Cosmology and Nongalactic Astrophysics
Constraining and Comparing the Dynamical Dark Energy and f(R) Modified Gravity Models with Cosmological Distance Measurements
Shuai Feng, Yan Gong, Xiaohui Liu et al. (+2 more)
We constrain and compare the $w_{0}w_{a}$CDM dynamical dark energy model and three $f(R)$ modified
gravity models using the current cosmological distance measurements, including 112 high-quality localized FRBs, BAO measurements from the DESI-DR2 and the BOSS-DR12, Type~Ia
supernovae (SNe~Ia) from the PantheonPlus compilation and the DESY5 sample,
cosmic chronometers (CC), and the angular scale of the first acoustic peak of the CMB from Planck~2018. These
datasets allow us to effectively break parameter degeneracy, obtain stringent cosmological constraint results, and conduct systematic model comparison and selection. By using the FRB+PantheonPlus+DESI+CC+CMB
dataset, we constrain the parameters of the dark energy equation of state in the $w_{0}w_{a}$CDM model, obtaining $w_{0} = -0.867 \pm 0.060$ and $w_{a} = -0.35^{+0.29}_{-0.25}$. For the $f(R)$ modified
gravity models, the deviation parameter $b$, which characterizes departure from general relativity, is constrained to be $b = 0.206 \pm 0.084$, $b = 0.700^{+0.190}_{-0.130}$, and $b = 0.198 \pm 0.081$ for Hu-Sawicki, Starobinsky, and ArcTanh models, respectively. Besides, we compare the impacts of different SNe Ia
datasets (PantheonPlus and DESY5) and BAO
datasets (DESI-DR2 and BOSS-DR12) on the constraints of the cosmological models. By employing
Bayesian evidence and other model selection criteria, we find that the choice of SNe Ia and BAO
datasets can significantly influence the inferred preference for cosmological models. Specifically, the DESY5 and DESI
datasets tend to favor $w_{0}w_{a}$CDM and $f(R)$ models, whereas the PantheonPlus and BOSS
datasets show a comparatively stronger preference for the $\Lambda$CDM model.
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All authors Shuai Feng, Yan Gong, Xiaohui Liu, Jun-Hui Yan, Xuelei Chen
High Energy Astrophysical Phenomena
A Search for Supermassive Black Hole Binary Candidates in 46-Year Radio Light Curves of 83 Blazars
B. Molina, P. Mróz, P. V. De la Parra et al. (+23 more)
The combined University of Michigan
Radio Astronomy Observatory (UMRAO) and Owens Valley
Radio Observatory (OVRO) blazar monitoring programs at 14.5/15 GHz provide uninterrupted light curves of $\sim~46-50$ yr duration for 83 blazars, selected from amongst the brightest and most rapidly flaring blazars north of declination $-20^\circ$. In a search for supermassive black hole binary (SMBHB) candidates, we carried out tests for periodic variability using generalized Lomb-Scargle (GLS), weighted wavelet-Z (WWZ), and sine-wave fitting (SWF) analyses of this sample. We used simulations to test the effects of the power law spectrum of the power spectral density (PSD) on our findings, and show that the irregular sampling in the observed light curves has very little effect on the GLS spectra. Apparent periodicities and putative harmonics appear in all 83 of the GLS spectra of the blazars in our sample. We tested the reality of these apparent periodicities and harmonics with simulations, and found that in the overwhelming majority of cases they are due to the steep slope of the PSD, and should therefore be treated with great caution. We find one new SMBHB candidate: PKS 1309+1154, which exhibits a 17.9 year periodicity. The fraction of SMBHB candidates in our sample is $2.4_{-0.8}^{+3.2}\%$.
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All authors B. Molina, P. Mróz, P. V. De la Parra, A. C. S. Readhead, T. Surti, M. F. Aller, J. D. Scargle, R. A. Reeves, H. Aller, M. C. Begelman, R. D. Blandford, Y. Ding, M. J. Graham, F. Harrison, T. Hovatta, I. Liodakis, M. L. Lister, W. Max-Moerbeck, V. Pavlidou, T. J. Pearson, V. Ravi, A. G. Sullivan, A. Synani, K. Tassis, S. E. Tremblay, J. A. Zensus
Instrumentation and Methods for Astrophysics · Cross-listed from physics.optics
Tensor network methods for quantum-inspired image processing and classical optics
Nicolas Allegra
Tensor network methods strike a middle ground between fully-fledged
quantum computing and classical computing, as they take inspiration from
quantum systems to significantly speed up certain classical operations. Their strength lies in their compressive power and the wide variety of efficient
algorithms that operate within this compressed space. In this work, we focus on applying these methods to fundamental problems in image compression and processing and classical optics such as wave-front propagation and optical image formation, by using directly or indirectly parallels with
quantum mechanics and computation. These
quantum-inspired methods are expected to yield faster
algorithms with applications ranging from astronomy and earth observation to microscopy and classical imaging more broadly.
