Discovery of Interstellar Hydrogen Fluoride

Details Discovery of Interstellar Hydrogen Fluoride Discovery of Interstellar Hydrogen Fluoride

1997-08-01

arxiv.org/abs/astro-ph/9708013v1

Astronomy and Astrophysics

Astrophysics

11 pages (AASTeX using aaspp4.sty) plus 2 figures; to appear in ApJ Letters

Scientific paper

10.1086/310942

We report the first detection of interstellar hydrogen fluoride. Using the Long Wavelength Spectrometer (LWS) of the Infrared Space Observatory (ISO), we have detected the 121.6973 micron J = 2 - 1 line of HF in absorption toward the far-infrared continuum source Sagittarius B2. The detection is statistically significant at the 13 sigma level. On the basis of our model for the excitation of HF in Sgr B2, the observed line equivalent width of 1.0 nm implies a hydrogen fluoride abundance of 3E-10 relative to H2. If the elemental abundance of fluorine in Sgr B2 is the same as that in the solar system, then HF accounts for ~ 2% of the total number of fluorine nuclei. We expect hydrogen fluoride to be the dominant reservoir of gas-phase fluorine in Sgr B2, because it is formed rapidly in exothermic reactions of atomic fluorine with either water or molecular hydrogen; thus the measured HF abundance suggests a substantial depletion of fluorine onto dust grains. Similar conclusions regarding depletion have previously been reached for the case of chlorine in dense interstellar clouds. We also find evidence at a lower level of statistical significance (~ 5 sigma) for an emission feature at the expected position of the 4(3,2)-4(2,3) 121.7219 micron line of water. The emission line equivalent width of 0.5 nm for the water feature is consistent with the water abundance of 5E-6 relative to H2 that has been inferred previously from observations of the hot core of Sgr B2.

Affiliated with

Also associated with

No associations

Rating

Discovery of Interstellar Hydrogen Fluoride 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 Discovery of Interstellar Hydrogen Fluoride, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Discovery of Interstellar Hydrogen Fluoride will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-639037