Results 11 to 20 of about 6,949,336 (206)

Astroinformatics of galaxies and quasars: a new general method for photometric redshifts estimation [PDF]

Monthly Notices of the Royal Astronomical Society, 2011
A novel method to evaluate photometric redshifts for both galaxiesa and quasars with application to the SDSS ...
O. Laurino, R. D’Abrusco, G. Longo, G. Riccio   +3 more
core   +11 more sources

Discovery of 24 radio-bright quasars at 4.9 ≤ [PDF]

Astronomy & Astrophysics, 2022
High-redshift quasars (z >  5) that also shine brightly at radio wavelengths are unique signposts of supermassive black hole activity in the early universe.
Zeimann, G. R., Röttgering, H., Gloudemans, A., Hill, G., Hardcastle, M., G. K. Miley, Venemans, B., A. Saxena, Saxena, A., Best, P.N., Harikane, Y., Hill, G.J., Magliocchetti, M., Röttgering, H.J.A., Wagenveld, J., Hardcastle, M.J., Hardcastle, M. J., Venemans, B. P., Wagenveld, J.D., J. D. Wagenveld, Zeimann, G.R., Drabent, A., Nanni, R., P. N. Best, Hennawi, J.F., Duncan, K., E. Bañados, Miley, G. K., K. J. Duncan, Miley, G., B. P. Venemans, Gloudemans, A. J., Hennawi, J. F., Y. Harikane, Smith, D.J.B., Best, P., H. J. A. Röttgering, Wagenveld, J. D., D. Yang, G. J. Hill, Yang, D., Duncan, K. J., T. W. Shimwell, Venemans, B.P., Miley, G.K., Lansbury, G., Shimwell, T.W., M. J. Hardcastle, Hennawi, J., G. R. Zeimann, Hill, G. J., G. Lansbury, Duncan, K.J., Smith, D. J. B., R. Nanni, Gloudemans, A.J., Shimwell, T., D. J. B. Smith, A. Drabent, Shimwell, T. W., Rottgering, H. J. A., Zeimann, G., Best, P. N., M. Magliocchetti, Bañados, E., J. F. Hennawi, A. J. Gloudemans, Smith, D.   +67 more
core   +2 more sources

Variability in Quasar Light Curves: using quasars as standard candles [PDF]

Journal of Cosmology and Astroparticle Physics, 2022
A relation between the variational slope, $s_F$ , and the mean absolute magnitude, $\langle M \rangle$, in the light curves of 58 spectroscopically confirmed quasars is measured with a dispersion of 0.15dex.
Solomon, Rance, Stojkovic, Dejan
core   +2 more sources

High Metal Content of Highly Accreting Quasars [PDF]

Astrophysical Journal, 2021
We present an analysis of UV spectra of 13 quasars believed to belong to extreme Population A (xA) quasars, aimed at the estimation of the chemical abundances of the broad-line-emitting gas.
Del Olmo A., Sniegowska M., Marziani P., Czerny B., Martinez-Aldama M. L., D'Onofrio M., Panda S.   +6 more
core   +2 more sources

Far-infrared emission in luminous quasars accompanied by nuclear outflows [PDF]

, 2017
Combining large-area optical quasar surveys with the new far-infrared (FIR) Herschel-ATLAS Data Release 1, we search for an observational signature associated with the minority of quasars possessing bright FIR luminosities.
Hewett, PC, Dunne, Loretta, Valiante, Elisabetta, M. W. L. Smith, Eales, Stephen, Smith, Matthew William L., P. C. Hewett, N. Bourne, S. Eales, Jarvis, Matthew, Valiante, E, S. Dye, Maddox, N, Valiante, E., Furlanetto, C., Jarvis, M.J., M. Banerji, E. Valiante, Banerji, M., Banerji, M, L. Dunne, Smith, M.W.L., Hewett, P.C., C. Furlanetto, Eales, S., Furlanetto, C, Maddox, SJ, Maddox, Natasha, Dye, S, Maddox, Steve, M. J. Jarvis, Bourne, N., Dunne, L., Dye, S., S. J. Maddox, Bourne, N, Eales, S, Maddox, S.J., Dunne, L, Natasha Maddox, Smith, MWL   +40 more
core   +3 more sources

Quadruply-imaged quasars: some general features [PDF]

, 2020
11 pages, 12 figures, accepted for publication in Journal of the Korean Astronomical Society (JKAS)
P. Tuan-Anh, Tran Thi Thai, N. A. Tuan, P. Darriulat, Pham Ngoc Diep, Do Thi Hoai, Nguyen Bich Ngoc, Pham Tuyet Nhung, Nguyễn Thị Phương   +8 more
openalex   +3 more sources

The general relativistic theory of quasars [PDF]

, 2000
The paper was a preliminary and rejected by the author attempt to describe compact relativistic objects.
Zahid Zakir
openalex   +3 more sources

Chemical enrichment and accretion of nitrogen-loud quasars⋆⋆⋆ [PDF]

, 2017
We present rest-frame optical spectra of 12 “nitrogen-loud” quasars at z ~ 2.2, whose rest-frame ultraviolet (UV) spectra show strong nitrogen broad emission lines.
A. Marconi, Matsuoka, K., Park, D., Nagao, T., K. Matsuoka, Taniguchi, Y., R. Maiolino, Y. Taniguchi, T. Nagao, Marconi, Alessandro, Maiolino, R., D. Park   +11 more
core   +2 more sources

General Formulation of the Gravitational Lens and Analysis of the Multiple Quasar PG1115 + 080 [PDF]

Progress of Theoretical Physics, 1988
Hiroshi Yoshida, M. Omote
openalex   +2 more sources

Testing general relativity on cosmological scales at redshift z ∼ 1.5 with quasar and CMB lensing [PDF]

Monthly Notices of the Royal Astronomical Society, 2020
ABSTRACT We test general relativity (GR) at the effective redshift $\bar{z} \sim 1.5$ by estimating the statistic EG, a probe of gravity, on cosmological scales $19 - 190\, h^{-1}{\rm Mpc}$. This is the highest redshift and largest scale estimation of EG so far.
Yucheng Zhang, Anthony R. Pullen, Shadab Alam, Sukhdeep Singh, E. Burtin, Chia-Hsun Chuang, Jiamin Hou, Brad W. Lyke, Adam D. Myers, Richard Neveux, Ashley J. Ross, Graziano Rossi, Cheng Zhao   +12 more
openalex   +6 more sources