SALT Visits/Scholarships: Apply now!

 

Background: As part of a broader SALT Collateral Benefits Plan, the Stobie-SALT Scholarship initiative (2003-2013) was aimed at training the next generation of astronomers to make use of SALT and other optical astronomy facilities in SA and beyond. In partnership with SALT consortium institutions, SA students had the opportunity to undertake doctoral studies in astronomy at Rutgers University, Dartmouth College and Wisconsin University in the USA, as well as at Southampton University and University of Central Lancashire in the UK. The programme has resulted in major benefits for both SA and the participating institutions: 10 students were trained, the majority are now in senior leadership positions in astronomy (many on a national and international level), training students in their own groups and continuing to work with astronomers in their doctoral institutions. For the international partners, the programme has indeed forged stronger ties and highly productive collaborations with astronomers in SA.

To ensure maximum benefit from our continued investment in SALT, for astronomy and its broader impact on areas such as technology, engineering, data science, the NRF has provided funding to re-launch the SALT scholarships programme, extending it to also include research visits for students, postdoctoral fellows and early career researchers (hereafter referred to as “participants”) from SA to spend time at SALT partner institutes.

The envisioned scheme aims to

• support/build scientific collaborations and networks for participants and their hosts;
• give participants international exposure and opportunities for specialized training and research;
• give SALT partners the opportunity to work with exceptional students and postdocs;
• further strengthen the SALT partnership (a “whole that is greater than the sum of its parts”)

Proposed projects: See the tables below for a list of available projects for research visits and scholarships/fellowships. Researchers at any SALT partner institution may offer further project opportunities at any time. To add a project, hosts should send a brief CV, project abstract (max 250 words) and outline (max 1 page, see the examples below). To remove or make changes to a project listing, please also email scholarshipsandvisits@salt.ac.za.

Selection/eligibility: The focus will be on SALT and SALT-related projects including instrumentation, activities linked to the Vera C. Rubin Observatory, optical-radio synergies, theory/computation, and/or data science.

• Available funding, costs, and partner contributions will determine the number and duration of participant visits/(post)doctoral positions that can be supported.
• Partners will contribute to local costs, such as accommodation, visa costs etc., either directly or by leveraging existing funding instruments.
• Selection of participants will be in line with NRF employment equity considerations.
• In addition:
  • For visits, participants enrolled or employed at a South African university or institution are eligible.
  • MSc/PhD scholarship and postdoctoral fellowship positions are only open to South African citizens and permanent residents.
• A strong proposal will involve exceptional participants, clear and compelling scientific goals, evidence of thorough preparation for visits, excellent host support and infrastructure, and specific, measurable outcomes, e.g., MSc/doctoral degree, publications, skills transfer, collaborations etc.

How to apply: Participants should contact potential hosts directly to discuss the application (see available projects below). It is recommended that this be done early as it is necessary to prepare the application.

A complete application will include:

• An application form available HERE which includes a detailed motivation, budget and project plan, goals, and expected outcomes
• Letter from the host confirming the project plan, dates, and any support/funding contribution
• Letter from participant’s current supervisor agreeing to the planned visit (if applicable)

There will be 3 calls each year, this first call is for visits and positions beginning between 1 June 2022 – December 2022.

Deadline: All application materials should be submitted as a single pdf to scholarshipsandvisits@salt.ac.za by 30 April 2022. 

Visits:

Project	Host	Level
BEARS with SALT	Stephen Serjeant, The Open University, UK stephen.serjeant@open.ac.uk	MSc, PhD, Postdoc
Abstract: We request funding to support our ongoing large follow-up programmes of the brightest submm galaxies on the sky from Herschel. We are leading the Bright Extragalactic ALMA Redshift Survey (BEARS, 91.6hr on ALMA) that has yielded spectroscopic redshifts of 71 bright submm galaxies in the Southern hemisphere (Urquhart+21), and the Z-GAL NOEMA redshift campaign (co-Is Serjeant and Marchetti) in the North has brought the all-sky total to over 200 redshifts. These data have rich prospects for science exploitation and follow-ups, probing the drivers of the fuelling of star formation and its consumption into stars to form the most massive present-day galaxies. Dr Lucia Marchetti (UCT) has HST data for many of our BEARS and Z-GAL galaxies, and has obtained SALT spectroscopy for many BEARS galaxies. Depending on the interests and technical background of the visitor, and the duration of the visit, we would like e.g. (a) to try lens modelling of these systems (b) to make headway in the optical spectroscopy reduction and look for hints of optical lines that match the CO redshift (c) to stack the optical spectra at the ALMA/NOEMA source redshift to see if we can say anything statistical about eg [OII], Hbeta, [OIII] etc in the background sources (d) to search the ALMA data (or stack it) for lines at the redshift of the lens, etc. We will seek additional UK funding from the visitors’ line in our STFC Consolidated Grant and other sources. For more details see: BEARS_with_SALT_Serjeant
Data Fusion and Deconvolution	Stephen Serjeant, The Open University, UK stephen.serjeant@open.ac.uk	MSc, PhD, Postdoc
Abstract: Wide-field submillimetre surveys have driven many major advances in galaxy evolution in the past decade, but without extensive follow-up observations the coarse angular resolution of these surveys limits the science exploitation. This has driven the development of various analytical deconvolution methods. In the last half a decade Generative Adversarial Networks have been used to attempt deconvolutions on optical data. We have developed an auto-encoder with a novel loss function to overcome this problem in the submillimeter wavelength range (Lauritsen+21 MNRAS, 507, 1546). This approach is successfully demonstrated on Herschel SPIRE 500 micron COSMOS data, with the superresolving target being the JCMT SCUBA-2 450 micron observations of the same field. We reproduce the JCMT SCUBA-2 images with high fidelity using this auto-encoder. We are now deconvolving much larger Herschel survey areas, with a view to identifying rare ultra-high-redshift systems to probe the demographics and mechanisms of star formation at the earliest epochs, strong gravitational lenses to enable follow-up observations of the resolved physical processes in the progenitors of present-day giant ellipticals, and foreground interlopers, all using multi-wavelength supplementary data. We would like funding for a visit from Dr Lucia Marchetti’s UCT group (or Dr Marchetti herself) for furthering the analysis with the Herschel data fusion to facilitate this cross-correlation with our machine learning deconvolution outputs. We will seek additional UK funding from the visitors’ line in our STFC Consolidated Grant and other sources. For more details see: Data_Fusion_and_Deconvolution_Serjeant
Strong gravitational lensing with Euclid and Herschel	Stephen Serjeant, The Open University, UK stephen.serjeant@open.ac.uk	MSc, PhD, Postdoc
Abstract: Rubin LSST and Euclid’s Wide and Deep optical/near-infrared imaging and grism surveys will be transformative for the discovery of strong gravitational lenses, increasing the known number by two orders of magnitude. Lensed systems at z>6 will be the premier high-z lensing systems in LSST and Euclid and prime targets for JWST, illuminating at high angular resolution the physical processes that drive the earliest stellar mass assembly at z>6. However LSST and Euclid are very far from having an algorithm for the reliable discovery of these very rare z>6 strongly lensed galaxies (e.g. Marchetti+17 MNRAS 470, 5007). Over all redshifts, Euclid and LSST are expected to find more than 10^5 strong gravitational lens systems, including many rare and exotic populations such as compound lenses, but these 10^5 systems will be interspersed among much larger catalogues of around 10^9 galaxies. The z>6 rare population is therefore a “needle in a haystack in a huge field of haystacks” data mining problem. This volume of data is too much for visual inspection by volunteers alone to be feasible and gravitational lenses will only appear in a small fraction of these data which could cause a large amount of false positives. Machine learning is one obvious approach to finding a solution. We have developed Convolutional Neural Networks to identify strong gravitational lenses in large imaging data sets, and interpretability tools to understand whether it will detect or select out rare populations such as z>6 galaxies or compound lenses. Dr Lucia Marchetti (UCT) has obtained HST data on large numbers of submm-selected lenses so we seek visitor funding to try the HST imaging of these lenses through our lens-detecting convolutional neural net. Our suspicion is that submm-selected lenses will not fare as well as simulated LSST/Euclid lenses, because they are optically quite faint, so this will be a useful salutary lesson in LSST/Euclid’s false-negative detection rate. We will seek additional UK funding from the visitors’ line in our STFC Consolidated Grant and other sources. For more details see: Euclid_Herschel_Lensing_Serjeant
Hydrogen-Deficient Stars in the Galaxy	Simon Jeffery, Armagh Observatory simon.jeffery@armagh.ac.uk	PhD, Postdoc
Abstract: As stars approach the ends of their lives, their interiors comprise products of nucleosynthesis, principally, helium, carbon and oxygen. Without some external agency, such products are rarely exposed at the stellar surface – especially in low-mass stars. The hydrogen-deficient surfaces of extreme helium stars, helium-rich subdwarfs, and AM CVn binaries, to name a few, suggest that binary stars which evolve to become double white dwarfs acquire a new lease of life when their components reach contact. Some of these include significant sources of Galactic foreground gravitational wave (GW) radiation. SALT projects with Southern African and Armagh participation include i) the SALT survey of chemically-peculiar subdwarfs, ii) a SALT study of contraction in post-merger extreme helium stars, and iii) SALT follow-up of candidate AM CVn stars and other potential GW sources. Substantial data have accumulated for over 250 hydrogen-deficient objects, which need to be processed and analysed consistently, and correlated with Gaia distances, broad-band photometry, TESS and other variability studies, and early-epoch data from other observatories. Correlation presents a significant data challenge, as well as an opportunity for discovery. Armagh and UCT lead several of these SALT projects with limited human resource. This ‘pre-call’ is based on current Armagh/UCT/SAAO/SALT collaborations (Jeffery, Monageng, de Groot, Ramsay, Woudt), and seeks to establish the potential for postdoctoral exchange visits or a joint PhD studentship, to attack the data mountain, and to identify routes to knowledge exchange which will strengthen the Southern African science base in stellar spectroscopy, stellar physics and data science. For more details see: Hydrogen_Deficient_Stars_Jeffery
Exploring the background behind the Magellanic Clouds	Jacco van Loon, Keele University  j.t.van.loon@keele.ac.uk	PhD, Postdoc
Abstract: We study AGN, galaxy interaction and galaxy clustering behind the Magellanic Clouds, based on several medium-wide, medium-deep multi-wavelength surveys, time variability, machine learning and spectroscopic followup in part with SALT and the SAAO 1.9m telescope. We would like to collaborate in particular on photometric redshift determination, morphological characterisation or radio counterpart matching, to achieve various science goals. For more details see: Magellanic_Clouds – vanLoon
Probing the cosmic density of neutral hydrogen at intermediate redshifts	Andrew Baker (+Eric Gawiser), Rutgers University ajbaker@physics.rutgers.edu	PhD
Abstract: The Looking At the Distant Universe with the MeerKAT Array (LADUMA) project is an approved MeerKAT Large Survey Project (LSP) aiming to measure neutral hydrogen (HI) gas in galaxies out to redshifts z ~ 1.4. Understanding galaxy evolution through large survey projects such as LADUMA requires a close relationship between radio and optical astronomy. We propose funding for a student member of the LADUMA team to travel to Rutgers to work on a project using LADUMA MeerKAT and SALT data. In particular, SALT spectroscopic redshifts are to be used in LADUMA stacking analyses to explore the gas and stellar content of intermediate redshift galaxies. The visit will also facilitate work on future SALT proposals to follow up galaxies within the LADUMA field. This travel opportunity will further support collaborations between SALT partner institutions. For more details see: Density_of_Neutral_Hydrogen_BakerGawiser
Supernovae	Saurabh Jha, Rutgers University saurabh@physics.rutgers.edu	MSc, PhD, Postdoc
Abstract: The Rutgers Supernova Group led by Prof. Saurabh W. Jha uses SALT to obtain optical spectroscopy of new and interesting exploding stars. Observations of distant and nearby type Ia supernovae (SN Ia) revolutionized our cosmological understanding that we live in an accelerating Universe. At Rutgers we continue to observe SN Ia for their cosmological application, using SN Ia distances to measure the expansion rate of the Universe (the Hubble constant) and study the expansion history of the Universe to better understand dark energy. We are also interested in understanding the astrophysics of supernovae: what kinds of stars explode and how? We use SALT spectroscopy, combined with spectral modeling, at early and late times, to study the expanding supernova ejecta and connect to models for supernova progenitors and explosions. We are particularly interested in “peculiar” white dwarf supernovae, aiming to understand how and why they differ from normal SN Ia. We have built up a large sample of SALT spectroscopy with many interesting objects to study using data already in hand. Excitingly, this research topic is dynamic: we are continuously observing new objects and prospective researchers are likely to work on objects that have not even been discovered yet. Much of our work is in collaboration with researchers around the world, combining our SALT data with observations from many different telescope on the ground and in space.
