227 datasets found

We report on the discovery of one of the most extreme cases of high-frequency radio variability ever measured in active galactic nuclei (AGNs), observed on time-scales of days...

(no description available) Cone search capability for table VII/181/table2 (Catalog for PG Quasars) Cone search capability for table VII/181/table3 (Catalog for Seyfert 1 and...

A list of 959 Seyfert galaxies whose data were obtained up to the beginning of 1987 is compiled. Coordinates, redshifts, UBVR-photoelectric magnitudes, absolute magnitudes,...

The objects of this catalogue were detected by using the 61-cm aperture Curtis Schmidt telescope in combination with a thin objective prism (1.8{deg}) at the Cerro Tololo...

The authors have used the IRAS data to compile a sample of 893 galaxies, including 118 Seyfert galaxies. Please refer to the "12micron.doc" (ascii) or "12micron.tex" (LaTeX)...

Based on our UBVRI observations and X-ray data from the RXTE satellite we have investigated the variabilities of the Seyfert Galaxy 3C 120 over the period 1996-2008.

UBVRI observations of the nucleus of the Seyfert galaxy NGC 5548 from 1990 until 2000 at four astronomical observatories are given in Table2. All data have been reduced to a...

Broadband UBVRI observations of the nucleus of the Seyfert galaxy NGC 4151 from 1989 until 2000 at three astronomical observatories: the Crimean Station of the Sternberg...

Two CCD spectra of the star BM Ori were obtained with the echelle spectrograph of the 6-m telescope. Measured line equivalent widths were used to estimate atmospheric parameters...

The UBV observations of performed between 1972 and 1998 are presented. The aperture is 27.5".

Variability of the continuum, H{beta}, H{gamma} and HeII(4686{AA}) fluxes of the Seyfert I galaxy Mrk 509 is studied using spectra obtained on the 2.6-m telescope of the Crimean...

The results of three-color UBV observations of rapid variability in the nucleus of the Seyfert galaxy NGC 7469 carried out in 1990-1994 are presented. The observations have been...

Accretion rates and their correlation with cosmological redshifts for a sample of blazars and Seyfert galaxies are presented. The sample includes 77 blazars (28 FSRQs, 26 LBLs,...

Confusing sources of Seyfert and HII galaxies in IRAS point source catalogue may be caused by companion objects of those galaxies. Comparison between confused galaxies and...

The validity of the unified active galactic nuclei (AGN) model has been challenged in the last decade, especially when different types of AGNs are considered to only differ in...

We present a near-infrared spectroscopic survey of narrow-line Seyfert 1 galaxies in the southern hemisphere (using the SOFI instrument on the ESO-NTT telescope), sampled from...

Polycyclic aromatic hydrocarbons (PAHs) are of great astrochemical and astrobiological interest due to their potential to form prebiotic molecules. We analyse the 7.7 and...

We build detailed composite models of photoionization and shock ionization based on the SUMA code to reproduce emission lines emitted from the Narrow Line Regions (NLR) of...

We present the results of new radio observations carried out with the Karl G. Jansky Very Large Array C-configuration at 5.5GHz for a sample of southern narrow-line Seyfert 1...

A thorough study of radio emission in active galactic nuclei (AGNs) is of fundamental importance to understand the physical mechanisms responsible for the emission and the...