간행물
천문학논총 KCI 등재 Publications of the Korean Astronomical Society
- 발행기관 한국천문학회
- 자료유형 학술지
- 간기 연3회
- ISSN 1225-1534 (Print)2287-6936 (Online)
- 수록기간 1984 ~ 2024
- 주제분류 자연과학 > 천문학 자연과학 분류의 다른 간행물
- 십진분류KDC 440DDC 520
권호리스트/논문검색
Volume 32 Issue 1 (2017년 3월) 77건
1.
2017.03
구독 인증기관 무료, 개인회원 유료
Some after-dinner thoughts on the giants of infrared space astronomy. I here describe important events in infrared astronomy starting from 1964 when I started working on my PhD. Here I describe how I became involved in IRAS, Infrared Space Observatrory (ISO), Herschel , Spitzer and AKARI, together with important events that led to these great missions.
3,000원
2.
2017.03
구독 인증기관 무료, 개인회원 유료
This paper provides an overview of the AKARI mission, which was the rst Japanese satellite dedicated to infrared astronomy. The AKARI satellite was launched in 2006, and performed both an all-sky survey and pointed observations during its 550 days in the He-cooled mission phases (Phases 1 and 2). After the He ran out, we continued near-infrared observations with mechanical cryocoolers (Phase 3). Due to a failure of its power supply, AKARI was turned o in 2011. The AKARI data are unique in terms of the observed wavelengths as well as the sky coverage, and provide a unique legacy resource for many astronomical studies. Since April 2013, a dedicated new team has been working to re ne the AKARI data processing. The goal of this activity is to provide processed datasets for most of the AKARI observations in a Science Ready form, so that more users can utilize the AKARI data in their astronomical research. The data to be released will include revised All-Sky Point Source Catalogues, All-Sky Image Maps, as well as high-sensitivity images and spectra obtained by pointed observations. We expect that the data will be made public by in the Spring of 2016.
4,000원
3.
2017.03
구독 인증기관 무료, 개인회원 유료
Yasuo Doi, Satoshi Takita, Takafumi Ootsubo, Ko Arimatsu, Masahiro Tanaka, Takahiro Morishima, Mitsunobu Kawada, Shuji Matsuura, Yoshimi Kitamura, Makoto Hattori, Mitsunobu Kawada, Shuji Matsuura, Yoshimi Kitamura, Makoto Hattori, Takao Nakagawa, Glenn White, Norio Ikeda
We present the AKARI far-infrared (FIR) all-sky maps and describe its characteristics, calibration accuracy and scienti c capabilities. The AKARI FIR survey has covered 97% of the whole sky in four photometric bands, which cover continuously 50{180 micron with band central wavelengths of 65, 90, 140, and 160 microns. The data have been publicly released in 2014 (Doi et al., 2015) with improved data quality that have been achieved since the last internal data release (Doi et al., 2012). The accuracy of the absolute intensity is 10% for the brighter regions. Quantitative analysis of the relative intensity accuracy and its dependence upon spatial scan numbers has been carried out. The data for the rst time reveal the whole sky distribution of interstellar matter with arcminute- scale spatial resolutions at the peak of dust continuum emission, enabling us to investigate large-scale distribution of interstellar medium in great detail. The lamentary structure covering the whole sky is well traced by the all-sky maps. We describe advantages of the AKARI FIR all-sky maps for the study of interstellar matter comparing to other observational data.
4,000원
4.
2017.03
구독 인증기관 무료, 개인회원 유료
The rst version of the AKARI far-infrared All-Sky Bright Source Catalogue (BSC ver.1) was released to public in March 2010. It has been widely used for various astrophysical researches. We are continuing efforts to produce the next edition. The new version is expected to be improved in accuracy and reliability, as well as its volume. Many improvements to the next version are in progress. The time-line signal is being re-examined throughout the entire data processing. Correction processes for signal linearity and detector responsivity, and procedure for masking signal anomaly are revised. The source extraction process is further tuned and operating parameters will be optimized. These bring better reliability of the source detection and possibly an increase of source numbers. The position accuracy is expected to be improved. Systematic position error seen around the Galactic plane will also be corrected. We also plan to deliver the Faint Source Catalogue version 1.
