J/AJ/162/236 Photometry of young stellar objects in Cepheus OB4 (Mintz+, 2021)
Testing models of triggered star formation with young stellar objects in
Cepheus OB4.
Mintz A., Hora J.L., Winston E.
<Astron. J., 162, 236-236 (2021)>
=2021AJ....162..236M 2021AJ....162..236M (SIMBAD/NED BibCode)
ADC_Keywords: YSOs; Stars, OB; Star Forming Region; Photometry, infrared;
Stars, ages; Effective temperatures
Keywords: Young stellar objects; Star formation; Star forming regions
Infrared excess; Protoplanetary disks
Abstract:
OB associations are home to newly formed massive stars, whose
turbulent winds and ionizing flux create HII regions rich with star
formation. Studying the distribution and abundance of young stellar
objects (YSOs) in these ionized bubbles can provide essential insight
into the physical processes that shape their formation, allowing us to
test competing models of star formation. In this work, we examined one
such OB association, Cepheus OB4 (CepOB4)-a well-suited region for
studying YSOs due to its Galactic location, proximity, and geometry.
We created a photometric catalog from Spitzer/Infrared Array Camera
(IRAC) mosaics in bands 1 (3.6µm) and 2 (4.5µm). We supplemented
the catalog with photometry from the Wide-field Infrared Survey
Explorer, the Two Micron All Sky Survey, IRAC bands 3 (5.8µm) and 4
(8.0µm), MIPS 24µm, and MMIRS near-infrared data. We used
color-color selections to identify 821 YSOs, which we classified using
the IR slope of the YSOs' spectral energy distributions, finding 67
Class I, 103 flat spectrum, 569 Class II, and 82 Class III YSOs. We
conducted a clustering analysis of the Cep OB4 YSOs and fit their
spectral energy distributions. We found many young Class I objects
distributed in the surrounding shell and pillars as well as a relative
age gradient of unclustered sourcesin the bubble surrounding the OB
association, with YSOs generally decreasing in age with distance from
the central cluster. Both of these results indicate that the expansion
of the HII region may have triggered star formation in CepOB4.
Description:
We have conducted a study of YSOs in the Cep OB4 OB association, using
new Spitzer Infrared Array Camera (IRAC) and MMIRS images, publicly
available MIPS images, and photometry from 2MASS and WISE.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 284 752615 Photometry table
table3.dat 402 821 Cep OB4 YSOs
table6.dat 106 821 SED fitting results
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See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/ApJ/827/96 : WISE census of YSOs in Canis Major (Fischer+, 2016)
J/ApJS/229/28 : SFiNCs: X-ray, IR and membership catalogs (Getman+, 2017)
J/A+A/620/A27 : Taurus ultra-wide pairs. II. (Joncour+, 2018)
J/A+A/621/A115 : Vela OB2 members (Cantat-Gaudin+, 2019)
J/ApJ/880/9 : Spitzer obs. of YSOs in the SMOG field (Winston+, 2019)
J/AJ/155/44 : Prop. of PMS stars in young cluster Berkeley 59 (Panwar+, 2018)
J/ApJ/870/32 : Kinematics in young star clusters & associations (Kuhn+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- Name YSO name
27- 37 F11.7 deg RAdeg [0/360] Right Ascension (J2000)
