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High-resolution imaging of Virgo Cluster galaxies. I - The distance based on the brightest stars in NGC 4571

1992; IOP Publishing; Volume: 393; Linguagem: Inglês

10.1086/171525

1538-4357

Michael Pierce, R. D. McClure, Réne Racine,

Stellar, planetary, and galactic studies

view Abstract Citations (26) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS High-Resolution Imaging of Virgo Cluster Galaxies. I. The Distance Based on the Brightest Stars in NGC 4571 Pierce, Michael J. ; McClure, Robert D. ; Racine, Rene Abstract Deep, high-resolution images (FWHM = 0.43") of a relatively face-on, late-type spiral galaxy (NGC 4571) in the Virgo Cluster have been obtained using the High-Resolution Camera (HRCam) and the Canada-France- Hawaii Telescope. The galaxy is apparently resolved into stars. The combined image has a limiting magnitude of m_R_~26, enabling the brightest three magnitudes of the luminosity function to be examined, where the photometry is complete. Point-spread function fitting photometric techniques (i.e., DAOPHOT) are applied to the data allowing the application of quantitative and objective criteria for distinguishing stars from H II regions and compact clusters/associations. Approximately 50% of the brightest sources appear stellar (γφ<= 0.04"), a fraction in reasonable agreement with that found elsewhere from spectroscopic studies of the brightest "stars" in nearby galaxies. These unresolved images are interpreted as the brightest supergiants in NGC 4571. The apparent magnitudes of the brightest blue and red supergiants are used to estimate the distance to the Virgo Cluster, assuming both classes of stars to be "standard candles." Multicolor, low-resolution data (FWHM~1.4") are used to distinguish between the red and blue supergiants. We obtain a distance modulus for NGC 4571 of m - M = 30.9 +/- 0.2 mag, or 14.9 +/- 1.5 Mpc with both techniques. This estimate is in excellent agreement with results obtained from the majority of other modern techniques which imply a "short", distance for the Virgo Cluster, and hence large values for H_0_ (~85 km s^-1^ Mpc^-1^). With this distance estimate for the Virgo Cluster we obtain an absolute calibration for Type Ia supernovae given the apparent magnitudes for those events in E/S0 galaxies in the cluster. We find M_B_ = - 19.0 +/- 0.2 where the uncertainty is dominated by that in our distance estimate. The prospects for the detection of Cepheid and long-period variables in the Virgo Cluster using ground-based high-resolution imaging techniques are briefly discussed. Publication: The Astrophysical Journal Pub Date: July 1992 DOI: 10.1086/171525 Bibcode: 1992ApJ...393..523P Keywords: Astrometry; Astronomical Photography; Spiral Galaxies; Stellar Luminosity; Virgo Galactic Cluster; High Resolution; Point Spread Functions; Red Shift; Stellar Magnitude; Astrophysics; GALAXIES: CLUSTERING; GALAXIES: DISTANCES AND REDSHIFTS; GALAXIES: INDIVIDUAL NGC NUMBER: NGC 4571; GALAXIES: STELLAR CONTENT full text sources ADS | data products SIMBAD (2) NED (1)