UNDERSTANDING PHYSICAL INTERPRETATIONS OF TWO MERGING COMPACT OBJECTS: A GRAVITATIONAL WAVE DATA PROCESSING STUDY USING GWPY

• Main Author: Ahmad Ramadhan, Satria
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/71952
• Institution: Institut Teknologi Bandung

Gravitational waves are messengers of space information that were only been detected less than ten years ago, roughly a century after they were originally predicted to exist. Gravitational waves are an observation media with enormous potential, because gravitational waves do not interact with anything, so nothing will interfere with their travel except another gravitational disturbances. Because the detection of gravitational waves is relatively new, our ability to accurately detect gravitational waves is still limited, as well as analysis of the physical characteristics of the sources that produce these gravitational waves. Currently, all data and information regarding gravitational waves is provided in a database called the Gravitational Wave Open Science Center or GWOSC. GWOSC is the result of cooperation from all gravitational wave observatories in the world including LIGO, Virgo, KAGRA, and GEO600. GWOSC provides gravitational wave data in the form of a time domain which is commonly referred to as a time series, this time domain data is then processed in several stages such as noise whitening, band-pass filtering, conversion into a frequency domain, and conversion into a spectrogram to produce a gravitational wave profile that can be visually analyzed through its features. In this Thesis I use the Python application and utilize GWpy, which is a Python programming tool that has been specially created to access and process gravitational wave data directly from GWOSC. In this Thesis I have studied the effects and objectives of each stage of data processing. For time domain data, the process of whitening and band-pass filtering are performed to bring out the profile of a gravitational wave from signals that is still dominated by noise. In the frequency domain data, conversion to a spectrogram is performed to provide an overview of the gravitational waves morphology. The gravitational wave profile in the time domain signal will provide several informations such as period, amplitude, and frequency which will eventually be derived to obtain other information such as chirp mass and the distance from the source. Determination of chirp mass is done by observing the gravitational wave profile, so it will be difficult to do if the detected gravitational waves do not give a clear gravitational wave profile. This causes the estimation of the physical parameters of gravitational waves to have a very large error and is not very accurate. Apart from that, I have also studied the interpretation of the gravitational wave profile feature which was carried out to determine the physical parameters of the source.