A5057915992- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- History and Developments in Astronomy
- Scientific Research and Discoveries
- Radio Astronomy Observations and Technology
- Impact of Light on Environment and Health
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Spectroscopy and Laser Applications
- Remote Sensing in Agriculture
- Planetary Science and Exploration
- Particle Accelerators and Free-Electron Lasers
- Atmospheric Ozone and Climate
- Pulsars and Gravitational Waves Research
- Cosmology and Gravitation Theories
- Pharmacogenetics and Drug Metabolism
- Material Science and Thermodynamics
Jacobs (United Kingdom)
2025
Seoul National University
2015-2024
SINTEF
2024
Astronomy and Space
2022
Netherlands Institute for Radio Astronomy
2010
Northern Netherlands Provinces alliance
2001-2008
Korea Astronomy and Space Science Institute
2008
Sejong University
2008
Korea Institute for Advanced Study
2008
Association of Universities For Research In Astronomy
1998-2007
This paper describes the Seventh Data Release of Sloan Digital Sky Survey (SDSS), marking completion original goals SDSS and end phase known as SDSS-II. It includes 11,663 deg2 imaging data, with most ∼2000 increment over previous data release lying in regions low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. survey also repeat on a 120° long, 25 wide stripe along celestial equator Southern Cap, some covered by many 90 individual runs. We...
We present the fifth edition of Sloan Digital Sky Survey (SDSS) Quasar Catalog, which is based upon SDSS Seventh Data Release. The catalog, contains 105,783 spectroscopically confirmed quasars, represents conclusion SDSS-I and SDSS-II quasar survey. catalog consists objects that have luminosities larger than M_i = -22.0 (in a cosmology with H_0 70 km/s/Mpc Omega_M 0.3, Omega_Lambda 0.7) at least one emission line FWHM 1000 km/s or interesting/complex absorption features, are fainter i > 15.0...
view Abstract Citations (617) References (39) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Tip of the Red Giant Branch as a Distance Indicator for Resolved Galaxies Lee, Myung Gyoon ; Freedman, Wendy L. Madore, Barry F. We show that I magnitude tip first-ascent red giant branch (TRGB) low-mass stars is distance indicator resolved galaxies with metal-poor ([Fe/H] < -0.7 dex) old populations, having precision comparable to primary indicators such...
view Abstract Citations (578) References (50) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Hubble Space Telescope Extragalactic Distance Scale Key Project. I. Discovery of Cepheids and a New to M81 Freedman, Wendy L. ; Hughes, Shaun M. Madore, Barry F. Mould, Jeremy R. Lee, Myung Gyoon Stetson, Peter Kennicutt, Robert C. Turner, Anne Ferrarese, Laura Ford, Holland Graham, John A. Hill, Hoessel, G. Huchra, Illingworth, Garth D. We report on the...
We present a new and independent determination of the local value Hubble constant based on calibration Tip Red Giant Branch (TRGB) applied to Type Ia supernovae (SNeIa). find Ho = 69.8 +/- 0.8 (+/-1.1\% stat) 1.7 (+/-2.4\% sys) km/sec/Mpc. The TRGB method is both precise accurate, parallel to, but Cepheid distance scale. Our sits midway in range defined by current tension. It agrees at 1.2-sigma level with that Planck 2018 estimate, 1.7-sigma SHoES measurement distances have been measured...
Abstract The tip of the red giant branch (TRGB) method provides one most accurate and precise means measuring distances to nearby galaxies. Here we present a multi-wavelength, VIJHK absolute calibration TRGB based on observations stars in Large Magellanic Cloud (LMC), grounded geometric distance, determined by detached eclipsing binaries (DEBs). This paper presents more detailed description first presented Freedman et al. for corrections total line-of-sight extinction reddening LMC. In this...
We present a dynamical analysis of the globular cluster system associated with M87 (=NGC 4486), cD galaxy near center Virgo Cluster. The utilizes new spectroscopic and photometric database, which is described in companion paper. Using sample 278 clusters measured radial velocities metallicities surface density profiles based on wide-field Washington photometry, we study dynamics both globally (for entire sample) separately metal-rich metal-poor samples). This constitutes largest for pure...
view Abstract Citations (208) References (53) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Infrared extinction and polarization due to partially aligned spheroidal grains : models for the dust toward BN object. Lee, H. M. ; Draine, B. T. Methods computing aligned, precessing in dipole aproximation regime are described. The methods employed develop theoretical of on line sight Becklin-Neugebauer (BN) object dense molecular cloud OMC-1. In models, it is...