3,000원
5.
2017.03
구독 인증기관 무료, 개인회원 유료
Hidetoshi Sano, Tomoya Amatsutsu, Toru Kondo, Keichiro Nakamichi, Mitsuyoshi Yamagishi, Daisuke Ishihara, Shinki Oyabu, Hidehiro Kaneda, Kengo Tachihara, Yasuo Fukui
We present a comparative study of CO and polycyclic aromatic hydrocarbon (PAH) emission toward a region including the massive star-forming regions of NGC 6334 and NGC 6357. We use the NANTEN 12CO(J=1{0) data and the AKARI 9 m All-Sky diffuse map in order to evaluate the calibration accuracy of the AKARI data. We con rm that the overall CO distribution shows a good spatial correspondence with the PAH emission, and their intensities exhibit a good power-law correlation with a spatial resolution down to 4′ over the region of 10◦10◦. We also reveal poorer correlation for small scale structures between the two quantities toward NGC 6357, due to strong UV radiation from local sources. Larger scatter in the correlation toward NGC 6357 indicates higher ionization degree and/or PAH excitation than that of NGC 6334.
3,000원
6.
2017.03
구독 인증기관 무료, 개인회원 유료
Tomoya Amatsutsu, Daisuke Ishihara, Toru Kondo, Hidehiro Kaneda, Shinki Oyabu, Mitsuyoshi Yamagishi, Keichiro Nakamichi, Hidetoshi Sano, Takashi Onaka
We are creating all-sky diffuse maps from the AKARI mid-infrared survey data with the two photometric bands centered at wavelengths of 9 and 18 m. The AKARI mid-infrared diffuse maps achieve higher spatial resolution and higher sensitivity than the IRAS maps. In particular, the 9 m data are unique resources as an all-sky tracer of the emission of polycyclic aromatic hydrocarbons (PAHs). However, the original data suffer many artifacts. Thus, we have been developing correction methods. Among them, we have recently improved correction methods for the non-linearity and the reset anomaly of the detector response. These corrections successfully reduce the artifact level down to 0.1 MJy sr1 on average, which is essential for discussion on faint extended emission (e.g., the Galactic PAH emission). We have also made progress in the subtraction of the scattered light caused in the camera optics. We plan to release the improved diffuse maps to the public within a year.
3,000원
7.
2017.03
구독 인증기관 무료, 개인회원 유료
Keichiro Nakamichi, Daisuke Ishihara, Hidehiro Kaneda, Shinki Oyabu, Toru Kondo, Tomoya Amatsutsu, Hidetoshi Sano, Takashi Onaka
We plan to produce a faint source catalogue from the AKARI mid-infrared (IR) all-sky diffuse maps. In the publicly-available AKARI mid-IR point source catalogue (PSC), sources were extracted from single- scan images, and con rmed by using the other scan images. By stacking multiple scan images, we can detect fainter sources which are not listed in the PSC. We optimized the source extraction process using a 6◦ 6◦ area around the star-forming region, Cepheus B. Then, we divided the all-sky data into three seasonal images, and checked the positions and the uxes of the detected sources on the images. As a result, our new source extraction method works well; 90% of the sources are also identi ed in the WISE catalogue. In this method, we obtain the detection limit twice deeper than that of the PSC. The number of sources increases by a factor of 2, as compared with the PSC.
3,000원
8.
2017.03
구독 인증기관 무료, 개인회원 유료
We have been working on data processing and calibration of AKARI/IRC images from pointed observations. As of September 2014, a data package for each pointing only contains raw data and quick- look data, so that users have to process them using the toolkit by themselves. We plan to change this situation and to provide science-ready data sets, which are easy-to-use for non-AKARI experts. For Phase 1&2, we have updated dark and at calibrations, and also the toolkit itself to produce images more reliable and easier to use. A new data package includes fully calibrated images with WCS information. We released it for about 4000 pointings at the end of March 2015.
