Negative / Null Result ReportOpen accessPhysics and Astronomy
Francesco D’Eugenio, Ignas Juodžbalis, Xihan Ji et al. · 2025 · Monthly Notices of the Royal Astronomical Society
ABSTRACT We present a ‘Little Red Dot’ (LRD) broad-line active galactic nucleus (AGN) at $z=5.077 $, observed with NIRSpec/MSA (micro-shutter assembly) and NIRSpec/IFU (integral-field unit) by the JADES (JWST Advanced Deep Extragalactic Survey) and BlackTHUNDER (Black holes in THe early Universe aNd their DensE surRoundings) surveys. Combining spatially resolved and high-resolution spectroscopy, we characterize its central engine, host, and environment. H$\alpha $ has multiple components, including two broad Gaussians, yielding a black-hole mass $\log (M_{\bullet }/{\rm M}_\odot) = 7.65 $, whi
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Fengqiu Adam Dong, Kaitlyn Shin, Casey Law et al. · 2025 · The Astrophysical Journal Letters
Abstract We report the discovery of CHIME J1634+44, a long-period radio transient (LPT) unique for two aspects: it is the first known LPT to emit fully circularly polarized radio bursts, and it is the first LPT with a significant spin-up. Given that high circular polarization (>90%) has been observed in FRB 20201124A and in some giant pulses of PSR B1937+21, we discuss the implications of the high circular polarization of CHIME J1634+44 and conclude its emission mechanism is likely to be “pulsar-like.” While CHIME J1634+44 has a pulse period of 841 s, its burst arrival patterns are indicati
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X. J. Li, Desheng Zhao, Desheng Jiang et al. · 2014 · Journal of Applied Physics
The significant effect of the thickness of Ni film on the performance of the Ohmic contact of Ni/Au to p-GaN is studied. The Ni/Au metal films with thickness of 15/50 nm on p-GaN led to better electrical characteristics, showing a lower…
View details →Negative / Null Result ReportOpen accessPhysics and Astronomy
Aayush Saxena, Alex J. Cameron, Harley Katz et al. · 2026 · Monthly Notices of the Royal Astronomical Society
ABSTRACT The ultraviolet (UV) continuum slope of galaxies, $\beta$, is a powerful diagnostic of the metallicity and ages of stars, nebular gas properties, dust content, and the escape of Lyman continuum (LyC) photons. In this study, we present $\beta$ measurements for 395 spectroscopically confirmed galaxies at $5 \lt z \lt 14.3$ selected primarily from JADES, using high-quality JWST (James Webb Space Telescope) NIRSpec/PRISM spectra. We find a median $\beta = -2.15$, finding a mild increase in blueness of $\beta$ with increasing redshift and fainter UV magnitudes. Interestingly, we find evide
View details →Failed Experiment ReportPhysics and Astronomy
Prabir Kumar Haldar, Sanjib Kumar Manna · 2011 · Chinese Physics Letters
We present an analysis of ring-like and jet-like events in terms of factorial correlations and oscillatory multiplicity moments of 32S-Ag/Br interactions at 200 A GeV. The investigation reveals that the correlated moments increase with…
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Chuneeta D. Nunhokee, Donald M. Null, Cathryn M. Trott et al. · 2025 · The Astrophysical Journal
Abstract This paper presents the spherically averaged 21 cm power spectrum derived from Epoch of Reionization (EoR) observations conducted with the Murchison Widefield Array (MWA). The analysis uses EoR0-field data, centered at (R.A. = 0 h , decl. = −27 ∘ ), collected between 2013 and 2023. Building on the improved methodology described in C. M. Trott et al. (2024), we incorporate additional data quality control techniques introduced in C. D. Nunhokee (2020). We report the lowest-power-level limits on the EoR power spectrum at redshifts z = 6.5, z = 6.8, and z = 7.0. These power levels, measur
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Sara Kurkowska, Julia Brosch-Lenz, Yuni K. Dewaraja et al. · 2025 · Journal of Nuclear Medicine
Individualized radiopharmaceutical therapies guided by patient-specific absorbed dose (AD) assessments using nuclear medicine imaging have the potential to improve both efficacy and safety. Understanding sources of variability in AD calculations is critical for standardization. The Society of Nuclear Medicine and Molecular Imaging Dosimetry Task Force launched the 177Lu Dosimetry Challenge to evaluate variability across steps within the dosimetry workflow. This work aimed to assess the variability in ADs due to different fitting and integration methods. Methods: Anonymized datasets from 2 pati
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Callum T. Donnan, Mark Dickinson, Anthony J. Taylor et al. · 2025 · The Astrophysical Journal
Abstract We present JWST/NIRSpec PRISM observations of three luminous ( M UV < −20) galaxies at z ∼ 10 observed with the CANDELS-Area Prism Epoch of Reionization Survey (CAPERS) Cycle 3 program. These galaxies exhibit extreme UV slopes compared to typical galaxies at z = 10. Of the three sources, two of them are a close pair (0 . ″ 22) of blue galaxies at z = 9.800 ± 0.003 and z = 9.808 ± 0.002 with UV slopes of β = −2.87 ± 0.15 and β = −2.46 ± 0.10, respectively, selected from PRIMER COSMOS NIRCam imaging. We perform spectrophotometric modeling of the galaxies, which suggests extre
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Gonzalo Morrás, G. Pratten, P. Schmidt · 2026 · The Astrophysical Journal Letters
