Article
Astronomy & Astrophysics
S. Chalise, A. M. Lohfink, J. Chauhan, T. D. Russell, D. J. K. Buisson, L. Mallick
Summary: The X-ray spectra of some active galactic nuclei (AGNs) show a soft X-ray excess, which can be attributed to relativistic ionized reflection, extreme blurring of reprocessed emission from the innermost region of the accretion disc, or Comptonization from a warm corona. In the case of Mrk 926, it is difficult to determine the exact cause of the observed soft excess, although a warm coronal-like component is slightly favored by the data. The study also detects an optically thin radio component in Mrk 926, which requires further multiwavelength observations to investigate its origin.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
D. Lawther, M. Vestergaard, S. Raimundo, J. Y. Koay, B. M. Peterson, X. Fan, D. Grupe, S. Mathur
Summary: Mrk 590 is a changing-look AGN that turned off in 2012 and partially re-ignited into a repeat flaring state in 2017. Swift observations reveal higher X-ray and UV variability amplitudes compared to "steady-state" AGN, indicating a complicated reprocessing geometry. The X-rays are reprocessed by two UV components, with the dominant one at a lag of approximately 3 days and a faint additional reprocessor. The observed flares display characteristic time-scales consistent with thermal time-scale in an accretion disc.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Mark Durre, Jeremy Mould
Summary: This study conducted a near-infrared spectroscopic survey of narrow-line Seyfert 1 galaxies in the Southern hemisphere, examining the kinematics of the broad-line region (BLR) and reevaluating the catalogue black hole (BH) mass estimates. The results suggest a new understanding of the BH mass estimation and the differential absorption of line radiation of the BLR by a mixture of dusty and dust-free clouds.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
William C. Keel, Alexei Moiseev, D. Kozlova, A. I. Ikhsanova, D. Oparin, R. Uklein, A. A. Smirnova, M. Eselevich
Summary: We present a narrow-band [O III] imaging survey of distant extended emission-line regions (EELRs) around active galactic nucleus (AGN) hosts and merging-galaxy systems. Spectroscopic follow-up confirms two new distant AGN-ionized clouds in merging systems NGC 235 and NGC 5514, as well as recovering the previously known region in NGC 7252. These results strengthen the connection between EELRs and tidal features, and suggest that kinematically quiescent distant EELRs are photoionized tidal debris.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
F. C. Cerqueira-Campos, A. Rodriguez-Ardila, R. Riffel, M. Marinello, A. Prieto, L. G. Dahmer-Hahn
Summary: Coronal-line forest (CLiF) active galactic nuclei (AGNs) are not a separate category of AGNs, but rather an extension to the low/high ends of the distribution within the AGN class. The physical conditions of the NLR gas suggest that the ionization mechanism is primarily associated with photoionization by the AGN.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Clay S. Turner, Hugh R. Miller, Jeremy D. Maune, Joseph R. Eggen
Summary: This study reports the monitoring of the optical flux of 1H 0323+342, one of the nearest and brightest vRL NLSy1 galaxies, for over six and a half years. The results show the existence of low amplitude microvariability events with durations of a few hours, suggesting a fundamental time scale related to the underlying source region. The study also presents an enhanced method for detecting microvariability using Howell's comparison star method.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Zhiyuan Zheng, Yong Shi, Fuyan Bian, Xiaoling Yu, Junfeng Wang, Jianhang Chen, Xin Li, Qiusheng Gu
Summary: AGN feedback is important in massive galaxies, and it also plays a significant role in dwarf galaxies. We observed a spatially extended and fast AGN-driven outflow in the dwarf galaxy Sloan Digital Sky Survey J022849.51-090153.8. The outflow has a size of about 3 kpc and a velocity of about 471 km/s.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
F. Salvestrini, C. Gruppioni, E. Hatziminaoglou, F. Pozzi, C. Vignali, V. Casasola, R. Paladino, S. Aalto, P. Andreani, S. Marchesi, T. Stanke
Summary: The presence of an active galactic nucleus (AGN) in local Seyfert 2 galaxies has limited impact on the interstellar medium properties, although it does suppress the emission of certain molecules.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
H. A. Pena-Herazo, F. Massaro, V Chavushyan, N. Masetti, A. Paggi, A. Capetti
