Low-frequency Faraday rotation measures towards pulsars using LOFAR: probing the 3D Galactic halo magnetic field

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 484:3 (2019) 3646-3664

Authors:

C Sobey, AV Bilous, J-M Grießmeier, JWT Hessels, A Karastergiou, EF Keane, VI Kondratiev, M Kramer, D Michilli, A Noutsos, M Pilia, EJ Polzin, BW Stappers, CM Tan, J van Leeuwen, JPW Verbiest, P Weltevrede, G Heald, MIR Alves, E Carretti, T Enßlin, M Haverkorn, M Iacobelli, W Reich, C Van Eck

Broadband aperiodic variability in X-ray pulsars: accretion rate fluctuations propagating under the influence of viscous diffusion

Monthly Notices of the Royal Astronomical Society Oxford University Press 486:3 (2019) 4061-4074

Authors:

AA Mushtukov, GV Lipunova, Adam Ingram, SS Tsygankov, J Mönkkönen, MVD Klis

Abstract:

We investigate aperiodic X-ray flux variability in accreting highly magnetized neutron stars – X-ray pulsars (XRPs). The X-ray variability is largely determined by mass accretion rate fluctuations at the NS surface, which replicate accretion rate fluctuations at the inner radius of the accretion disc. The variability at the inner radius is due to fluctuations arising all over the disc and propagating inwards under the influence of viscous diffusion. The inner radius varies with mean mass accretion rate and can be estimated from the known magnetic field strength and accretion luminosity of XRPs. Observations of transient XRPs covering several orders of magnitude in luminosity give a unique opportunity to study effects arising due to the changes of the inner disc radius. We investigate the process of viscous diffusion in XRP accretion discs and construct new analytical solutions of the diffusion equation applicable for thin accretion discs truncated both from inside and outside. Our solutions are the most general ones derived in the approximation of Newtonian mechanics. We argue that the break observed at high frequencies in the power density spectra of XRPs corresponds to the minimal time-scale of the dynamo process, which is responsible for the initial fluctuations. Comparing data from the bright X-ray transient A 0535+26 with our model, we conclude that the time-scale of initial variability in the accretion disc is a few times longer than the local Keplerian time-scale.

Broadband aperiodic variability in X-ray pulsars: accretion rate fluctuations propagating under the influence of viscous diffusion

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (2019)

Authors:

Alexander A Mushtukov, Galina V Lipunova, Adam Ingram, Sergey S Tsygankov, Juhani Mönkkönen, Michiel van der Klis

Monte Carlo studies for the optimisation of the Cherenkov Telescope Array layout

(2019)

Authors:

A Acharyya, I Agudo, EO Angüner, R Alfaro, J Alfaro, C Alispach, R Aloisio, R Alves Batista, J-P Amans, L Amati, E Amato, G Ambrosi, LA Antonelli, C Aramo, T Armstrong, F Arqueros, L Arrabito, K Asano, H Ashkar, C Balazs, M Balbo, B Balmaverde, P Barai, A Barbano, M Barkov, U Barres de Almeida, JA Barrio, D Bastieri, J Becerra González, J Becker Tjus, L Bellizzi, W Benbow, E Bernardini, MI Bernardos, K Bernlöhr, A Berti, M Berton, B Bertucci, V Beshley, B Biasuzzi, C Bigongiari, R Bird, E Bissaldi, J Biteau, O Blanch, J Blazek, C Boisson, G Bonanno, A Bonardi, C Bonavolontà, G Bonnoli, P Bordas, M Böttcher, J Bregeon, A Brill, AM Brown, K Brügge, P Brun, P Bruno, A Bulgarelli, T Bulik, M Burton, A Burtovoi, G Busetto, R Cameron, R Canestrari, M Capalbi, A Caproni, R Capuzzo-Dolcetta, P Caraveo, S Caroff, R Carosi, S Casanova, E Cascone, F Cassol, F Catalani, O Catalano, D Cauz, M Cerruti, S Chaty, A Chen, M Chernyakova, G Chiaro, M Cieślar, SM Colak, V Conforti, E Congiu, JL Contreras, J Cortina, A Costa, H Costantini, G Cotter, P Cristofari, P Cumani, G Cusumano, A D'Aì, F D'Ammando, L Dangeon, P Da Vela, F Dazzi, A De Angelis, V De Caprio, R de Cássia dos Anjos, F De Frondat, EM de Gouveia Dal Pino, B De Lotto, D De Martino, M de Naurois, E de Oña Wilhelmi, F de Palma, V de Souza, M Del Santo, C Delgado, D della Volpe, T Di Girolamo, F Di Pierro, L Di Venere, C Díaz, S Diebold, A Djannati-Ataï, A Dmytriiev, D Dominis Prester, A Donini, D Dorner, M Doro, J-L Dournaux, J Ebr, TRN Ekoume, D Elsässer, G Emery, D Falceta-Goncalves, E Fedorova, S Fegan, Q Feng, G Ferrand, E Fiandrini, A Fiasson, M Filipovic, V Fioretti, M Fiori, S Flis, MV Fonseca, G Fontaine, L Freixas Coromina, S Fukami, Y Fukui, S Funk, M Füßling, D Gaggero, G Galanti, RJ Garcia López, M Garczarczyk, D Gascon, T Gasparetto, M Gaug, A Ghalumyan, F Gianotti, G Giavitto, N Giglietto, F Giordano, M Giroletti, J Gironnet, J-F Glicenstein, R Gnatyk, P Goldoni, JM González, MM González, KN Gourgouliatos, T Grabarczyk, J Granot, D Green, T Greenshaw, M-H Grondin, O Gueta, D Hadasch, T Hassan, M Hayashida, M Heller, O Hervet, J Hinton, N Hiroshima, B Hnatyk, W Hofmann, P Horvath, M Hrabovsky, D Hrupec, TB Humensky, M Hütten, T Inada, F Iocco, M Ionica, M Iori, Y Iwamura, M Jamrozy, P Janecek, D Jankowsky, P Jean, L Jouvin, J Jurysek, P Kaaret, LHS Kadowaki, S Karkar, D Kerszberg, B Khélifi, D Kieda, S Kimeswenger, W Kluźniak, J Knapp, J Knödlseder, Y Kobayashi, B Koch, J Kocot, N Komin, A Kong, G Kowal, M Krause, H Kubo, J Kushida, P Kushwaha, V La Parola, G La Rosa, M Lallena Arquillo, RG Lang, J Lapington, O Le Blanc, J Lefaucheur, MA Leigui de Oliveira, M Lemoine-Goumard, J-P Lenain, G Leto, R Lico, E Lindfors, T Lohse, S Lombardi, F Longo, A Lopez, M López, A Lopez-Oramas, R López-Coto, S Loporchio, PL Luque-Escamilla, E Lyard, MC Maccarone, E Mach, C Maggio, P Majumdar, G Malaguti, M Mallamaci, D Mandat, G Maneva, M Manganaro, S Mangano, M Marculewicz, M Mariotti, J Martí, M Martínez, G Martínez, H Martínez-Huerta, S Masuda, N Maxted, D Mazin, J-L Meunier, M Meyer, S Micanovic, R Millul, IA Minaya, A Mitchell, T Mizuno, R Moderski, L Mohrmann, T Montaruli, A Moralejo, D Morcuende, G Morlino, A Morselli, E Moulin, R Mukherjee, P Munar, C Mundell, T Murach, A Nagai, T Nagayoshi, T Naito, T Nakamori, R Nemmen, J Niemiec, D Nieto, M Nievas Rosillo, M Nikołajuk, D Ninci, K Nishijima, K Noda, D Nosek, M Nöthe, S Nozaki, M Ohishi, Y Ohtani, A Okumura, RA Ong, M Orienti, R Orito, M Ostrowski, N Otte, Z Ou, I Oya, A Pagliaro, M Palatiello, M Palatka, R Paoletti, JM Paredes, G Pareschi, N Parmiggiani, RD Parsons, B Patricelli, A Pe'er, M Pech, P Peñil Del Campo, J Pérez-Romero, M Perri, M Persic, P-O Petrucci, O Petruk, K Pfrang, Q Piel, E Pietropaolo, M Pohl, M Polo, J Poutanen, E Prandini, N Produit, H Prokoph, M Prouza, H Przybilski, G Pühlhofer, M Punch, F Queiroz, A Quirrenbach, S Rainò, R Rando, S Razzaque, O Reimer, N Renault-Tinacci, Y Renier, D Ribeiro, M Ribó, J Rico, F Rieger, V Rizi, G Rodriguez Fernandez, JC Rodriguez-Ramirez, JJ Rodríguez Vázquez, P Romano, G Romeo, M Roncadelli, J Rosado, G Rowell, B Rudak, A Rugliancich, C Rulten, I Sadeh, L Saha, T Saito, S Sakurai, F Salesa Greus, P Sangiorgi, H Sano, M Santander, A Santangelo, R Santos-Lima, A Sanuy, K Satalecka, FG Saturni, U Sawangwit, S Schlenstedt, P Schovanek, F Schussler, U Schwanke, E Sciacca, S Scuderi, K Sedlaczek, M Seglar-Arroyo, O Sergijenko, K Seweryn, A Shalchi, RC Shellard, H Siejkowski, A Sillanpää, A Sinha, G Sironi, V Sliusar, A Slowikowska, H Sol, A Specovius, S Spencer, G Spengler, A Stamerra, S Stanič, Ł Stawarz, S Stefanik, T Stolarczyk, U Straumann, T Suomijarvi, P Świerk, T Szepieniec, G Tagliaferri, H Tajima, T Tam, F Tavecchio, L Taylor, LA Tejedor, P Temnikov, T Terzic, V Testa, L Tibaldo, CJ Todero Peixoto, F Tokanai, L Tomankova, D Tonev, DF Torres, G Tosti, L Tosti, N Tothill, F Toussenel, G Tovmassian, P Travnicek, C Trichard, G Umana, V Vagelli, M Valentino, B Vallage, P Vallania, L Valore, J Vandenbroucke, GS Varner, G Vasileiadis, V Vassiliev, M Vázquez Acosta, M Vecchi, S Vercellone, S Vergani, GP Vettolani, A Viana, CF Vigorito, J Vink, V Vitale, H Voelk, A Vollhardt, S Vorobiov, SJ Wagner, R Walter, F Werner, R White, A Wierzcholska, M Will, DA Williams, R Wischnewski, L Yang, T Yoshida, T Yoshikoshi, M Zacharias, L Zampieri, M Zavrtanik, D Zavrtanik, AA Zdziarski, A Zech, H Zechlin, A Zenin, VI Zhdanov, S Zimmer, J Zorn

Identifying transient and variable sources in radio images

Astronomy and Computing Elsevier 27 (2019) 111-129

Authors:

A Rowlinson, AJ Stewart, JW Broderick, JD Swinbank, RAMJ Wijers, D Carbone, Y Cendes, R Fender, A van der Horst, G Molenaar, B Scheers, T Staley, S Farrell, J-M Grießmeier, M Bell, J Eislöffel, CJ Law, J van Leeuwen, P Zarka