R. Turolla - Dept. of Physics and Astronomy University of Padua, Italy

R. Turolla
Are you R. Turolla?

Claim your profile, edit publications, add additional information:

Contact Details

Name
R. Turolla
Affiliation
Dept. of Physics and Astronomy University of Padua, Italy
City
Padua
Country
Italy

Pubs By Year

External Links

Pub Categories

 
High Energy Astrophysical Phenomena (48)
 
Astrophysics of Galaxies (5)
 
Solar and Stellar Astrophysics (3)
 
Instrumentation and Methods for Astrophysics (3)
 
Nuclear Experiment (1)

Publications Authored By R. Turolla

We report on the results of a detailed phase-resolved spectroscopy of archival XMM--Newton observations of X-ray Dim Isolated Neutron Stars (XDINSs). Our analysis revealed a narrow and phase-variable absorption feature in the X-ray spectrum of RX J1308.6+2127. Read More

2016Nov
Affiliations: 1on behalf of the e-ASTROGAM Collaboration, 2on behalf of the e-ASTROGAM Collaboration, 3on behalf of the e-ASTROGAM Collaboration, 4on behalf of the e-ASTROGAM Collaboration, 5on behalf of the e-ASTROGAM Collaboration, 6on behalf of the e-ASTROGAM Collaboration, 7on behalf of the e-ASTROGAM Collaboration, 8on behalf of the e-ASTROGAM Collaboration, 9on behalf of the e-ASTROGAM Collaboration, 10on behalf of the e-ASTROGAM Collaboration, 11on behalf of the e-ASTROGAM Collaboration, 12on behalf of the e-ASTROGAM Collaboration, 13on behalf of the e-ASTROGAM Collaboration, 14on behalf of the e-ASTROGAM Collaboration, 15on behalf of the e-ASTROGAM Collaboration, 16on behalf of the e-ASTROGAM Collaboration, 17on behalf of the e-ASTROGAM Collaboration, 18on behalf of the e-ASTROGAM Collaboration, 19on behalf of the e-ASTROGAM Collaboration, 20on behalf of the e-ASTROGAM Collaboration, 21on behalf of the e-ASTROGAM Collaboration, 22on behalf of the e-ASTROGAM Collaboration, 23on behalf of the e-ASTROGAM Collaboration, 24on behalf of the e-ASTROGAM Collaboration, 25on behalf of the e-ASTROGAM Collaboration, 26on behalf of the e-ASTROGAM Collaboration, 27on behalf of the e-ASTROGAM Collaboration, 28on behalf of the e-ASTROGAM Collaboration, 29on behalf of the e-ASTROGAM Collaboration, 30on behalf of the e-ASTROGAM Collaboration, 31on behalf of the e-ASTROGAM Collaboration, 32on behalf of the e-ASTROGAM Collaboration, 33on behalf of the e-ASTROGAM Collaboration, 34on behalf of the e-ASTROGAM Collaboration, 35on behalf of the e-ASTROGAM Collaboration, 36on behalf of the e-ASTROGAM Collaboration, 37on behalf of the e-ASTROGAM Collaboration, 38on behalf of the e-ASTROGAM Collaboration, 39on behalf of the e-ASTROGAM Collaboration, 40on behalf of the e-ASTROGAM Collaboration, 41on behalf of the e-ASTROGAM Collaboration, 42on behalf of the e-ASTROGAM Collaboration, 43on behalf of the e-ASTROGAM Collaboration, 44on behalf of the e-ASTROGAM Collaboration, 45on behalf of the e-ASTROGAM Collaboration, 46on behalf of the e-ASTROGAM Collaboration, 47on behalf of the e-ASTROGAM Collaboration, 48on behalf of the e-ASTROGAM Collaboration, 49on behalf of the e-ASTROGAM Collaboration, 50on behalf of the e-ASTROGAM Collaboration, 51on behalf of the e-ASTROGAM Collaboration, 52on behalf of the e-ASTROGAM Collaboration, 53on behalf of the e-ASTROGAM Collaboration, 54on behalf of the e-ASTROGAM Collaboration, 55on behalf of the e-ASTROGAM Collaboration, 56on behalf of the e-ASTROGAM Collaboration, 57on behalf of the e-ASTROGAM Collaboration, 58on behalf of the e-ASTROGAM Collaboration, 59on behalf of the e-ASTROGAM Collaboration, 60on behalf of the e-ASTROGAM Collaboration, 61on behalf of the e-ASTROGAM Collaboration, 62on behalf of the e-ASTROGAM Collaboration, 63on behalf of the e-ASTROGAM Collaboration, 64on behalf of the e-ASTROGAM Collaboration, 65on behalf of the e-ASTROGAM Collaboration, 66on behalf of the e-ASTROGAM Collaboration, 67on behalf of the e-ASTROGAM Collaboration, 68on behalf of the e-ASTROGAM Collaboration, 69on behalf of the e-ASTROGAM Collaboration, 70on behalf of the e-ASTROGAM Collaboration

e-ASTROGAM (`enhanced ASTROGAM') is a breakthrough Observatory mission dedicated to the study of the non-thermal Universe in the photon energy range from 0.3 MeV to 3 GeV. The mission is based on an advanced space-proven detector technology, with unprecedented sensitivity, angular and energy resolution, combined with polarimetric capability. Read More

2016Oct
Affiliations: 1INAF/IASF, Milan, Janusz Gil Institut of Astronomy, University of Zielona Gora, 2INAF/OAR, 3UCL/MSSL, 4Dipartimento di Fisica e Astronomia, Universita' di Padova, 5Dipartimento di Fisica e Astronomia, Universita' di Padova, UCL/MSSL, 6UCL/MSSL, 7UCL/MSSL

The "Magnificent Seven" (M7) are a group of radio-quiet Isolated Neutron Stars (INSs) discovered in the soft X-rays through their purely thermal surface emission. Owing to the large inferred magnetic fields ($B\approx 10^{13}$ G), radiation from these sources is expected to be substantially polarised, independently on the mechanism actually responsible for the thermal emission. A large observed polarisation degree is, however, expected only if quantum-electrodynamics (QED) polarisation effects are present in the magnetised vacuum around the star. Read More

2016Oct

The evolution of magnetic field in isolated neutron stars is one of the most important ingredients in the attempt to build a unified description of these objects. A prediction of field evolution models is the existence of an equilibrium configuration, in which the Hall cascade vanishes. Recent calculations have explored the field structure in this stage, called the Hall attractor. Read More

Ultraluminous x-ray sources (ULXs) in nearby galaxies shine brighter than any X-ray source in our Galaxy. ULXs are usually modeled as stellar-mass black holes (BHs) accreting at very high rates or intermediate-mass BHs. We present observations showing that NGC5907 ULX is instead an x-ray accreting neutron star (NS) with a spin period evolving from 1. Read More

