Far-Infrared Polarimetry of the Interstellar Medium

AbstractUsing data from the new infrared facility the Herschel Space Observatory, we have analyzed correlations between morphological type, far-infrared (FIR) luminosity, and Hα luminosity for star-forming galaxies, composite galaxies, and AGNs. We found a trend in scatter from 100μm to 500μm, which indicates that the submillimeter bands are not a good star formation tracer in these galaxies, being contaminated either by the old stellar population or by the interstellar medium (ISM). AGNs have no significant effect on our fitting results since the far-infrared to submillimeter emission is from cold dust/large dust grains.

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Fractal Dust Grains

Symposium - International Astronomical Union ◽

10.1017/s0074180900125343 ◽

1989 ◽

Vol 135 ◽

pp. 337-342

Author(s):

Edward L. Wright

Keyword(s):

Interstellar Medium ◽

Analytical Calculation ◽

Far Infrared ◽

Interplanetary Dust ◽

Infrared Emission ◽

Dipole Approximation ◽

Extinction Curve ◽

Dust Particles ◽

Interplanetary Dust Particles ◽

Emission Efficiency

Dust particles in the interstellar medium are almost certainly not spherical or any other shape which allows an analytical calculation of the extinction curve, even in the Rayleign limit. Particles in soot and interplanetary dust particles are aggregates formed by subclusters which stick together. This paper uses the discrete dipole approximation (DDA) to compute the absorption and extinction curves for fractal shapes generated by this clustering process. For fractals made from graphite the UV extinction curve shows a bump near the observed 220 nm feature, and a far infrared emission efficiency many times greater than that for spheres.

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The Interstellar Medium in Star Burst Galaxies

Symposium - International Astronomical Union ◽

10.1017/s0074180900096510 ◽

1987 ◽

Vol 115 ◽

pp. 614-614

Author(s):

R. Genzel ◽

J. B. Lugten ◽

M. K. Crawford ◽

D. M. Watson

Keyword(s):

Star Formation ◽

Interstellar Medium ◽

Line Emission ◽

Far Infrared ◽

High Rate ◽

Interstellar Gas ◽

Infrared Observations ◽

Bolometric Luminosity ◽

Neutral Gas ◽

Molecular Lines

We report far-infrared observations of [0 I], [C II] and [O III] fine structure emission lines toward the nuclei of M82 and 7 other galaxies with a high rate of star formation. The far-infrared line emission is bright, contains about 0.5% of the bolometric luminosity in the central 60″, and is spatially concentrated toward the nuclei. In these galaxies between 10 and 30% of the interstellar gas near the nuclei is contained in a warm, atomic component. This atomic gas is probably located at the UV photodissociated surfaces of molecular clouds. The neutral gas in M82 has a temperature of ∼ 200 K, hydrogen density of ∼ 3 × 104 cm−3 and is very clumpy, indicating that the interstellar medium in this star burst galaxy is very different from that in the disk of our own galaxy. We discuss the implications of the infrared observations for the interpretation of mm molecular lines and for star formation at the nuclei of star burst galaxies.

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Physical properties of dust particles around white dwarf in far infrared sky at 12.8o galactic latitude

BIBECHANA ◽

10.3126/bibechana.v15i0.18488 ◽

2017 ◽

Vol 15 ◽

pp. 43-49

Author(s):

B B Sapkota ◽

B Aryal ◽

R Weinberger

Keyword(s):

Active Region ◽

Interstellar Medium ◽

White Dwarf ◽

Far Infrared ◽

Dust Particles ◽

Galactic Latitude ◽

Cavity Formation ◽

Number Density ◽

Colour Temperature ◽

Dust Mass

We study the active region in the interstellar medium in which the process of cavity formation is expected. The interaction between wind and its surroundings in the interstellar medium (ISM) provides a laboratory to study the behavior of dust particles. The information obtained from the dust colour temperature and dust mass of WD2116+675 will be presented. It is found that the dust colour temperature and dust mass lie in the range 20 K to 22.3 K and 2.1×1023 kg to 2.9×1023 kg respectively. With the help of number density, flux density, dust colour temperature and dust mass maps, the variation of temperature and mass in different position of dust will be presented and discussed. BIBECHANA 15 (2018) 43-49

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