Article
Astronomy & Astrophysics
Ruchi Tamang, Manoj Ghising, Mohammed Tobrej, Binay Rai, Bikash Chandra Paul
Summary: We present the X-ray spectral and timing analysis of the high mass X-ray binary EXO 2030+375 during the 2021 type II outburst. Our comprehensive analysis using multiple observations reveals the evolution of pulse profiles, the presence of iron emission line, and the variations in absorption features and continuum flux. The study helps interpret the characteristics of the source.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Christian Malacaria, Jeremy Heyl, Victor Doroshenko, Sergey S. Tsygankov, Juri Poutanen, Sofia V. Forsblom, Fiamma Capitanio, Alessandro Di Marco, Yujia Du, Lorenzo Ducci, Fabio La Monaca, Alexander A. Lutovinov, Herman L. Marshall, Ilya A. Mereminskiy, Sergey V. Molkov, Alexander A. Mushtukov, Mason Ng, Pierre-Olivier Petrucci, Andrea Santangelo, Andrey E. Shtykovsky, Valery F. Suleimanov, Ivan Agudo, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolo Bucciantini, Simone Castellano, Elisabetta Cavazzuti, Chien-Ting Chen, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolo Di Lalla, Immacolata Donnarumma, Michal Dovciak, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Wataru Iwakiri, Svetlana G. Jorstad, Philip Kaaret, Vladimir Karas, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Henric Krawczynski, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Frederic Marin, Andrea Marinucci, Alan P. Marscher, Francesco Massaro, Giorgio Matt, Ikuyuki Mitsuishi, Tsunefumi Mizuno, Fabio Muleri, Michela Negro, Chi-Yung Ng, Stephen L. O'Dell, Nicola Omodei, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Matteo Perri, Melissa Pesce-Rollins, Maura Pilia, Andrea Possenti, Simonetta Puccetti, Brian D. Ramsey, John Rankin, Ajay Ratheesh, Oliver J. Roberts, Roger W. Romani, Carmelo Sgro, Patrick Slane, Paolo Soffitta, Gloria Spandre, Douglas A. Swartz, Toru Tamagawa, Fabrizio Tavecchio, Roberto Taverna, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Roberto Turolla, Jacco Vink, Martin C. Weisskopf, Kinwah Wu, Fei Xie, Silvia Zane
Summary: Accreting X-ray pulsars are expected to have a high polarization degree, but recent observations of EXO 2030+375 with IXPE show a low degree of polarization in both phase-averaged and phase-resolved studies. Using the rotating vector model, the magnetic obliquity is estimated to be around 60 degrees, indicating that the magnetic axis swings close to the observer's line of sight. The joint analysis of polarization, spectral, and timing data suggests a complex accreting geometry influenced by magnetic multipoles and gravitational light bending.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
J. Alonso-Hernandez, F. Furst, P. Kretschmar, I Caballero, A. M. Joyce
Summary: This study focuses on energy-resolved pulse profiles of a sample of X-ray pulsars and aims to classify them based on their observed pulse profiles and explore the correlations between this classification and their physical observables. The results show that despite the large variety of pulse profiles, clear categories emerged with the approach used. However, no conclusive correlation was found between the pulse profile shapes or groups and other parameters of the systems.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
A. Miraval Zanon, F. Ambrosino, F. Coti Zelati, S. Campana, A. Papitto, G. Illiano, G. L. Israel, L. Stella, P. D'Avanzo, M. C. Baglio
Summary: The transitional millisecond pulsar PSR J1023+0038 emits UV and X-ray pulses, with variability in amplitude observed in both bands. The variations in pulse amplitude do not occur simultaneously in the UV and X-ray bands and are not correlated with the orbital phase. These oscillations in pulse amplitude may be caused by random variations in the mass accretion rate. The pulsed flux spectral distribution from X-ray to UV bands can be well fitted with a power-law relation, supporting a common physical mechanism underlying the emissions in PSR J1023+0038.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
F. Furst, D. J. Walton, M. Heida, M. Bachetti, C. Pinto, M. J. Middleton, M. Brightman, H. P. Earnshaw, D. Barret, A. C. Fabian, P. Kretschmar, K. Pottschmidt, A. Ptak, T. Roberts, D. Stern, N. Webb, J. Wilms
