J/AJ/156/84 APOGEE-2 survey of Orion Complex. II. (Kounkel+, 2018)
The APOGEE-2 survey of the Orion star-forming Complex.
II. Six-dimensional structure.
Kounkel M., Covey K., Suarez G., Roman-Zuniga C., Hernandez J., Stassun K.,
Jaehnig K.O., Feigelson E.D., Ramirez K.P., Roman-Lopes A., Da Rio N.,
Stringfellow G.S., Kim J.S., Borissova J., Fernandez-Trincado J.G.,
Burgasser A., Garcia-Hernandez D.A., Zamora O., Pan K., Nitschelm C.
<Astron. J., 156, 84-84 (2018)>
=2018AJ....156...84K 2018AJ....156...84K (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Star Forming Region ; YSOs ; Spectroscopy ;
Radial velocities ; Parallaxes, trigonometric ; Proper motions ;
Stars, ages ; Stars, diameters ; Surveys
Keywords: open clusters and associations: individual: Orion Complex -
stars: kinematics and dynamics - stars: pre-main sequence
Abstract:
We present an analysis of spectroscopic and astrometric data from
APOGEE-2 and Gaia DR2 (Cat. I/345) to identify structures toward the
Orion Complex. By applying a hierarchical clustering algorithm to the
six-dimensional stellar data, we identify spatially and/or kinematically
distinct groups of young stellar objects with ages ranging from 1 to
12 Myr. We also investigate the star-forming history within the Orion
Complex and identify peculiar subclusters. With this method we reconstruct
the older populations in the regions that are currently largely devoid
of molecular gas, such as Orion C (which includes the σ Ori cluster)
and Orion D (the population that traces Ori OB1a, OB1b, and Orion X). We
report on the distances, kinematics, and ages of the groups within the
Complex. The Orion D group is in the process of expanding. On the other
hand, Orion B is still in the process of contraction. In λ Ori the
proper motions are consistent with a radial expansion due to an explosion
from a supernova; the traceback age from the expansion exceeds the age
of the youngest stars formed near the outer edges of the region, and their
formation would have been triggered when they were halfway from the cluster
center to their current positions. We also present a comparison between
the parallax and proper-motion solutions obtained by Gaia DR2 and those
obtained toward star-forming regions by the Very Long Baseline Array.
Description:
NIR high-resolution spectral observations of stars toward the Orion
Complex were conducted with the Apache Point Observatory Galactic
Evolution Experiment (APOGEE) spectrograph, mounted on the 2.5 m Sloan
Digital Sky Survey (SDSS) telescope (Gunn et al. 2006AJ....131.2332G 2006AJ....131.2332G;
Blanton et al. 2017AJ....154...28B 2017AJ....154...28B). This instrument covers the spectral
range of 1.51-1.7 µm with R∼22500 (Wilson et al. 2010SPIE.7735E..1CW;
Majewski et al. 2017AJ....154...94M 2017AJ....154...94M), and it is capable of observing up
to 300 targets simultaneously in a field of view of 1.5°. A total of
8991 unique targets have been observed toward the Orion Complex (4259
toward the Orion B/Ori OB1ab region, 2991 toward the Orion A molecular
cloud, and 1741 toward λ Ori), most of which were observed
repeatedly over the course of two to three epochs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 219 8991 Properties derived from the APOGEE spectra
towards the stars in Orion
table2.dat 202 16754 Astrometric solutions from Gaia utilized
in the analysis
table3.dat 268 190 Identified groups and their properties