2016Jul
Authors: S. N. Zhang, M. Feroci, A. Santangelo, Y. W. Dong, H. Feng, F. J. Lu, K. Nandra, Z. S. Wang, S. Zhang, E. Bozzo, S. Brandt, A. De Rosa, L. J. Gou, M. Hernanz, M. van der Klis, X. D. Li, Y. Liu, P. Orleanski, G. Pareschi, M. Pohl, J. Poutanen, J. L. Qu, S. Schanne, L. Stella, P. Uttley, A. Watts, R. X. Xu, W. F. Yu, J. J. M. in 't Zand, S. Zane, L. Alvarez, L. Amati, L. Baldini, C. Bambi, S. Basso, S. Bhattacharyya, R. Bellazzini, T. Belloni, P. Bellutti, S. Bianchi, A. Brez, M. Bursa, V. Burwitz, C. Budtz-Jorgensen, I. Caiazzo, R. Campana, X. L. Cao, P. Casella, C. Y. Chen, L. Chen, T. X. Chen, Y. Chen, Y. Chen, Y. P. Chen, M. Civitani, F. Coti Zelati, W. Cui, W. W. Cui, Z. G. Dai, E. Del Monte, D. De Martino, S. Di Cosimo, S. Diebold, M. Dovciak, I. Donnarumma, V. Doroshenko, P. Esposito, Y. Evangelista, Y. Favre, P. Friedrich, F. Fuschino, J. L. Galvez, Z. L. Gao, M. Y. Ge, O. Gevin, D. Goetz, D. W. Han, J. Heyl, J. Horak, W. Hu, F. Huang, Q. S. Huang, R. Hudec, D. Huppenkothen, G. L. Israel, A. Ingram, V. Karas, D. Karelin, P. A. Jenke, L. Ji, T. Kennedy, S. Korpela, D. Kunneriath, C. Labanti, G. Li, X. Li, Z. S. Li, E. W. Liang, O. Limousin, L. Lin, Z. X. Ling, H. B. Liu, H. W. Liu, Z. Liu, B. Lu, N. Lund, D. Lai, B. Luo, T. Luo, B. Ma, S. Mahmoodifar, M. Marisaldi, A. Martindale, N. Meidinger, Y. P. Men, M. Michalska, R. Mignani, M. Minuti, S. Motta, F. Muleri, J. Neilsen, M. Orlandini, A T. Pan, A. Patruno, E. Perinati, A. Picciotto, C. Piemonte, M. Pinchera, A. Rachevski, M. Rapisarda, N. Rea, E. M. R. Rossi, A. Rubini, G. Sala, X. W. Shu, C. Sgro, Z. X. Shen, P. Soffitta, L. M. Song, G. Spandre, G. Stratta, T. E. Strohmayer, L. Sun, J. Svoboda, G. Tagliaferri, C. Tenzer, H. Tong, R. Taverna, G. Torok, R. Turolla, A. Vacchi, J. Wang, J. X. Wang, D. Walton, K. Wang, J. F. Wang, R. J. Wang, Y. F. Wang, S. S. Weng, J. Wilms, B. Winter, X. Wu, X. F. Wu, S. L. Xiong, Y. P. Xu, Y. Q. Xue, Z. Yan, S. Yang, X. Yang, Y. J. Yang, F. Yuan, W. M. Yuan, Y. F. Yuan, G. Zampa, N. Zampa, A. Zdziarski, C. Zhang, C. L. Zhang, L. Zhang, X. Zhang, Z. Zhang, W. D. Zhang, S. J. Zheng, P. Zhou, X. L. Zhou

eXTP is a science mission designed to study the state of matter under extreme conditions of density, gravity and magnetism. Primary targets include isolated and binary neutron stars, strong magnetic field systems like magnetars, and stellar-mass and supermassive black holes. The mission carries a unique and unprecedented suite of state-of-the-art scientific instruments enabling for the first time ever the simultaneous spectral-timing-polarimetry studies of cosmic sources in the energy range from 0. Read More

We report on simultaneous X-ray and radio observations of the mode-switching pulsar PSR B0943+10 obtained with the XMM-Newton satellite and the LOFAR, LWA and Arecibo radio telescopes in November 2014. We confirm the synchronous X-ray/radio switching between a radio-bright (B) and a radio-quiet (Q) mode, in which the X-ray flux is a factor ~2.4 higher than in the B-mode. Read More

The observed polarization properties of thermal radiation from isolated, cooling neutron stars depend on both the emission processes at the surface and the effects of the magnetized vacuum which surrounds the star. Here we investigate the polarized thermal emission from X-ray Dim Isolated Neutron Stars, taking RX J1856.5-3754 as a representative case. Read More

We have analyzed XMM-Newton and Chandra observations of the transient magnetar XTE J1810-197, spanning more than 11 years, from the initial phases of the 2003 outburst to the current quiescent level. We investigated the evolution of the pulsar spin period and we found evidence for two distinct regimes: during the outburst decay, the spin derivative (nu_dot) was highly variable in the range -(2-4.5)x10^-13 Hz/s, while during quiescence the spin-down rate was more stable at an average value of -1x10^{-13} Hz/s. Read More

We report on the discovery of a new member of the magnetar class, SGR J1935+2154, and on its timing and spectral properties measured by an extensive observational campaign carried out between July 2014 and March 2015 with Chandra and XMM-Newton (11 pointings). We discovered the spin period of SGR J1935+2154 through the detection of coherent pulsations at a period of about 3.24s. Read More

Giant $\gamma$-ray flares comprise the most extreme radiation events observed from magnetars. Developing on (sub)millisecond timescales and generating vast amounts of energy within a fraction of a second, the initial phase of these extraordinary bursts present a significant challenge for candidate trigger mechanisms. Here we assess and critically analyse the linear growth of the relativistic tearing instability in a globally twisted magnetosphere as the trigger mechanism for giant $\gamma$-ray flares. Read More

We study the timing and spectral properties of the low-magnetic field, transient magnetar SWIFT J1822.3-1606 as it approached quiescence. We coherently phase-connect the observations over a time-span of ~500 days since the discovery of SWIFT J1822. Read More

New-generation X-ray polarimeters currently under development promise to open a new window in the study of high-energy astrophysical sources. Among them, neutron stars appear particularly suited for polarization measurements. Radiation from the (cooling) surface of a neutron star is expected to exhibit a large intrinsic polarization degree due to the star strong magnetic field ($\approx 10^{12}-10^{15}$ G), which influences the plasma opacity in the outermost stellar layers. Read More

The isolated neutron star (INS) 2XMM J104608.7-594306 is one of the only two to be discovered through their thermal emission since the ROSAT era. In a first dedicated XMM-Newton observation of the source, we found intriguing evidence of a very fast spin period. Read More

