Rendkívüli Intézeti Dupla Szeminárium: Ilaria Pascucci, Apai Dániel


1. előadás
Előadó: Ilaria Pascucci (University of Arizona)

Előadás címe: An enhanced carbon chemistry in disks around very low-mass stars and brown dwarfs?
There is growing observational evidence that disk evolution is stellar-mass dependent. In this talk, I will show that these dependencies extend to the atomic and molecular content of disk atmospheres. I will summarize the main results from a unique dataset of high-resolution Spitzer/IRS spectra from 8 very low-mass star and brown dwarf disks. I will present the first detections of ionized neon, molecular hydrogen, carbon dioxide, and water in these disks and discuss implications for the heating and ionization of disk atmospheres. Finally, I will show that BD disks have on average higher C2H2/HCN and HCN/H2O line flux and column density ratios than T Tauri disks. I will speculate on the implications of these trends for the O/C ratio in inner disks and the bulk composition of rocky planets.

Előadás időpontja: 2013. június 25. (kedd), 14:00

2. előadás

Előadó: Apai Dániel (University of Arizona)

Előadás címe: Extrasolar Storms: Exploring Clouds and Atmospheric Dynamics in Brown Dwarfs and Exoplanets
Astronomy has entered an exciting new era when the atmospheres of exoplanets can be studied in detail. Observations of directly imaged exoplanets and brown dwarfs revealed the presence of condensate clouds that strongly influence the energy transport through the planetary atmospheres and, therefore, influence the evolution of the atmospheres and the emerging spectra.The physical nature and properties of these cloud layers remain mostly unknown, but pose one of the outstanding challenges in understanding ultracool atmospheres. I will introduce a new observing technique in this field, rotational phase mapping, that provides an exciting look into the atmospheres and clouds of exoplanets and ultracool brown dwarfs. I will discuss multiple Hubble and Spitzer programs, including a 1,144-hour Exploration Science program, that applies this new technique to a large number of targets. The data paints an exciting and often surprising picture on ultracool photospheres. I will show that the success of this observational technique also motivates future applications to directly imaged giant exoplanets and super-earths, whose photospheres and surface can be mapped in the near future.

Előadás időpontja: 2013. június 25. (kedd), 14:45

Előadások helyszíne: MTA CSFK CSI Előadóterme
1121 Budapest, Konkoly T. M. út 15-17.

2013.06.25. 14:00