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宇宙工学・惑星科学・宇宙物理の最新プレプリント。

astro-ph.SR

CPD-82 291: Multi-sector TESS Photometry and SED Analysis of an Active Eclipsing Binary

Volkan Bakış, Gökhan Yücel

We present a multi-sector $TESS$ photometric and spectral energy distribution analysis of the eclipsing binary CPD--82~291 (RX~J0853.1--8244). Eight $TESS$ sectors reveal well-defined eclipses and substantial, changing out-of-eclipse modulation. The asymmetries are reproduced by different surface-brightness configurations at different epochs, consistent with strong and evolving stellar activity, although the fitted circular regions are not unique maps of individual starspots. A detached-binary l…

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astro-ph.GA

Indirect evidence of the $2175\,\mathring{\mathrm{A}}$ extinction bump within the dusty torus of SDSS J141945.50+524648.0

Ze Li, Gaoyang Chen, Qifan Cui, Zheng Cai, Jianzhen Chen, Zhijian Luo, Chenggang Shu, Fengwu Sun et al.

We present a multi-wavelength study of the quasar SDSS J141945.50$+$524648.0 ($z=1.1599$), a member of the newly identified population of quasar-associated $2175\,\mathring{\mathrm{A}}$ dust absorbers. Utilizing JWST/NIRCam observations from the SAPPHIRES survey and archival data, we analyze the prominent $2175\,\mathring{\mathrm{A}}$ extinction bump detected in this object. The bump parameters are highly consistent with the Milky Way extinction curve, implying similar dust properties. Spectral…

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astro-ph.GA

Constraining the Inner Dark-Matter Slope of Sculptor: A Comparative Analysis of Dynamical Methods

Rishi Sanjeev

The core-cusp problem is a discrepancy between simulations and observations of the slopes of inner dark matter density profiles. The two-population estimator, separating dwarf spheroidals into metallicity-split subcomponents, is a standard method to break the mass-anisotropy degeneracy. Four dynamical methods are applied to the 1339-star Tolstoy et al. (2023) VLT/FLAMES Sculptor catalog: spherical Jeans, GravSphere, the Walker and Penarrubia (2011) two-population estimator, and a continuous $f(J…

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astro-ph.EPcond-mat.mtrl-sci

A surviving pink spinel records an early aluminous melt on the ureilite parent body

Yaozhu Li, Phil J. A. McCausland, Roberta L. Flemming, Noriko T. Kita, Carsten Detlefs

Ureilites are ultramafic achondrites interpreted as fragments of a differentiated parent body, yet their origin and evolution remain debated because textural equilibrium coexists with chemically primitive compositions. Here we report mineralogical, isotopic, and microstructural observations from polymict ureilite Elephant Moraine (EET) 87720. The sample contains unusually magnesian olivine (Mg# up to 98.7), Ca-poor pyroxene (Wo as low as 1.0), and rare coarse-grained pink aluminous spinel contai…

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astro-ph.COastro-ph.IM

Simulation Tests of PSF Modeling for Cosmic Shear with the Vera C. Rubin Observatory

Claire-Alice Hébert, Erin S. Sheldon, Tianqing Zhang, Joachim Harnois-Déraps, Mike Jarvis, the LSST Dark Energy Science Collaboration

Exceptional control of systematic effects is required in order to achieve unbiased cosmic shear two-point correlation function measurements with the next generation of galaxy imaging surveys, such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). One critical challenge is accurately modeling the point-spread function (PSF), as errors in PSF estimation can introduce spatially correlated biases in galaxy shape measurements. The LSST Science Pipelines, which will be used to p…

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astro-ph.HE

Galactic Electron-Positron Annihilation Emission from X-Ray Binaries with Transient and Persistent Jets

Argen Gian Detoito, Henric Krawczynski

The Galactic Center exhibits a persistent 0.511 MeV emission characteristic of electron-positron annihilation. Various astrophysical sources may be responsible for supplying the positrons, yet their contributions with respect to the total annihilation rate is uncertain. X-ray binaries have historically been a primary candidate, possibly contributing a significant fraction of the Galactic positrons. X-ray binaries can produce positrons through the Blandford-Znajek mechanism, two-photon pair produ…

