English

Hot methanol in the [BHB2007] 11 protobinary system: hot corino versus shock origin? : FAUST V

Astrophysics of Galaxies 2022-08-31 v1 Solar and Stellar Astrophysics

Abstract

Methanol is a ubiquitous species commonly found in the molecular interstellar medium. It is also a crucial seed species for the building-up of the chemical complexity in star forming regions. Thus, understanding how its abundance evolves during the star formation process and whether it enriches the emerging planetary system is of paramount importance. We used new data from the ALMA Large Program FAUST (Fifty AU STudy of the chemistry in the disk/envelope system of Solar-like protostars) to study the methanol line emission towards the [BHB2007] 11 protobinary system (sources A and B), where a complex structure of filaments connecting the two sources with a larger circumbinary disk has been previously detected. Twelve methanol lines have been detected with upper energies in the range [45-537] K along with one 13CH3OH transition. The methanol emission is compact and encompasses both protostars, separated by only 28 au and presents three velocity components, not spatially resolved by our observations, associated with three different spatial regions, with two of them close to 11B and the third one associated with 11A. A non-LTE radiative transfer analysis of the methanol lines concludes that the gas is hot and dense and highly enriched in methanol with an abundance as high as 1e-5. Using previous continuum data, we show that dust opacity can potentially completely absorb the methanol line emission from the two binary objects. Although we cannot firmly exclude other possibilities, we suggest that the detected hot methanol is resulting from the shocked gas from the incoming filaments streaming towards [BHB2007] 11 A and B, respectively. Higher spatial resolution observations are necessary to confirm this hypothesis.

Keywords

Cite

@article{arxiv.2206.10176,
  title  = {Hot methanol in the [BHB2007] 11 protobinary system: hot corino versus shock origin? : FAUST V},
  author = {C. Vastel and F. Alves and C. Ceccarelli and M. Bouvier and I. Jimenez-Serra and T. Sakai and P. Caselli and L. Evans and F. Fontani and R. Le Gal and C. J. Chandler and B. Svoboda and L. Maud and C. Codella and N. Sakai and A. Lopez-Sepulcre and G. Moellenbrock and Y. Aikawa and N. Balucani and E. Bianchi and G. Busquet and E. Caux and S. Charnley and N. Cuello and M. De Simone and F. Dulieu and A. Duran and D. Fedele and S. Feng and L. Francis and T. Hama and T. Hanawa and E. Herbst and T. Hirota and M. Imai and A. Isella and D. Johnstone and B. Lefloch and L. Loinard and M. Maureira and N. M. Murillo and S. Mercimek and S. Mori and F. Menard and A. Miotello and R. Nakatani and H. Nomura and Y. Oba and S. Ohashi and Y. Okoda and J. Ospina-Zamudio and Y. Oya and J. E. Pineda and L. Podio and A. Rimola and D. Segura Cox and Y. Shirley and L. Testi and S. Viti and N. Watanabe and Y. Watanabe and A. Witzel and C. Xue and Y. Zhang and B. Zhao and S. Yamamoto},
  journal= {arXiv preprint arXiv:2206.10176},
  year   = {2022}
}

Comments

17 pages, accepted in A&A