Tag Archives: high-redshift

Interview with Lucia Guaita

Lucia Guaita is one of the Oskar Klein Centre postdocs, working at the astronomy department here in Stockholm. She started as postdoc at OKC about one year ago, on November 2010, and is working on high-redshift star forming galaxies. Let’s get to know her better.

Why did you choose the okc for doing your postdoc?

This is my first post doc. I chose to apply to this position because the topic would have been very close to what I was doing during my PhD. It seemed quite a nice continuation of my PhD thesis work and it is.

What is your field of research?

I am working on star forming galaxies at high redshift. We are interested in observing these galaxies where the Universe was less than 3 billion years old (redshift more than 2). In a star forming galaxy there are regions where stars, of different mass, are continuously produced.
The high-energy radiation produced by the just-formed high-mass stars interacts with neutral Hydrogen in the interstellar medium. One of the consequences of this interaction is the production of Lyman alpha photons. It was proposed since the 60’s that star forming galaxies at high-redshift should show a strong Lyman alpha emission line, even if they are faint in the continuum. In these last 10 years a lot of surveys were designed to detect Lyman alpha emission from star forming galaxies at high redshift, the so called Lyman Alpha Emitters (LAE). The technique, we used, involves a narrow band filter, about 50 Angstrom wide, centered at the redshifted Lyman alpha emission line. The idea is to detect an excess in narrow-band flux density with respect to the continuum.
As Lyman alpha photons are absorbed by dust, LAEs are thought to be dust-free galaxies in their first phases of star formation. Continue reading Interview with Lucia Guaita