J/AJ/149/200 VRI photometry in NGC 7129 (Dahm+, 2015)
An optical survey of the partially embedded young cluster in NGC 7129.
Dahm S.E., Hillenbrand L.A.
<Astron. J., 149, 200 (2015)>
=2015AJ....149..200D 2015AJ....149..200D
ADC_Keywords: Nebulae ; Clusters, open ; Stars, emission ; X-ray sources ;
Photometry, VRI ; Photometry, infrared ; Equivalent widths ;
Spectral types
Keywords: open clusters and associations: individual: NGC 7129 -
stars: formation - stars: pre-main sequence
Abstract:
NGC7129 is a bright reflection nebula located in the molecular cloud
complex near l=105.4°, b=+9.9°, about 1.15kpc distant.
Embedded within the reflection nebula is a young cluster dominated by
a compact grouping of four early-type stars: BD+65°1638 (B3V),
BD+65°1637 (B3e), SVS 13 (B5e), and LkHα 234 (B8e). About 80
Hα emission sources brighter than V∼23 are identified in the
region, many of which are presumably T Tauri star members of the
cluster. We also present deep (V∼23), optical (VRCIC) photometry
of a field centered on the reflection nebula and spectral types for
more than 130 sources determined from low dispersion, optical
spectroscopy. The narrow pre-main sequence evident in the
color-magnitude diagram suggests that star formation was rapid and
coeval. A median age of about 1.8Myr is inferred for the Hα and
literature-identified X-ray emission sources having established
spectral types, using pre-main sequence evolutionary models. Our
interpretation of the structure of the molecular cloud and the
distribution of young stellar objects is that BD+65°1638 is
primarily responsible for evacuating the blister-like cavity within
the molecular cloud. LkHα 234 and several embedded sources
evident in near-infrared adaptive optics imaging have formed recently
within the ridge of compressed molecular gas. The compact cluster of
low-mass stars formed concurrently with the early-type members,
concentrated within a central radius of ∼0.7pc. Star formation is
simultaneously occurring in a semi-circular arc some ∼3pc in radius
that outlines remaining dense regions of molecular gas. High
dispersion, optical spectra are presented for BD+65°1638,
BD+65°1637, SVS 13, LkHα 234, and V350 Cep. These spectra
are discussed in the context of the circumstellar environments
inferred for these stars.
Description:
Three epochs of optical imaging data were obtained of the NGC 7129
region between 1993 and 1999. The first and most extensive survey
consisted of VRCIC-band CCD imaging obtained using the T2KA CCD at
the Kitt Peak National Observatory (KPNO) 0.9m telescope in 1993 June
by LAH and S. Strom. The T2KA detector is a 2048*2048 CCD with 24µm
pixels yielding a platescale of 0.69pixel-1. The complete list of
all ∼2500 sources from the T2KA CCD imaging survey of NGC 7129
including J2000 coordinates, optical (V, V-RC, and RC-IC)
photometry, and associated photometric errors is provided in Table 4.
The second epoch of RCIC-band photometry was obtained using the
Low Resolution Imaging Spectrograph (LRIS) on Keck II in 1999 June by
LAH. Finally BVRCIC photometry of the NGC 7129 region was obtained
in 1999 October at the f/10 focus of the University of Hawaii (UH)
2.2m telescope on Mauna Kea by G. H. Herbig. The detector was a
Tektronix 2048*2048 CCD with 24µm pixels. The field was imaged in
all filters during photometric conditions and in average seeing
conditions for Mauna Kea, 0.75". The plate scale was 0.22pixel-1,
and the imaged field was approximately 7.5'*7.5' in area.
