Astrochemical evolution along star formation: overview of the IRAM Large Program ASAI

Leflóch, B.; Bachiller, R.; Ceccarelli, C.; Cernicharo, J.; Codella, C.; Fuente, A.; Kahane, C.; López-Sepulcre, A.; Tafalla, M.; Vastel, C.; Caux, E.; Gonzalez-Garcia, M. C.; Bianchi, E.; Gómez-Ruiz, Arturo I.; Holdship, Jonathan; Mendoza, Edgar; Ospina-Zamudio, J.; Podio, L.; Quenard, D.; Roueff, E.; Sakai, Nami; Viti, S.; Yamamoto, Satoshi; Yoshida, Kento; Favre, Cécile; Monfredini, Thiago; Quitián-Lara, Heidy Mayerly; Marcelino, N.; Boechat-Roberty, H. M.; Cabrit, S.

doi:10.1093/mnras/sty937

Cited by 97 publications

(74 citation statements)

References 139 publications

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“…The ASAI survey performed with the IRAM 30 m telescope has revealed the chemical composition at large scale of a sample of low-mass star forming regions, from prestellar cores to protostars. Lefloch et al (2018) used the ratio of the number of detected O-bearing species to hydrocarbons to classify the sources into WCCC sources or hot corinos. Four sources are in common with CALYPSO: L1157 and L1527 were classified as WCCC sources, and IRAS4A and SVS13A as hot corinos on the basis of the ASAI results.…”

Section: Comparison To Other Com Surveysmentioning

confidence: 99%

Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO survey

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Maury

Maret

et al. 2020

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Context. Complex organic molecules (COMs) have been detected in a few Class 0 protostars but their origin is not well understood. While the usual picture of a hot corino explains their presence as resulting from the heating of the inner envelope by the nascent protostar, shocks in the outflow, a disk wind, the presence of a flared disk, or the interaction region between envelope and disk at the centrifugal barrier have also been claimed to enhance the abundance of COMs. Aims. Going beyond studies of individual objects, we want to investigate the origin of COMs in young protostars on a statistical basis. Methods. We use the CALYPSO survey performed with the Plateau de Bure Interferometer of the Institut de Radioastronomie Millimétrique (IRAM) to search for COMs at high angular resolution in a sample of 26 solar-type protostars, including 22 Class 0 and four Class I objects. We derive the column densities of the detected molecules under the local thermodynamic equilibrium approximation and search for correlations between their abundances and with various source properties. Results. Methanol is detected in 12 sources and tentatively in one source, which represents half of the sample. Eight sources (30%) have detections of at least three COMs. We find a strong chemical differentiation in multiple systems with five systems having one component with at least three COMs detected but the other component devoid of COM emission. All sources with a luminosity higher than 4 L ⊙ have at least one detected COM whereas no COM emission is detected in sources with internal luminosity lower than 2 L ⊙ , likely because of a lack of sensitivity. The internal luminosity is found to be the source parameter impacting the most the COM chemical composition of the sources, while there is no obvious correlation between the detection of COM emission and that of a disk-like structure. A canonical hot-corino origin may explain the COM emission in four sources, an accretion-shock origin in two or possibly three sources, and an outflow origin in three sources. The CALYPSO sources with COM detections can be classified into three groups on the basis of the abundances of oxygen-bearing molecules, cyanides, and CHO-bearing molecules. These chemical groups correlate neither with the COM origin scenarii, nor with the evolutionary status of the sources if we take the ratio of envelope mass to internal luminosity as an evolutionary tracer. We find strong correlations between molecules that are a priori not related chemically (for instance methanol and methyl cyanide), implying that the existence of a correlation does not imply a chemical link.Conclusions. The CALYPSO survey has revealed a chemical differentiation in multiple systems that is markedly different from the case of the prototypical binary IRAS16293-2422. This raises the question whether all low-mass protostars go through a phase showing COM emission. A larger sample of young protostars and a more accurate determination of their internal luminosity will be necessary to make further progress. ...