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/121/2124 : λ Ori pre-main-sequence stars photometry
(Dolan+, 2001)
J/AJ/123/387 : VRI photometry of λ Ori star-forming region
(Dolan+, 2002)
J/AJ/129/907 : New Ori OB1 members (Briceno+, 2005)
J/ApJ/661/1119 : Spectroscopy in the 25 Ori group (Briceno+, 2007)
J/A+A/485/931 : Young stars and brown dwarfs in Ori OB1b (Caballero+, 2008)
J/A+A/488/167 : Low-mass stars in σ Ori and λ Ori
(Sacco+, 2008)
J/ApJ/676/1109 : Velocities of stars in the Orion Nebula Cluster
(Furesz+, 2008)
J/MNRAS/385/2210 : Spectroscopy around lam Ori and sig Ori (Maxted+, 2008)
J/ApJ/697/1103 : Kinematics of Orion Nebula Cluster (Tobin+, 2009)
J/ApJ/722/1092 : Optical photometry of the ONC. II. (Da Rio+, 2010)
J/ApJ/722/1226 : IR photometry in λ Orionis cluster (Hernandez+, 2010)
J/AJ/144/192 : Spitzer survey of Orion A and B. I. YSO catalog
(Megeath+, 2012)
J/ApJ/754/30 : VISTA IR photometry of σ Ori cluster
(Pena Ramirez+, 2012)
J/ApJ/764/114 : BVRI photometry of stars in Orion A (Hsu+, 2013)
J/ApJ/768/99 : X-ray survey of YSOs in Orion A (Pillitteri+, 2013)
J/A+A/564/A29 : Optical and near-infrared photometry in Orion A
(Bouy+, 2014)
J/ApJ/782/8 : Spectroscopy of 104 objects in the ONC (Ingraham+, 2014)
J/ApJ/794/36 : σ Orionis cluster stellar population
(Hernandez+, 2014)
J/MNRAS/444/1793 : 25 Ori group low-mass stars (Downes+, 2014)
J/ApJ/818/59 : IN-SYNC. IV. YSOs in Orion A (Da Rio+, 2016)
J/A+A/608/A148 : Stellar populations towards Orion with Gaia DR1
(Zari+, 2017)
J/AJ/153/188 : Spectroscopy of the foreground population in Orion A
(Fang+, 2017)
J/AJ/154/14 : Low-mass stars in 25 Ori group and Orion OB1a
(Suarez+, 2017)
J/ApJ/844/138 : Optical spectroscopy toward Orion B fields (Kounkel+, 2017)
J/A+A/610/A12 : Clustering the Orion B giant molecular cloud (Bron+, 2018)
J/A+A/619/A106 : 3D shape of Orion A from Gaia DR2 (Grossschedl+, 2018)
J/ApJS/236/27 : APOGEE-2 survey of Orion Complex (OSFC). I. (Cottle+, 2018)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 F17.14 deg RAdeg Right Ascension in decimal degrees (J2000)
19- 36 F18.14 deg DEdeg Declination in decimal degrees (J2000)
38- 55 A18 --- 2MASS 2MASS position based identifier
(2MHHMMSSss+DDMMSSs)
57- 75 I19 --- Gaia ? Gaia DR2 identifier
77- 78 I2 --- Nep [1/27] Number of epochs
80- 87 F8.2 K Teff [2300.05/14999.8] Effective temperature
89-100 F12.5 K e_Teff [1.14962/109706] Uncertainty in Teff
102-110 F9.6 [cm/s2] logg [-0.497235/5.99984] Surface gravity
112-121 F10.8 [cm/s2] e_logg [0.0061962/3.78714] Uncertainty in logg
123 A1 --- l_RVmean [<] Limit flag on RVmean
124-133 F10.5 km/s RVmean [-170.587/552.16] Mean radial velocity
135-143 F9.7 km/s e_RVmean [0.0658911/0.999541]? Uncertainty in RVmean
145-155 F11.6 10-13W/m2 Fbol [0.028791/2481.34]? Bolometric flux
(in 10-10 erg/s/cm2)
157-166 F10.6 10-13W/m2 e_Fbol [0/272.365]? Uncertainty in Fbol
(in 10-10 erg/s/cm2)
168-171 F4.2 mag Av [0.05/4.5]? Visual extinction
173-181 F9.7 mag e_Av [0/4.5]? Uncertainty in Av
183-192 F10.6 uarcsec Theta [4.91477/166.521]? Stellar angular radius
Θ
194-203 F10.6 uarcsec e_Theta [0.055472/534.068]? Uncertainty in Theta
205-206 I2 --- Flag [-1/2]? Flag (1)
208-219 A12 --- Group Stellar group in Orion (see Table 3)
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Note (1): Fit flag as follows:
0 = Photosphere;
1 = Photosphere with poor goodness of fit;
-1 = This source could not be fit owing to either high veiling or large
infrared excess;
2 = Photosphere up to H band.
