ABSTRACT We present a revised Tip of the Red Giant Branch (TRGB) calibration, accurate to 2.7% of distance. A modified TRGB magnitude corrected for its color dependence, the QT magnitude, is ...introduced for better measurement 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 ( )) is obtained from photometry of two distance anchors, NGC 4258 (M106) and the Large Magellanic Cloud (LMC), to which precise geometric distances are known: MQT,TRGB = −4.023 0.073 mag from NGC 4258 and MQT,TRGB = −4.004 0.096 mag from the LMC. A weighted mean of the two zero-points is MQT,TRGB = −4.016 0.058 mag. Quoted uncertainty is ∼2× smaller than those of previous calibrations. We compare the empirical TRGB calibration derived in this study with theoretical stellar models, finding that there are significant discrepancies, especially for red color ( ). We provide the revised TRGB calibration in several magnitude systems for future studies.
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 F814W 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; Paper IV), 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−1 Mpc−1 (a 3.6% uncertainty including systematics) from all eight SNe, and H0 = 73.72 2.03 1.94 km s−1 Mpc−1 (a 3.8% uncertainty) from six low-reddened SNe. We present our best estimate, H0 = 71.17 1.66 1.87 km s−1 Mpc−1 (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 analysis, lowering the Hubble tension.
The tip of the red giant branch (TRGB) method provides one of the most accurate and precise means of measuring the distances to nearby galaxies. Here we present a multi-wavelength, VIJHK absolute ...calibration of the TRGB based on observations of TRGB stars in the Large Magellanic Cloud (LMC), grounded on a geometric distance, determined by detached eclipsing binaries (DEBs). This paper presents a more detailed description of the method first presented by Freedman et al. for measuring corrections for the total line-of-sight extinction and reddening to the LMC. In this method, we use a differential comparison of the red giant population in the LMC, first with red giants in the Local Group galaxy IC 1613, and then with those in the Small Magellanic Cloud (SMC). As a consistency check, we derive an independent calibration of the TRGB sequence using the SMC alone, invoking its geometric distance also calibrated by DEBs. An additional consistency check comes from near-infrared observations of Galactic globular clusters covering a wide range of metallicities. In all cases we find excellent agreement in the zero-point calibration. We then examine the recent claims by Yuan et al., demonstrating that, in the case of the SMC, they corrected for extinction alone while neglecting the essential correction for reddening. In the case of IC 1613, we show that their analysis contains an incorrect treatment of (over-correction for) metallicity. Using our revised (and direct) measurement of the LMC TRGB extinction, we find a value of H0 = 69.6 0.8 ( 1.1% stat) 1.7 ( 2.4% sys) km s−1 Mpc−1.
Abstract
We present a new and independent determination of the local value of the Hubble constant based on a calibration of the tip of the red giant branch (TRGB) applied to Type Ia supernovae ...(SNe Ia). We find a value of
H
0
= 69.8 ± 0.8 (±1.1% stat) ± 1.7 (±2.4% sys) km s
−1
Mpc
−1
. The TRGB method is both precise and accurate and is parallel to but independent of the Cepheid distance scale. Our value sits midway in the range defined by the current Hubble tension. It agrees at the 1.2
σ
level with that of the Planck Collaboration et al. estimate and at the 1.7
σ
level with the
Hubble Space Telescope
(
HST
)
SHoES
measurement of
H
0
based on the Cepheid distance scale. The TRGB distances have been measured using deep
HST
Advanced Camera for Surveys imaging of galaxy halos. The zero-point of the TRGB calibration is set with a distance modulus to the Large Magellanic Cloud of 18.477 ± 0.004 (stat) ± 0.020 (sys) mag, based on measurement of 20 late-type detached eclipsing binary stars, combined with an
HST
parallax calibration of a 3.6
μ
m Cepheid Leavitt law based on
Spitzer
observations. We anchor the TRGB distances to galaxies that extend our measurement into the Hubble flow using the recently completed Carnegie Supernova Project I ( CSP-I ) sample containing about 100 well-observed SNe Ia . There are several advantages of halo TRGB distance measurements relative to Cepheid variables; these include low halo reddening, minimal effects of crowding or blending of the photometry, only a shallow (calibrated) sensitivity to metallicity in the
I
band, and no need for multiple epochs of observations or concerns of different slopes with period. In addition, the host masses of our TRGB host-galaxy sample are higher, on average, than those of the Cepheid sample, better matching the range of host-galaxy masses in the CSP-I distant sample and reducing potential systematic effects in the SNe Ia measurements.
