Study of radial and vertical structure of the edge-on protoplanetary disk surrounding SSTtau042021

Understanding the complexity of gas and dust structures in planet-forming disks is essential for a comprehensive view of planetary formation. We present an analysis of the nearly edge- on protoplanetary disk around SSTTau 042021 (inclination 90.6 ± 0.4deg), based on archival ALMA data. Edge-on disks like SSTTau 042021 are valuable laboratories for directly observing molecular stratification, bypassing challenges in vertical structure analysis faced by inclined disks. Using the tomographic method of Dutrey et al., we reconstruct the 2D brightness temperature distribution Tb(r,z) for CO isotopologues (12CO, 13CO, and C18O). We investigate the disk molecular layer location and the dust disk properties. This method, performed on high-resolution data (∼0.3′′), allows for accurate measurements of CO temperatures. Our results show, in particular, a good agreement between the CO and dust temperatures (within 8-12 K ) near the mid-plane. This study highlights the power of high-resolution tomography for probing disk stratification and provides insights for refining model approximations of vertical temperature gradients in protoplanetary disks.