Vernesa Smolcic (University of Zagreb, Croatia)
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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| « Black Hole Mass Growth across Cosmic Time: Insights from the VLA-COSMOS Survey » |
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Vernesa Smolcic (University of Zagreb, Croatia) |
| Understanding how galaxies form and evolve through cosmic time, and how these processes are influenced by active galactic nuclei (AGN) are important goals of modern astrophysics. In this context, “radio-mode AGN feedback” is a regular ingredient in cosmological models, yet from an observational perspective still rather poorly understood. It is considered to be a key feedback mechanism, related to central supermassive black hole mass growth, at work in the latest phases of massive galaxy formation, and controlling the galaxy’s stellar mass build-up. Over the past decades our understanding of radio AGN was significantly advanced by panchromatic look-back sky surveys, and we have recently entered a “golden age” of radio astronomy thanks to upgraded and new facilities delivering now an order of magnitude increase in sensitivity. The VLA-COSMOS 3 GHz Large Project is based on 384 hours of observations with the upgraded, Karl G. Jansky Very Large Array (VLA) at 3 GHz (10 cm) toward the two square degree COSMOS field. The survey, reaching a median rms of 2.3 uJy/beam over the two square degrees at an angular resolution of 0.75", contains 10,830 radio sources down to 5 times the rms. It simultaneously provides the largest and deepest radio continuum survey at such angular resolution to date, bridging the gap between last-generation and next-generation radio surveys. These radio data, in conjunction with the panchromatic COSMOS data sets, allowed us to study the physical properties, composite nature (i.e., star-formation vs. AGN related contributions to the total radio emission of the sources), and cosmic evolution of radio AGN out to a redshift of about 6, which can directly be linked to the radio-mode feedback, as postulated in cosmological models. |
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vendredi 25 novembre 2022 - 11:00 Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |