The Astrophysical Journal Letters最新文献

{"title":"Euclid and Roman with JWST Could Reveal Supermassive Black Holes at up to z ∼ 15","authors":"Muhammad A. Latif and Daniel J. Whalen","doi":"10.3847/2041-8213/adfec6","DOIUrl":"https://doi.org/10.3847/2041-8213/adfec6","url":null,"abstract":"Although supermassive black holes (SMBHs) are found at the centers of most galaxies today, over 300 have now been discovered at z > 6, including UHZ1 at z = 10.1 and GHZ9 at z = 10.4. They are thought to form when 104 to 105M⊙ primordial stars die as direct-collapse black holes (DCBHs) at z ∼ 20–25. While studies have shown that DCBHs should be visible at birth at z ≳ 20 in the near-infrared (NIR) to the James Webb Space Telescope (JWST), none have considered SMBH detections at later stages of growth down to z ∼ 6–7. Here, we present continuum NIR luminosities for a black hole (BH) like ULAS J1120+0641, a 1.35 × 109M⊙ quasar at z = 7.1, from a cosmological simulation for Euclid, Roman Space Telescope (RST), and JWST bands from z = 6 to 15. We find that Euclid and RST could detect such BHs, including others like UHZ1 and GHZ9, at much earlier stages of evolution, out to z ∼ 14–15, and that their redshifts could be confirmed spectroscopically with JWST. Synergies between these three telescopes could thus reveal the numbers of SMBHs at much higher redshifts and discriminate between their evolution pathways because Euclid and RST can capture large numbers of them in wide-field surveys for further study by JWST.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical Spectroscopy of the Most Compact Accreting Binary Harboring a Magnetic White Dwarf and a Hydrogen-rich Donor","authors":"Ilkham Galiullin, Antonio C. Rodriguez, Kareem El-Badry, Ilaria Caiazzo, Paula Szkody, Pranav Nagarajan and Samuel Whitebook","doi":"10.3847/2041-8213/adff82","DOIUrl":"https://doi.org/10.3847/2041-8213/adff82","url":null,"abstract":"Accreting white dwarfs (WDs) in close binary systems, commonly known as cataclysmic variables (CVs), with orbital periods below the canonical period minimum (≈80 minutes) are rare. Such short periods can only be reached if the donor star in the CV is either significantly evolved before initiating mass transfer to the WD or is metal-poor. We present optical photometry and spectroscopy of Gaia19bxc, a high-amplitude variable identified as a polar CV with an exceptionally short orbital period of 64.42 minutes—well below the canonical CV period minimum. High-speed photometry confirms persistent double-peaked variability consistent with cyclotron beaming, thus indicating the presence of a magnetic WD. Phase-resolved Keck/Low-Resolution Imaging Spectrometer (LRIS) spectroscopy reveals strong hydrogen and helium emission lines but no donor features, indicating the accretor is a magnetic WD and the donor is hydrogen-rich, but cold and faint. The absence of a detectable donor and the low inferred temperature (≲3500 K) disfavor an evolved donor scenario. Instead, the short period and the system’s halo-like kinematics suggest Gaia19bxc may be the first known metal-poor polar. Because metal-poor donors are more compact than solar-metallicity donors of the same mass, they can reach shorter minimum periods. Gaia19bxc is one of only a handful of known metal-poor CVs below the canonical period minimum and has the shortest period of any such magnetic system discovered to date.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145008984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Upper Limit of 106 M ⊙ in Dust from ALMA Observations in 60 Little Red Dots","authors":"Caitlin M. Casey, Hollis B. Akins, Steven L. Finkelstein, Maximilien Franco, Seiji Fujimoto, Daizhong Liu, Arianna S. Long, Georgios Magdis, Sinclaire M. Manning, Jed McKinney, Marko Shuntov and Takumi S. Tanaka","doi":"10.3847/2041-8213/adfa91","DOIUrl":"https://doi.org/10.3847/2041-8213/adfa91","url":null,"abstract":"By virtue of their red color, the dust in little red dots (LRDs) has been thought to be of appreciable influence, whether that dust is distributed in a torus around a compact active galactic nucleus or diffuse in the interstellar medium of nascent galaxies. In C. M. Casey