Evolving parsec-scale radio structure in the most distant blazar known

Abstract

Blazars are a sub-class of quasars with Doppler boosted jets oriented close to the line of sight, and thus efficient probes of supermassive black hole growth and their environment, especially at high redshifts.Here we report on Very Long Baseline Interferometry observations of a blazar J0906+6930 at z = 5.47, which enabled the detection of polarised emission and measurement of jet proper motion at parsec scales. The observations suggest a less powerful jet compared with the general blazar population, including lower proper motion and bulk Lorentz factor. This coupled with a previously inferred high accretion rate indicate a transition from an accretion radiative power to a jet mechanical power based transfer of energy and momentum to the surrounding gas.While alternative scenarios could not be fully ruled out, our results indicate a possibly nascent jet embedded in and interacting with a dense medium resulting in a jet bending.Here, we report the measurement of proper motion and linear polarisation in the parsec-scale jet of this high redshift blazar. We use new 15-GHz data observed with the VLBA in 2017 and 2018, archival VLBA data obtained in 2004-2005 (see details in Supplementary Table 1) and the flux densities reported by the 40 m telescope at the Owens Valley Radio Observatory (OVRO) to explore the evolution of the source morphology and infer its physical characteristics. The jet parameters (lower proper motion and bulk Lorentz factor) are inclined to support a less powerful jet, compared with the general blazar population. The jet interacts with the surrounding interstellar medium resulting in a jet bending and polarised emission.

Blazars at the Cosmic Dawn

“…We have not used data points bluer to the Lyman-α frequency in the modeling and show them only for completeness. insights about the blazar evolution scenario and they are consistent not only with other studies where a low Γ was estimated from the SED modeling (An & Romani 2018) but also that inferred from radio studies (e.g., An et al 2020). However, we cannot make a strong claim due to lack of >10 keV data for most of the sources.…”

A Relativistic Orbit Model for Temporal Properties of AGN

“…There is an oscillatory behavior seen in both γ-ray and optical light curves [11][12][13][14][15][16]66,67] that supports the above trend. There is also evidence of the radio structure that is supported by the basic model of [52] as observed by [68,69].…”

Fitness landscape of a dynamic RNA structure

“…Recovered cells were then grown on LB agar containing 100 μg/mL carbenicillin at 37˚C for 16 hours. The next day, the total number of transformed colonies was estimated to bẽ 5.5 x 10 5 , corresponding to at least 8-fold oversampling of the target library size of 4 8 variants. All transformed colonies were scraped off the agar plates and pooled in 10 mL LB + 100 μg/mL carbenicillin.…”

“…Helical stability for P1ex and P10 across all possible 4 8 and 4 4 genotypes, respectively, was computed from primary sequence using the efn2 function in RNAStructure v6.2 (https://rna. urmc.rochester.edu/RNAstructure.html).…”

“…Over the last decade, mutational effects on molecular fitness have been elucidated at scale for a handful of model RNAs using deep mutational scanning experiments, both in vitro [3][4][5][6][7][8] and in vivo [9][10][11][12][13][14]. These studies have revealed complex fitness landscapes, in which both pairwise and higher-order epistasis are prevalent [12,[15][16][17].…”