Some Preliminary Results from AKARI’s NEP Survey and Clusters of Galaxies Program Hyung Mok Lee (Seoul National University) with Myungshin Im. Hyunjin Shim. Seong Jin Kim, Myung Gyoon Lee, Narae Hwang, H. Matsuhara, K. Wada, S. Oyabu & AKARI NEP and Cluster of Galaxies Survey Team February 19, SDSS-KSG 동계워크샵

The AKARI (ASTRO-F) Project  IR Space Mission by Japan Aerospace Exploration Institutes (JAXA)/Institute for Space and Aeronautical Science (ISAS) with ESA support  Collaborative Institutes in Japan: - University of Tokyo - Nagoya University - Communications Research lab. - National Astronomical Observatory (NAOJ)  International Collaboration - Seoul National University (Pre- and post-flight simulations/data reduction) - European Consortium (Imperial, Open Univ., Sussex, Groningen: data reduction ) February 19, SDSS-KSG 동계워크샵

Telescope  Mirror 68 cm, F/6 SiC Cryogenic System –170 liter LHe + Stirling Cooler –T(tel) = 5.8 K, T(detector) = 1.8 K (st. Ge:Ga), 15 K (InSb) February 19, SDSS-KSG 동계워크샵

Focal Plane Instruments  IRC: Near- and Mid-IR Camera  FIS: Far-IR Surveyor February 19, SDSS-KSG 동계워크샵

February 19, 2008 SDSS-KSG 동계워크샵 Orbit and Observing Modes  Sun Syncrhonous Orbit with a= km e= Altitude ~ 750 km  Orbital Period ~100 minutes  Max Pointings 3 / revol.  Pointing Obs. < 10 min per pointing 5

Features  Main purpose: all sky survey in mid to far infrared + pointing observations  Higher resolution compared to IRAS (e.g., ’ compared to 6’ at far IR)  Wide field of view (10’ x 10’ for IRC)  Wide and continuous wavelength coverage from near to far IR (2-170 microns) for both wide-band imaging and spectroscopy  Scientific programs include all sky survey, large area surveys (NEP, SEP), Mission Programs, and open time programs February 19, SDSS-KSG 동계워크샵

AKARI Sensitivity (pre-flight estimates) Spitzer cannot cover this range February 19, SDSS-KSG 동계워크샵

Timeline of AKARI  Launched on February 21, 2006, 9:28 am (UT)  Due to some problems in AOCS, aperture lid jettison was delayed by about a month (April 13, 2006)  Started all sky survey on May 8, 2006 (Phase 1)  Phase 2 observation started in November, 2006  Helium boiled out on August 26, 2007 (550 days after launch)  Phase-3 observation will begin early April, 2004 with NIR channel only February 19, SDSS-KSG 동계워크샵

AKARI NEP Survey  One of the Large Area Surveys of AKARI because of high visibility  Consists of Deep (0.38 sq. deg) + Wide area (5.8 sq. deg.) surveys (Matsuhara et al. 2006)  Other wavelength data: - Optical surveys that include the NEP Deep area are done with CFHT (Hwang et al. 2007) and Subaru telescope - Optical survey for the entire NEP Wide survey area has been carried out using 1.5 m Telescope at Maidanak Observatory by SNU team - Radio survey with WSRT at 20 cm has been carried out by Open Univ. team. February 19, SDSS-KSG 동계워크샵

North Ecliptic Pole (NEP) Survey A wide area, multi-wavelength blank field survey February 19, SDSS-KSG 동계워크샵

NEP Survey Area Green: Wide Pink: Deep Yellow: CFHT Optical Survey February 19, SDSS-KSG 동계워크샵

NEP publications (PASJ special issue, October 2007)  Nature of Infrared Sources in 11  m Selected Sample from Early Data of the AKARI North Ecliptic Pole Deep Survey (Lee et al. )  Optical Identification of 15  m Sources in the AKARI Performance Verification Field toward the North Ecliptic Pole (Matsuhara et al.)  Multi-Wavelength Analysis of 18  m-Selected Galaxies in the AKARI/Infrared-Camera monitor field towards the North Ecliptic Pole (Takagi et al.) February 19, SDSS-KSG 동계워크샵

Nature of 11  m Selected Sample  Partial data of NEP- Deep survey carried out during the PV phase (May 2006)  The field lies within CFHT NEP-W field, where g’, r’, i’, z’-band data are available.  N2, N3, N4, S7, S9, S11 bands, 3 exposures each  Total exposure time: 10 – 20 minutes per filter February 19, SDSS-KSG 동계워크샵

S11 Flux Limited Sample  Why 11  m sample? & 7.7  m PAH feature can be redshifted to S11 band for z= objects  5-  detection =19.5 m(AB), or 60  Jy  Total number of detected sources ~ 180  Complete test: >90% at 18.5 mag. (72 sources)  Source distribution n(m) ~ m 0.6 February 19, SDSS-KSG 동계워크샵

Classification of sources  Optical morphology + optical-IR SED -Stars (13 [18%]) -Star forming disk galaxies (51 [70%]) -Early type galaxies (4 [6%]) -AGNs (4 [6%]) February 19, SDSS-KSG 동계워크샵

Optical-IR Atlases z=0.64 X-ray source star AGN? CFHT N2N3 N4S5S9W S11 February 19, SDSS-KSG 동계워크샵

Disk galaxy February 19, SDSS-KSG 동계워크샵

Optical to Mid-IR SEDs: Disk galaxies  Broad peak in near IR (redshifted 1.6 micron bump) + brightening at mid-IR  Majority of (~70 % ) the S(<18.5) sample February 19, SDSS-KSG 동계워크샵

SEDs of AGN  4 out of 72 (6%) sources are classified as AGNs  Two X-ray sources with measured redshifts (z=0.64, 1.43)  Well fitted by power- law SED February 19, SDSS-KSG 동계워크샵

SEDs of stars Well fitted by black-bodies 13 sources (18%) February 19, SDSS-KSG 동계워크샵

SED fitting to disk galaxies: redshift and L IR  SED templates by Chary & Elbaz (2001)  PAH features allow us to determine the redshift  0.2<z<0.7, L IR ~ – L sun February 19, SDSS-KSG 동계워크샵

Other interesting sources with S11>18.5 T eff ~ 2500 K BB with IR excess?  A candidate for brown dwarf February 19, SDSS-KSG 동계워크샵

A Very Red Object No optical detection but seen at all IRC bands 1.Power-law with -2.8 (dust obscured AGN) 2.Dust extinct star forming galaxy at z>5 3.A few hundred Myr object at z~9.5 (too massive)? February 19, SDSS-KSG 동계워크샵

A flat spectrum Object Very flat spectrum (not an AGN) A galaxy at z~3.5? February 19, SDSS-KSG 동계워크샵

Summary of 11 micron sources  We have looked at the properties of s11 selected sources in the early data of NEP survey -Mostly star forming disk galaxies at moderate redshifts (0.2<z<0.7) -Stars -AGNs at various redshifts -A number of interesting objects: brown dwarf, dusty AGN, flat spectrum -few interesting objects must be looked at more carefully  The depth of the current data set is similar to that of NEP- Wide  useful for the study of star forming galaxies in moderate redshifts February 19, SDSS-KSG 동계워크샵

NEP -Wide Data  Consists of 446 frames  Mosaic images have been produced for N2, N3, N4, S7, S9, S11, L15, L18 bands  A band-merged image has been produced  Sources are detected in band- merged image  Photometry has been done on single band images  catalogue has been produced February 19, SDSS-KSG 동계워크샵

Band merged mage : N2+N3+N4+S7+S9+S11+L15+L sources are detected February 19, SDSS-KSG 동계워크샵

Some Preliminary Numbers  Area coverage: 5.8 sq. deg. = 20,880 sq. arc. Min > 200 times larger area than the analized area  Total number of sources ~100,000  11 micron sources ~20,000 (<18.5 mag) * If 70% are spirals, total number of S-galaxies will be ~14,000 February 19, SDSS-KSG 동계워크샵

Clusters of Galaxies Mission Program February 19, 2008 SDSS-KSG 동계워크샵 29

 Purposes: -Study the evolution of galaxies in cluster environments  Divided into 3 subprograms depending on z: - Low-z (z<0.3) + how star formation activities are affected by the cluster merging? + 10 clusters of galaxies with different merging stages: quiescent, minor merger, major merger - Mid-z (0.4<z<1.3) + Sources selected from Subaru/S-cam imaging data + Deep MIR imaging of selected clusters to detect hidden star formation, stellar mass, etc. - High-z (z>1.3) + Try to find overdensity around the High-z Radio Galaxies. + Deep imaging in NIR and MIR Outline of the program February 19, SDSS-KSG 동계워크샵

Low-z example: Abell 2065 Data reduction by Hyun Jong SEO -Redshift : February 19, SDSS-KSG 동계워크샵

A2065 Model fitting ■ Chary & Elbaz (2001) ■ Piovan et al. (2003) February 19, SDSS-KSG 동계워크샵

A2065 Distribution of E and S galaxies: effects of ram pressure stripping? [very preliminary] February 19, SDSS-KSG 동계워크샵

Summary  AKARI’s survey of NEP region provides a wealth of data for galactic and extragalactic sources  11 micron sample is composed of mostly star forming galaxies at z=0.2~0.7  Other wavelength selected samples probe different redshift ranges (i.e., 15 micron and 18 micron for z~1)  Studies of clusters of galaxies should provide important clues to the environmental effects  Complementary observations during warm mission is now being planned February 19, SDSS-KSG 동계워크샵