J/A+A/664/A11 NIR spectroscopic survey of protostellar jets (Massi+, 2022)
NIR spectroscopic survey of protostellar jets in the
star forming region IC 1396N.
Massi F., Lopez R., Beltran M.T., Estalella R., Girart J.M.
<Astron. Astrophys. 664, A11 (2022)>
=2022A&A...664A..11M 2022A&A...664A..11M (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Infrared sources ; Spectra, infrared ;
Photometry, narrow-band
Keywords: ISM: jets and outflows - ISM: individual objects: IC1396N -
stars: formation - infrared: ISM - techniques: spectroscopic
Abstract:
The bright-rimmed cloud IC 1396N, associated with an intermediate-mass
star-forming region, hosts a number of CO, molecular hydrogen, and
Herbig-Haro (HHs) outflows powered by a set of millimetre compact
sources.
The aim of this work is to characterise the kinematics and physical
conditions of the H2 emission features spread throughout the IC 1396N
region. The features appear as chains of knots with a jet-like
morphology and trace different H2 outflows. We also obtain further
information about (and an identification of) the driving sources.
Low-resolution, long-slit near-infrared spectra were acquired with the
NICS camera at the TNG telescope, using grisms KB (R∼1200), HK, and
JH (R∼500). Several slit pointings and position angles were used
throughout the IC 1396N region in order to sample a number of the H2
knots that were previously detected in deep H2 2.12um images.
The knots exhibit rich ro-vibrational spectra of H2, consistent
with shock-excited excitation, from which radial velocities and
relevant physical conditions of the IC 1396N H2 outflows were
derived. These also allowed estimating extinction ranges towards
several features. [FeII] emission was only detected towards a few
knots that also display unusually high H2 1-0 S(3)/S(1) flux
ratios. The obtained radial velocities confirm that most of the
outflows are close to the plane of the sky. Nearby knots in the same
chain often display different radial velocities, both blue-shifted
and red-shifted, which we interpret as due to ubiquitous jet
precession in the driving sources or the development of oblique
shocks. One of the chains (strand A, i.e. knots A1 to A15) appears as
a set of features trailing a leading bow-shock structure consistent
with the results of 3D magneto-hydrodynamical models. The sides of the
leading bow shock (A15) exhibit different radial velocities. We
discuss possible explanations. Our data cannot confirm whether strands
A and B have both originated in the intermediate mass young stellar
object [BGE2002] BIMA 2 because a simple model of a precessing jet
cannot account for their locations.
Near-infrared spectroscopy has confirmed that most of the H2
ro-vibrational emission in IC 1396N is shock-excited rather than
uv-excited in photon-dominated regions. It has shown a complex
kinematical structure in most strands of emitting knots as well.
Description:
Table 3 lists the fluxes of all the lines identified, knot by knot, in
the bands HK and JH. For each knot, all line fluxes are normalised to
the H2 1-0 S(1) ro-vibrational line flux in the HK band, and to the
H2 1-0 S(7) ro-vibrational line flux in the JH band. If a flux error
is marked by 9999, this indicates that the corresponding flux is an
upper limit. If both flux and flux error are marked by 9999, this
indicates that either the band does not cover the corresponding
wavelength or the knot has not been observed through the corresponding
grism. If a flux is marked by 8000, this indicates that line detection
was impossible due to problems (usually bad pixels or noise due to the
telluric correction).
Table 4 lists the fluxes of all the lines identified, knot by knot, in
the band of grism KB. For each knot, all line fluxes are normalised to
the H2 1-0 S(1) ro-vibrational line flux. If a flux error is marked
by 9999, this indicates that the corresponding flux is an upper limit.
If a flux is marked by 8000, this indicates that line detection was
impossible due to problems (usually bad pixels). Quoted uncertainties
have been obtained by multiplying the r.m.s. measured outside the line
by the FWHM of an unresolved line. Upper limits have been calculated
as the r.m.s. times the expected FWHM (which is just instrumental)
multiplied by 3. All line fluxes, excepted those of knots observed
only in the JH band, can be calibrated using the fluxes provided in
Table 5.
