scholarly journals The Hubble Space Telescope Key Project to Measure the Hubble Constant

1999 ◽  
Vol 183 ◽  
pp. 17-30 ◽  
Author(s):  
Wendy L. Freedman ◽  
Jeremy R. Mould ◽  
Robert C. Kennicutt ◽  
Barry F. Madore
Keyword(s):  
Hubble Space Telescope ◽  
Hubble Constant ◽  
Distance Scale ◽  
General Assembly ◽  
Host Galaxies ◽  
Space Telescope ◽  
Type Ia Supernova ◽  
Type Ia ◽  
Extragalactic Distance Scale

A Joint Discussion on the extragalactic distance scale and the Hubble constant took place fifteen years ago, at the 1982 XVIIIth General Assembly of the IAU, held in Patras, Greece. At that time, the newest applications of infrared photometers to Tully-Fisher measurements (Aaronson 1983) and Cepheid distances (Madore 1983) were reported. CCDs were just coming into use and had not yet been applied to extragalactic distance determinations; all of the extragalactic Cepheid distances were based on photographic Argelander (eye-estimated) photometry (Tammann and Sandage 1983 and references therein). No Cepheid distances to type Ia supernova-host galaxies were available.

scholarly journals Variable Stars and the Cosmic Distance Scale

1989 ◽  
Vol 111 ◽  
pp. 169-176
Author(s):  
Jeremy Mould
Keyword(s):  
Hubble Space Telescope ◽  
Hubble Constant ◽  
Variable Stars ◽  
Virgo Cluster ◽  
Distance Scale ◽  
Stellar Structure ◽  
Space Telescope ◽  
Pulsating Variable Stars ◽  
Extragalactic Distance Scale ◽  
Detector Technology

For three quarters of a century pulsating variable stars have lain at the foundation of the extragalactic distance scale. The construction of larger telescopes, advances in detector technology, hard work by observers, and our understanding of stellar structure have all contributed to the expansion of the realm of the Cepheids to the distance of M101. Now, with the advent of Hubble Space Telescope (HST), we can look forward to the detection of Cepheids in the Virgo cluster and the removal of much of the remaining uncertainty in the Hubble constant.

scholarly journals MEASURING THE HUBBLE CONSTANT WITH THE HUBBLE SPACE TELESCOPE

2009 ◽  
Vol 5 (H15) ◽  
pp. 1-16 ◽  
Author(s):  
W. L. Freedman ◽  
R. C. Kennicutt ◽  
J. R. Mould
Keyword(s):  
Hubble Space Telescope ◽  
Hubble Constant ◽  
Distance Scale ◽  
Space Telescope ◽  
Peculiar Velocities ◽  
Extragalactic Distance Scale ◽  
Distance Indicators

AbstractTen years ago our team completed the Hubble Space Telescope Key Project on the extragalactic distance scale. Cepheids were detected in some 25 galaxies and used to calibrate four secondary distance indicators that reach out into the expansion field beyond the noise of galaxy peculiar velocities. The result was H0 = 72 ± 8 km s−1 Mpc−1 and put an end to galaxy distances uncertain by a factor of two. This work has been awarded the Gruber Prize in Cosmology for 2009.

scholarly journals Lens modelling of the strongly lensed Type Ia supernova iPTF16geu

2020 ◽  
Vol 496 (3) ◽  
pp. 3270-3280
Author(s):  
E Mörtsell ◽  
J Johansson ◽  
S Dhawan ◽  
A Goobar ◽  
R Amanullah ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Hubble Constant ◽  
Host Galaxy ◽  
Total Probability ◽  
Lens Model ◽  
Density Profiles ◽  
Type Ia Supernova ◽  
Standard Candle ◽  
Type Ia ◽  
Universal Expansion