Magnetars are the strongest magnets in the present universe and the combination of extreme magnetic field, gravity and density makes them unique laboratories to probe current physical theories (from quantum electrodynamics to general relativity) in the strong field limit. Magnetars are observed as peculiar, burst--active X-ray pulsars, the Anomalous X-ray Pulsars (AXPs) and the Soft Gamma Repeaters (SGRs); the latter emitted also three "giant flares," extremely powerful events during which luminosities can reach up to 10^47 erg/s for about one second. The last five years have witnessed an explosion in magnetar research which has led, among other things, to the discovery of transient, or "outbursting," and "low-field" magnetars. Read More

2015Jun
Affiliations: 1U. Amsterdam, 2U. Amsterdam/CSIC-IEEC, 3U. Insubria/U. Amsterdam/INAF, 4IUSS-Pavia/INAF, 5U. Padova/MSSL

We present the discovery of a strongly phase-variable absorption feature in the X-ray spectrum of the nearby, thermally-emitting, isolated neutron star RX J0720.4-3125. The absorption line was detected performing detailed phase-resolved spectroscopy in 20 XMM-Newton observations, covering the period May 2000 - September 2012. Read More

In 2013 April a new magnetar, SGR 1745-2900, was discovered as it entered an outburst, at only 2.4 arcsec angular distance from the supermassive black hole at the Centre of the Milky Way, Sagittarius A*. SGR 1745-2900 has a surface dipolar magnetic field of ~ 2x10^{14} G, and it is the neutron star closest to a black hole ever observed. Read More

This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of magnetospheres of isolated neutron stars. For a summary, we refer to the paper. Read More

Diffuse radio emission was detected around the soft gamma-ray repeater SGR 1806-20, after its 2004 powerful giant flare. We study the possible extended X-ray emission at small scales around SGR 1806-20, in two observations by the High Resolution Camera Spectrometer (HRC-S) on board of the Chandra X-ray Observatory: in 2005, 115 days after the giant flare, and in 2013, during quiescence. We compare the radial profiles extracted from data images and PSF simulations, carefully considering various issues related with the uncertain calibration of the HRC PSF at sub-arcsecond scales. Read More

