Astrophysical Journal最新文献

{"title":"Numerical Simulation on the Leading Edge of Coronal Mass Ejection in the Near-Sun Region","authors":"Zhixing Mei, Jing Ye, Yan Li, Shanshan Xu, Yuhao Chen, Jialiang Hu","doi":"10.3847/1538-4357/acf8c5","DOIUrl":"https://doi.org/10.3847/1538-4357/acf8c5","url":null,"abstract":"Abstract The coronal mass ejections (CMEs) observed by white-light coronagraphs, such as the Large Angle and Spectrometric Coronagraph (LASCO) C2/C3, commonly exhibit the three-part structure, with the bright leading edge as the outermost part. In this work, we extend previous work on the leading edge by performing a large-scale 3D magnetohydrodynamic numerical simulation on the evolution of an eruptive magnetic flux rope (MFR) in a near-Sun region based on a radially stretched calculation grid in spherical coordination and the incorporation of solar wind. In the early stage, the new simulation almost repeats the previous results, i.e., the expanding eruptive MFR and associated CME bubble interact with the ambient magnetic field, which leads to the appearance of the helical current ribbon/boundary (HCB) wrapping around the MFR. The HCB can be interpreted as a possible mechanism of the CME leading edge. Later, the CME bubble propagates self-consistently to a larger region beyond a few solar radii from the solar center, similar to the early stage of evolution. The continuous growth and propagation of the CME bubbles leading to the HCB can be traced across the entire near-Sun region. Furthermore, we can observe the HCB in the white-light synthetic images as a bright front feature in the large field of view of LASCO C2 and C3.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"7 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135510259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hidden Giants in JWST's PEARLS: An Ultramassive z = 4.26 Submillimeter Galaxy that Is Invisible to HST","authors":"Ian Smail, Ugnė Dudzevičiūtė, Mark Gurwell, Giovanni G. Fazio, S. P. Willner, A. M. Swinbank, Vinodiran Arumugam, Jake Summers, Seth H. Cohen, Rolf A. Jansen, Rogier A. Windhorst, Ashish Meena, Adi Zitrin, William C. Keel, Cheng Cheng, Dan Coe, Christopher J. Conselice, Jordan C. J. D’Silva, Simon P. Driver, Brenda Frye, Norman A. Grogin, Anton M. Koekemoer, Madeline A. Marshall, Mario Nonino, Nor Pirzkal, Aaron Robotham, Michael J. Rutkowski, Russell E. Ryan Jr., Scott Tompkins, Christopher N. A. Willmer, Haojing Yan, Thomas J. Broadhurst, José M. Diego, Patrick Kamieneski, Min Yun","doi":"10.3847/1538-4357/acf931","DOIUrl":"https://doi.org/10.3847/1538-4357/acf931","url":null,"abstract":"Abstract We present a multiwavelength analysis using the Submillimeter Array (SMA), James Clerk Maxwell Telescope, NOEMA, JWST, the Hubble Space Telescope (HST), and the Spitzer Space Telescope of two dusty strongly star-forming galaxies, 850.1 and 850.2, seen through the massive cluster lens A 1489. These SMA-located sources both lie at z = 4.26 and have bright dust continuum emission, but 850.2 is a UV-detected Lyman-break galaxy, while 850.1 is undetected at ≲ 2 μ m, even with deep JWST/NIRCam observations. We investigate their stellar, interstellar medium, and dynamical properties, including a pixel-level spectral energy distribution analysis to derive subkiloparsec-resolution stellar-mass and A V maps. We find that 850.1 is one of the most massive and highly obscured, A V ∼ 5, galaxies known at z &gt; 4 with M * ∼10 11.8 M ⊙ (likely forming at z &gt; 6), and 850.2 is one of the least massive and least obscured, A V ∼ 1, members of the z &gt; 4 dusty star-forming population. The diversity of these two dust-mass-selected galaxies illustrates the incompleteness of galaxy surveys at z ≳ 3–4 based on imaging at ≲ 2 μ m, the longest wavelengths feasible from HST or the ground. The resolved mass map of 850.1 shows a compact stellar-mass distribution, <?CDATA ${R}_{{rm{e}}}^{mathrm{mass}}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msubsup> <mml:mrow> <mml:mi>R</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant=\"normal\">e</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>mass</mml:mi> </mml:mrow> </mml:msubsup> </mml:math> ∼1 kpc, but its expected evolution means that it matches both the properties of massive, quiescent galaxies at z ∼ 1.5 and ultramassive early-type galaxies at z ∼ 0. We suggest that 850.1 is the central galaxy of a group in which 850.2 is a satellite that will likely merge in the near future. The stellar morphology of 850.1 shows arms and a linear bar feature that we link to the active dynamical environment it resides within.