Seminar: Observing the Cosmic Dawn using multi-wavelength line intensity mapping

  • Date: –11:00
  • Location: Ångströmlaboratoriet, Lägerhyddsvägen 1 95110Å and Zoom:
  • Lecturer: Suman Majumdar, IIT Indore
  • Contact person: Anish Amarsi
  • Seminarium

The strive to understand the history of our Universe represents a major goal of modern cosmology. The Cosmic Dawn (CD) era is one of the most poorly understood chapters of this story. It refers to the period during which the very first sources of light – primordial stars, galaxies, and accreting black holes – formed, and the ultraviolet and X-ray radiation emitted by these objects gradually heated and reionized the cold hydrogen gas between the galaxies, the so-called intergalactic medium (IGM). However, many pressing questions regarding the CD are still unresolved: When did it start? How did it develop over time? What were the major sources of ionizing photons during this period?

A radically different way of observing the CD has recently been proposed: the so-called Line Intensity Mapping (LIM) technique. LIM comes in two flavours. One observes the very first sources of light. The other observes the neutral hydrogen gas spread between the galaxies. Both of these methods rely on observations of specific spectral lines. This will be the approach that will be employed in radio by the upcoming Square Kilometre Array (SKA) and in far-infrared by the CONCERTO, TIME, and FYST.

I will discuss how these two flavours of LIM observations in multiwavelengths can be combined and an optimal amount of information can be extracted from them to answer the fundamental questions regarding this era.