Search Publications
The pulsating variable star population in DDO210
Sarajedini, Ata; Ordoñez, Antonio J.
We have probed the pulsating variable star content of the isolated Local Group dwarf galaxy, DDO210 (Aquarius), using archival Advanced Camera for Surveys/Hubble Space Telescope imaging in the F475W and F814W passbands. We find a total of 32 RR Lyrae stars (24 ab-type; 8 c-type) and 75 Cepheid variables. The mean periods of the ab-type and c-type …
Period-Luminosity relations derived from the OGLE-III first-overtone mode Cepheids in the Magellanic Clouds
Ngeow, Chow-Choong; Kanbur, Shashi M.; Bhardwaj, Anupam +1 more
We present multiband Period-Luminosity (PL) relations for first-overtone mode Cepheids in the Small Magellanic Cloud (SMC). We derive optical band PL relations and the Wesenheit function using VI mean magnitudes from the Optical Gravitational Lensing Experiment (OGLE-III) survey. We cross-match OGLE-III first-overtone mode Cepheids to the 2MASS an…
The SLUGGS survey: chromodynamical modelling of the lenticular galaxy NGC 1023
Cortesi, Arianna; Chies-Santos, Ana L.; Forbes, Duncan A. +12 more
Globular clusters (GCs) can be considered discrete, long-lived, dynamical tracers that retain crucial information about the assembly history of their parent galaxy. In this paper, we present a new catalogue of GC velocities and colours for the lenticular galaxy NGC 1023, we study their kinematics and spatial distribution, in comparison with the un…
Broad-band X-ray emission and the reality of the broad iron line from the neutron star-white dwarf X-ray binary 4U 1820-30
Misra, R.; Dewangan, G. C.; Mondal, Aditya S. +3 more
Broad relativistic iron lines from neutron star X-ray binaries are important probes of the inner accretion disc. The X-ray reflection features can be weakened due to strong magnetic fields or very low iron abundances such as is possible in X-ray binaries with low mass, first generation stars as companions. Here, we investigate the reality of the b…
The data processing pipeline for the Herschel SPIRE Fourier Transform Spectrometer
Valtchanov, I.; Hopwood, R.; Lu, N. +13 more
We present the data processing pipeline to generate calibrated data products from the Spectral and Photometric Imaging Receiver (SPIRE) imaging Fourier Transform Spectrometer on the Herschel Space Observatory. The pipeline processes telemetry from SPIRE observations and produces calibrated spectra for all resolution modes. The spectrometer pipelin…
The ISW effect and the lack of large-angle CMB temperature correlations
Starkman, Glenn D.; Copi, Craig J.; O'Dwyer, Márcio
It is by now well established that the magnitude of the two-point angular-correlation function of the cosmic microwave background temperature anisotropies is anomalously low for angular separations greater than about 60°. Physics explanations of this anomaly typically focus on the properties of the Universe at the surface of last scattering, relyi…
Far-infrared/submillimetre properties of pre-stellar cores L1521E, L1521F and L1689B as revealed by the Herschel SPIRE instrument - I. Central positions
Abergel, A.; Ward-Thompson, D.; van der Wiel, M. H. D. +5 more
Dust grains play a key role in the physics of star-forming regions, even though they constitute only ∼1 per cent of the mass of the interstellar medium. The derivation of accurate dust parameters such as temperature (Td), emissivity spectral index (β) and column density requires broad-band continuum observations at far-infrared waveleng…
Modelling the structure of molecular clouds - I. A multiscale energy equipartition
Klessen, Ralf S.; Veltchev, Todor V.; Donkov, Sava
We present a model for describing the general structure of molecular clouds (MCs) at early evolutionary stages in terms of their mass-size relationship. Sizes are defined through threshold levels at which equipartitions between gravitational, turbulent and thermal energy |W| ∼ f(Ekin + Eth) take place, adopting interdependent…
A new model of the microwave polarized sky for CMB experiments
Bonaldi, Anna; Brown, Michael L.; Hervías-Caimapo, Carlos
We present a new model of the microwave sky in polarization that can be used to simulate data from cosmic microwave background polarization experiments. We exploit the most recent results from the Planck satellite to provide an accurate description of the diffuse polarized foreground synchrotron and thermal dust emission. Our model can include the…
Far-infrared and sub-millimetre imaging of HD 76582's circumstellar disc
Matthews, Brenda C.; Booth, Mark; Zuckerman, Ben +3 more
Debris discs, the tenuous rocky and icy remnants of planet formation, are believed to be evidence for planetary systems around other stars. The JCMT/SCUBA-2 debris disc legacy survey `SCUBA-2 Observations of Nearby Stars' (SONS) observed 100 nearby stars, amongst them HD 76582, for evidence of such material. Here, we present imaging observations b…