The SVBABU/XMM-Newton deep survey (SXDS). V. Optically faint variable object survey

We present our survey for optically faint variable objects using multiepoch (8-10 epochs over 2-4 years) i′-band imaging data obtained with Subaru Suprime-Cam over 0.918 deg2 in the Subaru/XMM-Newton Deep Field (SXDF). We found 1040 optically variable objects by image subtraction for all the combina...

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Main Authors: Morokuma, T, Doi, M, Yasuda, N, Akiyama, M, Sekiguchi, K, Furusawa, H, Ueda, Y, Totani, T, Oda, T, Nagao, T, Kashikawa, N, Murayama, T, Ouchi, M, Watson, MG, Richmond, M, Lidman, C, Perlmutter, S, Spadafora, A, Aldering, G, Wang, L, Hook, I, Knop, R
Format: Journal article
Language:English
Published: Institute of Physics Publishing 2008
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author Morokuma, T
Doi, M
Yasuda, N
Akiyama, M
Sekiguchi, K
Furusawa, H
Ueda, Y
Totani, T
Oda, T
Nagao, T
Kashikawa, N
Murayama, T
Ouchi, M
Watson, MG
Richmond, M
Lidman, C
Perlmutter, S
Spadafora, A
Aldering, G
Wang, L
Hook, I
Knop, R
author_facet Morokuma, T
Doi, M
Yasuda, N
Akiyama, M
Sekiguchi, K
Furusawa, H
Ueda, Y
Totani, T
Oda, T
Nagao, T
Kashikawa, N
Murayama, T
Ouchi, M
Watson, MG
Richmond, M
Lidman, C
Perlmutter, S
Spadafora, A
Aldering, G
Wang, L
Hook, I
Knop, R
author_sort Morokuma, T
collection OXFORD
description We present our survey for optically faint variable objects using multiepoch (8-10 epochs over 2-4 years) i′-band imaging data obtained with Subaru Suprime-Cam over 0.918 deg2 in the Subaru/XMM-Newton Deep Field (SXDF). We found 1040 optically variable objects by image subtraction for all the combinations of images at different epochs. This is the first statistical sample of variable objects at depths achieved with 8-10 m class telescopes or the Hubble Space Telescope. The detection limit for variable components is i′vari ∼ 25.5 mag. These variable objects were classified into variable stars, supernovae (SNe), and active galactic nuclei (AGNs), based on the optical morphologies, magnitudes, colors, and optical-mid-infrared colors of the host objects, spatial offsets of variable components from the host objects, and light curves. Detection completeness was examined by simulating light curves for periodic and irregular variability. We detected optical variability for 36% ± 2% (51% ± 3% for a bright sample with i′ < 24.4 mag) of X-ray sources in the field. Number densities of variable objects as functions of time intervals Δt and variable component magnitudes i′vari are obtained. Number densities of variable stars, SNe, and AGNs are 120, 489, and 579 objects deg-2, respectively. Bimodal distributions of variable stars in the color-magnitude diagrams indicate that the variable star sample consists of bright (V ∼ 22 mag) blue variable stars of the halo population and faint (V ∼ 23.5 mag) red variable stars of the disk population. There are a few candidates of RR Lyrae providing a possible number density of ∼10-2 kpc-3 at a distance of >150 kpc from the Galactic center. © 2008. The American Astronomical Society. All rights reserved.
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spelling oxford-uuid:4b99dfee-eb83-4198-8f3a-46e6b2e4d4c52022-03-26T15:44:39ZThe SVBABU/XMM-Newton deep survey (SXDS). V. Optically faint variable object surveyJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4b99dfee-eb83-4198-8f3a-46e6b2e4d4c5EnglishSymplectic Elements at OxfordInstitute of Physics Publishing2008Morokuma, TDoi, MYasuda, NAkiyama, MSekiguchi, KFurusawa, HUeda, YTotani, TOda, TNagao, TKashikawa, NMurayama, TOuchi, MWatson, MGRichmond, MLidman, CPerlmutter, SSpadafora, AAldering, GWang, LHook, IKnop, RWe present our survey for optically faint variable objects using multiepoch (8-10 epochs over 2-4 years) i′-band imaging data obtained with Subaru Suprime-Cam over 0.918 deg2 in the Subaru/XMM-Newton Deep Field (SXDF). We found 1040 optically variable objects by image subtraction for all the combinations of images at different epochs. This is the first statistical sample of variable objects at depths achieved with 8-10 m class telescopes or the Hubble Space Telescope. The detection limit for variable components is i′vari ∼ 25.5 mag. These variable objects were classified into variable stars, supernovae (SNe), and active galactic nuclei (AGNs), based on the optical morphologies, magnitudes, colors, and optical-mid-infrared colors of the host objects, spatial offsets of variable components from the host objects, and light curves. Detection completeness was examined by simulating light curves for periodic and irregular variability. We detected optical variability for 36% ± 2% (51% ± 3% for a bright sample with i′ < 24.4 mag) of X-ray sources in the field. Number densities of variable objects as functions of time intervals Δt and variable component magnitudes i′vari are obtained. Number densities of variable stars, SNe, and AGNs are 120, 489, and 579 objects deg-2, respectively. Bimodal distributions of variable stars in the color-magnitude diagrams indicate that the variable star sample consists of bright (V ∼ 22 mag) blue variable stars of the halo population and faint (V ∼ 23.5 mag) red variable stars of the disk population. There are a few candidates of RR Lyrae providing a possible number density of ∼10-2 kpc-3 at a distance of >150 kpc from the Galactic center. © 2008. The American Astronomical Society. All rights reserved.
spellingShingle Morokuma, T
Doi, M
Yasuda, N
Akiyama, M
Sekiguchi, K
Furusawa, H
Ueda, Y
Totani, T
Oda, T
Nagao, T
Kashikawa, N
Murayama, T
Ouchi, M
Watson, MG
Richmond, M
Lidman, C
Perlmutter, S
Spadafora, A
Aldering, G
Wang, L
Hook, I
Knop, R
The SVBABU/XMM-Newton deep survey (SXDS). V. Optically faint variable object survey
title The SVBABU/XMM-Newton deep survey (SXDS). V. Optically faint variable object survey
title_full The SVBABU/XMM-Newton deep survey (SXDS). V. Optically faint variable object survey
title_fullStr The SVBABU/XMM-Newton deep survey (SXDS). V. Optically faint variable object survey
title_full_unstemmed The SVBABU/XMM-Newton deep survey (SXDS). V. Optically faint variable object survey
title_short The SVBABU/XMM-Newton deep survey (SXDS). V. Optically faint variable object survey
title_sort svbabu xmm newton deep survey sxds v optically faint variable object survey
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