Search Publications
Fragments of harmony amid apparent chaos: A closer look at the X-ray quasi-periodic eruptions of the galaxy RX J1301.9+2747
Alexander, Kate D.; Miniutti, Giovanni; Kara, Erin +17 more
Quasi-periodic eruptions (QPEs) are an extreme X-ray variability phenomenon associated with low-mass (MBH < 107 M⊙) supermassive black holes (SMBHs). First discovered in the nucleus of the galaxy GSN 069, they have been so far securely detected in five other galaxies, including RX J1301.9+2747. When detected, th…
XMM-Newton - NuSTAR monitoring campaign of the Seyfert 1 galaxy IC 4329A
Paltani, S.; Tombesi, F.; Privon, G. C. +13 more
We present the results of a joint XMM-Newton and NuSTAR campaign on the active galactic nucleus (AGN) IC 4329A, consisting of 9 × 20 ks XMM-Newton observations, and 5 × 20 ks NuSTAR observations within nine days, performed in August 2021. Within each observation, the AGN is not very variable, and the fractional variability never exceeds 5%. Flux v…
High-resolution spectroscopy of the intermediate polar EX Hydrae. II. The inner disk radius
Beuermann, K.; Reinsch, K.
ExoplANETS-A: A virtual observatory database for host stars and planetary systems. The effect of XUV on planet atmospheres
Huélamo, N.; García, R. A.; Solano, E. +12 more
Context. ExoplANETS-A is an EU Horizon-2020 project with the primary objective of establishing new knowledge on exoplanet atmospheres. Intimately related to this topic is the study of the host stars' radiative properties in order to understand the environment in which exoplanets lie.
Aims: The aim of this work is to exploit archived data from…
Current and secular accretion rates of EX Hydrae
Beuermann, K.; Reinsch, K.
We report an observed accretion rate of Ṁ1 = (3.86 ± 0.60) × 10−11 M⊙ yr−1 for the white dwarf in the short-period, intermediate polar
Observing the onset of the accretion wake in Vela X-1
Santangelo, A.; Grinberg, V.; Kretschmar, P. +7 more
High-mass X-ray binaries (HMXBs) offer a unique opportunity to investigate accretion onto compact objects and the wind structure in massive stars. A key source for such studies is the bright neutron star HMXB Vela X-1 whose convenient physical and orbital parameters facilitate analyses and in particular enable studies of the wind structure in HMXB…
Revisiting the archetypical wind accretor Vela X-1 in depth. Case study of a well-known X-ray binary and the limits of our knowledge
Degenaar, N.; Utrilla, E.; Ramos-Lerate, M. +9 more
Context. The Vela X-1 system is one of the best-studied X-ray binaries because it was detected early, has persistent X-ray emission, and a rich phenomenology at many wavelengths. The system is frequently quoted as the archetype of wind-accreting high-mass X-ray binaries, and its parameters are referred to as typical examples. Specific values for t…
Long-term variations in the X-ray activity of HR 1099
Schmitt, J. H. M. M.; Robrade, J.; Schneider, P. C. +6 more
Context. Although timing variations in close binary systems have been studied for a long time, their underlying causes are still unclear. A possible explanation is the so-called Applegate mechanism, where a strong, variable magnetic field can periodically change the gravitational quadrupole moment of a stellar component, thus causing observable pe…
New orbital ephemerides for the dipping source 4U 1323-619: constraining the distance to the source
Sanna, A.; Di Salvo, T.; Burderi, L. +6 more
Context. 4U 1323-619 is a low mass X-ray binary system that shows type I X-ray bursts and dips. The most accurate estimation of the orbital period is 2.941923(36) h and a distance from the source that is lower than 11 kpc has been proposed.
Aims: We aim to obtain the orbital ephemeris, the orbital period of the system, as well as its derivati…
Signature of the presence of a third body orbiting around XB 1916-053
Sanna, A.; Romano, P.; Di Salvo, T. +9 more
Context. The ultra-compact dipping source