The ALMA-PILS survey: 3D modeling of the envelope, disks and dust filament of IRAS 16293–2422

Abstract

Context. The Class 0 protostellar binary IRAS 16293-2422 is an interesting target for (sub)millimeter observations due to, both, the rich chemistry toward the two main components of the binary and its complex morphology. Its proximity to Earth allows the study of its physical and chemical structure on solar system scales using high angular resolution observations. Such data reveal a complex morphology that cannot be accounted for in traditional, spherical 1D models of the envelope. Aims. The purpose of this paper is to study the environment of the two components of the binary through 3D radiative transfer modeling and to compare with data from the Atacama Large Millimeter/submillimeter Array. Such comparisons can be used to constrain the protoplanetary disk structures, the luminosities of the two components of the binary and the chemistry of simple species. Methods. We present 13 CO, C 17 O and C 18 O J=3-2 observations from the ALMA Protostellar Interferometric Line Survey (PILS), together with a qualitative study of the dust and gas density distribution of IRAS 16293-2422. A 3D dust and gas model including disks and a dust filament between the two protostars is constructed which qualitatively reproduces the dust continuum and gas line emission.Results. Radiative transfer modeling in our sampled parameter space suggests that, while the disk around source A could not be constrained, the disk around source B has to be vertically extended. This puffed-up structure can be obtained with both a protoplanetary disk model with an unexpectedly high scale-height and with the density solution from an infalling, rotating collapse. Combined constraints on our 3D model, from observed dust continuum and CO isotopologue emission between the sources, corroborate that source A should be at least six times more luminous than source B. We also demonstrate that the volume of high-temperature regions where complex organic molecules arise is sensitive to whether or not the total luminosity is in a single radiation source or distributed into two sources, affecting the interpretation of earlier chemical modeling efforts of the IRAS 16293-2422 hot corino which used a single-source approximation. Conclusions. Radiative transfer modeling of source A and B, with the density solution of an infalling, rotating collapse or a protoplanetary disk model, can match the constraints for the disk-like emission around source A and B from the observed dust continuum and CO isotopologue gas emission. If a protoplanetary disk model is used around source B, it has to have an unusually high scale-height in order to reach the dust continuum peak emission value, while fulfilling the other observational constraints. Our 3D model requires source A to be much more luminous than source B; L A ∼ 18 L and L B ∼ 3 L .

Methyl cyanide (CH3CN) and propyne (CH3CCH) in the low-mass protostar IRAS 16293–2422

“…Integrating the total hydrogen nucleon density column density from Crimier et al (2010) within these radii, we obtain abundances of 2×10 −10 for CH 3 CCH and 8×10 −9 for CH 3 CN (with respect to the total hydrogen nucleon density). In addition, the structure determined by Crimier et al (2010) has to be taken with caution as the authors assumed a distance of 120 pc for the source while this value has recently been revisited to a larger one ( be spherical, although it is a binary source with a complex structure in the inner regions (Jørgensen et al 2016;Jacobsen et al 2018). The dust properties are also very uncertain in these regions.…”

Ingredients for solar-like systems: protostar IRAS 16293-2422 B versus comet 67P/Churyumov–Gerasimenko

“…Unfortunately, estimates of the column density are not provided in those works as too few lines are targeted at a time. Jacobsen et al (2018b) developed sophisticated models of the binary IRAS 16293-2422 system based on 13 CO, C 17 O and C 18 O J = 3 − 2 observations. The latest derivation of the column density is presented in Appendix A. H2CO, H 13 2 CO, HDCO, H2C 18 O and D2CO have been detected on envelope scales, and with both ortho-and para-versions showing self-absorption Ceccarelli et al 1998a;Loinard et al 2000;Chandler et al 2005;van der Wiel et al 2019) and towards both protostars, even as D 13 2 CO .…”

“…The masses and luminosities have been estimated to be on the order of 18 L ⊙ , 1.0 M ⊙ for source A and 3 L ⊙ , 0.1 M ⊙ for source B, based on previous observations and theoretical models (Jacobsen et al 2018b). The total amount of mass encompassed by the circumbinary envelope of ∼ 50 ′′ in size is ∼ 4 M ⊙ (Jacobsen et al 2018b). High spatial resolution observations with ALMA have resolved the scales of the two individual discs, i.e., on scales of a few tens of au.…”

The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. IV. Unveiling the Embedded Intermediate-Mass Protostar and Disk within OMC2-FIR3/HOPS-370

“…Furthermore, observations by the NSF's Karl G. Jansky Very Large Array (VLA) and the Atacama Large Millimeter/submillimeter Array (ALMA) have observed the region with ∼0 1 resolution, resolving an apparent disk in the dust continuum and indications of rotation in methanol, H 13 CN, and NS (Tobin et al 2019). The combination of observational results toward this region from Tobin et al (2019), Furlan et al (2014), and Osorio et al (2017) indicates that HOPS-370 is a candidate intermediate-mass protostar with similar spectral properties to hot corinos (Ceccarelli 2004;Taquet et al 2015;Drozdovskaya et al 2016;Jacobsen et al 2018;Lee et al 2018).…”