Matches in DBpedia 2015-10 for { <http://dbpedia.org/resource/Megamaser> ?p ?o }
- Megamaser abstract "A megamaser is a type of astrophysical maser, which is a naturally occurring source of stimulated spectral line emission. Megamasers are distinguished from astrophysical masers by their large isotropic luminosity. Megamasers have typical luminosities of 103 solar luminosities (L☉), which is 100 million times brighter than masers in the Milky Way, hence the prefix mega. Likewise, the term kilomaser is used to describe masers outside the Milky Way that have luminosities of order L☉, or thousands of times stronger than the average maser in the Milky Way, gigamaser is used to describe masers billions of times stronger than the average maser in the Milky Way, and extragalactic maser encompasses all masers found outside the Milky Way. Most known extragalactic masers are megamasers, and the majority of megamasers are hydroxyl (OH) megamasers, meaning the spectral line being amplified is one due to a transition in the hydroxyl molecule. There are known megamasers for three other molecules: water (H2O), formaldehyde (H2CO), and methine (CH).Water megamasers were the first type of megamaser discovered. The first water megamaser was found in 1979 in NGC 4945, a galaxy in the nearby Centaurus A/M83 Group. The first hydroxyl megamaser was found in 1982 in Arp 220, which is the nearest ultraluminous infrared galaxy to the Milky Way. All subsequent OH megamasers that have been discovered are also in luminous infrared galaxies, and there are a small number of OH kilomasers hosted in galaxies with lower infrared luminosities. Most luminous infrared galaxies have recently merged or interacted with another galaxy, and are undergoing a burst of star formation. Many of the characteristics of the emission in hydroxyl megamasers are distinct from that of hydroxyl masers within the Milky Way, including the amplification of background radiation and the ratio of hydroxyl lines at different frequencies. The population inversion in hydroxyl molecules is produced by far infrared radiation that results from absorption and re-emission of light from forming stars by surrounding interstellar dust. Zeeman splitting of hydroxyl megamaser lines may be used to measure magnetic fields in the masing regions, and this application represents the first detection of Zeeman splitting in a galaxy other than the Milky Way.Water megamasers and kilomasers are found primarily associated with active galactic nuclei, while galactic and weaker extragalactic water masers are found in star forming regions. Despite different environments, the circumstances that produce extragalactic water masers do not seem to be very different from those that produce galactic water masers. Observations of water megamasers have been used to make accurate measurements of distances to galaxies in order to provide constraints on the Hubble constant.".
- Megamaser thumbnail Stimulated_Emission.svg?width=300.
- Megamaser wikiPageExternalLink ?id=kajIH3t_750C.
- Megamaser wikiPageExternalLink books?id=M8XvAAAAMAAJ.
- Megamaser wikiPageExternalLink books?id=qg4xe_mVXP0C.
- Megamaser wikiPageID "3790398".
- Megamaser wikiPageLength "39309".
- Megamaser wikiPageOutDegree "132".
- Megamaser wikiPageRevisionID "679296178".
- Megamaser wikiPageWikiLink Absorption_(electromagnetic_radiation).
- Megamaser wikiPageWikiLink Acceleration.
- Megamaser wikiPageWikiLink Active_galactic_nuclei.
- Megamaser wikiPageWikiLink Active_galactic_nucleus.
- Megamaser wikiPageWikiLink Angular_diameter.
- Megamaser wikiPageWikiLink Angular_resolution.
- Megamaser wikiPageWikiLink Arp_220.
- Megamaser wikiPageWikiLink Astrophysical_maser.
- Megamaser wikiPageWikiLink Atom.
- Megamaser wikiPageWikiLink Bulge_(astronomy).
- Megamaser wikiPageWikiLink Carbon_monoxide.
- Megamaser wikiPageWikiLink Category:Astronomical_radio_sources.
- Megamaser wikiPageWikiLink Category:Radio_astronomy.
- Megamaser wikiPageWikiLink M83_Group.
- Megamaser wikiPageWikiLink Centripetal_acceleration.
- Megamaser wikiPageWikiLink Cosmic_distance_ladder.
- Megamaser wikiPageWikiLink Cosmic_dust.
- Megamaser wikiPageWikiLink Cosmological_redshift.
- Megamaser wikiPageWikiLink Density.
- Megamaser wikiPageWikiLink Earth.
- Megamaser wikiPageWikiLink Energy_level.