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Solar and Stellar Astrophysics
Evaluating the chromospheric structure model of AD Leo using RH1.5D and magnetic field data
Shuai Liu, Jianrong Shi, Huigang Wei et al. (+4 more)
Context. The interplay between surface
magnetic topology and chromospheric heating in active M
dwarfs remains poorly constrained, limiting our understanding of their
magnetic cycles and high-energy environments. Aims. We aim to test whether detailed Zeeman-Doppler imaging (ZDI) maps of AD Leo can be used to spatially anchor a multi-component chromospheric model and validate the link between
magnetic flux distribution and emission-line formation. Methods. We analyze high-resolution CARMENES spectra of H-alpha and the Ca II infrared triplet, together with ZDI maps. Synthetic profiles are computed using the RH1.5D non-LTE radiative transfer code with two active atmospheric components (low-latitude near the equator and polar near the pole) and a quiet background. Their relative filling factors and temperature structures are optimized per epoch. The ZDI maps serve as qualitative references for the large-scale
magnetic topology but are not used as input to the optimization. Results. Our model reproduces the spectral line profiles across multiple epochs. The low-latitude active region shows notable variability, accounting for approximately 55-86% of the emission, while the polar region remains relatively constant in area (12-17%) but exhibits temperature variations over time, particularly during periods of increased activity. The spatial locations of the active regions derived from spectroscopy agree well with the radial
magnetic field distribution from ZDI. Conclusions. Combining spectroscopic modeling with
magnetic field maps is an effective approach for mapping magneto-chromospheric structures in M
dwarfs. This framework deepens our understanding of
stellar magnetic cycles and chromospheric dynamics, paving the way for detailed time-resolved studies in active low-mass
stars.
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All authors Shuai Liu, Jianrong Shi, Huigang Wei, Wenxian Li, Jifeng Liu, Shangbin Yang, Henggeng Han
Solar and Stellar Astrophysics
A Statistical Study of delta-Sunspots from Solar Cycle 23 to 25
Rohan E. Louis
Sunspots or active regions (ARs) with a delta-
magnetic configuration are known to be associated with strong eruptions such as
flares and mass ejections. This article investigates the relationship between delta-ARs and
flares over the course of three
solar cycles (SCs), from 1996 to 2024, with respect to the former's area, lifetime, latitudinal distribution, and phase of its
magnetic complexity.
Solar cycle 25 has produced the least number of delta-ARs in comparison to the previous two
solar cycles, yet the number of M- and X-class
flares exceed that of cycle 24 by 25%.
Flare occurrence is higher in C-, M-, and X-class events during the presence of the delta-configuration which is seen in all 3 SCs. The total number of
flares produced by delta- and non-delta-ARs were 15875 and 17033, respectively across all 3 SCs. The latter are dominated by B- and C-class
flares, while the number of M- and X-class
flares across all 3 SCs was significantly less than compared to delta-ARs. The median lifetime of an AR in the delta- and non-delta phase is about 5 and 8 days, respectively. The typical number of
flares produced by a delta-AR is 20, with maximum values ranging from 80-156 for lifetimes between 6-13 days. However, about 30% of delta-ARs do not produce
flares when their lifetimes are between 6-12 days. The latitudinal distribution of delta-ARs across the northern and southern hemispheres is nearly symmetric on either side of the equator for SCs 23 and 24, peaking around +/-10 deg-20 deg. For
solar cycles 23 and 24, about 30% of the host delta-ARs have an area exceeding the mean value over the above latitudinal belt while for SC 25, there is a large scatter possibly due to the cycle still being in progress. It remains to be seen if the latter phase of SC 25 will be as active as its earlier phase and whether the number of delta-ARs emerging during that period scale with the total sunspot number.
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Cosmology and Nongalactic Astrophysics
Testing the cosmic distance duality relation using model-independent approach
Shubham Barua, Sujit K. Dalui, Rikiya Okazaki et al. (+1 more)
In this work, we test the
cosmic distance duality relation (CDDR) using the arbitrary
redshift pivot Padé-(2,1) expansion methodology developed in arXiv:2509.16196. This approach allows us to constrain cosmography parameters and test CDDR at any
redshift. Further, it does not rely on data reconstructions or extrapolations of the cosmography parameters to higher
redshifts. We employ observational data from the Dark Energy Spectroscopic Instrument (DESI)
Baryon Acoustic Oscillation
dataset,
cosmic chronometers (CC), and Type Ia
supernovae from the Pantheon Plus (PP) and Dark Energy Survey Year 5 (DESY5) compilations. We find no significant deviations from the standard CDDR relation in the range $0\lesssim z \lesssim 1$ when considering DESI$+r_d$
dataset in combination with PP$+$CC and DESY5$+$CC
datasets. However, on imposing a Gaussian prior on $M_B \in \mathcal{N}(-19.253, 0.027)$ (instead of treating it as a free parameter) in the
dataset combination PP$+$CC, we find CDDR violation at a level of $(3-5)\sigma.$
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All authors Shubham Barua, Sujit K. Dalui, Rikiya Okazaki, Shantanu Desai
Cosmology and Nongalactic Astrophysics · Cross-listed from hep-ph
Exploring the Landscape of Spontaneous CP Violation in Supersymmetric Theories
Fangchao Liu, Shota Nakagawa, Yuichiro Nakai et al. (+1 more)
The strong CP problem remains one of the most important unresolved issues in the Standard Model. Spontaneous CP violation (SCPV) is a promising approach to the problem by assuming that CP is an exact
symmetry of the Lagrangian but broken spontaneously at the
vacuum, which enables the generation of the observed Cabibbo-Kobayashi-Maskawa (CKM) phase without reintroducing a nonzero strong CP phase. Supersymmetry (SUSY) provides a natural framework to accommodate such a mechanism, as SUSY can not only protect the scale of SCPV from radiative corrections but also suppress problematic higher-dimensional operators generating a strong CP phase. In the present study, we explore the realization of SCPV in two distinct SUSY scenarios. First, we investigate SCPV in the exact SUSY limit by extending the spurion formalism developed in non-supersymmetric theories to identify the necessary condition for stabilizing CP-violating phases, and by analyzing the stabilization of radial
vacuum expectation values through R-
symmetry constraints on the superpotential. Second, we construct a model in which CP is spontaneously broken at an intermediate scale along pseudo-flat directions, stabilized by soft SUSY breaking and non-perturbative effects of a gauge theory. The latter setup predicts light scalars in the SCPV sector whose masses are determined by the SUSY breaking scale.
