Pub Date : 2026-02-24DOI: 10.3847/2041-8213/ae3da2
Elizabeth J. McGrath, Steven L. Finkelstein, Guillermo Barro, Viraj Pandya, Henry C. Ferguson, Jeyhan S. Kartaltepe, Dale D. Kocevski, Ricardo O. Amorín, Bren E. Backhaus, Fernando Buitrago, Antonello Calabrò, Yingjie Cheng, Luca Costantin, Isa G. Cox, Kelcey Davis, Giovanni Gandolfi, Yuchen Guo, Nimish P. Hathi, Michaela Hirschmann, Benne W. Holwerda, Marc Huertas-Company, Anton M. Koekemoer, Ray A. Lucas, Bahram Mobasher, Fabio Pacucci, Casey Papovich, Pablo G. Pérez-González, Jonathan R. Trump, L. Y. Aaron Yung, Pablo Arrabal Haro, Micaela B. Bagley, Mark Dickinson, Adriano Fontana, Andrea Grazian, Norman A. Grogin, Lisa J. Kewley, Allison Kirkpatrick, Jennifer M. Lotz, Laura Pentericci, Nor Pirzkal, Swara Ravindranath, Rachel S. Somerville, Stephen M. Wilkins, Guang Yang, Lise-Marie Seillé and Xin Wang
We present measurements of morphological parameters from fitting 53,885 galaxies detected to a magnitude limit of F356W < 28.5 in the CEERS NIRCam imaging with galfit in six broadband filters: F115W, F150W, F200W, F277W, F356W, and F444W. We provide a public catalog of Sérsic indices, effective semimajor axes, axis ratios, integrated magnitudes, and position angles for these galaxies in each of the filters. Uncertainties in the measured parameters are estimated from simulated galaxies that have similar noise and background properties as the observed galaxies. We compare our measurements with those in the CANDELS/Extended Groth Strip field measured with Hubble Space Telescope/WFC3 and find that the sizes agree to within 0.09 dex and the Sérsic indices agree to within 0.13 dex. We further present the evolution in the size–mass relation, and find that the evolution to z ∼ 9 is consistent with previous results derived at lower redshift. Finally, we look at the color gradients of galaxies at 1 < z < 5 and find that for late-type galaxies (n < 2.5), there is a strong dependence on mass, but no apparent evolution with redshift, indicating that the stellar populations and dust attenuation in more massive galaxies vary substantially with radius and contribute to significant morphological k-corrections. For early-type galaxies (n > 2.5), the color gradients are nearly flat with no dependence on mass, indicating that the stellar populations are more uniform throughout. The structural measurements presented are accurate to 20% or better for most galaxies with F356W < 27.0 mag and will enable further studies of galaxy morphology to z ∼ 10.
{"title":"A Morphology Catalog of Galaxies in CEERS: Evolution in the Size and Color Gradients of Galaxies Since Cosmic Dawn","authors":"Elizabeth J. McGrath, Steven L. Finkelstein, Guillermo Barro, Viraj Pandya, Henry C. Ferguson, Jeyhan S. Kartaltepe, Dale D. Kocevski, Ricardo O. Amorín, Bren E. Backhaus, Fernando Buitrago, Antonello Calabrò, Yingjie Cheng, Luca Costantin, Isa G. Cox, Kelcey Davis, Giovanni Gandolfi, Yuchen Guo, Nimish P. Hathi, Michaela Hirschmann, Benne W. Holwerda, Marc Huertas-Company, Anton M. Koekemoer, Ray A. Lucas, Bahram Mobasher, Fabio Pacucci, Casey Papovich, Pablo G. Pérez-González, Jonathan R. Trump, L. Y. Aaron Yung, Pablo Arrabal Haro, Micaela B. Bagley, Mark Dickinson, Adriano Fontana, Andrea Grazian, Norman A. Grogin, Lisa J. Kewley, Allison Kirkpatrick, Jennifer M. Lotz, Laura Pentericci, Nor Pirzkal, Swara Ravindranath, Rachel S. Somerville, Stephen M. Wilkins, Guang Yang, Lise-Marie Seillé and Xin Wang","doi":"10.3847/2041-8213/ae3da2","DOIUrl":"https://doi.org/10.3847/2041-8213/ae3da2","url":null,"abstract":"We present measurements of morphological parameters from fitting 53,885 galaxies detected to a magnitude limit of F356W < 28.5 in the CEERS NIRCam imaging with galfit in six broadband filters: F115W, F150W, F200W, F277W, F356W, and F444W. We provide a public catalog of Sérsic indices, effective semimajor axes, axis ratios, integrated magnitudes, and position angles for these galaxies in each of the filters. Uncertainties in the measured parameters are estimated from simulated galaxies that have similar noise and background properties as the observed galaxies. We compare our measurements with those in the CANDELS/Extended Groth Strip field measured with Hubble Space Telescope/WFC3 and find that the sizes agree to within 0.09 dex and the Sérsic indices agree to within 0.13 dex. We further present the evolution in the size–mass relation, and find that the evolution to z ∼ 9 is consistent with previous results derived at lower redshift. Finally, we look at the color gradients of galaxies at 1 < z < 5 and find that for late-type galaxies (n < 2.5), there is a strong dependence on mass, but no apparent evolution with redshift, indicating that the stellar populations and dust attenuation in more massive galaxies vary substantially with radius and contribute to significant morphological k-corrections. For early-type galaxies (n > 2.5), the color gradients are nearly flat with no dependence on mass, indicating that the stellar populations are more uniform throughout. The structural measurements presented are accurate to 20% or better for most galaxies with F356W < 27.0 mag and will enable further studies of galaxy morphology to z ∼ 10.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147279035","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}
