Search Publications
Long XMM observation of the narrow-line Seyfert 1 galaxy IRAS 13224-3809: rapid variability, high spin and a soft lag
Young, A. J.; Brandt, W. N.; Ponti, G. +21 more
The narrow-line Seyfert 1 galaxy IRAS 13224-3809 has been observed with XMM-Newton for 500 ks. The source is rapidly variable on time-scales down to a few 100 s. The spectrum shows strong broad Fe - K and L emission features which are interpreted as arising from reflection from the inner parts of an accretion disc around a rapidly spinning black h…
The Herschel and JCMT Gould Belt Surveys: Constraining Dust Properties in the Perseus B1 Clump with PACS, SPIRE, and SCUBA-2
Bernard, J. -P.; Hill, T.; André, Ph. +29 more
We present Herschel observations from the Herschel Gould Belt Survey and SCUBA-2 science verification observations from the JCMT Gould Belt Survey of the B1 clump in the Perseus molecular cloud. We determined the dust emissivity index using four different techniques to combine the Herschel PACS+SPIRE data at 160-500 µm with the SCUBA-2 data …
Planck constraints on holographic dark energy
Zhang, Xin; Li, Miao; Ma, Yin-Zhe +2 more
We perform a detailed investigation on the cosmological constraints on the holographic dark energy (HDE) model by using the Plank data. We find that HDE can provide a good fit to the Plank high-l (l gtrsim 40) temperature power spectrum, while the discrepancy at l simeq 20-40 found in the ΛCDM model remains unsolved in the HDE model. The Plank dat…
Cryovolcanism on Titan: New results from Cassini RADAR and VIMS
Barnes, J. W.; Janssen, M. A.; Lunine, J. I. +13 more
The existence of cryovolcanic features on Titan has been the subject of some controversy. Here we use observations from the Cassini RADAR, including Synthetic Aperture Radar (SAR) imaging, radiometry, and topographic data as well as compositional data from the Visible and Infrared Mapping Spectrometer (VIMS) to reexamine several putative cryovolca…
"TNOs are Cool": A survey of the trans-Neptunian region. IX. Thermal properties of Kuiper belt objects and Centaurs from combined Herschel and Spitzer observations
Fornasier, S.; Groussin, O.; Lellouch, E. +14 more
Aims: The goal of this work is to characterize the ensemble thermal properties of the Centaurs / trans-Neptunian population.
Methods: Thermal flux measurements obtained with Herschel/PACS and Spitzer/MIPS provide size, albedo, and beaming factors for 85 objects (13 of which are presented here for the first time) by means of standard radi…
Gas fraction and star formation efficiency at z < 1.0
Braine, J.; Colina, L.; Walter, F. +3 more
After new observations of 39 galaxies at z ~ 0.6-1.0 obtained at the IRAM 30-m telescope, we present our full CO line survey covering the redshift range 0.2 < z < 1. Our aim is to determine the driving factors accounting for the steep decline in the star formation rate during this epoch. We study both the gas fraction, defined as Mgas
Global investigation of olivine on Mars: Insights into crust and mantle compositions
Bibring, J. -P.; Gondet, B.; Langevin, Y. +4 more
present the distribution of olivine on Mars, derived from spectral parameters based on the 1 µm olivine absorption band. The olivine can be defined with respect to two spectral end-members: type 1 corresponds to olivine with low iron content and/or small grain size and/or small abundance, and type 2, which corresponds to olivine with higher iron c…
X-ray follow-ups of XSS J12270-4859: a low-mass X-ray binary with gamma-ray Fermi-LAT association
Mukai, K.; Belloni, T.; de Martino, D. +10 more
Context. XSS J1227.0-4859 is a peculiar, hard X-ray source recently positionally associated to the Fermi-LAT source 1FGL J1227.9-4852/2FGL J1227.7-4853. Multi-wavelength observations have added information on this source, indicating a low-luminosity low-mass X-ray binary (LMXB), but its nature is still unclear.
Aims: To progress in our unders…
Flux calibration of the Herschel★-SPIRE photometer
Valtchanov, I.; Bock, J. J.; Spencer, L. D. +16 more
We describe the procedure used to flux calibrate the three-band submillimetre photometer in the Spectral and Photometric Imaging Receiver instrument on the Herschel Space Observatory. This includes the equations describing the calibration scheme, a justification for using Neptune as the primary calibration source, a description of the observations…
Galaxy Evolution in Overdense Environments at High Redshift: Passive Early-type Galaxies in a Cluster at z ~ 2
Finoguenov, A.; Cimatti, A.; Daddi, E. +8 more
We present a study of galaxy populations in the central region of the IRAC-selected, X-ray-detected galaxy cluster Cl J1449+0856 at z = 2. Based on a sample of spectroscopic and photometric cluster members, we investigate stellar populations and the morphological structure of cluster galaxies over an area of ~0.7 Mpc2 around the cluster…