The Astrophysical Journal Letters最新文献_第2页

Reconnection Nanojets in an Erupting Solar Filament with Unprecedented High Speeds 以前所未有的高速在太阳灯丝喷发中重新连接纳米射流

The Astrophysical Journal Letters Pub Date : 2025-05-14 DOI: 10.3847/2041-8213/add33a

Yuhang Gao, Hui Tian, David Berghmans, Yadan Duan, Tom Van Doorsselaere, Hechao Chen and Emil Kraaikamp

{"title":"Reconnection Nanojets in an Erupting Solar Filament with Unprecedented High Speeds","authors":"Yuhang Gao, Hui Tian, David Berghmans, Yadan Duan, Tom Van Doorsselaere, Hechao Chen and Emil Kraaikamp","doi":"10.3847/2041-8213/add33a","DOIUrl":"https://doi.org/10.3847/2041-8213/add33a","url":null,"abstract":"Solar nanojets are small-scale jets generated by component magnetic reconnection, characterized by collimated plasma motion perpendicular to the reconnecting magnetic field lines. As an indicator of nanoflare events, they are believed to play a significant role in coronal heating. Using high-resolution extreme-ultraviolet imaging observations from the Extreme Ultraviolet Imager on board the Solar Orbiter mission, we identified 27 nanojets in an erupting filament on 2024 September 30. They are potentially associated with the untwisting of magnetic field lines of the filament. Most nanojets exhibit velocities around 450 km s−1, with the fastest reaching approximately 800 km s−1, significantly higher than previously reported but comparable to the typical coronal Alfvén speed. To our knowledge, these are the highest speeds ever reported for small-scale jets (less than ∼1 Mm wide) in the solar atmosphere. Our findings suggest that these nanoflare-type phenomena can be more dynamic than previously recognized and may contribute to the energy release process of solar eruptions and the heating of coronal active regions.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066524","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}

引用次数: 0

The Case for Edge-on Binaries: An Avenue Toward Comparative Exoplanet Demographics 边对双星的案例：比较系外行星人口统计的途径

The Astrophysical Journal Letters Pub Date : 2025-05-13 DOI: 10.3847/2041-8213/adce04

Joseph E. Hand, Konstantin Gerbig and Malena Rice

{"title":"The Case for Edge-on Binaries: An Avenue Toward Comparative Exoplanet Demographics","authors":"Joseph E. Hand, Konstantin Gerbig and Malena Rice","doi":"10.3847/2041-8213/adce04","DOIUrl":"https://doi.org/10.3847/2041-8213/adce04","url":null,"abstract":"Most Sun-like and higher-mass stars reside in systems that include one or more gravitationally bound stellar companions. These systems offer an important probe of planet formation in the most common stellar systems, while also providing key insights into how gravitational perturbations and irradiation differences from a companion star alter the outcomes of planet formation. Recent dynamical clues have begun to emerge that reveal systematic, nonrandom structure in the configurations of many planet-hosting binary systems: in close- to moderate-separation (s < 800 au) binary star systems, the orbits of exoplanets around individual stellar components are preferentially aligned with the orbital plane of their host stellar binary. In this work, we flip this narrative and search for nearby, edge-on binary star systems that, due to this preferential alignment, are top candidates for radial velocity and transiting exoplanet searches. We present a sample of 591 moderate-separation, relatively bright (G < 14) Gaia-resolved binary star systems in likely near-edge-on configurations. Using a simulated population of exoplanets drawn from transit survey occurrence rate constraints, we provide an overview of the expected planet yields from a targeted search in these systems. We describe the opportunities for comparative exoplanet demographics in the case that both stars can be inferred to host edge-on planetary systems—a configuration toward which the presented sample may be biased, given recent observations of orbit–orbit alignment in exoplanet-hosting binary systems.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143946083","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}

引用次数: 0

The Stellar Initial Mass Function of Early Dark Matter–free Gas Objects 早期无暗物质气体天体的恒星初始质量函数

The Astrophysical Journal Letters Pub Date : 2025-05-13 DOI: 10.3847/2041-8213/add347

