相关论文: The Luminosity function of Narrow-Line Seyfert gal…

During commissioning observations, the Sloan Digital Sky Survey (SDSS) has produced one of the largest existing galaxy redshift samples selected from CCD images. Using 11,275 galaxies complete to r^* = 17.6 over 140 square degrees, we…

Narrow-line Seyfert 1 galaxies (NLS1s) is one of the few classes of active galactic nuclei (AGN) harboring powerful relativistic jets and detected in $\gamma$ rays. NLS1s are well-known X-ray sources. While in non-jetted sources the origin…

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 modeling and interpretation of the continuum and emission lines for a sample of 51 unobscured Type 1 active galactic nuclei (AGN). All of these AGNs have high quality spectra from both XMM-Newton and Sloan Digital Sky Survey…

We present a multi-waveband analysis of a 126 galaxy sub-sample of the 12 micron galaxy sample (12MGS), for which we have carried out a detailed X-ray spectral analysis of in a previous paper. We present optical activity classes and we…

While [OIII] narrow-band imaging is commonly used to measure the size of the narrow-line regions (NLRs) in active galactic nuclei (AGNs), it can be contaminated by emission from surrounding starbursts. Recently, we have shown that long-slit…

We studied optical variability (OV) of a large sample of narrow-line Seyfert 1 (NLSy1) and broad-line Seyfert 1 (BLSy1) galaxies with z<0.8 to investigate any differences in their OV properties. Using archival optical V-band light curves…

For a sample of $\sim$80 local ($0.02 \leq z \leq 0.1$) Seyfert-1 galaxies with high-quality long-slit Keck spectra and spatially-resolved stellar-velocity dispersion ($\sigma_{\star}$) measurements, we study the profile of the…

A new method is presented to obtain a non-parametric maximum likelihood estimate of the luminosity function and the selection function of a flux limited redshift survey. The method parameterizes the selection function as a series of…

SMBHs are theorised to undergo significant growth in the early Universe, however, the X-ray Luminosity Function (XLF), used as a principal tracer of the SMBH accretion density, lacks observational constraints at z>6, until now. We present…

A fraction of active galactic nuclei do not show the classical Seyfert-type signatures in their optical spectra, i.e. they are optically "elusive". X-ray observations are an optimal tool to identify this class of objects. We combine new…

Extragalactic surveys in the emission line of [O III] 5007 have provided us with the absolute line strengths of large, homogeneous sets of planetary nebulae. These data have been used to address a host of problems, from the measurement of…

While NLS1s have been studied intensively at X-ray and optical wavelengths, comparatively little is known about their characteristics in the radio band. Therefore, we have carried out an investigation of the radio luminosities, source…

We analyze UV spectra for a large sample of 578 Type 1 AGNs and derive Eddington ratios, L/Ledd, from the bolometric luminosities and emission line widths for each object in the sample. The sample spans 5 orders of magnitude in supermassive…

We estimate black hole masses in Narrow Line Seyfert 1 (NLS1) galaxies at the basis of their X-ray excess variance. We apply the standard approach appropriate for Broad Line Seyfert 1 (BLS1) galaxies. In general, we find that the obtained…

As part of the TANAMI multiwavelength progam, we discuss new X-ray observations of the $\gamma$-ray and radio-loud Narrow Line Seyfert galaxy ($\gamma$-NLS1) PKS 2004-447. The active galaxy is a member of a small sample of radio-loud NLS1s…

We present the results of X-ray spectral analysis of 22 active galactic nuclei (AGNs) with a small scattering fraction selected from the Second XMM-Newton Serendipitous Source Catalogue using hardness ratios. They are candidates of buried…

In this work, we revisit the size-luminosity relation of the extended narrow line regions (ENLRs) using a large sample of nearby active galactic nuclei (AGN) from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey. The…

We present the results of our broadband study of the $\gamma$-ray emitting narrow line Seyfert 1 (NLSy1) galaxy SBS 0846+513 ($z=0.585$). This includes multi-band flux variations, $\gamma$-ray spectral analysis, broad band spectral energy…

Recently growing evidence has been accumulated that the NLS1s are viewed from nearly pole-on viewing angles. However, there has been no theoretical model which explains the following important correlations; 1) weaker optical Fe II emitters…