Search Publications
Discovery of Alfvén Waves Planetward of Saturn's Rings
Dougherty, M. K.; Cao, H.; Southwood, D. J. +3 more
Between April and September 2017 in the final stages of the Cassini Saturn Orbiter mission the spacecraft executed 22 orbits passing planetward of the innermost ring, the D ring. During all periapsis passes oscillations were detected in the azimuthal magnetic field components on typical time scales of a few minutes. We argue that these time varyin…
A Single Point Method to Quantitatively Diagnose the Magnetotail Flapping Motion
Wei, Y.; Rong, Z. J.; Shen, C. +4 more
Quantitatively estimating magnetotail flapping motion is critical for understanding and characterizing its dynamical behaviors. Such estimation can be achieved in principle by the multipoint analysis of spacecraft tetrahedron, for example, Cluster or MMS mission, but, owing to the inability of single point measurement to separate the spatial tempo…
Analysis of Selected Runaway Stars in the Orion Nebula Based on Data from the Gaia EDR3 Catalogue
Bobylev, V. V.; Bajkova, A. T.
We have performed Monte Carlo simulations of the trajectories of several runaway stars using their parallaxes and proper motions from the Gaia EDR3 catalogue. We have confirmed the hypothesis that the stars AE Aur and $µ$ Col are a product of the multiple system breakup ${∼}2.5$ Myr ago and the Orion Trapezium may be the parent cluster for t…
A warm molecular ring in AG Car: composing the mass-loss puzzle
Umana, G.; Loru, S.; Rizzo, J. R. +9 more
We present APEX observations of CO J = 3 → 2 and ALMA observations of CO J = 2 → 1, 13CO J = 2 → 1, and continuum towards the Galactic luminous blue variable AG Car. These new observations reveal the presence of a ring-like molecular structure surrounding the star. Morphology and kinematics of the gas are consistent with a slowly expand…
Polarimetric and photometric observations of CB54, with analysis of four other dark clouds
Sen, A. K.; Il'in, V. B.; Prokopjeva, M. S. +1 more
We present the results of our BVR-band photometric and R-band polarimetric observations of ∼40 stars in the periphery of the dark cloud CB54. From different photometric data, we estimate E(B - V) and E(J - H). After involving data from other sources, we discuss the extinction variations towards CB54. We reveal two main dust layers: a foreground, E…
Phase-resolved hard X-ray emission of the high-mass binary LS 5039: a spectral hardening above 50 keV detected with INTEGRAL
Bozzo, E.; Bykov, A. M.; Krassilchtchikov, A. M. +3 more
Aims: LS 5039 is an enigmatic high-mass gamma-ray binary which hosts a powerful O6.5V companion, but the nature of the compact object is still to be established using multi-wavelength observations.
Methods: We analyzed phase-resolved multi-instrument spectra of nonthermal emission from LS 5039 in order to produce reliable spectral models…
Possible substellar companions in dwarf eclipsing binaries. SDSS J143547.87+373338.5, NSVS 7826147, and NSVS 14256825
Merc, J.; Wolf, M.; Zejda, M. +4 more
We present the new results of our long-term observational project to detect the small variations in the orbital periods of low-mass and short-period eclipsing binaries. About 120 new precise mid-eclipse times were obtained for three relatively well-known dwarf eclipsing binaries: SDSS J143547.87+373338.5 (P = 0.126 d), NSVS 07826147 (0.162 d), and…
New mid-infrared imaging constraints on companions and protoplanetary disks around six young stars
Waters, L. B. F. M.; Kamp, I.; Quanz, S. P. +13 more
Context. Mid-infrared (mid-IR) imaging traces the sub-micron and micron-sized dust grains in protoplanetary disks and it offers constraints on the geometrical properties of the disks and potential companions, particularly if those companions have circumplanetary disks.
Aims: We use the VISIR instrument and its upgrade NEAR on the VLT to take …
Exotic image formation in strong gravitational lensing by clusters of galaxies - II. Uncertainties
Ghosh, Agniva; Williams, Liliya L. R.; Meena, Ashish Kumar +1 more
Due to the finite amount of observational data, the best-fitting parameters corresponding to the reconstructed cluster mass have uncertainties. In turn, these uncertainties affect the inferences made from these mass models. Following our earlier work, we have studied the effect of such uncertainties on the singularity maps in simulated and actual …
Herschel and Odin observations of H2O, CO, CH, CH+, and [N II] in the barred spiral galaxy NGC 1365. Bar-induced activity in the outer and inner circumnuclear tori
Larsson, B.; Rydbeck, G.; Frisk, U. +3 more
Context. The Odin satellite is now into its twentieth year of operation, much surpassing its design life of two years. One of its major astronomical pursuits was the search for and study of water vapor in diverse regions of the Solar System and the Milky Way galaxy. The Herschel space observatory was needed to detect water vapor in external galaxi…