Astrophysical Journal Letters最新文献

{"title":"First Metis Detection of the Helium D₃ Line Polarization in a Large Eruptive Prominence","authors":"Petr Heinzel, Sonja Jejčič, Jiří Štěpán, Roberto Susino, Vincenzo Andretta, Giuliana Russano, Silvano Fineschi, Marco Romoli, Alessandro Bemporad, Arkadiusz Berlicki, Aleksandr Burtovoi, Vania Da Deppo, Yara De Leo, Catia Grimani, Giovanna Jerse, Federico Landini, Giampiero Naletto, Gianalfredo Nicolini, Maurizio Pancrazzi, Tanausú del Pino Alemán, Clementina Sasso, Daniele Spadaro, Marco Stangalini, Daniele Telloni, Luca Teriaca, Michela Uslenghi, Andrés Vicente Arévalo","doi":"10.3847/2041-8213/acff62","DOIUrl":"https://doi.org/10.3847/2041-8213/acff62","url":null,"abstract":"Abstract Metis on board Solar Orbiter is the space coronagraph developed by an Italian–German–Czech consortium. It is capable of observing solar corona and various coronal structures in the visible-light (VL) and UV (hydrogen Ly α ) channels simultaneously for the first time. Here we present observations of a large eruptive prominence on 2021 April 25–26, in the VL, taken during the mission cruise phase, and demonstrate that apart from the broadband continuum emission, which is due to the Thomson scattering on prominence electrons, we detect a significant radiation in the neutral-helium D 3 line (587.6 nm), which lies within the Metis VL passband. We show how the prominence looks like in Stokes I , Q , and U . We consider two extreme cases of the prominence magnetic field, and we separate the Stokes I and Q signals pertinent to Thomson scattering and to the D 3 line. The degree of linear polarization of the D 3 line (both Q and U ) indicates the presence of the prominence magnetic field; hence Metis can serve as a magnetograph for eruptive prominences located high in the corona.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"197 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136069469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Quasi-simultaneous Optical Flux and Polarization Variability of the Binary Super Massive Black Hole Blazar OJ 287 from 2015 to 2023: Detection of an Anticorrelation in Flux and Polarization Variability","authors":"Alok C. Gupta, Pankaj Kushwaha, Mauri J. Valtonen, Sergey S. Savchenko, Svetlana G. Jorstad, Ryo Imazawa, Paul J. Wiita, Minfeng Gu, Alan P. Marscher, Zhongli Zhang, Rumen Bachev, G. A. Borman, Haritma Gaur, T. S. Grishina, V. A. Hagen-Thorn, E. N. Kopatskaya, V. M. Larionov, E. G. Larionova, L. V. Larionova, D. A. Morozova, T. Nakaoka, A. Strigachev, Yulia V. Troitskaya, I. S. Troitsky, M. Uemura, A. A. Vasilyev, Z. R. Weaver, A. V. Zhovtan","doi":"10.3847/2041-8213/acfd2e","DOIUrl":"https://doi.org/10.3847/2041-8213/acfd2e","url":null,"abstract":"Abstract We study the optical flux and polarization variability of the binary black hole blazar OJ 287 using quasi-simultaneous observations from 2015 to 2023 carried out using telescopes in the USA, Japan, Russia, Crimea, and Bulgaria. This is one of the most extensive quasi-simultaneous optical flux and polarization variability studies of OJ 287. OJ 287 showed large amplitude, ∼3.0 mag flux variability, large changes of ∼37% in degree of polarization, and a large swing of ∼215° in the angle of the electric vector of polarization. During the period of observation, several flares in flux were detected. Those flares are correlated with a rapid increase in the degree of polarization and swings in electric vector of polarization angle. A peculiar behavior of anticorrelation between flux and polarization degree, accompanied by a nearly constant polarization angle, was detected from JD 2,458,156 to JD 2,458,292. We briefly discuss some explanations for the flux and polarization variations observed in OJ 287.