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A conserved fungal glycosyltransferase facilitates pathogenesis of plants by enabling hyphal growth on solid surfaces
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Pathogenic fungi must extend filamentous hyphae across solid surfaces to cause diseases of plants. However, the full inventory of genes which support this is incomplete and many may be currently concealed due to their essentiality for the hyphal growth form. During a random T-DNA mutagenesis screen performed on the pleomorphic wheat (Triticum aestivum) pathogen Zymoseptoria tritici, we acquired a mutant unable to extend hyphae specifically when on solid surfaces. In contrast “yeast-like” growth, and all other growth forms, were unaffected. The inability to extend surface hyphae resulted in a complete loss of virulence on plants. The affected gene encoded a predicted type 2 glycosyltransferase (ZtGT2). Analysis of >800 genomes from taxonomically diverse fungi highlighted a generally widespread, but discontinuous, distribution of ZtGT2 orthologues, and a complete absence of any similar proteins in non-filamentous ascomycete yeasts. Deletion mutants of the ZtGT2 orthologue in the taxonomically un-related fungus Fusarium graminearum were also severely impaired in hyphal growth and non-pathogenic on wheat ears. ZtGT2 expression increased during filamentous growth and electron microscopy on deletion mutants (ΔZtGT2) suggested the protein functions to maintain the outermost surface of the fungal cell wall. Despite this, adhesion to leaf surfaces was unaffected in ΔZtGT2 mutants and global RNAseq-based gene expression profiling highlighted that surface-sensing and protein secretion was also largely unaffected. However, ΔZtGT2 mutants constitutively overexpressed several transmembrane and secreted proteins, including an important LysM-domain chitin-binding virulence effector, Zt3LysM. ZtGT2 likely functions in the synthesis of a currently unknown, potentially minor but widespread, extracellular or outer cell wall polysaccharide which plays a key role in facilitating many interactions between plants and fungi by enabling hyphal growth on solid matrices
Examining the effectiveness of general practitioner and nurse promotion of electronic cigarettes versus standard care for smoking reduction and abstinence in hardcore smokers with smoking-related chronic disease:protocol for a randomised controlled trial
BACKGROUND: Despite the clear harm associated with smoking tobacco, many people with smoking-related chronic diseases or serious mental illnesses (SMI) are unwilling or unable to stop smoking. In many cases, these smokers have tried and exhausted all methods to stop smoking and yet clinicians are repeatedly mandated to offer them during routine consultations. Providing nicotine through electronic cigarettes (e-cigarettes) may reduce the adverse health consequences associated with tobacco smoking, but these are not currently offered. The aim of this study is to examine the feasibility, acceptability and effectiveness of general practitioners (GPs) and nurses delivering a brief advice intervention on e-cigarettes and offering an e-cigarette starter pack and patient support resources compared with standard care in smokers with smoking-related chronic diseases or SMI who are unwilling to stop smoking. METHODS/DESIGN: This is an individually randomised, blinded, two-arm trial. Smokers with a smoking-related chronic condition or SMI with no intention of stopping smoking will be recruited through primary care registers. Eligible participants will be randomised to one of two groups if they decline standard care for stopping smoking: a control group who will receive no additional support beyond standard care; or an intervention group who will receive GP or nurse-led brief advice about e-cigarettes, an e-cigarette starter pack with accompanying practical support booklet, and telephone support from experienced vapers and online video tutorials. The primary outcome measures will be smoking reduction, measured through changes in cigarettes per day and 7-day point-prevalence abstinence at 2 months. Secondary outcomes include smoking reduction, 7-day point-prevalence abstinence and prolonged abstinence at 8 months. Other outcomes include patient recruitment and follow-up, patient uptake and use of e-cigarettes, nicotine intake, contamination of randomisation and practitioner adherence to the delivery of the intervention. Qualitative interviews will be conducted in a subsample of practitioners, patients and the vape team to garner their reactions to the programme. DISCUSSION: This is the first randomised controlled trial to investigate whether e-cigarette provision alongside a brief intervention delivered by practitioners leads to reduced smoking and abstinence among smokers with smoking-related chronic diseases or SMI. TRIAL REGISTRATION: ISRCTN registry, ISRCTN59404712. Registered 28/11/17
The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy
Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations.
Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves.
Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p 90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score.
Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care
Adjunctive rifampicin for Staphylococcus aureus bacteraemia (ARREST): a multicentre, randomised, double-blind, placebo-controlled trial.
