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 27 Issue 4 (2012년 9월) 71건
61.
2012.09
구독 인증기관·개인회원 무료
We present the first measurement of the angular two-point correlation function for AKARI 90μm point sources, detected outside of the Milky Way plane and selected as candidates for extragalactic sources. This is the first measurement of the large-scale angular clustering of galaxies selected in the far-infrared after IRAS. We find a positive clustering signal in both hemispheres extending up to ~ 40 degrees, without any significant fluctuations at larger scales. The observed correlation function is well fitted by a power law function. However, southern galaxies seem to be more strongly clustered than northern ones and the difference is statistically significant. The reason for this difference - technical or physical - is still to be found.
62.
2012.09
구독 인증기관·개인회원 무료
Starting from an infrared selected GALEX-SDSS-2MASS-AKARI sample of local star forming galaxies, we built mock samples from redshift 0 to 2.5 to investigate star formation rate (SFR) calibrations using WISE luminosities. We find W3 and W4 band fluxes can indicate SFRs with small scatters when the rest-frame wavelengths are longer than ∼6μm . When the wavelength becomes shorter, the observed luminosities are more tightly connected to the emission of old stellar populations than dust, therefore lose the reliability to trace the SFR. The current SFR calibrations are consistent with previous studies.
63.
2012.09
구독 인증기관 무료, 개인회원 유료
Understanding infrared (IR) luminosity is fundamental to understanding the cosmic star formation history and AGN evolution, since their most intense stages are often obscured by dust. Japanese infrared satellite, AKARI, provided unique data sets to probe this both at low and high redshifts. The AKARI performed an all sky survey in 6 IR bands (9, 18, 65, 90, 140, and 160μm ) with 3-10 times better sensitivity than IRAS, covering the crucial far-IR wavelengths across the peak of the dust emission. Combined with a better spatial resolution, AKARI can measure the total infrared luminosity ( LTIR) of individual galaxies much more precisely, and thus, the total infrared luminosity density of the local Universe. In the AKARI NEP deep field, we construct restframe 8μm, 12μm , and total infrared (TIR) luminosity functions (LFs) at 0.15 < z < 2.2 using 4,128 infrared sources. A continuous filter coverage in the mid-IR wavelength (2.4, 3.2, 4.1, 7, 9, 11, 15, 18, and 24μm ) by the AKARI satellite allows us to estimate restframe 8μm and 12μm luminosities without using a large extrapolation based on a SED fit, which was the largest uncertainty in previous work. By combining these two results, we reveal dust-hidden cosmic star formation history and AGN evolution from z = 0 to z = 2.2, all probed by the AKARI satellite.
4,000원
64.
2012.09
구독 인증기관 무료, 개인회원 유료
We present new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of the data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue ( ∼0.44μm) and red (∼0.64μm ) bands. Accurate starlight subtraction was achieved by referring to all-sky star catalogs and a Galactic stellar population synthesis model down to 32.0 mag. We find that the residual light is separated into two components: one component shows a clear correlation with the thermal 100μm brightness, whilst the other shows a constant level in the lowest 100μm brightness region. The presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, thus it most likely has an extragalactic origin (i.e., the COB). The derived COB brightness is ((1.8±0.9)×10−9 and (1.2±0.9)×10−9ergs−1cm−2sr−1 \AA−1 in the blue and red spectral regions, respectively, or 7.9±4.0 and 7.7±5.8nWm−2sr−1 . Based on a comparison with the integrated brightness of galaxies, we conclude that the bulk of the COB is comprised of normal galaxies which have already been resolved by the current deepest observations. There seems to be little room for contributions from other populations including "first stars" at these wavelengths. On the other hand, the first component of the IPP residual light represents the diffuse Galactic light (DGL)-scattered starlight by the interstellar dust. We derive the mean DGL-to- 100μm brightness ratios of 2.1×10−3 and 4.6×10−3 at the two bands, which are roughly consistent with previous observations toward denser dust regions. Extended red emission in the diffuse interstellar medium is also confirmed.
3,000원
65.
2012.09
구독 인증기관 무료, 개인회원 유료
CHRIS SEDGWICK, STEPHEN SERJEANT, CHRIS PEARSON, TOSHINOBU TAKAGI, HIDEO MATSUHARA, TAKEHIKO WADA, HYUNG MOK LEE, MYUNGSHIN IM, WOONG-SEOB JEONG, SHINKI OYABU, GLENN J. WHITE
This paper presents Hα emission line detections for four galaxies at z > 3.5 made with AKARI as part of the FUHYU mission program. These are the highest-redshift Hα detections to date in star-forming galaxies. AKARI's unique near-infrared spectroscopic capability has made these detections possible. For two of these galaxies, this represents the first evidence of their redshifts and confirms their physical association with a companion radio galaxy. The star formation rates (SFRs) estimated from the Hα lines under-predict the SFRs estimated from their far-infrared luminosities by a factor of ~ 2 - 3. We have also detected broad Hα components in the two radio galaxies which indicate the presence of quasars.
