Search Publications
Swift, NuSTAR, and INTEGRAL observations of the symbiotic X-ray binary IGR J16194-2810
Ducci, L.; Romano, P.; Ferrigno, C. +1 more
We report on a simultaneous observational campaign with both Swift/XRT and NuSTAR targeting the symbiotic X-ray binary (SyXB) IGR J16194-2810. The main goal of the campaign was to investigate the possible presence of cyclotron scattering absorption features in the broad-band spectrum of the source, and help advance our understanding of the process…
Discovery of the first olivine-dominated A-type asteroid family
Galluccio, L.; Delbo, M.; Avdellidou, C. +1 more
The classical theory of differentiation states that due to the heat generated by the decay of radioactive elements, some asteroids form an iron core, an olivine-rich mantle, and a crust. The collisional breakup of these differentiated bodies is expected to lead to exposed mantle fragments, creating families of newly-formed asteroids. Among these n…
Sun-as-a-star Observations of Obscuration Dimmings Caused by Filament Eruptions
Veronig, Astrid M.; Dissauer, Karin; Tian, Hui +1 more
Filament eruptions often lead to coronal mass ejections (CMEs) on the Sun and are one of the most energetic eruptive phenomena in the atmospheres of other late-type stars. However, the detection of filament eruptions and CMEs on stars beyond the solar system is challenging. Here, we present six filament eruption cases on the Sun and show that fila…
Flux Contribution and Geometry of Charge Exchange Emission in the Starburst Galaxy M82
Foster, Adam R.; Smith, Randall K.; Okon, Hiromichi +1 more
Recent X-ray studies of starburst galaxies have found that charge exchange (CX) commonly occurs between outflowing hot plasma and cold gas, possibly from swept-up clouds. However, the total CX flux and the regions where CX occurs have been poorly understood. We present an analysis of XMM-Newton observations of M82, a prototype starburst galaxy, ai…
New ACV variables discovered in the Zwicky Transient Facility survey
Paunzen, E.; Prišegen, M.; Piecka, M. +8 more
Context. The manifestation of surface spots on magnetic chemically peculiar (mCP) stars is most commonly explained by the atomic diffusion theory, which requires a calm stellar atmosphere and only moderate rotation. While very successful and well described, this theory still needs to be revised and fine-tuned to the observations.
Aims: Our st…
Catalogue of dual-field interferometric binary calibrators
Lutz, D.; Förster Schreiber, N. M.; Genzel, R. +96 more
Context. Dual-field interferometric observations with VLTI/GRAVITY sometimes require the use of a binary calibrator. This is a binary star whose individual components remain unresolved by the interferometer, with a separation between 400 and 2000 mas for observations with the Unit Telescopes (UTs), or 1200-3000 mas for the Auxiliary Telescopes (AT…
Dynamical Phenomena in the Martian Atmosphere Through Mars Express Imaging
Sánchez-Lavega, A.; Tirsch, D.; Spiga, A. +5 more
This review describes the dynamic phenomena in the atmosphere of Mars that are visible in images taken in the visual range through cloud formation and dust lifting. We describe the properties of atmospheric features traced by aerosols covering a large range of spatial and temporal scales, including dynamical interpretations and modelling when avai…
X-Ray Variability in the Symbiotic Binary RT Cru: Principal Component Analysis
Luna, G. J. M.; Drake, J. J.; Danehkar, A.
Hard X-ray-emitting (δ-type) symbiotic binaries, which exhibit a strong hard X-ray excess, have posed a challenge to our understanding of accretion physics in degenerate dwarfs. RT Cru, which is a member of the δ-type symbiotics, shows stochastic X-ray variability. Timing analyses of X-ray observations from XMM-Newton and NuSTAR, which we consider…
Wide Area VISTA Extra-galactic Survey (WAVES): unsupervised star-galaxy separation on the WAVES-Wide photometric input catalogue using UMAP and HDBSCAN
Holwerda, Benne W.; Driver, Simon P.; Robotham, Aaron S. G. +13 more
Star-galaxy separation is a crucial step in creating target catalogues for extragalactic spectroscopic surveys. A classifier biased towards inclusivity risks including high numbers of stars, wasting fibre hours, while a more conservative classifier might overlook galaxies, compromising completeness and hence survey objectives. To avoid bias introd…
Gas-phase metallicity for the Seyfert galaxy NGC 7130
Lehmer, B. D.; Marconi, A.; Knapen, J. H. +2 more
Metallicity measurements in galaxies can provide valuable clues about galaxy evolution. One of the mechanisms postulated for metallicity redistribution in galaxies is gas flows induced by active galactic nuclei (AGNs), but the details of this process remain elusive. We report the discovery of a positive radial gradient in the gas-phase metallicity…