能丸 淳一 (国立天文台)
(Title) 計算機 (申請時 すばる計算機システムの現状と更新について)
(Title) STARS2/ProMS2 (申請時 STARS2 and ProMS2)
(Title) SMOKA (申請時 SMOKAの現状報告)
(Title) 装置開発進捗状況 (申請時 PFS進捗状況)
(Abstract) すばる望遠鏡用 Prime Focus Spectrograph (PFS)は大望遠鏡における将来装置の中でもユニークな装置です。Wide Field Correctorによって拡大される主焦点視野の利点を活かし、1.3°直径内での2400天体のファイバ多天体分光を可能にします。これらのファイバは、3色腕を持った分光器4台につながれ、0.38um-1.3umの波長範囲での同時分光を分解能R~3000程度で行うことになります。装置開発を国際共同で行うためそれを組織化すべくPFSプロジェクトオフィスが2011年4月に発足されました。現在、2012年3月に行われる概念設計審査に向けて準備が進められています。
[[ Science Session (English)]]
Satoshi Honda (Kyoto Univ.)
(Title) Heavy elements in globular clusters and dwarf galaxies as probes of the origin of r-process elements
(Abstract) Chemical abundances of very metal-poor stars record the nucleosynthesis products in the early Galaxy. Previous observational studies have revealed that the r-process is the dominant source of neutron-capture elements in extremely metal-poor stars, but the total amount of neutron-capture elements relative to lighter elements (e.g. Fe) shows large star-to-star scatter. These features are key to understanding the astrophysical sites of the r-process as well as the formation of stellar systems including extremely metal-poor stars. Such abundance studies for neutron-capture elements have been extended to metal-poor stars in globular clusters and dwarf galaxies around the Milky Way, in addition to field halo stars. We investigated the abundance ratios of neutron-capture elements for an extremely metal-poor star in the Sextans dwarf galaxy for which a significant excess of Ba was detected by a previous study, and found that the origin of heavy elements in this object is the s-process. Although the sample size is still small, no r-process enhanced star has been found in dwarf galaxies at such low metallicity, in contrast to the Galactic halo. From our measurements of neutron-capture elements in three very metal-poor globular clusters, we confirmed star-to-star scatter of Eu abundance ratios in M15, but found that these clusters are almost homogeneously enriched in lighter neutron-capture elements.
Masayuki Akiyama (Tohoku Univ.)
(Title) Active Super Massive Black Hole Mass Function at z~1.5: Results from FMOS GTO
(Abstract) During the FMOS GTO observing run, we have conducted intensive spectroscopic follow-ups on the X-ray sources in the SXDS field. Using the NIR spectra in combination with the optical spectra of the X-ray-selected AGNs, we examined the active black hole mass function at z~1.5. Thanks to the depth of the observations, the mass function covers much lower activities than that derived from SDSS. The derived mass function suggests that the number density of the active SMBH at z~1.5 in the high-mass range is comparable to that of the non-active SMBH in the local universe.
Kiyoto Yabe (Kyoto Univ.)
(Title) NIR Spectroscopy of Star-Forming Galaxies at z~1.4 with Subaru/FMOS
(Abstract) We present near-infrared spectroscopic observations of star-forming galaxies at z~1.4 with FMOS on the Subaru Telescope. The sample galaxies are selected in the SXDS/UDS fields with K < 23.9 mag, 1.2 < z_ph < 1.6, M_star > 10^9.5M_sun, and expected F(Hα) > 5x10^-17 erg/s/cm^2. The sample is observed mainly in the FMOS/GTO runs. About 300 objects have significant detections of Hα. For these objects, excluding possible AGNs identified from the BPT diagram, gas-phase metallicities are obtained from [NII]/Hα line ratios. The sample is split into stellar mass bins and the spectra are stacked in each bin. The derived stellar mass-metallicity relation is located between those at z~0.8 and z~2.2, and it evolves smoothly from z~3 to z~0. In this talk, we also present the dependency of other parameters on the mass-metallicity relation and discuss the chemical evolution of galaxies at high redshift.
Mikito Tanaka (Tohoku Univ.)
