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Research Trends

Latest preprints in space engineering and astrophysics.

astro-ph.SRastro-ph.IM

Automated Solar Radio Burst Detection Using Deep Learning on Augmented e-Callisto Data

Vincenzo Timmel, André Csillaghy, Christian Monstein

Solar radio bursts are signatures of energetic events associated with solar flares and coronal mass ejections and can interfere with terrestrial and space-based communication systems. Real-time automatic burst monitoring enables early warnings tens of minutes to hours before associated particles reach Earth and provides the basis for long-term statistical studies. The e-Callisto network is a worldwide system of solar radio spectrometers providing continuous observations, with its instruments col…

astro-ph.COastro-ph.GA

Anisotropic Secondary Bias of Dark Matter Haloes in a $Λ$CDM Universe

Qinglin Ma, Cheng Li

Secondary bias is the dependence of halo clustering on properties beyond halo mass. Using the $z=0$ TNG300-1-Dark simulation, we study anisotropic secondary bias (ASB): the variation of secondary bias with direction relative to the halo major axis. We first use ordinary, orientation-averaged secondary bias (OSB) as a baseline to compare three environmental manifestations: halo-environment alignment, outer matter anisotropy, and tidal anisotropy. Matching tidal anisotropy suppresses much of the O…

astro-ph.IMastro-ph.GAastro-ph.HEastro-ph.SR

The IMF package: a toolkit implementing mass functions and statistical tools to analyze them

Theo Richardson, Adam Ginsburg, Sergey Koposov

Mass functions are used in all areas of astrophysics. The stellar initial mass function (IMF), in particular, plays a central role in modeling stellar populations in galaxies. However, few dedicated tools for working directly with the IMF and its precursor functions are widely available. We present the $\texttt{imf}$ package, a Python library integrated into the wider scientific Python ecosystem that implements common and variant forms of mass functions, especially the IMF and its pre- and proto…

astro-ph.SR

Understanding the Travel-time Asymmetry of Acoustic Waves in Sunspots With Time-distance Helioseismology

Haiyu Li, Tobías Felipe, Elena Khomenko, Hui Tian, Paul Rajaguru, Yuhang Gao

Mapping the subsurface structure and flow field of sunspots has been a challenging task for helioseismology. In this work, we investigate the propagation of acoustic waves in a sunspot in NOAA active region 11312 using time-distance helioseismology. Travel times of waves traveling into and out of the sunspot are measured as functions of travel distance and azimuthal angle relative to the local radial direction. The same time-distance analysis is also applied to a simulated data based on a magnet…

astro-ph.IM

Advancing X-Ray Camera Front-End Electronics Architecture through the AXIS-TAP Technology Platform

Jill Juneau, Declan O'Neill, Peter Orel, Eric Miller, Sven Herrmann, Gregory Prigozhin, Robert Goeke, Elio Angile et al.

Advancing time-domain soft X-ray astronomy demands focal plane readout electronics capable of high-speed digitization with low noise while maintaining spectral fidelity across multiple detector channels. The Advanced X-ray Imaging Satellite (AXIS), a NASA Probe-class mission concept, provided the driving requirements and heritage for developing a generalized high-speed (>=5 fps) camera Front-End Electronics (FEE) architecture applicable to future soft X-ray missions. The FEE architecture defines…

astro-ph.HEastro-ph.GAhep-ex

High-energy neutrino emission from the Milky Way

R. Abbasi, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, J. M. Alameddine, S. Ali, N. M. Amin et al.

The Milky Way hosts astrophysical objects that accelerate cosmic rays to energies beyond the reach of terrestrial particle accelerators. It remains a longstanding goal to locate the sites of these powerful Galactic engines and understand how cosmic rays propagate through the Galaxy, leading to the production of high-energy neutrinos. In this paper, we combine event morphologies characteristic of all three neutrino flavours and apply recent improvements in ice modelling, calibration and reconstru…

astro-ph.EP

Volcanic Satellites and Ion Escape in the Magnetospheres of Ultra-Cool and Brown Dwarf Stars