BACKGROUND: Staphylococcus aureus bacteraemia is a common cause of severe community-acquired and hospital-acquired infection worldwide. We tested the hypothesis that adjunctive rifampicin would reduce bacteriologically confirmed treatment failure or disease recurrence, or death, by enhancing early S aureus killing, sterilising infected foci and blood faster, and reducing risks of dissemination and metastatic infection. METHODS: In this multicentre, randomised, double-blind, placebo-controlled trial, adults (≥18 years) with S aureus bacteraemia who had received ≤96 h of active antibiotic therapy were recruited from 29 UK hospitals. Patients were randomly assigned (1:1) via a computer-generated sequential randomisation list to receive 2 weeks of adjunctive rifampicin (600 mg or 900 mg per day according to weight, oral or intravenous) versus identical placebo, together with standard antibiotic therapy. Randomisation was stratified by centre. Patients, investigators, and those caring for the patients were masked to group allocation. The primary outcome was time to bacteriologically confirmed treatment failure or disease recurrence, or death (all-cause), from randomisation to 12 weeks, adjudicated by an independent review committee masked to the treatment. Analysis was intention to treat. This trial was registered, number ISRCTN37666216, and is closed to new participants. FINDINGS: Between Dec 10, 2012, and Oct 25, 2016, 758 eligible participants were randomly assigned: 370 to rifampicin and 388 to placebo. 485 (64%) participants had community-acquired S aureus infections, and 132 (17%) had nosocomial S aureus infections. 47 (6%) had meticillin-resistant infections. 301 (40%) participants had an initial deep infection focus. Standard antibiotics were given for 29 (IQR 18-45) days; 619 (82%) participants received flucloxacillin. By week 12, 62 (17%) of participants who received rifampicin versus 71 (18%) who received placebo experienced treatment failure or disease recurrence, or died (absolute risk difference -1·4%, 95% CI -7·0 to 4·3; hazard ratio 0·96, 0·68-1·35, p=0·81). From randomisation to 12 weeks, no evidence of differences in serious (p=0·17) or grade 3-4 (p=0·36) adverse events were observed; however, 63 (17%) participants in the rifampicin group versus 39 (10%) in the placebo group had antibiotic or trial drug-modifying adverse events (p=0·004), and 24 (6%) versus six (2%) had drug interactions (p=0·0005). INTERPRETATION: Adjunctive rifampicin provided no overall benefit over standard antibiotic therapy in adults with S aureus bacteraemia. FUNDING: UK National Institute for Health Research Health Technology Assessment
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Resolving the inner parsec of the blazar J1924–2914 with the Event Horizon Telescope
Rest of authors: Ikeda, Shiro; Impellizzeri, C. M. Violette; Inoue, Makoto; James, David J.; Jannuzi, Buell T.; Jeter, Britton; Jiang, Wu; Jimenez-Rosales, Alejandra; Johnson, Michael D.; Joshi, Abhishek, V; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Dong-Jin; Kim, Jae-Young; Kim, Jongsoo; Kim, Junhan; Kino, Motoki; Koay, Jun Yi; Kocherlakota, Prashant; Kofuji, Yutaro; Koch, Patrick M.; Koyama, Shoko; Kramer, Carsten; Kramer, Michael; Kuo, Cheng-Yu; La Bella, Noemi; Lauer, Tod R.; Lee, Daeyoung; Lee, Sang-Sung; Leung, Po Kin; Levis, Aviad; Li, Zhiyuan; Lindahl, Greg; Lindqvist, Michael; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Lonsdale, Colin; Mao, Jirong; Marchili, Nicola; Markoff, Sera; Marrone, Daniel P.; Marscher, Alan P.; Matsushita, Satoki; Matthews, Lynn D.; Medeiros, Lia; Menten, Karl M.; Michalik, Daniel; Mizuno, Izumi; Mizuno, Yosuke; Moran, James M.; Mueller, Cornelia; Mus, Alejandro; Musoke, Gibwa; Myserlis, Ioannis; Nadolski, Andrew; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Nathanail, Antonios; Neilsen, Joey; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Nowak, Michael A.; Oh, Junghwan; Okino, Hiroki; Olivares, Hector; Ortiz-Leon, Gisela N.; Oyama, Tomoaki; Ozel, Feryal; Palumbo, Daniel C. M.; Paraschos, Georgios Filippos; Park, Jongho; Parsons, Harriet; Patel, Nimesh; Pen, Ue-Li; Pietu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Porth, Oliver; Potzl, Felix