Jun 22, 2018

Linear spectropolarimetry across H_alpha and H_beta lines of Herbig Ae/Be stars


Characterising the host star and protoplanetary disk environment in nearby young star systems


The young star β Pictoris is seen orbited by a warped edge-on debris disc of gas and dust, as well as a massive planet. In order to gain insights into the mechanisms of planetary system formation, it is useful to study the properties, behaviour and interaction of exocomets within this and other similar young planetary systems.

SALT Spectroscopic Survey of IR 12MGS Seyfert Galaxies


Our program aims to study the optical properties of dust-obscured galaxies in the local Universe. These intriguing objects are the local analogs of the more distant sources responsible for the bulk of star formation in our Universe, but yet most of the physical processes driving them remain poorly explained. Our proposed SALT observations will help in shedding the light on such physical mechanisms and therefore contribute to the study of galaxy formation and evolution in our Universe.

Symbiotic stars – important tracers of late evolutionary stages III


We propose a large spectroscopic monitoring of a sample of Magellanic symbiotic stars composed of cold red giant stars and hot white dwarfs, which challenge the binary star evolution models because they do not predict their existence. Our proposed observations will allow us to measure the masses of the two stars in the binary system. They will also help us to understand the formation and evolution of these theoretically impossible although existing binaries.

Optical Spectroscopy for the NuSTAR Serendipitous Survey with SALT


The cosmic X-ray background (CXB) was first discovered in the early 1960’s, several years before the detection of the cosmic microwave background (CMB). However, unlike the CMB, which is truly diffuse in origin, the CXB is dominated by the emission from high-energy distant point sources: Active Galactic Nuclei (AGNs), the sites of intense black-hole growth. Surveys with Chandra and XMM-Newton have resolved ≈ 70–90% of the CXB at low energies ( 10 keV observatory with focusing optics. We focus our study on NuSTAR serendipitous sources to identify spectral features in order to measure the distances to these sources (redshifts), as well as to establish their classification and characteristics. In order to achieve our goals we aim to obtain longslit spectra with the Robert Stobie Spectrograph (RSS), mounted at prime focus of SALT, of 18 NuSTAR serendipitous sources.

Spectroscopic observations of central stars of mid-infrared nebulae discovered w ith Spitzer and WISE


Spectroscopic observations of central stars of mid-infrared nebulae discovered with Spitzer and WISE

Systematic radial velocity monitoring of likely intermediate period post-AGB binaries


We are searching for binary stars in some of the most beautiful stellar remnants in the Galaxy.

Observing Spectroscopic Binaries for Dynamical Mass Measurements to Constraint their Ages


This monitoring program aims to measure the ages of the youngest stars in the universe closest to us. By weighing them and comparing their mass and brightness to models, we can infer just how old (or young) they are. Using the SALT High resolution Spectrograph, we are able to probe these young stars and measure there compositions, thereby estimating the formation mechanisms occurring for these objects. With this knowledge we able then able to fits models to the data and make assumptions on how planets are formed.

Observing the Transient Universe


This large SALT program is aimed at studying “things that go bang in the night”, namely transient objects in the Universe which either are newly discovered objects, or known objects who suddenly change their appeatance. Such things include binary stars with accreting compact companions, many of them X-ray or gamma ray sources, eruptive stars which suddenly brighten, black holes systems, including active galaxies powered by them, and all manner of explosions including the most energetic of all, gamma ray bursts.

Jun 19, 2018

Demographics of the most extreme starburst galaxies


Starbursts are galaxies in which, in their current state, their star-formation is so intense that it cannot be sustained for extended (cosmological) times. They will rapidly exhaust their fuel, prompting unanswered questions about how and why the episodes of star formation begin. We have identified a small population of very rare local starbursts, for which the bursts are among the most intense of all known systems; we will now use the SALT to study the properties of their gas and stars in more detail.