J/ApJ/904/146 Young stars in North the America & Pelican Nebulae (Fang+, 2020)
The First Extensive Spectroscopic Study of Young Stars in the North America and
Pelican Nebulae.
Fang M., Hillenbrand L.A., Kim J.S., Findeisen K., Herczeg G.J.,
Carpenter J.M., Rebull L.M., Wang H.
<Astrophys. J., 904, 146 (2020)>
=2020ApJ...904..146F 2020ApJ...904..146F
ADC_Keywords: Star Forming Region; YSOs; Spectra, optical; Spectral types;
Parallaxes, trigonometric
Keywords: Stellar accretion disks ; Protoplanetary disks ; Pre-main
sequence stars ; Stellar spectral types ; Star formation ;
Star forming regions ; Stellar associations
Abstract:
We present a spectroscopic survey of over 3400 potential members in
the North America and Pelican Nebulae (NAP) using several
low-resolution (R∼1300-2000) spectrographs: Palomar/Norris,
WIYN/Hydra, Keck/DEep Imaging Multi-Object Spectrograph (DEIMOS), and
the Multiple Mirror Telescope (MMT)/Hectospec. We identify 580 young
stars as likely members of the NAP region based on criteria involving
infrared excess, LiI 6708Å absorption, X-ray emission, parallax,
and proper motions. The spectral types of individual spectra are
derived by fitting them with templates that are either empirical
spectra of pre-main-sequence stars or model atmospheres. The templates
are artificially veiled, and a best-fit combination of spectral type
and veiling parameter is derived for each star. We use the spectral
types with archival photometry to derive V-band extinction and stellar
luminosity. From the Hertzsprung-Russell diagram, the median age of
the young stars is about 1Myr, with a luminosity dispersion of
∼0.3-0.4dex. We investigate the photometric variability of the
spectroscopic member sample using Zwicky Transient Facility data and
conclude that photometric variability, while present, does not
significantly contribute to the luminosity dispersion. While larger
than the formal errors, the luminosity dispersion is smaller than if
veiling were not taken into account in our spectral typing process.
The measured ages of the stellar kinematic groups, combined with the
inferred ages for embedded stellar populations revealed by Spitzer,
suggest a sequential history of star formation in the NAP region.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 58 971 Young stars in North America Nebula and Pelican
Nebulae Region
table4.dat 134 580 Young stars in North America Nebula and Pelican
table6.dat 80 40 List of nonmembers of NAP with infrared excess in
our sample
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See also:
II/82 : Galactic O-type Stars (Garmany+ 1982)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
VII/7 : Lynds' Catalogue of Dark Nebulae (LDN) (Lynds 1962)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/ApJ/573/366 : Infrared photometry of Trapezium cluster (Muench+, 2002)
J/A+A/504/461 : YSOs in L1630N and L1641 (Fang+, 2009)
J/ApJ/697/787 : The NAN complex. I. IRAC observations (Guieu+, 2009)
J/ApJS/193/25 : The NAN complex. II. MIPS observations (Rebull+, 2011)
J/ApJS/207/5 : YSOs in LDN 1641 with Hectochelle spectra (Fang+, 2013)
J/A+A/551/A107 : X-shooter spectra of 24 young stellar objects (Manara+, 2013)
J/ApJ/786/97 : Photospheric properties of T Tauri stars (Herczeg+, 2014)
J/AJ/147/46 : Properties of clumps in the NAN complex (Zhang+, 2014)
J/A+A/602/A115 : X-ray survey of NGC7000/IC5070 (Damiani+, 2017)
J/AJ/153/188 : Spectro. of the foreground population in Orion A (Fang+, 2017)
J/A+A/605/A86 : Pre-main sequence stars VLT/X-Shooter spectra (Manara+, 2017)
J/A+A/627/A135 : VRI photometry of IC5070 variable stars (Bhardwaj+, 2019)
J/ApJ/899/128 : Validated & new members NGC7000/IC5070 Complex (Kuhn+, 2020)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/579] Sequential running number identifier (1)
5- 6 I2 h RAh [20]? Hour of Right Ascension (J2000)
8- 9 I2 min RAm [48/59]? Minute of Right Ascension (J2000)
11- 15 F5.2 s RAs ? Second of Right Ascension (J2000)
17- 17 A1 --- DE- [+]? Sign of the Declination (J2000)
18- 19 I2 deg DEd [43/45]? Degree of Declination (J2000)
21- 22 I2 arcmin DEm ? Arcminute of Declination (J2000)
24- 27 F4.1 arcsec DEs ? Arcsecond of Declination (J2000)
29- 34 A6 --- Inst Telescope used (Deimos, Hecto, Hydra, Norris)
36- 39 A4 --- SpT Spectral type derived with veiling
41- 41 A1 --- f_r7465 Flag on veiling, H=High
43- 46 F4.2 --- r7465 [0.01/3.54]? Veiling at 7465Å
48- 51 A4 --- SpT2 Spectral type derived w/o veiling
58- 58 I1 --- Temp [1/2]? Templates used for SpT2 derivation (2)
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Note (1): Multiple observations are listed on sequential rows for the same
sequential identifier. The position of the source is given only on the
first row of each set.
