The Astrophysical Journal Letters最新文献

{"title":"The Formation Rate and Luminosity Function of Fast Radio Bursts","authors":"J. H. Chen, X. D. Jia, X. F. Dong and F. Y. Wang","doi":"10.3847/2041-8213/ad7b39","DOIUrl":"https://doi.org/10.3847/2041-8213/ad7b39","url":null,"abstract":"Fast radio bursts (FRBs) are millisecond-duration flashes with unknown origins. Their formation rate is crucial for unveiling physical origins. However, the luminosity and formation rate are degenerate when directly fitting the redshift distribution of FRBs. In contrast to previous forward-fitting methods, we use Lynden-Bell’s c− method to derive the luminosity function and formation rate of FRBs without any assumptions. Using the nonrepeating FRBs from the first Canadian Hydrogen Intensity Mapping Experiment FRB catalog, we find a relatively strong luminosity evolution, and luminosity function can be fitted by a broken power-law model with a break at 1.33 × 1041 erg s−1. The formation rate declines rapidly as (1 + z)−4.9±0.3 with a local rate of 1.13 × 104 Gpc−3 yr−1. This monotonic decrease is similar to the rate of short gamma-ray bursts. After comparing this function with the star formation rate and stellar mass density, we conclude that the old populations, including neutron stars and black holes, are closely related to the origins of FRBs.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328962","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 Observations of Starbursts: Massive Star Clusters in the Central Starburst of M82","authors":"Rebecca C. Levy, Alberto D. Bolatto, Divakara Mayya, Bolivia Cuevas-Otahola, Elizabeth Tarantino, Martha L. Boyer, Leindert A. Boogaard, Torsten Böker, Serena A. Cronin, Daniel A. Dale, Keaton Donaghue, Kimberly L. Emig, Deanne B. Fisher, Simon C. O. Glover, Rodrigo Herrera-Camus, María J. Jiménez-Donaire, Ralf S. Klessen, Laura Lenkić, Adam K. Leroy, Ilse De Looze, David S. Meier, Elisabeth A. C. Mills, Juergen Ott, Mónica Relaño, Sylvain Veilleux, Vicente Villanueva, Fabian Walter and Paul P. van der Werf","doi":"10.3847/2041-8213/ad7af3","DOIUrl":"https://doi.org/10.3847/2041-8213/ad7af3","url":null,"abstract":"We present a near-infrared (NIR) candidate star cluster catalog for the central kiloparsec of M82 based on new JWST NIRCam images. We identify star cluster candidates using the F250M filter, finding 1357 star cluster candidates with stellar masses >104M⊙. Compared to previous optical catalogs, nearly all (87%) of the candidates we identify are new. The star cluster candidates have a median intrinsic cluster radius of ≈1 pc and stellar masses up to 106M⊙. By comparing the color–color diagram to dust-free yggdrasil stellar population models, we estimate that the star cluster candidates have AV ∼ 3−24 mag, corresponding to A2.5μm ∼ 0.3−2.1 mag. There is still appreciable dust extinction toward these clusters into the NIR. We measure the stellar masses of the star cluster candidates, assuming ages of 0 and 8 Myr. The slope of the resulting cluster mass function is β = 1.9 ± 0.2, in excellent agreement with studies of star clusters in other galaxies.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328664","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":"Metis Observation of the Onset of Fully Developed Turbulence in the Solar Corona","authors":"Daniele Telloni, Luca Sorriso-Valvo, Gary P. Zank, Marco Velli, Vincenzo Andretta, Denise Perrone, Raffaele Marino, Francesco Carbone, Antonio Vecchio, Laxman Adhikari, Lingling Zhao, Sabrina Guastavino, Fabiana Camattari, Chen Shi, Nikos Sioulas, Zesen Huang, Marco Romoli, Ester Antonucci, Vania Da Deppo, Silvano Fineschi, Catia Grimani, Petr Heinzel, John D. Moses, Giampiero Naletto, Gianalfredo Nicolini, Daniele Spadaro, Marco Stangalini, Luca Teriaca, Michela Uslenghi, Lucia Abbo, Frédéric Auchère, Regina Aznar Cuadrado, Arkadiusz Berlicki, Roberto Bruno, Aleksandr Burtovoi, Gerardo Capobianco, Chiara Casini, Marta Casti, Paolo Chioetto, Alain J. Corso, Raffaella D’Amicis, Yara De Leo, Michele Fabi, Federica Frassati, Fabio Frassetto, Silvio Giordano, Salvo L. Guglielmino, Giovanna Jerse, Federico Landini, Alessandro Liberatore, Enrico Magli, Giuseppe Massone, Giuseppe Nisticò, Maurizio Pancrazzi, Maria G. Pelizzo, Hardi Peter, Christina Plainaki, Luca Poletto, Fabio Real..","doi":"10.3847/2041-8213/ad5a8c","DOIUrl":"https://doi.org/10.3847/2041-8213/ad5a8c","url":null,"abstract":"This Letter reports the first observation of the onset of fully developed turbulence in the solar corona. Long time series of white-light coronal images, acquired by Metis aboard Solar Orbiter at 2 minutes cadence and spanning about 10 hr, were studied to gain insight into the statistical properties of fluctuations in the density of the coronal plasma in the time domain. From pixel-by-pixel spectral frequency analysis in the whole Metis field of view, the scaling exponents of plasma fluctuations were derived. The results show that, over timescales ranging from 1 to 10 hr and corresponding to the photospheric mesogranulation-driven dynamics, the density spectra become shallower moving away from the Sun, resembling a Kolmogorov-like spectrum at 3 R⊙. According to the latest observation and interpretive work, the observed 5/3 scaling law for density fluctuations is indicative of the onset of fully developed turbulence in the corona. Metis observation-based evidence for a Kolmogorov turbulent form of the fluctuating density spectrum casts light on the evolution of 2D turbulence in the early stages of its upward transport from the low corona.