检索结果-内蒙古大学图书馆

arXiv 2019年

作者： Zhou, X. Soonthornthum, B. P.O. Box 110 Kunming650216 China National Astronomical Research Institute of Thailand 260 Moo 4 T. Donkaew A. MaerimChiangmai50180 Thailand Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences P. O. Box 110 Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang Dis-trict Beijing100012 China

Multi-color light curves of V1197 Her were obtained with the 2.4 meter optical telescope at Thai National Observatory and the Wilson-Devinney (W-D) program is used to model the observational light curves. The photometric solutions reveal that V1197 Her is a W-subtype shallow contact binary system with a mass ratio of q = 2.61 and fill-out factor to be f = 15.7 %. The temperature difference between the primary star and secondary star is only 140K in spite of the low degree of contact, which means that V1197 Her is not only in geometrical contact configuration but also already under thermal contact status. The orbital inclination of V1197 Her is as high as i = 82.7◦, and the primary star is completely eclipsed at the primary minimum. The totally eclipsing characteristic implies that the determined physical parameters are highly reliable. The masses, radii and luminosities of the primary star (star 1) and secondary star (star 2) are estimated to be M1 = 0.30(1)Mo, M2 = 0.77(2)Mo, R1 = 0.54(1)Ro, R2 = 0.83(1)Ro, L1 = 0.18(1)Lo and L2 = 0.38(1)Lo. The evolutionary status of the two component stars are drawn in the H - R diagram, which shows that the less massive but hotter primary star is more evolved than the secondary star. The period of V1197 Her is decreasing continuously at a rate of dP/dt = −2.58×10−7day·year−1, which can be explained by mass transfer from the more massive star to the less massive one with a rate of dMdt2 = −1.61 × 10−7Mo/year. The light curves of V1197 Her is reported to have the O’Connell effect. Thus, a cool spot is added to the massive star to model the asymmetry on light curves. Copyright © 2019, The Authors. All rights reserved.

关键词： Photometry

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The outcomes of carbon-oxygen white dwarfs accreting CO-rich material

arXiv

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arXiv 2018年

作者： Wu, Chengyuan Wang, Bo Liu, Dongdong Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan Observatories CAS Kunming650216 China University of Chinese Academy of Sciences Beijing100049 China Centre for Astronomical Mega-Science CAS Beijing100012 China

The double-degeneratemodel, involving the merger of double carbon-oxygenwhite dwarfs (CO WDs), is one of the two classic models for the progenitors of type Ia supernovae (SNe Ia). Previous studies suggested that off-centre carbon burning would occur if the mass-accretion rate (Macc) is relatively high during the merging process, leading to the formation of oxygen-neon (ONe) cores that may collapse into neutron stars. However, the off-centre carbon burning is still incompletely understood, especially when the inwardly propagating burning wave reaches the centre. In this paper, we aim to investigate the propagating characteristics of burning waves and the subsequently evolutionary outcomes of these CO cores. We simulated the long-term evolution of CO WDs that accrete CO-rich material by employing the stellar evolution code MESA on the basis of the thick-disc assumption. We found that the final outcomes of CO WDs strongly depend on Macc(Moyr-1) based on the thick-disc assumption, which can be divided into four regions: (1) explosive carbon ignition in the centre, then SNe Ia (Macc-6);(2) OSi cores, then neutron stars (2.45 × 10-6. Macc -6);(3) ONe cores, then e-capture SNe (4.5 × 10-6 Macc-5);(4) off-centre oxygen and neon ignition, then off-centre explosion or Si-Fe cores (Macc 1.05 × 10-5). Our results indicate that the final fates of double CO WD mergers are strongly dependent on the merging processes (e.g. slow merger, fast merger, composite merger, violent merger, etc.). Copyright © 2018, The Authors. All rights reserved.

