적색거성가지 최대밝기를 이용한 제1a형 초신성 모은하까지의 거리측정 그리고 허블상수

학위논문(박사)--서울대학교 대학원 :자연과학대학 물리·천문학부,2016. 8. 이명균.Measuring the value of the Hubble constant is a fundamental step in extragalactic astronomy and cosmology. A tremendous work to determine the value of the Hubble constant has been carried out over the past decades. However, the estimated values have been controversial until recently. Type Ia Supernovae (SNe Ia) are one of the most powerful indicators for distant galaxies in the cosmic expansion dominated field (d ≳ 100 Mpc). The value of the Hubble constant can be obtained from the absolute calibration of SNe Ia. Previous absolute calibrations of SNe Ia were carried out using Cepheids, a population I distance indicator. However, recent values of H0 show a significant discrepancy with the values from the Cosmic Microwave Background Radiation (CMBR) analysis. It is called "the Hubble tension", being an issue in the modern cosmology. The Tip of the Red Giant Branch (TRGB) is a precise and population II distance indicator for resolved stellar systems. It has several advantages over the Cepheids. An absolute calibration of SNe Ia with the TRGB will be useful for more accurate calibration of SNe Ia and the Hubble constant. We present the results of an absolute calibration of SNe Ia based on the TRGB. In order to derive an accurate calibration of SNe Ia, we refine the TRGB calibration. A modified TRGB calibration corrected for the color (metallicity) dependence of the TRGB, the QT magnitude, is introduced for better detection of the TRGB. We determine the color-magnitude relation of the TRGB from photometry of deep images of HST/ACS fields around eight nearby galaxies. The zero-point of the TRGB at the fiducial metallicity ([Fe/H] = -1.6, (V-I)0,TRGB = 1.5)) is obtained from photometry of two distance anchors, NGC 4258 (M106) and the LMC, to which precise geometric distances are known: MI,TRGB = -4.121 ± 0.067 mag from NGC 4258 and MI,TRGB = -4.033 ± 0:063 mag from the LMC. A weighted mean of the two zero-points is MI,TRGB = -4.074 ± 0.046 mag. The quoted uncertainty is 2 ~ 3 times smaller than those of the previous calibrations. With the revised TRGB calibration, we determine the distances to eight SN Ia host galaxies: M101 hosting SN 2011fe, M66 hosting SN 1989B, M96 hosting SN 1998bu, NGC 4038/39 hosting SN 2007sr, NGC 5584 hosting SN 2007af, NGC 3021 hosting SN 1995al, NGC 3370 hosting SN 1994ae, and NGC 1309 hosting SN 2002fk. Luminosity functions of red giant stars in the outer regions of these galaxies show the TRGB to range from I ~ QT = 25.083 ± 0.034 (M101) to 28.398 ± 0.048 (NGC 1309) mag. The TRGB distances to these galaxies are estimated to range from (m-M)0 = 29.168 ± 0.034 (M101) to 32.475 ± 0.048 (NGC 1309). By combining the TRGB distance estimates to SN Ia host galaxies derived from this study with the SN Ia calibration provided by Riess et al. (2011), we obtain a value of the Hubble constant: H0 = 71.15 ± 1.80(random) ± 1.51(systematic) km/s/Mpc (a 3.3% uncertainty including systematics) from all eight SNe, and H0 = 72.95 ± 2.03(random) ± 1.55(systematic) km/s/Mpc (a 3.5% uncertainty including systematics) from six low-reddened SNe. We obtain our best estimate, H0 = 70.45 ± 1.67(random) ± 1.65(systematic) km/s/Mpc (a 3.2% uncertainty including systematics), from the combination of the absolute magnitude of six lowreddened SNe with the recent SN Ia calibration given by Riess et al. (2016). This value is between those from Cepheid calibrated SNe Ia and those from CMB analysis.Chapter 1 INTRODUCTION 1 1.1 Introduction 1 1.1.1 Determining Cosmological Parameters and the Hubble constant 1 1.1.2 SNe Ia as a Cosmological Probe 4 1.1.3 Luminosity calibration of SNe Ia through Cepheids 9 1.1.4 The TRGB as a Distance Indicator 11 1.1.5 Purpose of This Thesis 14 Chapter 2 The Distance to M101 Hosting SN Ia 2011fe Based on the TRGB 17 2.1 Introduction 17 2.2 Data Reduction 18 2.3 Results 20 2.3.1 Color-magnitude Diagrams of Resolved Stars 20 2.3.2 Distance Estimation 22 2.4 Discussion 24 2.4.1 Comparison with Previous Distance Estimates 24 2.4.2 The Absolute Calibration of SNe Ia and the Hubble Constant 28 2.5 Summary 30 Chapter 3 The TRGB Distances to SN Ia Host Galaxies. II. M66 and M 96 in the Leo I Group 33 3.1 Introduction 33 3.2 Data Reduction 36 3.3 Results 38 3.3.1 Photometry of Resolved Stars 38 3.3.2 TRGB Distance Measurement 38 3.4 Discussion 40 3.4.1 Comparison with Previous Distance Estimates 40 3.4.2 The Membership of the Leo I Group 46 3.4.3 The Calibration of the Absolute Magnitudes of SNe Ia and the Hubble Constant 47 3.5 Summary 51 Chapter 4 The TRGB Distances to SN Ia Host Galaxies. III. NGC 4038/39 and NGC 5584 53 4.1 Introduction 53 4.2 Data and Data Reduction 56 4.2.1 Photometric Transformations 60 4.2.2 Arti cial star test 66 4.3 Results 68 4.3.1 Color-magnitude Diagrams 68 4.3.2 Distance Estimation 70 4.4 Discussion 74 4.4.1 Comparison with Previous Distance Estimates 74 4.4.2 The Calibration of SNe Ia and the Hubble Constant 77 4.5 Summary 81 Chapter 5 The TRGB Distances to SN Ia Host Galaxies. IV. Color Dependence and Zero-Point Calibration 83 5.1 Introduction 83 5.2 Color Dependence Calibration 87 5.2.1 Target Selection and Data Reduction 87 5.2.2 CMDs of Resolved Stars and the TRGB detection 90 5.2.3 Color Transformation between F555W-F814W and F606W-F814W 92 5.2.4 Deriving Color - Magnitude relation 95 5.3 Zero-point Calibration 99 5.3.1 NGC 4258 as a Distance Anchor 99 5.3.2 The Large Magellanic Cloud as a Distance Anchor 104 5.4 Summary of the Revised TRGB Calibration 110 5.5 Discussion 113 5.5.1 Comparison with Previous TRGB Calibrations 113 5.5.2 Comparison with Stellar Isochrones 119 5.5.3 Implications on the Distance Scale and the Hubble Constant 121 5.6 Summary and Conclusion 122 Chapter 6 The TRGB Distances to SN Ia Host Galaxies. V. NGC 3021, NGC 3370 and NGC 1309 125 6.1 Introduction 125 6.2 Data and Data Reduction 128 6.3 Results 130 6.3.1 CMDs of Resolved Stars 130 6.3.2 Distance Estimation 133 6.4 Discussion 135 6.4.1 Updating the TRGB Distances in Our Previous Studies 135 6.4.2 Comparison with the SH0ES Project 140 6.4.3 A Distance Discrepancy for NGC 4038/39 143 6.4.4 The Calibration of SNe Ia and the Hubble Constant 145 6.5 Summary 151 Chapter 7 Summary and Conclusion 153 BIBLIOGRAPHY 159 초록 173Docto