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RW Dor: A shallow contact binary with new orbital period investigation

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arXiv 2018年

作者： Sarotsakulchai, T. Qian, S.-B. Soonthornthum, B. Lajus, E. Fernandez Liu, N.-P. Zhou, X. Zhang, J. Liao, W.-P. Reichart, D.E. Haislip, J.B. Kouprianov, V.V. Poshyachinda, S. Yunnan Observatories Chinese Academy of Sciences Kunming650216 China University of Chinese Academy of Sciences 19 A Yuquan Rd. Shijingshan Beijing100049 China National Astronomical Research Institute of Thailand Ministry of Science and Technology Bangkok Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Rd. Chaoyang District Beijing100012 China Facultad de Ciencias Astronómicas y Geofísicas UNLP La Plata Buenos Aires1900 Argentina Instituto de Astrofisica de La Plata CONICET UNLP La PlataProvincia de Buenos Aires Argentina Department of Physics and Astronomy University of North Carolina CB #3255 Chapel HillNC27599 United States

New CCD photometric light curves of short period (P=0.285d) eclipsing binary RW Dor are presented. The observations performed with the PROMPT-8 robotic telescope at CTIO in Chile from March 2015 to March 2017. The other eclipse timings were obtained from the 2.15-m JS telescope at CASLEO, San Juan, Argentina in December 2011. By light-curve analysis, it is found that RW Dor is a W-type shallow contact binary with a fill-out factor f ∼ 11% and high mass ratio q ∼ 1.587 (1/q = 0.63), where the hotter component is the less massive one (M1 ∼ 0.52Mo and M2 ∼ 0.82Mo). For orbital period investigation, the new fifteen eclipse times and those in previous published were compiled. Based on O-C analysis with very weak evidence suggests that a long-term period decrease with a rate of dP/dt =-9.61 × 10-9d yr-1is superimposed on a cyclic variation (A3= 0.0054 days and P3= 49.9 yrs). The long-term period decrease can be interpreted as mass transfer from the more massive component to the less massive one or combine with the angular momentum loss (AML) via magnetic braking. In addition, with the marginal contact phase, high mass ratio (1/q > 0.4) and the long-term period decrease, all suggest that RW Dor is a newly formed contact binary via a Case A mass transfer and it will evolve into a deeper normal contact binary. If the cyclic change is correct, the light-travel time effect via the presence of a cool third body will be more plausible to explain for this. Copyright © 2018, The Authors. All rights reserved.

关键词： Travel time

Optical and near-infrared observations of the nearby type Ia supernova 2017cbv

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arXiv 2020年

作者： Wang, Lingzhi Contreras, Carlos Hu, Maokai Hamuy, Mario A. Hsiao, Eric Y. Sand, David J. Anderson, Joseph P. Ashall, Chris Burns, Christopher R. Chen, Juncheng Diamond, Tiara R. Davis, Scott Förster, Francisco Galbany, Lluís González-Gaitán, Santiago Gromadzki, Mariusz Hoeflich, Peter Li, Wenxiong Marion, G.H. Morrell, Nidia Pignata, Giuliano Prieto, Jose L. Phillips, Mark M. Shahbandeh, Melissa Suntzeff, Nicholas Valenti, Stefano Wang, Lifan Wang, Xiaofeng Young, D.R. Yu, Lixin Zhang, Jujia CAS Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China Chinese Academy of Sciences South America Center for Astronomy National Astronomical Observatories CAS Beijing100101 China Carnegie Observatories Las Campanas Observatory Colina El Pino Casilla601 Chile Purple Mountain Observatory NanjingJiangsu201008 China Departamento de Astronomía Universidad de Chile Camino El Observatorio 1515 Las Condes Santiago Chile Millennium Institute of Astrophysics Santiago Chile Department of Physics Florida State University TallahasseeFL32306 United States Department of Astronomy and Steward Observatory University of Arizona 933 North Cherry Avenue TucsonAZ85721-0065 United States European Southern Observatory Alonso de Córdova 3107 Casilla 19 Santiago Chile Observatories of the Carnegie Institution for Science 813 Santa Barbara St. PasadenaCA91101 United States School of Electronics and Information Engineering Wuzhou University Wuzhou543002 China Departamento de Física Teórica y del Cosmos Universidad de Granada GranadaE-18071 Spain CENTRA/COSTAR Instituto Superior Técnico Universidade de Lisboa Av. Rovisco Pais 1 Lisboa1049-001 Portugal Astronomical Observatory University of Warsaw Al. Ujazdowskie 4 Warszawa00-478 Poland Physics Department/Tsinghua Center for Astrophysics Tsinghua University Beijing100084 China Department of Astronomy University of Texas at Austin 1 University Station C1400 AustinTX78712-0259 United States Departamento de Ciencias Físicas Universidad Andres Bello Avda. República 252 Santiago8320000 Chile Núcleo de Astronomía de la Facultad de Ingeniería Universidad Diego Portales Av. Ejército 441 Santiago Chile George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy Department of Physics and Astronomy Texas United States A&M University College Station TX77843 United States Department of Physics University of California 1 S

