相关论文: The millimeter-wave continuum spectrum of Centauru…
We present high-angular (~0.4") resolution mid-infrared (MIR) polarimetric observations in the 8.7 ${\mu}$m and 11.6 ${\mu}$m filters of Cygnus A using CanariCam on the 10.4-m Gran Telescopio CANARIAS. A highly polarized nucleus is observed…
Long-term measurements have been carried out of the Crab Nebula radio emission flux density relative to Orion A at 927 MHz and relative to Cygnus A and Virgo A at 151.5 MHz. As a result the mean rates have been found of the secular change…
We have acquired radio continuum data between 70\,MHz and 48\,GHz for a sample of 19 southern starburst galaxies at moderate redshifts ($0.067 < z < 0.227$) with the aim of separating synchrotron and free-free emission components. Using a…
We propose that neutron emission from Cen A dominates the cosmic ray sky at the high end of the spectrum. Neutrons that are able to decay generate proton diffusion fronts, whereas those that survive decay produce a spike in the direction of…
Comparison of 8.4-GHz radio images of a sample of 11 early-type Seyfert galaxies with previous observations reveals possible variation in the nuclear radio flux density in 5 of them over a 7-yr period. We find no correlation between radio…
We present new CO and C^o line measurements of the compact circumnuclear disk in the center of NGC 128 (Centaurus~A) obtained with the Herschel Space Observatory, as well as SEST, JCMT, and APEX. The Cen A center CO ladder is quite…
We present almost-simultaneous detections of Cygnus X-1 in the radio and mm regimes, obtained during the low/hard X-ray state. The source displays a flat spectrum between 2 and 220 GHz, with a spectral index flatter than 0.15 (3sigma).…
We present submm images of Sgr A* and its surroundings obtained at 800, 600 and 450 $\mu$m with the JCMT and derive flux densities of Sgr A* at all three wave- lengths. Combined with upper limits by Gezari and associates at MIR wavelengths…
We investigate the nuclear environment of galaxies with observed 22 GHz water megamaser in their subparsec edge-on accretion disks, using 33 GHz (9mm) radio continuum data from VLA, with a resolution of ~ 0.2-0.5 arcsecs, and relate the…
We search for variations in the disk of Centaurus A of the emission from atomic fine structure lines using Herschel PACS and SPIRE spectroscopy. In particular we observe the [C II](158 $\mu$m), [N II](122 and 205 $\mu$m), [O I](63 and 145…
We present measurements obtained with the Spitzer Space Telescope in five bands from 3.6-24 microns of the northern inner radio lobe of Centaurus A, the nearest powerful radio galaxy. We show that this emission is synchrotron in origin.…
We present Chandra X-ray observations of the nearby Seyfert 1.5 galaxy NGC 4151. The images show the extended soft X-ray emission on the several hundreds of pc scale with better sensitivity than previously obtained. The spectrum of the…
Results of a long-term spectral monitoring of the active galactic nucleus of NGC 4151 are presented (11 years, from 1996 to 2006). High quality spectra (S/N>50 in the continuum near Halpha and Hbeta) were obtained in the spectral range…
Based on Bremer et al. (2011) and Eckart et al. (2012) we report on simultaneous observations and modeling of the millimeter, near-infrared, and X-ray flare emission of the source Sagittarius A* (SgrA*) associated with the super-massive…
We present Chandra data from a 31.7 ks observation of the Centaurus cluster, using the ACIS-S detector. Images of the X-ray emission show a plume-like feature at the centre of the cluster, of extent 60 arcsec (20 kpc in projection). The…
We present the kpc-scale behaviour of the powerful extragalactic radio source Hercules A and the behaviour of the intracluster gas in which the radio source is situated. We have found that Hercules A exhibits a strong Laing-Garrington…
We report on the results of infrared spectroscopic mapping observations carried out in the nuclear region of Centaurus A (NGC5128). The 500 pc bipolar dust shell discovered by Quillen et al.(2006) is even more clearly seen in the 11.3…
We present preliminary results from two observations of the radio galaxy Centaurus A performed by the BeppoSAX satellite. We did not detect any spectral variation of the nuclear continuum in spite of the long-term flux change (by a factor…
We present the first clear detection of ionized Fe-K emission and absorption components in the nearby radio galaxy Centaurus A, revealed by the high-resolution XRISM/Resolve detector. In the 6.5-6.9 keV band, XRISM reveals multiple Fe XXV…
M81 is the nearest galaxy with an active galactic nucleus, with the possibly exception of Cen A. The nucleus is exceptionally compact. Here we present results from new VLA and VLBI observations of the nucleus of M81. The VLA shows that its…