Joy Oluchi Anih
Gather.town id
BOD01
Poster Title
Infrared Variability of Active Galactic Nuclei
Institution
Keele University
Abstract (short summary)
We are using the high sensitivity and angular resolution of the VISTA Magellanic Clouds (VMC) multi-epoch survey at 1-2.5 micron as a basis for characterising the variability of Active Galactic Nuclei (AGN) out to redshift >1. Two AGN, at redshifts 0.14 and 1 that are dominated in the infrared (IR) by the emission from nuclear dust are studied in-depth, and the prevalence of IR variability is studied in a larger sample. We are using the hot dust (variability) as a tracer of the accretion instabilities, but the dust grains are subject to extreme conditions. The findings are placed in context of optical (OGLE) and mid-IR (Spitzer, WISE) variability studies and new radio data from the Australian SKA Pathfinder to identify the causes for the near-IR variations.
Please note: I will be using hot dust variability as a tracer.
Please note: I will be using hot dust variability as a tracer.
Plain text (extended) Summary
One of the reasons why we are looking at SAGE0534AGN which is dominated in the near-infrared by nuclear dust, is due to the lack of far-infrared emission, and therefore star formation, as well as the Silicate emission (which for SAGE0546AGN at z = 0.14 is one of the strongest Silicate emitters known), is what led us to believe that we are looking at the central AGN without (or with very little obscuration by the host galaxy). This agrees with the results as shown in the figure of the near-infrared light curve of SAGE0534AGN from the VMC. Another reason why we are interested in SAGE0536AGN and SAGE0534AGN is that both were mistaken as evolved stars before being identified as AGN, which could indicate a sample of AGN that are not widely studied as they were assumed to be stars at first look.
References:
Hony, S., Kemper, F., Woods, P. M., et al. 2011, AAP, 531, A137 (The original discovery of SAGE0536AGN, z~0.14)
van Loon, J. T., & Sansom, A. E. 2015, MNRAS, 453, 2341 (Second observation of SAGE0536AGN)
Cioni, M.-R. L., Clementini, G., Girardi, L., et al. 2011, AAP, 527, A116 (VMC data)
References:
Hony, S., Kemper, F., Woods, P. M., et al. 2011, AAP, 531, A137 (The original discovery of SAGE0536AGN, z~0.14)
van Loon, J. T., & Sansom, A. E. 2015, MNRAS, 453, 2341 (Second observation of SAGE0536AGN)
Cioni, M.-R. L., Clementini, G., Girardi, L., et al. 2011, AAP, 527, A116 (VMC data)
URL
j.o.anih@keele.ac.uk
Poster file