Search Publications
The CFHTLS-Strong Lensing Legacy Survey (SL2S): Investigating the Group-scale Lenses with the SARCS Sample
Kneib, J. -P.; Alard, C.; Gavazzi, R. +5 more
We present the Strong Lensing Legacy Survey-ARCS (SARCS) sample compiled from the final T0006 data release of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) covering a total non-overlapping area of 159 deg2. We adopt a semi-automatic method to find gravitational arcs in the survey that makes use of an arc-finding algorithm. T…
Properties of Galactic early-type O-supergiants. A combined FUV-UV and optical analysis
Bouret, J. -C.; Hillier, D. J.; Fullerton, A. W. +1 more
Aims: We aim to constrain the properties and evolutionary status of early and mid-spectral type supergiants (from O4 to O7.5). These posses the highest mass-loss rates among the O stars, and exhibit conspicuous wind profiles.
Methods: Using the non-LTE wind code cmfgen we simultaneously analyzed the FUV-UV and optical spectral range to d…
The Star Formation Rate Function for Redshift z ~ 4-7 Galaxies: Evidence for a Uniform Buildup of Star-forming Galaxies during the First 3 Gyr of Cosmic Time
van Dokkum, Pieter G.; Franx, Marijn; Illingworth, Garth D. +4 more
We combine recent estimates of dust extinction at z ~ 4-7 with UV luminosity function (LF) determinations to derive star formation rate (SFR) functions at z ~ 4-7. SFR functions provide a more physical description of galaxy buildup at high redshift and allow for direct comparisons to SFRs at lower redshifts determined by a variety of techniques. O…
HST-COS Observations of AGNs. I. Ultraviolet Composite Spectra of the Ionizing Continuum and Emission Lines
Shull, J. Michael; Danforth, Charles W.; Stevans, Matthew
The ionizing fluxes from quasars and other active galactic nuclei (AGNs) are critical for interpreting the emission-line spectra of AGNs and for photoionization and heating of the intergalactic medium. Using ultraviolet spectra from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST), we have directly measured the rest-frame …
The Nature of Double-peaked [O III] Active Galactic Nuclei
Djorgovski, S. G.; Myers, Adam D.; Aldering, G. +4 more
Active galactic nuclei (AGNs) with double-peaked [O III] lines are suspected to be sub-kpc or kpc-scale binary AGNs. However, pure gas kinematics can produce the same double-peaked line profile in spatially integrated spectra. Here we combine integral-field spectroscopy and high-resolution imaging of 42 double-peaked [O III] AGNs from the Sloan Di…
Polarimetric Imaging of Large Cavity Structures in the Pre-transitional Protoplanetary Disk around PDS 70: Observations of the Disk
Kuzuhara, M.; Tamura, M.; Ishii, M. +52 more
We present high-resolution H-band polarized intensity (FWHM = 0farcs1: 14 AU) and L'-band imaging data (FWHM = 0farcs11: 15 AU) of the circumstellar disk around the weak-lined T Tauri star PDS 70 in Centaurus at a radial distance of 28 AU (0farcs2) up to 210 AU (1farcs5). In both images, a giant inner gap is clearly resolved for the first time, an…
Herschel-ATLAS: multi-wavelength SEDs and physical properties of 250 µm selected galaxies at z < 0.5
Ivison, R. J.; Clements, D. L.; Scott, D. +38 more
We present a pan-chromatic analysis of an unprecedented sample of 1402 250 µm selected galaxies at z < 0.5 (z¯=0.24) from the Herschel-ATLAS survey. We complement our Herschel 100-500 µm data with UV-K-band photometry from the Galaxy And Mass Assembly (GAMA) survey and apply the MAGPHYS energy-balance technique to produce pan-chroma…
A multi-scale, multi-wavelength source extraction method: getsources
André, Ph.; Schneider, N.; Men'shchikov, A. +3 more
We present a multi-scale, multi-wavelength source extraction algorithm called getsources. Although it has been designed primarily for use in the far-infrared surveys of Galactic star-forming regions with Herschel, the method can be applied to many other astronomical images. Instead of the traditional approach of extracting sources in the observed …
IDCS J1426.5+3508: Discovery of a Massive, Infrared-selected Galaxy Cluster at z = 1.75
Dey, Arjun; Gonzalez, Anthony H.; Stanford, S. A. +6 more
We report the discovery of an IR-selected massive galaxy cluster in the IRAC Deep Cluster Survey (IDCS). We present new data from the Hubble Space Telescope and the W. M. Keck Observatory that spectroscopically confirm IDCS J1426.5+3508 at z = 1.75. Moreover, the cluster is detected in archival Chandra data as an extended X-ray source, comprising …
On the Detection of Ionizing Radiation Arising from Star-forming Galaxies at Redshift z ~ 3-4: Looking for Analogs of "Stellar Re-ionizers"
Castellano, Marco; Dickinson, Mark; Ferguson, Henry C. +15 more
We use the spatially resolved, multi-band photometry in the GOODS South field acquired by the CANDELS project to constrain the nature of candidate Lyman continuum (LyC) emitters at redshift z ~ 3.7 identified using ultradeep imaging below the Lyman limit (1σ limit of ≈30 AB in a 2'' diameter aperture). In 19 candidates out of a sample of 20 with f…