Tracing the cold and warm physico-chemical structure of deeply embedded protostars: IRAS 16293−2422 vs. VLA 1623−2417

N. M. Murillo; E. F. Van Dishoeck; M. H. D. Van Der Wiel; J. K. Jørgensen; M. N. Drozdovskaya; H. Calcutt; D. Harsono

doi:10.1051/0004-6361/201731724

Tracing the cold and warm physico-chemical structure of deeply embedded protostars: IRAS 16293−2422 vs. VLA 1623−2417

N. M. Murillo, E. F. Van Dishoeck, M. H. D. Van Der Wiel, J. K. Jørgensen, M. N. Drozdovskaya, H. Calcutt, D. Harsono

Astrophysics and Planetary Science

16 Citations (Scopus)

Abstract

Context. Much attention has been placed on the dust distribution in protostellar envelopes, but there are still many unanswered questions regarding the physico-chemical structure of the gas. Aims. Our aim is to start identifying the factors that determine the chemical structure of protostellar regions, by studying and comparing low-mass embedded systems in key molecular tracers. Methods. The cold and warm chemical structures of two embedded Class 0 systems, IRAS 16293-2422 and VLA 1623-2417 were characterized through interferometric observations. DCO⁺, N₂H⁺, and N₂D⁺ were used to trace the spatial distribution and physics of the cold regions of the envelope, while c-C₃H₂ and C₂H from models of the chemistry are expected to trace the warm (UV-irradiated) regions. Results. The two sources show a number of striking similarities and differences. DCO⁺ consistently traces the cold material at the disk-envelope interface, where gas and dust temperatures are lowered due to disk shadowing. N₂H⁺ and N₂D⁺, also tracing cold gas, show low abundances toward VLA 1623-2417, but for IRAS 16293-2422, the distribution of N₂D⁺ is consistent with the same chemical models that reproduce DCO⁺. The two systems show different spatial distributions c-C₃H₂ and C₂H. For IRAS 16293-2422, c-C₃H₂ traces the outflow cavity wall, while C₂H is found in the envelope material but not the outflow cavity wall. In contrast, toward VLA 1623-2417 both molecules trace the outflow cavity wall. Finally, hot core molecules are abundantly observed toward IRAS 16293-2422 but not toward VLA 1623-2417. Conclusions. We identify temperature as one of the key factors in determining the chemical structure of protostars as seen in gaseous molecules. More luminous protostars, such as IRAS 16293-2422, will have chemical complexity out to larger distances than colder protostars, such as VLA 1623-2417. Additionally, disks in the embedded phase have a crucial role in controlling both the gas and dust temperature of the envelope, and consequently the chemical structure.

Original language	English
Article number	A120
Journal	Astronomy & Astrophysics
Volume	617
Number of pages	25
ISSN	0004-6361
DOIs	https://doi.org/10.1051/0004-6361/201731724
Publication status	Published - 1 Sept 2018

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@article{f79bb33bb2584406935a1148d88d4791,

title = "Tracing the cold and warm physico-chemical structure of deeply embedded protostars: IRAS 16293−2422 vs. VLA 1623−2417",

abstract = "Context. Much attention has been placed on the dust distribution in protostellar envelopes, but there are still many unanswered questions regarding the physico-chemical structure of the gas. Aims. Our aim is to start identifying the factors that determine the chemical structure of protostellar regions, by studying and comparing low-mass embedded systems in key molecular tracers. Methods. The cold and warm chemical structures of two embedded Class 0 systems, IRAS 16293-2422 and VLA 1623-2417 were characterized through interferometric observations. DCO+, N2H+, and N2D+ were used to trace the spatial distribution and physics of the cold regions of the envelope, while c-C3H2 and C2H from models of the chemistry are expected to trace the warm (UV-irradiated) regions. Results. The two sources show a number of striking similarities and differences. DCO+ consistently traces the cold material at the disk-envelope interface, where gas and dust temperatures are lowered due to disk shadowing. N2H+ and N2D+, also tracing cold gas, show low abundances toward VLA 1623-2417, but for IRAS 16293-2422, the distribution of N2D+ is consistent with the same chemical models that reproduce DCO+. The two systems show different spatial distributions c-C3H2 and C2H. For IRAS 16293-2422, c-C3H2 traces the outflow cavity wall, while C2H is found in the envelope material but not the outflow cavity wall. In contrast, toward VLA 1623-2417 both molecules trace the outflow cavity wall. Finally, hot core molecules are abundantly observed toward IRAS 16293-2422 but not toward VLA 1623-2417. Conclusions. We identify temperature as one of the key factors in determining the chemical structure of protostars as seen in gaseous molecules. More luminous protostars, such as IRAS 16293-2422, will have chemical complexity out to larger distances than colder protostars, such as VLA 1623-2417. Additionally, disks in the embedded phase have a crucial role in controlling both the gas and dust temperature of the envelope, and consequently the chemical structure.",

author = "Murillo, {N. M.} and {Van Dishoeck}, {E. F.} and {Van Der Wiel}, {M. H. D.} and J{\o}rgensen, {J. K.} and Drozdovskaya, {M. N.} and H. Calcutt and D. Harsono",

year = "2018",

month = sep,

day = "1",

doi = "10.1051/0004-6361/201731724",

language = "English",

volume = "617",

journal = "Astronomy and Astrophysics Supplement Series",

issn = "0004-6361",

publisher = "E D P Sciences",

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TY - JOUR

T1 - Tracing the cold and warm physico-chemical structure of deeply embedded protostars: IRAS 16293−2422 vs. VLA 1623−2417

AU - Murillo, N. M.

