J/ApJ/643/965 Spitzer photometry of the Trifid nebula (M20) (Rho+, 2006)
Spectacular Spitzer images of the Trifid nebula:
protostars in a young, massive-star-forming region.
Rho J., Reach W.T., Lefloch B., Fazio G.G.
<Astrophys. J., 643, 965-977 (2006)>
=2006ApJ...643..965R 2006ApJ...643..965R
ADC_Keywords: H II regions ; Infrared sources ; Photometry, infrared
Keywords: H II regions - infrared: stars - ISM: individual (Trifid Nebula) -
stars: formation
Abstract:
Spitzer IRAC and MIPS images of the Trifid Nebula (M20) reveal its
spectacular appearance in infrared light, highlighting the nebula's
special evolutionary stage. The images feature recently formed massive
protostars and numerous young stellar objects, and a single O star
that illuminates the surrounding molecular cloud from which it formed,
and unveil large-scale, filamentary dark clouds. Multiple protostars
are detected in the infrared, within the cold dust cores of TC3 and
TC4, which were previously defined as Class 0. The cold dust continuum
cores of TC1 and TC2 contain only one protostar each. The Spitzer
color-color diagram allowed us to identify 160 young stellar objects
(YSOs) and classify them into different evolutionary stages. The
diagram also revealed a unique group of YSOs that are bright at 24um
but have the spectral energy distribution peaking at 58um.
Description:
We performed our infrared observations of the Trifid Nebula with the
Spitzer Space Telescope, the fourth NASA Great Observatory. The
Infrared Array Camera (IRAC) and Multiband Imaging Photometer for
Spitzer (MIPS) observations took place on 2004 March 31 (AOR 6049024)
and 2004 April 11 (AOR 6048768), respectively.
Objects:
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RA (2000) DE Designation(s)
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18 02 23.0 -23 01 48 M 20 = NAME TRIFID NEBULA
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 122 161 Protostars and Young Stellar Objects in the Trifid
Nebula Identified by the Spitzer Color-Color Diagram
table2.dat 132 12 Properties of Protostars within the Four Dust
Continuum Cores
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See also:
J/ApJ/562/446 : X-rays and protostars in Trifid nebula (Rho+, 2001)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- [RRL2006] Source name
13- 14 I2 h RAh Right ascension (J2000)
16- 17 I2 min RAm Right ascension (J2000)
19- 23 F5.2 s RAs Right ascension (J2000)
25 A1 --- DE- Declination sign (J2000)
26- 27 I2 deg DEd Declination (J2000)
29- 30 I2 arcmin DEm Declination (J2000)
32- 35 F4.1 arcsec DEs Declination (J2000)
37- 40 F4.2 mag MIPS24 MIPS 24um magnitude
42- 45 F4.2 mag e_MIPS24 rms uncertainty on MIPS24
47- 50 F4.2 mag IRAC8 IRAC 8um magnitude
52- 55 F4.2 mag e_IRAC8 rms uncertainty on IRAC8
57- 62 F6.3 mag IRAC5.8 ?=99.99 IRAC 5.8um magnitude
64- 67 F4.2 mag e_IRAC5.8 ?=9.99 rms uncertainty on IRAC5.8
69- 73 F5.2 mag IRAC4.5 ?=99.99 IRAC 4.5um magnitude
75- 78 F4.2 mag e_IRAC4.5 ?=9.99 rms uncertainty on IRAC4.5
80- 84 F5.2 mag IRAC3.6 ?=99.99 IRAC 3.6um magnitude
86- 89 F4.2 mag e_IRAC3.6 ?=9.99 rms uncertainty on IRAC3.6
91- 95 F5.2 mag Kmag ?=99.99 Johnson K magnitude (1)
97-100 F4.2 mag e_Kmag ?=9.99 rms uncertainty on Kmag
102-106 F5.2 mag Hmag ?=99.99 Johnson H magnitude (1)
108-111 F4.2 mag e_Hmag ?=9.99 rms uncertainty on Hmag
113-117 F5.2 mag Jmag ?=99.99 Johnson J magnitude (1)
119-122 F4.2 mag e_Jmag ?=9.99 rms uncertainty on Jmag
124-127 F4.1 arcsec Sep ? Separation from central core protostar
(table2 only)
129-132 F4.1 solLum LmidIR ? Mid-IR luminosity (table2 only)
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Note (1): Near-infrared data are from Palomar 200 inch measurements.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 24-Aug-2007