A. F. Lanza, A. V. Oza

Radio emissions at $\sim$ GHz frequencies of ultra-cool dwarf and brown dwarf stars suggest the presence of radiation belts not unlike Jupiter's. We investigate the possibility the inferred magnetospheric plasma at the primary star is sourced by an active planet or via ion escape modeled as a weak ionospheric outflow. We consider indirect methods to estimate the magnetospheric plasma mass flow from auroral radio emission and apply them to the ultra-cool dwarf LSR J1835+3259. We find that an iono…

astro-ph.IM

CNN-Based Reanalysis of Optical Turbulence at the Canary Islands Observatories (OCAN)

Airam Salas, Begoña García-Lorenzo, Julio A. Castro-Almazán, Gelys Trancho

Atmospheric optical turbulence, caused by refractive-index fluctuations driven by wind and temperature inhomogeneities, is the primary source of image degradation in ground-based telescopes. Its vertical distribution, described by the refractive-index structure constant (Cn2(h)), determines essential parameters such as seeing, isoplanatic angle, and coherence time, which characterize astronomical sites and are also crucial for the design and performance of high-resolution instruments. The Observ…

astro-ph.EP

Orbital Motion and History of Sungrazing Comet C/2026 A1 (MAPS)

Zdenek Sekanina, Malgorzata Krolikowska

We report results of our extensive computations of the orbital motion of comet C/2026 A1, including its integration back to the fourth century and parallel integration of 1000 virtual clones. We focus on this Kreutz sungrazer's apparent association with the daylight comets in AD 363, recorded by Ammianus Marcellinus. We show that the derived time of the previous perihelion is strongly affected by erratic outgassing-driven nongravitational forces and depends on the chosen set of observations. We…

astro-ph.GAastro-ph.SR

The influence of dust destruction on gas cooling

S. A. Drozdov, M. P. Yudkevich

The observed dust abundance in the early Universe significantly exceeds the predictions of models assuming its efficient destruction at supernova shock wave fronts. We investigate the effect of dust on gas cooling behind the shock wave front, taking into account both dust cooling and thermal sputtering of dust grains for various interstellar dust models. Isochoric cooling of a gas element is considered for various initial temperatures (from $3\cdot 10^{5}$ K to $3\cdot 10^{7}$ K) and metalliciti…

astro-ph.SRastro-ph.HE

A systematic assessment of the short-term X-ray behaviour of the $γ$ Cas analogues

Robbie Webbe, Yaël Nazé, N. A. Webb

Context. Overall, $γ$ Cas analogues represent a class of OBe stars displaying bright and hard X-ray emission. This emission was recently determined to be the result of accretion onto a companion white dwarf (WD), which might possibly be a magnetic WD. Aims. We present a systematic review of the properties of $γ$ Cas analogues on short-term (kilosecond, ks) scales to further investigate the nature of the X-ray source. In particular, the presence of periodicities could be associated with the rotat…

cs.CLastro-ph.COastro-ph.IMcs.HCgr-qc

AI's Capability in Assisting Scientific Research in Physics, Astrophysics, and Cosmology II: Project Planning and Proposal Evaluation

Jia Liu, Veena Krishnaraj, Kateryna Vovk, Kosuke Aizawa, Adrian E. Bayer, Linda Blot, Jessica Cowell, Suyog Garg et al.

We investigate how well large language models (LLMs) can assist scientific project planning and proposal evaluation. One-page project plans were independently generated for eight expert-conceived research projects in physics, astrophysics, and cosmology by human researchers and three contemporary LLMs (ChatGPT, Claude, and DeepSeek; mid-2025 models, used with their default tool access). The resulting 32 proposals were blindly evaluated by four human reviewers and two newer frontier LLMs (Claude…

astro-ph.GA

A new look at old devils. II: New insights on classical radio galaxies from MeerKAT and uGMRT

Portia P. Legodi, Tiziana Venturi, Dharam V. Lal, Bernie Fanaroff, Oleg M. Smirnov, Simona Giacintucci

