1) User interface automation, launching programs, file management, text processing, custom dialogs, internet functions, web page automation, Excel automation, database/XML/CSV functions, regular expressions, VBScript, C#.

2) Many triggers, including hotkeys, mouse, window, autotext, scheduler, toolbars and menus. 

    - Records keyboard and mouse actions.

3) Captures, finds and clicks web page objects, other UI objects, on-screen images and text.

4) Programming language with functions, classes, full dll/API/COM support.

5) You can create programs for various purposes. Run in Quick Macros or as exe files.

1) SN Ia 를 이용한 Dark Energy 발견 연구 소개 (2011 노벨상)

     - SN Ia 의 특성과 이를 표준촉광으로 사용한 가속팽창 연구 내용? 

     - SN Ia 를 표준촉광으로 사용하기 위한 가정 및 연구의 특수성

2) SN Ia 가 표준촉광으로 활용 가능/불가능 에 관한 최근 연구 소개

     - 노벨상 연구팀: 은하 진화와 SN Ia 광도는 무관

     - 최근 연구: 은하의 age 또는 metallicity 에 따른 SN Ia 광도 차이 발견

3) 현대우주론에서 SN Ia 연구가 가지는 의미

4) SN Ia 이외의 우주가속팽창(Dark Energy 존재) 증거

     - CMB power spectrum (structure of CMB peaks change)? 

     - ISW (about Gravitational well of galaxy supercluster)

star-galaxy separation은 전천후 측광 관측 데이터에서 좋은 galaxy (또는 star, quasar 등) catalogue를 만드는데 중요한 이슈이다.

기존에 주로 쓰이던 방법(& 이것의 문제점) 및 최근에 제안된 방법을 소개하고, 몇가지 데이터(SDSS, HSC, DECaLS)에 대해 진행된 star-galaxy separation을 담은 논문들의 일부를 소개한다.

---

----------------------------------------------------------------------------------------------

---

---

---

Star/galay separation - SDSS DR7

The SDSS photometric pipeline performs a morphological star/galaxy separation. The quality of this separation is therefore intimately related to the seeing and sky brightness. Photo's classifications have been tested against those of the COMBO survey (which effectively uses low-resolution spectroscopy for star/galaxy separation) in a region of the sky that both surveys have scanned. While the comparison was carried out for DR1 data, the DR2/DR3 data are not significantly different.

-----------------------------------------------------------------------------------------------

How to separate stars from galaxies

The classificaiton_extendedness? parameter, which is based on the difference between the CModel and PSF magnitudes, is stored in the database and is a reasonable star/galaxy classifier.  Using the star/galaxy separation from HST/ACS in COSMOS as the truth table, here we characterize the accuracy of our star/galaxy separation.  The completeness is defined as a fraction of ACS stars properly classified as stars in HSC. The contamination is a fraction of ACS galaxies among objects classified as stars in HSC.  Both the completeness and contamination rates are strong function of the seeing size and depth.

------------------------------------------------------------------------------------------------

First Data Release of the Hyper Suprime-Cam Subaru Strategic Program

The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is a three-layered imaging survey aimed at addressing some of the most outstanding questions in astronomy today, including the nature of dark matter and dark energy. The survey has been awarded 300 nights of observing time at the Subaru Telescope and it started in March 2014. This paper presents the first public data release of HSC-SSP. This release includes data taken in the first 1.7 years of observations (61.5 nights) and each of the Wide, Deep, and UltraDeep layers covers about 108, 26, and 4 square degrees down to depths of i~26.4, ~26.5, and ~27.0 mag, respectively (5sigma for point sources). All the layers are observed in five broad bands (grizy), and the Deep and UltraDeep layers are observed in narrow bands as well. We achieve an impressive image quality of 0.6 arcsec in the i-band in the Wide layer. We show that we achieve 1-2 per cent PSF photometry (rms) both internally and externally (against Pan-STARRS1), and ~10 mas and 40 mas internal and external astrometric accuracy, respectively. Both the calibrated images and catalogs are made available to the community through dedicated user interfaces and database servers. In addition to the pipeline products, we also provide value-added products such as photometric redshifts and a collection of public spectroscopic redshifts. Detailed descriptions of all the data can be found online.

