Search Publications
The first Frontier Fields cluster: 4.5 µm excess in a z ~ 8 galaxy candidate in Abell 2744
Kneib, J. -P.; Pérez-Fournon, I.; Schaerer, D. +10 more
Aims: We present in this letter the first analysis of a z ~ 8 galaxy candidate found in the Hubble and Spitzer imaging data of Abell 2744 as part of the Hubble Frontier Fields legacy program.
Methods: We applied the most commonly used methods to select exceptionally high-redshift galaxies by combining non-detection and color criteria usi…
NuSTAR Observations of Heavily Obscured Quasars at z ~ 0.5
Harrison, F. A.; Stern, D.; Zhang, W. W. +23 more
We present NuSTAR hard X-ray observations of three Type 2 quasars at z ≈ 0.4-0.5, optically selected from the Sloan Digital Sky Survey. Although the quasars show evidence for being heavily obscured, Compton-thick systems on the basis of the 2-10 keV to [O III] luminosity ratio and multiwavelength diagnostics, their X-ray absorbing column densities…
Gaia photometry for white dwarfs
Jordi, C.; Luri, X.; Carrasco, J. M. +5 more
Context. White dwarfs can be used to study the structure and evolution of the Galaxy by analysing their luminosity function and initial mass function. Among them, the very cool white dwarfs provide the information for the early ages of each population. Because white dwarfs are intrinsically faint only the nearby (~ 20 pc) sample is reasonably comp…
Solar Transition Region Lines Observed by the Interface Region Imaging Spectrograph: Diagnostics for the O IV and Si IV Lines
Mason, H. E.; Golub, L.; Del Zanna, G. +2 more
The formation of the transition region O IV and Si IV lines observable by the Interface Region Imaging Spectrograph (IRIS) is investigated for both Maxwellian and non-Maxwellian conditions characterized by a κ-distribution exhibiting a high-energy tail. The Si IV lines are formed at lower temperatures than the O IV lines for all κ. In non-Maxwelli…
The first submillimeter observation of CO in the stratosphere of Uranus
Fletcher, L. N.; Hartogh, P.; Lellouch, E. +8 more
Context. Carbon monoxide (CO) has been detected in all giant planets and its origin is both internal and external in Jupiter and Neptune. Despite its first detection in Uranus a decade ago, the magnitude of its internal and external sources remains unconstrained.
Aims: We targeted CO lines in Uranus in the submillimeter range to constrain its…
A Hard X-Ray Power-law Spectral Cutoff in Centaurus X-4
Hailey, Charles J.; Chakrabarty, Deepto; Kaspi, Victoria M. +17 more
The low-mass X-ray binary (LMXB) Cen X-4 is the brightest and closest (<1.2 kpc) quiescent neutron star transient. Previous 0.5-10 keV X-ray observations of Cen X-4 in quiescence identified two spectral components: soft thermal emission from the neutron star atmosphere and a hard power-law tail of unknown origin. We report here on a simultaneou…
Correlations between the stellar, planetary, and debris components of exoplanet systems observed by Herschel
Ivison, R. J.; Olofsson, G.; Eiroa, C. +18 more
Context. Stars form surrounded by gas- and dust-rich protoplanetary discs. Generally, these discs dissipate over a few (3-10) Myr, leaving a faint tenuous debris disc composed of second-generation dust produced by the attrition of larger bodies formed in the protoplanetary disc. Giant planets detected in radial velocity and transit surveys of main…
Measurement of the TCMB evolution from the Sunyaev-Zel'dovich effect
Aghanim, N.; Douspis, M.; Hurier, G. +1 more
In the standard hot cosmological model, the black-body temperature of the cosmic microwave background (CMB), TCMB, increases linearly with redshift. Across the line of sight CMB photons interact with the hot (~ 107-8 K ) and diffuse gas of electrons from galaxy clusters. This interaction leads to the well-known thermal Sunyae…
Is Solar Cycle 24 Producing More Coronal Mass Ejections Than Cycle 23?
Wang, Y. -M.; Colaninno, R.
Although sunspot numbers are roughly a factor of two lower in the current cycle than in cycle 23, the rate of coronal mass ejections (CMEs) appears to be at least as high in 2011-2013 as during the corresponding phase of the previous cycle, according to three catalogs that list events observed with the Large Angle and Spectrometric Coronagraph (LA…
Theoretical power spectra of mixed modes in low-mass red giant stars
Dupret, M. -A.; Samadi, R.; Mosser, B. +3 more
Context. CoRoT and Kepler observations of red giant stars revealed very rich spectra of non-radial solar-like oscillations. Of particular interest was the detection of mixed modes that exhibit significant amplitude, both in the core and at the surface of the stars. It opens the possibility of probing the internal structure from their innermost lay…