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In astronomy, the interstellar medium (ISM) is the matter and radiation that exist in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstellar space and blends smoothly into the surrounding intergalactic space. The energy that occupies the same volume, in the form of electromagnetic radiation, is the interstellar radiation field.
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Cosmochemistry or chemical cosmology is the study of the chemical composition of matter in the universe and the processes that led to those compositions. This is done primarily through the study of the chemical composition of meteorites and other physical samples. Given that the asteroid parent bodies of meteorites were some of the first solid material to condense from the early solar nebula, cosmochemists are generally, but not exclusively, concerned with the objects contained within the Solar System.
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In astronomy, extinction is the absorption and scattering of electromagnetic radiation by dust and gas between an emitting astronomical object and the observer. Interstellar extinction was first documented as such in 1930 by Robert Julius Trumpler. However, its effects had been noted in 1847 by Friedrich Georg Wilhelm von Struve, and its effect on the colors of stars had been observed by a number of individuals who did not connect it with the general presence of galactic dust. For stars that lie near the plane of the Milky Way and are within a few thousand parsecs of the Earth, extinction in the visual band of frequencies is roughly 1.8 magnitudes per kiloparsec.
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The Space Infrared Telescope for Cosmology and Astrophysics (SPICA), was a proposed infrared space telescope, follow-on to the successful Akari space observatory. It was a collaboration between European and Japanese scientists, which was selected in May 2018 by the European Space Agency (ESA) as a finalist for the next Medium class Mission 5 of the Cosmic Vision programme, to launch in 2032. At the time the other two finalists were THESEUS and EnVision, with the latter that was eventually selected for further development. SPICA would have improved on the spectral line sensitivity of previous missions, the Spitzer and Herschel space telescopes, between 30 and 230 µm by a factor of 50—100.
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Jean-Loup Puget is a French astrophysicist. His current research interests lie in the Cosmic Microwave Background. Jean-Loup Puget and his collaborators reported the first identification of the Cosmic infrared background using COBE data. He is also, along with Alain Léger, credited with the origin of the hypothesis that the series of infrared lines observed in numerous astrophysical objects are caused by emission from polycyclic aromatic hydrocarbons. He is currently principal investigator of the HFI module of the Planck space mission.
2-Methylnaphthalene is a polycyclic aromatic hydrocarbon (PAH).
NGC 3511 is an intermediate spiral galaxy located in the constellation Crater. It is located at a distance of circa 45 million light years from Earth, which, given its apparent dimensions, means that NGC 3511 is about 70,000 light years across. It was discovered by William Herschel on December 21, 1786. It lies two degrees west of Beta Crateris.
NGC 1549 is an elliptical galaxy located in the constellation Dorado. It is located at a distance of circa 50 million light years from Earth, which, given its apparent dimensions, means that NGC 1549 is about 75,000 light years across. NGC 1549 was discovered by John Herschel on 6 December 1835 and may have been observed by James Dunlop in 1826. It is a member of the Dorado Group.
HD 73882 is a visual binary system with the components separated by 0.6″ and a combined spectral class of O8. One of stars is an eclipsing binary system. The period of variability is listed as both 2.9199 days and 20.6 days, possibly due to the secondary being a spectroscopic binary star.
References
- ↑ Duley, W. W.; Williams, D. A. (1 September 1981). "The infrared spectrum of interstellar dust: Surface functional groups on carbon". Monthly Notices of the Royal Astronomical Society. 196 (2): 269–274. doi: 10.1093/mnras/196.2.269 .
- ↑ Leger, A.; Puget, J. L. (1984). "Identification of the 'unidentified' IR emission features of interstellar dust?". Astronomy and Astrophysics. 500: 279. Bibcode:1984A&A...137L...5L.
- ↑ Allamandola, L. J.; Tielens, A. G. G. M.; Barker, J. R. (1985). "Polycyclic aromatic hydrocarbons and the unidentified infrared emission bands - Auto exhaust along the Milky Way". The Astrophysical Journal. 290: L25. Bibcode:1985ApJ...290L..25A. doi:10.1086/184435.
- ↑ Allamandola, L. J.; Tielens, A. G. G. M.; Barker, J. R. (1989). "Interstellar polycyclic aromatic hydrocarbons - The infrared emission bands, the excitation/emission mechanism, and the astrophysical implications". The Astrophysical Journal Supplement Series. 71: 733–75. Bibcode:1989ApJS...71..733A. doi:10.1086/191396. PMID 11542189.
- 1 2 "New clues to the origin of creation". CBS News . 2011-10-27. Retrieved 2012-02-21.