This issue includes material about the messengers from nuclear physics processes which underlie formation of all the elements heaver than helium in the universe, and which make stars and supernovae shine. ‘Radioactivities’ is the common theme, with the papers originating from an interdisciplinary workshop discussing the diversified views on radioactive isotopes in astrophysics.
Publications of the Astronomical Society of Australia
Volume 29 Number 2 2012
RESEARCH FRONT: Astronomy with Radioactivities
No evidence was found in nanodiamond stardust for the former presence of extinct 26Al or 44Ti. Observed overabundances of r-process-only 198Pt are in line with previously found excesses of heavy Xe and Te isotopes. As an alternative to dedicated scenarios, we have explored the r-process as a possible explanation.
Many neutron stars and runaway stars apparently come from the same regions on the sky. This suggests that they share the same birth places. To identify these birth places, we attempt to find NS-runaway pairs that could be possible former companions that were disrupted in a supernova. If nearby and recent, the remains are still visible in emission of radioisotopes.
We estimate the intensity of possible supernova-produced radionuclides 26Al, 53Mn, 60Fe, and the pure r-process element 244Pu in two marine sediment cores from the Indian Ocean. Detecting these radionuclides with accelerator mass spectrometry allows us to link the signal to a supernova event in the solar vicinity ~2 Myr ago.
The complementary technique of neutron activation and subsequent accelerator mass spectrometry (AMS) measurement was for the first time applied to studying 14C production from 13C(n,γ) and 14N(n,p). New data for these neutron poisons obtained for neutron energies between 25 and 178 keV are slightly lower than previous results and evaluations suggest.
AS11078 Transformations from WISE to 2MASS, SDSS and BVI Photometric Systems: II. Transformation Equations for Red-Clump Stars
We present colour transformations for the conversion of WISE magnitudes to the BVIc, gri, and JHKs photometric systems for red clump stars. The selected samples were used to obtain metallicity-dependent and free-of-metallicity transformations. These transformations can be used in the studies of the Galactic structure.
Expanding upon Pimbblet's 2011 analysis of career h-indices for members of the Astronomical Society of Australia, we provide additional citation metrics which are geared to quantifying the current performance of all professional astronomers in Australia.
We monitored the Ca ii lines of HD 179949 at the McDonald Observatory to observe planet induced emission (PIE) as an effect of star–planet interaction. Detailed statistical analysis revealed fluctuations in the Ca ii K core consistent with previous studies. We also confirmed the reality and temporal evolution of the phase shift of the maximum of star–planet interaction.
We analysed GSC 02038-00293's light curve and modelled its light variation at out-of-eclipse phases using the phoebe and spotmodel programs. The analyses indicated that there are two migrating active longitudes for the active component. The amplitude at out-of-eclipse phases varies in a sinusoidal way with a period of 8.9 yr, while the mean brightness is dramatically decreasing.
In this article, we investigate the behavior of orbits in an axially symmetric galactic-type potential. Our numerical calculations suggest that in this potential, there are two kinds of orbits: (i) escaping and (ii) trapped, which do not escape at all. Among the chaotic orbits, there are orbits that escape fast and also orbits that remain trapped for vast time intervals.
This project uses the 2MASS all-sky image database to study the structure of galaxies over a range of luminosities, sizes and morphological types. This first paper in this series will outline the techniques, reliability and data products to our surface photometry program.
A coronal jet ejection from a sunspot light bridge is presented. It is confirmed that the jet has its root near the light bridge. This suggests that the jet may be a result of reconnection between the main sunspot and the light bridge.
This is a design study into using the Australian Square Kilometre Array Pathfinder full-sky low redshift neutral hydrogen survey, WALLABY, to measure the galaxy power spectrum. With 66 × 105 redshifts, WALLABY, when combined with Planck CMB data, will constrain the Dark Energy equation of state to 20%.