| Abstract : | Investigating the evolution of protoplanetary disks surrounding young stellar objects (YSOs) is paramount for understanding the mechanisms underlying star and planet formation. We chose 32 clusters(within 500 pc) in the age range of 1-100 Myrs, whose membership is based on Gaia DR2, to understand when the disk dissipation comes to a stop. The Age and mass information of the sources were obtained through SED fitting, conducted using VOSA, and by employing PARSEC 1.2 isochrones. The IR data was obtained from 2MASS and WISE catalogs, and we employed three methods to identify disks across the different wavelength regimes(1.1- 22µm). We find that disk-fraction consistently decreases as stellar systems age, a trend observed across all wavelengths. However, there is an increase in the time scale of disk decay as wavelength increases. The different wavelength regime corresponds to different disk radii: short wavelengths(1.2-4µm) for disk radii within 0.01-1AU, 12µm for 0.03-5AU, and 22µm for disk radii in the range 0.3-60AU. This indicates that dust particles at larger radii evolve at a slower pace. In contrast to shorter wavelengths, we observed 12µm and 22µm excess sources at relatively older ages, ≈ 50Myr. These sources may represent evolved disks, such as debris or transitional disks. Based on the optical spectra obtained from LAMOST DR8, we calculated the H-alpha equivalent widths(EW) to identify possible accretors in our sample. We derived the mass accretion rate based on the EW and found that the accretors in our sample are all within ≈10 Myr, indicating no accretion observed beyond this age. We also perform a simulation-based analysis using D’Alessio models to determine the disk structure in the 12µm and 22µm range, focusing on the degree of dust settling and disk wall height.
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