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Monthly Notices of the Royal Astronomical Society 2021年第3期506卷 4446-4446页

作者： Chen, Hai-Liang Tauris, Thomas M Han, Zhanwen Chen, Xuefei Yunnan Observatories Chinese Academy of Sciences (CAS) Kunming 650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650011 China Department of Physics and Astronomy Aarhus University Ny Munkegade 120 DK-8000 Aarhus C Denmark Aarhus Institute of Advanced Studies (AIAS) Aarhus University Høegh-Guldbergs Gade 6B DK-8000 Aarhus C Denmark University of the Chinese Academy of Sciences Yuquan Road 19 Shijingshan Block Beijing 100049 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing 100012 China

Optical and Near-infrared Observations of SN 2023ixf for over 600 days after the Explosion

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arXiv 2025年

作者： Li, Gaici Wang, Xiaofeng Yang, Yi Pastorello, A. Reguitti, A. Valerin, G. Ochner, P. Cai, Yongzhi Iijima, T. Munari, U. Salmaso, I. Farina, A. Cazzola, R. Trabacchin, N. Fiscale, S. Ciroi, S. Mura, A. Siviero, A. Cabras, F. Pabst, M. Taubenberger, S. Vogl, C. Fiorin, C. Liu, Jialian Chen, Liyang Xiang, Danfeng Mo, Jun Li, Liping Wang, Zhenyu Zhang, Jujia Zhai, Qian Mirzaqulov, D.O. Ehgamberdiev, S.A. Filippenko, Alexei V. Yan, Shengyu Hu, Maokai Ma, Xiaoran Xia, Qiqi Gao, Xing Li, Wenxiong Department of Physics Tsinghua University Beijing100084 China Department of Astronomy University of California BerkeleyCA94720-3411 United States INAF - Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 Padova35122 Italy INAF - Osservatorio Astronomico di Brera Via E. Bianchi 46 LC Merate23807 Italy Dipartimento di Fisica e Astronomia Università Degli Studi di Padova PD Padova35121 Italy 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 INAF-Osservatorio Astronomico di Capodimonte Salita Moiariello 16 Napoli80131 Italy CISAS G. Colombo University of Padova via Venezia 15 Padova35131 Italy UNESCO Chair"Environment Resources and Sustainable Development" Department of Science and Technology Parthenope University of Naples Italy INAF Osservatorio Astronomico di Capodimonte Salita Moiariello 16 NaplesI-80131 Italy Max-Planck-Institut fur Astrophysik Karl-Schwarzschild Straße 1 Garching85748 Germany Beijing Planetarium Beijing Academy of Sciences and Technology Beijing100044 China University of Chinese Academy of Sciences Beijing100049 China Ulugh Beg Astronomical Institute Astronomy Street 33 Tashkent100052 Uzbekistan National University of Uzbekistan Tashkent100174 Uzbekistan School of Space Science and Technology Shandong University Shandong Weihai264209 China Xingming Observatory Urumqi830000 China National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China

Context. We present a comprehensive photometric and spectroscopic study of the nearby Type II supernova (SN) 2023ixf, with our extensive observations spanning the phases from ∼3 to over 600 days after the first light. Aims. The aim of this study is to obtain key information on the explosion properties of SN 2023ixf and the nature of its progenitor. Methods. The observational properties of SN 2023ixf are compared with those of a representative sample of Type IIP/IIL SNe to investigate commonalities and diversities. We conduct a detailed analysis of temporal evolution of major spectral features observed throughout different phases of the SN 2023ixf explosion. Several key interpretations are addressed through a comparison between the data and the model spectra predicted by non-local thermodynamic equilibrium (non-LTE) radiative-transfer calculations for progenitor stars within a range of zero-age main sequence (ZAMS) masses. Results. Our observations indicate that SN 2023ixf is a transitional SN that bridges the gap between Type IIP and IIL subclasses of H-rich SNe, characterized by a relatively short plateau ( 70 d) in the light curve. It shows a rather prompt spectroscopic evolution toward the nebular phase;emission lines of Na, O, H, and Ca in nebular spectra all exhibit multipeak profiles, which might be attributed to bipolar distribution of the ejecta. In particular, the Hα profile can be separated into two central peaked components (with a velocity of about 1500 km s−1) that is likely due to nickel-powered ejecta and two outer peak/box components (with a velocity extending up to ∼ 8000 km s−1) that can arise from interaction of the outermost ejecta with a circumstellar shell at a distance of ∼ 6.2 × 1015 cm. The nebular-phase spectra of SN 2023ixf show good agreement with those predicted by a non-LTE radiative-transfer code for progenitor stars with a ZAMS mass ranging from 15 to 19 M☉. A distance D = 6.35+−00.3139 Mpc is estimated for M101 based on the expanding