Table 5 lists the H2 1-0 S(1) line fluxes for the knots with entries
in Table 3 and 4 based on the narrow-band photometry (2.12 micron) by
Beltran et al. (2009). We have updated the photometry to include
feature unclassified in that paper, as well.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 75 79 List of studied knots
table3.dat 69 1399 Normalised line fluxes per knot in the
HK and JH bands
table4.dat 49 598 Normalised line fluxes per knot in the KB band
table5.dat 19 49 Knot line fluxes in the H2 1-0 S(1) line
--------------------------------------------------------------------------------
See also:
J/A+A/504/97 : JHKs photometry of IC 1396N (Beltran+, 2009)
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- ID Knot identification
11- 20 A10 ---- FileName1 First table name with data for the knot
22- 31 A10 ---- FileName2 Second table name with data for the knot
33- 42 A10 ---- FileName3 Third table name with data for the knot
45- 47 A3 --- Name Knot name or near knot name in
Beltran et al. (2009, Cat. J/A+A/504/97)
52- 53 I2 h RAh ? Right ascension (J2000) for source in
Beltran et al. (2009, Cat. J/A+A/504/97)
55- 56 I2 min RAm ? Right ascension (J2000) for source in
Beltran et al. (2009, Cat. J/A+A/504/97)
58- 62 F5.2 s RAs ? Right ascension (J2000) for source in
Beltran et al. (2009, Cat. J/A+A/504/97)
64 A1 --- DE- Declination sign (J2000) for source in
Beltran et al. (2009, Cat. J/A+A/504/97)
65- 66 I2 deg DEd ? Declination (J2000) for source in
Beltran et al. (2009, Cat. J/A+A/504/97)
68- 69 I2 arcmin DEm ? Declination (J2000) for source in
Beltran et al. (2009, Cat. J/A+A/504/97)
71- 75 F5.2 arcsec DEs ? Declination (J2000) for source in
Beltran et al. (2009, Cat. J/A+A/504/97)
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 6 A5 --- ID Knot identification (1)
8- 11 A4 --- SP Emitting molecular or ionic species (2)
13 I1 --- Up [1/4] Upper vibrational level (H2) or flag
for upper electronic level ([FeII]) (3)
15 I1 --- Low [0/4] Lower vibrational level (H2) or flag
for lower electronic level ([FeII]) (3)
17 A1 --- DJ [0OQS] Difference between initial and final
rotational level (H2) or 0 ([FeII]) (4)
19- 20 I2 --- J Final rotational level (H2) or 0 ([FeII])
22- 27 F6.4 um lambda Transition wavelength (in vacuum)
29- 37 F9.4 --- FHK ?=9999 Normalised flux of lines in HK band (5)
39- 47 F9.4 --- e_FHK ?=9999 Error on normalised flux (5)
49- 57 F9.4 --- FJH ?=9999 Normalised flux of lines in JH band (6)
59- 67 F9.4 --- e_FJH ?=9999 Error on normalised flux (6)
69 A1 --- Flag Notes (7)
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Note (1): Following the notation by Beltran et al. (2009, Cat. J/A+A/504/97).
In case the first letter is lowercase: a,b,c,d indicate the frame where the
knot spectrum was recorded (used when the same knots were observed with
different slit settings);
N and S as last letters indicate that the slit probably encompassed the
northern or southern part of the knot.
In a few cases, notably A15N and A15S, we checked that they are actually
different knots and updated the photometry of Beltran et al.
(2009, Cat. J/A+A/504/97) accordingly.
