Seeds of Life in Space (SOLIS). IX. Chemical Segregation of SO<sub>2</sub> and SO toward the Low-mass Protostellar Shocked Region of L1157

Feng, Siyi; Codella, C.; Ceccarelli, C.; Caselli, P.; López-Sepulcre, A.; Neri, R.; Fontani, F.; Podio, L.; Leflóch, B.; Liu, Hauyu Baobab; Bachiller, R.; Viti, S.

doi:10.3847/1538-4357/ab8813

Cited by 17 publications

(18 citation statements)

References 64 publications

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“…6.2). In astrochemical studies of the interstellar medium (ISM), S-bearing species are often assumed to trace shocks (Pineau des Forets et al 1993;Feng et al 2020), corroborating our interpretation. The interaction of the merger ejecta with the B-type star and its environment poses an interesting case for circumstellar shock-induced chemistry worthy of further investigation.…”

Section: Molecular Gas In the Remnant Of V838 Monsupporting

confidence: 84%

V838 Monocerotis as seen by ALMA: A remnant of a binary merger in a triple system

Kamiński

Tylenda

Kiljan

et al. 2021

A&A

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Context. V838 Mon erupted in 2002, quickly becoming the prototype of a new type of stellar eruption known today as the (luminous) red nova. Red nova outbursts are thought to be caused by stellar mergers. The merger in V838 Mon took place in a triple or higher system involving two B-type stars. Aims. We wish to characterize the merger remnant ~17 yr after the eruption to learn more about the remaining system, the progenitor, and the merger physics. Methods. We mapped the merger site with ALMA at a resolution of ~25 mas, or 148 au for a distance of 5.9 kpc, in continuum dust emission and in rotational lines of simple molecules, including CO, SiO, SO, SO2, AlOH, and H2S. We use radiative transfer calculations to reproduce the architecture of the remnant at the epoch of the ALMA observations. We also make use of optical spectroscopy data obtained mainly with VLT/X-shooter and SALT/HRS. Results. For the first time, we identify the position of the B-type companion relative to the outbursting component of V838 Mon. The stellar remnant is surrounded by a clumpy wind with characteristics similar to those of the winds of red supergiants. The merger product is also associated with an elongated structure of 17.6 × 7.6 mas (104 × 45 au) seen in continuum emission, and which we interpret as a disk seen at a moderate inclination. Maps of continuum and molecular emission also show a complex region of interaction between the B-type star (its gravity, radiation, and wind) and the flow of matter ejected in 2002. The remnant’s molecular mass is about 0.1 M⊙ and the dust mass is 8.3 × 10−3 M⊙. The mass of the atomic component remains unconstrained. Conclusions. The most interesting region for understanding the merger of V838 Mon lies in its direct vicinity and appears elongated, but details of its substructure remain unknown. To study it further and in more detail will require even higher angular resolutions. ALMA maps show us an extreme form of interaction between the merger ejecta and the distant (~250 au) companion. This interaction is similar to that known from the Anteres AB system but at a much higher mass loss rate. The B-type star not only deflects the merger ejecta but also changes its molecular composition with an involvement of circumstellar shocks. The ALMA view of V838 Mon offers the best images of a merger site so far.

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Section: Molecular Gas In the Remnant Of V838 Monsupporting

confidence: 84%

V838 Monocerotis as seen by ALMA: A remnant of a binary merger in a triple system

Kamiński

Tylenda

Kiljan

et al. 2021

A&A

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“…0.1-0.3 (L1157 Feng et al 2020). In conclusion, these recent findings support the use the [SO 2 ]/[SO] ratio to date gas enriched in sulphur around protostars, using high-spatial interferometric images to disentangle contributions due to different physical components.…”

Section: So Versus Sosupporting

confidence: 74%

“…in the Class 0/I hot corinos) or because of gas-grain sputtering and grain-grain shattering in shocked regions (e.g. Charnley et al 1997;Bachiller et al 2001;Wakelam et al 2004a;Codella et al 2005;Sakai et al 2014b,a;Podio et al 2014;Imai et al 2016;Holdship et al 2016;Taquet et al 2020;Feng et al 2020). In both cases, S-bearing species have proved to be extremely useful in the reconstruction of both the chemical history and dynamics of the studied objects.…”

Section: Introductionmentioning

confidence: 99%

The SVS13-A Class I chemical complexity as revealed by S-bearing species. SOLIS XIII