Abstract The observation of gravitational waves (GWs) from merging black holes and neutron stars provides a unique opportunity to discern information about their astrophysical environment. Two signatures that are considered powerful tracers to distinguish between different binary formation channels are general relativistic spin-induced orbital precession and orbital eccentricity. Both effects leave characteristic imprints in the GW signal that can be extracted from observations. To date, neither precession nor eccentricity has been confidently discerned in merging neutron star–black hole binar
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Andrei Kudriashov, Xiong Zhou, Razmik A. Hovhannisyan et al. · 2025 · Science Advances
Josephson junctions (JJs) are key to superconducting quantum technologies and the search for self-conjugate quasiparticles potentially useful for fault-tolerant quantum computing. In topological insulator (TI)–based JJs, measuring the current-phase relation (CPR) can reveal unconventional effects such as Majorana bound states (MBS) and nonreciprocal transport. However, reconstructing CPR as a function of magnetic field has not been attempted. Here, we present a platform for field-dependent CPR measurements in planar JJs made of NbSe 2 and few-layer Bi 2 Se 3 . When a flux quantum Φ 0 thr
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R. J. Stewart, George Younes, A. K. Harding et al. · 2025 · The Astrophysical Journal Letters
Abstract We report on IXPE and NuSTAR observations beginning 40 days after the 2024 outburst onset of magnetar 1E 1841−045, marking the first IXPE observation of a magnetar in an enhanced state. Our spectropolarimetric analysis indicates that both a blackbody (BB) plus double power-law (PL) and a double blackbody plus power-law spectral model fit the phase-averaged intensity data well, with a hard PL tail (Γ = 1.19 and 1.35, respectively) dominating above ≈5 keV. For the former model, we find the soft PL (the dominant component at soft energies) exhibits a polarization degree (PD) of ≈30% whil
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Chris J. Willott, Yoshihisa Asada, Kartheik G. Iyer et al. · 2025 · The Astrophysical Journal
Abstract We present JWST observations of a gravitationally lensed, extremely metal-poor galaxy at redshift z = 8.203 ± 0.001 from the CANUCS survey. Based on the low oxygen to Balmer line ratios, we infer a gas-phase metallicity of 12 + log(O/H) = 6.85 (1.4% solar), making CANUCS-A370-z8-LAE one of the most metal-poor galaxies known at z > 7. The galaxy has a high H β equivalent width of 225 ± 50 Å, small half-light radius of only r hl = 3 8 − 19 + 3 pc, and high star formation rate density of 50–100 M ⊙ yr −1 kpc −2 . The galaxy shows high-equivalent-width Ly α emission with an i
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Matthias Klein, J. J. Mohr, C. T. Davies · 2024 · Astronomy and Astrophysics
Galaxy clusters are useful cosmological probes and interesting astrophysical laboratories. As the cluster samples continue to grow in size, a deeper understanding of the sample characteristics and improved control of systematics becomes more crucial. For this analysis we created a new and larger ACT-DR5-based thermal Sunyaev–Zel’dovich Effect- (tSZE-) selected galaxy cluster catalog with improved control over sample purity and completeness. We employed the red sequence based cluster redshift and confirmation tool MCMF together with optical imaging data from the Legacy Survey DR-10 and infrared
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Eliza Neights, Eric Burns, Chris L. Fryer et al. · 2025 · Monthly Notices of the Royal Astronomical Society
ABSTRACT Gamma-ray bursts are the most luminous electromagnetic events in the Universe. Their prompt gamma-ray emission has typical durations between a fraction of a second and several minutes. A rare subset of these events have durations in excess of a thousand seconds, referred to as ultra-long gamma-ray bursts. Here, we report the discovery of the longest gamma-ray burst ever seen with a $\sim$25 000 s gamma-ray duration, GRB 250702B, and characterize this event using data from four instruments in the InterPlanetary Network and the Monitor of All-sky X-ray Image. We find a hard spectrum, su
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S. H. Suyu, Ana Acebrón, C. Grillo et al. · 2026 · Astronomy and Astrophysics
Robust mass modeling of strong-lensing galaxy clusters is crucial for studying cosmology and galaxy evolution. We present and compare seven mass models of the galaxy cluster MACS J0138−2155, constructed using six independent modeling software programs, including parametric and free-form approaches. By conducting a blind analysis where all the mass-modeling teams constructed their models independently without exchanging results, we quantified uncertainties arising from modeling software and assumptions. MACS J0138−2155 is unique as the only cluster found to strongly lens two supernovae (SNe), R
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Lucie E. Rowland, Mauro Stefanon, R. J. Bouwens et al. · 2026 · Monthly Notices of the Royal Astronomical Society
