Draft version April 23, 2018 A Preprint typeset using LTEX style emulateapj v. 5/2/11 THE TIP OF THE RED GIANT BRANCH DISTANCES TO TYPE IA SUPERNOVA HOST GALAXIES. III. NGC 4038/39 AND NGC 5584 In Sung Jang and Myung Gyoon Lee Astronomy Program, Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 151-742, Korea Draft version April 23, 2018 ABSTRACT We present the tip of the red giant branch (TRGB) distances to Type Ia supernova (SNe Ia) host galaxies NGC 4038/39 and NGC 5584. Based on the deep images constructed using archival Hubble Space Telescope data, we detect red giant branch stars in each galaxy. V I photometry of the resolved stars and corresponding I-band luminosity functions show the TRGB to be at ITRGB = 27.67 0.05 ± for NGC 4038/39 and ITRGB = 27.77 0.04 for NGC 5584. From these estimates, we determine ± the distance modulus to NGC 4038/39 to be (m M)0 = 31.67 0.05 (random) 0.12 (systematic) (corresponding to a linear distance of 21.58 0.50− 1.19 Mpc)± and the distance± modulus to NGC 5584 to be (m M) = 31.76 0.04(random)± 0.12± (systematic) (corresponding to a linear distance − 0 ± ± of 22.49 0.41 1.24 Mpc). We derive a mean absolute maximum magnitude of SNe Ia of MV = 19.27 ±0.08 from± the distance estimates of five SNe Ia (including two SNe in this study and three − ± SNe Ia from our previous studies), and we derive a value of MV = 19.19 0.10 using three low- reddened SNe Ia among the five SNe Ia. With these estimates, we− derive± a value of the Hubble −1 −1 constant, H0 = 69.8 2.6(random) 3.9 (systematic) km s Mpc and 72.2 3.3(random) 4.0 (systematic) km s−1 Mpc± −1, respectively.± The value from the five SNe is similar± to those from± the cosmic microwave background analysis, and not much different within errors, from those of recent Cepheid calibrations of SNe Ia. The value from the three SNe is between the values from the two methods. Subject headings: galaxies: distances and redshifts — galaxies: individual (NGC 4038/39, NGC 5584) — galaxies: stellar content — supernovae: general — supernovae: individual (SN 2007sr, SN 2007af) 1. INTRODUCTION ters from the analysis of the angular power spectrum Type Ia supernovae (SNe Ia) are one of the most pow- of CMBR in WMAP9 assuming a flat ΛCDM cosmol- ogy, and presented H = 69.32 0.80 km s−1 Mpc−1. erful distance indicators for distant galaxies in the cosmic 0 ± expansion dominated field (d & 100 Mpc). Three advan- Later, the Planck Collaboration lead to an even smaller value of the Hubble constant, H0 = 67.8 0.9 km tages of SNe Ia - a bright peak luminosity, a small lu- −1 −1 ± minosity dispersion, and a homogeneity in the universe s Mpc , using new CMBR data from the Planck - have enabled us to investigate the cosmic expansion satellite (Planck Collaboration et al. 2014, 2015). Thus the traditional distance ladder method and the CMBR rate (H0) (Freedman et al. 2001, 2012; Sandage et al. 2006; Riess et al. 2011) and the cosmic acceleration rate analysis based on ΛCDM cosmology show a 2–3σ level (Λ) (Riess et al. 1998; Perlmutter et al. 1999). Although of difference in the estimates of the Hubble constant great progress has been made over the last two decades, (Bennett et al. 2014). This is called ”the Hubble ten- more accurate calibration of peak luminosity of SNe Ia sion”, one of the most critical issues in modern cosmol- is needed to derive more accurate values of cosmological ogy. In addition, recent studies of the baryon acoustic parameters. oscillation (BAO) in the range of redshift combined with arXiv:1506.03089v1 [astro-ph.GA] 9 Jun 2015 SNe Ia data presented similar values to those from the Recently, two large projects, Supernovae and H0 for the Equation of State (SH0ES, (Riess et al. 2011)) CMBR analysis (Aubourg et al. 2014). and Carnegie Hubble Program (CHP, (Freedman et al. We have been working on the luminosity calibration 2012)), have been working on the calibration of SNe of SN Ia by measuring the precise distances to SN Ia Ia to improve the measurement of cosmological parame- host galaxies based on the Tip of the Red Giant Branch ters. They performed the luminosity calibration of SNe (TRGB) (Lee et al. 1993). The TRGB method uses old Ia based on the Cepheid distance estimates of 8 SNe Ia red giant branch (RGB) stars, classified as population host galaxies and derived similar values of the Hubble II. The metallicity dependence of I-band luminosities constant: 74.8 3.1 km s−1 Mpc−1(Riess et al. 2011) of TRGB stars is known to be small (Lee et al. 1993; − − Bellazzini et al. 2001; Rizzi et al. 2007; Madore et al. and 74.3 2.1 km± s 1 Mpc 1 (Freedman et al. 2012). 