J/AJ/144/101 Multiwavelength data of IRAS 20050+2720 young SFR (Guenther+, 2012)
IRAS 20050+2720: anatomy of a young stellar cluster.
Guenther H.M., Wolk S.J., Spitzbart B., Gutermuth R.A., Forbrich J.,
Wright N.J., Allen L., Bourke T.L., Megeath S.T., Pipher J.L.
<Astron. J., 144, 101 (2012)>
=2012AJ....144..101G 2012AJ....144..101G (SIMBAD/NED BibCode)
ADC_Keywords: X-ray sources ; Stars, pre-main sequence ; Associations, stellar ;
YSOs ; Photometry, UBVRI ; Photometry, infrared ; Extinction
Keywords: circumstellar matter - infrared: stars - stars: formation -
stars: pre-main sequence - X-rays: stars
Abstract:
IRAS 20050+2720 is young star-forming region at a distance of 700pc
without apparent high-mass stars. We present results of our
multi-wavelength study of IRAS 20050+2720 which includes observations
by Chandra and Spitzer, and Two Micron All Sky Survey and UBVRI
photometry. In total, about 300 young stellar objects (YSOs) in
different evolutionary stages are found. We characterize the
distribution of YSOs in this region using a minimum spanning tree
analysis. We newly identify a second cluster core, which consists
mostly of class II objects, about 10' from the center of the cloud.
YSOs of earlier evolutionary stages are more clustered than more
evolved objects. The X-ray luminosity function (XLF) of IRAS
20050+2720 is roughly lognormal, but steeper than the XLF of the more
massive Orion Nebula complex. IRAS 20050+2720 shows a lower NH/AK
ratio compared with the diffuse interstellar medium.
Description:
We use Spitzer data from two initial observations performed in 2004,
which are described in detail in Gutermuth et al. (2009, Cat.
J/ApJS/184/18). This data set misses an extended population beyond the
cluster core, so follow-up observations were performed in 2007 as part
of the Spitzer "Clusters Near Clusters" GTO program (Program ID 40147;
Masiunas et al., 2012ApJ...752..127M 2012ApJ...752..127M).
On 2004 Jun 9, the cluster center was imaged with IRAC (3.6-8.0µm,
AORKEY 3656448). In 2007 Jun 29, two additional maps were obtained
with IRAC to the northeast and southwest of the original pointing
(AORKEY 21893120 and AORKEY 21893376).
MIPS mosaics (24-160µm) were taken at medium scan rate with
full-width scan stepping. The observation in 2004 Sep 25 (AORKEY
3665152) contains three scanning stripes, one stripe toward the
southeast was added in 2007 Oct 27 (AORKEY 21891840). Because of the
low angular resolution, the 70 and 160µm data cannot be used for
individual sources in a dense region like IRAS 20050+2720.
IRAS 20050+2720 was observed with Chandra using the VFAINT mode of the
ACIS-I detector in three different epochs (2006 Dec 10, ObsID 6438;
2006 Jan 7, ObsID 7254; and 2007 Jan 29, ObsID 8492).
Optical photometry of IRAS 20050+2720 was obtained on 2009 Nov 18 and
2009 Nov 21 at the Fred Lawrence Whipple Observatory (FLWO) with the
1.2m telescope and the Keplercam instrument. Keplercam is a camera
with a Fairchild "CCD 486" detector. We use observations taken in
u'BHVHr'i'. The BH and VH filters belong to the Harris set,
the u', r', and i' filters are part of a Sloan Digital Sky Survey
(SDSS) set (Fukugita et al., 1996AJ....111.1748F 1996AJ....111.1748F). The optical
photometry is supplemented by data from IPHAS, the Isaac Newton
Telescope (INT) Photometric Hα Survey (Drew et al.,
2005MNRAS.362..753D 2005MNRAS.362..753D). IPHAS is a survey of the northern Galactic plane
in broad band r', i', and narrowband Hα filters to a depth of
r'∼20(10σ). Using the IPHAS Initial Data Release
(Gonzalez-Solares et al., 2008MNRAS.388...89G 2008MNRAS.388...89G) we extracted all
stellar sources (morphological classification=-1) within 15' of the
center of IRAS 20050+2720.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 111 348 X-Ray sources and spectral fits
table3.dat 324 40593 Optical and infra-red photometry of the sources
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2013)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/AJ/140/266 : NGC 1333 X-ray luminous YSOs properties (Winston+, 2010)
J/ApJ/713/871 : Sources in star-forming region Cyg-OB2 from X-ray
(Wright+, 2010)
J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)
J/ApJ/674/336 : Spitzer observations of NGC 1333 (Gutermuth+, 2008)
J/A+A/481/93 : CO and HC3N maps of IRAS 20050+2720 (Beltran+, 2008)
J/AJ/135/693 : X-ray and IR sources in RCW 108 (Wolk+, 2008)
J/ApJ/675/464 : Chandra observations of NGC 2244 (Wang+, 2008)
J/ApJ/677/401 : Xray properties of protostars in ONC (Prisinzano+, 2008)
J/ApJ/669/493 : Spitzer/Chandra YSOs in Serpens cloud core (Winston+, 2007)
