Search Publications
Effects of resonant scattering of the Si IV doublet near 140 nm in a solar active region
Vial, J. -C.; Gontikakis, C.
Aims: In a previous study we analysed the C IV 1548.189 Å and 1550.775 Å lines observed with the Solar Ultraviolet Measurements of Emitted Radiation (SUMER), showing cases where the 1548.189 Å spectral profile was noticeably different from the 1550.775 Å one, profiles that we dubbed differentially shaped profiles. We explained this differenti…
A depth versus diameter scaling relationship for the best-preserved melt-bearing complex craters on Mars
Tornabene, Livio L.; Osinski, Gordon R.; Harrison, Tanya N. +4 more
We use topographic data to show that impact craters with pitted floor deposits are among the deepest on Mars. This is consistent with the interpretation of pitted materials as primary crater-fill impactite deposits emplaced during crater formation. Our database consists of 224 pitted material craters ranging in size from ∼1 to 150 km in diameter. …
Properties and redshift evolution of star-forming galaxies with high [O III]/[O II] ratios with MUSE at 0.28 < z < 0.85
Inami, H.; Richard, J.; Verhamme, A. +21 more
We present a study of the [O III]/[O II] ratios of star-forming galaxies drawn from Multi-Unit Spectroscopic Explorer (MUSE) data spanning a redshift range 0.28 < z < 0.85. Recently discovered Lyman continuum (LyC) emitters have extremely high oxygen line ratios: [O III]λ5007/[O II]λλ3726, 3729 > 4. Here we aim to understand the propertie…
The Kormendy relation of galaxies in the Frontier Fields clusters: Abell S1063 and MACS J1149.5+2223
Tortorelli, Luca; Annunziatella, Marianna; Lombardi, Marco +12 more
We analyse the Kormendy relations (KRs) of the two Frontier Fields clusters, Abell S1063, at z = 0.348, and MACS J1149.5+2223, at z = 0.542, exploiting very deep Hubble Space Telescope photometry and Very Large Telescope (VLT)/Multi Unit Spectroscopic Explorer (MUSE) integral field spectroscopy. With this novel data set, we are able to investigate…
Pulsations and eclipse-time analysis of HW Vir
Dhillon, V. S.; Marsh, T. R.; Reed, M. D. +9 more
We analysed recent K2 data of the short-period eclipsing binary system HW Vir, which consists of a hot subdwarf-B type primary with an M-dwarf companion. We determined the mid-times of eclipses, calculated O-C diagrams, and an average shift of the secondary minimum. Our results show that the orbital period is stable within the errors over the cour…
Gaia transients in galactic nuclei
Harrison, D. L.; Koposov, S. E.; van Leeuwen, F. +9 more
The high spatial resolution and precise astrometry and photometry of the Gaia mission should make it particularly apt at discovering and resolving transients occurring in, or near, the centres of galaxies. Indeed, some nuclear transients are reported by the Gaia Science Alerts (GSA) team, but not a single confirmed tidal disruption event (TDE) has…
The Acceleration Process of a Solar Quiescent Filament in the Inner Corona
Chen, Y.; Song, H. Q.; Cheng, X. +5 more
Coronal mass ejections (CMEs) are frequently associated with filament eruptions. Theoretical studies propose that both magnetic reconnection and ideal magnetohydrodynamic instability of magnetic flux ropes can convert coronal magnetic energy into the filament/CME kinetic energy. Numerical simulations and analytical considerations demonstrate that …
Comet 67p/Churyumov-Gerasimenko, possible origin of the depression Hatmehit
Czechowski, Leszek; Kossacki, Konrad J.
On the nucleus of comet 67P/Churyumov-Gerasimenko numerous pits and depressions of different sizes are identified. In the present work the origin of depression Hatmehit is investigated. We propose a mechanism that includes recession of the surface due to sub-dust sublimation together with formation of cavities. Recession of the surface is calculat…
Testing the Universality of Free Fall towards Dark Matter with Radio Pulsars
Kramer, Michael; Shao, Lijing; Wex, Norbert
The violation of the weak equivalence principle (EP) in the gravitational field of Earth, described by the Eötvös parameter η⊕ , was recently constrained to the level |η⊕| ≲10-14 by the MICROSCOPE space mission. The Eötvös parameter ηDM, pertaining to the differential couplings of dark matter (DM) and or…
K2-139 b: a low-mass warm Jupiter on a 29-d orbit transiting an active K0 V star
Erikson, A.; Pätzold, M.; Rauer, H. +27 more
We announce the discovery of K2-139 b (EPIC 218916923 b), a transiting warm-Jupiter (Teq = 547 ± 25 K) on a 29-d orbit around an active (log R^' _HK = -4.46 ± 0.06) K0 V star in K2 Campaign 7. We derive the system's parameters by combining the K2 photometry with ground-based follow-up observations. With a mass of 0.387 _{ - 0.075 } ^ {+…