The apparent dynamical age is low – only 10(4) years or so. Thus (as ever!) further observations were required to try and decipher exactly what was going on. However, upon calculating the gas parameters and analyzing the energetics it became clear that the data could still be interpreted as a rotationally supported disc. The latter initially seemed a better choice, especially as the survey by Fukui (1989) revealed a CO outflow in this region. Fifteen years ago, the reaction to this would have been ‘A rotating disc!’ these days the reaction tends to be ‘Outflow!’. Closer examination of the HCO+ J=3-2 spectra revealed the presence of spatially-separated blue- and red- shifted wing emission, centered on LBS17H. It was first identified as one of five massive cores by a survey of well-known star-forming complexes. “LBS17 is a dense cloud core which lies close to NGC 2068 in L1630. Said Andy Gibb of the University of Kent: Called Herbig-Haro objects, astronomers believe these are jets of matter ejected from neophyte newly formed inside M78 – LBS17. We find three populations of evolved disks (IRAC weak, MIPS weak, and transition disks) all of which show decreased accretion activity in addition to the evidence for evolution in the dust disk.”Ī significant number of dramatic outflow sources are found in the region of M78. A substantial fraction (79%) of the 67 members have an infrared excess while all of the stars with significant infrared excess show evidence for active accretion. Using high-resolution spectra of the H? line we study the accretion activity of these likely members and also examine the disk properties of the likely members using IRAC and MIPS mid-infrared photometry. Using low-resolution optical spectra, we define a membership sample and determine an age for the region of ~2 Myr. “We study the disk and accretion properties of young stars in the NGC 2068 and NGC 2071 clusters. Flaherty and James Mazerolle said in a 2007 study: In the area are 45 low mass stars with hydrogen emission lines – irregular variable stars similar to the star T Tauri – which may very well be at the beginning stages of their stellar life.Īs K. It is illuminated over an expanse of four light years by the by the energy of its embedded, bright blue, early B-type stars which emit a continuous spectrum. M78 is a cloud of interstellar dust located about 1,600 light years from Earth.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |