相关论文: Constraints on cometary surface evolution derived …

The cometary materials are thought to be the reservoir of primitive materials in the Solar System. The recent detection of glycine and CH$_3$NH$_2$ by the ROSINA mass spectrometer in the coma of 67P/Churyumov-Gerasimenko suggests that amino…

There is now strong evidence that the current energy density of the Universe is dominated by dark energy with an equation of state w<-1/3, which is causing accelerated expansion. The build-up of structure within such Universes is subject to…

We study the evolution of long-period comets by numerical integration of their orbits, following comets from their origin in the Oort cloud until their final escape or destruction, in a model solar system consisting of the Sun, the four…

This paper presents new findings concerning the dynamics of the slow height variations in surfaces produced by the two-dimensional isotropic Kuramoto-Sivashinsky equation with an additional nonlinear term. In addition to the disordered…

The interest in the structure of ice-rich planetary bodies, in particular the differentiation between ice and rock, has grown due to the discovery of Kuiper belt objects and exoplanets. We thus carry out a parameter study for a range of…

Infrared observations of the coma of 67P/Churyumov-Gerasimenko were carried out from July to September 2015, i.e., around perihelion (13 August 2015), with the high-resolution channel of the VIRTIS instrument onboard Rosetta. We present the…

We report on observations of the dust trail of comet 67P/Churyumov-Gerasimenko (CG) in visible light with the Wide Field Imager at the ESO/MPG 2.2m telescope at 4.7 AU before aphelion, and at 24 micron with the MIPS instrument on board the…

We present observations of comet 67P/Churyumov-Gerasimenko acquired in support of the $Rosetta$ mission. We obtained usable data on 68 nights from 2014 September until 2016 May, with data acquired regularly whenever the comet was…

We analyze the physical properties and dynamical origin of a curved jet of comet 67P/Churyumov-Gerasimenko that was observed repeatedly in several nucleus rotations starting on May 30 and persisting until early August, 2015. We simulated…

For a sample of 22 core ellipticals and 22 power law ellipticals, I examine the apparent axis ratios of isophotes as a function of the dynamical time at the isophote's mean radius. The two types of elliptical galaxy have a significantly…

We show, by comparing observations with theoretical models, that the observed Kuiper Belt size distribution is well matched by coagulation models, which start from an initial planetesimal population with radii of about 1km, and subsequent…

We describe new planetesimal accretion calculations in the Kuiper Belt that include fragmentation and velocity evolution. All models produce two power law cumulative size distributions, N_C propto r^{-q}, with q = 2.5 for radii less than…

We here study the transfer process of material from one hemisphere to the other (deposition of airfall material) on an active comet nucleus, specifically 67P/Churyumov-Gerasimenko. Our goals are to: 1) quantify the thickness of the airfall…

The Nuker law was designed to match the inner few (~3-10) arcseconds of predominantly nearby (< 30 Mpc) early-type galaxy light-profiles; it was never intended to describe an entire profile. The Sersic model, on the other hand, was…

"Power Law Cosmologies" are defined by their growth of the cosmological scale factor as $ t^\alpha$ regardless of the matter content or cosmological epoch. Constraints from the current age of the Universe and from the high redshift…

We analyze the geometry of the species- and genotype-size distribution in evolving and adapting populations of single-stranded self-replicating genomes: here programs in the Avida world. We find that a scale-free distribution (power law)…

There are significant discrepancies between observational evidence and the hierarchical galaxy formation theory with respect to the shape of dark matter halos, the correlation between galaxy characteristics, and galaxy evolutionary history.…

On January 18-19 and June 28-29 of 2010, the Wide-field Infrared Survey Explorer (WISE) spacecraft imaged the Rosetta mission target, comet 67P/Churyumov-Gerasimenko. We present a preliminary analysis of the images, which provide a…

Because of the high fraction of refractory material present in comets, the heat produced by the radiogenic decay of elements such as aluminium and iron can be high enough to induce the loss of ultravolatile species such as nitrogen, argon…

To date, no compelling evidence has been found that the universe has non-trivial spatial topology. Meanwhile, anomalies in the observed CMB temperature map, such as the lack of correlations at large angular separations, remain…