246 datasets found

We present optical observations of the low-luminosity Seyfert 1 nucleus of NGC 4395, as part of a multiwavelength reverberation-mapping program. Observations were carried out...

We present a three-dimensional study of the local (<=100h^-1^kpc) and the large-scale (<=1h^-1^Mpc) environment of the two main types of Seyfert AGN galaxies. For this...

A reverberation-mapping program on NGC 4395, the least luminous known Seyfert 1 galaxy, undertaken with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope...

We present UBVRcIc magnitudes of 49 comparison stars in the fields of the Seyfert galaxies Mrk 335, Mrk 79, Mrk 279, Mrk 506, 3C 382, 3C 390.3, NGC 6814, Mrk 304, Ark 564, and...

Star Formation Across Cosmic Time (SFACT) is a new narrowband (NB) survey designed to detect faint emission-line galaxies (ELGs) and QSOs over a broad range of redshifts. Here...

We present the second catalog of serendipitously discovered compact extragalactic emission-line sources-H{alpha} Dots. These objects have been discovered in searches of...

The discovery of spectral type transition of active galactic nuclei (AGNs), the so-called "changing-look" (CL) phenomenon, challenges the widely accepted AGN paradigm, not only...

Broadband photometric redshifts are routinely obtained for galaxies to estimate their distances. While effective for many uses, the common resolution in z of 0.01-0.02 is too...

We present a statistical study of a large, homogeneously analyzed sample of narrow-line Seyfert 1 (NLS1) galaxies, accompanied by a comparison sample of broad-line Seyfert 1...

During a wide-field narrowband H{alpha} imaging survey, we noted the presence of numerous isolated emission-line point sources in the data. These objects could represent...

We present a study of the nuclear morphology of a sample of narrow- and broad-line Seyfert 1 galaxies (NLS1s and BLS1s, respectively) based on broadband images in the Hubble...

We present results from the analysis of the optical spectra of 47 radio-selected narrow-line Seyfert 1 (NLS1) galaxies. These objects are a subset of the First Bright Quasar...

We have searched the Faint Images of the Radio Sky at Twenty centimeters (FIRST, ) and the NRAO VLA Sky Survey (NVSS, ) 1.4GHz radio surveys for sources that are coincident with...

The KPNO International Spectroscopic Survey (KISS) is an objective-prism survey for extragalactic emission-line objects. It combines many of the features of previous slitless...

The magnitude-limited catalog of the Southern Sky Redshift Survey (SSRS2, Cat. ) is used to characterize the properties of galaxies hosting active galactic nuclei (AGNs). Using...

We present a study of the X-ray properties of a volume-limited sample of optically selected emission-line galaxies. The sample is derived from a correlation between the KPNO...

We present a sample of 150 narrow-line Seyfert 1 galaxies (NLS1's) found within the Sloan Digital Sky Survey (SDSS) Early Data Release (EDR) (Stoughton et al.,...

This is the second paper of the series about our Multiwavelength Quasar Survey. We present the observational results for the X-ray candidates in the field of the Coma Cluster....

The KPNO International Spectroscopic Survey (KISS) is an objective-prism survey for extragalactic emission-line objects. It combines many of the features of previous slitless...

The KPNO International Spectroscopic Survey (KISS) is a new objective-prism survey for extragalactic emission-line objects. It combines many of the features of previous slitless...