关键词： Carbon

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Doppler imaging and differential rotation of σ2Coronae Borealis using SONG

arXiv

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arXiv 2020年

作者： Xiang, Yue Gu, Shenghong Collier Cameron, A. Barnes, J.R. Christensen-Dalsgaard, J. Grundahl, F. Antoci, V. Andersen, M.F. Pallé, P.L. Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China School of Astronomy and Space Sciences University of Chinese Academy of Sciences Beijing101408 China School of Physics and Astronomy University of St Andrews FifeKY16 9SS United Kingdom Department of Physical Sciences Open University Walton Hall Milton KeynesMK7 6AA United Kingdom Department of Physics and Astronomy Aarhus University Ny Munkegade 120 AarhusDK-8000 Denmark Instituto de Astrofísica de Canarias La Laguna TenerifeE-38205 Spain Departamento de Astrofísica Universidad de la Laguna La Laguna TenerifeE-38205 Spain

We present new Doppler images of both components of the double-lined binary σ2CrB, based on the high-resolution spectroscopic data collected during 11 nights in 2015 March-April. The observed spectra form two independent data sets with sufficient phase coverage. We apply the least-squares deconvolution to all observed spectra to obtain high signal-to-noise mean profiles, from which we derive the Doppler images of both components of σ2CrB simultaneously. The surfaces of both F9 and G0 components are dominated by pronounced polar spots. The F9 component exhibits a weak spot at latitude 30° and its mid-to-low latitudes are relatively featureless. The G0 star shows an extended spot structure at latitude 30°, and its surface spot coverage is larger than that of the F9 star, which suggests a higher level of magnetic activity. With the cross-correlation method, we derive a solar-like surface differential rotation on the G0 star of cr2CrB for the first time, and the surface shear rate is ΔΩ = 0.180 + 0.004 rad d-1and a = ΔΩ/Ωeq= 0.032 + 0.001. We do not obtain a clear surface shear law for the F9 star due to the lack of mid-to-low latitude features, but detect a systematic longitude shift of high-latitude spots, which indicates a slower rotation with respect to the co-rotating frame. Copyright © 2020, The Authors. All rights reserved.

关键词： Stars

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Search for intra-day optical variability in γ-ray–loud blazars s5 0716+714 and 3c 273

arXiv

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arXiv 2019年

作者： Liu, H.T. Feng, Hai Cheng Xin, Y.X. Bai, J.M. Li, S.K. Wang, Fang Yunnan Observatories Chinese Academy of Sciences KunmingYunnan650011 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences KunmingYunnan650011 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China University of Chinese Academy of Sciences Beijing100049 China School of Physics and Space Science China West Normal University Nanchong637009 China

We present the photometric observations of blazars S5 0716+714 and 3C 273 with high temporal resolution (30–60s) in the I or R bands. The observations were performed with a 1.02 m optical telescope from 2007 March 07 to 2012 May 16. The F-test, one-way analysis of variance (ANOVA) test, and z-transformed discrete correlation function (ZDCF) cross-correlation zero lag test are used to search for intra-day variability (IDV). Four and five reliable IDVs survive three tests for S5 0716+714 and 3C 273, respectively. IDVs are found for S5 0716+714 and 3C 273. A flare on 2008 May 08 has ∆I ≈ 0.06±0.01 mag in a duration of 0.54 hr for S5 0716+714. A flare on 2011 May 10 shows ∆R ≈ 0.05±0.01 mag in a duration of 0.40 hr for 3C 273. Sharp dips appear on 2011 May 9 for 3C 273, and show ∆R ≈ 0.05±0.01 mag. Under the assumptions that the IDV is tightly connected to black hole mass, M•, and that the flare durations are representative of the minimum characteristic timescales, we can estimate upper bounds to M•. In the case of the Kerr black holes, M• . 108.91Mo and M• . 109.02Mo are given for S5 0716+714 and 3C 273, respectively. These mass measurements are consistent with those measurements reported in the literatures. Also, we discuss the origins of optical variations found in this work. Copyright © 2019, The Authors. All rights reserved.