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All authors Fangchao Liu, Shota Nakagawa, Yuichiro Nakai, Yaoduo Wang
High Energy Astrophysical Phenomena
Exploring the accelerating black holes from the observations of quasi-periodic oscillations in X-ray binaries
Hamza Rehman, Saddam Hussain, G. Abbas et al. (+1 more)
Black holes in dense astrophysical environments, such as globular clusters or in the vicinity of other massive objects, may possess accelerations. Such acceleration would modulate the characteristics of the quasi-periodic oscillations (QPOs) observed in X-ray black hole binaries. In this paper, we explore the influence of
spin-aligned acceleration of a black hole on QPOs observed in X-ray binaries. For this purpose, we compute the fundamental frequencies arising from the motion of test particles around an accelerating (
spin-aligned) black hole and apply the relativistic precession, parametric resonance, and forced resonance models to establish their correspondence with several observed QPOs of X-ray binaries (GRO J1655-40, XTE J1550-564, XTE J1859+226, GRS 1915+105, H1743-322, M82~X-1, and Sgr~A$^{*}$). We then employ the
Bayesian Markov-Chain Monte Carlo method to constrain the black hole parameters. Our results show no evidence for
spin-aligned acceleration in any of the analyzed sources, suggesting that most of these X-ray binaries reside in isolated environments and therefore experience only small perturbations to the background spacetime geometries.
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All authors Hamza Rehman, Saddam Hussain, G. Abbas, Tao Zhu
Astrophysics of Galaxies
Spatially Resolved, Multiphase Mass Outflows of the Seyfert 1 Galaxy NGC 3227
Julia Falcone, D. Michael Crenshaw, Mitchell Revalski et al. (+6 more)
We present spatially resolved mass
outflow rates of the ionized and molecular gas in the narrow line region of the Seyfert 1
galaxy NGC 3227. Using long-slit spectroscopy and [O III] imaging from from Hubble Space
Telescope's Space
Telescope Imaging Spectrograph and Apache Point Observatory's Kitt Peak Ohio State Multi-Object Spectrograph, in conjunction with Cloudy photoionization models and emission line diagnostics, we find a peak ionized mass
outflow rate of $\dot M_{\text{ion}} =$ $19.9\pm9.2$ M$_\odot$ yr$^{-1}$ at a distance of $47\pm6$ pc from the supermassive black hole (SMBH). Using archival data from the Gemini-North Near-infrared Field Spectrograph measuring H$_2$ $\lambda2.1218$ $\mu$m emission, we find a maximum peak warm molecular
outflow rate of $\dot M_{\mathrm{H_2}} \le 9 \times 10^{-4}$ M$_\odot$ yr$^{-1}$ at a distance of $36\pm6$ pc from the SMBH. Using archival data from the Atacama Large Millimeter/submillimeter Array measuring CO(2-1) emission, we find a maximum peak cold molecular gas mass
outflow rate of $\dot M_{\mathrm{CO}} \le$ $23.1$ M$_\odot$ year$^{-1}$ at a distance of $57\pm6$ pc from the SMBH. For the first time, we calculate spatially resolved gas evacuation timescales for the cold molecular gas reservoirs ostensibly sourcing the
outflows, and find that evacuating gas to $\sim$400 pc from the SMBH occurs on timescales of $10^{6.0} - 10^{7.6}$ years. These results indicate that the multi-phase AGN
outflows are effective in clearing the inner few hundred parsecs of NGC 3227's gas content on timescales that may set the AGN duty cycle of $10^5 - 10^8$ years.