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Section: Comparison To Other Com Surveysmentioning

confidence: 99%

Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO survey

Беллоче

Maury

Maret

et al. 2020

A&A

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111

153

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“…A noteworthy case is that of L1157, whose outflow shocks are rich in formamide, as mentioned above, but the protostar itself is devoid of emission from this molecule, as well as from other 7 iCOMs typical of hot corinos. 43,53 4. Formamide remains undetected in pre-stellar cores: While more dedicated studies are needed, formamide does not appear to be present in detectable levels in pre-stellar cores, i.e.…”

Section: Not All Protostars Contain Formamidementioning

confidence: 99%

Interstellar Formamide (NH₂CHO), a Key Prebiotic Precursor

López-Sepulcre

Balucani²,

Ceccarelli³

et al. 2019

ACS Earth Space Chem.

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Formamide (NH 2 CHO) has been identified as a potential precursor of a wide variety of organic compounds essential to life, and many biochemical studies propose it likely played a crucial role in the context of the origin of life on our planet. The detection of formamide in comets, which are believed to have -at least partially-inherited their current chemical composition during the birth of the Solar System, raises the question whether a non-negligible amount of formamide may have been exogenously delivered onto a very young Earth about four billion years ago. A crucial part of the effort to 1 arXiv:1909.11770v1 [astro-ph.SR] 25 Sep 2019 answer this question involves searching for formamide in regions where stars and planets are forming today in our Galaxy, as this can shed light on its formation, survival, and chemical re-processing along the different evolutionary phases leading to a star and planetary system like our own.The present review primarily addresses the chemistry of formamide in the interstellar medium, from the point of view of (i) astronomical observations, (ii) experiments, and (iii) theoretical calculations. While focusing on just one molecule, this review also more generally reflects the importance of joining efforts across multiple scientific disciplines in order to make progress in the highly interdisciplinary science of astrochemistry.

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“…In our survey of five protostellar disk candidates, we see evidence for warm, organic-rich, hot-corino-like emission from three of five targeted sources. This is a high occurrence rate given that only 9 hot corinos have been previously identified in the literature: IRAS 16293-2422 (Cazaux et al 2003 (Lefloch et al 2018). Our sources were selected due to their classification as protostellar disk candidates, suggesting that hot corinos and protostellar disks may be evolutionarily or structurally linked.…”

Section: Frequency Of Hot Corino Chemistry Around Protostellar Disk Cmentioning

confidence: 99%

Organic Complexity in Protostellar Disk Candidates

Bergner

Martín-Doménech

Öberg

et al. 2019

ACS Earth Space Chem.

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We present ALMA observations of organic molecules towards five low-mass Class 0/I protostellar disk candidates in the Serpens cluster. Three sources (Ser-emb 1, Ser-emb 8, and Ser-emb 17) present emission of CH 3 OH as well as CH 3 OCH 3 , CH 3 OCHO, and CH 2 CO, while NH 2 CHO is detected in just Ser-emb 8 and Ser-emb 17. Detecting hot corino-type chemistry in three of five sources represents a high occurrence rate given the relative sparsity of these sources in the literature, and this suggests a possible link between protostellar disk formation and hot corino formation. For sources with CH 3 OH detections, we derive column densities of 10 17 -10 18 cm −2 and rotational temperatures of ∼200-250 K. The CH 3 OH-normalized column density ratios of large, oxygen-bearing COMs in the Serpens sources and other hot corinos span two orders of magnitude, demonstrating a high degree of chemical diversity at the hot corino stage. Resolved observations of a larger sample of objects are needed to understand the origins of chemical diversity in hot corinos, and the relationship between different protostellar structural elements on disk-forming scales.

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Astrochemical evolution along star formation: overview of the IRAM Large Program ASAI

Cited by 97 publications

References 139 publications

Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO survey

Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO survey

Interstellar Formamide (NH₂CHO), a Key Prebiotic Precursor

Organic Complexity in Protostellar Disk Candidates

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Astrochemical evolution along star formation: overview of the IRAM Large Program ASAI

Cited by 97 publications

References 139 publications

Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO survey

Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO survey

Interstellar Formamide (NH2CHO), a Key Prebiotic Precursor

Organic Complexity in Protostellar Disk Candidates

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Interstellar Formamide (NH₂CHO), a Key Prebiotic Precursor