(Title) [Galactic Archaeology] Observational Studies of the Stellar Halo of the Andromeda Galaxy using Subaru telescope
(Abstract) In this meeting, we present previous important studies and observational plans about the stellar halo of the Andromeda galaxy (M31) using Subaru telescope. According to Galactic Archaeological interests, M31 is one of unique laboratories to examine galaxy formation scenario since we can ethnographically investigate stellar population and structure of its halo based on detailed photometric and spectroscopic observations of individual old stars. In particular, the fact that many stellar density substructures such as a stellar stream and a shell have been found around M31 strongly supports hierarchical galaxy formation scenario through a lot of merging events of dwarf galaxies. However, considering the amount of predicted substructures, what we have known about such a scenario is only part of M31‘s formation history over 10 Gyr. To work on such an important problem, we have been planning a whole area survey of M31’s halo using Subaru next-generation instruments such as Hyper Suprime-Cam (HSC) and Prime Focus Spectrograph (PFS). One of our main goals of the studies is to completely describe fundamental properties of M31’s outer halo such as stellar density, abundance and kinematics, which are important clues to restrict structure and formation scenario of stellar halos of galaxies.
Masamune Oguri (IPMU)
(Title) Precise measurement of dark matter distribution with strong and weak gravitational lensing
(Abstract) I present precise measurements of dark matter distribution in massive clusters of galaxies with gravitational lensing. I obtained Subaru/Suprime-cam images for nearly 30 clusters with prominent strong lensing features discovered by the Sloan Giant Arcs Survey (SGAS). These clusters represent by far the largest sample of clusters for this kind of combined strong and weak lensing analysis. I will highlight results on the mass-concentration relation, and also on the shape (ellipticity) of the projected mass distribution accurately measured by the stacked lensing technique, and show how these results are compared with Lambda CDM predictions.
Masao Hayashi (NAOJ)
(Title) An evolving proto-cluster with two prominent clumps at z=2.53
(Abstract) We present the results of the panoramic mapping of Halpha emission in 4x7 arcmin2 region around USS1558-003 radio galaxy at z=2.53, which was conducted by NB2315 narrow-band imaging with MOIRCS. The surveyed region is known as a proto-cluster where distant red galaxies (DRGs) are clustered. Consequently, we find 68 Halpha emitters (HAEs) with fluxes down to 2.6E-17 erg/s/cm2. The distribution of the HAEs shows that there are the two prominent clumps around the radio galaxy and at the region ~1.5 Mpc away from it in physical scale. The small separation between them implies that they are likely to be merged later and may grow to be single massive cluster at lower redshift. While most HAEs reside in blue cloud in color-magnitude diagram, some have red colors similar to DRGs. Interestingly, such red HAEs are located on the faint end of red sequence, and high fraction of them are found in the two clumps. Also, star formation activity seems to be slightly higher in the second clump, but there is no significant difference in the distribution of star formation activity and stellar mass in HAEs over the whole surveyed region. These facts may suggest that there is still no strong environmental dependence in the activity and that galaxies are vigorously evolving within this proto-cluster.
Miho Ishigaki (NAOJ)
(Title) Chemical abundances of the Milky Way thick disk and stellar halo with Subaru/HDS
(Abstract) We present the results of a homogenious chemical abundance analysis
of the 97 nearby metal-poor stars based on spectra obtained with
Subaru/HDS. The sample stars have wide ranges of metallicity
($-3.4<$[Fe/H]$<-0.5$) and orbital parameters, including likely
members of the Milky Way thick disk, inner halo and outer
halo components. This allow us to see chemical abundance ratios
as a function of [Fe/H] and orbital parameters for each of the
three Galactic component, that are useful tracers of chemodynamical
evolution of their progenitors.
Previously, we have obtained abundnances of alpha elements
(Mg, Si, Ca, Ti) for the sample stars and have reported that
the thick disk stars have constantly high [Mg/Fe] and [Si/Fe]
abundance ratios with a small scatter, while the inner
and outer halo stars show those of lower mean values with
a larger scatter at [Fe/H]>-1.5. To get deeper insights
about chemical evolution in progenitors of these Galactic
components, we have estimated the abundance of Fe-peak
(Cr, Ni, Mn, Zn, etc.) and neutron capture (Y, Zr, Ba, Eu, etc.)
elements of the sample stars. Preliminarly results for
these element and their implications will be suggested.