Pub Date : 2026-02-24DOI: 10.3847/2041-8213/ae4008
Macarena Droguett-Callejas, Ezequiel Treister, Loreto Barcos-Muñoz, Makoto Johnstone, Franz E. Bauer, Taiki Kawamuro, Núria Torres-Albà, Claudio Ricci, Michael Koss, Yiqing Song, Alessandro Peca, Aaron Evans and Jorge González
The study of heavily obscured supermassive black hole (SMBH) growth in late-stage galaxy mergers is challenging: column densities NH > 1024 cm−2 can block most nuclear emission, leaving significant gaps in the SMBH growth census. Millimeter-wave continuum emission offers a potential window into this obscured phase, as it can trace active galactic nuclei (AGN) activity through mechanisms less affected by dust extinction. In this work, we test whether the observed correlation between millimeter (∼200 GHz) and hard X-ray (14–150 keV) luminosities can be used to plausibly identify hidden AGN in local ultraluminous infrared galaxies, including systems hosting confirmed dual AGN. We identify three sources—one confirmed AGN and two strong candidates—presenting significant evidence of AGN activity. The confirmed dual AGN lie within ∼3σ of the millimeter–X-ray correlation, suggesting this relation can be used to identify hidden pairs. By combining the position of each source relative to this correlation with independent star formation rate constraints, we propose a method to disentangle AGN and star formation contributions for sources with measured column densities. While our analysis is based on a small, heterogeneous local sample and relies on empirical scaling relations, these results indicate that millimeter continuum emission may provide a useful complementary diagnostic for obscured SMBH growth. Atacama Large Millimeter/submillimeter Array observations at high angular resolutions are particularly valuable for this approach, while future facilities such as the ngVLA will be essential to test its robustness in larger and more distant samples.
{"title":"Probing Heavily Obscured Active Galactic Nuclei in Major Galaxy Mergers Using the Millimeter–X-Ray Correlation","authors":"Macarena Droguett-Callejas, Ezequiel Treister, Loreto Barcos-Muñoz, Makoto Johnstone, Franz E. Bauer, Taiki Kawamuro, Núria Torres-Albà, Claudio Ricci, Michael Koss, Yiqing Song, Alessandro Peca, Aaron Evans and Jorge González","doi":"10.3847/2041-8213/ae4008","DOIUrl":"https://doi.org/10.3847/2041-8213/ae4008","url":null,"abstract":"The study of heavily obscured supermassive black hole (SMBH) growth in late-stage galaxy mergers is challenging: column densities NH > 1024 cm−2 can block most nuclear emission, leaving significant gaps in the SMBH growth census. Millimeter-wave continuum emission offers a potential window into this obscured phase, as it can trace active galactic nuclei (AGN) activity through mechanisms less affected by dust extinction. In this work, we test whether the observed correlation between millimeter (∼200 GHz) and hard X-ray (14–150 keV) luminosities can be used to plausibly identify hidden AGN in local ultraluminous infrared galaxies, including systems hosting confirmed dual AGN. We identify three sources—one confirmed AGN and two strong candidates—presenting significant evidence of AGN activity. The confirmed dual AGN lie within ∼3σ of the millimeter–X-ray correlation, suggesting this relation can be used to identify hidden pairs. By combining the position of each source relative to this correlation with independent star formation rate constraints, we propose a method to disentangle AGN and star formation contributions for sources with measured column densities. While our analysis is based on a small, heterogeneous local sample and relies on empirical scaling relations, these results indicate that millimeter continuum emission may provide a useful complementary diagnostic for obscured SMBH growth. Atacama Large Millimeter/submillimeter Array observations at high angular resolutions are particularly valuable for this approach, while future facilities such as the ngVLA will be essential to test its robustness in larger and more distant samples.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147278364","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}
Pub Date : 2026-02-24DOI: 10.3847/2041-8213/ae42cd
Daniel A. Yahalomi, Tiger Lu, 均 陆, Philip J. Armitage, Megan Bedell, Andrew R. Casey, Adrian M. Price-Whelan and Malena Rice
