Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2010-01-20
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
ApJ accepted. 45 pages, 8 figures
Scientific paper
We investigate 35 pre-stellar cores and 36 proto-stellar cores in the Perseus molecular cloud. We find a very tight correlation between the physical parameters describing the N2H+ and NH3 gas. Both the velocity centroids and the line widths of N2H+ and NH3 correlate much better than either species correlates with CO, as expected if the nitrogen-bearing species are probing primarily the dense core gas where the CO has been depleted. We also find a tight correlation in the inferred abundance ratio between N2H+ and para-NH3 across all cores, with N(p-NH3)/N(N2H+)= 22 +/- 10. We find a mild correlation between NH3 (and N2H+) column density and the (sub)millimeter dust continuum derived H2 column density for pre-stellar cores, N(p-NH3)/N(H2) ~ 10e-8, but do not find a fixed ratio for proto-stellar cores. The observations suggest that in the Perseus molecular cloud the formation and destruction mechanisms for the two nitrogen-bearing species are similar, regardless of the physical conditions in the dense core gas. While the equivalence of N2H+ and NH3 as powerful tracers of dense gas is validated, the lack of correspondence between these species and the (sub)millimeter dust continuum observations for proto-stellar cores is disconcerting and presently unexplained.
Johnstone Doug
Kirk Helen
Rosolowsky Erik
Tafalla Mario
No associations
LandOfFree
Dense Gas Tracers in Perseus: Relating the N2H+, NH3, and Dust Continuum Properties of Pre- and Proto-Stellar Cores 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 Dense Gas Tracers in Perseus: Relating the N2H+, NH3, and Dust Continuum Properties of Pre- and Proto-Stellar Cores, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dense Gas Tracers in Perseus: Relating the N2H+, NH3, and Dust Continuum Properties of Pre- and Proto-Stellar Cores will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-248467