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We construct a composite quasar spectrum from 284 HST FOS spectra of 101 quasars with redshifts z > 0.33. The spectrum covers the wavelengths between 350 and 3000 A in the rest frame. There is a significant steepening of the continuum slope…

Astrophysics · Physics 2009-10-28 W. Zheng , G. A. Kriss , R. C. Telfer , J. P. Grimes , A. F. Davidsen

We present a sample of 46 [OIII]-emitting galaxies at z<0.8 detected in the fibre spectra of quasars from the SDSS-DR7 through an automatic search procedure. We also detect [OII] and Hb emission lines from most of these galaxies in the SDSS…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 P. Noterdaeme , R. Srianand , V. Mohan

An experimental search for variation in the fundamental coupling constants is strongly motivated by modern high-energy physics theories. Comparison of quasar absorption line spectra with laboratory spectra provides a sensitive probe for…

We have derived the radiative-transfer equation for a point source with a specified intensity and spectrum, originating in the early Universe between the epochs of annihilation and recombination, at redshifts $z_\s =10^8\div 10^4$. The…

Astrophysics · Physics 2009-11-11 D. I. Nagirner S. L. Kirusheva

Quasars, as the most luminous persistent sources in the Universe, have broad applications for cosmological studies. In particular, they can be employed to directly measure the expansion history of the Universe, similarly to SNe Ia. The…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-02 J. Modzelewska , B. Czerny , M. Bilicki , K. Hryniewicz , M. Krupa , F. Petrogalli , W. Pych , A. Kurcz , A. Udalski

The shifting of spectral lines due to induced correlation effect, discovered first by Wolf for the single scattering case which mimics the Doppler mechanism has been extended and developed further by the present authors known as Dynamic…

Astrophysics · Physics 2007-05-23 Sisir Roy , Malabika Roy , Joydip Ghosh , Menas Kafatos

We present ALMA band 3 observations of the CO(6-5), CO(7-6), and [CI] 369micron emission lines in three of the highest redshift quasar host galaxies at 6.6<z<6.9. These measurements constitute the highest-redshift CO detections to date. The…

We investigate the evolution of compact galaxy number density over the redshift range $0.2<z<0.8$. Our sample consists of galaxies with secure spectroscopic redshifts observed in the COSMOS field. With the large uncertainties, the compact…

Astrophysics of Galaxies · Physics 2015-05-07 Ivana Damjanov , Margaret J. Geller , H. Jabran Zahid , Ho Seong Hwang

Line-of-sight interactions of cosmic rays provide a natural explanation of the hard gamma-ray spectra of distant blazars, which are believed to be capable of producing both gamma rays and cosmic rays. For sources with redshifts z> 0.1,…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Warren Essey , Alexander Kusenko

We present a new data release from the Fiber Multi-Object Spectrograph (FMOS)-COSMOS survey, which contains the measurements of spectroscopic redshift and flux of rest-frame optical emission lines (H$\alpha$, [NII], [SII], H$\beta$, [OIII])…

Current measurements of the Hubble constant $H_0$ on scale less than $\sim100$ Mpc appear to be controversial, while the observations made at high redshift seem to provide a relatively low value. On the other hand, the Hubble expansion is…

Astrophysics · Physics 2009-10-28 Xiang-Ping Wu , Bo Qin , Li-Zhi Fang

The introduction of low-frequency radio arrays is expected to revolutionize the study of the reionization epoch. Observation of the contrast in redshifted 21cm emission between a large HII region and the surrounding neutral inter-galactic…

Astrophysics · Physics 2009-11-13 Stuart Wyithe

We investigate the spatial clustering of galaxies around quasars at redshifts from 0.6 to 1.2 using the photometric data from Sloan Digital Sky Survey (SDSS) Stripe 82. The quasar and galaxy cross-correlation functions are measured through…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-24 Shao-Hua Zhang , Ting-Gui Wang , Hui-Yuan Wang , Hongyan Zhou

In the last years, progress has been very rapid in the domain of molecules at high redshift, and we know in better detail now the molecular and dust content in several systems beyond z=1 and up to z = 5. The first discovery in 1992 by Brown…

Astrophysics · Physics 2016-08-30 F. Combes

We present discovery spectra of a sample of eight lensed galaxies at high redshift, 3.7<z<5.2, selected by their red colors in the fields of four massive clusters: A1689, A2219, A2390, and AC114. Metal absorption lines are detected and…

Astrophysics · Physics 2009-11-07 Brenda Frye , Tom Broadhurst , Narciso Benitez

Using the Gemini Near-InfraRed Spectrograph (GNIRS), we have completed a near-infrared spectroscopic survey for K-bright galaxies at z~2.3, selected from the MUSYC survey. We derived spectroscopic redshifts from emission lines or from…

We consider astronomical and local bounds on time variation of fundamental constants to test some generic Kaluza-Klein-like models and some particular cases of Beckenstein theory. Bounds on the free parameters of the different theories are…

Astrophysics · Physics 2009-10-31 Susana J. Landau , Hector Vucetich

The offsets between the radial velocities of the rotational transitions of carbon monoxide and the fine structure transitions of neutral and singly ionized carbon are used to test the hypothetical variation of the fine structure constant,…

Astrophysics of Galaxies · Physics 2017-08-23 S. A. Levshakov , K. -W. Ng , C. Henkel , B. Mookerjea

Comparison of the observed evolution of the Ly-alpha transmitted flux in the spectra of four highest redshift quasars discovered by SLOAN survey with the theoretical prediction for this evolution based on the state-of-the-art numerical…

Astrophysics · Physics 2007-05-23 Nickolay Y. Gnedin

Comparison of quasar absorption spectra with laboratory spectra allow us to probe possible variations in the fundamental constants over cosmological time-scales. In a companion paper we present an analysis of Keck/HIRES spectra and report…

Astrophysics · Physics 2009-08-18 M. T. Murphy , J. K. Webb , V. V. Flambaum , C. W. Churchill , J. X. Prochaska
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