The Hα emission survey of NGC 7129 was carried out on 10 October
2003 by SED using the Wide-Field Grism Spectrograph (WFGS) installed
at the f/10 Cassegrain focus of the University of Hawaii 2.2m
telescope. A 420 line mm-1 grism blazed at 6400Å yielded a
dispersion of 3.85Å/pixel. The narrowband Hα filter isolated
a region of the first-order spectra between ∼6300 and 6750Å. The
WFGS imaged upon the central 1024*1024 pixels of a Tektronix 2048*2048
pixel CCD, yielding a nominal field of view ∼5.5'*5.5'. The WFGS
survey covered a region of about 150 arcmin2, roughly centered upon
LkHα 234. Low-dispersion spectra were obtained using HYDRA on
WIYN in 1993 and the RC Spectrograph on the Mayall 4m telescope in
1994 by LAH.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 183 94 Optical and infrared photometry for Hα
and X-ray emission sources in NGC 7129
table2.dat 125 31 Photometry for infrared sources without X-ray
or Hα emission
table3.dat 95 72 Photometry for spectroscopically classified
stars without X-ray or Hα emission
table4.dat 60 2435 Optical photometry from the T2KA CCD imaging
survey of NGC 7129
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See also:
II/328 : AllWISE Data Release (Cutri+ 2013)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/MNRAS/438/1848 : NGC 7129 Vilnius photometry (Straizys+, 2014)
J/A+A/568/A65 : NGC 7129 FIRS 2 interferometric 1-D spectrum (Fuente+, 2014)
J/AJ/143/3 : Hα emission stars in IC 1274 (Dahm+, 2012)
J/A+A/507/227 : NGC 7129 pre-main sequence stars (Stelzer+, 2009)
J/AJ/133/2072 : Spitzer observations of NGC 2362 (Dahm+, 2007)
J/AJ/131/1530 : Hα emission stars in LDN988 (Herbig+, 2006)
J/AJ/130/1805 : Hα emission stars in NGC 2362 (Dahm+, 2005)
J/AJ/129/829 : Hα emission stars in NGC 2264 (Dahm+, 2005)
J/AJ/128/1233 : LkHα101 and the cluster in NGC 1579 (Herbig+, 2004)
J/AJ/123/304 : BV(RI)CJHK Hα photometry in IC 5146 (Herbig+, 2002)
J/ApJ/497/736 : The young cluster IC 348. (Herbig, 1998)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- --- [IHalpha]
9- 11 I3 --- IHa [763/821]? IHα number of detected Hα
emission source (1)
14- 25 A12 --- Name Name of previously identified Hα emission
source (2)
27- 28 I2 h RAh Hour of Right Ascension (J2000)
30- 31 I2 min RAm Minute of Right Ascension (J2000)
33- 37 F5.2 s RAs Second of Right Ascension (J2000)
39 A1 --- DE- Sign of the Declination (J2000)
40- 41 I2 deg DEd Degree of Declination (J2000)
43- 44 I2 arcmin DEm Arcminute of Declination (J2000)
46- 49 F4.1 arcsec DEs Arcsecond of Declination (J2000)
51- 56 A6 --- SpT Spectral type
58- 62 F5.2 mag Vmag [10.4/23.25]? V band magnitude (G1)
64- 67 F4.2 mag V-R ? The (V-Rc) color index (G1)
69- 72 F4.2 mag V-I ? The (V-Ic) color index (G1)
74- 77 F4.2 mag J-H ? The 2MASS (J-H) color index (G2)
79- 82 F4.2 mag H-K ? The 2MASS (H-Ks) color index (G2)
84- 88 F5.2 mag Kmag [7/15.25]? The 2MASS Ks band magnitude (G2)
90- 94 F5.2 mag [3.6] [5.7/17.2]? Spitzer/IRAC 3.6µm magnitude (G3)
96-100 F5.2 mag [4.5] [5.1/16.2]? Spitzer/IRAC 4.5µm magnitude (G3)
102-106 F5.2 mag [5.8] [4.4/13.7]? Spitzer/IRAC 5.8µm magnitude (G3)
108-112 F5.2 mag [8.0] [3.3/13.5]? Spitzer/IRAC 8.0µm magnitude (G3)
114-118 F5.2 mag W1mag [4.6/15.3]? WISE W1 magnitude (3.35µm) (G4)
120-124 F5.2 mag W2mag [2.9/15.2]? WISE W2 magnitude (4.6µm) (G4)
126-130 F5.2 mag W3mag [1.3/11.2]? WISE W3 magnitude (11.6µm) (G4)
132-136 F5.2 mag W4mag [-1.75/9.5]? WISE W4 magnitude (22.1µm) (G4)
138 A1 --- u_WHa [:] Uncertainty flag on WHa
139-143 F5.1 0.1nm WHa [1/437]? Equivalent width of the Hα profile
(in Å) (3)
145-147 A3 --- f_WHa Emission detected (em or em?)
