We attempt to create an X-ray/radio AGN catalog and make its multiwavelength studies. ROSAT Bright Source Catalogue (BSC) contains 18,806 and ROSAT Faint Source Catalogue (FSC), 105,922 X-ray sources giving the total number of ROSAT X-ray sources 124,727 (one source is listed twice). On the other hand, NVSS radio catalogue contains 1,773,484 sources. Taking into account that X-ray sources contain AGN, bright stars and galaxies, clusters, white dwarfs (WD), cataclysmic variables (CV), etc., the cross-identification with radio catalogue may distinguish the extragalactic sources. We have cross-correlated ROSAT catalogs with NVSS one with a search radius 30 arcsec. 9,193 associations have been found. To distinguish AGN from the normal bright galaxies and clusters, Veron-Cetty & Veron AGN catalog (v.13, 2010; VCV-13) containing 168,940 objects have been used. A cross-correlation of the 9,193 ROSAT/NVSS sources with the VCV-13 with a search radius 30 arcsec resulted in 3,094 associations. Thus we are left with more 6,099 X-ray/radio sources without an optical identification. Brighter objects are normal bright galaxies, while we believe that all faint ones are candidate AGN with some contamination of distant clusters. SDSS spectroscopic survey allows us classify objects by activity types, and a number of our candidate AGN is found to be present in SDSS. We attempt to find connections between the fluxes in different wavelength ranges, which will allow us to confirm AGN and blazars candidates and in some cases find new ones.

Microlensing offers a unique way to constrain the physical extent of different emission regions in a lensed quasar, putting to test various accretion and continuum emission models. We perform a microlensing analysis using six Chandra observations (spanning six years) of the lensed quasar SDSS 0924+0219 (redshift zs=1.52), in which X-ray microlensing variability is detected with high confidence. The system exhibits pronounced microlensing variability in the X-rays compared to the optical, indicating a comparatively small extent of r1/2<3.8×104 cm (95% confidence) for the X-ray continuum emitting region, near the inner edge of the accretion disk.

We investigate the influence of close neighbor galaxies on the properties of supernovae (SNe) and their host galaxies using 56 SNe located in pairs of galaxies with different levels of star formation (SF) and nuclear activity. The mean distance of type II SNe from nuclei of hosts is greater by about a factor of 2 than that of type Ibc SNe. The distributions and mean distances of SNe are consistent with previous results compiled with the larger sample. For the first time it is shown that SNe Ibc are located in pairs with significantly smaller difference of radial velocities between components than pairs containing SNe Ia and II. We consider this as a result of higher star formation rate (SFR) of these closer systems of galaxies.

We present the dependence of the amount of nuclear star formation on the non-axisymmetry of a bulge of disk galaxies. For this, we use a volume-limited sample of spiral galaxies at 0.02 < = z < 0.055 from the SDSS DR7. Among 3173 final sample galaxies with an axis ratio b/a > 0.6 and a bulge fraction ranged in B/T <= 0.41, nuclear starburst galaxies are 10%. We find that a fraction of the nuclear starburst galaxies become higher when ellipticity of a bulge increases in early type galaxies. Also, the fraction increases clearly when early type galaxies are isolated and in low density region. Our results indicate that the non-axisymmetry of bulges assists gas to fall inside and affects the nuclear starburst process in disk galaxies.

I discuss feeding and feedback processes observed in the inner few hundred parsecs of nearby active galaxies using integral field spectroscopy at spatial resolutions of a few to tens of parsecs. Signatures of feedback include outflows from the nucleus with velocities ranging from 200 to 1000 km s−1, with mass outflow rates between 0.5 and a few M⊙ yr−1. Signatures of feeding include the observation of gas inflows along nuclear spirals and filaments, with velocities ranging from 50 to 100 km s−1 and mass flow rates from 0.1 to ∼1 M⊙ yr−1. These rates are 2–3 orders of magnitude larger than the mass accretion rate to the supermassive black hole (SMBH). These inflows can thus lead, during less than one activity cycle, to the accumulation of enough gas in the inner few hundred parsecs, to trigger the formation of new stars, leading to the growth of the galaxy bulge. Young to intermediate age stars have indeed been found in circumnuclear rings around a number of Active Galactic Nuclei (AGN). In particular, one of these rings, with radius of ≈ 100 pc is observed in the Seyfert 2 galaxy NGC 1068, and is associated to an off-centered molecular ring, very similar to that observed in the Milky Way (MW). On the basis of an evolutionary scenario in which gas falling into the nuclear region triggers star formation followed by the triggering of nuclear activity, we speculate that, in the case of the MW, molecular gas has already accumulated within the inner ≈ 100 pc to trigger the formation of new stars, as supported by the presence of blue stars close to the galactic center. A possible increase in the star-formation rate in the nuclear region will then be followed, probably tens of millions of years later, by the triggering of nuclear activity in Sgr A*.