Summary: The study of ULXP NGC7793 P13 over a four year monitoring campaign revealed a continuous spin-up rate independent of the observed X-ray flux, indicating consistent accretion rates despite a decrease in flux. The source entered an apparent off-state in early 2020, possibly resulting in a change in accretion geometry.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Yu-Cong Fu, L. M. Song, G. Q. Ding, M. Y. Ge, Y. L. Tuo, S. Zhang, S. N. Zhang, X. Hou, J. L. Qu, J. Zhang, L. Zhang, Q. C. Bu, Y. Huang, X. Ma, X. Zhou, W. M. Yan, Z. X. Yang, X. F. Lu, T. M. Li, Y. C. Xu, P. J. Wang, S. H. Xiao, H. X. Liu, X. Q. Ren, Y. F. Du, Q. X. Zhao, Y. X. Xiao
Summary: We present an analysis of the X-ray pulsations of EXO 2030+375 during its 2021 outburst using Insight-HXMT observations. Based on the accretion torque model, we investigate the relationship between the spin frequency derivatives and the luminosity. Pulsations are detected in the energy range of 1-160 keV. The pulse profile undergoes significant changes with increasing luminosity, revealing a transition between the supercritical and subcritical accretion modes. Our results suggest the presence of multipole magnetic fields in the neutron star, with inferred magnetic field strengths ranging from (0.41 - 0.74) x 10(12) to (2.4 - 4.3) x 10(13) G.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
C. Malacaria, L. Ducci, M. Falanga, D. Altamirano, E. Bozzo, S. Guillot, G. K. Jaisawal, P. Kretschmar, M. Ng, P. Pradhan, R. Rothschild, A. Sanna, P. Thalhammer, J. Wilms
Summary: When X-ray pulsars accrete and undergo bright X-ray outbursts, their spectral and timing features can be analyzed. The X-ray pulsar GRO J1750-27 recently went through an outburst episode and was observed with NuSTAR and monitored with NICER. The analysis of the data revealed a highly absorbed spectrum with an iron line, a blackbody component from the accretion disk, and the discovery of a deep cyclotron line. The pulse profiles observed remained steady throughout the outburst, contrary to expectations and other similar sources.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Chin-Ping Hu, Kristen C. Dage, William Clarkson, McKinley Brumback, Philip A. Charles, Daryl Haggard, Ryan C. Hickox, Tatehiro Mihara, Arash Bahramian, Rawan Karam, Wasundara Athukoralalage, Diego Altamirano, Joey Neilsen, Jamie Kennea
Summary: SMC X-1 is a high-mass X-ray binary system that exhibits unstable superorbital modulation with several excursion events. A new excursion event in 2020-2021 suggests the chaotic nature of the superorbital modulation. The accelerated spin-up rate before the new excursion indicates a possible connection between spin-up acceleration and superorbital excursion.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Armin Nabizadeh, Sergey S. Tsygankov, Sergey Molkov, Dmitri Karasev, Long Ji, Alexander A. Lutovinov, Juri Poutanen
Summary: This study investigated the poorly studied X-ray pulsar 2S 1845-024 and found no evidence of a cyclotron absorption feature. The analysis of spectral properties as a function of orbital phase revealed a high hydrogen column density near periastron. The accurate localization allowed for the rough classification of the optical counterpart as an OB supergiant at a distance of approximately 15 kiloparsecs.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Sergey S. Tsygankov, Victor Doroshenko, Alexander A. Mushtukov, Juri Poutanen, Alessandro Di Marco, Jeremy Heyl, Fabio La Monaca, Sofia V. Forsblom, Christian Malacaria, Herman L. Marshall, Valery F. Suleimanov, Jiri Svoboda, Roberto Taverna, Francesco Ursini, Ivan Agudo, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolo Bucciantini, Fiamma Capitanio, Simone Castellano, Elisabetta Cavazzuti, Chien-Ting Chen, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolo Di Lalla, Immacolata Donnarumma, Michal Dovciak, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Wataru Iwakiri, Svetlana G. Jorstad, Philip Kaaret, Vladimir Karas, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Henric Krawczynski, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Frederic Marin, Andrea Marinucci, Alan P. Marscher, Francesco Massaro, Giorgio Matt, Ikuyuki Mitsuishi, Tsunefumi Mizuno, Fabio Muleri, Michela Negro, Chi-Yung Ng, Stephen L. O'Dell, Nicola Omodei, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Matteo Perri, Melissa Pesce-Rollins, Pierre-Olivier Petrucci, Maura Pilia, Andrea Possenti, Simonetta Puccetti, Brian D. Ramsey, John Rankin, Ajay Ratheesh, Oliver J. Roberts, Roger W. Romani, Carmelo Sgro, Patrick Slane, Paolo Soffitta, Gloria Spandre, Douglas A. Swartz, Toru Tamagawa, Fabrizio Tavecchio, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Roberto Turolla, Jacco Vink, Martin C. Weisskopf, Kinwah Wu, Fei Xie, Silvia Zane
