J/AcA/52/241 QSO candidates in OGLE-II data (Eyer+, 2002)
Search for QSO candidates in OGLE-II data.
Eyer L.
<Acta Astron., 52, 241 (2002)>
=2002AcA....52..241E 2002AcA....52..241E
ADC_Keywords: Magellanic Clouds ; Stars, variable ; Photometry
Keywords: quasars: general - stars: variables: general
Abstract:
A search for faint slowly variable objects was undertaken in the hope
of finding QSO candidates behind the Small and Large Magellanic Clouds
(SMC and LMC). This search used the optical variability properties of
point sources from the Magellanic Cloud OGLE-II photometric data.
Objects bluer than V-I=0.9mag and within 17mag<I<20.5mag were studied.
Robust variograms/structure functions have been computed for each
time-series and only candidates showing a significantly increasing
variability over longer time scales were selected. Several light
curves were identified as having probable artifacts and were therefore
removed. Stars showing signs of periodicity or small trends in their
light curves were also removed and we are left with mostly either Be
stars (γ Cas stars) or QSO candidates. We present a list of 25
slowly varying objects for SMC and 155 for LMC, out of 15000 and 53000
variable objects respectively. Of these, about 15 objects for the SMC
and 118 objects for the LMC are QSO candidates.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 59 25 List of selected 25 objects from SMC data
table2.dat 59 155 List of selected 155 objects from LMC data
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See also:
J/AcA/48/113 : OGLE RR Lyrae VI photometry (Udalski, 1998)
J/AcA/48/147 : OGLE SMC BVI photometry (Udalski+ 1998)
J/AcA/48/175 : OGLE SMC clusters (Pietrzynski+ 1998)
J/AcA/48/563 : OGLE SMC eclipsing binaries BVI photometry (Udalski+ 1998)
J/AcA/49/223 : VI photometry of OGLE LMC Cepheids (Udalski+, 1999)
J/AcA/49/437 : BVI photometry of OGLE SMC Cepheids (Udalski+, 1999)
J/AcA/49/521 : OGLE LMC star clusters BVI photometry (Pietrzynski+, 1999)
J/AcA/49/543 : OGLE LMC + SMC Cepheids VI photometry (Pietrzynski+, 1999)
J/AcA/50/337 : OGLE LMC star clusters (Pietrzynski+, 2000)
J/AcA/51/317 : OGLE. Catalog of LMC and SMC images (Zebrun+, 2001)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Seq Sequential number (S NN, LNNN)
6- 9 A4 --- --- [OGLE] OGLE
10- 27 A18 --- OGLE OGLE designation (HHMMSS.ss+DDMMSS)
29- 34 F6.3 mag Imag I magnitude
36- 38 I3 --- o_Imag Number of measurements in I band
40- 45 F6.3 mag Vmag V magnitude
47- 52 F6.3 mag Bmag B magnitude
54- 55 A2 --- Class [QC Be U] Classification (1)
57- 59 I3 pix Dist Nearest distance to a saturated pixel
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Note (1): Classification as follows:
QC = QSO candidates
Be = {gam} Cas Be stars
U = Unclassified
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History:
Prepared via OCR at CDS.
(End) Patricia Bauer [CDS] 22-Sep-2003