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We have utilized the largest sample of $\gamma$-ray selected Fermi flat-spectrum radio quasars (FSRQs) ever used (519 sources) to construct the luminosity function and its evolution through the cosmic history. In addition to spanning large…

High Energy Astrophysical Phenomena · Physics 2025-12-02 Garima Rajguru , Lea Marcotulli , Marco Ajello , Mattia Di Mauro , Meg Urry

The wide survey of the Chinese Space Station Telescope (CSST) will observe a large field of 17,500 $\text{deg}^2$. The GU, GV, and GI grism observations of CSST will cover a wavelength range from 2550 to 10000\r{A} at a resolution of $R\sim…

Astrophysics of Galaxies · Physics 2025-01-23 Yuxuan Pang , Xue-Bing Wu , Yuming Fu , Rui Zhu , Bing Lyu , Huimei Wang , Xiaotong Feng

We constructed a sample of 185 Flat Spectrum Radio Quasars (FSRQs) by cross-correlating the Shen et al.'s SDSS DR3 X-ray quasar sample with FIRST and GB6 radio catalogues. From the spectrum energy distribution (SED) constructed using…

Astrophysics of Galaxies · Physics 2015-05-13 Zhaoyu Chen , Minfeng Gu , Xinwu Cao

The next generation interferometric radio telescope, the Square Kilometre Array (SKA), which will be the most sensitive and largest radio telescope ever constructed, could greatly contribute to the detection, survey and characterization of…

High Energy Astrophysical Phenomena · Physics 2017-09-05 Alan Cosimo Ruggeri , Salvatore Capozziello

The Square Kilometer Array (SKA) is an international effort to build the world's largest radio telescope, with one square kilometer collecting area. Besides its ambitious scientific objectives, such as probing the cosmic dawn and cradle of…

Instrumentation and Detectors · Physics 2015-04-23 B. Wang , X. Zhu , C. Gao , Y. Bai , J. W. Dong , L. J. Wang

In the near future, new surveys promise a significant increase in the number of quasars (QSO) at large redshifts. This will help to constrain the dark energy models using quasars. The Large Synoptic Survey Telescope (LSST) will cover over…

Astrophysics of Galaxies · Physics 2019-10-08 Mary Loli Martínez-Aldama , Swayamtrupta Panda , Bożena Czerny , Michal Zajaček

We present the results of near-infrared H-band (1.65 microns) imaging of 19 steep spectrum radio quasars (SSRQ) in the redshift range 0.5 < z < 1.0. This sample of SSRQs is matched with our previously studied complete sample of 20 flat…

Astrophysics · Physics 2007-05-23 J. K. Kotilainen , R. Falomo

SKA is a new technology radio-telescope array, about two orders of magnitude more sensitive and rapid in sky surveys than present instruments. It will probe the dark age of the universe, just afer recombination, and during the epoch of…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Francoise Combes

We have selected a complete sample of flat-spectrum radio quasars (FSRQs) from the WMAP 7-yr catalog within the SDSS area, all with measured redshift, and have compared the black hole mass estimates based on fitting a standard accretion…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Gianluca Castignani , Francesco Haardt , Andrea Lapi , Gianfranco De Zotti , Annalisa Celotti , Luigi Danese

We have conducted a pilot survey for z>3.5 quasars by combining the FIRST radio survey with the SDSS. While SDSS already targets FIRST sources for spectroscopy as quasar candidates, our survey includes fainter quasars and greatly improves…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Ian D. McGreer , David J. Helfand , Richard L. White

The Square Kilometre Array (SKA) provides an excellent opportunity for low cost searches for fast radio transients. The increased sensitivity and field of view of the SKA compared with other radio telescopes will make it an ideal instrument…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 T. M. Colegate , N. Clarke

The Square Kilometer Array (SKA) will enable studies of star formation in nearby galaxies with a level of detail never before possible outside of the Milky Way. Because the earliest stages of stellar evolution are often inaccessible at…

Astrophysics · Physics 2009-11-10 Kelsey E. Johnson

SKA-MID surveys will be the first in the radio domain to achieve clearly sub-arcsecond resolution at high sensitivity over large areas, opening new science applications for galaxy evolution. To investigate the potential of these surveys, we…

We present an empirical algorithm for obtaining photometric redshifts of quasars using 5-band Sloan Digital Sky Survey (SDSS) photometry. Our algorithm generates an empirical model of the quasar color-redshift relation, compares the colors…

We aim to illustrate the potentiality of the Advanced Large, Homogeneous Area, Medium-Band Redshift Astronomical (ALHAMBRA) survey to investigate the high redshift universe through the detection of quasi stellar objects (QSOs) at redshifts…

The Square Kilometer Array (SKA) is expected to detect high-redshift galaxies with star formation rates (SFRs) up to two orders of magnitude lower than Herschel surveys and will thus boost the ability of radio astronomy to study…

Astrophysics of Galaxies · Physics 2022-01-26 K. Tisanić , G. De Zotti , A. Amiri , A. Khoram , S. Tavasoli , Z. Vidović-Tisanić

The Square Kilometre Array (SKA) will conduct the biggest spectroscopic galaxy survey ever, by detecting the 21cm emission line of neutral hydrogen (HI) from around a billion galaxies over 3/4 of the sky, out to a redshift of z~2. This will…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-08 S. Yahya , P. Bull , M. G. Santos , M. Silva , R. Maartens , P. Okouma , B. Bassett

We have used the VLA FIRST survey and the APM catalog of the POSS-I plates as the basis for constructing a new radio-selected sample of optically bright quasars. This is the first radio-selected sample that is competitive in size with…

We obtained SDSS spectra for a set of 37 radio-quiet quasars (RQQSOs) that had been previously examined for rapid small scale optical variations, or microvariability. Their H-beta and Mg II emission lines were carefully fit to determine…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-04 Hum Chand , Paul J. Wiita , Alok C. Gupta