scholarly journals Infrared Emission from Interstellar Dust. II. The Diffuse Interstellar Medium

2001 ◽  
Vol 554 (2) ◽  
pp. 778-802 ◽  
Author(s):  
Aigen Li ◽  
B. T. Draine
Keyword(s):  
Interstellar Medium ◽  
Interstellar Dust ◽  
Infrared Emission

scholarly journals Infrared Emission from Interstellar Dust in the Local Interstellar Medium

1997 ◽  
Vol 166 ◽  
pp. 353-362
Author(s):  
W.T. Reach ◽  
F. Boulanger
Keyword(s):  
Interstellar Medium ◽  
Radiation Field ◽  
Spatial Correlation ◽  
Column Density ◽  
Interstellar Dust ◽  
Infrared Emission ◽  
Dust Content ◽  
Local Interstellar Medium ◽  
Local Bubble ◽  
Total Column

AbstractIn this contribution, we discuss some topics in the study of dust in the local interstellar medium. The spectrum of local clouds has recently been measured using ISO and COBE, confirming in general the models of excitation and cooling of dust illuminated by the the interstellar radiation field. We discuss in some detail the spatial correlation of interstellar dust and gas and the idea that infrared emission traces the total column density of the interstellar medium, with the particular application to the formation of H2. We also show that dust is present in the nearby Loop I shell, with properties similar to average, suggesting that the walls of the Local Bubble would also have relatively ‘normal’ dust content.

scholarly journals Circumstellar Infrared Emission. I: The Circumstellar Origin of Interstellar Dust

1973 ◽  
Vol 52 ◽  
pp. 485-504 ◽  
Author(s):  
Neville J. Woolf
Keyword(s):  
Interstellar Medium ◽  
Interstellar Dust ◽  
Infrared Emission ◽  
Infrared Light ◽  
Intrinsic Polarization ◽  
Cool Star ◽  
Stellar Astronomy ◽  
The Pacific ◽  
Infrared Studies ◽  
Galactic Astronomy

Infrared astronomy has in the past decade emerged from being a part-time occupation of a few astronomers. Three major subdivisions of research have become apparent, solar system, galactic and extragalactic studies. In each of these fields infrared studies have made unique contributions. Planets emit the bulk of their radiation in the infrared, and infrared studies are essential to study planetary thermal problems. Many extragalactic objects have been found to emit astonishingly large fluxes in the infrared.In galactic astronomy the current major contribution of infrared studies has been to act as a bridge between two separate disciplines, stellar astronomy, and studies of the interstellar medium. Infrared studies have proved invaluable for studying star birth and star death. Both of these phases had previously seemed mysterious and invisible. And indeed they were not visible, because they occurred shrouded in dust that blocked transmission of visible rays. However, the dust that is merely opaque in the visible, is self-luminous in the infrared, and so in the midst of this optical darkness there has appeared a great infrared light.At this time, we have progressed further with the study of star death than of star birth. The ejected matter from dying stars carries the dust shroud with it into space, and so the gas and dust become part of the interstellar medium. This process is clearly significant for understanding the composition and origin of interstellar dust.Because star death and birth are embedded in dust, there has developed a separate interest in explaining the physical processes at work in these dust clouds. This study explains processes of optical circumstellar absorption lines, intrinsic polarization of cool star light, and stellar molecular masers.Perhaps what these two paragraphs have just said is that our conceptual scheme of separating stellar astronomy and interstellar astronomy still acts as such a division that the infrared astronomer needs to present different aspects of this one topic, circumstellar infrared emission to different audiences. Such an opportunity has been given to the author in that he has been asked to give within a few weeks two talks. The first of these reviews is being presented at IAU Symposium # 52 on Interstellar Dust and Related Topics. The second is being given at the summer meeting of the Astronomical Society of the Pacific which has a symposium on Circumstellar Dust.The two reviews have been made complementary. The first of these is primarily an observational study. It shows the infrared observations of stellar and interstellar dust, and in a qualitative way shows that one gives rise to the other. The second review is theoretical and attempts to place the first study in its theoretical context. It deals almost exclusively with the stellar and circumstellar parts of the topic. Together they present one man's view of Circumstellar Infrared Emission.The literature relevant to this topic is voluminous. There have been false leads, dead ends, and irrelevant detail. This review has attempted to follow a thread through this detail, and to expose the skeleton of a scheme for understanding the processes at work. Such a review is intrinsically more dangerous, more likely to become obsolete than a comprehensive one. However, by carrying the seeds of its own destruction it seems to offer a greater opportunity for the growth of astronomy.

