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Variations of the harmonic components of the X-ray pulse profile of PSR B1509–58

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Research in Astronomy and Astrophysics 2015年第1期15卷 28-36页

作者： Pragati Pradhan biswajit paul Harsha Raichur Bikash Chandra paul St Joseph’s College Singamari Darjeeling 734104 West Bengal India North Bengal University Raja Rammohanpur District Darjeeling 734013 West Bengal India Raman Research Institute Sadashivnagar Bangalore 560080 India

We used the Fourier decomposition technique to investigate the stability of the X-ray pulse profile of a young pulsar PSR B1509–58 by studying the relative amplitudes and phase differences of its harmonic components with respect to the fundamental using data from the Rossi X-Ray Timing Explorer. Like most young rotation powered pulsars, PSR B1509–58 has a high spin down rate. It also has less timing noise, allowing accurate measurement of higher order frequency derivatives which in turn helps in the study of the physics of pulsar spin down. Detailed investigation of pulse profiles over the years will help us establish any possible connection between the timing characteristics and the high energy emission characteristics for this pulsar.Furthermore, the study of pulse profiles of short period X-ray pulsars can also be useful when used as a means of interplanetary navigation. The X-ray pulse profile of this source has been analyzed for 15 yr（1996–2011）. The long term average amplitudes of the first, second and third harmonics（and their standard deviation for individual measurements） compared to the fundamental are 36.9%（1.7%）, 13.4%（1.9%） and 9.4%（1.8%） respectively. Similarly, the phases of the three harmonics（and standard deviations） with respect to the fundamental are 0.36（0.06）, 1.5（0.2） and 2.5（0.3） radian respectively. We do not find any significant variation of the harmonic components of the pulse profile in comparison to the fundamental.

关键词： pulsars： individual：（PSR B1509–58） stars： neutron X-rays

Search for pulsations in the LMXB EXO 0748-676

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Research in Astronomy and Astrophysics 2011年第5期11卷 577-582页

作者： Chetana Jain biswajit paul Raman Research Institute SadashivnagarC.V.Raman AvenueBangalore 560080India

We present here results from our search for X-ray pulsations of the neu- tron star in the low mass X-ray binary EXO 0748-676 at a frequency near the burst- oscillation frequency of 44.7 Hz. Using the observations made with the Proportional Counter Array onboard the Rossi X-ray Timing Explorer, we did not find any pulsations in the frequency band of 44.4Hz to 45.0Hz and obtained a 3σ upper limit of 0.47% on the pulsed fraction for any possible underlying pulsation in this frequency band. We also discuss the importance of EXO 0748-676 as a promising source for the detection of Gravitational Waves.

关键词： X-ray： neutron stars - X-ray binaries： individual （EXO 0748-676）

Variations in the X-ray eclipse transitions of Cen X-3

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Research in Astronomy and Astrophysics 2010年第11期10卷 1127-1136页

作者： Jincy Devasia biswajit paul Marykutty James Kavila Indulekha School of Pure & Applied Physics Mahatma Gandhi University Raman Research Institute

We report here an investigation of the X-ray eclipse transitions of the high mass X-ray binary pulsar Cen X-3 in different intensity states. The long term light curve of Cen X-3 obtained with RXTE-ASM spanning more than 5000 d shows strong aperiodic flux variations with low and high states. We have investigated the eclipse transitions of Cen X-3 in different intensity states with data obtained from pointed observations with the more sensitive instruments onboard ASCA, BeppoSAX, XMM- Newton, Chandra and RXTE. We found a very clear trend of sharp eclipse transitions in the high state and longer transitions in the low state. This is a confirmation of this feature first observed with the RXTE-ASM but now observed with much better clarity. From the light curves obtained from several missions, it is seen that the eclipse egress in the low state starts earlier by an orbital phase of 0.02 compared to the eclipse egress in the high state indicating that the observed X-rays originate from a much larger region. We have also performed spectral analysis of the post-eclipse part of each observation. From BeppoSAX observations, the out-of-eclipse X-ray flux is found to differ by a factor of -26 during the high and low intensity states while the eclipse count rates differ by a factor of only ~ 4.7. This indicates that in the low state, there is an additional scattering medium which scatters some of the source photons towards the observer even when the neutron star is completely eclipsed. We could also resolve the three iron line components using XMM-Newton observation in the low state. By comparing the iron line equivalent width during the high and low states, it is seen that the width of the iron line is relatively large during the low state which supports the fact that significant reprocessing and scattering of X-rays takes place in the low state.