William Lake, Michael Y. Grudić, Smadar Naoz, Naoki Yoshida, Claire E. Williams, Blakesley Burkhart, Federico Marinacci, Mark Vogelsberger and Avi Chen

{"title":"The Stellar Initial Mass Function of Early Dark Matter–free Gas Objects","authors":"William Lake, Michael Y. Grudić, Smadar Naoz, Naoki Yoshida, Claire E. Williams, Blakesley Burkhart, Federico Marinacci, Mark Vogelsberger and Avi Chen","doi":"10.3847/2041-8213/add347","DOIUrl":"https://doi.org/10.3847/2041-8213/add347","url":null,"abstract":"Among the remarkable strides made by JWST is the discovery of the earliest star clusters found to date. These have been proposed as early progenitors of globular clusters, which are known to come from the early stages of star formation in the Universe. This is an exciting development in modern astronomy, as it offers an opportunity to connect theoretical models of globular cluster formation to actual observations of these high-redshift structures. In this work, we aim to develop observational signatures of a star cluster formation route known as supersonically induced gas objects, which are dark matter–less gas clouds in the early Universe proposed as a potential origin of some globular clusters. For the first time, we follow the star formation process of these early Universe objects using high-resolution hydrodynamical simulations, including mechanical feedback. Our results suggest that the first dark matter–less star clusters are top heavy, meaning that they have a flatter initial mass function slope compared to very young low-metallicity star clusters in the local Universe, and they also have extremely high stellar mass surface densities compared to their local counterparts.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143945744","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}

引用次数: 0

Angle-dependent in Situ Fast Flavor Transformations in Post-neutron-star-merger Disks 中子星合并后盘中依赖角度的原位快速风味变换

The Astrophysical Journal Letters Pub Date : 2025-05-13 DOI: 10.3847/2041-8213/add0a7

Kelsey A. Lund, Payel Mukhopadhyay, Jonah M. Miller and G. C. McLaughlin

{"title":"Angle-dependent in Situ Fast Flavor Transformations in Post-neutron-star-merger Disks","authors":"Kelsey A. Lund, Payel Mukhopadhyay, Jonah M. Miller and G. C. McLaughlin","doi":"10.3847/2041-8213/add0a7","DOIUrl":"https://doi.org/10.3847/2041-8213/add0a7","url":null,"abstract":"The remnant black hole–accretion disk system resulting from binary neutron star mergers has proven to be a promising site for synthesizing the heaviest elements via rapid neutron capture (r-process). A critical factor in determining the full r-process pattern in these environments is the neutron richness of the ejecta, which is strongly influenced by neutrino interactions. One key ingredient shaping these interactions is fast neutrino flavor conversions (FFCs), which arise due to angular crossings in neutrino distributions and occur on nanosecond timescales. We present the first three-dimensional in situ angle-dependent modeling of FFCs in postmerger disks, implemented within general relativistic magnetohydrodynamics with Monte Carlo neutrino transport. Our results reveal that, by suppressing electron neutrinos, FFCs more efficiently cool the disk and weaken the early thermally driven wind. Less releptonization due to electron neutrino absorption makes this cooler wind more neutron rich, producing a more robust r-process at higher latitudes of the outflow. This study underscores the necessity of incorporating FFCs in realistic simulations.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143979337","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}

引用次数: 0

PINN ME: A Physics-informed Neural Network Framework for Accurate Milne–Eddington Inversions of Solar Magnetic Fields PINN ME：用于太阳磁场精确Milne-Eddington反演的物理信息神经网络框架

The Astrophysical Journal Letters Pub Date : 2025-05-13 DOI: 10.3847/2041-8213/add342

Robert Jarolim, Momchil E. Molnar, Benoit Tremblay, Rebecca Centeno and Matthias Rempel

