Results 11 to 20 of about 11,049 (214)
The Cepheid distance to the maser-host galaxy NGC 4258: Studying systematics with the Large Binocular Telescope [PDF]
Monthly Notices of the Royal Astronomical Society, 2015 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
Fausnaugh, M. M. +5 more
core +5 more sources
The Cepheid distance to the Local Group Galaxy NGC 6822
Monthly Notices of the Royal Astronomical Society, 2012 Recent estimates of the Cepheid distance modulus of NGC 6822 differ by 0.18 mag. To investigate this we present new multi-epoch JHKs photometry of classical Cepheids in the central region of NGC 6822 and show that there is a zero-point difference from ...
Baldacci +23 more
core +3 more sources
Point-of-care nucleic acid testing - a step forward in controlling the HIV epidemic: A review. [PDF]
HIV MedAbstract Introduction The HIV/AIDS epidemic, with 85.6 million infections and 40.4 million AIDS‐related deaths globally, remains a critical public health challenge. Current diagnostic methods, primarily fourth‐generation immunoassays, have limitations due to their long window periods, and most viral load assays require centralized testing protocols ...
Pinar SS +4 more
europepmc +2 more sources
On Cepheid diameter and distance measurement
The Astrophysical Journal, 1994 Dimitar Sasselov, Margarita Karovska
openaire +3 more sources
Cepheid Distances from Interferometry [PDF]
, 2007 Long baseline interferometry is now able to resolve the pulsational changes of the angular diameters of a significant number of Cepheids in the solar neighborhood. This allows us to apply a new version of the Baade-Wesselink method to measure their distances, for which we do not need to estimate the star’s temperature.
Kervella, P. +5 more
openaire +2 more sources
A revised Cepheid distance to NGC 4258 and a test of the distance scale [PDF]
, 2000 In a previous paper (Maoz et al. 1999), we reported a Hubble Space Telescope (HST) Cepheid distance to the galaxy NGC 4258 obtained using the calibrations and methods then standard for the Key Project on the Extragalactic Distance Scale.
Alibert Y. +14 more
core +2 more sources
M33 Cepheids from CFHT/MegaCam Survey
The Astronomical Journal, 2022 In this paper we analyze Sloan g, r, i archival imaging data of M33 taken by Hartman et al. using MegaCam at the Canada–France–Hawaii Telescope. To determine the distance to the M33 galaxy, we performed several analytical steps to identify its Cepheid ...
Samuel Adair, Chien-Hsiu Lee
doaj +1 more source
Calibration of the Distance Scale from Cepheids [PDF]
, 2002 We have used the infrared surface brightness technique to obtain a new absolute calibration of the Cepheid PL relation in optical and near-infrared bands from improved data on Galactic stars.
Fouque, Pascal +2 more
core +4 more sources
Metallicity effects on the Cepheid distance scale [PDF]
Symposium - International Astronomical Union, 1991 We are undertaking empirical tests for the effects of metallicity on the zero-point of the Period-Luminosity relations for Cepheids in M31 and in the Small Magellanic Cloud (SMC), as compared to the Large Magellanic Cloud (LMC). For M31 we have used BVRI data on comparable sets of Cepheids in three radially separated, and chemically different, fields ...
Wendy L. Freedman, Barry F. Madore
openaire +1 more source
Reconciliation of the Surface Brightness Fluctuations and Type Ia Supernovae Distance Scales [PDF]
, 2001 We present Hubble Space Telescope measurements of surface brightness fluctuations (SBF) distances to early-type galaxies that have hosted Type Ia supernovae (SNIa).
Ajhar, Edward A. +4 more
core +3 more sources