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Hydrogen Isocyanide
Hydrogen isocyanide is a chemical with the molecular formula HNC. It is a minor tautomer of hydrogen cyanide (HCN). Its importance in the field of astrochemistry is linked to its ubiquity in the interstellar medium. Nomenclature Both ''hydrogen isocyanide'' and ''azanylidyniummethanide'' are correct IUPAC names for HNC. There is no preferred IUPAC name. The second one is according to the '' substitutive nomenclature rules'', derived from the '' parent hydride'' azane () and the anion methanide (). Molecular properties Hydrogen isocyanide (HNC) is a linear triatomic molecule with C∞v point group symmetry. It is a zwitterion and an isomer of hydrogen cyanide (HCN). Both HNC and HCN have large, similar dipole moments, with ''μ''HNC = 3.05 Debye and ''μ''HCN = 2.98 Debye respectively. These large dipole moments facilitate the easy observation of these species in the interstellar medium. HNC−HCN tautomerism As HNC is higher in energy than HCN by 392 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocyanonium
HCNH+, also known as protonated hydrogen cyanide, is a molecular ion of astrophysical interest. It also exists in the condensed state when formed by superacids. Structure In the ground state, HCH is a simple linear molecule, whereas its excited triplet state is expected to have ''cis'' and ''trans'' isomeric forms. The higher-energy structural isomers H2CN+ and CH2 have also been studied theoretically. Laboratory studies As a relatively simple molecular ion, HCNH+ has been extensively studied in the laboratory. The very first spectrum taken at any wavelength focused on the ''ν''2 (C−H stretch) ro-vibrational band in the infrared. Soon afterward, the same authors reported on their investigation of the ''ν''1 (N−H stretch) band. Following these initial studies, several groups published manuscripts on the various ro-vibrational spectra of HCNH+, including studies of the ''ν''3 band (C≡N stretch), the ''ν''4 band (H−C≡N bend), and the ''ν''5 band (H−N≡C be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debye
The debye (symbol: D) (; ) is a CGS unit (a non- SI metric unit) of electric dipole momentTwo equal and opposite charges separated by some distance constitute an electric dipole. This dipole possesses an electric dipole moment whose value is given as charge times length of separation, it is a vector whose direction is in the direction of the unit vector of the position vector of the positive charge w.r.t negative charge: :p = ''q''r. named in honour of the physicist Peter J. W. Debye. It is defined as statcoulomb-centimeters.The statcoulomb is also known as the franklin or electrostatic unit of charge. :1 statC = 1 Fr = 1 esu = 1 cm3/2⋅g1/2⋅s−1. Historically the debye was defined as the dipole moment resulting from two charges of opposite sign but an equal magnitude of 10−10 statcoulomb10−10 statcoulomb corresponds to approximately 0.2083 units of elementary charge. (generally called e.s.u. (electrostatic unit) in older scienti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Cyanide
Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on an industrial scale and is a highly valued precursor to many chemical compounds ranging from polymers to pharmaceuticals. Large-scale applications are for the production of potassium cyanide and adiponitrile, used in mining and plastics, respectively. It is more toxic than solid cyanide compounds due to its volatile nature. Structure and general properties Hydrogen cyanide is a linear molecule, with a triple bond between carbon and nitrogen. The tautomer of HCN is HNC, hydrogen isocyanide. Hydrogen cyanide is weakly acidic with a p''K''a of 9.2. It partially ionizes in water solution to give the cyanide anion, CN−. A solution of hydrogen cyanide in water, represented as HCN, is called ''hydrocyanic acid''. The salts of the cyanid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atacama Large Millimeter Array
The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer of 66 radio telescopes in the Atacama Desert of northern Chile, which observe electromagnetic radiation at millimeter and submillimeter wavelengths. The array has been constructed on the elevation Chajnantor plateau - near the Llano de Chajnantor Observatory and the Atacama Pathfinder Experiment. This location was chosen for its high elevation and low humidity, factors which are crucial to reduce noise and decrease signal attenuation due to Earth's atmosphere. ALMA provides insight on star birth during the early Stelliferous era and detailed imaging of local star and planet formation. ALMA is an international partnership amongst Europe, the United States, Canada, Japan, South Korea, Taiwan, and Chile. Costing about US$1.4 billion, it is the most expensive ground-based telescope in operation. ALMA began scientific observations in the second half of 2011 and the first images we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscopy
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associated with a spectral signature in the context of the Laser Interferometer Gravitational-Wave Observatory (LIGO) In simpler terms, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Historically, spectroscopy originated as the study of the wavelength dependence of the absorption by gas phase matter of visible light dispersed by a prism. Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of astronomy, chemistry, materials science, and physics, allowing the composition, physical structure an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Veleta (Sierra Nevada)