3,000원
66.
2012.09
구독 인증기관·개인회원 무료
We summarize the progress on the rest-frame optical spectroscopy of quasars at 3 2.5−5μm . This spectral window has been utilized for detecting redshifted Hα emission lines of our high redshift subsample of quasars. From the calculated emission line widths and luminosities we measured supermassive black hole masses using well calibrated optical mass estimators. Science topics regarding optical based black hole masses at high-z are discussed.
67.
2012.09
구독 인증기관 무료, 개인회원 유료
T. MATSUMOTO, H. J. SEO, W. -S. JEONG, H. M. LEE, S. MATSUURA, H. MATSUHARA, S. OYABU, J. PYO, T. WADA
We report a search for fluctuations of the sky brightness toward the North Ecliptic Pole with AKARI, at 2.4, 3.2, and 4.1 μm . The stacked images with a diameter of 10 arcminutes of the AKARI-Monitor Field show a spatial structure on the scale of a few hundred arcseconds. A power spectrum analysis shows that there is a significant excess fluctuation at angular scales larger than 100 arcseconds that cannot be explained by zodiacal light, diffuse Galactic light, shot noise of faint galaxies, or clustering of low-redshift galaxies. These findings indicate that the detected fluctuation could be attributed to the first stars of the universe, i.e., Population III stars.
3,000원
68.
2012.09
구독 인증기관 무료, 개인회원 유료
The first all-sky mid-/far-infrared survey by IRAS in the 1980s, has been followed by only two more, by AKARI, from 2006, and WISE in 2010. I discuss some features of the WISE survey, and highlight some key results from early extragalactic observations that have been made by the science team during the operation of the telescope, and the post-operation proprietary period during which the public release data products were being generated. The efficient survey strategy and very high-data rate from WISE produced a catalogue of 530 million objects that was released to the public in March 2012. The WISE survey strategy naturally provided the deepest coverage at the ecliptic poles, where matched comparison fields were obtained using Spitzer, and where AKARI also observed deep fields. I describe some of the follow-up work that has been carried out based on the WISE survey, and the prospects for enhancing the WISE data by combining the AKARI survey results are also discussed. While the all-sky AKARI survey is less deep than the WISE catalogue, and is still being worked on by the AKARI science team, it includes a larger number of bands, extends to longer wavelengths, and in particular has very complementary band passes to WISE in the mid-infrared waveband, which will provide enhanced spectral information for relatively bright targets.
4,000원
69.
2012.09
구독 인증기관 무료, 개인회원 유료
CHRIS PEARSON, STEPHEN SERJEANT, CHRIS SEDGWICK, GLENN J. WHITE, HIDEO MATSUHARA, TOSHINOBU TAKAGI, OI NAGISA, KAZUMI MURATA, TAKAO NAKAGAWA, ISSEI YAMAMURA
The Herschel Space Observatory is the European Space Agency's state of the art infrared space telescope launched into space on 14 May 2009, covering the wavelength range from 70-700 microns with 3 instruments SPIRE, PACS and HIFI. Large area surveys are being carried out by Herschel in the AKARI legacy fields at the North and South Ecliptic Poles and the AKARI All-Sky Survey provides additional synergy with the largest survey with Herschel, H-ATLAS, covering more than 500 square degrees. This paper reports on some of the early results of these synergies between Herschel and AKARI including the first comparison of the AKARI All-Sky Survey number counts with the deeper Herschel surveys.
4,000원
70.
2012.09
구독 인증기관·개인회원 무료
InfraRed Survey Facility (IRSF) is our facility for near-infrared (NIR) observation located at South African Astronomical Observatory. The NIR camera SIRIUS on the 1.4m telescope provides three 7.7′×7.7′ images in the J ( 1.25μm), H (1.63μm), and KS (2.14μm ) bands simultaneously with a pixel scale of 0.45". IRSF has three unique capabilities, which are suitable for follow-up observations of AKARI-selected objects. Several synergistic studies with AKARI are in progress from stars to galaxies. We introduce advantages of the above unique capabilities of IRSF for further synergistic studies between AKARI and IRSF.
71.
2012.09
구독 인증기관 무료, 개인회원 유료
This report presents a summary of the Legacy of AKARI: A Panoramic View of the Dusty Universe meeting held between 27-29th February 2012 at Jeju Island, South Korea.
4,000원
