Matches in SemOpenAlex for { <https://semopenalex.org/work/W3032758049> ?p ?o ?g. }
Showing items 1 to 69 of
69
with 100 items per page.
- W3032758049 startingPage "143" @default.
- W3032758049 abstract "We present detailed calculations of the free-free emission behind shock waves in media where the postshock gas may be optically thick at radio frequencies. Using a numerical shock code, we solve the free-free radiative transfer equation at frequencies of 1.5, 5, and 15 GHz for a family of planar shock models that cover a wide range of densities (1000 cm-3 ≤ n0 ≤ 109 cm-3) and shock velocities (30 km s-1 ≤ V0 ≤ 300 km s-1). These models also predict how different preshock magnetic fields and viewing angles affect the overall free-free emission. As the shock velocities and preshock densities increase, the free-free spectral indices generally rise from optically thin values (~-0.1) and approach optically thick ones (~2.0). We find that for V ≥ 120 km s-1, the ionized precursor produced by the emergent postshock UV radiation can itself become optically thick to free-free radiation when the preshock density exceeds 106 cm-3. We also find that for some combinations of shock parameters, the superposition of radiation from the precursor onto that of the postshock region can produce spectral indices exceeding 2.0. In addition, we find that magnetic fields can suppress the free-free radiation only if they are strong enough to lower the magnetosonic Mach number below 4 for V ≥ 100 km s-1. An observer who knows the resolved angular sizes, fluxes, and spectral indices of a thermal radio source can use our grids to determine the preshock density, shock velocity, and viewing angle to the source. Possible applications include HH objects, shocked cloudlets, and accretion shocks deep within molecular clouds. As an example, we use our results to predict shock parameters for HH 1-2 and several thermal radio sources in Cep A east. We find that the predicted shock parameters for HH 1 and 2 agree well with those inferred from optical line ratios and line profiles. Radio emission from sources in Cep A are explained reasonably well as arising from thermal radiation behind a dense, fast shock like one might expect from a stellar jet deeply embedded within the molecular cloud core." @default.
- W3032758049 created "2020-06-05" @default.
- W3032758049 creator A5018953434 @default.
- W3032758049 creator A5028577063 @default.
- W3032758049 date "1998-03-01" @default.
- W3032758049 modified "2023-09-27" @default.
- W3032758049 title "Free-Free Radiation from Dense Interstellar Shock Waves" @default.
- W3032758049 hasPublicationYear "1998" @default.
- W3032758049 type Work @default.
- W3032758049 sameAs 3032758049 @default.
- W3032758049 citedByCount "0" @default.
- W3032758049 crossrefType "journal-article" @default.
- W3032758049 hasAuthorship W3032758049A5018953434 @default.
- W3032758049 hasAuthorship W3032758049A5028577063 @default.
- W3032758049 hasConcept C120665830 @default.
- W3032758049 hasConcept C121332964 @default.
- W3032758049 hasConcept C126322002 @default.
- W3032758049 hasConcept C153385146 @default.
- W3032758049 hasConcept C27753989 @default.
- W3032758049 hasConcept C2781300812 @default.
- W3032758049 hasConcept C30475298 @default.
- W3032758049 hasConcept C44870925 @default.
- W3032758049 hasConcept C57879066 @default.
- W3032758049 hasConcept C62520636 @default.
- W3032758049 hasConcept C70477161 @default.
- W3032758049 hasConcept C71924100 @default.
- W3032758049 hasConcept C74902906 @default.
- W3032758049 hasConceptScore W3032758049C120665830 @default.
- W3032758049 hasConceptScore W3032758049C121332964 @default.
- W3032758049 hasConceptScore W3032758049C126322002 @default.
- W3032758049 hasConceptScore W3032758049C153385146 @default.
- W3032758049 hasConceptScore W3032758049C27753989 @default.
- W3032758049 hasConceptScore W3032758049C2781300812 @default.
- W3032758049 hasConceptScore W3032758049C30475298 @default.
- W3032758049 hasConceptScore W3032758049C44870925 @default.
- W3032758049 hasConceptScore W3032758049C57879066 @default.
- W3032758049 hasConceptScore W3032758049C62520636 @default.
- W3032758049 hasConceptScore W3032758049C70477161 @default.
- W3032758049 hasConceptScore W3032758049C71924100 @default.
- W3032758049 hasConceptScore W3032758049C74902906 @default.
- W3032758049 hasLocation W30327580491 @default.
- W3032758049 hasOpenAccess W3032758049 @default.
- W3032758049 hasPrimaryLocation W30327580491 @default.
- W3032758049 hasRelatedWork W1558218476 @default.
- W3032758049 hasRelatedWork W1601844672 @default.
- W3032758049 hasRelatedWork W1614625404 @default.
- W3032758049 hasRelatedWork W1668418907 @default.
- W3032758049 hasRelatedWork W1965695007 @default.
- W3032758049 hasRelatedWork W2002946607 @default.
- W3032758049 hasRelatedWork W2055769473 @default.
- W3032758049 hasRelatedWork W2104585881 @default.
- W3032758049 hasRelatedWork W2116441246 @default.
- W3032758049 hasRelatedWork W2529949903 @default.
- W3032758049 hasRelatedWork W2611295218 @default.
- W3032758049 hasRelatedWork W3028949753 @default.
- W3032758049 hasRelatedWork W3098173523 @default.
- W3032758049 hasRelatedWork W3099670731 @default.
- W3032758049 hasRelatedWork W3100194897 @default.
- W3032758049 hasRelatedWork W3100439906 @default.
- W3032758049 hasRelatedWork W3100949075 @default.
- W3032758049 hasRelatedWork W3101312597 @default.
- W3032758049 hasRelatedWork W3104750441 @default.
- W3032758049 hasRelatedWork W3125328958 @default.
- W3032758049 hasVolume "7" @default.
- W3032758049 isParatext "false" @default.
- W3032758049 isRetracted "false" @default.
- W3032758049 magId "3032758049" @default.
- W3032758049 workType "article" @default.