关键词： Stars

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The fast rise of the unusual Type IIL/IIb SN 2018ivc

arXiv

引用

arXiv 2024年

作者： Reguitti, Andrea Dastidar, R. Pignata, G. Maeda, K. Moriya, T.J. Kuncarayakti, H. Rodríguez, Ó. Bersten, M. Anderson, J.P. Charalampopoulos, P. Fraser, M. Gromadzki, M. Young, D.R. Benetti, S. Cai, Y.-Z. Elias-Rosa, N. Lundqvist, P. Carini, R. Cosentino, S.P. Galbany, L. Gonzalez-Bañuelos, M. Gutiérrez, C.P. Kopsacheili, M. Pineda, J.A.G. Ramirez, M. MerateI-23807 Italy INAF – Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 PadovaI-35122 Italy Instituto de Astrofìsica Universidad Andres Bello Fernandez Concha 700 Las Condes RM Santiago8320000 Chile Nuncio Monseñor Sótero Sanz 100 Providencia RM Santiago8320000 Chile Instituto de Alta Investigación Universidad de Tarapacá Casilla 7D Arica Chile Department of Astronomy Kyoto University Kitashirakawa-Oiwake-cho Sakyo-ku Kyoto606-8502 Japan National Astronomical Observatory of Japan National Institutes of Natural Sciences Graduate Institute for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan School of Physics and Astronomy Monash University ClaytonVIC3800 Australia Department of Physics and Astronomy University of Turku TurkuFI-20014 Finland University of Turku FI-20014 Finland CCT-CONICET-UNLP. Paseo del Bosque S/N La PlataB1900FWA Argentina Facultad de Ciencias Astronómicas y Geofísicas Universidad Nacional de La Plata Paseo del Bosque S/N La PlataB1900FWA Argentina The University of Tokyo 5-1-5 Kashiwanoha Kashiwa Chiba277-8583 Japan European Southern Observatory Alonso de Córdova 3107 Casilla 19 Santiago8320000 Chile School of Physics O’Brien Centre for Science North University College Dublin Belfield Dublin 4 Ireland Astronomical Observatory University of Warsaw Al. Ujazdowskie 4 Warszawa00-478 Poland Astrophysics Research Centre School of Mathematics and Physics Queen’s University Belfast BelfastBT7 1NN United Kingdom Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China Campus UAB Carrer de Can Magrans s/n BarcelonaE-08193 Spain The Oskar Klein Centre Department of Astronomy Stockholm University AlbaNova StockholmSE-10691 Sweden I-00078 Italy Università d

We present an analysis of the photometric and spectroscopic dataset of the Type II supernova (SN) 2018ivc in the nearby (10 Mpc) galaxy Messier 77. Thanks to the high cadence of the CHASE survey, we observed the SN rising very rapidly by nearly three magnitudes in five hours (or 18 mag d−1). The r-band light curve presents four distinct phases: the maximum light is reached in just one day, then a first, rapid linear decline precedes a short-duration plateau. Finally, a long, slower linear decline lasted for one year. Following a radio rebrightening, we detected SN 2018ivc four years after the explosion. The early spectra show a blue, nearly featureless continuum, but the spectra evolve rapidly: after about 10 days a prominent Hα line starts to emerge, with a peculiar profile, but the spectra are heavily contaminated by emission lines from the host galaxy. He I lines, namely λλ5876,7065, are also strong. On top of the former, a strong absorption from the Na i doublet is visible, indicative of a non-negligible internal reddening. From its equivalent width, we derive a lower limit on the host reddening of AV 1.5 mag, while from the Balmer decrement and a match of the B − V colour curve of SN 2018ivc to that of the comparison objects, a host reddening of AV 3.0 mag is obtained. The spectra are similar to those of SNe II, but with strong He lines. Given the peculiar light curve and spectral features, we suggest SN 2018ivc could be a transitional object between the Type IIL and Type IIb SNe classes. In addition, we found signs of interaction with circumstellar medium in the light curve, making SN 2018ivc also an interacting event. Finally, we modelled the early multi-band light curves and photospheric velocity of SN 2018ivc to estimate the explosion and CSM physical parameters. Copyright © 2024, The Authors. All rights reserved.

