We will make a big effort to release high-level data products and scripts from our survey (e.g., radio images, reduced data cubes). Information of our papers and where to find the data products are found here.
- Jarvis+21 (accepted for publication in MNRAS). This paper introduced the survey and presents VLA imaging for 42 quasars.
- Jarvis+20: APEX CO(2-1) and CO(6-5) for 9 pilot quasars
- Jarvis+19: VLA+eMERLIN+GMOS/VIMOS data for 10 quasars (9 of which are part of the Quasar Feedback Survey)
- Lansbury+18: Chandra data for Teacup AGN (J1430+1339)
- Harrison+15: VLA+VIMOS data for Teacup AGN (J1430+1339)
Jarvis+21 (Full Survey, Paper 1)
“The Quasar Feedback Survey: Discovering hidden Radio-AGN and their connection to the host galaxy ionised gas”
Jarvis et al. 2021, MNRAS, in press; arXiv:2103.00014 and detailed supplementary information
DATA: The VLA images for the 42 objects from this study are available a Newcastle University’s Data repository. The L-band images are available here; the C-band images are available here and the in-band spectral index maps (from the C-band) are available here. Machine readable versions of the tables will be made available shortly.
In this paper we present an overview of the survey and VLA images a medium resolution (MR: 1″/L-band/1.4GHz) and high resolution (HR: 0.3″/C-band/6GHz), for all 42 quasars. We also compare these to the low resolution (LR) FIRST images. Example images are show in the figure below which gives an overview of the range of morphologies that we observe. We find that 67% of the sample show extended radio structures on ~1-60 kpc scales. Furthermore, by using a range of criteria, we find a surprisingly high fraction of Radio-AGN in our sample of quasars. At least 57% harbour a Radio-AGN, despite the fact that only 9-21% would be classified as Radio-AGN by traditional criteria. The origin of the radio emission in the remainder of the sample remains ambiguous.
We also demonstrate a relationship between the radio emission and ionised gas properties (traced via [O III]). For example, we see a negative correlation between velocity width of the emission line and the size of the radio emission (see below). This has been observed previously in more powerful Radio-AGN, and is an indication that compact radio emission (either from jets or quasar winds) is having a dramatic impact on the host galaxy gas. Overall our paper shows the important or studying the radio emission at high spatial resolution to understand feedback from quasars – even for low radio luminosity (“radio quiet”) sources.
Jarvis+20 (Pilot Study)
“High molecular gas content and star formation rates in local galaxies that host quasars, outflows, and jets”
DATA: The APEX spectra for the nine objects from this study are available a Newcastle University’s Data repository here . This includes the 9 targets with CO(2-1) emission-line data and the 3 targets with CO(6-5) emission-line data. We also provide a small python script to plot the data. Machine readable versions of the main tables can be found here. All data products available from this study are available at the following DOI link: https://doi.org/10.25405/data.ncl.c.5207720
In this paper we obtained APEX observations of the CO(2-1) emission line of the 9 pilot quasars and CO(6-5) emission line of a subset of 3 of these quasars. We used these observations to measure the total molecular gas content inside the host galaxies. We also used careful analyses of the spectral energy distributions to measure the star formation rates and stellar masses of the host galaxies. Our results show that these powerful quasars at z~0.1 live inside gas rich, star-forming galaxies. Their molecular gas properties and star-formation properties (i.e., their gas fractions and star formation efficiencies) are consistent with the overall galaxy population. Therefore, the jets and ionised outflows that are known to exist in these systems have had no immediate impact on the gas content or star formation rates, at least on a galaxy-wide scale. Furthermore the CO(6-5)/CO(2-1) emission-line ratios for the three objects with the measurement tentatively suggest no extreme excitation of the molecular gas. Nonetheless, we can not rule out that the jets or outflows will have an impact on longer timescales or that they have an impact on smaller, unresolved scales.