Supernova (SN) 2017cbv in NGC 5643 is one of a handful of type Ia supernovae (SNe Ia) reported to have excess blue emission at early times. This paper presents extensive BV RIY JHKs-band light curves of SN 2017cbv, covering the phase from −16 to +125 days relative to B-band maximum light. SN 2017cbv reached a B-band maximum of 11.710±0.006 mag, with a post-maximum magnitude decline ∆m15(B)=0.990±0.013 mag. The supernova suffered no host reddening based on Phillips intrinsic color, Lira-Phillips relation, and the CMAGIC diagram. By employing the CMAGIC distance modulus µ = 30.58±0.05 mag and assuming H0 = 72 km s−1 Mpc−1, we found that 0.73 Mo56Ni was synthesized during the explosion of SN 2017cbv, which is consistent with estimates using reddening-free and distance-free methods via the phases of the secondary maximum of the NIR-band light curves. We also present 14 near-infrared spectra from −18 to +49 days relative to the B-band maximum light, providing constraints on the amount of swept-up hydrogen from the companion star in the context of the single degenerate progenitor scenario. No Paβ emission feature was detected from our post-maximum NIR spectra, placing a hydrogen mass upper limit of 0.1 Mo. The overall optical/NIR photometric and NIR spectral evolution of SN 2017cbv is similar to that of a normal SN Ia, even though its early evolution is marked by a flux excess no seen in most other well-observed normal SNe Ia. We also compare the exquisite light curves of SN 2017cbv with some Mch DDT models and sub-Mch double detonation models. Copyright © 2020, The Authors. All rights reserved.

关键词： Supernovae

Do SN 2002cx-like and SN Ia-CSM objects share the same origin?

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arXiv 2017年

作者： Meng, X. Podsiadlowski, Ph. 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 Oxford University OxfordOX1 3RH United Kingdom

SN 2002cx-like and SN Ia-CSM objects show similar early spectra and both belong to a young stellar population, suggesting that they could share the same progenitor origin. Adopting the framework of the common-envelope-wind (CEW) model developed in Meng & Podsiadlowski (2017), we here propose that both subclasses of SNe Ia are caused by the explosion of hybrid carbon-oxygen-neon white dwarfs (CONe WDs) in single-degenerate systems, where SNe Ia- CSM explode in systems with a massive common envelope (CE) of ∼ 1 Mo, while SN 2002cxlike events correspond to those events where most of the CE has been lost in a wind. Using binary-population-synthesis (BPS) calculations, we estimate a number ratio of SNe Ia-CSM to SN 2002cx-like objects between 1/3 and 2/3 , consistent with observational constraints, and an overall contribution from hybrid CONeWDs to the total SN Ia population that also matches the observed number from these peculiar objects. Our model predicts a statistical sequence of CSM density from SN Ia-CSM to SN 2002cx-like events and normal SNe Ia, consistent with existing radio constraints. We also find a new subclass of hybrid SNe which share the properties of Type II and Type Ia SNe, consistent with some observed SNe, which do not have a surviving companion. In some cases these could even produce SNe Ia from apparently single WDs. Copyright © 2017, The Authors. All rights reserved.

关键词： White dwarfs

A new derivation of the relationship between diffusion coefficient and entropy in classical Brownian motion by the ensemble method

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arXiv 2017年

作者： Liao, Yi Gong, Xiao-Bo Department of Physics College of Science Southern University of Science and Technology Shenzhen518055 China Yunnan Observatory and Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650011 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

The diffusion coefficient–a measure of dissipation, and the entropy–a measure of fluctuation are found to be intimately correlated in many physical systems. Unlike the fluctuation dissipation theorem in linear response theory, the correlation is often strongly non-linear. To understand this complex dependence, we consider the classical Brownian diffusion in this work. Under certain rational assumption, i.e. in the bi-component fluid mixture, the mass of the Brownian particle M is far greater than that of the bath molecule m, we can adopt the weakly couple limit. Only considering the first-order approximation of the mass ratio m/M, we obtain a linear motion equation in the reference frame of the observer as a Brownian particle. Based on this equivalent equation, we get the Hamiltonian at equilibrium. Finally, using canonical ensemble method, we define a new entropy that is similar to the Kolmogorov-Sinai entropy. Further, we present an analytic expression of the relationship between the diffusion coefficient D and the entropy S in the thermal equilibrium, that is to say, D = eM~ exp [S/(kB d)], where d is the dimension of the space, kB the Boltzmann constant, ~ the reduced Planck constant and e the Euler number. This kind of scaling relation has been well-known and well-tested since the similar one for single component is firstly derived by Rosenfeld with the expansion of volume ratio. Copyright © 2017, The Authors. All rights reserved.

关键词： Entropy

Physical parameters and orbital period variation of a newly discovered cataclysmic variable GSC 4560-02157

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arXiv 2017年

作者： Han, Zhong-Tao Qian, Sheng-Bang Voloshina, Irina Metlov, Vladimir G. Zhu, Li-Ying Li, Lin-Jia P. O. Box 110 Kunming650216 Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences P. O. Box 110 Kunming650216 University of Chinese Academy of Sciences Yuquan Road 19# Sijingshang Block Beijing100049 Sternberg Astronomical Institute Moscow State University Universitetskij prospect 13 Moscow119992

GSC 4560-02157 is a new eclipsing cataclysmic variable with an orbital period of 0.265359 days. By using the published V- and R-band data together with our observations, we discovered that the O - C curve of GSC 4560-02157 may shows a cyclic variation with the period of 3.51 years and an amplitude of 1.40 min. If this variation is caused by a light travel-time effect via the existence of a third body, its mass can be derived as M3sini' ≈ 91.08MJup, it should be a low-mass star. In addition, several physical parameters were measured. The colour of the secondary star was determined as V - R = 0.77(±0.03) which corresponds to a spectral type of K2-3. The secondary star's mass was estimated as M2 = 0.73(±0.02)Moby combing the derived V - R value around phase 0 with the assumption that it obeys the mass-luminosity relation of the main sequence stars. This mass is consistent with the mass'period relation of CV donor stars. For the white dwarf, the eclipse durations and contacts of the white dwarf yield an upper limit of the white dwarf's radius corresponding to a lower limit mass of Mi ≈ 0.501Mo. The overestimated radius and previously published spectral data indicate that the boundary layer may has a very high temperature. Copyright © 2017, The Authors. All rights reserved.

关键词： White dwarfs

Kerr-Newman-AdS black hole surrounded by scalar field matter in rastall gravity

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arXiv 2017年

作者： Xu, Zhaoyi 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

Rastall gravity is the modify Einstein general relativity, in which the energy-momentum conservation is assumed to be unsatisfied and generalized to T µν;µ = λR,ν. In this paper we investigate the Kerr-Newman-AdS black hole solutions surrounded by the scalar field matter of the Einstein-Maxwell equation in Rastall gravity using Newman-Jains method and complex computations. Through analyzing the root numbers of the horizon equation for two situations, we obtain the relations of α, M and κλ. For the quintessence dark energy (ω = −2/3), if 0 Copyright © 2017, The Authors. All rights reserved.

