| Name: | Aditya Tamar |
| Affiliation: | National Institute of Technology, Karnataka |
| Conference ID : | ASI2024_420 |
| Title : | Effect of Earth's Oblateness on Black Hole Imaging through Space VLBI |
| Authors : | Author: Aditya Tamar
Co-Authors: Ben Hudson, Daniel Palumbo |
| Authors Affiliation: | 1. Aditya Tamar (Department of Physics, National Institute of Technology, Karnataka, Surathkal-575025, India)
2. Ben Hudson (KISPE Space Systems Ltd, Farnborough, United Kingdom)
3. Daniel Palumbo (Center for Astrophysics, Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA) |
| Mode of Presentation: | Poster |
| Abstract Category : | Facilities, Technologies and Data science |
| Abstract : | Earth-based Very Long Baseline Interferometry (VLBI) has made rapid advances in imaging black holes. However, due to the limitations imposed by the physical features of Earth, it is imperative to have a space-based component in future VLBI missions. Herein, the talk describes the effect of the Earth's oblateness, also known as the J2 effect, on orbiters in Earth-Space and Space-Space VLBI.
In the talk, we shall discuss how the J2 effect can directly impact orbit selection for black hole observations and how through informed choices of orbital parameters, the effect can be used to the mission's advantage, a fact that has not been addressed in existing space-VLBI investigations. For black hole photon rings, it will be shown how the J2 effect leads to modest increase in shorter baseline coverage, thereby aiding filling gaps in the (u,v) plane.
In addition, a simple analytical formalism is constructed that allows to isolate the impact of the J2 effect on the (u,v) plane without requiring computationally intensive orbit propagation simulations. By directly constructing (u,v) plots using the J2 affected and invariant equations of motion, distinct coverage patterns for M87 and Sgr A* have been obtained that show extremely dense coverage on short baselines as well as long term orbital stability on longer baselines. Lastly, potential avenues for future investigations are discussed, including the potential role of India's space program in future space-based radio astronomy missions. |
