Search Publications
X-ray reverberation in 1H0707-495 revisited
Turner, T. J.; Reeves, J. N.; Braito, V. +1 more
The narrow-line Seyfert1 galaxy 1H0707-495 has previously been identified as showing time lags between flux variations in the soft-energy (0.3-1keV) and medium-energy (1-4keV) X-ray bands that oscillate between positive and negative values as a function of the frequency of the mode of variation. Here we measure and analyse the lags also between a …
Do black hole masses scale with classical bulge luminosities only? The case of the two composite pseudo-bulge galaxies NGC 3368 and NGC 3489
Saglia, R. P.; Nowak, N.; Davies, R. I. +3 more
It is now well established that all galaxies with a massive bulge component harbour a central supermassive black hole (SMBH). The mass of the SMBH correlates with bulge properties such as the bulge mass and the velocity dispersion, which implies that the bulge and the central BH of a galaxy have grown together during the formation process. As part…
The environmental dependence of the stellar-mass-size relation in STAGES galaxies
Wolf, Christian; Aragón-Salamanca, Alfonso; Barden, Marco +8 more
We present the stellar-mass-size relations for elliptical, lenticular and spiral galaxies in 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. We use a large sample of ~1200 field and cluster galaxies and a sub-sample of cluster core…
HST/NICMOS Paschen-α Survey of the Galactic Centre: Overview
Calzetti, D.; Muno, M. P.; Wang, Q. D. +6 more
We have recently carried out the first wide-field hydrogen Paschen-α line imaging survey of the Galactic Centre using the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument aboard the Hubble Space Telescope. The survey maps out a region of ) around the central supermassive black hole (Sgr A*) in the 1.87 and 1.90µm narrow…
Relativistic disc reflection in the extreme NLS1 IRAS13224-3809
Brandt, W. N.; Ponti, G.; Fabian, A. C. +7 more
We present a spectral variability study of the XMM-Newton and Suzaku observations of one of the most extreme narrow-line Seyfert 1 galaxies, IRAS13224-3809. The X-ray spectrum is characterized by two main peculiar features: (i) a strong soft excess with a steep rise below about 1.3 keV and (ii) a deep drop in flux above 8.2 keV. Although absorptio…
LoCuSS: connecting the dominance and shape of brightest cluster galaxies with the assembly history of massive clusters
Smith, Graham P.; Egami, E.; Dariush, A. +6 more
We study the luminosity gap, Δm12, between the first- and second-ranked galaxies in a sample of 59 massive (~1015Msolar) galaxy clusters, using data from the Hale Telescope, the Hubble Space Telescope, Chandra and Spitzer. We find that the Δm12 distribution, p(Δm12), is a declining function of…
A new population of planetary nebulae discovered in the Large Magellanic Cloud - III. The luminosity function
Parker, Quentin A.; Reid, Warren A.
Our previous identification and spectroscopic confirmation of 431 faint, new planetary nebulae (PNe) in the central 25 deg2 region of the Large Magellanic Cloud (LMC) permit us to now examine the shape of the LMC planetary nebula luminosity function (PNLF) through an unprecedented 10 mag range. The majority of our newly discovered and p…
Probing ~L* Lyman-break galaxies at z ~ 7 in GOODS-South with WFC3 on Hubble Space Telescope
Wilkins, Stephen M.; Bunker, Andrew J.; Ellis, Richard S. +5 more
We analyse recently acquired near-infrared Hubble Space Telescope imaging of the Great Observatories Origins Deep Survey (GOODS)-South field to search for star-forming galaxies at z ~ 7.0. By comparing Wide Field Camera 3 (WFC3) 0.98µm Y-band images with Advanced Camera for Surveys (ACS) z-band (0.85µm) images, we identify objects with…
Comparison of approximately isothermal gravitational potentials of elliptical galaxies based on X-ray and optical data
Böhringer, H.; Churazov, E.; Vikhlinin, A. +6 more
We analyse six X-ray bright elliptical galaxies, observed with Chandra and XMM-Newton, and approximate their gravitational potentials by isothermal spheres ϕ = v2c logr over a range of radii from ~0.5 to ~25 kpc. We then compare the circular speed vc derived from X-ray data with the estimators available from optica…
Contamination on Lyman continuum emission at z >~ 3: implication on the ionizing radiation evolution
Vanzella, E.; Cristiani, S.; Nonino, M. +1 more
We investigate the possibility of contamination by lower redshift interlopers in the measure of the ionizing radiation escaping from high-redshift galaxies. Taking advantage of the new ultradeep Very Large Telescope/Visible Multiobject Spectrograph U-band number counts in the Great Observatories Origins Deep Survey (GOODS)-South field, we calculat…