000002194 001__ 2194
000002194 005__ 20160706143800.0
000002194 0247_ $$2DOI$$a10.1051/0004-6361/201219696
000002194 037__ $$aASTROimport-351
000002194 100__ $$aCioni, M.-R. L.
000002194 245__ $$aThe VMC Survey. VI. Quasars behind the Magellanic system
000002194 260__ $$c2013
000002194 520__ $$aContext. The number and spatial distribution of confirmed quasi-stellar objects (QSOs) behind the Magellanic system is limited. This undermines their use as astrometric reference objects for different types of studies.  Aims: We have searched for criteria to identify candidate QSOs using observations from the VISTA survey of the Magellanic Clouds system (VMC) that provides photometry in the YJKs bands and 12 epochs in the Ks band.  Methods: The (Y - J) versus (J - Ks) diagram has been used to distinguish QSO candidates from Milky Way stars and stars of the Magellanic Clouds. Then, the slope of variation in the Ks band has been used to identify a sample of high confidence candidates. These criteria were developed based on the properties of 117 known QSOs presently observed by the VMC survey.  Results: VMC YJKs magnitudes and Ks light-curves of known QSOs behind the Magellanic system are presented. About 75% of them show a slope of variation in Ks > 10-4 mag/day and the shape of the light-curve is in general irregular and without any clear periodicity. The number of QSO candidates found in tiles including the south ecliptic pole and the 30 Doradus regions is 22 and 26, respectively, with a ~20% contamination by young stellar objects, planetary nebulae, stars and normal galaxies.  Conclusions: By extrapolating the number of QSO candidates to the entire VMC survey area we expect to find about 1200 QSOs behind the LMC, 400 behind the SMC, 200 behind the Bridge and 30 behind the Stream areas, but not all will be suitable for astrometry. Further, the Ks band light-curves can help support investigations of the mechanism responsible for the variations. Based on observations made with VISTA at the Paranal Observatory under program ID 179.B-2003.
000002194 700__ $$aKamath, D.
000002194 700__ $$aRubele, S.
000002194 700__ $$avan Loon, J. T.
000002194 700__ $$aWood, P. R.
000002194 700__ $$aEmerson, J. P.
000002194 700__ $$aGibson, B. K.
000002194 700__ $$aGroenewegen, M. A. T.
000002194 700__ $$aIvanov, V. D.
000002194 700__ $$aMiszalski, B.
000002194 700__ $$aRipepi, V.
000002194 773__ $$cA29$$pAstronomy and Astrophysics$$v549$$y2013
000002194 85642 $$ahttp://esoads.eso.org/abs/2013A%26A...549A..29C
000002194 905__ $$apublished in
000002194 980__ $$aREFERD