scholarly journals Penetration of Interstellar Dust Aggregates Into Circumstellar Dust Disks

2004 ◽  
Vol 202 ◽  
pp. 347-349
Author(s):  
Hiroshi Kimura ◽  
Ingrid Mann

Interstellar dust particles, which are supposedly aggregates, penetrate dust disks around stars because of the star's motion relative to the surrounding interstellar medium (ISM). We discuss the interrelation of the physical properties of local interstellar dust, the relative motion of the star and the surrounding ISM, and the evolution of the circumstellar disk.

Author(s):  
A V Mishchenko ◽  
E A Godenko ◽  
V V Izmodenov

Abstract Interstellar dust penetrates into the heliosphere/astrosphere due to relative motion of the Sun and the local interstellar medium (LISM). Inside the heliosphere/astrosphere and at the heliospheric boundaries, where the solar/stellar wind interacts with LISM, distribution of the interstellar dust is modified due to an action of electromagnetic forces, the solar gravitation and radiation pressure. In this paper we show that the distribution of the interstellar dust particles in the heliosphere has peculiarities of high density layers. In order to understand the nature of the peculiarities Osiptsov’s Lagrangian method has been employed and developed for the case when the force acting on the particles has discontinuity as it is for the electromagnetic force at the helioshperic current sheet. In the result of the modeling we demonstrate existence of multiple layers of high density of the interstellar dust located at 0.03 - 10 AU north and south with respect to the heliospheric current sheet.


2006 ◽  
Vol 2 (S237) ◽  
pp. 47-52
Author(s):  
François Boulanger

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.


2021 ◽  
Author(s):  
Silvan Hunziker ◽  
Veerle Sterken ◽  
Peter Strub ◽  
Harald Krüger ◽  
Aigen Li

<p>Interstellar Probe is an ambitious mission concept, to reach interstellar space (up to 1000 AU). Its launch date is between 2030 and 2042 and its goals cover different fields of science from planetary science, heliophysics (heliosphere), to astronomy. One main goal is to significantly expand our knowledge about our heliosphere, the interstellar medium, and how both interact with each other. Among many other instruments, the space probe is planned to carry a dust mass spectrometer that will be able to capture dust particles and measure their composition. This will be especially useful for measuring the interstellar dust of the local interstellar medium that continuously streams through the solar system and has been directly detected for the first time with the Ulysses spacecraft in the 1990s. The mass distributions from such in situ dust detections in the solar system so far have shown a significant discrepancy compared to the results from astronomical observations. We performed a series of simulations of the interstellar dust trajectories and distribution inside the solar system and use them to predict the ability of the Interstellar Probe to measure interstellar dust particles and how this ability is affected by different spacecraft trajectories and dust detector setups. We also discuss how the filtering of small dust particles at the boundary regions of the heliosphere affects our predictions and indicate how in situ dust measurements can be used to constrain the filtering process. In general, most of the dust particles can be measured if the spacecraft moves towards the nose of the heliosphere. However, we also find a significant correlation between the presence of small dust particles (<0.3 microns) in the inner solar system and the phase of the solar cycle which is caused by the filtering effect of the solar magnetic field via the Lorentz force. Inside the heliosphere, the interstellar Probe may be able to detect and analyze up to 1 interstellar dust particle per day for particle sizes >0.1 micron and many more of the smaller particles, depending on the state of the solar magnetic field and the dust filtering at the boundary of the heliosphere. Outside the heliosphere, the absence of dust filtering should increase the detection rate of small particles (<0.1 microns) to more than 10 per day.</p>


1994 ◽  
Vol 160 ◽  
pp. 429-442
Author(s):  
Bruno Sicardy

We briefly review recent advances in the observation and study of planetary bodies in extra-solar systems. We summarize in particular the main physical properties of the β-Pictoris dust disk, and the status of new disk observations. Theoretical implications of infalling discrete bodies are considered, in particular, the existence of possible perturbing planet(s) causing this influx. Such planets could spectacularly disturb circumstellar dust disks, thus revealing themselves in spite of their intrinsic faintness as mere point sources. Finally, we describe the recent possible discovery of at least two planets around a pulsar. This underlines the potential existence of planets in rather exotic circumstances.


2002 ◽  
Vol 4 ◽  
pp. 9-9
Author(s):  
I. Ristorcelli ◽  
B. Stepnik ◽  
X. Dupac ◽  
A. Abergel ◽  
J. P. Bernard ◽  
...  

2020 ◽  
Vol 64 (8) ◽  
pp. 693-710
Author(s):  
V. A. Sokolova ◽  
A. I. Vasyunin ◽  
A. B. Ostrovskii ◽  
S. Yu. Parfenov

2013 ◽  
Vol 9 (S297) ◽  
pp. 147-152 ◽  
Author(s):  
G. C. Clayton

AbstractThe relationship between DIBs and dust is still unknown. The correlation between reddening and DIB strength means that the DIBs are mixed in with the dust and gas in interstellar clouds. The DIBs are relatively stronger in the diffuse interstellar medium than in dense clouds. There is only a weak correlation between the DIBs and the UV extinction parameters including the 2175 Å bump strength and the far-UV rise. In addition, the bump dust grains are sometimes polarized, while the DIBs are not. However, observations of DIBs in the SMC show that when the 2175 Å bump is weak or missing so are the DIBs. Two of the four sightlines that deviate strongly from the CCM UV extinction in the Galaxy show weak DIBs.


2015 ◽  
Vol 112 (24) ◽  
pp. 7438-7443 ◽  
Author(s):  
Tetsuya Hama ◽  
Hirokazu Ueta ◽  
Akira Kouchi ◽  
Naoki Watanabe

Classical transition-state theory is fundamental to describing chemical kinetics; however, quantum tunneling is also important in explaining the unexpectedly large reaction efficiencies observed in many chemical systems. Tunneling is often indicated by anomalously large kinetic isotope effects (KIEs), because a particle’s ability to tunnel decreases significantly with its increasing mass. Here we experimentally demonstrate that cold hydrogen (H) and deuterium (D) atoms can add to solid benzene by tunneling; however, the observed H/D KIE was very small (1–1.5) despite the large intrinsic H/D KIE of tunneling (≳100). This strong reduction is due to the chemical kinetics being controlled not by tunneling but by the surface diffusion of the H/D atoms, a process not greatly affected by the isotope type. Because tunneling need not be accompanied by a large KIE in surface and interfacial chemical systems, it might be overlooked in other systems such as aerosols or enzymes. Our results suggest that surface tunneling reactions on interstellar dust may contribute to the deuteration of interstellar aromatic and aliphatic hydrocarbons, which could represent a major source of the deuterium enrichment observed in carbonaceous meteorites and interplanetary dust particles. These findings could improve our understanding of interstellar physicochemical processes, including those during the formation of the solar system.


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