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All authors Julia Falcone, D. Michael Crenshaw, Mitchell Revalski, Travis C. Fischer, Beena Meena, Maura Kathleen Shea, Jacob Tutterow, Zo Chapman, Kesha Patel
High Energy Astrophysical Phenomena
SN 2024iss: A Double-peaked Type IIb Supernova with Evidence of Circumstellar Interaction
Liyang Chen, Xiaofeng Wang, Qinyu Wu et al. (+54 more)
We present optical, ultraviolet, and X-ray observations of
supernova (SN) 2024iss, a Type IIb SN that shows a prominent double-peaked light curve. We modeled the first peak with a semianalytical shock-cooling model and the X-ray emission with a free-free model. We compare the envelope radius and mass-loss rate with other Type IIb SNe to explore the relationships between the progenitor envelope and the circumstellar material (CSM). The shock-cooling peak in the $V$-band light curve reached $M_V = -17.33\pm 0.26$mag, while the $^{56}$Ni-powered second peak attained $M_V = -17.43\pm 0.26$mag. Early spectra show an photospheric velocity of $\sim19,400\,km\,s^{-1}$ at 3.82days from the H$\alpha$ P~Cygni profile. The Balmer lines persist at least +87 days after the explosion, characterizing hydrogen-rich ejecta. Modeling the first light-curve peak suggests an extended envelope with a mass of $0.11\pm0.04\,M_{\odot}$ and a radius of $244\pm43~R_{\odot}$. Fitting the second light-curve peak with an Arnett-like model indicates a typical $^{56}$Ni mass of $ 0.117\pm0.013~M_{\odot}$ and a relatively low ejecta mass of $1.272\pm0.343\,M_{\odot}$. X-ray observations reveal bright thermal bremsstrahlung emission and indicate a mass-loss rate of $1.6\times10^{-5}\ M_{\odot} \ \rm{yr}^{-1}$. SN 2024iss occupies a transitional position between the two subclasses of extended (eIIb) and compact (cIIb) Type IIb SNe. Its envelope radius and pre-explosion mass-loss rate appear to be correlated as theoretically predicted. The observational properties of SN 2024iss are compatible with a binary interaction scenario being the dominant mechanism for envelope stripping. Furthermore, the low column density of neutral hydrogen suggests a compact CSM with an outer radius of $\lesssim1.3\times10^{14}$ cm, indicating that the progenitor
star experienced eruptive mass loss within $\sim4\,yr$ of its terminal explosion.
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All authors Liyang Chen, Xiaofeng Wang, Qinyu Wu, Moira Andrews, Joseph Farah, Paolo Ochner, Andrea Reguitti, Thomas G. Brink, Jujia Zhang, Cuiying Song, Jialian Liu, Alexei V. Filippenko, David J. Sand, Irene Albanese, Kate D. Alexander, Jennifer Andrews, K. Azalee Bostroem, Yongzhi Cai, Collin Christy, Ali Esamdin, Andrea Farina, Noah Franz, D. Andrew Howell, Brian Hsu, Maokai Hu, Abdusamatjan Iskandar, Liping Li, Gaici Li, Dongyue Li, Wenxiong Li, Jinzhong Liu, Curtis McCully, Megan Newsome, Yuan Qi Ni, Andrea Pastorello, Estefania Padilla Gonzalez, Jeniveve Pearson, Haowei Peng, Conor Ransome, Manisha Shrestha, Nathan Smith, Bhagya Subrayan, Giacomo Terreran, Giorgio Valerin, J. Vinkó, Sergiy S.Vasylyev, Letian Wang, Zhenyu Wang, Hao Wang, J. Craig Wheeler, Kathryn Wynn, Danfeng Xiang, Shengyu Yan, Weimin Yuan, Juan Zhang, WeiKang Zheng, Yu Zhang
Solar and Stellar Astrophysics
SN2017ckj: A linearly declining Type IIb supernova with a relatively massive hydrogen envelope
L.-H. Li, S. Benetti, Y.-Z. Cai et al. (+26 more)
We present optical observations of the Type IIb
supernova (SN) 2017ckj, covering approximately 180 days after the explosion. Its early-time multi-band light curves display no clear evidence of a shock-cooling tail, resembling the behavior of SN2008ax. The $V$-band light curve exhibits a short rise time of about 5 days and reaches an absolute fitted peak magnitude of $M_{\rm V}=-18.49\pm0.18\mathrm{mag}$. The late-time multi-band light curves reveal a linear decline. We modelled the bolometric light curve of SN2017ckj to constrain the progenitor and the explosion parameters. We estimated a total mass of $\rm ^{56}Ni$ synthesized by SN2017ckj of $M_{\rm Ni} = 0.21^{+0.05}_{-0.03}\ M_\odot$, with a massive H-rich envelope of $M_{\rm env} = 0.4^{+0.1}_{-0.1}\ M_\odot$. Both the $\rm ^{56}Ni$ mass and the envelope mass of SN2017ckj are higher than those of typical SNe IIb, in agreement with its peculiar light curve
evolution. The early-time spectra of SN2017ckj are dominated by a blue continuum, accompanied by narrow $\rm H_\alpha$ and \Heii emission lines. The earliest spectrum exhibits flash ionization features, from which we estimated a progenitor mass-loss rate of $\sim 3\times10^{-4}M_\odot \mathrm{yr}^{-1}$. At later epochs, the spectra develop broad P-Cygni profiles and become increasingly similar to those of SNe IIb, especially SN2018gk. The late-time spectrum at around 139 days does not show a distinct decline in the strength of $\rm H_\alpha$ emission profile, also indicating a relatively massive envelope of its progenitor. Aside from the $\rm H_\alpha$ feature, the nebular spectrum exhibits prominent emission lines of \Oi, \Caii, [\Caii], and \Mgi], which are consistent with the prototypical SN1993J.