Note (2): Templates used as follows:
1 = Using X-Shooter PMS spectral templates (876 occurrences)
2 = Using model atmospheres (84 occurrences)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/580] Sequential running number identifier
5- 6 I2 h RAh [20] Hour of Right Ascension (J2000)
8- 9 I2 min RAm Minute of Right Ascension (J2000)
11- 15 F5.2 s RAs Second of Right Ascension (J2000)
17- 17 A1 --- DE- [+] Sign of the Declination (J2000)
18- 19 I2 deg DEd [43/45] Degree of Declination (J2000)
21- 22 I2 arcmin DEm Arcminute of Declination (J2000)
24- 27 F4.1 arcsec DEs Arcsecond of Declination (J2000)
29- 32 A4 --- SpT Adopted Spectral type
34- 36 F3.1 --- e_SpT [0/7.5]? Spectral type subclass uncertainty
38- 38 A1 --- f_r7465 Veiling flag, H=High
40- 43 F4.2 --- r7465 [0/3.09]? Veiling at 7465 Angstroms
45- 45 I1 --- Q [1/3]? Ranking for the spectral classification
47- 51 I5 K Teff [2729/19000]? Surface effective temperature
53- 56 F4.1 mag Avmag-m1 [0/16.8]? Reddening, V band, model w/fixed
r7465 (1)
58- 65 F8.3 Lsun Lstar-m1 [0.01/2368]? Luminosity, solar units, model
w/fixed r7465 (1)
67- 70 F4.1 mag Avmag-m2 [0/10]? Reddening, V band, model w/varying
r7465 (1)
72- 79 F8.3 Lsun Lstar-m2 [0.01/2368]? Luminosity, solar units, model
w/varying r7465 (1)
81- 84 F4.1 mag Avmag-m [0/16.8]? Reddening V band, model, adopted (1)
86- 93 F8.3 Lsun Lstar-m [0.01/2368]? Luminosity, solar units, model,
adopted (1)
95- 97 F3.1 mag Avmag-t1 [0/8.6]? Reddening, V band, template w/fixed
r7465 (2)
99-104 F6.3 Lsun Lstar-t1 [0.01/25]? Luminosity, solar units, template
w/fixed r7465 (2)
106-108 F3.1 mag Avmag-t2 [0/8.6]? Reddening, V band, template w/varying
r7465 (2)
110-115 F6.3 Lsun Lstar-t2 [0.01/25]? Luminosity, solar units, template
w/varying r7465 (2)
117-119 F3.1 mag Avmag-t [0/8.6]? Reddening, V band, template, adopted
(2)
121-126 F6.3 Lsun Lstar-t [0.01/25]? Luminosity, solar units, template,
adopted (2)
128-128 A1 --- IRE YSO criteria, showing infrared excess
130-130 A1 --- Li YSO criteria, showing Li I 6708A absorption
132-132 A1 --- Xray YSO criteria, having a X-ray counterpart
134-134 A1 --- var YSO criteria, variable (3)
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Note (1): Fitting the SEDs of young stars with model atmosphere. Fixing
r7465: dur- ing the SED fitting, the used r7465 is fixed to be the one
derived from the spectral classification; Varying r7465: r7465 is a free
parameter during the SED fitting.
Note (2): Fitting the SEDs of young stars with model atmosphere. Fixing
r7465 and b Varying r7465 are same as for model fits.
Note (3): YSO criteria as follows:
H = highly variable
M = moderately variable
L = weakly variable
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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- 2 I2 --- Seq [1/40] Sequential running number identifier
4- 26 A23 --- Name Designation
28- 29 I2 h RAh [20/21] Hour of Right Ascension (J2000)
31- 32 I2 min RAm Minute of Right Ascension (J2000)
34- 38 F5.2 s RAs Second of Right Ascension (J2000)
40- 40 A1 --- DE- [+] Sign of the Declination (J2000)
41- 42 I2 deg DEd [43/45] Degree of Declination (J2000)
44- 45 I2 arcmin DEm Arcminute of Declination (J2000)
47- 50 F4.1 arcsec DEs Arcsecond of Declination (J2000)
52- 58 F7.4 mas plx [-0.71/1.08]? Gaia DR2 parallax
60- 65 F6.4 mas e_plx [0.01/0.7]? Uncertainty in plx
67- 80 A14 --- SpT Spectral type
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 15-Mar-2022