251 citations · 1.6k across the 36 of their papers we have counts for
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Fingerprints of thermal Comptonization in accreting neutron stars. Plasma-vacuum interplay in cyclotron lines and polarisation
E. Sokolova-Lapa, D. K. Maniadakis, J. J. R. Stierhof +11
X-ray emission from accreting, strongly magnetised neutron stars and its pulse-phase variability probe their magnetic-field geometry, spin orientation, and emission processes. Whet…
Spectroscopic modeling of ionic structure in stellar winds of high-mass X-ray binaries
G. Sanjurjo-Ferrín, V. Grinberg, I. El Mellah +6
High-mass X-ray binaries (HMXBs) provide a natural laboratory to study radiatively driven stellar winds under strong external X-ray irradiation. As the compact object moves along i…
Pulse profile variations in the accreting X-ray pulsar Vela X-1
V. Madurga-Favieres, A. Martin-Carrillo, C. M. Diez +7
Vela X-1 is a well-studied accreting X-ray pulsar, with a distinctive pulse profile that has been found to be very similar in different observations spread out over decades. On the…
Low-frequency spectra of neutron star + OB supergiant binaries: Does wind density drive persistent and flaring modes of accretion?
J. van den Eijnden, L. Sidoli, M. Díaz Trigo +10
Neutron star high-mass X-ray binaries are well-studied in wavebands between the infrared and hard X-rays. Their low-frequency millimeter and radio properties, on the other hand, re…
Characterisation of the stellar wind in Cyg X-1 via modelling of colour-colour diagrams
E. V. Lai, B. De Marco, Y. Cavecchi +11
Cygnus X-1 is a high mass X-ray binary where accretion onto the black hole is mediated by the stellar wind from the blue supergiant companion star HDE 226868. Depending on the posi…
The first mm detection of a neutron star high-mass X-ray binary
J. van den Eijnden, L. Sidoli, M. Diaz Trigo +9
Neutron stars accreting from OB supergiants are often divided between persistently and transiently accreting systems, called Supergiant X-ray Binaries (SgXBs) and Supergiant Fast X…
Reconnection-driven flares in 3D black hole magnetospheres -- A scenario for hot spots around Sagittarius A*
I. El Mellah, B. Cerutti, B. Crinquand
Low-luminosity supermassive and stellar-mass black holes (BHs) may be embedded in a collisionless and highly magnetized plasma. They show non-thermal flares indicative of efficient…
Stellar wind variability in Cygnus X-1 from high-resolution excess variance spectroscopy with Chandra
Lucia K. Härer, Michael L. Parker, Ileyk El Mellah +5
Stellar winds of massive stars are known to be driven by line absorption of UV photons, a mechanism which is prone to instabilities, causing the wind to be clumpy. The clumpy struc…
Observing the onset of the accretion wake in Vela X-1
C. M. Diez, V. Grinberg, F. Fürst +7
High-Mass X-ray Binaries (HMXBs) offer a unique opportunity for the investigation of accretion onto compact objects and of wind structure in massive stars. A key source for such st…
Clumpy wind studies and the non-detection of cyclotron line in OAO 1657-415
Pragati Pradhan, Carlo Ferrigno, Biswajit Paul +11
Winds of massive stars are suspected to be inhomogeneous (or clumpy), which biases the measures of their mass loss rates. In High Mass X-ray Binaries (HMXBs), the compact object ca…
Spinning black holes magnetically connected to a Keplerian disk -- Magnetosphere, reconnection sheet, particle acceleration and coronal heating
I. El Mellah, B. Cerutti, B. Crinquand +1
Context: Accreting black holes (BHs) may be surrounded by a highly magnetized plasma threaded by a poloidal magnetic field. Non-thermal flares and high energy components could orig…
Wind Roche lobe overflow in high mass X-ray binaries : a possible mass transfer mechanism for Ultraluminous X-ray sources
I. El Mellah, J. O. Sundqvist, R. Keppens
Ultra-luminous X-ray sources (ULX) have so high X-ray luminosities that they were long thought to be accreting intermediate mass black holes. Yet, some ULX have been shown to displ…
Formation of wind-captured discs in Supergiant X-ray binaries : consequences for Vela X-1 and Cygnus X-1
I. El Mellah, A. A. C. Sander, J. O. Sundqvist +1
In Supergiant X-ray binaries (SgXB), a compact object captures a fraction of the wind of an O/B supergiant on a close orbit. Proxies exist to evaluate the efficiency of mass and an…
Accretion form a clumpy massive-star wind in Supergiant X-ray binaries
I. El Mellah, J. O. Sundqvist, R. Keppens
Supergiant X-ray Binaries (SgXB) host a compact object, often a neutron star (NS), orbiting an evolved O/B star. Mass transfer proceeds through the intense line-driven wind of the…
The clumpy absorber in the high-mass X-ray binary Vela X-1
V. Grinberg, N. Hell, I. El Mellah +13
Bright and eclipsing, the high-mass X-ray binary Vela X-1 offers a unique opportunity to study accretion onto a neutron star from clumpy winds of O/B stars and to disentangle the c…
Wind accretion onto compact objects
Ileyk El Mellah
X-ray emission associated to accretion onto compact objects displays important levels of photometric and spectroscopic time-variability. When the accretor orbits a Supergiant star,…
A numerical investigation of wind accretion in persistent Supergiant X-ray Binaries I - Structure of the flow at the orbital scale
I. El Mellah, F. Casse
Classical Supergiant X-ray Binaries host a neutron star orbiting a supergiant OB star and display persistent X-ray luminosities of 10 to 10 erg/s. The stellar wind fr…
Numerical simulations of axisymmetric hydrodynamical Bondi-Hoyle accretion onto a compact object
Ileyk El Mellah, Fabien Casse
Bondi-Hoyle accretion configurations occur as soon as a gravitating body is immersed in an ambient medium with a supersonic relative velocity. From wind-accreting X-ray binaries to…