39- 48 F10.7 deg DEdeg [66/70] Declination (J2000) (deg)
50- 56 F7.4 mag magI1 ? IRAC 3.6 micron magnitude (1)
58- 64 F7.4 mag e_magI1 ? Error in IRAC 3.6 micron magnitude (1)
66- 72 F7.4 mag magI2 ? IRAC 4.5 micron magnitude (1)
74- 81 F8.4 mag e_magI2 ? Error in IRAC 4.5 micron magnitude
83- 89 F7.4 mag magI3 ? IRAC 5.8 micron magnitude (1)
91- 97 F7.4 mag e_magI3 ? Error in IRAC 5.8 micron magnitude (1)
99-105 F7.4 mag magI4 ? IRAC 8.0 micron magnitude (1)
107-113 F7.4 mag e_magI4 ? Error in IRAC 8.0 micron magnitude (1)
115-120 F6.3 mag jm2MASS ? 2MASS J-band magnitude
122-126 F5.3 mag e_jm2MASS ? Error in 2MASS J-band magnitude
128-133 F6.3 mag hm2MASS ? 2MASS H-band magnitude
135-139 F5.3 mag e_hm2MASS ? Error in 2MASS H-band magnitude
141-146 F6.3 mag km2MASS ? 2MASS K-band magnitude
148-152 F5.3 mag e_km2MASS ? Error in 2MASS K-band magnitude
154 A1 --- f_jm2MASS 2MASS J-band flag
156 A1 --- f_hm2MASS 2MASS H-band flag
158 A1 --- f_km2MASS 2MASS K-band flag
160-165 F6.3 mag w1mpro ? WISE 3.4 micron magnitude
167-171 F5.3 mag e_w1mpro ? Error in WISE 3.4 micron magnitude
173-178 F6.3 mag w2mpro ? WISE 4.6 micron magnitude
180-184 F5.3 mag e_w2mpro ? Error in WISE 4.6 micron magnitude
186-191 F6.3 mag w3mpro ? WISE 12 micron magnitude
193-197 F5.3 mag e_w3mpro ? Error in WISE 12 micron magnitude
199-203 F5.3 mag w4mpro ? WISE 22 micron magnitude
205-209 F5.3 mag e_w4mpro ? Error in WISE 22 micron magnitude
211 A1 --- f_w1mpro ? WISE 3.4 micron magnitude flag
213 A1 --- f_w2mpro ? WISE 4.6 micron magnitude flag
215 A1 --- f_w3mpro ? WISE 12 micron magnitude flag
217 A1 --- f_w4mpro ? WISE 22 micron magnitude flag
219-225 F7.4 mag magMIPS ? MIPS 24 micron magnitude (1)
227-233 F7.4 mag e_magMIPS ? Error in MIPS 24 micron magnitude (1)
235-241 F7.4 mag magHMMIRS ? MMIRs H-band magnitude
243-248 F6.4 mag e_magHMMIRS ? Error in MMIRs H-band magnitude
250-256 F7.4 mag magJMMIRS ? MMIRs J-band magnitude
258-263 F6.4 mag e_magJMMIRS ? Error in MMIRs J-band magnitude
265-271 F7.4 mag magKMMIRS ? MMIRs K-band magnitude
273-278 F6.4 mag e_magKMMIRS ? Error in MMIRs K-band magnitude
280-284 A5 --- YSO ? Boolean flag indicated whether source was
selected as a YSO
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Note (1): A '99.0' value is a null value.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- Name YSO name
27- 37 F11.7 deg RAdeg [0/360] Right Ascension (J2000)
39- 48 F10.7 deg DEdeg [66/70] Declination (J2000)
50- 55 I6 --- YSO Binary flag describes the selection method(s)
(1)
57- 60 A4 --- CLASS Evolutionary classification
62- 66 F5.2 --- ALPHA IR SED slope
68- 71 F4.2 --- e_ALPHA ? Error in IR SED slope
73 I1 --- CLUSTER ? Cluster membership
75- 81 F7.4 mag magI1 ? IRAC 3.6 micron magnitude
83- 88 F6.4 mag e_magI1 ? Error in IRAC 3.6 micron magnitude
90- 96 F7.4 mag magI2 ? IRAC 4.5 micron magnitude
98-103 F6.4 mag e_magI2 ? Error in IRAC 4.5 micron magnitude
105-111 F7.4 mag magI3 ? IRAC 5.8 micron magnitude
113-118 F6.4 mag e_magI3 ? Error in IRAC 5.8 micron magnitude
120-126 F7.4 mag magI4 ? IRAC 8.0 micron magnitude
128-133 F6.4 mag e_magI4 ? Error in IRAC 8.0 micron magnitude
135-140 F6.3 mag jm2MASS ? 2MASS J-band magnitude
