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. =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{deg}, b=+9.9{deg}, 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{deg}1638 (B3V), BD+65{deg}1637 (B3e), SVS 13 (B5e), and LkH{alpha} 234 (B8e). About 80 H{alpha} 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 (VR_C_I_C_) 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 H{alpha} 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{deg}1638 is primarily responsible for evacuating the blister-like cavity within the molecular cloud. LkH{alpha} 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{deg}1638, BD+65{deg}1637, SVS 13, LkH{alpha} 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 VR_C_I_C_-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 24{mu}m 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-R_C_, and R_C_-I_C_) photometry, and associated photometric errors is provided in Table 4. The second epoch of R_C_I_C_-band photometry was obtained using the Low Resolution Imaging Spectrograph (LRIS) on Keck II in 1999 June by LAH. Finally BVR_C_I_C_ 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 24{mu}m 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 H{alpha} 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 6400{AA} yielded a dispersion of 3.85{AA}/pixel. The narrowband H{alpha} filter isolated a region of the first-order spectra between ~6300 and 6750{AA}. 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 arcmin^2^, roughly centered upon LkH{alpha} 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: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 183 94 Optical and infrared photometry for H{alpha} and X-ray emission sources in NGC 7129 table2.dat 125 31 Photometry for infrared sources without X-ray or H{alpha} emission table3.dat 95 72 Photometry for spectroscopically classified stars without X-ray or H{alpha} emission table4.dat 60 2435 Optical photometry from the T2KA CCD imaging survey of NGC 7129 -------------------------------------------------------------------------------- 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 : H{alpha} 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 : H{alpha} emission stars in LDN988 (Herbig+, 2006) J/AJ/130/1805 : H{alpha} emission stars in NGC 2362 (Dahm+, 2005) J/AJ/129/829 : H{alpha} emission stars in NGC 2264 (Dahm+, 2005) J/AJ/128/1233 : LkH{alpha}101 and the cluster in NGC 1579 (Herbig+, 2004) J/AJ/123/304 : BV(RI)_C_JHK H{alpha} 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 -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 7 A7 --- --- [IHalpha] 9- 11 I3 --- IHa [763/821]? IH{alpha} number of detected H{alpha} emission source (1) 14- 25 A12 --- Name Name of previously identified H{alpha} 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 3.6{mu}m magnitude (G3) 96-100 F5.2 mag [4.5] [5.1/16.2]? Spitzer/IRAC 4.5{mu}m magnitude (G3) 102-106 F5.2 mag [5.8] [4.4/13.7]? Spitzer/IRAC 5.8{mu}m magnitude (G3) 108-112 F5.2 mag [8.0] [3.3/13.5]? Spitzer/IRAC 8.0{mu}m magnitude (G3) 114-118 F5.2 mag W1mag [4.6/15.3]? WISE W1 magnitude (3.35{mu}m) (G4) 120-124 F5.2 mag W2mag [2.9/15.2]? WISE W2 magnitude (4.6{mu}m) (G4) 126-130 F5.2 mag W3mag [1.3/11.2]? WISE W3 magnitude (11.6{mu}m) (G4) 132-136 F5.2 mag W4mag [-1.75/9.5]? WISE W4 magnitude (22.1{mu}m) (G4) 138 A1 --- u_WHa [:] Uncertainty flag on WHa 139-143 F5.1 0.1nm WHa [1/437]? Equivalent width of the H{alpha} profile (in {AA}) (3) 145-147 A3 --- f_WHa Emission detected (em or em?) 149-152 F4.1 0.1nm W8542 [0/25]? Equivalent width of CaII{lambda}8542 (in {AA}) (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 -------------------------------------------------------------------------------- Note (1): For the previously unknown emission-line sources, an IH{alpha} 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) 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 {lambda}8542 in absorption; ecr = Emission core reversal is evident; flat = Flat continuum noted at {lambda}8542. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- 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 3.6{mu}m magnitude (G3) 67- 71 F5.2 mag [4.5] [6.5/16.6] Spitzer/IRAC 4.5{mu}m magnitude (G3) 73- 77 F5.2 mag [5.8] [5.6/16]? Spitzer/IRAC 5.8{mu}m magnitude (G3) 79- 83 F5.2 mag [8.0] [5/14.4]? Spitzer/IRAC 8.0{mu}m magnitude (G3) 85- 89 F5.2 mag W1mag [8.3/16.1]? WISE W1 magnitude (3.35{mu}m) (G4) 91- 95 F5.2 mag W2mag [6.75/15.2]? WISE W2 magnitude (4.6{mu}m) (G4) 97-101 F5.2 mag W3mag [4.15/12.15]? WISE W3 magnitude (11.6{mu}m) (G4) 103-106 F4.2 mag W4mag [0.3/9]? WISE W4 magnitude (22.1{mu}m) (G4) 108-125 A18 --- OName Other name -------------------------------------------------------------------------------- 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. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- 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 (3.35{mu}m) (G4) 74- 78 F5.2 mag W2mag [7.9/15.1]? WISE W2 magnitude (4.6{mu}m) (G4) 80- 84 F5.2 mag W3mag [7.6/12.3]? WISE W3 magnitude (11.6{mu}m) (G4) 86- 95 A10 --- Com Comments: IR excess, or star name (SVS 14 and SVS 4) -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- 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