Detection of H2D+ in a massive prestellar core in Orion B

Abstract

Aims. The purpose of this study is to examine the prediction that the deuterated H3+ ion, H2D+, can be found exclusively in the coldest regions of molecular cloud cores. This is also a feasibility study for the detection of the ground-state line of ortho-H2D+ at 372 GHz with APEX. Methods. The 1(10)-1(11) transition of H2D+ at 372 GHz was searched towards selected positions in the massive star forming cloud OriB9, in the dark cloud L183, and in the low- to intermediate mass star-forming cloud R CrA. Results. The line was detected in cold, prestellar cores in the regions of OriB9 and L183, but only upper limits were obtained towards other locations which either have elevated temperatures or contain a newly born star. The H2D+ detection towards OriB9 is the first one in a massive star-forming region. The fractional ortho-H2D+ abundances (relative to H2) are estimated to be about 1.0E-10 in two cold cores in OriB9, and 3.0E-10 in the cold core of L183. Conclusions. The H2D+ detection in OriB9 shows that also massive star forming regions contain very cold prestellar cores which probably have reached matured chemical composition characterized, e.g., by a high degree of deuterium fractionation. Besides as a tracer of the interior parts of prestellar cores, H2D+ may therefore be used to put contraints on the timescales related to massive star formation.

arXiv comment5 pages, 1 figure, accepted for publication in Astronomy and Astrophysics

References in corpus (10)

• Ammonia in Infrared Dark Clouds
• Complete Depletion in prestellar cores
• The initial conditions of isolated star formation - VI. SCUBA mapping of prestellar cores
• Abundant H2D+ in the pre-stellar core L1544
• The importance of the ortho:para H2 ratio for the deuteration of molecules during pre-protostellar collapse
• Detection of D2H+ in the Dense Interstellar Medium
• Probing the Early Stages of Low-Mass Star Formation in LDN 1689N: Dust and Water in IRAS 16293-2422A, B, and E
• Detection of interstellar H_2D^+ emission
• Far infrared observations of pre-protostellar sources in Lynds 183
• Very cold and massive cores near ISOSS J18364-0221: Implications for the initial conditions of high-mass star-formation

Cited by in corpus (20)

• Survey of ortho-H2D+(1_{1,0}-1_{1,1}) in dense cloud cores
• Chemistry in Disks. IX. Observations and modeling of HCO+ and DCO+ in DM Tau
• A (sub)millimetre study of dense cores in Orion B9
• Survey of ortho-H${}_2$D${}^{+}$ in high-mass star-forming regions
• Identification of prestellar cores in high-mass star forming clumps via ${\mathrm{H}}_2{\mathrm{D}}^{+}$ observations with ALMA
• Deuterium Fractionation as an Evolutionary Probe in Massive Proto-stellar/cluster Cores
• Probing the physics of star formation (ProPStar): I. First resolved maps of the electron fraction and cosmic-ray ionization rate in NGC 1333
• H2D+ in the high mass star-forming Region Cygnus-X
• Two Massive, Low-Luminosity Cores Toward Infrared Dark Clouds
• The 3D structure of CO depletion in high-mass prestellar regions
• Deuterium fractionation and H2D+ evolution in turbulent and magnetized cloud cores
• Prestellar and protostellar cores in Ori B9
• Physical properties of dense cores in Orion B9
• Experimental and theoretical studies of D + H${}_3^{+}$ $\to$ H${}_2$D${}^{+}$ + H
• Mapping the H${}_2$D${}^{+}$ and N${}_2$H${}^{+}$ emission towards prestellar cores. Testing dynamical models of the collapse using gas tracers
• APEX observations of ortho-H${}_2$D${}^{+}$ towards dense cores in the Orion B9 filament
• Far-Infrared detection of H2D+ toward Sgr B2
• A computed line list for the H2D+ molecular ion
• H${}_2$D${}^{+}$ line emission in Proto-Planetary Disks
• Synthetic observations using POLARIS: an application to simulations of massive prestellar cores