Receiving Signals from the Stars

To commemorate National Science Week and National Women’s Month, the College of Agriculture, Engineering and Science is honouring its female scientists through its Wonder Women in Science campaign. These are passionate, pioneering and persistent heroines who are making waves in the field of science.

Ms Zahra Kader is a Master’s candidate in the Astrophysics and Cosmology Research Unit (ACRU) within the School of Mathematics, Statistics and Computer Science (SMSCS).

She has always found Science fascinating, loved Mathematics and Physics in school, and aimed for a career in the sciences to pursue knowledge of things humankind does not yet have answers to.

‘As a scientist, it is exciting to know that the small contributions I make today could lead to a big scientific breakthrough in the future,’ she said.

Kader’s interest in Astrophysics began over a decade ago when her mother presented her with a science magazine that included material about the planets, asteroids and comets in our solar system, and featured the Southern African Large Telescope (SALT) and the Square Kilometre Array (SKA) radio telescope.

Fast forward a few years later and Kader is the recipient of bursaries from SKA, and during her Honours year, visited the SALT telescope. She graduated with her undergraduate and Honours degrees from UKZN summa cum laude and was the top student in Physics in her first and third years. She also recently visited the Telescope Compact Array (ATCA) in Australia.

Kader’s research now focuses on data gleaned from the recently launched Hydrogen Intensity Real-Time Analysis eXperiment (HIRAX) radio telescope designed and built by UKZN. She is investigating HIRAX-Data analysis and cosmological cross correlations. This involves examining fringe patterns from the dishes to determine the system temperature, a very important parameter to know in order to make signal-to-noise estimates. She is also correlating the signal from the Kinetic Sunyaev-Z’eldovich effect (KSZ) and the 21cm signal.

Kader explained that clusters (large groups of gravitationally bound galaxies) reach very high temperatures, and free electrons in the cluster interact with photons from the cosmic microwave background (CMB) and distort the CMB signal (the signal from light that has been travelling since 380 000 years after the big bang).

‘The movement of the cluster relative to us results in Doppler shifting of the 21cm signal emitted by neutral hydrogen or star forming gas,’ said Kader. ‘These two signals provide insight into the Epoch of Reionization (EoR), so both signals give indications of large-scale structures and the EoR and combining signals can give us insight into these topics,’ she said.

As one of the few women working in Astrophysics, Kader has been encouraged by the equal treatment of women in ACRU.

Her heroes in the field include the greats; namely, Carl Sagan, Stephen Hawking and Neil deGrasse Tyson, and Nobel Prize winners such as Kip Thorne and twice-awarded Marie Curie. Another hero is Jocelyn Bell, the discoverer of dense, fast-spinning stars known as pulsars. She also admires little-known Henrietta Swan Leavitt, a deaf astronomer whose work with Cepheids enabled Edwin Hubble to determine that the universe was expanding.

Kader is motivated by the prospect of being an inspiration to others, even by simply sparking a growing interest in the sciences that leads young people to enter this field. Her Muslim faith is one of her biggest sources of strength and gratitude. Her advice to her younger self would include prioritising her faith, helping others, caring for the environment and developing a good conceptual understanding of the basic scientific concepts she learned at school.

Kader volunteers at Headway which aids those suffering from head traumas, regularly visits old age homes and supports the work of the Al-Imdaad Foundation.

A challenge facing the development of the sciences is, according to Kader, the stereotypes placed on the roles of men and women, with some careers being seen as inherently “male”. She advocates for diversity and representation in the sciences if these fields hope to grow.

She recommended that Mathematics and Science be emphasised in schools, and that passionate teachers be equipped to teach these subjects in order to produce skilled individuals for Engineering, Mathematics, Physics, Computer Science and similar fields.

She encouraged budding female scientists interested in Mathematics and Physics to ignore stereotypes and focus on what they would like to achieve despite the rarity of female scientists. She encouraged them to look up to the examples of what women like Cecilia Payne-Gaposchkin, Henrietta Swan Leavitt and Annie Jump Cannon had achieved.

Zahra’s plans include progressing to PhD level and then postdoctoral studies in Cosmology.

‘With the new upcoming telescopes, SKA and HIRAX, exciting times await those in the field of astrophysics and cosmology and I am privileged to be a part of it,’ she said.

* In August, the College of Agriculture, Engineering and Science will present an article on each one of the five Wonder Women in Science.

To read all the articles, visit: wwis.ukzn.ac.za

Words: Christine Cuénod

Photograph and graphics: Sashlin Girraj