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The analysis of monitoring control point displacement of Sermo Dam based on the 2015-2016 GNSS data

AIP Conference Proceedings 2017年第1期1857卷

作者： Yulaikhah W. Nurrohmat N. Prijono K. C. Bambang Waljiyanto D. A. Agus M. I. Taftazani 1Geodetic Engineering Department Engineering Faculty of Gadjah Mada University Indonesia 2Civil Engineering Department Engineering Faculty of Gadjah Mada University Indonesia 3Geomatics Engineering Study Program of Vocational School of Gadjah Mada University Indonesia

Sermo dam has operated for 20 years. This dam has a great benefit, especially as a water storage for water supply, irrigation and flood prevention. For the purposes of Sermo dam deformation monitoring, the control network was built around the Sermo dam in 2010. Then, this network was developed in 2015 by adding 5 new control points. For the time being, the network consists of 8 existing control points (micro) and 5 new control points (macro). The aim of the study is to monitor the control network displacement in the period of 2015 to 2016 based on GNSS observation *** measurement were conducted at 9 to10 of May 2015 and 12 to 15 of May 2016. The data observation was processed using GAMIT/GBLOK scientific software referenced to IGS station to determine the coordinates and its standard deviation. Further, horizontal and vertical displacement was analyzed by comparing with 2.5 times the standard deviation. The results showed that within a year, the coordinate difference varied from 0.12 to 1.68 cm on the N component, 0.21 to 0.65 cm on the E component, while the U component (the vertical displacement) have greater one, varied from 2.71 to 16.34 cm. Six control points (MAK2, MAK3, BMB2, BMB5, BMS2 and BMS5) have significant different in the horizontal displacement and six control points have significant different in vertical displacement (MAK5, BMB1, BMB2, BMS1, BMS2 and BMS3). In general, the horizontal displacement tends toward southeast. However, for obtaining more accurate and realistic results, further evaluation is required in the processing strategy such as the use of local control point as reference.

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Transverse single-spin asymmetry of midrapidity π0 and η mesons in p+Au and p+Al collisions at sNN=200 GeV

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Physical Review D 2023年第11期107卷 112004-112004页

