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Physics Astrophysics

astro-ph Watch Astrophysics

Sunday 12 April

Cosmology and Nongalactic Astrophysics

Low-ionization Metal Absorption at $0.7 \lesssim z \lesssim 2$ Confronting Cosmological Simulations with Observations

Ivan Rapoport, Ehud Behar and Vincent Desjacques

Low-ionization metal absorption lines provide a primary probe of cool gas in and around galaxies. We confront observations of metal-line absorption in quasar spectra with predictions from the IllustrisTNG cosmological simulation in order to benchmark how well current galaxy formation models reproduce the observed circumgalactic medium (CGM) and intergalactic medium (IGM) absorption signatures. We implement two ionization prescriptions: a purely collisional model and a model including photo-ionization by a uniform ultraviolet background (UVB). Using a grid-based framework, we compute MgI, MgII and FeII column densities and construct column density probability distribution functions (PDFs) and equivalent width (EW) statistics for comparison with observations. The observational samples considered here are based on the High Resolution Echelle Spectrometer (HIRES), the Ultraviolet and Visual Echelle Spectrograph (UVES), the Sloan Digital Sky Survey (SDSS) and the Dark Energy Spectroscopic Instrument (DESI). The computed PDFs broadly reproduce the observed ones across the sampled column density range of $10^{11.4}\lesssim \text{N}\lesssim 10^{16}\ \rm{cm^{-2}}$, indicating that the simulation captures the dominant physical drivers of low-ionization absorption. We then compute the cosmic incidence of MgII systems, namely the evolution of their number with redshift $d\mathcal{N}/{dz}$. The model that includes UVB accurately produces $d\mathcal{N}/{dz}$ up to equivalent widths (EW) of $\rm W_0^{2796} < 0.6\ \mathring{A}$, consistent with low-density photo-ionized gas in the outer CGM. At high EWs of $\rm W_0^{2796} > 1\ \mathring{A}$ TNG underestimates $d\mathcal{N}/{dz}$ and fails to capture its rise toward $z\sim2$.
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Cosmology and Nongalactic Astrophysics · Cross-listed from gr-qc

Energy-momentum and dark energy in $\boldsymbol{SU(\infty)}$-QGR quantum gravity

Houri Ziaeepour

$SU(\infty)$ Quantum GRavity (QGR) is a recently proposed fundamentally quantum approach to gravity and cosmology. In this model the Hilbert space of the Universe represents $SU(\infty)$ symmetry. Its fragmentation generates approximately isolated subsystems (particles) representing, in addition to $SU(\infty)$, finite-rank local symmetries. The common $SU(\infty)$ is associated to quantum gravity, and at lowest quantum order the effective action for all symmetries is Yang-Mills on a 4D parameter space $\Xi$. Nonetheless, physical processes and measurables must be independent of the geometry of $\Xi$. In previous works we demonstrated that diffeomorphism of $\Xi$ can be neutralized by $SU(\infty)$ gauge transformation. In this work we show that the invariance of action under variation of $\Xi$'s metric leads to a constraint resembling Einstein equation. It consists of energy-momentum tensors for all components of the model, including the spin-1 gravitons. In addition, through calculation of quantum information measures we study the effect of Hilbert Space Fragmentation (HSF) on the emergent classical spacetime and different cosmological era, such as inflation, reheating, and late time accelerating expansion. The results of this preliminary and approximate investigation show that HSF may be classically interpreted as these phenomena. Consequently, inflaton, quintessence, and similar fields associated to these processes may be order parameters that phenomenologically present them.
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High Energy Astrophysical Phenomena

Bayesian Geometrical Modeling of IXPE Polarization Angle Curves of the Magnetars 1E 2259+586 and 1E 1547.0-5408

Biao-Peng Li, Zhi-Fu Gao, Wen-Qi Ma et al. (+2 more)

X-ray polarimetry directly probes the radiation geometry and large-scale magnetic configuration of magnetars. We present a uniform Bayesian comparison between a dipole-dominated classical rotating vector model (CRVM) and a modified rotating vector model (MRVM) including a first-order magnetospheric twist correction. The models are applied to the phase-resolved IXPE polarization position angle (PA) curves of 1E~2259+586 and 1E~1547.0$-$5408. Parameters are inferred with a PA-level likelihood, and the models are compared using $\chi^2$, AIC, BIC, and Bayesian evidence. For 1E~1547.0$-$5408, we also test radio-derived geometrical constraints using radio-informed priors and radio-fixed fits. The current IXPE PA data for both sources are consistent with a dipole-dominated geometry and do not require a significant global twist. The MRVM gives only a marginal improvement for 1E~2259+586, with a Bayes factor of $\simeq3.3$, and no meaningful improvement for 1E~1547.0$-$5408, with a Bayes factor of $\simeq1.29$. We confirm that for 1E 1547, the nearly aligned radio geometry is not ruled out, but the radio RVM central geometry is not preferred by the X-ray PA data alone. The two sources show different impact angles, suggesting that magnetar X-ray polarization diversity reflects both viewing geometry and source-dependent emission physics. This work provides a framework for future Stokes-level and multi-epoch polarimetric studies with missions such as eXTP.
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All authors Biao-Peng Li, Zhi-Fu Gao, Wen-Qi Ma, Wei-Feng Zhang, L. C. Garcia de Andrade

Solar and Stellar Astrophysics

A Path to Constraints on Common Envelope Ejection in Massive Binaries: Full Evolutionary Reconstruction of Three Black Hole X-ray Binaries

Zhenwei Li, Dandan Wei, Shi Jia et al. (+6 more)