Summary: This study presents the first release of Turin-SyCAT, a multifrequency catalog of Seyfert galaxies. The catalog includes 351 Seyfert galaxies, with 233 type 1 and 118 type 2. The study found that type 1 Seyfert galaxies have mid-IR colors similar to blazars, while type 2 Seyfert galaxies have mid-IR colors more similar to quasars. The study also revealed a tight correlation between mid-IR fluxes and hard X-ray fluxes for both Seyfert types. This catalog will be used to search for heavily obscured Seyfert galaxies among unidentified hard X-ray sources and to investigate their large-scale environments.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Muryel Guolo, Daniel Ruschel-Dutra, Dirk Grupe, Bradley M. Peterson, Thaisa Storchi-Bergmann, Jaderson Schimoia, Rodrigo Nemmen, Andrew Robinson
Summary: The study analyzes the historical multiwavelength emission of the `Changing Look' AGN in NGC 2992 and finds a direct correlation between the presence and flux of Hα BEL and the X-ray luminosity, suggesting the AGN is operating at the threshold mass accretion rate between two accretion modes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
V. M. Sampaio, A. Aragon-Salamanca, M. R. Merrifield, R. R. de Carvalho, S. Zhou, I Ferreras
Summary: We use a sample of 80,000 central galaxies from the Sloan Digital Sky Survey to study the impact of active galactic nucleus (AGN) feedback on their evolution. We find that the dominance of AGN as the main ionizing mechanism increases with stellar mass, surpassing star formation for galaxies with a mass of 10^10 solar masses or higher. The percentage of AGN changes systematically with the galaxies' star formation activity, indicating that AGN feedback plays a key role in regulating and suppressing star formation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Rogemar A. Riffel, Marina Bianchin, Rogerio Riffel, Thaisa Storchi-Bergmann, Astor J. Schonell, Luis Gabriel Dahmer-Hahn, Natacha Z. Dametto, Marlon R. Diniz
Summary: In this study, J- and K-band integral field spectra of six luminous Seyfert galaxies were used to investigate the gas excitation within the galaxies. The results showed that shocks are the main excitation mechanism for H-2 gas in these galaxies, while AGN radiation plays a role in the emission lines in the AGN region of the diagnostic diagram.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
R. A. Riffel, O. L. Dors, M. Armah, T. Storchi-Bergmann, A. Feltre, G. F. Hagele, M. Cardaci, D. Ruschel-Dutra, A. C. Krabbe, E. Perez-Montero, N. L. Zakamska, I. C. Freitas
Summary: Maps of electron temperature in three luminous Seyfert galaxies were obtained using Gemini Multi-Object Spectrograph-integral field unit observations, showing temperatures varying in different ranges. Gas outflow shocks play a significant role in the temperature distributions of Mrk 79 and Mrk 348, while standard photoionization models are effective in reproducing the derived temperature values for Mrk 607. Direct evidence for shock ionization with overall orientation orthogonal to the ionization axis was found in Mrk 79 and Mrk 348.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
J. M. M. Neustadt, J. T. Hinkle, C. S. Kochanek, M. T. Reynolds, S. Mathur, M. A. Tucker, R. Pogge, K. Z. Stanek, A. Payne, B. J. Shappee, T. w-s Holoien, K. Auchettl, C. Ashall, T. de Jaeger, D. Desai, A. Do, W. B. Hoogendam, M. E. Huber
Summary: NGC 5273 is an AGN that exhibits optical and X-ray variability. By analyzing data from 2000 to 2022, researchers found that the AGN underwent multiple changing-look events, transitioning between different types of Seyfert galaxies. The varying luminosity and Eddington ratio of the source seem to influence how the broad-line region reprocesses the continuum emission.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Carolina Andonie, Claudio Ricci, Stephane Paltani, Patricia Arevalo, Ezequiel Treister, Franz Bauer, Marko Stalevski
Summary: In this study, we constructed a self-consistent X-ray model to investigate the circumnuclear environments of supermassive black holes. By incorporating various reprocessing structures, the model successfully reproduces the morphology and spectral properties of the target object.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
C. Pinto, P. Kosec
Summary: Ultraluminous X-ray sources (ULXs) are extreme X-ray binaries that emit X-rays above 10^39 erg/s, often due to super-Eddington accretion onto neutron stars and stellar-mass black holes. The study of ULX winds is crucial for understanding the accretion process onto compact objects and the impact they have on the surrounding medium, which is relevant for the growth of supermassive black holes. Recent advancements in X-ray spectroscopy have provided important insights, and future missions like XRISM, eXTP, and ATHENA are expected to further improve our understanding of ULXs.
