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J/A+A/509/A11   Hα emission-line objects in SMC clusters (Martayan+, 2010)

A slitless spectroscopic survey for Hα emission-line objects in SMC clusters. Martayan C., Baade D., Fabregat J. <Astron. Astrophys. 509, A11 (2010)> =2010A&A...509A..11M
ADC_Keywords: Magellanic Clouds ; Stars, emission ; Photometry, UBVRI ; Photometry, infrared Keywords: stars: early-type - stars: emission-line, Be - stars: fundamental parameters - stars: evolution - Magellanic Clouds - catalogs Abstract: Slitless CCD spectra were obtained covering the bulk (about 3 square degrees) of the Small Magellanic Cloud. For Hα line-emission twice as strong as the ambient continuum, the survey is complete to spectral type B2/B3 on the main sequence. About 8120 spectra of 4437 stars were searched for emission lines in 84 open clusters, and 370 emission-line stars were found, among them at least 231 close to the main sequence. For 176 of them, photometry is available from the OGLE database. For comparison with a higher-metallicity environment, the Galactic sample of the photometric Hα survey by McSwain & Gies (2005, Cat. J/ApJS/161/118) was used. Among early spectral sub-types, Be stars are more frequent by a factor ∼3-5 in the SMC than in the Galaxy. The distribution with spectral type is similar in both galaxies, i.e., not strongly dependent on metallicity. The fraction of Be stars does not seem to vary with local star density. The Be phenomenon mainly sets in towards the end of the main-sequence evolution (this trend may be more pronounced in the SMC); but some Be stars already form with Be-star characteristics. In small subsamples (such as single clusters), even if they appear identical, the fraction of emission-line stars can deviate drastically from the mean. In all probability, the fractional critical angular rotation rate, OMC, is one of the main parameters governing the occurrence of the Be phenomenon. If the Be character is only acquired during the course of evolution, the key circumstance is the evolution of OMC, which is not only dependent on metallicity but differently so for different mass ranges. As a result, even if the Be phenomenon is driven basically by a single parameter (namely OMC), it can assume a complex multi-parametric appearance. The large cluster-to-cluster differences, which seem stronger than all other variations, serve as a caveat that this big picture may undergo significant second-order modulations (e.g., pulsations, initial angular momentum, etc). Description: The observations were carried out on September 25 and 26, 2002 with the Wide Field Imager (WFI) attached to the 2.2m MPG Telescope at ESO's observatory on Cerro La Silla in Chile. In its slitless spectroscopic mode, the WFI has a roughly circular field of view of diameter 0.31°, and the R50 grism has a dispersion of 54nm/mm (0.811nm/pix); the nominal resolution at optimal focus and seeing is 5.1nm at Hα. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file tablea1.dat 137 55 Emission-line stars in NGC 346, part 1 tablea2.dat 130 55 Emission-line stars in NGC 346, part 2 tableb1.dat 102 159 *Data for individual observations of open clusters in the SMC tableb2.dat 81 83 Details about the individual open clusters with different observations merged tableca.dat 132 266 SMC cluster stars cross-correlation WFI with OGLE (Udalski et al., 1998, Cat. J/AcA/48/147) (tables C1, C3, C5 and C7 of paper) tablecb.dat 99 266 *SMC cluster stars corrected photometry and classification (tables C2, C4, and C6 of paper) tablec9.dat 88 49 Emission-line star from WFI without identification in SC catalogues from OGLE (Udalski et al. 1998, Cat. J/AcA/48/147)
