A survey of CH2DOH towards starless and pre-stellar cores in the Taurus molecular cloud

Ambrose, Hannah E; Shirley, Yancy L.; Scibelli, Samantha

doi:10.1093/mnras/staa3649

Cited by 22 publications

(21 citation statements)

References 69 publications

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“…The HCOOCH 3 /CH 3 OH ratio in CB 68 is derived to be 0.09 0.03 van Gelder et al 2020). It should be noted that the intrinsic line strength of CH 2 DOH could be uncertain (Ambrose et al 2021), so that the derived ratio may be changed by a factor of a few.…”

Section: Comparison With Other Sourcesmentioning

confidence: 99%

“…The column densities are also evaluated assuming the rotation temperature of 100 K and 150 K. Note that the CH 2 DOH (4 1,4 −4 1,3 e 1 −e 0 ) line at 246973 MHz was not included in the fit, because the line strength of this inter-vibrational transition is uncertain (Pickett et al 1998). Recently, the uncertainty of the line strength for this molecule has also been pointed out by Ambrose et al (2021).…”

Section: Abundances Of Icomsmentioning

confidence: 99%

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Chemical and Physical Characterization of the Isolated Protostellar Source CB68: FAUST IV

Imai

Oya

Svoboda

et al. 2022

ApJ

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The chemical diversity of low-mass protostellar sources has so far been recognized, and environmental effects are invoked as its origin. In this context, observations of isolated protostellar sources without the influence of nearby objects are of particular importance. Here, we report the chemical and physical structures of the low-mass Class 0 protostellar source IRAS 16544−1604 in the Bok globule CB 68, based on 1.3 mm Atacama Large Millimeter/submillimeter Array observations at a spatial resolution of ∼70 au that were conducted as part of the large program FAUST. Three interstellar saturated complex organic molecules (iCOMs), CH3OH, HCOOCH3, and CH3OCH3, are detected toward the protostar. The rotation temperature and the emitting region size for CH3OH are derived to be 131 ± 11 K and ∼10 au, respectively. The detection of iCOMs in close proximity to the protostar indicates that CB 68 harbors a hot corino. The kinematic structure of the C18O, CH3OH, and OCS lines is explained by an infalling–rotating envelope model, and the protostellar mass and the radius of the centrifugal barrier are estimated to be 0.08–0.30 M ⊙ and <30 au, respectively. The small radius of the centrifugal barrier seems to be related to the small emitting region of iCOMs. In addition, we detect emission lines of c-C3H2 and CCH associated with the protostar, revealing a warm carbon-chain chemistry on a 1000 au scale. We therefore find that the chemical structure of CB 68 is described by a hybrid chemistry. The molecular abundances are discussed in comparison with those in other hot corino sources and reported chemical models.

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Section: Comparison With Other Sourcesmentioning

confidence: 99%

Section: Abundances Of Icomsmentioning

confidence: 99%

Chemical and Physical Characterization of the Isolated Protostellar Source CB68: FAUST IV

Imai

Oya

Svoboda

et al. 2022

ApJ

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“…A survey of 12 starless and prestellar cores in the B10 region in the Taurus Molecular Cloud revealed CH 2 DOH in 9 out of the 12 sources. 82 Additionally, CH 2 DOH has been detected in the prestellar cores L183 83 and L1544. 69 L1544 has been the target of many extensive studies 11,84 and was the first prestellar core with a reported CH 2 DOH detection, 69 which was derived towards the dust peak of L1544.…”

Section: Comparison With Prestellar Core Observationsmentioning

confidence: 98%

Fevering Interstellar Ices Have More CH3OD

Kulterer¹,

Drozdovskaya²,

Antonellini³

et al. 2022

Preprint

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Mono-deuterated methanol is thought to form during the prestellar core stage of star formation. Observed variations in the CH 2 DOH/CH 3 OD ratio suggest that its formation is strongly dependent on the surrounding cloud conditions. Thus, it is a potential tracer of the physical conditions before the onset of star formation. A single-point physical model representative of a typical prestellar core is coupled to chemical models to investigate potential formation pathways towards deuterated methanol at the prestellar stage. Simple addition reactions of H and D are not able to reproduce observed abundances. The implementation of an experimentally verified abstraction scheme leads to the efficient formation of methyl-deuterated methanol, but lacks sufficient formation of hydroxy-deuterated methanol. CH 3 OD is most likely formed at a later evolutionary stage, potentially from H-D exchange reactions in warm ices between HDO (and D 2 O) 1 and CH 3 OH. The CH 2 DOH/CH 3 OD ratio is not an appropriate tracer of the physical conditions during the prestellar stage, but might be better suited as a tracer of ice heating.

