Deuteration in Hot Molecular Cores: Water as a piece of the puzzle

Data: 
26/06/2019 - 14:00 - 15:00
Local: 
Auditório "Prof. Dr. Paulo Benevides Soares", Bloco G

Deuteration in Hot Molecular Cores: Water as a piece of the puzzle

 

Edgar Mendoza

IAG/USP

 

In the last few years, we have dedicated several projects to observe Hot Molecular Cores with the Atacama Pathfinder Experiment (APEX). At the sub-mm range of the spectrum, Hot Molecular Cores (HMCs) are sources well known for exhibiting the so-called “line forest”, which is the direct evidence of their strong molecular emission associated with the sublimation of molecules formed in grains. HMCs are believed to be transient objects in massive star-forming regions - they are dense cores with gas components exceeding 100 K. As an important piece of the puzzle, water is a key molecule since the composition of pristine ices is dominated by it.

Through successful runs with APEX, we have observed HMCs and related sources at the frequency ranges 159-211 GHz, 213-275 GHz and 267-378 GHz. From frontline projects, I will present recent results on the detection of H218O and HDO, H2CO and HDCO, HCN and DCN, whose deuteration ratios shed light on the molecular evolution of HMCs and solide-state chemistry. Gas temperatures and hydrogen densities have been determined thanks to the detection of several O- and N-bearing molecules, whose values are in the intervals T=40–230 K and n=105–106 cm3, respectively. Simulations have been carried out to understand the time evolution of molecular abundances, and the resulting models are constrained within the timescale of 104 yr. In the golden age of modern and future radiotelescopes like LLAMA, surveys at sub-mm wavelengths contribute enormously to our comprehension of the molecular universe.