The mergers of galaxy clusters are the most energetic events in the universe after the Big Bang. With the increased availability of multi-object spectroscopy and X-ray data an ever increasing fraction of local clusters are recognised as exhibiting signs of recent or past merging events on various scales. Our goal is to probe how these mergers affect the evolution and content of their member galaxies. We specifically aim to answer the following questions: Is the quenching of star formation in merging clusters enhanced when compared with relaxed clusters? Is the quenching preceded by a (short lived) burst of star formation? We obtained optical spectroscopy of >400 galaxies in the field of the merging cluster Abell 520. We combine these observations with archival data to get a comprehensive picture of the state of star formation in the members of this merging cluster. Finally, we compare these observations with a control sample of 10 non-merging clusters at the same redshift from The Arizona Cluster Redshift Survey (ACReS). We split the member galaxies in passive, star forming or recently quenched depending on their spectra. The core of the merger shows a decreased fraction of star forming galaxies compared to clusters in the non-merging sample. This region, dominated by passive galaxies, is extended along the axis of the merger. We find evidence of rapid quenching of the galaxies during the core passage with no signs of a star burst on the time scales of the merger (~0.4Gyr). Additionally, we report the tentative discovery of an infalling group along the main filament feeding the merger, currently at ~2.5 Mpc from the merger centre. This group contains a high fraction of star forming galaxies as well as ~2/3 of all the recently quenched galaxies in our survey.

Shells are low surface brightness tidal debris that appear as interleaved caustics with large opening angles, often situated on both sides of the galaxy center. In this paper, we study the incidence and formation processes of shell galaxies in the cosmological gravity+hydrodynamics Illustris simulation. We identify shells at redshift z=0 using stellar surface density maps, and we use stellar history catalogs to trace the birth, trajectory and progenitors of each individual star particle contributing to the tidal feature. Out of a sample of the 220 most massive galaxies in Illustris (M200crit > 6 × 1012 M⊙), 18%±3% of the galaxies exhibit shells. This fraction increases with increasing mass cut: higher mass galaxies are more likely to have stellar shells. Furthermore, the fraction of massive galaxies that exhibit shells decreases with increasing redshift. We find that shell galaxies observed at redshift z = 0 form preferentially through relatively major mergers ( 1:10 in stellar mass ratio). Progenitors are accreted on low angular momentum orbits, in a preferred time-window between ∼4 and 8 Gyrs ago. Our study indicates that, due to dynamical friction, more massive satellites are allowed to probe a wider range of impact parameters at accretion time, while small companions need almost purely radial infall trajectories in order to produce shells. We also find a number of special cases, as a consequence of the additional complexity introduced by the cosmological setting. These include galaxies with multiple shell- forming progenitors, satellite-of-satellites also forming shells, or satellites that fail to produce shells due to multiple major mergers happening in quick succession.

Aims: 1156 + 295 is a flat-spectrum quasar that is loud at both radio and γ-ray wavelengths. Previous observations of the source revealed a radio morphology on pc to kpc scales consistent with a helical jet model. We carried out VLBA observations at centimeter and millimeter wavelengths to study the structure of the innermost jet and understand the relation between the helical structure and astrophysical processes in the central engine. 
Methods: The source 1156 + 295 was observed with the VLBA at 86, 43, and 15 GHz at four epochs from 10 May 2003 to 13 March 2005. The observations were carried out in a full polarization mode. The highest resolution of the observations is 0.08 mas (~0.5 pc) at 86 GHz. 

