Related papers: Enhanced Star Formation in Narrow Line Seyfert 1 A…

We present Spitzer rest-frame mid-infrared spectroscopy of twelve z~2 mm-bright type 1 QSOs, selected from unlensed and lensed QSO samples and covering a range of AGN optical luminosities L_5100=10^45 to 10^47 erg/s. On top of the AGN…

We investigated narrow line Seyfert 1 galaxies (NLS1s) at optical, mid-infrared (MIR) and X-ray wavelengths, comparing them to the broad line active galactic nuclei (BLAGNs). We found that black hole mass, coronal line luminosities, X-ray…

We study a combined sample of 264 star-forming, 51 composite, and 73 active galaxies using optical spectra from SDSS and mid-infrared (mid-IR) spectra from the Spitzer Infrared Spectrograph. We examine optical and mid-IR spectroscopic…

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…

Narrow-line Seyfert 1 AGNs (NLS1s) represent a unique stage in the black hole growth history, characterised by low black hole masses of approximately $10^{6}$-$10^{8}$ solar masses and around-Eddington accretion rates. X-ray studies of…

In the last decade of Active Galactic Nuclei (AGN) monitoring programs, the Mets\"ahovi Radio Observatory detected multiple times seven powerful flaring narrow-line Seyfert 1 (NLS1) galaxies at 37 GHz. Several hypotheses have been proposed,…

Narrow-line Seyfert 1 (NLS1) galaxies provide us with unique insights into the drivers of AGN activity under extreme conditions. Given their low black hole (BH) masses and near-Eddington accretion rates, they represent a class of galaxies…

The first high resolution Spitzer IRS 9-37um spectra of 29 Seyfert galaxies (about one quarter) of the 12um Active Galaxy Sample are presented and discussed. The high resolution spectroscopy was obtained with corresponding off-source…

We present near-infrared (NIR) spectroscopic observations of 28 X-ray and mid-infrared selected sources at a median redshift of z~0.8 in the Extended Groth Strip (EGS). To date this is the largest compilation of NIR spectra of active…

Several studies indicate that radio-loud (RL) Active Galactic Nuclei (AGN) are produced only by the most massive black holes (BH), $M_{\rm BH} \sim 10^8$-$10^{10} M_\odot$. This idea has been challenged by the discovery of RL Narrow Line…

This work presents the properties of 42 objects in the group of the most luminous, highest star formation rate LINERs at z = 0.04 - 0.11. We obtained long-slit spectroscopy of the nuclear regions for all sources, and FIR data (Herschel and…

We present an analysis of Spitzer IRS spectroscopy of 83 active galaxies from the extended 12 micron sample. We find rank correlations between several tracers of star formation which suggest that (1) the PAH feature is a reliable tracer of…

We use Spitzer IRS spectroscopy to study the nature 65 IR-luminous galaxies at 0.02 < z < 0.6 with F(24micron) > 1.2mJy. The IRS spectra cover wavelengths spanning the PAH features and important atomic diagnostic lines. Our sample…

[Abridged] Narrow-line Seyfert 1 (NLS1) galaxies are a class of active galactic nuclei (AGN) that have all the properties of type 1 Seyfert galaxies but show peculiar characteristics, including the narrowest Balmer lines, strongest Fe II…

We present the Spitzer 10-37um IRS high resolution (R~600) spectroscopic survey of the Seyfert galaxies of the 12 micron Galaxy Sample. The new spectra of 61 galaxies, with those already published, gives us a total of 91 12micron Seyfert…

The recent observations of highly accreting supermassive black holes (SMBH) at very high redshift ($>$4) with the James Webb Space Telescope (JWST) allowed us to shed light for the very first time on the early evolutionary phases of active…

The recent discovery by Fermi/LAT of high-energy (E>100 MeV) gamma rays from Narrow-Line Seyfert 1 Galaxies (NLS1s) made evident the existence of a third class of gamma-ray emitting Active Galactic Nuclei (AGN), after blazars and radio…

We present optical images of nearby 50 narrow-line Seyfert 1 galaxies (NLS1s) which cover all the NLS1s at z<0.0666 and $\delta \ge -25^{\circ}$ known at the time of 2001. Among the 50 NLS1s, 40 images are newly obtained by our observations…

We have selected a sample of 292 SDSS Narrow-Emission-Line galaxies known to have formed and evolved in relative isolation to study the nature and origin of the AGN phenomenon. The galaxies in our sample have line fluxes with S/N>3 and were…

We present oxygen abundances relative to hydrogen (O/H) in the narrow line regions (NLRs) gas phases of Seyferts 1 (Sy 1s) and Seyferts 2 (Sy 2s) Active Galactic Nuclei (AGNs). We used fluxes of the optical narrow emission line intensities…