All tracers show, to different degrees according to their properties, progressive warming with evolution. CH 3OH and CH 3CN are also abundant in the hot cores, and we suggest that their high-excitation transitions are good tools to study the kinematics in the hot gas associated with the inner envelope surrounding the young stellar objects that these clumps are hosting. Low temperatures are traced by ammonia, methanol, and CO (in the early phases), the warm and dense envelope can be probed with CH 3CN, CH 3CCH, and, in evolved sources where CO is abundant in the gas phase, via its optically thin isotopologues. The chemical properties of each species have a major role on the measured physical properties. Our findings are compared with results obtained from optically thin CO isotopologues, dust, and ammonia from previous studies on the same sample. From the spectroscopic follow-ups carried out towards submillimeter continuum (dust) emission-selected massive clumps (the ATLASGAL TOP100 sample) with the IRAM 30 m, Mopra, and APEX telescopes between 84 GHz and 365 GHz, we selected several multiplets of CH 3CN, CH 3CCH, and CH 3OH emission lines to derive and compare the physical properties of the gas in the clumps along the evolutionary sequence, fitting simultaneously the large number of lines that these molecules have in the observed band. We aim to use the progressive heating of the gas caused by the feedback of high-mass young stellar objects to prove the statistical validity of the most common schemes used to observationally define an evolutionary sequence for high-mass clumps, and characterise the sensitivity of different tracers to this process. Spectroscopic observations give the opportunity to test possible schemes and connect the phases identified to physical processes.Īims. Observational identification of a solid evolutionary sequence for high-mass star-forming regions is still missing. Gobetti 101, 40129 Bologna, Italyģ INAF–Osservatorio Astronomico di Cagliari, via della Scienza 5, 09047 Selargius (CA), ItalyĤ School of Physical Sciences, University of Kent, Ingram Building, Canterbury, Kent CT2 7NH, UKĬontext. Güsten 1ġ Max-Planck-Institut für Radioastronomie, auf dem Hügel 69, 53121, Bonn, GermanyĮ-mail: INAF–Istituto di Radioastronomia & Italian ALMA Regional Centre, via P.
Including author names using non-Roman alphabets.
Suggested resources for more tips on language editing in the sciences Punctuation and style concerns regarding equations, figures, tables, and footnotes
0 kommentar(er)