关键词： Supernovae

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On the diversity of strongly-interacting Type IIn supernovae

arXiv

引用

arXiv 2024年

作者： Salmaso, I. Cappellaro, E. Tartaglia, L. Anderson, J.P. Benetti, S. Bronikowski, M. Cai, Y.-Z. Charalampopoulos, P. Chen, T.-W. Concepcion, E. Elias-Rosa, N. Galbany, L. Gromadzki, M. Gutiérrez, C.P. Kankare, E. Lundqvist, P. Matilainen, K. Mazzali, P.A. Moran, S. Müller-Bravo, T.E. Nicholl, M. Pastorello, A. Pessi, P.J. Pessi, T. Petrushevska, T. Pignata, G. Reguitti, A. Sollerman, J. Srivastav, S. Stritzinger, M. Tomasella, L. Valerin, G. INAF-Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 Padova35122 Italy INAF-Osservatorio Astronomico d’Abruzzo Via M. Maggini snc Teramo64100 Italy European Southern Observatory Alonso de Córdova 3107 Casilla 19 Santiago Chile Millennium Institute of Astrophysics MAS Nuncio Monsenor Sotero Sanz 100 Off. 104 Providencia Santiago Chile Center for Astrophysics and Cosmology University of Nova Gorica Vipavska 11c Ajdovščina5270 Slovenia Yunnan Observatories Chinese Academy of Sciences Kunming650216 China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China Department of Physics and Astronomy University of Turku Vesilinnantie 5 20500 Finland Graduate Institute of Astronomy National Central University 300 Jhongda Road Jhongli32001 Taiwan Campus UAB Carrer de Can Magrans s/n Barcelona08193 Spain Castelldefels Barcelona08860 Spain Astronomical Observatory University of Warsaw Al. Ujazdowskie 4 Warszawa00-478 Poland The Oskar Klein Centre Department of Astronomy Stockholm University AlbaNova Stockholm106 91 Sweden Nordic Optical Telescope Aarhus Universitet Rambla José Ana Fernández Pérez 7 local 5 San Antonio Breña Baja Santa Cruz TenerifeE-38711 Spain Tuorla Observatory Department of Physics and Astronomy University of Turku Vesilinnantie 5 Turku20014 Finland Astrophysics Research Institute Liverpool John Moores University ic2 146 Brownlow Hill LiverpoolL3 5RF United Kingdom Max-Planck Institut für Astrophysik Karl-Schwarzschild-Str. 1 Garching bei München85741 Germany Astrophysics Research Centre School of Mathematics and Physics Queens University Belfast BelfastBT7 1NN United Kingdom Instituto de Estudios Astrofísicos Facultad de Ingeniería y Ciencias Universidad Diego Portales Av. Ejército Libertador 441 Santiago Chile Instituto de Alta Investigación Universidad de Ta

Context. Massive stars experience strong mass-loss rates, producing a dense, H-rich circumstellar medium (CSM). After the explosion, the collision and continued interaction of the supernova (SN) ejecta with the CSM power the light curve through the conversion of kinetic energy into radiation. When the interaction is strong, the light curve shows a broad peak and high luminosity lasting for several months. Also the spectral evolution is slower, compared to non-interacting SNe. Energetic shocks between the ejecta and the CSM create the ideal conditions for particle acceleration and production of high-energy (HE) neutrinos above 1 TeV. Aims. We study four strongly-interacting Type IIn SNe: 2021acya, 2021adxl, 2022qml, and 2022wed to highlight their peculiar characteristics, derive the kinetic energy of the explosion and the characteristics of the CSM, infer clues on the possible progenitors and their environment and relate them to the production of HE neutrinos. Methods. We analysed spectro-photometric data of a sample of interacting SNe to determine their common characteristics and derive physical properties (radii and masses) of the CSM and ejecta kinetic energies to compare them to HE neutrino production models. Results. The SNe analysed in this sample exploded in dwarf, star-forming galaxies and they are consistent with energetic explosions and strong interaction with the surrounding CSM. For SNe 2021acya and 2022wed, we find high CSM masses and mass-loss rates, linking them to very massive progenitors. For SN 2021adxl, the spectral analysis and less extreme CSM mass suggest a stripped-envelope massive star as possible progenitor. SN 2022qml is marginally consistent with being a Type Ia thermonuclear explosion embedded in a dense CSM. The mass-loss rates for all SNe are consistent with the expulsion of several solar masses of material during eruptive episodes in the last few decades before the explosion. Finally, we find that the SNe in our sample are marginally co

