Astron. Astrophys. 326, 69-76 (1997)

Near-infrared photometry of the jet of 3C 273

M. Neumann , K. Meisenheimer and H.-J. Röser

Max Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany

Received 9 December 1996 / Accepted 21 April 1997

Abstract

A deep infrared observation of the quasar 3C 273 and its jet is presented. The image ( m) resolves the jet into single knots and for the first time detects the infrared counterpart to the radio hot spot. On the basis of the flux densities derived for these components the run of the radio to IR and IR to optical spectral indices along the jet axis is discussed. Along the main body of the jet the spectral indices can be understood in terms of a constant shape of the synchrotron spectrum that is dominated by a power-law with a high frequency cut-off. The map detects IR counterparts to the extended radio emissions surrounding the knots and the hot spot indicating the presence of high energetic particles well aside the bright synchrotron components.

Key words: quasars: 3C 273 galaxies: jets infrared: galaxies

Send offprint requests to: K. Meisenheimer

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations
• 3. Data reduction
  • 3.1. Basic reduction steps
  • 3.2. Subtraction of the background underneath the jet
  • 3.3. Photometry
• 4. Results
  • 4.1. Morphology
    • 4.1.1. Infrared maps
    • 4.1.2. Comparison of the infrared and radio morphologies
  • 4.2. photometry of the jet
  • 4.3. Spectral analysis
    • 4.3.1. Radio to IR and IR to optical spectral indices
• 5. Discussion
  • 5.1. Morphology
  • 5.2. Radio to optical spectra along the jet
• 6. Conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 1997

Online publication: April 20, 1998
helpdesk.link@springer.de