Access to Astronomical Catalogues

← Click to display the menu
J/A+A/373/608  Early-type stars towards the Galactic Center. II. (Dufton+, 2001)

A UKST survey of blue objects towards the Galactic Centre - seven additional fields. Dufton P.L., Smartt S.J., Hambly N.C. <Astron. Astrophys. 373, 608 (2001)> =2001A&A...373..608D
ADC_Keywords: Stars, early-type ; Stars, blue ; Photometry ; Equivalent widths Keywords: stars: early-type - stars: fundamental parameters - stars: imaging - galaxy: center Abstract: We are searching for early-type stars towards the Galactic centre which are potentially young objects situated within the inner few kiloparsecs of the disk. Photographic photometry from the UK Schmidt Telescope has been used to identify the bluest candidates in nineteen Schmidt fields (centred close to the Galactic centre). We have previously obtained FLAIR low dispersion spectroscopy for three of these fields to estimate spectral types and here we present spectroscopy for an additional seven fields. Combining the results for all ten fields, 56 stars were initially classified as early-B type. Estimates of the equivalent widths of their Balmer and He I lines have been used to estimate atmospheric parameters and 32 targets have effective temperatures greater than or equal to 17000K (corresponding to a spectral type of B3 or earlier). The spectra of seven of these targets also have absorption lines due to O II and Si III and can be reliably classified as early-B type. Additionally 78 stars have estimated effective temperatures between 11000 and 16000K with a further 50 objects identified as late-B (or early-A) type. All but two of the early B-type candidates have magnitudes in the range 12.0≤V≤16.0, and our best estimates of their distance suggest that they could be close to (i.e. Rg<3kpc), or even beyond the Galactic centre. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 28 10 The 10 Galactic Centre Survey fields for which spectroscopy has been obtained. table2.dat 78 58 Blue stellar candidates for Field 279 table3.dat 78 61 Blue stellar candidates for Field 333 table4.dat 78 64 Blue stellar candidates for Field 391 table5.dat 78 64 Blue stellar candidates for Field 520 table6.dat 78 63 Blue stellar candidates for Field 522 table7.dat 78 61 Blue stellar candidates for Field 589 table8.dat 78 61 Blue stellar candidates for Field 591
See also: J/A+AS/139/231 : Early-type stars towards the Galactic Centre (Dufton+, 1999) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Field Field number (1) 6- 7 I2 h RAh Right ascension (J2000.0) 9- 10 I2 min RAm Right ascension (J2000.0) 12- 13 I2 s RAs Right ascension (J2000.0) 15 A1 --- DE- Declination sign (J2000.0) 16- 17 I2 deg DEd Declination (J2000.0) 19- 20 I2 arcmin DEm Declination (J2000.0) 22- 24 F3.1 h Blue Blue Exposure times 26- 28 F3.1 h Red ? Red Exposure times
Note (1): Standard United Kingdom Schmidt Telescope field numbers are defined in Tritton (1983, United Kingdom Schmidt Telescope Handbook, Royal Observatory Edinburgh) see also the UKSTU online catalogue at http://www.roe.ac.uk/ Spectroscopy for the fields 391, 454 and 456 has been discussed by DSH (Dufton et al., 1999, Cat. J/A+AS/139/231)
Byte-by-byte Description of file: table[2-8].dat
Bytes Format Units Label Explanations
1- 3 I3 --- Field Field number 5- 6 I2 --- Star Star number in the field ([DSH2001] FFF-NN in Simbad) 8- 9 I2 h RAh Right ascension (J2000.0) 11- 12 I2 min RAm Right ascension (J2000.0) 14- 18 F5.2 s RAs Right ascension (J2000.0) 20 A1 --- DE- Declination sign (J2000.0) 21- 22 I2 deg DEd Declination (J2000.0) 24- 25 I2 arcmin DEm Declination (J2000.0) 27- 30 F4.1 arcsec DEs Declination sign (J2000.0) 32- 36 F5.2 mag Vmag V magnitude 38- 42 F5.2 mag (u-v) (u-v) colour index 44- 49 I6 --- Cb ? Mean count in the summed spectra for the wavelength ranges 3900 to 4600Å (blue) 51- 55 I5 --- Cr ? Mean count in the summed spectra for the wavelength ranges 5600 to 6800Å (red) 57- 66 A10 --- BlueSp Blue spectra classification 69- 78 A10 --- RedSp Red spectra classification
History: From electronic version of the journal
(End) James Marcout, Patricia Bauer [CDS] 10-Sep-2001
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

catalogue service

© UDS/CNRS

Contact