Jeans instability in a self-gravitating dusty plasma

We present a multi-fluid theory for the Jeans instability accounting for an attractive force between two equally charged dust particles in a self-gravitating plasma. Our analyses which includes the electrostatic energy between two charged dust grains provides a possibility of resolving the ‘Jeans swindle’, in addition to obtaining a Jeans instability with a faster growth rate. The relevance of our investigation to the formation of planetesimals and collapse of interstellar clouds in star forming regions is discussed.

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Dust evolution in the star forming turbulent interstellar medium

Proceedings of the International Astronomical Union ◽

10.1017/s1743921307001202 ◽

2006 ◽

Vol 2 (S237) ◽

pp. 47-52

Author(s):

François Boulanger

Keyword(s):

Interstellar Medium ◽

Interstellar Dust ◽

Dust Particles ◽

Interstellar Clouds ◽

Star Forming ◽

Interstellar Turbulence ◽

Star Forming Regions ◽

Potential Impact ◽

Dust Evolution ◽

Small Dust

AbstractUnderstanding interstellar dust evolution is a major challenge underlying the interpretation of Spitzer observations of interstellar clouds, star forming regions and galaxies. I illustrate on-going work along two directions. I outline the potential impact of interstellar turbulence on the abundance of small dust particles in the diffuse interstellar medium and translucent sections of molecular clouds. I present results from an analysis of ISO and Spitzer observations of the central part of 30 Doradus, looking for dust evolution related to the radiative and dynamical impact of the R136 super star cluster on its parent molecular cloud.

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Future lunar missions and investigation of dusty plasma processes on the Moon

Journal of Plasma Physics ◽

10.1017/s0022377813000214 ◽

2013 ◽

Vol 79 (4) ◽

pp. 405-411 ◽

Cited By ~ 15

Author(s):

SERGEY I. POPEL ◽

LEV M. ZELENYI

Keyword(s):

Dusty Plasma ◽

Lunar Surface ◽

Dust Particles ◽

Maximum Height ◽

Charged Dust ◽

The Moon ◽

Plasma System ◽

Lunar Dust ◽

The Impact ◽

Dusty Plasma System

AbstractFrom the Apollo era of exploration, it was discovered that sunlight was scattered at the terminators giving rise to “horizon glow” and “streamers” above the lunar surface. Subsequent investigations have shown that the sunlight was most likely scattered by electrostatically charged dust grains originating from the surface. A renaissance is being observed currently in investigations of the Moon. The Luna-Glob and Luna-Resource missions (the latter jointly with India) are being prepared in Russia. Some of these missions will include investigations of lunar dust. Here we discuss the future experimental investigations of lunar dust within the missions of Luna-Glob and Luna-Resource. We consider the dusty plasma system over the lunar surface and determine the maximum height of dust rise. We describe mechanisms of formation of the dusty plasma system over the Moon and its main properties, determine distributions of electrons and dust over the lunar surface, and show a possibility of rising dust particles over the surface of the illuminated part of the Moon in the entire range of lunar latitudes. Finally, we discuss the effect of condensation of micrometeoriod substance during the expansion of the impact plume and show that this effect is important from the viewpoint of explanation of dust particle rise to high altitudes in addition to the dusty plasma effects.

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Models of Gas-Grain Chemistry in Star-forming Regions

Symposium - International Astronomical Union ◽

10.1017/s0074180900164757 ◽

2000 ◽

Vol 197 ◽

pp. 147-159 ◽

Cited By ~ 4

Author(s):

Eric Herbst

Keyword(s):

Temporal Variations ◽

Binding Energies ◽

Dust Particles ◽

Temperature Phase ◽

Mathematical Treatment ◽

Star Forming ◽

Physical Conditions ◽

Star Forming Regions ◽

Chemical Models ◽

Key Species

It is difficult if not impossible to explain the abundances of assorted interstellar molecules in both the gaseous and condensed phases without the use of grain chemistry. Unfortunately, the chemistry occurring on grains is not well understood because of a variety of uncertainties including the nature, size, and shape of dust particles, the binding energies of key species, the dominant mechanism of surface chemistry, and the correct mathematical treatment of surface processes. Still, intrepid astrochemists have used granular chemistry in chemical models of an assortment of sources including cold clouds, protostellar disks, and hot cores. Indeed, the dominant explanation of the saturated gas-phase molecules observed in hot cores involves grain chemistry during an earlier, low temperature phase. Although gas-grain models have elucidated major features of the chemistry, much more work remains to be accomplished before they can be used to help characterize the physical conditions in star-forming regions and their temporal variations.

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Dusty plasmas in interstellar clouds and star forming regions

Astrophysics and Space Science ◽

10.1007/bf00645644 ◽

1996 ◽

Vol 246 (2) ◽

pp. 243-289 ◽

Cited By ~ 23

Author(s):

T. W. Hartquist ◽

W. Pilipp ◽

O. Havnes

Keyword(s):

Dusty Plasmas ◽

Interstellar Clouds ◽

Star Forming ◽

Star Forming Regions

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Why do protoplanetary disks appear not massive enough to form the known exoplanet population?