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gr-qcastro-ph.HEhep-th

Kerr-Newman and genuine Kerr black holes in the Bertotti-Robinson magnetic field

Hryhorii Ovcharenko, Jiri Podolsky

We present a spacetime that describes a rotating and charged black hole immersed in an external magnetic field. This exact solution to the Einstein-Maxwell equations has a surprisingly simple form which reduces to standard Kerr-Newman metric, and to the uniform Bertotti-Robinson magnetic universe. We show that the Kerr-BR solution presented in [Phys. Rev. Lett. {\bf 135}, 181401 (2025)] has a special charge, and we identify a genuine Kerr black hole without any charge, in the magnetic field. In…

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astro-ph.IM

Image persistence flagging for SPHEREx

Candice Fazar, C. Darren Dowell, Brendan P. Crill, Phil Korngut, Chi Nguyen, Howard Hui

Image persistence in HAWAII-2RG HgCdTe detectors has been observed by multiple parties. Also known as latent signal, this effect occurs when sensor images following an illumination show a decayed form of the illuminated image even though the source has been removed and the detector has been reset. Using data from an engineering grade detector array delivered for SPHEREx testing illuminated with a wide range of fluxes, we demonstrate an interpretation and a working model from which the decaying s…

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

When the stars don't align: Investigating inconsistencies in binary black hole formation across population synthesis codes

Alexandra G. Guerrero, Michael Zevin, Duncan B. Maclean, Katelyn Breivik, Carl L. Rodriguez, Max M. Briel, Daniel E. Holz

Binary population synthesis (BPS) codes are extremely useful tools for investigating both the end-to-end lives of binary stars as well as a myriad of astrophysical phenomena observed in the Universe. Given the widespread use of BPS in modern astrophysical research, it is imperative to systematically compare BPS codes across the spectrum of computational efficiency, flexibility, and physical realism to gauge their consistency and robustness. In this work, we perform BPS using three modern codes--…

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astro-ph.GA

Supernovae Ia ejecta velocities and host galaxy environments: the role of survey-selection effects

L. V. Barkhudaryan, A. A. Hakobyan, M. H. Gevorgyan, D. Kunth, G. A. Mamon, U. Burgaz, V. Adibekyan, Zh. R. Martirosyan et al.

The origin of the near-maximum-light Si II $λ$6355 velocity diversity among supernovae Ia (SNe Ia) remains uncertain. Previous studies have suggested that high-velocity (HV) and normal-velocity (NV) SNe Ia occupy systematically different host galaxy environments, implying differences in their progenitor populations. We re-examine this hypothesis using a sample of 354 nearby ($z\leq0.04$) spectroscopically normal SNe Ia, comprising 239 NV and 115 HV events, identified in targeted and untargeted s…

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astro-ph.HE

Relativistic blob signatures in the M87 jet at sub-parsec scales

Donaldo Mora, Alejandro Cruz-Osorio, Erika Benítez, Yosuke Mizuno

In this work, we present results from general-relativistic radiative-transfer calculations of black hole accretion and jet launching to reproduce the observed properties of the M\,87 jet at sub-parsec scales. For the first time, in the simulations we have included a blob component at the launching region of the jet that allowed us to reproduce the quasi-simultaneous low-energy spectral energy distribution ($10^{10} \text{ Hz} \leq ν\leq 10^{16} \text{ Hz}$). Moreover, we obtain a better fit of t…

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astro-ph.EPastro-ph.IM

Assessing the Impact of High-Resolution Imaging on Statistical Validation of TESS Planet Candidates

Michael Collier, Steven Giacalone, Brian Derfer, David R. Ciardi, Catherine A. Clark, Ian J. M. Crossfield, Sarah Deveny, Sergio B. Fajardo-Acosta et al.

