Study of Dust Properties of two Far Infrared Cavities near by Asymptotic Giant Branch stars under Infrared Astronomical Satellite Maps

Abstract

The physical properties such as dust color temperature, dust mass, visual extinction, and Planck function with their distribution in the core region of two far-infrared cavities, namely FIC16-37 (size ~ 4.79 pc x 3.06 pc) located at R.A. (J2000): 16^h 33^m 57.25^s & Dec. (J2000): -37^d 47^m 04.3^s, and FIC12-58 (size ~ 22.54 pc x 14.84 pc) located at R.A. (J2000): 12^h 52^m 50.08^s & Dec. (J2000): -58^d 08^m 55.02^s, found within a galactic plane -10^o  to +10^o  nearby Asymptotic Giant Branch (AGB) stars namely AGB15-38 (R.A. (J2000): 15^h 37^m 40.74^s & Dec. (J2000): -38^d 20^m 24.6^s), and AGB12-57 (R.A (J2000): 12^h 56^m 38.50^s & Dec. (J2000): -57^d 54^m 34.70^s), respectively were studied using Infrared Astronomical Satellite (IRAS) survey. The dust color temperature was found to lie in the range of 23.95 ± 0.25 K to 23.44 ± 0.27 K with an offset about 0.5 K for FIC16-37, and 24.88 ± 0.27 K to 23.63 ± 0.98 K with an offset about 1 K for FIC12-58. The low offset in the dust color temperature indicated the symmetric distribution of density and temperature. The total mass of the cavities FIC16-37 and FIC12-58 were found to be 0.053 M☉ and 0.78 M☉, respectively. The contour plots of mass distribution of both of the cavities was found to follow the cosmological principle, suggesting the homogeneous and isotropic distribution of dust masses. The plot between temperature and visual extinction showed a negative correlation, suggesting that higher temperature has lower visual extinction and vice-versa. The distribution of Planck function along major and minor diameters of both of the cavities was found to be non-uniform, indicating oscillation of dust particles to get dynamical equilibrium. It further suggested the role of pressure-driven events nearby both cavities and suggested that dust particles are not in thermal equilibrium along the diameters.