We got Radio Observing Time

Observing Time Update from Ivy Wong:

The majority of the galaxies that we observe can be divided distinctly into 2 categories: star-forming spirals (late-types) and non-star-forming spheroidals (early-types). The purpose of my research is to study how one type of galaxies transform into the other. In a previous Zoo project, we studied a sample of local post-starburst galaxies— galaxies which have only recently stopped forming stars. Even though star formation has only recently ceased for these transition-type galaxies, they already have the same shape as that of non-star-forming galaxies.

To further investigate how the shape of a galaxy correlates with its colour (or star formation history), we now focus our efforts onto a sample of blue early-type galaxies (found by Zookeeper Kevin) which are thought to be the progenitors of the post-starburst galaxies. Blue early-types are unusual relative to regular early-types because they appear to still be forming stars. Why are they still forming stars? Did a recent interaction trigger this new wave of star formation ?

In other studies that I have made of nearby galaxies, I have found that studying the gas content (atomic hydrogen; HI) of galaxies is a good way of finding evidence for past interactions as well as a good way of finding galaxies which are still forming stars. This is because stars are formed from an initial reservoir of gas. The gas reservoir of a galaxy is highly sensitive to environmental effects and will show tell-tale features such as tidal tails and bridges which can point to external factors affecting the galaxy’s evolution.

We recently proposed for observing time to use the Westerbork Synthesis Radio Telescope (Netherlands) to map the HI content of a sample of 6 Northern blue early-types. It is extremely difficult to map HI because the emission comes from the spin-flip of the electron in the Hydrogen atom. We recently found out that we have gotten some non-guaranteed time to use the WSRT so in the event that all goes well, I hope to post some HI maps of these blue early-types.

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