2014Aug
Authors: M. Feroci1, J. W. den Herder2, E. Bozzo3, D. Barret4, S. Brandt5, M. Hernanz6, M. van der Klis7, M. Pohl8, A. Santangelo9, L. Stella10, A. Watts11, J. Wilms12, S. Zane13, M. Ahangarianabhari14, C. Albertus15, M. Alford16, A. Alpar17, D. Altamirano18, L. Alvarez19, L. Amati20, C. Amoros21, N. Andersson22, A. Antonelli23, A. Argan24, R. Artigue25, B. Artigues26, J. -L. Atteia27, P. Azzarello28, P. Bakala29, G. Baldazzi30, S. Balman31, M. Barbera32, C. van Baren33, S. Bhattacharyya34, A. Baykal35, T. Belloni36, F. Bernardini37, G. Bertuccio38, S. Bianchi39, A. Bianchini40, P. Binko41, P. Blay42, F. Bocchino43, P. Bodin44, I. Bombaci45, J. -M. Bonnet Bidaud46, S. Boutloukos47, L. Bradley48, J. Braga49, E. Brown50, N. Bucciantini51, L. Burderi52, M. Burgay53, M. Bursa54, C. Budtz-Jørgensen55, E. Cackett56, F. R. Cadoux57, P. Cais58, G. A. Caliandro59, R. Campana60, S. Campana61, F. Capitanio62, J. Casares63, P. Casella64, A. J. Castro-Tirado65, E. Cavazzuti66, P. Cerda-Duran67, D. Chakrabarty68, F. Château69, J. Chenevez70, J. Coker71, R. Cole72, A. Collura73, R. Cornelisse74, T. Courvoisier75, A. Cros76, A. Cumming77, G. Cusumano78, A. D'Aì79, V. D'Elia80, E. Del Monte81, A. De Luca82, D. De Martino83, J. P. C. Dercksen84, M. De Pasquale85, A. De Rosa86, M. Del Santo87, S. Di Cosimo88, S. Diebold89, T. Di Salvo90, I. Donnarumma91, A. Drago92, M. Durant93, D. Emmanoulopoulos94, M. H. Erkut95, P. Esposito96, Y. Evangelista97, A. Fabian98, M. Falanga99, Y. Favre100, C. Feldman101, V. Ferrari102, C. Ferrigno103, M. Finger104, M. H. Finger105, G. W. Fraser106, M. Frericks107, F. Fuschino108, M. Gabler109, D. K. Galloway110, J. L. Galvez Sanchez111, E. Garcia-Berro112, B. Gendre113, S. Gezari114, A. B. Giles115, M. Gilfanov116, P. Giommi117, G. Giovannini118, M. Giroletti119, E. Gogus120, A. Goldwurm121, K. Goluchová122, D. Götz123, C. Gouiffes124, M. Grassi125, P. Groot126, M. Gschwender127, L. Gualtieri128, C. Guidorzi129, L. Guy130, D. Haas131, P. Haensel132, M. Hailey133, F. Hansen134, D. H. Hartmann135, C. A. Haswell136, K. Hebeler137, A. Heger138, W. Hermsen139, J. Homan140, A. Hornstrup141, R. Hudec142, J. Huovelin143, A. Ingram144, J. J. M. in't Zand145, G. Israel146, K. Iwasawa147, L. Izzo148, H. M. Jacobs149, F. Jetter150, T. Johannsen151, H. M. Jacobs152, P. Jonker153, J. Josè154, P. Kaaret155, G. Kanbach156, V. Karas157, D. Karelin158, D. Kataria159, L. Keek160, T. Kennedy161, D. Klochkov162, W. Kluzniak163, K. Kokkotas164, S. Korpela165, C. Kouveliotou166, I. Kreykenbohm167, L. M. Kuiper168, I. Kuvvetli169, C. Labanti170, D. Lai171, F. K. Lamb172, P. P. Laubert173, F. Lebrun174, D. Lin175, D. Linder176, G. Lodato177, F. Longo178, N. Lund179, T. J. Maccarone180, D. Macera181, S. Maestre182, S. Mahmoodifar183, D. Maier184, P. Malcovati185, I. Mandel186, V. Mangano187, A. Manousakis188, M. Marisaldi189, A. Markowitz190, A. Martindale191, G. Matt192, I. M. McHardy193, A. Melatos194, M. Mendez195, S. Mereghetti196, M. Michalska197, S. Migliari198, R. Mignani199, M. C. Miller200, J. M. Miller201, T. Mineo202, G. Miniutti203, S. Morsink204, C. Motch205, S. Motta206, M. Mouchet207, G. Mouret208, J. Mulačová209, F. Muleri210, T. Muñoz-Darias211, I. Negueruela212, J. Neilsen213, A. J. Norton214, M. Nowak215, P. O'Brien216, P. E. H. Olsen217, M. Orienti218, M. Orio219, M. Orlandini220, P. Orleanski221, J. P. Osborne222, R. Osten223, F. Ozel224, L. Pacciani225, M. Paolillo226, A. Papitto227, J. M. Paredes228, A. Patruno229, B. Paul230, E. Perinati231, A. Pellizzoni232, A. V. Penacchioni233, M. A. Perez234, V. Petracek235, C. Pittori236, J. Pons237, J. Portell238, A. Possenti239, J. Poutanen240, M. Prakash241, P. Le Provost242, D. Psaltis243, D. Rambaud244, P. Ramon245, G. Ramsay246, M. Rapisarda247, A. Rachevski248, I. Rashevskaya249, P. S. Ray250, N. Rea251, S. Reddy252, P. Reig253, M. Reina Aranda254, R. Remillard255, C. Reynolds256, L. Rezzolla257, M. Ribo258, R. de la Rie259, A. Riggio260, A. Rios261, P. Rodríguez- Gil262, J. Rodriguez263, R. Rohlfs264, P. Romano265, E. M. R. Rossi266, A. Rozanska267, A. Rousseau268, F. Ryde269, L. Sabau-Graziati270, G. Sala271, R. Salvaterra272, A. Sanna273, J. Sandberg274, S. Scaringi275, S. Schanne276, J. Schee277, C. Schmid278, S. Shore279, R. Schneider280, A. Schwenk281, A. D. Schwope282, J. -Y. Seyler283, A. Shearer284, A. Smith285, D. M. Smith286, P. J. Smith287, V. Sochora288, P. Soffitta289, P. Soleri290, A. Spencer291, B. Stappers292, A. W. Steiner293, N. Stergioulas294, G. Stratta295, T. E. Strohmayer296, Z. Stuchlik297, S. Suchy298, V. Sulemainov299, T. Takahashi300, F. Tamburini301, T. Tauris302, C. Tenzer303, L. Tolos304, F. Tombesi305, J. Tomsick306, G. Torok307, J. M. Torrejon308, D. F. Torres309, A. Tramacere310, A. Trois311, R. Turolla312, S. Turriziani313, P. Uter314, P. Uttley315, A. Vacchi316, P. Varniere317, S. Vaughan318, S. Vercellone319, V. Vrba320, D. Walton321, S. Watanabe322, R. Wawrzaszek323, N. Webb324, N. Weinberg325, H. Wende326, P. Wheatley327, R. Wijers328, R. Wijnands329, M. Wille330, C. A. Wilson-Hodge331, B. Winter332, K. Wood333, G. Zampa334, N. Zampa335, L. Zampieri336, L. Zdunik337, A. Zdziarski338, B. Zhang339, F. Zwart340, M. Ayre341, T. Boenke342, C. Corral van Damme343, E. Kuulkers344, D. Lumb345
Affiliations: 11,1b, 2SRON, The Netherlands, 3ISDC, Geneve University, Switzerland, 4IRAP, Toulouse, France, 5National Space Institute, Lyngby, Denmark, 6IEEC-CSIC-UPC-UB, Barcelona, Spain, 7Astronomical Institute Anton Pannekoek, University of Amsterdam, The Netherlands, 8DPNC, Geneve University, Switzerland, 9IAAT Tuebingen, Germany, 10INAF-OA Rome, Italy, 11Astronomical Institute Anton Pannekoek, University of Amsterdam, The Netherlands, 12University of Erlangen-Nuremberg, Germany, 13MSSL, Surrey, United Kingdom, 14Politecnico Milano, Italy, 15Universidad de Granada, Spain, 16Washington University, United States, 17Sabanci University, Istanbul, Turkey, 18Astronomical Institute Anton Pannekoek, University of Amsterdam, The Netherlands, 19IEEC-CSIC-UPC-UB, Barcelona, Spain, 20INAF-IASF-Bologna, Italy, 21IRAP, Toulouse, France, 22Faculty of Physical and Applied Sciences, University of Southampton, United Kingdom, 23ASDC, Rome, Italy, 24IAPS-INAF, Rome, Italy, 25IRAP, Toulouse, France, 26IEEC-CSIC-UPC-UB, Barcelona, Spain, 27IRAP, Toulouse, France, 28ISDC, Geneve University, Switzerland, 29Silesian University in Opava, Czech Republic, 30University of Bologna, Italy, 31Middle East Technical University, Ankara, Turkey, 32Dipartimento di Chimica e