Search Publications
Debris discs in binaries: morphology and photometric signatures
Kral, Q.; Olofsson, J.; Thebault, P.
Context. Since about half of all main-sequence stars reside in multiple star systems, it is important to consider the effect of binarity on the evolution of planetesimal belts in these complex systems.
Aims: We aim to see whether debris belts evolving between two stars may be impacted by the presence of the companion and whether this leaves a…
Bayes-based Orbital Elements Estimation in Triple Hierarchical Stellar Systems
Mendez, Rene A.; Orchard, Marcos E.; Silva, Jorge F. +1 more
Under certain rather prevalent conditions (driven by dynamical orbital evolution), a hierarchical triple stellar system can be well approximated, from the standpoint of orbital parameter estimation, as two binary star systems combined. Even under this simplifying approximation, the inference of orbital elements is a challenging technical problem b…
Exploring sub-MeV sensitivity of AstroSat–CZTI for ON-axis bright sources
Rao, A. R.; Bhalerao, Varun; Mithun, N. P. S. +5 more
The Cadmium–Zinc–Telluride Imager (CZTI) onboard AstroSat is designed for hard X-ray imaging and spectroscopy in the energy range of 20–100 keV. The CZT detectors are of 5-mm thickness and hence have good efficiency for Compton interactions beyond 100 keV. The polarisation analysis using CZTI relies on such Compton events and have been verified ex…
Redshift identification of X-ray-selected active galactic nuclei in the J1030 field: searching for large-scale structures and high-redshift sources
Prandoni, I.; Bolzonella, M.; Vignali, C. +23 more
We publicly release the spectroscopic and photometric redshift catalog of the sources detected with Chandra in the field of the z = 6.3 quasar SDSS J1030+0525. This is currently the fifth-deepest extragalactic X-ray field, and reaches a 0.5-2 keV flux limit of f0.5 − 2 = 6 × 10−17 erg s−1 cm−2. Using two…
Dynamics of Sunspot Shock Waves in the Chromosphere and Transition Region
Kayshap, Pradeep; Tripathi, Durgesh; Jelínek, P.
We study the dynamics of shock waves observed in the umbra of a sunspot using the spectroscopic observations from the Interface Region Imaging Spectrograph. The presence of a shock significantly deforms the shape of the spectral lines of Mg II, C II, and Si IV. We found that C II 1335.71 Å and Si IV 1393.75 Å show double-peaked profiles that chang…
Multi-band observations of Swift J0840.7−3516: A new transient ultra-compact X-ray binary candidate
Campana, S.; Rea, N.; Esposito, P. +5 more
We report on multi-band observations of the transient source Swift J0840.7−3516, which was detected in outburst in 2020 February by the Neil Gehrels Swift Observatory. The outburst episode lasted just ∼5 days, during which the X-ray luminosity quickly decreased from LX ≈ 3 × 1037 d102 erg s−1 …
Fon Dushanbe Catalogue. Results of Processing in the Tycho-2 System
Andruk, V. M.; Protsyuk, Yu. I.; Yuldoshev, Q. +2 more
In the Tycho-2 catalogue system the processing of 1529 photographic plates of the FON Dushanbe project from the collection of the Institute of Astrophysics of the National Academy of Sciences of Tajikistan was completed. The photographic plates with the size of 8°×8° (30x30 cm) were exposed in the zones from -8° to + 84° in the period of 1985-1992…
FUGIN hot core survey. I. Survey method and initial results for l = 10°-20°
Hasegawa, Tetsuo; Saito, Hiro; Seta, Masumichi +4 more
We have developed a method to make a spectral-line-based survey of hot cores, which represent an important stage of high-mass star formation, and applied the method to the data of the FUGIN (FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope) survey. First, we select hot core candidates by searching the FUGIN data for t…
Future Venus missions and flybys: A collection of possible measurements with mass spectrometers and plasma instruments
Wurz, P.; Galli, A.; Vorburger, A. +1 more
This study contains predictions for mass spectrometry and plasma instrument measurements during upcoming Venus flybys of BepiColombo and Solar Orbiter and discusses the possibility of a phosphine detection with mass spectrometry in Venus' upper atmosphere. The results extend the ones published previously in Gruchola et al. (2019), where prediction…
Critical comments on publications by S. Hoffmann and N. Vogt on historical novae/supernovae and their candidates
Neuhäuser, Ralph; Neuhäuser, Dagmar L.
We critically discuss recent articles by S. Hoffmann and N. Vogt on historical novae and supernovae (SNe) as well as their list of "24 most promising events" "with rather high probability to be a nova" (Hoffmann et al., AN, 2020, 341, 79 (P3)). Their alleged positional accuracy of previously suggested historical nova/SN records is based on inhomog…