyzed here, the
magnetic connectivity starts on the flanks of CME-driven shocks, where shocks tend to be weak, and shifts toward the shock apex sampling stronger portions of the shock front. This
evolution of the shock properties at the connected field lines likely leads to the delayed arrival of high-energy particles and the progressive hardening of the SEP energy spectrum, observed in some of the events. We find a correlation between the transition energy at which the IVA begins and the shock speed along the connected field lines, consistent with expectations from time-dependent diffusive shock acceleration. Our results underscore the importance of the evolving shock properties,
magnetic connectivity, and instrumental sensitivity in shaping SEP intensity profiles and the formation of IVA signatures.
Read the full abstract ▾
All authors A. Kouloumvakos, D. Lario, G. M. Mason, A. Vourlidas, R. C. Allen, N. Wijsen, X. Chen, Z. Ding, I. C. Jebaraj, P. Riley, D. J. McComas, C. M. S. Cohen, E. Paouris, S. Raptis, L. Rodríguez-García, Z. G. Xu, G. D. Berland, G. C. Ho, D. G. Mitchell, E. C. Roelof, J. Rodriguez-Pacheco, M. E. Hill, R. F. Wimmer-Schweingruber
Astrophysics of Galaxies
Bayesian Analysis of Gravitational Wave Microlensing Effects from Galactic Double White Dwarfs
Yan Sun, Yong Yuan, Minghui Du et al. (+3 more)
Gravitational waves (GWs) from the
galactic double white
dwarf (DWD) systems are one of the primary targets for upcoming space-based detectors. Due to their vast abundance and widespread distribution throughout the
Galactic disk and bulge, these systems may provide a high-statistical population for probing GW microlensing effects induced by
Galactic compact objects. To evaluate the detectability of such effects, in this work we simulate the four-year observation of DWD systems by Taiji, in the form of a second-generation Time Delay Interferometry (TDI) data stream. Within a
Bayesian inference framework, we estimate parameters for lensed GWs from DWD systems for different values of the lens parameters, including the lens mass $M_\mathrm{L}\in [10, 10^6]$\,M$_\odot$, the effective velocity $v_\mathrm{eff}\in [50, 500]$\,km/s and the initial separation $L\in [R_\mathrm{E}, 3R_\mathrm{E}]$, and obtain the uncertainties of the corresponding parameters. These results characterize the capability of future Taiji observations to probe such systems. We further employ the
Bayesian model selection framework to distinguish between lensed and unlensed scenarios, and investigate the impacts of three key physical parameters of the lens system: $M_\mathrm{L}$, $v_\mathrm{eff}$, and $L$ on distinguishing
lensing events. Our results show that when $M_\mathrm{L}$ is below $10^5$\,M$_\odot$ or $L\geq3R_\mathrm{E}$, it is not possible to distinguish between lensed and unlensed models. For $v_\mathrm{eff}$, although the Bayes factor decreases as $v_\mathrm{eff}$ decreases, the lensed and unlensed models can still be distinguished within our parameter range.
Read the full abstract ▾
All authors Yan Sun, Yong Yuan, Minghui Du, Wen-Fan Feng, Xilong Fan, Peng Xu
Earth and Planetary Astrophysics
Large-scale Morphology of the Optical F-corona from a Total Solar Eclipse Observation During the Artemis II Lunar Flyby
Kohji Tsumura and Ko Arimatsu
We investigated the structure of the optical F-corona, i.e., inner zodiacal light, using a publicly released wide-field image of a total
solar eclipse that was obtained during the Artemis~II crewed lunar flyby. In this image, the
solar disk is fully occulted by the Moon, providing a rare view of diffuse circumsolar emission over a wide angular extent. Although the
dataset is derived from a rendered RGB JPEG image without full photometric calibration, the gamma correction inherent to the image format was explicitly accounted for and the instrumental response was validated using field
stars. The
stellar calibration demonstrates a linear response within the unsaturated regime relevant to our measurements, enabling a reliable analysis of the relative morphology and brightness profiles of the F-corona. The observed F-corona exhibits a flattened, nearly elliptical morphology aligned with the ecliptic plane, with flattening indices of 0.52, 0.54, and 0.56 for the red, green, and blue channels, respectively. Radial intensity profiles along ecliptic longitude and latitude are well described by power laws in
solar elongation, although the derived slopes are systematically steeper than previous observations. Comparison with the ZodiSURF zodiacal light model indicates that the observed radial profile of the F-corona along the ecliptic longitude is modestly reproduced by the model, supporting a radial
dust number-density power-law index of $\alpha$ ~1.3, even in regions near the Sun. In a broader historical context, these results provide an empirical proof-of-concept that supports future
solar coronal occultation observations from lunar orbit.