ASTRONOMISCHE NACHRICHTEN
(2023)
Article
Astronomy & Astrophysics
G. A. Matzeu, M. Brusa, G. Lanzuisi, M. Dadina, S. Bianchi, G. Kriss, M. Mehdipour, E. Nardini, G. Chartas, R. Middei, E. Piconcelli, V. Gianolli, A. Comastri, A. L. Longinotti, Y. Krongold, F. Ricci, P. O. Petrucci, F. Tombesi, A. Luminari, L. Zappacosta, G. Miniutti, M. Gaspari, E. Behar, M. Bischetti, S. Mathur, M. Perna, M. Giustini, P. Grandi, E. Torresi, C. Vignali, G. Bruni, M. Cappi, E. Costantini, G. Cresci, B. De Marco, A. De Rosa, R. Gilli, M. Guainazzi, J. Kaastra, S. Kraemer, F. La Franca, A. Marconi, F. Panessa, G. Ponti, D. Proga, F. Ursini, P. Baldini, F. Fiore, A. R. King, R. Maiolino, G. Matt, A. Merloni
Summary: We present a new X-ray spectroscopic study of 22 luminous AGNs at intermediate redshifts, focusing on the search for and characterization of ultra-fast outflows (UFOs). Through Monte Carlo procedures, we confirm the detection of highly ionized iron absorption lines in 7 out of 22 sources at a high confidence level, supporting the existence of highly ionized matter propagating at mildly relativistic speeds in a considerable fraction of AGNs. The SUpermassive Black hole Winds in the x-rAYS (SUBWAYS) campaign extends previous studies on Seyferts and finds a UFO detection fraction of approximately 30% of the total sample.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
M. Mehdipour, G. A. Kriss, M. Brusa, G. A. Matzeu, M. Gaspari, S. B. Kraemer, S. Mathur, E. Behar, S. Bianchi, M. Cappi, G. Chartas, E. Costantini, G. Cresci, M. Dadina, B. De Marco, A. De Rosa, J. P. Dunn, V. E. Gianolli, M. Giustini, J. S. Kaastra, A. R. King, Y. Krongold, F. La Franca, G. Lanzuisi, A. L. Longinotti, A. Luminari, R. Middei, G. Miniutti, E. Nardini, M. Perna, P. -O. Petrucci, E. Piconcelli, G. Ponti, F. Ricci, F. Tombesi, F. Ursini, C. Vignali, L. Zappacosta
Summary: We conducted a UV spectroscopic study of ionized outflows in 21 active galactic nuclei (AGN) using the Hubble Space Telescope (HST). Our findings show that 60% of the AGN exhibit outflowing H I absorption, while 40% display ionized outflows seen as absorption by C IV, N V, or O VI. These results are comparable to the occurrences observed in local Seyfert galaxies.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Fiamma Capitanio, Sergio Fabiani, Andrea Gnarini, Francesco Ursini, Carlo Ferrigno, Giorgio Matt, Juri Poutanen, Massimo Cocchi, Romana Mikusincova, Ruben Farinelli, Stefano Bianchi, Jari J. E. Kajava, Fabio Muleri, Celia Sanchez-Fernandez, Paolo Soffitta, Kinwah Wu, Ivan Agudo, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolo Bucciantini, Simone Castellano, Elisabetta Cavazzuti, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolo Di Lalla, Alessandro Di Marco, Immacolata Donnarumma, Victor Doroshenko, Michal Dovciak, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Jeremy Heyl, Wataru Iwakiri, Svetlana G. Jorstad, Vladimir Karas, Takao Kitaguchi, Jeffery J. Kolodziejczak, Henric Krawczynski, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Frederic Marin, Andrea Marinucci, Alan P. Marscher, Herman L. Marshall, Ikuyuki Mitsuishi, Tsunefumi Mizuno, C. -Y. 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, Roger W. Romani, Carmelo Sgro, Patrick Slane, Gloria Spandre, Toru Tamagawa, Fabrizio Tavecchio, Roberto Taverna, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Sergey S. Tsygankov, Roberto Turolla, Jacco Vink, Martin C. Weisskopf, Fei Xie, Silvia Zane