Results: A core-jet structure with six jet components is identified in 1156 + 295. Three jet components are detected for the first time. The apparent transverse velocities of the six jet components derived from proper motion measurements range between 3.6 c and 11.6 c, suggesting that highly relativistic jet plasma moves in the direction close to the line of sight. The overall jet has an oscillating morphology with multiple curvatures on pc scales, which might be indicative of a helical pattern. Models of a helical jet are discussed in the context of both Kelvin-Helmholtz (K-H) instability and jet precession. The K-H instability model is in closer agreement with the observed data. 

Conclusions: The overall radio structure on scales from sub-pc to kpc appears to be fitted with a hydrodynamic model in the fundamental helical mode of Kelvin-Helmholtz (K-H) instability. This helical mode with an initial characteristic wavelength of λ₀ = 0.2 pc is excited at the base of the jet on the scale of 0.005 pc (or 10³R_s, the typical size of the broad line region of a supermassive black hole of 4.3 × 10⁸ M_⊙). A precessing jet model can also fit the observed jet structure on scales of between 10 pc and 300 pc. However, with the precessing jet model, additional astrophysical processes may be required to explain the bendings of the inner jet structure (1 to 10 pc) and re-collimation of the large-scale jet outflow (>300 pc).

The deep connection between galaxies and their supermassive black holes is central to modern astrophysics and cosmology. The observed correlation between galaxy and black hole mass is usually attributed to the contribution of major mergers to both. We make use of a sample of galaxies whose disk-dominated morphologies indicate a major-merger-free history and show that such systems are capable of growing supermassive black holes at rates similar to quasars. Comparing black hole masses to conservative upper limits on bulge masses, we show that the black holes in the sample are typically larger than expected if processes creating bulges are also the primary driver of black hole growth. The same relation between black hole and total stellar mass of the galaxy is found for the merger-free sample as for a sample which has experienced substantial mergers, indicating that major mergers do not play a significant role in controlling the coevolution of galaxies and black holes. We suggest that more fundamental processes which contribute to galaxy assembly are also responsible for black hole growth.

1) 연구원 실적 관리 시스템

    - 개인업적평가 저널 분류 기준 (이전 년도 논문 등급을 JCR 기준으로 분류)

    - 직원평가요령

    - 연구관리시스템 (실적 검색 관련 팁)

2) 한국천문학회 수상 : 젊은 천문학자상, 우수논문상, 샛별상, 우수포스터상

3) 한국우주과학회 수상 : 두진 우주과학자상, 신진 우주과학자상, SELab상

4) 한국천문연구원 논문상 : 학생논문상 (SCI 기준 주저자 1~1.5편, 40점 이상)

5) 학생 연구원으로서 개인 실적 관리

6) 연구원 실적 평가 시스템의 문제점 (정량 평가의 문제점)

• 장보고 남극기지로 가게 된 계기와 그곳에서 우주과학 연구대원으로 활동한 발표자의 생생한 1년 간의 기록과 남극 기지로의 여정, 현황 등을 소개한다. 남극기지에서 주로 이루어지고 있는 연구와 그를 보조해주는 지원이 어떤 식으로 진행되고 있는지 알 수 있는 기회다.

1. 
   
2. 한국은 총 두 개의 남극기지를 가지고 있으며 우주/대기/기상/해양/지구물리 등 다양한 연구에 대한 지원을 하고 있음.
3. 발표자는 우주과학 전공으로, 기지에서 수집한 중요한 연구목적 데이터를 관리하는 역할로 1년간 생활하였음.
4. 다양한 국적의 사람들이 다양한 목적을 가지고 생활하기 때문에 좋은 국제적 교류현장이 될 수 있음.
5. 계절에 따라 연구 환경이 변하게 되고, 상주대원 뿐만 아니라 방문대원에 의해 생활 환경이 바뀌고 연구 활동 일정이 분배됨.
6. 빙하시추를 통한 역사적 표본 수집이 이루어지고, 해양생물(펭귄이나 갈매기, 바다표범 등)의 생태계를 조사함. 지구 고층 대기에서 발생하는 현상을 통해 우주기상을 연구하고, 남극환경이기에 비교적 쉽게 발견할 수 있는 운석 표본을 확보할 수 있음.
7. 쉽게 접할 수 없는 남극에서의 생활에 대해 간접적으로 체험할 수 있는 좋은 기회를 제공하고 극지연구소에 대한 접근/지원방법에 대한 정보를 공유함.