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"288 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135566535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Jupiter’s Equatorial Quasi-quadrennial Oscillation Forced by Internal Thermal Forcing","authors":"Yuchen Lian, Xianyu Tan, Yongyun Hu","doi":"10.3847/1538-4357/acfca6","DOIUrl":"https://doi.org/10.3847/1538-4357/acfca6","url":null,"abstract":"Abstract Observations have shown that there exists downward propagation of alternating westward/eastward jets in Jupiter’s equatorial stratosphere, with a quasi-period between 4 and 6 yr. This phenomenon is generally called the quasi-quadrennial oscillation (QQO). Here, we simulate the QQO by injecting isotropic small-scale thermal disturbances into a 3D general circulation model of Jupiter. It is found that the internal thermal disturbance is able to excite a wealth of waves that generate the equatorial QQO and multiple jet streams at the middle and high latitudes of both hemispheres. The dominant wave mode in generating the QQO-like oscillation is that with a zonal wavenumber of 10. The inhomogeneous evolution of potential vorticity favors the emergence of off-equatorial zonal jets. The off-equatorial jets migrate to the equator, strengthen the deep equatorial jets, and result in the prolonging of the QQO-like oscillations.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"37 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135566602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ALMA Observations of Supernova Remnant N49 in the Large Magellanic Cloud. II. Non-LTE Analysis of Shock-heated Molecular Clouds","authors":"H. Sano, Y. Yamane, J. Th. van Loon, K. Furuya, Y. Fukui, R. Z. E. Alsaberi, A. Bamba, R. Enokiya, M. D. Filipović, R. Indebetouw, T. Inoue, A. Kawamura, M. Lakićević, C. J. Law, N. Mizuno, T. Murase, T. Onishi, S. Park, P. P. Plucinsky, J. Rho, A. M. S. Richards, G. Rowell, M. Sasaki, J. Seok, P. Sharda, L. Staveley-Smith, H. Suzuki, T. Temim, K. Tokuda, K. Tsuge, K. Tachihara","doi":"10.3847/1538-4357/acffbe","DOIUrl":"https://doi.org/10.3847/1538-4357/acffbe","url":null,"abstract":"Abstract We present the first compelling evidence of shock-heated molecular clouds associated with the supernova remnant (SNR) N49 in the Large Magellanic Cloud (LMC). Using 12 CO( J = 2–1, 3–2) and 13 CO( J = 2–1) line emission data taken with the Atacama Large Millimeter/Submillimeter Array, we derived the H 2 number density and kinetic temperature of eight 13 CO-detected clouds using the large velocity gradient approximation at a resolution of 3.″5 (∼0.8 pc at the LMC distance). The physical properties of the clouds are divided into two categories: three of them near the shock front show the highest temperatures of ∼50 K with densities of ∼500–700 cm −3 , while other clouds slightly distant from the SNR have moderate temperatures of ∼20 K with densities of ∼800–1300 cm −3 . The former clouds were heated by supernova shocks, but the latter were dominantly affected by the cosmic-ray heating. These findings are consistent with the efficient production of X-ray recombining plasma in N49 due to thermal conduction between the cold clouds and hot plasma. We also find that the gas pressure is roughly constant except for the three shock-engulfed clouds inside or on the SNR shell, suggesting that almost no clouds have evaporated within the short SNR age of ∼4800 yr. This result is compatible with the shock-interaction model with dense and clumpy clouds inside a low-density wind bubble.