High-resolution imaging is widely used to constrain false-positive scenarios in exoplanet validation, but it is a finite follow-up resource that reaches only a subset of candidates, and its population-level impact on validation outcomes has not been quantified through controlled removal experiments. Using an automated pipeline built on TRICERATOPS, we compute the false-positive probability (FPP) of 443 TESS planet candidates. For the 264 planet candidates with high-resolution imaging observation…

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astro-ph.GA

The Milky Way Joins the Extragalactic World: I. PHANGS

Neal J. Evans, Davide Elia, Jiayi Sun, Sophia Stuber, Adam K. Leroy

Complete catalogs of molecular clouds in the Milky Way allow analysis of the molecular medium and the star formation properties of the Milky Way that closely follows the method used for nearby galaxies, in particular in the PHANGS project. The dependencies of the depletion time on other properties of molecular gas in the Milky Way are similar to those of other galaxies when analyzed in an analogous way. They exhibit a large scatter and relatively weak correlations. The strongest correlation is a…

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astro-ph.GA

Beyond orientation: Evidence for distinct physical regimes among Little Red Dots and Little Blue Dots

L. Barrufet, J. S. Dunlop, M. L. Hamadouche, M. Mezcua, D. Herrero-Carrion, M. Santos-Lleo, R. Gottumukkala, D. Spinoso et al.

Little Red Dots (LRDs) and Little Blue Dots (LBDs) may represent the same population of compact active galactic nuclei (AGN) observed along different lines of sight. We test this scenario using a spectroscopic sample from the DAWN {\it JWST} Archive, selected based on common criteria for H$α$ equivalent width, UV continuum slope, and compactness. We use the optical continuum slope to distinguish between samples of 89 LRDs and 191 LBDs spanning $1 \lesssim z \lesssim 7.5$, and compare their conti…

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astro-ph.IM

On the performance of pre-trained vision transformers for supernova spectral classification using different spectral representations

J. Serrano Bell, P. Gálvez Molina, V. Contreras Rojas, W. Fox Fortino, M. Rojas, P. Protopapas, F. Bianco

The spectroscopic classification of supernovae is a key component of time-domain astronomy and plays an important role in the identification of Type Ia events. The increasing volume and diversity of spectroscopic data motivate the development of automated classification approaches. In this work, we explore the use of Transformer-based vision models for supernova spectral classification, focusing on how different visual representations of spectra and fine-tuning strategies affect classification p…

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astro-ph.EP

A Highly Reflective Atmosphere on the Lava World TOI-561b Revealed by JWST/NIRSpec Phase Curve

Samuel Boucher, Lisa Dang, Alex McGinty, Johanna K. Teske, Raymond Pierrehumbert, Anjali A. A. Piette, Nicole L. Wallack, Angharad Weeks et al.

Ultra-short period (USP) rocky planets are expected to be depleted of any substantial gaseous envelope due to the intense irradiation they receive from their host star, making the recent detection of an atmosphere around TOI-561~b particularly surprising. That finding was based on the planet's bulk density and dayside emission spectrum, but full-orbit phase curve observations offer a more comprehensive way to constrain the presence and characteristics of a planet's atmosphere. In this paper, we…

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astro-ph.GA

EROSE: An algorithm searching for resolved Local Group satellites. The impact of combining different photometric bands on the detectability of Milky Way satellites in the LSST

Samuel Rusterucci, Nicolas F. Martin, Else Starkenburg

Systematic searches for ultra-faint Milky Way satellite galaxies typically combine local density estimators with colour-magnitude cuts, which are usually performed in 2D and have rarely, if ever, been extended to higher-dimensional spaces. These studies generally rely on $gri$ photometry, overlooking the shallower but metal-sensitive $u$ band. Entering the era of LSST, our study explores different $ugri$ combinations to determine which provides the best performance. We injected 36,000 dwarf gala…

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astro-ph.GA

On the importance of the IGM/CGM enrichment in determining chemical abundances during the first 600 Myr

Annalisa Citro, Yong-Zhong Qian, Claudia Scarlata

JWST observations show that galaxies at $z>8$ exhibit a wide range of carbon-to-oxygen (C/O) ratios at fixed metallicity and systematically elevated nitrogen-to-oxygen (N/O) ratios compared to local galaxies. Proposed explanations include finely tuned star-formation histories (SFHs), differential or pristine inflows, top- or bottom-heavy initial mass functions, or enrichment from Wolf-Rayet stars, supermassive stars (SMSs), or Population III stars. The observed abundances reflect both in situ pr…

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astro-ph.HE

VLASS Discovery of a Luminous Galactic Radio Transient Evolving on Decade Timescales

Jessie M. Miller, Gregg Hallinan, Dillon Dong, Adolfo S. Carvalho, S. T. Myers, Jean Somalwar, Casey Law, B. M. Gaensler et al.

