J/MNRAS/520/1390 Gaia view of the Cepheus OB2 (Szilagyi+, 2023)
The Gaia view of the Cepheus OB2 association.
Szilagyi M., Kun M., Abraham P., Marton G.
<Mon. Not. R. Astron. Soc. 520, 1390-1410 (2023)>
=2023MNRAS.520.1390S 2023MNRAS.520.1390S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Parallaxes, trigonometric ; Proper motions ;
Radial velocities ; Photometry ; Optical ; Photometry, infrared ;
Stars, distances
Keywords: stars: formation - stars: pre-main-sequence - ISM: clouds -
ISM: individual objects: Cepheus Bubble -
open clusters and associations: individual: Cepheus OB2
Abstract:
OB associations, birthplaces of the most luminous stars, are key
objects for understanding the formation of high-mass stars and their
effects on their environments. The aim of this work is to explore the
structure and kinematics of the Cepheus OB2 association and
characterize the history of star formation in the region - in
particular, the role of the Cepheus Bubble, surrounding Cepheus OB2.
Based on Gaia DR3 data, we study the spatial and age distribution and
kinematics of young stars in the region. We select candidate
pre-main-sequence stars in the MG versus GBP-GRP colour-magnitude
diagram, and using a clustering algorithm, we identify 13 stellar
groups belonging to Cep OB2. Four groups, consisting of 10-13Myr old
low- and intermediate-mass stars, are located in the interior of the
bubble and are part of the oldest subsystem of the association Cep
OB2a. Younger groups are found on the periphery. The tangential
velocities suggest that some groups on the periphery were born in an
expanding system of star-forming clouds, whereas others have been
formed due to the collision of their parent cloud with the expanding
bubble.
Description:
We have studied the stars from Gaia DR3 in the region of the Cepheus
OB2 association among 96°<l<108°, 2°<b<12°, and
800<d<1000pc. We selected candidate pre-main-sequence stars using
isochrones in the MG versus GBP-GRP colour-magnitude diagram. We
used HDBSCAN to find groups in the selected sample and found 13
stellar groups, consisting of 874 stars. These 13 groups, located
between 830-940pc, are subsystems of Cepheus OB2. 355 of the
clustered stars are classified as candidate YSOs by Marton et al.
(2022, in prep., arXiv:2211.17238). Based on WISE data, we identified
1 Class I source, 62 Class II sources, and 1 with transitional disc,
according to the classification of Koenig & Leisawitz
(2014ApJ...791..131K 2014ApJ...791..131K).
Table 1 contains the high-mass stars of Cepheus OB2 between 800 and 1000pc.
Table 2 contains the mean parameters of the groups.
Table 3 contains the parameters of the individual group members.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 209 52 High-mass stars of Cepheus OB2 between
800 and 1000pc
table2.dat 202 13 Mean parameters of the groups
table3.dat 453 874 Parameters of the individual group members
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See also:
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Simbad name
12- 21 A10 --- SpType Spectral type
23- 41 I19 --- GaiaDR3 Gaia DR3 source id
43- 51 F9.5 pc Dist Distance from Bailer-Jones et al.
(2021, Cat. I/352)
53- 61 F9.5 pc b_Dist 16th percentile of distance posterior from
Bailer-Jones et al. (2021, Cat. I/352)
63- 72 F10.5 pc B_Dist 84th percentile of distance posterior from
Bailer-Jones et al. (2021, Cat. I/352)
74- 92 F19.16 mas/yr pmRA Proper motion in right ascension
94-104 F11.9 mas/yr e_pmRA Error of the proper motion in right ascension
106-125 F20.16 mas/yr pmDE Proper motion in declination
127-137 F11.9 mas/yr e_pmDE Error of the proper motion in declination
139-149 F11.7 km/s RV ? Radial velocity from Gaia DR3
151-160 F10.8 km/s e_RV ? Error of the radial velocity from Gaia DR3
162-180 F19.15 km/s RVl ? Radial velocity from literature
182-200 F19.16 km/s e_RVl ? Error of the radial velocity from literature
202-206 A5 --- r_Memb Membership reference (1)
208-209 I2 --- r_RVl ? Radial velocity reference (2)
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Note (1): Membership references as follows:
1 = Simonson (1968ApJ...154..923S 1968ApJ...154..923S)
