Search Publications
ZEN2: a narrow J-band search for z ~ 9 Lyα emitting galaxies directed towards three lensing clusters
Kneib, J. -P.; Minniti, D.; Courbin, F. +1 more
We present the results of a continuing survey to detect Lyα emitting galaxies at redshifts z ~ 9: the `z equals nine' (ZEN) survey. We have obtained deep VLT Infrared Spectrometer and Array Camera observations in the narrow J-band filter NB119 directed towards three massive lensing clusters: Abell clusters 1689, 1835 and 114. The foreground cluste…
How rapidly do neutron stars spin at birth? Constraints from archival X-ray observations of extragalactic supernovae
Soria, Roberto; Stella, Luigi; Perna, Rosalba +1 more
Traditionally, studies aimed at inferring the distribution of birth periods of neutron stars are based on radio surveys. Here we propose an independent method to constrain the pulsar spin periods at birth based on their X-ray luminosities. In particular, the observed luminosity distribution of supernovae (SNe) poses a constraint on the initial rot…
On the radial distribution of white dwarfs in the globular cluster NGC 6397
Anderson, J.; Davis, D. S.; King, I. R. +5 more
We have examined the radial distribution of white dwarfs over a single Hubble Space Telescope/Advanced Camera for Surveys field in the nearby globular cluster NGC 6397. In relaxed populations, such as in a globular cluster, stellar velocity dispersion, and hence radial distribution, is directly dependent on stellar masses. The progenitors of very …
Suzaku observations of Markarian 335: evidence for a distributed reflector
Larsson, J.; Ponti, G.; Fabian, A. C. +3 more
We report on a 151-ks net exposure Suzaku observation of the narrow-line Seyfert 1 galaxy Mrk 335. The 0.5-40 keV spectrum contains a broad Fe line, a strong soft excess below about 2 keV and a Compton hump around 20-30 keV. We find that a model consisting of a power law and two reflectors provides the best fit to the time-averaged spectrum. In th…
A bright, dust-obscured, millimetre-selected galaxy beyond the Bullet Cluster (1E0657-56)
Yun, M. S.; Kohno, K.; Wilson, G. W. +24 more
Deep 1.1mm continuum observations of 1E0657-56 (the `Bullet Cluster') taken with the millimeter-wavelength camera AzTEC on the 10-m Atacama Submillimeter Telescope Experiment (ASTE), have revealed an extremely bright (S1.1mm = 15.9mJy) unresolved source. This source, MMJ065837-5557.0, lies close to a maximum in the density of underlying…
Extending the baseline: Spitzer mid-infrared photometry of globular cluster systems in the Centaurus A and Sombrero Galaxies
Spitler, Lee R.; Forbes, Duncan A.; Beasley, Michael A.
Spitzer IR Array Camera (IRAC) mid-infrared photometry is presented for the globular cluster (GC) systems of the NGC 5128 (`Centaurus A') and NGC 4594 (`Sombrero') galaxies. Existing optical photometric and spectroscopic are combined with this new data in a comprehensive optical-to-mid-IR colour catalogue of 260 GCs. Empirical colour-metallicity r…
On contamination and completeness in z >= 5 Lyman-break galaxy surveys
Lehnert, Matthew D.; Stanway, Elizabeth R.; Bremer, Malcolm N.
A large population of z > 5 Lyman-break galaxies has been identified in recent years. However, the high-redshift galaxies selected by different surveys are subject to a variety of selection effects - some overt, others more subtle. We present an analysis of sample completeness and contamination issues in high-redshift surveys, focusing on surve…
The early-type galaxies NGC 1407 and NGC 1400 - I. Spatially resolved radial kinematics and surface photometry
Forbes, Duncan A.; Proctor, Robert N.; Brough, Sarah +2 more
This is the first paper of a series focused on investigating the star formation and evolutionary history of the two early-type galaxies NGC 1407 and NGC 1400. They are the two brightest galaxies of the NGC 1407 (or Eridanus-A) group, one of the 60 groups studied as part of the Group Evolution Multi-wavelength Study.
Here, we present new high …On the detection of the progenitor of the type Ia supernova 2007on
Bassa, Cees; Nelemans, Gijs; Voss, Rasmus +1 more
We present new Chandra X-ray observations and detailed astrometry of the field of the type Ia supernova 2007on, for which the detection of a likely progenitor in archival Chandra data was recently reported.
No source is detected in the new Chandra images, taken six weeks after optical maximum. We calculate a 90-99 per cent probability that an…Galaxy populations in the Antlia cluster - II. Compact elliptical galaxy candidates
Richtler, Tom; Faifer, Favio R.; Smith Castelli, Analía V. +1 more
Continuing our study of galaxy populations in the Antlia cluster, we present a photometric analysis of four galaxies classified as compact elliptical (cE) galaxies in the 1990 Antlia Group catalogue of Ferguson and Sandage. Until now, there have been only six known members of this rare type of galaxy. Using data from various photometric systems (W…