Active galactic nuclei--Spectra
The central engine of Active Galactic Nuclei
... of Active Galactic Nuclei (AGN) began in the early 1940’s with the advancement in radio astronomy, the detection of powerful radio sources and radio jets, and the discovery of spiral Galaxies with ...
201
The many lives of active galactic nuclei II: the formation and evolution of radio jets and their impact on galaxy evolution
... The interaction between radio jets/lobes and the hot atmospheres into which they expand sets both the properties of the observed AGN, such as their sizes, morphologies, luminosities and radio spectra; and through ...
13
Unveiling the Structure of Active Galactic Nuclei with Hard X ray Spectroscopy
... of active galactic nuclei (AGN) invokes an anisotropic ob- scuring structure, usually referred to as a torus, to explain the diverse phenomenol- ogy of AGN as an angle-dependent ...X-ray ...
291
Relationship Between Spectral Indices and Flux Variability of the Active Galactic Nuclei 3C 273
... monitored active galactic nuclei (AGNs), has been observed for more than one hundred ...and spectra varying with time, it is well known that synchrotron flares from shock waves propagating ...
5
Constraining the Size of the Dusty Torus in Active Galactic Nuclei: An Optical/Infrared Reverberation Lag Study
... led to their categorization. Seyfert galaxies typically have high-ionization narrow forbidden lines and broad hydrogen lines with a rising ultraviolet continuum. Two broad categories of Seyfert type galaxies (due to ...
200
A multifrequency study of X-ray selected active galactic nuclei from the HEAO-1 survey
... The boundaries between the broad classes indicated in Table 1 (blazar, quasar, radio galaxy, Seyfert galaxy and low-luminosity AGN) are based primarily on observational differences. From their optical spectra, BL ...
334
Studying the potential of the [OII] emission line as a surrogate for stellar velocity dispersion in Active Galactic Nuclei
... To better understand the differences between the [OII] and [OIII] emission lines we perform an initial visual inspection of the emission lines for each galaxy. We first look for asymmetric line profiles, indicating red ...
35
The NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background
... the spectra shape of AGN in the hard X-ray band ( see Figure 5 ) ...harder spectra than those typically measured below 10 ...X-ray spectra is required to reconcile our NuSTAR data with prior, ...
8
Clear evidence for the early triggering of a luminous quasar-like active galactic nuclei in a major, gas-rich merger
... Before fitting, we also subtracted the higher order Balmer lines and a nebular continuum using the procedure outlined in Dick- son et al. (1995) and Holt, Tadhunter & Morganti (2003). The necessity of subtracting the ...
9
Dielectronic recombination of Fe 3pq ions: a key ingredient for describing x-ray absorption in active galactic nuclei
... give rise to strong X-ray absorption lines due to n = 2 − 3 electronic inner-shell transitions. These are seen in the spectra of active galactic nuclei (AGNs) observed by Chandra and ...
7
Differential Photometry of Active Galactic Nuclei using Time Resolved Observations with the 1m Nickel Telescope of Lick Observatory
... Using a technique called reverberation mapping, we are able to estimate the masses of the black holes in the center of AGNs by collecting three sets of data: the flux of the central source from photometry, the flux of ...
35
Extending the calibration of C IV-based single-epoch black hole mass estimators for active galactic nuclei
... STIS spectra using the object SBS 1116 + 583A, which shows the highest host-galaxy fraction in the ground-based spectroscopic observations ( see Park et ...
21
Active Galactic Nucleus and Starburst Classification from Spitzer Mid‐Infrared Spectra for High‐Redshift SWIRE Sources
... Imaging surveys with the Spitzer Space Telescope using the Multiband Imaging Photometer ( MIPS) ( Rieke et al. 2004) detect sufficient sources at 24 m to resolve the cosmic back- ground (Hauser et al. 1998) at ...
12
Time but no space : resolving the structure and dynamics of active galactic nuclei using time domain astronomy
... their most salient features can be summarised in a short paragraph. An AGN is the inner most light year or so of an Active Galaxy. It is the collective name for an ensemble of gas and dust that moves (likely ...
208
X-ray Evolution and Variability of Active Galactic Nuclei
... y spectra th an QSOs (Romero-Colmenero et ...eir spectra could be hard because of intrinsic absorption; this is certainly believed to be th e case for Seyfert 2 ...
206
Extragalactic Background Light expected from photon-photon absorption on spectra of distant Active Galactic Nuclei
... hard spectra of Active Galactic Nuclei with high red shifts allow the determination of a EBL ...those spectra are resolved at the energies from 800GeV to 30 ...
5
The role of environment in the observed Fundamental Plane of radio active galactic nuclei
... flat spectra (Blandford & K¨onigl 1979), takes place on parsec scales, and for typical jet powers, the synchrotron emission should be optically thin on kiloparsec (kpc) scales which are of interest in this ...
7
Variability of Active Galactic Nuclei From Differential Photometry
... rather than radiatively in high electron densities (for example in the BLR). Temperatures range from 10,000 K to 25,000 K which are measured from the ratio of certain forbidden line pairs. However, there is a dusty torus ...
37
X-ray and optical studies of active galactic nuclei
... the red portion of the d ata alone. There are a num ber of variables in constructing such simulations, such as the tem perature of the assumed black body, the power-law slope, and the ‘break p o in t’ where the black ...
194
Observing---and Imaging---Active Galactic Nuclei with the Event Horizon Telescope
... The imaging challenges faced by the EHT bear a strong resemblance to those confronted by the optical interferometry (OI) community [30]. Optical interferometers typically consist of a small number of telescopes, limiting ...
10