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"201 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136069592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Decomposing the Origin of TeV–PeV Emission from the Galactic Plane: Implications of Multimessenger Observations","authors":"Fang, Ke, Murase, Kohta","doi":"10.3847/2041-8213/ad012f","DOIUrl":"https://doi.org/10.3847/2041-8213/ad012f","url":null,"abstract":"High-energy neutrino and γ-ray emission has been observed from the Galactic plane, which may come from individual sources and/or diffuse cosmic rays. We evaluate the contribution of these two components through the multimessenger connection between neutrinos and γ-rays in hadronic interactions. We derive maximum fluxes of neutrino emission from the Galactic plane using γ-ray catalogs, including 4FGL, HGPS, 3HWC, and 1LHAASO, and measurements of the Galactic diffuse emission by Tibet ASγ and LHAASO. We find that the IceCube Galactic neutrino flux is larger than the contribution from all resolved sources when excluding promising leptonic sources such as pulsars, pulsar wind nebulae, and TeV halos. Our result indicates that the Galactic neutrino emission is likely dominated by the diffuse emission by the cosmic-ray sea and unresolved hadronic γ-ray sources. In addition, the IceCube flux is comparable to the sum of the flux of nonpulsar sources and the LHAASO diffuse emission especially above ∼30 TeV. This implies that the LHAASO diffuse emission may dominantly originate from hadronic interactions, either as the truly diffuse emission or unresolved hadronic emitters. Future observations of neutrino telescopes and air-shower γ-ray experiments in the Southern hemisphere are needed to accurately disentangle the source and diffuse emission of the Milky Way.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"23 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136376873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"UNCOVER: A NIRSpec Identification of a Broad-line AGN at z = 8.50","authors":"Vasily Kokorev, Seiji Fujimoto, Ivo Labbe, Jenny E. Greene, Rachel Bezanson, Pratika Dayal, Erica J. Nelson, Hakim Atek, Gabriel Brammer, Karina I. Caputi, Iryna Chemerynska, Sam E. Cutler, Robert Feldmann, Yoshinobu Fudamoto, Lukas J. Furtak, Andy D. Goulding, Anna de Graaff, Joel Leja, Danilo Marchesini, Tim B. Miller, Themiya Nanayakkara, Pascal A. Oesch, Richard Pan, Sedona H. Price, David J. Setton, Renske Smit, Mauro Stefanon, Bingjie 冰洁 Wang 王, John R. Weaver, Katherine E. Whitaker, Christina C. Williams, Adi Zitrin","doi":"10.3847/2041-8213/ad037a","DOIUrl":"https://doi.org/10.3847/2041-8213/ad037a","url":null,"abstract":"Abstract Deep observations with the James Webb Space Telescope (JWST) have revealed an emerging population of red pointlike sources that could provide a link between the postulated supermassive black hole seeds and observed quasars. In this work, we present a JWST/NIRSpec spectrum from the JWST Cycle 1 UNCOVER Treasury survey of a massive accreting black hole at z = 8.50 displaying a clear broad-line component as inferred from the H β line with FWHM = 3439 ± 413 km s −1 , typical of the broad-line region of an active galactic nucleus (AGN). The AGN nature of this object is further supported by high ionization, as inferred from emission lines, and a point-source morphology. We compute a black hole mass of <?CDATA ${mathrm{log}}_{10}({M}_{mathrm{BH}}/{M}_{odot })=8.17pm 0.42$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mi>log</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msub> <mml:mo stretchy=\"false\">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>BH</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy=\"true\">/</mml:mo> </mml:mrow> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> <mml:mo stretchy=\"false\">)</mml:mo> <mml:mo>=</mml:mo> <mml:mn>8.17</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.42</mml:mn> </mml:math> and a bolometric luminosity of L bol ∼ 6.6 × 10 45 erg s −1 . These values imply that our object is accreting at ∼40% of the Eddington limit. Detailed modeling of the spectral energy distribution in the optical and near-infrared, together with constraints from ALMA, indicate an upper limit on the stellar mass of <?CDATA ${mathrm{log}}_{10}({M}_{* }/{M}_{odot })lt 8.7$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mi>log</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msub> <mml:mo