et al. we predicted that, based on the compact sizes of LRDs (unresolved in JWST NIRCam imaging), detection of an appreciable dust mass would be unlikely. Here we present follow-up Atacama Large Millimeter/submillimeter Array 1.3 mm continuum observations of a sample of 60 LRDs drawn from H. B. Akins et al. None of the 60 LRDs are detected in imaging that reaches an average depth of σrms = 22 μJy. A stack of the 60 LRDs also results in a nondetection, with an inverse-variance weighted flux density measurement of S1.3 mm = 2.1 ± 2.9 μJy. This observed limit translates to a 3σ upper limit of 106M⊙ in LRDs’ dust mass, and ≲1011 L⊙ in total dust luminosity; both are a factor of 10× deeper than previous submillimeter stack limits for LRDs. These results are consistent with either the interpretation that LRDs are reddened due to compact but modest dust reservoirs (with AV ∼ 2–4) or, alternatively, that instead of being reddened by dust, they have extreme Balmer breaks generated by dense gas (>109 cm−3) enshrouding a central black hole.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145008985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"X-Ray Investigation of Possible Super-Eddington Accretion in a Radio-loud Quasar at z = 6.13","authors":"Luca Ighina, Alessandro Caccianiga, Thomas Connor, Alberto Moretti, Fabio Pacucci, Cormac Reynolds, José Afonso, Bruno Arsioli, Silvia Belladitta, Jess W. Broderick, Daniele Dallacasa, Roberto Della Ceca, Francesco Haardt, Erini Lambrides, James K. Leung, Alessandro Lupi, Israel Matute, Fabio Rigamonti, Paola Severgnini, Nick Seymour, Fabrizio Tavecchio and Cristian Vignali","doi":"10.3847/2041-8213/aded0a","DOIUrl":"https://doi.org/10.3847/2041-8213/aded0a","url":null,"abstract":"We present radio and X-ray observations of the recently discovered z = 6.13 radio-powerful quasar RACS J032021.44−352104.1 using the upgraded Giant Metrewave Radio Telescope, the Australia Telescope Compact Array, the Australian Large Baseline Array, and Chandra. The observed radio properties are in line with what is typically observed in high-z radio quasars (αr = 0.72 ± 0.02 and L1.4 GHz = 5.8 ± 0.9 × 1026 W Hz−1). Despite the relatively low X-ray flux observed, F0.5−7.0 keV = 2.3 ± 0.5 × 10−14 erg s−1 cm−2, the intrinsic luminosity in the 2–10 keV rest frame is markedly high, erg s−1, making RACS J032021.44−352104.1 one of the most luminous quasars currently known at z > 5.5. The high X-ray luminosity is largely driven by an extrapolation to energies below the observable X-ray window with Chandra and the slope derived in the 0.5–7 keV band (or 3.5–50 keV in the rest frame; ΓX = 3.3 ± 0.4). By analyzing the overall spectral energy distribution of the quasar, we found that the remarkably soft X-ray emission (1) cannot be produced by relativistic jets, even when relativistic boosting is considered, and (2) is consistent with expectations for a super-Eddington accreting supermassive black hole. If such a high accretion rate was confirmed, this source would be a unique laboratory to study high accretion in the early Universe and could help resolve some challenges inherent in early black hole growth paradigms.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145008989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Sun Reversed Its Decades-long Weakening Trend in 2008","authors":"Jamie M. Jasinski and Marco Velli","doi":"10.3847/2041-8213/adf3a6","DOIUrl":"https://doi.org/10.3847/2041-8213/adf3a6","url":null,"abstract":"Over the course of two decades until 2008, the solar wind became significantly weaker with a constant declining trend in many important solar wind parameters, and solar cycle 24 being the weakest on record since the start of the space age. Here we show that since 2008, the Sun has reversed this long-term weakening trend with a steady increase in various solar wind proton parameters observed at 1 au. Furthermore, comparison of values from a fitted trend to data between 2008 and 2025 show the following increases in solar wind proton parameters: speed (~6%), density (~26%), temperature (~29%), thermal pressure (~45%), mass flux (~27%), momentum flux or dynamic pressure (~34%), energy flux (~40%), interplanetary magnetic field magnitude (~31%), and the radial component of the magnetic field (~33%). This has important implications on long-term solar trends, implying that the exceptional weakness of solar cycle 24 was most likely a recent outlier and that the Sun is not entering a modern era Maunder/Dalton-like minimum phase in its solar variation, but is instead recovering from a ~20 yr decline. Presently, the trending average solar wind dynamic pressure of ~1.9 nPa in the current solar cycle, however, is still lower than the recorded ~2.4 nPa at the end of the 20th century. Continuous future measurements will reveal whether this increase will continue in upcoming solar cycles or whether these parameters will remain stable.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145008972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"JWST-TST DREAMS: NIRSpec/PRISM Transmission Spectroscopy of the Habitable Zone Planet TRAPPIST-1 e","authors":"Néstor Espinoza, Natalie H. Allen, Ana Glidden, Nikole K. Lewis, Sara Seager, Caleb I. Cañas, David Grant, Amélie Gressier, Shelby Courreges, Kevin B. Stevenson, Sukrit Ranjan, Knicole Colón, Brett M. Morris, Ryan J. MacDonald, Douglas Long, Hannah R. Wakeford, Jeff A. Valenti, Lili Alderson, Natasha E. Batalha, Ryan C. Challener, Jingcheng Huang, Zifan Lin, Dana R. Louie, Elijah Mullens, Daniel Valentine, C. Matt Mountain, Laurent Pueyo, Marshall D. Perrin, Andrea Bellini, Jens Kammerer, Mattia Libralato, Isabel Rebollido, Emily Rickman, Sangmo Tony Sohn and Roeland P. van der Marel","doi":"10.3847/2041-8213/adf42e","DOIUrl":"https://doi.org/10.3847/2041-8213/adf42e","url":null,"abstract":"TRAPPIST-1 e is one of the very few rocky exoplanets that is both amenable to atmospheric characterization and resides in the habitable zone of its star—located at a distance from its star such that it might, with the right atmosphere, sustain liquid water on its surface. Here, we present a set of four JWST/NIRSpec PRISM transmission spectra of TRAPPIST-1 e obtained in mid-to-late 2023. Our transmission spectra exhibit similar levels of stellar contamination as observed in prior works for other planets in the TRAPPIST-1 system but over a wider wavelength range, showcasing the challenge of characterizing the TRAPPIST-1 planets even at relatively long wavelengths (3–5 μm). While we show that current stellar modeling frameworks are unable to explain the stellar contamination features in our spectra, we demonstrate that we can marginalize over those features instead using Gaussian processes, which enables us to perform novel exoplanet atmospheric inferences with our transmission spectra. In particular, we are able to rule out cloudy, primary H2-dominated (≳80% by volume) atmospheres at better than a 3σ level. Constraints on possible secondary atmospheres on TRAPPIST-1 e are presented in a companion paper. Our work showcases how JWST is breaking ground in the precision needed to constrain the atmospheric composition of habitable-zone rocky exoplanets.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145008978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observational Constraints on the Radial Evolution of O6+ Temperature and Differential Flow in the Inner Heliosphere","authors":"Yeimy J. Rivera, Kristopher G. Klein, Joseph H. Wang, Lorenzo Matteini, Daniel Verscharen, Jesse T. Coburn, Samuel T. Badman, Susan T. Lepri, Ryan M. Dewey, Jim M. Raines, B. L. Alterman, Timothy J. Stubbs, Kevin C. Delano, Roberto Livi, Stefano A. Livi, Antoinette B. Galvin, Christopher J. Owen and Michael L. Stevens","doi":"10.3847/2041-8213/adfa97","DOIUrl":"https://doi.org/10.3847/2041-8213/adfa97","url":null,"abstract":"Over decades of solar wind observations, heavy ions have been observed to have a higher temperature and flow faster than protons in the solar corona and heliosphere. Remote observations have largely been limited to the low corona (<4 R⊙), while in situ observations for heavy ions (Z > 2) have only been sampled at 1 au and beyond. As a result, theories that address heavy ion heating and acceleration remain largely unconstrained. With the launch of Solar Orbiter, heavy ion kinetics can be probed