Series: Astronomy Colloquium
Date: Wednesday 21-Sep-2022
Time: 16:05-17:00 (4:05-5:00 pm)
Location: Zoom
Speaker: Violeta Gamez Rosas (Leiden)
Title: Resolving the dusty heart of NGC 1068 with MATISSE
In the Unification Theory of AGNs the concept of "the torus" plays a crucial role to discern between Type-1 and Type-2 AGNs. Its emission, coming from hot and warm dust peaks at infrared wavelengths, which makes MATISSE an ideal instrument to observe it. The wide spectral coverage of the L, M and N bands, and the high spatial resolution that MATISSE offers, together with its capability to combine the beams of four telescopes to do interferometry, therefore generating closure phases, make the instrument a versatile tool for the study of AGNs. NGC 1068, being one of the closest AGNs, has been considered a key science case for MATISSE. In this talk I will present the first image reconstructions of the dusty heart of NGC 1068, and the thermal and extinction map derived through Gaussian modelling and aperture photometry. By cross-identifying this map with ALMA and VLBA maps and the water masers, we can determine the position of the super massive black hole. This analysis unveils an optically thick ring that is obscuring the central engine at parsec scales and a less optically thick disk extending to at least 10 pc. We find a striking similarity between the morphologies of the radio free-free emission and the thermal emission of the dust in both, the L and N bands. We also find that the cold obscuring dust is mainly formed by amorphous olivines and carbon grains.
In-person colloquia are usually preceded by espresso and ice cream at 1:45 pm outside room PSC 1150 and are followed by an informal reception at 5:15 pm in that room. Anyone interested in talking with the speaker, or being added to the colloquium announcement email list, should contact the colloquium organizer Dr. Leslie Sage. Lunch will normally be reserved for the speaker to talk to graduate students. Anyone asking a question during a talk is asked to raise their hand and be acknowledged before speaking. Contact Dr. Leslie Sage for details.
Colloquium Organizer:
Dr. Leslie Sage
Special accommodations for individuals with disabilities can be made by calling (301) 405-3001. It would be appreciated if we are notified at least one week in advance.
