Search Publications
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…
Detecting exo-moons with photometric transit timing - I. Effect of realistic stellar noise
Lewis, Karen M.
The timing errors for individual planetary transits using the photometric transit timing technique (TTVp) are derived for light curves contaminated with either white additive noise, realistic stellar noise or filtered stellar noise. For the case of white noise, the timing errors are derived analytically, while timing errors for realisti…
The host galaxy of the z = 2.4 radio-loud AGN MRC 0406-244 as seen by HST
Pentericci, L.; Röttgering, H. J. A.; Miley, G. K. +7 more
We present multicolour Hubble Space Telescope images of the powerful z = 2.4 radio galaxy MRC 0406-244 and model its complex morphology with several components including a host galaxy, a point source and extended nebular and continuum emission. We suggest that the main progenitor of this radio galaxy was a normal, albeit massive (M⋆ ∼ 1…
The AT20G view of Swift/BAT selected AGN: high-frequency radio waves meet hard X-rays
Ghirlanda, G.; Ajello, M.; Murphy, T. +3 more
We cross-matched the 6-year Swift/Burst Alert Telescope (BAT) survey of active galactic nuclei (AGN) with the AT20G radio survey of the southern sky, which is one of the largest high-frequency radio surveys available. With these data we investigated the possible correlation between the radio and the X-ray emission at the highest radio and X-ray fr…
Magnitude and size evolution of bulgeless galaxies
Sachdeva, Sonali
We examine the magnitude and size evolution of bulgeless (discs with no-bulge or pseudo-bulge) galaxies up to z ∼ 0.9 in rest-frame B band. Their evolution is compared to that of normal-discs (or discs with classical bulge). The study is done for luminous sources (MB ≤ -20) in two equal-volume redshift bins (0.4 ≤ z < 0.77 and 0.77 ≤…