Search Publications
Extragalactic background light inferred from AEGIS galaxy-SED-type fractions
Barmby, P.; Cooper, M. C.; Huang, J. -S. +15 more
The extragalactic background light (EBL) is of fundamental importance both for understanding the entire process of galaxy evolution and for γ-ray astronomy, but the overall spectrum of the EBL between 0.1 and 1000 µm has never been determined directly from galaxy spectral energy distribution (SED) observations over a wide redshift range. The…
Defining the intrinsic AGN infrared spectral energy distribution and measuring its contribution to the infrared output of composite galaxies
Alexander, D. M.; Hickox, R. C.; Mullaney, J. R. +1 more
We use infrared spectroscopy and photometry to empirically define the intrinsic mid- to far-infrared spectral energy distribution (i.e. 6-100 µm SED) of thermal emission produced by typical (i.e. 2-10 keV luminosity, L2-10 keV∼ 1042-1044 erg s-1) active galactic nuclei (hereafter AGNs). The average…
Hubble Space Telescope transmission spectroscopy of the exoplanet HD 189733b: high-altitude atmospheric haze in the optical and near-ultraviolet with STIS
Mazeh, T.; Aigrain, S.; Pont, F. +10 more
We present Hubble Space Telescope (HST) optical and near-ultraviolet transmission spectra of the transiting hot Jupiter HD 189733b, taken with the repaired Space Telescope Imaging Spectrograph (STIS) instrument. The resulting spectra cover the range 2900-5700 Å and reach per exposure signal-to-noise ratio levels greater than 11 000 within a 500-Å …
The Australia Telescope Compact Array Broad-band Backend: description and first results
Wieringa, M. H.; Massardi, M.; Johnston, S. +30 more
Here, we describe the Compact Array Broad-band Backend (CABB) and present first results obtained with the upgraded Australia Telescope Compact Array (ATCA). The 16-fold increase in observing bandwidth, from 2 × 128 to 2 × 2048 MHz, high-bit sampling and the addition of 16 zoom windows (each divided into further 2048 channels) provide major improve…
An XMM-Newton spectral survey of 12 µm selected galaxies - I. X-ray data
Nandra, Kirpal; Brightman, Murray
We present an X-ray spectral analysis of 126 galaxies of the 12 µm galaxy sample. By studying this sample at X-ray wavelengths, we aim to determine the intrinsic power, continuum shape and obscuration level in these sources. We improve upon previous works by the use of superior data in the form of higher signal-to-noise ratio spectra, finer …
Luminous blue variable eruptions and related transients: diversity of progenitors and outburst properties
Filippenko, Alexei V.; Smith, Nathan; Li, Weidong +2 more
We present new light curves and optical spectra for a number of extragalactic optical transients or 'supernova impostors' related to giant eruptions of luminous blue variables (LBVs), and we provide a comparative discussion of LBV-like giant eruptions known thus far. New data include photometry and spectroscopy of supernovae (SNe) 1999bw, 2000ch, …
Creation of cosmic structure in the complex galaxy cluster merger Abell 2744
Okabe, N.; Zitrin, A.; Meneghetti, M. +15 more
We present a detailed strong-lensing, weak-lensing and X-ray analysis of Abell 2744 (z= 0.308), one of the most actively merging galaxy clusters known. It appears to have unleashed 'dark', 'ghost', 'bullet' and 'stripped' substructures, each ∼1014 M⊙. The phenomenology is complex and will present a challenge for numerical sim…
A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun
Neuhäuser, R.; Hohle, M. M.; Tetzlaff, N.
Traditionally, runaway stars are O- and B-type stars with large peculiar velocities. We would like to extend this definition to young stars (up to ≈50 Myr) of any spectral type and to identify those present in the Hipparcos catalogue by applying different selection criteria, such as peculiar space velocities or peculiar one-dimensional velocities.…
Herschel-ATLAS: rapid evolution of dust in galaxies over the last 5 billion years
Rodighiero, G.; Ivison, R. J.; Clements, D. L. +38 more
We present the first direct and unbiased measurement of the evolution of the dust mass function of galaxies over the past 5 billion years of cosmic history using data from the Science Demonstration Phase of the Herschel-Astrophysical Terahertz Large Area Survey (Herschel-ATLAS). The sample consists of galaxies selected at 250 ?m which have reliabl…
The persistent cosmic web and its filamentary structure - II. Illustrations
Pichon, C.; Sousbie, T.; Kawahara, H.
The recently introduced discrete persistent structure extractor (DisPerSE, Sousbie, Paper I) is implemented on realistic 3D cosmological simulations and observed redshift catalogues; it is found that DisPerSE traces very well the observed filaments, walls and voids seen both in simulations and in observations. In either setting, filaments are show…