AU - Van Dishoeck, E. F.

AU - Van Der Wiel, M. H. D.

AU - Jørgensen, J. K.

AU - Drozdovskaya, M. N.

AU - Calcutt, H.

AU - Harsono, D.

PY - 2018/9/1

Y1 - 2018/9/1

N2 - Context. Much attention has been placed on the dust distribution in protostellar envelopes, but there are still many unanswered questions regarding the physico-chemical structure of the gas. Aims. Our aim is to start identifying the factors that determine the chemical structure of protostellar regions, by studying and comparing low-mass embedded systems in key molecular tracers. Methods. The cold and warm chemical structures of two embedded Class 0 systems, IRAS 16293-2422 and VLA 1623-2417 were characterized through interferometric observations. DCO+, N2H+, and N2D+ were used to trace the spatial distribution and physics of the cold regions of the envelope, while c-C3H2 and C2H from models of the chemistry are expected to trace the warm (UV-irradiated) regions. Results. The two sources show a number of striking similarities and differences. DCO+ consistently traces the cold material at the disk-envelope interface, where gas and dust temperatures are lowered due to disk shadowing. N2H+ and N2D+, also tracing cold gas, show low abundances toward VLA 1623-2417, but for IRAS 16293-2422, the distribution of N2D+ is consistent with the same chemical models that reproduce DCO+. The two systems show different spatial distributions c-C3H2 and C2H. For IRAS 16293-2422, c-C3H2 traces the outflow cavity wall, while C2H is found in the envelope material but not the outflow cavity wall. In contrast, toward VLA 1623-2417 both molecules trace the outflow cavity wall. Finally, hot core molecules are abundantly observed toward IRAS 16293-2422 but not toward VLA 1623-2417. Conclusions. We identify temperature as one of the key factors in determining the chemical structure of protostars as seen in gaseous molecules. More luminous protostars, such as IRAS 16293-2422, will have chemical complexity out to larger distances than colder protostars, such as VLA 1623-2417. Additionally, disks in the embedded phase have a crucial role in controlling both the gas and dust temperature of the envelope, and consequently the chemical structure.

AB - Context. Much attention has been placed on the dust distribution in protostellar envelopes, but there are still many unanswered questions regarding the physico-chemical structure of the gas. Aims. Our aim is to start identifying the factors that determine the chemical structure of protostellar regions, by studying and comparing low-mass embedded systems in key molecular tracers. Methods. The cold and warm chemical structures of two embedded Class 0 systems, IRAS 16293-2422 and VLA 1623-2417 were characterized through interferometric observations. DCO+, N2H+, and N2D+ were used to trace the spatial distribution and physics of the cold regions of the envelope, while c-C3H2 and C2H from models of the chemistry are expected to trace the warm (UV-irradiated) regions. Results. The two sources show a number of striking similarities and differences. DCO+ consistently traces the cold material at the disk-envelope interface, where gas and dust temperatures are lowered due to disk shadowing. N2H+ and N2D+, also tracing cold gas, show low abundances toward VLA 1623-2417, but for IRAS 16293-2422, the distribution of N2D+ is consistent with the same chemical models that reproduce DCO+. The two systems show different spatial distributions c-C3H2 and C2H. For IRAS 16293-2422, c-C3H2 traces the outflow cavity wall, while C2H is found in the envelope material but not the outflow cavity wall. In contrast, toward VLA 1623-2417 both molecules trace the outflow cavity wall. Finally, hot core molecules are abundantly observed toward IRAS 16293-2422 but not toward VLA 1623-2417. Conclusions. We identify temperature as one of the key factors in determining the chemical structure of protostars as seen in gaseous molecules. More luminous protostars, such as IRAS 16293-2422, will have chemical complexity out to larger distances than colder protostars, such as VLA 1623-2417. Additionally, disks in the embedded phase have a crucial role in controlling both the gas and dust temperature of the envelope, and consequently the chemical structure.

U2 - 10.1051/0004-6361/201731724

DO - 10.1051/0004-6361/201731724

M3 - Journal article

SN - 0004-6361

VL - 617

JO - Astronomy and Astrophysics Supplement Series

JF - Astronomy and Astrophysics Supplement Series

M1 - A120

ER -

Tracing the cold and warm physico-chemical structure of deeply embedded protostars: IRAS 16293−2422 vs. VLA 1623−2417

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