Novel Analysis of the Multiwavelength Structure of Relativistic Jet in Quasar 3C 273

TL;DR

This study provides a detailed multi-wavelength analysis of the large-scale jet in quasar 3C 273, revealing extended knot structures and spatial offsets across different frequencies, which inform models of jet emission and particle acceleration.

Contribution

It offers the first high-resolution, multi-wavelength morphological analysis of 3C 273's jet, resolving knots transversely and identifying positional offsets across frequencies.

Findings

Knots are extended, about 0.5 kpc in size.

Radio jet is wider than X-ray/ultraviolet jet.

X-ray peaks are upstream of radio peaks by up to 1 kpc.

Abstract

We present a detailed analysis of the best-quality multi-wavelength data gathered for the large-scale jet in the core-dominated quasar 3C 273. We analyze all the archival observations of the target with the Chandra X-ray Observatory, the far-ultraviolet observations with the Hubble Space Telescope, and the 8.4 GHz map obtained with the Very Large Array. In our study we focus on investigating the morphology of the outflow at different frequencies, and therefore we apply various techniques for the image deconvolution, paying particular attention to a precise modeling of the Chandra and Hubble point spread functions. We find that the prominent brightness enhancements in the X-ray and far-ultraviolet jet of 3C 273 - the "knots" - are not point-like, and can be resolved transversely as extended features with sizes of about $\simeq 0.5$ kpc. Also, the radio outflow is wider than the deconvolved X-ray/ultraviolet jet. We have also found circumstantial evidence that the intensity peaks of the X-ray knots are located systematically upstream of the corresponding radio intensity peaks, with the projected spatial offsets along the jet ranging from $\lesssim 0.2$ kpc up to $\simeq 1$ kpc. We discuss our findings in the wider context of multi-component models for the emission and structure of large-scale quasar jets, and speculate on the physical processes enabling an efficient acceleration of the emitting ultra-relativistic electrons along the entire jet length that exceeds 100 kpc.