- Megamaser wikiPageWikiLink Extinction_(astronomy).
- Megamaser wikiPageWikiLink Extragalactic_astronomy.
- Megamaser wikiPageWikiLink Formaldehyde.
- Megamaser wikiPageWikiLink Frequency.
- Megamaser wikiPageWikiLink Galaxy.
- Megamaser wikiPageWikiLink Galaxy_formation.
- Megamaser wikiPageWikiLink Galaxy_formation_and_evolution.
- Megamaser wikiPageWikiLink Galaxy_merger.
- Megamaser wikiPageWikiLink Hertz.
- Megamaser wikiPageWikiLink Hubble_constant.
- Megamaser wikiPageWikiLink Hubble_flow.
- Megamaser wikiPageWikiLink Hubbles_law.
- Megamaser wikiPageWikiLink Hydrogen.
- Megamaser wikiPageWikiLink Hydrogen_cyanide.
- Megamaser wikiPageWikiLink Hydroxyl.
- Megamaser wikiPageWikiLink Infrared.
- Megamaser wikiPageWikiLink Interstellar_dust.
- Megamaser wikiPageWikiLink Interstellar_medium.
- Megamaser wikiPageWikiLink Isotropic.
- Megamaser wikiPageWikiLink Isotropy.
- Megamaser wikiPageWikiLink Kelvin.
- Megamaser wikiPageWikiLink Kepler_orbit.
- Megamaser wikiPageWikiLink Keplerian_orbit.
- Megamaser wikiPageWikiLink Laboratory.
- Megamaser wikiPageWikiLink Light.
- Megamaser wikiPageWikiLink Line-of-sight_propagation.
- Megamaser wikiPageWikiLink Low-ionization_nuclear_emission-line_region.
- Megamaser wikiPageWikiLink Luminosity.
- Megamaser wikiPageWikiLink Luminosity_function.
- Megamaser wikiPageWikiLink Luminous_infrared_galaxy.
- Megamaser wikiPageWikiLink M-sigma_relation.
- Megamaser wikiPageWikiLink Magnetic_field.
- Megamaser wikiPageWikiLink Malmquist_bias.
- Megamaser wikiPageWikiLink Maser.
- Megamaser wikiPageWikiLink Mega-.
- Megamaser wikiPageWikiLink Megahertz.
- Megamaser wikiPageWikiLink Messier_106.
- Megamaser wikiPageWikiLink Messier_51.
- Megamaser wikiPageWikiLink Messier_77.
- Megamaser wikiPageWikiLink Methanol.
- Megamaser wikiPageWikiLink Methine.
- Megamaser wikiPageWikiLink Methine_group.
- Megamaser wikiPageWikiLink Micrometre.
- Megamaser wikiPageWikiLink Microwave.
- Megamaser wikiPageWikiLink Milky_Way.
- Megamaser wikiPageWikiLink Molecular_cloud.
- Megamaser wikiPageWikiLink Molecule.
- Megamaser wikiPageWikiLink Monochromatic.
- Megamaser wikiPageWikiLink Monochrome.
- Megamaser wikiPageWikiLink Monthly_Notices_of_the_Royal_Astronomical_Society.
- Megamaser wikiPageWikiLink M–sigma_relation.
- Megamaser wikiPageWikiLink NGC_1068.
- Megamaser wikiPageWikiLink NGC_253.
- Megamaser wikiPageWikiLink NGC_4258.
- Megamaser wikiPageWikiLink NGC_4945.
- Megamaser wikiPageWikiLink Opacity_(optics).
- Megamaser wikiPageWikiLink Optical_amplification.
- Megamaser wikiPageWikiLink Optical_amplifier.
- Megamaser wikiPageWikiLink Optical_depth.
- Megamaser wikiPageWikiLink Parsec.
- Megamaser wikiPageWikiLink Photometric_system.
- Megamaser wikiPageWikiLink Photon.
- Megamaser wikiPageWikiLink Population_inversion.
- Megamaser wikiPageWikiLink Proportionality_(mathematics).
- Megamaser wikiPageWikiLink Radiation.
- Megamaser wikiPageWikiLink Radio_astronomy.
- Megamaser wikiPageWikiLink Resonant_cavity.
- Megamaser wikiPageWikiLink Resonator.
- Megamaser wikiPageWikiLink Rotational_spectroscopy.
- Megamaser wikiPageWikiLink Sculptor_Galaxy.