All posts by Serena Nobili

Measuring the supernova rate in the early Universe by using galaxy clusters as gravitational telescopes

Supernovae are very rare phenomena in the Universe and their transient nature made them difficult to find for a long time. So, it is not surprising that the discovery rate was around two supernovae per month 30 years ago. Today, we are able to find supernovae daily. For example, the Intermediate Palomar Transient Factory, in which our group at the Oskar Klein Centre is involved, has discovered almost 3000 supernovae in the last few years. However, these supernovae are all relatively nearby, since the survey is not sensitive … Continue Reading ››

Hunting light dark matter with gamma rays

Physicists around the globe are working relentlessly to pin down the nature of dark matter. This enigmatic entity hides itself from our view as it does neither emit nor absorb any radiation. It only reveals itself through its gravitational interaction. With a new analysis of data from NASA’s gamma-ray large area telescope (LAT) on board the Fermi satellite, we have now come closer to test very light dark matter candidates. Many regard the astrophysical evidence for dark matter as evidence for yet undiscovered fundamental particles. Well-motivated theories suggest that these particles … Continue Reading ››

ATLAS Thesis Award goes to the Dark Side

Ruth Pöttgen is a postdoctoral researcher in the ATLAS group at Stockholm University. In 2015, she obtained her Ph.D. at the Johannes Gutenberg – University in Mainz, Germany, for her thesis on a “Search for Dark Matter in Events with a highly energetic jet and missing transverse momentum at a centre-of-mass energy of 8 TeV with the ATLAS Detector”. At the ATLAS collaboration meeting in February, Ruth was awarded one out of 4 ATLAS Thesis Awards for outstanding contributions to the ATLAS-Experiment in the context of a Ph.D. thesis; more than 100 theses were eligible.

Gravitational waves finally detected

It seems that nearly exactly 100 years after their prediction by Albert Einstein, Gravitational Waves have finally been directly detected for the first time. Speakers of the LIGO experiment announced yesterday that they have witnessed the final stages of the inspiral and merger of a massive black hole binary system. This marks the beginning of a new type of astronomy with gravitational waves that allows to explore a so-far completely unknown side of the Universe.

Passerby become Supernova hunters in Kungsträdgården

Fysik i Kungsträdgården is one of the major outreach events in Stockholm where scientists have the chance to show their research (read more about the whole event in Fysikum blog). This year the supernova group at the OKC invited the public to look for supernovae with us using the intermediate Palomar (Transient) Factory (iPTF) collaboration telescope in Palomar, California, U.S.A (read more about the iPTF). Due to the time difference between Stockholm and California, we were able to look at live images as they were … Continue Reading ››

The young star cluster perspective of star formation

Star formation is one of the fundamental process contributing to galaxy evolution and therefore in shaping the Universe. Yet it is extremely challenging to build a complete view of this process and its interplay with galactic scale properties. The most challenging aspect is to reconcile physical mechanisms, which operate at the smallest spatial scales (i.e. the size of our solar system) all the way up to galactic scale features such as the large star-forming complexes.