{"title":"PINN ME: A Physics-informed Neural Network Framework for Accurate Milne–Eddington Inversions of Solar Magnetic Fields","authors":"Robert Jarolim, Momchil E. Molnar, Benoit Tremblay, Rebecca Centeno and Matthias Rempel","doi":"10.3847/2041-8213/add342","DOIUrl":"https://doi.org/10.3847/2041-8213/add342","url":null,"abstract":"Spectropolarimetric inversions of solar observations are fundamental for the estimation of the magnetic field in the solar atmosphere. However, instrumental noise, computational requirements, and varying levels of physical realism make it challenging to derive reliable solar magnetic field estimates. In this study, we present a novel approach for spectropolarimetric inversions based on physics-informed neural networks to infer the photospheric magnetic field under the Milne–Eddington approximation (PINN ME). Our model acts as a representation of the parameter space, mapping input coordinates (t, x, y) to the respective spectropolarimetric parameters, which are used to synthesize the corresponding Stokes profiles. By iteratively sampling coordinate points, synthesizing profiles, and minimizing the deviation from the observed stokes profiles, our method can find the set of Milne–Eddington parameters that best fit the observations. In addition, we directly include the point-spread function to account for instrumental effects. We use a predefined parameter space as well as synthetic profiles from a radiative MHD simulation to evaluate the performance of our method and to estimate the impact of instrumental noise. Our results demonstrate that PINN ME achieves an intrinsic spatiotemporal coupling, which can largely mitigate observational noise and provides a memory-efficient inversion even for extended fields of view. Finally, we apply our method to observations and show that our method provides a high spatial coherence and can resolve small-scale features in both strong- and weak-field regions.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143979338","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}

引用次数: 0

ADF22-WEB: Detection of a Molecular Gas Reservoir in a Massive Quiescent Galaxy Located in a z ≈ 3 Protocluster Core ADF22-WEB：位于z≈3原星团核心的大质量静止星系中分子气藏的探测

The Astrophysical Journal Letters Pub Date : 2025-05-13 DOI: 10.3847/2041-8213/add1d4

Hideki Umehata, Mariko Kubo and Kouichiro Nakanishi

{"title":"ADF22-WEB: Detection of a Molecular Gas Reservoir in a Massive Quiescent Galaxy Located in a z ≈ 3 Protocluster Core","authors":"Hideki Umehata, Mariko Kubo and Kouichiro Nakanishi","doi":"10.3847/2041-8213/add1d4","DOIUrl":"https://doi.org/10.3847/2041-8213/add1d4","url":null,"abstract":"We present a study of the molecular gas reservoirs and dust contents in three quiescent galaxies (QGs) located in the core of the z = 3.09 SSA22 protocluster. Using the Atacama Large Millimeter/submillimeter Array, we detect CO(3–2) emission in one galaxy, ADF22-QG1, marking the first direct detection of molecular gas in a QG from the early Universe. The detected galaxy, ADF22-QG1, has a molecular gas mass of log /M⊙ = 10.26 ± 0.07 assuming a CO-to-H2 conversion factor αCO = 4.4 (log /M⊙ = 9.52 ± 0.07 for αCO = 0.8), corresponding to a gas mass fraction of fgas ≈ 14% (2.5%). The gas-to-dust ratio δgdr ≳ 320 (δgdr ≳ 60) for αCO = 4.4 (αCO = 0.8) is also derived for the first time for a QG at the epoch. For the other two galaxies, ADF22-QG2 and ADF22-QG3, nondetections of CO(3–2) emission provide upper limits, fgas ≈ 17% (3.1%) and fgas ≈ 13% (2.4%), respectively. The inferred gas-consumption history of ADF22-QG1, based on its star formation history, suggests that (i) dusty star-forming galaxies at z = 4–6 are plausible progenitors, and (ii) the cessation of gas accretion from cosmic web filaments plays an important role in their evolution to quenched systems. Furthermore, the presence of a detectable molecular gas reservoir in ADF22-QG1 indicates that additional mechanisms, such as morphological quenching, may be required to fully explain its quiescent nature.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143946063","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}

引用次数: 0

The H2 Glow of a Quiescent Molecular Cloud Observed with JWST 用JWST观测静止分子云的H2辉光

The Astrophysical Journal Letters Pub Date : 2025-05-12 DOI: 10.3847/2041-8213/adcf9c

Paul F. Goldsmith, Shengzhe Wang, Xin Wang, Raphael Skalidis, Gary A. Fuller, Di Li, Chao-Wei Tsai, Lile Wang and Donghui Quan