closer to the Sun, as close as the orbit of Mercury (65 R⊙), to examine their radial behavior. Through a statistical analysis of O6+, this work provides a comprehensive analysis of the velocity and temperature of O6+ from 0.3 to 1 au. The study finds that the O6+ relative drift, normalized to the local Alfvén speed, and its temperature compared to protons both decrease with distance from the Sun and show some speed dependence. The O6+ temperature is well fit by a single temperature adiabatic profile across all wind speeds, suggesting that there is no significant heating at these heliocentric distances, which is in contrast to what is observed for protons and He2+. Alfvénic fluctuations, some with full 180∘ field rotation, create momentary negative differential streaming where the speed of O6+ trails the protons. The amount of negative differential streaming gradually increases at larger distances. These results provide critical constraints on the proposed mechanisms seeking to describe ion heating and acceleration in the solar wind.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Binary Stars Take What They Get: Evidence for Efficient Mass Transfer from Stripped Stars with Rapidly Rotating Companions","authors":"Thibault Lechien, Selma E. de Mink, Ruggero Valli, Amanda C. Rubio, Lieke A. C. van Son, Robert Klement, Harim Jin and Onno Pols","doi":"10.3847/2041-8213/adfdd4","DOIUrl":"https://doi.org/10.3847/2041-8213/adfdd4","url":null,"abstract":"Binary stars and their interactions shape the formation of compact binaries, supernovae, and gravitational-wave sources. The efficiency of mass transfer—the fraction of mass retained by the accretor during binary interaction—is a critical parameter that significantly impacts the final fates of these systems. However, this parameter is observationally poorly constrained, due to the scarcity of well-characterized post-mass-transfer binaries. Be+sdOB binaries, consisting of a rapidly rotating Be star and a stripped hot subdwarf companion, are particularly valuable for studying mass transfer, since they represent clear examples of past binary interaction. Recently, a significantly expanded observational sample of 16 Be+sdOB binaries with well-constrained masses was obtained through combined spectroscopic and interferometric observations. In this work, we compile and analyze this sample, to provide robust constraints on the mass-transfer efficiency in binaries that underwent stable mass transfer during the donor’s hydrogen-shell-burning phase. Our analysis reveals that the mass transfer was predominantly conservative: half of the systems require mass-transfer efficiencies above 50%. This challenges the commonly adopted assumptions of highly nonconservative mass transfer in binary evolution modeling. Our findings are inconsistent with models that account for spinup and limit accretion due to a centrifugal barrier. We also find tension with a commonly used mass-transfer model in rapid population synthesis that limits accretion based on the thermal timescale of the accretor. These results have strong implications for almost all products of binary evolution, including a variety of supernovae, white dwarfs, blue stragglers, runaway stars, X-ray binaries, and gravitational-wave sources.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"89 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144995701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High Resolution ALMA Data of the Fomalhaut Debris Disk Confirms Apsidal Width Variation","authors":"Jay S. Chittidi, Meredith A. MacGregor, Joshua Bennett Lovell, Gaspard Duchene, Mark Wyatt, Olja Panic, Paul Kalas, Margaret Pan, A. Meredith Hughes, David J. Wilner, Grant M. Kennedy, Luca Matrà, Michael P. Fitzgerald, Kate Y. L. Su","doi":"10.3847/2041-8213/adfadb","DOIUrl":"https://doi.org/10.3847/2041-8213/adfadb","url":null,"abstract":"We present long-baseline observations of the Fomalhaut outer debris disk at 223 GHz (1.3 mm) from Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 5, which we use along with archival short-baseline observations to produce a 0<inline-formula>\u0000<tex-math>\u0000<?CDATA $mathop{.}limits{^{primeprime} }$?