Search Publications
Triaxial strong-lensing analysis of the z > 0.5 MACS clusters: the mass-concentration relation
Zitrin, Adi; Sereno, Mauro
The high concentrations derived for several strong-lensing clusters present a major inconsistency between theoretical Λ cold dark matter (ΛCDM) expectations and measurements. Triaxiality and orientation biases might be at the origin of this disagreement, as clusters elongated along the line of sight would have a relatively higher projected mass de…
PowellSnakes II: a fast Bayesian approach to discrete object detection in multi-frequency astronomical data sets
Lasenby, A.; Carvalho, Pedro; Rocha, Graça. +1 more
PowellSnakes (PwS) is a Bayesian algorithm for detecting compact objects embedded in a diffuse background, and was selected and successfully employed by the Planck consortium in the production of its first public deliverable: the Early Release Compact Source Catalogue (ERCSC). We present the critical foundations and main directions of further deve…
On the central stellar mass density and the inside-out growth of early-type galaxies
Longhetti, M.; Gargiulo, A.; Saracco, P.
Recent theoretical and observational studies on the assembly of early-type galaxies (ETGs) point towards an inside-out growth of their stellar mass characterized by extended low-mass-density haloes grown around compact and dense cores. Models can form ETGs at high-z as compact spheroids that then grow in size through dry minor mergers. Dry mergers…
Automated classification of Hipparcos unsolved variables
Rimoldini, L.; Mowlavi, N.; Nienartowicz, K. +14 more
We present an automated classification of stars exhibiting periodic, non-periodic and irregular light variations. The Hipparcos catalogue of unsolved variables is employed to complement the training set of periodic variables of Dubath et al. with irregular and non-periodic representatives, leading to 3881 sources in total which describe 24 variabi…
Constraining the formation of inner bars: photometry, kinematics and stellar populations in NGC 357
Corsini, E. M.; Aguerri, J. A. L.; Debattista, Victor P. +2 more
Double-barred galaxies are common in the local Universe, with approximately one-third of barred spirals hosting a smaller, inner bar. Nested bars have been proposed as a mechanism to transport gas to the very central regions of the galaxy, trigger star formation and contribute to the growth of the bulge. To test this idea, we perform for the first…
The environmental dependence of the structure of outer galactic discs in STAGES spiral galaxies
Bell, Eric F.; Wolf, Christian; Aragón-Salamanca, Alfonso +7 more
We present an analysis of V-band radial surface brightness profiles for spiral galaxies from the field and cluster environments using Hubble Space Telescope/Advanced Camera for Surveys imaging and data from the Space Telescope A901/2 Galaxy Evolution Survey (STAGES). We use a large sample of ∼330 face-on to intermediately inclined spiral galaxies …
Systematic study of X-ray cavities in the brightest galaxy in the Draco constellation NGC 6338
David, L. P.; Pandge, M. B.; Patil, M. K. +1 more
We present results based on the systematic analysis of currently available Chandra archive data on the brightest galaxy in the Draco constellation, NGC 6338, in order to investigate the properties of the X-ray cavities. In the central ∼6 kpc, at least two, possibly three, X-ray cavities are evident. All these cavities are roughly of ellipsoidal sh…
Herschel-ATLAS: VISTA VIKING near-infrared counterparts in the Phase 1 GAMA 9-h data
Ivison, R. J.; Sutherland, W.; González-Nuevo, J. +38 more
We identify near-infrared Ks-band counterparts to Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) submillimetre (submm) sources, using a preliminary object catalogue from the VISTA Kilo-degree Infrared Galaxy (VIKING) survey. The submm sources are selected from the H-ATLAS Phase 1 catalogue of the Galaxy and Mass Assembly 9…
IC 4663: the first unambiguous [WN] Wolf-Rayet central star of a planetary nebula
Crowther, P. A.; De Marco, O.; Miszalski, B. +4 more
We report on the serendipitous discovery of the first central star of a planetary nebula (PN) that mimics the helium- and nitrogen-rich WN sequence of massive Wolf-Rayet (WR) stars. The central star of IC 4663 (PN G346.2-08.2) is dominated by broad He II and N V emission lines which correspond to a [WN3] spectral type. Unlike previous [WN] candida…
The G305 star-forming complex: embedded massive star formation discovered by Herschel Hi-GAL
Molinari, S.; Veneziani, M.; Thompson, M. A. +7 more
We present a Herschel far-infrared study towards the rich massive star-forming complex G305, utilizing PACS 70, 160 µm and SPIRE 250, 350, and 500 µm observations from the Hi-GAL survey of the Galactic plane. The focus of this study is to identify the embedded massive star-forming population within G305, by combining far-infrared data …