Related papers: Experiments on cometary activity: ejection of dust…
Before Rosetta, the space missions Giotto and Stardust shaped our view on cometary dust, supported by plentiful data from Earth based observations and interplanetary dust particles collected in the Earth's atmosphere. The Rosetta mission at…
Water ice is a fundamental building material of comets and other bodies in the outer solar system. Yet, the properties of cometary water ice are challenging to study, due to its volatility and the typical distances at which comets are…
Distant long-period comet C/2017 K2 has been outside the planetary region of the solar system for 3 Myr, negating the possibility that heat retained from the previous perihelion could be responsible for its activity. This inbound comet is…
Whenever a freely spinning body is found in a complex rotational state, this means that either the body is a recent victim of an impact or a tidal interaction, or is a fragment of a recently disrupted progenitor. Another factor (relevant…
Clustering is often presumed to lead to enhanced agglomeration between cohesive grains due to the reduced relative velocities of particles within a cluster. Our discrete-particle simulations on gravity-driven, gas-solid flows of cohesive…
Relativistic jets can interact with the ambient gas distribution of the host galaxy, before breaking out to larger scales. In the past decade several studies have simulated jet-driven outflows to understand how they affect the nearby…
Previous work on protoplanetary dust growth shows halt at centimeter sizes owing to the occurrence of bouncing at velocities of $\geq$ 0.1 $ms^{-1}$ and fragmentation at velocities $\geq$ 1 $ms^{-1}$. To overcome these barriers, spatial…
Condensing atmospheric water vapor on surfaces is a sustainable approach to potentially address the potable water crisis. However, despite extensive research, a key question remains: what is the physical mechanism governing the condensation…
Astrophysical gases such as the interstellar-, circumgalactic- or intracluster-medium are commonly multiphase, which poses the question of the structure of these systems. While there are many known processes leading to fragmentation of cold…
Quasar outflows may play a crucial role in regulating the host galaxy, although the spatial scale of quasar outflows remain a major enigma, with their acceleration mechanism poorly understood. The kinematic information of outflow is the key…
The occurrence of complex organic molecules (COMs) in the gas phase at low temperature in the dense phases of the ISM suggests that a non-thermal desorption mechanism is at work because otherwise, COMs should condense within a short…
Recent measurements of type Ia supernovae indicate that distant supernovae are substantially fainter than expected from the standard flat cold dark matter model. One possible explanation is that the energy density in our universe is in fact…
Equation of motion for a comet in the Oort cloud is numerically solved. Orbital evolution of the comet under the action of the gravity of the Sun and the Galaxy is presented for various initial conditions. Oscillations of the Sun with…
We used the UltraViolet-Optical Telescope on board Swift to observe the dynamically young comet C/2009 P1 (Garradd) from a heliocentric distance of 3.5 AU pre-perihelion until 4.0 AU outbound. At 3.5 AU pre-perihelion, comet Garradd had one…
Soot aggregates form as open, fractal-like structures, but aged atmospheric particles are often observed to be restructured into more compact shapes. This compaction has a major effect on the radiative properties of the aggregates, and may…
Whether ice in cold cosmic environments is physically separated from the silicate dust or mixed with individual silicate moieties is not known. However, different grain models give very different compositions and temperatures of grains. The…
Main Belt comets represent a recently discovered class of objects. They are quite intriguing because, while having a Tisserand invariant value higher than 3, are showing cometary activity. We study the activity of the Main Belt comets…
Dark matter halos are built from accretion and merging. During merging some of the dark matter particles may be ejected with velocities higher than the escape velocity. We use both N-body simulations and single-particle smooth-field…
Comets likely formed in the outer regions of the protosolar nebula where they incorporated and preserved primitive presolar materials, volatiles resident in the outer disk, and more refractory materials from throughout the disk. The return…
We show that condensation is an efficient particle growth mechanism, leading to growth beyond decimeter-sized pebbles close to an ice line in protoplanetary discs. As coagulation of dust particles is frustrated by bouncing and…