stretchy=\"false\">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>*</mml:mo> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy=\"true\">/</mml:mo> </mml:mrow> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> <mml:mo stretchy=\"false\">)</mml:mo> <mml:mo><</mml:mo> <mml:mn>8.7</mml:mn> </mml:math> , which would lead to an unprecedented ratio of black hole to host mass of at least ∼30%. This is orders of magnitude higher compared to the local QSOs but consistent with recent AGN studies at high redshift with JWST. This finding suggests that a nonnegligible fraction of supermassive black holes either started out from massive seeds and/or grew at a super-Eddington rate at high redshift. Given the predicted number densities of high- z faint AGN, future NIRSpec observations of larger samples will allow us to further investigate galaxy–black hole coevolution in the early Universe.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"1 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136376102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Discovery of A Large-scale Bent Radio Jet in the Merging Cluster A514","authors":"Wonki Lee, John ZuHone, M. James Jee, Kim HyeongHan, Ruta Kale, Eunmo Ahn","doi":"10.3847/2041-8213/acffc8","DOIUrl":"https://doi.org/10.3847/2041-8213/acffc8","url":null,"abstract":"Abstract We report a discovery of a large-scale bent radio jet in the merging galaxy cluster A514 ( z = 0.071). The radio emission originates from the two radio lobes of the active galactic nucleus (AGN) located near the center of the southern subcluster and extends toward the southern outskirts with multiple bends. Its peculiar morphology is characterized by a 400 kpc “bridge,” a 300 kpc “arc,” and a 400 kpc “tail,” which together contribute to its largest linear size of ∼0.7 Mpc. We find that both the flux and spectral features of the emission change with the distance from the AGN. Also, the “bridge” presents a 60% polarized radio emission, which coincided with an X-ray cold front. Based on our multiwavelength observations, we propose that A514 presents a clear case for the redistribution of an old AGN plasma due to merger-driven gas motions. We support our interpretation with idealized cluster merger simulations employing a passive tracer field to represent cosmic-ray electrons and find that merger-driven motions can efficiently create a cloud of these particles in the cluster outskirts, which later can be reaccelerated by the cluster merger shock and produce radio relics.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"17 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134973867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Recurring Activity Discovered on Quasi-Hilda 2009 DQ118","authors":"William J. Oldroyd, Colin Orion Chandler, Chadwick A. Trujillo, Scott S. Sheppard, Henry H. Hsieh, Jay K. Kueny, William A. Burris, Jarod A. DeSpain, Kennedy A. Farrell, Michele T. Mazzucato, Milton K. D. Bosch, Tiffany Shaw-Diaz, Virgilio Gonano","doi":"10.3847/2041-8213/acfcbc","DOIUrl":"https://doi.org/10.3847/2041-8213/acfcbc","url":null,"abstract":"Abstract We have discovered two epochs of activity on quasi-Hilda 2009 DQ 118 . Small bodies that display comet-like activity, such as active asteroids and active quasi-Hildas, are important for understanding the distribution of water and other volatiles throughout the solar system. Through our NASA Partner Citizen Science project, Active Asteroids, volunteers classified archival images of 2009 DQ 118 as displaying comet-like activity. By performing an in-depth archival image search, we found over 20 images from UT 2016 March 8–9 with clear signs of a comet-like tail. We then carried out follow-up observations of 2009 DQ 118 using the 3.5 m Astrophysical Research Consortium Telescope at Apache Point Observatory, Sunspot, New Mexico, USA and the 6.5 m Magellan Baade Telescope at Las Campanas Observatory, Chile. These images revealed a second epoch of activity associated with the UT 2023 April 22 perihelion passage of 2009 DQ 118 . We performed photometric analysis of the tail and find that it had a similar apparent length and surface brightness during