Markarian survey (or the First Byurakan Survey, FBS) was the first systematic survey for active galaxies and was a new method for search for such objects. Until now, it is the largest objective prism survey of the sky (17,000 deg2). It was carried out in 1965–1980 by B. E. Markarian and his colleagues and resulted in discovery of 1517 UV-excess (Markarian) galaxies. They contain many active galaxies, as well as powerful gamma-, X-ray, IR and radio sources (Mrk 180, 231, 421, 501, etc.), BCDGs (Mrk 116) and interacting/merging systems (Mrk 266, 273, etc.). They led to the classification of Seyfert galaxies into Sy1 and Sy2 and the definition of Starbursts (SB). Several catalogs of Markarian galaxies have been published (Mazzarella & Balzano 1986; Markarian et al. 1989; Bicay et al. 1995; Petrosian et al. 2007) and they are accessible in all corresponding databases. Markarian survey also served as a basis for search for UVX stellar objects (including QSOs and Seyferts), late-type stars and optical identification of IR sources. At present the survey is digitized and DFBS database is available. I will review the main characteristics of the Markarian survey, its comparison with other similar surveys and the importance of Markarian galaxies in modern astrophysics.

Over the last decade, quasar sample sizes have increased from several thousand to several hundred thousand, thanks mostly to SDSS imaging and spectroscopic surveys. LSST, the next-generation optical imaging survey, will provide hundreds of detections per object for a sample of more than ten million quasars with redshifts of up to about seven. We briefly review optical quasar selection techniques, with emphasis on methods based on colors, variability properties and astrometric behavior.

Photoionization models for AGN, including Seyfert and LINERs are discussed. These photoionization models can be used to derive emission-line diagnostics for AGN that can determine the properties of the AGN and surrounding ISM, including the relative AGN contribution to the EUV radiation field, the hardness of the AGN radiation field, the ionization state of the gas, and the metallicity of the narrow-line region. It is shown how the AGN emission-line diagnostics are expected to change with redshift. Finally, latest application of these models by the author to wide integral field spectroscopy to separate starburst and AGN contributions in composite galaxies are presented.

High-redshift quasars are unique probes of the evolution of supermassive black holes and the intergalactic medium at the end of the epoch of reionization. We present the optical spectra of eight new z ~ 6 quasars selected from the Panoramic Survey Telescope & Rapid Response System 1 (Pan-STARRS1). Details of the selection strategy can be found in Bañados et al. (2014). With this work we increase the number of known quasars at z < 5.7 by more than 10%. The quasars discovered here span a large range of luminosities (19.6 ≤ zP1 ≤ 21.2) and are remarkably heterogeneous in their spectral features: half of them show bright emission lines whereas the other half show weak or no Lyα emission line. We find a larger fraction of weak–line emission quasars than in lower redshift studies, although still based on low number statistics, this may imply that the quasar population could be more diverse than previously thought.

Supermassive black holes (BHs) live at the heart of essentially all massive galaxies with bulges, power AGN, and are thought to be important agents in the evolution of their hosts. Observations of high-redshift quasars demonstrate that supermassive BHs must start out with masses considerably in excess of normal stellar-mass BHs. However, we do not know how the initial “seed” BHs formed in the early Universe, how massive they were originally, or what types of galaxies they formed in. While direct observations of distant seed BHs and their hosts in the infant Universe are unobtainable with current capabilities, models of BH growth in a cosmological context indicate that present-day dwarf galaxies can place valuable constraints on seed masses and distinguish between various seed formation mechanisms at early times. Using optical spectroscopy from the SDSS, we have systematically assembled the largest sample of dwarf galaxies hosting AGN to date. These dwarf galaxies have stellar masses comparable to the Magellanic Clouds and contain some of the least-massive supermassive BHs known. I will present results from this study and discuss our ongoing efforts to find additional examples of AGN in dwarfs and help constrain theories for the formation of the first seed BHs at high redshift.

This work presents the main results from a selection of optical spectra of Seyfert and LINER galaxies taken from the 9th release of the SDSS with detectable coronal emission. A catalogue of 345 Seyfert 1 (Sy1) and Seyfert 2 (Sy2) galaxies with Forbidden High Ionization Lines (FHILs) emission is presented. By analysing their spectra as well as utilising data from the literature we found evidence of anisotropy in optical FHIL emissions between Sy1 and Sy2 galaxies for the following lines: [Ne v] λ3426, [Fe vii] λ6087, [Fe x] λ6374 and [Fe xi] λ7892. Results continue indicating that optical FHILs are not observed in LINER type galaxies.