Read the full abstract ▾
Instrumentation and Methods for Astrophysics
The 256-antenna Coherent All-Sky Monitor
Liam Connor, Vikram Ravi, Pranav Sanghavi et al. (+16 more)
Radio astronomy is uniquely coupled to exponential trends in computation because the optics (cross-correlation, beamforming, and imaging) and spectrometry (i.e. channelization) can now be done digitally. Inexpensive analog-to-digital converters (ADCs) can sample signals from large numbers of
antennas and graphics processing units (GPUs) allow us to coherently process wide-field
radio data in real time, motivating large-$N$ aperture arrays at moderate cost. We describe the 256-
antenna Coherent All-Sky Monitor (CASM-256), a dense aperture array operating at 375-500\,MHz, currently being deployed at the Owens Valley
Radio Observatory (OVRO) in Big Pine, California. The large field-of-view (FoV$\sim10^4$\,deg$^2$) and point-source sensitivity of CASM-256 will allow it to detect local Universe fast
radio bursts (FRBs). The nearby sample is ideal for unveiling the physical origin of FRBs, measuring the baryonic content of nearby
galaxy halos, and discovering
prompt multi-wavelength and multi-messenger counterparts to FRBs. CASM will search for fast transients in the Milky Way such as FRB analogs,
pulsar giant pulses, and the new source class known as long-period
radio transients. We describe the instrument and present on-sky data from the first two dozen
antennas, including an operational real-time GPU based FRB search pipeline. We emphasize the scalability of the concept and describe paths to a future CASM array with tens of thousands of
antennas that could detect one million FRBs.
Read the full abstract ▾
All authors Liam Connor, Vikram Ravi, Pranav Sanghavi, Vishnu Balakrishan, Luke Chung, Saren Daghlian, Liam Dunn, Anthony Griffin, Charlie Harnach, Mark Hodges, Andrew Jameson, Michael Gutierrez, Calvin Leung, Mei Lin, Advait Mehla, Obinna Modilim, Nimesh Patel, Kendrick Smith, Lingzhen Zeng
Instrumentation and Methods for Astrophysics · Cross-listed from eess.SP
Interferometer observations of pulse pairs in an interstellar communication experiment
William J. Crilly Jr
Synchronized
radio telescope-based experiments conducted since 2017, together with subsequent interferometer experiments, provide evidence of an anomalous source of 3.7 Hz bandwidth pulses, sourced from near the direction of the
star Rigel. The current experiment, reported here, uses a two-element phase-measuring interferometer to monitor the hypothetical pulse source across azimuths within the beam-widths of the elements of a south-facing interferometer. 123 days of phase measurements of 3.7 Hz bandwidth pulse pairs, adds to the prior evidence that the pulsing signal source has celestial origin. Associated measurements of noise power in 954 Hz and 50 MHz bandwidths, made simultaneous with the 0.27 second duration pulse pair measurements, are presented. Measurement results are presented to aid in the development of independent experimental replication, and alternate and auxiliary explanatory hypotheses.
Read the full abstract ▾
High Energy Astrophysical Phenomena
Correlation between Ultrahigh-Energy Neutrino KM3-230213A and Gamma-Ray Bursts
Ruiqi Wang and Bo-Qiang Ma
The KM3NeT Collaboration reported the detection of a
neutrino, designated as KM3-230213A, with a reconstructed energy peaking at 220 PeV and equatorial coordinates (J2000) of RA=$94.3\degree$ and Dec=$-7.8\degree$. As the highest-energy
neutrino event documented to date, its astrophysical origin remains unascertained. Prior preliminary investigations have probed potential associations between this
neutrino event and gamma-ray bursts (GRBs), factoring in the possibility of Lorentz invariance violation (LV). In this study, we perform a comprehensive analysis to explore correlations between KM3-230213A and all viable GRBs. We explicitly account for the angular uncertainties intrinsic to both the
neutrino event and the respective GRBs. Our analysis identifies a larger set of correlated GRBs. For each associated GRB, we compute the LV scale, integrating uncertainties from
redshift measurements and
neutrino energy determinations to enhance the robustness of our findings.