both epochs. We also explored the orbital history and future of 2009 DQ 118 through dynamical simulations. These simulations show that 2009 DQ 118 is currently a quasi-Hilda and that it frequently experiences close encounters with Jupiter. We find that 2009 DQ 118 is currently on the boundary between asteroidal and cometary orbits. Additionally, it has likely been a Jupiter family comet or Centaur for much of the past 10 kyr and will be in these same regions for the majority of the next 10 kyr. Since both detected epochs of activity occurred near perihelion, the observed activity is consistent with sublimation of volatile ices. 2009 DQ 118 is currently observable until ∼mid-October 2023. Further observations would help to characterize the observed activity.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"20 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134972739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Pavo: Discovery of a Star-forming Dwarf Galaxy Just Outside the Local Group*","authors":"Michael G. Jones, Burçin Mutlu-Pakdil, David J. Sand, Richard Donnerstein, Denija Crnojević, Paul Bennet, Catherine E. Fielder, Ananthan Karunakaran, Kristine Spekkens, Jay Strader, Ryan Urquhart, Dennis Zaritsky","doi":"10.3847/2041-8213/ad0130","DOIUrl":"https://doi.org/10.3847/2041-8213/ad0130","url":null,"abstract":"Abstract We report the discovery of Pavo, a faint ( M V = −10.0), star-forming, irregular, and extremely isolated dwarf galaxy at D ≈ 2 Mpc. Pavo was identified in Dark Energy Camera Legacy Survey imaging via a novel approach that combines low surface brightness galaxy search algorithms and machine-learning candidate classifications. Follow-up imaging with the Inamori-Magellan Areal Camera and Spectrograph on the 6.5 m Magellan Baade telescope revealed a color–magnitude diagram (CMD) with an old stellar population, in addition to the young population that dominates the integrated light, and a tip of the red giant branch distance estimate of <?CDATA ${1.99}_{-0.22}^{+0.20}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msubsup> <mml:mrow> <mml:mn>1.99</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.22</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.20</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> Mpc. The blue population of stars in the CMD is consistent with the youngest stars having formed no later than 150 Myr ago. We also detected no H α emission with SOAR telescope imaging, suggesting that we may be witnessing a temporary low in Pavo’s star formation. We estimate the total stellar mass of Pavo to be <?CDATA $mathrm{log}{M}_{* }/{M}_{odot }=5.6pm 0.2$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:mi>log</mml:mi> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>*</mml:mo> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy=\"true\">/</mml:mo> </mml:mrow> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>5.6</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.2</mml:mn> </mml:math> and measure an upper limit on its H i gas mass of 1.0 × 10 6 M ⊙ based on the HIPASS survey. Given these properties, Pavo’s closest analog is Leo P ( D = 1.6 Mpc), previously the only known isolated, star-forming, Local Volume dwarf galaxy in this mass range. However, Pavo appears to be even more isolated, with no other known galaxy residing within over 600 kpc. As surveys and search techniques continue to improve, we anticipate an entire population of analogous objects being detected just outside the Local Group.