Detection of narrow C 4 and SI 4 absorption features in spectra of stars within 200 PC F the Sun

Molaro, P.; Beckman, J. E.; Franco, M.; Morossi, C.; Ramella, M.
Referencia bibliográfica

In NASA. Goddard Space Flight Center Local Interstellar Medium, No. 81 p 185-188 (SEE N85-15539 06-90)

Fecha de publicación:
11
1984
Número de autores
5
Número de autores del IAC
0
Número de citas
6
Número de citas referidas
5
Descripción
Detection of narrow (δλ < 0.5 Å) absorption features in C IV at λλ1548 and 1550 have been made in the spectra of 4 late B dwarfs within 200 pc of the sun; the Si IV doublet at λλ1393 and 1403 shows up in two of them. The authors argue that it is difficult to account for the strengths, widths, shapes, and C IV/Si IV ratios in terms consistent with a circumstellar origin except possibly for an asymmetric C IV component in one star (HD 185037). The most probable source is "semi-torrid" gas (cf. Bruhweiler et al. 1980) in the 50,000K range forming the interfaces between cooler H I clouds and the ambient medium at coronal temperatures. The technique, using late B rapid rotators, is useful for LISM probing of this kind.