{"title":"The H2 Glow of a Quiescent Molecular Cloud Observed with JWST","authors":"Paul F. Goldsmith, Shengzhe Wang, Xin Wang, Raphael Skalidis, Gary A. Fuller, Di Li, Chao-Wei Tsai, Lile Wang and Donghui Quan","doi":"10.3847/2041-8213/adcf9c","DOIUrl":"https://doi.org/10.3847/2041-8213/adcf9c","url":null,"abstract":"We report JWST MIRI/MRS observations of the H2S(1) 17.04 μm transition in two regions in the boundary of the Taurus molecular cloud. The two regions, denoted “Edge” (near the relatively sharp boundary of the 13CO J = 1 → 0 emission) and “Peak” (the location of the strongest H2 emission observed with Spitzer), have average intensities of 14.5 and 32.1 MJy sr−1, respectively. We find small-scale structures of characteristic size 1 0–2 5, corresponding to 140–350 au, with characteristic intensity above the extended background of 10 MJy sr−1, corresponding to a J = 3 column density of 1.6 × 1017 cm−2. The most plausible explanation for the observed intensities from this level 845 K above the J = 1 ortho-H2 ground-state level is excitation by collisions with H2 molecules (the hydrogen in this region being predominantly molecular). Two mechanisms, turbulent dissipation and shocks, have been proposed for the heating of localized regions of the interstellar medium (ISM) to temperatures ≃1000 K to explain abundances of and emission from particular molecules. While we cannot determine unique values of density and kinetic temperature, the solutions in best agreement with predictions of shock models are n(H2) = 370 cm−3 and Tkin = 1000 K. The total H2 column density of the small-scale structures under these conditions is ≃8 × 1017 cm−2. This first direct detection of significantly heated tiny-scale structures in the quiescent molecular ISM has significant implications for the physical structure of this phase of the ISM and the maintaining of supersonic motions within it.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143945739","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}

引用次数: 0

Quasiperiodic Slow-propagating Extreme-ultraviolet “Wave” Trains after the Filament Eruption 灯丝喷发后的准周期慢传播极紫外“波”列

The Astrophysical Journal Letters Pub Date : 2025-05-11 DOI: 10.3847/2041-8213/add33b

Yining Zhang, Ting Li, Weilin Teng, Xinping Zhou, Yijun Hou, Zheng Sun, Xuchun Duan, Yilin Guo and Guiping Zhou

{"title":"Quasiperiodic Slow-propagating Extreme-ultraviolet “Wave” Trains after the Filament Eruption","authors":"Yining Zhang, Ting Li, Weilin Teng, Xinping Zhou, Yijun Hou, Zheng Sun, Xuchun Duan, Yilin Guo and Guiping Zhou","doi":"10.3847/2041-8213/add33b","DOIUrl":"https://doi.org/10.3847/2041-8213/add33b","url":null,"abstract":"The eruption of the filament/flux rope generates the coronal perturbations, which further form extreme-ultraviolet (EUV) waves. There are two types of EUV waves, namely, fast-mode magnetosonic waves and slow waves. In this Letter, we first report an event showing the quasiperiodic slow-propagating (QSP) EUV “wave” trains during an M6.4-class flare (SOL2023-02-25T18:40), using multiple observations from Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA), Chinese Hα Solar Explorer (CHASE)/Hα Imaging Spectrograph (HIS), Advanced Space-based Solar Observatory (ASO-S)/Full-disk vector MagnetoGraph (FMG), SUTRI, and Large Angle and Spectrometric Coronagraph (LASCO)/C2. The QSP “wave” trains occurred as the filament showed a rapid rise. The QSP “wave” trains have the projected speeds of 50–130 km s−1 on the plane of the sky, which is slower than the fast-mode magnetosonic speed in the solar corona. And the calculated period of the QSP wave trains is 117.9 s, which is in good agreement with the associated flare quasiperiodic pulsation (140.3 s). The QSP wave trains could be observed during the entire impulsive phase of the flare and lasted about 30 minutes in the field of view (FOV) of SDO/AIA. About 30 minutes later, they appeared in the FOV of LASCO/C2 and propagated to the northwest. We suggest that the QSP wave trains are probably apparent waves that are caused by the successive stretching of the inclined field lines overlying the eruptive filament. The periodic pattern of the QSP wave trains may be related to the intermittent energy release during the flare.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"230 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933449","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}