作者： N. J. Abdulameer U. Acharya C. Aidala Y. Akiba M. Alfred V. Andrieux N. Apadula H. Asano B. Azmoun V. Babintsev N. S. Bandara K. N. Barish S. Bathe A. Bazilevsky M. Beaumier R. Belmont A. Berdnikov Y. Berdnikov L. Bichon B. Blankenship D. S. Blau J. S. Bok V. Borisov M. L. Brooks J. Bryslawskyj V. Bumazhnov S. Campbell V. Canoa Roman R. Cervantes M. Chiu C. Y. Chi I. J. Choi J. B. Choi Z. Citron M. Connors R. Corliss Y. Corrales Morales N. Cronin M. Csanád T. Csörgő T. W. Danley M. S. Daugherity G. David C. T. Dean K. DeBlasio K. Dehmelt A. Denisov A. Deshpande E. J. Desmond A. Dion D. Dixit V. Doomra J. H. Do A. Drees K. A. Drees J. M. Durham A. Durum H. En’yo A. Enokizono R. Esha B. Fadem W. Fan N. Feege D. E. Fields M. Finger, Jr. M. Finger D. Firak D. Fitzgerald S. L. Fokin J. E. Frantz A. Franz A. D. Frawley Y. Fukuda P. Gallus C. Gal P. Garg H. Ge M. Giles F. Giordano Y. Goto N. Grau S. V. Greene M. Grosse Perdekamp T. Gunji H. Guragain T. Hachiya J. S. Haggerty K. I. Hahn H. Hamagaki H. F. Hamilton J. Hanks S. Y. Han M. Harvey S. Hasegawa T. O. S. Haseler T. K. Hemmick X. He J. C. Hill K. Hill A. Hodges R. S. Hollis K. Homma B. Hong T. Hoshino N. Hotvedt J. Huang K. Imai M. Inaba A. Iordanova D. Isenhower D. Ivanishchev B. V. Jacak M. Jezghani X. Jiang Z. Ji B. M. Johnson D. Jouan D. S. Jumper J. H. Kang D. Kapukchyan S. Karthas D. Kawall A. V. Kazantsev V. Khachatryan A. Khanzadeev A. Khatiwada C. Kim E.-J. Kim M. Kim T. Kim D. Kincses A. Kingan E. Kistenev J. Klatsky P. Kline T. Koblesky D. Kotov L. Kovacs S. Kudo B. Kurgyis K. Kurita Y. Kwon J. G. Lajoie D. Larionova A. Lebedev S. Lee S. H. Lee M. J. Leitch Y. H. Leung N. A. Lewis S. H. Lim M. X. Liu X. Li V.-R. Loggins D. A. Loomis K. Lovasz D. Lynch S. Lökös T. Majoros Y. I. Makdisi M. Makek V. I. Manko E. Mannel M. McCumber P. L. McGaughey D. McGlinchey C. McKinney M. Mendoza A. C. Mignerey A. Milov D. K. Mishra J. T. Mitchell M. Mitrankova Iu. Mitrankov G. Mitsuka S. Miyasaka S. Mizuno M. M. Mondal P. Montuenga T. Moon D. P. Morrison A. Muhammad B. Debrecen University H-4010 Debrecen Egyetem tér 1 Hungary Georgia State University Atlanta Georgia 30303 USA Department of Physics University of Michigan Ann Arbor Michigan 48109-1040 USA RIKEN Nishina Center for Accelerator-Based Science Wako Saitama 351-0198 Japan RIKEN BNL Research Center Brookhaven National Laboratory Upton New York 11973-5000 USA Department of Physics and Astronomy Howard University Washington DC 20059 USA Iowa State University Ames Iowa 50011 USA Kyoto University Kyoto 606-8502 Japan Physics Department Brookhaven National Laboratory Upton New York 11973-5000 USA IHEP Protvino State Research Center of Russian Federation Institute for High Energy Physics Protvino 142281 Russia Department of Physics University of Massachusetts Amherst Massachusetts 01003-9337 USA University of California-Riverside Riverside California 92521 USA Baruch College City University of New York New York New York 10010 USA University of Colorado Boulder Colorado 80309 USA Physics and Astronomy Department University of North Carolina at Greensboro Greensboro North Carolina 27412 USA Saint Petersburg State Polytechnic University St. Petersburg 195251 Russia Vanderbilt University Nashville Tennessee 37235 USA National Research Center “Kurchatov Institute” Moscow 123098 Russia National Research Nuclear University MEPhI Moscow Engineering Physics Institute Moscow 115409 Russia New Mexico State University Las Cruces New Mexico 88003 USA Los Alamos National Laboratory Los Alamos New Mexico 87545 USA Columbia University New York New York 10027 and Nevis Laboratories Irvington New York 10533 USA Department of Physics and Astronomy Stony Brook University SUNY Stony Brook New York 11794-3800 USA University of Illinois at Urbana-Champaign Urbana Illinois 61801 USA Jeonbuk National University Jeonju 54896 Korea Weizmann Institute Rehovot 76100 Israel ELTE Eötvös Loránd University H-1117 Budapest Pázmány P. s. 1/A Hungary MATE Laboratory of

Presented are the first measurements of the transverse single-spin asymmetries (AN) for neutral pions and eta mesons in p+Au and p+Al collisions at sNN=200 GeV in the pseudorapidity range |η|<0.35 with the PHENIX detector at the Relativistic Heavy Ion Collider. The asymmetries are consistent with zero, similar to those for midrapidity neutral pions and eta mesons produced in p+p collisions. These measurements show no evidence of additional effects that could potentially arise from the more complex partonic environment present in proton-nucleus collisions.

