2013A&A...552A..56W


C.D.S. - SIMBAD4 rel 1.7 - 2021.05.15CEST09:55:31

2013A&A...552A..56W - Astronomy and Astrophysics, volume 552A, 56-56 (2013/4-1)

OH far-infrared emission from low- and intermediate-mass protostars surveyed with Herschel-PACS.

WAMPFLER S.F., BRUDERER S., KARSKA A., HERCZEG G.J., VAN DISHOECK E.F., KRISTENSEN L.E., GOICOECHEA J.R., BENZ A.O., DOTY S.D., McCOEY C., BAUDRY A., GIANNINI T. and LARSSON B.

Abstract (from CDS):

The OH radical is a key species in the water chemistry network of star-forming regions, because its presence is tightly related to the formation and destruction of water. Previous studies of the OH far-infrared emission from low- and intermediate-mass protostars suggest that the OH emission mainly originates from shocked gas and not from the quiescent protostellar envelopes. We aim to study the excitation of OH in embedded low- and intermediate-mass protostars, determine the influence of source parameters on the strength of the emission, investigate the spatial extent of the OH emission, and further constrain its origin. This paper presents OH observations from 23 low- and intermediate-mass young stellar objects obtained with the PACS integral field spectrometer on-board Herschel in the context of the ``Water In Star-forming regions with Herschel'' (WISH) key program. Radiative transfer codes are used to model the OH excitation. Most low-mass sources have compact OH emission (≲5000AU scale), whereas the OH lines in most intermediate-mass sources are extended over the whole 47.0"x47.0" PACS detector field-of-view (>20000AU). The strength of the OH emission is correlated with various source properties such as the bolometric luminosity and the envelope mass, but also with the [OI] and H2O emission. Rotational diagrams for sources with many OH lines show that the level populations of OH can be approximated by a Boltzmann distribution with an excitation temperature at around 70K. Radiative transfer models of spherically symmetric envelopes cannot reproduce the OH emission fluxes nor their broad line widths, strongly suggesting an outflow origin. Slab excitation models indicate that the observed excitation temperature can either be reached if the OH molecules are exposed to a strong far-infrared continuum radiation field or if the gas temperature and density are sufficiently high. Using realistic source parameters and radiation fields, it is shown for the case of Ser SMM1 that radiative pumping plays an important role in transitions arising from upper level energies higher than 300K. The compact emission in the low-mass sources and the required presence of a strong radiation field and/or a high density to excite the OH molecules points toward an origin in shocks in the inner envelope close to the protostar.

Abstract Copyright:

Journal keyword(s): astrochemistry - stars: formation - ISM: molecules - ISM: jets and outflows

Simbad objects: 32

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Number of rows : 32

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 NAME W3 IRS 5 Y*O 02 25 40.54 +62 05 51.4           B1 330 0
2 RAFGL 490 Y*O 03 27 38.7928323987 +58 47 00.017662871           ~ 341 0
3 [JCC87] IRAS 2A Y*O 03 28 55.55 +31 14 36.7           ~ 410 3
4 [JCC87] IRAS 4A Y*O 03 29 10.49 +31 13 30.8           ~ 630 1
5 [JCC87] IRAS 4 FIR 03 29 10.9 +31 13 26           ~ 470 0
6 [JCC87] IRAS 4B Y*O 03 29 12.058 +31 13 02.05           ~ 568 0
7 LDN 1489 DNe 04 04 47.5 +26 19 42           ~ 200 0
8 IRAS 04361+2547 Y*O 04 39 13.89288 +25 53 20.8788           ~ 187 1
9 IRAS 04365+2535 Y*O 04 39 35.19360 +25 41 44.7252           ~ 247 0
10 LDN 1527 DNe 04 39 53 +25 45.0           ~ 530 0
11 TMC-1 MoC 04 41 45.9 +25 41 27           ~ 1423 0
12 NAME Orion Bright Bar reg 05 35 22.30 -05 24 33.0           ~ 756 0
13 LDN 1641 MoC 05 39.0 -07 00           ~ 438 0
14 [SMZ2000] L1643-S3 MMS 1 smm 05 39 55.9 -07 30 28           ~ 13 0
15 NGC 2071 RNe 05 47 10 +00 18.0           ~ 616 1
16 2MASS J08254384-5100326 Y*O 08 25 43.85 -51 00 32.7           ~ 299 1
17 IRAS 08448-4343 cor 08 46 33.8 -43 54 33           ~ 59 1
18 IRAS 08470-4321 cor 08 48 48.2 -43 32 25           ~ 42 0
19 IRAS 11051-7706 Y*O 11 06 46.025 -77 22 29.67           ~ 71 0
20 V* DK Cha Or* 12 53 17.2028372976 -77 07 10.727661977           F0 132 0
21 Barnard 228 cor 15 43 00.9 -34 08 48           ~ 64 0
22 IRAS 15398-3359 Y*? 15 43 02.21016 -34 09 07.7112       18.38 21.72 ~ 135 0
23 HBC 650 TT* 16 34 29.32 -15 47 01.4           K3.0 165 2
24 NAME LDN 483-mm mm 18 17 29.8 -04 39 38           ~ 19 0
25 LDN 483 DNe 18 17 35 -04 39.8           ~ 226 0
26 NAME SH 2-68 FIR 1 cor 18 29 49.63 +01 15 21.9           ~ 243 2
27 NAME Serpens Cluster As* 18 29 57 +01 14.4           ~ 60 0
28 NAME SERPENS SMM 3 smm 18 29 59.7 +01 14 00           ~ 86 1
29 NAME LDN 723-mm smm 19 17 53.70 +19 12 20.0           ~ 15 0
30 LDN 723 DNe 19 18 12 +19 13.6           ~ 153 0
31 NGC 7129 OpC 21 42 56 +66 06.2     11.5     ~ 237 0
32 NAME NGC 7129 FIR 2 IR 21 44 01.5 +66 03 40           ~ 88 0

    Equat.    Gal    SGal    Ecl

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2021.05.15-09:55:31

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