引用次数: 0

The Exoplanet Edge: Planets Do Not Induce Observable Transit Timing Variations with a Dominant Transit Timing Variation Period Faster than Half Their Orbital Period 系外行星边缘：行星不会引起可观测的凌日时间变化，主要凌日时间变化周期大于其轨道周期的一半

The Astrophysical Journal Letters Pub Date : 2025-05-08 DOI: 10.3847/2041-8213/adc563

Daniel A. Yahalomi, David Kipping, Eric Agol and David Nesvorný

{"title":"The Exoplanet Edge: Planets Do Not Induce Observable Transit Timing Variations with a Dominant Transit Timing Variation Period Faster than Half Their Orbital Period","authors":"Daniel A. Yahalomi, David Kipping, Eric Agol and David Nesvorný","doi":"10.3847/2041-8213/adc563","DOIUrl":"https://doi.org/10.3847/2041-8213/adc563","url":null,"abstract":"Transit timing variations (TTVs) are observed for exoplanets at a range of amplitudes and periods, yielding an ostensibly degenerate forest of possible explanations. We offer some clarity in this forest, showing that systems with a distant perturbing planet preferentially show TTVs with a dominant period equal to either the perturbing planet’s period or half the perturbing planet’s period. We demonstrate that planet-induced TTVs are not expected with dominant TTV periods below this exoplanet edge (lower period limit) and that systems with TTVs that fall below this limit likely contain additional mass in the system. We present an explanation for both of these periods, showing that both aliasing of the conjunction-induced synodic period and the near 1:2 resonance superperiod and tidal effects induce TTVs at periods equal to either the perturber’s orbit or half-orbit. We provide three examples of known systems for which the recovered TTV period induced by a distant perturbing planet is equal to the perturber’s orbital period or half its orbital period. We then investigate Kepler two-planet systems with TTVs and identify 13 two-planet systems with TTVs below this TTV period lower limit, thus potentially uncovering the gravitational influence of new planets and/or moons. We conclude by discussing how the exoplanet edge effects can be used to predict the presence of distant companion planets in situations where TTVs are detected and where nearby companions can be ruled out by additional observations, such as radial velocity data.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143927305","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}

引用次数: 0

On the Evidence of a Dark Matter Density Spike around the Primary Black Hole in OJ 287 关于oj287主黑洞周围暗物质密度峰值的证据

The Astrophysical Journal Letters Pub Date : 2025-05-07 DOI: 10.3847/2041-8213/adcee3

Debabrata Deb, Achamveedu Gopakumar and Mauri J. Valtonen

{"title":"On the Evidence of a Dark Matter Density Spike around the Primary Black Hole in OJ 287","authors":"Debabrata Deb, Achamveedu Gopakumar and Mauri J. Valtonen","doi":"10.3847/2041-8213/adcee3","DOIUrl":"https://doi.org/10.3847/2041-8213/adcee3","url":null,"abstract":"The central engine of blazar OJ 287 is arguably the most notable supermassive black hole (SMBH) binary candidate that emits nanohertz (nHz) gravitational waves. This inference is mainly due to our ability to predict and successfully monitor certain quasiperiodic doubly peaked high brightness flares with a period of ∼12 yr from this blazer. The use of post-Newtonian accurate SMBH binary orbital description that includes the effects of higher-order gravitational-wave emission turned out to be a crucial ingredient for accurately predicting the epochs of such Bremsstrahlung flares in our SMBH binary central engine description for OJ 287. It was very recently argued that one should include the effects of dynamical friction, induced by certain dark matter density spikes around the primary SMBH, to explain the observed decay of SMBH binary orbit in OJ 287. Invoking binary pulsar timing-based arguments, measurements, and OJ 287’s orbital description, we show that observationally relevant SMBH binary orbital dynamics in OJ 287 are insensitive to dark-matter-induced dynamical friction effects. This implies that we could only provide an upper bound on the spike index parameter rather than obtaining an observationally derived value, as argued by M. H. Chan and C. M. Lee.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143920148","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}

引用次数: 0