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Research Trends

Latest preprints in space engineering and astrophysics.

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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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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…

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astro-ph.IM

RAISE: A Low-Frequency Space-Based Payload for Solar Radio and RFI Measurements on the SMiLE Mission

Sangeetha A, Harsha Avinash Tanti, Abhirup Datta, Anshu Kumari, Rajesh Bodade

We present the Radio-wave Apparatus for Investigating Solar & Earth interference (RAISE), a compact low-frequency radio payload proposed for hosting on the SMiLE mission. Operating from Low Earth Orbit, RAISE targets a spectral regime that is largely inaccessible from the ground due to ionospheric effects. The payload is designed to enable space-based observations of low-frequency solar radio emissions while simultaneously characterizing terrestrial and ionospheric radio frequency interference i…

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astro-ph.GAastro-ph.SR

Low-Metallicity Star Formation Survey in Sh2-284 (LZ-STAR): The Core Mass Function

Yu Cheng, Jonathan C. Tan, Morten Andersen, Alva Kinman, Rubén Fedriani, Kei E. I. Tanaka, Yichen Zhang

We present an ALMA 1.3~mm dust continuum study of the dense core mass function (CMF) in Sh2-284, a low metallicity outer Galaxy star-forming complex with $Z\sim1/3$--$1/2~Z_\odot$. The observations cover six far-infrared bright subregions at $\sim$0.65" (3000~au) resolution. We identify a total of 91 candidate dense cores and define a robust catalog of 68 cores with Gaussian fitting. The high-mass CMF above 2.5 Msun is well described by a Salpeter-like slope, with a fiducial forward-modeled valu…

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astro-ph.SR

Toward 3D orbits of wide sdO/B binaries I. Six composite systems spatially resolved with VLTI/GRAVITY

K. Deshmukh, S. Geier, H. Sana, H. Dawson, M. Dorsch, A. J. Frost, U. Heber, T. Kupfer et al.

Hot subdwarf stars (sdO/Bs) are widely considered to be products of binary evolution. A significant fraction of them are found in long-period or wide binaries ($P>500$ d) with main sequence (MS) companions, likely resulting from a stable mass transfer episode where the MS companion stripped the hydrogen envelope of the sdO/B progenitor. Consequently, wide sdO/B binaries represent a key population in our pursuit of understanding stable mass transfer. They exhibit a modest range of orbital periods…

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astro-ph.SR

Herbig AeBe Star AS442A as a UXOR-type system

Nariman Ismailov, Faida Surkhai Huseynova, Volkan Bakış, Namiq Serdar Dzhalilov, Sabahaddin Amanulla Alishov, Shafaq Kamal Ismayilova

Detailed studies of the physical characteristics of young intermediate-mass Herbig Ae/Be (HAeBe) stars require extensive sets of homogeneous observational data collected over long periods. In this paper, we present the results of a multi-year study focusing on the faint Herbig Ae/Be star AS 442A. The goal of this study was to investigate the spectral and photometric variability of the star, utilizing long-term archival photometry alongside our own spectroscopic observations. The long-term photom…

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astro-ph.COastro-ph.GA

Robust Ly$α$ forest constraints on reionization from semi-analytic galaxy formation models

Yuxiang Qin, J. Stuart B. Wyithe

The high-redshift Ly$α$ forest provides one of the most sensitive probes of the final stages of reionization, but its interpretation can depend on how the ionizing sources are modelled. We test the robustness of Ly$α$ forest-inferred reionization histories using Meraxes, a semi-analytic model of galaxy formation and reionization applied to a cosmological volume of $(210h^{-1}{\rm cMpc})^3$ with merger trees augmented down to the atomic-cooling threshold. We construct a suite of source models in…

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astro-ph.GAastro-ph.SR

SKAO-ALMA Synergies in Star Formation Science

Jan Forbrich, Gary A. Fuller, Mark A. Thompson, Eleonora Bianchi, Jaime E. Pineda, Marta De Simone, Tomoya Hirota, Katharine Johnston et al.