关键词： Gravitation

Kerr-anti-de-sitter/de-sitter black hole in perfect fluid dark matter background

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arXiv 2017年

作者： Xu, Zhaoyi Hou, Xian 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

We obtain the Kerr-anti-de-sitter (Kerr-AdS) and Kerr-de-sitter (Kerr-dS) black hole (BH) solutions to the Einstein field equation in the perfect fluid dark matter background using the Newman-Janis method and Mathematica package. We discuss in detail the black hole properties and obtain the following main results: (i) From the horizon equation grr = 0, we derive the relation between the perfect fluid dark matter parameter α and the cosmological constant Λ when the cosmological horizon rΛ exists. For Λ = 0, we find that α is in the range 0 0 and −7.18M max decreases if α > 0, and αmin increases if α max increases if α > 0 and αmin decreases if α 0 and α 0 while is asymptotically flat only when α is close to zero if α Copyright © 2017, The Authors. All rights reserved.

关键词： Gravitation

The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope - Data Release 3

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arXiv 2022年

作者： Ajello, Marco Baldini, Luca Ballet, Jean Bastieri, Denis Gonzalez, Joseff Becerra Bellazzini, Ronaldo Berretta, Alessandra Bissaldi, Elisabetta Bonino, Raffaella Brill, Ari Bruel, Philippe Buson, Sara Caputo, Regina Caraveo, Patrizia A. Cheung, C.C. Chiaro, Graziano Cibrario, Nicolo Ciprini, Stefano Crnogorcevic, Milena Cutini, Sara D’Ammando, Filippo De Gaetano, Salvatore Di Lalla, Niccolo Di Venere, Leonardo Domínguez, Alberto Ramazani, Vandad Fallah Ferrara, Elizabeth C. Fiori, Alessio Fukazawa, Yasushi Funk, Stefan Fusco, Piergiorgio Gammaldi, Viviana Gargano, Fabio Garrappa, Simone Gasparrini, Dario Giglietto, Nico Giordano, Francesco Giroletti, Marcello Green, David Grenier, Isabelle A. Guiriec, Sylvain Horan, Deirdre Hou, Xian Kayanoki, Taishu Kuss, Michael Larsson, Stefan Latronico, Luca Lewis, Tiffany Li, Jian Liodakis, Ioannis Longo, Francesco Loparco, Francesco Lott, Benoit Lovellette, Michael N. Lubrano, Pasquale Madejski, Grzegorz M. Maldera, Simone Manfreda, Alberto Martí-Devesa, Guillem Mazziotta, Mario Nicola Mereu, Isabella Michelson, Peter F. Mirabal, Nestor Mitthumsiri, Warit Mizuno, Tsunefumi Monzani, Maria Elena Morselli, Aldo Moskalenko, Igor V. Negro, Michela Ojha, Roopesh Orienti, Monica Orlando, Elena Ormes, Jonathan F. Pei, Zhiyuan Peña-Herazo, Harold A. Persic, Massimo Pesce-Rollins, Melissa Petrosian, Vahe Pillera, Roberta Poon, Helen Porter, Troy A. Principe, Giacomo Rainò, Silvia Rando, Riccardo Rani, Bindu Razzano, Massimiliano Razzaque, Soebur Reimer, Anita Reimer, Olaf Scotton, Lorenzo Serini, Davide Sgrò, Carmelo Siskind, Eric J. Spandre, Gloria Spinelli, Paolo Suson, Dan J. Tajima, Hiro Torres, Diego F. Valverde, Janeth Yassin, Hend Zaharijas, Gabrijela Department of Physics and Astronomy Clemson University Kinard Lab of Physics ClemsonSC29634-0978 United States Università di Pisa Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy AIM CEA CNRS Université Paris-Saclay Université de Paris Gif-sur-YvetteF-91191 France Istituto Nazionale di Fisica Nucleare Sezione di Padova PadovaI-35131 Italy Dipartimento di Fisica e Astronomia "G. Galilei" Università di Padova Via F. Marzolo 8 PadovaI-35131 Italy Center for Space Studies and Activities "G. Colombo" University of Padova Via Venezia 15 PadovaI-35131 Italy Instituto de Astrofísica de Canarias Observatorio del Teide C/Via Lactea s/n La Laguna TenerifeE-38205 Spain Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Dipartimento di Fisica Università degli Studi di Perugia PerugiaI-06123 Italy Dipartimento di Fisica "M. Merlin" Università e del Politecnico di Bari via Amendola 173 BariI-70126 Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari BariI-70126 Italy Istituto Nazionale di Fisica Nucleare Sezione di Torino TorinoI-10125 Italy Dipartimento di Fisica Università degli Studi di Torino TorinoI-10125 Italy NASA Postdoctoral Program United States NASA Goddard Space Flight Center GreenbeltMD20771 United States Laboratoire Leprince-Ringuet École polytechnique CNRS IN2P3 PalaiseauF-91128 France Institut für Theoretische Physik and Astrophysik Universität Würzburg WürzburgD-97074 Germany INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica Milano via E. Bassini 15 MilanoI-20133 Italy Space Science Division Naval Research Laboratory WashingtonDC20375-5352 United States Istituto Nazionale di Fisica Nucleare Sezione di Roma "Tor Vergata" RomaI-00133 Italy Space Science Data Center - Agenzia Spaziale Italiana Via del Politecnico snc RomaI-00133 Italy Department of Astronomy University of Maryland College ParkMD20742 United States Istituto Nazionale di Fisica Nucleare Sezio