关键词： Kinetic energy

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The W-subtype active contact binary PZ UMa with a possible more massive tertiary component

arXiv

引用

arXiv 2019年

Two sets of multiple-color (B,V,Rc,Ic) light curves of PZ UMa were observed in dependently with the 2.4 meter telescope at the Thai National Observatory and the 1 meter telescope at Yunnan Observatories. The light curves were analyzed with the Wilson-Devinney program and the two sets of light curves produced consistent results, which show that PZ UMa is a W-subtype contact binary with an extreme mass ratio (M1/M2 = 0.18). The basic physical parameters of PZ UMa were determined to be M2 = 0.77(2)M, M1 = 0.14(1)M, R2 = 0.92(1)R, R1 = 0.43(1)R, L2 = 0.46(2)L and L1 = 0.15(3)L. The orbital period analysis of PZ UMa revealed a 13.22 year periodicity, which implies that there may be a tertiary component orbiting around the binary system. The mass and orbital radius of the tertiary component were calculated to be M3 = 0.88M and a3 = 3.67AU, if the orbit was coplanar with the central binary system. It is interesting that the minimum mass of the tertiary was calculated to be M3min = 0.84M, which means the tertiary component is even larger than the primary star and the secondary one of PZ UMa. PZ UMa is a late-type contact binary with stellar activity. The O’Connell effect appeared on its light curves when it was observed on April 2016. However, the O’Connell effect reversed when the target was observed again on December 2016. The changes of the O’Connell effect in such a short time-scale strongly support the occurrence of rapidly changing magnetic activity on this W UMa binary. Copyright © 2019, The Authors. All rights reserved.

关键词： Observatories

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Detailed spectrophotometric analysis of the superluminous and fast evolving SN 2019neq

arXiv

引用

arXiv 2023年

作者： Fiore, Achille Benetti, Stefano Tartaglia, Leonardo Jerkstrand, Anders Salmaso, Irene Tomasella, Lina Morales-Garoffolo, Antonia Geier, Stefan Elias-Rosa, Nancy Cappellaro, Enrico Wang, Xiaofeng Mo, Jun Chen, Zhihao Yan, Shengyu Pastorello, Andrea Mazzali, Paolo A. Ciolfi, Riccardo Cai, Yongzhi Fraser, Morgan Gutiérrez, Claudia P. Karamehmetoglu, Emir Kuncarayakti, Hanindyo Moran, Shane Ochner, Paolo Reguitti, Andrea Reynolds, Thomas M. Valerin, Giorgio Institut für Theoretische Physik Goethe Universität Max-von-Laue-Str. 1 Frankfurt am Main60438 Germany INFN-TIFPA Trento Institute for Fundamental Physics and Applications Via Sommarive 14 TrentoI-38123 Italy INAF - Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 PadovaI-35122 Italy INAF - Osservatorio Astronomico d’Abruzzo via M. Maggini snc TeramoI-64100 Italy The Oskar Klein Centre Department of Astronomy Stockholm University AlbaNova StockholmSE-10691 Sweden Dipartimento di Fisica e Astronomia ‘G. Galilei’ Università di Padova Vicolo dell’Osservatorio 3 PadovaI-35122 Italy Department of Applied Physics School of Engineering University of Cádiz Campus of Puerto Real CádizE-11519 Spain Instituto de Astrofisíca de Canarias Tenerife Canary Islands La Laguna38200 Spain GRANTECAN Cuesta de San José s/n La Palma Breña Baja38712 Spain Campus UAB Carrer de Can Magrans s/n Barcelona08193 Spain Tsinghua University Beijing100084 China Beijing Planetarium Beijing Academy of Science and Technology Beijing100044 China Astrophysics Research Institute Liverpool John Moores University LiverpoolL3 5RF United Kingdom Max-Planck Institute for Astrophysics Garching Germany INFN – Sezione di Padova Via Francesco Marzolo 8 PadovaI-35131 Italy Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China School of Physics O’Brien Centre for Science North University College Dublin Belfield Dublin 4 Ireland Gran Capità 2-4 Edifici Nexus Desp. 201 BarcelonaE-08034 Spain Campus UAB Carrer de Can Magrans s/n BarcelonaE-08193 Spain Department of Physics and Astronomy Aarhus University Ny Munkegade 120 Aarhus CDK-8000 Denmark Department of Physics and Astronomy University of Turku Vesilinnantie 5 20500 Finland INAF - Osse

