Bias Properties of Extragalactic Distance Indicators. VI. Luminosity Functions of M31 and M101 Look-alikes Listed in the RSA2: H0 Therefrom

1996 ◽  
Vol 111 ◽  
pp. 18 ◽  
Author(s):  
Allan Sandage
Keyword(s):  
Luminosity Functions ◽  
Distance Indicators

scholarly journals Problems Concerning the Extragalactic Distance Scale

1972 ◽  
Vol 44 ◽  
pp. 341-352
Author(s):  
G. O. Abell
Keyword(s):  
Galaxy Clusters ◽  
Hubble Parameter ◽  
Absolute Magnitude ◽  
Distance Scale ◽  
Luminosity Functions ◽  
The Absolute ◽  
The Difference ◽  
Extragalactic Distance Scale ◽  
Distance Indicators

The use of the brightest members of galaxy clusters as distance indicators is questioned because of a possible correlation between the absolute magnitude of the brightest galaxy and the richness of the cluster. Comparison of the clusters' luminosity functions is considered to be more appropriate. The difference between the two approaches is substantial when a comparison is made between the Coma and Virgo clusters. The value of the Hubble parameter may well be less than 50 km s−1 Mpc−1.

Magellanic Cloud Eclipsing Binaries: Primary Distance Indicators

1999 ◽  
Vol 190 ◽  
pp. 563-566
Author(s):  
J. D. Pritchard ◽  
W. Tobin ◽  
J. V. Clausen ◽  
E. F. Guinan ◽  
E. L. Fitzpatrick ◽  
...  
Keyword(s):  
New Zealand ◽  
Magellanic Cloud ◽  
Eclipsing Binaries ◽  
Fundamental Parameters ◽  
Distance Indicators

Our collaboration involves groups in Denmark, the U.S.A. Spain and of course New Zealand. Combining ground-based and satellite (IUEandHST) observations we aim to determine accurate and precise stellar fundamental parameters for the components of Magellanic Cloud Eclipsing Binaries as well as the distances to these systems and hence the parent galaxies themselves. This poster presents our latest progress.

Luminosity Functions for Globular Clusters

1998 ◽  
Vol 509 (1) ◽  
pp. 192-202 ◽  
Author(s):  
Fabio Silvestri ◽  
Paolo Ventura ◽  
Francesca D'Antona ◽  
Italo Mazzitelli
Keyword(s):  
Globular Clusters ◽  
Luminosity Functions

scholarly journals Carbon stars as standard candles – II. The median J magnitude as a distance indicator

2020 ◽  
Vol 501 (1) ◽  
pp. 933-947
Author(s):  
Javiera Parada ◽  
Jeremy Heyl ◽  
Harvey Richer ◽  
Paul Ripoche ◽  
Laurie Rousseau-Nepton
Keyword(s):  
Luminosity Function ◽  
Asymptotic Giant Branch ◽  
Distance Modulus ◽  
Asymptotic Giant Branch Stars ◽  
Luminosity Functions ◽  
Best Fitting ◽  
Distance Indicator ◽  
Ngc 6822 ◽  
The Given ◽  
Giant Branch Stars

ABSTRACT We introduce a new distance determination method using carbon-rich asymptotic giant branch stars (CS) as standard candles and the Large and Small Magellanic Clouds (LMC and SMC) as the fundamental calibrators. We select the samples of CS from the ((J − Ks)0, J0) colour–magnitude diagrams, as, in this combination of filters, CS are bright and easy to identify. We fit the CS J-band luminosity functions using a Lorentzian distribution modified to allow the distribution to be asymmetric. We use the parameters of the best-fitting distribution to determine if the CS luminosity function of a given galaxy resembles that of the LMC or SMC. Based on this resemblance, we use either the LMC or SMC as the calibrator and estimate the distance to the given galaxy using the median J magnitude ($\overline{J}$) of the CS samples. We apply this new method to the two Local Group galaxies NGC 6822 and IC 1613. We find that NGC 6822 has an ‘LMC-like’ CS luminosity function, while IC 1613 is more ‘SMC-like’. Using the values for the median absolute J magnitude for the LMC and SMC found in Paper I we find a distance modulus of μ0 = 23.54 ± 0.03 (stat) for NGC 6822 and μ0 = 24.34 ± 0.05 (stat) for IC 1613.

scholarly journals Semi-analytic forecasts forJWST– I. UV luminosity functions atz = 4–10

2018 ◽  
Vol 483 (3) ◽  
pp. 2983-3006 ◽  
Author(s):  
L Y Aaron Yung ◽  
Rachel S Somerville ◽  
Steven L Finkelstein ◽  
Gergö Popping ◽  
Romeel Davé
Keyword(s):  
Luminosity Functions

scholarly journals The effects of peculiar velocities in SN Ia environments on the local H0 measurement

2020 ◽  
Vol 500 (3) ◽  
pp. 3728-3742
Author(s):  
Thomas M Sedgwick ◽  
Chris A Collins ◽  
Ivan K Baldry ◽  
Philip A James
Keyword(s):  
Hubble Constant ◽  
Density Parameter ◽  
Host Galaxies ◽  
Peculiar Velocities ◽  
Standard Candle ◽  
Modern Cosmology ◽  
Type Ia ◽  
The Difference ◽  
Ia Supernovae ◽  
Distance Indicators

ABSTRACT The discrepancy between estimates of the Hubble constant (H0) measured from local (z ≲  0.1) scales and from scales of the sound horizon is a crucial problem in modern cosmology. Peculiar velocities (vpec) of standard candle distance indicators can systematically affect local H0 measurements. We here use 2MRS galaxies to measure the local galaxy density field, finding a notable z  <  0.05 underdensity in the SGC-6dFGS region of 27  ±  2 per cent. However, no strong evidence for a ‘Local Void’ pertaining to the full 2MRS sky coverage is found. Galaxy densities are used to measure a density parameter, Δϕ+−, which we introduce as a proxy for vpec that quantifies density gradients along a supernova (SN) line of sight. Δϕ+− is found to correlate with local H0 estimates from 88 Pantheon Type Ia supernovae (SNe Ia; 0.02  <  z  <  0.05). Density structures on scales of ∼50 Mpc are found to correlate strongest with H0 estimates in both the observational data and in mock data from the MDPL2-Galacticus simulation. Using trends of H0 with Δϕ+−, we can correct for the effects of density structure on local H0 estimates, even in the presence of biased vpec. However, the difference in the inferred H0 estimate with and without the peculiar velocity correction is limited to < 0.1  per cent. We conclude that accounting for environmentally induced peculiar velocities of SN Ia host galaxies does not resolve the tension between local and CMB-derived H0 estimates.

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