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321730","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":"Exotic Stable Branches with Efficient TOV Sequences","authors":"Reed Essick","doi":"10.3847/2041-8213/ad7399","DOIUrl":"https://doi.org/10.3847/2041-8213/ad7399","url":null,"abstract":"Modern inference schemes for the neutron star (NS) equation of state (EoS) require large numbers of stellar models constructed with different EoS, and these stellar models must capture all the behavior of stable stars. I introduce termination conditions for sequences of stellar models for cold nonrotating NSs that can identify all stable stellar configurations up to arbitrarily large central pressures along with an efficient algorithm to build accurate interpolators for macroscopic properties. I explore the behavior of stars with both high- and low-central pressures. Interestingly, I find that EoSs with monotonically increasing sound-speed can produce multiple stable branches (twin stars) and that large phase transitions at high densities can produce stable branches at nearly any mass scale, including sub-solar masses while still supporting stars with M > 2 M⊙. I conclude with some speculation about the astrophysical implications of this behavior.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325439","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":"Birth of Rapidly Spinning, Overmassive Black Holes in the Early Universe","authors":"Kohei Inayoshi and Kohei Ichikawa","doi":"10.3847/2041-8213/ad74e2","DOIUrl":"https://doi.org/10.3847/2041-8213/ad74e2","url":null,"abstract":"The James Webb Space Telescope (JWST) has unveiled numerous massive black holes (BHs) in faint, broad-line active galactic nuclei (AGNs). The discovery highlights the presence of dust-reddened AGN populations, referred to as “little red dots (LRDs),” more abundant than X-ray-selected AGNs, which are less influenced by obscuration. This finding indicates that the cosmic growth rate of BHs within this population does not decrease but rather increases at higher redshifts beyond z ∼ 6. The BH accretion rate density deduced from their luminosity function is remarkably higher than that from other AGN surveys in X-ray and infrared bands. To align the cumulative mass density accreted to BHs with the observed BH mass density at z ≃ 4–5, as derived from the integration of the BH mass function, the radiative efficiency must be doubled from the canonical 10% value, achieving significance beyond the >3σ confidence level. This suggests the presence of rapid spins with 96% of the maximum limit among these BHs under the thin-disk approximation, maintained by prolonged mass accretion instead of chaotic accretion with randomly oriented inflows. Moreover, we derive an upper bound for the stellar mass of galaxies hosting these LRDs, ensuring consistency with galaxy formation in the standard cosmological model, where the host stellar mass is limited by the available baryonic reservoir. Our analysis gives a lower bound for the BH-to-galaxy mass ratio that exceeds the typical value known in the nearby universe and aligns with that for JWST-detected unobscured AGNs. Accordingly, we propose a hypothesis that the dense, dust-rich environments within LRDs facilitate the emergence of rapidly spinning and overmassive BH populations during the epoch of reionization. This scenario predicts a potential association between relativistic jets and other high-energy phenomena with overmassive BHs in the early universe.