Read the full abstract ▾
Cosmology and Nongalactic Astrophysics · Cross-listed from gr-qc
Robust parameter inference for Taiji via time-frequency contrastive learning and normalizing flows
Tian-Yang Sun, Bo Liang, Ji-Yu Song et al. (+6 more)
Transient noise artifacts, commonly referred to as glitches, pose a major challenge to parameter inference for space-based gravitational-wave (GW) observations. We develop a glitch-robust amortized inference framework for massive black hole binaries in the Taiji detector configuration by combining conditional normalizing flows, a time-frequency
multimodal fusion encoder, and contrastive learning. To enable large-scale training on contaminated data, we further introduce a neural glitch generator that produces high-fidelity synthetic transients at substantially reduced computational cost. Systematic experiments show that, under glitch contamination, the proposed method yields more accurate and better-calibrated posteriors than a conventional Markov Chain Monte Carlo baseline. In ablation studies, the full time-frequency model with contrastive learning performs best overall and remains robust to variations in glitch duration and merger-relative timing. We further show that standard coverage diagnostics alone are insufficient to fully assess posterior fidelity. We therefore complement them with the continuous ranked probability score, which provides a stricter assessment of global distributional agreement in non-ideal GW data. Taken together, these results establish deep-learning-based amortized inference as a promising framework for fast and robust
Bayesian parameter estimation in future space-based GW observations.
Read the full abstract ▾
All authors Tian-Yang Sun, Bo Liang, Ji-Yu Song, Song-Tao Liu, Shang-Jie Jin, He Wang, Ming-Hui Du, Jing-Fei Zhang, Xin Zhang
Cosmology and Nongalactic Astrophysics
Dark energy, spatial curvature, and star formation efficiency from JWST photometric and spectroscopic high-redshift galaxies
Leonardo Comini, Sunny Vagnozzi and Abraham Loeb
Early observations from the James Webb Space
Telescope (JWST) have revealed an overabundance of massive high-
redshift galaxies, raising the question of whether this points to new physics beyond $\Lambda$CDM, or an enhanced formation efficiency of massive
stars. We revisit this issue going beyond earlier analyses based on direct comparisons to theoretical bounds at a fixed cosmology, by performing a full
Bayesian analysis of the most extreme
galaxies in the CEERS imaging and FRESCO spectroscopic samples, jointly constraining cosmological parameters and the
baryon-to-
star conversion efficiency $\epsilon$. We do so not only within the spatially flat $\Lambda$CDM model, but also in models where the dark energy equation of state $w$ and/or the spatial
curvature parameter $\Omega_K$ are allowed to vary, carefully discussing the impact of both $w$ and $\Omega_K$ on the cumulative comoving
stellar mass density. Within the flat $\Lambda$CDM model, once cosmological parameters are marginalized over, the CEERS sample provides a weak $2\sigma$ lower limit of $\epsilon \gtrsim 0.07$, compatible with astrophysical expectations. In contrast, the FRESCO sample requires $\epsilon \gtrsim 0.5$ at $2\sigma$, with values $\epsilon \lesssim 0.2$ disfavored at $>5\sigma$. These results do not qualitatively change when we allow $w$ and/or $\Omega_K$ to vary, with no evidence for deviations from $w=-1$ or $\Omega_K=0$. Our results therefore suggest that the origin of the “JWST tension” is unlikely to be cosmological, but lies in the astrophysics of
galaxy formation.
Read the full abstract ▾
Astrophysics of Galaxies
Witnessing the Earliest Phases of Galactic Wind Formation in Superluminous Supernova Hosts: Implications for Star-formation-driven Outflows in Low- and High-redshift Galaxies
A. Saldana-Lopez, A. Gkini, M. J. Hayes et al. (+6 more)
Direct observational constraints on the earliest phases of
galactic outflows remain scarce. We present Very Large
Telescope/X-shooter spectroscopy of seven Type I superluminous
supernova (SLSN-I) host
galaxies at $z = 0.15 - 0.51$, exploiting the bright SLSN continua as down-the-barrel probes of the host interstellar medium. Five of the seven hosts exhibit narrow, blueshifted MgII $\lambda\lambda$2796,2803 absorption, indicative of the presence of low-ionized
outflows. Voigt modeling of the MgII absorption yields bulk
outflow velocities of $45-99 {\rm ~km~s^{-1}}$ and terminal velocities of $v_{\rm max} \simeq 103-164 {\rm ~km~s^{-1}}$ the latter being below the ones reported for more evolved
galaxies of similarly low mass and
star formation rate. Given the expected short lifetimes of massive SLSN progenitors, we argue that these
outflows are most naturally explained as originating during the preceding
stellar-wind-dominated phase. We derive wind masses of $M_{\rm wind} \simeq 10^{4}-10^{5} M_{\odot}$, mass
outflow rates comparable to or lower than the
star formation rates, and kinetic energies of $10^{51}-10^{52}$ erg. These energies represent only a modest fraction ($\simeq 10\%$) of the mechanical energy expected from
stellar winds during the first few Myr, demonstrating that the observed
outflows can be powered entirely by pre-
supernova feedback. Together with their low terminal velocities, these results support a scenario in which
stellar winds and radiation pressure dominate the early acceleration of cold
outflows, before core-collapse
supernovae become dynamically important. Our work provides one of the first empirical constraints on early feedback phases relevant for high-
redshift galaxies and for time-dependent implementations of
stellar feedback in
galaxy formation simulations.
