Search Publications
Evidence for a [WR] or WEL-type binary nucleus in the bipolar planetary nebula Vy 1-2
Boumis, P.; López, J. A.; Akras, S. +3 more
We present high-dispersion spectroscopic data of the compact planetary nebula Vy 1-2, where high expansion velocities up to 100 km s-1 are found in the Hα, [N II] and [O III] emission lines. Hubble Space Telescope images reveal a bipolar structure. Vy 1-2 displays a bright ring-like structure with a size of 2.4 arcsec × 3.2 arcsec and t…
The warm molecular gas and dust of Seyfert galaxies: two different phases of accretion?
Prieto, M. A.; Fernández-Ontiveros, J. A.; Neumayer, N. +3 more
The distribution of warm molecular gas (1000-3000 K), traced by the near-IR H2 2.12 µm line, has been imaged with a resolution <0.5 arcsec in the central 1 kpc of seven nearby Seyfert galaxies. We find that this gas is highly concentrated towards the central 100 pc and that its morphology is often symmetrical. Lanes of warm H
The impact from survey depth and resolution on the morphological classification of galaxies
Cepa, J.; Infante, L.; Molino, A. +28 more
We consistently analyse for the first time the impact of survey depth and spatial resolution on the most used morphological parameters for classifying galaxies through non-parametric methods: Abraham and Conselice-Bershady concentration indices, Gini, M20 moment of light, asymmetry, and smoothness. Three different non-local data sets are used, Adv…
The changing UV and X-ray properties of the Of?p star CPD -28°2561
Wade, Gregg A.; Walborn, Nolan R.; Nazé, Yaël +4 more
The Of?p star CPD -28°2561 was monitored at high energies with XMM-Newton and HST. In X-rays, this magnetic oblique rotator displays bright and hard emission that varies by ∼55 per cent with rotational phase. These changes occur in phase with optical variations, as expected for magnetically confined winds; there are two maxima and two minima in X-…
IFU spectroscopy of 10 early-type galactic nuclei - III. Properties of the circumnuclear gas emission
Ricci, T. V.; Steiner, J. E.; Menezes, R. B.
Many early-type galaxies have ionized gas emission in their centres that extends to scales of ∼1 kpc. The majority of such objects are classified as low-ionization nuclear emission regions (LINERs), but the nature of their ionizing source is still not clear. The kinematics associated with these gaseous structures usually shows deviations from a pu…
New insights into the evolution of the FR I radio galaxy 3C 270 (NGC 4261) from VLA and GMRT radio observations
Raychaudhury, Somak; Giacintucci, Simona; Ishwara-Chandra, C. H. +4 more
We present the Giant Metrewave Radio Telescope 240 MHz observations of the nearby luminous Fanaroff-Riley type I radio source 3C 270, in the group-central elliptical NGC 4261. Combining these data with reprocessed Very Large Array 1.55 and 4.8 GHz observations, we produce spectral-index maps that reveal a constant spectral index along the jets and…
X-ray analysis of filaments in galaxy clusters
Fabian, A. C.; Sanders, J. S.; Walker, S. A. +1 more
We perform a detailed X-ray study of the filaments surrounding the brightest cluster galaxies in a sample of nearby galaxy clusters using deep Chandra observations, namely the Perseus, Centaurus and Virgo clusters, and Abell 1795. We compare the X-ray properties and spectra of the filaments in all of these systems, and find that their Chandra X-ra…
Deconstructing the narrow-line region of the nearest obscured quasar
Ramos Almeida, C.; Bellocchi, E.; Villar Martín, M. +3 more
We study the physical and kinematic properties of the narrow-line region (NLR) of the nearest obscured quasar MRK 477 (z = 0.037), using optical and near-infrared (NIR) spectroscopy. About 100 emission lines are identified in the optical+NIR spectrum (90 in the optical), including several narrow optical Fe+ lines. To our knowledge, this…
INTEGRAL 11-year hard X-ray survey above 100 keV
Sunyaev, R.; Krivonos, R.; Tsygankov, S. +3 more
We present the results of an all-sky survey, performed with data acquired by the Imager on-Board the INTEGRAL Satellite (IBIS) telescope on board the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observatory over 11 years of operation, at energies above 100 keV. The catalogue of detected sources includes 132 objects. The statistical s…
Post-starburst quasars: bridging the gap between post-starburst galaxies and quasars
Brotherton, Michael S.; Cales, Sabrina L.
In order to better understand the nature of post-starburst quasars (PSQs) in the context of galaxy evolution, we compare their properties to those of post-starburst galaxies and quasars from appropriately selected samples possessing similar redshift (z ∼ 0.3), luminosity (Mr ∼ -23), and data quality. We consider morphologies, spectral f…