Chandra X-ray Observations of the redshift 1.53, radio-loud quasar: 3C 270.1

TL;DR

This study presents Chandra X-ray observations of the high-redshift radio-loud quasar 3C 270.1, revealing nuclear properties, extended emission associated with radio features, and potential evidence of a high-redshift galaxy cluster.

Contribution

First detailed X-ray analysis of 3C 270.1 at z=1.532, including modeling of extended emission and insights into inverse-Compton processes and cluster environment.

Findings

Nucleus has a typical radio-loud quasar spectrum with Gamma=1.66.

Extended X-ray emission aligns with radio structures and hotspots.

Evidence suggests possible high-redshift galaxy cluster with luminosity consistent with lower-redshift relations.

Abstract

Chandra X-ray observations of the high redshift (z =1.532) radio-loud quasar 3C270.1 in 2008 February show the nucleus to have a power-law spectrum, Gamma = 1.66 +/- 0.08, typical of a radio-loud quasar, and a marginally-detected Fe Kalpha emission line. The data also reveal extended X-ray emission, about half of which is associated with the radio emission from this source. The southern emission is co-spatial with the radio lobe and peaks at the position of the double radio hotspot. Modeling this hotspot including Spitzer upper limits rules out synchrotron emission from a single power-law population of electrons, favoring inverse-Compton emission with a field of ~11nT, roughly a third of the equipartition value. The northern emission is concentrated close to the location of a 40 deg. bend where the radio jet is presumed to encounter external material. It can be explained by inverse Compton emission involving Cosmic Microwave Background photons with a field of ~3nT, roughly a factor of nine below the equipartition value. The remaining, more diffuse X-ray emission is harder (HR=-0.09 +/- 0.22). With only 22.8+/-5.6 counts, the spectral form cannot be constrained. Assuming thermal emission with a temperature of 4 keV yields an estimate for the luminosity of 1.8E44 erg/s, consistent with the luminosity-temperature relation of lower-redshift clusters. However deeper Chandra X-ray observations are required to delineate the spatial distribution, and better constrain the spectrum of the diffuse emission to verify that we have detected X-ray emission from a high-redshift cluster.