3,000원
9.
2017.03
구독 인증기관 무료, 개인회원 유료
We present the rst results of a new data analysis pipeline for processing extragalactic AKARI/IRC images. The main improvements of the pipeline over the standard analysis are the removal of Earth shine and image distortion correction. We present the di erential number counts of the AKARI/IRC S11 lter in the IRAC validation eld. The di erential number counts are consistent with S11 AKARI NEP deep and 12 m WISE NEP number counts, and with a phenomenological backward evolution galaxy model, at brighter uxes densities. There is a detection of fainter galaxies in the IRAC validation eld.
3,000원
10.
2017.03
구독 인증기관 무료, 개인회원 유료
AKARI performed about 10,000 spectroscopic observations with the Infrared Camera (IRC) during its mission phase. These IRC observations provide unique spectroscopic data at near- and mid-infrared wavelengths for studies of the next few decades because of its high sensitivity and unique wavelength coverage. In this paper, we present the current status of the activity for improving the IRC spectroscopic data reduction process, including the toolkit and related data packages, and also discuss the goal of this project.
3,000원
11.
2017.03
구독 인증기관 무료, 개인회원 유료
Shunsuke Baba, Takao Nakagawa, Naoki Isobe, Mai Shirahata, Youichi Ohyama, Kenichi Yano, Chihiro Kochi
The Infrared Camera onboard the AKARI satellite carried out spectroscopic observations with a grism mode named NG, whose wavelength coverage was 2.5{5.0 m. We reinvestigate the current ux calibration for the NG grism mode, with which calculated ux density implausibly decreases at 4.9 m especially for red objects due to the second-order light contamination. We perform a new spectral response calibration using blue and red standard objects simultaneously. New response curves which contain both the rst- and second-order light are able to separate each contribution consistently and useful for studies of red objects such as CO ro-vibrational absorption in active galactic nuclei.
3,000원
12.
2017.03
구독 인증기관 무료, 개인회원 유료
The point sources in the Bright Source Catalogue of the AKARI Far-Infrared Surveyor (FIS) were classi ed based on their FIR and mid-IR uxes and colours into young stellar object (YSO) and ex- tragalactic source types using a Quadratic Discriminant Analysis method (QDA) and Support Vector Machines (SVM). The reliability of the selection of YSO candidates is high, and the number of known YSO candidates were increased signi cantly, that we demonstrate in the case of the nearby open cluster IC348. Our results show that we can separate galactic and extragalactic AKARI point sources in the multidimensioal space of FIR uxes and colours with high reliability, however, di erentiating among the extragalactic sub-types needs further information.
4,000원
13.
2017.03
구독 인증기관 무료, 개인회원 유료
Presently, the number of known asteroids is more than 710,000. Knowledge of size and albedo is essential in many aspects of asteroid research, such as the chemical composition and mineralogy, the size-frequency distribution of dynamical families, and the relationship between small bodies in the outer solar system or comets. Recently, based on the infrared all-sky survey data obtained by IRAS, AKARI, and WISE, the large asteroid catalogs containing size and albedo data have been constructed. In this paper, we discuss the compositional distribution in the main belt regions based on the compiled data on size, albedo, and separately obtained taxonomic type information.
3,000원
14.
2017.03
구독 인증기관 무료, 개인회원 유료
Toru Kondo, Daisuke Ishihara, Hidehiro Kaneda, Shinki Oyabu, Tomoya Amatsutsu, Keichiro Nakamichi, Hidetoshi Sano, Takafumi Ootsubo, Takashi Onaka
The AKARI 9 and 18 m di use maps reveal the all-sky distribution of the interstellar medium with relatively high spatial resolution of 600. The zodiacal light is a dominant foreground component in the mid-infrared. Thus, removal of the zodiacal light is a critical issue to study low surface brightness Galactic di use emission. We carried out modeling of the zodiacal light based on the Kelsall model which is constructed from the COBE data. In the previous study, only a time-varying component of the zodiacal light brightness was used for determination of the model parameters. However, there remains a residual component of the zodiacal light around the ecliptic plane even after removal with the model. Therefore, instead of using a time-varying component, we use the absolute brightness of the zodiacal light and we nd that the new model can better remove the residual component. As a result, the best-fit model parameters are changed from those in the previous study. We discuss the properties of the zodiacal light based on our new result.
