Matches in DBpedia 2014 for { <http://dbpedia.org/resource/QSR_J1819+3845> ?p ?o. }
Showing items 1 to 23 of
23
with 100 items per page.
- QSR_J1819+3845 abstract "QSR J1819+3845 is a quasar notable for being the most variable known extragalactic radio source. This quasar shows variations of factors of four or more on a timescale of hours.The variations have been shown to be due to scattering in the interstellar medium (ISM). This quasar furnished the elegant proof of the role of scattering due to the ISM, or interstellar scintillation, by showing a time delay in arrival between the signal at widely spaced telescopes (in the USA and Netherlands). Interstellar scintillation is the observed effect of interference and refractive phenomena due to the ISM. It can be thought of as the ISM focusing and defocusing the radio waves from the source, producing a pattern of dark and bright patches, rather like light and dark patches at the bottom of a fish pond. As the Earth moves through these patches we observe a temporal variation in the radio intensity (like a fish swimming through light and dark patches).If the standard theory of diffractive scintillation is assumed to apply, ground-based radio traces would seem to require that J1819+3845 contains a component that must be less than about 5 microarcseconds across; this would require its temperature to be in excess of 1015 K. However, the scintillation may perhaps be interpreted as being due to an unusual piece of intervening interstellar medium. Nonetheless, its importance lies in having proved the importance of interstellar scintillation in creating the observed variations in brightness in at least some quasars, which had been the subject of some discussion.".
- QSR_J1819+3845 wikiPageID "914843".
- QSR_J1819+3845 wikiPageRevisionID "598332103".
- QSR_J1819+3845 constellationName Hercules_(constellation).
- QSR_J1819+3845 epoch Epoch_(astronomy).
- QSR_J1819+3845 hasPhotoCollection QSR_J1819+3845.
- QSR_J1819+3845 name "QSO J1819+3845".
- QSR_J1819+3845 names "QSR J1819+3845, QSO J1819+3845, QSO B1817+387, QSR B1817+387, QSR 1817+387, QSO 1817+387, MITG J181925+3844".
- QSR_J1819+3845 notes "Most variable quasar radio source".
- QSR_J1819+3845 type "EmG".
- QSR_J1819+3845 z "0.54".
- QSR_J1819+3845 subject Category:Hercules_(constellation).
- QSR_J1819+3845 subject Category:Quasars.
- QSR_J1819+3845 comment "QSR J1819+3845 is a quasar notable for being the most variable known extragalactic radio source. This quasar shows variations of factors of four or more on a timescale of hours.The variations have been shown to be due to scattering in the interstellar medium (ISM). This quasar furnished the elegant proof of the role of scattering due to the ISM, or interstellar scintillation, by showing a time delay in arrival between the signal at widely spaced telescopes (in the USA and Netherlands).".
- QSR_J1819+3845 label "QSO J1819+3845".
- QSR_J1819+3845 label "QSR J1819+3845".
- QSR_J1819+3845 label "Quasar J1819+3845".
- QSR_J1819+3845 sameAs Quasar_J1819+3845.
- QSR_J1819+3845 sameAs m.03phfk.
- QSR_J1819+3845 sameAs Q1003210.
- QSR_J1819+3845 sameAs Q1003210.
- QSR_J1819+3845 wasDerivedFrom QSR_J1819+3845?oldid=598332103.
- QSR_J1819+3845 isPrimaryTopicOf QSR_J1819+3845.