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...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , |
---|---|
Format: | Journal article |
Language: | English |
Published: |
Institute of Physics Publishing
2008
|
_version_ | 1797067136674299904 |
---|---|
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. |
first_indexed | 2024-03-06T21:52:01Z |
format | Journal article |
id | oxford-uuid:4b99dfee-eb83-4198-8f3a-46e6b2e4d4c5 |
institution | University of Oxford |
language | English |
last_indexed | 2024-03-06T21:52:01Z |
publishDate | 2008 |
publisher | Institute of Physics Publishing |
record_format | dspace |
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 |
work_keys_str_mv | AT morokumat thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT doim thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT yasudan thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT akiyamam thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT sekiguchik thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT furusawah thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT ueday thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT totanit thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT odat thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT nagaot thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT kashikawan thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT murayamat thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT ouchim thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT watsonmg thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT richmondm thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT lidmanc thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT perlmutters thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT spadaforaa thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT alderingg thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT wangl thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT hooki thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT knopr thesvbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT morokumat svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT doim svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT yasudan svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT akiyamam svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT sekiguchik svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT furusawah svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT ueday svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT totanit svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT odat svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT nagaot svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT kashikawan svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT murayamat svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT ouchim svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT watsonmg svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT richmondm svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT lidmanc svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT perlmutters svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT spadaforaa svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT alderingg svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT wangl svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT hooki svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey AT knopr svbabuxmmnewtondeepsurveysxdsvopticallyfaintvariableobjectsurvey |