关键词： stars pulsars individual （Cen X-3） -- （stars：） binaries eclipsing -- X-rays binaries

Pulse profile stability of the Crab pulsar

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Research in Astronomy and Astrophysics 2011年第10期11卷 1134-1142页

作者： Chetana Jain biswajit paul Hans Raj College University of Delhi Raman Research Institute Sadashivnagar C. V. Raman Avenue

We present an X-ray timing analysis of the Crab pulsar, PSR B0531＋21, using archival RXTE data. We have investigated the stability of the Crab pulse profile, in soft （2-20keV） and hard （30-100 keV） X-ray energies, over the last decade of RXTE operation. The analysis includes measurement of the separation between the two pulse peaks and the intensity and widths of the two peaks. We did not find any significant time dependency in the pulse shape. The two peaks have been stable in phase, intensity and width for the last ten years. The first pulse is relatively stronger at soft X-rays. The first pulse peak is narrower than the second peak in both soft and hard X-ray energies. Both the peaks show a slow rise and a steeper fall. The ratio of the pulsed photons in the two peaks is also constant in time.

关键词： pulsars individual： Crab （PSR B0531＋21） -- stars neutron -- X-rays

Physics and astrophysics of strong magnetic field systems with eXTP

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Science China(Physics,Mechanics & Astronomy) 2019年第2期62卷 74-96页

作者： Andrea Santangelo Silvia Zane Hua Feng RenXin Xu Victor Doroshenko Enrico Bozzo Ilaria Caiazzo Francesco Coti Zelati Paolo Esposito Denis González-Caniulef Jeremy Heyl Daniela Huppenkothen Gianluca Israel ZhaoSheng Li Lin Lin Roberto Mignani Nanda Rea Mauro Orlandini Roberto Taverna Hao Tong Roberto Turolla Cristina Baglio Federico Bernardini Niccolo'Bucciantini Marco Feroci Felix Fürst Ersin G??ü? Can Güngör Long Ji FangJun Lu Antonios Manousakis Sandro Mereghetti Romana Mikusincova biswajit paul Chanda Prescod-Weinstein George Younes Andrea Tiengo YuPeng Xu Anna Watts Shu Zhang Shuang-Nan Zhang Institut für Astronomie und Astrophysik Eberhard Karls Universität Key Laboratory for Particle Astrophysics Institute of High Energy Physics Mullard Space Science Laboratory University College LondonHolmbury St Mary Department of Engineering Physics and Center for Astrophysics Tsinghua University School of Physics Peking University Department of Astronomy University of Geneva Department of Physics and Astronomy University of British Columbia Universitädell’Insubria Anton Pannekoek Institute for Astronomy University of Amsterdam INAF-Osservatorio Astronomico di Brera Center for Data Science New York University INAF-Osservatorio Astronomico di Roma Department of Physics Xiangtan University Department of Astronomy Beijing Normal University INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica Milano Janusz Gil Institute of Astronomy University of Zielona Góra Instituto de Ciencias del Espacio(ICE) CSIC-IEEC INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica Bologna Department of Physics and Astronomy University of Padova School of Physics and Electronic Engineering Guangzhou University NYU Abu Dhabi Saadiyat Campus P.O. NAF Osservatorio di Arcetri Largo Enrico Fermi 5 INAF-Istituto di Astrofisica e Planetologia Spaziali INFN-Roma Tor Vergata European Space Astronomy Centre(ESA/ESAC) Science Operations Department Sabanci University Faculty of Engineering and Natural Sciences Centrum Astronomiczne im.M.Kopernika Department of Physics Sultan Qaboos University Institute of Theoretical Physics Faculty of Mathematics and PhysicsCharles University in Prague Raman Research Institute Sadashivanagar Department of Astronomy University of Washington The George Washington University Physics department 725 21st St NW Scuola Universitaria Superiore IUSS Pavia Palazzo del Broletto

In this paper we present the science potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies of strongly magnetized objects. We will focus on the physics and astrophysics of strongly magnetized objects, namely magnetars, accreting X-ray pulsars, and rotation powered pulsars. We also discuss the science potential of eXTP for QED studies. Developed by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences, the eXTP mission is expected to be launched in the mid 2020s.

关键词： neutron stars QED magnetars accreting pulsars eXTP

Observatory science with eXTP

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Science China(Physics,Mechanics & Astronomy) 2019年第2期62卷 97-138页

