UKZN astronomers discover mysterious magnetised radio burst with the Green Bank Telescope

A group of astronomers, including ACRU members Jonathan Sievers, Tabhitha Voytek, and PhD student Apratim Ganguly, have discovered a fast radio burst (FRB) using the Green Bank Telescope in West Virginia. Only 16 of these events, which last for only milliseconds, have been found to date. This is the first polarised FRB to be discovered, which indicates that the burst came from a dense, magnetised region: possibly a supernova or star forming nebula. The results are published in Nature.

For more on this story, see the press releases by NRAO and SKA South Africa.

Artist impression of a Fast Radio Burst (FRB) reaching Earth. The colors represent the burst arriving at different radio wavelengths, with long wavelengths (red) arriving several seconds after short wavelengths (blue). This delay is called dispersion and occurs when radio waves travel through cosmic plasma. Credit: Jingchuan Yu, Beijing Planetarium
Artist impression of a Fast Radio Burst (FRB) reaching Earth. The colors represent the burst arriving at different radio wavelengths, with long wavelengths (red) arriving several seconds after short wavelengths (blue). This delay is called dispersion and occurs when radio waves travel through cosmic plasma. Credit: Jingchuan Yu, Beijing Planetarium

New ACRU member finds missing matter

A group of astrophysicists, including new ACRU member Dr. Yin-Zhe Ma, has perhaps solved a long standing problem in cosmology.

A number of observations tell us that only 5% of the Universe is made up of the ordinary matter that we encounter in everyday life (baryons), with the remaining 95% being made from a combination of the mysterious ‘dark matter’ and ‘dark energy’. However, locating even the 5% of ordinary matter that is expected to exist has been a challenge – this is referred to as the “missing baryons” problem.

Using observations of the cosmic microwave background, taken with the Planck satellite, in the directions of galaxies identified in the Sloan Digital Sky Survey, the missing baryons may have been found. The motion of gas inside and around the galaxies indicates that these regions contain roughly half of the total amount of baryons in the Universe. If the spatial distribution of the ordinary matter follows that of the dark matter, then it seems likely that all of the baryons will be found in and around the galaxies.

The paper describing the study is published in Physical Review Letters and is highlighted as an Editor’s suggestion.

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UKZN to host 5th NRF Astronomy Advisory Council meeting-26th June 2015

UKZN will host the 5th National Research Foundation (NRF) Astronomy Advisory Council meeting on the 26th of June 2015 at the Westville campus. The Council is responsible for providing scientific advice to the NRF Astronomy sub-Agency, which is headed by the Deputy CEO for Astronomy, Prof Nithaya Chetty.

Ground breaking research, international academic collaborations and facilities such as the Karoo Array Telescope (MeerKAT) and the Southern African Large Telescope (SALT) have driven the growth of astronomy in South Africa. The Council, which is composed of leading researchers will guide the implementation of South Africa’s Astronomy strategy which aims to further grow this field of science and thereby benefit both the local and international community. In addition, it will also encourage the production of important new research in various areas of astronomy and strive to increase the number of local astronomers.

ACRU member helps launch Antarctic balloon-borne telescope

ACRU member Dr. Cynthia Chiang, returned in January from a two month visit to Antarctica where she participated in an experiment called SPIDER that studied the earliest moments of our universe’s creation.

SPIDER consisted of six telescopes that were launched into the stratosphere with a giant helium-filled balloon, which swelled to roughly the size of Durban’s Kings Park stadium at its 35-km cruising altitude.  From this lofty height, SPIDER observed the faint, leftover heat from the Big Bang: this afterglow, known as the cosmic microwave background (CMB), contains valuable clues that will help unravel the mysteries of our universe’s explosive beginnings.  The experiment was built by an international collaboration that includes Princeton University, the University of Toronto, Case Western Reserve University, the California Institute of Technology and the Jet Propulsion Laboratory, and the University of British Columbia.

Dr. Cynthia Chiang and SPIDER in Antarctica
Dr. Cynthia Chiang and SPIDER in Antarctica
The SPIDER cryostat in 2010 and some of the early team members (L to R): Miss Sasha Rahlin, Dr. Cynthia Chiang, Dr. Jon Gudmundsson and Professor William Jones
The SPIDER cryostat in 2010 and some of the early team members (L to R): Miss Sasha Rahlin, Dr. Cynthia Chiang, Dr. Jon Gudmundsson and Professor William Jones

 Dr. Chiang joined the SPIDER collaboration in 2009 as a postdoctoral research fellow at Princeton University. She was responsible for testing and operating SPIDER’s cryostat, a large vessel that houses the six telescopes and cools them to -270 degrees Celsius using 1000 litres of liquid helium. SPIDER was launched on January 1, 2015 and spent 17 days in flight.

 “I was absolutely thrilled to finally see SPIDER in the air.  It’s taken many long years of hard work and dedication from people across the globe, and collaborating with such a talented and cohesive team has truly been a blessing for me.  We’re all eager to see the data in full when the telescopes have been retrieved, and we look forward to facing the new challenges of sifting through our observations.  We at ACRU will be actively involved in the analysis, and we plan to continue collaborating on SPIDER for its second flight” said Dr. Chiang.

Registration open for Cosmology on Safari (26-30 January 2015)

Registration is now open for ‘Cosmology on Safari’ (26-30 January 2015), a small conference which aims to bring together theorists and observers to discuss the challenges that remain in cosmology. The topics to be covered by the conference are:

  • The early universe: constraints on primordial perturbations, dark radiation, gravitational waves and inflationary models from the cosmic microwave background.
  • The late-time universe: constraints on dark energy, dark matter, theories of gravity and the nature of the primordial perturbations from galaxy redshift surveys, cosmic shear, galaxy clusters, baryon acoustic oscillations, type Ia supernovae and laboratory alternatives.

See the conference website for full details, and to submit an abstract.

Public Talks in October and November

Public Talks in October and November

In the next two months, we will be holding two fascinating Public Talks:

Deep Cinematography of the Whole Sky with the Large Synoptic Survey Telescope (LSST)

On the 8th of October 2014, Dr Abhijit Saha from the National Optical Astronomy Observatory in Arizona will deliver a Public Talk on the Large Synoptic Survey Telescope (LSST). The Large Synoptic Survey Telescope is projected to come online in 2019 and begin a survey of the whole sky visible from Cerro Pachon in Chile. Read More

SKA, MeerKAT and more – radio astronomy in Africa

On the 5th of November 2014, Justin Jonas will speak on radio astronomy in Africa. Justin Jonas is the Associate Director: Science & Engineering, South African SKA Project Office, National Research Foundation (a joint appointment with Rhodes University). This talk will provide an overview of the strategies and initiatives that have led to Africa becoming a major “destination” for radio astronomy, and an update on the progress towards the completion of the MeerKAT and the design of the SKA Telescope. Read More

Registration open for SKA Introductory Radio Astronomy School 2014

ACRU will be hosting an introductory radio astronomy school, on behalf of Square Kilometre Array South Africa, from 9-14 December 2014. The school is primarily aimed at final year undergraduates, Hons, and MSc students.

Several leading radio astronomers, both from abroad and within SA, will be teaching at the school, covering topics such as the radio sky, interferometry, and synthesis imaging. There will be several hands-on sessions where students will have the opportunity to develop their skills in the analysis of radio data and apply what they have learned in the lectures.

Registration is now open.