Connecting outflows with radio emission in active galactic nuclei at cosmic noon

TL;DR

The study addresses whether radio jets contribute to galaxy-scale ionized outflows in typical AGN at cosmic noon ($z\sim2$). It combines new 6.2 GHz VLA data with spatially resolved [OIII] maps from SINFONI for three SUPER quasars, complemented by archival radio data to place jets in context. The results show that two objects (J1333+1649 and CID-346) host extended radio structures co-spatial with ionized outflows and with small PA offsets, consistent with jet–ISM interactions driving the winds, while XID-36 lacks extended radio emission. Energetic analysis indicates jet power can plausibly power the observed ionized outflows with a typical coupling efficiency of ~1%, though radiative driving remains possible in some cases; the findings extend jet–driven feedback scenarios to moderate-power AGN at cosmic noon and motivate larger, resolution-matched samples. $z\sim2$, $L_{\rm bol}\sim10^{45.7}-10^{47.9}$ erg s$^{-1}$, $P_{1.4\mathrm{GHz}}\sim10^{24.8}-10^{28.2}$ W Hz$^{-1}$, and W$_{80}>600$ km s$^{-1}$ anchor the physical scale and energetics discussed throughout.

Abstract

AGN feedback is a well known mechanism in the evolution of galaxies. One open question is the driving mechanism of galaxy-scale outflows. At low redshift, radio jets often interact with the ISM, generating turbulence and driving ionized outflows. Despite this evidence at low redshift, relatively few studies have investigated the radio-ionized gas connection at cosmic noon. Thus, our main goal is to conduct a pilot study using VLA data for three quasars with moderate/high radio power, which have ionized outflows identified in observations from the SUPER survey. We used [OIII] data from SINFONI analyzed in earlier studies, along with new 6.2 GHz VLA radio observations, at comparable spatial resolution. We also incorporate radio data from the literature to explore the radio emission. We detected extended radio structure in our VLA A-array data for two quasars. The extended structure in J1333+1649 aligns with the smaller-scale emission seen in archival images, suggesting a jet propagating from nuclear to galaxy-wide scales. In all three quasars, we found that the brightest radio emission and ionized gas have comparable spatial scales. Furthermore, the position angles of the radio emission and ionized gas present small offsets for the two targets with extended structures. Given that the kinematics of the ionized gas in all three quasars is dominated by outflows, our results suggest a strong connection between radio emission and ionized outflows in typical AGN at cosmic noon. Based on energetic considerations and comparisons with archival data, radio jets could be a significant mechanism for driving outflows in AGN from cosmic noon to low redshifts. However, with the exception of one object (J1333+1649), we cannot rule out the possibility that the radio emission arises from shocks in the interstellar medium caused by disk winds or radiatively driven outflows.

Figures (11)

• Figure 1: Properties of the SUPER sample highlighting the three targets of this work. Left: Bolometric luminosity (L$_{bol}$) vs. radio power at 1.4 GHz. The color bar shows the q$_{24obs}$ parameter, where q$_{24obs}$ = log(S$_{24\mu\text{m}}$/S$_{r}$ ). S$_{24\mu\text{m}}$ and S$_{r}$ are the observed 24 $\mu\text{m}$ and 1.4 GHz flux densities. Middle: q$_{24obs}$ parameter vs. redshift. The color bar shows the bolometric luminosity. The solid line represents the typical values for a star-forming galaxy Bonzini+13, while the dashed lines indicate the $\pm 2\sigma$ dispersion, which marks the locus of star-forming galaxies. Right: FIR luminosities vs. radio power at 1.4 GHz. The solid line is from Magnelli+15 and the dashed lines represent 2$\sigma$ relative to the solid line. The color bar shows the bolometric luminosity.
• Figure 2: Radio maps for J1333+1649. The beam is represented by a ellipse on each image. Left: VLA A-array 6.2 GHz radio map with contours plotted at levels of [36, 512, 1024, 2048, 4096, and 8192]$\sigma$. The dashed line indicates the position angle of the radio extended structure. Middle: MOJAVE 8.1 GHz radio map (background map) with MOJAVE 8.1 GHz and VIPS 5.0 GHz radio contours at [3, 4, 8, 16, 32, 64, 128, and 256]$\sigma$. The dashed line indicates the PA of the VIPS radio extended structure, which is similar to that of MOJAVE. Right: VLA A-array residual map from casa after subtracting the central source with contours plotted at [16, 32, 64, and 96]$\sigma$. The cyan arrow indicates the extended radio structure.
• Figure 3: Radio map contours and residual map of images of CID-346. The beam is represented by a ellipse on each image. The dashed lines indicate the position angles of the extended structure. Left: VLA A-array with contours [-2, 2, 4, 6, and 8]$\sigma$. Middle: VLA-COSMOS radio map with contours plotted at [-2, 2, 4, 6, and 8]$\sigma$. Right: VLA-COSMOS residual map after removing central source with casa with contours plotted at [-2, 2, and 4]$\sigma$. The VLA A-array observations were conducted at 6.2 GHz, while the VLA-COSMOS survey was performed at 1.4 GHz. The cyan arrows indicate the extended radio structure.
• Figure 4: Radio map for XID-36. The contours at [-2, 2, 4, 6, and 8]$\sigma$ show the VLA A-array radio data. The beam for the radio data is represented by an ellipse. The VLA A-array observations were conducted at 6.2 GHz. There is no strong evidence for extended radio structures in this source.
• Figure 5: [O iii]$\lambda$5007 maps for our three targets. The PSF and beam for the ionized gas maps and radio image are represented by a red and a black ellipse, respectively. The green dashed line indicates the position angle of [O iii]$\lambda$5007 emission, while the red dashed line indicates the radio PA. The dotted lines indicate the uncertainties of the PAs. Top: Maps for J1333+1649. The contours plotted at [36, 512, 1024, 2048, 4096, and 8192]$\sigma$ show the VLA-A array radio data. Middle: Maps for CID-346. The contours at [2, 4, 6, and 8]$\sigma$ show the VLA-A array radio data. Bottom: Maps for XID-36. The contours at [2, 4, 6, and 8]$\sigma$ show the VLA-A array radio data.