SIMBAD references

2018AJ....156..105A - Astron. J., 156, 105-105 (2018/September-0)

A robust tip of the red giant branch distance to the fireworks galaxy (NGC 6946).


Abstract (from CDS):

Archival HST data taken in F606W+F814W of two different fields in the outer regions of NGC 6946 is used to measure a tip of the red giant branch distance to the galaxy. We employ a Bayesian maximum-likelihood modeling method that incorporates the completeness of the photometry, and allows us to model the luminosity function of the RGB population. Our two fields provide us with distances of 7.74 ± 0.42 Mpc and 7.69 ± 0.50 Mpc, respectively. Our final distance of 7.72 ± 0.32 Mpc is higher than most values previously published in the literature. This has important implications for supernova measurements, as NGC 6946 is host to the most observed supernovae (10) of any galaxy to date. We find that the supernovae in NGC 6946 are on average ∼2.3 times more luminous than previous estimates. Our distance gives NGC 6946 a peculiar velocity of vpec = -229 ± 29 km s–1 in the Local Sheet frame. This velocity is the projected component of a substantial negative SGZ motion, indicating a coherent motion along with the other members of the M101 wall toward the plane of the Local Sheet. The M101 wall, a spur off the Local Sheet into the Local Void, is experiencing the expansion of the Local Void.

Abstract Copyright: © 2018. The American Astronomical Society. All rights reserved.

Journal keyword(s): distance scale - galaxies: distances and redshifts - galaxies: individual: NGC 6946 - galaxies: stellar content - Hertzsprung-Russell and C-M diagrams - large-scale structure of universe

Simbad objects: 12

goto Full paper

goto View the reference in ADS

To bookmark this query, right click on this link: simbad:2018AJ....156..105A and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact