J/ApJ/773/135 Disk-bearing stars in Cygnus OB2 (Guarcello+, 2013)
The protoplanetary disks in the nearby massive star-forming region Cygnus OB2.
Guarcello M.G., Drake J.J., Wright N.J., Drew J.E., Gutermuth R.A.,
Hora J.L., Naylor T., Aldcroft T., Fruscione A., Garcia-alvarez D.,
Kashyap V.L., King R.
<Astrophys. J., 773, 135 (2013)>
=2013ApJ...773..135G 2013ApJ...773..135G
ADC_Keywords: Associations, stellar ; Stars, pre-main sequence ; Photometry
Keywords: infrared: stars -
open clusters and associations: individual (Cygnus OB2) -
protoplanetary disks - stars: formation - stars: pre-main sequence
Abstract:
The formation of stars in massive clusters is one of the main modes of
the star formation process. However, the study of massive star-forming
regions is hampered by their typically large distances to the Sun. One
exception to this is the massive star-forming region Cygnus OB2 in the
Cygnus X region, at the distance of ∼1400pc. Cygnus OB2 hosts very
rich populations of massive and low-mass stars, being the best target
in our Galaxy to study the formation of stars, circumstellar disks,
and planets in the presence of massive stars. In this paper, we
combine a wide and deep set of photometric data, from the r band to
24µm, in order to select the disk-bearing population of stars in
Cygnus OB2 and identify the class I, class II, and stars with
transition and pre-transition disks. We selected 1843 sources with
infrared excesses in an area of 1°x1° centered on Cyg OB2 in
several evolutionary stages: 8.4% class I, 13.1% flat-spectrum
sources, 72.9% class II, 2.3% pre-transition disks, and 3.3%
transition disks. The spatial distribution of these sources shows a
central cluster surrounded by an annular overdensity and some clumps
of recent star formation in the outer region. Several candidate
subclusters are identified, both along the overdensity and in the rest
of the association.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 500 1843 Catalog of candidate stars with disk
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/321 : IPHAS DR2 Source Catalogue (Barentsen+, 2014)
J/ApJ/643/238 : Chandra/2MASS sources in Cygnus OB2 (Butt+, 2006)
J/A+A/464/211 : Cyg OB2 Chandra and near-IR obs (Albacete Colombo+, 2007)
J/A+A/472/557 : Cygnus OB2 region 610MHz sources (Marti+, 2007)
J/MNRAS/384/1277 : Hα emission line sources from IPHAS (Witham+, 2008)
J/A+A/486/453 : Early-type stars in Cyg OB2 NIR photometry (Comeron+, 2008)
J/ApJS/184/84 : X-ray sources in Cyg OB2 region (Wright+, 2009)
J/ApJ/713/871 : X-ray sources in star-forming region Cyg-OB2 (Wright+, 2010)
J/ApJ/720/679 : Optical spectroscopy in Cygnus X region (Beerer+, 2010)
J/ApJS/194/27 : Variable stars in Cygnus OB2 (Henderson+, 2011)
J/A+A/543/A101 : OB stars in Cygnus OB2 association (Comeron+, 2012)
J/ApJS/202/19 : GTC/OSIRIS riz photometry in Cyg OB2 (Guarcello+, 2012)
http://www.iphas.org/ : IPHAS Home Page
http://www.sdss.org/ : SDSS Home Page
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID [229/329368] Sequential star number
8- 29 F22.15 deg RAdeg Right ascension (J2000) (1)
31- 52 F22.15 deg DEdeg Declination (J2000) (1)
54- 60 F7.4 mag rmagO ?=- OSIRIS r magnitude (see J/ApJS/202/19)
62- 67 F6.4 mag e_rmagO ?=- rms uncertainty on rmagO
69- 74 F6.3 mag imagO ?=- OSIRIS i magnitude (see J/ApJS/202/19)
76- 81 F6.4 mag e_imagO ?=- rms uncertainty on imagO
83- 89 F7.4 mag zmagO ?=- OSIRIS z magnitude (see J/ApJS/202/19)
91- 96 F6.4 mag e_zmagO ?=- rms uncertainty on zmagO
98-103 F6.3 mag rmagI ?=- INT/IPHAS gR magnitude
105-109 F5.3 mag e_rmagI ?=- rms uncertainty on rmagI
111-116 F6.3 mag imagI ?=- INT/IPHAS gI magnitude
118-122 F5.3 mag e_imagI ?=- rms uncertainty on imagI
124-129 F6.3 mag HamagI ?=- INT/IPHAS Ha (Hα) magnitude
131-135 F5.3 mag e_HamagI ?=- rms uncertainty on HamagI
137-143 F7.4 mag umagS ?=- SDSS u magnitude
145-152 F8.6 mag e_umagS ?=- rms uncertainty on umagS
154-160 F7.4 mag gmagS ?=- SDSS g magnitude
162-169 F8.6 mag e_gmagS ?=- rms uncertainty on gmagS
171-177 F7.4 mag rmagS ?=- SDSS r magnitude
179-186 F8.6 mag e_rmagS ?=- rms uncertainty on rmagS
188-194 F7.4 mag imagS ?=- SDSS i magnitude
196-203 F8.6 mag e_imagS ?=- rms uncertainty on imagS
205-211 F7.4 mag zmagS ?=- SDSS z magnitude
213-220 F8.6 mag e_zmagS ?=- rms uncertainty on zmagS
222-227 F6.3 mag Jmag2 ?=- 2MASS J magnitude
229-233 F5.3 mag e_Jmag2 ?=- rms uncertainty on Jmag2
235-240 F6.3 mag Hmag2 ?=- 2MASS H magnitude
242-246 F5.3 mag e_Hmag2 ?=- rms uncertainty on Hmag2
248-253 F6.3 mag Kmag2 ?=- 2MASS Ks magnitude
255-259 F5.3 mag e_Kmag2 ?=- rms uncertainty on Kmag2
261-263 A3 --- phqual ph_qual quality flag from 2MASS/PSC catalog
265-267 A3 --- rdflg rd_flg quality flag from 2MASS/PSC catalog
269-271 A3 --- blflg bl_flg quality flag from 2MASS/PSC catalog
273-275 A3 --- ccflg cc_flg quality flag from 2MASS/PSC catalog
277-283 F7.4 mag JmagU ?=- UKIDSS J magnitude
285-292 F8.6 mag e_JmagU ?=- rms uncertainty on JmagU
294-300 F7.4 mag HmagU ?=- UKIDSS H magnitude
302-309 F8.6 mag e_HmagU ?=- rms uncertainty on HmagU
311-317 F7.4 mag KmagU ?=- UKIDSS K magnitude
319-330 E12.6 mag e_KmagU ?=- rms uncertainty on KmagU
332-339 F8.6 mag J-KU ?=- UKIDSS J-K colour index
341-348 F8.6 mag e_J-KU ?=- rms uncertainty on J-KU
350-357 F8.6 mag H-KU ?=- UKIDSS H-K colour index
359-366 F8.6 mag e_H-KU ?=- rms uncertainty on H-KU
368-373 F6.3 mag [3.6] ?=- Spitzer/IRAC 3.6um magnitude
375-379 F5.3 mag e_[3.6] ?=- rms uncertainty on [3.6]
381-386 F6.3 mag [4.5] ?=- Spitzer/IRAC 4.5um magnitude
388-392 F5.3 mag e_[4.5] ?=- rms uncertainty on [4.5]
394-399 F6.3 mag [5.8] ?=- Spitzer/IRAC 5.8um magnitude
401-405 F5.3 mag e_[5.8] ?=- rms uncertainty on [5.8]
407-412 F6.3 mag [8.0] ?=- Spitzer/IRAC 8.0um magnitude
414-418 F5.3 mag e_[8.0] ?=- rms uncertainty on [8.0]
420-425 F6.3 mag [24] ?=- Spitzer/MIPS 24um magnitude
427-431 F5.3 mag e_[24] ?=- rms uncertainty on [24]
433-434 I2 --- mOI [0]?=-1 >0 if source has a multiple match
between OSIRIS and IPHAS counterparts
436-437 I2 --- mU2 [0/2]?=-1 >0 if source has a multiple match
between UKIDSS and 2MASS counterparts
439-440 I2 --- mUo [0/4]?=-1 >0 if source has a multiple match
between UKIDSS+2MASS and optical counterparts
442-443 I2 --- mUS [0/3]?=-1 >0 if source has a multiple match
between UKIDSS+2MASS+optical and Spitzer
counterparts
445 I1 --- S1 [0/1] 1 if the star has been selected with the
Gutermuth et al. (2009ApJS..184...18G 2009ApJS..184...18G) method
447 I1 --- S2 [0/1] 1 if the star has been selected with the
[4.5] versus [4.5]-[8.0] diagram
449 I1 --- S3 [0/1] 1 if the star has been selected with the
[3.6] versus [3.6]-[24] diagram
451 I1 --- S4 [0/1] 1 if the star has been selected with the
[24] versus [8.0]-[24] diagram
453 I1 --- S5 [0/1] 1 if the star has been selected with the
[4.5]-[5.8] versus [5.8]-[24] diagram
455 I1 --- S6 [0/1] 1 if the star has been selected with the
[24] versus [4.5]-[8.0] diagram
457 I1 --- S7 [0/1] 1 if the star has been selected with the
QriJ[3.6] index (3)
459 I1 --- S8 [0/1] 1 if the star has been selected with the
QriJ[4.5] index (3)
461 I1 --- S9 [0/1] 1 if the star has been selected with the
QriJ[5.8] index (3)
463 I1 --- S10 [0/1] 1 if the star has been selected with the
QriJ[8.0] index (3)
465 I1 --- S11 [0/1] 1 if the star has been selected with the
J-H versus H-K diagram
467 I1 --- S12 [0/1] 1 if the star has been selected with the
QJHHK index (3)
469 I1 --- S13 [0/1] 1 if the star has been selected with the
QriHK index (3)
471-479 F9.6 --- alpha ?=- Infrared spectral index α =
dlog(λFλ)/dlog(λ).
481-500 A20 --- Class Classification (2)
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Note (1): Remember that the astrometric systems of all the merged catalogs are
referred to the 2MASS.
Note (2): a string describing the classification of the star. If more
classifications are present, they are divided by underscores.
The different codes are:
HE = highly embedded
CL1 = class I YSO
FS = flat-spectrum
CL2 = class II YSO
NC = not classifiable
BWE = blue stars with excesses (candidate stars with disks, but
with optical color bluer than the cluster locus, being more
compatible with the foreground population than with the
association)
TD = transition disk
PTD = pre-transition disk
lowmass = low-mass disk with excesses only in [8.0] and [24]
high-incl = highly inclined disk with excesses only in [8.0] and [24]
Ha = classified as Hα emitter in this paper or by
Vink et al. (2008MNRAS.387..308V 2008MNRAS.387..308V)
Note (3): the index Qabcd uses 2 reddening-free color indices from 4 colors
a b c d and is defined as Qabcd=(a-b)-(c-d).E(a-b)/E(c-d), if E(a-b)
represents the color excess in (a-b) color.
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Acknowledgements:
Mario Guarcello, mguarcello(at)cfa.harvard.edu
(End) Patricia Vannier [CDS] 21-Aug-2013