We present the detection of a large population of ultradiffuse galaxies (UDGs) in two massive galaxy clusters, Abell S1063 at z = 0.348 and Abell 2744 at z = 0.308, based on F814W and F105W images in ...the Hubble Frontier Fields Program. We find 47 and 40 UDGs in Abell S1063 and Abell 2744, respectively. Color-magnitude diagrams of the UDGs show that they are mostly located at the faint end of the red sequence. From the comparison with simple stellar population models, we estimate their stellar mass to range from 108 to 109 M . Radial number density profiles of the UDGs show a turnover or a flattening in the central region at r < 100 kpc. We estimate the total masses of the UDGs using the galaxy scaling relations. A majority of the UDGs have total masses M200 = 1010-1011 M , and only a few of them have total masses M200 = 1011-1012 M . The total number of UDGs within the virial radius is estimated to be N(UDG) = 770 114 for Abell S1063 and N(UDG) = 814 122 for Abell 2744. Combining these results with data in the literature, we fit the relation between the total numbers of UDGs and the masses of their host systems for M200 > 1013 M with a power law, N(UDG) = . These results suggest that a majority of the UDGs have a dwarf galaxy origin, while only a small number of the UDGs are massive L* galaxies that failed to form a normal population of stars.
An independent determination of H0 is crucial given the growing tension between the Hubble constant, H0, derived locally and that determined from the modeling of the cosmic microwave background (CMB) ...originating in the early universe. In this work, we present a new determination of H0 using velocities and tip of the red giant branch (TRGB) distances to 33 galaxies located between the Local Group and the Virgo cluster. We use a model of the infall pattern of the local Hubble flow modified by the Virgo mass, which is given as a function of the cosmological constants (H0, Λ), the radius of the zero-velocity surface R0, and the intrinsic velocity dispersion, v. Fitting velocities and TRGB distances of 33 galaxies to the model, we obtain H0 = 65.8 3.5 (stat) 2.4 (sys) km s−1 Mpc−1 and R0 = 6.76 0.35 Mpc. Our local H0 is consistent with the global H0 determined from CMB radiation, showing no tension. In addition, we present new TRGB distances to NGC 4437 and NGC 4592, which are located near the zero-velocity surface: D = 9.28 0.39 Mpc and D = 9.07 0.27 Mpc, respectively. Their spatial separation is 0.29 Mpc, suggesting that they form a physical pair.
NGC 4589, a bright E2 merger-remnant galaxy, hosts the peculiar fast and faint calcium-rich SN Ib SN 2005cz. The progenitor of Ca-rich SNe Ib has been controversial: it could be (1) a young, massive ...star with 6-12 M in a binary system, or (2) an old, low-mass star in a binary system that was kicked out from the galaxy center. Moreover, previous distance estimates for this galaxy have shown a large spread, ranging from 20 to 60 Mpc. Thus, using archival Hubble Space Telescope/ACS F435W, F555W, and F814W images, we search for star clusters in NGC 4589 in order to help resolve these issues. We find a small population of young star clusters with 25 < V ≤ 27 (−7.1 < MV ≤ −5.1) mag and age <1 Gyr in the central region at R < 0 5 (<3.8 kpc), thus supporting the massive-star progenitor scenario for SN 2005cz. In addition to young star clusters, we also find a large population of old globular clusters. In contrast to previous results in the literature, we find that the color distribution of the globular clusters is clearly bimodal. The turnover (Vega) magnitude in the V-band luminosity functions of the blue (metal-poor) globular clusters is determined to be V0(max) = 24.40 0.10 mag. We derive the total number of globular clusters, NGC = 640 50, and the specific frequency, SN = 1.7 0.2. Adopting a calibration for the metal-poor globular clusters, MV(max) = −7.66 0.14 mag, we derive a distance to this galaxy: (m − M)0 = 32.06 0.10(ran) 0.15(sys) (d = 25.8 2.2 Mpc).
