99 citations · 640 across the 22 of their papers we have counts for
22 papers
Discovery of strongly variable X-ray polarization in the neutron star low-mass X-ray binary transient XTE J1701462
Massimo Cocchi, Andrea Gnarini, Sergio Fabiani +105
After about 16 years since its first outburst, the transient neutron star low-mass X-ray binary XTE J1701462 turned on again in September 2022, allowing for the first study of i…
First detection of X-ray polarization from the accreting neutron star 4U 1820-303
Alessandro Di Marco, Fabio La Monaca, Juri Poutanen +116
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 99.999% confidence…
The First X-ray Polarization Observation of the Black Hole X-ray Binary 4U 1630-47 in the Steep Power Law State
Nicole Rodriguez Cavero, Lorenzo Marra, Henric Krawczynski +107
The Imaging X-ray Polarimetry Explorer (IXPE) observed the black hole X-ray binary 4U 1630-47 in the steep power law (or very high) state. The observations reveal a linear polariza…
X-ray Polarization of the Black Hole X-ray Binary 4U 1630-47 Challenges Standard Thin Accretion Disk Scenario
Ajay Ratheesh, Michal Dovčiak, Henric Krawczynski +112
Large energy-dependent X-ray polarization degree is detected by the Imaging X-ray Polarimetry Explorer ({IXPE}) in the high-soft emission state of the black hole X-ray binary 4U 16…
Transient obscuration event captured in NGC 3227 IV. Origin of the obscuring cloud variability
S. Grafton-Waters, J. Mao, M. Mehdipour +13
Obscuration events in type I active galactic nuclei (AGN) have been detected more frequently in recent years. The strong flux decrease in the soft X-ray band between observations h…
Cygnus X-3 revealed as a Galactic ultraluminous X-ray source by IXPE
Alexandra Veledina, Fabio Muleri, Juri Poutanen +127
The accretion of matter by compact objects can be inhibited by radiation pressure if the luminosity exceeds the critical value, known as the Eddington limit. Discovery of ultralumi…
X-ray pulsar GRO J100857 as an orthogonal rotator
Sergey S. Tsygankov, Victor Doroshenko, Alexander A. Mushtukov +99
X-ray polarimetry is a unique way to probe the geometrical configuration of highly magnetized accreting neutron stars (X-ray pulsars). GRO J100857 is the first transient X-ray p…
Polarization properties of the weakly magnetized neutron star X-ray binary GS 1826-238 in the high soft state
Fiamma Capitanio, Sergio Fabiani, Andrea Gnarini +94
The launch of the Imaging X-ray Polarimetry Explorer (IXPE) on 2021 December 9 has opened a new window in X-ray astronomy. We report here the results of the first IXPE observation…
Hard X-ray selected giant radio galaxies -- III. The LOFAR view
G. Bruni, M. Brienza, F. Panessa +12
Giant radio galaxies (GRGs), with extended structures reaching hundreds of kpc, are among the most spectacular examples of ejection of relativistic plasma from super-massive black…
Soft gamma-ray selected giant radio galaxies: an update
L. Bassani, F. Ursini, A. Malizia +9
We present an update on the sample of soft gamma-ray selected giant radio galaxies (GRGs) extracted from INTEGRAL/IBIS and Swift/BAT surveys; it includes 8 new sources and one cand…
A broadband X-ray view of the NLSy1 1E 0754.6+392.8
R. Middei, F. Tombesi, F. Vagnetti +8
The soft X-ray band of many active galactic nuclei (AGNs) is affected by obscuration due to partially ionised matter crossing our line of sight. In this context, two past XMM-Newto…
Radiation spectra of warm and optically thick coronae in AGN
P. -O. Petrucci, D. Gronkiewicz, A. Rozanska +9
A soft X-ray excess above the 2-10 keV power law extrapolation is generally observed in AGN X-ray spectra. Presently there are two competitive models to explain it: blurred ionized…
The coronal temperature of NGC 4388 and NGC 2110 measured with INTEGRAL
F. Ursini, L. Bassani, A. Malizia +4
We aim to measure the physical properties of the hot X-ray corona of two active galactic nuclei, NGC 4388 and NGC 2110. We analysed the hard X-ray (20-300 keV) INTEGRAL spectrum in…
Probing restarting activity in hard X-ray selected giant radio galaxies
G. Bruni, F. Ursini, F. Panessa +13
With their sizes larger than 0.7 Mpc, Giant Radio Galaxies (GRGs) are the largest individual objects in the Universe. To date, the reason why they reach such enormous extensions is…
High-energy monitoring of NGC 4593 II. Broadband spectral analysis: testing the two-corona model
R. Middei, S. Bianchi, P. -O. Petrucci +9
It is widely believed that the primary X-ray emission of AGN is due to the Comptonisation of optical-UV photons from a hot electron corona, while the origin of the 'soft-excess' is…
HST/COS observations of the newly discovered obscuring outflow in NGC 3783
G. A. Kriss, M. Mehdipour, J. S. Kaastra +24
To understand the nature of transient obscuring outflows in active galactic nuclei, we observed the Seyfert 1 galaxy NGC 3783 on two occasions in December 2016 triggered by Swift m…
Hard X-ray selected giant radio galaxies - I. The X-ray properties and radio connection
F. Ursini, L. Bassani, F. Panessa +6
We present the first broad-band X-ray study of the nuclei of 14 hard X-ray selected giant radio galaxies, based both on the literature and on the analysis of archival X-ray data fr…
The NuSTAR view of the Seyfert Galaxy HE 0436-4717
Riccardo Middei, Fausto Vagnetti, Francesco Tombesi +4
We present the multi epoch spectral analysis of HE 0436-4717, a bright Seyfert 1 galaxy serendipitously observed by the high energy satellite NuSTAR four times between December 201…
Where are Compton-thick radio galaxies? A hard X-ray view of three candidates
F. Ursini, L. Bassani, F. Panessa +4
We present a broad-band X-ray spectral analysis of the radio-loud active galactic nuclei NGC 612, 4C 73.08 and 3C 452, exploiting archival data from NuSTAR, XMM-Newton, Swift and I…
NuSTAR spectral analysis of two bright Seyfert 1 galaxies: MCG +8-11-11 and NGC 6814
A. Tortosa, S. Bianchi, A. Marinucci +10
We report on the NuSTAR observations of two bright Seyfert 1 galaxies, namely MCG +8-11-11 (100 ks) and NGC 6814 (150 ks). The main goal of these observations was to investigate th…
A deep X-ray view of the bare AGN Ark120. IV. XMM-Newton and NuSTAR spectra dominated by two temperature (warm, hot) Comptonization processes
D. Porquet, J. N. Reeves, G. Matt +16
We perform an X-ray spectral analysis of the brightest and cleanest bare AGN known so far, Ark 120, in order to determine the process(es) at work in the vicinity of the SMBH. We pr…
The NuSTAR X-ray spectrum of the low-luminosity AGN in NGC 7213
F. Ursini, A. Marinucci, G. Matt +11
We present an analysis of the 3-79 keV NuSTAR spectrum of the low-luminosity active galactic nucleus NGC 7213. In agreement with past observations, we find a lower limit to the hig…