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"10 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135613974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Insights in the Bubble Wall of NGC 3324: Intertwined Substructures and a Bipolar Morphology Uncovered by JWST","authors":"L. K. Dewangan, A. K. Maity, Y. D. Mayya, N. K. Bhadari, Suman Bhattacharyya, Saurabh Sharma, Gourav Banerjee","doi":"10.3847/1538-4357/ad004b","DOIUrl":"https://doi.org/10.3847/1538-4357/ad004b","url":null,"abstract":"Abstract We report the discovery of intertwined/entangled substructures toward the bubble wall of NGC 3324 below a physical scale of 4500 au, which is the sharp edge/ionization front/elongated structure traced at the interface between the H ii region and the molecular cloud. The sharp edge appears wavy in the Spitzer 3.6–8.0 μ m images (resolution ∼2″). Star formation signatures have mostly been traced on one side of the ionization front, which lies on the molecular cloud’s boundary. The James Webb Space Telescope’s (JWST) near- and mid-infrared images (resolution ∼0.″07—0.″7) are employed to resolve the sharp edge, which has a curvature facing the exciting O-type stars. The elongated structures are associated with the 3.3 μ m polycyclic aromatic hydrocarbon (PAH) emission, the 4.05 μ m ionized emission, and the 4.693 μ m H 2 emission. However, the PAH-emitting structures are depicted between the other two. The H 2 emission reveals numerous intertwined substructures that are not prominently traced in the 3.3 μ m PAH emission. The separation between two substructures in the H 2 emission is ∼1.″1 or 2420 au. The intertwined substructures are traced in the spatial areas associated with the neutral to H 2 transition zone, suggesting the origin of these structures by “thin-shell” instability. Furthermore, an arc-like feature traced in the Spitzer 3.6–8.0 μ m images is investigated as a bipolar H ii region (extent ∼0.35 pc) at T d ∼25–28 K using the JWST images. A massive-star candidate VPHAS-OB1 #03518 seems to be responsible for the bipolar H ii region.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"33 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135613991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bridging between Type IIb and Ib Supernovae: SN IIb 2022crv with a Very Thin Hydrogen Envelope","authors":"Anjasha Gangopadhyay, Keiichi Maeda, Avinash Singh, Nayana A. J., Tatsuya Nakaoka, Koji S. Kawabata, Kenta Taguchi, Mridweeka Singh, Poonam Chandra, Stuart D. Ryder, Raya Dastidar, Masayuki Yamanaka, Miho Kawabata, Rami Z. E. Alsaberi, Naveen Dukiya, Rishabh Singh Teja, Bhavya Ailawadhi, Anirban Dutta, D. K. Sahu, Takashi J. Moriya, Kuntal Misra, Masaomi Tanaka, Roger Chevalier, Nozomu Tominaga, Kohki Uno, Ryo Imazawa, Taisei Hamada, Tomoya Hori, Keisuke Isogai","doi":"10.3847/1538-4357/acfa94","DOIUrl":"https://doi.org/10.3847/1538-4357/acfa94","url":null,"abstract":"Abstract We present optical, near-infrared, and radio observations of supernova (SN) SN IIb 2022crv. We show that it retained a very thin H envelope and transitioned from an SN IIb to an SN Ib; prominent H α seen in the pre-maximum phase diminishes toward the post-maximum phase, while He i lines show increasing strength. SYNAPPS modeling of the early spectra of SN 2022crv suggests that the absorption feature at 6200 Å is explained by a substantial contribution of H α together with Si ii , as is also supported by the velocity evolution of H α . The light-curve evolution is consistent with the canonical stripped-envelope SN subclass but among the slowest. The light curve lacks the initial cooling phase and shows a bright main peak (peak M V = −17.82 ± 0.17 mag), mostly driven by radioactive decay of 56 Ni. The light-curve analysis suggests a thin outer H envelope ( M env ∼ 0.05 M ⊙ ) and a compact progenitor ( R env ∼ 3 R ⊙ ). An interaction-powered synchrotron self-absorption model can reproduce the radio light curves with a mean shock velocity of 0.1 c . The mass-loss rate is estimated to be in the range of (1.9−2.8) × 10 −5 M ⊙ yr −1 for an assumed wind velocity of 1000 km s −1 , which is on the high end in comparison with other compact SNe IIb/Ib. SN 2022crv fills a previously unoccupied parameter space of a very compact progenitor, representing a beautiful continuity between the compact and extended progenitor scenario of SNe IIb/Ib.