Related papers: Nitrogen fractionation towards a pre-stellar core …
The isotopic ratio of nitrogen in nearby protoplanetary disks, recently measured in CN and HCN, indicates that a fractionated reservoir of nitrogen is available at the stage of comet formation. This reservoir presents a 3:1 enrichment in…
(Abridged) The terrestrial planets, comets, and meteorites are significantly enriched in 15N compared to the Sun and Jupiter. While the solar and jovian nitrogen isotope ratio is believed to represent the composition of the protosolar…
The fractionation of nitrogen (N) in star-forming regions is a poorly understood process. To put more stringent observational constraints on the N-fractionation, we have observed with the IRAM-30m telescope a large sample of 66 cores in…
The ratio between the two stable isotopes of nitrogen, $^{14}$N and $^{15}$N, is well measured in the terrestrial atmosphere ($\sim 272$), and in the pre-Solar nebula ($\sim 441$). Interestingly, some pristine Solar System materials show…
Isotopic fractionation is an important tool to investigate the chemical history of our Solar System (SS). In particular, the isotopic fraction of nitrogen (14N/15N) is lower in comets and other pristine SS bodies with respect to the value…
Aims: The two stable isotopes of nitrogen, 14N and 15N, exhibit a range of abundance ratios both inside and outside the solar system. The elemental ratio in the solar neighborhood is 440. Recent ALMA observations showed HCN/HC15N ratios…
Measurements of the nitrogen isotopic ratio in Solar System comets show a constant value, ~140, which is three times lower than the protosolar ratio, a highly significant difference that remains unexplained. Observations of static starless…
The line intensities of the fundamental rotational transitions of H13CN and HC15N were observed towards two prestellar cores, L183 and L1544, and lead to molecular isotopic ratios 140 6 14N/15N 6 250 and 140 6 14N/15N 6 360, respectively.…
Context. The increased sensitivity and high spectral resolution of millimeter telescopes allow the detection of an increasing number of isotopically substituted molecules in the interstellar medium. The 14N/ 15N ratio is difficult to…
The origin of the heavily fractionated reservoir of nitrogen in comets remains an issue in the theory of their formation and hence of the solar system. Whether the fractionated reservoir traced by comets is inherited from the interstellar…
Understanding the origin of the composition of solar system cosmomaterials is a central question, not only in the cosmochemistry and astrochemistry fields, and requires various approaches to be combined. Measurements of isotopic ratios in…
We investigated the chemistry of nitrogen--containing species, principally isotopomers of CN, HCN, and HNC, in a sample of pre-protostellar cores. We used the IRAM 30 m telescope to measure the emission in rotational and hyperfine…
Photodissociation of 14N2 and 14N15N occurs in interstellar clouds, circumstellar envelopes, protoplanetary discs, and other environments due to UV radiation from stellar sources and the presence of cosmic rays. This source of N atoms…
Nitrogen is one of the most abundant elements in the Universe and its 14N/15N isotopic ratio has the potential to provide information about the initial environment in which our Sun formed. Recent findings suggest that the Solar System may…
Context: The $^{15}$N fractionation has been observed to show large variations among astrophysical sources, depending both on the type of target and on the molecular tracer used. These variations cannot be reproduced by the current chemical…
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…
Nitrogen (N) fractionation is used as a tool to search for a link between the chemical history of the Solar System and star-forming regions. A large variation of $^{14}$N/$^{15}$N is observed towards different astrophysical sources, and…
The isotopic ratio of nitrogen measured in primitive Solar System bodies shows a broad range of values, the origin of which remains unknown. One key question is whether these isotopic reservoirs of nitrogen predate the comet formation stage…
Element isotopic ratios are powerful tools to reconstruct the journey of planetary material, from the parental molecular cloud to protoplanetary disks, where planets form and accrete their atmosphere. Radial variations in isotopic ratios in…
The investigation of the isotopic ratio of interstellar nitrogen -- $^{14}$N versus $^{15}$N -- is done, for explaining its variations observed for N2H+ in different interstellar and Solar environments. The goal is to produce cross sections…