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NSVS 01286630: A detached binary with a close-in companion

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arXiv 2018年

作者： Zhang, Bin Qian, Sheng-bang Liao, Wen-ping Zhu, Li-ying Dong, Ai-jun Zhi, Qi-jun P. O. Box 110 Kunming650216 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences P. O. Box 110 Kunming650216 China University of Chinese Academy of Sciences Yuquan Road 19# Sijingshang Block Beijing100049 China School of Physics and Electronic Science Guizhou Normal University Guiyang550001 China

New photometric observations of NSVS 01286630 were performed and two sets of four-color (B, V, Rc, Ic) light curves (LCs) were obtained. Using the 2013 version of the Wilson-Devinney (W − D) code, we analyzed these data. The photometric solutions reveal that NSVS 01286630 is an active detached eclipsing binary (EB) with a high orbit inclination (nearly 90◦). Remarkably, the temperature of the primary component (the hotter star) is higher than the secondary one, but, the value of mass ratio q(MM21 ) for NSVS 0128663 is more than 1, which can be explained that the surface of the secondary component of NSVS 01286630 is covered with big cool-star-spots. Based on our new CCD mid-eclipse times and the data published until now, the variations of the mid-eclipse times were reanalyzed in detail using a weighted least-squares method. It is discovered that the (O − C) diagram of the system shows a cyclic oscillation with a period of 3.61 yr and an amplitude of 0.001 days. The cyclic variation may be caused by the light travel time effect (LTTE) due to the presence of a third companion, whose mass we calculated is M3sin(i3)=0.11 Mo. The third body may affect the orbital evolution of the central binary system by transferring the angular momentum. Copyright © 2018, The Authors. All rights reserved.

关键词： Photometry

Active galactic nuclei with ultra-fast outflows monitoring project: The broad-line region of MRK 79 as a disk wind

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arXiv 2019年

作者： Lu, Kai-Xing Bai, Jin-Ming Zhang, Zhi-Xiang Du, Pu Hu, Chen Kim, Minjin Wang, Jian-Min Ho, Luis C. Li, Yan-Rong Bian, Wei-Hao Yuan, Ye-Fei Xiao, Ming Feng, Hai-Cheng Wang, Jian-Guo Xu, Liang Ding, Xu Yu, Xiao-Guang Xin, Yu-Xin Ye, Kai Wang, Chuan-Jun Lun, Bao-Li Zhang, Ju-Jia Zhang, Xi-Liang Ji, Kai-Fan Fan, Yu-Feng Chang, Liang Yunnan Observatories Chinese Academy of Sciences Kunming650011 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650011 China Department of Astronomy Xiamen University Xiamen Fujian361005 China Key Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences 19B Yuquan Road Beijing100049 China Department of Astronomy and Atmospheric Sciences Kyungpook National University Daegu702-701 Korea Republic of Korea Astronomy and Space Science Institute Daejeon305-348 Korea Republic of Kavli Institute for Astronomy and Astrophysics Peking University Beijing100871 China Department of Astronomy School of Physics Peking University Beijing100871 China Physics Department Nanjing Normal University Nanjing210097 China Department of Astronomy University of Science and Technology of China Hefei230026 China

We developed a spectroscopic monitoring project to investigate the kinematics of the broad-line region (BLR) in active galactic nuclei (AGN) with ultra-fast outflows (UFOs). Mrk 79 is a radio-quiet AGN with UFOs and warm absorbers, had been monitored by three reverberation mapping (RM) campaigns, but its BLR kinematics is not understood yet. In this paper, we report the results from a new RM-campaign of Mrk 79, which was undertaken by Lijiang 2.4-m telescope. Mrk 79 is seeming to come out the faint state, the mean flux approximates a magnitude fainter than historical record. We successfully measured the lags of the broad emission lines including Hβ λ4861, Hγ λ4340, He II λ4686 and He I λ5876 with respect to the varying AGN continuum. Based on the broad Hβ λ4861 line, we measured black hole (BH) mass of M• = 5.13+1−1..5755×107M, estimated accretion rates of M• = (0.05 ± 0.02) LEdd c−2, indicating that Mrk 79 is a sub-Eddington accretor. We found that Mrk 79 deviates from the canonical Radius−Luminosity relationship. The marginal blueshift of the broad He II λ4686 line detected from rms spectrum indicates outflow of high-ionization gas. The velocity-resolved lag profiles of the broad Hγ λ4340, Hβ λ4861, and He I λ5876 lines show similar signatures that the largest lag occurs in the red wing of the lines then the lag decreases to both sides. These signatures should suggest that the BLR of Keplerian motion probably exists the outflow gas motion. All findings including UFOs, warm absorbers, and the kinematics of high- and low-ionization BLR, may provide an indirect evidence that the BLR of Mrk 79 probably originates from disk wind. Copyright © 2019, The Authors. All rights reserved.

