VLBI observations of VIK J2318-3113, a quasar at z = 6.44

Zhang, Y.; An, T.; Wang, A.; Frey, S.; Gurvits, L.; Gabányi, K. E.; Perger, K.; Paragi, Z.

doi:10.1051/0004-6361/202243785

VLBI observations of VIK J2318-3113, a quasar at z = 6.44

Title

VLBI observations of VIK J2318-3113, a quasar at z = 6.44

Author

Zhang, Y. (Ska Regional Centre Joint Lab; Chinese Academy of Sciences)
An, T. (Chinese Academy of Sciences; Ska Regional Centre Joint Lab; University of Chinese Academy of Sciences)
Wang, A. (Ska Regional Centre Joint Lab; Chinese Academy of Sciences; College of Astronomy and Space Sciences; University of Chinese Academy of Sciences)
Frey, S. (Konkoly Observatory Hungarian Academy of Sciences; Eötvös University)
Gurvits, L. (TU Delft Astrodynamics & Space Missions; Joint Institute for VLBI ERIC)
Gabányi, K. E. (Konkoly Observatory Hungarian Academy of Sciences; Eötvös University)
Perger, K. (Konkoly Observatory Hungarian Academy of Sciences)
Paragi, Z. (Joint Institute for VLBI ERIC)

Date

2022

Abstract

The nature of jets in active galactic nuclei (AGNs) in the early Universe and their feedback to the host galaxy remains a highly topical question. Observations of the radio structure of high-redshift AGNs enabled by very long baseline interferometry (VLBI) provide indispensable input into studies of their properties and role in the galaxies' evolution. To date, only five AGNs at redshift z 6 have been studied with the VLBI technique. Aims. VIK J2318-3113 is a recently discovered quasar at z = 6:44 that had not been imaged with VLBI before the current work. Here we present the first VLBI imaging results of this high-redshift quasar, with the aim of corroborating its high-resolution appearance with the physical model of the object. Methods. We carried out VLBI phase-referencing observations of VIK J2318-3113 using the Very Long Baseline Array at two frequencies, 1.6 and 4.7 GHz, and obtained the first view at the radio structure on the milliarcsecond scale. Results. The source was clearly detected at 1.6 GHz. We found that almost all of its radio emission comes from the parsec-scale core region. Our dual-frequency observations constrain the spectral index and brightness temperature of the radio core. Its properties are similar to those of other known high-redshift radio-loud AGNs.

Subject

Galaxies: high-redshift
Galaxies: jets
Quasars: general
Quasars: individual: VIK J2318-3113

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http://resolver.tudelft.nl/uuid:8017c584-6ea0-4538-9268-b23cb0af99ac

DOI

https://doi.org/10.1051/0004-6361/202243785

ISSN

0004-6361

Source

Astronomy & Astrophysics, 662

Part of collection

Institutional Repository