关键词： Supernovae

Convective overshooting in sdB stars using the k-ω model

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arXiv 2018年

作者： Li, Yan Chen, Xing-hao Xiong, He-ran Guo, Jun-jun Chen, Xue-fei Han, Zhan-wen Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing100012 China University of Chinese Academy of Sciences Beijing100049 China

Mixing in the convective core is quite uncertain in core helium burning stars. In order to explore the overshooting mixing beyond the convective core, we incorporated the k-ω proposed by Li (2012, 2017) into MESA, and investigated the overshooting mixing in evolution of sdB models. We found that the development of the convective core can be divided into three stages. When the radiative temperature gradient ∇rad monotonically decreases from the stellar center, the overshooting mixing presents a behaviour of exponential decay similar with Herwig (2000), and the overshooting distance is to make ∇rad ∇ad at the boundary of the convective core, in agreement with the prediction of the self-driving mechanism Castellani, Giannone & Renzini (1971a). When the radiative temperature gradient ∇rad shows a minimum value in the convective core, the convective core may be divided into two convection zones if the minimum value of ∇rad is smaller than the adiabatic temperature gradient ∇ad. For the single-zone case, the overshooting mixing still shows an exponential decay behaviour, but the overshooting distance is much smaller than in the initial stage. For the double-zone case, the overshooting mixing is similar to that of the single-case beyond the convective core, while it almost stops on both sides of the above convective shell. Our overshooting mixing scheme is similar to the maximal overshoot scheme of Constantino et al. (2015). In the final stage, continuous injection of fresh helium into the convective core by the overshooting mixing happens, which is similar to the"core breathing pulses" (Sweigart & Demarque 1973;Castellani et al. 1985). Copyright © 2018, The Authors. All rights reserved.

关键词： Mixing

Observations of the Very Young Type Ia Supernova 2019np with Early-excess Emission

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arXiv 2022年

作者： Sai, Hanna Wang, Xiaofeng Elias-Rosa, Nancy Yang, Yi Zhang, Jujia Lin, Weili Mo, Jun Piro, Anthony L. Zeng, Xiangyun Andrea, Reguitti Brown, Peter Burns, Christopher R. Cai, Yongzhi Fiore, Achille Hsiao, Eric Y. Isern, Jordi Itagaki, K. Li, Wenxiong Li, Zhitong Pessi, Priscila J. Phillips, M.M. Schuldt, Stefan Shahbandeh, Melissa Stritzinger, Maximilian D. Tomasella, Lina Vogl, Christian Wang, Bo Wang, Lingzhi Wu, Chengyuan Yang, Sheng Zhang, Jicheng Zhang, Tianmeng Zhang, Xinghan Tsinghua University Beijing100084 China Beijing Planetarium Beijing Academy of Science and Technology Beijing100044 China INAF - Osservatorio Astronomico di Padova Vicolo dell'Osservatorio 5 Padova35122 Italy Campus UAB Carrer de Can Magrans s/n Barcelona08193 Spain Department of Astronomy University of California BerkeleyCA94720-3411 United States Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China Carnegie Observatories 813 Santa Barbara Street PasadenaCA91101 United States Center for Astronomy and Space Sciences China Three Gorges University Yichang443000 China Departamento de Ciencias Físicas Universidad Andrés Bello Avda. República 252 Santiago8320000 Chile Millennium Institute of Astrophysics Nuncio Monsenor Sótero Sanz 100 Providencia Santiago8320000 Chile George P. and Cynthia Woods Mitchell Institute for Fundamental Physics & Astronomy Texas A. & M. University 4242 TAMU College StationTX77843 United States Department of Physics Florida State University 77 Chieftan Way TallahasseeFL32306 United States c/Gran Capitá 2-4 Edif. Nexus 201 Barcelona08034 Spain Itagaki Astronomical Observatory Yamagata Yamagata990-2492 Japan The School of Physics and Astronomy Tel Aviv University Tel Aviv69978 Israel Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China School of Astronomy and Space Science University of Chinese Academy of Sciences Beijing101408 China Facultad de Ciencias Astronómicas y Geofísicas Universidad Nacional de La Plata Paseo del Bosque S/N La PlataB1900FWA Argentina Carnegie Observatories Las Campanas Observatory Colina El Pino Casilla 601 Chile Max-Planck-Institut für Astrophysik Karl-Schwarzschild Str. 1 G

