Related papers: A Search for Ultraviolet Emission from LINERs

Imaging studies have shown that about 25% of LINER galaxies display a compact nuclear UV source. As part of a program to study the nature of LINERs and their connection to the active galaxy phenomenon, we compare the HST ultraviolet…

I review the UV properties of LINERs (low-ionization nuclear emission-line regions), based mostly on the recent {\it HST} UV imaging survey of nearby galaxies by Maoz et al. (1995). 25 of the galaxies in the northern subsample host a LINER…

Imaging studies have shown that about 25% of LINER galaxies display a compact nuclear UV source. I compare the HST ultraviolet spectra now available for seven such ``UV-bright'' LINERs. The spectra of NGC 404, NGC 4569, and NGC 5055 show…

Low-ionization nuclear emission-line regions (LINERs), which exist in a large fraction of galaxies, may be the least luminous manifestation of quasar activity. The nature of LINERs has, however, remained controversial because an AGN-like…

LINERs exist in the nuclei of a large fraction of luminous galaxies, but their connection with the AGN phenomenon has remained elusive. We present Hubble Space Telescope narrowband [O III]5007 and H-alpha+[N II] emission-line images of the…

As a step towards clarifying the ionization mechanism of LINERs, we have used the Hubble Space Telescope Faint Object Spectrograph to obtain an ultraviolet spectrum of the nucleus of NGC 6500. Compared with more luminous Seyfert nuclei, the…

LINER nuclei, which are present in many nearby galactic bulges, may be the manifestation of low-rate or low-radiative-efficiency accretion onto supermassive central black holes. However, it has been unclear whether the compact UV nuclear…

We have conducted a comprehensive mid-IR spectroscopic investigation of 67 Low Ionization Nuclear Emission Line Regions (LINERs) using archival observations from the high resolution modules of the Infrared Spectrograph on board the Spitzer…

In an effort to better understand the UV properties of ultraluminous infrared galaxies (ULIGs), and compare them to the rest-frame UV properties of high redshift sub-mm and Lyman-break galaxies, we have obtained far- and near-UV imaging…

We have studied the nuclei of 28 radio galaxies from the 3CR sample in the UV band. Unresolved nuclei (central compact cores, CCC) are observed in 10 of the 13 FR I, and in 5 of the 15 FR II. All sources that do not have a CCC in the…

We present evidence that the outflowing UV absorbers in Seyfert 1 galaxies arise primarily in their inner narrow (emission) line regions (NLRs), based on similarities in their locations, kinematics, and physical conditions. 1) Hubble Space…

We use X-ray observations of three galaxies hosting LINERs (NGC 404, NGC 4736, NGC 4579) with Chandra to study their power sources. We find very diverse properties within this small group: NGC 404 has an X-ray-faint nucleus with a soft,…

We present six galaxies at z~2 that show evidence of Lyman continuum (LyC) emission based on the newly acquired UV imaging of the Hubble Deep UV legacy survey (HDUV) conducted with the WFC3/UVIS camera on the Hubble Space Telescope (HST).…

In order to determine whether unified models of active galactic nuclei apply to low-luminosity objects, we have undertaken a spectropolarimetric survey of of LINERs and Seyfert nuclei at the Keck Observatory. The 14 objects observed have a…

Understanding the composition and structure of the broad-line region (BLR) of active galactic nuclei (AGN) is important for answering many outstanding questions in supermassive black hole evolution, galaxy evolution, and ionization of the…

Optical emission lines are used to categorize galaxies into three groups according to their dominant central radiation source: active galactic nuclei, star formation, or low-ionization (nuclear) emission regions [LI(N)ERs] that may trace…

We use ROSAT HRI spatial data and ASCA spectral measurements for a sample of seven nearby, early type spiral galaxies, to address the question of whether a low-luminosity Active Galactic Nucleus (LLAGN) is present in galaxies that have a…

In the last few years, prominent high-ionization nebular emission lines (i.e., OIII], CIII], CIV, HeII) have been observed in the deep UV spectra of z~5-7 galaxies, indicating that extreme radiation fields characterize reionization-era…

JWST spectroscopy has built large emission line samples at $z\gtrsim4$, but it has yet to confidently reveal many galaxies with the hard radiation fields commonly associated with AGN photoionization. While this may indicate a weaker UV…

We use the Hubble Space Telescope ACS/SBC and Very Large Telescope FORS cameras to observe the Brightest Cluster Galaxies in Abell 2597 and Abell 2204 in the far-ultraviolet (FUV) F150LP and optical U, B, V, R, I Bessel filters. The FUV and…