Note (2): Species as follows:
H2 = molecular hydrogen
FeII = ionised iron
Note (3): as for Fe+, forbidden lines ([FeII]) between levels, as follows:
1 = 3 d^6 (^5D) 4s (a^4D) J=7/2
2 = 3 d^7 (a^4F) J=9/2
3 = 3 d^6 (^5D) 4s (a^6D) J=7/2
4 = 3 d^6 (^5D) 4s (a^6D) J=9/2
Note (4): Jinitial - Jfinal = +2 (S), 0 (Q), -2 (O)
Note (5): lines in the HK band normalised to the flux of H2 1-0 S(1)
Note (6): lines in the JH band normalised to the flux of H2 1-0 S(7)
Note (7): Notes as follows:
c = when flux is not an upper limit, it flags the detection as
certain
p = when flux is not an upper limit, it flags the detection as
possible
e = values to be taken with caution due to heavy telluric absorption
f = it may be merged with H2 5-3 S(5) at 1.3103 micron
g = it may be merged with H2 4-2 S(3) at 1.2612 micron
h = it may be merged with H2 4-2 S(4) at 1.2418 micron
i = it may be merged with H2 3-1 S(6) at 1.1393 micron
l = it may be merged with H2 3-1 S(11) at 1.1208 micron
m = flux difficult to estimate due to nearby H2 lines, possible partial
merging
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 8 A7 --- ID Knot identification (1)
10- 11 A2 --- SP Emitting molecular or ionic species (2)
13 I1 --- Up [1/3] Upper vibrational level (H2)
15 I1 --- Low [0/2] Lower vibrational level (H2)
17 A1 --- DJ [S] Difference between initial and final
rotational level (H2) (3)
19- 20 I2 --- J Final rotational level (H2)
22- 27 F6.4 um lambda Transition wavelength (in vacuum)
29- 37 F9.4 --- FKB ?=8000 Normalised flux of lines in KB band (4)
39- 47 F9.4 --- e_FKB ?=9999 Error on normalised flux (4)
49 A1 --- Flag Notes (5)
--------------------------------------------------------------------------------
Note (1): Following the notation by Beltran et al. (2009, Cat. J/A+A/504/97).
In case the first letter is "u", this indicates that the knot is unclassified
in Beltran et al. (2009, Cat. J/A+A/504/97); in this case
i) if the name of just one knot follows the "u", this is the nearest knot
ii) if the names of two knots follow the "u", the unclassified knot lies
between the two
iii) if the name(s) of the knot(s) is(are) followed by N,S,E,W, this means
that the unclassified knot lies North, South, etc. of the indicated
knot(s).
In case N,S,E,W follows the name of a classified knot, this indicates
that the slit encompassed the northern, southern, etc. part of the knot.
In a few cases, e. g. A15N and A15S, we checked that they are actually
different knots and updated the photometry of Beltran et al.
(2009, Cat. J/A+A/504/97) accordingly, as we have done for the
"unclassified" knots.
In case two classified knots are indicated, either the emitting area
lies between the two or it was impossible to separate their
contribution to the detected spectrum.
A7p indicates that the emission comes from a plateau located near to A7,
located to the south-east.
A16 is a previously unclassified faint knot north-east of A15S.
The photo-ionised strip is indicated as "pis".
Note (2): Species as follows:
H2: molecular hydrogen
Note (3): Jinitial - Jfinal = +2 (S), 0 (Q), -2 (O)
Note (4): normalised to the flux of H2 1-0 S(1)
Note (5): Notes as follows:
c = when flux is not an upper limit, it flags the detection as "certain"
u = detection flagged as "uncertain" (only two cases)
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 8 A7 --- ID Knot identification (1)
10- 14 F5.2 aW/m2 F(H2) Flux measured in H2 filter
(narrow-band filter centred on 2.12 micron)
16- 19 F4.2 aW/m2 e_F(H2) rms uncertainty on flux
--------------------------------------------------------------------------------
Note (1): Following the notation by Beltran et al. (2009, Cat. J/A+A/504/97),
as modified in table 3 and 4.
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Acknowledgements:
Fabrizio Massi, fabrizio.massi(at)inaf.it,
INAF - Osservatorio Astrofisico di Arcetri, Italy
References:
Beltran et al., 2009A&A...504...97B 2009A&A...504...97B, Cat. J/A+a/504/A97
Beltran et al., 2012A&A...542L..26B 2012A&A...542L..26B,
Close encounters of the protostellar kind in IC 1396N.
Lopez et al., 2022A&A...661A.106L 2022A&A...661A.106L,
Collision of protostellar jets in the star-forming region IC 1396N.
Analysis of knot proper motions
(End) Fabrizio Mass [INAF, Italy], Patricia Vannier [CDS] 19-May-2022