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834076 ◽

2018 ◽

Vol 618 ◽

pp. L3 ◽

Cited By ~ 62

Author(s):

C. F. Manara ◽

A. Morbidelli ◽

T. Guillot

Keyword(s):

Protoplanetary Disks ◽

Protoplanetary Disk ◽

Giant Planets ◽

Dust Particles ◽

Low Mass Stars ◽

Star Forming ◽

Star Forming Regions ◽

Exoplanetary Systems ◽

Low Mass ◽

The Masses

When and how planets form in protoplanetary disks is still a topic of discussion. Exoplanet detection surveys and protoplanetary disk surveys are now providing results that are leading to new insights. We collect the masses of confirmed exoplanets and compare their dependence on stellar mass with the same dependence for protoplanetary disk masses measured in ∼1–3 Myr old star-forming regions. We recalculated the disk masses using the new estimates of their distances derived from Gaia DR2 parallaxes. We note that single and multiple exoplanetary systems form two different populations, probably pointing to a different formation mechanism for massive giant planets around very low-mass stars. While expecting that the mass in exoplanetary systems is much lower than the measured disk masses, we instead find that exoplanetary systems masses are comparable or higher than the most massive disks. This same result is found by converting the measured planet masses into heavy element content (core masses for the giant planets and full masses for the super-Earth systems) and by comparing this value with the disk dust masses. Unless disk dust masses are heavily underestimated, this is a big conundrum. An extremely efficient recycling of dust particles in the disk cannot solve this conundrum. This implies that either the cores of planets have formed very rapidly (<0.1–1 Myr) and a large amount of gas is expelled on the same timescales from the disk, or that disks are continuously replenished by fresh planet-forming material from the environment. These hypotheses can be tested by measuring disk masses in even younger targets and by better understanding if and how the disks are replenished by their surroundings.

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Water in the interstellar media of galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316005627 ◽

2015 ◽

Vol 11 (A29B) ◽

pp. 395-399

Author(s):

Floris F. S. van der Tak

Keyword(s):

High Resolution ◽

Water Chemistry ◽

Galactic Nuclei ◽

Radiation Environment ◽

Interstellar Clouds ◽

Star Forming ◽

Star Forming Regions ◽

Interstellar Media ◽

Ionization Rates

AbstractThis paper reviews recent observations of water in Galactic interstellar clouds and nearby galactic nuclei. Two results are highlighted: (1) Multi-line H2O mapping of the Orion Bar shows that the water chemistry in PDRs is driven by photodissociation and -desorption, unlike in star-forming regions. (2) High-resolution spectra of H2O and its ions toward 5 starburst / AGN systems reveal low ionization rates, unlike as found from higher-excitation lines. We conclude that the chemistry of water strongly depends on radiation environment, and that the ionization rates of interstellar clouds decrease by at least 10 between galactic nuclei and disks.

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Simulations of two-stream instability in opposite polarity dusty plasmas

Journal of Plasma Physics ◽

10.1017/s0022377811000626 ◽

2012 ◽

Vol 78 (3) ◽

pp. 211-224

Author(s):

S. ERIC CLARK ◽

M. ROSENBERG ◽

K. QUEST

Keyword(s):

Electric Field ◽

Dusty Plasma ◽

Electric Fields ◽

Dusty Plasmas ◽

Linear Instability ◽

Dust Particles ◽

Charged Dust ◽

Collision Rate ◽

Dust Trapping ◽

Nonlinear Development

AbstractOne-dimensional Particle in Cell simulations of a dust–dust counterstreaming instability in a plasma containing dust grains of opposite charge polarity are presented. This dust–dust instability has potentially the lowest threshold drift for a dust wave instability in an unmagnetized dusty plasma. The linear and nonlinear development of this instability is investigated, including the effects of collisions with background neutrals, and a background electric field that acts as a driver to impart the drift velocities of the counter-streaming oppositely charged dust particles. The saturation of the linear instability appears to be due to dust heating related to dust trapping. Potential double layer formation from dust–dust instability turbulence is observed in cases with a high neutral collision rate. A comparative study is done with varying collision rates and background electric fields to explore the nonlinear development as a function of collision rate and background electric field. Applications to possible dusty plasma experimental parameters are discussed.

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Organic matter in space - An overview

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308021078 ◽

2008 ◽

Vol 4 (S251) ◽

pp. 3-16 ◽

Cited By ~ 6

Author(s):

Ewine F. van Dishoeck

Keyword(s):

Interplanetary Dust ◽

Laboratory Astrophysics ◽

Dust Particles ◽

Minor Planets ◽

Interplanetary Dust Particles ◽

Star Forming ◽

Star Forming Regions ◽

Recent Developments ◽

Cometary Material ◽

Diffuse Clouds

AbstractOrganic compounds are ubiquitous in space: they are found in diffuse clouds, in the envelopes of evolved stars, in dense star-forming regions, in protoplanetary disks, in comets, on the surfaces of minor planets, and in meteorites and interplanetary dust particles. This brief overview summarizes the observational evidence for the types of organics found in these regions, with emphasis on recent developments. The Stardust sample-return mission provides the first opportunity to study primitive cometary material with sophisticated equipment on Earth. Similarities and differences between the types of compounds in different regions are discussed in the context of the processes that can modify them. The importance of laboratory astrophysics is emphasized.

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