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.

As we turn the page to a new year

As we close the book on 2015 we can again look back at a year of exciting science and great accomplishments by members of the Oskar Klein Centre for Cosmoparticle Physics. As in previous years, OKCers feature very prominently in the list of the most cited astrophysics and cosmology papers led by Swedish scientists published during the year. The list was compiled by Robert Cumming in populärastronomi and appears in today’s issue. In fact, half of top-10 2015 publications originate in our centre, starting … Continue Reading ››

The XENON1T inauguration

Dark matter is one of the basic ingredients of the Universe, and searches to detect it in laboratory-based experiments are being conducted since decades. However, until today dark matter has been observed via its gravitational interactions that govern the dynamics of the Cosmos at all length-scales. In 2014, with a grant of the Knut and Alice Wallenberg foundation, OKC has joined an international collaboration, called XENON, that builds and operates detectors to find the elusive dark matter particles in the laboratory.

The Nobel Prize in Physics 2015 for Neutrino Oscillations

The announcement of the Nobel Prize in Physics awarded to Takaaki Kajita (Univ. of Tokyo) and Arthur McDonald (Queen’s University, Canada) for the discovery of neutrino oscillations, and thus the revelation that neutrinos have mass, is an exciting occasion for its recognition of fundamental scientific research of the kind done by all of us at the Oskar Klein Centre.

Cosmic transients around the clock!

What do you do when you are studying an exciting transient optical phenomenon and the Sun rises, rendering further observations impossible from your observatory? Well, there is always dark sky somewhere else!

A project dubbed Global Relay of Observatories Watching Transients Happen (GROWTH), a collaboration among twelve institutions spread around the globe including OKC, has been awarded a $4.5 million over five years from NSF to perform coordinated follow-up studies of optical transients

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.