Clusters of Galaxies	Jack Hughes, Rutgers University jph@physics.rutgers.edu	MSc, PhD, Postdoc
Abstract: Galaxy clusters are the largest gravitationally bound systems in the universe; they are huge assemblages of galaxies, hot gas and dark matter. An accurate census of clusters can be used to determine how the universe evolves. Clusters, especially those that are caught while colliding, also tell us about the properties of dark matter as well as the nature of shocks in the gas. Wide-area surveys are the key to discovering large samples of clusters; currently there are on-going surveys of this type in the optical (e.g., the Dark Energy Survey – DES), X-ray (eROSITA) and mm-band (Atacama Cosmology Telescope – ACT). Mm-band surveys for clusters are sensitive to the “shadows” cast by the hot intracluster gas on the cosmic microwave background by inverse Compton scattering; this is called the Sunyaev-Zel’dovich (SZ) effect. Hughes and his group have acquired several semesters of SALT RSS spectra on several dozen newly confirmed SZ clusters from the Planck mission and ACT. A visiting researcher could make a substantial contribution to the data reduction and redshift determination of the observed sample over the source of several months. Plus new RSS observations of unobserved targets are in the SALT queue. Over the next few years, DES, eROSITA, and ACT surveys will produce large samples of well-selected clusters for cosmological applications as well as for follow-up dynamical studies using SALT multi-object spectroscopy for interesting disturbed systems. One example of an important on-going follow-up program is the MeerKAT Exploration of Relics, Giant Halos, and Extragalactic Radio Sources (MERGHERS) project, led by Dr. Kenda Knowles. This project is currently obtaining data on a number of ACT clusters, some of which would be interesting targets for SALT spectroscopy. The Rutgers cluster group has existing collaborations with Profs. Matt Hilton and Kavi Moodley (UKZN), Dr. Knowles (Rhodes University/SARAO), Dr. Rosalind Skelton (SAAO), and others. Longer term SALT projects are being developed to take advantage of this existing collaboration.
Studying Metal-poor Dwarf Galaxies	Kristen McQuinn, Rutgers University kristen.mcquinn@rutgers.edu	MSc, PhD, Postdoc
Abstract: Rutgers Prof. Kristen McQuinn leads a team of researchers studying the formation and history of low-mass galaxies in the nearby Universe using a broad range of multi-wavelength data from many telescopes including the Hubble Space Telescope (optical), Spitzer Space Telescope (infrared), and Jansky Very Large Array (radio). As part of this extensive research program, McQuinn and postdoctoral scholar Dr. Grace Telford have an ongoing SALT program to obtain RSS long-slit spectroscopy of an O-type star in the nearby, very metal-poor dwarf galaxy Sextans A. This target is one of just a handful of known massive stars below 10% solar metallicity, making observations that constrain its fundamental properties highly valuable. With RSS, we will obtain 12 individual observations of this faint star that must be combined to achieve a signal-to-noise ratio high enough to enable precise measurements of photospheric absorption lines. The visiting researcher will: (1) reduce the individual exposures of the O star in Sextans A; (2) combine the reduced and extracted spectra to produce a high-quality coadd; (3) measure the strengths of Balmer, He I, and He II absorption in the coadd, as well as any detected metal absorption lines; and (4) use these measurements to determine the star’s spectral type, effective temperature, and surface gravity. This project will not only characterize a rare, metal-poor O star, but will also enable future atmosphere modeling of its HST/COS far-ultraviolet spectrum to measure its mass-loss rate and metal abundances.
Spectroscopy of Compact Binary Accretors	Diego Altamirano, University of Southampton (Candidate already identified for project)	MSc
Abstract: The proposed visit is to allow the candidate to work on different aspects of compact binary research. The work will focus on the three systems: a  nova-like cataclysmic variable, a transitional millisecond pulsar candidate, and a transient black hole X-ray binary. These represent the three classes of compact binaries, namely those involving accreting white dwarfs, neutron stars, and black holes, respectively.