Hironao Miyatake (Univ. Tokyo)
(Title) Subaru weak lensing measurement of a high-redshift cluster discovered by the Atacama Cosmology Telescope Survey
(Abstract) One of the promising cosmological probes is cluster abundance, which can be measured efficiently and robustly by using Sunyaev-Zel'dovich (SZ) effect for cluster detection and weak lensing (WL) for mass determination. To carry out this study, Hyper Suprime-Cam (HSC), the next generation wide-field prime focus camera of the Subaru Telescope, is planning to collaborate with Atacama Cosmology Telescope (ACT), the high-angular resolution millimeter-wave telescope conducting SZ survey. Although WL measurements of clusters at low and intermediate redshift (z<~0.5) are well-established with Suprime-Cam data, that of high-redshift clusters is not yet. We carried out the follow-up observations of a high-redshift galaxy cluster (z=0.81) discovered by the ACT, ACT-CL J0022-0036, and performed WL mass measurement. We used a HSC pipeline, which is a software suite being developed for the HSC, for data reduction. Photometric redshift is used for clean separation between foreground and background galaxy. A galaxy shape measurement code newly implemented for the HSC pipeline is employed. As a result, we obtained tangential shear signals with signal-to-noise ratio of 3.6 and derived cluster mass of M_200 = 7.2+3.3/-2.7(stat.)+1.2/-0.6(syst.)x10^14 M_sun/h. Thus we established the weak lensing measurement of high-redshift clusters with the Suprime-Cam data, which can be used for the HSC survey data in the future. In addition, we tested the LCDM model with the high-redshift, massive cluster. We found the existence of the cluster is consistent with data sets that were used to establish the LCDM model.
Teruyuki Hirano (Univ. Tokyo)
(Title) Measurements of Stelar Obliquities for Transiting Exoplanets with Subaru/HDS
(Abstract) The relation between the stellar spin axis and planetary orbital axis is of great importance in discussing planetary formation and migration scenarios. Measurements of the Rossiter-McLaughlin (RM) effect, which is an apparent radial velocity anomaly during a planetary transit, have revealed that disk-planet interactions are not always responsible for the formations of close-in giant planets, and also provided interesting patterns on the spin-orbit angles.
In this talk, I will present our latest results of RM measurements by Subaru/HDS. In addition, I will briefly introduce our new technique to measure the spin-orbit angles by the combination of the ultra-precise photometry by Kepler and spectroscopic measurements by Subaru. I will also discuss the future prospects for the investigations of planetary formation and migrations.
Masayuki Tanaka (IPMU)
(Title) Deep near-IR spectroscopy of high-z groups of galaxies
(Abstract) We present our on-going survey of distant groups of galaxies. We construct an X-ray selected group of galaxies in deep fields such as COSMOS, CDFS, and SXDF. We have made deep near-IR spectroscopic follow-up observations of high-z groups with MOIRCS and we summarize our recent results. We also report on a spectroscopic confirmation of quiescent galaxies in a z=2.2 proto-cluster.
Masateru Ishiguro (Seoul National Univ.)
(Title) Evidence for recent impact ejecta plume on a main-belt asteroid
(Abstract) Asteroids are thought to have experienced collisions. Evidence of the effect of past collisions can be seen as impact craters and boulders on asteroids as we saw on the surface of Itokawa. However, little is known about impact process appeared immediately after collisions because of the rare opportunities, although the impact phenomena have been simulated by laboratory experiments. In this presentation, we show an evidence for recent impact phenomenon on a main-belt asteroid (596) Scheila. We made observations of (596) Scheila using Subaru/Suprime-Cam for one hour. The comet-like activity of (596) Scheila was discovered on 2010 December 11 by the Catalina Sky Survey. Our observation revealed that dust particles ranging from submicron to 100 μm were ejected into the interplanetary space impulsively on 2011 December 3.5±1.0. The ejecta mass was estimated to be (1.5~4.9)×108 kg, suggesting that equivalent mass of 500-800 m crater was excavated by the event. A model simulation that considers an oblique impact can reproduce the observed morphology of dust cloud. We conclude that the (596) Scheila outburst is the first evidence for the ejecta plume produced by collision with an asteroid of diameter 20-60 m only a week before the discovery.
Masaomi Tanaka (NAOJ)
(Title) Observational Studies of Supernovae with Subaru
Supernovae are the explosions of stars at the end of their lives,
and play important roles in chemical and dynamical aspects in the Universe.
However, the mechanisms of supernova explosion are not yet understood.
Spectropolarimetry is one of the most powerful methods to study
the multi-dimensional geometry of supernovae,
which is thought to be a key for the successful explosion.