Summary: X-ray polarimetry is a unique method for investigating the geometry of highly magnetized accreting neutron stars. The X-ray pulsar, GRO J1008-57, was observed at different flux levels by IXPE during its outburst in November 2022. Despite variations in luminosity, the polarization properties of GRO J1008-57 remained consistent, with a polarization degree of up to 15% over the pulse phase. By analyzing the data using the rotating vector model, estimations were made for the pulsar inclination, position angle of the pulsar spin axis, and magnetic obliquity.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Amy H. Knight, Adam Ingram, Matthew Middleton, Jeremy Drake
Summary: Determining the maximum possible neutron star mass helps to constrain the equation of state of ultra-dense matter. By analyzing X-ray eclipses in a low-mass X-ray binary, it is found that the companion star may be experiencing outer layer ablation, suggesting a transition into a redback millisecond pulsar. The derived mass ratio, inclination, and radial velocity measurements support a hard equation of state, but considering other emission lines, a canonical neutron star mass is also possible.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Armin Nabizadeh, Sergey S. Tsygankov, Long Ji, Victor Doroshenko, Sergey Molkov, Youli Tuo, Shuang-Nan Zhang, Fan-Jun Lu, Shu Zhang, Juri Poutanen
Summary: A detailed spectral analysis of emission from the X-ray pulsar 4U 1901+03 was conducted using data obtained by Insight-HXMT and NuSTAR observatories during the 2019 outburst. The study questioned the interpretation of a putative absorption feature at 10 keV as a cyclotron line, and found another absorption feature around 30 keV significantly detected in both phase-averaged and phase-resolved spectra.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Pragati Pradhan, Biswajit Paul, Enrico Bozzo, Chandreyee Maitra, B. C. Paul
Summary: A wide-band spectral analysis of accreting neutron stars was conducted using data from the Suzaku satellite, revealing correlations between various spectral parameters and distribution patterns of cut-off energies and cyclotron lines. The study showed saturation of cut-off energies for higher cyclotron line energies, with a weak correlation between the width of the cyclotron line and its energy. Additionally, an anticorrelation was found between spectral index and folding energy, and differences in the characteristics of iron Kα lines in SFXTs compared to classical NS-HMXBs were identified.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Rahul Sharma, Chetana Jain, Ketan Rikame, Biswajit Paul
Summary: We present the results of broad-band timing and spectral analysis of AstroSat observations of LMC X-4. We detected a complete X-ray eclipse and found coherent pulsations and a quasi-periodic oscillation feature in the power density spectrum. The joint analysis of the SXT and LAXPC spectral data revealed the spectral properties of LMC X-4, including a high-energy cut-off power law, a soft thermal component, and Gaussian components corresponding to emission lines. The determined luminosity was approximately 2 x 10^(38) erg s^(-1).
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jiren Liu, Georgios Vasilopoulos, MingYu Ge, Long Ji, Shan-Shan Weng, Shuang-Nan Zhang, Xian Hou
Summary: This study compares the super-Eddington accretion regimes of SMC X-3 and RX J0209.6-7427 with that of Swift J0243.6+6124. The results show that SMC X-3 and Swift J0243 have similar double-peak profiles at low luminosities. RX J0209 exhibits double-peak profiles at both high and low luminosities, with a 0.25 phase offset compared to SMC X-3 and Swift J0243, indicating a transition from a fan beam to a pencil beam. The study also finds that the surface magnetic fields of SMC X-3 and RX J0209 are approximately 4 x 10(13) G and 2 x 10(13) G, respectively.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