• (미시)중력렌즈 현상에 대한 기본 메커니즘 설명
• 2체(항성+행성)에 의한 미시중력렌즈 현상의 기본 메커니즘 설명
• OB150724 미시중력렌즈 사례에 대한 관측 결과 및 기본적인 자료 처리 과정
• 미시중력렌즈 현상의 이해를 위한 모델링 과정 소개 / 모델링의 중요성
• OB150724 자료에 대한 초기 및 정밀 모델링 과정과 결과
• 시차 정보 추가와 그에 따른 추가 모델링 과정과 결과
• 향후 분석 계획

We use the first Gaia data release, combined with RAVE and APOGEE spectroscopic surveys, to investigate the origin of halo stars within <~3 kpc from the Sun. We identify halo stars kinematically, as moving with a relative speed of at least 220 km/s with respect to the local standard of rest. These stars are in general more metal-poor than the disk, but surprisingly, half of our halo sample is comprised of stars with [Fe/H]>-1. The orbital directions of these metal-rich halo stars are preferentially aligned with the disk rotation, in sharp contrast with the isotropic orbital distribution of the more metal-poor halo stars. We find similar properties in the Latte cosmological zoom-in simulation of a Milky Way-like galaxy from the FIRE project. In Latte, metal-rich halo stars formed primarily inside of the solar circle, while lower-metallicity halo stars preferentially formed at larger distances (extending beyond the virial radius). This suggests that metal-rich halo stars in the Solar neighborhood in fact formed in-situ within the Galactic disk rather than having been accreted from satellite systems. These stars, currently on halo-like orbits, therefore have likely undergone substantial radial migration/heating.

The dense environment of galaxy clusters strongly influences the nature of galaxies. Here, we study the cause of the size distribution of a sample of 560 spectroscopic members spanning a wide dynamical range down to 10^8.5 M_sol (log(M)-2) in the massive CLASH cluster MACSJ 1206.2-0847 at z~0.44. We use Subaru SuprimeCam imaging covering the highest-density core out to the infall regions (3 virial radii) to look for cluster-specific effects. We also compare our measurements to a compatible large field study in order to span extreme environmental densities. This paper presents the trends we identified for cluster galaxies divided by their colors into star-forming and quiescent galaxies and into distinct morphological types (using S\'ersic index and bulge/disk decompositions). We observed larger sizes for early type and smaller sizes for massive late type galaxies in clusters in comparison to the field. We attribute this to longer quenching timescales of more massive galaxies in the cluster. Our analysis further revealed an increasing importance of recently quenched transition objects ("red disks"). This is a virialized population found at higher cluster-centric radii with sizes similar to the quiescent, spheroid-dominated population of the cluster center, but with disks still in-tact. The mass-size relation of cluster galaxies may therefore be understood as the consequence of a mix of progenitors formed at different quenching epochs. We also find that galaxy sizes smoothly decreasing as a function of bulge fraction. At same bulge-to-total ratio and same stellar mass, quiescent galaxies are smaller than star-forming galaxies. This is likely because of a fading of the outskirts of the disk, which we saw in comparing sizes of their disk-components. Ram-pressure stripping of the cold gas and other forms of more gradual gas starvation are likely responsible for this observation.