关键词： Beam polarization Hadron-hadron interactions Polarization phenomena Relativistic heavy-ion collisions Mesons Pions Polarization Spin

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Transverse single-spin asymmetry of charged hadrons at forward and backward rapidity in polarized p+p, p+Al, and p+Au collisions at sNN=200 GeV

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Physical Review D 2023年第7期108卷 072016-072016页

Reported here are transverse single-spin asymmetries (AN) in the production of charged hadrons as a function of transverse momentum (pT) and Feynman-x (xF) in polarized p↑+p, p↑+Al, and p↑+Au collisions at sNN=200 GeV. The measurements have been performed at forward and backward rapidity (1.4<|η|<2.4) over the range of 1.5 GeV/c0) in p↑+p collisions, whereas the p↑+Al and p↑+Au results show smaller asymmetries. This finding provides new opportunities to investigate the origin of transverse single-spin asymmetries and a tool to study nuclear effects in p+A collisions.

关键词： Beam polarization Hadron-hadron interactions Polarization phenomena Relativistic heavy-ion collisions Hadrons Spin

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Deformation of Ferrogel Based on Carboxyl Methyl Cellulose (CMC)/Polyvinyl Alcohol (PVA) Hydrogel

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IOP Conference Series: Materials Science and engineering 2018年第1期367卷

作者： Sunaryono M. N. Kholifah Yudyanto A. Taufiq N. Mufti R. Wulandari Munasir M. Diantoro Department of Physics Faculty of Mathematics and Natural Sciences Universitas Negeri Malang Jl. Semarang No 5 Malang 65145 Indonesia Research Center of Minerals and Advanced Materials Faculty of Mathematics and Natural Sciences Universitas Negeri Malang Jl. Semarang 5 Malang 65145 Engineering Physics Study Program Faculty of Industrial Technology Institut Teknologi Bandung Jl. Ganesha 10 Bandung 40132 Indonesia Departement of Physics Faculty of Mathematics and Natural Sciences Universitas Negeri Surabaya Ketintang Surabaya 60231 Indonesia

Ferrogel is a smart material that combines the elastic properties of hydrogel and magnetic behavior from the filler of magnetic materials. In this work, ferrogel was fabricated through a freezing-thawing process with matrix materials of Carboxyl Methyl Cellulose (CMC)/Polyvinyl Alcohol (PVA) and a filler of magnetite. Magnetite nanoparticles were successfully synthesized by using a coprecipitation method at room temperature. The magnetite filler was investigated via X-ray Diffractometer (XRD) and Transmission Electron Microscopy (TEM), respectively, to analyze the structure and morphology of the magnetite. Based on the XRD analysis, the magnetite nanoparticle was matched by ICSD number of 9013529 and has an average particle size of about ~ 9.67 nm. This result is well confirmed by the TEM characterization that showed an average particle size of 9.32 nm. Furthermore, ferrogel was explored by using a Vibrating Sample Magnetometer (VSM) and an electromagnetic instrument to measure the magnetic properties and deformation of ferrogel, respectively. The VSM analysis showed that CMC/PVA hydrogel-based ferrogel has a superparamagnetic behavior due to its magnetization remanent and field coercivity that is close to zero. Interestingly, the deflection of Fe3O4/CMC/PVA ferrogel under the effect of the external magnetic field exhibited a good response. The deformation of ferrogel significantly increased from 4.9 cm to 7.0 cm as the filler of magnetite in the ferrogel was increasing from 14 wt% to 22 wt%. This phenomenon could be improved and explored to change the ferrogel into an artificial muscle by engineering the concentration and magnetite response in the CMC/PVA hydrogel.

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study of sustainable production in two-phase liquid dominated with steam cap underlying brine reservoir by numerical simulation

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IOP Conference Series: Earth and Environmental Science 2017年第1期103卷

作者： Heru Berian Pratama Nenny Miryani Saptadji Study Program of Geothermal Engineering Faculty of Mining and Petroleum Engineering Bandung Institute of Technology Indonesia Jl. Ganesha No.10 Bandung West Java Indonesia. 40132

The main issue in the management of the two-phase liquid-dominated geothermal field is rapid decline pressure in the reservoir so that the supply of steam to the power plant cannot be fulfilled. To understanding that, modelling and numerical simulation used reservoir simulators. The model is developed on liquid-dominated geothermal fields are assessed in various scenarios of production strategies (focusing only steam cap, brine reservoir and a combination) and injection strategies (deep and shallow injection, centered and dispersed injection), with the calculation using separated steam cycle method. The simulation results of the model for sustainable production are production 25% from steam cap + 75% from brine reservoir, dispersed and deep reinjection with make-up wells from steam cap results 9 make-up well number. The implementation of production-injection strategy needs to be planned right from the beginning of exploitation so that the strategy can adapt to changes in reservoir characteristics.

