Recording: https://www.oact.inaf.it/seminars/
DATE: Wednesday, March 19, 11:30 a.m.
ORGANIZER: INAF-OACT
LOCATION: AULA OVEST (INAF-OACT) + remote
Link for the remote audience:
https://meet.google.com/wvf-uwxo-oyj
SPEAKER: Prof. Andrei Mesinger (Scuola Normale Superiore, Pisa)
ABSTRACT:
The 21-cm hyperfine line of neutral hydrogen is set to revolutionize studies of the first billion years, spanning the cosmic dawn of the first stars and eventual reionization of our Universe. I will discuss the potential of this probe in learning about the unknown astrophysics of the first galaxies as well as physical cosmology. Current upper limits on the cosmic 21-cm power spectrum already provide new insights into the heating of the intergalactic medium, and the X-ray sources in the first galaxies. I will discuss the upcoming steps, including the main challenges, that will eventually lead to the Nobel prize-worthy 3D map of half of our observable Universe with the Square Kilometer Array (SKA) telescope.
Our results show that a large scales we observe a continuous interplay between turbulence and gravity, where the former creates structures at all scales and the latter takes the lead above a critical value of the surface density is reached, ~ 0.1 g cm^-2. At the same time, the fragmentation properties show several indications that the fragment are “clump-fed”, i.e. the process is dynamical and the gravity dominates the collapse inside our massive clumps.
A few rules:
— in case of large in-person attendance, attendees may be asked to wear a face mask
— before joining, make sure you are using your institutional inaf.it account if you have one (otherwise we will grant you permission to join)
— please do not forget to mute your microphone and switch off your webcam when access the virtual room
— for questions leave a message in the chat, the answers at the end of the webinar
— the seminar will be recorded, so if you are interested in it, please contact us to get the link to the registration.