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 F17.14 deg RAdeg Right Ascension in decimal degrees (J2000)
19- 36 F18.14 deg DEdeg Declination in decimal degrees (J2000)
38- 56 I19 --- Gaia Gaia DR2 identifier
58- 79 F22.19 mas Plx [-0.280675/25.0894] Gaia DR2 parallax
81- 99 F19.17 mas e_Plx [0.0179231/0.0999935] Uncertainty in Plx
101-124 F24.19 mas/yr pmRA [-116.218/357.827] Gaia DR2 proper motion,
in Right Ascension (pmRA*cosDE)
126-144 F19.17 mas/yr e_pmRA [0.028026/0.199834] Uncertainty in pmRA
146-169 F24.19 mas/yr pmDE [-383.421/87.8759] Gaia DR2 proper motion,
in Declination
171-189 F19.17 mas/yr e_pmDE [0.0260162/0.199260] Uncertainty in pmDE
191-202 A12 --- Group Stellar group in Orion (see Table 3)
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Group Stellar group in Orion
14- 30 F17.14 deg RAdeg Mean group Right Ascension in decimal degrees
(J2000)
32- 51 F20.17 deg DEdeg Mean group Declination in decimal degrees
(J2000)
53- 61 F9.6 km/s VR [-0.855298/15.4463]? Mean group space velocity
in radial direction relative to LSR
63- 73 F11.8 mas/yr VRA [-3.38991/2.69296] Mean group space velocity,
in RA relative to LSR
75- 82 F8.6 mas/yr VDE [0.378125/5.53187] Mean group space velocity,
in DE relative to LSR
84- 90 F7.4 km/s HRV [15.8466/37.6226]? Mean group space velocity
in radial direction relative to heliocenter
92-111 F20.17 mas/yr pmRA [-3.23894/2.77745] Mean group space velocity,
proper motion in RA
113-134 F22.19 mas/yr pmDE [-3.73049/2.14493] Mean group space velocity,
proper motion in DE
136-142 F7.5 mas Plx [2.1517/3.5666] Mean group parallax
144-152 F9.6 Myr Age-CMD [0.501/18.2]? Mean group age, Color-Magnitude
diagram
154-162 F9.6 Myr Age-HR [0.35345/15.07]? Mean group age, HR diagram
164-182 F19.17 deg e_RAdeg 1σ dispersion about mean for RAdeg
184-202 F19.17 deg e_DEdeg 1σ dispersion about mean for DEdeg
204-212 F9.7 km/s e_VR [0.0858054/4.34537]? 1σ dispersion about
mean for VR
214-222 F9.7 mas/yr e_VRA [0.0509354/1.21063]? 1σ dispersion about
mean for VRA
224-232 F9.7 mas/yr e_VDE [0.0378445/1.1808]? 1σ dispersion about
mean for VDE
234-242 F9.7 mas e_Plx [0.0295239/0.214648]? 1σ dispersion about
mean for Plx
244-251 F8.6 Myr e_Age-CMD [0.534367/5.09486]? 1σ dispersion about
mean for Age-CMD
253-260 F8.6 Myr e_Age-HR [0.355818/6.65807]? 1σ dispersion about
mean for Age-HR
262-264 I3 --- Nstars [10/297] Number of stars in Group
266-268 I3 --- NAPOGEE [0/136]? Group members with APOGEE spectra
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History:
From electronic version of the journal
References:
Cottle et al. Paper I. 2018ApJS..236...27C 2018ApJS..236...27C, Cat. J/ApJS/236/27
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 14-Feb-2019