Photofragment spectroscopy of SO+ in the wavelength range from 308?514.5 nm

Bissantz, H.; Andrić, L.; Hertzler, Ch.; Foth, Hans‐Jochen; Linder, F.

doi:10.1007/bf01437255

Cited by 7 publications

(3 citation statements)

References 25 publications

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“…1f) suggesting that near the DF either n(e − ) is higher than in the model or, more likely, that the SO + photodissociation rate is larger. Indeed, SO + can be dissociated by lower E photons (<5 eV, Bissantz et al 1992). This process is not taken into account in the PDR model.…”

Section: Discussionmentioning

confidence: 99%

Spatially resolved images of reactive ions in the Orion Bar

Goicoechea

Cuadrado

Pety

et al. 2017

A&A

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We report high angular resolution (4.9 × 3.0 ) images of reactive ions SH + , HOC + , and SO + toward the Orion Bar photodissociation region (PDR). We used ALMA-ACA to map several rotational lines at 0.8 mm, complemented with multi-line observations obtained with the IRAM 30 m telescope. The SH + and HOC + emission is restricted to a narrow layer of 2 -to 10 -width (≈800 to 4000 AU depending on the assumed PDR geometry) that follows the vibrationally excited H * 2 emission. Both ions efficiently form very close to the H/H 2 transition zone, at a depth of A V 1 mag into the neutral cloud, where abundant C + , S + , and H * 2 coexist. SO + peaks slightly deeper into the cloud. The observed ions have low rotational temperatures (T rot ≈ 10−30 K T k ) and narrow line-widths (∼2−3 km s −1 ), a factor of 2 narrower that those of the lighter reactive ion CH + . This is consistent with the higher reactivity and faster radiative pumping rates of CH + compared to the heavier ions, which are driven relatively more quickly toward smaller velocity dispersion by elastic collisions and toward lower T rot by inelastic collisions. We estimate column densities and average physical conditions from an excitation model (n(H 2 ) ≈ 10 5 −10 6 cm −3 , n(e − ) ≈ 10 cm −3 , and T k ≈ 200 K). Regardless of the excitation details, SH + and HOC + clearly trace the most exposed layers of the UV-irradiated molecular cloud surface, whereas SO + arises from slightly more shielded layers.

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Section: Discussionmentioning

confidence: 99%

Spatially resolved images of reactive ions in the Orion Bar

Goicoechea

Cuadrado

Pety

et al. 2017

A&A

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“…2, the assumption made by Andrić et al 15 and Bissantz et al 16 of a constant transition dipole moment function in the calculation of the absorption cross section for direct photodissociation is not actually valid. In the region around R e of the a state, the moment is very small (Ϸ0.01 a.u.…”

Section: The State 1 4 ⌺ ؉ and The New 4 ⌸mentioning

confidence: 98%

“…9 as ͑1,1͒ to bring both spectroscopic data into mutual concordance. In recent ion photofragment experiments Andrić et al 15 and Bissantz et al 16 have investigated the direct photodissociation process SO ϩ (a 4 ⌸)ϩh →S ϩ ϩO via the 1 4 ⌺ ϩ state, thus characterizing for the first time the potential energy curve of the repulsive 1 4 ⌺ ϩ state. Very recently, additional insights into the photoelectron spectra of the SO molecule have been gained by Dyke et al 17 using synchrotron radiation.…”

Section: Introductionmentioning

confidence: 99%