Detections of long-period giant exoplanets will expand dramatically with Gaia Data Release 4, but interpreting these signals will require care. We derive the astrometric resoeccentric degeneracy: an astrometric analogue of the well-known radial velocity degeneracy in which a single eccentric planet can mimic two circular planets near a 2:1 period ratio. To first order in eccentricity, the sky-projected motion of a single eccentric orbit decomposes into a fundamental mode and first harmonic with an amplitude proportional to that eccentricity. A pair of coplanar, circular planets in a 2:1 orbital resonance produces the same harmonic structure: the outer planet sets the fundamental mode, while the inner planet supplies an apparent first harmonic. We present a mapping between the harmonic amplitudes and effective eccentricity (eeff) of a single planet that mimics a 2:1 configuration, demonstrating that eeff = 21/3(Mp,2/Mp,1), the masses of the inner and outer planets, respectively. Using simulated Gaia data, we show that (1) coplanar 2:1 systems are statistically indistinguishable from a single eccentric planet and (2) mutual inclination can break this degeneracy. This bias favors detecting mutually inclined systems, often fingerprints of a dynamically hot history—traces for processes such as planet–planet scattering or secular chaos. Determining the planetary architectures in which this degeneracy holds will be essential for measuring cool-giant occurrence rates with Gaia and for inferring their dynamical evolution histories.
{"title":"The Astrometric Resoeccentric Degeneracy: Eccentric Single Planets Mimic 2:1 Resonant Planet Pairs in Astrometry","authors":"Daniel A. Yahalomi, Tiger Lu, 均 陆, Philip J. Armitage, Megan Bedell, Andrew R. Casey, Adrian M. Price-Whelan and Malena Rice","doi":"10.3847/2041-8213/ae42cd","DOIUrl":"https://doi.org/10.3847/2041-8213/ae42cd","url":null,"abstract":"Detections of long-period giant exoplanets will expand dramatically with Gaia Data Release 4, but interpreting these signals will require care. We derive the astrometric resoeccentric degeneracy: an astrometric analogue of the well-known radial velocity degeneracy in which a single eccentric planet can mimic two circular planets near a 2:1 period ratio. To first order in eccentricity, the sky-projected motion of a single eccentric orbit decomposes into a fundamental mode and first harmonic with an amplitude proportional to that eccentricity. A pair of coplanar, circular planets in a 2:1 orbital resonance produces the same harmonic structure: the outer planet sets the fundamental mode, while the inner planet supplies an apparent first harmonic. We present a mapping between the harmonic amplitudes and effective eccentricity (eeff) of a single planet that mimics a 2:1 configuration, demonstrating that eeff = 21/3(Mp,2/Mp,1), the masses of the inner and outer planets, respectively. Using simulated Gaia data, we show that (1) coplanar 2:1 systems are statistically indistinguishable from a single eccentric planet and (2) mutual inclination can break this degeneracy. This bias favors detecting mutually inclined systems, often fingerprints of a dynamically hot history—traces for processes such as planet–planet scattering or secular chaos. Determining the planetary architectures in which this degeneracy holds will be essential for measuring cool-giant occurrence rates with Gaia and for inferring their dynamical evolution histories.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"78 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147278366","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}
Pub Date : 2026-02-24DOI: 10.3847/2041-8213/ae4508
Sebastian Lopez, Colton Ring, Adam K. Leroy, Serena A. Cronin, Alberto D. Bolatto, Laura A. Lopez, Vicente Villanueva, Deanne B. Fisher, Todd A. Thompson, Grant P. Donnelly, Lee Armus, Torsten Böker, Leindert A. Boogaard, Martha L. Boyer, Ryan Chown, Daniel A. Dale, Keaton Donaghue, Kimberly Emig, Simon C. O. Glover, Rodrigo Herrera-Camus, Ralf S. Klessen, Thomas S.-Y. Lai, Laura Lenkić, Rebecca C. Levy, David S. Meier, Elisabeth Mills, Juergen Ott, Evan D. Skillman, J. D. T. Smith, Elizabeth J. Tarantino, Sylvain Veilleux, Fabian Walter and Paul P. van der Werf
Stellar feedback drives multiphase gas outflows from starburst galaxies, but the interpretation of dust emission in these winds remains uncertain. To investigate this, we analyze new JWST mid-infrared images tracing polycyclic aromatic hydrocarbon (PAH) emission at 7.7 and 11.3 μm from the outflow of the prototypical starburst M82 out to 3.2 kpc. We find that PAH emission shows significant correlations with CO, Hα, and X-ray emission within the outflow, though the strengths and behaviors of these correlations vary with gas phase and distance from the starburst. PAH emission correlates strongly with cold molecular gas, with PAH–CO scaling relations in the wind nearly identical to those in galaxy disks despite the very different conditions. The Hα–PAH correlation indicates that Hα traces the surfaces of PAH-bearing clouds, consistent with arising from ionized layers produced by shocks. Meanwhile, the PAH–X-ray correlation disappears once distance effects are controlled for past 2 kpc, suggesting that PAHs are decoupled from the hot gas and the global correlation merely reflects the large-scale structure of the outflow. The PAH-to-neutral gas ratio remains nearly flat to 2 kpc, with variations following changes in the radiation field. This implies that the product of PAH abundance and dust-to-gas ratio does not change significantly over the inner portion of the outflow. Together, these results demonstrate that PAHs robustly trace the cold phase of M82’s wind, surviving well beyond the starburst and providing a powerful, high-resolution proxy for mapping the life cycle of entrained cold material in galactic outflows.