关键词： Kinematics

Early-Time Observations of SN 2023wrk: A Luminous Type Ia Supernova with Significant Unburned Carbon in the Outer Ejecta

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arXiv 2024年

作者： Liu, Jialian Wang, Xiaofeng Andrade, Cristina Duverne, Pierre-Alexandre Zhang, Jujia Li, Liping Wang, Zhenyu Navarete, Felipe Reguitti, Andrea Schuldt, Stefan Cai, Yongzhi Filippenko, Alexei V. Yang, Yi Brink, Thomas G. Zheng, WeiKang Esamdin, Ali Iskandar, Abdusamatjan Bai, Chunhai Liu, Jinzhong Li, Xin Hu, Maokai Li, Gaici Li, Wenxiong Ma, Xiaoran Yan, Shengyu Mo, Jun Adami, Christophe Akl, Dalya Antier, Sarah Broens, Eric Ducoin, Jean-Grégoire Elhosseiny, Eslam Esposito, Thomas M. Freeberg, Michael Gokulass, Priya Hello, Patrice Karpov, Sergey Márquez, Isabel Mašek, Martin Pyshna, Oleksandra Rajabov, Yodgor Saint-Gelais, Denis Serrau, Marc Sokoliuk, Oleksii Takey, Ali Tanasan, Manasanun Turpin, Damien Physics Department Tsinghua University Beijing100084 China School of Physics and Astronomy University of Minnesota MinneapolisMN55455 United States Université Paris Cité CNRS Astroparticule et Cosmologie ParisF-75013 France 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 University of Chinese Academy of Sciences Beijing100049 China SOAR Telescope/NSF’s NOIRLab Avda Juan Cisternas 1500 La Serena1700000 Chile Merate23807 Italy INAF – Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 Padova35122 Italy Dipartimento di Fisica Università degli Studi di Milano via Celoria 16 MilanoI-20133 Italy INAF - IASF Milano via A. Corti 12 MilanoI-20133 Italy Department of Astronomy University of California BerkeleyCA94720-3411 United States Xinjiang Astronomical Observatory Chinese Academy of Sciences Urumqi Xinjiang830011 China School of Astronomy and Space Science University of Chinese Academy of Sciences Beijing100049 China Beijing Planetarium Beijing Academy of Science and Technology Beijing100044 China Natioal Astronomical Observatories of China Chinese Academy of Sciences Beijing100012 China Aix Marseille Univ CNRS CNES LAM Marseille France Physics Department American University of Sharjah Sharjah United Arab Emirates Université Côte d’Azur Observatoire de la Côte d’Azur CNRS Laboratoire J.-L. Lagrange Boulevard de l’Observatoire Nice06304 France KNC Vereniging Voor Sterrenkunde Balen-Neetlaan 18A MolB-2400 Belgium CPPM Aix Marseille Univ CNRS IN2P3 CPPM Marseille France 1 El-marsad St. Helwan Cairo11421 Egypt ColfaxWI54730 United States iTelescope Utah Desert Remote Observatory Beryl Junction UT84714 United States Department of Physical Sciences College of Arts and Sciences Embry-Riddle

We present extensive photometric and spectroscopic observations of the nearby Type Ia supernova (SN) 2023wrk at a distance of about 40 Mpc. The earliest detection of this SN can be traced back to a few hours after the explosion. Within the first few days the light curve shows a bump feature, while the B − V color is blue and remains nearly constant. The overall spectral evolution is similar to that of an SN 1991T/SN 1999aa-like SN Ia, while the C ii λ6580 absorption line appears to be unusually strong in the first spectrum taken at t ≈ −15.4 days after the maximum light. This carbon feature disappears quickly in subsequent evolution but it reappears at around the time of peak brightness. The complex evolution of the carbon line and the possible detection of Ni iii absorption around 4700 Å and 5300 Å in the earliest spectra indicate macroscopic mixing of fuel and ash. The strong carbon lines is likely related to collision of SN ejecta with unbound carbon, consistent with the predictions of pulsational delayed-detonation or carbon-rich circumstellar-matter interaction models. Among those carbon-rich SNe Ia with strong C ii λ6580 absorption at very early times, the line-strength ratio of C ii to Si ii and the B − V color evolution are found to exhibit large diversity, which may be attributed to different properties of unbound carbon and outward-mixing 56Ni. Copyright © 2024, The Authors. All rights reserved.

