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Titolo:
Multifrequency very long baseline array observations of the compact doubleB2 2050+36: Constraints on interstellar scattering revisited
Autore:
Lazio, TJW; Fey, AL;
Indirizzi:
USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA USN WashingtonDC USA 20375 Remote Sensing Div, Washington, DC 20375 USA USN Observ, Washington, DC 20375 USA USN Observ Washington DC USA 20375USN Observ, Washington, DC 20375 USA
Titolo Testata:
ASTROPHYSICAL JOURNAL
fascicolo: 2, volume: 560, anno: 2001,
parte:, 1
pagine: 698 - 706
SICI:
0004-637X(20011020)560:2<698:MVLBAO>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
ANGULAR BROADENING MEASUREMENTS; MHZ VLBI OBSERVATIONS; DOUBLE RADIO-SOURCES; PULSAR SCINTILLATION; GALACTIC DISTRIBUTION; DENSITY FLUCTUATIONS; PLASMA TURBULENCE; FREE-ELECTRONS; CYGNUS REGION; INNER SCALE;
Keywords:
galaxies : active; galaxies : individual (B2 2050+36); ISM : structure; radio continuum : ISM; scattering; turbulence;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
37
Recensione:
Indirizzi per estratti:
Indirizzo: Lazio, TJW USN, Res Lab, Remote Sensing Div, Code 7213,4555 Overlook Ave SW, Washington, DC 20375 USA USN Code 7213,4555 Overlook Ave SW Washington DC USA 20375 USA
Citazione:
T.J.W. Lazio e A.L. Fey, "Multifrequency very long baseline array observations of the compact doubleB2 2050+36: Constraints on interstellar scattering revisited", ASTROPHYS J, 560(2), 2001, pp. 698-706

Abstract

We present multifrequency observations with the Very Long Baseline Array of the compact double radio source B2 2050+36. Our observations are at 0.33,0.61, 1.67, 2.3, and 8.4 GHz, with the 0.61 GHz observations forming the third epoch of observation of this source at that frequency. At 0.61 GHz, the structure of B2 2050+36 is dominated by two components 56 mas apart. Within the uncertainties of the various measurements, this separation has remained unchanged for the past 16 yr. Any differential image wander caused by refractive interstellar scattering is less than 4 mas. Both the lack of differential image wander and the frequency dependence of the angular diameter of B2 2050+36 below 1 GHz indicate that the electron density power spectrumalong this line of sight has a spectral index near the Kolmogorov value, with a value of 4 being highly unlikely. We conclude that diffractive scattering dominates along this line of sight; results in the literature indicatethat this conclusion also holds true for the line of sight to the pulsar PSR B2020+28 from B2 2050+36). Comparison of our 1.67 GHz observations (8 degrees .7 with those obtained 21 yr previously place a limit on the projected linear separation velocity of the two components of c.

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Documento generato il 22/09/20 alle ore 22:58:38