We present the results from a multiepoch H2O maser survey toward low-mass young stellar objects using the Nobeyama 45 m telescope and the Very Large Array. Our Nobeyama survey is the first complete H2O maser survey toward known Class 0 sources in the northern sky (δ > -35°). During the series of the monitoring observations, we detected the maser emission toward none of the 31 pre-protostellar cores, 15 of 30 Class 0, two of 32 Class I, and zero of nine Class II sources. From this, we conclude that Class 0 sources are favorable sites to harbor the masers: the detection rates are derived to be 39.7% for Class 0, 4.0% for Class I, and 0.0% for Class II sources taking time variation into account. In addition, we found that the H2O maser luminosities in low-mass stars are more closely related to the luminosities of 100 AU scale radio jets rather than the mechanical luminosities of large-scale CO outflows. This fact suggests that the masers are associated with the shocked regions that are impacted by neutral protostellar jets emanating from the central stars. The drastic decrease of the maser detection rate in Class I sources is likely to be caused by the dissipation of dense gas around the central objects. We base this on the fact that the radio jets are found to have similar luminosities in Class 0 and Class I. It seems difficult even for active protostellar jets to excite masers in the remaining tenuous gas around Class I sources.

One puzzle in understanding how stars form in clusters is the source of mass -- is all of the mass in place before the first stars are born, or is there an extended period when the cluster accretes material which can continuously fuel the star formation process? We use a multi-line spectral survey of the southern filament associated with the Serpens South embedded cluster-forming region in order to determine if mass is accreting from the filament onto the cluster, and whether the accretion rate is significant. Our analysis suggests that material is flowing along the filament's long axis at a rate of ~30Msol/Myr (inferred from the N2H+ velocity gradient along the filament), and radially contracting onto the filament at ~130Msol/Myr (inferred from HNC self-absorption). These accretion rates are sufficient to supply mass to the central cluster at a similar rate to the current star formation rate in the cluster. Filamentary accretion flows may therefore be very important in the ongoing evolution of this cluster.

In the cold dark matter cosmology, the baryonic components of galaxies—stars and gas—are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo1. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius—a hallmark of the dark-matter model2. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks3, 4, 5, 6. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter7. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early (high-redshift) Universe efficiently condensed at the centres of dark-matter haloes when gas fractions were high and dark matter was less concentrated.

We present the results of a closure phase analysis of 3 mm very long baseline interferometry
measurements performed on Sagittarius A* (Sgr A*).We have analysed observations made in
2015 May using the Very Long Baseline Array, the Robert C. Byrd Green Bank Telescope and
the Large Millimeter Telescope Alfonso Serrano and obtained non-zero closure phase measurements
on several station triangles – indicative of a non-point-symmetric source structure.
The data are fitted with an asymmetric source structure model in Sgr A*, represented by a
simple two-component model, which favours a fainter component due east of the main source.
This result is discussed in light of a scattering screen with substructure or an intrinsically
asymmetric source.

This is a report on the status and prospects of the quantification of neutrino properties through the cosmological neutrino background for the Cosmic Frontier of the Division of Particles and Fields Community Summer Study long-term planning exercise. Experiments planned and underway are prepared to study the cosmological neutrino background in detail via its influence on distance-redshift relations and the growth of structure. The program for the next decade described in this document, including upcoming spectroscopic galaxy surveys eBOSS and DESI and a new Stage-IV CMB polarization experiment CMB-S4, will achieve sigma(sum m_nu) = 16 meV and sigma(N_eff) = 0.020. Such a mass measurement will produce a high significance detection of non-zero sum m_nu, whose lower bound derived from atmospheric and solar neutrino oscillation data is about 58 meV. If neutrinos have a minimal normal mass hierarchy, this measurement will definitively rule out the inverted neutrino mass hierarchy, shedding light on one of the most puzzling aspects of the Standard Model of particle physics --- the origin of mass. This precise a measurement of N_eff will allow for high sensitivity to any light and dark degrees of freedom produced in the big bang and a precision test of the standard cosmological model prediction that N_eff = 3.046.

When students answer an in-class conceptual question individually using ers, discuss it with their neighbors, and then revote on the same question, the percentage of correct answers typically increases. This outcome could result from gains in understanding during discussion, or simply from peer influence of knowledgeable students on their neighbors. To distinguish between these alternatives in an undergraduate genetics course, we followed the above exercise with a second, similar (isomorphic) question on the same concept that students answered individually. Our results indicate that peer discussion enhances understanding, even when none of the students in a discussion group originally knows the correct answer.