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"2 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135168886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"JWST CEERS and JADES Active Galaxies at z = 4–7 Violate the Local M _•–M _⋆ Relation at &gt;3σ: Implications for Low-mass Black Holes and Seeding Models","authors":"Fabio Pacucci, Bao Nguyen, Stefano Carniani, Roberto Maiolino, Xiaohui Fan","doi":"10.3847/2041-8213/ad0158","DOIUrl":"https://doi.org/10.3847/2041-8213/ad0158","url":null,"abstract":"Abstract JWST is revolutionizing our understanding of the high- z Universe by expanding the black hole horizon, looking farther and to smaller masses, and revealing the stellar light of their hosts. By examining JWST galaxies at z = 4–7 that host H α -detected black holes, we investigate (i) the high- z M • – M ⋆ relation and (ii) the black hole mass distribution, especially in its low-mass range ( M • ≲ 10 6.5 M ⊙ ). With a detailed statistical analysis, our findings conclusively reveal a high- z M • – M ⋆ relation that deviates at &gt;3 σ confidence level from the local relation. The high- z relation is &lt;?CDATA $mathrm{log}({M}_{bullet }/,{M}_{odot })=-{2.43}_{-0.83}^{+0.83}+{1.06}_{-0.09}^{+0.09}mathrm{log}({M}_{star }/,{M}_{odot })$?&gt; &lt;mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"&gt; &lt;mml:mi&gt;log&lt;/mml:mi&gt; &lt;mml:mo stretchy=\"false\"&gt;(&lt;/mml:mo&gt; &lt;mml:msub&gt; &lt;mml:mrow&gt; &lt;mml:mi&gt;M&lt;/mml:mi&gt; &lt;/mml:mrow&gt; &lt;mml:mrow&gt; &lt;mml:mo&gt;•&lt;/mml:mo&gt; &lt;/mml:mrow&gt; &lt;/mml:msub&gt; &lt;mml:mrow&gt; &lt;mml:mo stretchy=\"true\"&gt;/&lt;/mml:mo&gt; &lt;/mml:mrow&gt; &lt;mml:mspace width=\"0.25em\" /&gt; &lt;mml:msub&gt; &lt;mml:mrow&gt; &lt;mml:mi&gt;M&lt;/mml:mi&gt; &lt;/mml:mrow&gt; &lt;mml:mrow&gt; &lt;mml:mo&gt;⊙&lt;/mml:mo&gt; &lt;/mml:mrow&gt; &lt;/mml:msub&gt; &lt;mml:mo stretchy=\"false\"&gt;)&lt;/mml:mo&gt; &lt;mml:mo&gt;=&lt;/mml:mo&gt; &lt;mml:mo&gt;−&lt;/mml:mo&gt; &lt;mml:msubsup&gt; &lt;mml:mrow&gt; &lt;mml:mn&gt;2.43&lt;/mml:mn&gt; &lt;/mml:mrow&gt; &lt;mml:mrow&gt; &lt;mml:mo&gt;−&lt;/mml:mo&gt; &lt;mml:mn&gt;0.83&lt;/mml:mn&gt; &lt;/mml:mrow&gt; &lt;mml:mrow&gt; &lt;mml:mo&gt;+&lt;/mml:mo&gt; &lt;mml:mn&gt;0.83&lt;/mml:mn&gt; &lt;/mml:mrow&gt; &lt;/mml:msubsup&gt; &lt;mml:mo&gt;+&lt;/mml:mo&gt; &lt;mml:msubsup&gt; &lt;mml:mrow&gt; &lt;mml:mn&gt;1.06&lt;/mml:mn&gt; &lt;/mml:mrow&gt; &lt;mml:mrow&gt; &lt;mml:mo&gt;−&lt;/mml:mo&gt; &lt;mml:mn&gt;0.09&lt;/mml:mn&gt; &lt;/mml:mrow&gt; &lt;mml:mrow&gt; &lt;mml:mo&gt;+&lt;/mml:mo&gt; &lt;mml:mn&gt;0.09&lt;/mml:mn&gt; &lt;/mml:mrow&gt; &lt;/mml:msubsup&gt; &lt;mml:mi&gt;log&lt;/mml:mi&gt; &lt;mml:mo stretchy=\"false\"&gt;(&lt;/mml:mo&gt; &lt;mml:msub&gt; &lt;mml:mrow&gt; &lt;mml:mi&gt;M&lt;/mml:mi&gt; &lt;/mml:mrow&gt; &lt;mml:mrow&gt; &lt;mml:mo&gt;⋆&lt;/mml:mo&gt; &lt;/mml:mrow&gt; &lt;/mml:msub&gt; &lt;mml:mrow&gt; &lt;mml:mo stretchy=\"true\"&gt;/&lt;/mml:mo&gt; &lt;/mml:mrow&gt; &lt;mml:mspace width=\"0.25em\" /&gt; &lt;mml:msub&gt; &lt;mml:mrow&gt; &lt;mml:mi&gt;M&lt;/mml:mi&gt; &lt;/mml:mrow&gt; &lt;mml:mrow&gt; &lt;mml:mo&gt;⊙&lt;/mml:mo&gt; &lt;/mml:mrow&gt; &lt;/mml:msub&gt; &lt;mml:mo stretchy=\"false\"&gt;)&lt;/mml:mo&gt; &lt;/mml:math&gt; . Black holes are overmassive by ∼10–100× compared to their low- z counterparts in galactic hosts of the same stellar mass. This fact is not due to a selection effect in surveys. Moreover, our analysis predicts the possibility of detecting in high- z JWST surveys 5–15× more black holes with M • ≲ 10 6.5 M ⊙ , and 10–30× more with M • ≲ 10 8.5 M ⊙ , compared to local relation’s predictions. The lighter black holes preferentially occupy galaxies with a stellar mass of ∼10 7.5 –10 8 M ⊙ . We have yet to detect these sources because (i) they may be inactive (duty cycles 1%–10%), (ii) the host overshines the active galactic nucleus (AGN), or (iii) the AGN is obscured and not immediately recognizable by line diagnostics. A search of low-mass black holes in existing JWST surveys will further test the M • – M ⋆ relation. Current JWST fields represent a treasure trove of black hole systems at z = 4–7; their ","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"52 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135366268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Size and Albedo Constraints for (152830) Dinkinesh Using WISE Data","authors":"Kiana D. McFadden, Amy K. Mainzer, Joseph R. Masiero, James M. Bauer, Roc M. Cutri, Dar Dahlen, Frank J. Masci, Jana Pittichová, Akash Satpathy, Edward L. Wright","doi":"10.3847/2041-8213/acff61","DOIUrl":"https://doi.org/10.3847/2041-8213/acff61","url":null,"abstract":"Abstract Probing small main-belt asteroids provides insight into their formation