Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-12-27
Astrophys.J.642:319-329,2006
Astronomy and Astrophysics
Astrophysics
28 pages, 1 figure, 3 tables, to appear in the 2006 May 1 issue of the Astrophysical Journal
Scientific paper
10.1086/500657
In this work we present a sensitive and systematic single-dish survey of CCS emission (complemented with ammonia observations) at 1 cm, toward a sample of low- and intermediate-mass young star forming regions known to harbor water maser emission, made with NASA's 70 m antenna at Robledo de Chavela, Spain. Out of the 40 star forming regions surveyed in the CCS(2_{1}-1_{0}) line, only 6 low-mass sources show CCS emission: one transitional object between pre-stellar and protostellar Class 0 phase (GF9-2), three Class 0 protostars (L1448-IRS3, L1448C, and B1-IRS), a Class I source (L1251A), and a young T Tauri star (NGC2071-North). Since CCS is considered an ``early-time'' (<10E+5 yr) molecule, we explain these results by either proposing a revision of the classification of the age of NGC2071-North and L1251A, or suggesting the possibility that the particular physical conditions and processes of each source affect the destruction/production of the CCS. No statistically significant relationship was found between the presence of CCS and parameters of the molecular outflows and their driving sources. Nevertheless, we found a significant relationship between the detectability of CCS and the ammonia peak intensity (higher in regions with CCS), but not with its integrated intensity. This tendency found may suggest that the narrower ammonia line widths in the less turbulent medium associated with younger cores may compensate for the differences in ammonia peak intensity, rendering differences in integrated intensity negligible. From the CCS detection rate we derive a lifetime of this molecule of ~(0.7-3) x 10E+4 yr in low-mass star forming regions.
Gomez Jose F.
Gregorio-Monsalvo Itziar de
Jimenez-Bailon Elena
Kuiper Thomas B. H.
Rodriguez Luis F.
No associations
LandOfFree
CCS and NH3 emission associated with low-mass young stellar objects does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with CCS and NH3 emission associated with low-mass young stellar objects, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and CCS and NH3 emission associated with low-mass young stellar objects will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-290625