Relationship between the gamma-ray variability and the pc- scale jet in the blazar 3C 454.3
Abstract
This work aims to identify the structure, dynamics, and radiative processes common to the innermost regions of the blazar 3C 454.3. We use very long-baseline interferometry (VLBI) techniques in the range of millimeter and radio wavelengths, which allow us to achieve the highest possible spatial resolution today. We use VLBA maps from the MOJAVE program and the Boston University VLBA monitoring program. We also track the temporal evolution of the radial separation between the different jet components and the radio core between 2008 and 2020, which enables the calculation of their proper motions as well as their apparent velocities. Additionally, we study the correlation between multi-wavelength variability and the pc-scale jet behavior, combined with multi-wavelength observations from existing public databases: 15 GHz from OVRO, 1 mm from SMA, NIR from SMARTS, optical from SMARTS and the Steward Observatory, X-rays from Swift-XRT, and gamma-rays from Fermi-LAT. For the above, we analyze quasi-simultaneous observations in the different bands already mentioned and compare them with changes in the VLBI images, such as variability in the brightness of the stationary and moving jet components. Some of the main objectives of this work are to identify the gamma-ray emission region within the VLBA components observed in the different maps; measure the distance between the radio core and this emission region; explore the gamma-ray emission mechanism of this region, e.g. external inverse Compton or synchrotron inverse Compton. We also investigate whether the gamma-ray emission region accounts for the total emission, or if it is necessary to consider more regions to describe it. Given the lack of consensus on the mechanism responsible for the gamma-ray emission and the region or regions where it happens, we offer additional constraints to it thanks to this work and the prior knowledge we have from the multi-wavelength emission mechanisms at different epochs for 3C 454.3.
- Publication:
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44th COSPAR Scientific Assembly. Held 16-24 July
- Pub Date:
- July 2022
- Bibcode:
- 2022cosp...44.2012M