We present a multiwavelength analysis of the radio transient VT J1906+0849, discovered as a 70 mJy source in Epoch 1 of the Very Large Array Sky Survey (VLASS), 21 yr after an NRAO VLA Sky Survey (NVSS) non-detection. Radio observations reveal the source was first detected in 2005, peaking at $\gtrsim200$ mJy in 2014, then declining until a late 2025 rebrightening. The transient sits at a Galactic latitude of $\approx0.74^\circ$ and the properties of its optical-infrared counterpart support a Ga…

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astro-ph.GAastro-ph.HE

The Random Magnetic Field of the Milky Way

Michael Unger, Glennys R. Farrar

We constrain the large-scale isotropic random component of the Galactic magnetic field using the Planck reconstruction of the 408 MHz synchrotron sky. Our analysis simultaneously fits the random-field structure, the synchrotron contributions of the coherent field and local foregrounds, and isotropic and dipolar offsets. A new element of the analysis is the use of excess polarized emission at 30 GHz to model local foregrounds, allowing us to retain 97% of the sky without absorbing these structure…

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astro-ph.EP

Does Cumulative XUV Unify the Neptunian Desert?

Qunfeng Jiang

The architecture of close-in planetary systems includes a conspicuous scarcity of Neptune-size worlds, known as the Neptunian desert. The deficit spans roughly $2$--$10\,R_{\oplus}$ at orbital periods of a few days. Atmospheric erosion by stellar X-rays and extreme-ultraviolet (XUV) radiation may shape its lower boundary, while the strong mass dependence of stellar activity complicates comparisons across spectral type. We test whether standardized cumulative XUV exposure places the lower boundar…

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astro-ph.GA

The [Ne V] AGN Diagnostic in SDSS-IV/eBOSS: An Anticorrelation Between Ionization State and AGN Luminosity in Low-Redshift Coronal-Line Galaxies

Owen S. Matthews Acuña, Christy A. Tremonti, Nikko J. Cleri, Kyle B. Westfall, Bee R. Erena, Jacob B. Stimac, Britt Lundgren, Drake Miller et al.

Traditional narrow-line diagnostics fail at high redshift, where low metallicity drives star-forming galaxies and Active Galactic Nuclei (AGN) into overlapping regions of the Baldwin-Phillips-Terlevich (BPT) diagram. Coronal lines, with ionization potentials exceeding 100 eV, offer a robust alternative: they cannot be produced by normal stellar populations, arise almost exclusively from AGN or fast shocks, and are insensitive to abundance evolution. Among these, the [Ne V] doublet is the brighte…

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astro-ph.HEhep-ph

Generation of TeV Photons by PeV Neutrinos in Dense Astrophysical Environments

Jun-Chen Wang, Hanlin Song, Hao Li, Jie Zhu, Bo-Qiang Ma

Recent observations by IceCube and KM3Net of PeV-scale ultra-high-energy (UHE) neutrinos, together with detections of TeV-PeV photons from various sources such as the Crab Nebula, the Galactic Center, and gamma-ray burst by ground-based observatories including Tibet AS$γ$, MAGIC, Carpet-3, and LHAASO, point to the existence of extreme astrophysical environments capable of accelerating particles to ultra-high energies. These findings motivate investigations of possible connections between UHE neu…

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astro-ph.HE

Constraining neutron-star properties with ensembles of thermonuclear bursts: application to SRGA J144459.2-604207

Duncan K. Galloway, Serena Jones, Luke Waterson, Tao Fu, Adelle J. Goodwin, Zhaosheng Li