We explore the variability and cross-frequency correlation of the flux density and polarization of the blazar OJ287,
using imaging at 43 GHz with the Very Long Baseline Array, as well as optical and near-infrared (near-IR)
polarimetry. The polarization and flux density in both the optical waveband and the 43 GHz compact core increased
by a small amount in late 2005, and increased significantly along with the near-IR polarization and flux density over
the course of 10 days in early 2006. Furthermore, the values of the electric vector position angle (EVPA) at the three
wavebands are similar. At 43 GHz, the EVPA of the blazar core is perpendicular to the flow of the jet, while the
EVPAs of emerging superluminal knots are aligned parallel to the jet axis. The core polarization is that expected if
shear aligns the magnetic field at the boundary between flows of disparate velocities within the jet. Using variations
in flux density, percentage polarization, and EVPA, we model the inner jet as a spine-sheath system. The model jet
contains a turbulent spine of half-width 1. ? 2 and maximum Lorentz factor of 16.5, a turbulent sheath with Lorentz
factor of 5, and a boundary region of sheared field between the spine and sheath. Transverse shocks propagating along
the fast, turbulent spine can explain the superluminal knots. The observed flux density and polarization variations
are then compatible with changes in the direction of the inner jet caused by a temporary change in the position of
the core if the spine contains wiggles owing to an instability. In addition, we can explain a stable offset of optical
and near-IR percentage polarization by a steepening of spectral index with frequency, as supported by the data.

We investigate the properties of microlensing events caused by planetary systems where planets with a moon are widely separated from their host stars. From this investigation, we find that the moon feature generally appears as a very short-duration perturbation on the smooth asymmetric light curve of the lensing event induced by the wide-separation planet; thus it can be easily discriminated from the planet feature responsible for the overall asymmetric light curve. For typical Galactic lensing events with an Einstein radius of ∼2 au, the asymmetry of the light curves due to bound planets can be noticed up to ∼20 au. We also find that the perturbations of wide planetary systems become dominated by the moon as the projected star–planet separation increases, and eventually the light curves of events produced by such systems appear as the single lensing light curve of the planet itself with a very short-duration
perturbation induced by the moon, which is a representative light curve of the event induced by a star and a planet, except on the Einstein timescale of the planet. We also study the effect of a finite source star on the moon feature in wide planetary lensing events. From this study, we find that when the lunar caustic is sufficiently separated from the planetary caustic, the lower limit on the ratio of the size of the lunar caustic to the source radius causing a ~5% lunar deviation depends mostly on the projected planet–moon separation regardless of the moon/star mass ratio, and it decreases as the planet–moon separation becomes smaller or larger than the planetary Einstein radius

본 연구는자연재해에 대한 공중의 위험특성과 위험인식이 위험 심각성에 어떠한 영향을 미치는지를 규 명하고자 하였다. 연구결과는 다음과같다. 첫째, 자연재해 위험평가차원에서 일반 공중이 인식하는 자연재 해의 심각성을 분류한 결과, 지변재해, 풍수해, 한해로 분류되었고, 자연재해 중태풍을 가장 심각한 자연재 해로 인식하였다. 자연재해 대한위험특성은 ‘친근하지않은’, ‘과학에의해 알려지지 않은’, ‘발견할수 없는’ 등이 비교적높은 평균을 보여 자연재해를 미지의 위험영역으로 인식하는 경향이 강하였다. 둘째, 공중이 인식하는자연재해 위험특성과 위험인식 간의 상관관계를 살펴본 결과, 유의한상관이 있는 것으로 나타났 다. 셋째, 자연재해에 대한위험특성이 위험평가 차원의 심각성에 미치는 영향을 살펴본 결과, 위험특성은 위험평가 차원의 심각성에 정적 영향을 미쳤고, 자연재해중에서도 호우나 태풍, 홍수와같은 풍수해를 지 변재해나 한해보다심각한 것으로 인식하였다. 넷째, 공중의 자연재해에대한 위험인식이 위험평가 차원의 심각성에 미치는 영향을 살펴본 결과, 자연재해에대한 위험인식은 자연재해의 심각성에 정적 영향을 미쳤 고, 자연재해 심각성 중에서도 풍수해를 가장 심각하게 인식하는 것으로 나타났다.

