Search Publications
Symbiotic Stars in the Apache Point Observatory Galactic Evolution Experiment Survey: The Case of LIN 358 and SMC N73 (LIN 445a)
Pan, Kaike; Cunha, Katia; Smith, Verne V. +9 more
LIN 358 and SMC N73 are two symbiotic binaries in the halo of the Small Magellanic Cloud, each composed of a hot white dwarf accreting from a cool giant companion. In this work, we characterize these systems using a combination of spectral energy distribution (SED)-fitting to the extant photometric data spanning a broad wavelength range (X-ray/ult…
Ion acoustic waves near a comet nucleus: Rosetta observations at comet 67P/Churyumov-Gerasimenko
Henri, Pierre; Nilsson, Hans; Goetz, Charlotte +6 more
Ion acoustic waves were observed between 15 and 30 km from the centre of comet 67P/Churyumov-Gerasimenko by the Rosetta spacecraft during its close flyby on 28 March 2015. There are two electron populations: one cold at kBTe≈0.2 eV and one warm at kBTe≈2 eV. The ions are dominated by a cold (a few hundre…
Astrometric Mass Ratios of 248 Long-period Binary Stars Resolved in Hipparcos and Gaia EDR3
Makarov, Valeri V.; Fabricius, Claus
Using the absolute astrometric positions and proper motions for common stars in the Hipparcos and Gaia catalogs separated by 24.75 yr in the mean epoch, we compute mass ratios for long-period, resolved binary systems without any astrophysical assumptions or dependencies, except the presence of inner binary subsystems that may perturb the observed …
Solar activity classification based on Mg II spectra: Towards classification on compressed data
Ivanov, S.; Tsizh, M.; Ullmann, D. +2 more
Although large volumes of solar data are available for investigation and study, the vast majority of these data remain unlabeled and are therefore not amenable to modern supervised machine learning methods. Having a way to accurately and automatically classify spectra into categories related to the degree of solar activity is highly desirable and …
Chlorine-bearing species and the 37Cl/35Cl isotope ratio in the coma of comet 67P/Churyumov-Gerasimenko
De Keyser, Johan; Wurz, Peter; Altwegg, Kathrin +6 more
A full-mission analysis has been conducted of Cl-bearing species in the coma of comet 67P/Churyumov-Gerasimenko as detected by the Double Focusing Mass Spectrometer (DFMS) of Rosetta's ROSINA instrument. The isotope ratio of the two stable chlorine isotopes 37Cl/35Cl is found to be 0.336 ± 0.017, to be compared with the stand…
The onset of jets in classical novae
Blundell, Katherine M.; Lee, Steven; McLoughlin, Dominic +1 more
We present two further classical novae, V906 Car and V5668 Sgr, which show jets and accretion disc spectral signatures in their H α complexes throughout the first 1000 d following their eruptions. From extensive densely time-sampled spectroscopy, we measure the appearance of the first high-velocity absorption component in V906 Car, and the duratio…
A multiline study of the filamentary infrared dark cloud G351.78-0.54
Zinchenko, I. I.; Ryabukhina, O. L.
We present results of a multiline study of the filamentary infrared dark cloud G351.78-0.54 in the 1.3 and 0.8 mm wavelength bands. The lines of the three isotopologues of carbon monoxide CO, N2H+, CH3CCH, and HNCO were observed. The aim was to study the general structure of the filamentary cloud, its fragmentation…
Optical performance evaluation of the high spatial resolution imaging camera of BepiColombo space mission
Debei, Stefano; Cremonese, Gabriele; Palumbo, Pasquale +2 more
Thermo-elastic analyses of the High spatial Resolution Imaging Camera (HRIC), which is mounted on Mercury Planetary Orbiter BepiColombo Integrated Observatory SYStem suit (SIMBIO-SYS) of BepiColombo space mission, are carried out in order to evaluate the effect of thermo-elastic deformations on the optical performance experienced by the camera at …
Hot graphite dust in the inner regime of NGC 4151
Shalima, P.; Swain, Subhashree; Latha, K. V. P. +1 more
We model the near-infrared (NIR) spectral energy distribution (SED) of NGC 4151 with a 3D radiative transfer SKIRT code, using which torus only (TO) and ring and torus (RAT) scenarios are studied. In the RAT models, a graphite ring-like structure (clumpy or smooth) is incorporated between the torus and the accretion disc. We vary the inclination a…
An X-Ray Study of the White Dwarf Binary AR Scorpii
Takata, J.; Kong, A. K. H.; Li, K. L. +4 more
We report a study of X-ray emission from the white dwarf/M-type star binary system AR Scorpii using archival data taken in 2016-2020. It has been known that the X-ray emission is dominated by optically thin thermal plasma emission and its flux level varies significantly over the orbital phase. The X-ray emission also contains a component that modu…