On the origin of Lithium

Paolo Molaro (Astronomical Observatory of Trieste)

Abstract: Li is the element with the largest number of astrophysical nucleosynthetic processes. Although a primordial element, it is also produced by spallation processes in the interstellar medium, in a slow process lasting billions of years. The Li abundance in the old halo population of the Galaxy, however, is lower by a factor 3 than predicted by Big Bang models. This well known issue is known as the Cosmological Lithium problem. In this talk, I will present a tentative stellar fix to the problem, dealing with pre-main sequence depletion.
One or more Galactic sources of Li are still to be identified in order to reach the Li abundance observed in the pre-solar nebula. Only recently, after decades of unsuccessful Li search, its parent nuclei Be-7 has been detected in novae outburst. Observations of Be-7 in few recent novae will be presented. The  Li yields obtained from novae overproduce the meteoritic Li abundance by several orders of magnitude, and are therefore candidates for “the” source of Galactic lithium. Within this framework,  the different Li evolution of the disk stars could be explained. The Li abundance in some Gaia – Enceladus candidate stars will be also presented and discussed.   

Tensions in cosmological data: impact of non standard models and systematic effects

Matteo Martinelli (Instituto de Fisica Teorica UAM/CSIC)

Abstract: In recent years, measurements of cosmological parameters coming from different observables have shown tensions between each other, the most striking the approximately 4.5 sigma tension on the Hubble constant between CMB and local measurements. In this talk I will briefly review the status of these tensions and some 
attempts to solve them modifying the late time evolution of the Universe. I will focus on a specific model, where Vacuum energy and Dark Matter interact with each other, and I will investigate the possibility that unaccounted systematic effects in Supernovae observations might help to reduce these tensions.

Announcement of NRF One Call for Proposals 2020/2021

https://www.nrf.ac.za/funding

The Call includes the following funding categories:

1)     Concept Notes

2)     Customised Programmes

3)     Infrastructure

4)     Institutional Grants

5)     Postdoctoral Grants

6)     Research Grants: General

7)     Research Grants: International

8)     Research Grants: Thuthuka

9)     Research Grants: Without Student Support 

10)  Travel, Training and Conference Grants

11)  Travel, Training and Conference Grants: Scholarship- and Fellowship-holders 

Applications must be submitted electronically on the NRF Online Submission System at https://nrfsubmission.nrf.ac.za.

All Framework and Funding and Application Guide documents are available on the NRF website at https://www.nrf.ac.za/funding/framework-documents.  These documents should also be consulted for the relevant contact persons for each Funding Instrument.

Building stars, planets and the ingredients for life in space

“The cosmos is within us. We are made of star-stuff. We are a way for the universe to know itself.”Carl Sagan

On January 29th, the UWC Astro group was delighted to host Prof. Ewine F. van Dishoeck from the Leiden Observatory. Prof van Dishoeck is a world-leading expert in the realm of molecular astrophysics, a field which brings chemistry, astronomy and physics together. The talk showcased the ingredients and recipes for the formation of celestial objects at a molecular level.

Apart from being a prestigious academic, Prof. Ewine F. van Dishoeck is also president of the International Astronomical Union (IAU) which oversees the global astronomical community in areas of professional research and education in astronomy. In her role as President, she also visited the Khayelitsha-based Molo Mhlaba school which, in collaboration with UWC Astro, coordinates the IAU-OAD funded Astro Molo Mhlaba project. 

Visitors from Missouri (USA)

The UWC Astrophysics group is playing host to two visitors from the Missouri University of Science and Technology; Prof. Shun Saito and Dr Sid Gurung Lopez. With over 30 years of partnership between the two universities, strengthening the ties between the two astrophysics groups would aide in improving international collaboration. 

Our guests also presented their research which covered, theoretical cosmology and computational cosmology. Prof. Saito talk covered ‘Towards a robust analysis of the redshift-space bispectrum’  which sees to trace the large-scale structure of the Universe in 3D with galaxy clustering and/or with intensity mapping. Dr Lopez presented ‘Modeling Lyman alpha emitters in the epoch of reionization’ which looks at detecting galaxies in the early Universe.

Students and staffs from the UWC Astro Group attended 2019 SARAO Scholarship Conference

Students and staff from the UWC Astro Group attended the South African Radio Astronomical Observatory (SARAO) Postgraduate Bursary conference in Durban from the 2nd – 6th December. The conference is held for those funded by the SARAO in order to showcase their work as well as to network with the South African radio astronomy community. The UWC group which attended consisted of 11 MSc and 7 PhD candidates, 8 Post-Doctoral and 2 staff members as well as a few of our international collaborators.

The week-long conference comprised of talks and a poster session for all to see. The topics varied from the science that SARAO can do with MeerKAT to the engineering aspect and issues facing MeerKAT.

18 students and 8 postdocs from the UWC Astro Group presented their research works on the conference.