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Connections between millimetre continuum variations and VLBI structure in 27 AGN. / Savolainen, T.; Wiik, K.; Valtaoja, E.; Jorstad, S. G.; Marscher, A. P.

In: Astronomy and Astrophysics, Vol. 394, No. 3, 11.2002, p. 851-861.

Research output: Contribution to journal › Article › peer-review

Harvard

Savolainen, T, Wiik, K, Valtaoja, E, Jorstad, SG & Marscher, AP 2002, 'Connections between millimetre continuum variations and VLBI structure in 27 AGN', Astronomy and Astrophysics, vol. 394, no. 3, pp. 851-861. https://doi.org/10.1051/0004-6361:20021236

APA

Savolainen, T., Wiik, K., Valtaoja, E., Jorstad, S. G., & Marscher, A. P. (2002). Connections between millimetre continuum variations and VLBI structure in 27 AGN. Astronomy and Astrophysics, 394(3), 851-861. https://doi.org/10.1051/0004-6361:20021236

Vancouver

Savolainen T, Wiik K, Valtaoja E, Jorstad SG, Marscher AP. Connections between millimetre continuum variations and VLBI structure in 27 AGN. Astronomy and Astrophysics. 2002 Nov;394(3):851-861. https://doi.org/10.1051/0004-6361:20021236

Author

Savolainen, T. ; Wiik, K. ; Valtaoja, E. ; Jorstad, S. G. ; Marscher, A. P. / Connections between millimetre continuum variations and VLBI structure in 27 AGN. In: Astronomy and Astrophysics. 2002 ; Vol. 394, No. 3. pp. 851-861.

BibTeX

@article{0da4701618254ef4919c19cdfe6da310,
title = "Connections between millimetre continuum variations and VLBI structure in 27 AGN",
abstract = "We compare total flux density variations in 27 γ-ray blazars with structural changes in their parsec-scale jets using multi-epoch VLBA observations at 22 and 43 GHz together with data from the Mets{\"a}hovi quasar monitoring program at 22 and 37 GHz. There is a clear connection between total flux density outbursts and VLBI components emerging into the jet. For essentially every new moving VLBI component, there is a coincident total flux density flare, with evolution similar to that of the component. Furthermore, extrapolated ejection times of the new VLBI components correspond to the beginnings of associated flares. Our results suggest that it is possible to explain all the radio variations as shocks propagating down the jet. A large fraction of the shocks grow and decay within the innermost few tenths of a milliarcsecond and therefore we see them only as {"}core flares{"} in the VLBI images. However, with present data we cannot exclude the possibility that the core itself also brightens (and thus contributes to the flare) as a shock passes through it.",
keywords = "BL Lacertae objects: general, Galaxies: active, Galaxies: jets, Quasars: general, Radio continuum: galaxies, Techniques: interferometric",
author = "T. Savolainen and K. Wiik and E. Valtaoja and Jorstad, {S. G.} and Marscher, {A. P.}",
year = "2002",
month = nov,
doi = "10.1051/0004-6361:20021236",
language = "English",
volume = "394",
pages = "851--861",
journal = "ASTRONOMY & ASTROPHYSICS",
issn = "0004-6361",
publisher = "EDP Sciences",
number = "3",

}

RIS

TY - JOUR

T1 - Connections between millimetre continuum variations and VLBI structure in 27 AGN

AU - Savolainen, T.

AU - Wiik, K.

AU - Valtaoja, E.

AU - Jorstad, S. G.

AU - Marscher, A. P.

PY - 2002/11

Y1 - 2002/11

N2 - We compare total flux density variations in 27 γ-ray blazars with structural changes in their parsec-scale jets using multi-epoch VLBA observations at 22 and 43 GHz together with data from the Metsähovi quasar monitoring program at 22 and 37 GHz. There is a clear connection between total flux density outbursts and VLBI components emerging into the jet. For essentially every new moving VLBI component, there is a coincident total flux density flare, with evolution similar to that of the component. Furthermore, extrapolated ejection times of the new VLBI components correspond to the beginnings of associated flares. Our results suggest that it is possible to explain all the radio variations as shocks propagating down the jet. A large fraction of the shocks grow and decay within the innermost few tenths of a milliarcsecond and therefore we see them only as "core flares" in the VLBI images. However, with present data we cannot exclude the possibility that the core itself also brightens (and thus contributes to the flare) as a shock passes through it.

AB - We compare total flux density variations in 27 γ-ray blazars with structural changes in their parsec-scale jets using multi-epoch VLBA observations at 22 and 43 GHz together with data from the Metsähovi quasar monitoring program at 22 and 37 GHz. There is a clear connection between total flux density outbursts and VLBI components emerging into the jet. For essentially every new moving VLBI component, there is a coincident total flux density flare, with evolution similar to that of the component. Furthermore, extrapolated ejection times of the new VLBI components correspond to the beginnings of associated flares. Our results suggest that it is possible to explain all the radio variations as shocks propagating down the jet. A large fraction of the shocks grow and decay within the innermost few tenths of a milliarcsecond and therefore we see them only as "core flares" in the VLBI images. However, with present data we cannot exclude the possibility that the core itself also brightens (and thus contributes to the flare) as a shock passes through it.

KW - BL Lacertae objects: general

KW - Galaxies: active

KW - Galaxies: jets

KW - Quasars: general

KW - Radio continuum: galaxies

KW - Techniques: interferometric

UR - http://www.scopus.com/inward/record.url?scp=0036845019&partnerID=8YFLogxK

U2 - 10.1051/0004-6361:20021236

DO - 10.1051/0004-6361:20021236

M3 - Article

AN - SCOPUS:0036845019

VL - 394

SP - 851

EP - 861

JO - ASTRONOMY & ASTROPHYSICS

JF - ASTRONOMY & ASTROPHYSICS

SN - 0004-6361

IS - 3

ER -

ID: 88371551