The massive binary common envelope (CE) phase plays a pivotal role in the formation of close black hole/neutron star (BH/NS) binaries, yet significant uncertainties remain in our understanding of this process. In this study, we aim to constrain the massive binary CE phase by systematically reconstructing three observed BH X-ray binaries (BHXBs): GRO J1655-40, SAX J1819.3-2525, and 4U 1543-47. Through comprehensive binary evolution simulations and parametric supernova (SN) modeling, we establish lower limits for the CE efficiency parameters under different energy considerations within the standard energy formalism. Specifically, we derive minimum values for three cases: $\alpha_{\rm 0.5U}$ and $\alpha_{\rm U}$ representing CE efficiencies with half and all of the internal energy contributing to the envelope ejection, respectively, and $\alpha_{\rm H}$ accounting for the envelope's enthalpy. Our analysis reveals that the self-consistent formation of these three BHXBs requires CE efficiency parameters satisfying: $\alpha_{\rm 0.5U}\gtrsim 6.7$, $\alpha_{\rm U}\gtrsim 4.2$ and $\alpha_{\rm H}\gtrsim 1.7$. Notably, we find no viable solutions with CE efficiency values below unity, even when considering the most extreme scenarios in which the envelope binding energy is significantly reduced through enthalpy inclusion. {Our results strongly imply that either additional energy sources are required, or the formalism itself must be revised.} Furthermore, we quantitatively assess the impact of BH natal kicks on our results. A key finding is that 4U 1543-47's formation requires substantial natal kicks ($\gtrsim 50 \;\rm km/s$), as lower kick velocities are incompatible with isolated binary evolution.
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All authors Zhenwei Li, Dandan Wei, Shi Jia, Hailiang Chen, Hongwei Ge, Zhuo Chen, Yangyang Zhang, Xuefei Chen, Zhanwen Han

High Energy Astrophysical Phenomena · Cross-listed from physics.plasm-ph

3D Kinetic Simulations of Driven Reconnection in Merging Flux Tubes

Camille Granier, Fabio Bacchini, Daniel Groselj et al. (+1 more)

We present 2D and 3D Particle-in-Cell simulations of driven collisionless magnetic reconnection triggered by the compression and merger of two Lundquist-type force-free flux tubes in a strongly magnetized pair plasma, with a focus on magnetic energy dissipation and particle acceleration. We show that 3D effects systematically delay the onset of reconnection in comparison with equivalent 2D runs, an effect further enhanced by a strong guide field, due to reduced linear growth rates and phase decoherence of oblique modes. Increasing the external drive accelerates both tearing and drift-kink instabilities, while a strong guide field suppresses coherent drift-kink activity and has a comparatively mild impact on tearing. Despite these differences in early-time dynamics, all simulations enter a fast-merging phase characterized by a normalized reconnection rate 0.08–0.10, coinciding with a transient reduction of the guide-to-reconnecting field ratio inside the current sheet. The high-energy cutoff of accelerated particles converges to a common asymptotic value, gamma_cut/sigma_in ~ 50, with only a weak dependence on the driving strength. This behavior is consistent with an electric-field-limited acceleration process, in which the maximum energy is set by the reconnection electric field and the duration of the energization phase. The resulting nonthermal particle spectra are similar across all runs, with power-law indices p ~ 1.6–2.0.
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All authors Camille Granier, Fabio Bacchini, Daniel Groselj, Lorenzo Sironi

Saturday 11 April

Instrumentation and Methods for Astrophysics · Cross-listed from physics.hist-ph

Amerigo Vespucci and the discovery of the Southern Sky

Davide Neri

During the voyages that led him to discover the new continent bearing his name, Amerigo Vespucci made interesting astronomical observations of the southern sky. In the past, his data have been interpreted with criteria that do not follow Vespucci's indications, resulting in identifications that are not credible or even leading to the assertion that the data themselves are incomprehensible. However, it is possible to construct a coherent picture of all the information, arriving at an identification that is in some cases very probable, in other cases almost certain, of the stars described by Vespucci. Analysis of documents shows that he made good-quality measurements, but his incomplete knowledge of ancient texts prevented him from distinguishing the new stars from the already known ones, giving rise to a period of confusion in 16th century celestial cartography.
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High Energy Astrophysical Phenomena

Multi-TeV $\gamma$-ray candidates from GRB 221009A: a downturn in the intrinsic $\gamma$-ray spectrum, an echo of the prompt emission phase, and intergalactic electromagnetic cascades

Timur A. Dzhatdoev, Jagdish C. Joshi, Abhijit Roy et al. (+2 more)

The detection of $\gamma$-ray candidates up to the energy of $\approx$13 TeV from the exceptionally bright $\gamma$-ray burst GRB 221009A by the Large High Altitude Air-Shower Observatory (LHAASO) has raised considerable interest in the astrophysical community. The $\gamma$-ray dataset resulting from the LHAASO observations allows one to reconstruct the intrinsic spectrum of GRB 221009A with an unprecedented precision. This intrinsic spectrum reveals a downturn at the energy of several TeV (statistical significance $\gt 5 \sigma$), i.e. the reconstructed intensity is below the intensity expected for a power-law spectrum. We show that a significant TeV $\gamma$-ray component may be produced by neutrons from photohadronic interactions inside the fireball. These neutrons escape the fireball and interact with the surrounding matter, giving rise to a flux of electrons and positrons, eventually resulting in an observable flux of GeV–TeV synchrotron photons – a high energy "echo" of the GRB prompt emission phase. Finally, we show that at multi-TeV energies the contribution of $\gamma$ rays from intergalactic electromagnetic cascades initiated by primary ultra high energy protons is severely limited during the early afterglow phase for the typical magnetic field strength in the intergalactic filaments above 1 nG.
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All authors Timur A. Dzhatdoev, Jagdish C. Joshi, Abhijit Roy, Grigory I. Rubtsov, Anatoly A. Semenov

Earth and Planetary Astrophysics

Miscibility and Transport Properties in Hydrogen-Neon Mixtures

Armin Bergermann, Siegfried Glenzer, Arianna Glaeson et al. (+1 more)

The mixing behavior of hydrogen with heavier elements plays a key role in modeling the interiors of giant planets such as Jupiter and Saturn. Using density functional theory combined with molecular dynamics, we investigate hydrogen-neon mixtures and find that the minimum pressure required to trigger phase separation is substantially lower than in hydrogen-helium mixtures. Our simulations further reveal that the presence of neon stabilizes hydrogen molecules even at temperatures of 10000 K and pressures of 10 Mbar, similar to trends observed in hydrogen-helium mixtures but significantly more pronounced. This stabilization is accompanied by a reduction of several orders of magnitude in the electrical conductivity compared to pure hydrogen. These results, together with the larger X-ray scattering cross section of neon, establish hydrogen-neon as a valuable experimental surrogate for probing phase separation in hydrogen-rich mixtures and provide new insight into the physical mechanisms in hydrogen and mixtures with heavier elements under planetary interior conditions
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All authors Armin Bergermann, Siegfried Glenzer, Arianna Glaeson, Ronald Redmer

