ISO-LWS detection of the 112 micron HD J=1-0 line toward the Orion Bar

Details ISO-LWS detection of the 112 micron HD J=1-0 line toward the Orion Bar ISO-LWS detection of the 112 micron HD J=1-0 line toward the Orion Bar

1999-01-28

arxiv.org/abs/astro-ph/9901391v1

Astronomy and Astrophysics

Astrophysics

18 pages including 1 figure, accepted for publication in Astrophysical Journal Letters

Scientific paper

We report the first detection outside of the solar system of the lowest pure rotational J=1-0 transition of the HD molecule at 112 microns. The detection was made toward the Orion Bar using the Fabry-Perot of the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). The line appears in emission with an integrated flux of (0.93+/-0.17)e-19 Watts per cm squared in the LWS beam, implying a beam-averaged column density in the v=0, J=1 state of (1.2+/-0.2)e17 molecules per cm squared. Assuming LTE excitation, the total HD column density is (2.9+/-0.8)e17 molecules per cm squared for temperatures between 85 and 300 K. Combined with the total warm molecular hydrogen (H2) column density of about (1.5-3.0)e22 molecules per cm squared derived from either the H2 pure rotational lines, C18O observations or dust continuum emission, the implied HD abundance, HD/H2, ranges from 0.7e-5 to 2.6e-5, with a preferred value of (2.0+/-0.6)e-5. The corresponding deuterium abundance of [D]/[H]=(1.0+/-0.3)e-5 is compared with recent values derived from ultraviolet absorption line observations of atomic HI and DI in interstellar clouds in the solar neighborhood and in Orion.

Affiliated with

Also associated with

No associations

Rating

ISO-LWS detection of the 112 micron HD J=1-0 line toward the Orion Bar does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with ISO-LWS detection of the 112 micron HD J=1-0 line toward the Orion Bar, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and ISO-LWS detection of the 112 micron HD J=1-0 line toward the Orion Bar will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-598585