Read the full abstract ▾
All authors A. Saldana-Lopez, A. Gkini, M. J. Hayes, R. Lunnan, C. A. Carr, M. Huberty, C. Scarlata, S. Schulze, J. Sollerman
Cosmology and Nongalactic Astrophysics
Denoising clustering covariance matrices with Rotational Invariant Estimators
Antonio Farina, Massimo Guidi, Alfonso Veropalumbo et al. (+1 more)
Cosmological parameter inference from
galaxy clustering relies critically on accurate estimates of the covariance and precision
matrices. These are often obtained from a limited number of mock catalogs, introducing noise and bias in the precision
matrix when the data-vector dimension becomes comparable to the number of available realizations. We present the first application of the Rotational Invariant
Estimator (RIE) to the large-scale clustering of
galaxies, benchmarking it against the standard sample covariance and the non-linear shrinkage
estimator NERCOME for both the two-point correlation function (2PCF) and power spectrum. Using controlled synthetic data sets with analytically known covariance
matrices, we estimate the covariance with all three methods across a range of mock-to-dimension ratios $q = N/D$ and data-vector sizes $D$. We then perform
Bayesian inference with an EFT-based model and quantify each
estimator through the Figure of Bias (FoB) and Figure of Merit (FoM). After correction for finite-$N$ effects, the sample covariance recovers unbiased average uncertainty volumes but suffers from growing best-fit scatter and bias at small $q$ due to the Dodelson–Schneider effect. Both NERCOME and RIE substantially reduce these
stochastic shifts; however, the uncertainties they assign are probe-dependent. In configuration space, both
estimators can yield overly tight constraints, with a bias that grows with $D$. In
Fourier space, RIE delivers markedly improved best-fit stability with only mild FoM bias, whereas NERCOME tends to overestimate the constraining power. Among the
estimators tested, RIE emerges as the most effective at stabilizing best-fit recovery, particularly in
Fourier space, where it closely reproduces the reference posteriors even when the number of mocks barely exceeds the data-vector dimension.
Read the full abstract ▾
All authors Antonio Farina, Massimo Guidi, Alfonso Veropalumbo, Claudio Guida
High Energy Astrophysical Phenomena · Cross-listed from gr-qc
Basilic: An end-to-end pipeline for Bayesian burst inference and model classification in gravitational-wave data
Iuliu Cuceu and Marie Anne Bizouard
We present Basilic, a dedicated pipeline for
Bayesian model selection and parameter estimation of short-duration gravitational-wave burst signals observable with ground-based detectors. Built on top of the bilby framework, Basilic combines modularity, pre-implemented burst models, and HTCondor integration to enable rapid, user-friendly analyses with minimal technical overhead. This work outlines the design philosophy, operational flow, and a set of example use cases demonstrating its scientific potential. As a case study, we also undertake an in-depth exploration of the comparison between a binary black hole merger and a
cosmic string signal, through a parameter space exploration injection campaign. In addition to the well-known high-mass binary black-hole signal morphology degeneracy with
cosmic string-like signals, we find that high anti-aligned component
spins, even at moderate mass, can result in a similar degeneracy. Motivated by the likely low-SNR expected regime of possible future detections, we propose a data-driven study of model degeneracy, to be employed in the event of an inconclusive Bayes factor.
Read the full abstract ▾
Instrumentation and Methods for Astrophysics · Cross-listed from physics.soc-ph
Projections of Earth's Technosphere: Civilization Collapse-Recovery Dynamics and Detectability
Celia Blanco, Jacob Haqq-Misra and George Profitiliotis
How long a technological civilization remains active, and what determines whether it collapses or persists, is a central question for both projecting humanity's future and assessing the prevalence of detectable intelligence in the
galaxy. We model collapse-recovery dynamics across ten plausible futures for Earth-originating civilization using a hybrid deterministic-
stochastic simulation over a 1000-year window. The duty cycle, defined as the fraction of its total lifespan that a civilization is technologically active, ranges from ~0.38 to 1.00, with trajectory outcomes shaped by the interplay of governance structure, resource pressure, and hazard exposure. Several model parameters map onto actionable resilience levers, and modest improvements can qualitatively alter long-term trajectories. Sensitivity analysis reveals that the resource depletion rate and the post-collapse recovery fraction are consistently the most impactful levers across scenarios, suggesting that reducing resource consumption may be at least as important as mitigating existential hazards for avoiding civilizational collapse. We discuss implications for Earth's civilizational resilience and for the search for extraterrestrial technosignatures. We also derive an effective detectability duration that accounts for intermittent civilizational activity, and show that the apparent absence of extraterrestrial signals may reflect the prevalence of low-duty-cycle civilizations rather than the rarity of intelligent life.
Read the full abstract ▾
Solar and Stellar Astrophysics
JOYS$+$: A JWST/MIRI survey of the evolution of H$_2$ winds and jets from low-mass protostars
L. Francis, Ł. Tychoniec, E. F. van Dishoeck et al. (+20 more)
Protostellar
outflows display wide-angle winds and collimated jets, the magnetocentrifugal launching of which enables
accretion onto the protostar. The majority of the
outflow mass is likely ejected or entrained molecular H$_2$, which can now be studied in unprecedented detail with JWST. Using JWST MIRI/MRS observations towards 13 single and 20 multiple Class 0 and I protostars, we investigate the nature and
evolution of the H$_2$ wind and jet morphology, mass
outflow rate, and velocity and temperature structure. We construct line flux and velocity maps of the H$_2$ S(1) and S(7) lines as well as the sub-mm CO traced by ALMA. Low-$J$ ($J\le4$) H$_2$ transitions trace extended wide-angle, low-velocity (0-20 km s$^{-1}$) winds within the contours of the low-velocity ($< 30$ km s$^{-1}$) sub-mm CO emission, while high-$J$ ($J >5$) transitions are associated with shocks and
knots. In Class 0 sources with a known high-velocity ($> 30$ km s$^{-1}$) molecular CO or SiO jet, higher H$_2$ velocities are found along the jet axis. The opening angle of the wind traced by the H$_2$ S(1) line broadens from $\sim20^\circ$ to $\sim90^\circ$ through the Class 0 to Class I stage. Near the base of each blue-shifted
outflow lobe, we extract representative spectra, where rotation diagram fitting of the H$_2$ lines is combined with the
outflow width and H$_2$ line velocity to measure the mass-loss rates. The rotation diagrams show a warm $\sim 600$ K, component with two orders of magnitude more mass than the hot, 1500-3000 K component. The H$_2$
outflow mass-loss rates decline by two orders of magnitude from the Class 0 to Class II stage and are correlated with bolometric luminosity. The declining warm H$_2$ mass loss rates and increasing opening angles from the Class 0 to I stages, and the absence of H$_2$ jets in the Class I sources, are consistent with the predictions of MHD disk wind models.
Read the full abstract ▾
All authors L. Francis, Ł. Tychoniec, E. F. van Dishoeck, A. D. Sellek, A.Caratti o Garatti, V. J. M. Le Gouellec, C. Gieser, H. Beuther, J. M. Vorster, M. E. Ressler, P. Nazari, B. Tabone, K. Assani, R. Devaraj, J. J. Tobin, Maria Gabriela Navarro, P. C. Cortés, J. M. Girart, M. Güdel, Th. Henning, G. Östlin, G. Wright, T. Ray
High Energy Astrophysical Phenomena
Radiative cooling effects on black hole hot accretion flows around the sub-Bondi radius
Mu-Qing Liu, Xiao-Hong Yang and De-Fu Bu
It is difficult to implement numerical simulations on a region extending from the vicinity of a black hole to the Bondi radius. Most previous numerical simulations have primarily concentrated on the region close to the black hole. They found that strong winds can be generated in the hot
accretion flows near the black hole, and that radiative cooling significantly affects the strength of these winds. However, the effects of radiative cooling on the production and properties of winds around the Bondi radius remain unclear. In this paper, we perform two-dimensional magnetohydrodynamic simulations to study the impact of radiative cooling on the dynamics and wind production in hot
accretion flows around the sub-Bondi radius. As the increase of mass
accretion rate, radiative cooling gradually becomes strong, resulting in a reduction in the thickness of the
accretion disk (defined as the
accretion flows within the density scale height). Based on the Høiland criterion, we find that within the
accretion disk, the region of convective stability accounts for $\sim$ 55 - 62 %, and therefore the
accretion flows are marginally stable in convective stability. In the runs with weak radiative cooling, the winds play a significant role in the inward decrease of the mass inflow rate. In the runs with strong radiative cooling, the mass
outflow rate of winds is significantly reduced and then the inward decrease of the mass inflow rate is mainly attributed to
turbulence driven by magnetorotational instability and convection. Radiative cooling has the potential to suppress
accretion processes and reduce the power of winds.