Astrophysics of Galaxies · Cross-listed from gr-qc

Geometrically Significant Surfaces of Black Holes from a Single Scalar

Cagdas Ulus Agca and Bayram Tekin

Black hole spacetimes contain several geometrically distinguished hypersurfaces, including event and Cauchy horizons, stationary-limit surfaces, and curvature singularities. These structures are usually identified by different geometric or causal criteria. We show that, for the Kerr–Newman black hole, the membrane-paradigm pressure of a stretched horizon admits an analytically continued scalar representative whose fully factorized form has zeros, poles, and singular factors aligned with these standard Kerr–Newman loci. Its zeros occur at the outer and inner horizons, its poles occur at the outer and inner stationary-limit surfaces, its higher-order divergence contains the ring-singularity factor, and its large-$r$ behavior records the asymptotic decay of the scalar. The construction is not proposed as a new invariant characterization of the spacetime, nor as a physical extension of the membrane fluid into the black-hole interior. Rather, it gives a compact membrane-pressure-based diagnostic whose analytic structure reorganizes several familiar surfaces of the Kerr–Newman geometry. We also note a secondary, purely algebraic analogy with generalized multi-component van der Waals-type equations of state.
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Astrophysics of Galaxies

Full-polarization millimeter wavelength variability of Sagittarius A* during the 2018 EHT campaign

Ezequiel Albentosa-Ruiz, Jasmin E. Washington, Nicola Marchili et al. (+272 more)

Sagittarius A* (Srg A*), the supermassive black hole at the center of the Milky Way, provides a unique laboratory to study accretion dynamics and plasma processes near the event horizon. We investigated the variability and polarization properties of Srg A* using ALMA observations during the 2018 Event Horizon Telescope campaign. We analyzed high-cadence full-polarization light curves from ALMA at millimeter wavelengths, performed time-series analysis, and investigated the temporal behavior during an X-ray flare observed by Chandra on 2018 April 24. The variability characteristics are compared with expectations from standard accretion flow models. We find low variability in total intensity ($\sigma/\mu < 10\%$), but significantly higher variability in linear and circular polarization (~ 30% and ~ 50%, respectively). A time-series analysis reveals red-noise variability, with power spectral densities between -2 and -3 across all Stokes parameters. Polarized intensity shows stable intra-day timescales, while total intensity exhibits more variable timescales, suggesting distinct emission regions, with polarization likely arising from a coherent structure. On April 24, a statistically significant inter-band delay in polarized intensity coincides with a near-simultaneous X-ray and millimeter peak that deviates from the typical delayed flare scenario. This event also features enhanced millimeter variability and coherent polarization loop evolution. The observed simultaneity challenges standard models of transient synchrotron emission with cooling delays, favoring instead a scenario of continuous energy injection in an optically thin region. Our results offer new constraints on the physical mechanisms driving variability in Srg A*, and provide key observational input for refining theoretical models of accretion and plasma behavior in the vicinity of supermassive black holes.
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All authors Ezequiel Albentosa-Ruiz, Jasmin E. Washington, Nicola Marchili, Iván Martí-Vidal, Ciriaco Goddi, Maciek Wielgus, Alejandro Mus, Angelo Ricarte, Daniel P. Marrone, León D. S. Salas, Yuhei Iwata, Douglas F. Carlos, Alexandra J. Tetarenko, Kotaro Moriyama, Vedant Dhruv, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislav Baloković, Bidisha Bandyopadhyay, John Barrett, Michi Bauböck, Bradford A. Benson, Dan Bintley, Lindy Blackburn, Raymond Blundell, Katherine L. Bouman, Geoffrey C. Bower, Michael Bremer, Roger Brissenden, Silke Britzen, Avery E. Broderick, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamante, John E. Carlstrom, Andrew Chael, Chi-kwan Chan, Dominic O. Chang, Koushik Chatterjee, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, Pierre Christian, Ilje Cho, Nicholas S. Conroy, John E. Conway, Thomas M. Crawford, Geoffrey B. Crew, Alejandro Cruz-Osorio, Yuzhu Cui, Brandon Curd, Rohan Dahale, Jordy Davelaar, Mariafelicia De Laurentis, Roger Deane, Jessica Dempsey, Gregory Desvignes, Jason Dexter, Indu K. Dihingia, Sheperd S. Doeleman, Sergio A. Dzib, Ralph P. Eatough, Razieh Emami, Heino Falcke, Joseph Farah, Vincent L. Fish, Edward Fomalont, H. Alyson Ford, Marianna Foschi, Antonio Fuentes, Raquel Fraga-Encinas, William T. Freeman, Per Friberg, Christian M. Fromm, Peter Galison, Charles F. Gammie, Roberto García, Olivier Gentaz, Gertie Geertsema, Boris Georgiev, Roman Gold, José L. Gómez, Arturo I. Gómez-Ruiz, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Ronald Hesper, Dirk Heumann, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei Huang, David H. Hughes, Shiro Ikeda, C. M. Violette Impellizzeri, Makoto Inoue, Sara Issaoun, David J. James, Buell T. Jannuzi, Michael Janssen, Britton Jeter, Wu Jiang, Alejandra Jiménez-Rosales, Michael D. Johnson, Adam C. Jones, Svetlana Jorstad, Abhishek V. Joshi, Taehyun Jung, Ramesh Karuppusamy, Tomohisa Kawashima, Garrett K. Keating, Mark Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Prashant Kocherlakota, Yutaro Kofuji, Patrick M. Koch, Shoko Koyama, Carsten Kramer, Joana A. Kramer, Michael Kramer, Thomas P. Krichbaum, Cheng-Yu Kuo, Noemi La Bella, Sang-Sung Lee, Aviad Levis, Zhiyuan Li, Rocco Lico, Greg Lindahl, Michael Lindqvist, Mikhail Lisakov, Jun Liu, Kuo Liu, Elisabetta Liuzzo, Wen-Ping Lo, Andrei P. Lobanov, Laurent Loinard, Colin J. Lonsdale, Amy E. Lowitz, Ru-Sen Lu, Jirong Mao, Sera Markoff, Alan P. Marscher, Satoki Matsushita, Lynn D. Matthews, Lia Medeiros, Karl M. Menten, Izumi Mizuno, Yosuke Mizuno, Joshua Montgomery, James M. Moran, Monika Moscibrodzka, Wanga Mulaudzi, Hendrik Müller, Cornelia Müller, Gibwa Musoke, Ioannis Myserlis, Hiroshi Nagai, Neil M. Nagar, Dhanya G. Nair, Masanori Nakamura, Gopal Narayanan, Iniyan Natarajan, Antonios Nathanail, Santiago Navarro Fuentes, Joey Neilsen, Chunchong Ni, Michael A. Nowak, Junghwan Oh, Hiroki Okino, Héctor Raúl Olivares Sánchez, Tomoaki Oyama, Feryal Özel, Daniel C. M. Palumbo, Georgios Filippos Paraschos, Jongho Park, Harriet Parsons, Nimesh Patel, Ue-Li Pen, Dominic W. Pesce, Vincent Piétu, Aleksandar PopStefanija, Oliver Porth, Ben Prather, Giacomo Principe, Dimitrios Psaltis, Hung-Yi Pu, Venkatessh Ramakrishnan, Ramprasad Rao, Mark G. Rawlings, Luciano Rezzolla, Bart Ripperda, Jan Röder, Freek Roelofs, Cristina Romero-Cañizales, Eduardo Ros, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Ignacio Ruiz, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sánchez, David Sánchez-Argüelles, Miguel Sánchez-Portal, Mahito Sasada, Kaushik Satapathy, Saurabh, Tuomas Savolainen, F. Peter Schloerb, Jonathan Schonfeld, Karl-Friedrich Schuster, Lijing Shao, Zhiqiang Shen, Sasikumar Silpa, Des Small, Bong Won Sohn, Jason SooHoo, Kamal Souccar, Joshua S. Stanway, He Sun, Fumie Tazaki, Paul Tiede, Remo P. J. Tilanus, Michael Titus, Kenji Toma, Pablo Torne, Teresa Toscano, Efthalia Traianou, Tyler Trent, Sascha Trippe, Matthew Turk, Ilse van Bemmel, Huib Jan van Langevelde, Daniel R. van Rossum, Jesse Vos, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Robert Wharton, Kaj Wiik, Gunther Witzel, Michael F. Wondrak, George N. Wong, Qingwen Wu, Nitika Yadlapalli, Paul Yamaguchi, Aristomenis Yfantis, Doosoo Yoon, André Young, Ziri Younsi, Wei Yu, Feng Yuan, Ye-Fei Yuan, Ai-Ling Zeng, J. Anton Zensus, Shuo Zhang, Guang-Yao Zhao, Shan-Shan Zhao