SN 2019neq was a very fast evolving superluminous supernova. At a redshift Z = 0.1059, its peak absolute magnitude was -21.5 ± 0.2 mag in g band. In this work, we present data and analysis from an extensive spectrophotometric follow-up campaign using multiple observational facilities. Thanks to a nebular spectrum of SN 2019neq, we investigated some of the properties of the host galaxy at the location of SN 2019neq and found that its metallicity and specific star formation rate are in a good agreement with those usually measured for SLSNe-I hosts. We then discuss the plausibility of the magnetar and the circumstellar interaction scenarios to explain the observed light curves, and interpret a nebular spectrum of SN 2019neq using published sumo radiative-transfer models. The results of our analysis suggest that the spindown radiation of a millisecond magnetar with a magnetic field B 6 × 1014 G could boost the luminosity of SN 2019neq. Copyright © 2023, The Authors. All rights reserved.

关键词： Supernovae

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Matter ejections behind the highs and lows of the transitional millisecond pulsar PSR J1023+0038

arXiv

引用

arXiv 2023年

作者： Baglio, M.C. Zelati, F. Coti Campana, S. Busquet, G. D’Avanzo, P. Giarratana, S. Giroletti, M. Ambrosino, F. Crespi, S. Zanon, A. Miraval Hou, X. Li, D. Li, J. Wang, P. Russell, D.M. Torres, D.F. Alabarta, K. Casella, P. Covino, S. Bramich, D.M. de Martino, D. Méndez, M. Motta, S.E. Papitto, A. Saikia, P. Vincentelli, F. Center for Astro Particle and Planetary Physics New York University Abu Dhabi P.O. Box 129188 Abu Dhabi United Arab Emirates INAF Osservatorio Astronomico di Brera Via Bianchi 46 LC MerateI-23807 Italy Campus UAB Carrer de Can Magrans s/n BarcelonaE-08193 Spain Carrer Gran Capità 2–4 BarcelonaE-08034 Spain c/ Martí Franquès 1 BarcelonaE-08028 Spain c/ Martí Franquès 1 BarcelonaE-08028 Spain INAF Istituto di Radioastronomia via Gobetti 101 BolognaI-40129 Italy Department of Physics and Astronomy University of Bologna via Gobetti 93/2 BolognaI-40129 Italy INAF Osservatorio Astronomico di Roma Via Frascati 33 RM Monteporzio CatoneI-00078 Italy INAF–Istituto di Astrofisica e Planetologia Spaziali Via Fosso del Cavaliere 100 RomeI-00133 Italy Sapienza Università di Roma Piazzale Aldo Moro 5 RomeI-00185 Italy ASI - Agenzia Spaziale Italiana Via del Politecnico snc RomeI-00133 Italy Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China National Astronomical Observatories Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100101 China University of Chinese Academy of Sciences Beijing100049 China Research Center for Intelligent Computing Platforms Zhejiang Laboratory Hangzhou311100 China CAS Key Laboratory for Research in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China Hefei China School of Astronomy and Space Science University of Science and Technology of China Hefei China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University Beijing102206 China Passeig Lluís Companys 23 BarcelonaE-08010 Spain Division of Engineering New York University Abu Dhabi P.O. Box 129188 Saadiyat Island Abu Dhabi United Arab Emirates INAF−-Osservatorio Astronomico di Capodimonte Salita Moiariello 16 NapoliI-80131 Italy Kaptey