Early-time radiative signals from type Ia supernovae (SNe Ia) can provide important constraints on the explosion mechanism and the progenitor system. We present observations and analysis of SN 2019np, a nearby SN Ia discovered within 1-2 days after the explosion. Follow-up observations were conducted in optical, ultraviolet, and near-infrared bands, covering the phases from ∼ −16.7 days to ∼+367.8 days relative to its B−band peak luminosity. The photometric and spectral evolutions of SN 2019np resembles the average behavior of normal SNe Ia. The absolute B-band peak magnitude and the post-peak decline rate are Mmax(B) =−19.52 ± 0.47 mag and ∆m15(B) =1.04±0.04 mag, respectively. No Hydrogen line has been detected in the near-infrared and nebular-phase spectra of SN 2019np. Assuming that the 56Ni powering the light curve is centrally located, we find that the bolometric light curve of SN 2019np shows a flux excess up to 5.0% in the early phase compared to the radiative diffusion model. Such an extra radiation perhaps suggests the presence of an additional energy source beyond the radioactive decay of central nickel. Comparing the observed color evolution with that predicted by different models such as interactions of SN ejecta with circumstellar matter (CSM)/companion star, a double-detonation explosion from a sub-Chandrasekhar mass white dwarf (WD), and surface 56Ni mixing, the latter one is favored. © 2022, CC BY.

关键词： Supernovae

Overshooting in the core helium burning stage of a 30Mostar using the k-ω model

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arXiv 2018年

作者： Li, Yan Chen, Xing-Hao Chen, Hai-Liang Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing100012 China University of Chinese Academy of Sciences Beijing100049 China

Overshooting and semiconvection are among the most uncertainties in the evolution of massive stars. Complete mixing over a certain distance beyond the convective boundary (Stothers & Chin 1985) and an exponentially decaying diffusion outside the convection zone (Herwig 2000) are commonly adopted for the overshoot mixing. Recently, Li (2012, 2017) developed the k-ω model, which can be used in both convection zones and overshooting regions. We incorporated it in calculations of 30Mostellar models. We find that in the main sequence stage, models with the k-ω model are almost identical to models with complete mixing in the overshooting region beyond the convective core, and the overshooting in the k-ω model is equivalent to an overshooting distance of about 0.15HP . In the post main sequence stage, we find that the overshooting below the bottom of the intermediate convection zone beyond the hydrogen-burning shell can significantly restrict the size of the hydrogendepleted core, and can penetrate effectively into the hydrogen-burning shell. These two effects are crucial for the evolution of the core helium burning stage. During the core helium burning stage, we find that the overshooting model based on the k-ω model results in a similar complete mixing region but a much wider partial mixing region than the overshooting model based on Herwig (2000). In particular, the overshooting distance in the core helium burning stage may be significantly smaller than that in the main sequence phase for massive stars. Copyright © 2018, The Authors. All rights reserved.

关键词： Mixing

Sn 2018hti: A nearby superluminous supernova discovered in a metal-poor galaxy

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arXiv 2020年

作者： Lin, W.L. Wang, X.F. Li, W.X. Zhang, J.J. Mo, J. Sai, H.N. Zhang, X.H. Filippenko, A.V. Zheng, W.K. Brink, T.G. Baron, E. DerKacy, J.M. Ehgamberdiev, S.A. Mirzaqulov, D. Li, X. Zhang, J.C. Yan, S.Y. Xi, G.B. Hsiao, Y. Zhang, T.M. Wang, L.J. Liu, L.D. Xiang, D.F. Wu, C.Y. Rui, L.M. Chen, Z.H. Tsinghua University Beijing100084 China Beijing Planetarium Beijing Academy of Science and Technology Beijing100044 China Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China Department of Astronomy University of California BerkeleyCA94720-3411 United States Miller Institute for Basic Research in Science University of California BerkeleyCA94720 United States Homer L. Dodge Department of Physics and Astronomy University of Oklahoma NormanOK73019 United States Ulugh Beg Astronomical Institute Uzbekistan Academy of Sciences Uzbekistan Tashkent100052 Uzbekistan Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing10101 China School of Astronomy and Space Science University of Chinese Academy of Sciences Beijing101408 China Astroparticle Physics Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Department of Astronomy Beijing Normal University Beijing100875 China