Astrophysics of Galaxies

The Milky Way Tomography with Subaru Hyper Suprime-Cam: Implications for the past orbit of the Large Magellanic Cloud

Yoshihisa Suzuki, Masashi Chiba and Rosemary F. G. Wyse

We report the discovery of diffuse stellar substructure in the Milky Way's outer halo toward Boötes, unveiled by deep imaging data of the Subaru/Hyper Suprime-Cam. This substructure is detected as an excess of faint main-sequence stars, at heliocentric distances beyond 30 kpc, extending over at least 100 $\mathrm{deg^2}$. To infer its origin, we compare the projected spatial distribution of these stars to that of simulated tidal debris from the Large Magellanic Cloud (LMC), under the assumptions that the LMC is on either its first or second passage of the Milky Way. We found that the observed overdensity lies in a region of the halo where debris from the LMC is expected if it is on its initial pericentric phase 7-8 Gyr ago, which is predicted in the second-passage model, while the first-passage model is unable to explain the observed substructure. Chemo-kinematical data are required to further constrain its past orbit and to understand the origin of this new halo substructure, as should be obtained in the near future with deep photometric surveys such as UNIONS and LSST, and wide-field spectroscopy such as possible with PFS and DESI.
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Astrophysics of Galaxies

The Milky Way Tomography with Subaru Hyper Suprime-Cam. II. Global halo structure

Yoshihisa Suzuki, Masashi Chiba, Rosemary F. G. Wyse et al. (+1 more)

We investigate the structure of the Milky Way's stellar halo within 70 kpc of the Sun using a wide-field photometric catalog obtained from the Hyper Suprime-Cam (HSC) Subaru Strategic Program (HSC-SSP). We employ a large sample of main-sequence turn-off stars as distance tracers. To robustly derive the structural parameters of the stellar halo, we develop a forward-modeling framework that explicitly accounts for distance uncertainties, the solar position, and the limited sky coverage of the survey. Applying this method to the HSC-SSP catalog, we found that the smooth stellar halo is well described by a double power-law density profile, with inner and outer slope of approximately -3.3 and -4.8, respectively, with a break radius of 17.4 kpc. The outer steep density slope derived in this work supports a picture in which the present-day structure of the Milky Way's stellar halo is influenced by early massive accretion events, consistent with inferences from kinematic substructures such as Gaia Enceladus/Sausage. Ongoing wide-field imaging surveys, including UNIONS and LSST, will provide further constraints on the structure of the stellar halo and key insights into its formation history.
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All authors Yoshihisa Suzuki, Masashi Chiba, Rosemary F. G. Wyse, Shunichi Horigome

Instrumentation and Methods for Astrophysics

A Fast Direct Solver for Mutual Coupling Analysis of Large Arrays of Reflector Antennas

Quentin Gueuning, Eloy de Lera Acedo, Anthony Keith Brown et al. (+1 more)

Mutual coupling is a dominant systematic effect in dense reflector arrays, imprinting direction-dependent and frequency-dependent structure on embedded element patterns (EEPs) and currently limiting sensitivity in precision radio measurements. Accurate modelling of these effects requires full-wave simulations of structures that are electrically large at both the array and element levels, making conventional approaches computationally prohibitive. We present a Method-of-Moments (MoM) framework accelerated by a fast direct solver (FDS). The rotational symmetry of reflector dishes is exploited to efficiently compress self-interaction blocks of the impedance matrix. Mutual interactions are treated using a broadband multipole decomposition that remains efficient and accurate for closely spaced elements. We demonstrate the method on arrays of tens of reflectors from the Hydrogen Epoch of Reionization Array (HERA) telescope. To scale to larger arrays, the FDS is used to construct macro-basis functions (MBFs) from a smaller representative array and embed them within a conventional MBF scheme. This allows the first computation of EEPs for the 320-element HERA core on a 128-core workstation.
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All authors Quentin Gueuning, Eloy de Lera Acedo, Anthony Keith Brown, Nicolas Fagnoni

