The quasar feedback survey: discovering hidden Radio-AGN and their connection to the host galaxy ionized gas

We present the first results from the Quasar Feedback Survey, a sample of 42 z 1042.1 ergs s−1) with moderate radio luminosities (i.e. L1.4GHz > 1023.4 W Hz−1; median L1.4GHz = 5.9 × 1023 W Hz−1). Using high spatial resolution (∼0.3–1 arcsec), 1.5–6 GHz radio images from the Very Large Array, we find that 67 per cent of the sample have spatially extended radio features on ∼1–60 kpc scales. The radio sizes and morphologies suggest that these may be lower radio luminosity versions of compact, radio-loud AGNs. By combining the radio-to-infrared excess parameter, spectral index, radio morphology, and brightness temperature, we find radio emission in at least 57 per cent of the sample that is associated with AGN-related processes (e.g. jets, quasar-driven winds, or coronal emission). This is despite only 9.5–21 per cent being classified as radio-loud using traditional criteria. The origin of the radio emission in the remainder of the sample is unclear. We find that both the established anticorrelation between radio size and the width of the [O III] line, and the known trend for the most [O III] luminous AGNs to be associated with spatially extended radio emission, also hold for our sample of moderate radio luminosity quasars. These observations add to the growing evidence of a connection between the radio emission and ionized gas in quasar host galaxies. This work lays the foundation for deeper investigations into the drivers and impact of feedback in this unique sample

Quasar feedback survey: multiphase outflows, turbulence, and evidence for feedback caused by low power radio jets inclined into the galaxy disc

We present a study of a luminous, z =0.15, type-2 quasar (LO III]} = 1042.8 erg s-1) from the Quasar Feedback Survey. It is classified as 'radio-quiet' (L1.4\GHz}}= 1023.8 W Hz-1); however, radio imaging reveals ∼1 kpc low-power radio jets (Pjet = 1044 erg s-1) inclined into the plane of the galaxy disc. We combine MUSE and ALMA observations to map stellar kinematics and ionized and molecular gas properties. The jets are seen to drive galaxy-wide bi-conical turbulent outflows, reaching W80 = 1000 - 1300 km s-1, in the ionized phase (traced via optical emission lines), which also have increased electron densities compared to the quiescent gas. The turbulent gas is driven perpendicular to the jet axis and is escaping along the galaxy minor axis, reaching 7.5 kpc on both sides. Traced via CO(3-2) emission, the turbulent material in molecular gas phase is one-third as spatially extended and has three times lower velocity-dispersion as compared to ionized gas. The jets are seen to be strongly interacting with the interstellar medium (ISM) through enhanced ionized emission and disturbed/depleted molecular gas at the jet termini. We see further evidence for jet-induced feedback through significantly higher stellar velocity-dispersion aligned, and co-spatial with, the jet axis (<5). We discuss possible negative and positive feedback scenarios arising due to the interaction of the low-power jets with the ISM in the context of recent jet-ISM interaction simulations, which qualitatively agree with our observations. We discuss how jet-induced feedback could be an important feedback mechanism even in bolometrically luminous 'radio-quiet' quasars

The quasar feedback survey: discovering hidden Radio-AGN and their connection to the host galaxy ionized gas

We present the first results from the Quasar Feedback Survey, a sample of 42 z 1042.1 ergs s−1) with moderate radio luminosities (i.e. L1.4GHz > 1023.4 W Hz−1; median L1.4GHz = 5.9 × 1023 W Hz−1). Using high spatial resolution (∼0.3-1 arcsec), 1.5-6 GHz radio images from the Very Large Array, we find that 67 per cent of the sample have spatially extended radio features on ∼1-60 kpc scales. The radio sizes and morphologies suggest that these may be lower radio luminosity versions of compact, radio-loud AGNs. By combining the radio-to-infrared excess parameter, spectral index, radio morphology, and brightness temperature, we find radio emission in at least 57 per cent of the sample that is associated with AGN-related processes (e.g. jets, quasar-driven winds, or coronal emission). This is despite only 9.5-21 per cent being classified as radio-loud using traditional criteria. The origin of the radio emission in the remainder of the sample is unclear. We find that both the established anticorrelation between radio size and the width of the [O III] line, and the known trend for the most [O III] luminous AGNs to be associated with spatially extended radio emission, also hold for our sample of moderate radio luminosity quasars. These observations add to the growing evidence of a connection between the radio emission and ionized gas in quasar host galaxies. This work lays the foundation for deeper investigations into the drivers and impact of feedback in this unique sample

Discovery of a faint, star-forming, multiply lensed, Lyman-alpha blob

We report the discovery of a multiply lensed Lyman-alpha blob (LAB) behind the galaxy cluster AS1063 using the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT). The background source is at z = 3.117 and is intrinsically faint compared to almost all previously reported LABs. We used our highly precise strong lensing model to reconstruct the source properties, and we find an intrinsic luminosity of L-Ly alpha = 1.9 x 10(42) erg s(-1), extending to 33 kpc. We find that the LAB is associated with a group of galaxies, and possibly a protocluster, in agreement with previous studies that find LABs in overdensities. In addition to Lyman-alpha (Ly alpha) emission, we find C IV, He II, and O III] ultraviolet (UV) emission lines arising from the centre of the nebula. We used the compactness of these lines in combination with the line ratios to conclude that the Ly alpha nebula is likely powered by embedded star formation. Resonant scattering of the Ly alpha photons then produces the extended shape of the emission. Thanks to the combined power of MUSE and strong gravitational lensing, we are now able to probe the circumgalatic medium of sub-L-* galaxies at z approximate to 3

Discovery of a faint, star-forming, multiply lensed, Lyman-alpha blob

We report the discovery of a multiply lensed Lyman-alpha blob (LAB) behind the galaxy cluster AS1063 using the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT). The background source is at z = 3.117 and is intrinsically faint compared to almost all previously reported LABs. We used our highly precise strong lensing model to reconstruct the source properties, and we find an intrinsic luminosity of L-Ly alpha = 1.9 x 10(42) erg s(-1), extending to 33 kpc. We find that the LAB is associated with a group of galaxies, and possibly a protocluster, in agreement with previous studies that find LABs in overdensities. In addition to Lyman-alpha (Ly alpha) emission, we find C IV, He II, and O III] ultraviolet (UV) emission lines arising from the centre of the nebula. We used the compactness of these lines in combination with the line ratios to conclude that the Ly alpha nebula is likely powered by embedded star formation. Resonant scattering of the Ly alpha photons then produces the extended shape of the emission. Thanks to the combined power of MUSE and strong gravitational lensing, we are now able to probe the circumgalatic medium of sub-L-* galaxies at z approximate to 3