PRONAOS observations of the interstellar medium: New insights on interstellar Dust

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

scholarly journals DIBs, Interstellar Dust, and Extinction

2013 ◽  
Vol 9 (S297) ◽  
pp. 147-152 ◽  
Author(s):  
G. C. Clayton
Keyword(s):  
Interstellar Medium ◽  
Interstellar Dust ◽  
Dust Grains ◽  
Weak Correlation ◽  
Interstellar Clouds ◽  
The Galaxy ◽  
The Relationship

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.

scholarly journals Asymmetric mass-loss from the white dwarf WD 0253+209 : Secret revealed

BIBECHANA ◽  
2012 ◽  
Vol 8 ◽  
pp. 1-7
Author(s):  
Binil Aryal
Keyword(s):  
Interstellar Medium ◽  
Mass Loss ◽  
Flux Density ◽  
White Dwarf ◽  
Total Mass ◽  
Interstellar Dust ◽  
Mass Loss Rate ◽  
Infrared Image ◽  
Asymptotic Giant Branch ◽  
Color Temperature

Dust structures around the white dwarf WD 0253+209 is studied in 100 and 60 micron infrared image. These images are received from Infrared Astronomical Satellite Survey (IRAS Survey). The post Asymptotic Giant Branch (AGB) emission of the white dwarf's precursors' wind and the ambient interstellar matter is studied. The distribution of the relative flux density is studied and analyzed in the context of the dust color temperature, mass loading trend and the amount of total mass deposited due the interaction in the interstellar medium. The twisted curved emission structure at 100 micron in the region of interest is probably due to the interaction between the ambient interstellar medium and the He-flashes of the parent planetary nebula of the central white dwarf WD 0253+209. The total mass of the filamentary arc is found to be ~ 5 solar masses, as predicted. The mass loss rate of the post AGB star goes up to 10-5 solar masses per year. It is concluded that the first He-flash occurred at least ~2500 years ago.Keywords: white dwarf; interstellar medium; flux density; interstellar dust; mass of the gasDOI: http://dx.doi.org/10.3126/bibechana.v8i0.4806BIBECHANA 8 (2012) 1-7

scholarly journals Polyaromatic disordered carbon grains as carriers of the UV bump: Far-UV to mid-IR spectroscopy of laboratory analogs

2017 ◽  
Vol 607 ◽  
pp. A73 ◽  
Author(s):  
L. Gavilan ◽  
K. C. Le ◽  
T. Pino ◽  
I. Alata ◽  
A. Giuliani ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Interstellar Dust ◽  
Vacuum Ultraviolet ◽  
Interstellar Extinction ◽  
Electronic Transitions ◽  
Mid Infrared ◽  
Pressure Experiment ◽  
Circumstellar Extinction ◽  
Integrated Intensities ◽  
Far Ultraviolet

Context. A multiwavelength study of laboratory carbons with varying degrees of hydrogenation and sp2 hybridization is required to characterize the structure of the carbonaceous carriers of interstellar and circumstellar extinction. Aims. We study the spectral properties of carbonaceous dust analogs from the far-ultraviolet to the mid-infrared and correlate features in both spectral ranges to the aromatic/aliphatic degree. Methods. Analogs to carbonaceous interstellar dust encountered in various phases of the interstellar medium have been prepared in the laboratory. These are amorphous hydrogenated carbons (a-C:H), analogs to the diffuse interstellar medium component, and soot particles, analogs to the polyaromatic component. Thin films (d < 100 nm) have been measured in transmission in the vacuum-ultraviolet (VUV; 120–210 nm) within the atmospheric pressure experiment (APEX) chamber of the DISCO beam line at the SOLEIL synchrotron radiation facility. Spectra of these films were further measured through the UV-Vis (210 nm–1 μm) and in the mid-infrared (3–15 μm). Results. Tauc optical gaps, Eg, are derived from the visible spectra. The major spectral features are fitted through the VUV to the mid-infrared to obtain positions, full-widths at half maximum (FWHM), and integrated intensities. These are plotted against the position of the π-π∗ electronic transitions peak. Unidentified or overlapping features in the UV are identified by correlations with complementary infrared data. A correlation between the optical gap and position of the π-π∗ electronic transitions peak is found. The latter is also correlated to the position of the sp3 carbon defect band at ~8 μm, the aromatic C=C stretching mode position at ~6 μm, and the H/C ratio. Conclusions. Ultraviolet and infrared spectroscopy of structurally diverse carbon samples are used to constrain the nanostructural properties of carbon carriers of both circumstellar and interstellar extinction, such as the associated coherent lengths and the size of polyaromatic units. Our study suggests that carriers of the interstellar UV bump should exhibit infrared bands akin to the A/B classes of the aromatic infrared bands, while the circumstellar bump carriers should exhibit bands corresponding to the B/C classes.

