J/MNRAS/356/331 QSO-candidates in OGLE-II Galactic bulge fields (Sumi+, 2005)
Variability-selected QSO candidates in OGLE-II Galactic bulge fields.
Sumi T., Wozniak P.R., Eyer L., Dobrzycki A., Udalski A., Szymanski M.K.,
Kubiak M., Pietrzynski G., Soszynski I., Zebrun K., Szewczyk O.,
Wyrzykowski L.
<Mon. Not. R. Astron. Soc., 356, 331-335 (2005)>
=2005MNRAS.356..331S 2005MNRAS.356..331S
ADC_Keywords: QSOs ; Photometry, CCD
Keywords: stars: variables: other - Galaxy: bulge - Galaxy: centre -
quasars: general
Abstract:
We present 97 QSO candidates in 48 Galactic bulge fields of the
Optical Gravitational Lensing Experiment II (OGLE-II) covering
∼11deg2, which are selected via their variability. We extend light
curves of variable objects which were detected in a 3-yr baseline in
the OGLE-II variable star catalogue to fourth year. We search for
objects that are faint (16<I0<18.5) and slowly variable over 4-yr in
this catalogue by using the variogram/structure function. Finding the
QSOs in such stellar-crowded and high extinction fields is
challenging, but should be useful for the astrometric reference frame.
Spectroscopic follow-up observations are required to confirm these QSO
candidates. Follow-up observations are being prepared for four of
these fields (BUL_SC1, 2, 32 and 45). Follow-up observations for other
fields are strongly encouraged. The complete list and light curves of
all 97 candidates are available in electronic format at
http://www.astro.princeton.edu/sumi/QSO-OGLEII/ .
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 89 97 The list of the 97 QSO candidates
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See also:
ftp://sirius.astrouw.edu.pl/ogle : OGLE DataBase
http://www.astro.princeton.edu/~sumi/QSO-OGLEII : Home Page of the paper
J/AcA/52/129 : DIA OGLE2 candidate variable stars catalog (Wozniak+ 2002)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Field Field number (field name is BUL_SC NN)
4- 7 I4 ---- VID Variable number, in the field (1)
10- 15 I6 --- ID Identification number, in the field (2)
17- 23 F7.2 pix Xpos X position
25- 31 F7.2 pix Ypos Y position
33- 34 I2 h RAh Right ascension (J2000)
36- 37 I2 min RAm Right ascension (J2000)
39- 43 F5.2 s RAs Right ascension (J2000)
45 A1 --- DE- Declination sign (J2000)
46- 47 I2 deg DEd Declination (J2000)
49- 50 I2 arcmin DEm Declination (J2000)
52- 55 F4.1 arcsec DEs Declination (J2000)
58- 63 F6.3 mag Imag I magnitude
65- 69 F5.3 mag V-I ?=9.999 V-I colour index
71- 76 F6.3 mag Icmag ?=99.999 Extinction corrected I magnitude
78- 83 F6.3 mag (V-I)c ?=9.999 Extinction corrected V-I colour index
85- 89 F5.3 --- Svar Variogram slope (3)
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Note (1): Numbering of Udalski et al, 2002, Cat. J/AcA/52/217,
OGLEII DIA BUL-SCNN NNNN in Simbad
Note (2): OGLE BUL-SCNN NNNNNN in Simbad
Note (3): The larger Svar, the larger the variability on larger time-scales.
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History:
* 07-Feb-2006: Copied at http://www.astro.princeton.edu/~sumi/QSO-OGLEII
(End) Patricia Vannier [CDS] 07-Feb-2006