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All authors L.-H. Li, S. Benetti, Y.-Z. Cai, B. Wang, A. Pastorello, N. Elias-Rosa, A. Reguitti, L. Borsato, E. Cappellaro, A. Fiore, M. Fraser, M. Gromadzki, J. Harmanen, J. Isern, T. Kangas, E. Kankare, P. Lundqvist, S. Mattila, P. Ochner, Z.-H. Peng, T. M. Reynolds, I. Salmaso, S. Srivastav, M. D. Stritzinger, L. Tomasella, G. Valerin, Z.-Y. Wang, J.-J. Zhang, C.-Y. Wu
Astrophysics of Galaxies
The Velocity Map Asymmetry of Ionized Gas in MaNGA II. Correlation between Velocity Map Morphology, Star Formation, and Metallicity in Regular Disk Galaxies
Shuai Feng, Shiyin Shen, Yanmei Chen et al. (+5 more)
The morphology of ionized gas velocity maps provides a direct probe of the internal gas kinematics of
galaxies. Using integral field spectroscopy from SDSS-IV MaNGA, we analyze a sample of 528 low-inclination, regular disk
galaxies to investigate the correlations between velocity map morphology,
star formation rate, and gas-phase
metallicity. We quantify velocity map morphology using harmonic expansion and adopt two complementary diagnostics: the global kinematic asymmetry, which traces non-axisymmetric perturbations, and the first-order term ratio, which captures axisymmetric radial motions. We find that
galaxies with higher kinematic asymmetry are more likely to deviate from the scaling relations, typically lying either above or below the
star formation main sequence and systematically below the mass-
metallicity relation. In contrast, the first-order term ratio shows only a correlation with gas-phase
metallicity in the low-mass range and no significant dependence on
star formation rate. Moreover,
galaxies below the mass-
metallicity relation generally exhibit higher HI gas fractions. These results suggest that external gas
accretion is the primary driver of the observed phenomena: inflowing metal-poor gas increases velocity map asymmetry in disk
galaxies, dilutes the
metallicity, and triggers enhanced
star formation. Feedback-driven
outflows, bar- and spiral-driven inflows, and
galaxy mergers may also contribute, but likely play a secondary role.
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All authors Shuai Feng, Shiyin Shen, Yanmei Chen, Y.Sophia Dai, Jun Yin, Wenyuan Cui, Mengting Ju, Linlin Li
High Energy Astrophysical Phenomena
A test of Amati relation using HII galaxy distances
Rikiya Okazaki and Shantanu Desai
We use model-independent luminosity distances of 186 HII
galaxy observations to address the circularity problem in the Amati relation for Gamma-ray Bursts (GRBs). For this purpose, we used Artificial Neural Network based interpolation to reconstruct the luminosity distance corresponding to the GRB
redshift. We then use two independent GRB
datasets to test the robustness of the Amati relation at
redshifts below $z=2.6$. Our best-fit Amati relation parameters are consistent for the same
datasets to within $1\sigma$. The intrinsic scatters which we obtain for the two
datasets of about 28% and 35%, are comparatively larger. This implies that the Amati relation using HII
galaxies as distance anchors cannot be used as a probe of precision cosmology.
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Astrophysics of Galaxies
Detecting Intermediate-Mass Black Holes out to 20 Mpc with ELT/HARMONI: The Case of FCC 119
Hai N. Ngo, Dieu D. Nguyen, Tinh T.Q. Le et al. (+3 more)
Intermediate-mass black holes (IMBHs; $M_{BH} \approx 10^{3-5} M_\odot$) play a critical role in understanding the formation of supermassive black holes in the early universe. In this study, we expand on Nguyen et al. simulated measurements of IMBH masses using
stellar kinematics, which will be observed with the High Angular Resolution Monolithic Optical and Near-infrared Integral (HARMONI) field spectrograph on the Extremely Large
Telescope (ELT) up to the distance of 20 Mpc. Our sample focuses on both the Virgo Cluster in the northern sky and the Fornax Cluster in the southern sky. We begin by identifying
dwarf galaxies hosting
nuclear star clusters, which are thought to be nurseries for IMBHs in the local universe. As a case study, we conduct simulations for FCC 119, the second faintest
dwarf galaxies in the Fornax Cluster at 20 Mpc, which is also fainter than most of Virgo Cluster members. We use the
galaxy's surface brightness profile from Hubble Space
Telescope (HST) imaging, combined with an assumed synthetic spectrum, to create mock observations with the HSIM simulator and Jeans Anisotropic Models (JAM). These mock HARMONI datacubes are analyzed as if they were real observations, employing JAM within a
Bayesian framework to infer IMBH masses and their associated uncertainties. We find that ELT/HARMONI can detect the
stellar kinematic signature of an IMBH and accurately measure its mass for $M_{BH} \gtrsim 10^5 M_\odot$ out to distances of $\sim$20 Mpc.
