Delving into massive stars: the colliding wind binaries, relations and various interferometric radio observations

Massive stars are rare and possess strong winds that provide feedback mechanisms to the interstellar medium. They are usually found in binary or multiple systems, which complicates the wind interaction between stars. This work has primarily involved massive stars, focusing on the colliding-wind binary at radio wavelengths as well as other wavelengths, such as the X-ray. A new Güdel-Benz style relation uncovered in an archival sample of massive stars suggests a positive correlation between X-ray and radio luminosities. Several new radio observations of the archetypal colliding-wind binary WR140 at low and high frequencies have been made using the currently available radio interferometers. The low frequencies radio observations using the upgraded broad bandwidth Giant Metre Radio Telescope at 0.3−1.4 GHz revealed that WR140 has a thermal spectrum, a vital baseline to disentangle the non-thermal emission in future works. The high-frequency radio observation of WR140 at 22 GHz to observe the colliding wind region closer to apastron was unsuccessful due to the high rms of the East Asia Very Large Baseline Interferometer Network (EAVN). We introduced the Distributed Radio Emission Measure model to capture the shape of the non-thermal radio emission spectra from various archival WR140 radio data. The outcomes of the model indicate that the radio emission from the wind collision region is the result of a distributed emission measure, where the line-of-sight has travelled across different regions. The radio emission measure is large at apastron consistent with thermal emission and progressively small leading up to periastron, revealing the non-thermal emission region, coherent with the observational radio data

Atom bottom-up manipulation controlled by light for microbattery use

In this paper, we propose a new design of the atom bottom-up technique that uses an optical trapping tool to form the atom trapping layer within a thin-film grating. By using a PANDA ring resonator, where atoms can be trapped, pumped, and controlled by light, the trapped atoms/molecules can be selected, filtered, and embedded within the required thin-film grating layers to manufacture nanobattery. In application, P-type or N-type atom can be prepared, trapped, and embedded within the desired thin- film layers, and finally, the microbattery can be manipulated. The theoretical background of light pulse in a PANDA ring resonator is also reviewed