Jarvis+19 (Pilot Study)
“Prevalence of radio jets associated with galactic outflows and feedback from quasars”
DATA: The main radio images (as shown in the figure below), the IFU data cubes and all of the derived [O III] property maps (e.g., velocities and velocity widths) for all 10 targets from this study are available at Newcastle University’s data repository. You can navigate to the individual target’s data products from the objects page or find them through the following DOI link: https://doi.org/10.25405/data.ncl.c.5203919
Using the VLA radio interferometer we performed multi-resolution and multi-frequency observations of a sample of 10 quasars (i.e, the most rapidly growing black holes!) at redshift z<0.2. Despite these not being classified as “radio AGN” by most traditional methods, we found that the radio emission is dominated by the AGN (>~90%) in 9 of the 10 targets. Furthermore our high-resolution imaging revealed jet-like structures in at least 8 of these sources, indicating that radio jets are (perhaps surprisingly) prevalent in such systems. The figure shows the distribution of ionised gas ([O III] emission) in the background and the contours show the distribution of radio emission from our various observations.
Lansbury+18 (Pilot Study):
“Storm in a Teacup: X-ray view of an obscured quasar and superbubble“
DATA: The Chandra images and the XMM and Chandra spectra from this study are available to down load from Newcastle University’s data repository at DOI: https://doi.org/10.25405/data.ncl.13387625.v1
Using Chandra time the team observed the Teacup AGN, which we had previously identified as having large bubbles of ionised gas (green colour in image) and radio emission (red colour in image) to obtain spatially-resolved X-ray measurements. Using these data, in combination with existing XMM-Newton X-ray observations , we obtained the best constraints to date on the bolometric output (and level of obscuring material) of the growing supermassive black hole at the centre of this galaxy. These results revealed that the quasar may not be “fading away” as previously thought, based on earlier less robust constraints on the bolometric output. Furthermore, in the Chandra data we detected the large bubble in X-ray emission (see blue contours in image), providing tentative evidence for a very hot outflowing gas component within the bubble. This source appears to be showing outflows in multiple phases of gas, driven by the supermassive black hole lurking at its centre.
Chandra Popular Releases about publication:
Harrison+15 (Pilot Study)
“Storm in a ‘Teacup’: A Radio-quiet Quasar with ≈10 kpc Radio-emitting Bubbles and Extreme Gas Kinematics“
ApJ, 800, 45 (2015), (arXiv:1410.4198)
Using the VLA radio interferometer we performed multi-resolution and multi-frequency observations of the Teacup AGN; a z=0.1 radio-quiet quasar. The Teacup AGN was observed by us in 2014 to have a high-velocity gas component ~1kpc from the central core. This is seen in the high-velocity wing of the [O III] emission-line profile at this location (see the inset spectrum at the bottom of the image). Additionally, HST narrow-band imaging reveals a ~10kpc arc of ionised gas to the East (see image). Our new VLA data revealed that both the high-velocity outflow and ionised arc are associated with radio emission. Our interpretation of these results is that a radio jet (or possibly quasar wind) is interacting with the gas ~1kpc from the core and driving the high-velocity outflow. Additionally there are bi-polar radio bubbles being inflated by the central AGN that are interacting with the gas on ~10-12kpc scales. This AGN is “radio-quiet”, which means that its radio luminosity is typical for its optical radio luminosity, and is therefore more representative of the overall population than radio-loud AGN. Our results show in the importance of radio observations for understanding AGN feedback for systems with low radio luminosities. This is the first object from the larger sample that is presented in Jarvis+19,20.
- NRAO Press Release, VLA Finds Unexpected “Storm” at Galaxy’s Core and Durham University Press Release, “Massive black hole causes storm in “Teacup” galaxy”
- Appeared on over 30 news and popular science magazines or websites (across UK, USA, India, Singapore) including: Sky at Night Magazine, Fox News; Astronomy Magazine; Sky and Telescope; the “Top Story” on NSF’s science news and This Week’s “Must Read” on CNET
- Television appearance on “Made in Tyne and Wear” (12th and 14th February 2015)