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Make-up wells drilling cost in financial model for a geothermal project

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IOP Conference Series: Earth and Environmental Science 2017年第1期103卷

作者： Fitri Oktaviani Purwaningsih Ruly Husnie Waldy Afuar Gugun Abdurrahman Study Program of Geothermal Engineering Faculty of Mining and Petroleum Bandung Institute of Technology Bandung Indonesia PT Geo Dipa Energy Jakarta Indonesia

After commissioning of a power plant, geothermal reservoir will encounter pressure decline, which will affect wells productivity. Therefore, further drilling is carried out to enhance steam production. Make-up wells are production wells drilled inside an already confirmed reservoir to maintain steam production in a certain level. Based on Sanyal (2004), geothermal power cost consists of three components, those are capital cost, O&M cost and make-up drilling cost. The make-up drilling cost component is a major part of power cost which will give big influence in a whole economical value of the project. The objective of this paper it to analyse the make-up wells drilling cost component in financial model of a geothermal power project. The research will calculate make-up wells requirements, drilling costs as a function of time and how they influence the financial model and affect the power cost. The best scenario in determining make-up wells strategy in relation with the project financial model would be the result of this research.

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Probabilistic approach: back pressure turbine for geothermal vapor-dominated system

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IOP Conference Series: Earth and Environmental Science 2017年第1期103卷

作者： Angga Alfandi Ahmad Fransiscus Xaverius Guwowijoyo Heru Berian Pratama Geothermal Engineering Study Program Faculty of Mining and Petroleum Bandung Institute of Technology Jl. Ganesha No.10 Bandung Indonesia 40132

Geothermal bussiness nowadays needs to be accelerated in a way that profit can be obtained as soon as reasonable possible. One of the many ways to do this is by using one of geothermal wellhead generating unit (GWGU), called backpressure turbine. Backpressure turbine can be used in producing electricity as soon as there is productive or rather small-scale productive well existed after finished drilling. In a vapor dominated system, steam fraction in the wellhead capable to produce electricity based on each well productivity immediately. The advantage for using vapor dominated system is reduce brine disposal in the wellhead so it will be a cost benefit in operation. The design and calculation for backpressure turbine will use probablistic approach with Monte Carlo simulation. The parameter that will be evaluated in sensitivity would be steam flow rate, turbine inlet pressure, and turbine exhaust pressure/atmospheric pressure. The result are probability for P10, P50, and P90 of gross power output which are 1.78 MWe, 2.22 MWe and 2.66 Mwe respectively. Whereas the P10, P50, and P90 of SSC are 4.67 kg/s/MWe, 5.19 kg/s/MWe and 5.78 kg/s/MWe respectively.

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Contribution of student involvement in production/service unit and experience of industry practices to entrepreneurial attitude and the impact entrepeneurship readiness of vocational high school students of great Malang

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AIP Conference Proceedings 2017年第1期1887卷

作者： Halimahtus Mukminna Isnandar Muladi 1Vocational Education Study Program Postgraduate State University of Malang Malang Indonesia 2Department of Civil Engineering Faculty of Engineering State University of Malang Malang Indonesia 3Department of Electrical Engineering Faculty of Engineering State University of Malang Malang Indonesia

