381 citations · 1.5k across the 23 of their papers we have counts for
23 papers
Well-being in French Astrophysics
N. A. Webb, C. Bot, S. Charpinet +8
It has become clear that early career astrophysics researchers (doctoral researchers, post-docs, etc) have a very diverse appreciation of their career, with some declaring it the b…
Long-term X-ray spectral evolution of Ultraluminous X-ray sources: implications on the accretion flow geometry and the nature of the accretor
Andrés Gúrpide, Olivier Godet, Filippos Koliopanos +2
The discovery of pulsations in several Ultraluminous X-ray sources (ULXs) demonstrated that a fraction of ULXs are powered by super-Eddington accretion onto neutron stars (NSs). Th…
Chandra probes the X-ray variability of M51 ULX-7: evidence of propeller transition and X-ray dips on orbital periods
G. Vasilopoulos, F. Koliopanos, F. Haberl +4
We report on the temporal properties of the ULX pulsar M51 ULX-7 inferred from the analysis of the 2018-2020 Swift/XRT monitoring data and archival Chandra data obtained over a per…
Discovery of a ~30-Year-Duration Post-Nova Pulsating Supersoft Source in the Large Magellanic Cloud
G. Vasilopoulos, F. Koliopanos, T. E. Woods +3
Supersoft X-ray sources (SSS) have been identified as white dwarfs accreting from binary companions and undergoing nuclear-burning of the accreted material on their surface. Althou…
The XMM-Newton serendipitous survey. X: The second source catalogue from overlapping XMM-Newton observations and its long-term variable content
I. Traulsen, A. D. Schwope, G. Lamer +12
The XMM-Newton Survey Science Centre Consortium (SSC) develops software in close collaboration with the Science Operations Centre to perform a pipeline analysis of all XMM-Newton o…
The XMM-Newton serendipitous survey IX. The fourth XMM-Newton serendipitous source catalogue
N. A. Webb, M. Coriat, I. Traulsen +28
Sky surveys produce enormous quantities of data on extensive regions of the sky. The easiest way to access this information is through catalogues of standardised data products. {\e…
Identification of 3XMM J000511.8+634018 as a new polar at P(orb)=133.5 min -- is it inside or outside the period gap?
A. D. Schwope, H. Worpel, N. A. Webb +2
We aimed to identify the variable X-ray source 3XMM J000511.8+634018, which was serendipitously discovered through routine inspections while the 3XMM catalogue was compiled. We ana…
NuSTAR X-ray spectrum of Be-X-ray pulsar Swift J1845.7-0037: Bulk and thermal Comptonization of cyclotron seed photons in the accretion column
Filippos Koliopanos, Georgios Vasilopoulos, Michael T. Wolff
Aims: Spectral and temporal analysis of the NuSTAR observation Galactic Be-XRB Swift J1845.7-0037. during its recent outburst. Methods: For the spectral analysis we use both phenom…
The chemical composition of the accretion disk and donor star in Ultra Compact X-ray Binaries: A comprehensive X-ray analysis
Filippos Koliopanos, Mathias Peault, Georgios Vasilopoulos +1
We have analyzed the X-ray spectra of all known Ultra Compact X-ray Binaries (UCXBs), with the purpose of constraining the chemical composition of their accretion disk and donor st…
Disappearance of the Fe K emission line in Ultra Compact X-ray Binaries 4U 1543-624 and Swift J1756.9-2508
Filippos Koliopanos, Georgios Vasilopoulos, Sebastien Guillot +1
We investigate the long-term variability of the K line of iron in the spectra of two Ultra Compact X-ray Sources (UCXBs) with C/O-rich donors. We revisit archival observations b…
M51 ULX-7: super-orbital periodicity and constraints on the neutron star magnetic field
G. Vasilopoulos, S. K. Lander, F. Koliopanos +1
In the current work we explore the applicability of standard theoretical models of accretion to the observed properties of M51 ULX-7. The spin-up rate and observed X-ray luminosity…