{"title":"JWST Observations of Starbursts: Polycyclic Aromatic Hydrocarbons Closely Trace the Cool Phase of M82’s Galactic Wind","authors":"Sebastian Lopez, Colton Ring, Adam K. Leroy, Serena A. Cronin, Alberto D. Bolatto, Laura A. Lopez, Vicente Villanueva, Deanne B. Fisher, Todd A. Thompson, Grant P. Donnelly, Lee Armus, Torsten Böker, Leindert A. Boogaard, Martha L. Boyer, Ryan Chown, Daniel A. Dale, Keaton Donaghue, Kimberly Emig, Simon C. O. Glover, Rodrigo Herrera-Camus, Ralf S. Klessen, Thomas S.-Y. Lai, Laura Lenkić, Rebecca C. Levy, David S. Meier, Elisabeth Mills, Juergen Ott, Evan D. Skillman, J. D. T. Smith, Elizabeth J. Tarantino, Sylvain Veilleux, Fabian Walter and Paul P. van der Werf","doi":"10.3847/2041-8213/ae4508","DOIUrl":"https://doi.org/10.3847/2041-8213/ae4508","url":null,"abstract":"Stellar feedback drives multiphase gas outflows from starburst galaxies, but the interpretation of dust emission in these winds remains uncertain. To investigate this, we analyze new JWST mid-infrared images tracing polycyclic aromatic hydrocarbon (PAH) emission at 7.7 and 11.3 μm from the outflow of the prototypical starburst M82 out to 3.2 kpc. We find that PAH emission shows significant correlations with CO, Hα, and X-ray emission within the outflow, though the strengths and behaviors of these correlations vary with gas phase and distance from the starburst. PAH emission correlates strongly with cold molecular gas, with PAH–CO scaling relations in the wind nearly identical to those in galaxy disks despite the very different conditions. The Hα–PAH correlation indicates that Hα traces the surfaces of PAH-bearing clouds, consistent with arising from ionized layers produced by shocks. Meanwhile, the PAH–X-ray correlation disappears once distance effects are controlled for past 2 kpc, suggesting that PAHs are decoupled from the hot gas and the global correlation merely reflects the large-scale structure of the outflow. The PAH-to-neutral gas ratio remains nearly flat to 2 kpc, with variations following changes in the radiation field. This implies that the product of PAH abundance and dust-to-gas ratio does not change significantly over the inner portion of the outflow. Together, these results demonstrate that PAHs robustly trace the cold phase of M82’s wind, surviving well beyond the starburst and providing a powerful, high-resolution proxy for mapping the life cycle of entrained cold material in galactic outflows.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147278372","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}
Pub Date : 2026-02-23DOI: 10.3847/2041-8213/ae447a
Zachary P. Scofield, Kyle Finner, Hyungjin Joo, M. James Jee, Wonki Lee, Sangjun Cha, Jinhyub Kim, Yu-heng Lin, Ranga-Ram Chary, Andreas Faisst and Bomee Lee
The galaxy cluster XLSSC 122 is a rare system at z = 1.98, hosting surprisingly evolved member galaxies when the Universe was only one-third of its present age. Leveraging deep JWST/NIRCam imaging, we perform a weak-lensing analysis and reconstruct the cluster’s mass distribution, finding a mass peak that coincides with both the X-ray peak and the position of the brightest cluster galaxy. Consistent with recent strong-lensing analyses, we obtain a mass estimate of 1.60 ± 0.30 (stat.) ± 0.26 (LSS) × 1014M⊙ and an implied concentration of c200c = 6.3 ± 0.4, where the uncertainty represents the propagation of the mass error through the adopted concentration–mass relation and excludes intrinsic scatter. Placing our weak-lensing mass map in the context of Chandra X-ray data, MeerKAT radio imaging, Atacama Large Millimeter/submillimeter Array + Atacama Compact Array/Atacama Cosmology Telescope Sunyaev–Zel’dovich (SZ) mapping, and new JWST intracluster light measurements, we identify consistent NE–SW elongation across datasets and a pronounced offset along the same axis between the SZ and mass/X-ray peaks, pointing to significant merger activity. XLSSC 122 thus serves as a JWST pilot study for high-z lensing, demonstrating the telescope’s unique ability to map cluster mass distributions at z ∼ 2. The concordance of the multiwavelength analysis here, together with the high concentration relative to ΛCDM expectations, motivates a uniform sample of analogous systems with joint lensing, X-ray, SZ, and radio data to probe cluster assembly at cosmic noon.