149-152 F4.1 0.1nm W8542 [0/25]? Equivalent width of CaIIλ8542
(in Å) (3)
154-157 A4 --- f_W8542 Flag on CaII line (abs, ecr, flat) (4)
159-166 A8 --- OName1 Other name
168-175 A8 --- OName2 Other name
177-183 A7 --- Note Note: "binary", "em?"=possible emission?,
"wk cont"= weak continuum on grism images
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Note (1): For the previously unknown emission-line sources, an IHα number
is assigned, continuing the numbering convention initiated by Herbig 1998
(J/ApJ/497/736) in IC 348 and subsequently continued by:
* Herbig & Dahm 2002 (J/AJ/123/304) in IC 5146,
* Herbig et al. 2004 (J/AJ/128/1233) in NGC 1579,
* Dahm & Simon 2005 (J/AJ/129/829) in NGC 2264,
* Dahm 2005 (J/AJ/130/1805) in NGC 2362,
* Herbig & Dahm 2006 (J/AJ/131/1530) in L988, and
* Dahm et al. 2012 (J/AJ/143/3) in IC 1274.
Note (2): Previously identified by Magakian et al. (2004Ap.....47..519M 2004Ap.....47..519M) or the
Herbig Bell Catalog (HBC).
Note (3): Positive values indicate emission.
Note (4): The flags on the equivalent widths are defined as follows:
abs = CaII λ8542 in absorption;
ecr = Emission core reversal is evident;
flat = Flat continuum noted at λ8542.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name Name of the source (1)
10- 11 I2 h RAh Hour of Right Ascension (J2000)
13- 14 I2 min RAm Minute of Right Ascension (J2000)
16- 20 F5.2 s RAs Second of Right Ascension (J2000)
22 A1 --- DE- Sign of the Declination (J2000)
23- 24 I2 deg DEd Degree of Declination (J2000)
26- 27 I2 arcmin DEm Arcminute of Declination (J2000)
29- 32 F4.1 arcsec DEs Arcsecond of Declination (J2000)
34- 37 F4.2 mag R-I ? The (Rc-Ic) color index (2)
39- 43 F5.2 mag Imag [17/21.8]? The Ic band magnitude (2)
45- 48 F4.2 mag J-H ? The (J-H) color index (G2)
50- 53 F4.2 mag H-K ? The (H-K) color index (G2)
55- 59 F5.2 mag Kmag [10.8/15.1]? The Ks band magnitude (G2)
61- 65 F5.2 mag [3.6] [7.5/16.9]? Spitzer/IRAC 3.6µm magnitude (G3)
67- 71 F5.2 mag [4.5] [6.5/16.6] Spitzer/IRAC 4.5µm magnitude (G3)
73- 77 F5.2 mag [5.8] [5.6/16]? Spitzer/IRAC 5.8µm magnitude (G3)
79- 83 F5.2 mag [8.0] [5/14.4]? Spitzer/IRAC 8.0µm magnitude (G3)
85- 89 F5.2 mag W1mag [8.3/16.1]? WISE W1 magnitude (3.35µm) (G4)
91- 95 F5.2 mag W2mag [6.75/15.2]? WISE W2 magnitude (4.6µm) (G4)
97-101 F5.2 mag W3mag [4.15/12.15]? WISE W3 magnitude (11.6µm) (G4)
103-106 F4.2 mag W4mag [0.3/9]? WISE W4 magnitude (22.1µm) (G4)
108-125 A18 --- OName Other name
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Note (1): Young Stellar Objects identified by Stelzer & Scholz 2009
(J/A+A/507/227) based upon infrared excess emission.
