OBSERVATIONS OF ASTEROIDS IN SUBMILLIMETER WAVELENGTH USING ALMA RADIO INTERFEROMETER

• Main Author: Asri Yasdana, Nada
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/38994
• Institution: Institut Teknologi Bandung

Imaging of asteroids is very dicult from ground based observations since the diameter of the asteroids is too small (for example, Ceres only appears with an angular diameter of 0,468") and in visual wavelengths, imaging of asteroids is limited by seeing of the atmosphere which is usually greater than 1". Besides imaging, spectroscopic and photometric observations were also carried out to study the surface's physical properties and thermal conditions of the asteroids target. With the advent of ALMA, astronomers have the opportunity to observe asteroids and get radio images, because of the sensitivity and high spatial resolution that ALMA can produce. One of the objects of ALMA observations is the asteroid Juno, which was successfully obtained in 2013. This is the first imaging in observing asteroids in submillimeter wavelength. Some large asteroids, such as Ceres, Pallas, and Vesta are also used as calibrators in ALMA observations. So far, there have been more than 300 observations of Ceres and Pallas. However, observations of Juno and Vesta were not as much as Ceres and Pallas because of the distance and size of these asteroids. Further data selection is needed, especially in terms of data having a high spatial resolution that can be processed with CASA to get good quality images. In the photometric aspect, Ceres and Pallas data are used as the calibrator of observing programs. The results in this Final Project are images with high spatial resolution resulting in better surface details. This is dierent from low-resolution images since the lower the resolution is, the less detail the area can be analyzed. The photometric aspect is to show that the Ceres and Pallas spectra seem like the black body spectra and the spectroscopic aspect shows emissions found at Pallas from project 2013.1.00260.S in the frequency range of 693,302 to 693.31 GHz. However, it is not yet known the origin of this emissions.