Zobrazeno 1 - 10
of 5 254
pro vyhledávání: '"A. Ursini"'
Autor:
Ursini, Francesco, Gnarini, Andrea, Capitanio, Fiamma, Bobrikova, Anna, Cocchi, Massimo, Di Marco, Alessandro, Fabiani, Sergio, Farinelli, Ruben, La Monaca, Fabio, Rankin, John, Saade, Mary Lynne, Poutanen, Juri
Low-mass X-ray binaries hosting weakly magnetized neutron stars (NS-LMXBs) are among the brightest sources in the X-ray sky. Since 2021, the Imaging X-ray Polarimetry Explorer (IXPE) has provided new measurements of the X-ray polarization of these so
Externí odkaz:
http://arxiv.org/abs/2409.07161
Autor:
Ursini, F., Gnarini, A., Bianchi, S., Bobrikova, A., Capitanio, F., Cocchi, M., Fabiani, S., Farinelli, R., Kaaret, P., Matt, G., Ng, M., Poutanen, J., Ravi, S., Tarana, A.
We present simultaneous X-ray polarimetric and spectral observations of the bright atoll source Ser~X-1 carried out with the Imaging X-ray Polarimetry Explorer (IXPE), NICER, and NuSTAR. We obtain an upper limit of 2% (99% confidence level) on the po
Externí odkaz:
http://arxiv.org/abs/2408.16713
Autor:
Gnarini, Andrea, Saade, M. Lynne, Ursini, Francesco, Bianchi, Stefano, Capitanio, Fiamma, Kaaret, Philip, Matt, Giorgio, Poutanen, Juri, Zhang, Wenda
Publikováno v:
A&A 690, A230 (2024)
We present the spectro-polarimetric results obtained from simultaneous X-ray observations with IXPE, NuSTAR and NICER of the dipping neutron star X-ray binary 4U 1624-49. This source is the most polarized Atoll source so far observed with IXPE, with
Externí odkaz:
http://arxiv.org/abs/2408.02309
Autor:
Gianolli, V. E., Bianchi, S., Kammoun, E., Gnarini, A., Marinucci, A., Ursini, F., Parra, M., Tortosa, A., De Rosa, A., Kim, D. E., Marin, F., Matt, G., Serafinelli, R., Soffitta, P., Tagliacozzo, D., Di Gesu, L., Done, C., Marshall, H. L., Middei, R., Mikusincova, R., Petrucci, P-O., Ravi, S., Svoboda, J., Tombesi, F.
Publikováno v:
A&A 691, A29 (2024)
We report on the second observing program of the active galactic nucleus NGC 4151 with simultaneous Imaging X-ray Polarimetry Explorer (IXPE; {\sim}750 ks), NuSTAR ({\sim}60 ks), XMM-Newton ({\sim}75 ks), and NICER ({\sim}65 ks) pointings. NGC 4151 i
Externí odkaz:
http://arxiv.org/abs/2407.17243
Autor:
Serafinelli, Roberto, De Rosa, Alessandra, Tortosa, Alessia, Stella, Luigi, Vagnetti, Fausto, Bianchi, Stefano, Ricci, Claudio, Kammoun, Elias, Petrucci, Pierre-Olivier, Middei, Riccardo, Lanzuisi, Giorgio, Marinucci, Andrea, Ursini, Francesco, Matt, Giorgio
Publikováno v:
A&A 690, A145 (2024)
Active galactic nuclei (AGN) are extremely variable in the X-ray band down to very short timescales. However, the driver behind the X-ray variability is still poorly understood. Previous results suggest that the hot corona responsible for the primary
Externí odkaz:
http://arxiv.org/abs/2407.06769
Autor:
Palit, B., Rozanska, A., Petrucci, P. O., Gronkiewicz, D., Barnier, S., Bianchi, S., Ballantyne, D. R., Gianolli, V. E., Middei, R., Belmont, R., Ursini, F.
In the X-ray spectra of AGNs, a noticeable excess of soft X-rays is typically detected beyond the extrapolation of the power-law trend observed between 2-10 keV. In the scenario of warm Comptonization, observations propose a warm corona temperature r
Externí odkaz:
http://arxiv.org/abs/2406.14378
Autor:
Vaia, B., Ursini, F., Matt, G., Ballantyne, D. R., Bianchi, S., De Rosa, A., Middei, R., Petrucci, P. O., Piconcelli, E., Tortosa, A.