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328663","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":"Circumstellar Interaction in the Ultraviolet Spectra of SN 2023ixf 14–66 Days After Explosion","authors":"K. Azalee Bostroem, David J. Sand, Luc Dessart, Nathan Smith, Saurabh W. Jha, Stefano Valenti, Jennifer E. Andrews, Yize Dong, 一泽 董, Alexei V. Filippenko, Sebastian Gomez, Daichi Hiramatsu, Emily T. Hoang, Griffin Hosseinzadeh, D. Andrew Howell, Jacob E. Jencson, Michael Lundquist, Curtis McCully, Darshana Mehta, Nicolas E. Meza-Retamal, Jeniveve Pearson, Aravind P. Ravi, Manisha Shrestha and Samuel Wyatt","doi":"10.3847/2041-8213/ad7855","DOIUrl":"https://doi.org/10.3847/2041-8213/ad7855","url":null,"abstract":"SN 2023ixf was discovered in M101 within a day of the explosion and rapidly classified as a Type II supernova with flash features. Here we present ultraviolet (UV) spectra obtained with the Hubble Space Telescope 14, 19, 24, and 66 days after the explosion. Interaction between the supernova ejecta and circumstellar material (CSM) is seen in the UV throughout our observations in the flux of the first three epochs and asymmetric Mg ii emission on day 66. We compare our observations to CMFGEN supernova models that include CSM interaction ( M⊙ yr−1) and find that the power from CSM interaction is decreasing with time, from Lsh ≈ 5 × 1042 erg s−1 to Lsh ≈ 1 × 1040 erg s−1 between days 14 and 66. We examine the contribution of individual atomic species to the spectra on days 14 and 19, showing that the majority of the features are dominated by iron, nickel, magnesium, and chromium absorption in the ejecta. The UV spectral energy distribution of SN 2023ixf sits between that of supernovae, which show no definitive signs of CSM interaction, and those with persistent signatures assuming the same progenitor radius and metallicity. Finally, we show that the evolution and asymmetric shape of the Mg iiλλ 2796, 2802 emission are not unique to SN 2023ixf. These observations add to the early measurements of dense, confined CSM interaction, tracing the mass-loss history of SN 2023ixf to ∼33 yr prior to the explosion and the density profile to a radius of ∼5.7 × 1015 cm. They show the relatively short evolution from a quiescent red supergiant wind to high mass loss.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313614","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":"Sculpting of Exoplanetary Systems Driven by a Misaligned Disk and Stellar Oblateness: Origin of Perpendicular Orbits in HD 3167","authors":"Tao Fu, 韬 伏, Yue Wang and 悦 王","doi":"10.3847/2041-8213/ad77d6","DOIUrl":"https://doi.org/10.3847/2041-8213/ad77d6","url":null,"abstract":"A significant proportion of exoplanets have been detected with highly tilted or even polar orbits relative to their host stars’ equatorial planes. These unusual orbital configurations are often linked to postdisk secular interactions among multiple bodies. However, many aspects remain elusive. In this study, we investigate the role of disk-induced spin–orbit misalignments in shaping the architecture of multiplanet systems, taking into account the combined effect of the host star’s oblateness and the full-space disk potential. We demonstrate that large mutual planetary inclinations can arise from a saddle-center bifurcation occurring during the photoevaporation of the disk. This bifurcation triggers an instant, nonadiabatic transition in the planet’s libration. Following this process, the orbital evolution diverges into several distinct patterns. Notably, in scenarios involving a near-polar primordial misalignment, the orbit, consistently librating about a coplanar equilibrium axis, can be captured by an orthogonal equilibrium during the decay of the stellar oblateness. However, the orbit will be eventually recaptured by the coplanar equilibrium, aligned or antialigned with the orientation of the outer orbit, resulting in either a prograde or retrograde inner–outer orbit configuration. Additionally, general relativity contributes to maintaining eccentricity stability within these dynamic scenarios. Through the proposed mechanism, we can provide a plausible explanation for the unique, near-perpendicular, and likely retrograde orbit architecture observed in the HD 3167 system, enhancing our understanding of exoplanetary system dynamics.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313613","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":"Theoretical Modeling of the Exceptional GRB 221009A Afterglow","authors":"Luca Foffano, Marco Tavani and Giovanni Piano","doi":"10.3847/2041-8213/ad76a3","DOIUrl":"https://doi.org/10.3847/2041-8213/ad76a3","url":null,"abstract":"The extraordinary gamma-ray burst GRB 221009A provides a great opportunity to investigate the enigmatic origin and evolution of gamma-ray bursts (GRBs). However, the complexity of the observations associated with this GRB provides significant challenges to developing a theoretical modeling in a coherent framework. In this paper, we present a theoretical interpretation of the GRB 221009A afterglow within the relativistic fireball scenario, aiming to describe the broadband data set with a consistent model evolution. We find that the adiabatic fireball evolution in the slow-cooling regime provides a viable scenario in good agreement with observations. Crucial to our analysis is the set of simultaneous GeV and TeV gamma-ray data obtained by AGILE and LHAASO during the early afterglow phases. Having successfully modeled as inverse Compton emission the high-energy spectral and lightcurve properties of the afterglow up to 104 s, we extend our model to later times when also optical and X-ray data are available. This approach results in a coherent physical framework that successfully describes all observed properties of the afterglow up to very late times, approximately 106 s. Our model requires time-variable microphysical parameters, with a moderately increasing efficiency εe of a few percent for transferring the shock energy to radiating particles and a decreasing efficiency for magnetic field generation εB in the range 10−5–10−7. Fitting the detailed multifrequency spectral data across the afterglow provides a unique test of our model.