Thumbnail
Access Restriction
Open

Author Bizzocchi, Luca ♦ Caselli, Paola ♦ Dore, Luca
Source arXiv.org
Content type Text
File Format PDF
Date of Submission 2010-01-27
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Natural sciences & mathematics ♦ Astronomy & allied sciences ♦ Physics
Subject Keyword Astrophysics - Astrophysics of Galaxies ♦ Astrophysics - Earth and Planetary Astrophysics ♦ physics:astro-ph
Abstract Excess levels of 15N isotopes which have been detected in primitive solar system materials are explained as a remnant of interstellar chemistry which took place in regions of the protosolar nebula. Chemical models of nitrogen fractionation in cold clouds predict an enhancement in the gas-phase abundance of 15N-bearing molecules, thus we have searched for 15N variants of the N2H+ ion in L1544, which is one of the best candidate sources for detection owing to its low central core temperature and high CO depletion. With the IRAM 30m telescope we have obtained deep integrations of the N2H+(1-0) line at 91.2 GHz. The N2H+(1-0) line has been detected toward the dust emission peak of L1544. The 14N/15N abundance ratio in N2H+ resulted 446+/-71, very close to the protosolar value of ~450, higher than the terrestrial ratio of ~270, and significantly lower than the lower limit in L1544 found by Gerin et al. (2009, ApJ, 570, L101) in the same object using ammonia isotopologues.
Description Comment: Accepted for publication in Astronomy and Astrophysics
Educational Use Research
Learning Resource Type Article


Open content in new tab

   Open content in new tab