This paper presents a detailed morphological and spectral analysis of a sample of ten radio galaxies observed with the MeerKAT in L-band ($856\, \text{-}\,1712\ \mathrm{MHz}$) and the upgraded Giant Metrewave Radio Telescope in Band-4 ($550\,\text{-}\,850\ \mathrm{MHz}$). Our main goals are to revisit the current classification scheme for classical radio galaxies and study the properties of new radio features in jets, lobes and hot spots, which are becoming increasingly numerous due to the sensi…

astro-ph.SR

A Citizen Science Search for Compact Emission Line Nebulae

Bringfried Stecklum, Peter Bresseler

In recent years, citizen science became an integral part of astronomy. Numerous projects contribute to important studies by involving large communities. While these are getting quite some attention, there are also individual efforts, which are nevertheless very valuable. Here, we report on results of a search for compact optical emission line nebulae, which are signposts of both young and evolved stars. The increased brightness in red photometric bands due to the contribution of shock-excited em…

nucl-thastro-ph.HE

Nuclear matter equation of state and astrophysics

Mateus Reinke Pelicer

Neutron-star masses, radii, and inspiral tidal deformabilities now provide quantitative constraints on the cold equation of state (\eos), favoring relatively soft matter around one to two times nuclear saturation density and substantial stiffening at larger density. These bulk constraints, however, do not uniquely determine the microscopic composition of the stellar core. Hyperons, deconfined quarks, quarkyonic matter, and strong first-order phase transitions remain viable possibilities. This ar…

astro-ph.SR

Binary-induced mass increase and helium enrichment of the envelopes of Type~IIP supernova progenitors

Caroline Mannes, Norbert Langer, Andrea Ercolino

Binary interactions are expected to play a major role in shaping the progenitor population of core-collapse supernovae, particularly in the era of deep, high-cadence transient surveys. Using ComBinE, a rapid binary population synthesis code combining tabulated stellar structure models with physically motivated mass-transfer stability criteria, we find that ~40% of Type II supernova progenitors at Milky Way metallicity originate from mergers between a post-main-sequence star and a main-sequence c…

astro-ph.SR

Exploring if a coronal dimming event can produce coronal hole-like properties

Adriana De-Sassi, Louise Harra, Krzysztof Barczynski, David H. Brooks, Lakshmi Pradeep Chitta, Ioannis Kontogiannis, Säm Krucker, Cristina H. Mandrini et al.

Coronal dimmings, or transient coronal holes, are manifested as a sudden reduction in extreme ultraviolet (EUV) and X-ray emission, often following solar eruptions. We investigate whether a dimming event can produce coronal hole-like plasma characteristics by comparing imaging and spectroscopic observations from Solar Orbiter, Hinode, IRIS, and SDO prior and during the dimming. The SDO/AIA 193 Å emission intensity in the dimming region was reduced to the same level as the neighbouring coronal ho…

astro-ph.EPastro-ph.IM

Constraining the lives and times of exoplanets through evolutionary Bayesian retrievals

Harrison Nicholls, Tim Lichtenberg, Ben Riegler, Robb Calder, Vincent Fortuin

Static retrieval frameworks are leading tools for interpreting exoplanet observations, yet time-independent modelling leaves them prone to degeneracy and unable to resolve exoplanets' histories. The compositions and structures of surveyed super-Earth and sub-Neptune sub-populations remain unclear, but are shaped by physics acting across Gyr timescales. Interpreting these planets as static non-evolving snapshots allows multiple degenerate scenarios to explain their observed properties. We develop…

astro-ph.GAastro-ph.HE

Compiling the largest multiwavelength database of known changing-look AGN: Prospects in the Rubin era