High Energy Astrophysical Phenomena

Lorentz invariance violation search with flaring active galactic nuclei observations of the first Large-Sized Telescope of CTAO

Cyann Plard, Sami Caroff and the CTAO-LST project

The rapid variability observed in very-high-energy (VHE) sources-such as pulsars, gamma-ray bursts (GRBs), and flares from active galactic nuclei (AGN)-can be used to detect or constrain a potential violation of Lorentz invariance (LIV). These effects can be investigated by measuring time lags in the arrival of VHE photons. However, an important source of uncertainty arises from intrinsic processes within the sources themselves that may induce photon delays unrelated to LIV. To address this challenge, we aim to combine observations of different sources, located at different redshifts. In this study, we present the results of a standardized analysis applied to all AGN observations conducted by the first Large-Sized Telescope of the upcoming Cherenkov Telescope Array Observatory. Our analysis includes a systematic search for intra-night variability in archival data from nights with significant excess detections for target candidates. By combining these observations, we derive constraints on the characteristic energy scales at which LIV deterministic or stochastic effects are expected to manifest.
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Solar and Stellar Astrophysics

A Theoretical Investigation of He I Line Profiles for the Spectroscopic Analysis of DB White Dwarfs

Patrick Tremblay, Pierre Bergeron and Alain Beauchamp

We present a comprehensive investigation of He I line profile calculations used in the spectroscopic analyses of DB white dwarfs. Our study includes an in-depth photometric and spectroscopic analysis of all DB white dwarfs in the Data Release 17 of the Sloan Digital Sky Survey, examining the effects of frequency sampling, Doppler broadening, line dissolution, broadening by neutral particles, and 3D hydrodynamical corrections on our results. More importantly, we compare the outcomes obtained from the semi-analytical He I Stark profiles commonly used in DB white dwarf spectroscopic analyses with our recent calculations of Stark-broadened profiles derived from computer simulations.
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Cosmology and Nongalactic Astrophysics

An Analytic Formalism of Inflation for Derivative Coupled Scalar Field and Validating its predictions for Some Inflationary Potentials

Aayush Randeep and Rajib Saha

One of the fundamental objectives of contemporary cosmology is to understand the physics of the inflationary universe, owing to its observably verifiable predictions about the very early universe with an energy scale of $\sim 10^{16}$ GeV. Recent observations from the ACT and the Planck mission, constrain the values of the scalar spectral index, $n_s$, and the tensor-to-scalar ratio, with state-of-the-art accuracy and upper limits, respectively. In the current work, a type of non minimally coupled inflationary model in which the gravity and the background scalar field interact through a covariant product of the Ricci tensor and derivatives of the scalar field. With this interaction at the backdrop, we estimate $n_s$ and $r$ for a wide range of inflaton self-interaction potentials, including power law, exponential $\alpha$ attractor, Arctan, Hilltop, and polynomial model. We show that the higher derivative terms involving the scalar field resulting from the derivative coupling term can be handled without facing any singularity within the slow-roll regime. We show that it is possible to produce $n_s$ and $r$ values consistent with ACT and Planck observations for each of the chosen sets of potentials for the derivative coupled action.
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Solar and Stellar Astrophysics

Uncovering the Dominant Spatial Scales of the Sun's Magnetic Field in Solar Cycle 24

Ananya Hore and Prantika Bhowmik

The internal dynamics of the Sun generate magnetic and plasma structures in the photosphere and overlying atmosphere across a wide range of spatial scales. Identifying the critical spatial scale is essential for interpreting physical processes, selecting appropriate observations, optimizing numerical simulations and guiding future instrumentations and space missions. With the growing availability of high-resolution data, we investigate the spatial resolution required to capture the global evolution of the photospheric and atmospheric magnetic field during sunspot cycle 24. We address this problem using a quantitative spherical-harmonic-based modal decomposition. Full-disk photospheric magnetic fields are obtained from the Michelson Doppler Imager and the Helioseismic and Magnetic Imager. The corresponding global coronal field is derived using a newly developed potential field source surface extrapolation (PFSSE) model applied to observed magnetograms. Our analysis reveals two robust results. First, more than 80% of the total modal power is captured by low harmonic degrees corresponding to a spatial scale of approximately 145 Mm, which is significantly larger than individual sunspot dimensions. Second, the effective harmonic degree decreases with height in the corona, indicating that sunspots have little direct and immediate influence on the quasi-static global coronal field. It explains the PFSSE model's success in reproducing and predicting large-scale solar coronal structures, such as streamers and open-field variations, throughout the solar cycle. These results highlight the continued relevance of low-resolution magnetic maps from historical solar observations and contemporary stellar surveys, with direct implications for mission design and for characterizing magnetic environments relevant to exoplanetary systems.
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Cosmology and Nongalactic Astrophysics

Inflationary magnetogenesis from non-minimal coupling in large- and small-field potentials

Orlando Luongo, Antonino Giacomo Marino and Tommaso Mengoni

We investigate inflationary magnetogenesis in a scenario where conformal invariance of electromagnetism is broken through a non-minimal Yukawa-like coupling between the inflaton and the Ricci scalar. We account for electromagnetic backreaction and the Schwinger effect, analyzing both standard single-field inflation and a generalized K-essence framework, dubbed quasi-quintessence. We consider inflationary potentials compatible with Planck satellite constraints, including Starobinsky and $\alpha$-attractor models for large fields, as well as hilltop scenarios for small fields. Moreover, we explore very different functional electromagnetic couplings, introducing a novel ansatz modeled for small-fields. We show that the non-minimal coupling plays a central role in controlling the dynamics, acting as a timing parameter that regulates the onset of electric backreaction and the Schwinger regime. This leads to a deep modification of the magnetogenesis process. Indeed, the amplitude of the generated magnetic fields can be enhanced by several orders of magnitude with respect to the minimally coupled case, reaching present-day values up to $B_0 \sim 10^{-13}\,\mathrm{G}$ in large-field scenarios, which appear as the only ones compatible with observational bounds. Conversely, small-field models yield negligible magnetic amplitudes and appear non-predictive within our non-minimal framework.
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Instrumentation and Methods for Astrophysics

A seeing measurement device for the PoET solar telescope

Bachar Wehbe, André Silva, Manuel Abreu et al. (+3 more)