Codella,

Bianchi,

Podio

et al. 2021

Preprint

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Context. Recent results in astrochemistry revealed that some molecules such as interstellar complex organic species and deuterated species represent precious tools to investigate star forming regions. Sulphuretted species can also be used to follow the chemical evolution of the early stages of the Sun-like star forming process. Aims. The goal is to obtain a census of S-bearing species using interferometric images, towards SVS13-A, a Class I object associated with a hot corino rich in interstellar complex organic molecules. Methods. To this end, we used the NGC1333 SVS13-A data at3mm and 1.4mm obtained with the IRAM-NOEMA interferometer in the framework of the Large Program SOLIS. The line emission of S-bearing species has been imaged and analysed using LTE and LVG approaches. Results. We imaged the spatial distribution on ≤ 300 au scale of the line emission of 32 SO, 34 SO, C 32 S, C 34 S, C 33 S, OCS, H 2 C 32 S, H 2 C 34 S, and NS. The low excitation (9 K) 32 SO line is tracing (i) the low-velocity SVS13-A outflow and (ii) the fast (up to 100 km s −1 away from the systemic velocity) collimated jet driven by the nearby SVS13-B Class 0 object. Conversely, the rest of the lines are confined in the inner SVS13-A region, where complex organics have been previously imaged. More specifically the non-LTE LVG analysis of SO, SO 2 , and H 2 CS indicates a hot corino origin (size in the 60-120 au range). Temperatures between 50 K and 300 K, and volume densities larger than 10 5 cm −3 have been derived. The abundances of the sulphuretted are in the following ranges: 0.3-6 × 10 −6 (CS), 7 × 10 −9 -1 × 10 −7 (SO), 1-10 × 10 −7 (SO 2 ), a few 10 −10 (H 2 CS and OCS), and 10 −10 -10 −9 (NS). The N(NS)/N(NS + ) ratio is larger than 10, supporting that the NS + ion is mainly formed in the extended envelope. Conclusions. The [H 2 CS]/[H 2 CO] ratio, once measured at high-spatial resolutions, increases with time (from Class 0 to Class II objects) by more than one order of magnitude (from ≤ 10 −2 to a few 10 −1 ). This suggests that [S]/[O] changes along the Sun-like star forming process. Finally, the estimate of the [S]/[H] budget in SVS13-A is 2%-17% of the Solar System value (1.8 × 10 −5 ), being consistent with what was previously measured towards Class 0 objects (1%-8%). This supports that the enrichment of the sulphuretted species with respect to dark clouds keeps constant from the Class 0 to the Class I stages of low-mass star formation. The present findings stress the importance of investigating the chemistry of star forming regions using large observational surveys as well as sampling regions on a Solar System scale.

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“…In these outflow-shocked regions, the chemical composition of the gas is drastically changed, mainly due to liberation of molecules from dust grains and subsequent gas-phase reactions. In L1157, the shocked region in the blueshifted outflow lobe (L1157-B1) is traced by SO, SiO, CH 3 OH, H 2 CO, HCN, CN, and SO 2 line emission (Mikami et al 1992;Gueth et al 1996;Bachiller & Pérez Gutiérrez 1997;Codella et al 2010Codella et al , 2020Podio et al 2017;Feng et al 2020). Enhancement of the same molecules has also been reported for other protostellar outflows: e.g., L1448-C/L1448-mm (Jiménez-Serra et al 2005;Hirano et al 2010), HH211 (Hirano et al 2006), NGCC1333-IRAS4A (Wakelam et al 2005), and BHR71 (Gusdorf et al 2015).…”

Section: Shocks In the Arc-like Structurementioning

confidence: 66%

FAUST. II. Discovery of a Secondary Outflow in IRAS 15398−3359: Variability in Outflow Direction during the Earliest Stage of Star Formation?

Okoda

Oya

Francis

et al. 2021

ApJ

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We have observed the very low-mass Class 0 protostar IRAS 15398−3359 at scales ranging from 50 to 1800 au, as part of the Atacama Large Millimeter/Submillimeter Array Large Program FAUST. We uncover a linear feature, visible in H 2 CO, SO, and C 18 O line emission, which extends from the source in a direction almost perpendicular to the known active outflow. Molecular line emission from H 2 CO, SO, SiO, and CH 3 OH further reveals an arc-like structure connected to the outer end of the linear feature and separated from the protostar, IRAS 15398−3359, by 1200 au. The arc-like structure is blueshifted with respect to the systemic velocity. A velocity gradient of 1.2 km s −1 over 1200 au along the linear feature seen in the H 2 CO emission connects the protostar and the arc-like structure

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Seeds of Life in Space (SOLIS). IX. Chemical Segregation of SO₂ and SO toward the Low-mass Protostellar Shocked Region of L1157

Cited by 17 publications

References 64 publications

V838 Monocerotis as seen by ALMA: A remnant of a binary merger in a triple system

V838 Monocerotis as seen by ALMA: A remnant of a binary merger in a triple system

The SVS13-A Class I chemical complexity as revealed by S-bearing species. SOLIS XIII

FAUST. II. Discovery of a Secondary Outflow in IRAS 15398−3359: Variability in Outflow Direction during the Earliest Stage of Star Formation?

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Seeds of Life in Space (SOLIS). IX. Chemical Segregation of SO2 and SO toward the Low-mass Protostellar Shocked Region of L1157

Cited by 17 publications

References 64 publications

V838 Monocerotis as seen by ALMA: A remnant of a binary merger in a triple system

V838 Monocerotis as seen by ALMA: A remnant of a binary merger in a triple system

The SVS13-A Class I chemical complexity as revealed by S-bearing species. SOLIS XIII

FAUST. II. Discovery of a Secondary Outflow in IRAS 15398−3359: Variability in Outflow Direction during the Earliest Stage of Star Formation?

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Seeds of Life in Space (SOLIS). IX. Chemical Segregation of SO₂ and SO toward the Low-mass Protostellar Shocked Region of L1157