Zobrazeno 1 - 10
of 280
pro vyhledávání: '"Sipilä, O."'
We investigated the effect of time-dependent ice growth on dust grains on the opacity and hence on the dust temperature in a collapsing molecular cloud core, with the aim of quantifying the effect of the dust temperature variations on ice abundances
Externí odkaz:
http://arxiv.org/abs/2408.17202
Autor:
Jensen, S. S., Spezzano, S., Caselli, P., Sipilä, O., Redaelli, E., Giers, K., Asensio, J. Ferrer
We aim to determine the $^{14}$N/$^{15}$N and $^{12}$C/$^{13}$C ratios for HCN in six starless and prestellar cores and compare the results between the direct method using radiative transfer modeling and the indirect double isotope method assuming a
Externí odkaz:
http://arxiv.org/abs/2403.04408
Autor:
Petrashkevich, I. V., Punanova, A. F., Caselli, P., Sipilä, O., Pineda, J. E., Friesen, R. K., Korotaeva, M. G., Vasyunin, A. I.
In this work, we study deuterium fractionation in four starless cores in the low-mass star-forming region L1688 in the Ophiuchus molecular cloud. We study how the deuterium fraction ($R_D$) changes with environment, compare deuteration of ions and ne
Externí odkaz:
http://arxiv.org/abs/2401.04415
Publikováno v:
A&A 680, A87 (2023)
Aims. We aim to improve a previous model for the prediction of column densities and deuterium fractions of non- and singly deuterated methanol. Thereby, we try to identify crucial chemical and physical parameters, for which the study of deuteration c
Externí odkaz:
http://arxiv.org/abs/2310.08389
Publikováno v:
A&A 678, A120 (2023)
We present a new gas-grain chemical model for the combined isotopic fractionation of carbon and nitrogen in molecular clouds, in which the isotope chemistry of carbon and nitrogen is coupled with a time-dependent description of spin-state chemistry.
Externí odkaz:
http://arxiv.org/abs/2309.02066
Autor:
Giers, K., Spezzano, S., Caselli, P., Wirström, E., Sipilä, O., Pineda, J. E., Redaelli, E., Bop, C. T., Lique, F.
Publikováno v:
A&A 676, A78 (2023)
In the centre of pre-stellar cores, deuterium fractionation is enhanced due to the low temperatures and high densities. Therefore, the chemistry of deuterated molecules can be used to study the earliest stages of star formation. We analyse the deuter
Externí odkaz:
http://arxiv.org/abs/2306.12775
Autor:
Redaelli, E., Chacón-Tanarro, A., Caselli, P., Tafalla, M., Pineda, J. E., Spezzano, S., Sipilä, O.
Prestellar cores, the birthplace of Sun-like stars, form from the fragmentation of the filamentary structure that composes molecular clouds, from which they must inherit at least partially the kinematics. Furthermore, when they are on the verge of gr
Externí odkaz:
http://arxiv.org/abs/2210.13571
Publikováno v:
A&A 668, A131 (2022)
We aim to quantify the effect of chemistry on the infall velocity in the prestellar core L1544. Previous observational studies have found evidence for double-peaked line profiles for the rotational transitions of several molecules, which cannot be ac
Externí odkaz:
http://arxiv.org/abs/2209.14025
Autor:
Asensio, J. Ferrer, Spezzano, S., Caselli, P., Alves, F. O., Sipilä, O., Redaelli, E., Bizzocchi, L., Lique, F., Mullins, A.
Spectral line profiles of several molecules observed towards the pre-stellar core L1544 appear double-peaked. For abundant molecular species this line morphology has been linked to self-absorption. However, the physical process behind the double-peak
Externí odkaz:
http://arxiv.org/abs/2209.02489
Autor:
Giers, K., Spezzano, S., Alves, F., Caselli, P., Redaelli, E., Sipilä, O., Khalifa, M. Ben, Wiesenfeld, L., Brünken, S., Bizzocchi, L.
Publikováno v:
A&A 664, A119 (2022)
Context: In the centre of pre-stellar cores, the deuterium fractionation is enhanced due to the cold temperatures and high densities. Therefore, the chemistry of deuterated molecules can be used to probe the evolution and the kinematics in the earlie
Externí odkaz:
http://arxiv.org/abs/2205.14963