2018A&A...617A.120M


Query : 2018A&A...617A.120M

2018A&A...617A.120M - Astronomy and Astrophysics, volume 617A, 120-120 (2018/9-1)

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

MURILLO N.M., VAN DISHOECK E.F., VAN DER WIEL M.H.D., JORGENSEN J.K., DROZDOVSKAYA M.N., CALCUTT H. and HARSONO D.

Abstract (from CDS):


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.

Abstract Copyright: © ESO 2018

Journal keyword(s): astrochemistry - stars: formation - stars: low-mass - stars: individual: IRAS 16293-2422 - methods: observational - stars: individual: VLA 1623-2417

Simbad objects: 21

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Number of rows : 21
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 V* V512 Per Or* 03 29 03.7578170808 +31 16 03.947525688           ~ 367 0
2 [JCC87] IRAS 4 FIR 03 29 10.9 +31 13 26           ~ 473 0
3 NGC 1333 OpC 03 29 11 +31 18.6           ~ 1325 1
4 [JCC87] IRAS 4C Y*O 03 29 13.54 +31 13 58.2           ~ 97 1
5 LDN 1527 DNe 04 39 53 +25 45.0           ~ 561 0
6 LDN 1544 DNe 05 04 16.6 +25 10 48           ~ 776 0
7 NAME Orion Bright Bar reg 05 35 22.30 -05 24 33.0           ~ 797 0
8 NAME Horsehead Nebula DNe 05 40 59.0 -02 27 30           ~ 480 0
9 V* TW Hya TT* 11 01 51.9053285064 -34 42 17.033218380   11.94 10.50 10.626 9.18 K6Ve 1736 1
10 QSO B1514-24 BLL 15 17 41.8134049824 -24 22 19.482207024   15.13 14.00 13.95   ~ 697 3
11 * rho Oph A * 16 25 35.1185711280 -23 26 49.831640736 4.3 5.22 5.05     B2/3V 393 0
12 QSO B1622-253 QSO 16 25 46.8886080600 -25 27 38.336613804   21.3 20.6 19.60   ~ 322 1
13 NAME VLA 1623-243 Y*O 16 26 26.42 -24 24 30.0           ~ 395 0
14 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 3337 1
15 WLY 2-67 Y*O 16 32 00.99624 -24 56 41.9640           ~ 57 0
16 IRAS 16293-2422 cor 16 32 22.56 -24 28 31.8           ~ 1158 1
17 LDN 1689N DNe 16 32 25.96 -24 28 46.2           ~ 114 0
18 QSO B1730-130 QSO 17 33 02.7055087032 -13 04 49.545516612   18 18.5 18.78 17.39 ~ 1058 1
19 IRAS 20343+4129 HII 20 36 07.1 +41 40 01           ~ 52 0
20 2MASS J20360725+4139528 NIR 20 36 07.2353206632 +41 39 52.634342844           ~ 5 0
21 [CPR2002] B1 Y*O 20 36 07.53 +41 40 09.1           ~ 9 0

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2022.05.25-10:02:46

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