Fisica, Palermo University, Italy, 33SRON, The Netherlands, 34Tata Institute of Fundamental Research, Mumbai, India, 35Middle East Technical University, Ankara, Turkey, 36INAF-OA Brera, Italy, 37Wayne State University, Detroit, United States, 38Politecnico Milano, Italy, 39University of Rome III, Italy, 40Dept. of Physics and Astronomy University of Padua, Italy, 41ISDC, Geneve University, Switzerland, 42University of Valencia, Spain, 43INAF-OA Padova, Padova, Italy, 44CNES, Toulouse, France, 45University of Pisa, Italy, 46CEA Saclay, DSM/IRFU/SAp, France, 47IAAT Tuebingen, Germany, 48MSSL, Surrey, United Kingdom, 49INPE, São José dos Campos, Brazil, 50Michigan state University, United States, 51Arcetri Observatory, INAF, Firenze, Italy, 52Cagliari University, Italy, 53INAF-OA Cagliari, Italy, 54Astronomical Institute of the Academy of Sciences of the Czech Republic, Czech Republic, 55National Space Institute, Lyngby, Denmark, 56Wayne State University, Detroit, United States, 57DPNC, Geneve University, Switzerland, 58Laboratoire d'Astrophysique de Bordeaux, France, 59IEEC-CSIC-UPC-UB, Barcelona, Spain, 601,1b, 61INAF-OA Brera, Italy, 62IAPS-INAF, Rome, Italy, 63Instituto de Astrofisica de Canarias, Tenerife, Spain, 64INAF-OA Rome, Italy, 65Instituto Astrofisica de Andalucia, Granada, Spain, 66ASDC, Rome, Italy, 67University of Valencia, Spain, 68MIT, Cambridge, United States, 69CEA Saclay, DSM/IRFU/SAp, France, 70National Space Institute, Lyngby, Denmark, 71MSSL, Surrey, United Kingdom, 72MSSL, Surrey, United Kingdom, 73INAF- Osservatorio Astronomico di Palermo, Italy, 74Instituto de Astrofisica de Canarias, Tenerife, Spain, 75ISDC, Geneve University, Switzerland, 76IRAP, Toulouse, France, 77INAF-OA Capodimonte, Napoli, Italy, 78INAF IFC, Palermo, Italy, 79Dipartimento di Chimica e Fisica, Palermo University, Italy, 80ASDC, Rome, Italy, 811,1b, 82INAF-IASF-Milano, Italy, 83INAF-OA Capodimonte, Napoli, Italy, 84SRON, The Netherlands, 85MSSL, Surrey, United Kingdom, 86IAPS-INAF, Rome, Italy, 87IAPS-INAF, Rome, Italy, 88IAPS-INAF, Rome, Italy, 89IAAT Tuebingen, Germany, 90Dipartimento di Chimica e Fisica, Palermo University, Italy, 91IAPS-INAF, Rome, Italy, 92Ferrara University, Ferrara, Italy, 93Department of Medical Biophysics, University of Toronto, Canada, 94School of Physics and Astronomy, University of Southampton, United Kingdom, 95Istanbul Kültür University, Turkey, 96INAF-IASF-Milano, Italy, 971,1b, 98Cambridge University, Cambridge, United Kingdom, 99ISSI Bern, Switzerland, 100DPNC, Geneve University, Switzerland, 101Leicester University, United Kingdom, 102Sapienza University, Rome, Italy, 103ISDC, Geneve University, Switzerland, 104Charles University in Prague, Czech Republic, 105Universities Space Research Association, Huntsville, United States, 106Leicester University, United Kingdom, 107SRON, The Netherlands, 108INAF-IASF-Bologna, Italy, 109University of Valencia, Spain, 110Monash Centre for Astrophysics, School of Physics and School of Mathematical Sciences, Monash University, Australia, 111IEEC-CSIC-UPC-UB, Barcelona, Spain, 112IEEC-CSIC-UPC-UB, Barcelona, Spain, 113ASDC, Rome, Italy, 114University of Maryland, United States, 115University of Tasmania, Australia, 116MPA Garching, Germany, 117ASDC, Rome, Italy, 118INAF-IRA-Bologna, Italy, 119INAF-IRA-Bologna, Italy, 120Sabanci University, Istanbul, Turkey, 121APC, Université Paris Diderot, CEA/Irfu, Observatoire de Paris, France, 122Silesian University in Opava, Czech Republic, 123CEA Saclay, DSM/IRFU/SAp, France, 124CEA Saclay, DSM/IRFU/SAp, France, 125Pavia University, Italy, 126Clemson University, United States, 127IAAT Tuebingen, Germany, 128Sapienza University, Rome, Italy, 129Ferrara University, Ferrara, Italy, 130ISDC, Geneve University, Switzerland, 131SRON, The Netherlands, 132Copernicus Astronomical Center, Warsaw, Poland, 133MSSL, Surrey, United Kingdom, 134National Space Institute, Lyngby, Denmark, 135Clemson University, United States, 136Open University, United Kingdom, 137Institut für Kernphysik, Technische Universität Darmstadt and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Germany, 138Monash Centre for Astrophysics, School of Physics and School of Mathematical Sciences, Monash University, Australia, 139SRON, The Netherlands, 140MIT, Cambridge, United States, 141National Space Institute, Lyngby, Denmark, 142Astronomical Institute of the Academy of Sciences of the Czech Republic, Czech Republic, 143University of Helsinki, Finland, 144Astronomical Institute Anton Pannekoek, University of Amsterdam, The Netherlands, 145SRON, The Netherlands, 146INAF-OA Rome, Italy, 147DAM and ICC-UB, Universitat de Barcelona, Spain, 148Sapienza University and ICRA, Rome, Italy, 149SRON, The Netherlands, 150IAAT Tuebingen, Germany, 151Perimeter Institute for Theoretical Physics, Waterloo, Canada, 152SRON, The Netherlands, 153SRON, The Netherlands, 154Technical University of Catalonia, Barcelona, Spain, 155Michigan state University, United States, 156Max-Planck-Institut fuer extraterrestrische Physik, Garching, Germany, 157Astronomical Institute of the Academy of Sciences of the Czech Republic, Czech Republic, 158IEEC-CSIC-UPC-UB, Barcelona, Spain, 159MSSL, Surrey, United Kingdom, 160Michigan state University, United States, 161MSSL, Surrey, United Kingdom, 162IAAT Tuebingen, Germany, 163Copernicus Astronomical Center, Warsaw, Poland, 164IAAT Tuebingen, Germany, 165University of Helsinki, Finland, 166NASA/Marshall Space Flight Center, United States, 167University of Erlangen-Nuremberg, Germany, 168SRON, The Netherlands, 169National Space Institute, Lyngby, Denmark, 170INAF-IASF-Bologna, Italy, 171Cornell University, Ithaca, United States, 172University of Illinois, United States, 173SRON, The Netherlands, 174APC, Université Paris Diderot, CEA/Irfu, Observatoire de Paris, France, 175IRAP, Toulouse, France, 176MSSL, Surrey, United Kingdom, 177Dipartimento di Fisica, Università degli Studi di Milano, Italy, 178University of Trieste, Italy, 179National Space Institute, Lyngby, Denmark, 180Texas Tech. University, United States, 181Politecnico Milano, Italy, 182IRAP, Toulouse, France, 183University of Maryland, United States, 184IAAT Tuebingen, Germany, 185Pavia University, Italy, 186School of Physics and Astronomy, University of Birmingham, United Kingdom, 187The Pennsylvania State University, United States, 188Copernicus Astronomical Center, Warsaw, Poland, 189INAF-IASF-Bologna, Italy, 190University of California, San Diego, United States, 191Leicester University, United