Atmospheric seeing arises from stochastic fluctuations in the refractive index of the Earth's atmosphere, producing random variations in the apparent direction of incoming light from astronomical sources. Scintillation refers to the associated intensity fluctuations induced by these refractive index inhomogeneities. A quantitative relationship between seeing and scintillation was established in 1993, enabling daytime seeing measurements by exploiting the Sun as an extended, bright source and using non-telescopic instrumentation. PoET, the Paranal solar ESPRESSO Telescope, will feed the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations, ESPRESSO, at the European Southern Observatory (ESO) Very Large Telescope (VLT). By using the Sun as a proxy for solar-type stars, PoET will facilitate detailed investigations of the physical processes that drive stellar noise in ultra-high-precision radial-velocity measurements for exoplanet studies. The instrument is capable of targeting any region on the solar disk and acquiring spatially resolved spectra over areas ranging from 1 to 55 arcseconds. Accurate characterization of daytime atmospheric seeing is therefore essential for selecting the optimal observing aperture and ensuring the scientific performance of PoET. To support this requirement, we have developed and implemented a dedicated solar seeing monitor for daytime deployment at Paranal, Chile, where PoET will operate. In this work, we describe the instrument design and present the results from commissioning and initial on-sky validation.
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All authors Bachar Wehbe, André Silva, Manuel Abreu, Alexandre Cabral, Nuno Santos, Pit Sütterlin

High Energy Astrophysical Phenomena

Joint Observation of SGR J1935+2154 with Insight-HXMT and KM40m during the active episode of October 2022

Wang-Chen Xue, Wen-Jun Tan, Yu-Xiang Huang et al. (+32 more)

SGR J1935+2154 is the unique magnetar so far from which fast radio bursts have been detected. In October 2022, it resumed its burst activity, and we implemented a dedicated target-of-opportunity (ToO) observation on it from Oct. 13th to Nov. 1st, 2022 (about 940 ks in total) with Insight-HXMT, while the KM40m radio telescope observed this source for about 1400 hours since Oct. 15th. We searched the LE, ME, and HE data of Insight-HXMT in the overlapping observation time windows with the KM40m radio telescope and revealed 60 magnetar X-ray bursts (MXBs), while KM40m only detected 1 radio burst. In particular, we find that there is an X-ray burst on October 21 (denoted as MXB 221021) temporally associated with this radio burst. Interestingly, this association event shows very different morphology from those X-ray and radio association events from this source reported before (e.g., MXB/FRB 200428). Moreover, we systematically analyzed the temporal and spectral properties of the sample of MXBs during this observation and found that % the (radio-associated) MXB 221021 shows some different properties from other MXBs without associated radio bursts. These findings shed new light on the physical mechanisms of X-ray bursts and radio burst emission in magnetars.
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All authors Wang-Chen Xue, Wen-Jun Tan, Yu-Xiang Huang, Xiao-Bo Li, Long-Fei Hao, Shao-Lin Xiong, Ce Cai, Chen-Wei Wang, Yue Wang, Ke-Jia Lee, Heng Xu, Peng Zhang, Ming-Yu Ge, Hao-Xuan Guo, Yue Huang, Cheng-Kui Li, Jia-Cong Liu, Yang-Zhao Ren, Shuo Xiao, Sheng-Lun Xie, Shu-Xu Yi, Zheng-Hang Yu, Jin-Peng Zhang, Yan-Qiu Zhang, Chao Zheng, Shi-Jie Zheng, Shu-Mei Jia, Xiang Ma, Jin Wang, Hai-Sheng Zhao, Yong Chen, Cong-Zhan Liu, Yu-Peng Xu, Li-Ming Song, Shuang-Nan Zhang

Astrophysics of Galaxies

Starbursts at Cosmic Dawn: Formation of Globular Clusters, Ultra-Faint Dwarfs, and Population III star clusters at z > 6

Olof Nebrin

In the standard model of cosmology ($\Lambda$CDM) the first stars, star clusters, and galaxies are expected to have formed in low-mass dark matter halos at high redshifts ($z \sim 6 - 30$). Attempts to predict the properties and abundances of these objects have mainly relied on numerically expensive cosmological simulations, which often lack the sub-parsec resolution needed to resolve compact star clusters and/or neglect potentially important stellar feedback processes. Motivated by this, I introduce Anaxagoras, a detailed analytical ab initio model of starbursts in low-mass halos. The model includes gas cooling, central gas accretion and disk formation, and stellar feedback from direct radiation pressure, Ly$\alpha$ scattering and IR photons, stellar winds, expanding H II regions, and (crudely) supernovae. I apply Anaxagoras to star formation at $z > 6$ in satellite halos of the Milky Way, as well as to Population III (Pop III) star formation in minihalos. For the Milky Way setup, hundreds of galaxies are predicted to form with luminosities, half-mass radii, mass-to-light ratios, and ages in good agreement with the observed local population of Ultra-Faint Dwarfs. Furthermore, at least $\sim 40$ old globular cluster candidates with initial stellar masses $10^5 - 10^6\,M_\odot$ are predicted to form at the centers of low-mass halos. Finally, if Pop III stars are not overly massive ($25\,M_\odot$), between $\sim 1 - 30$ stars could form per minihalo at $z > 20$, increasing to $\sim 10 - 500$ at $z < 15$ as Lyman-Werner feedback delays star formation until halos reach larger masses; if Pop III stars are more massive ($140\,M_\odot$), most minihalos form just a single star.
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2604.10119 · 11 Apr · 153 pages, 27 figures. M.Sc. thesis defended in 2022 at Stockholm University (supervisor: Garrelt Mellema). For more recent modelling of the critical halo mass for star formation, and Ly$\alpha$ stellar feedback, see arXiv:2303.08024 and arXiv:2409.19288, respectively. Original thesis can also be found at: https://www.diva-portal.org/smash/record.jsf?pid=diva2%3A1667717&dswid=-6362

Abstract PDF $STAR ×11$HALO ×5$STELR ×4$DWRF ×2 +6

High Energy Astrophysical Phenomena

Impact of Observational and Modelling Assumptions on Intergalactic Magnetic Field Constraints from TeV Gamma-Ray Bursts with the Cherenkov Telescope Array Observatory