2 = Blaha & Humphreys (1989AJ.....98.1598B 1989AJ.....98.1598B)
3 = de Zeeuw et al. (1999AJ....117..354D 1999AJ....117..354D, Cat. J/AJ/117/354)
Note (2): Radial velocity references as follows:
1 = Wilson (1953, Cat. III/21)
2 = Petrie & Pearce (1961PDAO...12....1P 1961PDAO...12....1P)
3 = Hilditch, McLean & Reid (1982MNRAS.200.1153H 1982MNRAS.200.1153H)
4 = Barbier-Brossat & Figon (2000A&AS..142..217B 2000A&AS..142..217B, Cat. III/213)
5 = Pourbaix et al. (2004A&A...424..727P 2004A&A...424..727P, Cat. V/122)
6 = Gontcharov (2006AstL...32..759G 2006AstL...32..759G, Cat. III/252)
7 = Kharchenko et al. (2007AN....328..889K 2007AN....328..889K, Cat. J/AN/328/889)
8 = Boyajian et al. (2007PASP..119..742B 2007PASP..119..742B)
9 = de Bruijne & Eilers (2014A&A...561A..61K 2014A&A...561A..61K)
10 = Holgado et al. (2018A&A...613A..65H 2018A&A...613A..65H, Cat. J/A+A/613/A65)
11 = Katz et al. (2022, in prep., arXiv:2206.05902
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Group Group identifier
4- 21 A18 --- Name Historical name
23- 40 F18.14 deg GLON Galactic longitude
42- 58 F17.15 deg GLAT Galactic latitude
60- 76 F17.13 pc Dist Distance
78- 96 F19.16 pc e_Dist Standard deviation of the distance
98-116 F19.15 km/s vlLSRmean Tangential velocity in galactic longitude
compared to the LSR
118-135 F18.16 km/s e_vlLSRmean Standard deviation of the tangential velocity
in galactic longitude compared to the LSR
137-156 F20.17 km/s vbLSRmean Tangential velocity in galactic latitude
compared to the LSR
158-175 F18.16 km/s e_vbLSRmean Standard deviation of the tangential velocity
in galactic latitude compared to the LSR
177-180 F4.2 mag E(B-V) Colour excess E(B-V)
182-186 F5.2 Myr Age Age (million yrs)
188-190 I3 --- N Number of group members
192-193 I2 --- Nrad Number of group members with radial velocities
measured by Gaia
195-197 I3 --- Nyso Number of group members identified as YSOs in
Marton et al. (2022, in prep.,
arXiv:2211.17238)
199-200 I2 --- Nrs Number of group members identified as
RS Canum Venaticorum variable in Gaia DR3
202 I1 --- Nother Number of group members identified as other
type of variables in Gaia DR3
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Byte-by-byte Description of file: table3.dat
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Bytes Format Unit s Label Explanations
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1- 2 I2 --- Group Group identifier
4- 35 A32 --- Name Name
37- 55 I19 --- GaiaDR3 Gaia DR3 source id
57- 72 A16 --- 2MASS 2MASS identifier
74- 92 A19 --- AllWISE AllWISE identifier
94-111 F18.14 deg RAdeg Right ascension (ICRS) at Ep=2016.0
113-130 F18.15 deg DEdeg Declination (ICRS) at Ep=2016.0
132-149 F18.14 deg GLON Galactic longitude
151-169 F19.16 deg GLAT Galactic latitude
171-179 F9.5 pc Dist Distance from Bailer-Jones et al.
(2021, Cat. I/352)
181-189 F9.5 pc b_Dist 16th percentile of distance posterior
from Bailer-Jones et al. (2021,
Cat. I/352)
191-200 F10.5 pc B_Dist 84th percentile of distance posterior
from Bailer-Jones et al. (2021,
Cat. I/352)
202-219 F18.16 mas plx Parallax
221-232 F12.10 mas e_plx Error of the parallax
234-252 F19.16 mas/yr pmRA Proper motion in right ascension
254-265 F12.10 mas/yr e_pmRA Error of the proper motion in Ra
267-285 F19.16 mas/yr pmDE Proper motion in declination
287-298 F12.10 mas/yr e_pmDE Error of the proper motion in Dec
300-312 F13.8 km/s RV ? Radial velocity
314-323 F10.7 km/s e_RV ? Error of the radial velocity
325-334 F10.8 --- RUWE Renormalized unit-weight error
336-345 F10.7 mag Gmag Magnitude in G band
347-356 F10.7 mag BPmag Magnitude in GBP band
358-367 F10.7 mag RPmag Magnitude in GRP band
369-374 F6.3 mag Jmag ? Magnitude in 2MASS J band
376-381 F6.3 mag Hmag ? Magnitude in 2MASS H band
383-388 F6.3 mag Kmag ? Magnitude in 2MASS Ks band
390-408 F19.17 mag E(B-V) Colour excess E(B-V) from STILISM
410-426 A17 --- ALLWISEClass YSO type by the classification of
Koenig & Leisawitz (2014ApJ...791..131K 2014ApJ...791..131K)
428-453 A26 --- BestClassName Variable star type in Gaia DR3
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Acknowledgements:
Mate Szilagyi, szilagyi.mate(at)csfk.org
(End) Patricia Vannier [CDS] 10-Mar-2023