NGC 4993 hosts a binary neutron star merger, GW170817/GRB 170817A, emitting gravitational waves and electromagnetic waves. The distance to this galaxy is not well established. We select the globular ...cluster candidates from the Hubble Space Telescope (HST)/ACS F606W images of NGC 4993 in the archive, using the structural parameters of the detected sources. The radial number density distribution of these candidates shows a significant central concentration around the galaxy center at the galactocentric distance r < 50″, showing that they are mostly the members of NGC 4993. Also, the luminosity function of these candidates is fit well by a Gaussian function. Therefore, the selected candidates at r < 50″ are mostly considered to be globular clusters in NGC 4993. We derive an extinction-corrected turnover Vega magnitude in the luminosity function of the globular clusters at 20″ < r < 50″, F606W (max)0 = 25.36 0.08 (V0 = 25.52 0.11) mag. Adopting the calibration of the turnover magnitudes of the globular clusters, MV(max) = −7.58 0.11, we derive a distance to NGC 4993, d = 41.65 3.00 Mpc ( ). The systematic error of this method can be as large as 0.3 mag. This value is consistent with the previous distance estimates based on the fundamental plane relation and the gravitational wave method in the literature. The distance in this study can be used to constrain the values of the parameters including the inclination angle of the binary system in the models of gravitational wave analysis.
Abstract
NGC 4839 is the brightest galaxy (cD) of the NGC 4839 group at
R
≈ 1 Mpc in the southwest of the Coma cluster, which is known to be falling into Coma. However, it has been controversial ...whether it is in the first phase of infall or in the second phase of infall after passing the Coma center. We present a wide field study of globular clusters (GCs) in NGC 4839 and its environment based on Hyper Suprime-Cam
gr
images in the Subaru archive. We compare the GC system of NGC 4839 with that of NGC 4816, which is the brightest member (S0) of the nearby group and lies at a similar distance in the west from the Coma center. Interestingly the spatial distribution of the GCs in NGC 4839 is significantly more compact than that of the GCs in NGC 4816. In addition, the radial number density profile of the GCs in NGC 4839 shows an abrupt drop at
R
N4839
≈ 80 kpc, while that of the GCs in NGC 4816 shows a continuous slow decline even in the outer region at 80 <
R
N4816
< 500 kpc. The effective radius of the NGC 4839 GC system is about 3 times smaller than that of the NGC 4816 GC system. This striking difference can be explained if NGC 4839 lost a significant fraction of the GCs in its outskirt when it passed through Coma. This supports strongly the second-infall scenario where the NGC 4839 passed the Coma center about 1.6 Gyr ago, and began the second infall after reaching the apocenter in the southwest recently.
We investigate the dependence of the occurrence of bars in galaxies on galaxy properties and environment. We use a volume-limited sample of 33,391 galaxies brighter than M sub(r) = -19.5 + 5logh at ...0.02 < or =, slant z < or =, slant 0.05489, drawn from the Sloan Digital Sky Survey Data Release 7. We classify the galaxies into early and late types, and identify bars by visual inspection. Among 10,674 late-type galaxies with axis ratio b/a > 0.60, we find 3240 barred galaxies (functionof sub(bar) = 30.4%) which divide into 2542 strong bars (functionof sub(SB1) = 23.8%) and 698 weak bars (functionof sub(SB2) = 6.5%). We find that functionof sub(SB1) increases as u - r color becomes redder and that it has a maximum value at intermediate velocity dispersion (sigma Asymptotically = to150 km s super(-1)). This trend suggests that strong bars are dominantly hosted by intermediate-mass systems. Weak bars prefer bluer galaxies with lower mass and lower concentration. In the case of strong bars, their dependence on the concentration index appears only for massive galaxies with sigma > 150 km s super(-1). We also find that functionof sub(bar) does not directly depend on the large-scale background density when other physical parameters (u - r color or sigma) are fixed. We discover that functionof sub(SB1) decreases as the separation to the nearest neighbor galaxy becomes smaller than 0.1 times the virial radius of the neighbor regardless of neighbor's morphology. These results imply that strong bars are likely to be destroyed during strong tidal interactions and that the mechanism for this phenomenon is gravitational and not hydrodynamical. The fraction of weak bars has no correlation with environmental parameters. We do not find any direct evidence for environmental stimulation of bar formation.
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