We report results of a study of the ionized gas towards the Galactic center with radio recombination lines at cm wavelengths. Both the Green Bank Telescope and the Very Large Array were utilized to probe the kinematics of the ionized gas on a global scale for both diffuse and discrete sources within the inner 2.0° × 0.5° (l × b). A diffuse ∼0 km s−1 gas, a thermal flux continuum fraction exceeding 40%, and an asymmetry where ∼70% of the ionized gas is found at positive Galactic longitudes are the preliminary results briefly discussed here.

The bulk of the FeKα emission detected in the central molecular zone (CMZ) is thought to be associated with reflection by the central molecular clouds of enhanced past emission from an external X-ray source, most likely Sgr A*. In order to follow the propagation of the reflected emission through the Galactic center (GC), we analyzed all XMM-Newton observations carried out from 2000 to 2012. Preliminary results indicate that while most of the regions that were bright at 6.4 keV in 2000–2001 have a significantly lower flux in 2012, a few other experienced a flux increase. We report for the first time a significant decrease of the FeKα emission in the Sgr C complex, supporting the reflection origin of the 6.4 keV emission detected in this region.

The diffuse interstellar bands (DIBs) are a set of absorption features, some of which are broad (“diffuse”), that are formed in the diffuse ISM. Since their discovery nearly a century ago their numbers have increased to over 500. The strongest of these are known to be ubiquitous in the universe. There is general consensus that they are produced by large carbon-bearing molecules; however, no specific identification of any single DIB has survived scrutiny. The overwhelming majority of DIBs are at optical and very near infrared wavelengths. In 1990 two DIBs were identified in J-band spectra, at 1.18 μm and 1.31 μm by Joblin et al. (1990); until recently these were the longest wavelength examples known.

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.

We present the very first detection of N2H+J = (1 – 0) and CH3OH(2k−1k) line emission on 5″ scales in the circumnuclear disk (CND) around Sgr A*. The emission matches the position and shape of the dark clouds in the near-infrared. Our findings suggest that these molecular clouds in the eastern CND are significantly colder and denser than the rest of the CND, and partially shocked. The research on these dark clouds will contribute to understanding the processes of star formation close to a supermassive black hole.

In this contribution, we briefly describe how an observed mid-infrared (5.5-14 μm) spectrum can be used to trace key physical conditions along a given line of sight, such as the UV radiation field, the ionization parameter and the dust column density. These parameters are often difficult to determine independently from PDR models. The PAHTAT toolbox offers the opportunity to analyze mid-IR spectra using a limited number of parameters, that are associated with the physical properties of the dust and gas being observed.

In this work, we investigated the correlation between the γ-ray luminosity, logLγ and the core-dominance parameter, log (1+R), for a sample of 124 Fermi blazars with available core and extended radio emissions. Our analysis shows that there is no correlation between the γ-ray luminosity, log Lγ and the core-dominance parameter, log (1+R). However, there is a closely linear correlation between log Lγ − log LExt and log (1+R), log Lγ−log LExt = (0.95 ± 0.08) log (1+R) + (2.72 ± 0.11), for the whole sample. The result suggests that the γ-ray emissions are composed of two components, one is beamed, the other is unbeamed.

Using a set of simulations in the ΛCDM cosmology, and the mass of intermediate X-Ray Active Galactic Nuclei (AGN) dark matter halos (DMH), we study the Halo Occupation Distribution (HOD) of their host DMH and compare with recent observations. We assume that intermediate X-Ray AGNs have been triggered by a major merger of sub-halos inside larger host halos. We find that the binary major merger HOD slope (α ≈ 0.8) do not seem to reproduce the observed HOD slope (α < 0.6) for these type of AGNs. Other mechanisms may be igniting these AGNs.

