Hot corinos in NGC 1333-IRAS4B and IRAS2A

By S. Bottinelli, Cecilia Ceccarelli, Jonathan P. Williams, Bertrand Lefloch Laboratoire d'Astrophysique de l'Observato Astronomy, U. Hawaii. 2006

147 citations recorded by the source corpus.

Context: Complex organic molecules have been detected in massive hot cores for over two decades, and only recently in three hot corinos (the inner regions surrounding Sun-like protostars, where the dust temperature exceeds 100 K). Since hot corinos have sizes of ~100 AU (i.e., of the order of the extent of the Solar System), it is particularly relevant to understand whether they are common and to identify the formation route(s) of complex organic molecules. Much has yet to be learned on this topic, since even recent models predicted it was not possible to form these molecules in low-mass protostars. Aims: We aim to enlarge the number of known hot corinos and carry out a first comparative study with hot cores. The ultimate goal is to understand whether complex organic molecules form in the gas phase or on grain surfaces, and what the possible key parameters are. Methods: We observed millimeter rotational transitions of HCOOH, HCOOCH3 CH_3OCH3 CH_3CN and C_2H_5CN in a sample of low-mass protostars with the IRAM-30 m. Using the rotational diagram method coupled with the information about the sources' structure, we calculate the abundances of the observed molecules. To interpret these abundances, we review the proposed formation processes of the above molecules. Results: We report the detection of HCOOCH3 and/or CH_3CN towards NGC 1333-IRAS4B and NGC 1333-IRAS2A. We find that abundance ratios of O-bearing molecules to methanol or formaldehyde in hot corinos are comparable and about unity, and are relatively (depending on how the ratios are determined) higher than those in hot cores and in Galactic center clouds. Conclusions: .So far, complex organic molecules were detected in all the hot corinos where they were searched for, suggesting that it is a common phase for low-mass protostars. While some evidence points to grain-surface synthesis (either in the cold or warm-up phase) of these molecules (in particular for HCOOH and HCOOCH_3), the present data do not allow us to disregard gas-phase formation. More observational, laboratory, and theoretical studies are required to improve our understanding of hot corinos. Appendix is only available in electronic form at http://www.aanda.org

Subfields: Astronomy and Astrophysics, Atmospheric Science, Spectroscopy

View Paper: https://www.semanticscholar.org/paper/681b392bde68ccbe0b24e2c202bd36013b85011d

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Atmospheric Science

In Spectroscopy

Citations in the corpus

A COLD COMPLEX CHEMISTRY TOWARD THE LOW-MASS PROTOSTAR B1-b: EVIDENCE FOR COMPLEX MOLECULE PRODUCTION IN ICES (2010, background): “Assuming the same source sizes of CH3OH and complex molecules toward protostars observed with single-dish telescopes result in abundances of a few % with respect to CH3OH, comparable to those observed toward B1-b (Maret et al. 2005; Bottinelli et al. 2004, 2007).”
Formation rates of complex organics in UV irradiated CH3OH-rich ices I: Experiments (2009, background): “…complexity are being detect d in star-forming regions (Blake et al. 1987; Nummelin et al. 2000; Bisschop et al. 2007b; van Dishoeck et al. 1995; Cazaux et al. 2003; Bottinelli et al. 2004, 2007; Belloche et al. 2009); however, the origins of these complex molecules are the subject of debate.”
NON-RACEMIC AMINO ACID PRODUCTION BY ULTRAVIOLET IRRADIATION OF ACHIRAL INTERSTELLAR ICE ANALOGS WITH CIRCULARLY POLARIZED LIGHT (2011, background): “However, this simulation remains astrophysically relevant, particularly in hot molecular core environments, where grains are heated and complex gas-phase molecules, thermally desorbed from the ices, are observed (Bottinelli et al. 2007).”
Complex Molecules in the L1157 Molecular Outflow (2008, methodology): “The abundance ratio of the complex molecules with respect to CH3OH (another, more abundant, grain mantle constituent) can be used to investigate the origin and evolution of these complex species (e.g., Bottinelli et al. 2007).”
The chemical history of molecules in circumstellar disks - I. Ices (2009, background): “The gas-phase route towards complex organics involves the hot inner envelope (Td > 100 K), also called the hot core or hot corino in the case of low-mass protostars (Ceccarelli 2004; Bottinelli et al. 2004, 2007).”
Our astrochemical heritage (2012, background): “Since then, more low-mass hot cores have been discovered and, to distinguish them from the high-mass hot cores, they were called hot corinos (Bottinelli et al. 2004a, 2004b, 2007; Lahuis et al. 2006; Jørgensen et al. 2012); see also the review by Herbst and van Dishoeck (2009).”
Complex Chemistry in Star-forming Regions: An Expanded Gas-Grain Warm-up Chemical Model (2008, background): “Bottinelli et al. (2007) report that the ratios of HCOOCH3, CH3OCH3 and HCOOH to their putative parent molecules, CH3OH and H2CO, appear greater for hot corinos than hot cores, with the HCOOH ratios being more strongly affected.”
Formation of complex organic molecules in cold objects: the role of gas-phase reactions (2015, background): “…‡ E-mail: vianney.taquet@nasa.gov paradigm has lasted for almost two decades, until new observations (e.g. Cazaux et al. 2003; Bottinelli et al. 2007; Requena-Torres et al. 2006), laboratory experiments (Geppert et al. 2007) and theoretical studies (Horn et al 2004)…”