SN 2018hti is a Type I superluminous supernova (SLSN I) with an absolute g-band magnitude of −22.2 at maximum brightness, discovered in a metal-poor galaxy at a redshift of 0.0612. We present extensive photometric and spectroscopic observations of this supernova, covering the phases from ∼ −35 days to more than +340 days from the r-band maximum. Combining our BVgri-band photometry with Swift UVOT optical/ultraviolet photometry, we calculated the peak luminosity as ∼ 3.5 × 1044 erg s−1. Modeling the observed light curve reveals that the luminosity evolution of SN 2018hti can be produced by an ejecta mass of 5.8 M and a magnetar with a magnetic field of B = 1.8 × 1013 G having an initial spin period of P0 = 1.8 ms. Based on such a magnetar-powered scenario and a larger sample, a correlation between the spin of the magnetar and the kinetic energy of the ejecta can be inferred for most SLSNe I, suggesting a self-consistent scenario. Like for other SLSNe I, the host galaxy of SN 2018hti is found to be relatively faint (Mg = −17.75 mag) and of low metallicity (Z = 0.3 Z ), with a star-formation rate of 0.3 M yr−1. According to simulation results of single-star evolution, SN 2018hti could originate from a massive, metal-poor star with a zero-age main sequence (ZAMS) mass of 25–40 M , or from a less massive rotating star with MZAMS ≈ 16–25 M . For the case of a binary system, its progenitor could also be a star with MZAMS & 25 M . Copyright © 2020, The Authors. All rights reserved.

关键词： Luminance

Variations of the mixing character of dipolar mixed modes in red giant stars

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arXiv 2020年

作者： Jiang, C. Cunha, M. Christensen-Dalsgaard, J. Zhang, Q.S. School of Physics and Astronomy Sun Yat-Sen University No. 135 Xingang Xi Road Guangzhou510275 China Instituto de Astrofísica e Ciências do Espaço Universidade do Porto CAUP Rua das Estrelas PortoPT4150-762 Portugal School of Physics and Astronomy University of Birmingham BirminghamB15 2TT United Kingdom Stellar Astrophysics Centre Department of Physics and Astronomy Aarhus University Ny Munkegade 120 Aarhus CDK-8000 Denmark Yunnan Observatories 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 Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China University of Chinese Academy of Sciences Beijing100049 China

Thanks to the high quality data of space missions, the detection of mixed modes has become possible in numerous stars. In this work, we investigate how the mixing character of dipolar mixed modes changes with stellar evolution, as well as with frequency within each stellar model. This is achieved by monitoring the variations in the coupling strength and the period spacing of dipolar mixed modes in red-giant models. These parameters are measured by fitting the asymptotic expansion of mixed modes to the model frequencies of a grid of red-giant models with masses between 1.0 and 2.0 Mo and three different chemical abundances. The coupling strength and the period spacing decrease with stellar evolution. We find that the slopes of their decreasing trends depend on the radial order of the pressure mode component. A non-negligible increase of the coupling strength with frequency by up to around 40% is found in the observable frequency range for a set of red-giant models. On the contrary, no significant changes of the period spacing with frequency are found. The changes in the mixing character of the modes are in most cases affected by the model mass and metallicity. Buoyancy glitches also have an impact on the mixing character. Significant fluctuations in the estimated coupling strength and period spacing are found for models approaching the luminosity bump, if the glitch impact of the frequencies is not considered in the applied asymptotic expansion. Copyright © 2020, The Authors. All rights reserved.

关键词： Giant stars

Study of photometric phase curve:assuming a cellinoid ellipsoid shape for asteroid(106)Dione

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Research in Astronomy and Astrophysics 2017年第9期17卷 61-70页

作者： Yi-Bo Wang Xiao-Bin Wang Donald E Pray Ao Wang Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100012China Sugarloaf Mountain Observatory South DeerfieldMA 01373USA

We carried out new photometric observations of asteroid （106） Dione at three apparitions （2004, 2012 and 2015） to understand its basic physical properties. Based on a new brightness model, new photometric observational data and published data of （106） Dione were analyzed to characterize the morphology of Dione＇s photometric phase curve. In this brightness model, a cellinoid ellipsoid shape and three-parameter （H, G1, G2） magnitude phase function system were involved. Such a model can not only solve the phase function system parameters of （106） Dione by considering an asymmetric shape of an asteroid, but also can be applied to more asteroids, especially those without enough photometric data to solve the convex shape. Using a Markov Chain Monte Carlo （MCMC） method, Dione＇s absolute magnitude of H = 7.66＋0.03-0.03 mag, and phase function parameters G1 = 0.682＋0.077-0.077 and G2 = 0.081＋0.042-0.042 were obtained. Simultaneously, Dione＇s simplistic shape, orientation of pole and rotation period were also determined preliminarily.

