2025/03/18 by S., Neha, Saurabh
#Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Solar and Stellar Astrophysics (astro-ph.SR)
paper · doi:10.48550/arxiv.2503.13971
The variability of Young Stellar Objects (YSOs) is a crucial tool for understanding the mechanisms driving flux changes. In this study, we present an infrared variability analysis of a large sample of over 20,000 candidate YSOs, using data from the ALLWISE and NEOWISE surveys, which span around a decade with a 6-month cadence. We applied Lomb-Scargle Periodogram (LSP) analysis and linear fitting to the light curves, classifying them into distinct categories: \it Secular (\it Linear, \it Curved, and \it Periodic) and \it Stochastic (\it Burst, \it Drop, and \it Irregular). Our findings show that 5,467 (26.2±0.3%) of the sources exhibit variability, with most (19.7±0.3%) showing \it Irregular variations, followed by \it Curved and \it Periodic variations. In addition, 235 sources of \it Bursts and 122 \it Drop sources were identified. Variability is more pronounced in Class I sources with a higher fraction of variables (36.3±0.6%) compared to Class II (22.1±0.4%) and Class III (22.5±1.0%) sources. The color (W1 - W2) versus magnitude analysis (W2) using linear fitting shows that the trend ``redder-when-brighter" (RWB) is more prevalent (85.4±0.5%) among YSOs. In contrast, the trend ``bluer-when-brighter" (BWB) is more common in younger sources compared to more evolved ones, having a BWB fraction of 29.0±1.1% for Class I to 4.0±0.9% for Class III.