We study the dust properties of galaxies in redshift range 0.1<z<2.8 observed by Herschel Space Observatory field Great Observatories Origins Deep Survey-North as part PEP and HerMES key programmes. Infrared (IR) luminosity (L_IR) temperature (T_dust) are derived from spectral energy distribution (SED) fit far-infrared (FIR) flux densities obtained with PACS SPIRE instruments onboard Herschel. As a reference sample, we also obtain IR luminosities temperatures local at z<0.1 using AKARI IRAS...
We present an overview of the Carnegie-Chicago Hubble Program, ongoing program to obtain a 3 per cent measurement constant using alternative methods traditional Cepheid distance scale. aim establish completely independent route RR Lyrae variables, tip red giant branch (TRGB), and Type Ia supernovae (SNe Ia). This ladder can be applied galaxies any Type, inclination, and, utilizing old stars in low density environments, is robust degenerate effects metallicity interstellar extinction. Given...
We present integrated Washington CT_1_ photometry of the globular cluster system NGC 4472 (M49), brightest galaxy in Virgo cluster. The is deep, reaching beyond T_1_~R ~25 and allows us to investigate metallicities at an unprecedented level. first examine age, horizontal branch morphology metallicity sensitivities (C-T_1_,) color reconfirm its utility as efficient metal abundance index. As for other broadband colors, index much more sensitive than age old clusters (~> 10 Gyr), but (C - T_1_)...
We present the Chandra Multiwavelength Project (ChaMP) X-ray point source catalog with ~6800 sources detected in 149 observations covering ~10 deg2. The full ChaMP sample is 7 times larger than initial published catalog. exposure time of fields our ranges from 0.9 to 124 ks, corresponding a deepest flux limit f0.5-8.0 = 9 × 10-16 ergs cm-2 s-1. data have been uniformly reduced and analyzed ChaMP-specific pipelines then carefully validated by visual inspection. includes photometric eight...
AKARI (formerly ASTRO-F) is an infrared space telescope designed for all-sky survey at 10-180 (mu)m, and deep pointed surveys of selected areas 2-180 (mu)m. The with will significantly advance our understanding galaxy evolution, the structure formation Universe, nature buried AGNs, cosmic background. Here we describe important characteristics mission: orbit, attitude control system, investigate optimum area based on updated pre-flight sensitivities AKARI, taking into account cirrus confusion...
We present the Chandra Multiwavelength Project (ChaMP) X-ray point source number counts and cosmic background (CXRB) flux densities in multiple energy bands. From ChaMP catalog, ~5500 sources are selected, covering 9.6 deg2 sky area. To quantitatively characterize sensitivity completeness of sample, we perform extensive simulations. also include ChaMP+CDFs (Chandra Deep Fields) to cover large ranges from 2 × 10-17 2.4 10-12 (0.5-2 keV) 10-16 7.1 (2-8 ergs cm-2 s-1. The differential well...
Abstract We present final results of a program for the determination Hubble constant based on calibration Type Ia supernovae (SNe Ia) using Tip Red Giant Branch (TRGB). report TRGB distances to three SN host galaxies, NGC 3021, 3370, and 1309. obtain F555W F814W photometry resolved stars from archival Space Telescope data. Luminosity functions red giant in outer regions these galaxies show be at ≈ QT = 28.2 ∼ 28.5 mag. From magnitudes revised two distance anchors (NGC 4258 LMC) Jang &...
We present the rest-frame optical spectral properties of 155 luminous quasars at 3.3<z<6.4 taken with AKARI space telescope, including first detection H$\alpha$ emission line as far out z~6. extend scaling relation between continuum and luminosity active galactic nuclei (AGNs) to high luminosity, redshift regime that has rarely been probed before. Remarkably, we find a single log-linear can be applied 5100${\rm \AA}$ AGN luminosities over wide range (10$^{42}$<$L_{5100}$<10$^{47}$ergs/s) or...