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"12 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135410162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy Conversion through a Fluctuation–Dissipation Relation at Kinetic Scales in the Earth’s Magnetosheath","authors":"Federica Chiappetta, Emiliya Yordanova, Zoltán Vörös, Fabio Lepreti, Vincenzo Carbone","doi":"10.3847/1538-4357/acfca2","DOIUrl":"https://doi.org/10.3847/1538-4357/acfca2","url":null,"abstract":"Abstract Low-frequency fluctuations in the interplanetary medium represent a turbulent environment where universal scaling behavior, generated by an energy cascade, has been investigated. On the contrary, in some regions, for example, the magnetosheath, universality of statistics of fluctuations is lost. However, at kinetic scales where energy must be dissipated, the energy conversion seems to be realized through a mechanism similar to the free solar wind. Here we propose a Langevin model for magnetic fluctuations at kinetic scales, showing that the resulting fluctuation–dissipation relation is capable of describing the gross features of the spectral observations at kinetic scales in the magnetosheath. The fluctuation–dissipation relation regulates the energy conversion by imposing a relationship between fluctuations and dissipation, which at high frequencies are active at the same time in the same range of scales and represent two ingredients of the same physical process.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135411689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracing the Total Stellar Mass and Star Formation of High-redshift Protoclusters","authors":"Roxana Popescu, Alexandra Pope, Kyoung-Soo Lee, Stacey Alberts, Yi-Kuan Chiang, Sowon Lee, Mark Brodwin, Jed McKinney, Vandana Ramakrishnan","doi":"10.3847/1538-4357/acee79","DOIUrl":"https://doi.org/10.3847/1538-4357/acee79","url":null,"abstract":"Abstract As the progenitors of present-day galaxy clusters, protoclusters are excellent laboratories to study galaxy evolution. Since existing observations of protoclusters are limited to the detected constituent galaxies at UV and/or infrared wavelengths, the details of how typical galaxies grow in these young, pre-virialized structures remain uncertain. We measure the total stellar mass and star formation within protoclusters, including the contribution from faint undetected members by performing a stacking analysis of 211 z = 2–4 protoclusters selected as Planck cold sources. We stack Wide-field Infrared Survey Explorer and Herschel/SPIRE images to measure the angular size and the spectral energy distribution of the integrated light from the protoclusters. The fluxes of protoclusters selected as Planck cold sources can be contaminated by line-of-sight interlopers. Using the WebSky simulation, we estimate that a single protocluster contributes 33% ± 15% of the flux of a Planck cold source on average. After this correction, we obtain a total star formation rate of 7.3 ± 3.2 × 10 3 M ⊙ yr −1 and a total stellar mass of 4.9 ± 2.2 × 10 12 M ⊙ . Our results indicate that protoclusters have, on average, 2× more star formation and 4× more stellar mass than the total contribution from individually detected galaxies in spectroscopically confirmed protoclusters. This suggests that much of the total flux within z = 2–4 protoclusters comes from galaxies with luminosities lower than the detection limit of SPIRE ( L IR < 3 × 10 12 L ⊙ ). Lastly, we find that protoclusters subtend a half-light radius of 2.′8 (4.2–5.8 cMpc), which is consistent with simulations.