{"title":"An Active Galaxy Cluster Merger at Cosmic Noon Revealed by JWST Weak Lensing and Multiwavelength Probes","authors":"Zachary P. Scofield, Kyle Finner, Hyungjin Joo, M. James Jee, Wonki Lee, Sangjun Cha, Jinhyub Kim, Yu-heng Lin, Ranga-Ram Chary, Andreas Faisst and Bomee Lee","doi":"10.3847/2041-8213/ae447a","DOIUrl":"https://doi.org/10.3847/2041-8213/ae447a","url":null,"abstract":"The galaxy cluster XLSSC 122 is a rare system at z = 1.98, hosting surprisingly evolved member galaxies when the Universe was only one-third of its present age. Leveraging deep JWST/NIRCam imaging, we perform a weak-lensing analysis and reconstruct the cluster’s mass distribution, finding a mass peak that coincides with both the X-ray peak and the position of the brightest cluster galaxy. Consistent with recent strong-lensing analyses, we obtain a mass estimate of 1.60 ± 0.30 (stat.) ± 0.26 (LSS) × 1014M⊙ and an implied concentration of c200c = 6.3 ± 0.4, where the uncertainty represents the propagation of the mass error through the adopted concentration–mass relation and excludes intrinsic scatter. Placing our weak-lensing mass map in the context of Chandra X-ray data, MeerKAT radio imaging, Atacama Large Millimeter/submillimeter Array + Atacama Compact Array/Atacama Cosmology Telescope Sunyaev–Zel’dovich (SZ) mapping, and new JWST intracluster light measurements, we identify consistent NE–SW elongation across datasets and a pronounced offset along the same axis between the SZ and mass/X-ray peaks, pointing to significant merger activity. XLSSC 122 thus serves as a JWST pilot study for high-z lensing, demonstrating the telescope’s unique ability to map cluster mass distributions at z ∼ 2. The concordance of the multiwavelength analysis here, together with the high concentration relative to ΛCDM expectations, motivates a uniform sample of analogous systems with joint lensing, X-ray, SZ, and radio data to probe cluster assembly at cosmic noon.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146778111","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}
Pub Date : 2026-02-23DOI: 10.3847/2041-8213/ae36aa
Momoko Makita, Tomoharu Oka, Shiho Tsujimoto and Tatsuya Kotani
We report the discovery of multiple compact molecular features exhibiting extremely broad velocity widths toward the W44 molecular cloud. Atacama Large Millimeter/submillimeter Array CO J = 3–2 data reveal eight “Petit-Bullets” surrounding the previously known “Bullet.” Each Petit-Bullet shows a distinct V-shaped structure in position–velocity space, reminiscent of the Y-shaped morphology of the Bullet, suggesting a common origin. These features are interpreted as the result of high-velocity plunges of compact gravitational objects into dense molecular gas. The spatial and kinematic properties of the Petit-Bullets suggest that the plunging material was not a single object but rather a small cluster of compact bodies. A virial mass of 1.0 × 105M⊙ inferred from their velocity dispersion is comparable to that of typical globular clusters. Momentum analysis further implies that the main Bullet likely formed by an isolated black hole. These findings provide new evidence for dynamical interactions between halo clusters and disk molecular gas.
{"title":"Discovery of Multiple Ultra-broad-velocity Molecular Features Associated with the W44 Molecular Cloud","authors":"Momoko Makita, Tomoharu Oka, Shiho Tsujimoto and Tatsuya Kotani","doi":"10.3847/2041-8213/ae36aa","DOIUrl":"https://doi.org/10.3847/2041-8213/ae36aa","url":null,"abstract":"We report the discovery of multiple compact molecular features exhibiting extremely broad velocity widths toward the W44 molecular cloud. Atacama Large Millimeter/submillimeter Array CO J = 3–2 data reveal eight “Petit-Bullets” surrounding the previously known “Bullet.” Each Petit-Bullet shows a distinct V-shaped structure in position–velocity space, reminiscent of the Y-shaped morphology of the Bullet, suggesting a common origin. These features are interpreted as the result of high-velocity plunges of compact gravitational objects into dense molecular gas. The spatial and kinematic properties of the Petit-Bullets suggest that the plunging material was not a single object but rather a small cluster of compact bodies. A virial mass of 1.0 × 105M⊙ inferred from their velocity dispersion is comparable to that of typical globular clusters. Momentum analysis further implies that the main Bullet likely formed by an isolated black hole. These findings provide new evidence for dynamical interactions between halo clusters and disk molecular gas.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"104 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147278406","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}
Pub Date : 2026-02-23DOI: 10.3847/2041-8213/ae4337
Yici Zhong and Elias R. Most
Recent observations of long period radio transients, such as GLEAM-X J0704–37 and ILT J1101+5521, have revealed a previously unrecognized population of Galactic radio transient sources associated with white dwarf (WD)–M dwarf (MD) binaries. It is an open question how to produce coherent radio emission in these systems, though a model driven by binary interaction seems likely given the nature and correlation of the emission with the binaries’ orbital period. Using kinetic plasma simulations, we demonstrate that the relativistic electron cyclotron maser instability (ECMI) is a viable mechanism for generating radio pulses in WD–MD systems, akin to planetary radio emission, such as that from the Jupiter–Io system. We quantify the relativistic ECMI in the nonlinear regime under conditions relevant for WD radio emission for the first time. Our simulations demonstrate that the ECMI can intrinsically produce partially linearly polarized emission relevant to explaining the observed emission spectra of two Galactic sources, though the precise details will depend on the plasma composition. Our work paves the way for a systematic and fully nonlinear computational modeling of radio emission from interacting WD sources.
{"title":"Unraveling the Emission Mechanism Powering Long Period Radio Transients from Interacting White Dwarf Binaries via Kinetic Plasma Simulations","authors":"Yici Zhong and Elias R. Most","doi":"10.3847/2041-8213/ae4337","DOIUrl":"https://doi.org/10.3847/2041-8213/ae4337","url":null,"abstract":"Recent observations of long period radio transients, such as GLEAM-X J0704–37 and ILT J1101+5521, have revealed a previously unrecognized population of Galactic radio transient sources associated with white dwarf (WD)–M dwarf (MD) binaries. It is an open question how to produce coherent radio emission in these systems, though a model driven by binary interaction seems likely given the nature and correlation of the emission with the binaries’ orbital period. Using kinetic plasma simulations, we demonstrate that the relativistic electron cyclotron maser instability (ECMI) is a viable mechanism for generating radio pulses in WD–MD systems, akin to planetary radio emission, such as that from the Jupiter–Io system. We quantify the relativistic ECMI in the nonlinear regime under conditions relevant for WD radio emission for the first time. Our simulations demonstrate that the ECMI can intrinsically produce partially linearly polarized emission relevant to explaining the observed emission spectra of two Galactic sources, though the precise details will depend on the plasma composition. Our work paves the way for a systematic and fully nonlinear computational modeling of radio emission from interacting WD sources.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146778110","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}
Pub Date : 2026-02-23DOI: 10.3847/2041-8213/ae3f2a
Abdujappar Rusul, Z. G. Wen, J. P. Yuan, Ali Esamdin, X. P. Zheng and Michael Kramer
Pulsars are typically characterized by their stable, highly magnetized, and fast-rotating nature, which underpins their persistent radio emissions. However, the discovery of prolonged radio-quiet (“off”) states in intermittent pulsars, such as PSR B1931+24, has been challenging the fundamental theory of pulsar magnetospheric emission. Despite long-term monitoring with several telescopes over 20 yr, the observations of PSR B1931+24 had not detected any significant emission during its “off” states. Recently, sensitive observations via the Five-hundred-meter Aperture Spherical radio Telescope revealed the mysterious weak emissions containing occasional faint bursting pulses during the “off” states of PSR B1931+24, signifying the theory of pulsar magnetospheric emission that the pulsar cannot remain off for long unless it truly dies. Along with a substantial decrease in flux density, a contraction and change in the integrated pulse profile are measured in the “off” state compared to the radio-loud (“on”) state, indicating alterations in the plasma supply and magnetospheric structure. Additionally, previously unobserved asynchronous, nonuniform emission patterns are found in both states, implying a spatially inhomogeneous pair-cascade associated with the coherent radio emission of the pulsar. Furthermore, statistical comparisons between the faint off-state bursts and the on-state emission show that the faint bursts cannot be explained simply as a scaled-down version of the on-state emission. Instead, they constitute a distinct emission mode, plausibly linked to changes in plasma supply and the magnetospheric configuration of PSR B1931+24. These findings greatly advance our understanding of pulsar magnetospheric dynamics and emission mechanisms.