Purpose of this research was to determine the contribution of student involvement in production/ service unit (X1), experience of industry practices (X2), and entrepreneurial attitude (Y) towards readiness entrepreneurship (Z) of vocational student regional Malang. The design of the study using a quantitative approach. The samples used as many as 130 respondents. Instruments used for collecting data in the form of questionnaires. Data analysis included descriptive and test of hypothesis. The result showed: that the description of data on the level of student involvement in production/ service unit, experience of industry practices, entrepreneurial attitude and entrepreneurship readiness in the high category. The contribution student involvement in production/ service unit of entrepreneurial attitude of 10.6%. The contribution experience of industry practices of entrepreneurial attitude of 17.4%. The contribution student involvement in production/ service unit and experience of industry practices simultaneously to entrepreneurial attitude of 44.1%. The contribution student involvement in production/ service unit of readiness entrepreneurship of 4%. The contribution experience of industry practices of readiness entrepreneurship of 5%. The contribution entrepreneurial attitude of readiness entrepreneurship of 16%. Finally, the contribution student involvement in production/ service unit, experience of industry practices, and entrepreneurial attitude simultaneously to readiness entrepreneurship of 50.3%.

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Hearing loss prevalence and years lived with disability, 1990-2019: Findings from the Global Burden of Disease study 2019

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The Lancet 2021年第10278期397卷 996-1009页

作者： Haile, Lydia M. Kamenov, Kaloyan Briant, Paul Svitil Orji, Aislyn U. Steinmetz, Jaimie D. Abdoli, Amir Abdollahi, Mohammad Abu-Gharbieh, Eman Afshin, Ashkan Ahmed, Haroon Rashid, Tarik Ahmed Akalu, Yonas Alahdab, Fares Alanezi, Fahad Mashhour Alanzi, Turki M. Al Hamad, Hanadi Ali, Liaqat Alipour, Vahid Al-Raddadi, Rajaa M. Amu, Hubert Arabloo, Jalal Arab-Zozani, Morteza Arulappan, Judie Ashbaugh, Charlie Atnafu, Desta Debalkie Babar, Zaheer-Ud-Din Baig, Atif Amin Banik, Palash Chandra Bärnighausen, Till Winfried Barrow, Amadou Bender, Rose G. Bhagavathula, Akshaya Srikanth Bhardwaj, Nikha Bhardwaj, Pankaj Bibi, Sadia Bijani, Ali Burkart, Katrin Cederroth, Christopher R. Charan, Jaykaran Choudhari, Sonali Gajanan Chu, Dinh-Toi Couto, Rosa A.S. Dagnew, Amare Belachew Dagnew, Baye Dahlawi, Saad M.A. Dai, Xiaochen Dandona, Lalit Dandona, Rakhi Desalew, Assefa Dhamnetiya, Deepak Dhimal, Mandira Lamichhane Dhimal, Meghnath Doyle, Kerrie E. Duncan, Bruce B. Ekholuenetale, Michael Filip, Irina Fischer, Florian Franklin, Richard Charles Gaidhane, Abhay Motiramji Gaidhane, Shilpa Gallus, Silvano Ghamari, Farhad Ghashghaee, Ahmad Ghozali, Ghozali Gilani, Syed Amir Glǎvan, Ionela-Roxana Golechha, Mahaveer Goulart, Barbara Niegia Garcia Gupta, Veer Bala Gupta, Vivek Kumar Hamidi, Samer Hammond, Billy Randall Hay, Simon I. Hayat, Khezar Heidari, Golnaz Hoffman, Howard J. Hopf, Kathleen Pillsbury Hosseinzadeh, Mehdi Househ, Mowafa Hussain, Rabia Hwang, Bing-Fang Iavicoli, Ivo Ibitoye, Segun Emmanuel Ilesanmi, Olayinka Stephen Irvani, Seyed Sina Naghibi Islam, Sheikh Mohammed Shariful Iwagami, Masao Jacob, Louis Jayapal, Sathish Kumar Jha, Ravi Prakash Jonas, Jost B. Kalhor, Rohollah Al-Salihi, Nawzad Kameran Kandel, Himal Kasa, Ayele Semachew Kayode, Gbenga A. Khalilov, Rovshan Khan, Ejaz Ahmad Khatib, Mahalaqua Nazli Kosen, Soewarta Koyanagi, Ai Kumar, G. Anil Landires, Ivan Lasrado, Savita Lim, Stephen S. Liu, Xuefeng Lobo, Stany W. Lugo, Alessandra Makki, Alaa Mendoza, Walter Mersha, Amanual Getnet Mihretie, Kebadnew Mulatu Institute for Health Metrics and Evaluation University of Washington Seattle WA United States Department of Noncommunicable Diseases World Health Organization (WHO) Geneva Switzerland Department of Parasitology and Mycology Jahrom University of Medical Sciences Jahrom Iran The Institute of Pharmaceutical Sciences (TIPS) Tehran University of Medical Sciences Tehran Iran School of Pharmacy Tehran University of Medical Sciences Tehran Iran Clinical Sciences Department University of Sharjah Sharjah United Arab Emirates Department of Health Metrics Sciences School of Medicine University of Washington Seattle WA United States Department of Biosciences COMSATS Institute of Information Technology Islamabad Pakistan Department of Computer Science and Engineering University of Kurdistan Hewler Erbil Iraq Department of Medical Physiology University of Gondar Gondar Ethiopia Mayo Evidence-based Practice Center Mayo Clinic Foundation for Medical Education and Research Rochester MN United States Imam Abdulrahman Bin Faisal University Dammam Saudi Arabia Health Information Management and Technology Department Dammam Saudi Arabia Geriatric and Long Term Care Department Hamad Medical Corporation Doha Qatar Rumailah Hospital Hamad Medical Corporation Doha Qatar Department of Biological Sciences National University of Medical Sciences (NUMS) Rawalpindi Pakistan Health Management and Economics Research Center Tehran Iran Department of Community Medicine King Abdulaziz University Jeddah Saudi Arabia Department of Population and Behavioural Sciences University of Health and Allied Sciences Ho Ghana Social Determinants of Health Research Center Birjand University of Medical Sciences Birjand Iran Department of Maternal and Child Health Sultan Qaboos University Muscat Oman Department of Health System and Health Economics Bahir Dar University Bahir Dar Ethiopia Department of Pharmacy University of Huddersfield Huddersfield United Kingdom Unit of Biochemistry Universiti

