OpticalNIR Imaging of AKARI NEPWide Survey Field Yiseul

Optical/NIR Imaging of AKARI NEP-Wide Survey Field Yiseul Jeon, Myungshin Im, Eugene Kang, and Induk Lee Astronomy Program, Department of Physics and Astronomy, Seoul National University We present the results from a B, R and I band observation, and the current status of a NIR-imaging of the NEP-Wide survey field. The NEP-Wide is an AKARI’s extragalactic survey of the North Ecliptic Pole covering 5. 8 square degree area centered at α=18 h 00 m 00 s, δ=+66° 36’ 00”. Our optical/NIR imaging supports the AKARI IR imaging data by providing a crucial coverage in optical/NIR. We describe the observations and reductions and show the properties of the data in this poster. Optical B, R & I at Maidanak NIR J & H at KPNO 1. OBSERVATION § § § Using FLAMINGOS on KPNO 2. 1 m telescope § From June 13 to 23, 2008 § Covering area : 5. 2 deg 2 for J- and 5. 4 deg 2 for H-band At Maidanak Astronomical Observatory in Uzbekistan From June 12 to August 5, 2007 Using 1. 5 m telescope and 4 k CCD B, R and I filter covered 4. 9 deg 2 area. Filter Total Exposure Time [min] Seeing [arcsec] (Median value) Filter Depth [5σ for diameter 3” aperture] (Median value) B 20 -45 (21) 0. 9 -1. 3 (1. 21) 23. 24 -24. 62 (23. 80) R 18 -40 (30) 0. 9 -1. 3 (1. 19) 21. 99 -23. 97 (23. 20) I 16 -64 (20) 0. 8 -1. 3 (1. 18) 21. 20 -22. 33 (21. 91) • AKARI NEP-Wide (Red, 5. 8 deg 2) • CFHT optical survey (Blue, 2 deg 2) • Maidanak optical survey (Black) Total Exposure Time [min] Seeing [arcsec] (Median value) Depth [10σ for diameter 3” aperture] (Median value) J 28. 5 -52. 5 (36. 0) 1. 2 -1. 6 (1. 5) 20. 46 -21. 23 (20. 86) H 11. 3 -34. 0 (21. 3) 1. 1 -1. 4 (1. 3) 19. 25 -20. 50 (20. 01) • NIR optical survey (Black squares) • Imai et. al. (2007) covered the green squares with J- and Ks band. 2. DATA REDUCTION 2. 1 Preprocessing § Using the XDIMSUM package in IRAF 2. DATA REDUCTION 2. 1 Preprocessing 2. 2 I band Fringe correction 2. 2 Astrometry Before and After the preprocessing § Using the SCAMP of Terapix § Gaussian fitting 1σ astrometric errors : ΔRA=0. 7”, ΔDec=0. 6” 2. 3 Object detection and Photometry Using SExtractor, we detected 225, 361 sources both J- and H-band. (a) Before and (b) After the preprocessing (a) Fringe Pattern (b) Before and After Fringe Removing 2. 2 Astrometry § Using the SCAMP of Terapix § Gaussian fitting 1σ astrometric errors : ΔRA=0. 15”, ΔDec=0. 16” 3. PROPERTIES of the DATA 3. 1 Source Properties 2. 3 Object detection and Photometry § Using SExtractor (Bertin & Arnouts 1996) § We detected 137, 373 sources at B, 256, 844 at R, 194, 808 at I filter. 3. PROPERTIES of the DATA CMD and CCD. We define galaxies as B-J>2. 5 and stellarity of R <0. 9 for J < 19 3. 1 Source Properties 3. 2 Galaxy number counts & Completeness Galaxy number counts • We define galaxies as B-J>2. 5 and stellarity of R <0. 9 for J < 19 and H < 19 magnitude. All the faint objects are considered as galaxies. Point sources Extended sources Completeness test • The solid lines are from artificial images using the artdata package in IRAF. • The dashed lines are calculated by dividing galaxy number counts from other studies. (a) Photometric error distribution (b) SExtractor stellarity distribution (c) Magnitude number counts < The B-R vs. R-I color-color diagram > Blue points are the point sources (Stellarity > 0. 9) and red points are the extended source (Stellarity < 0. 2) with R < 21. 3. 2 Galaxy number counts & Completeness 4. STAMP IMAGE of NEP-Wide FIELD 3. 3 Redshift track on the CCD 30” B Galaxy number counts • We define galaxies as B-J>2. 5 and stellarity of R <0. 9 for B<22, R<21. 5 and I<21 magnitude. All the faint objects are considered as galaxies. Completeness test • The solid lines are from artificial Redshift tracks of galaxies and QSO • The blue line is the star-forming galaxy, M 82, the red line is templates of Bruzual & Charlot (2003) assuming simple stellar populations (SSPs) of metallicities Z=0. 02 (solar) at ages images using the artdata package 10 Gyr, for Salpeter IMF. The violet line is a in IRAF. SDSS median composite QSO spectrum form • The dashed lines are calculated by Vanden Berk et. al. (2001). dividing galaxy number counts • We considered the IGM attenuation Landau from other studies. 1995 for all z tracks. R I J H N 2 N 3 N 4 < SUMMARY & FUTURE WORKS > § We present the BRI and JH band observation of the NEP-Wide survey field. § The photometric data are being used for identifying optical counterparts of the IR data provided by AKARI. § Using multi-wavelength data of the NEP-Wide field, we can make their complete SEDs and study MANY interesting objects.