We present a method to improve the radial velocity measurements accuracy by using telluric lines. In general, absorption cells which are a superimposed wavelength reference used to measure the radial velocity. Telluric lines can be also good a big absorption cell to estimate the wavelength scale shift over the detector of the spectrograph. Although these are in complementary relations, we expect that the measuring method with telluric lines have the advantages on future instruments. Therefore we show the precise radial velocity technique with telluric lines.

We study calendrical calculations of solar eclipse times in the Zhongxiu-Daming calendar of the Jin Dynasty (A.D. 1115 – 1234) in China. This calendar was made by Zhi-Wei Zhao in 1180 as an improvement (i.e., Zhongxiu in Chinese) to the Daming calendar, which was made in 1127 by Ji Yang of the same dynasty. It was used in China until 1281, when the Shoushi calendar was enforced in the Yuan Dynasty (A.D. 1279 – 1368). Meanwhile, since the reign of King Sejong (1418 – 1450) of the Joseon Dynasty (A.D. 1392 – 1910) in Korea, the Chiljeongsan-Naepyeon (i.e., Datong calendar) was used as the main calendar with the Zhongxiu-Daming and Chiljeongsan-Oepyeon (i.e., Huihui calendar) as supplementary calendars for calculating
astronomical events, particularly solar and lunar eclipses. For this reason, not only books on each calendar but also series of Jeongmyoyeon-Gyeosik-Garyeong (Example Supplement for the Calculations of Solar and Lunar Eclipses Occurred in 1447) for each calendar are preserved at the Kyujanggak Institute for Korean Studies. In this study, we develop a computer program for calculating solar eclipse times using the Zhongxiu-Daming calendar by referring to the Jeongmyoyeon-Gyeosik-Garyeong for that calendar. We also calculate the times at Seoul (the capital of the Joseon dynasty) using the astronomical algorithms of Meeus and the Bessellian elements extracted from a modern ephemeris. We compare first contact, greatest, and last contact times calculated using the Zhongxiu calendar with the results of modern calculations. We find that the difference in greatest time the smallest among the
three calendars at ~1.2 min but the differences in contact times were relatively large, with an average of ~33 min. In the future, we plan to verify the solar eclipse records listed in the Yuanshi (History of the Yuan Dynasty) and to investigate the accuracy of the Zhongxiu calendar for other periods.

We present a deep imaging survey of the Virgo Cluster, designed to study the connection between cluster galaxies and Virgo's diffuse intracluster light (ICL). Our observations span roughly 16 square degrees and reach a 3-sigma depth of mu(B)=29.5 and mu(V)=28.5 mag/arcsec^2. At these depths, the limiting systematic uncertainties are astrophysical: scattered starlight from foreground Galactic dust, and variations in faint background sources. The dust-scattered starlight is well-traced by deep far-infrared imaging, making it distinguishable from true Virgo diffuse light. Our imaging maps the Virgo core around M87 and the adjacent M86/M84 region, in subcluster B around M49, and in the more distant W' cloud around NGC 4365. Most of the detected ICL is found in the Virgo core and within the W' cloud, with little evidence for extensive ICL in subcluster B. The large amount of diffuse light seen in the infalling W' cloud likely illustrates the importance of the group environment for generating ICL. The bulk of the detected ICL is fairly red (B-V=0.7-0.9), indicative of old stellar populations. We estimate a total Virgo ICL fraction of 7-15%, somewhat smaller than expected for massive, evolved clusters, suggesting that Virgo is still growing its ICL component. We trace M87's extremely boxy halo out to ~ 150 kpc, and show that the current stripping rate of low luminosity galaxies is insufficient to have built M87's outer halo over a Hubble time. Finally, we identify another large ultra-diffuse galaxy in Virgo, likely in the process of being shredded by the cluster tidal field.

