Search Publications
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 ≤…
Discovery of the spectroscopic binary nature of six southern Cepheids
Szabados, L.; Derekas, A.; Kovács, J. +6 more
We present the analysis of photometric and spectroscopic data of six bright Galactic Cepheids: GH Carinae, V419 Centauri, V898 Centauri, AD Puppis, AY Sagittarii and ST Velorum. Based on new radial velocity data (in some cases supplemented with earlier data available in the literature), these Cepheids have been found to be members in spectroscopic…
Revisiting SW J2000.6+3210: a persistent Be X-ray pulsar?
Maitra, Chandreyee; Paul, Biswajit; Pradhan, Pragati +1 more
We present a detailed timing and spectral analysis of the Be X-ray binary SW J2000.6+3210 discovered by the Burst Alert Telescope Galactic plane survey. Two Suzaku observations of the source made at six months interval, reveal pulsations at ∼890 s for both observations with a much weaker pulse fraction in the second one. Pulsations are clearly see…
X-ray emission around the z = 4.1 radio galaxy TN J1338-1942 and the potential role of far-infrared photons in AGN feedback
Smail, Ian; Blundell, Katherine M.
We report the discovery in an 80-ks observation of spatially extended X-ray emission around the high-redshift radio galaxy TN J1388-1942 (z = 4.11) with the Chandra X-ray Observatory. The X-ray emission extends over a ∼30-kpc diameter region and although it is less extended than the GHz-radio lobes, it is roughly aligned with them. We suggest that…
Three active galactic nuclei close to the effective Eddington limit for dusty gas
Fabian, A. C.; Mushotzky, R. F.; Trippe, M. L. +3 more
The effective Eddington limit for dusty gas surrounding active galactic nucleus (AGN) is lower than the canonical Eddington limit for hydrogen gas. Previous results from the Swift/Burst Alert Telescope 9-month catalogue suggested that in the overwhelming majority of local AGN, the dusty absorbing gas is below this effective Eddington limit, implyi…
The three-dimensional geometry and merger history of the massive galaxy cluster MACS J0358.8-2955
Richard, Johan; Ebeling, Harald; Hsu, Li-Yen
We present results of a combined X-ray/optical analysis of the dynamics of the massive cluster MACS J0358.8-2955 (z = 0.428) based on observations with the Chandra X-ray Observatory, the Hubble Space Telescope and the Keck-I telescope on Mauna Kea. MACS J0358.8-2955 is found to be one of the most X-ray luminous clusters known at z > 0.3, featur…
Spectropolarimetric investigation of the photosphere during a solar microflare
Kondrashova, N. N.
The results of the study of the thermodynamical parameters and the magnetic field in the solar photosphere during the solar microflare on 2009 July 4 in the active region NOAA 11024 are presented. The analysis is based on the observations with the French-Italian telescope THEMIS (Heliographic Telescope for the Study of the Magnetism and Instabilit…