Measuring interstellar dust grains from the haloes of binary X-ray sources

Observational results of cosmic diffuse X-rays are reviewed with particular emphasis on soft X-rays. The intensity distribution of soft X-rays over the celestial sphere indicates that the diffuse component of soft X-rays consists of an extra-galactic and a galactic component. The absorption of the soft X-rays in the interstellar medium results in heating and ionization of interstellar matter. The ionization rate by X-rays is estimated as about 10–16 s–1 per H atom.The scattering of X-rays by interstellar dust grains produces a halo of an X-ray source and smears out the pulsation of X-ray emission. The scattering coefficient and the halo size are given for some typical grain models.The possibility that the dust grains gain relativistic energy is suggested. It is speculated that the relativistic dust grains in metagalactic space may be responsible for cosmic rays of ultrahigh energies and also for the diffuse X-rays by the interactions with cosmic black-body radiation.

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The X-Ray Pulsed Fraction of NP0532 and Interstellar Grains

Publications of the Astronomical Society of Australia ◽

10.1017/s1323358000014120 ◽

1975 ◽

Vol 2 (6) ◽

pp. 325-327

Author(s):

R.M. Thomas

Keyword(s):

Spectral Index ◽

Interstellar Dust ◽

Crab Nebula ◽

X Rays ◽

Dust Grains ◽

X Ray ◽

Interstellar Dust Grains ◽

Low Energies ◽

Pulse Structure ◽

The Crab Nebula

In this paper we report that the available data on the measured pulsed fraction of X-rays from the Crab Nebula between the energies 0.7 and 300 keV indicate that it is no longer necessary to postulate an intrinsic change in the pulsar spectral index near 30 keV. Furthermore the spectral flattening which is evident at low energies can be entirely attributed, within the precision of the available statistics to the destruction of time coherence of the pulse structure by the scattering action of interstellar dust grains.

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Temperature fluctuations in interstellar dust grains

Astrophysics and Space Science ◽

10.1007/bf00643496 ◽

1979 ◽

Vol 65 (1) ◽

pp. 155-166 ◽

Cited By ~ 9

Author(s):

Per A. Aannestad ◽

Scott J. Kenyon

Keyword(s):

Interstellar Dust ◽

Temperature Fluctuations ◽

Dust Grains ◽

Interstellar Dust Grains

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CO2formation on interstellar dust grains: a detailed study of the barrier of the CO + O channel

Astronomy and Astrophysics ◽

10.1051/0004-6361/201321453 ◽

2013 ◽

Vol 559 ◽

pp. A49 ◽

Cited By ~ 26

Author(s):

M. Minissale ◽

E. Congiu ◽

G. Manicò ◽

V. Pirronello ◽

F. Dulieu

Keyword(s):

Interstellar Dust ◽

Dust Grains ◽

Interstellar Dust Grains

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The formation of the building blocks of peptides on interstellar dust grains

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320000010 ◽

2019 ◽

Vol 15 (S350) ◽

pp. 216-219

Author(s):

N. F. W. Ligterink ◽

J. Terwisscha van Scheltinga ◽

V. Kofman ◽

V. Taquet ◽

S. Cazaux ◽

...

Keyword(s):

Interstellar Dust ◽

Reaction Network ◽

Building Blocks ◽

Dust Grains ◽

Reaction Products ◽

Experimental Conditions ◽

Interstellar Dust Grains ◽

Temperature Programmed ◽

Life On Earth ◽

Emergence Of Life

AbstractThe emergence of life on Earth may have its origin in organic molecules formed in the interstellar medium. Molecules with amide and isocyanate groups resemble structures found in peptides and nucleobases and are necessary for their formation. Their formation is expected to take place in the solid state, on icy dust grains, and is studied here by far-UV irradiating a CH4:HNCO mixture at 20 K in the laboratory. Reaction products are detected by means of infrared spectroscopy and temperature programmed desorption - mass spectrometry. Various simple amides and isocyanates are formed, showing the importance of ice chemistry for their interstellar formation. Constrained by experimental conditions, a reaction network is derived, showing possible formation pathways of these species under interstellar conditions.

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