Summary: The launch of IXPE on December 9, 2021 has provided a new perspective in X-ray astronomy. In this study, we present the first observation results of GS 1826-238, a weakly magnetized neutron star, using IXPE on March 29-31, 2022. The upper limit of linear polarization degree (99.73% confidence level) is found to be 1.3% in the energy range of 2-8 keV. Coordinated observations with INTEGRAL and NICER were conducted simultaneously to constrain the geometry and inclination angle of GS 1826-238.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Erin Kara, Aaron J. Barth, Edward M. Cackett, Jonathan Gelbord, John Montano, Yan-Rong Li, Lisabeth Santana, Keith Horne, William N. Alston, Douglas Buisson, Doron Chelouche, Pu Du, Andrew C. Fabian, Carina Fian, Luigi Gallo, Michael R. Goad, Dirk Grupe, Diego H. Gonzalez Buitrago, Juan V. Hernandez Santisteban, Shai Kaspi, Chen Hu, S. Komossa, Gerard A. Kriss, Collin Lewin, Tiffany Lewis, Michael Loewenstein, Anne Lohfink, Megan Masterson, Ian M. McHardy, Missagh Mehdipour, Jake Miller, Christos Panagiotou, Michael L. Parker, Ciro Pinto, Ron Remillard, Christopher Reynolds, Daniele Rogantini, Jian-Min Wang, Jingyi Wang, Dan Wilkins
Summary: We present the first results from a 100-day observing campaign of the Seyfert 1 galaxy Mrk 335 using three instruments. Despite a low X-ray flux state, we observed UV-optical lags as expected. Interestingly, both low- and high-flux states revealed longer UV-optical lags than expected. The optical rise preceded a sharp rise in X-rays, suggesting a departure from previous reprocessing models.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Efrain Gatuzz, J. S. Sanders, K. Dennerl, A. Liu, A. C. Fabian, C. Pinto, D. Eckert, H. Russell, T. Tamura, S. A. Walker, J. ZuHone
Summary: We found bulk velocities following AGN bubbles in the Virgo cluster and galaxy motions in the Centaurus cluster. To understand the ICM better, we mapped the Ophiuchus cluster and measured bulk flows using accurate Fe-K measurements. We created 2D spectral maps for various parameters and found similarities in velocities between ICM and the brightest cluster galaxy, as well as a sharp transition in gas velocities and no change in metallicities and temperatures in the outer regions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
V. E. Gianolli, D. E. Kim, S. Bianchi, B. Agis-Gonzalez, G. Madejski, F. Marin, A. Marinucci, G. Matt, R. Middei, P. O. Petrucci, P. Soffitta, D. Tagliacozzo, F. Tombesi, F. Ursini, T. Barnouin, A. De Rosa, L. Di Gesu, A. Ingram, V. Loktev, C. Panagiotou, J. Podgorny, J. Poutanen, S. Puccetti, A. Ratheesh, A. Veledina, W. Zhang, I. Agudo, L. A. Antonelli, M. Bachetti, L. Baldini, W. H. Baumgartner, R. Bellazzini, S. D. Bongiorno, R. Bonino, A. Brez, N. Bucciantini, F. Capitanio, S. Castellano, E. Cavazzuti, C. T. Chen, S. Ciprini, E. Costa, E. Del Monte, N. Di Lalla, A. Di Marco, I. Donnarumma, V. Doroshenko, M. Dovciak, S. R. Ehlert, T. Enoto, Y. Evangelista, S. Fabiani, R. Ferrazzoli, J. A. Garcia, S. Gunji, J. Heyl, W. Iwakiri, S. G. Jorstad, P. Kaaret, V. Karas, F. Kislat, T. Kitaguchi, J. J. Kolodziejczak, H. Krawczynski, F. La Monaca, L. Latronico, I. Liodakis, S. Maldera, A. Manfreda, A. P. Marscher, H. L. Marshall, F. Massaro, I. Mitsuishi, T. Mizuno, F. Muleri, M. Negro, C. -Y. Ng, S. L. O'Dell, N. Omodei, C. Oppedisano, A. Papitto, G. G. Pavlov, A. L. Peirson, M. Perri, M. Pesce-Rollins, M. Pilia, A. Possenti, B. D. Ramsey, J. Rankin, O. J. Roberts, R. W. Romani, C. Sgro, P. Slane, G. Spandre, D. A. Swartz, T. Tamagawa, F. Tavecchio, R. Taverna, Y. Tawara, A. F. Tennant, N. E. Thomas, A. Trois, S. S. Tsygankov, R. Turolla, J. Vink, M. C. Weisskopf, K. Wu, F. Xie, S. Zane
Summary: In this study, X-ray spectropolarimetric analysis of the Seyfert galaxy NGC 4151 revealed a polarization degree of 4.9% ± 1.1% and an angle of 86° ± 7° in the 2-8 keV energy range. The analysis suggests that the polarization may be entirely due to reflection and that the hot corona of NGC 4151 has a slab-like geometry, possibly a wedge.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Ping Zhou, Dmitry Prokhorov, Riccardo Ferrazzoli, Yi-Jung Yang, Patrick Slane, Jacco Vink, Stefano Silvestri, Niccolo Bucciantini, Estela Reynoso, David Moffett, Paolo Soffitta, Doug Swartz, Philip Kaaret, Luca Baldini, Enrico Costa, C. -Y. Ng, Dawoon E. Kim, Victor Doroshenko, Steven R. Ehlert, Jeremy Heyl, Frederic Marin, Tsunefumi Mizuno, Melissa Pesce-Rollins, Carmelo Sgro, Toru Tamagawa, Martin C. Weisskopf, Fei Xie, Ivan Agudo, Lucio A. Antonelli, Matteo Bachetti, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Fiamma Capitanio, Simone Castellano, Elisabetta Cavazzuti, Chien-Ting Chen, Stefano Ciprini, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolo Di Lalla, Alessandro Di Marco, Immacolata Donnarumma, Michal Dovciak, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Wataru Iwakiri, Svetlana G. Jorstad, Fabian Kislat, Vladimir Karas, Takao Kitaguchi, Jeffery J. Kolodziejczak, Henric Krawczynski, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Andrea Marinucci, Alan P. Marscher, Herman L. Marshall, Giorgio Matt, Ikuyuki Mitsuishi, Fabio Muleri, Michela Negro, Stephen L. O'Dell, Nicola Omodei, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Matteo Perri, Pierre-Olivier Petrucci, Maura Pilia, Andrea Possenti, Juri Poutanen, Simonetta Puccetti, Brian D. Ramsey, John Rankin, Ajay Ratheesh, Oliver Roberts, Roger W. Romani, Gloria Spandre, Fabrizio Tavecchio, Roberto Taverna, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Sergey S. Tsygankov, Roberto Turolla, Kinwah Wu, Silvia Zane
Summary: Young supernova remnants significantly alter the magnetic fields around them, and X-ray polarization measurements can provide insight into the magnetic field morphology and turbulence. In this study, we observed the northeastern shell of SN 1006 using the Imaging X-ray Polarimetry Explorer and found that the magnetic fields behind the shock are almost parallel or radially distributed, consistent with radio observations and the quasi-parallel cosmic ray acceleration scenario. The X-ray polarization degree in SN 1006 is higher than that in Cas A and Tycho, indicating that CR-induced instabilities contribute to the magnetic turbulence in SN 1006.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Roberto Turolla, Roberto Taverna, Gian Luca Israel, Fabio Muleri, Silvia Zane, Matteo Bachetti, Jeremy Heyl, Alessandro Di Marco, Ephraim Gau, Henric Krawczynski, Mason Ng, Andrea Possenti, Juri Poutanen, Luca Baldini, Giorgio Matt, Michela Negro, Ivan Agudo, Lucio A. Antonelli, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolo Bucciantini, Fiamma Capitanio, Simone Castellano, Elisabetta Cavazzuti, Chieng-Ting Chen, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolo Di Lalla, Immacolata Donnarumma, Victor Doroshenko, 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, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Frederic Marin, Andrea Marinucci, Alan P. Marscher, Herman L. Marshall, Francesco Massaro, Ikuyuki Mitsuishi, Tsunefumi Mizuno, C. -y. 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, 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, Sergey S. Tsygankov, Jacco Vink, Martin C. Weisskopf, Kinwah Wu, Fei Xie