M. Ozbey Arabaci, A. Camero-Arranz, C. Zurita, J. Gutierrez-Soto, E. Nespoli, J. Suso, F. Kiaeerad, J. Garcia-Rojas, U. Kiziloglu
ASTRONOMY & ASTROPHYSICS
(2015)
Article
Astronomy & Astrophysics
M. Ozbey Arabaci, A. Camero-Arranz, C. Zurita, J. Gutierrez-Soto, E. Nespoli, J. Suso, F. Kiaeerad, J. Garcia-Rojas, U. Kiziloglu
ASTRONOMY & ASTROPHYSICS
(2015)
Article
Astronomy & Astrophysics
M. D. Caballero-Garcia, A. Camero-Arranz, M. Ozbey Arabaci, C. Zurita, J. Suso, J. Gutierrez-Soto, E. Beklen, F. Kiaeerad, R. Garrido, R. Hudec
ASTRONOMY & ASTROPHYSICS
(2016)
Article
Astronomy & Astrophysics
M. D. Caballero-Garcia, A. Camero-Arranz, M. Ozbey Arabaci, C. Zurita, J. Suso, J. Gutierrez-Soto, E. Beklen, F. Kiaeerad, R. Garrido, R. Hudec
ASTRONOMY & ASTROPHYSICS
(2016)
Article
Astronomy & Astrophysics
J. Rodi, M. L. Cherry, G. L. Case, A. Camero-Arranz, V. Chaplin, M. H. Finger, P. Jenke, C. A. Wilson-Hodge
ASTRONOMY & ASTROPHYSICS
(2014)
Article
Astronomy & Astrophysics
A. Camero, C. Zurita, J. Gutierrez-Soto, M. Ozbey Arabaci, E. Nespoli, F. Kiaeerad, E. Beklen, J. Garcia-Rojas, M. Caballero-Garcia
ASTRONOMY & ASTROPHYSICS
(2014)
Article
Astronomy & Astrophysics
Richard Rothschild, Alex Markowitz, Paul Hemphill, Isabel Caballero, Katja Pottschmidt, Matthias Kuehnel, Joern Wilms, Felix Fuerst, Victor Doroshenko, Ascension Camero-Arranz
ASTROPHYSICAL JOURNAL
(2013)
Article
Astronomy & Astrophysics
I. Caballero, K. Pottschmidt, D. M. Marcu, L. Barragan, C. Ferrigno, D. Klochkov, J. A. Zurita Heras, S. Suchy, J. Wilms, P. Kretschmar, A. Santangelo, I. Kreykenbohm, F. Fuerst, R. Rothschild, R. Staubert, M. H. Finger, A. Camero-Arranz, K. Makishima, T. Enoto, W. Iwakiri, Y. Terada
ASTROPHYSICAL JOURNAL LETTERS
(2013)
Article
Astronomy & Astrophysics
N. Rea, P. Esposito, J. A. Pons, R. Turolla, D. F. Torres, G. L. Israel, A. Possenti, M. Burgay, D. Vigano, A. Papitto, R. Perna, L. Stella, G. Ponti, F. K. Baganoff, D. Haggard, A. Camero-Arranz, S. Zane, A. Minter, S. Mereghetti, A. Tiengo, R. Schoedel, M. Feroci, R. Mignani, D. Goetz
ASTROPHYSICAL JOURNAL LETTERS
(2013)
Article
Astronomy & Astrophysics
A. Camero-Arranz, N. Rea, N. Bucciantini, M. A. McLaughlin, P. Slane, B. M. Gaensler, D. F. Torres, L. Stella, E. de Ona, G. L. Israel, F. Camilo, A. Possenti
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2013)
Article
Astronomy & Astrophysics
A. Camero, A. Papitto, N. Rea, D. Vigano, J. A. Pons, A. Tiengo, S. Mereghetti, R. Turolla, P. Esposito, S. Zane, G. L. Israel, D. Goetz
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2014)
Article
Education & Educational Research
Noemi Pena-Sanchez, Ascension Camero-Arranz
Summary: This visual essay is a reflective interdisciplinary encounter between three undergraduate students in a Bachelor of Elementary Education participating in a final year degree project narrated by two educators, one from art education and the other from science education. It applies a situated art intervention to sensory land walking methodologies to raise awareness about the loss of biodiversity in the Canary Islands.
INTERNATIONAL JOURNAL OF EDUCATION THROUGH ART
(2023)
Article
Astronomy & Astrophysics
P. A. Jenke, M. Linares, V. Connaughton, E. Beklen, A. Camero-Arranz, M. H. Finger, C. A. Wilson-Hodge
ASTROPHYSICAL JOURNAL
(2016)
Proceedings Paper
Physics, Applied
K. Pottschmidt, S. Suchy, E. Rivers, R. E. Rothschild, D. M. Marcu, L. Barragan, M. Kuehnel, F. Fuerst, F. Schwarrn, I. Kreykenbohm, J. Wilms, G. Schoenherr, I. Caballero, A. Camero-Arranz, A. Bodaghee, V. Doroshenko, D. Klochkov, A. Santangelo, R. Staubert, P. Kretschmar, C. Wilson-Hodge, M. H. Finger, Y. Terada
SUZAKU 2011: EXPLORING THE X-RAY UNIVERSE: SUZAKU AND BEYOND
(2012)
Proceedings Paper
Physics, Applied
I. Caballero, S. Mueller, P. Bordas, C. Ferrigno, M. Kuehnel, K. Pottschmidt, P. Kretschmar, J. Wilms, I. Kreykenbohm, D. Klochkov, A. Santangelo, R. Staubert, S. Suchy, R. Rothschild, A. Camero-Arranz, M. Finger
SUZAKU 2011: EXPLORING THE X-RAY UNIVERSE: SUZAKU AND BEYOND
(2012)