关键词： asteroids general photometric phase curve -- asteroids individual （106） Dione - techniques： photometric - Markov Chain Monte Carlo method

Probing the Final-stage Progenitor evolution for Type IIP Supernova 2017eaw in NGC 6946

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arXiv 2019年

作者： Rui, Liming Wang, Xiaofeng Mo, Jun Xiang, Danfeng Zhang, Jujia Maund, Justyn R. Gal-Yam, Avishy Wang, Lifan Zhang, Tianmeng Physics Department and Tsinghua Center for Astrophysics Tsinghua University Beijing100084 China Yunnan Observatories Chinese Academy of Sciences Kunming650011 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China Department of Physics and Astronomy University of Sheffield Hicks Building Hounsfield Road SheffieldS3 7RH United Kingdom Department of Particle Physics and Astrophysics Weizmann Institute of Sciencem Rehovot76100 Israel Physics and Astronomy Department Texas A&M University College StationTX77843 United States Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100012 China

We presented a detailed analysis of progenitor properties of type IIP supernova 2017eaw in NGC 6946, based on the pre-explosion images and early-time observations obtained immediately after the explosion. An unusually red star, with MF814W = −6.9 mag and mF606W− mF814W =2.9±0.2 mag, can be identified at the SN position in the pre-discovery Hubble Space Telescope(HST) images taken in 2016. The observed spectral energy distribution of this star, covering the wavelength of 0.6-2.0 µm, matches that of an M4-type red supergiant (RSG) with a temperature of about 3550 K. These results suggest that SN 2017eaw has a RSG progenitor with an initial mass of 12±2 M. The absolute F814W-band magnitude of this progenitor star is found to evolve from −7.2 mag in 2004 to −6.9 mag in 2016. Such a dimming effect is, however, unpredicted for a RSG in its neon/oxygen burning phase when its luminosity should modestly increase. The spectrum of SN 2017eaw taken a few hours after discovery clearly shows a narrow Hα emission feature blueshifted by ∼160 km s−1. This narrow component disappeared in the spectrum taken two days later, suggesting the presence of a circumstellar material (CSM) shell (i.e., at a distance of 14 cm). Combining the inferred distance with the expansion velocity of the CSM, we suggest that the progenitor of SN 2017eaw should have experienced violent mass loss at about 1-2 years prior to explosion, perhaps invoked by pulsational envelop ejection. This mechanism may help explain its luminosity decline in 2016 as well as the lack of detections of RSGs with initial mass in the range of 17 M Copyright © 2019, The Authors. All rights reserved.

关键词： Supernovae

Rates and delay times of Type Ia supernovae in the helium-enriched main-sequence donor scenario

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arXiv 2018年

作者： Liu, Zheng-Wei Stancliffe, Richard J. Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Cas Kunming650216 China Center for Astronomical Mega-Science Cas Beijing100012 China Argelander-Institut für Astronomie Auf dem Hügel 71 BonnD-53121 Germany

The nature of the progenitors of Type Ia supernovae (SNe Ia) remains a mystery. Comparing theoretical rates and delay-time distributions of SNe Ia with those inferred observationally can constrain their progenitor models. In this work, taking thermohaline mixing into account in the helium-enriched main-sequence (HEMS) donor scenario, we address rates and delay times of SNe Ia in this channel by combining the results of self-consistent binary evolution calculations with population synthesis models. We find that the Galactic SN Ia rate from the HEMS donor scenario is around 0.6-1.2 × 10-3yr-1, which is about 30% of the observed rate. Delay times of SNe Ia in this scenario cover a wide range of 0.1-1.0Gyr. We also present the pre-explosion properties of companion stars in the HEMS donor scenario, which will be helpful for placing constraints on SN Ia progenitors through analyzing their pre-explosion images. Copyright © 2018, The Authors. All rights reserved.

关键词： Helium