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µ Eridani from MOST and from the ground: an orbit, the SPB component's fundamental parameters and the SPB frequencies
Niemczura, E.; Leto, G.; Jerzykiewicz, M. +15 more
MOST time series photometry of µ Eri, an SB1 eclipsing binary with a rapidly rotating SPB primary, is reported and analysed. The analysis yields a number of sinusoidal terms, mainly due to the intrinsic variation of the primary, and the eclipse light curve. New radial-velocity observations are presented and used to compute parameters of a sp…
Variable X-ray reflection from 1H 0419-577
Dewangan, Gulab C.; Pal, Main
We present detailed broad-band X-ray spectral variability of a Seyfert 1 galaxy 1H 0419-577 based on an archival Suzaku observation in 2007 July, a new Suzaku observation performed in 2010 January and the two latest XMM-Newton observations from 2010 May. All the observations show soft X-ray excess emission below 2 keV and both Suzaku observations …
X-ray spectral analysis of the low-luminosity active galactic nucleus NGC 7213 using long XMM-Newton observations
Papadakis, I. E.; Emmanoulopoulos, D.; Nicastro, F. +1 more
We present the X-ray spectral results from the longest X-ray Multi-mirror Mission-Newton observation, 133 ks, of the low-luminosity active galactic nucleus NGC 7213. The hardness-ratio analysis of the X-ray light curves discloses a rather constant X-ray spectral shape, at least for the observed exposure time, enabling us to perform X-ray spectral …
An XMM-Newton view of the merging activity in the Centaurus cluster
Fabian, A. C.; Sanders, J. S.; Walker, S. A.
We report the results of XMM-Newton observations of the regions around the core of the Centaurus cluster where evidence for merging activity between the subgroup Cen 45 and the main Centaurus cluster has previously been observed using ASCA and ROSAT data. We confirm the ASCA findings of a temperature excess surrounding Cen 45. We find that this te…
Probing nuclear activity versus star formation at z ∼ 0.8 using near-infrared multi-object spectroscopy
Pérez García, A. M.; Acosta-Pulido, J. A.; Alonso-Herrero, A. +3 more
We present near-infrared (NIR) spectroscopic observations of 28 X-ray and mid-infrared selected sources at a median redshift of z ∼ 0.8 in the Extended Groth Strip (EGS). To date this is the largest compilation of NIR spectra of active galactic nuclei (AGN) at this redshift. The data were obtained using the multi-object spectroscopic mode of the L…
Hα to FUV ratios in resolved star-forming region populations of nearby spiral galaxies
Kennicutt, Robert C.; Eldridge, John J.; Hermanowicz, Maciej T.
We present a new study of Hα/FUV flux ratios of star-forming regions within a sample of nearby spiral galaxies. We search for evidence of the existence of a cluster-mass-dependent truncation in the underlying stellar initial mass function (IMF). We use an automated approach to identification of extended objects based on the SEXTRACTOR algorithm to…
The Planck-ATCA Co-eval Observations project: the spectrally selected sample
De Zotti, Gianfranco; Bonaldi, Anna; Massardi, Marcella +1 more
The Planck Australia Telescope Compact Array (Planck-ATCA) Co-eval Observations (PACO) have provided multi-frequency (5-40 GHz) flux density measurements of complete samples of Australia Telescope 20 GHz (AT20G) radio sources at frequencies below and overlapping with Planck frequency bands, almost simultaneously with Planck observations. In this w…
Constrained simulations of the Antennae galaxies: comparison with Herschel-PACS observations
Juvela, M.; Klaas, U.; Lunttila, T. +3 more
We present a set of hydro-dynamical numerical simulations of the Antennae galaxies in order to understand the origin of the central overlap starburst. Our dynamical model provides a good match to the observed nuclear and overlap star formation, especially when using a range of rather inefficient stellar feedback efficiencies (0.01 ≲ qEoS
The preferentially magnified active nucleus in IRAS F10214+4724 - III. VLBI observations of the radio core
McKean, J. P.; Heywood, I.; Jarvis, M. J. +5 more
We report 1.7 GHz very long baseline interferometry (VLBI) observations of IRAS F10214+4724, a lensed z = 2.3 obscured quasar with prodigious star formation. We detect what we argue to be the obscured active nucleus with an effective angular resolution of <50 pc at z = 2.3. The S1.7 = 210 µJy (9σ) detection of this unresolved s…
A minor merger scenario for the ultraluminous X-ray source ESO 243-49 HLX-1 - II. Constraints from photometry
Soria, R.; Zampieri, L.; Mapelli, M. +1 more
The point-like X-ray source HLX-1, close to the S0 galaxy ESO 243-49, is the brightest known ultraluminous X-ray source and one the strongest intermediate-mass black hole candidates. We argue that the counterpart of HLX-1 may be the nucleus of a satellite galaxy, undergoing minor merger with the S0 galaxy. We investigate this scenario by running a…