Veleta (from the Arab word "Balata", meaning cliff) or Pico del Veleta is the second highest peak of the Iberian peninsula and the Sierra Nevada. Its height is given variously as , and . The mountain can be seen from the city of Granada. Veleta's northern slopes are home to the Sierra Nevada Ski Station. The access road that takes one to approximately 10 metres below the summit is the highest paved road in Europe across the mountains from Granada to the western Alpujarras. This road was built before the creation of the Sierra Nevada National Park in 1999. It has since been closed to general traffic beyond Hoya de la Mora, just above the ski station. However, the road is still used by ski station employees, national park rangers, observatory staff, cyclists and walkers, and a microbus service also takes hikers up to Posiciones del Veleta, a viewpoint 3,100 metres above sea level. In summer it is a relatively easy walk up to the summit from there. The Corral de la Veleta or Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IRAM 30-m
The IRAM 30-meter telescope is a radio telescope used for astronomical observations in the millimeter range of wavelengths, operated by the Institute for Radio Astronomy in the Millimeter Range (IRAM) and located in the Sierra Nevada, Spain, close to the Pico Veleta peak. Its large surface and wide-angle camera make it a perfect tool for the exploration of large cosmic objects such as interstellar clouds, birthplaces for stars, and even galaxies. The 30-meter telescope also allows astronomers to observe the black hole and the center of the Milky way by granting access to parts of the southern skies. The IRAM is one of the most sensitive single dish radio telescopes in the world. Each year, more than 200 scientists from all over the world visit this observatory to explore the universe at millimeter wavelengths, with interests going from the Solar System to interstellar dust and gas or cosmology. Together with IRAM's second facility, the NOEMA observatory, the 30-meter telescope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trihydrogen Cation
The trihydrogen cation or protonated molecular hydrogen is a cation (positive ion) with formula , consisting of three hydrogen nuclei (protons) sharing two electrons. The trihydrogen cation is one of the most abundant ions in the universe. It is stable in the interstellar medium (ISM) due to the low temperature and low density of interstellar space. The role that plays in the gas-phase chemistry of the ISM is unparalleled by any other molecular ion. The trihydrogen cation is the simplest triatomic molecule, because its two electrons are the only valence electrons in the system. It is also the simplest example of a three-center two-electron bond system. History was first discovered by J. J. Thomson in 1911. While studying the resultant species of plasma discharges, he discovered something very odd. Using an early form of mass spectrometry, he discovered a large abundance of a molecular ion with a mass-to-charge ratio of 3. He stated that the only two possibilities were C4+ or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissociative Recombination
Dissociative recombination is a chemical process where a positive polyatomic ion recombines with an electron, and as a result, the neutral molecule dissociates. This reaction is important for extraterrestrial and atmospheric chemistry. On Earth, dissociative recombination rarely occurs naturally, as free electrons react with any molecule (even neutral molecules) they encounter. Even in the best laboratory conditions, dissociative recombination is hard to observe, but is an important reaction in systems that have large populations of ionized molecules, for instance in atmospheric-pressure plasmas. In astrophysics, dissociative recombination is one of the main mechanisms via which molecules are broken down, and other molecules are formed. The existence of dissociative recombination is possible due to the vacuum of the interstellar medium. A typical example of dissociative recombination in astrophysics is: :CH3+ + e- -> CH2 + H See also *Ionization Ionization, or Ionisation is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photodissociation Region
In astrophysics, photodissociation regions (or photon-dominated regions, PDRs) are predominantly neutral regions of the interstellar medium in which far ultraviolet photons strongly influence the gas chemistry and act as the most important source of heat. They occur in any region of interstellar gas that is dense and cold enough to remain neutral, but that has too low a column density to prevent the penetration of far-UV photons from distant, massive stars. A typical and well-studied example is the gas at the boundary of a giant molecular cloud. PDRs are also associated with HII regions, reflection nebulae, active galactic nuclei, and Planetary nebulae. All the atomic gas and most of the molecular gas in the galaxy is found in PDRs. History The study of photodissociation regions began from early observations of the star-forming regions Orion A and M17 which showed neutral areas bright in infrared radiation lying outside ionised HII regions An H II region or HII regio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Hole
A black hole is a region of spacetime where gravity is so strong that nothing, including light or other electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary of no escape is called the event horizon. Although it has a great effect on the fate and circumstances of an object crossing it, it has no locally detectable features according to general relativity. In many ways, a black hole acts like an ideal black body, as it reflects no light. Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is of the order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly. Objects whose gravitational fields are too strong for light to escape were fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Formation
Star formation is the process by which dense regions within molecular clouds in The "medium" is present further soon.-->interstellar space, sometimes referred to as "stellar nurseries" or "-forming regions", and form s. As a branch of , star formation includes the study of the interstellar medium (ISM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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