Neutrino mass from cosmology: Impact of high-accuracy measurement of the Hubble constant (2009)
Sekiguchi, Toyokazu, Ichikawa, Kazuhide, Takahashi, Tomo, Greenhill, Lincoln
Non-zero neutrino mass would affect the evolution of the Universe in observable ways, and a strong constraint on the mass can be achieved using combinations of cosmological data sets. We focus on the...
Cepheid Calibrations of Modern Type Ia Supernovae:Implications for the Hubble Constant (2009)
Riess, Adam G., Macri, Lucas, Li, Weidong, Lampeitl, Hubert, Casertano, Stefano, Ferguson, Henry C., ...
This is the first of two papers reporting measurements from a program to determine the Hubble constant to 5% precision from a refurbished distance ladder. We present new observations of 110 Cepheid...
Digital Instrumentation for the Radio Astronomy Community (2009)
Parsons, Aaron, Werthimer, Dan, Backer, Donald, Bastian, Tim, Bower, Geoffrey, Brisken, Walter, ...
Time-to-science is an important figure of merit for digital instrumentation serving the astronomical community. A digital signal processing (DSP) community is forming that uses shared hardware...
Estimation of the Hubble Constant and Constraint on Descriptions of Dark Energy (2009)
Greenhill, Lincoln, Humphreys, Elizabeth, Hu, Wayne, Macri, Lucas, Murphy, David, Masters, Karen, ...
Joint analysis of Cosmic Microwave Background, Baryon Acoustic Oscillation, and supernova data has enabled precision estimation of cosmological parameters. New programs will push to 1% uncertainty in...
Cosmology from the Highly-Redshifted 21 cm Line (2009)
Furlanetto, Steven, Lidz, Adam, Loeb, Abraham, McQuinn, Matthew, Pritchard, Jonathan, Shapiro, Paul, ...
One of the next decade's most exciting prospects is to explore the cosmic "dark ages," during which the first stars in the Universe formed, with the 21 cm line of neutral hydrogen. At z>6, this light...
Astrophysics from the Highly-Redshifted 21 cm Line (2009)
Furlanetto, Steven, Lidz, Adam, Loeb, Abraham, McQuinn, Matthew, Pritchard, Jonathan, Aguirre, James, ...
The cosmic dark ages and the epoch of reionization, during which the first generations of stars and galaxies formed, are among the most compelling frontiers of extragalactic astrophysics and...
A Deep 0.3-10 keV Spectrum of the H$_{2}$O Maser Galaxy IC 2560 (2008)
Tilak, Avanti, Greenhill, Lincoln, Done, Chris, Madejski, Grzegorz
We present a new XMM-Newton spectrum of the Seyfert 2 nucleus of IC 2560, which hosts H$_{2}$O maser emission from an inclined Keplerian accretion disk. The X-ray spectrum shows soft excess due to...
Moran, Jim, Humphreys, Liz, Greenhill, Lincoln, Reid, Mark, Argon, Alice
A wealth of new information about the structure of the maser disk in NGC 4258 has been obtained from a series of 18 VLBA observations spanning three years, as well as from 32 additional epochs of...
X-ray Emission from Megamaser Galaxy IC 2560 (2005)
Madejski, Greg, Done, Chris, Zycki, Piotr, Greenhill, Lincoln
Observation of the H2O megamaser galaxy IC 2560 with the Chandra Observatory reveals a complex spectrum composed of soft X-ray emission due to multi-temperature thermal plasma, and a hard continuum...
Q0906+6930: The Highest-Redshift Blazar (2004)
Romani, Roger W., Sowards-Emmerd, David, Greenhill, Lincoln, Michelson, Peter
We report the discovery of a radio-loud flat-spectrum QSO at z=5.47 with properties similar to those of the EGRET gamma-ray blazars. This source is the brightest radio QSO at z>5, with a pc-scale...
Seth, Anil, Greenhill, Lincoln, Holder, Benjamin
We have mapped the water maser emission associated with the infrared centers IRS1 and IRS3 of the NGC 2071IR star forming region at four epochs over ~4 months with the Very Long Baseline Array...