Parsec-Scale Properties of Markarian 501

By M. Giroletti, G. Giovannini, L. Feretti, W. Cotton, P. Edwards, L. Lara, A. Marscher, J. Mattox, B. Piner, T. Venturi. 2003

199 citations recorded by the source corpus.

We present the results of a high angular resolution study of the BL Lac object Markarian 501 in the radio band. We consider data taken at 14 different epochs, ranging between 1.6 and 22 GHz in frequency, and including new Space VLBI observations obtained on 2001 March 5 and 6 at 1.6 and 5 GHz. We study the kinematics of the parsec-scale jet and estimate its bulk velocity and orientation with respect to the line of sight. Limb-brightened structure in the jet is clearly visible in our data, and we discuss its possible origin in terms of velocity gradients in the jet. Quasi-simultaneous, multiwavelength observations allow us to map the spectral index distribution and to compare it to the jet morphology. Finally, we estimate the physical parameters of the parsec-scale jet.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/62183280e916898d0b3e5f36b362ab1d456bc76b

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Bing Zhang
2. G. Ghisellini
3. F. Tavecchio
4. D. Giannios
5. C. Dermer
6. L. Maraschi
7. Y. Kovalev
8. E. Orlando

In Nuclear and High Energy Physics

1. D. Giannios
2. G. Ghisellini
3. F. Tavecchio
4. C. Dermer
5. L. Maraschi
6. E. Orlando
7. Y. Kovalev
8. M. Lister

Citations in the corpus

• INSIGHTS INTO THE HIGH-ENERGY γ-RAY EMISSION OF MARKARIAN 501 FROM EXTENSIVE MULTIFREQUENCY OBSERVATIONS IN THE FERMI ERA (2011, result): “0.2 mas) and its sub-mas jet, namely B ≃ (10−30) mG (Giroletti et al. 2004, 2008), is in very good agreement with the value emerging from our model fits (15 mG), assuring self-consistency of the approach adopted.”
• Implications of very rapid TeV variability in blazars (2007, background): “VLBI measurements of superluminal motion in PKS 2155–304 (Piner & Edwards 2004) and Mrk 501 (Giroletti et al. 2004) suggest lower values of Γ in these objects, but we stress that the regions producing radio emission and gamma-ray flares may have very different properties.”
• Fast TeV variability in blazars: jets in a jet (2009, background): “On the other hand, the jets of PKS 2155–304 and Mrk 501 have been resolved on sub-pc scales and show patterns that move with moderate Lorentz factorΓj <∼ 10 (Piner & Edwards 2004; Giroletti et al. 2004), much less than the one needed for TeVγrays to escape.”
• FROM THE BLAZAR SEQUENCE TO THE BLAZAR ENVELOPE: REVISITING THE RELATIVISTIC JET DICHOTOMY IN RADIO-LOUD ACTIVE GALACTIC NUCLEI (2011, background): “…jets of HSP BL Lacs which show that they are barely super-luminal, with average bulk Lorentz factors Γ ∼ 2−3 (Piner et al. 2001; Edwards & Piner 2002; Giroletti et al. 2004; Piner et al. 2008, 2010); however, several LSP BL Lacs show high velocities on VLBI scales (Jorstad et al. 2001; Cohen et…”
• The blazar sequence: a new perspective (2008, background): “…objects comes from the fact that these sources have ‘slow’ very long baseline interferometry (VLBI) knots, often moving subluminally (Piner & Edwards 2004; Piner, Pant & Edwards 2008, and references therein), and from direct observations of some radio edge-brightening (Giroletti et al. 2004, 2006).”
• Are Quasar Jets Dominated by Poynting Flux? (2005, background): “There, the one-sidedness of the jet and the lack of superluminal motion of the VLBI features strongly suggest that the the knots represent stationary or very slowly moving patterns, presumably oblique shocks (Giroletti et al. 2004; Ghisellini, Tavecchio, & Chiaberge 2004).”