A NEW COSMOLOGICAL DISTANCE MEASURE USING ACTIVE GALACTIC NUCLEI

@article{Watson2011ANC,
  title={A NEW COSMOLOGICAL DISTANCE MEASURE USING ACTIVE GALACTIC NUCLEI},
  author={Douglas F. Watson and Kelly D. Denney and Marianne Vestergaard and Tamara M. Davis},
  journal={The Astrophysical Journal Letters},
  year={2011},
  volume={740}
}
Accurate distances to celestial objects are key to establishing the age and energy density of the universe and the nature of dark energy. A distance measure using active galactic nuclei (AGNs) has been sought for more than 40 years, as they are extremely luminous and can be observed at very large distances. We report here the discovery of an accurate luminosity distance measure using AGNs. We use the tight relationship between the luminosity of an AGN and the radius of its broad-line region… 

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References

SHOWING 1-10 OF 32 REFERENCES

The Radius-Luminosity Relationship for Active Galactic Nuclei: The Effect of Host-Galaxy Starlight on Luminosity Measurements

We have obtained high-resolution images of the central regions of 14 reverberation-mapped active galactic nuclei (AGNs) using the Hubble Space Telescope Advanced Camera for Surveys High Resolution

Quasar Parallax: A Method for Determining Direct Geometrical Distances to Quasars

We describe a novel method to determine direct geometrical distances to quasars that can measure the cosmological constant, Λ, with minimal assumptions. This method is equivalent to geometric

The Relationship between Luminosity and Broad-Line Region Size in Active Galactic Nuclei

We reinvestigate the relationship between the characteristic broad-line region size (RBLR) and the Balmer emission-line, X-ray, UV, and optical continuum luminosities. Our study makes use of the best

Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant

We present spectral and photometric observations of 10 Type Ia supernovae (SNe Ia) in the redshift range 0.16 ≤ z ≤ 0.62. The luminosity distances of these objects are determined by methods that

Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei

Correlated variations in the line and continuum emission from active galactic nuclei (AGNs) can be used to determine the size and geometry of the broad emission-line regions (BLRs). We have

The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances

We report data for I-band surface brightness fluctuation (SBF) magnitudes, (V-I) colors, and distance moduli for 300 galaxies. The survey contains E, S0, and early-type spiral galaxies in the

THE LICK AGN MONITORING PROJECT: BROAD-LINE REGION RADII AND BLACK HOLE MASSES FROM REVERBERATION MAPPING OF Hβ

We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with the aim of measuring the masses of the black holes in 12 nearby (z < 0.05)

Reverberation Mapping of High-Luminosity Quasars: First Results

Reverberation mapping of nearby active galactic nuclei (AGNs) has led to estimates of broad-line region (BLR) sizes and central object masses for some 37 objects to date. However, successful

A NEW DIRECT METHOD FOR MEASURING THE HUBBLE CONSTANT FROM REVERBERATING ACCRETION DISCS IN ACTIVE GALAXIES

ABSTRA C T We show how wavelength-dependent time delays between continuum flux variations of active galactic nuclei (AGNs) can be used to test the standard black hole-accretion disc paradigm, by

REVERBERATION MAPPING MEASUREMENTS OF BLACK HOLE MASSES IN SIX LOCAL SEYFERT GALAXIES

We present the final results from a high sampling rate, multi-month, spectrophotometric reverberation mapping campaign undertaken to obtain either new or improved Hβ reverberation lag measurements