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URN: urn:nbn:de:bsz:16-opus-18069
URL: http://www.ub.uni-heidelberg.de/archiv/1806
Hinweis zum Urheberrecht.
High-resolution multi-wavelength study of the jet in 3C273
Hochaufgelöste Multifrequenzanalyse des Jets in 3C273
pdf-Format:
Dokument 1.pdf (3.401 KB)
SWD-Schlagwörter:
Jet <Astronomie>, Aktiver galaktischer Kern , Teilchenbeschleunigung , Synchrotronstrahlung
Freie Schlagwörter (Englisch):
Jet (astronomy), Active Galactic Nuclei , Particle acceleration , Synchrotron emission , Inverse Compton emission
PACS - Klassifikation:
98.54.Cm 9
Institut:
MPI fuer Astronomie
Fakultät:
Fakultät für Physik und Astronomie
DDC-Sachgruppe:
Physik
Dokumentart:
Dissertation
Hauptberichter:
Röser, Hermann-Josef Dr.
Sprache:
Englisch
Tag der mündlichen Prüfung:
17.10.2001
Erstellungsjahr:
2001
Publikationsdatum:
13.11.2001
Kurzfassung in Deutsch:
Kurzfassung in Englisch:
The jet in 3C273 is one of only a few extragalactic optical
synchrotron jets which are large and bright enough to be studied in
detail. We present new broad-band observations of this jet at the
unprecedented common resolution of 0.3' which have been obtained
with the Very Large Array at radio and the Hubble Space
Telescope at infrared, optical and ultraviolet wavelengths. These
observations reveal a flattening of the high-frequency spectrum of the
jet, a surprising feature which cannot be accounted for by any
single-population synchrotron model. Both the observed flattening of
the high-frequency spectrum and the X-ray emission from the jet can be
explained by a model in which two distinct electron populations
contribute to the jet's emission.
We fit spatially resolved synchrotron spectra for the jet and determine
the run of the maximum particle energy. The decrease of the maximum
particle energy along the jet is much slower than expected from the
observed synchrotron emission. We find no evidence for localised
acceleration or loss sites. We show that relativistic beaming and/or
sub-equipartition magnetic fields cannot remove the discrepancy between
light-travel time along the jet and the shorter lifetime of electrons
emitting optical synchrotron radiation. We consider this further
evidence in favour of a distributed electron acceleration process.
