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…
AB Dor: Coronal Imaging and Activity Cycles
Pandey, J. C.; Singh, Gurpreet
Using long-term X-ray observations, we present short-term and long-term X-ray variability analysis of the ultrafast rotating active star AB Dor. Flaring events are common in X-ray observations of AB Dor and occupy a substantial portion of the total observation time, averaging at around 57% ± 23%. The flare-free X-ray light curves show rotational m…
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…
A catalogue of unusually long thermonuclear bursts on neutron stars
Degenaar, N.; in't Zand, J. J. M.; Kuulkers, E. +10 more
Rare, energetic (long) thermonuclear (Type I) X-ray bursts are classified either as intermediate-duration or 'supern' bursts, based on their duration. Intermediate-duration bursts lasting a few to tens of minutes are thought to arise from the thermonuclear runaway of a relatively thick (≈1010 g cm-2) helium layer, while super…
A helium-burning white dwarf binary as a supersoft X-ray source
Burgess, J. M.; Werner, K.; Haberl, F. +12 more
Type Ia supernovae are cosmic distance indicators1,2, and the main source of iron in the Universe3,4, but their formation paths are still debated. Several dozen supersoft X-ray sources, in which a white dwarf accretes hydrogen-rich matter from a non-degenerate donor star, have been observed5 and suggested as Type I…
The false widow link between neutron star X-ray binaries and spider pulsars
Ingram, Adam; Middleton, Matthew; Rhodes, Lauren +3 more
The discovery of transitional millisecond pulsars (tMSPs) provided conclusive proof that neutron star (NS) low-mass X-ray binaries (LMXBs) comprise part of the evolutionary pathway towards binary millisecond pulsars (MSPs). Redback and black widow 'spider' pulsars are a subcategory of binary MSPs that 'devour' their companions through ablation - t…