Note on tableb1.dat: Several open clusters were observed twice or three times in different images at different locations Note on tablecb.dat: using calibration from Lang (1992, Astrophysical data, Planets and Stars, New York, Springer Verlag Eds)
See also: J/MNRAS/311/741 : SMC emission-line objects (Murphy+, 2000) J/A+AS/102/451 : Emission-line stars and PNe in the SMC (Meyssonnier+ 1993) Byte-by-byte Description of file: tablea1.dat
Bytes Format Units Label Explanations
1- 17 A17 --- --- WFI[S11] NGC 346- 18- 19 I02 --- Seq [1/55] WFI[S11] NGC 346- number 22 I1 h RAh WFI right ascension (J2000) 24- 25 I2 min RAm WFI right ascension (J2000) 27- 32 F6.3 s RAs WFI right ascension (J2000) 34 A1 --- DE- WFI declination sign (J2000) 35- 36 I2 deg DEd WFI declination (J2000) 38- 39 I2 arcmin DEm WFI declination (J2000) 41- 45 F5.2 arcsec DEs WFI declination (J2000) 47 I1 h RA2.h ?=- 2MASS right ascension (J2000) 49- 50 I2 min RA2.m ?=- 2MASS right ascension (J2000) 52- 56 F5.2 s RA2.s ?=- 2MASS right ascension (J2000) 58 A1 --- DE2.- 2MASS declination sign (J2000) 59- 60 I2 deg DE2.d ?=- 2MASS declination (J2000) 62- 63 I2 arcmin DE2.m ?=- 2MASS declination (J2000) 65- 68 F4.1 arcsec DE2.s ?=- 2MASS declination (J2000) 70 I1 h RAe.h ?=- EIS right ascension (J2000) 72- 73 I2 min RAe.m ?=- EIS right ascension (J2000) 75- 80 F6.3 s RAe.s ?=- EIS right ascension (J2000) 82 A1 --- DEe.- EIS declination sign (J2000) 83- 84 I2 deg DEe.d ?=- EIS declination (J2000) 86- 87 I2 arcmin DEe.m ?=- EIS declination (J2000) 89- 93 F5.2 arcsec DEe.s ?=- EIS declination (J2000) 95-100 F6.3 mag Bmag ?=- EIS B magnitude 101 A1 --- n_Bmag [s] s when magnitude from Simbad 103-108 F6.3 mag Vmag EIS V magnitude 109 A1 --- n_Vmag [s] s when magnitude from Simbad 111-116 F6.3 mag Imag ?=- Denis I magnitude 118-123 F6.3 mag Jmag ?=- 2MASS J magnitude 125-130 F6.3 mag Hmag ?=- 2MASS H magnitude 132-137 F6.3 mag Kmag ?=- 2MASS K magnitude
Byte-by-byte Description of file: tablea2.dat
Bytes Format Units Label Explanations
1- 8 A8 --- --- [NGC 346-] 9- 10 I02 --- Seq [1/55] WFI NGC 346- number 12- 22 A11 --- EIS EIS name (SMC5 NNNNNN) 24- 33 A10 --- OName Other name 35- 40 F6.3 mag B-V ? B-V colour index 42- 45 F4.2 mag E(B-V) Colour excess 47- 52 F6.3 mag (B-V)0 ? Deredenned B-V colour index 54- 58 F5.2 mag V0mag Deredenned V magnitude 60- 64 F5.2 mag VMAG Absolute V magnitude 66- 69 A4 --- SpT WFI spectral type 70 A1 --- n_SpT [*] *: not main-sequence 71- 81 A11 --- class Simbad spectral class 83- 92 A10 --- Vclass VFS (Hunter et al., 2008, Cat. J/A+A/479/541) class 94-104 A11 --- Wclass WB07 (Wisniewski et al., 2007, Cat. J/ApJ/671/2040) class 106-119 A14 --- Sclass Spitzer (Nota et al., 2006ApJ...640L..29N) class 121-130 A10 --- Hclass H08 (Hennekemper et al., 2008ApJ...672..914H) class
Byte-by-byte Description of file: tableb1.dat
Bytes Format Units Label Explanations