Background: Hearing loss affects access to spoken language, which can affect cognition and development, and can negatively affect social wellbeing. We present updated estimates from the Global Burden of Disease (GBD) study on the prevalence of hearing loss in 2019, as well as the condition's associated disability. Methods: We did systematic reviews of population-representative surveys on hearing loss prevalence from 1990 to 2019. We fitted nested meta-regression models for severity-specific prevalence, accounting for hearing aid coverage, cause, and the presence of tinnitus. We also forecasted the prevalence of hearing loss until 2050. Findings: An estimated 1·57 billion (95% uncertainty interval 1·51–1·64) people globally had hearing loss in 2019, accounting for one in five people (20·3% [19·5–21·1]). Of these, 403·3 million (357·3–449·5) people had hearing loss that was moderate or higher in severity after adjusting for hearing aid use, and 430·4 million (381·7–479·6) without adjustment. The largest number of people with moderate-to-complete hearing loss resided in the Western Pacific region (127·1 million people [112·3–142·6]). Of all people with a hearing impairment, 62·1% (60·2–63·9) were older than 50 years. The Healthcare Access and Quality (HAQ) Index explained 65·8% of the variation in national age-standardised rates of years lived with disability, because countries with a low HAQ Index had higher rates of years lived with disability. By 2050, a projected 2·45 billion (2·35–2·56) people will have hearing loss, a 56·1% (47·3–65·2) increase from 2019, despite stable age-standardised prevalence. Interpretation: As populations age, the number of people with hearing loss will increase. Interventions such as childhood screening, hearing aids, effective management of otitis media and meningitis, and cochlear implants have the potential to ameliorate this burden. Because the burden of moderate-to-complete hearing loss is concentrated in countries with low health-ca

