A RADIO-CONTINUUM AND H-I STUDY OF IC-63, IC-59, AND IRAS-00556- NEBULAE IN THE VICINITY OF GAMMA-CAS(6048 )

Citation
D. Blouin et al., A RADIO-CONTINUUM AND H-I STUDY OF IC-63, IC-59, AND IRAS-00556- NEBULAE IN THE VICINITY OF GAMMA-CAS(6048 ), Monthly Notices of the Royal Astronomical Society, 287(2), 1997, pp. 455-471
Citations number
37
Categorie Soggetti
Astronomy & Astrophysics
ISSN journal
00358711
Volume
287
Issue
2
Year of publication
1997
Pages
455 - 471
Database
ISI
SICI code
0035-8711(1997)287:2<455:ARAHSO>2.0.ZU;2-X
Abstract
Sh 185, which is associated with the B0-B0.5IV star gamma Cas and cont ains the two nebulae IC 63 and IC 59, has been observed with the DRAG synthesis telescope in continuum emission at 408 and 1420 MHz, and in H I line emission. Continuum emission is clearly detected for IC 63 an d weakly detected for IC 59. The emission from both nebulae is thermal , with the masses of ionized gas being 0.08 and 0.07 M., respectively. The masses of H I detected are 0.15 M. for IC 63, and 0.64 M. for IC 59. Infrared emission was detected in the IRAS survey from both IC 63 and IC 59, and also from a point source, IRAS 00556 + 6048, located be tween the two clouds. The infrared and radio luminosities of IC 63 and IC 59 are consistent with the heating and ionization being produced b y gamma Cas. However, the time required to produce the observed H I th rough photodissociation is less than any reasonable age for gamma Cas by orders of magnitude. This suggests that the nebulae are density-bou nded and the production of H I through photodissociation by radiation from gamma Cas has mostly ceased. The exception occurs in a small regi on of molecular gas in IC 63, where extended red emission and molecula r hydrogen fluorescent emission are still observed. H I is also detect ed near IRAS 00556 + 6048. This H I appears to be associated with the infrared source, and with a velocity of -34 km s(-1) suggests that the infrared source is not associated with Sh 185. The exciting star for IRAS 00556 + 6048 may be another example of a dissociating star.