168 research outputs found
Discovery of the Interstellar Chiral Molecule Propylene Oxide (CHCHCHO)
Life on Earth relies on chiral molecules, that is, species not superimposable
on their mirror images. This manifests itself in the selection of a single
molecular handedness, or homochirality, across the biosphere. We present the
astronomical detection of a chiral molecule, propylene oxide (CHCHCHO),
in absorption toward the Galactic Center. Propylene oxide is detected in the
gas phase in a cold, extended molecular shell around the embedded, massive
protostellar clusters in the Sagittarius B2 star-forming region. This material
is representative of the earliest stage of solar system evolution in which a
chiral molecule has been found
Science with an ngVLA: Observing the Effects of Chemistry on Exoplanets and Planet Formation
One of the primary mechanisms for inferring the dynamical history of planets
in our Solar System and in exoplanetary systems is through observation of
elemental ratios (i.e. C/O). The ability to effectively use these observations
relies critically on a robust understanding of the chemistry and evolutionary
history of the observed abundances. Significant efforts have been devoted to
this area from within astrochemistry circles, and these efforts should be
supported going forward by the larger exoplanetary science community. In
addition, the construction of a next-generation radio interferometer will be
required to test many of these predictive models in situ, while simultaneously
providing the resolution necessary to pinpoint the location of planets in
formation.Comment: To be published in the ASP Monograph Series, "Science with a
Next-Generation VLA", ed. E. J. Murphy (ASP, San Francisco, CA
Interstellar Carbodiimide (HNCNH) - A New Astronomical Detection from the GBT PRIMOS Survey via Maser Emission Features
In this work, we identify carbodiimide (HNCNH), which is an isomer of the
well-known interstellar species cyanamide (NH2CN), in weak maser emission,
using data from the GBT PRIMOS survey toward Sgr B2(N). All spectral lines
observed are in emission and have energy levels in excess of 170 K, indicating
that the molecule likely resides in relatively hot gas that characterizes the
denser regions of this star forming region. The anticipated abundance of this
molecule from ice mantle experiments is ~10% of the abundance of NH2CN, which
in Sgr B2(N) corresponds to ~2 x 10^13 cm-2. Such an abundance results in
transition intensities well below the detection limit of any current
astronomical facility and, as such, HNCNH could only be detected by those
transitions which are amplified by masing.Comment: Accepted in The Astrophysical Journal Letters, 13 pages, 2 figures,
generated using AAS LaTeX Macros v 5.
CSO and CARMA Observations of L1157. I. A Deep Search for Hydroxylamine (NHOH)
A deep search for the potential glycine precursor hydroxylamine (NHOH)
using the Caltech Submillimeter Observatory (CSO) at mm and the
Combined Array for Research in Millimeter-wave Astronomy (CARMA) at mm is presented toward the molecular outflow L1157, targeting the B1 and B2
shocked regions. We report non-detections of NHOH in both sources. We a
perform non-LTE analysis of CHOH observed in our CSO spectra to derive
kinetic temperatures and densities in the shocked regions. Using these
parameters, we derive upper limit column densities of NHOH of ~cm and ~cm toward the B1
and B2 shocks, respectively, and upper limit relative abundances of
and ,
respectively.Comment: Accepted in the Astrophysical Journa
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