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All authors Hai N. Ngo, Dieu D. Nguyen, Tinh T.Q. Le, Tien H.T. Ho, Truong N. Nguyen, Trung H. Dang
Solar and Stellar Astrophysics
Coronal Mass Ejections Deflected by Newly Emerging Flux: A Combined Analytic and Numerical Study
Yuhao Chen, Chengcai Shen, Zhixing Mei et al. (+8 more)
Newly emerging flux (NEF) has been widely studied as a trigger of
solar filament eruptions, but its influence on the subsequent dynamics remains poorly explored. Because NEF typically emerges adjacent to filaments, it imposes
magnetic asymmetry that can drive non-radial eruptions and complicate space-weather
forecasting. We bridge analytic catastrophe theory with 2D resistive MHD simulations: analytic solutions provide
magnetic configurations containing a flux rope at the loss-of-
equilibrium point, which are then used as initial conditions for simulations to examine the following dynamics. We find that NEF governs the kinematics of filament eruptions in two ways. First, by reshaping coronal stability, NEF can create or eliminate a higher
equilibrium in corona, thereby producing failed eruptions or CMEs. In the transitional situation where a metastable
equilibrium appears, the rising filament decelerates and stalls before re-accelerating into a CME, consistent with observed two-step eruptions. Second, by breaking
symmetry, NEF deflects eruptions away from the radial direction: depending on its polarity, it acts as a repulsor or an attractor on eruptive filaments, and the deflection magnitude increases with the degree of asymmetry. Our theory yields two characteristic angles that predict the deflection directions of CMEs and failed eruptions, and simulations closely aligns with these predictors. These results highlight the NEF not only as a trigger but also as a key factor that governs both the acceleration and deflection of eruptions during their propagation in the low corona.
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All authors Yuhao Chen, Chengcai Shen, Zhixing Mei, Jing Ye, Jialiang Hu, Zehao Tang, Guanchong Cheng, Shanshan Xu, Abdullah Zafar, Yujia Song, Jun Lin
Astrophysics of Galaxies
Revisiting the 150 MHz Radio Luminosity Function of Star-Forming Galaxies with LOFAR Deep Fields through a Refined Statistical Framework
Wenjie Wang, Zunli Yuan, Hongwei Yu et al. (+3 more)
We present a comprehensive analysis of the 150~MHz
radio luminosity function (LF) of
star-forming
galaxies (SFGs) using deep observations from the LOFAR Two-metre Sky Survey in the ELAIS-N1, Boötes, and Lockman Hole fields. Our sample comprises $\sim$56,000 SFGs over $0 < z < 5.7$. We first analyze the deepest field (ELAIS-N1), then jointly model all three fields while accounting for their distinct flux limits and selection functions. Using adaptive kernel density estimation (KDE), we reconstruct the LF continuously across
redshift and luminosity without binning or parametric assumptions. The KDE results reveal clear signatures of joint luminosity and density
evolution (LADE). Motivated by this, we construct and fit three parametric models–pure luminosity
evolution (PLE) and two LADE variants–using a full maximum-likelihood method that includes completeness corrections and constraints from the local
radio LF and Euclidean-normalized source counts (SCs). Model selection using Akaike and
Bayesian Information Criteria strongly favors LADE over PLE. For ELAIS-N1, the more flexible LADE model (Model C) provides the best fit, while for the combined fields, the simpler Model B balances fit quality and complexity more effectively. Both LADE models reproduce the observed LFs and SCs across luminosity and flux density ranges, whereas PLE underperforms. We also identify a mild excess at the bright end of the LF, likely due to residual AGN contamination. This study demonstrates that combining KDE with parametric modeling offers a robust framework for quantifying the evolving
radio LF of SFGs, paving the way for future work with next-generation surveys like the SKA.
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All authors Wenjie Wang, Zunli Yuan, Hongwei Yu, Yang Liu, Yu Luo, Puxun Wu
Earth and Planetary Astrophysics
Impact of Subsurface Temperature Gradients on Emission Spectra of Airless Exoplanets: the Solid-state Greenhouse and Anti-Greenhouse
Xintong Lyu and Daniel D.B. Koll
An emerging goal of
exoplanet science is to constrain the surface composition of airless
exoplanets. Without the protection of an atmosphere, these
planets are likely covered by a powder-like regolith, similar to the Moon. Laboratory studies show that, under
vacuum conditions, such regoliths can develop subsurface temperature gradients, also known as the solid-state greenhouse effect. This effect can significantly modify the emission features of airless bodies, but its potential impact on
exoplanets is still unexplored. Here we derive analytic solutions of the two-stream radiative transfer equations with scattering, absorption, plus emission, and combine them with Mie theory calculations to model subsurface temperature gradients and emission spectra of airless
exoplanets. The results show exo-regoliths can develop strong solid-state greenhouse or anti-greenhouse effects, with temperature gradients $>200$~K in the upper-most subsurface ($\mathcal{O}(100)\mu$m). These temperature gradients alter surface emission features, modify secondary eclipse depths by up to $\sim50\%$, and can produce higher-than-blackbody emission at some wavelengths. In addition, we study whether subsurface temperature gradients can be disentangled from other microscopic effects, such as changes in space weathering or particle size. At least in some cases, the co-existence of these effects makes it essentially impossible to distinguish different surface compositions within the precisions achievable by JWST. Overall, subsurface temperature gradients thus open potentially new ways to characterize surfaces of airless
exoplanets, but they also complicate the interpretation of airless
exoplanet spectra. In either case, their effect can be important and should be included in future modeling studies.
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Solar and Stellar Astrophysics
Morphological and Kinematical Diagnostic of FU Orionis-type Outburst Mechanisms
Jinshi Sai, Eduard I. Vorobyov, Alexandr Skliarevskii et al. (+1 more)
We investigated the possibility of determining the mechanism of the FU Orionis-type outburst based on molecular line observations of protoplanetary disks with synthetic observations of distinct numerical burst models. The morphology of the synthetic $\mathrm{C^{18}O}$ emission is sensitive to gas temperature and does not coincide with the actual gas disk structures, particularly in the magnetorotational instability (MRI) and clump-infall models, which exhibit peculiar temperature distributions. This highlights the need for careful interpretation of morphologies of line emission from disks under
accretion outbursts. The synthetic $\mathrm{C^{18}O}$ emission of each model exhibits distinct kinematic features that can be used to distinguish outburst scenarios. In the MRI model, kinematic features of the gravitational instability (GI), which fuels MRI-driven
accretion bursts, are small in both amplitude and spatial extent, resulting in no prominent local features in the residual velocity map at a typical distance for FU Orionis-type objects. In contrast, the clump-infall model shows a clear sign of gas expansion along a spiral, which is caused by exchange of angular momentum between an infalling clump and surrounding gas. The intruder model exhibits a highly asymmetric velocity structure with respect to the systemic velocity of the primary protostar in velocity channel maps. These distinct kinematic features may serve as promising diagnostics for distinguishing the physical mechanisms responsible for FU Orionis-type outbursts.
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All authors Jinshi Sai, Eduard I. Vorobyov, Alexandr Skliarevskii, Michihiro Takami
Earth and Planetary Astrophysics
The cosmochemistry of planetary systems
Martin Bizzarro, Anders Johansen and Caroline Dorn
Planets form and obtain their compositions from the leftover material present in protoplanetary disks of
dust and gas surrounding young
stars. The chemical make-up of a disk influences every aspect of planetary composition including their overall chemical properties, volatile content, atmospheric composition, and potential for habitability. This Review discusses our knowledge of the chemical and isotopic composition of
Solar System materials and how this information can be used to place constraints on the formation pathways of terrestrial
planets. We conclude that planetesimal formation by the streaming instability followed by rapid
accretion of drifting pebbles within the protoplanetary disk lifetime reproduces most of the chemical and isotopic observables in
Solar System. This finding has important implications for planetary habitability beyond the
Solar System because in pebble
accretion, volatiles important for life are accreted during the main growth phase of rocky
planets as opposed to the late-stage. Finally, we explore how bulk chemical inventories and masses of planetary bodies control the composition of their
primordial atmospheres and their potential to develop habitable conditions.
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High Energy Astrophysical Phenomena
Constraint on the Physical Origin of Gamma-Ray Burst Prompt Emission via Its Nondetected Diffuse Neutrino Emission
Yang-Dong-Jun Ou, Hou-Jun Lü, Jia-Ming Chen et al. (+2 more)
The physical origin of
prompt emission in gamma-ray bursts (GRBs) remains an open question since it has been studied more than half a century. Three alternative models (i.e. dissipative photosphere, internal shock, and Internal-Collision-induced
MAgnetic Reconnection and
Turbulence, ICMART) have been proposed to interpret the observations of GRB
prompt emission, but none of them can fully interpret all of the observational data collected so far. The question is what is the fraction of these three theoretical models in the
prompt emission of GRBs. In this paper, we propose to utilize an innovative method and constrain the fraction of GRB
prompt emission models via its nondetected diffuse
neutrinos. By adopting two methods (e.g., summing up the individual GRB contributions and assumed luminosity functions of GRB) to calculate diffuse
neutrino flux of GRBs for given the
benchmark parameters of $\Gamma=300$ and $\varepsilon_{p} \text{/} \varepsilon_{e}=10$, both approaches indicate that most GRBs should be originated from the ICMART model. Moreover, we find that the fractions of the dissipative photosphere model, the internal shock model, and the ICMART model are constrained to be [0, $0.5\%$], [0, $1.1\%$], and [$98.9\%$, 1], respectively, for the method of summing up the individual GRB contributions. For the method of luminosity functions, the fractions of above three models are constrained to be [0, $6.1\%$], [0, $8.2\%$], and [$91.8\%$, 1], respectively. However, such fractions of different models are also dependent on the parameters of $\Gamma$ and $\varepsilon_{p} \text{/} \varepsilon_{e}$.
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All authors Yang-Dong-Jun Ou, Hou-Jun Lü, Jia-Ming Chen, Ben-Yang Zhu, En-Wei Liang
High Energy Astrophysical Phenomena
Discovery and Timing Follow-Up of Two FAST-Discovered Pulsars from the FAST CRAFTS Survey
Victoria A. Blackmon, Maura A. McLaughlin, De Zhao et al. (+6 more)
We present the results of Green Bank
Telescope (GBT) observations of two
pulsars discovered with the Five-hundred-meter Aperture Spherical
Radio Telescope (FAST) during the 19-beam Commensal
Radio Astronomy FasT Survey (CRAFTS). We highlight the first timing solutions, pulse profiles, flux densities, and polarization measurements at 820 MHz for PSR J0535-0231, with a
spin period of 415 ms, and PSR J1816-0518, with a
spin period of 1.93 s, from a year-long follow-up campaign. PSR J0535-0231 appears to be partially recycled, but isolated, and likely belongs to the class of disrupted recycled
pulsars (DRPs). We find that the two widely used electron density models, NE2001 and YMW16, both fall short of accurately modeling the line-of-sight to PSR J0535-0231, as the maximum dispersion measure (DM) predicted by both models is lower than the
pulsar's DM of 118.1 pc cm$^{-3}$. Finally, we place both
pulsar discoveries in the context of other FAST
pulsars discovered in the CRAFTS survey and of the currently known
pulsar population, in general, and discuss ways in which future FAST discoveries of faint, distant
pulsars might facilitate the development of improved versions of the aforementioned electron density models in certain regions of our
Galaxy.
