Poster Presentation

Follow-up detection of Water Vapour in IRAS4A, IRAS4B and IRAS2A using NOEMA

Author(s): Manogna Donthi Kiran, Daniel Harsono

Presenter: Manogna Donthi kiran (National Tsing Hua University)

Water is an abundant molecule present in the form of ice on dust grains and in the gas phase. In the millimeter regime, water vapor serves as a diagnostic for tracing its chemical evolution from the protostellar phase to the disk phase. To trace the chemical inheritance the interferometric data from the Northern Extended Millimeter Array is used to measure the optically thin rotational transition of H218O 3(1,3)-2(2,0) at 203.4 GHz with EU=203.7K. Imaging and deconvolution of the interferometric data is done with the help of Imager from Grenoble Image and Line Data Analysis Software to create a spatially resolved spectral line cube. This resulting spectra and the continuum emission from the dust is fit in the uv-plane using GALARIO to calculate the column density of H218O . Finally, the abundance of the gas phase water is estimated to be lower than the canonical abundance of 10^(-4) (relative to H2) in IRAS4A, IRAS4B and IRAS2A. Future millimeter observations of such young stellar objects will better constrain these abundances.