Glycolaldehyde in Perseus young solar analogs

Abstract

Context. The earliest evolutionary stages of low-mass protostars are characterised by the so-called hot-corino stage, when the newly born star heats the surrounding material and enrich the gas chemically. Studying this evolutionary phase of solar protostars may help understand the evolution of prebiotic complex molecules in the development of planetary systems. Aims. In this paper we focus on the occurrence of glycolaldehyde (HCOCH 2 OH) in young solar analogs by performing the first homogeneous and unbiased study of this molecule in the Class 0 protostars of the nearby Perseus star forming region. Methods. We obtained sub-arcsec angular resolution maps at 1.3mm and 1.4mm of glycolaldehyde emission lines using the IRAM Plateau de Bure (PdB) interferometer in the framework of the CALYPSO IRAM large program. Results. Glycolaldehyde has been detected towards 3 Class 0 and 1 Class I protostars out of the 13 continuum sources targeted in Perseus: NGC1333-IRAS2A1, NGC1333-IRAS4A2, NGC1333-IRAS4B1, and SVS13-A. The NGC1333 star forming region looks particularly glycolaldehyde rich, with a rate of occurrence up to 60%. The glycolaldehyde spatial distribution overlaps with the continuum one, tracing the inner 100 au around the protostar. A large number of lines (up to 18), with upper-level energies E u from 37 K up to 375 K has been detected. We derived column densities ≥ 10 15 cm −2 and rotational temperatures T rot between 115 K and 236 K, imaging for the first time hot-corinos around NGC1333-IRAS4B1 and SVS13-A. Conclusions. In multiple systems glycolaldehyde emission is detected only in one component. The case of the SVS13-A+B and IRAS4-A1+A2 systems support that the detection of glycolaldehyde (at least in the present Perseus sample) indicates older protostars (i.e. SVS13-A and IRAS4-A2), evolved enough to develop the hot-corino region (i.e. 100 K in the inner 100 au). However, only two systems do not allow us to firmly conclude whether the primary factor leading to the detection of glycolaldehyde emission is the environments hosting the protostars, evolution (e.g. low value of L submm /L int ), or accretion luminosity (high L int ).

The census of interstellar complex organic molecules in the Class I hot corino of SVS13-A

“…A previous analysis of the HDO lines detected in the ASAI observations revealed the presence of a hot ( 150 K), dense ( 3 × 10 7 cm −3 ) and compact (∼ 25 au) region, which could indicate the presence of a hot corino (Codella et al 2016). The actual confirmation of the hot corino arrived soon after with the detection of glycolaldehyde (HCOCH2OH), which emits over a ∼ 70 au diameter region centered on SVS13-A (De Simone et al 2017). Subsequent higher spatial resolution observations by Lefèvre et al (2017) found that VLA4A is associated with compact continuum emission, suggestive of a disk smaller than about 50 au.…”

CALYPSO view of SVS 13A with PdBI: Multiple jet sources

“…Interestingly, complex organic molecules (COMs) from the hot corino of SVS13A (e.g. López-Sepulcre et al 2015;De Simone et al 2017) peak on or close to VLA4A (see Fig. 2 and Belloche et al, in prep.…”

Chronology of Episodic Accretion in Protostars—An ALMA Survey of the CO and H2O Snowlines

“…Codella et al (2014) found a knotty jet driven by Per-emb-27 with a dynamical time of < 30 − 90 yr, which is considered to be a signature of episodic accretion (Vorobyov et al 2018). Per-emb-44 contains also a central hot region with a detection of glycolaldehyde (De Simone et al 2017;Bianchi et al 2019). Multiple components are found in continuum observations by Tobin et al (2016Tobin et al ( , 2018, including a close binary with a separation of 0.…”