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“…8. Abundance ratios [XD]/[XH] measured for organic species in sources at different evolutionary stages: prestellar cores (D 2 CO(Bacmann et al 2003;Chacón-Tanarro et al 2019), CH 2 DOH(Bizzocchi et al 2014;Chacón-Tanarro et al 2019;Ambrose et al 2021), and HDCS(Marcelino et al 2005;Vastel et al 2018)); Class 0 protostars (D 2 CO(Parise et al 2006;Watanabe et al 2012;Persson et al 2018;Manigand et al 2020), CH 2 DOH(Parise et al 2006;Bianchi et al 2017b;Jørgensen et al 2018;Jacobsen et al 2019;van Gelder et al 2020;Manigand et al 2020), and HDCS(Drozdovskaya et al 2018); Class I protostars (SVS13-A; D 2 CO, CH 2 DOH(Bianchi et al 2017a), and HDCS(Bianchi et al 2019a)); comets (Hale-Bopp; CH 2 DOH(Crovisier et al 2004) and 67P/C-G; CH 2 DOH (Drozdovskaya et al 2021)). The [XD]/[XH] values inferred for L1489-IRS, B5-IRS1, L1455-IRS1, and L1551-IRS5 are in magenta (from this work).…”

mentioning

confidence: 99%

Chemical survey of Class I protostars with the IRAM-30 m

Mercimek

Codella

Podio

et al. 2022

A&A

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Context. Class I protostars are a bridge between Class 0 protostars (≤105 yr old), and Class II (≥106 yr) protoplanetary disks. Recent studies show gaps and rings in the dust distribution of disks younger than 1 Myr, suggesting that planet formation may start already at the Class I stage. To understand what chemistry planets will inherit, it is crucial to characterize the chemistry of Class I sources and to investigate how chemical complexity evolves from Class 0 protostars to protoplanetary disks. Aims. There are two goals: (i) to perform a census of the molecular complexity in a sample of four Class I protostars, and (ii) to compare the data with the chemical compositions of earlier and later phases of the Sun-like star formation process. Methods. We performed IRAM-30 m observations at 1.3 mm towards four Class I objects (L1489-IRS, B5-IRS1, L1455-IRS1, and L1551-IRS5). The column densities of the detected species were derived assuming local thermodynamic equilibrium (LTE) or large velocity gradients (LVGs). Results. We detected 27 species: C-chains, N-bearing species, S-bearing species, Si-bearing species, deuterated molecules, and interstellar complex organic molecules (iCOMs; CH3OH, CH3CN, CH3CHO, and HCOOCH3). Among the members of the observed sample, L1551-IRS5 is the most chemically rich source. Different spectral profiles are observed: (i) narrow lines (~1 km s−1) towards all the sources, (ii) broader lines (~4 km s−1) towards L1551-IRS5, and (iii) line wings due to outflows (in B5-IRS1, L1455-IRS1, and L1551-IRS5). Narrow c-C3H2 emission originates from the envelope with temperatures of 5–25 K and sizes of ~2′′−10′′. The iCOMs in L1551-IRS5 reveal the occurrence of hot corino chemistry, with CH3OH and CH3CN lines originating from a compact (~0.′′15) and warm (T > 50 K) region. Finally, OCS and H2S seem to probe the circumbinary disks in the L1455-IRS1 and L1551-IRS5 binary systems. The deuteration in terms of elemental D/H in the molecular envelopes is: ~10−70% (D2CO/H2CO), ~5−15% (HDCS/H2CS), and ~1−23% (CH2DOH/CH3OH). For the L1551-IRS5 hot corino we derive D/H ~2% (CH2DOH/CH3OH). Conclusions. Carbon chain chemistry in extended envelopes is revealed towards all the sources. In addition, B5-IRS1, L1455-IRS1, and L1551-IRS5 show a low-excitation methanol line that is narrow and centered at systemic velocity, suggesting an origin from an extended structure, plausibly UV-illuminated. The abundance ratios of CH3CN, CH3CHO, and HCOOCH3 with respect to CH3OH measured towards the L1551-IRS5 hot corino are comparable to that estimated at earlier stages (prestellar cores, Class 0 protostars), and to that found in comets. The deuteration in our sample is also consistent with the values estimated for sources at earlier stages. These findings support the inheritance scenario from prestellar cores to the Class I phase when planets start forming.

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A survey of CH2DOH towards starless and pre-stellar cores in the Taurus molecular cloud

Cited by 22 publications

References 69 publications

Chemical and Physical Characterization of the Isolated Protostellar Source CB68: FAUST IV

Chemical and Physical Characterization of the Isolated Protostellar Source CB68: FAUST IV

Fevering Interstellar Ices Have More CH3OD

Chemical survey of Class I protostars with the IRAM-30 m

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