The recently published ZORROASTER catalogue is being expanded into what will eventually be a complete list of known ‘nearby’ (z < 0.1) AGN, with optical spectral images, detailed spectral descriptors and waveband-specific flux ratios included where available. The first version of ZORROASTER contained 2843 entries characterised by confirmed or previously suspected broad H-beta emission, and 1000 spectral images. The 2nd version of ZORROASTER was released during the conference, and (in addition to serendipitous updates) includes all z < 0.1 objects from the list of Markarian. Activity classes and spectral descriptions of Markarian objects have been reviewed, and comparisons of flux ratios derived from the 100 ZORROASTER wavelength-specific pass bands are presented for those Markarian AGN for which Sloan Digital Sky Survey spectra exist. The value of the improved parameterizations and classifications of the Markarian objects on AGN studies, and the implications on some past investigations based on the Markarian lists, are briefly discussed.

To study the nature of Lyα blobs (aka LABs), we conduct a deep C IV and He II narrowband imaging survey of 13 Lyα blobs located in SSA22 proto-cluster at z ~ 3.1. We reach the unprecedented sensitivity, 5σ surface brightness limit of 2.1 − 3.4 × 10−18 erg s−1 cm−2 arcsec−2 per 1 arcsec2 aperture for two emission lines. We do not detect any extended C IV and He II emission, placing strong upper limits on the He II/Lyα and C IV/Lyα line ratios. We compare our limits with data in the literature related to the nebulae associated with high-redshift radio galaxies (HzRGs) and quasars, and we recover the data by modeling the LABs as nebulosities powered by a central QSO. For further information see Arrigoni Battaia et al. (2014).

Physical conditions and oxygen and nitrogen abundances in 36 SBS UV-excess and/or emission-line galaxies from the SDSS DR7 were determined. We have found that SBS 0808+578 is AGN. The others are HII galaxies or HII regions in galaxies. For all objects the oxygen abundance 12+log(O/H) lies in the range of 7.85 ÷ 8.61 and log(N/O) ratio in the range of −1.45 ÷ −0.4. They occupy the same area in the diagram N/O O/H as the high-excitation HII regions. We found no extremely metal-deficient galaxy. Using H-alpha fluxes star formation rates (SFR) for our samples galaxies were determined. Determined SFRs, being in the range of 0.001 ÷ 6 o year−1, are similar of that observed in typical star forming regions in spiral and irregular galaxies.

It is known that the main criterion for the selection of active objects in the First Byurakan, otherwise Markarian survey was the presence of signs of UV-excess in their low-dispersion spectra. Using the presence of emission lines as the second criteria became real during the Second Byurakan survey because of its improved technique. Extended (not stellated) objects, selected with the use of this criterion, made the main part of the separate sample of SBS galaxies. Originally, this sample included 1286 objects, selected in 65 fields of the survey (16 square degree each), to which, with the help of other sources than the survey, there were later added some objects. We studied a subsample of SBS galaxies in seven selected fields (the deepest according to the V/Vmax criterion), including about the third of the whole sample. The first, already completed phase of this program was started with carrying out a follow-up slit spectroscopy of all, about 500 objects, based on observations with long-slit spectrographs with 6m telescope of SAO Russia and 2.6.m telescope of Byurakan. As a result redshifts were determined, as well as spectral classification was made for all of objects, using the scheme adapted to the spectral material. Besides other, obtained data allowed us to estimate the efficiency of used criteria for the selection of galaxies of different classes of starformation and nuclear activity along the full scale of the apparent magnitudes, including close to the limit values (18.5 < mpg < 19.5), etc. The fact that the total area of seven fields as the total number of objects in them comparable with these values for the survey as a whole, allows us to extrapolate the results to the whole sample of galaxies as an upper estimate. The second stage is to conduct detailed studies of individual galaxies in the first place, the most interesting in terms of morphology. They are based on panoramic spectroscopy obtained from observations at 6 m telescope of Russia and 2.6m telescope of Byurakan carried out with multipupil spectrographs MPFS and VAGR, correspondently. Processing of the data obtained for more than twenty objects are at different stages (see arXiv:1403.0127 for extended version).

