4-8 October 2015
Hans Harnack Haus
Europe/Berlin timezone
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Contribution Contributed Talk

Hans Harnack Haus -

The dense core Barnard 1b, a laboratory for star formation studies


  • Prof. Maryvonne GERIN

Primary authors



The Barnard 1b core in the Perseus molecular cloud is remarkable in several aspects :

i) It hosts three protostars, including two class 0 sources and a more evolved object. One of the class 0 sources is very young and could still be at the first hydrostatic core stage.

ii) The core is magnetized with a ratio $\mu$ of mass to flux to critical mass to flux between 2 and 10. Protostellar outflows are not aligned with the direction of the ambient magnetic field.

iii) It shows high abundances of deuterated species, including triply deuterated ammonia and several doubly deuterated molecules and all main nitrogen species with their $^{15}$N isotopologues.

iv) Organic species are also present including dimethyl ether and methyl mercaptan.

Our team has obtained a high sensitivity line survey of this source (presented in the contribution by N. Marcelino) and deep, high angular resolution observations with NOEMA and with the VLA, which allowed the detection of several new species, and a good characterization of the structure and chemistry of this core, including the two condensations hosting the young protostars and their molecular outflows. We have derived the $^{12}$C/$^{13}$C, D/H, $^{15}$N/$^{14}$N isotopic ratios, constrained the age and evolutionary stage of the protostars and the mass inflow rate. We show that the properties are consistent with predictions of MHD simulations adapted to the appropriate initial conditions of Barnard1b.