Read the full abstract ▾
Cosmology and Nongalactic Astrophysics
Optical depth to reionization in a Universe with multiple inhomogeneous domains
Shashank Shekhar Pandey, Ruchika, Subhadeep Mukherjee et al. (+1 more)
We study the optical depth to reionization in a cosmological setting that includes backreaction from matter inhomogeneities, using the Buchert averaging formalism. We construct a spacetime model consisting of multiple inhomogeneous domains, hereafter referred to as the backreaction model, characterized by a set of parameters. We first examine how these parameters influence the computation of the optical depth to reionization, $\tau_{reion}$. Next, we carry out a Markov Chain Monte Carlo (MCMC) analysis based on the PantheonPlus+SH0ES Type Ia
supernova sample to infer the best-fit values of the model parameters, and then use these to evaluate $\tau_{reion}$. We obtain $\tau_{reion} = 0.0581^{+0.0105}_{-0.0096}$ (68$\%$ confidence limits). This result indicates that, when PantheonPlus+SH0ES data are used to constrain the model parameters, our backreaction model yields a value of $\tau_{reion}$ that aligns more closely with observational estimates than the value predicted by the standard cosmological model. We further demonstrate that the backreaction model leads to a modest reduction of the Hubble tension, while avoiding the need for exotic or non-standard physics.
Read the full abstract ▾
All authors Shashank Shekhar Pandey, Ruchika, Subhadeep Mukherjee, A. S. Majumdar
Cosmology and Nongalactic Astrophysics
Reanalysing large-scale structure using an updated gamma-ray burst spatial density approach
Istvan Horvath, Zsolt Bagoly, Jon Hakkila et al. (+6 more)
In the past few decades, large universal structures have been found that challenge the homogeneity and isotropy expected in standard cosmological models. This study examines burst clustering in both
galactic hemispheres using a recently developed methodology, using spheres in 3D space for testing regularities. Using our new method in both hemisphere we find only one deviation from isotropy. A small one in the Southern and a huge one in the Northern hemisphere. This itself suggests that the two deviations do not likely to come from statistical fluctuation. The northern huge group contains app. 125 gamma-ray bursts (GRBs) corresponds with the so - called Hercules-Corona Borealis Great Wall. The southern group contains 4-5 GRBs locating very close to each other. Two of them (GRB050822 and GRB050318) are close not just in
redshift and the angular position but they are very close in observing time (5 months). We concluded that the third important result of this work that this method could not find other overdensity deviation from homogeneity in the GRBs spatial distribution. We have shown that the large-scale density increase in the spatial distribution of gamma-ray bursts does not necessarily violate the cosmological principle.
Read the full abstract ▾
All authors Istvan Horvath, Zsolt Bagoly, Jon Hakkila, Lajos G. Balazs, Janos Horvath, Sandor Pinter, Istvan I. Racz, Peter Veres, L. Viktor Toth
High Energy Astrophysical Phenomena
JWST spectroscopy of SN 2010da/NGC 300 ULX-1: a surviving star hidden by dust
Emma R. Beasor, Ryan Lau, Nathan Smith et al. (+3 more)
We present new James Webb Space
Telescope ($JWST$) NIRSpec and MIRI integral-field spectroscopy of the remarkable system SN~2010da / NGC~300 ULX-1, the only known ultraluminous X-ray source powered by a
neutron star with a supergiant donor. Our new data, taken in November 2024, reveal that the optical and near-infrared counterpart has dramatically faded since 2018 and no longer exhibits molecular absorption features characteristic of a red supergiant. Instead, the spectral energy distribution shows the donor has returned to its pre-outburst appearance, and is dominated by infrared continuum consistent with an optically thick warm ($\approx$900~K)
dust shell. The bolometric luminosity indicates the presence of a surviving luminous source with $\log(L/L_{\odot})=4.11\pm0.02$. Radiative transfer modelling of the mid-infrared spectral energy distribution (SED) reveals a broad emission feature peaking near $\sim$11\,$\mu$m, best reproduced by silicon carbide (SiC)
dust grains, a composition typically associated with carbon-rich evolved
stars. We rule out a failed
supernova scenario, which would predict a large drop in luminosity and continued fading. Given the association of SiC
dust with AGB
stars, we suggest the donor
star may be an AGB
star that has survived and is now heavily enshrouded - having returned to a
dust-obscured state following a transient post-outburst phase in which the system appeared as a red supergiant. We propose a revised evolutionary timeline in which the 2010 outburst initiated sustained super-Eddington
accretion and temporarily altered the circumstellar environment. These observations provide rare insight into eruptive mass loss,
dust formation, and binary interaction in a unique system.