SN 2010jl was an extremely bright, Type IIn supernova (SN) which showed a significant infrared (IR) excess no later than 90 days after explosion. We have obtained Spitzer 3.6 and 4.5μm and JHK observations of SN 2010jl ∼90 days post-explosion. Little to no reddening in the host galaxy indicated that the circumstellar material lost from the progenitor must lie in a torus inclined out of the plane of the sky. The likely cause of the high mid-IR flux is the reprocessing of the initial flash of the SN by pre-existing circumstellar dust. Using a three-dimensional Monte Carlo radiative-transfer code, we have estimated that between 0.03 and 0.35 M of dust exists in a circumstellar torus around the SN located 6 × 1017 cm away from the SN and inclined between 60? and 80? to the plane of the sky. On day 90, we are only seeing the illumination of approximately 5% of this torus, and expect to see an elevated IR flux from this material up until day ∼ 450. It is likely this dust was created in a luminous blue variable (LBV) like mass-loss event of more than 3 M, which is large but consistent with other LBV progenitors such as η Carinae.

Galaxies are thought to grow through accretion; as less massive galaxies are disrupted and merge over time, their debris results in diffuse, clumpy stellar halos enveloping the central galaxy. Here we present a study of the variation in the stellar halos of galaxies, using data from the Dragonfly Nearby Galaxies Survey (DNGS). The survey consists of wide field, deep ({μ}g/gt 31 mag arcsec?2) optical imaging of nearby galaxies using the Dragonfly Telephoto Array. Our sample includes eight spiral galaxies with stellar masses similar to that of the Milky Way, inclinations of 16-19 degrees and distances between 7-18 Mpc. We construct stellar mass surface density profiles from the observed g-band surface brightness in combination with the g?r color as a function of radius, and compute the halo fractions from the excess stellar mass(relative to a disk+bulge fit) beyond 5 half-mass radii. We find a mean halo fraction of 0.009±0.005 and a large rms scatter of {1.01}-0.26+0.9 dex. The peak-to-peak scatter of the halo fraction is a factor of greater than 100—while some galaxies feature strongly structured halos resembling that of M31, three of the eight have halos that are completely undetected in our data. We conclude that spiral galaxies as a class exhibit a rich variety interstellar halo properties, implying that their assembly histories have been highly non-uniform. We find no convincing evidence for an environmental or stellar mass dependence of the halo fraction in the sample.

Super-Alfv&eae;nic shocks associated with coronal mass ejections (CMEs) can produce radio emission known as Type II bursts. In the absence of direct imaging, accurate estimates of coronal electron densities, magnetic field strengths, and Alfv&eae;n speeds are required to calculate the kinematics of shocks. To date, 1D radial models have been used, but these are not  ppropriate for shocks propagating in non-radial directions. Aims. Here, we study a coronal shock wave associated with a CME and Type II radio burst using 2D electron density and Alfv&eae;n speed maps to determine the locations that shocks are excited as the CME expands through the corona. Methods. Coronal density maps were obtained from emission measures derived from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) and polarized brightness measurements from the Large Angle and Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SOHO). Alfv&eae;n speed maps were calculated using these density maps and magnetic field extrapolations from the Helioseismic and Magnetic Imager (SDO/HMI). The computed density and Alfv&eae;n speed maps were then used to calculate the shock kinematics in non-radial directions. Results. Using the kinematics of the Type II burst and associated shock, we find our observations to be consistent with the formation of a shock located at the CME flanks where the Alfv&eae;n speed has a local minimum.
Conclusions. The 1D density models are not appropriate for shocks that propagate non-radially along the flanks of a CME. Rather, the 2D density, magnetic field and Alfv&eae;n speed maps described here give a more accurate method for determining the fundamental properties of shocks and their relation to CMEs.