Results 41 to 50 of about 120,003 (344)

A Future Percent-level Measurement of the Hubble Expansion at Redshift 0.8 with Advanced LIGO [PDF]

Astrophysical Journal, 2019
Simultaneous measurements of distance and redshift can be used to constrain the expansion history of the universe and associated cosmological parameters.
W. Farr, M. Fishbach, Jiani Ye, D. Holz
semanticscholar   +1 more source

Does the Black Hole Merger Rate Evolve with Redshift? [PDF]

Astrophysical Journal, 2018
We explore the ability of gravitational-wave detectors to extract the redshift distribution of binary black hole (BBH) mergers. The evolution of the merger rate across redshifts 0 < z ≲ 1 is directly tied to the formation and evolutionary processes ...
M. Fishbach, D. Holz, W. Farr
semanticscholar   +1 more source

Variable G versus the Accelerated Expansion of the Universe

Open Astronomy, 2017
It is shown that the hypothesis of permitting variability of the Newtonian constant G, increasing with the local density of dark matter, implies that there is no need for the introduction of a cosmological constant or accelerated expansion of the ...
Colenbrander Bernard G., Hulscher Willem S.   +1 more
doaj   +1 more source

The Zwicky Transient Facility Bright Transient Survey. I. Spectroscopic Classification and the Redshift Completeness of Local Galaxy Catalogs [PDF]

Astrophysical Journal, 2019
The Zwicky Transient Facility (ZTF) is performing a three-day cadence survey of the visible northern sky (∼3π) with newly found transient candidates announced via public alerts.
U. C. Fremling, A. Miller, Y. Sharma, A. Dugas, D. Perley, Kirsty Taggart, J. Sollerman, A. Goobar, M. Graham, J. Neill, J. Nordin, M. Rigault, R. Walters, I. Andreoni, A. Bagdasaryan, J. Belicki, C. Cannella, E. Bellm, S. Cenko, K. De, R. Dekany, S. Frederick, V. Golkhou, M. Graham, G. Helou, A. Ho, M. Kasliwal, T. Kupfer, R. Laher, A. Mahabal, F. Masci, R. Riddle, B. Rusholme, S. Schulze, D. Shupe, R. Smith, Lin Yan, Y. Yao, Z. Zhuang, S. Kulkarni   +39 more
semanticscholar   +1 more source

The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample: a tomographic measurement of cosmic structure growth and expansion rate based on optimal redshift weights [PDF]

Monthly notices of the Royal Astronomical Society, 2018
We develop a new method, which is based on the optimal redshift weighting scheme, to extract the maximal tomographic information of baryonic acoustic oscillations (BAO) and redshift space distortions (RSD) from the extended Baryon Oscillation ...
Gong-Bo Zhao, Yuting Wang, S. Saito, H. Gil-Mar'in, W. Percival, Dandan Wang, C. Chuang, R. Ruggeri, E. Mueller, Fangzhou Zhu, A. Ross, R. Tojeiro, I. Pâris, A. Myers, J. Tinker, Jian Li, É. Burtin, P. Zarrouk, F. Beutler, Falk Baumgarten, J. Bautista, J. Brownstein, K. Dawson, Jiamin Hou, A. de la Macorra, G. Rossi, J. Peacock, Ariel G. S'anchez, A. Shafieloo, D. Schneider, Cheng Zhao   +30 more
semanticscholar   +1 more source

A massive, quiescent galaxy at a redshift of 3.717 [PDF]

Nature, 2017
Finding massive galaxies that stopped forming stars in the early Universe presents an observational challenge because their rest-frame ultraviolet emission is negligible and they can only be reliably identified by extremely deep near-infrared surveys ...
K. Glazebrook, C. Schreiber, I. Labbé, T. Nanayakkara, G. Kacprzak, P. Oesch, C. Papovich, L. Spitler, C. Straatman, K. Tran, T. Yuan   +10 more
semanticscholar   +1 more source

Status of racial disparities between black and white women undergoing assisted reproductive technology in the US

Reproductive Biology and Endocrinology, 2020
Background Numerous studies have demonstrated substantial differences in assisted reproductive technology outcomes between black non-Hispanic and white non-Hispanic women. We sought to determine if disparities in assisted reproductive technology outcomes
D. B. Seifer, B. Simsek, E. Wantman, A. M. Kotlyar   +3 more
doaj   +1 more source

Hubble Parameter and Baryon Acoustic Oscillation Measurement Constraints on the Hubble Constant, the Deviation from the Spatially Flat ΛCDM Model, the Deceleration–Acceleration Transition Redshift, and Spatial Curvature [PDF]

, 2017
We compile a complete collection of reliable Hubble parameter H(z) data to redshift z ≤ 2.36 and use them with the Gaussian Process method to determine continuous H(z) functions for various data subsets.
Hai-Bo Yu, Bharat Ratra, Fa-yin Wang
semanticscholar   +1 more source

Evolution of the AGN UV luminosity function from redshift 7.5 [PDF]

Monthly notices of the Royal Astronomical Society, 2018
Determinations of the ultraviolet (UV) luminosity function of active galactic nuclei (AGN) at high redshifts are important for constraining the AGN contribution to reionization and understanding the growth of supermassive black holes.
Girish Kulkarni, G. Worseck, J. Hennawi
semanticscholar   +1 more source

Morpho-photometric redshifts [PDF]

Monthly Notices of the Royal Astronomical Society, 2019
ABSTRACT Machine learning (ML) is one of two standard approaches (together with SED fitting) for estimating the redshifts of galaxies when only photometric information is available. ML photo-z solutions have traditionally ignored the morphological information available in galaxy images or partly included it in the form of hand-crafted ...
openaire   +2 more sources