Fast and accurate computational tools for gravitational waveforms from binary stars with any orbital eccentricity

The relevance of orbital eccentricity in the detection of gravitational radiation from (steady state) binary stars is emphasized. Computationally effective (fast and accurate) tools for constructing gravitational wave templates from binary stars with any orbital eccentricity are introduced including tight estimation criteria of the pertinent truncation and approximation errors.     

Hubble Space Telescope Wide Field Planetary Camera 2 observations of hyperluminous infrared galaxies

We present Hubble Space Telescope Wide Field Planetary Camera 2 I -band imaging for a sample of nine hyperluminous infrared galaxies (HLIRGs) spanning a redshift range     . Three of the sample have morphologies showing evidence for interactions and six are quasi-stellar objects (QSOs). Host galaxies in the QSOs are detected reliably out to     . The detected QSO host galaxies have an elliptical morphology with scalelengths spanning     and absolute k -corrected magnitudes spanning     There is no clear correlation between the infrared (IR) power source and the optical morphology. None of the sources in the sample, including F15307+3252, shows any evidence for gravitational lensing. We infer that the IR luminosities are thus real. Based on these results, and previous studies of HLIRGs, we conclude that this class of object is broadly consistent with being a simple extrapolation of the ULIRG population to higher luminosities; ULIRGs being mainly violently interacting systems powered by starbursts and/or active galactic nuclei. Only a small number of sources, the infrared luminosities of which exceed 10¹³ L_⊙, are intrinsically less luminous objects that have been boosted by gravitational lensing.     

Spectra of faint sources in crowded fields with FRODOSpec on the Liverpool Robotic Telescope

We check the performance of the FRODOSpec integral‐field spectrograph for observations of faint sources in crowded fields. Although the standard processing pipeline L2 yields too noisy fibre spectra, we present a new processing software (L2LENS) that gives rise to accurate spectra for the two images of the gravitationally lensed quasar Q0957+561. Among other things, this L2LENS reduction tool accounts for the presence of cosmic‐ray events, scattered‐light backgrounds, blended sources, and chromatic source displacements due to differential atmospheric refraction. Our non‐standard reduction of Q0957+561 data shows the ability of FRODOSpec to provide useful information on a wide variety of targets, and thus, the big potential of integral‐field spectrographs on current and future robotic telescopes. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)