Related papers: Nitrogen Isotopic Fractionation in Interstellar Am…
Carbon containing molecules in cold molecular clouds show various levels of isotopic fractionation through multiple observations. To understand such effects, we have developed a new gas-grain chemical model with updated 13C fractionation…
We report on the detection of a narrow feature at 262816.73 MHz towards Orion and the cold prestellar core B1-bS, that we attribute to the 1(0)-0(0) line of the deuterated Ammonium ion, NH3D+. The observations were performed with the IRAM…
We report on the first detection of C3N- and C5N- towards the cold dark core TMC-1 in the Taurus region, using the Yebes 40 m telescope. The observed C3N/C3N- and C5N/C5N- abundance ratios are 140 and 2, respectively; that is similar to…
We have used the Odin submillimetre-wave satellite telescope to observe the ground state transitions of ortho-ammonia and ortho-water, including their 15N, 18O, and 17O isotopologues, towards Sgr B2. The extensive simultaneous velocity…
The determination of absolute widths of two observed levels above the proton threshold in $^{15}$N has been improved by a combined analysis of our recent $^{15}$N($\gamma$,$\gamma'$)$^{15}$N$^\ast$ photon scattering data, resonance…
We present a new constraint on the Galactic $^{12}$C/$^{13}$C gradient with sensitive HCO$^+$ absorption observations against strong continuum sources. The new measurements suffer less from beam dilution, optical depths, and chemical…
Identifying the nucleosynthesis processes behind heavy-element enrichment in stellar atmospheres is challenging. It typically relies on comparing observed abundance-to-iron ratios with theoretical predictions relative to the Sun, but this…
Molecular nitrogen is one of the key species in the chemistry of interstellar clouds and protoplanetary disks and the partitioning of nitrogen between N and N2 controls the formation of more complex prebiotic nitrogen-containing species.…
We study collisions between neutral, deuterated ammonia molecules (ND$_3$) stored in a 50 cm diameter synchrotron and argon atoms in co-propagating supersonic beams. The advantages of using a synchrotron in collision studies are twofold:…
The Super-Kamiokande detector has measured solar neutrinos for more than $25$ years. The sensitivity for solar neutrino measurement is limited by the uncertainties of energy scale and background modeling. Decays of unstable isotopes with…
Recent measurements of carbon isotope ratios in both protoplanetary disks and exoplanet atmospheres have suggested a possible transfer of significant carbon isotope fractionation from disks to planets. For a clearer understanding of the…
Context. Investigations of abundances of carbon and nitrogen in the atmospheres of evolved stars of open clusters may provide comprehensive information on chemical composition changes caused by stellar evolution. Aims. Our main aim is to…
We have carried out observations of CCH and its two $^{13}$C isotopologues, $^{13}$CCH and C$^{13}$CH, in the 84 - 88 GHz band toward two starless cores, L1521B and L134N (L183), using the Nobeyama 45 m radio telescope. We have detected…
Nitrous oxide is a long-lived greenhouse gas. Its isotopic composition provides valuable insights into sources and sinks, and about the mechanism of formation. A major challenge in the spectroscopic analysis of the isotopocule compositions…
The iron depletion level and the gas-phase iron abundance in the hot ~10^6 K interstellar medium (ISM) is critical to the understanding of its energy balance as well as the thermal sputtering, cooling, and heating processes of dust grains.…
N$_2$ plays a profound role in supporting processes on the surface and in the atmosphere of Pluto, yet the origin of Pluto's N$_2$ remains a mystery. However, this may begin to change as the $^{14}$N/$^{15}$N ratio of N$_2$ was recently…
We use NH3 inversion transitions to trace the dense gas in the NGC 1333 region of the Perseus molecular cloud. NH3(1,1) and NH3(2,2) maps covering an area of 102 square arcminutes at an angular resolution of ~3.7" are produced by combining…
We use the absorption features from neutral argon at 1048 and 1066 A to determine interstellar abundances or their lower limits toward nine early-type stars. These features were observed with the Interstellar Medium Absorption Profile…
We present Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph observations of the weak interstellar N I doublet at 1160 Angstroms toward 17 high-density sight lines [N(Htot)>=10^21 cm^-2]. When combined…
With the goal of deriving the physical and chemical conditions of star forming regions in the Large Magellanic Cloud (LMC), a spectral line survey of the prominent star forming region N113 is presented. The observations cover parts of the…