Deducing the properties of the host neutron stars from thermonuclear (type-I) X-ray bursts remains a challenge, due to incomplete data, multidimensional parameter space, and dearth of suitable models and analysis tools. Here we describe further development of the BEANSP package, with a new "ensemble" analysis mode utilising the consistent and regular "clocked" bursting exhibited by some sources. This mode requires only one model evaluation per epoch, and so is much more efficient than the previo…

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gr-qcastro-ph.SRmath.DS

Resonance crossings as entire functions of the Koopman operator

Priscilla Canizares

Astrophysical binaries formed by a stellar-mass compact object and a massive black hole are among the most promising sources for future space-based gravitational-wave detectors. These extreme mass-ratio inspiral (EMRI) systems are tracked coherently over more than $10^{5}$ orbits, encoding detailed information about strong-field gravity. Translating a detection into physical parameters requires models of comparable precision. One outstanding difficulty is the treatment of transient orbital reson…

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gr-qcastro-ph.SRmath.DS

Resonance crossings as entire functions of the Koopman operator

Priscilla Canizares

Astrophysical binaries formed by a stellar-mass compact object and a massive black hole are among the most promising sources for future space-based gravitational-wave detectors. These extreme mass-ratio inspiral (EMRI) systems are tracked coherently over more than $10^{5}$ orbits, encoding detailed information about strong-field gravity. Translating a detection into physical parameters requires models of comparable precision. One outstanding difficulty is the treatment of transient orbital reson…

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astro-ph.SR

alpha_theta waves in the tachoclines of Sun-like stars

T. V. Zaqarashvili, M. Dikpati, P. A. Gilman

Vertical gradient of mean turbulent electromotive force (expressed by the dynamo coefficient, alpha, caused by the penetrating convection into the tachoclines of Sun-like stars leads to the non-propagating alpha-mode patterns, which result in the periodic variations of magnetic field horizontal components. The aim of the paper is to study the influence of the latitudinal variation of the dynamo coefficient on the linear dynamics of large-scale waves in the overshoot layers of the tachoclines in…

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astro-ph.HE

CtaAgnVar : a Pipeline for Variability Studies with the Cherenkov Telescope Array Observatory

G. Grolleron, J. -P. Lenain, J. Biteau, C. Boisson, M. Cerruti

Blazars are active galactic nuclei whose relativistic jet points toward the observer, accelerating particles that radiate across the electromagnetic spectrum. Characterizing their flux and spectral variability constrains the physics of the central black hole and its jet, making blazars a key science case for the Cherenkov Telescope Array Observatory (CTAO). The CTAO, with two sites and a sensitivity five to ten times better than current Imaging Atmospheric Cherenkov Telescopes, should reconstruc…

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astro-ph.GA

Angular momentum in isolated disc galaxies: Insights from TNG100

A. Sorgho, L. Verdes-Montenegro, M. Baes, R. Ianjamasimanana, M. Korsaga, B. Namumba, S. Sanchez-Expósito, J. Garrido et al.

Angular momentum is a fundamental property that shapes the evolution of disc galaxies, strongly influencing the internal mechanisms that regulate star formation. Its content within disc galaxies is predicted to change over time, mainly as a result of external processes that regulate galaxy evolution. While several numerical studies paint a complex picture of angular momentum variation with environmental mechanisms, a recent observational finding suggests that galaxies are subject to angular mome…

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astro-ph.GA

The curious case of HCO$^+$: Extreme abundances under extreme conditions

Katarzyna M. Dutkowska, Bin Jia, Serena Viti, Tobias M. Dijkhuis, Gijs Vermariën

Context. HCO$^+$ is widely observed in both Galactic and extragalactic environments and typically exhibits abundances of $10^{-9}-10^{-8}$. However, recent modeling studies suggest that in environments exposed to elevated cosmic-ray ionization rates and strong thermal or mechanical processing its abundance may increase by several orders of magnitude. Aims. To interpret these predictions, we need to understand the physical conditions that produce extreme HCO$^+$ abundances and the chemical pathwa…

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