S3-U1350 was very likely a misprint for S2-U1350 (corrected at CDS).
Note (2): Optical photometry from Keck Low Resolution Imaging Spectrograph
(LRIS) imaging, University of Hawaii (UH) 2.2m telescope on Mauna Kea or
the Kitt Peak National Observatory (KPNO) 0.9m telescope.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Star [1/72] Running sequence number of the star
4- 5 I2 h RAh Hour of Right Ascension (J2000)
7- 8 I2 min RAm Minute of Right Ascension (J2000)
10- 14 F5.2 s RAs Second of Right Ascension (J2000)
16 A1 --- DE- Sign of the Declination (J2000)
17- 18 I2 deg DEd Degree of Declination (J2000)
20- 21 I2 arcmin DEm Arcminute of Declination (J2000)
23- 27 F5.2 arcsec DEs Arcsecond of Declination (J2000)
29- 33 A5 --- SpT Spectral type
35- 39 F5.2 mag Vmag [10.5/23] The V band magnitude (G1)
41- 44 F4.2 mag V-R The (V-Rc) color index (G1)
46- 49 F4.2 mag R-I The (Rc-Ic) color index (G1)
51- 54 F4.2 mag J-H The (J-H) color index (G2)
56- 60 F5.2 mag H-K The (H-Ks) color index (G2)
62- 66 F5.2 mag Kmag [7.9/15.1] The Ks band magnitude (G2)
68- 72 F5.2 mag W1mag [7.8/15.2]? WISE W1 magnitude (3.35µm) (G4)
74- 78 F5.2 mag W2mag [7.9/15.1]? WISE W2 magnitude (4.6µm) (G4)
80- 84 F5.2 mag W3mag [7.6/12.3]? WISE W3 magnitude (11.6µm) (G4)
86- 95 A10 --- Com Comments: IR excess, or star name (SVS 14 and
SVS 4)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Hour of Right Ascension (J2000)
4- 5 I2 min RAm Minute of Right Ascension (J2000)
7- 11 F5.2 s RAs Second of Right Ascension (J2000)
13 A1 --- DE- Sign of the declination (J2000)
14- 15 I2 deg DEd Degree of Declination (J2000)
17- 18 I2 arcmin DEm Arcminute of Declination (J2000)
20- 23 F4.1 arcsec DEs Arcsecond of Declination (J2000)
25- 30 F6.3 mag Vmag [9/27] The V-band magnitude
32- 36 F5.3 mag e_Vmag Uncertainty in Vmag
38- 42 F5.3 mag V-R The (V-Rc) color index
44- 48 F5.3 mag e_V-R Uncertainty in V-R
50- 54 F5.3 mag R-I The (Rc_-Ic) color index
56- 60 F5.3 mag e_R-I Uncertainty in R-I
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Global Notes:
Note (G1): Optical photometry from the University of Hawaii (UH) 2.2m telescope
or the Kitt Peak National Observatory (KPNO) 0.9m telescope.
Note (G2): Near-infrared photometry from the 2MASS Point Source Catalog
(cat. II/246).
Note (G3): Spitzer IRAC mid-infrared photometry from Stelzer & Scholz 2009
(cat. J/A+A/507/227) and references therein.
Note (G4): WISE mid-infrared photometry from the AllWISE Source Catalog
(cat. II/328).
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 17-Jun-2015