关键词： Supernovae

Observation of Cassini's Entry into Saturn: No Detection, and Lessons Learned

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Research Notes of the AAS 2021年第6期5卷

作者： Ralph D. Lorenz Frank Crary Laurent Lamy Peter Jenniskens Liang Ge Xi-Liang Zhang Jian-Yang Li Masataka Imai Tatsuharu Ono Matthew R. Arnison Lee Spitler Johns Hopkins Applied Physics Laboratory Laurel MD 20723 USA University of Colorado Laboratory for Space and Atmospheric Science CO USA LESIA Observatoire de Paris PSL CNRS Meudon France LAM Pythéas Univ. Aix-Marseille CNES CNRS Marseille France SETI Institute Mountain View CA 94043 USA NASA Ames Research Center Moffett Field CA 94035 USA Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Science Beijing People's Republic of China Yunnan Observatories Chinese Academy of Sciences Kunming 650216 People's Republic of China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kuming 650216 People's Republic of China Planetary Science Institute Tucson AZ 85719 USA Faculty of Science Kyoto Sangyo University Kyoto Japan Department of Cosmosciences Graduate School of Science Hokkaido University Hokkaido Japan Canon Australia Sydney NSW 2113 Australia Bandicoot Imaging Sciences Sydney NSW 2101 Australia Research Centre in Astronomy Astrophysics & Astrophotonics Macquarie University Sydney NSW 2109 Australia Ralph.Lorenz@jhuapl.edu

The mission of the 2000 kg Cassini spacecraft concluded on 2017 September 15, by its deliberate entry into Saturn's atmosphere at some 31.1 km s−1. Observations, using Hubble and groundbased observatories, to attempt optical detection of this 0.25 kT 'artificial meteor' are summarized. No signatures were identified. A challenge with observing the event is that due to atmospheric drag, its timing was not completely deterministic months or even days in advance, a particular problem for space observatories. While imaging observations needed no geometric specification more than 'Saturn,' observations with spectrometers required pointing the instrument aperture or slit at the specific impact site. Since giant planet longitude systems are not always familiar, distribution of an unambiguous 'finder chart' showing the location of the predicted entry site on the disk is essential, as is clarity on whether stated times are spacecraft event time, or Earth received time (light-travel time, 83 minutes, later).

关键词： Space vehicles Meteors Meteoroids

Black hole space-time in dark matter halo

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arXiv 2018年

作者： Xu, Zhaoyi Hou, Xian Gong, Xiaobo Wang, Jiancheng Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China University of Chinese Academy of Sciences Beijing100049 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

For the first time, we obtain the analytical form of black hole space-time metric in dark matter halo for the stationary situation. Using the relation between the rotation velocity (in the equatorial plane) and the spherical symmetric space-time metric coefficient, we obtain the space-time metric for pure dark matter. By considering the dark matter halo in spherical symmetric space-time as part of the energy-momentum tensors in the Einstein field equation, we then obtain the spherical symmetric black hole solutions in dark matter halo. Utilizing Newman-Jains method, we further generalize spherical symmetric black holes to rotational black holes. As examples, we obtain the space-time metric of black holes surrounded by Cold Dark Matter and Scalar Field Dark Matter halos, respectively. Our main results regarding the interaction between black hole and dark matter halo are as follows: (i) For both dark matter models, the density profile always produces "cusp" phenomenon in small scale in the relativity situation;(ii) Dark matter halo makes the black hole horizon to increase but the ergosphere to decrease, while the magnitude is small;(iii) Dark matter does not change the singularity of black holes. These results are useful to study the interaction of black hole and dark matter halo in stationary situation. Particularly, the "cusp" produced in the 0 ∼ 1 kpc scale would be observable in the Milky Way. Perspectives on future work regarding the applications of our results in astrophysics are also briefly discussed. Copyright © 2018, The Authors. All rights reserved.

