Related papers: Unveiling the Active Nucleus of Centaurus A
We studied the nearby, interacting galaxy NGC 5195 (M51b) in the radio, optical and X-ray bands. We mapped the extended, low-surface-brightness features of its radio-continuum emission; determined the energy content of its complex structure…
We used the Atacama Large Millimeter/Submillimeter Array (ALMA) to map the CO(3-2) and [CI](1-0) lines, as well as their underlying continuum emission, from the central $\sim 200$ pc region of the Circinus galaxy that hosts the nearest type…
The ultra--high energy cosmic rays recently detected by several air shower experiments could have an extragalactic origin. In this case, the nearest active galaxy Centaurus A might be the source of the most energetic particles ever detected…
We present an HST study of the nuclear region of the E4 radio galaxy NGC 7052, which has a nuclear disk of dust and gas. The WFPC2 was used to obtain B, V and I broad-band images and an H_alpha+[NII] narrow-band image. The FOS was used to…
NGC 4945 is one of the nearest (~3.8 Mpc; 1" ~ 19 pc) starburst galaxies. ALMA band 3 (3--4\,mm) observations of HCN, HCO+, CS, C3H2, SiO, HCO, and CH3C2H were carried out with ~2" resolution. The lines reveal a rotating nuclear disk of…
We report the first direct X-ray evidence that an AGN is hidden in the center of IRAS12393+3520. An ASCA observation of this target unveiled a bright (0.5-10 keV luminosity 3.9 x 10^42 erg/s) and variable source, with minimum observed…
The prototypical powerful FR \Romannum{2} radio galaxy Cygnus A fits extremely well into the quasar/radio galaxy unified model: high polarization with an angle almost perpendicular to the radio jet and polarized flux showing broad permitted…
In the unification scheme, narrow-lined (type 2) active galactic nuclei (AGN) are intrinsically similar to broad-lined (type 1) AGN with the exception that the line of sight to the broad emission line region and accretion disk is blocked by…
Revealing the properties of molecular gas in starburst galaxies is key to understand the process of star formation across cosmic history. In this paper, we present our recent high-resolution ($\sim1''$ or 50 pc) ALMA observations of the…
We present results from Chandra HETGS (250 ks over two epochs) and XMM-Newton EPIC and RGS (60 ks) observations of NGC 2110, which has been historically classified as a Narrow Emission Line Galaxy galaxy. Our results support the…
As a prerequisite for interpreting new observations of the most distant radio galaxies, we make an optical study of the closest powerful radio source, Cygnus A. Using Keck imaging- and spectro-polarimetry in conjunction with HST, WFPC2…
The sub-parsec masing disk recently found to be orbiting a central mass of $\sim3.6\times10^7$~\msun\ in the Seyfert/LINER galaxy NGC~4258 provides the most compelling evidence to date for the existence of a massive black hole in the…
A recent ALMA study of the Seyfert 2 Active Galactic Nucleus (AGN) NGC 2110 by Rosario et al. (2019) has reported a remarkable lack of CO 2-1 emission from the circumnuclear region, where optical lines and H2 emission are observed, leading…
We present large scale 870 micron maps of the nearby starburst galaxies NGC253, NGC4945 and the nearest giant elliptical radio galaxy Centaurus A (NGC 5128) obtained with the newly commissioned Large Apex Bolometer Camera (LABOCA) operated…
We used the NSF Jansky Very Large Array at a frequency $\nu =$ 22\,GHz to study the nearest billion-solar-mass black hole, in the early-type galaxy NGC\,3115 at a distance of 9.7\,Mpc. We localize a faint continuum nucleus, with flux…
We present multiband photometric observations of nine Centaurs. Five of the targets are known active Centaurs (167P/CINEOS, 174P/Echeclus, P/2008 CL94, P/2011 S1, and C/2012 Q1), and the other four are inactive Centaurs belonging to the…
We report observations at mid-infrared and sub-millimeter wavelengths of Centaurus A (CenA, NGC 5128), the giant elliptical galaxy that harbors the closest radio loud Active Galactic Nucleus (AGN) to Earth. The dust emission from the deep…
We present the results of X-ray spectral analysis of 22 active galactic nuclei (AGNs) with a small scattering fraction selected from the Second XMM-Newton Serendipitous Source Catalogue using hardness ratios. They are candidates of buried…
We present results on the Seyfert 2 galaxy NGC4388 in the Virgo cluster observed with ASCA during its PV phase. The 0.5-10 keV X-ray spectrum consists of multiple components; (1) a continuum component heavily absorbed by a column density NH…
We consider whether the hard X-ray and soft gamma-ray emission from Centaurus A is beamed radiation from the active nucleus which is Compton-scattered into our line-of-sight. We derive the spectrum and degree of polarization of scattered…