Johannes Puschnig at IAU conference: galaxies in 3D across the Universe

Johannes Puschnig


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Works at Department of Astronomy
Telephone 08-553 785 42
Visiting address Roslagstullsbacken 21, C 6 & D 6
Room C6:3015
Postal address Institutionen för astronomi 10691 Stockholm

About me

I am an observational astronomer currently doing PhD studies at the Department of Astronomy of the University of Stockholm under supervision of Matthew Hayes.


Lyman Alpha and UV Continuum-Emission

My thesis is based on the still poorly understood role of Lyman Alpha Emitters (LAE) within the cosmological epoch of reionization, about only 0.4 to 1 billion (109) years after the Big Bang corresponding to a redshift of z=11 to z=6, respectively. In order to get a better understanding of observations at these high redshifts, I am using local counterparts of those high-z LAEs. Thereby, I rely on the so called “Lyman Alpha Reference Sample” (LARS), which was defined by Hayes et al. (2013) and consists of 14 galaxies up to a redshift of z=0.2. The advantage is that LARS galaxies can be studied in much more detail compared to LAEs at high-z. I aim to learn about the underlying physical conditions responsible for effective UV emission on a galactic scale. Morphological and kinematical aspects certainly play an important role as well as the overall atomic hydrogen content. However, since UV radiation is intimately linked to an ongoing process of star-formation, the molecular gas must play a major role too, because molecular hydrogen is the main ingredient – the fuel – for star formation.
Beside LARS, I am working on HST/COS data of Tololo 1247-232, which is the second known Lyman Continuum Emitter in the local universe to date. From its leakage, I am trying to learn about underlying physical properties leading to an effective UV emission shortward to the Lyman limit.

Last updated: April 17, 2018

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