Ténéman Keita, Renaud Belmont and Thierry Stolarczyk

The Intergalactic Magnetic Field (IGMF), permeating cosmic voids, is thought to be a relic of primordial magnetic fields generated in the early Universe and that gave rise to all astrophysical magnetic fields. While it has escaped direct detection, lower limits on its intensity can be derived by characterising the time-delayed secondary emission initiated when primary very high-energy (VHE) photons from gamma-ray bursts (GRBs) produce lepton pairs that are deflected by the IGMF before generating a secondary gamma-ray flux. Most current studies exclude IGMF values below $10^{-18}\;\mathrm{G}$, however, they are typically performed under idealised conditions. Focusing on the impact of modelling and observational choices, we simulate CTAO observations of GRBs 190114C and 221009A under varying conditions. For GRB 190114C-like sources, we establish a stable lower limit of $2\times10^{-16}\;\mathrm{G}$, robust against most variations in source properties and detection strategies. For more extreme GRB 221009A-like events, we demonstrate that CTAO could probe fields up to at least $10^{-16}\;\mathrm{G}$ under harsh conditions, improving significantly the current IGMF constraints.
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Instrumentation and Methods for Astrophysics

A Multi-modal Fusion Network for Star-Galaxy Classification from CSST Simulated Datasets

Zhuoming Han, Tianmeng Zhang, Chao Liu et al. (+1 more)

The distinction between stars and galaxies is a fundamental problem in the field of celestial classification. This issue has become challenging for these ongoing and upcoming digital surveys, which will produce terabytes and even petabytes of astronomical data. While deep learning offers a powerful solution for star-galaxy classification in large-scale datasets, most current approaches are limited by their reliance on catalog data alone, which consists primarily of multi-band magnitudes and imprecise morphological parameters. Therefore, we utilize China Space Station Telescope (CSST) simulation data to build a dataset with both image and photometric catalog, including 32,371 stars and 93,525 galaxies. A supervised deep learning network based on ResNet-50 and BiLSTM is proposed to improve the classification of two types of astronomical objects. The features of the catalog and image are integrated by the model, achieving 99.81% recall for galaxies and 99.66% recall for stars after training on GPU for 50 epochs. We evaluated the effects of data augmentation and multi-modal data fusion, which demonstrate that our model has commendable performance. Furthermore, our model also has a high accuracy rate for faint astronomical objects and high redshift galaxies, demonstrating its applicability to the upcoming CSST scientific data.
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All authors Zhuoming Han, Tianmeng Zhang, Chao Liu, Chenxiaoji Ling

Earth and Planetary Astrophysics · Cross-listed from physics.space-ph

Ion pickup and velocity space thermalization at outer planet moons

Xin An, Miranda Chang, Hao Cao et al. (+2 more)

Ion pickup at the outer planets' active moons is a fundamental plasma process in which newly ionized particles from moon exospheres interact with the ambient corotating plasma and are accelerated to match the background flow. Spacecraft observations have revealed intense electromagnetic wave activity commonly attributed to this pickup process. Here we investigate ion pickup using hybrid-kinetic simulations in which ions are treated kinetically while electrons are modeled as a massless fluid. In the moon's rest frame, ambient ions initially stream perpendicular to the background magnetic field at the corotation velocity, creating a nongyrotropic velocity distribution with two ion populations clustered at opposite gyrophases. Within a few ion gyroperiods, this configuration simultaneously excites transverse magnetic perturbations associated with electromagnetic ion cyclotron waves and compressional perturbations associated with mirror-mode and ion Bernstein waves, reaching amplitudes of several percent of the background field strength. Using field-particle correlation analysis, we quantify the energy transfer between waves and particles and demonstrate how these perturbations scatter ions in velocity space, efficiently incorporating newly created ions into the background plasma and leading to isotropization in both gyrophase and pitch angle. These results provide a kinetic framework for understanding pickup-driven wave-particle interactions and offer guidance for interpreting in situ measurements at active moons throughout the outer solar system.
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All authors Xin An, Miranda Chang, Hao Cao, Vassilis Angelopoulos, Anton Artemyev

Solar and Stellar Astrophysics

Daily Predictions of F10.7 and F30 Solar Indices with Deep Learning

Zhenduo Wang, Yasser Abduallah, Jason T. L. Wang et al. (+6 more)

The F10.7 and F30 solar indices are the solar radio fluxes measured at wavelengths of 10.7 cm and 30 cm, respectively, which are key indicators of solar activity. F10.7 is valuable for explaining the impact of solar ultraviolet (UV) radiation on the upper atmosphere of Earth, while F30 is more sensitive and could improve the reaction of thermospheric density to solar stimulation. In this study, we present a new deep learning model, named the Solar Index Network, or SINet for short, to predict daily values of the F10.7 and F30 solar indices. The SINet model is designed to make medium-term predictions of the index values (1-60 days in advance). The observed data used for SINet training were taken from the National Oceanic and Atmospheric Administration (NOAA) as well as Toyokawa and Nobeyama facilities. Our experimental results show that SINet performs better than five closely related statistical and deep learning methods for the prediction of F10.7. Furthermore, to our knowledge, this is the first time deep learning has been used to predict the F30 solar index.
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All authors Zhenduo Wang, Yasser Abduallah, Jason T. L. Wang, Haimin Wang, Yan Xu, Vasyl Yurchyshyn, Vincent Oria, Khalid A. Alobaid, Xiaoli Bai

Earth and Planetary Astrophysics

Ring formation around giant planets by tidal disruption of a single passing large Kuiper belt object II: The dynamical fate of tidal fragments

Naoya Torii, Shigeru Ida and Ryuki Hyodo

Planetary rings are ubiquitous structure in our Solar System, but their formation mechanisms remain under debate. One of the proposed scenarios is the tidal disruption of a nearby passing body that enters within a planet's Roche limit, producing fragments that are gravitationally captured and finally form the rings. In this study, we investigate the detailed dynamical path and fate of such tidally captured fragments using direct Nbody simulations including collisional fragmentation with analytical arguments. Focusing on Saturn as a representative case, we explore how the inclination iTD and pericenter distance qTD of the orbit of the passing body control the subsequent orbital evolution, collisional grinding, and the survival of fragments mass. Our simulations show that initially highly eccentric and inclined fragments experience differential precession driven by the planet's J2 potential, followed by destructive high-velocity collisions that damp their eccentricities and inclinations. The timing and pathway of this evolution strongly depend on iTD, modifying the dynamical picture proposed in the previous work. For low to moderate iTD, a narrow, circular and equatorial rings finally form whose orbital radius is well predicted by an analytically derived equivalent circular radius based on the conservation of the vertical component of angular momentum. In contrast, for high iTD, collisional damping causes a substantial fraction of the material to fall onto the planet, preventing the formation of a massive ring. We compile our results of Nbody simulations with the analytical predictions on (qTD, iTD) parameter space and specify the parameter region where sufficient mass to form Saturn's present rings and inner satellites survives.
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Solar and Stellar Astrophysics

