English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We aim to further constrain the properties and evolutionary stages of densecores in Orion B9. The central part of Orion B9 was mapped at 350 micron withAPEX/SABOCA. A sample of nine cores in the region were observed in C17O(2-1),H13CO+(4-3) (towards 3 sources), DCO+(4-3), N2H+(3-2), and N2D+(3-2) withAPEX/SHFI. These data are used in conjunction with our previous APEX/LABOCA870-micron dust continuum data. Many of the LABOCA cores show evidence ofsubstructure in the higher-resolution SABOCA image. In particular, we report onthe discovery of multiple very low-mass condensations in the prestellar coreSMM 6. Based on the 350-to-870 micron flux density ratios, we determine dusttemperatures of ~7.9-10.8 K, and dust emissivity indices of ~0.5-1.8. The COdepletion factors are in the range ~1.6-10.8. The degree of deuteration in N2H+is ~0.04-0.99, where the highest value (seen towards the prestellar core SMM 1)is, to our knowledge, the most extreme level of N2H+ deuteration reported sofar. The level of HCO+ deuteration is about 1-2%. We also detected D2CO towardstwo sources. The detection of subcondensations within SMM 6 shows that corefragmentation can already take place during the prestellar phase. The origin ofthis substructure is likely caused by thermal Jeans fragmentation of theelongated parent core. A low depletion factor and the presence of gas-phaseD2CO in SMM 1 suggest that the core chemistry is affected by the nearbyoutflow. The very high N2H+ deuteration in SMM 1 is likely to be remnant of theearlier CO-depleted phase.

A (sub)millimetre study of dense cores in Orion B9