M.; Prather, Ben; Preciado-Lopez, Jorge A.; Psaltis, Dimitrios; Pu, Hung-Yi; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ricarte, Angelo; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Romero-Canizales, Cristina; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruiz, Ignacio; Ruszczyk, Chet; Rygl, Kazi L. J.; Sanchez, Salvador; Sanchez-Arguelles, David; Sanchez-Portal, Miguel; Sasada, Mahito; Satapathy, Kaushik; Savolainen, Tuomas; Schloerb, F. Peter; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Souccar, Kamal; Sun, He; Tazaki, Fumie; Tetarenko, Alexandra J.; Tilanus, Remo P. J.; Titus, Michael; Torne, Pablo; Trent, Tyler; Trippe, Sascha; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Vos, Jesse; Wagner, Jan; Ward-Thompson, Derek; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wiik, Kaj; Witzel, Gunther; Wondrak, Michael; Wong, George N.; Wu, Qingwen; Yamaguchi, Paul; Yoon, Doosoo; Young, Andre; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhang, Shuo; Zhao, Shan-Shan.The blazar J1924–2914 is a primary Event Horizon Telescope (EHT) calibrator for the Galactic center’s black hole
Sagittarius A*. Here we present the first total and linearly polarized intensity images of this source obtained with
the unprecedented 20 μas resolution of the EHT. J1924–2914 is a very compact flat-spectrum radio source with
strong optical variability and polarization. In April 2017 the source was observed quasi-simultaneously with the
EHT (April 5–11), the Global Millimeter VLBI Array (April 3), and the Very Long Baseline Array (April 28),
giving a novel view of the source at four observing frequencies, 230, 86, 8.7, and 2.3 GHz. These observations
probe jet properties from the subparsec to 100 pc scales. We combine the multifrequency images of J1924–2914 to
study the source morphology. We find that the jet exhibits a characteristic bending, with a gradual clockwise
rotation of the jet projected position angle of about 90° between 2.3 and 230 GHz. Linearly polarized intensity
images of J1924–2914 with the extremely fine resolution of the EHT provide evidence for ordered toroidal
magnetic fields in the blazar compact core.We thank the anonymous reviewer for their thoughtful and
helpful comments. The Event Horizon Telescope Collaboration
thanks the following organizations and programs: the Academy
of Finland (projects 274477, 284495, 312496, 315721); the
Agencia Nacional de Investigación y Desarrollo (ANID), Chile
via NCN19_058 (TITANs) and Fondecyt 3190878, the
Alexander von Humboldt Stiftung; an Alfred P. Sloan Research
Fellowship; Allegro, the European ALMA Regional Centre
node in the Netherlands, the NL astronomy research network
NOVA and the astronomy institutes of the University of
Amsterdam, Leiden University and Radboud University; the
black hole Initiative at Harvard University, through a grant
(60477) from the John Templeton Foundation; the China Scholarship Council; Consejo Nacional de Ciencia y Tecnología
(CONACYT, Mexico, projects U0004-246083, U0004-
259839, F0003-272050, M0037-279006, F0003-281692,
104497, 275201, 263356); the Delaney Family via the Delaney
Family John A. Wheeler Chair at Perimeter Institute; Dirección
General de Asuntos del Personal Académico-Universidad
Nacional Autónoma de México (DGAPA-UNAM, projects
IN112417 and IN112820); the European Research Council
Synergy Grant “BlackHoleCam: Imaging the Event Horizon of
Black Holes” (grant 610058); the Generalitat Valenciana
postdoctoral grant APOSTD/2018/177 and GenT Program
(project CIDEGENT/2018/021); MICINN Research Project
PID2019-108995GB-C22; the Gordon and Betty Moore
Foundation (grant GBMF-3561); the Istituto Nazionale di
Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche
TEONGRAV; the International Max Planck Research School
for Astronomy and Astrophysics at the Universities of Bonn
and Cologne; Joint Princeton/Flatiron and Joint Columbia/
Flatiron Postdoctoral Fellowships, research at the Flatiron
Institute is supported by the Simons Foundation; the Japanese
Government (Monbukagakusho: MEXT) Scholarship; the
Japan Society for the Promotion of Science (JSPS) Grant-in-
Aid for JSPS Research Fellowship (JP17J08829); the Key
Research Program of Frontier Sciences, Chinese Academy of
Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJSSWSYS008,
ZDBS-LY-SLH011); the Leverhulme Trust Early
Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the
CAS; the MEXT/JSPS KAKENHI (grants 18KK0090,
JP18K13594, JP18K03656, JP18H03721, 18K03709,
18H01245, 25120007); the Malaysian Fundamental Research
Grant Scheme (FRGS) FRGS/1/2019/STG02/UM/02/6; the
MIT International Science and Technology Initiatives (MISTI)
Funds; the Ministry of Science and Technology (MOST) of
Taiwan (105-2112-M-001-025-MY3, 106-2112-M-001-011,
106-2119- M-001-027, 107-2119-M-001-017, 107-2119-M-
001-020, 107-2119-M-110-005, 108-2112-M-001-048, and
109-2124-M-001-005); the National Aeronautics and Space
Administration (NASA, Fermi Guest Investigator grant
80NSSC20K1567, NASA Astrophysics Theory Program grant
80NSSC20K0527, NASA NuSTAR award 80NSSC20K0645);
the National Institute of Natural Sciences (NINS) of Japan; the
National Key Research and Development Program of China
(grant 2016YFA0400704, 2016YFA0400702); the National
Science Foundation (NSF, grants AST-0096454, AST-
0352953, AST-0521233, AST-0705062, AST-0905844, AST-
0922984, AST-1126433, AST-1140030, DGE-1144085, AST-
1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-
1248097, AST-1310896, AST-1555365,AST-1615796, AST-
1715061, AST-1716327, AST-1903847,AST-2034306); the
Natural Science Foundation of China (grants 11573051,
11633006, 11650110427, 10625314, 11721303, 11725312,
11933007, 11991052, 11991053); a fellowship of China
Postdoctoral Science Foundation (2020M671266); the Natural Sciences and Engineering Research Council of Canada
(NSERC, including a Discovery Grant and the NSERC
Alexander Graham Bell Canada Graduate Scholarships-Doctoral
Program); the National Youth Thousand Talents Program
of China; the National Research Foundation of Korea (the
Global PhD Fellowship Grant: grants NRF-
2015H1A2A1033752, 2015- R1D1A1A01056807, the Korea
Research Fellowship Program: NRF-2015H1D3A1066561, Basic Research Support Grant 2019R1F1A1059721); the
Netherlands Organization for Scientific Research (NWO) VICI
award (grant 639.043.513) and Spinoza Prize SPI 78-409; the
New Scientific Frontiers with Precision Radio Interferometry
Fellowship awarded by the South African Radio Astronomy
Observatory (SARAO), which is a facility of the National
Research Foundation (NRF), an agency of the Department of
Science and Technology (DST) of South Africa; the Onsala
Space Observatory (OSO) national infrastructure, for the
provisioning of its facilities/observational support (OSO
receives funding through the Swedish Research Council under
grant 2017-00648) the Perimeter Institute for Theoretical
Physics (research at Perimeter Institute is supported by the
Government of Canada through the Department of Innovation,
Science and Economic Development and by the Province of
Ontario through the Ministry of Research, Innovation and
Science); the Spanish Ministerio de Economía y Competitividad
(grants PGC2018-098915-B-C21, AYA2016-80889-P,
PID2019-108995GB-C21); the State Agency for Research of
the Spanish MCIU through the “Center of Excellence Severo
Ochoa” award for the Instituto de Astrofísica de Andalucía
(SEV-2017-0709); the Toray Science Foundation; the Consejería
de Economía, Conocimiento, Empresas y Universidad of the
Junta de Andalucía (grant P18-FR-1769), the Consejo Superior
de Investigaciones Científicas (grant 2019AEP112); the US
Department of Energy (USDOE) through the Los Alamos
National Laboratory (operated by Triad National Security, LLC,
for the National Nuclear Security Administration of the USDOE
(Contract 89233218CNA000001); the European Unionʼs Horizon
2020 research and innovation program under grant
agreement No 730562 RadioNet; ALMA North America
Development Fund; the Academia Sinica; Chandra DD7-
18089X and TM6-17006X; the GenT Program (Generalitat
Valenciana) Project CIDEGENT/2018/021. This work used the
Extreme Science and Engineering Discovery Environment
(XSEDE), supported by NSF grant ACI-1548562, and CyVerse,
supported by NSF grants DBI-0735191, DBI-1265383, and
DBI-1743442. XSEDE Stampede2 resource at TACC was
allocated through TG-AST170024 and TG-AST080026N.