Read the full abstract ▾
All authors Emma R. Beasor, Ryan Lau, Nathan Smith, Dominic J. Walton, Marianne Heida, Ben Davies
Instrumentation and Methods for Astrophysics · Cross-listed from gr-qc
Automatic classification pipeline for glitches in the Virgo detector
Tiago Fernandes, Francesco Di Renzo, Antonio Onofre et al. (+2 more)
Glitches frequently contaminate data in gravitational-wave detectors, complicating the observation and analysis of astrophysical signals. This work introduces VIGILant, an automatic pipeline for classification and visualization of glitches in the Virgo detector. Using a curated
dataset of Virgo O3b glitches, two machine learning approaches are evaluated: tree-based models (Decision Tree, Random Forest and XGBoost) using structured Omicron parameters, and Convolutional Neural Networks (ResNet) trained on spectrogram images. While tree-based models offer higher interpretability and fast training, the ResNet34 model achieved superior performance, reaching a F1 score of 0.9772 and accuracy of 0.9833 in the testing set, with inference times of tens of milliseconds per glitch. The pipeline has been deployed for daily operation at the Virgo site since observing run O4c, providing the Virgo collaboration with an interactive dashboard to monitor glitch populations and detector behavior. This allows to identify low-confidence predictions, highlighting glitches requiring further
attention.
Read the full abstract ▾
All authors Tiago Fernandes, Francesco Di Renzo, Antonio Onofre, Alejandro Torres-Forné, José A. Font
Astrophysics of Galaxies
CHILES XII: The H I evolution of Luminous Compact Blue Galaxies between 0<z<0.48
H. Arlow, D. J. Pisano, M. A. Bershady et al. (+6 more)
We study the
evolution of Luminous Compact Blue
Galaxies (LCBGs) by making use of H I emission line data provided by the full 856 h COSMOS H I Large Extragalactic Survey (CHILES), which spans a
redshift range of $0\leq z\leq 0.48$ within the COSMOS field. We report the results on a cubelet stacking analysis, which we use to estimate the average H I mass
evolution of LCBGs in the field up to $z=0.48$. For the stacks that do not show a detection, we report an upper limit estimate of the average H I mass. We also report on two directly detected LCBGs. We find the average H I mass in LCBGs at
redshifts $z=0.26$, $z=0.35$ and $z=0.45$ respectively to be $\langle M_{\rm HI}\rangle<4.89\times10^9$ M$_\odot$, $\langle M_{\rm HI}\rangle=(2.49\pm0.75)\times10^9$ M$_\odot$ and $\langle M_{\rm HI}\rangle=(6.44\pm2.71)\times10^9$ M$_\odot$. We see no strong evidence for
evolution in the average H I mass over this
redshift range, consistent with other recent studies of the
evolution of the H I in
galaxies at $z<0.5$. On average, LCBGs appear to retain substantial gas reservoirs, with gas fractions staying constant and remaining broadly consistent with those of the larger
star-forming population. LCBG gas depletion timescales are nearly an order of magnitude shorter than in normal
star-forming
galaxies across the studied
redshift range, aligning with the period during which their number density drops sharply.
Read the full abstract ▾
All authors H. Arlow, D. J. Pisano, M. A. Bershady, L. R. Hunt, N. Luber, J. Donovan Meyer, E. Momjian, J. Blue Bird, H. B. Gim
Cosmology and Nongalactic Astrophysics · Cross-listed from hep-ph
Axion Inflation from Heavy-Fermion One-Loop Effects
Kai-Ge Zhang, Jian-Feng He, Chengjie Fu et al. (+1 more)
We derive a one-loop effective description of
axion inflation by integrating out a heavy Dirac
fermion with an inflaton-dependent complex mass undergoing a smooth localized threshold transition. The threshold induces correlated corrections to the inflaton and gauge sectors, including a Coleman-Weinberg term, a
vacuum-polarization correction, and an anomaly-induced Chern-Simons coupling. Together, these effects transiently enhance and localize gauge-field production, generating a
chiral stochastic gravitational-wave background in the deci-hertz band within the projected sensitivities of BBO and DECIGO, while remaining below representative
primordial-black-hole bounds.
Read the full abstract ▾
All authors Kai-Ge Zhang, Jian-Feng He, Chengjie Fu, Zong-Kuan Guo
Astrophysics of Galaxies
ALMA-QUARKS view of W49N: Multipolar episodic outflow associated with the most energetic Galactic water maser
Yunfan Jiao, Tie Liu, Wenyu Jiao et al. (+28 more)
We present a detailed investigation of a multipolar episodic molecular
outflow in the mini-starburst region W49N, which hosts the most luminous water maser in the
Galaxy. Using high-resolution ($\sim$0.3 arcsec) Atacama Large Millimeter/submillimeter Array (ALMA) observations of the $\mathrm{^{12}CO}$ emission as part of the ALMA-
QUARKS survey, we analyze the morphology and kinematics of the
outflow. Our observations reveal four newly identified
outflow lobes in addition to the previously known central bipolar jet. These lobes appear more jet-like rather than exhibiting wide opening angles. Based on the $\mathrm{^{12}CO}$ (2-1) and $\mathrm{^{13}CO}$ (2-1) emission, we provide a more reliable estimate of the
outflow's physical parameters, confirming it as one of the most energetic
outflows in the
Galaxy. Notably, these newly discovered lobes exhibit chains of
knots, a characteristic signature of episodic ejection. Furthermore, two of the lobes display prominent S-shaped wiggles, suggestive of a precessing jet. The discovery of these features – commonly observed in
outflows from low-mass protostars – in such an extreme massive
star-forming environment provides compelling evidence that some underlying physical mechanisms for launching
outflows are conserved across a wide range of
stellar masses.