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"16 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135510572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A New Index to Describe the Relationship between Solar Extreme Ultraviolet Variation and Solar Activity","authors":"Zhou Chen, Kecheng Zhou, Jing-Song Wang, Qiao Song, Zhihai Ouyang, Haimeng Li, Meng Zhou, Xiaohua Deng","doi":"10.3847/1538-4357/acf9f7","DOIUrl":"https://doi.org/10.3847/1538-4357/acf9f7","url":null,"abstract":"Abstract In this paper, a new solar activity index based on a novel disturbance extraction method, the spectral whitening method (SWM), is introduced to process the solar EUV data on the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. Our research suggests that the spatial information derived by SWM can well reflect the location of disturbance extraction, which is consistent with the location of the solar active region. It indicates that the disturbance extraction is effective. From AIA 094 Å to AIA 335 Å, SWM results are strongly correlated with solar radio flux F107 and the sunspot number (SSN), especially at AIA 211 Å, where the correlation coefficient reaches the maximum, while at AIA 1600 Å and AIA 1700 Å there are no detectable correlations. The proposed new solar activity index, <?CDATA ${J}_{P}left(mathrm{AIA}right)$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mi>J</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>P</mml:mi> </mml:mrow> </mml:msub> <mml:mfenced close=\")\" open=\"(\"> <mml:mrow> <mml:mi>AIA</mml:mi> </mml:mrow> </mml:mfenced> </mml:math> , has the following characteristics: (1) the new index can reflect the main variations of F107 and SSN, indicating that the index is valid; (2) the new index has higher temporal resolution, which is more conducive to the more detailed study of solar activities on short timescales; (3) the new index reveals that the solar atmosphere still has significant variability during solar minimum characterized by low F107 and SSN; (4) the new index can be used in conjunction with the new magnetospheric and ionospheric indices, which are also derived by SWM to deepen the understanding of the causal chain of space weather and promote the improvement of forecasting capabilities.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"139 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135714767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Black Hole Polarimetry I. A Signature of Electromagnetic Energy Extraction","authors":"Andrew Chael, Alexandru Lupsasca, George N. Wong, Eliot Quataert","doi":"10.3847/1538-4357/acf92d","DOIUrl":"https://doi.org/10.3847/1538-4357/acf92d","url":null,"abstract":"Abstract In 1977, Blandford and Znajek showed that the electromagnetic field surrounding a rotating black hole can harvest its spin energy and use it to power a collimated astrophysical jet, such as the one launched from the center of the elliptical galaxy M87. Today, interferometric observations with the Event Horizon Telescope (EHT) are delivering high-resolution, event-horizon-scale, polarimetric images of the supermassive black hole M87* at the jet launching point. These polarimetric images offer an unprecedented window into the electromagnetic field structure around a black hole. In this paper, we show that a simple polarimetric observable—the phase ∠ β 2 of the second azimuthal Fourier mode of the linear polarization in a near-horizon image—depends on the sign of the electromagnetic energy flux and therefore provides a direct probe of black hole energy extraction. In Boyer–Lindquist coordinates, the Poynting flux for axisymmetric electromagnetic fields is proportional to the product B ϕ B r . The phase ∠ β 2 likewise depends on the ratio B ϕ / B r , thereby enabling an observer to determine the direction of electromagnetic energy flow in the near-horizon environment experimentally. Data from the 2017 EHT observations of M87* are consistent with electromagnetic energy outflow. Currently envisioned multifrequency observations of M87* will achieve higher dynamic range and angular resolution, and hence deliver measurements of ∠ β 2 closer to the event horizon as well as better constraints on Faraday rotation. Such observations will enable a definitive test for energy extraction from the black hole M87*.","PeriodicalId":50735,"journal":{"name":"Astrophysical Journal","volume":"139 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135714768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}