A submillimeter study of the star-forming region NGC 7129

被引:20
作者
Font, AS
Mitchell, GF
Sandell, G
机构
[1] St Marys Univ, Dept Phys & Astron, Halifax, NS B3H 3C3, Canada
[2] NASA, Univ Space Res Assoc, Ames Res Ctr, Moffett Field, CA 94035 USA
关键词
dust; extinction; ISM : molecules; stars : formation; stars : individual (LkHa 234); stars : pre-main-sequence; submillimeter;
D O I
10.1086/321503
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
New molecular ((CO)-C-13 J = 3-2) and dust continuum (450 and 850 mum) maps of the NGC 7129 star-forming region are presented. The maps include the Herbig Ae/Be star LkH alpha 234, the far-infrared source NGC 7129 FIRS 2, and several other prestellar sources embedded within the molecular ridge. The data are complemented with (CO)-O-18 J = 3-2 spectra at several positions within the mapped region. Both the submillimeter and the (CO)-C-13 emission show a similar morphology, displaying a sharp boundary toward the cavity. The submillimeter maps also reveal a second source, SMM 2, which is not clearly seen in any earlier data set. This is either a prestellar core or possibly a protostar. Also, the highest continuum peak emission is identified with the deeply embedded source IRS 6 a few arcseconds away from LkHa 234. These new 450 and 850 mum observations are combined with previous continuum observations of the three compact far-infrared sources in the field, in order to make fits to the spectral energy distributions and to obtain the source sizes, dust temperatures, luminosities, and masses. For nine positions where both (CO)-C-13 and (CO)-O-18 spectra are available, gas masses have been obtained and compared with masses derived from the continuum fluxes. The masses are found to be consistent, implying little or no CO depletion onto grains. The dust emissivity index is found to be low toward the dense compact sources, beta similar to1-1.6, and high, beta similar to 2.0, in the surrounding cloud.
引用
收藏
页码:950 / 960
页数:11
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