סמינר באסטרונומיה ובאסטרופיזיקה

Yi Mao: Machine Learning Application to 21cm Data Analysis
 
Abstract: The 21-cm signal from the epoch of reionization (EOR) contains a wealth of information with regard to how astrophysical sources ionized the intergalactic medium at high redshifts. Upcoming radio interferometric experiments such as the Square Kilometre Array (SKA) will have enough sensitivity to uncover details of cosmic reionization. However, endeavors must be taken to ensure that we understand the signal in depth and prepare for analysis of big data. In this talk, we will report our recent efforts in applying machine learning techniques to 21cm data analysis. We demonstrate that the artificial neutral networks can be used to recover the ionized bubble size distribution from the 21-cm power spectrum of the EOR, with high accuracy. Furthermore, we apply the technique of 3D convolutional neural networks to recover the parameters of reionization model directly from the 21-cm lightcone 3D images.

Xuelei Chen: Discovering the Sky at the Longest wavelength: a lunar orbit array
 
Abstract: Due to ionosphere absorption and the radio interference from Earth, ground or near-space observation of the sky at the decameter or longer wavelength is very difficult. This unexplored part of electromagnetic spectrum has the potential of great discoveries.

I describe the prospect of opening up this window for astronomical observations by using a constellation of small or micro-satellites on lunar orbit, which can make synthesized map of the whole sky, as well as measure the global spectrum.

מארגן הסמינר: ד"ר עומר ברומברג