ABSTRACT In 2016, the first strongly lensed Type Ia supernova (SN Ia), iPTF16geu, at redshift z = 0.409 with four resolved images arranged symmetrically around the lens galaxy at z = 0.2163, was discovered. Here, refined observations of iPTF16geu, including the time delay between images, are used to decrease uncertainties in the lens model, including the the slope of the projected surface density of the lens galaxy, Σ ∝ r1 − η, and to constrain the universal expansion rate H0. Imaging with Hubble Space Telescope provides an upper limit on the slope η, in slight tension with the steeper density profiles indicated by imaging with Keck after iPTF16geu had faded, potentially due to dust extinction not corrected for in host galaxy imaging. Since smaller η implies larger magnifications, we take advantage of the standard candle nature of SNe Ia constraining the image magnifications, to obtain an independent constraint of the slope. We find that a smooth lens density fails to explain the iPTF16geu fluxes, regardless of the slope, and additional substructure lensing is needed. The total probability for the smooth halo model combined with star microlensing to explain the iPTF16geu image fluxes is maximized at 12 per cent for η ∼ 1.8, in excellent agreement with Keck high-spatial-resolution data, and flatter than an isothermal halo. It also agrees perfectly with independent constraints on the slope from lens velocity dispersion measurements. Combining with the observed time delays between the images, we infer a lower bound on the Hubble constant, $H_0 \gtrsim 40\, {\rm km \ s^{-1} Mpc^{-1}}$, at 68.3 per cent confidence level.

The Hubble Space Telescope extragalactic distance scale key project. 2: Photometry of WFC images of M81

1994 ◽  
Vol 428 ◽  
pp. 143 ◽  
Author(s):  
Shaun M. G. Hughes ◽  
Peter B. Stetson ◽  
Anne Turner ◽  
Robert C., Jr. Kennicutt ◽  
Robert Hill ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Distance Scale ◽  
Space Telescope ◽  
Extragalactic Distance Scale

The Extragalactic Distance Scale Key Project. III. The Discovery of Cepheids and a New Distance to M101 Using the Hubble Space Telescope

1996 ◽  
Vol 463 ◽  
pp. 26 ◽  
Author(s):  
Daniel D. Kelson ◽  
Garth D. Illingworth ◽  
Wendy F. Freedman ◽  
John A. Graham ◽  
Robert Hill ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Distance Scale ◽  
Space Telescope ◽  
Extragalactic Distance Scale

scholarly journals Hubble Space Telescope spectra of the Type Ia supernova SN 2011fe: a tail of low-density, high-velocity material with Z < Z⊙

2014 ◽  
Vol 439 (2) ◽  
pp. 1959-1979 ◽  
Author(s):  
P. A. Mazzali ◽  
M. Sullivan ◽  
S. Hachinger ◽  
R. S. Ellis ◽  
P. E. Nugent ◽  
...  
Keyword(s):  
High Velocity ◽  
Hubble Space Telescope ◽  
Low Density ◽  
Space Telescope ◽  
Type Ia Supernova ◽  
Type Ia

scholarly journals The Linearity of the Cosmic Expansion Field and the Value of the Hubble Constant

1999 ◽  
Vol 183 ◽  
pp. 31-47
Author(s):  
G. A. Tammann
Keyword(s):  
Hubble Constant ◽  
Physical Distance ◽  
Mean Value ◽  
Distance Scale ◽  
Gravitational Lenses ◽  
Cosmic Expansion ◽  
Type Ia ◽  
The Mean ◽  
Extragalactic Distance Scale ◽  
Linearity Test

A linearity test shows H0 to decrease by 7% out to 18 000 km s–1. The value at 10 000 km s–1 is a good approximation to the mean value of H0 over very large scales. The construction of the extragalactic distance scale is discussed. Field galaxies, cluster distances relative to Virgo, and blue supernovae of type Ia yield H0 (cosmic) with increasing weight; they give consistently H0 = 57 ± 7 (external error). This value is supported by purely physical distance determinations (SZ effect, gravitational lenses, MWB fluctuations). Arguments for H0 > 70 are discussed and shown to be flawed.

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