ABSTRACT Metallicity is a crucial tracer of galaxy evolution, providing insights into gas accretion, star formation, and feedback. At high redshift, these processes reveal how early galaxies assembled and enriched their interstellar medium. In this work, we present rest-frame optical spectroscopy of 12 massive ($\log (M_*/\mathrm{{\rm M}_{\odot }})&gt;9$) galaxies at $z\sim 6$–8 from the Reionization Era Bright Emission Line Survey (REBELS) Atacama Large Millimetre/submillimetre Array (ALMA) large program, observed with the James Webb Space Telescope (JWST) NIRSpec integral field unit spec
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Yin-Jie Li, Yuan-Zhu Wang, Shao-Peng Tang et al. · 2025 · The Astrophysical Journal
Abstract The origin of the correlation between the effective spins ( χ eff ) and mass ratios ( q ) of LIGO–Virgo–KAGRA’s binary black holes (BBHs) is still an open question. Motivated by the recent identification of two subpopulations of the BBHs, in this work we investigate the potential χ eff – q correlation for each subpopulation. Surprisingly, the χ eff – q correlation either significantly weakens or disappears for the low-mass subpopulation if we introduce a second χ eff distribution for the high-mass subpopulation, which likely originates from hierarchical mergers. This suggests that the
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R. Abbasi, M. Ackermann, J. Adams et al. · 2026 · The Astrophysical Journal Letters
Abstract Recently, IceCube reported neutrino emission from the Seyfert galaxy NGC 1068. Using 13.1 yr of IceCube data, we present a follow-up search for neutrino sources in the northern sky. NGC 1068 remains the most significant neutrino source among 110 preselected gamma-ray emitters while also being spatially compatible with the most significant location in the northern sky. Its energy spectrum is characterized by an unbroken power-law with spectral index γ = 3.4 ± 0.2. Consistent with previous results, the observed neutrino flux exceeds its gamma-ray counterpart by at least 2 orders of magn
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D. W. P. Amaral, Dennis G. Uitenbroek, Tjerk H. Oosterkamp et al. · 2025 · Physical Review Letters
We perform the first search for ultralight dark matter using a magnetically levitated particle. A submillimeter permanent magnet is levitated in a superconducting trap with a measured force sensitivity of 0.2 fN/sqrt[Hz]. We find no evidence of a signal and derive limits on dark matter coupled to the difference between baryon and lepton number, B-L, in the mass range (1.10360-1.10485)×10^{-13} eV/c^{2}. Our most stringent limit on the coupling strength is g_{B-L}≲2.98×10^{-21}. We propose the POLONAISE (Probing Oscillations using Levitated Objects for Novel Accelerometry In Searches of Exotic
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A. J. Nayana, R. Margutti, Eli Wiston et al. · 2025 · The Astrophysical Journal Letters
Abstract We present X-ray (0.3–79 keV) and radio (0.25–203 GHz) observations of the most luminous fast blue optical transient (LFBOT) AT 2024wpp at z = 0.0868, spanning 2–280 days after first light. AT 2024wpp shows luminous ( L X ≈ 1.5 × 10 43 erg s −1 ), variable X-ray emission with a Compton hump peaking at δt ≈ 50 days. The X-ray spectrum evolves from a soft ( F ν ∝ ν −0.6 ) to an extremely hard state ( F ν ∝ ν 1.26 ) accompanied by a rebrightening at δt ≈ 50 days. The X-ray emission properties favor an embedded high-energy source shining through asymmetric expanding ejecta. We detect radi
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Luca Boccioli, David Vartanyan, Evan O’Connor et al. · 2025 · Monthly Notices of the Royal Astronomical Society
ABSTRACT Massive stars can end their lives with a successful supernova explosion (leaving behind a neutron star or, more rarely, a black hole), or a failed explosion that leaves behind a black hole. The density structure of the pre-collapse progenitor star already encodes much of the information regarding the outcome and properties of the explosion. However, the complexity of the collapse and subsequent shock expansion phases prevents drawing a straightforward connection between the pre-collapse and post-explosion properties. In order to derive such a connection several explodability studies h
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Zengyou He, Hao Liang, Zheng Chen et al. · 2020 · IEEE Transactions on Knowledge and Data Engineering
Community detection is a key data analysis problem across different fields. During the past decades, numerous algorithms have been proposed to address this issue. However, most work on community detection does not address the issue of…
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Junyao Li, Ming-Yang Zhuang, Yue Shen et al. · 2025 · The Astrophysical Journal
Abstract Kiloparsec-scale dual and offset active galactic nuclei (AGNs) are signposts of accreting supermassive black holes (SMBHs) triggered during late-stage galaxy mergers, offering crucial insights into the coevolution of SMBHs and galaxies. However, robustly confirmed systems at high redshift (e.g., z > 1) are scarce and biased toward the most luminous and unobscured systems. In this study, we systematically search for kiloparsec-scale (projected separation <15 kpc) dual and offset AGNs around 571 moderate-luminosity, X-ray-selected AGNs, including the obscured population, utilizing
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