Examinando por Autor "Majumdar, L."

Mostrando 1 - 1 de 1

Acceso Abierto
Evolutionary view through the starless cores in Taurus Deuteration in TMC 1-C and TMC 1-CP
(EDP Sciences, 2021-06-15) Navarro Almaida, D.; Fuente, A.; Majumdar, L.; Wakelam, V.; Caselli, P.; Rivière Marichalar, P.; Treviño Morales, S. P.; Cazaux, S.; Jiménez Serra, I.; Kramer, C.; Chacón Tanarro, A.; Kirk, J. M.; Ward Thompson, D.; Tafalla, M.; Centre National D'Etudes Spatiales (CNES); Agencia Estatal de Investigación (AEI); European Research Council (ERC); Navarro Almaida, D. [0000-0002-8499-7447]; Fuente, A. [0000-0001-6317-6343]; Wakelam, V. [0000-0001-9676-2605]; Caselli, P. [0000-0003-1481-7911]; Rivière Marichalar, P. [0000-0003-0969-8137]; Treviño Morales, S. P. [0000-0002-4033-2881]; Ward Thompson, D. [0000-0003-1140-2761]; Jiménez Serra, I. [0000-0003-4493-8714]; Tafalla, M. [0000-0002-2569-1253]
Context. The chemical and physical evolution of starless and pre-stellar cores are of paramount importance to understanding the process of star formation. The Taurus Molecular Cloud cores TMC 1-C and TMC 1-CP share similar initial conditions and provide an excellent opportunity to understand the evolution of the pre-stellar core phase. Aims. We investigated the evolutionary stage of starless cores based on observations towards the prototypical dark cores TMC 1-C and TMC 1-CP. Methods. We mapped the prototypical dark cores TMC 1-C and TMC 1-CP in the CS 3 → 2, C34S 3 → 2, 13CS 2 → 1, DCN 1 → 0, DCN 2 → 1, DNC 1 → 0, DNC 2 → 1, DN13C 1 → 0, DN13C 2 → 1, N2H+ 1 → 0, and N2D+ 1 → 0 transitions. We performed a multi-transitional study of CS and its isotopologs, DCN, and DNC lines to characterize the physical and chemical properties of these cores. We studied their chemistry using the state-of-the-art gas-grain chemical code NAUTILUS and pseudo time-dependent models to determine their evolutionary stage. Results. The central nH volume density, the N2H+ column density, and the abundances of deuterated species are higher in TMC 1-C than in TMC 1-CP, yielding a higher N2H+ deuterium fraction in TMC 1-C, thus indicating a later evolutionary stage for TMC 1-C. The chemical modeling with pseudo time-dependent models and their radiative transfer are in agreement with this statement, allowing us to estimate a collapse timescale of ~1 Myr for TMC 1-C. Models with a younger collapse scenario or a collapse slowed down by a magnetic support are found to more closely reproduce the observations towards TMC 1-CP. Conclusions. Observational diagnostics seem to indicate that TMC 1-C is in a later evolutionary stage than TMC 1-CP, with a chemical age ~1 Myr. TMC 1-C shows signs of being an evolved core at the onset of star formation, while TMC 1-CP appears to be in an earlier evolutionary stage due to a more recent formation or, alternatively, a collapse slowed down by a magnetic support.