关键词： Gravitation

Massive stars exploding in a He-rich circumstellar medium − X. Flash spectral features in the Type Ibn SN 2019cj and observations of SN 2018jmt

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arXiv 2024年

作者： Wang, Z.-Y. Pastorello, A. Maeda, K. Reguitti, A. Cai, Y.-Z. Howell, D. Andrew Benetti, S. Buckley, D. Cappellaro, E. Carini, R. Cartier, R. Chen, T.-W. Elias-Rosa, N. Fang, Q.-L. Gal-Yam, A. Gangopadhyay, A. Gromadzki, M. Gan, W.-P. Hiramatsu, D. Hu, M.-K. Inserra, C. McCully, C. Nicholl, M. Olivares, F.E. Pignata, G. Pineda-García, J. Pursiainen, M. Ragosta, F. Rau, A. Roy, R. Sollerman, J. Tartaglia, L. Terreran, G. Valerin, G. Wang, Q. Wang, S.-Q. Young, D.R. Aryan, A. Bronikowski, M. Concepcion, E. Galbany, L. Lin, H. Melandri, A. Petrushevska, T. Ramirez, M. Shi, D.-D. Warwick, B. Zhang, J.-J. Wang, B. Wang, X.-F. Zhu, X.-J. School of Physics and Astronomy Beijing Normal University Beijing100875 China Department of Physics Faculty of Arts and Sciences Beijing Normal University Zhuhai519087 China INAF - Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 Padova35122 Italy Department of Astronomy Kyoto University Kitashirakawa-Oiwake-cho Sakyo-ku Kyoto606-8502 Japan Merate23807 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 Las Cumbres Observatory 6740 Cortona Drive Suite 102 GoletaCA93117-5575 United States Department of Physics University of California Santa BarbaraCA93106-9530 United States South African Astronomical Observatory PO Box 9 Observatory Cape Town7935 South Africa INAF - Osservatorio Astronomico di Roma via Frascati 33 Monte Porzio CatoneI-00078 Italy Instituto de Estudios Astrofísicos Facultad de Ingeniería y Ciencias Universidad Diego Portales Av. Ejército Libertador 441 Santiago Chile Graduate Institute of Astronomy National Central University 300 Jhongda Road Jhongli32001 Taiwan Campus UAB Carrer de Can Magrans s/n BarcelonaE-08193 Spain Department of Particle Physics and Astrophysics Weizmann Institute of Science Rehovot76100 Israel The Oskar Klein Centre Department of Astronomy Stockholm University AlbaNova StockholmSE-10691 Sweden Astronomical Observatory University of Warsaw Al. Ujazdowskie 4 Warszawa00-478 Poland Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and Technology Guangxi University Nanning530004 China Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138-1516 United States The NSF AI Institute for Artificial Intelligence and Fundamental Interactions United States Department of Physics Tsinghua University Beijing10008

We present optical and near-infrared observations of two Type Ibn supernovae (SNe), SN 2018jmt and SN 2019cj. Their light curves have rise times of about 10 days, reaching an absolute peak magnitude of Mg(SN 2018jmt) = −19.07 ± 0.37 and MV(SN 2019cj) = −18.94 ± 0.19 mag, respectively. The early-time spectra of SN 2018jmt are dominated by a blue continuum, accompanied by narrow (600−1000 km s−1) He i lines with P-Cygni profile. At later epochs, the spectra become more similar to those of the prototypical SN Ibn 2006jc. At early phases, the spectra of SN 2019cj show flash ionisation emission lines of C iii, N iii and He ii superposed on a blue continuum. These features disappear after a few days, and then the spectra of SN 2019cj evolve similarly to those of SN 2018jmt. The spectra indicate that the two SNe exploded within a He-rich circumstellar medium (CSM) lost by the progenitors a short time before the explosion. We model the light curves of the two SNe Ibn to constrain the progenitor and the explosion parameters. The ejecta masses are consistent with either that expected for a canonical SN Ib (~ 2 M☉) or those from a massive WR star (> ~ 4 M☉), with the kinetic energy on the order of 1051 erg. The lower limit on the ejecta mass (> ~ 2 M☉) argues against a scenario involving a relatively low-mass progenitor (e.g., MZAMS ~ 10 M☉). We set a conservative upper limit of ~ 0.1 M☉ for the 56Ni masses in both SNe. From the light curve modelling, we determine a two-zone CSM distribution, with an inner, flat CSM component, and an outer CSM with a steeper density profile. The physical properties of SN 2018jmt and SN 2019cj are consistent with those expected from the core collapse of relatively massive, stripped-envelope (SE) stars. © 2024, CC BY.

