J/A+A/445/971 Mid-infrared images of W75N (Persi+, 2006)
Mid-infrared images of the massive star forming region W75 N.
Persi P., Tapia M., Smith H.A.
<Astron. Astrophys., 445, 971-978 (2006)>
=2006A&A...445..971P 2006A&A...445..971P
ADC_Keywords: H II regions ; YSOs ; Infrared sources
Keywords: stars: formation - infrared: stars - ISM: clouds - ISM: HII regions
Abstract:
An infrared study that includes ground-based mid-infrared images
between 8.7 and 18.7um and IRAC images at 3.6, 4.5, 5.8 and 8.0um
of the W75 N massive star forming region is presented. The 12.5um
image shows the presence of four mid-infrared sources in the region
W75 N(B), three of which have bright near-infrared counterparts,
IRS 1, IRS 2 and IRS 3, all with significant excess emission at
lambda>2.0um. IRS 2 has a steep energy distribution and the computed
infrared luminosity is consistent with the presence of a young B3
star. The observed IRAC colors of IRS 3 indicate that this source is a
Class II intermediate mass young star, consistent with its infrared
energy distribution and luminosity. The fourth, newly discovered,
mid-infrared source appears coincident with the ultracompact HII
region VLA 3, and is located within the millimeter core MM 1. We
derived a luminosity of ∼750L☉ and a visual extinction AV∼90
for this source. From the IRAC images, we detected 75 sources in an
area of 120"x120" centered in W75 N. At least 25 of these sources are
associated with the molecular cloud and form a young stellar cluster
as shown in the IRAC two-color and the H-Ks versus Ks-[3.6] diagrams.
Description:
Mid-infrared images between 8.7 and 18.7um of W75N were taken during
three observing runs on September 2000, November 2001 and September
2003 with the mid-infrared camera CID on the 2.1 m telescope of the
Observatorio Astronomico Nacional at San Pedro Martir, Baja
California, Mexico.
The images at 3.6, 4.5, 5.8 and 8.0um of W75N presented here are
sections of the original IRAC images of the star forming region DR21
observed during the science verification period of the Spitzer
satellite.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 84 24 Coordinates and photometry from IRAC and 2MASS
of sources with infrared excess
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- [PTS2006] Sequential number
4- 5 I2 h RAh Right ascension (J2000)
7- 8 I2 min RAm Right ascension (J2000)
10- 14 F5.2 s RAs Right ascension (J2000)
16 A1 --- DE- Declination sign (J2000)
17- 18 I2 deg DEd Declination (J2000)
20- 21 I2 arcmin DEm Declination (J2000)
23- 26 F4.1 arcsec DEs Declination (J2000)
28- 32 F5.2 mag [3.6]mag IRAC magnitude at 3.6um (3.6 micron)
34- 38 F5.2 mag [4.5]mag IRAC magnitude at 4.5um
40- 44 F5.2 mag [5.8]mag ? IRAC magnitude at 5.8um
46- 50 F5.2 mag [8.0]mag ? IRAC magnitude at 8.0um
52- 56 F5.2 mag Jmag ? J magnitude
58- 62 F5.2 mag Hmag ? H magnitude
64- 68 F5.2 mag Kmag ? K magnitude
70- 84 A15 --- Notes Notes (1)
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Note (1): The following abbreviations are used:
clII = class II
clI = class I
ps = point source
psneb = point source in nebulosity
neb = nebulous
HII = IRAC colors reminiscent of HII regions
sat = saturated in IRAC band
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 05-Feb-2007