24 September 2019: Paper highlight - Making sens of the infrared and sub-mm
Seb's new paper takes a look at recent ALMA and VLTI observations and tries to unify what we are seeing by analysing the physical conditions that govern the different emission regions. The result is a multi-phase multi-component picture of accretion and outflow from tens of parsecs to sub-parsec scales. One interesting new aspect is that the mass outflow rates of dusty winds may be sufficient to remove the bulk of the mass flowing from the host galaxy onto the supermassive black hole.
Hoenig 2019, ApJ, in press
12 August 2019: Paper highlight - Polar dust on tens of parsec scales
Daniel presents results from his recent VLT/VISIR runs where he shows that mid-IR polar dust features are not only common on parsec scales, but also beyond. He uses PSF subtraction techniques and his intricate knowledge of the ins and out of VISIR to confirm that our limit of detecting these features is probably surface brightness sensitivity, not frequency. This may bode well for JWST.
Asmus 2019, MNRAS, in press
14 May 2019: Paper highlight - 3D radiation-hydrodynamics in the AGN environment
Our new 3D radiation-hydrodynamical model of the dusty environment of AGN has been published. The simulations are based on a Lagrangian SPH code to achive high resolution in the densest regions and resolve the high dynamic range in density, temperature, and ionisation parameter found in this region. Have a look at the paper to see how the AGN "torus" is not reallly a torus but a multi-phase disk + wind structure.
Williamson, Hoenig, & Venanzi 2019, ApJ 876, 137
12 December 2018: TORUS2018
Eight members of the group went to Puerto Varas in Chile to present our latest work at the triennial TORUS conference. This includes first results from VEILS and our local reverberation mapping sample, new radiation-hydrodynamical simulations, and high-angular resolution observations in the near- and mid-infrared from the VLT and VLTI.
28 November 2018: Paper highlight - GRAVITY observes a BLR
Seb is part of a team that used the new VLTI GRAVITY instrument to spatially resolve the broad-line region in the nearby quasar 3C273. The angular resolution of these observations is better than 10 micro-arcseconds and shows orderly rotation around the supermassive black hole, which could be weighed by modelling the motion of the orbiting gas clouds.
GRAVITY collaboration 2018, Nature, 563, 657
1 October 2018: Welcome Ella
We welcome our new PhD student Ella Guise. Ella graduated from the University of Southampton and will join the research group to work on AGN variability and transients in VEILS and VOILETTE.
22 June 2018: Welcome Nadiya and Josh
We welcome summer students Nadiya Ikonnikova and Joshua Weston who will undertake 8-week summer projects in the group. Nadiya will focus on futher developing Triana's time-resolved radiative transfer code and applying it to optical and near-infrared light curves of NGC3783. Josh will modify and test the machine learning tool we developed for varaibility and transient detection within VEILS and VOILETTE.
21 June 2018: Congratulations Dr Jens Juel Jensen
Jens Juel Jensen successfully defended his PhD at the University of Copenhagen. Jens was co-supervised by Seb and spent some time in Southampton working on PAH emission around AGN using observations and CLOUDY models . He recently co-founded a start-up company and is now working full-time to continue its success story.
11 June 2018: The group at the Cosmic Dust conference in Copenhagen and LSST@Europe
Bella, David, Marta, and Seb presented their recent work at the Cosmic Dust conference in Copehagen, while Daniel served on the SOC. While Marta and David gave an update on our radiative hydrodynamics simulations, Bella showcased her work on dust reverberation mapping and Seb reviewed the latest on observations and modeling of dust destruction and formation around AGN. At the same time, Triana represented the group at the LSST@Europe meeting where she presented our planning for time-domain observations of AGN in the 2020s.
29 January 2018: Congratulations Daniel!
Daniel Asmus was awarded a prestigious and highly competitive Marie Sklodowsak Curie Fellowship. The fellowship will allow Daniel to continue his successful independent research on the dusty environment of AGN with his project DUSTDEVILS hosted in our group in Southampton. Only 15% of all applications to the scheme were successful.
22 December 2017: Et voila - VOILETTE!
Today we received a major allocation of observing time (453 hours) on ESO's VLT Survey Telescope to perform an optical support survey of the infrared public survey VEILS
. The survey will observe the same fields as VEILS in the optical griz bands with a cadence of 8(r)-14(giz) days during the 2018 and 2019 VEILS observing seasons. The VOILETTE survey (=VEILS OptIcal Lightcurves of Extragalactic TransienT Events; French for "veil") will essentially replace the optical monitoring of the VEILS fields that has been carried out with DES over the last years.
1 September 2017: Welcome Triana!
Triana R. Almeyda joins the group as a new research fellow. She recently completed her PhD at the Rochester Institute for Technology (Rochester, NY, USA) with Prof. Andy Robinson on modelling the optical and infrared variability of AGN. Triana will become responsible for data reduction and analysis of the VEILS survey. In particular, she will extract AGN light curves and determine dust time lags as required to use AGN as standard candles.
31 March 2017: CAT3D-WIND: Reconciling radiative transfer models with the latest developments in infrared observations of AGN
A new model has been published for the infrared emission of AGN. The model is an extension to CAT3D and takes into account the latest developments in infrared observations. Instead of a classical torus, CAT3D-WIND invokes a disk and a wind to reproduce the observed polar emission features in the mid-IR emission of AGN. This way, it is also possible account for the near-IR bumps between 3-5um seen in many type 1 AGN. The paper is available here:
Hoenig & Kishimoto 2017, ApJL 838, L20: Dusty Winds in Active Galactic Nuclei: Reconciling Observations with Models
Model SEDs can be downloaded from this site:
10 January 2017: VEILS -- the VISTA Extragalactic Infrared Legacy Survey
A new ESO Public Survey is currently undergoing its first observations -- and we are part of it! The survey is a 3-year project to monitor 9 sqrdeg of extragalactic fields in the infrared J and K band. This will facilitate research in galaxy evolution, supernova cosmology, and AGN variability. Manda Banerji (Cambridge) and Seb Hoenig are Co-PIs of the survey and we just published our first paper on the AGN science case
Hoenig et al. 2017, MNRAS 464, 1693: Cosmology with AGN dust time lags -- simulating the new VEILS survey
You can read more on the VEILS survey homepage:
08 September 2016: New 2017 job opening
We have an opening for a postdoc position in observational astrophysics. Please check out the jobs page if you are interested. Applications should be submitted by 15 November 2016. The ad will also be posted to the AAS job register in October.
30 August 2016: Welcome David, Marta and James!
David J. Williamson will join our group as a postdoc in September. He is an expert in hydrodynamic simulations and will work on developing a new radiative-hydrodynamical model of the dusty environment around AGN (see DUST-IN-THE-WIND project description). David received his PhD from St. Mary's University (Halifax, CA) in 2013 and spent the last 3 years as a postdoc in Dr Hugo Martel's group at the University of Laval (Quebec, CA).
Marta Venanzi will start as a PhD student at the end of September. She graduated from University of Rome La Sapienza with a Masters in Physics this summer. In the course of her final research project, she spent some time at QMUL. Marta's thesis project will focus on developing and exploiting effective and efficient methods to solve the radiative transfer problem in hydrodynamical simulations of dusty gas around AGN.
James H. Leftley will start a joint PhD project with ESO this October. His first two years will be spent at ESO's Chilean headquarters in Santiago before he returns to Southampton to finish his thesis. James graduates with a Master of Physics degree from the University of Southampton. He will use infrared interferometry to understand more about the mass distribution ad accretion processes around supermassive black holes.