Astronomers inspect a powerful radio-loud high-redshift quasar

Utilizing the European VLBI Community (EVN), a global crew of astronomers has carried out high-resolution imaging observations of a robust and radio-loud high-redshift quasar often known as J2102+6015. Outcomes of the observational marketing campaign, offered January 18 on the preprint server arXiv, may assist us higher perceive the character of this peculiar quasar and different {powerful} radio sources.

Quasars, or quasi-stellar objects (QSOs), are extraordinarily luminous lively galactic nuclei (AGN) containing supermassive central black holes with accretion disks. Their redshifts are measured from the sturdy spectral traces that dominate their seen and ultraviolet spectra.

Astronomers are particularly concerned with discovering new high-redshift quasars (at redshift greater than 4.5) as they’re essentially the most luminous and most distant compact objects within the observable universe. Spectra of such QSOs can be utilized to estimate the mass of supermassive black holes that constrain the evolution and formation fashions of quasars. Due to this fact, high-redshift quasars may function a robust instrument to probe the early universe.

J2102+6015 is a robust radio quasar at a spectroscopic redshift of roughly 4.575 with a outstanding advanced radio construction. Nonetheless, though a number of observations of J2102+6015 have been performed so far, its true nature stays unsure. Some research have steered that it might be a gigahertz peaked-spectrum (GPS) supply, whereas others have proposed that it might be a younger compact symmetric object (CSO), excluding a blazar situation.

Due to this fact, with a view to shed extra mild on the properties of J2102+6015, a gaggle of astronomers led by Sándor Frey of the Konkoly Observatory in Budapest, Hungary, carried out a really lengthy baseline interferometry (VLBI) evaluation of this supply.

“The quasar J2102+6015 has by no means been studied with VLBI at frequency bands completely different from 2 and eight GHz. Motivated by the apparently non-blazar nature and the puzzling mas-scale radio construction of this supply, we performed 5- and 22-GHz imaging experiments with the European VLBI Community (EVN) in June 2021,” the researchers wrote within the paper.

The brand new VLBI observations allowed the crew to tell apart two important structural parts of J2102+6015—the brighter japanese (E) and the fainter western (W) options. These options are recognized from the sooner photographs of the supply and their separation was calculated to be about 10 mas.

Moreover, the brand new EVN photographs revealed a faint “central” element between the E and W options which can be a core of a CSO. Basically, the outcomes point out a slowly rising jet within the CSO phase, which is in keeping with the expectation from earlier research. In line with the astronomers, which means that the radio energy will proceed to extend with time with the supply enlargement.

The researchers famous that J2102+6015 is subsequently a younger radio supply with its jets misaligned with respect to the road of sight. It seems that the quasar experiences quasi-periodic variation, with a length of about three years, in its absolute place.

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