Kingdom, 192University of Rome III, Italy, 193School of Physics and Astronomy, University of Southampton, United Kingdom, 194University of Melbourne, Australia, 195Kapteyn Astronomical Institute, University of Groningen, The Netherlands, 196INAF-IASF-Milano, Italy, 197Space Research Centre, Warsaw, Poland, 198DAM and ICC-UB, Universitat de Barcelona, Spain, 199INAF-IASF-Milano, Italy, 200University of Maryland, United States, 201Michigan state University, United States, 202INAF IFC, Palermo, Italy, 203Centro de Astrobiologia, 204University of Alberta, Canada, 205Observatoire Astronomique de Strasbourg, France, 206INAF-OA Brera, Italy, 207Université Paris Diderot France, 208IRAP, Toulouse, France, 209National Space Institute, Lyngby, Denmark, 2101,1b, 211Oxford University, United Kingdom, 212University of Alicante, Spain, 213MIT, Cambridge, United States, 214Open University, United Kingdom, 215MIT, Cambridge, United States, 216Leicester University, United Kingdom, 217National Space Institute, Lyngby, Denmark, 218INAF-IRA-Bologna, Italy, 219INAF-OA Padova, Padova, Italy, 220INAF-IASF-Bologna, Italy, 221Space Research Centre, Warsaw, Poland, 222Leicester University, United Kingdom, 223Space Telescope Institute, United States, 224University of Arizona, United States, 2251,1b, 226Università di Napoli Fedelico II, Italy, 227IEEC-CSIC-UPC-UB, Barcelona, Spain, 228DAM and ICC-UB, Universitat de Barcelona, Spain, 229Leiden Observatory, The Netherlands, 230Raman Research Institute, India, 231IAAT Tuebingen, Germany, 232INAF-OA Cagliari, Italy, 233Sapienza University and ICRA, Rome, Italy, 234Facultad de Ciencias-Trilingüe University of Salamanca, Spain, 235Czech Technical University in Prague, Czech Republic, 236ASDC, Rome, Italy, 237University of Alicante, Spain, 238IEEC-CSIC-UPC-UB, Barcelona, Spain, 239INAF-OA Cagliari, Italy, 240Tuorla Observatory, University of Turku, Finland, 241Ohio University, United States, 242CEA Saclay, DSM/IRFU/SAp, France, 243University of Arizona, United States, 244IRAP, Toulouse, France, 245IRAP, Toulouse, France, 246Armagh Observatory, United Kingdom, 2471,1b, 248INFN, Trieste, Italy, 249INFN, Trieste, Italy, 250NRL, Washington, United States, 251IEEC-CSIC-UPC-UB, Barcelona, Spain, 252Institute for Nuclear Theory, University of Washington, United States, 253Foundation for Research and Technology, Heraklion, Greece, 254National Institute of Aerospace Technology, 255MIT, Cambridge, United States, 256University of Maryland, United States, 257Max Planck Institute for Gravitational Physics, Germany, 258DAM and ICC-UB, Universitat de Barcelona, Spain, 259SRON, The Netherlands, 260INAF-OA Cagliari, Italy, 261University of Surrey, United Kingdom, 262Instituto de Astrofisica de Canarias, Tenerife, Spain, 263CEA Saclay, DSM/IRFU/SAp, France, 264ISDC, Geneve University, Switzerland, 265INAF IFC, Palermo, Italy, 266Leiden Observatory, The Netherlands, 267Copernicus Astronomical Center, Warsaw, Poland, 268MSSL, Surrey, United Kingdom, 269KTH Royal Institute of Technology, Stockholm, Sweden, 270National Institute of Aerospace Technology, 271IEEC-CSIC-UPC-UB, Barcelona, Spain, 272INAF-IASF-Milano, Italy, 273Kapteyn Astronomical Institute, University of Groningen, The Netherlands, 274Jorgen Sandberg Consulting, Denmark, 275Institute for Astronomy K.U. Leuven, Leuven, Belgium, 276CEA Saclay, DSM/IRFU/SAp, France, 277Silesian University in Opava, Czech Republic, 278University of Erlangen-Nuremberg, Germany, 279University of Pisa, Italy, 280INAF-OA Rome, Italy, 281Institut für Kernphysik, Technische Universität Darmstadt and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Germany, 282Leibniz-Institut fuer Astrophysik Potsdam, Germany, 283CNES, Toulouse, France, 284National University of Ireland, Ireland, 285MSSL, Surrey, United Kingdom, 286University of California, United States, 287MSSL, Surrey, United Kingdom, 288Astronomical Institute of the Academy of Sciences of the Czech Republic, Czech Republic, 289IAPS-INAF, Rome, Italy, 290Kapteyn Astronomical Institute, University of Groningen, The Netherlands, 291MSSL, Surrey, United Kingdom, 292University of Manchester, United Kingdom, 293Institute for Nuclear Theory, University of Washington, United States, 294Aristotle University of Thessaloniki, Greece, 295ASDC, Rome, Italy, 296Goddard Space Flight Center, Greenbelt, United States, 297Silesian University in Opava, Czech Republic, 298IAAT Tuebingen, Germany, 299IAAT Tuebingen, Germany, 300ISAS, Kanagawa, Japan, 301Dept. of Physics and Astronomy University of Padua, Italy, 302Argelander-Institut für Astronomie, Bonn, Germany, 303IAAT Tuebingen, Germany, 304IEEC-CSIC-UPC-UB, Barcelona, Spain, 305University of Maryland, United States, 306University of California, Berkeley, Space Sciences Laboratory, United States, 307Silesian University in Opava, Czech Republic, 308University of Alicante, Spain, 309ICREA, Barcelona, Spain, 310ISDC, Geneve University, Switzerland, 311IAPS-INAF, Rome, Italy, 312Dept. of Physics and Astronomy University of Padua, Italy, 313University of Rome Tor Vergata, Italy, 314IAAT Tuebingen, Germany, 315Astronomical Institute Anton Pannekoek, University of Amsterdam, The Netherlands, 316INFN, Trieste, Italy, 317APC, Université Paris Diderot, CEA/Irfu, Observatoire de Paris, France, 318Leicester University, United Kingdom, 319INAF IFC, Palermo, Italy, 320Physical Institute of the Academy of Sciences of the Czech Republic, Czech Republic, 321MSSL, Surrey, United Kingdom, 322ISAS, Kanagawa, Japan, 323Space Research Centre, Warsaw, Poland, 324IRAP, Toulouse, France, 325MIT, Cambridge, United States, 326IAAT Tuebingen, Germany, 327University of Warwick, United Kingdom, 328Astronomical Institute Anton Pannekoek, University of Amsterdam, The Netherlands, 329Astronomical Institute Anton Pannekoek, University of Amsterdam, The Netherlands, 330University of Erlangen-Nuremberg, Germany, 331NASA/Marshall Space Flight Center, Huntsville, United States, 332MSSL, Surrey, United Kingdom, 333NRL, Washington, United States, 334INFN, Trieste, Italy, 335INFN, Trieste, Italy, 336INAF-OA Padova, Padova, Italy, 337Copernicus Astronomical Center, Warsaw, Poland, 338Copernicus Astronomical Center, Warsaw, Poland, 339University of Nevada, Las Vegas, United States, 340SRON, The Netherlands, 341European Space Agency, ESTEC, The Netherlands, 342European Space Agency, ESTEC, The Netherlands, 343European Space Agency, ESTEC, The Netherlands, 344European Space Astronomy Centre, Madrid, Spain, 345European Space Agency, ESTEC, The Netherlands

