2011A&A...526A..31P


C.D.S. - SIMBAD4 rel 1.7 - 2019.10.15CEST07:19:17

2011A&A...526A..31P - Astronomy and Astrophysics, volume 526A, 31-31 (2011/2-1)

Extended emission of D2H+ in a prestellar core.

PARISE B., BELLOCHE A., DU F., GUESTEN R. and MENTEN K.M.

Abstract (from CDS):

In the past years, the H2D+ and D2H+ molecules have gained attention as probes of cold and depleted dense molecular cloud cores. These ions are the basis of molecular deuterium fractionation, a common characteristic observed in star-forming regions. H2D+ is now routinely observed, but the search for its isotopologue D2H+ is still difficult because of the high frequency of its ground para transition (692GHz). We observed molecular transitions of H2D+ and D2H+ in a cold prestellar core to characterize the roots of deuterium chemistry. Thanks to the sensitive multi-pixel CHAMP+ receiver on the APEX telescope where the required excellent weather conditions are met, we not only successfully detect D2H+ in the H-MM1 prestellar core located in the L1688 cloud, but also obtain information on the spatial extent of its emission. We also detect H2D+ at 372GHz in the same source. We analyze these detections using a non-LTE radiative transfer code and a state-of-the-art spin-dependent chemical model. This observation is the first secure detection of D2H+ in space. The emission is moreover extended over several pixels of the CHAMP+ array, i.e. on a scale of at least 40'', corresponding to ∼4800AU. We derive column densities on the order of 1012-1013cm–2 for both molecules in the LTE approximation depending on the assumed temperature, and up to two orders of magnitude higher based on a non-LTE analysis. Our modeling suggests that the level of CO depletion must be extremely high (>10, and even >100 if the temperature of the core is around 10K) at the core center, contradicting CO depletion levels directly measured in other cores. Observation of the H2D+ spatial distribution and direct measurement of the CO depletion in H-MM1 will be essential to confirm whether present chemical models investigating the basis of deuterium fractionation of molecules need to be revised.

Abstract Copyright:

Journal keyword(s): astrochemistry - line: identification - stars: formation - ISM: molecules

Errata: + corrigendum vol. 528, p. C2

Simbad objects: 15

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Number of rows : 15

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 [PCW91] Ced 110 IRS 10 Y*O 11 06 33.38 -77 23 34.6           ~ 57 1
2 NAME Cha I MoC 11 06 48 -77 18.0           ~ 932 1
3 NAME rho Oph A Cloud MoC 16 26 26.4 -24 22 33           ~ 235 1
4 NAME rho Oph G PoC 16 26 56.1 -24 18 40           ~ 4 0
5 NAME rho Oph E MoC 16 27 02.0 -24 38 31           ~ 53 0
6 NAME rho Oph Cloud B1 PoC 16 27 10.5 -24 29 30           ~ 49 1
7 NAME rho Oph 1 PoC 16 27.3 -24 34           ~ 7 0
8 NAME rho Oph B2 Cloud PoC 16 27 27.9 -24 26 29           ~ 73 1
9 NAME rho Oph F MoC 16 27 37.3 -24 42 28           ~ 55 0
10 JCMTSF J162758.6-243343 cor 16 27 58.3 -24 33 42           ~ 15 0
11 JCMTSE J162759.0-243325 mm 16 27 58.6 -24 33 34           ~ 3 0
12 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 2925 0
13 NAME Ophiuchus D MoC 16 28 29.2 -24 18 25           ~ 102 0
14 IRAS 16293-2422 cor 16 32 22.56 -24 28 31.8           ~ 997 1
15 NAME IRAS 16293E cor 16 32 29.3 -24 29 13           ~ 51 1

    Equat.    Gal    SGal    Ecl

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2019.10.15-07:19:17

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