Publikováno v:
A&A 688, A189 (2024)
The enigmatic and intriguing phenomenon of the "soft excess" observed in the X-ray spectra of luminous quasars continues to be a subject of considerable interest and debate in the field of high-energy astrophysics. This study focuses on the quasar HE
Externí odkaz:
http://arxiv.org/abs/2405.13479
Autor:
Ballantyne, D. R., Sudhakar, V., Fairfax, D., Bianchi, S., Czerny, B., De Rosa, A., De Marco, B., Middei, R., Palit, B., Petrucci, P. -O., Rozanska, A., Ursini, F.
The soft excess in active galactic nuclei (AGNs) may arise through a combination of relativistic reflection and the effects of a warm corona at the surface of the accretion disc. Detailed examination of the soft excess can therefore constrain models
Externí odkaz:
http://arxiv.org/abs/2404.03040
Autor:
Gianolli, V. E., Bianchi, S., Petrucci, P-O, Brusa, M., Chartas, G., Lanzuisi, G., Matzeu, G. A., Parra, M., Ursini, F., Behar, E., Bischetti, M., Comastri, A., Costantini, E., Cresci, G., Dadina, M., De Marco, B., De Rosa, A., Fiore, F., Gaspari, M., Gilli, R., Giustini, M., Guainazzi, M., King, A. R., Kraemer, S., Kriss, G., Krongold, Y., La Franca, F., Longinotti, A. L., Luminari, A., Maiolino, R., Marconi, A., Mathur, S., Matt, G., Mehdipour, M., Merloni, A., Middei, R., Miniutti, G., Nardini, E., Panessa, F., Perna, M., Piconcelli, E., Ponti, G., Ricci, F., Serafinelli, R., Tombesi, F., Vignali, C., Zappacosta, L.
Publikováno v:
A&A 687, A235 (2024)
The detection of blue-shifted absorption lines likely associated with ionized Iron K-shell transitions in the X-ray spectra of many Active Galactic Nuclei (AGN) suggests the presence of a highly ionized gas outflowing with mildly relativistic velocit
Externí odkaz:
http://arxiv.org/abs/2403.09538
X-ray polarization measurement of the gold standard of radio-quiet active galactic nuclei : NGC 1068
Autor:
Marin, F., Marinucci, A., Laurenti, M., Kim, D. E., Barnouin, T., Di Marco, A., Ursini, F., Bianchi, S., Ravi, S., Marshall, H. L., Matt, G., Chen, C. -T., Gianolli, V. E., Ingram, A., Maksym, W. P., Panagiotou, C., Podgorny, J., Puccetti, S., Ratheesh, A., Tombesi, F., Agudo, I., Antonelli, L. A., Bachetti, M., Baldini, L., Baumgartner, W., Bellazzini, R., Bongiorno, S., Bonino, R., Brez, A., Bucciantini, N., Capitanio, F., Castellano, S., Cavazzuti, E., Ciprini, S., Costa, E., De Rosa, A., Del Monte, E., Di Gesu, L., Di Lalla, N., Donnarumma, I., Doroshenko, V., Dovciak, M., Ehlert, S., Enoto, T., Evangelista, Y., Fabiani, S., Ferrazzoli, R., Garcia, J., Gunji, S., Heyl, J., Iwakiri, W., Jorstad, S., Kaaret, P., Karas, V., Kislat, F., Kitaguchi, T., Kolodziejczak, J., Krawczynski, H., La Monaca, F., Latronico, L., Liodakis, I., Madejski, G., Maldera, S., Manfreda, A., Marscher, A., Massaro, F., Mitsuishi, I., Mizuno, T., Muleri, F., Negro, M., Ng, S., O'Dell, S., Omodei, N., Oppedisano, C., Papitto, A., Pavlov, G., Perri, M., Pesce-Rollins, M., Petrucci, P. -O., Pilia, M., Possenti, A., Poutanen, J., Ramsey, B., Rankin, J., Roberts, O., Romani, R., Sgro, C., Slane, P., Soffitta, P., Spandre, G., Swartz, D., Tamagawa, T., Tavecchio, F., Taverna, R., Tawara, Y., Tennant, A., Thomas, N., Trois, A., Tsygankov, S., Turolla, R., Vink, J., Weisskopf, M., Wu, K., Xie, F., Zane, S.
Publikováno v:
A&A 689, A238 (2024)
We used the Imaging X-ray Polarimetry Explorer (IXPE) satellite to measure, for the first time, the 2-8 keV polarization of NGC 1068. We pointed IXPE for a net exposure time of 1.15 Ms on the target, in addition to two ~ 10 ks each Chandra snapshots
Externí odkaz:
http://arxiv.org/abs/2403.02061