Read the full abstract ▾
All authors Yunfan Jiao, Tie Liu, Wenyu Jiao, Fengwei Xu, Qilao Gu, Xindi Tang, Xiaofeng Mai, Qiuyi Luo, Siju Zhang, Paul F. Goldsmith, Chang Won Lee, Guido Garay, Yuhan Yang, Prasanta Gorai, Manuel Merello, Pablo Garcia, Sami Dib, Jihye Hwang, Ariful Hoque, Mika Juvela, Yankun Zhang, Patricio Sanhueza, Jixiang Weng, Kee-Tae Kim, Swagat R. Das, Archana Soam, Tapas Baug, Jianjun Zhou, Leonardo Bronfman, Aiyuan Yang, Lei Zhu
Solar and Stellar Astrophysics
Probing Coronal Activity Using Radio Signals Based on the 2021 superior conjunction of Mars: the Downlink Data from Tianwen-1
Yu-Chen Liu, De-Qing Kong, Song Tan et al. (+6 more)
During the first superior conjunction of the Tianwen-1 Mars probe in October 2021, its downlink signal received by the Wuqing 70-m
radio telescope passed within 4.53
solar radii of the Sun. The signal was significantly perturbed by the
solar wind, providing a mechanism to probe coronal activity. We analyze the Doppler frequency scintillation spectrum of the
solar wind within 10
solar radii to derive a characteristic frequency scintillation parameter. Statistical analysis indicates this parameter increases as the signal path approaches the Sun, with notable anomalies observed on October 5, 13, and 15. Comparisons with SOHO and SDO data reveal strong spatio-temporal correlations between these scintillation anomalies and coronal activity. We demonstrate that this parameter effectively identifies
solar phenomena, including coronal streamers, high-speed
solar wind, and coronal mass ejections (CMEs). Quantitative analysis confirms a distinct temporal correlation and delay between frequency scintillation and
solar wind speed changes, validating the feasibility of spatially localizing
solar activity.
Read the full abstract ▾
All authors Yu-Chen Liu, De-Qing Kong, Song Tan, Zi-Han Zhao, Zan Wang, Dong-Hao Liu, Xin-Ying Zhu, Yan Su, Hong-Bo Zhang
Astrophysics of Galaxies
Massive star clusters and clumps in the collisional ring galaxy Arp 147
Z. Randriamanakoto, M. Rakototafika, B. Mongwane et al. (+2 more)
We conduct a photometric study of
star clusters (or
knots) in the collisional ring
galaxy (CRG) Arp 147 to trace the
star formation history across its empty ring. Using HST F450W, F606W and F814W images, we find that Arp 147 hosts 211
knots and six kpc-size clumps, nearly 60 per cent of which have ages below 10 Myr, and two thirds have masses above $\rm 10^{5}\,M_{\odot}$. The cluster mass function (CMF) of
knots with ages between $10 - 200$ Myr deviates from a power-law and follows a Schechter function with a characteristic truncation mass of ${\rm M}_{c} = 6.2 \times 10^{5} \, {\rm M}_{\odot}$. This shape of the CMF is more prominent for a subsample of
knots in the eastern region of the ring. Over the same age interval, we derive a low rate of disruption ($\delta \sim 0.25$) from the cluster age function and a cluster formation efficiency (CFE) of $\sim$ 3 per cent. In contrast, the CFE in the $1 - 10$ Myr age range is nearly 40 per cent. We note the lack of high-resolution UV and H$\alpha$ observations to help break age-extinction degeneracy which affects the derived ages for dusty young clusters and old ones with low reddening. Nevertheless, this study has shown, at least to a first-order approximation, that collision-triggered starburst events happening across the CRG offer an ideal environment for a second generation of young blue
knots to form in abundance. It also suggests that the drop-through collision between the two
galaxies can fuel at least mild cluster disruption over time.
Read the full abstract ▾
All authors Z. Randriamanakoto, M. Rakototafika, B. Mongwane, P. Väisänen, M. Rakotomanga