Related papers: Evidence for Two Distinct Broad-Line Regions from …
The changes of broad emission lines should be a crucial issue to understanding the physical properties of changing-look active galactic nucleus (CL-AGN). Here, we present the results of an intensive and homogeneous 6-month long…
We present multi-epoch optical observations of the blazar 3C 454.3 (z = 0.859) from 2008 August through 2011 December, using the SMARTS Consortium 1.5m+RCSpectrograph and 1.3m+ANDICAM in Cerro Tololo, Chile. The spectra reveal that the…
NGC 2617 has attracted a lot of attention after the detection of the changes in spectral type, and its geometry and kinematics of broad-line region (BLR) are still ambiguous. In this paper, we present the high cadence ($\sim$ 2 days)…
We report on a spectral principal component analysis (SPCA) of a sample of 816 quasars, selected to have small Fe II velocity shifts with spectral coverage in the rest wavelength range 3500--5500 \AA. The sample is explicitly designed to…
We present spectroscopic observations of the quasar PG~1512+370, covering the Hbeta line spectral range and collected at moderate resolution (2-7 A FWHM) from 1988 to 1996. The observations show that the blue wing of the Hbeta broad profile…
[Abridged] We compare broad emission line profiles and estimate line ratios for all major emission lines between Ly-alpha and H-beta in a sample of six quasars. The sources were chosen with two criteria in mind: the existence of high…
Results of the analysis of the variability of the H$\beta$ and H$\alpha$ broad emission-line profiles and the He II $\lambda4686$A emission-line fluxes in the 3C 390.3 nucleus during 1992-2014 are present. The observed velocity-dependent…
Here we present results of the long-term (1987-2010) optical spectral monitoring of the broad line radio galaxy Arp 102B, a prototype of active galactic nuclei with the double-peaked broad emission lines, usually assumed to be emitted from…
We present the results of a new reverberation mapping campaign for the broad-lined active galactic nucleus (AGN) in the edge-on spiral IC4329A. Monitoring of the optical continuum with $V-$band photometry and broad emission-line flux…
We present the final installment of an intensive 13-year study of variations of the optical continuum and broad H-beta emission line in the Seyfert 1 galaxy NGC 5548. The data base consists of 1530 optical continuum measurements and 1248…
Results of a ground-based optical monitoring campaign on 3C 390.3 in 1994-95 are presented. The broad-band fluxes (B, V, R, and I), the spectrophotometric optical continuum flux F(5177) and the integrated emission-line fluxes of Ha, Hb, Hg,…
We present the results of a recent reverberation-mapping campaign undertaken to improve measurements of the radius of the broad line region and the central black hole mass of the quasar PG 2130+099. Cross correlation of the 5100 angstrom…
We present reverberation mapping results from the first year of combined spectroscopic and photometric observations of the Sloan Digital Sky Survey Reverberation Mapping Project. We successfully recover reverberation time delays between the…
The mid-IR flux ratios F_A/F_B = 2.84 +/- 0.06 of the two images of the gravitationally lensed quasar HE 1104-1805 show no wavelength dependence to within 3% across 3.6-8.0 um, no time dependence over 6 months and agree with the broad…
We describe the first results from a six-month long reverberation-mapping experiment in the ultraviolet based on 170 observations of the Seyfert 1 galaxy NGC 5548 with the Cosmic Origins Spectrograph on the Hubble Space Telescope.…
We conduct a reverberation mapping (RM) campaign to spectroscopically monitor a sample of selected bright active galactic nuclei with large anticipated broad-line region (BLR) sizes adequate for spectroastrometric observations by the…
We report the results of long-term reverberation mapping (RM) campaigns of the nearby active galactic nuclei (AGN) NGC 4151, spanning from 1994 to 2022, based on archived observations of the FAST Spectrograph Publicly Archived Programs and…
We present high S/N spectra of the H-beta region in 17 intermediate redshift (0.85 le z le 2.5) quasars. The spectra represent first results of our campaign to test the redshift/luminosity robustness of the so-called Eigenvector 1 (E1)…
Results of a long-term spectral monitoring of the active galactic nucleus of NGC 4151 are presented (11 years, from 1996 to 2006). High quality spectra (S/N>50 in the continuum near Halpha and Hbeta) were obtained in the spectral range…
A detailed analysis of the data from a high sampling rate, multi-month reverberation mapping campaign, undertaken primarily at MDM Observatory with supporting observations from telescopes around the world, reveals that the Hbeta emission…