Active galaxies are the most luminous objects observed in the Universe and are believed to be powered by mass accretion processes taking place in the vicinity of the central Super massive black hole (MBH ≥ 108Msun). However, the details of the power generation mechanisms are not understood well yet. In this paper, we are presenting a comparative study of luminosity-distance estimations for the complete sample of active galaxies observed by IUE satellite by different methods. IUE has made UV spectroscopic observations of nearly 400 active galaxies comprising mostly Seyfert 1 galaxies and quasars. We have chosen all the active galaxies observed by IUE satellite for the study of luminosity-distance with redshift. The luminosity-distances (DL) have been calculated using the Hubbles law under non-relativistic and relativistic limits with H0 = 73 Km/sec/Mpc and Terrell (1979) also. We have found that all DL estimations are consistent with each other for z ≤ 1 and diverge for z ≥ 1. The results of cosmological calulator I and II are found to consistent with each other and higher by several factors over cosmological calculator IV and the predictions of the Hubble's law under relativistic case. We observe a kind bimodal distributions in DL for z ≤ 3.5.

Kaz 163 is a close double galaxy. Its southern component S is compact, with a very blue nucleus, in which heated active processes take place. From time to time gas formations are ejected from it, which behave themselves like emission components around the main emission lines Hα and Hβ, around both from their long-wave and short-wave sides. This paper presents the spectral data of new observations, which were carried out with the 2.6m telescope at the Byurakan Astrophysical Observatory in September 2011. During the former observation in October 1981, lines [NII] λλ 6584,6548 were not visible in the spectrum of the component S. In 2001 they were already visible on the spectrum, and on the spectrum obtained in 2011 they already surpassed the intensity of Hα. The magnitude of the component S is also changing: its nucleus is very blue and its U-B = −0m.63. In the soft X-ray spectral range (0.1–2 keV) the flux of the radiation changed by 45% during 55,000 sec, and in the hard one (2–10keV) it changed up to 3.4 times. Photoindices Γ for the soft and hard ranges in the spectrum of galaxy S, unlike other objects, do not so much differ from each other. The mean value for the first interval is approximately 2.5 and is equal −2.0 for the second one. On the histogram of redshifts Kaz 163 corresponds to the first big peak of the distribution. It is concluded that the component S of the galaxy Kaz 163 is a NLS1 galaxy, with the development of their evolution, is in the preliminary stage. Component N is a normal elliptical galaxy with no activity.

The sample of Markarian galaxies consists of 1515 UV-excess galaxies containing many active galaxies, both AGN and Starburst (SB). Several catalogs of Markarian galaxies have been published; however activity types are based on old spectroscopic data. The SDSS spectroscopy and some other recent spectral observations allow classify or re-classify many of Markarian galaxies, altogether we have retrieved and studied 779 SDSS and 300 other spectra. Out of 779 SDSS spectra, we have classified 533 HII, 31 Composites, 12 LINERs, 4 S2.0, 5 S1.9, 8 S1.8, 5 NLS1.5, 11 S1.5, 8 NLS1.2, 21 S1.2, 4 NLS1, 4 S1.0, 2 QSO, 11 AGN (without an exact class), 52 Em (HII or AGN), 65 Abs, and 3 Stars. On the other hand, the galaxies are being classified depending on the fact in which wavelength range they have been observed and studied. E.g. some Sy2 type galaxies turn to be Sy1 when classified in IR. Many hidden AGN (in X-ray and IR) appear to be normal galaxies in optical range. So for better understanding, IR spectra are necessary as well.

Obscured AGN may correspond to a substantial fraction of the supermassive black hole growth rate. I will present new surveys with the SCUBA-2 instrument on the James Clerk Maxwell Telescope of the Chandra Deep Fields and discuss whether we can distinguish obscured AGN in hard X-ray and radio selected samples using submillimeter observations.

We present the first results from a mid-infrared survey of local Active Galactic Nuclei (AGN) using the CanariCam (CC) instrument on the 10.4 m Gran Telescopio Canarias (GTC). We are obtaining sub-arcsecond angular resolution (0.3 − 0.6 arcsec) mid-IR imaging and spectroscopic observations of a sample of 100 local AGN, which are complemented with data taken with T-ReCS, VISIR, and Michelle. The full sample contains approximately 140 AGN, covers nearly six orders of magnitude in AGN luminosity, and includes low-luminosity AGN (LLAGN), Seyfert 1s and 2s, QSO, radio galaxies, and (U)LIRGs. The main goals of this project are: (1) to test whether the properties of the dusty tori of the AGN Unified Model depend on the AGN type, (2) to study the nuclear star formation activity and obscuration of local AGN, and (3) to explore the role of the dusty torus in LLAGN.