3,000원
15.
2017.03
구독 인증기관 무료, 개인회원 유료
Takafumi Ootsubo, Yasuo Doi, Satoshi Takita, Shuji Matsuura, Mitsunobu Kawada, Takao Nakagawa, Ko Arimatsu, Masahiro Tanaka, Toru Kondo, Daisuke Ishihara, Fumihiko Usui, Makoto Hattori
The zodiacal light emission is the thermal emission from the interplanetary dust and the dominant di use radiation in the mid- to far-infrared wavelength region. Even in the far-infrared, the contribution of the zodiacal emission is not negligible at the region near the ecliptic plane. The AKARI far-infrared all-sky survey covered 97% of the whole sky in four photometric bands with band central wavelengths of 65, 90, 140, and 160 m. AKARI detected the small-scale structure of the zodiacal dust cloud, such as the asteroidal dust bands and the circumsolar ring, in far-infrared wavelength region. Although the most part of the zodiacal light structure in the AKARI far-infrared all-sky image can be well reproduced with the DIRBE zodiacal light model, there are discrepancies in the small-scale structures. In particular, the intensity and the ecliptic latitude of the peak position of the asteroidal dust bands cannot be repro- duced precisely with the DIRBE models. The AKARI observational data during more than one year has advantages over the 10-month DIRBE data in modeling the full-sky zodiacal dust cloud. The resulting small-scale zodiacal light structure template has been used to subtract the zodiacal light from the AKARI all-sky maps.
3,000원
16.
2017.03
구독 인증기관 무료, 개인회원 유료
Daisuke Ishihara, Nami Takeuchi, Toru Kondo, Hiroshi Kobayashi, Hidehiro Kaneda, Shu-ichiro Inutsuka, Shinki Oyabu, Takahiro Nagayama, Hideaki Fujiwara, Takashi Onaka
Debris disks are circumstellar dust disks around main-sequence stars. They are important observational clues to understanding the planetary system formation. The zodiacal light is the thermal emission from the dust disk in our Solar system. For a comprehensive understanding of the nature and the evolution of dust disks around main-sequence stars, we try a comparative study of debris disks and the zodiacal light. We search for debris disks using the AKARI mid-infrared all-sky point source catalog. By applying accurate ux estimate of the photospheric emission based on the follow-up near-infrared observations with IRSF, we have improved the detection rate of debris disks. For a detailed study of the structure and grain properties in the zodiacal dust cloud, as an example of dust disks around main-sequence stars, we analyze the AKARI mid-infrared all-sky diffuse maps. As a result of the debris disks search, we found old (>1 Gyr) debris disks which have large excess emission compared to their age, which cannot be explained simply by the conventional steady-state evolution model. From the zodiacal light analysis, we nd the possibility that the dust grains trapped in the Earth's resonance orbits have increased by a factor of 3 in the past 20 years. Combining these results, we discuss the non-steady processes in debris disks and the zodiacal light.
4,000원
17.