Predicting Associations between Solar Flares and Coronal Mass Ejections Using SDO/HMI Magnetograms and a Hybrid Neural Network

Jialiang Li, Vasyl Yurchyshyn, Jason T. L. Wang et al. (+6 more)

Solar eruptions, including flares and coronal mass ejections (CMEs), have a significant impact on Earth. Some flares are associated with CMEs, and some flares are not. The association between flares and CMEs is not always obvious. In this study, we propose a new deep learning method, specifically a hybrid neural network (HNN) that combines a vision transformer with long short-term memory, to predict associations between flares and CMEs. HNN finds spatio-temporal patterns in the time series of line-of-sight magnetograms of solar active regions (ARs) collected by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and uses the patterns to predict whether a flare projected to occur within the next 24 hours will be eruptive (i.e., CME-associated) or confined (i.e., not CME-associated). Our experimental results demonstrate the good performance of the HNN method. Furthermore, the results show that magnetic flux cancellation in polarity inversion line regions may well play a role in triggering flare-associated CMEs, a finding consistent with literature.
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All authors Jialiang Li, Vasyl Yurchyshyn, Jason T. L. Wang, Haimin Wang, Manolis K. Georgoulis, Wen He, Yasser Abduallah, Hameedullah A. Farooki, Yan Xu

Astrophysics of Galaxies

Possible Supermassive Dark Object Composed of Light Fermionic Gas with an Embedded Neutron Star Core

Daichen Zou, Xudong Wang and Bin Qi

The structure of dark matter admixed neutron stars (DANSs) are investigated, adopting a non-annihilating self-interacting fermionic dark matter (DM) model, with a particular focus on the case of the light DM particle mass $m_D \in [10^{-10}, 1]$ GeV. The DANSs become DM-dominated configurations when $m_D <10^{-1}$ GeV, where a compact neutron star core becomes embedded within an extremely large DM halo. It is found that the maximum mass of DANSs is inversely proportional to $m_{ D}$, approximately as $ 0.627 (\mathrm{GeV/} m_{\rm D})^2 ~\mathrm{M_{\odot}}$, which implies that extremely large masses can be achieved for small $m_{\rm D}$. For $m_D \sim5\times10^{-4}$ GeV, the calculated mass and size of the DM halo can be comparable to those of supermassive black holes such as Sgr A*. Our findings hint at a scenario where neutron stars might serve as strong gravitational seeds for such supermassive dark objects.
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Solar and Stellar Astrophysics

Estimating the Luminosities of Protostars with Limited Infrared Photometry

Michael M. Dunham, Aina Palau, Nuria Huélamo et al. (+3 more)

The luminosities of protostars provide one of the only indirect methods of measuring their masses and mass accretion rates in their earliest stages of evolution. Accurate measurements of protostellar luminosities traditionally requires assembling complete spectral energy distributions (SEDs) from the near-infrared through millimeter wavelengths. In this work, we use published evolutionary radiative transfer models of collapsing protostellar cores to evaluate the extent to which protostellar luminosities can be estimated from a limited number of infrared photometric measurements. We confirm previous results showing a tight correlation (in log-log space) between the luminosity of a protostar and its flux at 70 microns, although we demonstrate that these previous results yield luminosity estimates that are too low by factors of 2-3. We expand this work to additional wavelengths, finding that single wavelengths at 40 - 350 microns provide luminosity estimates with a 1sigma uncertainty of a factor of 3 (0.477 dex of solar luminosities) or lower, with the uncertainty reduced to a factor of 2 (0.301 dex of solar luminosities) or lower at 70 - 160 microns. While the shorter wavelengths observed by JWST (0.6 - 27.9 microns) do not correlate as well with luminosity, we demonstrate that using a single photometric measurement in two different JWST filters simultaneously can result in luminosity estimates that are less uncertain than even the best estimates obtained using a single JWST filter. Using a single photometric measurement in three different JWST filters simultaneously can result in luminosity estimates that are comparable in accuracy to those obtained using single far-infrared photometric flux measurements.
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All authors Michael M. Dunham, Aina Palau, Nuria Huélamo, Eduard I. Vorobyov, Zach Yek, Sean Rand

High Energy Astrophysical Phenomena

To understand the radiative processes of pulsars and fast radio bursts with the FAST

Wei-Yang Wang, Shunshun Cao, Zhipeng Huang et al. (+39 more)

The radiative mechanism of coherent radio emission has remained an enigma since the discovery of pulsars, even the emergence of fast radio bursts (FRBs), which exhibit similarities to the single-pulse behavior of pulsars and have opened a new view for deciphering the long-standing mystery. Besides tremendous efforts in modelling, advanced facilities matter for solving the problem. The authors review the observational breakthroughs from the Five-hundred-meter Aperture Spherical radio Telescope (FAST), which are providing pivotal insights to unravel the underlying physics of pulsars and FRBs. This study offers a novel perspective in the era when pulsars meet FRBs, and further investigations are encouraged to utilize the highly sensitive telescope, the FAST.
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All authors Wei-Yang Wang, Shunshun Cao, Zhipeng Huang, Jiguang Lu, Yunpeng Men, Lingqi Meng, Jiarui Niu, Zhichen Pan, Pengfei Wang, Dejiang Zhou, Yi Feng, Jinlin Han, Jinchen Jiang, Bin Liu, Rui Luo, Honguang Wang, Shuangqiang Wang, Tao Wang, Zhengli Wang, Heng Xu, Jiangwei Xu, Renxin Xu, Yonghua Xu, Yi Yan, Zhen Yan, Yukai Zhou, Siyuan Chen, Yinfeng Dai, Mingyu Ge, Zejun Jiang, Kejia Lee, Yujie Lian, Kuo Liu, Lei Qian, Hao Tong, Lin Wang, Yujie Wang, Zihao Xu, Jumei Yao, Dejiang Yin, Li Zhang, Weiwei Zhu