相关论文: An Oort cloud origin of the Halley-type comets
The Gaia space telescope has transformed our understanding of random stellar encounters with the Solar System. This study examines how such perturbations influence the most eccentric comets in the Oort Cloud (OC), a thermalized reservoir of…
The evolution of a prolate cloud at an Hii boundary is investigated using Smoothed Particle Hydrodynamics (SPH). The prolate molecular clouds in our investigation are set with their semi-major axis perpendicular to the radiative direction…
We have used data from the Sloan Digital Sky Survey (SDSS) Data Release 5 to explore the overall structure and substructure of the stellar halo of the Milky Way using about 4 million color-selected main sequence turn-off stars. We fit…
Comets have been invoked in numerous studies as a potentially important source of dust and gas around stars, but none has studied the thermo-physical evolution, out-gassing rate, and dust ejection of these objects in such stellar systems.…
In the late stages of accretion leading up to the formation of planetesimals, particles grew to pebbles the size of 1-mm to tens of cm. That is the same size range that dominates the present-day comet mass loss. Meteoroids that size cause…
The 2023 perihelion passage of comet C/2022 E3 (ZTF) afforded an opportunity to measure the abundances and spatial distributions of coma volatiles in an Oort cloud comet at high spatial resolution near its close approach to Earth…
We numerically investigate the features of typical orbits occurring in the Oort cloud (r\approx 50-150 kAU) in the low-acceleration regime of the MOdified Newtonian Dynamics (MOND). We take into account the so-called External Field Effect…
Using all the RXTE archival data of Sco X-1 and GX 5-1, which amount to about 1.6 mega seconds in total, we searched for possible occultation events caused by Oort Cloud Objects. The detection efficiency of our searching approach was…
Recent observations of small bodies of the Solar System showed evidence of the presence of refractory (asteroidal) material in the Oort cloud. Different models of the origin of the Solar System predict different numbers of rocky objects in…
We study the influence of an open cluster environment on the formation and current structure of the Oort cloud. To do this, we have run 19 different simulations of the formation of the Oort Cloud for 4.5 Gyrs. In each simulation, the solar…
We calculate the expected flux profile of comets into the planetary system from the Oort cloud arising from Galactic tides and encounters with molecular clouds. We find that both periodic and sporadic bombardment episodes, with amplitudes…
We show that the effects of radial galactic tides alone can change the dynamics of an Oort cloud of comets around a star in a highly sensitive manner. The Oort cloud dynamics depends primarily from the star's position in the Galaxy and its…
We use the GIBLE suite of cosmological zoom-in simulations of Milky Way-like galaxies with additional super-Lagrangian refinement in the circumgalactic medium (CGM) to quantify the origin and evolution of CGM cold gas clouds. The origin of…
Gas accretion, hot ($\sim 10^6\,{\rm K}$) atmospheres, and a tilt between the rotation axes of the disc and the atmosphere are all common predictions of standard galaxy evolution theory for massive star-forming galaxies at low redshift.…
Wide-orbit exoplanets are starting to be detected, and planetary formation models are under development to understand their properties. We propose a population of "Oort" planets around other stars, forming by a mechanism analogous to how…
The atomic and molecular compounds of cometary ices serve as valuable knowledge into the chemical and physical properties of the outer solar nebula, where comets are formed. From the cometary atmospheres, the atoms and gas-phase molecules…
Planet formation is accompanied by the formation of comet clouds. In systems where planets migrate on rapid timescales, the diffusive evolution of comet orbits may stall, resulting in a comet cloud intermediate between a flattened Kuiper…
We discuss the chemical evolution of dwarf irregular and blue compact galaxies in light of recent data, new stellar yields and chemical evolution models. We examine the abundance data for evidence of HII region self-enrichment effects,…
The high-velocity clouds (HVCs) in the outer Milky Way at $20^{\circ} < l < 190^{\circ}$ have similar spatial locations, metallicities, and kinematics. Moreover, their locations and kinematics are coincident with several extraplanar stellar…
The present paper reviews selected aspects of the Guliyev's hypothesis about the massive celestial body at a distance of 250-400 AU from the Sun as well as the factor of comets transfer. It is shown, that the conjecture of the point around…