相关论文: Nitrogen Isotopic Fractionation in Interstellar Am…
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…
We present new radio-frequency interferometric maps of emission from the 14NH3, 15NH3, and 14NH2D isotopologues of ammonia, and the 12CH3OH and 13CH3OH isotopologues of methanol toward Sgr B2(N). With a resolution of ~3'' (0.1 pc), we are…
Nitrogen isotopic ratios are a key tool for tracing Galactic stellar nucleosynthesis. We present the first study of the $^{14}$N/$^{15}$N abundance ratio in the outer regions of the Milky Way (namely, for galactocentric distances, $R_{\rm…
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…
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…
The isotopic ratio of nitrogen presents a wide range of values in the Solar System and in star forming system whose origin is still unclear. Chemical reactions in the gas phase are one of the possible processes that could modify the…
Isotopic ratios are keys to understanding the origin and early evolution of the solar system in the context of Galactic nucleosynthesis. The large range of measured $^{14}$N/$^{15}$N isotopic ratios in the solar system reflects distinct…
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…
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…
Each of the nitriles present in the atmosphere of Titan can be expected to exhibit different \ce{^{14}N/^{15}N} values depending on their production processes, primarily because of the various \ce{N2} dissociation processes induced by…
We investigate nitrogen isotope fractionation in forming and evolving molecular clouds using gas-ice astrochemical simulations. We find that the bulk gas can become depleted in heavy nitrogen (15N) due to the formation of 15N-enriched ices.…
The 14N/15N ratio in molecules exhibits a large variation in star-forming regions, especially when measured from N2H+ isotopologues. However, there are only a few studies performed at high-angular resolution. We present the first…
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…
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…
Organic material found in meteorites and interplanetary dust particles is enriched in D and 15N. This is consistent with the idea that the functional groups carrying these isotopic anomalies, nitriles and amines, were formed by ion-molecule…
The Texas Echelon cross Echelle Spectrograph (TEXES), mounted on NASA's Infrared Telescope Facility (IRTF), was used to map mid-infrared ammonia absorption features on both Jupiter and Saturn in February 2013. Ammonia is the principle…
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…
We use spectra and maps of NH2D, ND2H, and ND3, obtained with the CSO, IRAM 30m and Arecibo telescopes, to study deuteration processes in dense cores. The data include the first detection of the hyperfine structure of ND2H. The emission of…
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…
Partitioning of elemental nitrogen in star-forming regions is not well constrained. Most nitrogen is expected to be partitioned among atomic nitrogen, molecular nitrogen (N2), and icy N-bearing molecules, such as ammonia (NH3) and N2.…