Transitional millisecond pulsars are an emerging class of sources that link low-mass X-ray binaries to millisecond radio pulsars in binary systems. These pulsars alternate between a radio pulsar state and an active low-luminosity X-ray disc state. During the active state, these sources exhibit two distinct emission modes (high and low) that alternate unpredictably, abruptly, and incessantly. X-ray to optical pulsations are observed only during the high mode. The root cause of this puzzling behaviour remains elusive. This paper presents the results of the most extensive multi-wavelength campaign ever conducted on the transitional pulsar prototype, PSR J1023+0038, covering from the radio to X-rays. The campaign was carried out over two nights in June 2021 and involved 12 different telescopes and instruments, including XMM-Newton, HST, VLT/FORS2 (in polarimetric mode), ALMA, VLA, and FAST. By modelling the broadband spectral energy distributions in both emission modes, we show that the mode switches are caused by changes in the innermost region of the accretion disc. These changes trigger the emission of discrete mass ejections, which occur on top of a compact jet, as testified by the detection of at least one short-duration millimetre flare with ALMA at the high-to-low mode switch. The pulsar is subsequently re-enshrouded, completing our picture of the mode switches. © 2023, CC BY.

关键词： Pulsars

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Lijiang 2.4-meter Telescope and its Instruments∗

arXiv

引用

arXiv 2019年

作者： Wang, Chuan-Jun Bai, Jin-Ming Fan, Yu-Feng Mao, Jirong Chang, Liang Xin, Yu-Xin Zhang, Ju-Jia Lun, Bao-Li Wang, Jian-Guo Zhang, Xi-Liang Ying, Mei Lu, Kai-Xing Wang, Xiao-Li Ji, Kai-Fan Xiong, Ding-Rong Yu, Xiao-Guang Ding, Xu Ye, Kai Xing, Li-Feng Yi, Wei-Min Xu, Liang Zheng, Xiang-Ming Feng, Yuan-Jie He, Shou-Sheng Wang, Xue-Li Liu, Zhong Chen, Dong Xu, Jun Qin, Song-Nian Zhang, Rui-Long Tan, Hui-Song Li, Zhi Lou, Ke Li, Jian Liu, Wei-Wei Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang GuanduKunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China University of Chinese Academy of Sciences Beijing100049 China Astrophysics Center of Guangzhou University Guangzhou510006 China

Lijiang 2.4-meter Telescope(LJT), the largest common-purpose optical telescope in China, has been applied to the world-wide astronomers since 2008. It is located at Gaomeigu site, Lijiang Observatory(LJO), the southwest of China. The site has very good observational conditions. Since 10-year operation, several instruments have been equipped on the LJT. Astronomers can perform both photometric and spectral observations. The main scientific goals of LJT include photometric and spectral evolution of supernova, reverberation mapping of active galactic nucleus, physical properties of binary star and near-earth object(comet and asteroid), identification of exoplanet, and all kinds of transients. Until now, the masses of 41 high accretion rate black holes have been measured, and more than 168 supernova have been identified by the LJT. More than 190 papers related to the LJT have been published. In this paper, the general observation condition of the Gaomeigu site is introduced at first. Then, the LJT structure is described in detail, including the optical, mechanical, motion and control system. The specification of all the instruments, and some detailed parameters of the YFOSC is also presented. Finally, some important scientific results and future expectations Copyright © 2019, The Authors. All rights reserved.

关键词： Photometry

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