TY - CONF

T1 - Kinematics of Parsec-scale Jets of Gamma-Ray Blazars at 43 GHZ within the VLBA-BU-BLAZAR Program: 2013-2019

AU - Jorstad, S.G.

AU - Marscher, A.P.

AU - Morozova, D.A.

AU - Weaver, Z. R.

AU - Agudo, I.

AU - Gomez, J.L.

N1 - American Astronomical Society meeting #235, id. 305.06. Bulletin of the American Astronomical Society, Vol. 52, No. 1

PY - 2020/1

Y1 - 2020/1

N2 - We analyze the parsec-scale jet kinematics from 2013 January to 2019 February of a sample of gamma-ray bright blazars monitored roughly monthly with the Very Long Baseline Array at 43 GHz. From a total of 1927 images, we measure the apparent speeds of roughly 300 emission knots in 23 quasars, 12 BL Lacertae objects (BLLacs), and 3 radio galaxies. The apparent speeds range from < 1c to ~40c; ~22% of the knots are quasi-stationary. Approximately 70 of the moving knots execute non-ballistic motions, defined as deviations from a linear trajectory using a chi-square test. We derive the physical parameters of about 200 superluminal knots using the apparent speeds and timescales of flux variability. These physical parameters include the variability Doppler factors, Lorentz factors, and viewing angles. With previous work (Jorstad et al. 2017), the VLBA-BU-BLAZAR data base now consists of 3856 images and measurements of apparent speeds of about 550 emission knots among the sources in the sample, spanning a time range from 2007 June to 2019 February. This research is supported by NASA through Fermi Guest Investigator Program grant 80NSSC17K0649.

AB - We analyze the parsec-scale jet kinematics from 2013 January to 2019 February of a sample of gamma-ray bright blazars monitored roughly monthly with the Very Long Baseline Array at 43 GHz. From a total of 1927 images, we measure the apparent speeds of roughly 300 emission knots in 23 quasars, 12 BL Lacertae objects (BLLacs), and 3 radio galaxies. The apparent speeds range from < 1c to ~40c; ~22% of the knots are quasi-stationary. Approximately 70 of the moving knots execute non-ballistic motions, defined as deviations from a linear trajectory using a chi-square test. We derive the physical parameters of about 200 superluminal knots using the apparent speeds and timescales of flux variability. These physical parameters include the variability Doppler factors, Lorentz factors, and viewing angles. With previous work (Jorstad et al. 2017), the VLBA-BU-BLAZAR data base now consists of 3856 images and measurements of apparent speeds of about 550 emission knots among the sources in the sample, spanning a time range from 2007 June to 2019 February. This research is supported by NASA through Fermi Guest Investigator Program grant 80NSSC17K0649.

M3 - Abstract

SP - 482

T2 - 235th Meeting of the American Astronomical Society

Y2 - 4 January 2020 through 8 January 2020

ER -