Local interstellar medium

Bochkarev, N. G.

doi:10.1007/bf00637850

Cited by 51 publications

(32 citation statements)

References 156 publications

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“…Assuming a 10 nm interstellar dust particle impact velocity v d $ 10 2 km s À1 , our data would suggest an atomic plasma mass of $3 Á 10 À17 g per collision, yielding N d $ 10 3 molecules of average mass 30 amu, at the observed 0.1% relative yield. Assuming the 100 km s À1 particles comprise only 10% of the dust population [Spitzer, 1978], the synthetic rate would be modulated by a collision time t d $ [v d (0.1 n d )(2s d )] À1 = 5 Á 10 13 s, where n d % 10 À8 cm À3 and s d % 10 À12 cm 2 are the particle concentration and cross section, respectively [Bochkarev, 1992]. By comparison, the adsorption of hydrogen atoms striking dust particles at v H $ 1 km s À1 may produce H 2 at a rate limited by t H 0 $ (v H n d s d ) À1 = 10 15 s. In a given volume of space, the much higher hydrogen density n H $ 1 cm À3 = 10 9 (0.1 n d ) leads to a relative collision rate for H of $10 9 t d /t H 0 = 5 Á 10 7 for each such hypervelocity dust-dust impact that produces N d molecules.…”

Section: Discussionmentioning

confidence: 99%

“…[2] Hypervelocity impacts are part of the fundamental dynamics of matter in space, occurring statistically over vast spatial and temporal scales [Spitzer, 1978;Bochkarev, 1992]. At the multiple-kilometer scale, catastrophic impacts between small bodies and planets in the early solar system strongly influenced the geology and geochemistry of those bodies.…”

Section: Introductionmentioning

confidence: 99%

“…For example, the pressure of light or electromagnetic shocks can accelerate dust to well over 100 km s À1 [Bochkarev, 1992] causing ''supercritical'' impacts with atomization and ionization fractions approaching unity. Laboratory investigations of impacts are typically carried out in special dust accelerators [Knabe and Krüger, 1982;Ratcliff et al, 1997;Roybal et al, 1995], with particles of 10 À11 -10 À17 g mass now achieving speeds up to 100 km s…”

Section: Introductionmentioning

confidence: 99%

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Molecular synthesis in hypervelocity impact plasmas on the primitive Earth and in interstellar clouds

Managadze

Brinckerhoff

Chumikov

2003

Geophysical Research Letters

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[1] When impact speeds exceed a critical range of $15-20 km s À1 , the resulting plasma plume energizes very rapidly from a few eV, to as high as 30-50 eV when speeds reach 50-100 km s À1, and can be completely atomized and ionized. During post-impact adiabatic dispersion, the degree of ionization drops. The remaining ion population is mostly atomic, sampling the elemental composition of the colliding bodies, but some molecular ions are also formed. We present here results of experiments in which the physical and chemical conditions in the plume of a hypervelocity micrometeorite impact well above 20 km s À1 were modeled with Q-switched laser ablation. The formed molecular ions were analyzed with a time-of-flight (TOF) mass reflectron capable of distinguishing plasma-synthesized from surfacedesorbed species. Singly-and multiply-charged small organic molecules were identified as having formed in laser plasmas induced from inorganic carbonaceous substances. The results show the possibility of abiogenic synthesis of organic molecules in hypervelocity impacts of meteors on the primitive Earth during heavy bombardment and of dust particles in interstellar clouds.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Molecular synthesis in hypervelocity impact plasmas on the primitive Earth and in interstellar clouds

Managadze

Brinckerhoff

Chumikov

2003

Geophysical Research Letters

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“…Frisch 1981Frisch , 1995Frisch and York 1986;Bochkarev 1987;Maíz-Apellániz 2001;Fuchs et al 2006;Wolleben 2007;. Shells swept up by the winds of young stars in the ScorpiusCentaurus Association may be coincident with the location of the Sun today, and may be responsible for the very local warm ISMa clouds observed in our immediate vicinity.…”

Section: Origin Of Local Interstellar Mediummentioning

confidence: 99%

The Galactic Environment of the Sun: Interstellar Material Inside and Outside of the Heliosphere

et al. 2009

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Interstellar material (ISMa) is observed both inside and outside of the heliosphere. Relating these diverse sets of ISMa data provides a richer understanding of both the interstellar medium and the heliosphere. The galactic environment of the Sun is dominated by warm, low-density, partially ionized interstellar material consisting of atoms and dust grains. The properties of the heliosphere are dependent on the pressure, composition, radiation field, ionization, and magnetic field of ambient ISMa. The very low-density interior of the Local Bubble, combined with an expanding superbubble shell associated with star formation in the Scorpius-Centaurus Association, dominate the properties of the local interstellar medium (LISM). Once the heliosphere boundaries and interaction mechanisms are understood, interstellar gas, dust, pickup ions, and anomalous cosmic rays inside of the heliosphere can be directly compared to ISMa outside of the heliosphere. Our understanding of ISMa at the Sun is further enriched when the circumheliospheric interstellar material is compared to observations of other nearby ISMa and the overall context of our galactic environment. The IBEX mission will map the interaction region between the heliosphere and ISMa, and improve the accuracy of comparisons between ISMa inside and outside the heliosphere.

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“…300° < / < 330°; 0° < b < 30° Loop I 3. -20° < I < 20°; -60° < 6 < -40° Southern maximum of soft X-ray BG (B and C bands, McCammon et al 1983 Tunnel free of interstellar extinction (Bochkarev 1987b(Bochkarev , 1990 indices (Table 1). Three other maxima, though probably real, are not as definite as the three first ones.…”

Section: Observational Data and Analysismentioning

confidence: 99%

Interstellar Scintillation of Radio Sources as a Probe for Investigations of the Local Interstellar Medium

Bochkarev

Ryabov²

1997

International Astronomical Union Colloquium

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A b s t r a c t . A possibility of obtaining information on small scale inhomogeneities of the electron component of the local interstellar medium (LISM) is investigated using interstellar scintillations of extragalactic radio sources. We analyse Culgoora array observational data on variability of 190 extragalactic radio sources, covering most of the sky, at 80 and 160 MHz. The variability at time scales from 1 month to 15 years is interpreted as refractive interstellar scintillations in fast-moving nearby (less than 150 pc) hot gas near shock waves in the LISM. All-sky map of scintillation indices m averaged over 3-5 sources closest to one another shows several m maxima. Two of the 3 most pronounced maxima are probably connected with Loop I; the third one coincides with the soft X-ray (0.1-0.3 keV) background maximum near the South Galactic Pole. Other, less certain, m maxima probably correspond to the Orion star-formation region and to a soft X-ray maximum near the North Galactic Pole. The "free-of-gas" tunnel in the direction / = 240° corresponds to low values of m . The estimated time scale of interstellar scintillations on the above-mentioned LISM structures is in agreement with that of the observed radio-source variations.

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Local interstellar medium

Cited by 51 publications

References 156 publications

Molecular synthesis in hypervelocity impact plasmas on the primitive Earth and in interstellar clouds

Molecular synthesis in hypervelocity impact plasmas on the primitive Earth and in interstellar clouds

The Galactic Environment of the Sun: Interstellar Material Inside and Outside of the Heliosphere

Interstellar Scintillation of Radio Sources as a Probe for Investigations of the Local Interstellar Medium

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