Great Ideas Speaker Nights: Searching for the First Stars at Cosmic Dawn

Great Ideas Speaker Nights with Dr. Omar López-Cruz on Saturday April 24th 2021 at 7:00pmEDT

Zoom link (Meeting ID: 850 1103 3763 Passcode: 653518)

We believe that the first stars in the universe formed about 200 million years after the Big Bang. Yet, we lack solid observational evidence about the timing of this epoch, called Cosmic Dawn.

The experiment SCI-HI is searching for the first stars at Cosmic Dawn by the detection of variations in the 21 cm Hydrogen line background as a function of cosmic time. Towards achieving our goal, we have sought radio quiet zones within Mexican Territory and have identified Isla Guadalupe in the Mexican Pacific Ocean 300 km off the Baja California Peninsula, as one of the best radio quiet zones in North America.

In this talk, Dr. López-Cruz will present the first SCI-HI results, some current improvements, and perspectives.


Dr. Omar López-Cruz is a Mexican Astronomer (M.Sc. & Ph.D.; Department of Astronomy, University of Toronto) who has worked on stellar classification and the evolution of galaxies in large density environments.

In 2014, he led an international team that proposed the cD galaxy Holm 15A as the host of the largest supermassive black hole (SMBH) in the local universe. In 2019, a German team led by Kianusch Mehrgan measured a mass of 40 billion times the mass of the Sun in Holm 15A, confirming the López-Cruz et al. conjecture. He also likes the popularization of Science. Recently he became the co-director of a book collection called La Biblioteca Científica del Ciudadano (The Citizen’s Scientific Library) aimed at encouraging the debate of scientific ideas in democratic societies. He appears on radio programs regularly and lectures widely on Astronomy and Scientific Affairs. He writes for magazines and newspapers in Mexico.

Zoom link (Meeting ID: 850 1103 3763 Passcode: 653518)

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