{"title":"Revealing the Unseen: The Discovery of Long-awaited Radiation from the Intermittent Pulsar PSR B1931+24","authors":"Abdujappar Rusul, Z. G. Wen, J. P. Yuan, Ali Esamdin, X. P. Zheng and Michael Kramer","doi":"10.3847/2041-8213/ae3f2a","DOIUrl":"https://doi.org/10.3847/2041-8213/ae3f2a","url":null,"abstract":"Pulsars are typically characterized by their stable, highly magnetized, and fast-rotating nature, which underpins their persistent radio emissions. However, the discovery of prolonged radio-quiet (“off”) states in intermittent pulsars, such as PSR B1931+24, has been challenging the fundamental theory of pulsar magnetospheric emission. Despite long-term monitoring with several telescopes over 20 yr, the observations of PSR B1931+24 had not detected any significant emission during its “off” states. Recently, sensitive observations via the Five-hundred-meter Aperture Spherical radio Telescope revealed the mysterious weak emissions containing occasional faint bursting pulses during the “off” states of PSR B1931+24, signifying the theory of pulsar magnetospheric emission that the pulsar cannot remain off for long unless it truly dies. Along with a substantial decrease in flux density, a contraction and change in the integrated pulse profile are measured in the “off” state compared to the radio-loud (“on”) state, indicating alterations in the plasma supply and magnetospheric structure. Additionally, previously unobserved asynchronous, nonuniform emission patterns are found in both states, implying a spatially inhomogeneous pair-cascade associated with the coherent radio emission of the pulsar. Furthermore, statistical comparisons between the faint off-state bursts and the on-state emission show that the faint bursts cannot be explained simply as a scaled-down version of the on-state emission. Instead, they constitute a distinct emission mode, plausibly linked to changes in plasma supply and the magnetospheric configuration of PSR B1931+24. These findings greatly advance our understanding of pulsar magnetospheric dynamics and emission mechanisms.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146777172","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}
Pub Date : 2026-02-23DOI: 10.3847/2041-8213/ae43ec
Zesen Huang, 泽森 黄, Marco Velli, Olga Panasenco, Richard J. Morton, Chen Shi, 辰 时, Yeimy J. Rivera, Benjamin Chandran, Samuel T. Badman, Yuliang Ding, 宇量 丁, Nour Raouafi, Stuart D. Bale, Michael Stevens, Tamar Ervin, Chuanpeng Hou, Kristopher G. Klein, Orlando Romeo, Jia Huang, 佳 黄, Mingzhe Liu, 明哲 刘, Davin E. Larson, Marc Pulupa, Roberto Livi and Federico Fraschetti
The Sun’s surface vibrates in characteristic 5 minute oscillations, known as p-modes, generated by sound waves trapped within the convection zone. Although these oscillations have long been hypothesized to reach into the solar wind, direct in situ evidence has remained elusive, even during previous close encounters by Parker Solar Probe (PSP). Here, we present strong in situ evidence of 5 minute oscillations in the upper solar corona, based on observations from PSP’s three closest perihelia. In two events at 9.9 solar radii (R⊙), we identify statistically significant (∼6σ) 3.1–3.2 mHz peaks in the magnetic field power spectrum, each appearing as a large-amplitude, spherically polarized Alfvénic wave train lasting approximately 35 minutes. These results demonstrate that global solar oscillations can reach the solar wind.