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All authors Victoria A. Blackmon, Maura A. McLaughlin, De Zhao, Jianping Yuan, Qingdong Wu, Chen-Chen Miao, Meng-Yao Xue, Di Li, Wei-Wei Zhu
Astrophysics of Galaxies
HI Content of Group Galaxies from the FAST All Sky HI Survey
Shulan Yan, Andrew Ma, Qingzheng Yu et al. (+3 more)
We investigate the atomic gas (HI) content of
galaxies in groups using early data from the FAST All Sky HI survey (FASHI). Taking advantage of FAST's blind, wide-area coverage and uniform sensitivity, we assemble a sample of $230$ group
galaxies belonging to $182$ groups at $z\leq0.03$. These groups were identified using a
halo-based group finder, and they have an median membership of $4$
galaxies. We also derived a matched control sample of isolated systems, and apply censored-data modeling to include both detections and non-detections. At fixed
stellar mass and color, we find that the global median HI fraction of group
galaxies differs from that of controls by only $-0.04$ dex ($95\%$ CI [$-0.18,\ 0.16$]), indicating at most a mild average offset. The signal is not uniform across populations: satellites are HI-poor (median $\Delta f_{\mathrm{HI}}=-0.12$ dex), whereas centrals are not HI-deficient (median $\Delta f_{\mathrm{HI}}=0.13$ dex). Group
galaxies located within $0.5R_{180}$ and in denser systems (richness $>10$ or local density $\Sigma>10\ \mathrm{gal\ Mpc^{-2}}$) show stronger negative offsets, whereas
galaxies in the outskirts are statistically indistinguishable from the controls. These results refine earlier reports of global group HI deficiency: with deeper blind data and uniform treatment of upper limits, we show that HI depletion is primarily confined to satellites and compact cores rather than being ubiquitous across groups.
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All authors Shulan Yan, Andrew Ma, Qingzheng Yu, Taotao Fang, Chuan He, Ming Zhu
Instrumentation and Methods for Astrophysics
The MDW H{\alpha} Sky Survey: Data Release 1
Noor Aftab, Xunhe Zhang, Sean Walker et al. (+6 more)
The Mittelman-di Cicco-Walker (MDW) H$\alpha$ Sky Survey is an autonomously-operated all-sky narrow-band (3nm) H$\alpha$ imaging survey. The survey was founded by amateur astronomers and the northern sky (Decl. $\geq$ 0$^\circ$) is presented here in its second stage of refinement for academic use. Each 3.6$\times$3.6 sq. deg MDW field has 12 20-minute individual exposures with a pixel scale of 3.6", a typical PSF of 6", and a stack point source depth of 16-17 magnitudes. The northern MDW Survey Data Release 1 (DR1) includes: calibrated and raw mean and individual images,
star-removed mean fields, and point source catalogs for all images matched to Data Release 1 of the Panoramic Survey
Telescope and Rapid Response System (Pan-STARRS1) and the INT
Galactic Plane Survey (IGAPS). Our initial study of H$\alpha$ filament widths finds a typical FWHM of 30-45" in the Lyra region. The matched catalogs (with a median match distance of ~0.5"), combined with our distinctive narrow-band photometry, are used to identify H$\alpha$ variable and excess sources. These initial studies highlight some of the many scientific uses of the MDW H$\alpha$ survey.
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All authors Noor Aftab, Xunhe Zhang, Sean Walker, Dennis di Cicco, David R. Mittelman, Sanya Gupta, Andrew K. Saydjari, Mary Putman, David Schiminovich
High Energy Astrophysical Phenomena
Stellar Wind-Blown Bubbles as Environments for Late-Time Rebrightening of Gamma-Ray Burst Afterglows
Jia Ren, Xiao-Yan Li, Yun Wang et al. (+5 more)
We presented the multi-wavelength afterglow fitting results for three events that exhibit late afterglow rebrightening behavior: EP240414a ($z=0.401$), GRB 240529A ($z=2.695$), and GRB 240218A ($z=6.782$), which span a broad range of
redshifts, from the local to the high-
redshift universe.We prove that the peculiar afterglow light curves of three bursts can be well fitted by structured jets propagated in free-to-shocked
stellar wind environment of
stellar wind blown bubbles. This scenario offers a self-consistent explanation for the observed subclass of afterglows that exhibit rebrightening that is characterized by steep rises and rapid decays. It also provides a unified solution for such events and offers pathways to study both the jet generation mechanism and the propagation process of jets through the envelope of the progenitor. This study reveals that the structured jets produced by such events exhibit a narrow jet core and a steep angle-dependent energy decay index, suggesting highly magnetized jets. The derived transition radii from free
stellar winds to shocked
stellar winds for all three events are smaller than 0.5 pc, with statistical analysis of similar events indicating a median value of 0.1 pc, which conflicts with numerical simulation results. We anticipate that future observations by EP and SVOM missions will enhance the understanding of analogous events and further reveal information about progenitors and their circum-environments.
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All authors Jia Ren, Xiao-Yan Li, Yun Wang, Lu-Lu Zhang, Da-Ming Wei, Zi-Gao Dai, Zhi-Ping Jin, Da-Bin Lin