Search Publications
The WIRCAM Deep Infrared Cluster Survey. I. Groups and clusters at z ⪆ 1.1
Finoguenov, A.; Daddi, E.; Ilbert, O. +12 more
Aims: We use a combination of CFHTLS deep optical data, WIRcam Deep Survey (WIRDS) near-infrared data and XMM-Newton survey data to identify z ⪆ 1.1 clusters in the CFHTLS D1 and D4 fields. Counterparts to such clusters can not be identified without deep near-infrared data and as such the total of ≈ 1 deg2 of J, H and Ks…
Testing Models for Molecular Gas Formation in Galaxies: Hydrostatic Pressure or Gas and Dust Shielding?
Hunt, Leslie K.; Fumagalli, Michele; Krumholz, Mark R.
Stars in galaxies form in giant molecular clouds that coalesce when the atomic hydrogen is converted into molecules. There are currently two dominant models based on the property of the galactic disk that determines its molecular fraction: either hydrostatic pressure driven by the gravity of gas and stars, or a combination of gas column density an…
The central star of the planetary nebula PB 8: a Wolf-Rayet-type wind of an unusual WN/WC chemical composition
Hamann, W. -R.; Todt, H.; Gräfener, G. +1 more
A considerable fraction of the central stars of planetary nebulæ (CSPNe) are hydrogen-deficient. As a rule, these CSPNe exhibit a chemical composition of helium, carbon, and oxygen with the majority showing Wolf-Rayet-like emission line spectra. These stars are classified as CSPNe of a spectral type [WC]. We perform a spectral analysis of CSPN PB …
Optical Images and Source Catalog of AKARI North Ecliptic Pole Wide Survey Field
Im, Myungshin; Lee, Hyung Mok; Lee, Myung Gyoon +3 more
We present the source catalog and the properties of the B-, R-, and I-band images obtained to support the AKARI North Ecliptic Pole Wide (NEP-Wide) survey. The NEP-Wide is an AKARI infrared imaging survey of the north ecliptic pole covering a 5.8 deg2 area over 2.5-6 µm wavelengths. The optical imaging data were obtained at the Ma…
Spitzer Mid-Infrared Spectroscopy of Compact Symmetric Objects: What Powers Radio-Loud Active Galactic Nuclei?
Perlman, Eric S.; Stocke, John T.; Darling, Jeremy +1 more
We present low- and high-resolution mid-infrared (mid-IR) spectra and photometry for eight compact symmetric objects (CSOs) taken with the Infrared Spectrograph on the Spitzer Space Telescope. The hosts of these young, powerful radio galaxies show significant diversity in their mid-IR spectra. This includes multiple atomic fine-structure lines, H<…
X-ray Evolution of Pulsar Wind Nebulae
Dotani, Tadayasu; Ebisawa, Ken; Vink, Jacco +4 more
During the search for counterparts of very high energy gamma-ray sources, we serendipitously discovered large, extended, low surface brightness emission from pulsar wind nebulae (PWNe) around pulsars with the ages up to ~100 kyr, a discovery made possible by the low and stable background of the Suzaku X-ray satellite. A systematic study of a sampl…
Multiwavelength observations of 1RXH J173523.7-354013: revealing an unusual bursting neutron star
D'Avanzo, P.; de Luca, A.; Degenaar, N. +14 more
On 2008 May 14, the Burst Alert Telescope onboard the Swift mission triggered on a type-I X-ray burst from the previously unclassified ROSAT object 1RXH J173523.7-354013, establishing the source as a neutron star X-ray binary. We report on X-ray, optical and near-infrared observations of this system. The X-ray burst had a duration of ~2 h and belo…
Physical properties of the ESA Rosetta target asteroid (21) Lutetia. II. Shape and flyby geometry
Colas, F.; Fornasier, S.; Carry, B. +22 more
Aims: We determine the physical properties (spin state and shape) of asteroid (21) Lutetia, target of the International Rosetta Mission of the European Space Agency, to help in preparing for observations during the flyby on 2010 July 10 by predicting the orientation of Lutetia as seen from Rosetta.
Methods: We use our novel KOALA inversi…
Bathymetry and absorptivity of Titan's Ontario Lacus
Callahan, P.; Hayes, A. G.; Kirk, R. L. +9 more
Ontario Lacus is the largest and best characterized lake in Titan's south polar region. In June and July 2009, the Cassini RADAR acquired its first Synthetic Aperture Radar (SAR) images of the area. Together with closest approach altimetry acquired in December 2008, these observations provide a unique opportunity to study the lake's nearshore bath…
Magnetosonic Mach number effect of the position of the bow shock at Mars in comparison to Venus
Barabash, S.; Fränz, M.; Lester, M. +3 more
We study the effect of the magnetosonic Mach number on the position of the bow shock (BS) at Mars. The magnetosonic Mach number is calculated from solar wind data obtained by the ACE satellite upstream of Earth and extrapolated to Mars during two intervals, starting in 2005 and 2007, when Mars and Earth were close to opposition. An increased Mach …