 

Scholarships/Fellowships:

Project	Host	Level
Hydrogen-Deficient Stars in the Galaxy	Simon Jeffery, Armagh Observatory simon.jeffery@armagh.ac.uk	PhD
Abstract: As stars approach the ends of their lives, their interiors comprise products of nucleosynthesis, principally, helium, carbon and oxygen. Without some external agency, such products are rarely exposed at the stellar surface – especially in low-mass stars. The hydrogen-deficient surfaces of extreme helium stars, helium-rich subdwarfs, and AM CVn binaries, to name a few, suggest that binary stars which evolve to become double white dwarfs acquire a new lease of life when their components reach contact. Some of these include significant sources of Galactic foreground gravitational wave (GW) radiation. SALT projects with Southern African and Armagh participation include i) the SALT survey of chemically-peculiar subdwarfs, ii) a SALT study of contraction in post-merger extreme helium stars, and iii) SALT follow-up of candidate AM CVn stars and other potential GW sources. Substantial data have accumulated for over 250 hydrogen-deficient objects, which need to be processed and analysed consistently, and correlated with Gaia distances, broad-band photometry, TESS and other variability studies, and early-epoch data from other observatories. Correlation presents a significant data challenge, as well as an opportunity for discovery. Armagh and UCT lead several of these SALT projects with limited human resource. This ‘pre-call’ is based on current Armagh/UCT/SAAO/SALT collaborations (Jeffery, Monageng, de Groot, Ramsay, Woudt), and seeks to establish the potential for postdoctoral exchange visits or a joint PhD studentship, to attack the data mountain, and to identify routes to knowledge exchange which will strengthen the Southern African science base in stellar spectroscopy, stellar physics and data science. For more details see: Hydrogen_Deficient_Stars_Jeffery
Exploring the background behind the Magellanic Clouds	Jacco van Loon, Keele University j.t.van.loon@keele.ac.uk	PhD, Postdoc
Abstract: We study AGN, galaxy interaction and galaxy clustering behind the Magellanic Clouds, based on several medium-wide, medium-deep multi-wavelength surveys, time variability, machine learning and spectroscopic followup in part with SALT and the SAAO 1.9m telescope. We would like to collaborate in particular on photometric redshift determination, morphological characterisation or radio counterpart matching, to achieve various science goals. For more details see: Magellanic_Clouds – vanLoon
Photospheric parameters and pulsations in A stars	Daniel L. Holdsworth; Anne E. Sansom,University of Central Lancashire, DLHoldsworth@uclan.ac.uk, AESansom@uclan.ac.uk	MSc by research
Abstract: The advent of large photometric surveys has provided a plethora of high-quality data on the brightness of hundreds of thousands of stars in recent years that have been exploited for the identification and study of chemically peculiar A stars. The analysis of these light curves can only go so far before secondary sources of data are needed to fully characterize the target of interest. To that end, we have been collecting spectroscopic data with both RSS on SALT and SpUpNIC on the 1.9-m to enable a complete study of our targets of interest. To date, we have a library of over 300 low-resolution, high signal-to-noise stellar spectra. This project will bring together photometric and spectroscopic strands of observational astrophysics together with theoretical model fitting to extract precise stellar parameters (rotation, effective temperatures, surface gravities and abundances) through light curve analysis and the use of new theoretical stellar. The student will work on some of the most unusual stars in the sky, learning about the interactions between rotation, pulsation and magnetic fields in the atmospheres of A stars. Further, the project will expose the student to the world class instrumentation/science capabilities of SA. We propose an MSc by Research project to be held at the University of Central Lancashire (UCLan) in the UK, building on the strong collaborations between UCLan, SALT, SAAO and the wider astronomical community in Southern Africa. For more details see: Pulsations_in_A_stars_ Holdsworth