2009; Salaris & Cassisi 1997). Moreover, the TRGB However,± these values of the Hubble constant are method often uses RGB stars located in the halo, where somewhat larger than those based on recent analysis of the internal extinction is expected to be negligible and the cosmic microwave background radiation (CMBR). the crowing of stars is much less than the disk or the Bennett et al. (2013) derived the cosmological parame- bulge. Lee & Jang (2012) (Paper I) measured the TRGB distance to M101 hosting SN 2011fe, which is the near- [email protected], [email protected] est SN Ia with modern CCD photometry. Lee & Jang 2 Jang & Lee 48 (a) NGC 4038/39 (b) NGC 5584 50 20 52 22 54 (2000) (2000) δ 56 δ 24 SN 2007af -18o 58' SN 2007sr 26 00 o -19 02' -00o 28' 12h 02m 10s 01m 50s 30s 10s 14h 22m 40 s 30s 20s 10s α(2000) α(2000) Fig. 1.— Identification of HST fields for NGC 4038/39 (a) and NGC 5584 (b) overlaid on grey scale maps of the Digitized Sky Survey images. Only resolved stars in the hatched region of each field were used in the analysis. Locations of known SNe Ia are marked by open circles. (2013) (Paper II) determined the TRGB distances to Cepheid variables in the main bodies of NGC 4038/39 M66 and M96 in the Leo I Group, hosting SN 1989B and derived a distance modulus, (m M)0 = 31.66 0.08 and SN 1998bu. By combining the TRGB distance esti- (d = 21.5 0.6 Mpc). This is similar− to the value± in mates of three SNe Ia from Papers I and II, and optical Schweizer et± al. (2008), but much larger than the value light curves for three SNe Ia, we derived the Hubble con- given by Saviane et al. (2008). −1 ◦ stant, H0 = 68.4 2.6(random) 3.7(systematic) km s NGC 5584 is a moderately inclined (θ = 42.4 ) spi- Mpc−1 (Lee & Jang± 2013), which± is slightly smaller than ral galaxy hosting SN 2007af, which is one of the values from the Cepheid calibrated SNe Ia (Riess et al. most well monitored SNe Ia. Before its pre-maximum, 2011; Freedman et al. 2012). spectroscopic and photometric observations from opti- In this paper, we present the TRGB distances to two cal to near infrared have been made (Hamuy et al. 2006; additional SN Ia host galaxies, NGC 4038/39 hosting Hicken et al. 2009). Moreover the internal reddening for SN 2007sr and NGC 5584 hosting SN 2007af. NGC SN 2007af is known to be small, AV = 0.39 0.06 4038/39 are a well known pair of galaxies showing (Simon et al. 2007). Thus, SN 2007af is an ideal± tar- early stage merger of disk galaxies. In 2007, a super- get for the luminosity calibration of SNe Ia. Previ- nova was discovered near the southern tidal tail of this ous distance estimates based on the Tully-Fisher rela- galaxy, SN 2007sr (Drake et al. 2007). Spectroscopic tion show a wide range of values with large uncertainty: observations confirmed that it is a SN Ia (Naito et al. (m M)0 = 31.12 31.59 with uncertainties of 0.4 2007; Umbriaco et al. 2007). Photometric follow-up (Theureau− et al. 2007;∼ Springob et al. 2009; Sorce∼ et al. observations were made from optical to near-infrared 2012). Riess et al. (2011) detected 94 Cepheid variables (Schweizer et al. 2008; Hicken et al. 2009). Light curve based on the optical/near-infrared image data taken with fits on this SN suggested that its internal reddening is HST /WFC3, and derived a distance, (m M)0 = − expected to be small, AV 0.2 (Schweizer et al. 2008; 31.72 0.07 (d = 22.1 0.7 Mpc). This value is much Phillips et al. 2013). ∼ larger± than those based± on the Tully-Fisher relations. To There are three distance estimates to NGC 4038/39 date, there is no TRGB distance estimate for NGC 5584. based on the TRGB in the literature. Saviane et al. This paper is composed as follows. Section 2 describes (2004) analysed Hubble Space Telescope (HST )/Wide data reduction. Section 3 presents color-magnitude dia- Field Planetary Camera 2 (WFPC2) images of a field grams and distance estimates for each galaxy. Implica- on the southern tidal tail and derived a TRGB dis- tions of our results are discussed in Section 4. tance, (m M) = 30.70 0.25 (d = 13.8 1.7 Mpc).