Speaker
Description
Numerous high-energy gamma-ray sources have been detected along the Galactic Plane. While some of them are associated to objects like supernova remnants or pulsar wind nebulae, a significant portion remains unassociated, hindering our understanding of the objects and detailed mechanisms that produce such extreme energies. To pinpoint the origins of the gamma-ray emission, we need to identify nearby energetic objects that have the potential to produce the observed emission. Since energetic objects and the interstellar medium (ISM) can influence each other, we can search the ISM for signatures of such interactions. For instance, the presence of ionised gas indicates the presence of shocks, detectable with optical spectral lines such as H$\alpha$ or [SII]. A shock propagating through the ISM can sweep up material, creating voids, while relativistic electrons within shocks and magnetic fields generate synchrotron radiation across the radio to X-ray bands. Many of these signatures appear as circular features. Given the high resolution and vast data volume of such astronomical observations, an automatic feature detection is essential.
In this contribution, we will introduce a circular feature detection method based on the Hough transform, and we will discuss the results and challenges of its application to a range of different astronomical observations (e.g. molecular hydrogen, radio continuum, H$\alpha$).
