STScI Research | STScI Discovery Seminar Series - Darshan Kakkad (STScI) and Petia Yanchulova (STScI) @stsciresearch6722 | Uploaded 2 years ago | Updated 1 hour ago
This Discovery Seminar features talks by Darshan Kakkad (STScI) on the Outflow-AGN Scaling Relations Across Cosmic Time and Petia Yanchulova (STScI) on S mall Magellanic Cloud Catalog of Stellar and Dust Properties.
Tuesday May 17, 2022.
Speaker: Darshan Kakkad
Title: AGN-driven Outflows and Their Impact on Star Formation Across Cosmic Time
Abstract: Outflows in AGN host galaxies are believed to be a medium to shut off star formation by removing the gas supply. Both from observational and theoretical perspective, the existence of a direct evidence of negative or positive AGN feedback is highly disputed. I will present an overview of our ongoing efforts to characterise the spatially-resolved properties of multi-phase outflows, namely velocity, mass outflow rates and kinetic power, in low and high redshift galaxies using integral field spectroscopy in the optical and near-infrared regime ([OIII]5007 and Halpha lines with VLT/MUSE and VLT/SINFONI) and ALMA sub-mm spectroscopy (Multiple CO transitions). I will show how these multi-phase outflow properties relate with the AGN bolometric luminosity and the black hole mass and whether these relations change if fibre or slit spectra were to be used. Lastly, I will show whether these outflows affect the host galaxies themselves by comparing spatial locations of outflows and star formation.
Speaker: Petia Yanchulova
Title: SMC Stellar, Dust and 3D Geometry Properties From Resolved Stars
Abstract: We present interstellar dust extinction and stellar properties for about 500,000 individual sightlines observed with the Hubble Space Telescope (HST). These sources are a part of the Small Magellanic Cloud Investigation of Dust and Gas Evolution survey (SMIDGE) which we model with the open-source Bayesian Extinction and Stellar Tool (BEAST). SMIDGE covers a ~ 200 x 100 pc region in the Southwest Bar of the Small Magellanic Cloud (SMC) and comprises multiband near-UV to near-IR deep HST photometric observations. The BEAST - a probabilistic tool which models the dust-extinguished SEDs of stars using an observational uncertainty model - is particularly suitable for large photometric surveys and allows us to derive the dust extinction (A(V), R(V), and fA) and stellar (temperature, mass, surface gravity, luminosity) properties and to generate high-resolution maps in a key region in the SMC. Understanding these properties is fundamental for answering questions ranging from how dust grains form to what drives galaxy evolution. We compare our parsec-scale maps to tracers of the SMC interstellar medium (ISM) environment such as HI column density, CO, and dust mass maps from Herschel IR data to analyze the drivers of dust and stellar properties in a low-metallicity environment. The BEAST is a under active development to allow the study of stellar ensemble properties, such as distance, and enable an understanding of how the 3D structure may be related to the ISM environment and to galactic characteristics.
This Discovery Seminar features talks by Darshan Kakkad (STScI) on the Outflow-AGN Scaling Relations Across Cosmic Time and Petia Yanchulova (STScI) on S mall Magellanic Cloud Catalog of Stellar and Dust Properties.
Tuesday May 17, 2022.
Speaker: Darshan Kakkad
Title: AGN-driven Outflows and Their Impact on Star Formation Across Cosmic Time
Abstract: Outflows in AGN host galaxies are believed to be a medium to shut off star formation by removing the gas supply. Both from observational and theoretical perspective, the existence of a direct evidence of negative or positive AGN feedback is highly disputed. I will present an overview of our ongoing efforts to characterise the spatially-resolved properties of multi-phase outflows, namely velocity, mass outflow rates and kinetic power, in low and high redshift galaxies using integral field spectroscopy in the optical and near-infrared regime ([OIII]5007 and Halpha lines with VLT/MUSE and VLT/SINFONI) and ALMA sub-mm spectroscopy (Multiple CO transitions). I will show how these multi-phase outflow properties relate with the AGN bolometric luminosity and the black hole mass and whether these relations change if fibre or slit spectra were to be used. Lastly, I will show whether these outflows affect the host galaxies themselves by comparing spatial locations of outflows and star formation.
Speaker: Petia Yanchulova
Title: SMC Stellar, Dust and 3D Geometry Properties From Resolved Stars
Abstract: We present interstellar dust extinction and stellar properties for about 500,000 individual sightlines observed with the Hubble Space Telescope (HST). These sources are a part of the Small Magellanic Cloud Investigation of Dust and Gas Evolution survey (SMIDGE) which we model with the open-source Bayesian Extinction and Stellar Tool (BEAST). SMIDGE covers a ~ 200 x 100 pc region in the Southwest Bar of the Small Magellanic Cloud (SMC) and comprises multiband near-UV to near-IR deep HST photometric observations. The BEAST - a probabilistic tool which models the dust-extinguished SEDs of stars using an observational uncertainty model - is particularly suitable for large photometric surveys and allows us to derive the dust extinction (A(V), R(V), and fA) and stellar (temperature, mass, surface gravity, luminosity) properties and to generate high-resolution maps in a key region in the SMC. Understanding these properties is fundamental for answering questions ranging from how dust grains form to what drives galaxy evolution. We compare our parsec-scale maps to tracers of the SMC interstellar medium (ISM) environment such as HI column density, CO, and dust mass maps from Herschel IR data to analyze the drivers of dust and stellar properties in a low-metallicity environment. The BEAST is a under active development to allow the study of stellar ensemble properties, such as distance, and enable an understanding of how the 3D structure may be related to the ISM environment and to galactic characteristics.
