Results 21 to 30 of about 245,319 (342)

Hydrogen Intramolecular Stretch Redshift in the Electrostatic Environment of Type II Clathrate Hydrates from Schrödinger Equation Treatment

open access: yesApplied Sciences, 2020
The one-dimensional Schrödinger equation, applied to the H2 intramolecular stretch coordinate in singly to quadruply occupied large cages in extended Type II (sII) hydrogen clathrate hydrate, was solved numerically herein via potential-energy scans from ...
Christian J. Burnham   +3 more
doaj   +1 more source

The VIMOS VLT Deep Survey - First epoch VVDS-Deep survey: 11564 spectra with 17.5<=IAB<=24, and the redshift distribution over 0< z <=5 [PDF]

open access: yes, 2004
This paper presents the ``First Epoch'' sample from the VIMOS VLT Deep Survey (VVDS). The VVDS goals, observations, data reduction with VIPGI, and redshift measurement with KBRED are discussed.
A. Bongiorno   +47 more
core   +4 more sources

Redshifts and distances [PDF]

open access: yesNature, 1979
Evidence concerning the associations between QSOs and galaxies with similar redshifts, and pairs with very different redshifts is reviewed. It is concluded that both kinds of associations are likely to be real.
openaire   +3 more sources

Metals at High Redshifts [PDF]

open access: yesProceedings of the International Astronomical Union, 2001
The amount of metals present in the Universe and its cosmological evolution is a key issue for our understanding of how star formation proceeds from the collapse of the first objects to the formation of present day galaxies. We discuss here recent results at the two extremes of the density scale.1.
Patrick Petitjean, Patrick Petitjean
openaire   +5 more sources

The redshift of GRB970508 [PDF]

open access: yesFourth Huntsville gamma-ray burst symposium, 1998
GRB 970508 is the second gamma-ray burst (GRB) for which an optical afterglow has been detected. It is the first GRB for which a distance scale has been determined: absorption and emission features in spectra of the optical afterglow place GRB 970508 at a redshift of z >= 0.835 [1,2].
openaire   +6 more sources

A new statistic for redshift surveys: the redshift dispersion of galaxies [PDF]

open access: yesNew Astronomy, 1997
LaTex 27 pages, 8 Postscript figures, added one figure and some changes to the ...
F. J. Summers   +2 more
openaire   +3 more sources

An Optical View of Extragalactic γ-Ray Emitters

open access: yesFrontiers in Astronomy and Space Sciences, 2017
The Fermi Gamma-ray Observatory discovered about a thousand extragalactic sources emitting energy from 100 MeV to 100 GeV. The majority of these sources belong to the class of blazars characterized by a quasi-featureless optical spectrum (BL Lac Objects).
Simona Paiano   +6 more
doaj   +1 more source

High-z Sudoku: A diagnostic tool for identifying robust (sub)mm redshifts [PDF]

open access: yes, 2022
We present methods to (i) graphically identify robust redshifts using emission lines in the (sub)mm regime, (ii) evaluate the capabilities of different (sub)mm practices for measuring spectroscopic redshifts, and (iii) optimise future (sub)mm observations towards increasing the fraction of robust redshifts.
arxiv   +1 more source

Redshift Surveys With 2DF [PDF]

open access: yesHighlights of Astronomy, 1998
This IAU Joint Discussion proposes to address the subject of redshift surveys in the 21st century. This paper, however, deals with two major new redshift surveys that those involved sincerely hope will be completed in the 20th century. Nonetheless, these surveys are relevant to the topic of the meeting, as they clearly foreshadow the scope and style of
B. J. Boyle, Matthew Colless
openaire   +3 more sources

Automated reliability assessment for spectroscopic redshift measurements [PDF]

open access: yes, 2018
We present a new approach to automate the spectroscopic redshift reliability assessment based on machine learning (ML) and characteristics of the redshift probability density function (PDF).
A. Schmitt   +41 more
core   +3 more sources

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