The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final down-selection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supra-nuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m 2 effective area, 2-30 keV, 240 eV spectral resolution, 1 deg collimated field of view) and a WideField Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). Read More

We present a long-term phase-coherent timing analysis and pulse-phase resolved spectroscopy for the two outbursts observed from the transient anomalous X-ray pulsar CXOU J164710.2-45521. For the first outburst we used 11 Chandra and XMM-Newton observations between September 2006 to August 2009, the longest baseline yet for this source. Read More

2013Dec
Affiliations: 1Institut Ciencies de l'Espai, 2Institut Ciencies de l'Espai, 3Institut Ciencies de l'Espai, 4Institut Ciencies de l'Espai, 5Univ. d'Alacant, 6INFN, 7INAF- Ist. Astrof. Spaziale e Fisica Cosmica, 8Mullard Space Science Laboratory, 9INAF- Ist. Astrof. Spaziale e Fisica Cosmica, 10Mullard Space Science Laboratory, 11INAF- Obs. Astron. di Roma, 12AIM Irfu/Service d'Astrophysique-Saclay

We report on the quiescent state of the Soft Gamma Repeater SGR 0501+4516 observed by XMM-Newton on 2009 August 30. The source exhibits an absorbed flux ~75 times lower than that measured at the peak of the 2008 outburst, and a rather soft spectrum, with the same value of the blackbody temperature observed with ROSAT back in 1992. This new observation is put into the context of all existing X-ray data since its discovery in August 2008, allowing us to complete the study of the timing and spectral evolution of the source from outburst until its quiescent state. Read More

The study of magnetars is of particular relevance since these objects are the only laboratories where the physics in ultra-strong magnetic fields can be directly tested. Until now, spectroscopic and timing measurements at X-ray energies in soft gamma-repeaters (SGRs) and anomalous X-ray pulsar (AXPs) have been the main source of information about the physical properties of a magnetar and of its magnetosphere. Spectral fitting in the ~ 0. Read More

2013Sep
Affiliations: 1Sobolev Institute of Astronomy, Saint Petersburg State University, Russia, 2Sternberg Astronomical Institute, Russia, 3Univ. Padua, Mullard Space Science Lab. UCL

The variety of the observational appearance of young isolated neutron stars must find an explanation in the framework of some unifying approach. Nowadays it is believed that such scenario must include magnetic field decay, the possibility of magnetic field emergence on a time scale $\lesssim 10^4$--$10^5$ yrs, significant contribution of non-dipolar fields, and appropriate initial parameter distributions. We present our results on the initial spin period distribution, and suggest that inconsistences between distributions derived by different methods for samples with different average ages can uncover field decay or/and emerging field. Read More

Soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are slowly rotating, isolated neutron stars that sporadically undergo episodes of long-term flux enhancement (outbursts) generally accompanied by the emission of short bursts of hard X-rays. This behaviour can be understood in the magnetar model, according to which these sources are mainly powered by their own magnetic energy. This is supported by the fact that the magnetic fields inferred from several observed properties of AXPs and SGRs are greater than - or at the high end of the range of - those of radio pulsars. Read More

The old pulsar PSR B0943+10 (P=1.1 s, characteristic age tau=5 Myr) is the best example of mode-switching radio pulsar. Its radio emission alternates between a highly organized state with regular drifting subpulses (B mode) and a chaotic emission pattern (Q mode). Read More

The center of our Galaxy hosts a supermassive black hole, Sagittarius (Sgr) A*. Young, massive stars within 0.5 pc of SgrA* are evidence of an episode of intense star formation near the black hole a few Myr ago, which might have left behind a young neutron star traveling deep into SgrA*'s gravitational potential. Read More

The problem of computing the pulse profiles from thermally emitting spots on the surface of a neutron star in general relativity is reconsidered. We show that it is possible to extend Beloborodov (2002) approach to include (multiple) spots of finite size in different positions on the star surface. Results for the pulse profiles are expressed by comparatively simple analytical formulas which involve only elementary functions. Read More

It is now widely accepted that soft gamma repeaters and anomalous X-ray pulsars are the observational manifestations of magnetars, i.e. sources powered by their own magnetic energy. Read More

We report on the long term X-ray monitoring of the outburst decay of the low magnetic field magnetar SGR 0418+5729, using all the available X-ray data obtained with RXTE, SWIFT, Chandra, and XMM-Newton observations, from the discovery of the source in June 2009, up to August 2012. The timing analysis allowed us to obtain the first measurement of the period derivative of SGR 0418+5729: \dot{P}=4(1)x10^{-15} s/s, significant at ~3.5 sigma confidence level. Read More

2012Dec
Affiliations: 1MSSL-UCL, Kepler Institute of Astronomy, University of Zielona Gora, 2MSSL-UCL, 3MSSL-UCL, 4Dipartimento di Fisica e Astronomia, Universita' di Padova, MSSL-UCL, 5MSSL-UCL, 6Instituto de Astronomia y Fisica del Espacio, 7Instituto de Astronomia y Fisica del Espacio, 8INAF - Istituto di Astrofisica Spaziale e Fisica Cosmica Milano, 9Dipartimento di Fisica e Matematica, Universita' dell'Insubria

X-ray observations unveiled various types of radio-silent Isolated Neutron Stars (INSs), phenomenologically very diverse, e.g. the Myr old X-ray Dim INS (XDINSs) and the kyr old magnetars. Read More

We present a long-term study of the 2011 outburst of the magnetar Swift J1834.9-0846 carried out using new Chandra observations, as well as all the available Swift, RXTE, and XMM-Newton data. The last observation was performed on 2011 November 12, about 100 days after the onset of the bursting activity that had led to the discovery of the source on 2011 August 07. Read More

We report on the long term X-ray monitoring with Swift, RXTE, Suzaku, Chandra, and XMM-Newton of the outburst of the newly discovered magnetar Swift J1822.3-1606 (SGR 182-1606), from the first observations soon after the detection of the short X-ray bursts which led to its discovery (July 2011), through the first stages of its outburst decay (April 2012). Our X-ray timing analysis finds the source rotating with a period of P = 8. Read More

We report on a detailed spectral analysis of all the available XMM-Newton data of RX J1856.5-3754, the brightest and most extensively observed nearby, thermally emitting neutron star. Very small variations (~1-2%) in the single-blackbody temperature are detected, but are probably due to an instrumental effect, since they correlate with the position of the source on the detector. Read More

2012Jun
Affiliations: 1University of Padova, Italy, and MSSL-UCL, UK, 2Sternberg Astronomical Institute, Russia

SXP 1062, a newly discovered Be/X-ray binary in the Small Magellanic Cloud, provides the first example of a robust association with a supernova remnant (SNR). The short age estimated for the SNR qualifies SXP 1062 as the youngest known source in its class, ~ 10^4 yr. Here we discuss possible evolutionary scenarios for SXP 1062 in the attempt to reconcile its long spin period, P=1062 s, and short age. Read More

2012Jun
Affiliations: 1Sternberg Astronomical Institute, 2University of Padova, Mullard Space Science Lab. UCL

A subpopulation of neutron stars (NSs), known as central compact objects (CCOs) in supernova remnants, are suspected to be low-field objects basing on $P$-$\dot P$ measurements for three of them. The birth rate of low-field NSs is probably comparable with the birth rate of normal radio pulsars. However, among compact objects in High-Mass X-ray Binaries (HMXBs) we do not see robust candidates for low-field NSs. Read More