We have performed ToO spectropolarimetric observations of
supernovae with the Subaru/FOCAS.
The data clearly show a “loop” in the Stokes Q-U plane.
By combining the observational data and 3D radiative transfer simulations,
we show that supernovae have 3D, non-axisymmetric geometry.
We also briefly discuss prospects for future observations
of supernovae or transient objects with Subaru.
Nana Morimoto (Tohoku Univ.)
(Title) Variability Survey for low-mass high-redshift galaxies
(Abstract) We present the result of optical variability survey for high-redshift galaxies selected by the color criteria, using multiepoch imaging data in z’-band obtained with Subaru / Suprime-Cam. Based on stellar mass estimated from deep NIR data, we discuss about the presence or absence of BHs in low-mass galaxies at high redshift.
Kenta Matsuoka (Ehime Univ.)
(Title) Black hole massese for moderate-luminosity AGNs in the COSMOS
(Abstract) We present infrared spectra of high-redshift AGNs in the COSMOS field obtained by Subaru/FMOS, to measure the black hole masses by using Balmer series (i.e., Hb and Ha lines). By comparison of virial masses between different line estimators, i.e., these Balmer series and MgII that obtained from optical spectra, we investigate whether there is the difference in Hb, Ha, and MgII estimates of black hole mass for moderate-luminosity AGNs.
Jun Hashimoto (NAOJ)
(Title) Fine Structures of Giant Planet Forming Regions around a Young Star of AB Aur
(Abstract) We present the results of the high-resolution near-infrared dual-beam polarimetry of the circumstellar disk around AB Aur (2.4 Mo) using a high contrast instrument HiCIAO mounted on the Subaru 8.2 m telescope.
As a result of stellar evolution, it is widely known that planets are formed in circumstellar disks around young stars. Thus, investigating the detailed structures of circumstellar disks and their evolutions are of great importance in understanding the nature of planet formation mechanisms. However, since the speckle noise is dominant in the inner disk regions (r<1 arcsec) around bright central young star, the observations at the planet forming radius (r <100 AU) are quite challenging so far. The dual-beam polarimetry enable us to suppress the speckle noise and to approach the inner disk regions within tens AU in nearby star forming regions.
Thanks to the better polarimetry performance of both the inner working angle (22 AU) and the resolution (9 AU) at the distance of AB Aur, we detect the rich structure including a bumpy double ring and a ring-like gap at the possible giant-planet location. Our results suggest giant-planet formation in the disk and provides essential information for understanding disk instability and planet formation models.
Kevin Bundy (IPMU)
(Title) Galaxy formation in the era of large surveys
(Abstract) We are in an exciting period where the advent of wide-field imaging and spectroscopic surveys promise great advances in our understanding of galaxy formation and evolution. I will mention new opportunities from three surveys of particular interest to the Japanese community: the HSC (Hyper Suprime Cam) Survey, the PFS (Prime Focus Spectrograph) Survey, and MaNGA (Mapping Nearby Galaxies at APO). I will focus primarily on the recently approved MaNGA project, a next-generation program for the SDSS starting in 2014 that will obtain resolved spectroscopy for 10,000 nearby galaxies. MaNGA represents an exciting opportunity to begin applying the insights of galactic archaeology to a large, statistical sample of galaxies beyond the local group.
Norio Narita (NAOJ)
(Title) High Frequency of Candidate Companions around Planetary Systems with High Obliquity
(Abstract) Recent measurements of the Rossiter-McLaughlin effect have revealed that about one-third of transiting planets have tilted orbits. Those inclined planets are believed to form through dynamical planetary migration due to the interaction with some kind of outer massive bodies. We started high-contrast direct imaging observations as a part of SEEDS (Strategic Explorations of Exoplanets and Disks with Subaru) project to search for counterparts of planetary migration mechanisms. In this talk, we report SEEDS first/second year results which may shed light on the relation between high obliquity of inner planets and the existence of outer companions.
Kazuya Matsubayashi (Ehime Univ.)
