The Cepheid distance to the maser-host galaxy NGC 4258: Studying systematics with the Large Binocular Telescope

Abstract

We identify and phase a sample of 81 Cepheids in the maser-host galaxy NGC 4258 using the Large Binocular Telescope (LBT), and obtain calibrated mean magnitudes in up to 4 filters for a subset of 43 Cepheids using archival HST data. We employ 3 models to study the systematic effects of extinction, the assumed extinction law, and metallicity on the Cepheid distance to NGC 4258. We find a correction to the Cepheid colors consistent with a grayer extinction law in NGC 4258 compared to the Milky Way ($R_V=4.9$), although we believe this is indicative of other systematic effects. If we combine our Cepheid sample with previously known Cepheids, we find a significant metallicity adjustment to the distance modulus of ${\gamma }_1=-0.61\pm 0.21$ mag/dex, for the Zaritsky et al. (1994) metallicity scale, as well as a weak trend of Cepheid colors with metallicity. Conclusions about the absolute effect of metallicity on Cepheid mean magnitudes appear to be limited by the available data on the metallicity gradient in NGC 4258, but our Cepheid data require at least some metallicity adjustment to make the Cepheid distance consistent with independent distances to the LMC and NGC 4258. From our ensemble of models and the geometric maser distance of NGC 4258 (${\mu }_{N4258}=29.40\pm 0.06$ mag), we estimate ${\mu }_{LMC}=18.57\pm 0.14$ mag ($51.82\pm 3.23$ kpc).

Accepted for publication in MNRAS. 28 pages, 13 figures, 11 tables. A brief video summarizing the key results of this paper can be found at http://youtu.be/ICTTNyxZ89I

References in corpus (9)

• Some Aspects of Measurement Error in Linear Regression of Astronomical Data
• An eclipsing binary distance to the Large Magellanic Cloud accurate to 2 per cent
• A new Cepheid distance to the maser-host galaxy NGC 4258 and its implications for the Hubble Constant
• The influence of chemical composition on the properties of Cepheid stars. II-The iron content
• The performance of the blue prime focus Large Binocular Camera at the Large Binocular Telescope
• A Survey of Galaxy Kinematics to z ~ 1 in the TKRS/GOODS-N Field. II. Evolution in the Tully-Fisher Relation
• Cepheids in external galaxies. I. The maser-host galaxy NGC 4258 and the metallicity dependence of P-L and P-W relations
• Period-Luminosity Relations Derived from the OGLE-III Fundamental Mode Cepheids
• The extinction law inside the 30 Doradus nebula

Cited by in corpus (11)

• Measurements of the Hubble Constant: Tensions in Perspective
• The Search for Failed Supernovae with The Large Binocular Telescope: First Candidates
• An independent determination of the local Hubble constant
• Hubble tension or a transition of the Cepheid SnIa calibrator parameters?
• Sensitivity of the Hubble Constant Determination to Cepheid Calibration
• Optical Identification of Cepheids in 19 Host Galaxies of Type Ia Supernovae and NGC 4258 with the Hubble Space Telescope
• An updated metal-dependent theoretical scenario for Classical Cepheids
• Cepheid Metallicity in the Leavitt Law (C-MetaLL) survey: I. HARPS-N@TNG spectroscopy of 47 Classical Cepheid and 1 BL Her variables
• On the Period--Luminosity--Metallicity relation of Classical Cepheids
• Absolute Calibration of Cepheid Period-Luminosity Relations in NGC 4258
• The Cepheid Distance to the Narrow-Line Seyfert 1 Galaxy NGC 4051