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The electron-capture origin of supernova 2018zd

arXiv

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arXiv 2020年

作者： Hiramatsu, Daichi Howell, D. Andrew van Dyk, Schuyler D. Goldberg, Jared A. Maeda, Keiichi Moriya, Takashi J. Tominaga, Nozomu Nomoto, Ken'ichi Hosseinzadeh, Griffin Arcavi, Iair McCully, Curtis Burke, Jamison Bostroem, K. Azalee Valenti, Stefano Dong, Yize Brown, Peter J. Andrews, Jennifer E. Bilinski, Christopher Williams, G. Grant Smith, Paul S. Smith, Nathan Sand, David J. Anand, Gagandeep S. Xu, Chengyuan Filippenko, Alexei V. Bersten, Melina C. Folatelli, Gastón Kelly, Patrick L. Noguchi, Toshihide Itagaki, Koichi Las Cumbres Observatory 6740 Cortona Drive Suite 102 GoletaCA93117-5575 United States Department of Physics University of California Santa BarbaraCA93106-9530 United States Caltech/Spitzer Science Center Caltech IPAC Mailcode 100-22 PasadenaCA91125 United States Department of Astronomy Kyoto University Kitashirakawa-Oiwake-cho Sakyo-ku Kyoto606-8502 Japan University of Tokyo Institutes for Advanced Study University of Tokyo 5-1-5 Kashiwanoha Kashiwa Chiba277-8583 Japan National Astronomical Observatory of Japan National Institutes of Natural Sciences 2-21-1 Osawa Mitaka Tokyo181-8588 Japan School of Physics and Astronomy Faculty of Science Monash University ClaytonVIC3800 Australia Department of Physics Faculty of Science and Engineering Konan University 8-9-1 Okamoto Hyogo Kobe658-8501 Japan Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138-1516 United States School of Physics and Astronomy Tel Aviv University Tel Aviv69978 Israel CIFAR Azrieli Global Scholars Program CIFAR Toronto Canada Department of Physics University of California 1 Shields Ave DavisCA95616-5270 United States Mitchell Institute for Fundamental Physics and Astronomy Texas A&M University College StationTX77843 United States Steward Observatory University of Arizona 933 North Cherry Avenue TucsonAZ85721-0065 United States MMT Observatory P.O. Box 210065 TucsonAZ85721-0065 United States Infrared Processing and Analysis Center California Institute of Technology PasadenaCA91125 United States Institute for Astronomy University of Hawai'i 2680 Woodlawn Drive HonoluluHI96822 United States Media Arts and Technology University of California Santa BarbaraCA93106-6065 United States Department of Astronomy University of California BerkeleyCA94720-3411 United States Miller Institute for Basic Research in Science University of California BerkeleyCA94720 United States CONICET Argentina Facultad de Ciencias Astronómi

In the transitional mass range (∼ 8-10 solar masses) between white dwarf formation and iron core-collapse supernovae, stars are expected to produce an electron-capture supernova. Theoretically, these progenitors are thought to be super-asymptotic giant branch stars with a degenerate O+Ne+Mg core, and electron capture onto Ne and Mg nuclei should initiate core collapse1,2,3,4. However, no supernovae have unequivocally been identified from an electron-capture origin, partly because of uncertainty in theoretical predictions. Here we present six indicators of electron-capture supernovae and show that supernova 2018zd is the only known supernova having strong evidence for or consistent with all six: progenitor identification, circumstellar material, chemical composition5,6,7, explosion energy, light curve, and nucleosynthesis8,9,10,11,12. For supernova 2018zd, we infer a super-asymptotic giant branch progenitor based on the faint candidate in the pre-explosion images and the chemically-enriched circumstellar material revealed by the early ultraviolet colours and flash spectroscopy. The light-curve morphology and nebular emission lines can be explained by the low explosion energy and neutron-rich nucleosynthesis produced in an electron-capture supernova. This identification provides insights into the complex stellar evolution, supernova physics, cosmic nucleosynthesis, and remnant populations in the transitional mass range. Copyright © 2020, The Authors. All rights reserved.

关键词： Supernovae

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