2002ApJ...574..246N


Query : 2002ApJ...574..246N

2002ApJ...574..246N - Astrophys. J., 574, 246-257 (2002/July-3)

Evolution in the far-infrared spectra of low-mass young embedded sources.

NISINI B., GIANNINI T. and LORENZETTI D.

Abstract (from CDS):

The far-infrared spectra (45-197 µm) of 28 low-luminosity young embedded objects have been studied in order to search for possible evolutive trends in the observed spectral features. The low-resolution spectra from 45 to 197 µm of 17 Class 0 and 11 Class I sources taken with the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory have been used for this analysis. The most prominent features presented by these spectra are the [O I] 63 and 145 µm fine-structure lines and pure rotational lines from the abundant molecules CO, H2O, and OH. Clear differences are found, however, between the spectra of the two classes of objects. Water lines, which are prominent in the spectra of Class 0 sources, are not observed in Class I objects, with an upper limit ≲10–5 on the H2O abundance. Furthermore, the total cooling due to molecular emission in Class 0 sources is on average significantly larger than in Class I sources, while the cooling due to atomic oxygen is fairly constant among the two classes of objects. Finally, the total gas cooling as traced by the far-infrared lines (LFIR) is correlated with the bolometric luminosity for the Class 0 sample of sources, with an LFIR/Lbol ratio (∼10–2) of about an order of magnitude larger than in Class I sources. We suggest that most of the observed emission lines originate from shocks at the base and along the source outflows. In such a case these results can be interpreted in terms of a change in the modality of the interaction between the protostellar jet and the circumstellar environment. During the Class 0 phase the impact of energetic flows with the dense ambient medium gives rise to a strong component of nondissociative C-type shock, while during the Class I phase such impact produces less energetic shocks with an enhanced dissociative J-type component. Finally, the low H2O abundance found in Class I sources can be explained by the action of the progressively less shielded interstellar UV field.

Abstract Copyright:

Journal keyword(s): Infrared: ISM - ISM: Jets and Outflows - ISM: Molecules - Stars: Formation - Stars: Mass Loss - Stars: Pre-Main-Sequence

Simbad objects: 42

goto Full paper

goto View the references in ADS

Number of rows : 42
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 IRAS 03225+3034 IR 03 25 36.49 +30 45 22.2           ~ 154 1
2 SSTc2d J032536.4+304522 Y*O 03 25 36.49 +30 45 22.2           ~ 190 1
3 LDN 1448NA smm 03 25 36.49 +30 45 22.2           ~ 178 1
4 [SDA2014] West4 Y*O 03 25 38.83 +30 44 06.2           ~ 245 1
5 IRAS F03226+3033 Y*O 03 25 38.83 +30 44 06.2           ~ 319 0
6 IRAS 03258+3104 Y*O 03 28 55.30 +31 14 27.8           ~ 160 1
7 [JCC87] IRAS 2A Y*O 03 28 55.55 +31 14 36.7           ~ 421 3
8 ASR 114 Y*O 03 29 01.16520 +31 20 24.4140           ~ 73 1
9 2MASS J03290842+3115284 NIR 03 29 08.420 +31 15 28.48           ~ 226 1
10 [JCC87] IRAS 4A Y*O 03 29 10.49 +31 13 30.8           ~ 640 1
11 [JCC87] IRAS 4 FIR 03 29 10.9 +31 13 26           ~ 473 0
12 [JCC87] IRAS 4B Y*O 03 29 12.058 +31 13 02.05           ~ 573 0
13 IRAS 03282+3035 cor 03 31 20.98 +30 45 30.1           ~ 164 0
14 NAME HH 211-mm Y*O 03 43 56.816 +32 00 50.06           ~ 61 1
15 V* T Tau TT* 04 21 59.4323326335 +19 32 06.439974179   11.22 10.12 9.80   K0IV/Ve 1344 1
16 RAFGL 5123 Y*O 04 31 34.07736 +18 08 04.9020           K3V/M3III 823 0
17 2MASS J04314444+1808315 Y*O 04 31 44.44680 +18 08 31.5384           ~ 156 0
18 LDN 1527 DNe 04 39 53 +25 45.0           ~ 539 0
19 GBS-VLA J053622.86-064606.6 Y*O 05 36 22.84 -06 46 06.2           ~ 100 0
20 2MASS J05460363-0014493 Y*O 05 46 03.63 -00 14 49.3           ~ 50 0
21 NAME HH 25MMS Y*O 05 46 07.8 -00 13 41           ~ 56 0
22 LMZ 3 IR 05 46 08.8 -00 10 47           ~ 85 0
23 HH 47C HH 08 25 32.96 -51 01 37.4           ~ 42 0
24 2MASS J08254384-5100326 Y*O 08 25 43.85 -51 00 32.7           ~ 301 1
25 HH 46A HH 08 25 44.2 -51 00 16           ~ 3 0
26 V* DK Cha Or* 12 53 17.2028372976 -77 07 10.727661977           F0 132 0
27 WL 16 Y*O 16 27 02.33520 -24 37 27.2316           A0-F3 154 0
28 Elia 2-29 Y*O 16 27 09.43032 -24 37 18.7716           ~ 273 1
29 YLW 15 Y*O 16 27 26.93640 -24 40 50.8224           ~ 246 1
30 YLW 16A Y*O 16 27 28.02744 -24 39 33.5052           K8 187 0
31 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 3219 1
32 IRAS 16293-2422 cor 16 32 22.56 -24 28 31.8           ~ 1113 1
33 HBC 645 Em* 16 32 27.22 -44 55 36.0           ~ 25 0
34 NAME LDN 483-mm mm 18 17 29.8 -04 39 38           ~ 20 0
35 LDN 483 DNe 18 17 35 -04 39.8           ~ 237 0
36 NAME SH 2-68 FIR 1 cor 18 29 49.63 +01 15 21.9           ~ 246 2
37 V* R CrA Ae* 19 01 53.6850227874 -36 57 08.145519972 12.781 12.651 11.917 11.242 10.412 B5IIIpe 459 1
38 NAME LDN 723-mm smm 19 17 53.70 +19 12 20.0           ~ 16 0
39 LDN 663 DNe 19 36 55 +07 34.4           ~ 578 0
40 HH 375 Y*O 20 39 06.2 +68 02 15           ~ 170 0
41 EM* LkHA 234 Ae* 21 43 06.8214472757 +66 06 54.199354231 13.65 13.61 12.73 11.98 11.20 B5Ve 280 0
42 NAME Cep E HII 23 03 12.779 +61 42 25.75           ~ 160 0

To bookmark this query, right click on this link: simbad:objects in 2002ApJ...574..246N and select 'bookmark this link' or equivalent in the popup menu


2021.09.24-23:28:58

© Université de Strasbourg/CNRS

    • Contact