{"title":"Evidence of 5 minute Oscillations from Parker Solar Probe","authors":"Zesen Huang, 泽森 黄, Marco Velli, Olga Panasenco, Richard J. Morton, Chen Shi, 辰 时, Yeimy J. Rivera, Benjamin Chandran, Samuel T. Badman, Yuliang Ding, 宇量 丁, Nour Raouafi, Stuart D. Bale, Michael Stevens, Tamar Ervin, Chuanpeng Hou, Kristopher G. Klein, Orlando Romeo, Jia Huang, 佳 黄, Mingzhe Liu, 明哲 刘, Davin E. Larson, Marc Pulupa, Roberto Livi and Federico Fraschetti","doi":"10.3847/2041-8213/ae43ec","DOIUrl":"https://doi.org/10.3847/2041-8213/ae43ec","url":null,"abstract":"The Sun’s surface vibrates in characteristic 5 minute oscillations, known as p-modes, generated by sound waves trapped within the convection zone. Although these oscillations have long been hypothesized to reach into the solar wind, direct in situ evidence has remained elusive, even during previous close encounters by Parker Solar Probe (PSP). Here, we present strong in situ evidence of 5 minute oscillations in the upper solar corona, based on observations from PSP’s three closest perihelia. In two events at 9.9 solar radii (R⊙), we identify statistically significant (∼6σ) 3.1–3.2 mHz peaks in the magnetic field power spectrum, each appearing as a large-amplitude, spherically polarized Alfvénic wave train lasting approximately 35 minutes. These results demonstrate that global solar oscillations can reach the solar wind.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146778127","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}
Pub Date : 2026-02-20DOI: 10.3847/2041-8213/ae42c1
Yingjie Luo, 英杰 骆, Eduard P. Kontar, Roelf Du Toit Strauss, Gert J. J. Botha, Tomasz Mrozek, Gelu M. Nita, Sarah Buchner and James O. Chibueze
Radio observations provide powerful diagnostics of energy release, particle acceleration, and transport processes in solar flares. However, despite recent progress in radio interferometric imaging spectroscopy, current instruments still face limitations in image fidelity and resolution, restricting detailed spectroscopic studies of flaring regions. Here we present high-fidelity imaging spectroscopy of an M1.3 GOES class flare with MeerKAT, a precursor to the future-generation array SKA-Mid. Radio emissions at the observed frequencies typically originate in the low corona, offering valuable insights into magnetic reconnection and primary energy-release sites. The obtained images achieve an unprecedented dynamic range exceeding 103, enabling simultaneous analysis of bright coherent bursts and faint incoherent emission from the active region. Multiple spatially distinct coherent sources are identified, implying contributions from different populations of accelerated electrons. The incoherent emission extends beyond Atmospheric Imaging Assembly structures, highlighting MeerKAT’s ability to detect dilute but hot plasma invisible to extreme-ultraviolet instruments. Combined with cotemporal hard X-ray images and magnetic field extrapolations, the radio sources are located within distinct magnetic structures, further revealing their association with different populations of accelerated electrons. These results demonstrate MeerKAT imaging spectroscopy as a powerful diagnostic of solar flares and pave the way for future solar flare studies with SKA-Mid.
{"title":"First Detailed MeerKAT Imaging Spectroscopy of a Solar Flare","authors":"Yingjie Luo, 英杰 骆, Eduard P. Kontar, Roelf Du Toit Strauss, Gert J. J. Botha, Tomasz Mrozek, Gelu M. Nita, Sarah Buchner and James O. Chibueze","doi":"10.3847/2041-8213/ae42c1","DOIUrl":"https://doi.org/10.3847/2041-8213/ae42c1","url":null,"abstract":"Radio observations provide powerful diagnostics of energy release, particle acceleration, and transport processes in solar flares. However, despite recent progress in radio interferometric imaging spectroscopy, current instruments still face limitations in image fidelity and resolution, restricting detailed spectroscopic studies of flaring regions. Here we present high-fidelity imaging spectroscopy of an M1.3 GOES class flare with MeerKAT, a precursor to the future-generation array SKA-Mid. Radio emissions at the observed frequencies typically originate in the low corona, offering valuable insights into magnetic reconnection and primary energy-release sites. The obtained images achieve an unprecedented dynamic range exceeding 103, enabling simultaneous analysis of bright coherent bursts and faint incoherent emission from the active region. Multiple spatially distinct coherent sources are identified, implying contributions from different populations of accelerated electrons. The incoherent emission extends beyond Atmospheric Imaging Assembly structures, highlighting MeerKAT’s ability to detect dilute but hot plasma invisible to extreme-ultraviolet instruments. Combined with cotemporal hard X-ray images and magnetic field extrapolations, the radio sources are located within distinct magnetic structures, further revealing their association with different populations of accelerated electrons. These results demonstrate MeerKAT imaging spectroscopy as a powerful diagnostic of solar flares and pave the way for future solar flare studies with SKA-Mid.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"235 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146222935","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：