作者： Jean J.M.in 't Zand Enrico Bozzo JinLu Qu Xiang-Dong Li Lorenzo Amati Yang Chen Immacolata Donnarumma Victor Doroshenko Stephen A.Drake Margarita Hernanz Peter A.Jenke Thomas J.Maccarone Simin Mahmoodifar Domitilla de Martino Alessandra De Rosa Elena M.Rossi Antonia Rowlinson Gloria Sala Giulia Stratta Thomas M.Tauris Joern Wilms XueFeng Wu Ping Zhou Iván Agudo Diego Altamirano Jean-Luc Atteia Nils A.andersson M.Cristina Baglio David R.Ballantyne Altan Baykal Ehud Behar Tomaso Belloni Sudip Bhattacharyya Stefano Bianchi Anna Bilous Pere Blay Joao Braga Sφren Brandt Edward F.Brown Niccolo Bucciantini Luciano Burderi Edward M.Cackett Riccardo Campana Sergio Campana Piergiorgio Casella Yuri Cavecchi Frank Chambers Liang Chen Yu-Peng Chen Jér?me Chenevez Maria Chernyakova ChiChuan Jin Riccardo Ciolfi Elisa Costantini Andrew Cumming Antonino D'Aì Zi-Gao Dai Filippo D'Ammando Massimiliano De Pasquale Nathalie Degenaar Melania Del Santo Valerio D'Elia Tiziana Di Salvo Gerry Doyle Maurizio Falanga XiLong Fan Robert D.Ferdman Marco Feroci Federico Fraschetti Duncan K.Galloway Angelo F.Gambino Poshak Gandhi MingYu Ge Bruce Gendre Ramandeep Gill Diego G?tz Christian Gouiffès Paola Grandi Jonathan Granot Manuel Güdel Alexander Heger Craig O.Heinke Jeroen Homan Rosario Iaria Kazushi Iwasawa Luca Izzo Long Ji Peter G.Jonker Jordi José Jelle S.Kaastra Emrah Kalemci Oleg Kargaltsev Nobuyuki Kawai Laurens Keek Stefanie Komossa Ingo Kreykenbohm Lucien Kuiper Devaky Kunneriath Gang Li En-Wei Liang Manuel Linares Francesco Longo FangJun Lu Alexander A.Lutovinov Denys Malyshev Julien Malzac Antonios Manousakis Ian McHardy Missagh Mehdipour YunPeng Men Mariano Méndez Roberto P.Mignani Romana Mikusincova M.Coleman Miller Giovanni Miniutti Christian Motch Joonas Nättilä Emanuele Nardini Torsten Neubert paul T.O'Brien Mauro Orlandini Julian P.Osborne Luigi Pacciani Stéphane Paltani Maurizio Paolillo Iossif E.Papadakis biswajit paul Alberto Pellizzoni Uria Peretz Miguel A.Pérez Torres Emanuele Perinati Chanda Prescod-Weinstein Pablo Reig SRON Netherlands Institute for Space Research Department of Astronomy University of Geneva Key Laboratory for Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Sciences School of Astronomy and Space Science Nanjing University INAF-IASF Bologna ASI Via del Politecnico snc INAF-Istituto di Astrofisica e Planetologie Spaziali Institut für Astronomie und Astrophysik Tübingen Universit?t Tübingen NASA Goddard Space Flight Center ICREA&Institute of Space Sciences(IEEC-CSIC) Campus UABCarrer de Can Magrans CSPAR SPA University of Alabama in Huntsville Department of Physics Texas Tech University INAF Osservatorio Astronomico di Capodimonte Leiden Observatory Leiden University Anton Pannekoek Institute University of Amsterdam ASTRON Netherlands Institute for Radio Astronomy Universitat Politecnica de Catalunya(UPC-IEEC) Universitádegli Studi di Urbino‘Carlo Bo’ Max-Planck-Institut für Radioastronomie Dr.Karl-Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics(ECAP) Friedrich Alexander Universit?t Erlangen-Nurnberg Purple Mountain Observatory Chinese Academy of Sciences Instituto de Astrofysíca de Andalucia-CSIC Department of Physics and Astronomy University of Southampton IRAP Universitéde ToulouseCNRSUPSCNES Mathematical Sciences and STAG Research Centre University of Southampton New York University Abu Dhabi Center for Relativistic Astrophysics School of PhysicsGeorgia Institute of Technology Physics Department Middle East Technical University Department of Physics Technion-Israel Institute of Technology INAF Osservatorio Astronomico di Brera Tata Institute of Fundamental Research Dipartimento di Matematica e Fisica Universitàdegli Studi Roma Tre Instituto de Astrofísica de Canarias Instituto Nacional de Pesquisas Espaciais-INPE National Space Institute Technical University of Denmark(DTU Space) Department of Physics and Astronomy Michigan State University INAF Osservatorio Astrofisico di Arcetri Dipartimento di Fisica Universitádegli Studi di Cagliari Department of Physics and A

In this White Paper we present the potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies related to Observatory Science targets. These include flaring stars, supernova remnants, accreting white dwarfs, low and high mass X-ray binaries, radio quiet and radio loud active galactic nuclei, tidal disruption events, and gamma-ray bursts. eXTP will be excellently suited to study one common aspect of these objects: their often transient nature. Developed by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Science, the eXTP mission is expected to be launched in the mid 2020s.

关键词： space research in struments nuclear astrophysics flare stars accretion and accretion disks mass loss and stellar winds cataclysmic binaries X-ray binaries supernova remnants active galactic nuclei X-ray bursts gamma-ray bursts gravitational waves