1- 6 A6 --- Cluster Cluster name (SMCNNN) 8- 9 I2 --- WFImg WFI image number 11 I1 h RAh Right ascension (J2000) 13- 14 I2 min RAm Right ascension 9J2000) 16- 20 F5.2 s RAs Right ascension (J2000) 22 A1 --- DE- Declination sign (J2000) 23- 24 I2 deg DEd Declination (J2000) 26- 27 I2 arcmin DEm Declination (J2000) 29- 32 F4.1 arcsec DEs Declination (J2000) 34- 36 I3 arcsec r Radius (1) 38 A1 --- l_logt Limit flag on logt 39- 41 F3.1 [yr] logt Age (from Pietrzynski & Udalski, 1999AcA....49..157P) 43- 44 A2 --- l_Z [≤ ] Limit flag on Z 45- 49 F5.3 --- Z Area of metallicity (from Cioni et al., 2006A&A...452..195C) 50 A1 --- --- [-] 51- 55 F5.3 --- Z2 ? Area of metallicity (from Cioni et al., 2006A&A...452..195C) 57- 59 I3 --- N* Total number of stars/spectra extracted 61- 62 I2 --- Nem Number of definite emission-line stars found 64 I1 --- Nem? Number of candidate emission-line stars found 66- 67 I2 --- Nem+ Total number of (definite+candidate) emission line stars 69- 72 F4.1 % em/t Proportion in % of emission-line stars to the whole sample by open cluster 74- 76 I3 --- O* OGLE Total number of stars/spectra extracted (2) 78- 79 I2 --- Oem OGLE Number of definite emission-line stars found (2) 81 I1 --- Oem? OGLE Number of candidate emission-line stars found (2) 83- 90 A8 --- Comm Comments (3) 92- 96 F5.1 --- N OGLE/WFI Total number of stars/spectra extracted 98-102 F5.1 --- ELS ? OGLE/WFI Number of definite emission-line stars found
Note (1): The radii used in this study is generally equal to 1.5x the radii from Pietrzynski & Udalski (1999AcA....49..157P). Note (2): Number of stars for each category found in OGLE catalogues (Udalski et al., 1998, Cat. J/AcA/48/147). Note (3): Comments as follows: 1 = SMC17 and SMC18 have common stars since it appears to be a binary cluster 2 = The extracted spectrum of the candidate emission-line star is a blend of 2 emission-line stars spectra
Byte-by-byte Description of file: tableb2.dat
Bytes Format Units Label Explanations
1- 6 A6 --- Cluster Cluster name (SMCNNN) 8- 10 I3 --- On* OGLE number of normal stars 12- 13 I2 --- Oem OGLE number of emission-line stars 15 I1 --- Oem? OGLE number of candidate emission-line stars 17- 18 I2 --- Nem Number of emission-line stars not from OGLE 20- 23 F4.1 % ELS/all Ratio of emission-line to all stars 25- 26 I2 --- Be ? Number of Be stars 28 I1 --- Be? ? Number of candidate Be stars 30- 31 I2 --- B ? Number of B stars 33- 37 F5.2 % Be/B ? Ratio of Be to all B stars 39- 44 F6.2 % Be+/B ? Ratio of (Be + candidate Be) to all b stars 46 I1 --- Oe ? Number of Oe stars 48 I1 --- O ? Number of O stars 50- 55 F6.2 % Oe/O ? Ratio of Oe to all O stars 57 I1 --- Ae ? Number of Ae stars 59- 60 I2 --- A ? Number of A stars 61- 66 F6.2 % Ae/A ? Ratio of Ae to all A stars 68- 69 I2 --- OBAe ? Number of emission-line stars (Oe, Be and Ae) 71- 73 I3 --- OBA ? Number of all O, B and A stars 75- 79 F5.2 --- OBAe/OBA ? Ratio of OBA emissions stars to all OBA stars 81 I1 --- F-Me ? Number of emission-line stars from main sequence but not OBA type
Byte-by-byte Description of file: tableca.dat
Bytes Format Units Label Explanations