Summary: Recent joint observations with IXPE and XMMNewton of the soft.-repeater SGR 1806-20 revealed strong polarization in its X-ray emission, with the source found at an all-time low persistent flux level. The detection of probable polarization at 4-5 keV energy range suggests a resonance Compton scattering mechanism in the magnetosphere, similar to that proposed for another bright magnetar 4U 0142+61.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Alessandro Di Marco, Fabio La Monaca, Juri Poutanen, Thomas Russell, Alessio Anitra, Ruben Farinelli, Guglielmo Mastroserio, Fabio Muleri, Fei Xie, Matteo Bachetti, Luciano Burderi, Francesco Carotenuto, Melania Del Santo, Tiziana Di Salvo, Michal Dovciak, Andrea Gnarini, Rosario Iaria, Jari J. E. Kajava, Kuan Liu, Riccardo L. Middei, Stephen O'Dell, Maura Pilia, John Rankin, Andrea Sanna, Jakob van den Eijnden, Martin C. Weisskopf, Anna Bobrikova, Fiamma Capitanio, Enrico Costa, Philip Kaaret, Alessio Marino, Paolo Soffitta, Francesco Ursini, Filippo Ambrosino, Massimo Cocchi, Sergio Fabiani, Herman Marshall, Giorgio Matt, Sara Elisa Motta, Alessandro Papitto, Luigi Stella, Antonella Tarana, Silvia Zane, Ivan Agudo, Lucio A. Antonelli, Luca H. 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, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolo Di Lalla, Immacolata Donnarumma, Victor Doroshenko, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Jeremy Heyl, Wataru Iwakiri, Svetlana G. Jorstad, Vladimir Karas, Fabian Kislat, Takao J. Kitaguchi, Jeffery Kolodziejczak, Henric Krawczynski, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Frederic Marin, Andrea Marinucci, Alan P. Marscher, Francesco Massaro, Ikuyuki Mitsuishi, Tsunefumi Mizuno, Michela Negro, Chi-Yung Ng, Nicola Omodei, Chiara G. Oppedisano, George L. Pavlov, Abel Peirson, Matteo Perri, Melissa Pesce-Rollins, Pierre-Olivier Petrucci, Andrea Possenti, Simonetta D. Puccetti, Brian Ramsey, Ajay J. Ratheesh, Oliver W. Roberts, Roger Romani, Carmelo Sgro, Patrick Slane, Gloria Spandre, Douglas A. Swartz, Toru Tamagawa, Fabrizio Tavecchio, Roberto Taverna, Yuzuru F. Tawara, Allyn E. Tennant, Nicholas Thomas, Francesco Tombesi, Alessio Trois, Sergey Tsygankov, Roberto Turolla, Jacco Vink, Kinwah Wu
Summary: This paper reports the first detection of polarization in the X-rays for atoll-source 4U 1820-303, obtained with the Imaging X-ray Polarimetry Explorer (IXPE) at a 99.999% confidence level. The source shows a significant polarization above 4 keV, with the polarization degree increasing with energy. The spectro-polarimetric fit indicates an orthogonal polarization direction between the hard spectral component and the accretion disk.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
Fabrizio Nicastro, Y. Krongold, T. Fang, F. Fraternali, S. Mathur, S. Bianchi, A. De Rosa, E. Piconcelli, L. Zappacosta, M. Bischetti, C. Feruglio, A. Gupta, Z. Zhou
Summary: The number of baryons in galactic disks is lower than expected, leading to the galaxy missing-baryon problem. Research suggests that the missing baryons may exist in a hotter gaseous phase of the circumgalactic medium.
ASTROPHYSICAL JOURNAL LETTERS
(2023)