from 1 - Physics of H2 and HD
Published online by Cambridge University Press: 04 August 2010
Two observable quantities have been calculated by using the data blocks which provide all details of interstellar UV absorption in H2 gas from the electronic ground state of H2 into 6 electronically excited states and fluorescence emission back into bound and continuum states of the electronic ground state. Both quantities describe details happening in the edges of interstellar H2 abundances where UV radiation is very efficiently shielded and HI gas is produced by fluorescent radiative dissociation. The first is the fluorescence spectrum of H2 in the wavelength range between 1350 and 1700 Å. Comparisons with published spectra show very nice agreement of the resolved features. The second is the velocity distribution of HI produced in fluorescent radiative dissociation. Subject of this comparison are the observed 21 cm spin-flip line profiles of the CNM and WNM (Cold and Warm Neutral Medium) HI species. The profile of the HI velocity dispersion, compared with the “narrow” WNM component, has been obtained at ≈ 9 km/s FWHM which is slightly below the statistical average, and this profile was found to be a molecular property of the H2 gas rather than a function of intensity of the incident UV field or the temperature. The required long tail (“wide” Gaussian component) is provided by all LTE models.
The rest of the paper is devoted to an outline of a dark matter model which fulfills the condition of statistical equilibrium in an active gaseous interphase between the interstellar UV field and the constituent dark matter mass.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.