Obscured quasars hidden in deep X-ray surveys can be recovered by looking at mid-infrared wavelengths, where dust re-radiates the absorbed radiation. Here we present a sample of obscured quasars in the redshift range 1 < z < 4 based on data from the UKIDSS Ultra-Deep Survey (UDS), the deepest near-IR survey over ~ 1 sq. deg. to date. Candidates that are primarily selected by their 24 μm emission are probed by decomposing their spectral energy distribution (SED) to disentangle the emission from the AGN and its host galaxy. We show preliminary results on their host galaxy properties as well as their clustering, showing that obscured quasars are found in galaxies located in the green valley, residing in dark matter haloes not different from normal galaxies at those redshifts.

One of the remaining open issues in the context of the analysis of Active Galactic Nuclei (AGN) is the evidence that nuclear gravitational accretion is often accompanied by a concurrent starburst activity. We developed a spectral energy distribution (SED) fitting technique to derive simultaneously the physical properties of active galaxies and coexisting starbursts making the best use of Spitzer and Herschel IR observations. We apply the SED fitting procedure to a large sample of extragalactic sources representing the HerMES (Herschel/Multi-tiered Extragalactic Survey) population with IRS spectra with a plethora of multi-wavelength data in order to study the impact of a possible presence of an AGN on the host galaxy's properties. We analyze the star formation rate (SFR) in conncetion to the presence of an AGN and compared the properties of the hot (AGN) and cold (starburst) dust component. Our findings are consistent with no evidence for the presence of an AGN affecting the star formation processes of the host galaxies.

The Wide-field Infrared Survey Explorer (WISE) has scanned the entire sky with unprecedented sensitivity in four infrared bands, at 3.4, 4.6, 12, and 22 μm. The WISE Point Source Catalog contains more than 560 million objects, among them hundreds of thousands of galaxies with Active Nuclei (AGN). While type 1 AGN, owing to their bright and unobscured nature, are easy to detect and constitute a rather complete and unbiased sample, their type 2 counterparts, postulated by AGN unification, are not as straightforward to identify. Matching the WISE catalog with known QSOs in the Sloan Digital Sky Survey we confirm previous identification of the type 1 locus in the WISE color space. Using a very large database of the popular Clumpy torus models, we find the colors of the putative type 2 counterparts, and also, for the first time, predict their number vs. flux relation that can be expected to be observed in any given WISE color range. This will allow us to put statistically very significant constraints on the torus parameters. Our results are a successful test of the AGN unification scheme.

We have undertaken a spectroscopic survey of luminous AGNs and quasars selected in the mid-infrared from Spitzer IRAC surveys. Mid-infrared selection is much less biased with respect to obscuration than optical techniques, and hence enables the discovery of obscured quasars as well as normal, unobscured ones. Our survey is designed to include brighter 24 micron sources over wider areas and also to go to much lower fluxes limits in more limited spatial regions to allow us to disentangle dependences on redshift and luminosity. We have used 4m class telescopes to obtain spectra of the brighter 24 micron targets (targeting high luminosity objects at low z), and 8m class telescopes to identify lower luminosity high-redshift obscured quasars by targeting the fainter 24 micron targets. Fron this survey we have been able to compile a statistically complete sample of ~ 500 AGN, both obscured and unobscured, over a large range of redshift and luminosity. We find that obscured objects outnumber unobscured AGN with an obscured fraction ranging from ~ 90% to ~ 50%. For the most luminous quasars, the number densities of unobscured quasars peaks at z ~ 2.8, and for the obscured objects, the peak may be at slightly higher redshift.

Most astronomers know about B. E. Markarians discovery and further study of galaxies with UV excess. It is less known that in 1963 Markarian drew attention to a small group of galaxies with color index-spectral type discrepancy. Early spectral type of these galaxies is combined with large color index (e.g. M82). Later studies showed that galaxies with large intrinsic color indices (CI ≥ 0.85) exhibit properties typical for active galaxies - galaxies with “red excess” are as active as galaxies with UV excess.