142-146 F5.3 mag e_jm2MASS ? Error in 2MASS J-band magnitude
148-153 F6.3 mag hm2MASS ? 2MASS H-band magnitude
155-159 F5.3 mag e_hm2MASS ? Error in 2MASS H-band magnitude
161-166 F6.3 mag km2MASS ? 2MASS K-band magnitude
168-172 F5.3 mag e_km2MASS ? Error in 2MASS K-band magnitude
174 A1 --- f_jm2MASS 2MASS J-band flag
176 A1 --- f_hm2MASS 2MASS H-band flag
178 A1 --- f_km2MASS 2MASS K-band flag
180-185 F6.3 mag w1mpro ? WISE 3.4 micron magnitude
187-191 F5.3 mag e_w1mpro ? Error in WISE 3.4 micron magnitude
193-198 F6.3 mag w2mpro ? WISE 4.6 micron magnitude
200-204 F5.3 mag e_w2mpro ? Error in WISE 4.6 micron magnitude
206-211 F6.3 mag w3mpro ? WISE 12 micron magnitude
213-217 F5.3 mag e_w3mpro ? Error in WISE 12 micron magnitude
219-223 F5.3 mag w4mpro ? WISE 22 micron magnitude
225-229 F5.3 mag e_w4mpro ? Error in WISE 22 micron magnitude
231 A1 --- f_w1mpro ? WISE 3.4 micron magnitude flag
233 A1 --- f_w2mpro ? WISE 4.6 micron magnitude flag
235 A1 --- f_w3mpro ? WISE 12 micron magnitude flag
237 A1 --- f_w4mpro ? WISE 22 micron magnitude flag
239-245 F7.4 mag magMIPS ? MIPS 24 micron magnitude
247-253 F7.4 mag e_magMIPS ? Error in MIPS 24 micron magnitude
255-261 F7.4 mag magHMMIRS ? MMIRs H-band magnitude
263-268 F6.4 mag e_magHMMIRS ? Error in MMIRs H-band magnitude
270-276 F7.4 mag magJMMIRS ? MMIRs J-band magnitude
278-283 F6.4 mag e_magJMMIRS ? Error in MMIRs J-band magnitude
285-291 F7.4 mag magKMMIRS ? MMIRs K-band magnitude
293-298 F6.4 mag e_magKMMIRS ? Error in MMIRs K-band magnitude
300-317 F18.15 mag rApMag ? PanSTARRS r-band magnitude
319-339 F21.19 mag e_rApMag ? Error in PanSTARRS r-band magnitude
341-358 F18.15 mag iApMag ? PanSTARRS i-band magnitude
360-380 F21.19 mag e_iApMag ? Error in PanSTARRS i-band magnitude
382-386 F5.2 mag Vmag ? V-band magnitude from Panwar+, 2018,
J/AJ/155/44
388-391 F4.2 mag e_Vmag ? Error in V-band magnitude from Panwar+,
2018, J/AJ/155/44
393-397 F5.2 mag Imag ? I-band magnitude from Panwar+, 2018,
J/AJ/155/44
399-402 F4.2 mag e_Imag ? Error in I-band magnitude from Panwar+,
2018, J/AJ/155/44
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Note (1): binary flag describes the selection method(s) used to identify the
YSO with digits representing 2MASS, WISE, IRAC+WISE, MMIRS, IRAC bands 3
and 4, and MIPS selections respectively.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- Name Source name
27- 29 F3.1 kpc Dist Distance to source (1)
31 I1 --- Ndata Number of photometry data points in the SED
33- 43 F11.6 --- chi2 Chi-squared of the best SED fit
45- 50 F6.4 Msun Mass Mass of center source
52- 57 F6.3 mag AVmag Visual extinction
59- 67 F9.1 yr Age Stellar age
69- 77 A9 Msun Mdisk Disk mass
79- 87 A9 Msun/yr Mdot Accretion rate
89- 95 F7.1 K Teff Stellar temperature
97-106 F10.5 Lsun Lum Total luminosity
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Note (1): Distance was fixed to value for Ceph OB4, Kuhn+, 2019, J/ApJ/870/32
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History:
12-Apr-2022: From electronic version of the journal
17-Aug-2023: Some names in table3 and table6 corrected
(End) Prepared by [AAS], Coralie Fix [CDS], 29-Feb-2022