scholarly journals X-ray extinction from interstellar dust

2019 ◽  
Vol 629 ◽  
pp. A78 ◽  
Author(s):  
E. Costantini ◽  
S. T. Zeegers ◽  
D. Rogantini ◽  
C. P. de Vries ◽  
A. G. G. M. Tielens ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Interstellar Dust ◽  
Simulated Data ◽  
X Ray ◽  
Cosmic Abundance ◽  
Grain Size Distributions ◽  
Edge Features ◽  
Different Grain Size ◽  
Near Future

Aims. We present a study on the prospects of observing carbon, sulfur, and other lower abundance elements (namely Al, Ca, Ti, and Ni) present in the interstellar medium using future X-ray instruments. We focus in particular on the detection and characterization of interstellar dust along the lines of sight. Methods. We compared the simulated data with different sets of dust aggregates, either obtained from past literature or measured by us using the SOLEIL-LUCIA synchrotron beamline. Extinction by interstellar grains induces modulations of a given photolelectric edge, which can be in principle traced back to the chemistry of the absorbing grains. We simulated data of instruments with characteristics of resolution and sensitivity of the current Athena, XRISM, and Arcus concepts. Results. In the relatively near future, the depletion and abundances of the elements under study will be determined with confidence. In the case of carbon and sulfur, the characterization of the chemistry of the absorbing dust will be also determined, depending on the dominant compound. For aluminum and calcium, despite the large depletion in the interstellar medium and the prominent dust absorption, in many cases the edge feature may not be changing significantly with the change of chemistry in the Al- or Ca-bearing compounds. The exinction signature of large grains may be detected and modeled, allowing a test on different grain size distributions for these elements. The low cosmic abundance of Ti and Ni will not allow us a detailed study of the edge features.

scholarly journals The Far-Infrared emission of the first (z ∼ 6) massive galaxies

2019 ◽  
Vol 15 (S352) ◽  
pp. 246-247
Author(s):  
George H. Rieke ◽  
Maria Emilia De Rossi ◽  
Irene Shivaei ◽  
Volker Bromm ◽  
Jianwei Lyu
Keyword(s):  
Interstellar Dust ◽  
Far Infrared ◽  
High Energy ◽  
Infrared Emission ◽  
High Energy Density ◽  
Spectral Energy ◽  
Energy Distributions ◽  
Massive Galaxies ◽  
Very High Energy ◽  
Lower Redshift

AbstractThe first massive galaxies (z ∼ 6) have (1) very high energy density due to their small diameters and extreme luminosities in young stars and (2) interstellar dust relatively deficient in carbon compared with silicates. Both of these attributes should raise their interstellar dust temperatures compared with lower redshift galaxies. Not only is this temperature trend observed, but the high-z spectral energy distributions (SEDs) are very broad due to very warm dust. As a result total infrared luminosities – and star formation rates – at the highest redshifts estimated by fitting blackbodies to submm- and mm-wave observations can be low by a factor of ∼2.

scholarly journals The Interstellar Dust Emission Seen by ISO

1998 ◽  
Vol 11 (2) ◽  
pp. 1142-1144 ◽  
Author(s):  
J.L. Puget
Keyword(s):  
Interstellar Medium ◽  
Small Molecules ◽  
Interstellar Dust ◽  
Solid Phase ◽  
Dust Emission ◽  
Atom Clusters ◽  
Interstellar Grains ◽  
Small Atom

Among the important contributions of ISO to the physics of the interstellar medium, this paper concentrates only on the emission from the solid phase (the interstellar grains) and the small atom clusters which are the bridge between the grains and the small molecules with less than about 10 atoms.

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