J/ApJS/163/306 : Chandra study of the Cep B star-forming region (Getman+, 2006)
J/AJ/132/1100 : X-ray and IR sources in RCW 38 (Wolk+, 2006)
J/AJ/126/1916 : JHK photometry of young clusters near the Sun (Porras+, 2003)
http://cda.harvard.edu/chaser/mainEntry.do : Chandra observation search
http://sha.ipac.caltech.edu/applications/Spitzer/SHA : Spitzer search
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- Src [1/32824] Running X-ray source number
<[GWS2012] NNNNN> in Simbad (1)
7- 16 F10.6 deg RAdeg Right Ascension (J2000)
18- 26 F9.6 deg DEdeg Declination (J2000)
28- 31 A4 --- Cl Source classification (G1)
33- 37 F5.1 ct NCts Net 0.3-8keV counts in X-ray
39- 47 F9.5 ct/ks/m2 FX ? The 0.3-8 keV flux count rate
(in 10-7ct/s/cm2)
49- 55 F7.4 ct/ks/m2 e_FX ? Statistical error in FX
57- 63 F7.4 10+22/cm2 NH ? Hydrogen column density
65- 70 F6.4 10+22/cm2 e_NH ? Statistical error in NH
72- 78 F7.4 keV kT ? Energy (X-ray temperature)
80- 85 F6.4 keV e_kT ? Statistical error in kT
87- 93 F7.4 aW/m2 Flux ? Observed 0.3-8 keV flux
(in 10-15erg/s/cm2)
95-103 F9.6 aW/m2 e_Flux ? Statistical error in Flux
105-111 F7.4 [10-7W] logLX ? Log of X-ray luminosity (unabsorbed
luminosity assuming a distance of 700pc)
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Note (1): This table shows only X-ray sources that are identified as YSOs and
have valid spectral fits.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- Src [1/40593] Running X-ray source number
<[GWS2012] NNNNN> in Simbad
7- 16 F10.6 deg RAdeg Right Ascension (J2000)
18- 26 F9.6 deg DEdeg Declination (J2000)
28- 34 F7.4 mag Umag ? FLWO SDSS U band magnitude (1)
36- 43 F8.6 mag e_Umag ? Statistical error in Umag
45- 51 F7.4 mag Bmag ? FLWO Harris B band magnitude (1)
53- 60 F8.6 mag e_Bmag ? Statistical error in Bmag
62- 68 F7.4 mag Vmag ? FLWO Harris V band magnitude (1)
70- 77 F8.6 mag e_Vmag ? Statistical error in Vmag
79- 86 F8.5 mag Rmag ? FLWO SDSS R band magnitude (1)
88- 95 F8.6 mag e_Rmag ? Statistical error in Rmag
97-104 F8.5 mag Imag ? FLWO SDSS I band magnitude (1)
106-113 F8.6 mag e_Imag ? Statistical error in Imag
115-120 F6.3 mag Jmag ? 2MASS J band magnitude
122-126 F5.3 mag e_Jmag ? Statistical error in Jmag
128-133 F6.3 mag Hmag ? 2MASS H band magnitude
135-139 F5.3 mag e_Hmag ? Statistical error in Hmag
141-146 F6.3 mag Kmag ? 2MASS Ks band magnitude
148-152 F5.3 mag e_Kmag ? Statistical error in Kmag
154-161 F8.5 mag [3.6] ? Spitzer/IRAC 3.6µm band magnitude
163-172 F10.8 mag e_[3.6] ? Statistical error in [3.6]
174-181 F8.5 mag [4.5] ? Spitzer/IRAC 4.5µm band magnitude
183-192 F10.8 mag e_[4.5] ? Statistical error in [4.5]
194-202 F9.5 mag [5.8] ? Spitzer/IRAC 5.8µm band magnitude
204-214 F11.9 mag e_[5.8] ? Statistical error in [5.8]
216-223 F8.5 mag [8.0] ? Spitzer/IRAC 8.0µm band magnitude
225-235 F11.9 mag e_[8.0] ? Statistical error in [8.0]
237-246 F10.7 mag [24] ? Spitzer/MIPS 24µm band magnitude
248-257 F10.8 mag e_[24] ? Statistical error in [24]
259-264 F6.3 mag Hamag ? IPHAS Hα band magnitude (1)
266-270 F5.3 mag e_Hamag ? Statistical error in Hamag
272-277 F6.3 mag rmag ? IPHAS r band magnitude (1)
279-283 F5.3 mag e_rmag ? Statistical error in rmag
285-290 F6.3 mag imag ? IPHAS i band magnitude (1)
292-296 F5.3 mag e_imag ? Statistical error in imag
298-301 A4 --- Cl Source classification (G1)
303-313 F11.9 mag AK ? Extinction in the K band (see Section 3.2)
315-324 F10.7 mag AV Extinction in the V band (from extinction map)
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Note (1): the instruments used are:
FLWO = Fred Lawrence Whipple Observatory.
IPHAS = Isaac Newton Telescope (INT) Photometric Hα Survey
(Drew et al., 2005MNRAS.362..753D 2005MNRAS.362..753D).
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Global notes:
Note (G1): Source as follows:
I = Source less embedded than class I* sources (see Section 3.2 for more
details);
I* = Source which is highly reddened and thus invisible at short wavelengths
but bright in the MIPS 24µm band (see Section 3.2 for more details);
II = Source with less surrounding material but an IR excess in all bands due
to a disk (see Section 3.2 for more details);
II* = Transition disk. Source where the IRAC bands follow the energy
distribution of a stellar photosphere, but where an excess is found in
MIPS 24µm (see Section 3.2 for more details);
III = Sources that have lost their envelope and their disk (see Section 3.4
for details);
XYSO = X-ray (detected) YSO ; X-ray source in the region 301.76<α<301.81
and 27.47<δ<27.49 (see Section 3.4.2 for more details).
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 30-Oct-2013