ﻻ يوجد ملخص باللغة العربية
We present final results of a program for the determination of the Hubble constant based on the calibration of the Type Ia supernovae (SNe Ia) using the Tip of the Red Giant Branch (TRGB). We report TRGB distances to three SN Ia host galaxies, NGC 3021, NGC 3370, and NGC 1309. We obtain F555W and F814W photometry of resolved stars from the archival Hubble Space Telescope data. Luminosity functions of red giant stars in the outer regions of these galaxies show the TRGB to be at I ~ QT = 28.2 ~ 28.5 mag. From these TRGB magnitudes and the revised TRGB calibration based on two distance anchors (NGC 4258 and the LMC) in Jang&Lee 2017, we derive the distances: (m-M)0 = 32.178 +- 0.033 for NGC 3021, 32.253 +- 0.041 for NGC 3370, and 32.471 +- 0.040 for NGC 1309. We update our previous results on the TRGB distances to five SN Ia host galaxies using the revised TRGB calibration. By combining the TRGB distance estimates to SN Ia host galaxies in this study with the SN Ia calibration provided by Riess et al. 2011, we obtain a value of the Hubble constant: H0 = 71.66 +- 1.80 (random) +- 1.88 (systematic) km/s/Mpc (a 3.6% uncertainty including systematics) from all eight SNe, and H0 = 73.72 +- 2.03 +- 1.94 km/s/Mpc (a 3.8% uncertainty) from six low-reddened SNe. We present our best estimate, H0 = 71.17 +- 1.66 +- 1.87 km/s/Mpc (a 3.5% uncertainty) from six low-reddened SNe with the recent SN Ia calibration in Riess et al. 2016. This value is between those from the Cepheid calibrated SNe Ia and those from the Cosmic Microwave Background (CMB) analysis, lowering the Hubble tension.
The Carnegie-Chicago Hubble Program (CCHP) is undertaking a re-calibration of the extragalactic distance scale, using Type Ia supernovae that are tied to Tip of the Red Giant Branch (TRGB) distances to local galaxies. We present here deep Hubble Spac
The Carnegie-Chicago Hubble Program (CCHP) is re-calibrating the extragalactic SN Ia distance scale using exclusively Population II stars. This effort focuses on the Tip of the Red Giant Branch (TRGB) method, whose systematics are entirely independen
The primary goal of the Carnegie Chicago Hubble Program (CCHP) is to calibrate the zero-point of the Type Ia supernova (SN Ia) Hubble Diagram through the use of Population II standard candles. So far, the CCHP has measured direct distances to 11 SNe
We have used WFPC2 VRI observations to calculate the distances to three nearby galaxies, NGC 4214, UGC 685, and UGC 5456 using the tip of the red giant branch method. Our values for NGC 4214 (2.94 +/- 0.18 Mpc) and UGC 685 (4.79 +/- 0.30 Mpc) are the
We present year-long, near-infrared Hubble Space Telescope WFC3 observations used to search for Mira variables in NGC 1559, the host galaxy of the Type Ia supernova (SN Ia) 2005df. This is the first dedicated search for Miras, highly-evolved low-mass