>\u0000</tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mover accent=\"true\"><mml:mrow><mml:mi>.</mml:mi></mml:mrow><mml:mrow><mml:mi>″</mml:mi></mml:mrow></mml:mover></mml:math>\u0000<inline-graphic xlink:href=\"apjladfadbieqn1.gif\"></inline-graphic>\u0000</inline-formula>57 resolution mosaic of the disk at a sensitivity of 7 <italic toggle=\"yes\">μ</italic>Jy bm⁻¹. We use radial profiles to measure the disk at the ansae and find that the southeast (SE) side of the disk is 4 au wider than the northwest (NW) side as observed by ALMA. We also find that the peak brightness of the NW ansa is 21% ± 1% brighter than the SE ansa. We perform Markov Chain Monte Carlo fits of the ALMA visibilities using two analytical, eccentric disk models. Our results suggest that the model including a dispersion parameter for the proper eccentricity (<inline-formula>\u0000<tex-math>\u0000<?CDATA ${sigma }_{{e}_{p}}$?>\u0000</tex-math>\u0000<mml:math overflow=\"scroll\"><mml:msub><mml:mrow><mml:mi>σ</mml:mi></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mi>p</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:msub></mml:math>\u0000<inline-graphic xlink:href=\"apjladfadbieqn2.gif\"></inline-graphic>\u0000</inline-formula>), which accounts for additional scatter in the eccentricity of individual orbits, is preferred over the model without one. Such a model implies that self-gravitation, particle collisions, and close-packing could play a role in shaping the overall structure of the Fomalhaut disk, as is seen in eccentric planetary rings. Crucially, neither model can reproduce the brightness or width asymmetry near the NW ansa. No emission from the intermediate belt is detected, allowing us to place a 3<italic toggle=\"yes\">σ</italic> upper limit of 396 <italic toggle=\"yes\">μ</italic>Jy at 1.3 mm. We also discover a spectral line in archival Cycle 3 data centered at <italic toggle=\"yes\">ν</italic>_obs ≈ 230.25 GHz at the location of the “Great Dust Cloud,” whose redshift from the expected CO line for Fomalhaut confirms the source is a background galaxy.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144987419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CHIME/Fast Radio Burst/Pulsar Discovery of a Nearby Long-period Radio Transient with a Timing Glitch","authors":"Fengqiu Adam Dong, Tracy E Clarke, Alice Curtin, Ajay Kumar, Ryan Mckinven, Kaitlyn Shin, Ingrid Stairs, Charanjot Brar, Kevin Burdge, Shami Chatterjee, Amanda M. Cook, Emmanuel Fonseca, B. M. Gaensler, Jason W. Hessels, Victoria M. Kaspi, Mattias Lazda, Robert Main, Kiyoshi W. Masui, James W. McKee, Bradley W. Meyers, Aaron B. Pearlman, Scott M. Ransom, Paul Scholz, Kendrick M. Smith and Chia Min Tan","doi":"10.3847/2041-8213/adfa8e","DOIUrl":"https://doi.org/10.3847/2041-8213/adfa8e","url":null,"abstract":"We present the discovery of a 421 s long period transient using the CHIME telescope, CHIME J0630+25. The source is localized to R.A. = 06:30:38.4 decl. = 25:26:23 using voltage data acquired with the CHIME baseband system. A timing analysis shows that a model including a glitch is preferred over a nonglitch model with dF/F = 1.3 × 10−6, consistent with other glitching neutron stars. The timing model suggests a surface magnetic field of ∼1.5 × 1015 G and a characteristic age of ∼1.28 × 106 yr. A separate line of evidence to support a strong local magnetic field is an abnormally high rotation measure of RM = −347.8(6) rad m−2 relative to CHIME J0630+25’s modest dispersion measure of 22(1) pc cm−2, implying a dense local magneto-ionic structure. As a result, we believe that CHIME J0630+25 is a magnetized, slowly spinning, isolated neutron star. This marks CHIME J0630+25 as the longest period neutron star and the second-longest period neutron star with an inferred magnetar-like field. Based on dispersion measure models and comparison with pulsars with distance measurements, CHIME J0630+25 is located at a nearby distance of 170 pc (95.4%), making it an ideal candidate for follow-up studies.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"2010 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145002866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}