The Astrophysical Distance Scale. V. A 2% Distance to the Local Group Spiral M33 via the JAGB Method, Tip of the Red Giant Branch, and Leavitt Law

Abstract

The J-region asymptotic giant branch (JAGB) method is a new standard candle that is based on the stable intrinsic J-band magnitude of color-selected carbon stars, and has a precision comparable to other primary distance indicators such as Cepheids and the TRGB. We further test the accuracy of the JAGB method in the Local Group galaxy M33. M33's moderate inclination, low metallicity, and nearby proximity make it an ideal laboratory for tests of systematics in local distance indicators. Using high-precision optical BVI and near-infrared JHK photometry, we explore the application of three independent distance indicators: the JAGB method, the Cepheid Leavitt law, and the TRGB. We find: μ 0(TRGB I ) = 24.72 ± 0.02 (stat) ± 0.07 (sys) mag, μ 0(TRGBNIR) = 24.72 ± 0.04 (stat) ± 0.10 (sys) mag, μ 0(JAGB) = 24.67 ± 0.03 (stat) ± 0.04 (sys) mag, and μ 0(Cepheid) = 24.71 ± 0.04 (stat) ± 0.01 (sys) mag. For the first time, we also directly compare a JAGB distance using ground-based and space-based photometry. We measure μ 0(JAGBF110W) = 24.71 ± 0.06 (stat) ± 0.05 (sys) mag using the (F814W−F110W) color combination to effectively isolate the JAGB stars. In this paper, we measure a distance to M33 accurate to 2% and provide further evidence that the JAGB method is a powerful extragalactic distance indicator that can effectively probe a local measurement of the Hubble constant using spaced-based observations. We expect to measure the Hubble constant via the JAGB method in the near future, using observations from the James Webb Space Telescope.

A 1.3% Distance to M33 from Hubble Space Telescope Cepheid Photometry

“…The error of the Pellerin & Macri (2011) distance was revised to 0.05 mag to include the systematic uncertainties from the photometric comparison with Massey et al (2006) in their Section 3. The Cepheid distance to M33 by Lee et al (2022) is larger than our value by 0.10 mag (1.7σ). This difference matches the size and direction of the metallicity dependence of Cepheids, ∼−0.2 mag dex −1 (Breuval et al 2022), where metal-poor Cepheids are fainter.…”

“…As early as 1926, Edwin Hubble used this galaxy as one of the spiral nebulae to learn about the structure of the universe and observed 35 Cepheid variables to measure its distance (Hubble 1926). Since then, it has been extensively studied, and is still a crucial object for the distance scale (Freedman et al 1991;Lee et al 2022): M33 has intermediate inclination (i = 57°± 4°; Kourkchi et al 2020), 7 which limits the effects of reddening and of geometry that can produce additional scatter in the PL relation. Additionally, M33 is known for its steep metallicity gradient, which was measured using red giant branch (RGB) stars (Tiede et al 2004), planetary nebulae (Magrini et al 2009), and H II regions (Bresolin 2011;Toribio San Cipriano et al 2016;Rogers et al 2022).…”

CHAOS. VII. A Large-scale Direct Abundance Study in M33

“…Note that the single values of position angle and inclination do not account for the outer warp (see Corbelli et al 2014), but that feature appears beyond ∼8 kpc and is not relevant for our H II region sample. There are many distances to M33 in the literature to choose from (see discussion in de Grijs et al 2017;Lee et al 2022). We adopt the distance modulus of 24.67 ± 0.06 (corresponding to -+ 859 23 24 kpc) based on HST observations of RR Lyrae (Savino et al 2022) anchored to the GAIA eDR3 reference frame (Nagarajan et al 2022), which is consistent with the values favored by de Grijs et al (2017) and Lee et al (2022).…”

“…There are many distances to M33 in the literature to choose from (see discussion in de Grijs et al 2017;Lee et al 2022). We adopt the distance modulus of 24.67 ± 0.06 (corresponding to -+ 859 23 24 kpc) based on HST observations of RR Lyrae (Savino et al 2022) anchored to the GAIA eDR3 reference frame (Nagarajan et al 2022), which is consistent with the values favored by de Grijs et al (2017) and Lee et al (2022). The effective radius of M33, R e , is determined from the z0MGS WISE 3.4 μm maps (Leroy et al 2019) with the same fitting method that is described in Leroy et al (2021) and has been utilized in previous CHAOS studies (e.g., Berg et al 2020).…”

Young stellar distance indicators and the extragalactic distance scale

“…Bernard et al 2013) and the consistency of distance estimates based on different stellar standard candles (e.g. Lee et al 2022).…”