(Title) Ionization Source of the M82 Cap Region Investigated by Optical Line Ratio Maps
(Abstract) The M82 cap is an Ha and X-ray emission region, located 11.6 kpc north from the M82 center, and is consider to be related to starburst and superwind phenomena. In order to investigate the ionization source of the cap, we observed a part of the M82 Cap with Kyoto3DII Fabry-Perot mode mounted on Subaru Telescope. Deep continuum, Ha, [N II]6583/Ha, and [S II]6716,6731/Ha maps were obtained with the spatial resolution of 0 .9. The observed [N II]/Ha ratio of 0.1 -- 0.3 and [S II]/Ha ratio of 0.45 -- 0.65 are similar to those of star-forming galaxies. We will discuss the dominant ionization source of the M82 cap, and evolution of M82 superwind.
Takashi Hamana (NAOJ)
(Title) Measurement of cosmic shear correlation functions from SuprimeCam imaging data
(Abstract) I will present weak lensing shear correlation functions measured from 10 sq degrees of SuprimeCam imaging data. I will discuss useful lessons learned from the analysis.
Yoshiki Matsuoka (Nagoya Univ.)
(Title) Co-evolution of galaxies and central black holes: extended emission-line region around quasars
(Abstract) A comprehensive analysis of extended emission-line region (EELR) around quasars is presented. EELR is a massive ionized nebula observed in some active galactic nuclei (AGNs). It extends to several tens of kiloparsec from the central engine and is dominantly photoionized by the AGN radiation. By combining new Subaru/Suprime-Cam observation with the archival data mainly from SDSS, I find that the presence or absence of EELR phenomenon is not clearly correlated with mass accretion rate to central super-massive black holes (SMBHs) or Eddington ratio characterizing the emergent radiation. On the other hand, EELR is preferentially associated with gas-rich, massive blue galaxies. These facts indicate that the primary determinant of EELR creation is the gas availability rather than the AGN radiation, and that the gas may be brought in by galaxy merger triggering the current star formation as well as AGN activity. I argue that EELR quasars occupy the extreme corner of the green valley, the AGN realm, on the galaxy color-magnitude diagram. Once a galaxy is pushed to this area, activated AGN would create EELR by the energy injection into the interstellar gas and eventually blow it away, leading to star-formation quenching. The presented results provide a piece of evidence for such AGN feedback process, which may be playing a leading role in the co-evolution of galaxies and central SMBHs.
Tetsuya Hashimoto (NAOJ)
(Title) Possible high metallicity environment of GRB 080325 and 100418A
(Abstract) We present two case studies of host galaxies of GRB 080325 and 100418A
observed with Subaru telescope. We obtained near-infrared and optical
spectra of GRB 080325 and 100418A hosts respectively.
The metallicites of the hosts are estimated to be 12+log(O/H)=8.75 and
8.8 (KK04) by using emission-line diagnostics. Although these metallicites
are comparable to or below the mass-metallisity relations explored
for typical star-forming galaxies at each redshift, these clearly exceed the
previously proposed critical metallicity below which GRBs occur, suggesting
possible high-metallicity environment around GRBs. Because the single star
scenario of GRB (massive single star explosion) requires low metallicity
environment, these GRBs do not match up with such model. One possible
origin is binary-star merger scenario for long GRBs; GRBs can occur even
in high metallicity environment.
John Silverman (IPMU)
(Title) A Subaru/FMOS survey of AGNs in deep fields
(Abstract) I will present recent progress on our near-infrared spectroscopic survey of AGNs in COSMOS and Chandra Deep Field South - Survey. We are determining the black hole mass distribution of active galaxies (based upon broad emission lines used to calibrate local scaling relations) up to z ~ 2.6, an epoch of rapid mass assembly. Furthermore, this unique data set is enabling us to determine (1) the relationship between supermassive black holes and their host galaxies, (2) nature of obscured AGN, and (3) whether correlations between black hole mass and other spectral properties are realized. To conclude, I will detail a new survey to map the distribution of star-forming galaxies at z~1.5 in COSMOS with FMOS.
[[ Next Generation AO Session (Japanese/English)]]
(Title) 次世代AOのサイエンスケース2 (ngAOWSから) (申請時: Astrometry at the Galactic center with NGAO)
(Abstract) Observations with the Keck telescopes and VLT over the last decade showed
that astrometry is a very powerful technique for studies of the Galactic center.
However, the observations are limited to the central 1 - 2 pc region due to
small field-of-view of current AO instruments. A wide-field infrared camera and
next generation AO system will provide a good opportunity to start up
astrometry at the Galactic center with Subaru. I will talk about possible science
themes with these future instruments: proper motion studies of hyper-velocity
stars, stellar clusters, and the nuclear star cluster.