Related papers: Seyfert 1 Composite Spectrum using SDSS Legacy Sur…
The study of narrow-line Seyfert 1 galaxies (NLS1s) is now mostly limited to low redshift ($z<0.8$) because their definition requires the presence of the H$\beta$ emission line, which is redshifted out of the spectral coverage of major…
We present the composite optical spectrum for the largest sample of giant radio quasars (GRQs). They represent a rare subclass of radio quasars due to their large projected linear sizes of radio structures, which exceed 0.7 Mpc. To…
New far-infrared photometry with ISOPHOT, onboard the Infrared Space Observatory, is presented for 58 galaxies with homogeneous published data for another 32 galaxies all belonging to the 12 micron galaxy sample. In total 29 Seyfert 1's, 35…
We present the results of VLA A-array 8.46 GHz continuum imaging of 55 Seyfert galaxies (19 Seyfert 1's and 36 Seyfert 2's). These galaxies are part of a larger sample of 88 Seyfert galaxies, selected from mostly isotropic properties, the…
The Spitzer Extended Deep Survey (SEDS) as a deep and wide mid-infrared (MIR) survey project provides a sample of 500000+ sources spreading 1.46 square degree and a depth of 26 AB mag (3$\sigma$). Combining with the previous available data,…
We present the results of a detailed multi-wavelength study of a sample of sixteen narrow-line Seyfert 1 (NLSy1) galaxies known in $\gamma$-rays so far. This includes a focused X-ray spectral analysis, to compare them with a more general…
X-ray observations of Seyfert 1 galaxies offer the unique possibility of observing spectral variability on timescales comparable to the dynamical time of the inner accretion flow. They typically show highly variable lightcurves, with Power…
We report here preliminary results from a survey of nearby Seyfert galaxies using the EPIC CCDs on board XMM-Newton. The total sample consists of 28 Seyfert galaxies, and constitute a well-defined, complete (B<12.5 mag), and volume-limited…
The 15R-North galaxy redshift survey is a uniform spectroscopic survey (S/N $\sim $10) covering the range 3650---7400\AA for 3149 galaxies with median redshift 0.05. The sample is 90% complete to $R=15.4$. The median slit covering fraction…
Traditional classification for subclass of the Seyfert galaxies is visual inspection or using a quantity defined as a flux ratio between the Balmer line and forbidden line. One algorithm of deep learning is Convolution Neural Network (CNN)…
We have improved upon our previous search technique of systematically searching QSO spectra for narrow galactic H-alpha emission, which indicates a foreground galaxy within the Sloan Digital Sky Survey (SDSS) spectral fiber. We now search…
We report here our comparative analysis of active galactic nucleus (AGN) and star formation (SF) characteristics of a sample of narrow-line Seyfert 1 (NLS1) and broad-line Seyfert 1 (BLS1) galaxies. Our sample consisted of 373 BLS1 and 240…
An empirical method of modeling the stellar spectrum of galaxies is proposed, based on two successive applications of Principal Component Analysis (PCA). PCA is first applied to the newly available stellar library STELIB, supplemented by…
A field of 1.013 ster in the ROSAT all-sky survey (RASS), centered on the south galactic pole (SGP), has been searched in a systematic, objective manner for clusters of galaxies. The procedure relied on a correlation of the X-ray positions…
The large scale structure catalogs within DESI Data Release 1 (DR1) use nearly 6 million galaxies and quasars as tracers of the large-scale structure of the universe to measure the expansion history with baryon acoustic oscillations and the…
We present a measurement of the 1D Ly$\alpha$ forest flux power spectrum, using the complete Baryon Oscillation Spectroscopic Survey (BOSS) and first extended-BOSS (eBOSS) quasars at $z_{\rm qso}>2.1$, corresponding to the fourteenth data…
We present the second and final data release of the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). Data are presented for 63 new galaxies not included in the first data release, and we provide 2D emission-line fitting…
In this paper we investigate the power of spectral synthesis as a mean to estimate physical properties of galaxies. Spectral synthesis is nothing more than the decomposition of an observed spectrum in terms of a superposition of a base of…
We study 16,707 quasar spectra from the SDSS using the Karhunen-Lo\`eve (KL) transform (or Principal Component Analysis, PCA). The quasar eigenspectra of the full catalog reveal the following: 1st order - the mean spectrum; 2nd order - a…
We built r-band surface brightness profiles by SDSS data for 16 Seyfert galaxies observed in Crimean Astrophysical Observatory. Obtained profiles can be used for finding more accurate lightcurves for these galaxies.