NGC 300 ULX1: spin evolution, super-Eddington accretion and outflows
G. Vasilopoulos, M. Petropoulou, F. Koliopanos +4
NGC300 ULX1 is an ultra-luminous X-ray pulsar, showing an unprecedented spin evolution, from about 126 s to less than 20 s in only 4 years, consistent with steady mass accretion ra…
Investigating ULX accretion flows and cyclotron resonance in NGC 300 ULX1
Filippos Koliopanos, Georgios Vasilopoulos, Johannes Buchner +2
Methods. We analyzed broadband XMM-Newton and NuSTAR observations of NGC 300 ULX1, performing phase-averaged and phase-resolved spectroscopy. We compared two physically motivated m…
Titans of the Early Universe: The Prato Statement on the Origin of the First Supermassive Black Holes
Tyrone E. Woods, Bhaskar Agarwal, Volker Bromm +30
In recent years, the discovery of massive quasars at z~7 has provided a striking challenge to our understanding of the origin and growth of supermassive black holes in the early Un…
The XMM-Newton serendipitous survey. VIII: The first XMM-Newton serendipitous source catalogue from overlapping observations
I. Traulsen, A. D. Schwope, G. Lamer +13
XMM-Newton has observed the X-ray sky since early 2000. The XMM-Newton Survey Science Centre Consortium has published catalogues of X-ray and ultraviolet sources found serendipitou…
Accreting, highly magnetized neutron stars at the Eddington limit: A study of the 2016 outburst of SMC X-3
Filippos Koliopanos, Georgios Vasilopoulos
We study the temporal and spectral characteristics of SMC X-3 during its 2016 outburst. To probe accretion onto highly magnetized neutron stars (NSs), at the Eddington limit. We ob…
Intermediate Mass Black Holes: A brief review
Filippos Koliopanos
Intermediate mass black holes (IMBHs) are an (as yet) elusive class of black holes that are expected to lie in the range, between the firmly established stel…
ULX spectra revisited: Accreting, highly magnetized neutron stars as the engines of ultraluminous X-ray sources
Filippos Koliopanos, Georgios Vasilopoulos, Olivier Godet +3
Aims: In light of recent discoveries of pulsating ULXs and recently introduced models, that propose neutron stars (NSs) as the central engines of ULXs, we revisit the (XMM-Newton a…
Searching for Intermediate Mass Black Holes in galaxies with Low Luminosity AGN: A multiple-method approach
Filippos Koliopanos, Bogdan C. Ciambur, Alister W. Graham +7
Aims: This work is the first stage of a campaign to search for IMBHs, in low luminosity AGN (LLAGN) and dwarf galaxies. An additional, and equally important, aim of this pilot stud…
Luminosity dependent change of the emission diagram in the X-ray pulsar 4U 1626-67
Filippos Koliopanos, Marat Gilfanov
We detect variability of the Fe Ka emission line in the spectrum of X-ray pulsar 4U 1626-67, correlated with changes in its luminosity and in the shape of its pulse profile. Analys…
The XMM-Newton serendipitous survey. VII. The third XMM-Newton serendipitous source catalogue
S. R. Rosen, N. A. Webb, M. G. Watson +37
Thanks to the large collecting area (3 x ~1500 cm at 1.5 keV) and wide field of view (30' across in full field mode) of the X-ray cameras on board the European Space Agency X-r…
X-ray diagnostics of chemical composition of the accretion disk and donor star in UCXBs II: XMM-Newton observations
Filippos Koliopanos, Marat Gilfanov, Lars Bildsten +1
We search for the Fe K line in spectra of Ultra Compact X-ray Binaries (UCXBs). For this purpose we have analyzed XMM-Newton observations of five confirmed UCXBs. We find that t…
X-ray diagnostics of chemical composition of the accretion disk and donor star in ultra-compact X-ray binaries
Filippos Koliopanos, Marat Gilfanov, Lars Bildsten
Non-solar composition of the donor star in ultra-compact X-ray binaries may have a pronounced effect on the fluorescent lines appearing in their spectra due to reprocessing of prim…