Jonathon Pierce

• The University of Sheffield

It has previously been found that the galaxy cluster environment can affect the fueling and evolution of Active Galactic Nuclei (AGN). This work examines the effect of the merging cluster environment on the properties of radio-AGN by comparing the radio morphology of cluster members in a sample of four merging and eight relaxed galaxy clusters at l...

The triggering mechanism for the most luminous, quasar-like active galactic nuclei (AGN) remains a source of debate, with some studies favouring triggering via galaxy mergers, but others finding little evidence to support this mechanism. Here, we present deep Isaac Newton Telescope/Wide Field Camera imaging observations of a complete sample of 48 o...

The triggering mechanism for the most luminous, quasar-like active galactic nuclei (AGN) remains a source of debate, with some studies favouring triggering via galaxy mergers, but others finding little evidence to support this mechanism. Here, we present deep Isaac Newton Telescope/Wide Field Camera imaging observations of a complete sample of 48 o...

We analyze Near-Infrared Integral Field Spectrograph (NIFS) observations of the type-2 quasar (QSO2) SDSS J094521.33+173753.2 to investigate its warm molecular and ionized gas kinematics. This QSO2 has a bolometric luminosity of 10$^{45.7}$ erg s$^{-1}$ and a redshift of z = 0.128. The K-band spectra provided by NIFS cover a range of 1.99-2.40 $\mu...

We analyse Near-Infrared Integral Field Spectrograph (NIFS) observations of the type-2 quasar (QSO2) SDSS J094521.33+173753.2 to investigate its warm molecular and ionized gas kinematics. This QSO2 has a bolometric luminosity of 10 45.7 erg s ⁻¹ and a redshift of z = 0.128. The K -band spectra provided by NIFS cover a range of 1.99–2.40 μm where lo...

We analyze Near-Infrared Integral Field Spectrograph (NIFS) observations of the type-2 quasar (QSO2) SDSS J094521.33+173753.2 to investigate its warm molecular and ionized gas kinematics. This QSO2 has a bolometric luminosity of 10$^{45.7}$ erg s$^{-1}$ and a redshift of z = 0.128. The K-band spectra provided by NIFS cover a range of 1.99-2.40 $\mu...

We use deep Herschel observations of the complete 2Jy sample of powerful radio AGNs in the local universe (0.05 < z < 0.7) to probe their cool interstellar medium (ISM) contents and star-forming properties, comparing them against other samples of nearby luminous AGNs and quiescent galaxies. This allows us to investigate triggering and feedback mech...

Investigation of the triggering mechanisms of radio active galactic nuclei (radio AGN) is important for improving our general understanding of galaxy evolution. In the first paper in this series, detailed morphological analysis of high-excitation radio galaxies (HERGs) with intermediate radio powers suggested that the importance of triggering via g...

We present CO(2−1) and adjacent continuum observations of seven nearby radio-quiet type-2 quasars (QSO2s) obtained with ALMA at ∼0.2″ resolution (370 pc at z ∼ 0.1). These QSO2s are luminous ( L [OIII] > 10 8.5 L ⊙ ∼ M B < −23), and their host galaxies massive ( M * ∼ 10 ¹¹ M ⊙ ). The CO morphologies are diverse, including disks and interacting sys...

We present CO(2-1) and adjacent continuum observations of 7 nearby radio-quiet type-2 quasars (QSO2s) obtained with ALMA at ~0.2" resolution (370 pc at z~0.1). The CO morphologies are diverse, including discs and interacting systems. Two of the QSO2s are red early-type galaxies with no CO(2-1) detected. In the interacting galaxies, the central kpc...

Investigation of the triggering mechanisms of radio AGN is important for improving our general understanding of galaxy evolution. In the first paper in this series, detailed morphological analysis of high-excitation radio galaxies (HERGs) with intermediate radio powers suggested that the importance of triggering via galaxy mergers and interactions...

In the past decade, high-sensitivity radio surveys have revealed that the local radio active galactic nucleus population is dominated by moderate-to-low power sources with emission that is compact on galaxy scales. High-excitation radio galaxies (HERGs) with intermediate radio powers (22.5 < log (L1.4 GHz) < 25.0 W Hz−1) form an important sub-group...

In the past decade, high sensitivity radio surveys have revealed that the local radio AGN population is dominated by moderate-to-low power sources with emission that is compact on galaxy scales. High-excitation radio galaxies (HERGs) with intermediate radio powers (22.5 $<$ log(L$_{\rm 1.4GHz}$) $<$ 25.0 W Hz$^{-1}$) form an important sub-group of...

Active galactic nuclei (AGNs) with intermediate radio powers are capable of driving multiphase outflows in galaxy bulges, and are also more common than their high-radio-power counterparts. In-depth characterization of the typical host galaxies and likely triggering mechanisms for this population is therefore required in order to better understand t...

We use deep, μ r lesssim 28 mag arcsec−2, r-band imaging from the Dark Energy Camera Legacy Survey to search for past, or ongoing, merger activity in a sample of 282 low-excitation radio galaxies (LERGs) at z < 0.07. Our principal aim is to assess the the role of mergers in the evolution of LERGs. Exploiting the imaging depth, we classify tidal rem...

Radio AGNs with intermediate radio powers are capable of driving multi-phase outflows in galaxy bulges, and are also more common than their high-radio-power counterparts. In-depth characterisation of the typical host galaxies and likely triggering mechanisms for this population is therefore required in order to better understand the role of radio A...

We use deep, $\mu_{r} \lesssim 28\,\text{mag}\,\text{arcsec}^{-2}$, $r$-band imaging from the Dark Energy Camera Legacy Survey (DECaLS) to search for past, or ongoing, merger activity in a sample of $282$ Low Excitation Radio Galaxies (LERGs) at $z<0.07$. Our principle aim is to assess the the role of mergers in the evolution of LERGs. Exploiting t...