关键词： Kinetic energy

Black hole shadow of Sgr a∗ in dark matter halo

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arXiv 2018年

作者： Hou, Xian Xu, Zhaoyi Zhou, Ming Wang, Jiancheng Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 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

We study, for the first time, the shadow of the supermassive black hole Sgr A∗ at the center of the Milky Way in dark matter halos. For the Cold Dark Matter and Scalar Field Dark Matter models considered in this work, the apparent shape of the shadow depends upon the black hole spin a and the dark matter parameter k. We find that both dark matter models influence the shadow in a similar way. The shadow is a perfect circle in the non-rotating case ( a = 0) and a deformed one in the rotating case ( a ≠ 0). The size of the shadow increases with increasing k in both non-rotating and rotating cases, while the shadow gets more and more distorted with increasin g a in the rotating case. We further investigate the black hole emission rate in both dark matter halos. We find that the emission rate decreases with increasing k and the peak of the emission shifts to lower frequency. Finally, by calculating the angular radius of the shadow, we estimate that the dark matter halo could influence the shadow of Sgr A∗ at a level of order of magnitude of 10-3μas and 10-5μas, for CDM and SFDM, respectively. Future astronomical instruments with high angular resolution would be able to observe this effect and shed light on the nature of Sgr A∗. More interestingly, it may be possible to distinguish between CDM and SFDM models given the resolutions required differing by two orders of magnitude from each other. Copyright © 2018, The Authors. All rights reserved.

关键词： Galaxies

A scenario on the power-law total mass-density profile of the inner regions of early-type-galaxies

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arXiv 2018年

作者： Li, Rui Xu, Zhaoyi Wang, Jiancheng Hou, Xian Tang, Meirong Guo, Xiaotong Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China University of Chinese Academy of Sciences Beijing100049 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

We naturally obtain a power-law total mass-density profile for the inner regions (within several effective radius) of early-type galaxies(ETGs) from space-time structures, which are described by the static spherically-symmetric solutions of Einstein equations with the perfect fluid matters. We point out that, in the inner region of an early type galaxy, the average value of the equation of state ω determines the power-law index γ of the total mass-density profile given by Koopmans et al. (2006). We then use 119 galaxy-galaxy strong gravitational lensing systems from SLACS, BELLS, BELLS GALLERY and SL2S, to constrain the equation of state ω for the inner regions of ETGs. We find that the average value of ω for totally 119 ETGs is ω = −0.315 ± 0.073 (68% CL), which is very close to −1/3. If ω = −1/3 is the best value to describe the equation of state of the inner regions of the dark matter in galaxies, the deviation from −1/3 could represent the mixture of baryonic matter and dark matter in galaxies. Copyright © 2018, The Authors. All rights reserved.

关键词： Galaxies

Verification of the diffusive shock acceleration in Mrk 501

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arXiv 2018年

作者： Zheng, Y.G. Long, G.B. Yang, C.Y. Bai, J.M. Department of Physics Yunnan Normal University Kunming650092 China Yunnan Observatories Chinese Academy of Sciences Kunming650011 China Shandong Prov. Key Lab. of Optical Astronomy and Solar-Terrestrial EnvironmentShandong University Weihai264209 Key Laboratory for Structure and Evolution of Celestial Objects Chinese Academy of Sciences China Department of Physics and Astronomy Sun Yat-Sen University Zhuhai519082 China

The present work considers a plane shock front propagating along a cylindrical jet. Electrons experience the diffusive shock acceleration around the shock front, and sub-sequently drift away into the downstream flow in which they emit most of their energy. Assuming a proper boundary condition at the interface between the shock zone and the downstream zone, we solve the transport equation for the electrons in the down-stream flow zone, where the combined effects of escape, synchrotron and IC cooling in the Thomson regime are taken into account. Using the electron spectrum obtained in this manner we calculate the multi-wavelength spectral energy distribution of Mrk 501 in the synchrotron self-Compton scenario. We check numerically if the Klein-Nishina cross-section could be approximated to the Thomsom regime. We consider whether the model results yield physically reasonable parameters, and further discuss some of implications of the model results. It suggests that the process of diffusive shock acceleration operates in the outflow of Mrk 501. Copyright © 2018, The Authors. All rights reserved.

关键词： Shock waves