1999A&A...342..717B


Query : 1999A&A...342..717B

1999A&A...342..717B - Astronomy and Astrophysics, volume 342, 717-735 (1999/2-3)

Ionization and density along the beams of Herbig-Haro jets.

BACCIOTTI F. and EISLOEFFEL J.

Abstract (from CDS):

Physical properties of several well-known Herbig-Haro jets are investigated using an improved version of the spectroscopic diagnostic technique originally developed by Bacciotti et al. (1995A&A...296..185B) The procedure allows one to derive in a model-independent way the hydrogen ionization fraction in regions of low excitation. The ionization fraction, the electron and gas density, and the average excitation temperature are derived for various positions along the flows. We find that the hydrogen ionization fraction, with typical initial values of 20-30%, generally decreases along the whole jet or along parts of the flow, following well-defined recombination laws. These results are consistent with the idea that the gas is initially ionized in the jet acceleration region, and then slowly recombines while traveling away from the source. If shocks along the jet beam are present, they can at most have a minor contribution to the ionization of the gas, as apparent in HH34 and in the first 45"of the HH46/47 jet, where the ionization fraction decreases almost monotonically. In the jets in which re-ionization episodes occur (i.e. HH24C/E and HH24G), the ionization fraction suddenly increases and then gently decays downstream of the re-ionization event. Both findings apparently disfavour a mini-bow shock interpretation for the production of the ionization of the beam. The total densities derived from the ratio between the electron density and the ionization fraction range from about 103 to a few 104cm–3. Without applying a correction for shock compression, the average mass loss rate varies from 3.8x10–8 (in the HL Tau jet) to 1.2x10–6M/yr (in HH24G), while momentum supply rates vary between 1.6x10–5 (in the HL Tau jet) and 3.1x10–4M/yr.km/s (in HH24G). Taking shock compression into account, these values may be reduced by a factor 3-5.

Abstract Copyright:

Journal keyword(s): ISM: kinematics and dynamics - ISM: jets and outflows - stars: formation - line: formation

CDS comments: HL-E = [MRB88] HL-E

Simbad objects: 22

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Number of rows : 22
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* HL Tau Or* 04 31 38.5107609312 +18 13 57.859747968   15.89 14.49 14.39   K5 1318 0
2 IRAS 04287+1807 mul 04 31 38.8 +18 13 57           ~ 796 0
3 HH 34 HH 05 35 31.30 -06 28 43.0     16     ~ 477 2
4 HH 24G HH 05 46 -00.2           ~ 19 0
5 HH 24C HH 05 46 07.69 -00 09 40.3           ~ 23 0
6 IRAS 05435-0011 Y*O 05 46 08.45544 -00 10 02.9568           ~ 79 0
7 HH 24E HH 05 46 08.5 -00 09 28           ~ 14 0
8 HH 24 HH 05 46 09 -00 10.2           ~ 157 1
9 HH 24A HH 05 46 09.2296069344 -00 10 25.627182960           ~ 34 0
10 HH 24G2 HH 05 46 11.70 -00 09 12.5           ~ 3 0
11 M 78 RNe 05 46 45.8 +00 04 45   8.0       ~ 360 0
12 HH 111 HH 05 51 44.2 +02 48 34           ~ 397 0
13 NAME HH 46-47 HH 08 25 43.6 -51 00 36           ~ 189 2
14 2MASS J08254384-5100326 Y*O 08 25 43.85 -51 00 32.7           ~ 307 1
15 HH 47 HH 08 25 44.30 -51 00 26.2           ~ 244 0
16 HH 47A HH 08 25 50.28 -50 58 52.4           ~ 88 0
17 WRAY 16-203 Or* 16 08 29.7275063376 -39 03 11.024360496   16.26 15.91 15.38 15.69 K0: 159 1
18 Ass Lup T 1 As* ~ ~           ~ 3 0
19 HH 228W HH ~ ~           ~ 6 0
20 [CJ87] HL Tau Knot E PoC ~ ~           ~ 5 0
21 HH 228E2 HH ~ ~           ~ 5 0
22 HH 228E1 HH ~ ~           ~ 6 0

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2022.05.24-21:35:10

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