Dust-obscured star-formation becomes much more important with increasing intensity, and redshift. We aim to reveal cosmic history obscured by dust using deep infrared observation the AKARI. construct restframe 8um, 12um, total (TIR) luminosity functions (LFs) at 0.15<z<2.2 4128 sources in AKARI NEP-Deep field. A continuous filter coverage mid-IR wavelength (2.4, 3.2, 4.1, 7, 9, 11, 15, 18, 24um) satellite allows us estimate 8um 12um luminosities without a large extrapolation based on SED...
We investigate the dependence of occurrence bars in galaxies on galaxy properties and environment. use a volume-limited sample 33,391 brighter than Mr = −19.5 + 5logh at 0.02 ⩽ z 0.05489, drawn from Sloan Digital Sky Survey Data Release 7. classify into early late types, identify by visual inspection. Among 10,674 late-type with axis ratio b/a > 0.60, we find 3240 barred (fbar 30.4%) which divide 2542 strong (fSB1 23.8%) 698 weak (fSB2 6.5%). that fSB1 increases as u − r color becomes redder...
Globular clusters are found usually in galaxies and they an excellent tracer of dark matter. Long ago it was suggested that there may exist intracluster globular (IGCs) bound to a galaxy cluster rather than any single galaxy. Here we present map showing the large scale distribution over entire Virgo cluster. It shows IGCs out 5 million light years from center, concentrated several substructures much larger galaxies. These objects might have been mostly stripped off low-mass dwarf
We present a revised TRGB calibration, accurate to 2.7% of distance. A modified magnitude corrected for the color dependence TRGB, QT magnitude, is introduced better measurement TRGB. determine color-magnitude relation from photometry deep images HST/ACS fields around eight nearby galaxies. The zero-point at fiducial metallicity ([Fe/H]=-1.6 ((V-I)_{0,TRGB}=1.5)) obtained two distance anchors, NGC 4258 (M106) and LMC, which precise geometric distances are known: M_{QT,TRGB}=-4.023+-0.073 mag...
An Observational Model is a conceptual framework, with quantitative elements, for the behaviour of ground and groundwater system, within which calculations performance assessments may be made. It built up by observations from variety sources, including literature existing information through desk study, an intrusive investigation, in situ laboratory tests, monitoring data. There particular emphasis on topology, stratigraphy, boundary conditions flow properties hydraulic conductivity (Darcy...
We present a systematic study of the low-mass X-ray binary (LMXB) populations six elliptical galaxies, aimed at investigating detected LMXB-globular cluster (GC) connection. utilize Chandra archival data to identify point sources and HST supplemented by ground observations 6173 GCs. After screening cross-matching, we associate 209 LMXBs with red GC (RGCs) 76 blue GCs (BGCs), while find no optical counterpart for 258 LMXBs. This is largest GC-LMXB sample studied so far. confirm previous...
We present the star formation history and chemical evolution of Sextans dSph dwarf galaxy as a function galactocentric distance.We derive these from V I photometry stars in 42 ′ × 28 field using SMART model developed by Yuk & Lee (2007, ApJ, 668, 876) adopting closed-box for evolution.For adopted age 15 Gyr, we find that >84% formed prior to 11 Gyr ago, significant extends ago (∼ 65% 13 while ∼ 25% ago), detectable continued at least 8 is more extended central regions than outskirts,...
We study the environmental dependence of local luminous infrared galaxies (LIRGs) and ultraluminous (ULIRGs) found in Sloan Digital Sky Survey (SDSS) data. The LIRG ULIRG samples are constructed by cross-correlating spectroscopic catalogs SDSS Data Release 7 Infrared Astronomical Satellite Faint Source Catalog. examine effects large-scale background density (Sigma_5), galaxy clusters, nearest neighbor on properties (IRGs). find that fraction LIRGs plus ULIRGs among IRGs (f_(U)LIRGs)...
We have performed two-dimensional multicomponent decomposition of 144 local barred spiral galaxies using 3.6 $\mu {\rm m}$ images from the Spitzer Survey Stellar Structure in Galaxies. Our model fit includes up to four components (bulge, disk, bar, and a point source) and, most importantly, takes into account disk breaks. find that ignoring break single scale length for Type II (down-bending) can lead differences 40% length, 10% bulge-to-total luminosity ratio (B/T), 25% bar-to-total ratios....