2012May
Affiliations: 1Leibniz-Institut für Astrophysik Potsdam, 2CNRS, Université de Strasbourg, Observatoire Astronomique, 3Universitá di Padova, 4Leibniz-Institut für Astrophysik Potsdam, 5Netherlands Foundation for Research in Astronomy, 6Universitá dell'Insubria, 7Sternberg Astronomical Institute, Lomonosov Moscow State University, 8Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo

While fewer in number than the dominant rotation-powered radio pulsar population, peculiar classes of isolated neutron stars (INSs) -- which include magnetars, the ROSAT-discovered "Magnificent Seven" (M7), rotating radio transients (RRATs), and central compact objects in supernova remnants (CCOs) -- represent a key element in understanding the neutron star phenomenology. We report the results of an observational campaign to study the properties of the source 2XMM J104608.7-594306. Read More

2012Apr
Affiliations: 1SAI MSU, 2Univ. Padua, Mullard Space Science Lab. UCL

We present estimates of initial spin periods, $P_0$, for radio pulsars associated with supernova remnants. By using the published data on 30 objects, we were able to derive a reliable estimate for the initial spin period, assuming standard magneto-dipole spin-down (braking index n=3), in many cases. Our set of estimates is still not sufficient to infer the exact shape of the initial period distribution. Read More

2012Mar
Affiliations: 1CSIC-IEEC, 2INAF, 3INAF, 4Alicante, 5CSIC-IEEC, 6MSSL, 7Padova, 8MSSL, 9INAF, 10INAF, 11INAF, 12Stanford, 13NASA, 14Sabanci, 15CEA, 16NASA, 17Tokyo, 18INAF, 19MSSL, 20LANL, 21Boulder, 22INAF, 23INAF

We report on the long term X-ray monitoring with Swift, RXTE, Suzaku, Chandra and XMM-Newton of the outburst of the newly discovered magnetar Swift J1822.3-1606 (SGR 1822-1606), from the first observations soon after the detection of the short X-ray bursts which led to its discovery, through the first stages of its outburst decay (covering the time-span from July 2011, until end of April 2012). We also report on archival ROSAT observations which witnessed the source during its likely quiescent state, and on upper limits on Swift J1822. Read More

RX J0720.4-3125 is the most peculiar object among a group of seven isolated X-ray pulsars (the so-called "Magnificent Seven"), since it shows long-term variations of its spectral and temporal properties on time scales of years. This behaviour was explained by different authors either by free precession (with a seven or fourteen years period) or possibly a glitch that occurred around $\mathrm{MJD=52866\pm73 days}$. Read More

2012Feb
Affiliations: 1CSIC-IEEC, 2U. Alicante, 3CSIC-IEEC, ICREA, 4U. Padua

High magnetic fields are a distinguishing feature of neutron stars and the existence of sources (the soft gamma repeaters and the anomalous X-ray pulsars) hosting an ultra-magnetized neutron star (or magnetar) has been recognized in the past few decades. Magnetars are believed to be powered by magnetic energy and not by rotation, as with normal radio pulsars. Until recently, the radio quietness and magnetic fields typically above the quantum critical value (Bq~4. Read More

Using a large set of XMM-Newton observations we searched for long term spectral and flux variability of the isolated neutron star RX J1856.5-3754 in the time interval from April 2002 to October 2011. This is the brightest and most extensively observed source of a small group of nearby, thermally emitting isolated neutron stars, of which at least one member (RX J0720. Read More

RX J0822-4300 is the Central Compact Object associated with the Puppis A supernova remnant. Previous X-ray observations suggested RX J0822-4300 to be a young neutron star with a weak dipole field and a peculiar surface temperature distribution dominated by two antipodal spots with different temperatures and sizes. An emission line at 0. Read More

The newly discovered Be/X-ray binary in the Small Magellanic Cloud, SXP 1062, provides the first example of a robust association with a supernova remnant (SNR). The short age estimated for the SNR qualifies SXP 1062 as the youngest known source in its class, tau ~ 1e4 yr. As such, it allows to test current models of magneto-rotational evolution of neutron stars ina still unexplored regime. Read More

2011Nov
Affiliations: 1Universitat d'Alacant, 2University of Liverpool, 3MSSL London, 4Università di Padova, 5Universitat d'Alacant, 6Universitat d'Alacant

Nowadays, the analysis of the X-ray spectra of magnetically powered neutron stars or magnetars is one of the most valuable tools to gain insight into the physical processes occurring in their interiors and magnetospheres. In particular, the magnetospheric plasma leaves a strong imprint on the observed X-ray spectrum by means of Compton up-scattering of the thermal radiation coming from the star surface. Motivated by the increased quality of the observational data, much theoretical work has been devoted to develop Monte Carlo (MC) codes that incorporate the effects of resonant Compton scattering in the modeling of radiative transfer of photons through the magnetosphere. Read More

SGR 0418+5729 is a transient Soft Gamma-ray Repeater which underwent a major outburst in June 2009, during which the emission of short bursts was observed. Its properties appeared quite typical of other sources of the same class until long-term X-ray monitoring failed to detect any period derivative. The present upper limit on $\dot P$ implies that the surface dipole field is $B_p\lesssim 7. Read More

The X-ray source 1E 161348-5055 lies at the centre of the 2-kyr-old supernova remnant RCW 103. Owing to its 24-ks modulation, orders-of-magnitude flux variability over a few months/years, and lack of an obvious optical counterpart, 1E 161348-5055 defies assignment to any known class of X-ray sources. Starting from April 2006, Swift observed 1E 161348-5055 with its X-ray telescope for 2 ks approximately once per month. Read More

We present high-speed optical photometry of the soft gamma repeater SGR 0501+4516, obtained with ULTRACAM on two consecutive nights approximately 4 months after the source was discovered via its gamma-ray bursts. We detect SGR 0501+4516 at a magnitude of i' = 24.4+/-0. Read More

SGR 1833-0832 was discovered on 2010 March 19 thanks to the Swift detection of a short hard X-ray burst and follow-up X-ray observations. Since then, it was repeatedly observed with Swift, Rossi X-ray Timing Explorer, and XMM-Newton. Using these data, which span about 225 days, we studied the long-term spectral and timing characteristics of SGR 1833-0832. Read More

2011Mar
Affiliations: 1MSSL-UCL, Institute of Astronomy, University of Zielona Gora, 2MSSL-UCL, 3Department of Physics, University of Padua, 4Max Planck Institut fur Extraterrestrische Physik, 5MSSL-UCL, 6CNRS, Universite' de Strasbourg, 7Dipartimento di Fisica e Matematica, Universita' dell'Insubria, 8INAF, Osservatorio Astronomico di Padova

X-ray observations performed with ROSAT led to the discovery of a group (seven to date) of X-ray dim and radio-silent middle-aged isolated neutron stars (a.k.a. Read More