Mariangella Camus, Swayamtrupta Panda

Changing-look active galactic nuclei (CL-AGN) provide a direct way to study accretion and spectral-state changes on timescales of months to years. Still, the known population remains scattered across heterogeneous literature samples. We present a compilation of a homogenized catalog of known CL-AGN and related candidates, designed as a traceable reference database for time-domain and multiwavelength studies. After coordinate homogenization, duplicate removal, and validation, the optical parent c…

astro-ph.SRastro-ph.HE

Progenitor models of supernovae interacting with their binary companions

Andrea Ercolino

The appearance of nearly all core-collapse (CC) supernovae (SNe) is largely affected by the interaction between their progenitors and a close binary companion. Using a comprehensive, state-of-the-art grid of single- and binary stellar evolution models, the relative frequencies of SN types are predicted, as well as the distribution functions of their main properties. SNe that interact with nearby circumstellar material are included, namely those that explode during ongoing binary mass transfer, a…

astro-ph.SRphysics.plasm-phphysics.space-ph

Shear interaction and acceleration of a corotating stream detected by Parker Solar Probe

Andrea Verdini, Simone Landi, Emanuele Papini, Luca Franci, Petr Hellinger, Roberto Livi, Orlando Romeo

Recent analysis of Parker Solar Probe (PSP) and Solar Orbiter data indicates that fluctuations energy is transferred to the bulk flow in fast streams of the solar wind at heliocentric distances between 15 and 120 Rsun. To gain insight into this process, we analyze data collected during the inbound orbit of PSP in Encounter 10, when it is in approximate corotation with the Sun and an accelerating stream is detected between 25 and 45 Rsun. The geometry of the flow indicates that a neighboring very…

astro-ph.SR

Solar Wind Proton Heating and its Effect on Temperature Anisotropy Evolution between 0.05 and 1 au

Etienne Berriot, Arnaud Zaslavsky, Olga Alexandrova, Pascal Démoulin, Petr Hellinger, Lorenzo Matteini

This study focuses on the radial evolution of the solar wind proton adiabatic invariants and temperature anisotropies in the inner heliosphere. More specifically, we study in-situ measurements provided by the Parker Solar Probe, between 0.05 au and 0.25 au from the Sun, and Solar Orbiter spacecraft between 0.3 au and 1 au. Throughout the studied range of radial distances, we observe a significant average heating in the direction perpendicular to the local magnetic field for both fast and slow so…

astro-ph.GA

Ly$α$ Escape in JWST/NIRCam F430M-Selected H$α$ Emitters at $z\simeq5.5$

Cheng Cheng, Zhen-Ya Zheng, Chunyan Jiang, Fengwu Sun, Edo Ibar, Xin Wang, Haojing Yan, Fang-Ting Yuan et al.

We study the Ly$α$ escape fraction ($f_{\rm esc}$) in an H$α$-selected sample of star-forming galaxies at $z\simeq5.5$, identified via JWST/NIRCam F430M excess and covered by archival VLT/MUSE data. By anchoring the intrinsic Ly$α$ production to H$α$ emission, our approach provides a direct and Ly$α$-unbiased probe of the escape of Ly$α$ photons in galaxies with SFR $\gtrsim 0.1\,M_\odot\,{\rm yr^{-1}}$ at this epoch. Ly$α$ emission is detected in 3 out of 12 galaxies covered by VLT/MUSE. Combin…

astro-ph.GA

HI Depletion Begins Well Beyond the Virial Radius: A FAST Stacking Study of 36 Galaxy Clusters to 5R200

Cheng Cheng, Chuan-Peng Zhang, Edo Ibar, Rory Smith, Weiwei Xu, Hyowon Kim, Jia-Sheng Huang, Wei Zhang et al.

We present a stacking study of the neutral atomic hydrogen (HI) content in and around 36 local galaxy clusters at $z<0.07$, using a combination of the FAST all sky HI survey (FASHI) and the extensive spectroscopic catalog mainly from the Dark Energy Spectroscopic Instrument (DESI). We employ spectral stacking techniques to probe the average HI mass and HI-to-stellar mass ratio ($M_{\rm HI}/M_*$) for member galaxies down to stellar masses of $M_*\sim 10^9M_\odot$, spanning a projected cluster-cen…

astro-ph.SRphysics.space-ph

High-Frequency Magnetohydrodynamic Waves with Substantial Energy in the Solar Polar Corona

Yuhang Gao, Hui Tian, Richard Morton, Tom Van Doorsselaere, Daye Lim, Mingzhe Guo, Jiansen He, Zhenyong Hou et al.