XSEDE JetStream resource at PTI and TACC was allocated
through AST170028. The simulations were performed in part on
the SuperMUC cluster at the LRZ in Garching, on the LOEWE
cluster in CSC in Frankfurt, and on the HazelHen cluster at the
HLRS in Stuttgart. This research was enabled in part by support
provided by Compute Ontario (http://computeontario.ca),
Calcul Quebec (http://www.calculquebec.ca) and Compute
Canada (http://www.computecanada.ca). We thank the staff at
the participating observatories, correlation centers, and institutions
for their enthusiastic support. This paper makes use of the
following ALMA data: ADS/JAO.ALMA#2016.1.01154.V
and ADS/JAO.ALMA2016.1.00413.V. ALMA is a partnership
of the European Southern Observatory (ESO; Europe, representing
its member states), NSF, and National Institutes of Natural
Sciences of Japan, together with National Research Council
(Canada), Ministry of Science and Technology (MOST;
Taiwan), Academia Sinica Institute of Astronomy and Astrophysics
(ASIAA; Taiwan), and Korea Astronomy and Space
Science Institute (KASI; Republic of Korea), in cooperationwith
the Republic of Chile. The Joint ALMA Observatory is operated
by ESO, Associated Universities, Inc. (AUI)/NRAO, and the
National Astronomical Observatory of Japan (NAOJ). The
NRAO is a facility of the NSF operated under cooperative
agreement by AUI. APEX is a collaboration between the Max-
Planck-Institut für Radioastronomie (Germany), ESO, and the
Onsala Space Observatory (Sweden). The SMA is a joint project
between the SAO and ASIAA and is funded by the Smithsonian
Institution and the Academia Sinica. The JCMT is operated by
the East Asian Observatory on behalf of the NAOJ, ASIAA, and
KASI, as well as the Ministry of Finance of China, Chinese
Academy of Sciences, and the National Key R&D Program (No.
2017YFA0402700) of China. Additional funding support for the
JCMT is provided by the Science and Technologies Facility
Council (UK) and participating universities in the UK and
Canada. The LMT is a project operated by the Instituto Nacional
de Astrófisica, Óptica, y Electrónica (Mexico) and the University
of Massachusetts at Amherst (USA). The IRAM 30 m telescope
on Pico Veleta, Spain is operated by IRAM and supported by
CNRS (Centre National de la Recherche Scientifique, France),
MPG (Max-Planck- Gesellschaft, Germany) and IGN (Instituto
Geográfico Nacional, Spain). The SMT is operated by the
Arizona Radio Observatory, a part of the Steward Observatory
of the University of Arizona, with financial support of operations
from the State of Arizona and financial support for instrumentation
development from the NSF. Support for SPT participation in
the EHT is provided by the National Science Foundation
through award OPP-1852617 to the University of Chicago.
Partial support is also provided by the Kavli Institute of
Cosmological Physics at the University of Chicago. The SPT
hydrogen maser was provided on loan from the GLT, courtesy
of ASIAA. The EHTC has received generous donations of
FPGA chips from Xilinx Inc., under the Xilinx University
Program. The EHTC has benefited from technology shared under open-source license by the Collaboration for Astronomy
Signal Processing and Electronics Research (CASPER). The
EHT project is grateful to T4Science and Microsemi for their
assistance with Hydrogen Masers. This research has made use of
NASAʼs Astrophysics Data System. We gratefully acknowledge
the support provided by the extended staff of the ALMA, both
from the inception of the ALMA Phasing Project through the
observational campaigns of 2017 and 2018. We would like to
thank A. Deller and W. Brisken for EHT-specific support with
the use of DiFX. We acknowledge the significance that
Maunakea, where the SMA and JCMT EHT stations are located,
has for the indigenous Hawaiian people.
We also thank Alexandra Elbakyan for her contributions to
the open science initiative. This research has made use of data
obtained with the Global Millimeter VLBI Array (GMVA),
coordinated by the VLBI group at the Max-Planck-Institut für
Radioastronomie (MPIfR). The GMVA consists of telescopes
operated by MPIfR, IRAM, Onsala, Metsahovi, Yebes, the
Korean VLBI Network, the Green Bank Observatory, and the
Very Long Baseline Array (VLBA). The VLBA and the GBT
are facilities of the National Science Foundation under
cooperative agreement by Associated Universities, Inc. The
data were correlated at the DiFX correlator of the MPIfR in
Bonn, Germany. We thank the National Science Foundation
(awards OISE-1743747, AST-1816420, AST-1716536, AST-
1440254, AST-1935980) and the Gordon and Betty Moore
Foundation (GBMF-5278) for financial support of this work.
Support for this work was also provided by the NASA Hubble
Fellowship grant HST-HF2-51431.001-A awarded by the
Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc.,
for NASA, under contract NAS5-26555.http://iopscience.iop.org/0004-637Xam2023Physic
Broadband multi-wavelength properties of M87 during the 2017 Event Horizon Telescope campaign
In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the
center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations
for a weakly accreting supermassive black hole of mass ∼6.5 × 109Me. The EHTC also partnered with several
international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength
campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a
legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at
high energies, making it possible to combine core flux constraints with the more spatially precise very long
baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active
nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one
broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the
basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude
that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the
EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of
HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and
secondaries cannot yet be excluded.http://iopscience.iop.org/2041-8205am2022Physic
Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
Abstract: In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M ⊙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded
- …