Download - DIAGNOSIS FROM JET OBSERVATIONS: KINEMATICS (v field: velocity components of the jet knots)
DIAGNOSIS FROM JET OBSERVATIONS:
A) KINEMATICS (v field: velocity components of the jet knots) a1) RADIAL VELOCITY line shifts: spectroscopy a2) TANG. VELOCITY “proper motions”: imaging
B) PHYSICAL CONDITIONS : excitation, density, ionization fraction…. Appropriate flux line ratios: spectroscopy (quite rough estimation from imaging in different filters, however)
A+B) “simultaneously: 3D spectroscopy:
IMAGING: WHAT CAN BE DERIVED FROM?IMAGING: WHAT CAN BE DERIVED FROM?
Obtain images through “narrow-band” ( FWHM ~ 50 A) filters of the HHs field:
HHs emission is mainly “pure line emission” (except near the source) use filters centered on brighter characteristic jet emission lines, eg, Optical: H, [SII] red doublet, [OIII] (less used: extinction and excitation conditions..)
Infrared: [FeII], H2
Morphology: “history” of the mass-ejection
jet/environment interaction
(indirect) evidence on the nature of the jet source and ejection
mechanisms
spatial distribution of the physical conditions through the jet…
Kinematics: VT, from “proper motions”
NARROW-BAND (OPTICAL) FILTERSNARROW-BAND (OPTICAL) FILTERS
Commonly used for HHs (from NOT webpage):
“H” filter [SII] “red” filter
(6563+part of [NII] 6584 A) ([SII] 6717, 6731 A)
Narrow-band (NIR) filtersNarrow-band (NIR) filters
Commonly used for HHs imaging (from ING webpage)
[FeII] 1.64 m (H band)H2 2.12 m (K band)
KINEMATICS:KINEMATICS: TANGENTIAL VELOCITY OF THE KNOTS (VT)
Knots of the jets appear “displaced” relative to the field stars when images obtained at different epochs are compared. By measuring these “displacements” between two epochs, the VT can be obtained (for a knwon distance).
HST high-spatial resolution images have shown the “displacement”of the knot structures with time, with high degree of detai,l in several wellknown HH jets.
HH 111HH 111
HST images from (Hartigan et al..)
Bally et al. (2002), Bally et al. (2002), AJ,123,2627.AJ,123,2627.
HST (1997)HST (1997)
NN
CS *CS *
HH 1HH 1
HH 2HH 2
Bally et al. (2002), AJ,123,2627.
HST (1994); proper HST (1994); proper motions after 5 yrs.motions after 5 yrs.
Bally et al. (2002), AJ,123,2627.
HST (1994); HST (1994); proper motions proper motions in 5 yrs.in 5 yrs.
Arrow:: displacement in 30 yrsArrow:: displacement in 30 yrs
HH 47HH 47HH 47
Proper Proper motionsmotions
Arrows: Arrows: displacement in displacement in 30 yrs30 yrs
Arrows: Arrows: displacemdisplacement in 10 ent in 10 yrsyrs
Proper-motions from ground-based images: two examplesProper-motions from ground-based images: two examples
Summary:1) Obtain several images of the jet field, with appropriate time spacing, through narrow-band filters covering emission from [SII] or H(strong emission lines at visible wavelengths).2) Convert all the images on to a common reference system, using positions of field stars. . Highly recommended: reference stars, well distributed around jet (not always possible, extinction!) . Different images from different instruments: care with their spatial scale!3) Identify each of the knots of the jet in all the images Care! Some structures may have changed with time4) Evaluate the (spatial) displacement of each of the knots, with respect to the (fixed) reference star system, during the time elapsed between two images n pixel/yr n pixel/yr n arcsec/yr : PROPER MOTION (+ distance) n arcsec/yr : PROPER MOTION (+ distance) VVTT (kms (kms-1-1))
Ex. 1: HH 110Ex. 1: HH 110
Reipurt & Bally (90 ´s)
. In Orion B cloud complex (d~450pc). It shows “peculiarities, eg, : rather chaotic morphology exciting source, unknown originated by deflection of HH 270 that collides with a high-density clump (see later)
HH 110
HH 270
Sepúlveda et al., 2011, AA, 527, 41[SII] image, 2.5m INT- 1993
HH 110HH 110
NN ~4 ARCMIN
[SII] image, 2.6m NOT, 2002
HH 110HH 110
Knot identification
10/2002
12/1993
12/1987
HH 110 knot AHH 110 knot A
López et al. 2005, A&A, López et al. 2005, A&A, 432,567432,567
Displacement of knot A from 1987 to 2002(after convert all images on to a common reference system).
Displacement obtained for the HH 110 knot, using images from three epochs
Knot M
2002
1993
1987
HH 110: Proper motions obtained HH 110: Proper motions obtained from a time baseline ~ 15 yr; for a from a time baseline ~ 15 yr; for a distance ~ 450pc distance ~ 450pc VVTT
Ex 2 HH 30Ex 2 HH 30
Mundt et al. A&A, 232, 37 (1990) HST archive
In L1551, TMC (d~140pc)Prototypical jet/disk system. Jet/counterjet structure. “wiggling morphology”. Exciting source, “hidden” (invisible at optical/ir wavelengths)
Anglada et al.,AJ,133,2799
HH 30:[SII] image, 2.6m NOT, 1998
Displacements of the jet knots of HH 30Displacements of the jet knots of HH 30
Anglada et al. 2007, AJ,133,2799
Proper motions of the jet knots of HH 30Proper motions of the jet knots of HH 30
Anglada et al. 2007, AJ,133,2799
HH 30[SII] image, 4.2m WHT, 2010
Displacements of the knots of the HH 30 jet/counterjet system Displacements of the knots of the HH 30 jet/counterjet system
Estalella et al, 2012,AJ,144,61
with a longer time baseline:
Appreciable differentkinematic behaviourjet/counterjet
jet counterjet
HH 30 jet/counterjet proper motionsHH 30 jet/counterjet proper motions
Estalella et al, 2012,AJ,144,61