The acceleration and heating of the fast solar wind remain long-standing challenges in space physics. One type of leading theoretical models requires high-frequency magnetohydrodynamic (MHD) waves to transport and dissipate sufficient energy in the corona. However, such high-frequency waves with energetically significant amplitudes have never been unambiguously observed, leaving a key gap between theories and observations. Using high-cadence, high-resolution extreme-ultraviolet imaging from Sola…

astro-ph.EPastro-ph.IM

Unmasking (44) Nysa: Evidence for a trilobate structure

Kate Minker, Anthony Berdeu, Gianluca Li Causi, Josef Hanuš, Michaël Marsset, Al Conrad, Fernando Pedichini, Simone Antoniucci et al.

Context. (44) Nysa is one of the largest known E-type asteroids. Light curve inversion models have indicated that it may have an elongated shape commonly found in large binary systems. Aims. We aimed to identify the morphology and presence of possible satellites orbiting Nysa. Methods. We observed Nysa with the visible-wavelengths adaptive-optics instruments SHARK-VIS and SPHERE/ZIMPOL in order to image the object with the highest possible spatial resolution, and visually identified surface feat…

astro-ph.SRastro-ph.EPastro-ph.GA

JWST/MIRI Detection of Molecular H$_2$ Winds from an Edge-on Class II Source HV Tau C

Vinod Chandra Pathak, P. Manoj, Himanshu Tyagi, B. Shridharan, Th. Henning, I. Kamp, A. Caratti o Garatti, B. Banerjee et al.

The evolution of protoplanetary disks is regulated by accretion onto the central star and mass loss through jets and winds. While atomic and ionized outflows are commonly observed, molecular winds in evolved Class II disks remain rarely detected. We characterize the spatial, thermal, kinematic, and dynamical properties of molecular hydrogen (H$_2$) emission from the nearly edge-on Class II disk HV Tau C and assess the impact of its molecular wind. We also constrain accretion using H I recombinat…

astro-ph.HEhep-ph

Pair luminosity and cooling of newborn strange star: Color-flavor-locked and two-flavor color superconducting quarks

Mikalai Prakapenia, Cheng-Jun Xia, Gregory Vereshchagin

Following the previous wor k[1] here we consider early thermal evolution of hot strange stars made of color superconducting quarks in two different pairing states: two-flavor color superconductor (2SC) and color-flavor-locked (CFL) phases, taking into account cooling by neutrinos and electron-positron pair creation due to the Schwinger process. We show that Schwinger luminosity in the electrosphere is a universal function of temperature, independent of quark matter phase for quark chemical poten…

astro-ph.IM

The Lunar Farside Transients and Technology Telescope (LFT3) Mission

David R. DeBoer, Charlie K. Ashe, Owen A. Johnson, Evan F. Keane, Andrew C. Lesh, Richard Lynch, Ella J. Marshall, Steve Prabu et al.

We present here an overview of the Lunar Farside Transients and Technology Telescope (LFT3) mission to take advantage of the extremely clear radio frequency environment on the lunar farside. Radio observations performed from the lunar farside effectively and fully mitigate two unavoidable limitations of terrestrial-based radio telescopes: (i) the prevalence of interfering radio transmitters from human activity; and (ii) the impact of the Earth's ionosphere. However, in the era of cost-effective…

astro-ph.GAastro-ph.EPastro-ph.SR

Detection of HNCOH+ in the interestellar medium

M. Rey-Montejo, I. Jimenez-Serra, T. Millar, R. C. Fortenberry, S. Viti, J. Garcia de la Concepcion, G. Vermarien, M. Sanz-Novo et al.

The detection of magnesium sulphide (MgS) and sodium sulphide (NaS) towards the Galactic Center molecular cloud G+0.693 constitutes the first detection of metal sulphides in the interstellar medium (ISM). However, there is scarce information about the key reactions (either in the gas phase or on grains) involved in their formation. In this paper, we model the chemistry of MgS simulating the passage of a low-velocity shock to recover the abundances recently measured towards G+0.693. Through this…