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.

We present a radio survey of molecules in a sample of Galactic center molecular clouds, including M0.25 + 0.01, the clouds near Sgr A, and Sgr B2. The molecules detected are primarily NH3 and HC3N; in Sgr B2-N we also detect non-metastable NH3, vibrationally-excited HC3N, torsionally-excited CH3OH, and numerous isotopologues of these species. 36 GHz Class I CH3OH masers are ubiquitous in these fields, and in several cases are associated with new NH3 (3,3) maser candidates. We also find that NH3 and HC3N are depleted or absent toward several of the highest dust column density peaks identified in submillimeter observations, which are associated with water masers and are thus likely in the early stages of star formation.

One of the most important features in active galactic nuclei (AGN) is the variability of their emission. Variability has been discovered at X-ray, UV, and radio frequencies on time scales from hours to years. Among the AGN family and according to theoretical studies, Low-Ionization Nuclear Emission Line Region (LINER) nuclei would be variable objects on long time scales. Our purpose is to investigate spectral X-ray variability in LINERs and to understand the nature of these kinds of objects, as well as their accretion mechanism. Chandra and XMM–Newton public archives were used to compile X-ray spectra of LINER nuclei at different epochs with time scales of years. To search for variability we fit all the spectra from the same object with a set of models, in order to identify the parameters responsible for the variability pattern. We found that long term spectral variability is very common, with variations mostly related to hard energies (2-10 keV). These variations are due to changes in the soft excess, and/or changes in the absorber, and/or intrinsic variations of the source.

We present AGNfitter: a Markov Chain Monte Carlo algorithm developed to fit the spectral energy distributions (SEDs) of active galactic nuclei (AGN) with different physical models of AGN components. This code is well suited to determine in a robust way multiple parameters and their uncertainties, which quantify the physical processes responsible for the panchromatic nature of active galaxies and quasars. We describe the technicalities of the code and test its capabilities in the context of X-ray selected obscured AGN using multiwavelength data from the XMM-COSMOS survey.

Polarimetry of the far infrared emission from magnetically-aligned interstellar grains is one of the best ways of studying the magnetic field at the Galactic center. We describe the HAWC+ instrument, under development for flight on SOFIA starting in 2015, which will provide a major advance in capability for these critically important measurements.

Because of its large angular extent, the central molecular zone (CMZ) has to date only been mapped in the mm with single dish telescopes, with resolution about 30″ (1.4 pc). We present the first interferometric maps of a 90 × 50 pc region of the CMZ, with spatial resolution of ∼10″ (0.4 pc). We mapped ∼0.25 square degrees of the CMZ with CARMA in 3mm continuum and the spectral lines SiO J = (2 − 1), HCO+J = (1 − 0), HCN J = (1 − 0), N2H+J = (1 − 0), and CS J = (2 − 1), covering roughly VLSR = −200 to 200 km s−1 with spectral resolution ΔV ∼ 2.5 km s−1. To recover the large scale structure resolved out by the interferometer, the continuum-subtracted spectral line images were combined with the Mopra 22-m telescope survey.

The central molecular zone (CMZ) in the central half kpc of the Milky Way is a massive concentration of molecular gas in the center of a barred spiral galaxy. Current and past activities in the Galactic center include the formation of massive stars/clusters, AGN feeding, and feedback. At the same time, observations of molecular gas in external galaxies show that many disk galaxies have similar condensations of molecular gas in their central kpc or so. They also have CMZs, or nuclear molecular rings or concentrations in more common terms among extragalactic observers. The formation of the CMZs are often, but not always, related to stellar bars. The centers of nearby galaxies can provide valuable information on the general properties of galactic centers and CMZs through comparative studies of multiple galactic centers of different characteristics from various viewing angles. Linear resolutions achieved toward nearby extragalactic CMZs with modern radio interferometers are now comparable to those achieved toward the Galactic CMZ with small single-dish telescopes. I review and present work on the formation mechanism and properties of the CMZs in external galaxies with some comparisons with the CMZ of our Galaxy.