An incremental version of the fourth catalog of active galactic nuclei (AGNs) detected by the Fermi-Large Area Telescope is presented. This version (4LAC-DR3) derives from the third data release of the 4FGL catalog based on 12 years of E>50 MeV gamma-ray data, where the spectral parameters, spectral energy distributions (SEDs), yearly light curves, and associations have been updated for all sources. The new reported AGNs include 587 blazar candidates and four radio galaxies. We describe the properties of the new sample and outline changes affecting the previously published one. We also introduce two new parameters in this release, namely the peak energy of the SED high-energy component and the corresponding flux. These parameters allow an assessment of the Compton dominance, the ratio of the Inverse-Compton to the synchrotron peak luminosities, without relying on X-ray data. © 2022, CC BY.

关键词： Active Galactic Nuclei

Search for intra-day optical variability in Mrk 501

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arXiv 2017年

作者： Feng, Hai-Cheng Liu, H.T. Fan, X.L. Zhao, Yinghe Bai, J.M. Wang, Fang Xiong, D.R. Li, S.K. 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

We present our observations of the optical intra-day variability (IDV) in γ-ray BL Lac object Mrk 501. The observations were run with the 1.02 m and 2.4 m optical telescopes at Yunnan Observatories from 2005 April to 2012 May. The light curve at the R band on 2010 May 15 passes both variability tests (the F test and the ANOVA test). A flare within the light curve on 2010 May 15 has a magnitude change ∆m = 0.03±0.005stat±0.007sys mag, a darkening timescale of τd = 26.7 minutes, and an amplitude of IDV Amp = 2.9%±0.7%. A decline described by 11 consecutive flux measurements within the flare can be fitted linearly with a Pearson’s correlation coefficient r = 0.945 at the confidence level of > 99.99%. Under the assumptions that the IDV is tightly connected to the mass of the black hole, and that the flare duration, being two times τd, is representative of the minimum characteristic timescale, we can derive upper bounds to the mass of the black hole. In the case of the Kerr black hole, the timescale of ∆tobmin = 0.89 hours gives M• . 109.20M☉, which is consistent with measurements reported in the literature. This agreement indicates that the hypothesis about M• and ∆tobmin is consistent with the measurements/data. Copyright © 2017, The Authors. All rights reserved.

关键词： Galaxies