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313612","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":"Bulk and Atmospheric Metallicities as Direct Probes of Sequentially Varying Accretion Mechanisms of Gas and Solids Onto Planets","authors":"Yasuhiro Hasegawa and Mark R. Swain","doi":"10.3847/2041-8213/ad7957","DOIUrl":"https://doi.org/10.3847/2041-8213/ad7957","url":null,"abstract":"Core accretion is the standard scenario of planet formation, wherein planets are formed by sequential accretion of gas and solids, and is widely used to interpret exoplanet observations. However, no direct probes of the scenario have been discussed yet. Here, we introduce an onion-like model as one idealization of sequential accretion and propose that bulk and atmospheric metallicities of exoplanets can be used as direct probes of the process. Our analytical calculations, coupled with observational data, demonstrate that the trend of observed exoplanets supports the sequential accretion hypothesis. In particular, accretion of planetesimals that are ≳100 km in size is most favored to consistently explain the observed trends. The importance of opening gaps in both planetesimal and gas disks following planetary growth is also identified. A new classification is proposed, wherein most observed planets are classified into two interior statuses: globally mixed and locally (well) mixed. Explicit identification of the locally (well) mixed status enables reliable verification of sequential accretion. During the JWST era, the quality and volume of observational data will increase drastically and improve exoplanet characterization. This work provides one key reference of how both the bulk and atmospheric metallicities can be used to constrain gas and solid accretion mechanisms of planets.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313616","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":"Discovery of Limb Brightening in the Parsec-scale Jet of NGC 315 through Global Very Long Baseline Interferometry Observations and Its Implications for Jet Models","authors":"Jongho Park, Guang-Yao Zhao, Masanori Nakamura, Yosuke Mizuno, Hung-Yi Pu, Keiichi Asada, Kazuya Takahashi, Kenji Toma, Motoki Kino, Ilje Cho, Kazuhiro Hada, Phil G. Edwards, Hyunwook Ro, Minchul Kam, Kunwoo Yi, Yunjeong Lee, Shoko Koyama, Do-Young Byun, Chris Phillips, Cormac Reynolds, Jeffrey A. Hodgson and Sang-Sung Lee","doi":"10.3847/2041-8213/ad7137","DOIUrl":"https://doi.org/10.3847/2041-8213/ad7137","url":null,"abstract":"We report the first observation of the nearby giant radio galaxy NGC 315 using a global very long baseline interferometry (VLBI) array consisting of 22 radio antennas located across five continents, including high-sensitivity stations, at 22 GHz. Utilizing the extensive uv-coverage provided by the array, coupled with the application of a recently developed superresolution imaging technique based on the regularized maximum-likelihood method, we were able to transversely resolve the NGC 315 jet at parsec scales for the first time. Previously known for its central ridge-brightened morphology at similar scales in former VLBI studies, the jet now clearly exhibits a limb-brightened structure. This finding suggests an inherent limb brightening that was not observable before due to limited angular resolution. Considering that the jet is viewed at an angle of ∼50°, the observed limb brightening is challenging to reconcile with the magnetohydrodynamic models and simulations, which predict that the Doppler-boosted jet edges should dominate over the nonboosted central layer. The conventional jet model that proposes a fast spine and a slow sheath with uniform transverse emissivity may pertain to our observations. However, in this model, the relativistic spine would need to travel at speeds of Γ ≳ 6.0–12.9 along the deprojected jet distance of (2.3–10.8) × 103 gravitational radii from the black hole. We propose an alternative scenario that suggests higher emissivity at the jet boundary layer, resulting from more efficient particle acceleration or mass loading onto the jet edges, and consider prospects for future observations with even higher angular resolution.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313610","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}