We highlight the potential for synergies between the SKA telescopes and ALMA, which will begin to be significant already with SKA Early Science. Broadly within star formation science, we focus on 1) (simultaneous) time domain and variability studies (e.g., of (proto-)stars), which is systematically opening a new observing window that will enable us to better constrain the physics of extreme stellar flares and their interplay with mass accretion in young stars, 2) possibilities for complementary…

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astro-ph.SRastro-ph.GA

Project Hephaistos -- III. Characterizing anomalous infrared sources identified as Dyson-sphere candidates

Andreas J. Korn, Matías Suazo, Erik Zackrisson, Pía Cortés-Zuleta, Adam D. Rains, Armin Nabizadeh

The infrared-flux excess of stars harbouring Dyson spheres represent one potential technosignature of extraterrestrial intelligence. In a previous Project Hephaistos paper, we highlighted seven M dwarfs within 300 pc with unusual infrared properties that seem to resemble those expected for Dyson spheres. In the present study, we present an analysis of photometric and, in some cases, spectroscopic data on these seven objects, plus three additional objects with similar properties, to further const…

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astro-ph.GA

Tracing Obscured AGN Contribution and Number Fraction Across 0 < z < 6 with JWST

Angel Rodriguez Barbosa, Tomotsugu Goto, Daryl Joe D. Santos, Chih-Teng Ling, Tetsuya Hashimoto, Ece Kilerci, Priyanka Jalan, Terry Long Phan et al.

Active galactic nuclei (AGN) are key drivers of galaxy evolution, yet many remain undetected in ultraviolet and optical surveys due to heavy dust obscuration. In these systems, absorbed emission is re-radiated at infrared (IR) wavelengths, making IR observations essential for identifying the full AGN population. Tracking the AGN IR contribution and number fraction provides insight into both the dominance and prevalence of AGN activity across cosmic time. Using the JWST Systematic Mid-infrared In…

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astro-ph.IMastro-ph.COcs.CLgr-qc

AI's Capability in Assisting Scientific Research in Physics, Astrophysics, and Cosmology I: Literature Review

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

We investigate how well large language models (LLMs) can assist with literature reviews for scientific research. We perform a controlled study of eight expert-conceived research projects across the areas of physics, astrophysics, and cosmology. Each project has a defined background and goal, and human experts and AI prompters are asked to perform identical literature review tasks in parallel. We compare the relevant literature selected by humans with that selected by mid-2025 LLMs (ChatGPT-4o, C…

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astro-ph.SR

From simulations to observations of cool plasma: What we can learn from synthetic spectra

V. Jerčić, T. A. Kucera, A. G. M. Pietrow, P. Antolin, J. M. Jenkins

Cool plasma of coronal rain or prominences and filaments is ubiquitous in the solar corona. We explored the synthetic spectra of MgII h&k lines in detail and analyse how well a non-adiabatic magnetohydrodynamic (MHD) simulation of condensations in the corona matches observations when comparing the synthetic with the observed spectra. We applied, a Python implemented, non-local thermodynamic equilibrium (non-LTE) radiative-transfer framework, Promweaver to create synthetic spectra from a 2.5D MHD…

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astro-ph.GA

Distribution of the magnetic field relative to the plane of the Galaxy in the region of the Sagittarius spiral arm

R. R. Andreasyan, H. R. Andreasyan, A. M. Mickaelian, A. G. Suqiasyan, G. M. Paronyan

Faraday rotation data for 492 pulsars and more than 2,700 extragalactic radio sources were used to study the magnetic field, in detail, in the direction of Galactic longitude $33^o$ <l< $63^o$, which partially covers the Sagittarius spiral arm region. It was proposed that the Sagittarius spiral arm lies north of the h=-300 pc plane, where h is the distance from the Galactic plane. The (-) sign indicates that this plane is located in the southern hemisphere of the Galaxy. The magnetic field of th…

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astro-ph.HE

Progenitor and Explosion Mechanism of 3C 397 Indicated from XRISM High-resolution Spectroscopy of Fe-group Elements

Hiroshi Nakajima, Yuken Ohshiro, Shing-Chi Leung, Koji Mori, Yoshiaki Kanemaru, Yoshitomo Maeda, Hiroya Yamaguchi, Masayoshi Nobukawa et al.

We present spatially resolved X-ray spectroscopy of the Type Ia supernova remnant 3C 397, one of the most promising candidates to have originated from a white dwarf with a mass close to the Chandrasekhar limit. The remnant was observed during the performance verification phase of the X-ray Imaging and Spectroscopy Mission (XRISM), with the field of view of the Resolve calorimeter array positioned on the eastern half of the remnant. We divide the Resolve field of view into southeastern and northe…

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