Search Publications
Unveiling dark haloes in lensing galaxies
Saha, Prasenjit; Ferreras, Ignacio; Burles, Scott
We present a spatially resolved comparison of the stellar mass and total mass surface distributions of nine early-type galaxies. The galaxies are a subset of the Sloan Lens ACS Survey. The total mass distributions are obtained by exploring pixelated mass models that reproduce the lensed images. The stellar mass distributions are derived from popul…
Photometric properties of the Local Volume dwarf galaxies
Dolphin, A. E.; Tully, R. Brent; Sharina, M. E. +9 more
We present surface photometry and metallicity measurements for 104 nearby dwarf galaxies imaged with the Advanced Camera for Surveys and Wide Field and Planetary Camera 2 aboard the Hubble Space Telescope. In addition, we carried out photometry for 26 galaxies of the sample and for Sextans B on images of the Sloan Digital Sky Survey. Our sample co…
Unresolved emission and ionized gas in the bulge of M31
Bogdán, Á.; Gilfanov, M.
We study the origin of unresolved X-ray emission from the bulge of M31 based on archival Chandra and XMM-Newton observations. We demonstrate that three different components are present. (i) Broad-band emission from a large number of faint sources - mainly accreting white dwarfs and active binaries, associated with the old stellar population, simil…
First high-energy observations of narrow-line Seyfert 1s with INTEGRAL/IBIS
de Rosa, A.; Masetti, N.; Bird, A. J. +8 more
Narrow-line Seyfert 1 (NLS1) galaxies are very interesting objects which display peculiar properties when compared to their broad-line analogues (BLS1). Although well studied in many wavebands, their behaviour at >10 keV is poorly studied and yet important to discriminate between models invoked to explain the complexity observed in the X-ray ba…
Two-dimensional kinematics of SLACS lenses - I. Phase-space analysis of the early-type galaxy SDSSJ2321-097 at z ~ 0.1
Treu, Tommaso; Czoske, Oliver; Koopmans, Léon V. E. +2 more
We present the first results of a combined VLT VIMOS integral-field unit and Hubble Space Telescope (HST)/ACS study of the early-type lens galaxy SDSSJ2321-097 at z = 0.0819, extending kinematic studies to a look-back time of 1Gyr. This system, discovered in the Sloan Lens ACS Survey, has been observed as part of a VLT Large Programme with the goa…
NGC 3147: a `true' type 2 Seyfert galaxy without the broad-line region
Bianchi, S.; Jiménez-Bailón, E.; Barcons, X. +5 more
We report on simultaneous optical and X-ray observations of the Seyfert galaxy, NGC 3147. The XMM-Newton spectrum shows that the source is unabsorbed in the X-rays (NH < 5 × 1020 cm-2). On the other hand, no broad lines are present in the optical spectrum. The origin of this optical/X-rays misclassification (wit…
SDSSJ124155.33+114003.7 - a missing link between compact elliptical and ultracompact dwarf galaxies
Mamon, Gary A.; Chilingarian, Igor V.
We report the discovery of a compact object (Re = 32 pc, MB = -12.34 mag) at a projected distance of 9 kpc from Messier 59, a giant elliptical in the Virgo cluster. Using HST imaging and SDSS spectroscopy, both available in the Virtual Observatory, we find that this object has a blue core containing one-quarter of the light, …
Integral field spectroscopy of planetary nebulae: mapping the line diagnostics and hydrogen-poor zones with VLT FLAMES
Tsamis, Y. G.; Walsh, J. R.; Barlow, M. J. +3 more
Results from the first dedicated study of Galactic planetary nebulae (PNe) by means of optical integral field spectroscopy with the Very Large Telescope Fibre Large Array Multi Element Spectrograph Argus integral field unit are presented. Three typical Galactic disc PNe have been mapped with the 11.5 × 7.2-arcsec2 Argus array: 2D spectr…
Diffuse UV light associated with the Spiderweb Galaxy: evidence for in situ star formation outside galaxies
Röttgering, H. J. A.; Miley, G. K.; Overzier, R. A. +2 more
We present detailed images of diffuse ultraviolet (UV) intergalactic light (IGL), situated in a 60-kpc halo that surrounds the radio galaxy MRC1138-262 at z = 2. We discuss the nature of the IGL and rule out faint cluster galaxies, nebular continuum emission, synchrotron, inverse Compton, synchrotron self-Compton emission and scattering of galacti…
Gravitational lenses and lens candidates identified from the COSMOS field
Jackson, Neal
A complete manual search has been carried out of the list of 285423 objects, nearly all of them galaxies, identified in the Cosmic Evolution Survey (COSMOS) field that are brighter than I = 25. Two certain and one highly probable new gravitational lenses are found, in addition to the lenses and candidate lens systems previously found by Faure et a…