1 I1 --- Code [1/4] Code for object type (G1) 3- 8 A6 --- Cluster Cluster name (SMCNNN) 10- 11 I2 --- WFImg WFI image number 13- 16 A4 --- OGLEimg OGLE image number 18- 22 I5 --- WFI WFI sequential number 24- 29 I6 --- OGLE OGLE sequential number 31- 33 F3.1 arcsec Rad Distance between OGLE and WFI positions 35 I1 h RAh WFI right ascension (J2000) 37- 38 I2 min RAm WFI right ascension (J2000) 40- 45 F6.3 s RAs WFI right ascension (J2000) 47 A1 --- DE- WFI declination sign (J2000) 48- 49 I2 deg DEd WFI declination (J2000) 51- 52 I2 arcmin DEm WFI declination (J2000) 54- 59 F6.3 arcsec DEs WFI declination (J2000) 61 I1 h RA2h OGLE right ascension (J2000) 63- 64 I2 min RA2m OGLE right ascension (J2000) 66- 71 F6.3 s RA2s OGLE right ascension (J2000) 73 A1 --- DE2- OGLE declination sign (J2000) 74- 75 I2 deg DE2d OGLE declination (J2000) 77- 78 I2 arcmin DE2m OGLE declination (J2000) 80- 85 F6.3 arcsec DE2s OGLE declination (J2000) 87- 92 F6.3 mag Vmag V magnitude 94- 99 F6.3 mag Bmag ?=99.999 B magnitude 101-106 F6.3 mag Imag I magnitude 108-113 F6.3 mag B-V ?=9.999 B-V colour index 115-120 F6.3 mag V-I V-I colour index 122-126 F5.3 mag E(B-V) Colour excess 128-130 F3.1 [yr] logt Age 132 I1 --- Mult Code for multiple WFI observations (1)
Note (1): indicates whether the star is found several times as emission- line star in case of different observations in WFI (different images). 1 means that the star was observed once (or the spectrum extracted once).
Byte-by-byte Description of file: tablecb.dat
Bytes Format Units Label Explanations
1 I1 --- Code Code for object type (G1) 3- 8 A6 --- Cluster Cluster name (SMCNNN) 10- 11 I2 --- WFImg WFI image number 13- 17 I5 --- WFI WFI sequential number 19- 24 F6.3 mag (B-V)0 ? Corrected B-V colour index 26- 31 F6.3 mag V0mag Corrected V magnitude 33- 38 F6.3 mag VMAG Absolute V magnitude 40- 45 F6.3 mag (V-I)0 Corrected V-I colour index 47- 57 A11 --- SpT Spectral type 59- 83 A25 --- SName Simbad name 84 A1 --- u_SName [?] ? indicates a poor degree of confidence on the identification in Simbad 86- 99 A14 --- Stype Simbad object type
Byte-by-byte Description of file: tablec9.dat
Bytes Format Units Label Explanations
1- 6 A6 --- Cluster Cluster name (SMCNNN) 8- 9 I2 --- WFImg WFI image number 11- 15 I5 --- WFI WFI sequential number 17 I1 h RAh WFI right ascension (J2000) 19- 20 I2 min RAm WFI right ascension (J2000) 22- 27 F6.3 s RAs WFI right ascension (J2000) 29 A1 --- DE- WFI declination sign (J2000) 30- 31 I2 deg DEd WFI declination (J2000) 33- 34 I2 arcmin DEm WFI declination (J2000) 36- 41 F6.3 arcsec DEs WFI declination (J2000) 43- 47 F5.3 mag E(B-V) Colour excess 48- 50 F3.1 [yr] logt Age 52- 55 A4 --- Status Status (ELS or ELS?) 57- 81 A25 --- SName Simbad name 82 A1 --- u_SName [?] ? indicates a poor degree of confidence on the identification in Simbad 84- 88 A5 --- Stype Simbad object type
Global notes: Note (G1): Code for type as follows: 1 = Be stars 2 = candidate Be stars 3 = Ae and Oe stars 4 = Other emission-line star (not main-sequence)
Acknowledgements: Christophe Martayan, cmartaya(at)eso.org History: * 03-Nov-2009: Original version * 27-Mar-2010: Rewritten cluster names with leading zeroes (e.g. SMC002 instead of SMC2) in order to keep identical names between tables.
(End) Christophe Martayan [ESO], Patricia Vannier [CDS] 03-Nov-2009
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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