2017.03
구독 인증기관 무료, 개인회원 유료
Nami Takeuchi, Daisuke Ishihara, Hidehiro Kaneda, Shinki Oyabu, Hiroshi Kobayashi, Takahiro Nagayama, Takashi Onaka, Hideaki Fujiwara
Debris disks are important observational clues to understanding on-going planetary system formation. They are usually identi ed by signi cant mid-infrared excess on top of the photospheric emission of a central star on the basis of prediction from J-, H-, and Ks-band uxes and the stellar model spectra. For bright stars, 2MASS near-infrared uxes suffer large uncertainties due to the near-infrared camera satu- ration. Therefore we have performed follow-up observations with the IRSF 1.4 m near-infrared telescope located in South Africa to obtain accurate J-, H-, and Ks-band uxes of the central stars. Among 754 main-sequence stars which are detected in the AKARI 18 m band, we have performed photometry for 325 stars with IRSF. As a result, we have successfully improved the ux accuracy of the central stars from 9.2 % to 0.5 % on average. Using this dataset, we have detected 18 m excess emission from 57 stars in our samples with a 3 level. We nd that some of them have high ratios of the excess to the photospheric emission even around very old stars, which cannot be explained by the current planet-formation theories.
3,000원
18.
2017.03
구독 인증기관 무료, 개인회원 유료
Takashi Onaka, Tamami I. Mori, Ryou Ohsawa, Itsuki Sakon, Aaron C. Bell, Mark Hammonds, Takashi Shimonishi, Daisuke Ishihara, Hidehiro Kaneda, Yoko Okada, Masahiro Tanaka
A wide spectral coverage from near-infrared (NIR) to far-infrared (FIR) of AKARI both for imaging and spectroscopy enables us to eciently study the emission from gas and dust in the interstellar medium (ISM). In particular, the Infrared Camera (IRC) onboard AKARI o ers a unique opportunity to carry out sensitive spectroscopy in the NIR (2{5 m) for the rst time from a spaceborn telescope. This spectral range contains a number of important dust bands and gas lines, such as the aromatic and aliphatic emission bands at 3.3 and 3.4{3.5 m, H2O and CO2 ices at 3.0 and 4.3 m, CO, H2, and HI gas emission lines. In this paper we concentrate on the aromatic and aliphatic emission and ice absorption features. The balance between dust supply and destruction suggests signi cant dust processing taking place as well as dust formation in the ISM. Detailed analysis of the aromatic and aliphatic bands of AKARI observations for a number of Hii regions and Hii region-like objects suggests processing of carbonaceous dust in the ISM. The ice formation process can also be studied with IRC NIR spectroscopy eciently. In this review, dust processing in the ISM divulged by recent analysis of AKARI data is discussed.
4,000원
19.
2017.03
구독 인증기관 무료, 개인회원 유료
We conducted an unbiased near- to mid-infrared imaging and spectroscopic survey of the Large Magellanic Cloud (LMC) as a part of the AKARI Mission Program \Large-area Survey of the LMC" (LSLMC, PI: T. Onaka). An area of about 10 square degrees of the LMC was observed by ve photometric bands (3.2, 7, 11, 15, and 24 m) and a low-resolution slitless prism (2 { 5 m, R 20) equipped with AKARI/IRC. We constructed and publicly released photometric and spectroscopic catalogues of point sources in the LMC based on the survey data. The catalogues provide a large number of near-infrared spectral data, coupled with complementary broadband photometric data. Combined use of the present AKARI LSLMC catalogues with other infrared point source catalogues of the LMC possesses scienti c potential that can be applied to various astronomical studies.
3,000원
20.
2017.03
구독 인증기관 무료, 개인회원 유료
Polycyclic aromatic hydrocarbons (PAHs) are considered to be carriers of the unidentified infrared bands, which are ubiquitously observed in the Universe. PAHs are mainly formed around evolved carbon-rich stars and injected into interstellar space. Planetary nebulae (PNe), a late stage of low- and intermediate stellar mass evolution, are suitable objects to investigate the formation and evolution of PAHs. The shortest PAH feature is located in 3.3 μm, which is important to examine the excitation and size distribution of PAHs. While the number of samples had been limited before, the high sensitivity of AKARI/IRC has drastically increased the number of samples. We obtained the 2-5 μm spectra of Galactic PNe with AKARI/IRC and compiled a near-infrared spectral catalog, containing 73 PNe. We investigate the detection rate and the evolution of the PAH features. The characteristics of the catalog are illustrated and the origin of the evolution of the PAH features is discussed.
4,000원
