J/ApJ/767/147 Spitzer-IRAC photometry of jets in Vela-D (Giannini+, 2013)
Spitzer-IRAC survey of molecular jets in Vela-D.
Giannini T., Lorenzetti D., De Luca M., Strafella F., Elia D., Maiolo B.,
Marengo M., Maruccia Y., Massi F., Nisini B., Olmi L., Salama A.,
Smith H.A.
<Astrophys. J., 767, 147 (2013)>
=2013ApJ...767..147G 2013ApJ...767..147G (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Interstellar medium ; Photometry, infrared
Keywords: infrared: stars - ISM: clouds -
ISM: individual: Vela Molecular Ridge - ISM: jets and outflows -
stars: formation - surveys
Abstract:
We present a survey of H2 jets from young protostars in the Vela-D
molecular cloud (VMR-D), based on Spitzer-IRAC data between 3.6 µm
and 8.0 µm. Our search has led to the identification of 15 jets
(two new discoveries) and about 70 well-aligned knots within 1.2 deg2.
We compare the Infrared Array Camera (IRAC) maps with observations of
the H2 1-0 S(1) line at 2.12 µm, with a Spitzer-MIPS map at 24 µm
and 70 µm, and with a map of the dust continuum emission at 1.2 mm.
From such a comparison, we find a tight association between molecular
jets and dust peaks. The jet candidate exciting sources have been
searched for in the published catalog of the young stellar objects of
VMR-D. In particular, we searched for all the sources of Class II or
(preferentially) earlier which are located close to the jet center and
aligned with it. Furthermore, the association between jet and exciting
source was validated by estimating the differential extinction between
the jet opposite lobes. We are able to find a best-candidate exciting
source in all but two jets, for which two alternative candidates are
given. Four exciting sources are not (or very barely) observed at
wavelengths shorter than 24 µm, suggesting that they are very young
protostars. Three of them are also associated with the most compact
jets (projected length≲0.1 pc). The exciting source spectral energy
distributions (SEDs) have been constructed and modeled by means of all
the available photometric data between 1.2 µm and 1.2 mm. From SEDs
fits, we derive the main source parameters, which indicate that most
of them are low-mass protostars. A significant correlation is found
between the projected jet length and the [24]-[70] color, which is
consistent with an evolutionary scenario according to which shorter
jets are associated with younger sources. A rough correlation is found
between IRAC line cooling and exciting source bolometric luminosity,
in agreement with the previous literature. The emerging trend suggests
that mass loss and mass accretion are tightly related phenomena and
that both decrease with time.
Description:
We have observed VMR-D as part of the IRAC-Spitzer Cycle 3 GTO
(PID 30335; PI: G. Fazio). The observations cover a region of about
1.2 deg2 delimited in longitude by 264°29'~<l~<263°00'
and in latitude by 0°42'~<b~<0°50'. We have presented the
photometric results of Strafella et al. (2010, J/ApJ/719/9; SEC10), who
describe in detail the observational strategy, source extraction, and
photometry. This work resulted in a catalog, which we use in the
present paper to identify the jet exciting sources (ES).
Objects:
------------------------------------------------------------------------
RA (ICRS) DE Designation(s)
------------------------------------------------------------------------
08 53 -45.0 Vela Molecular Ridge = NAME VMR
08 39 -41.0 Vela-D molecular cloud = NAME Vela D Cloud
------------------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 99 69 Jets Photometry
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See also:
J/A+A/419/999 : Infrared knots along protostellar jets (Giannini+, 2004)
J/ApJ/671/470 : MIPS survey of YSOs in Vela Molecular Ridge-D (Giannini+, 2007)
J/ApJ/704/606 : Protostars in the Vela Molecular Cloud (Giannini+, 2009)
J/ApJ/719/9 : IRAC point-source catalog of Vela-D cloud (Strafella+, 2010)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- KnotID Knot identifier
5 A1 --- n_KnotID [def] Note on KnotID (1)
7- 8 I2 h RAh Hour of Right Ascension (J2000) (2)
10- 11 I2 min RAm Minute of Right Ascension (J2000) (2)
13- 16 F4.1 s RAs Second of Right Ascension (J2000) (2)
18 A1 --- DE- Sign of the Declination (J2000) (2)
19- 20 I2 deg DEd Degree of Declination (J2000) (2)
22- 23 I2 arcmin DEm Arcminute of Declination (J2000) (2)
25- 26 I2 arcsec DEs Arcsecond of Declination (J2000) (2)
28- 30 I3 arcsec2 Size Knot size evaluated on the image at 4.5 µm
32- 36 F5.3 mJy F2.12 ? 2.12 µm flux density
38- 42 F5.3 mJy e_F2.12 ? 1σ uncertainty in F2.12
44 A1 --- l_F3.6 [<] 3σ upper limit flag on F3.6
45- 48 F4.2 mJy F3.6 Spitzer/IRAC 3.6 µm flux density
50- 53 F4.2 mJy e_F3.6 ? 1σ uncertainty in F3.6
55- 58 F4.2 mJy F4.5 Spitzer/IRAC 4.5 µm flux density
60- 63 F4.2 mJy e_F4.5 1σ uncertainty in F4.5
65 A1 --- l_F5.8 [<] 3σ upper limit flag on F5.8
66- 70 F5.2 mJy F5.8 ? Spitzer/IRAC 5.8 µm flux density
72- 75 F4.2 mJy e_F5.8 ? 1σ uncertainty in F5.8
77 A1 --- l_F8.0 [<] 3σ upper limit flag on F8.0
78- 81 F4.2 mJy F8.0 ? Spitzer/IRAC 8.0 µm flux density
83- 86 F4.2 mJy e_F8.0 ? 1σ uncertainty in F8.0
88- 93 F6.3 10-2Lsun LIRAC IRAC total luminosity
95- 99 F5.3 10-2Lsun L2.12 ? 2.12 µm luminosity (L1-0S(1))
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Note (1): Note as follows:
d = Knots tentatively attributed to jet 13;
e = The photometry is contaminated by the emission of the exciting source;
f = Knot that could belong either to jet 14 (knot 14-1) or to jet 15
(knot 15-5).
Note (2): Center of the corresponding box.
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History:
From electronic version of the journal
(End) Prepared by Tiphaine Pouvreau [CDS] 22-Aug-2017