and evolution through multiple dynamical and collisional processes. These asteroids also overlap in size with the potentially hazardous near-Earth object population and supply the majority of these objects. The Lucy mission will perform a flyby of the small main-belt asteroid, (152830) Dinkinesh, on 2023 November 1, in preparation for its mission to the Jupiter Trojan asteroids. In this Letter, we present data to support the planning of Lucy’s imminent encounter of Dinkinesh. We employed aperture photometry on stacked frames of Dinkinesh obtained by the Wide-field Infrared Survey Explorer and performed thermal modeling on a detection at 12 μ m to compute diameter and albedo values. Through this method, we determined Dinkinesh has an effective spherical diameter of <?CDATA ${0.76}_{-0.21}^{+0.11}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msubsup> <mml:mrow> <mml:mn>0.76</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.21</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.11</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> km and a visual geometric albedo of <?CDATA ${0.27}_{-0.06}^{+0.25}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msubsup> <mml:mrow> <mml:mn>0.27</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.06</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.25</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> at the 16th and 84th percentiles. This albedo is consistent with typical stony (S-type) asteroids. These measurements will enable the Lucy team to optimize planning for the flyby of Dinkinesh, including refinement of exposure times and flyby geometry. The data obtained from this mission will, in turn, allow us to better understand the calibration of our thermal models by providing ground truth data. The Lucy flyby presents a rare opportunity to study the smallest main-belt asteroid ever observed in situ.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"23 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135366266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"The Force-freeness of the Solar Photosphere: Revisit with New Approach and Large Data Sets","authors":"Mei Zhang, Haocheng Zhang","doi":"10.3847/2041-8213/acfcbd","DOIUrl":"https://doi.org/10.3847/2041-8213/acfcbd","url":null,"abstract":"Abstract Although it is generally believed that the solar photosphere is not magnetically force-free owing to its high plasma β , the estimations of force-freeness using observed magnetograms have produced disputable results. Some studies confirmed that the photosphere is largely not force-free whereas some authors argued that the photosphere is not far away from being force-free. In a previous paper of ours we demonstrated that, due to the fact that the noise levels of the transverse field in the magnetograms are much larger than those of the vertical field, wrong judgments on the force-freeness could be made: a truly force-free field could be judged as being not-force-free and a truly not-force-free field could be judged as being force-free. Here in this Letter, we propose an approach to overcome this serious problem. By reducing the spatial resolution to lower the noise level, the heavy influence of the measurement noise on the force-freeness judgment can be significantly suppressed. We first use two analytical solutions to show the success and effectiveness of this approach. Then, we apply this new approach to two large data sets of active region magnetograms, obtained with the Helioseismic and Magnetic Imager/Solar Dynamics Observatory and Spectro-Polarimeter (SP)/Hinode, respectively. Our analysis shows that the photospheric magnetic fields are actually far away from being force-free. Particularly, and most notably, the mean value of F z / F p (where F z is the net Lorentz force in the vertical direction and F p the total Lorentz force) is as low as −0.47, with more than 98% of the active regions having ∣ F z / F p ∣ &gt; 0.1 when using the SP/Hinode magnetograms of true field strength.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135607002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}