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Constraining dynamical neutrino mass generation with cosmological data
Koksbang, S. M.; Hannestad, S.
We study models in which neutrino masses are generated dynamically at cosmologically late times. Our study is purely phenomenological and parameterized in terms of three effective parameters characterizing the redshift of mass generation, the width of the transition region, and the present day neutrino mass. We also study the possibility that neut…
CSI 2264: Simultaneous optical and X-ray variability in pre-main sequence stars. I. Time resolved X-ray spectral analysis during optical dips and accretion bursts in stars with disks
Micela, G.; Stauffer, J.; Sciortino, S. +6 more
Context. Pre-main sequence stars are variable sources. The main mechanisms responsible for their variability are variable extinction, unsteady accretion, and rotational modulation of both hot and dark photospheric spots and X-ray-active regions. In stars with disks, this variability is related to the morphology of the inner circumstellar region (≤…
Bars as seen by Herschel and Sloan
Consolandi, Guido; Gavazzi, Giuseppe; Dotti, Massimo +2 more
We present an observational study of the effect of bars on the gas component and on the star formation properties of their host galaxies in a statistically significant sample of resolved objects, the Herschel Reference Sample. The analysis of optical and far-infrared images allows us to identify a clear spatial correlation between stellar bars and…
The X-ray continuum time-lags and intrinsic coherence in AGN
Papadakis, I. E.; Epitropakis, A.
We present the results from a systematic analysis of the X-ray continuum ('hard') time-lags and intrinsic coherence between the 2-4 keV and various energy bands in the 0.3-10 keV range, for 10 X-ray bright and highly variable active galactic nuclei (AGN). We used all available archival XMM-Newton data, and estimated the time-lags following Epitrop…
An abundance analysis from the STIS-HST UV spectrum of the non-magnetic Bp star HR 6000
Leone, F.; Castelli, F.; Catanzaro, G. +2 more
Context. The sharp-line spectrum of the non-magnetic, main-sequence Bp star HR 6000 has peculiarities that distinguish it from those of the HgMn stars with which it is sometimes associated. The position of the star close to the center of the Lupus 3 molecular cloud, whose estimated age is on the order of 9.1 ± 2.1 Myr, has lead to the hypothesis t…
The 34S/32S isotopic ratio measured in the dust of comet 67P/Churyumov-Gerasimenko by Rosetta/COSIMA
Hilchenbach, M.; Hornung, K.; Kissel, J. +4 more
The isotopic ratio 34S/32S has been measured in cometary gas for a few comets, but it has only been measured in cometary dust by stardust. The dust measurements find a value of the ratio that is consistent with the Vienna Canyon Diablo Troilite value of 0.0442 within errors, but there is more spread in the values from cometar…
Ultrafast outflows in ultraluminous X‑ray sources
Pinto, C.; Walton, D.; Fabian, A. +1 more
Ultraluminous X-ray sources (ULXs) are bright extragalactic sources with X-ray luminosities above 10^39 erg/s powered by accretion onto compact objects. According to the first studies performed with XMM-Newton ULXs seemed to be excellent candidates to host intermediate-mass black holes (10^2-4 solar masses). However, in the last years the interpre…
Three-dimensional illumination and thermal model of the Abydos region on comet 67P/Churyumov-Gerasimenko
Spohn, Tilman; Finke, Felix; Jorda, Laurent +9 more
On 2014 November 12 Rosetta's comet lander Philae arrived on the surface of Comet 67P/Churyumov-Gerasimenko. Among the data collected by the instruments on board are images from the panorama camera CIVA and the down looking camera ROLIS, as well as temperature measurements recorded by the sensors of the MUPUS experiment and by various housekeeping…
Herschel and Hubble Study of a Lensed Massive Dusty Starbursting Galaxy at z ∼ 3
Ivison, R. J.; Frayer, D. T.; Cooray, A. +19 more
We present the results of combined deep Keck/NIRC2, HST/WFC3 near-infrared, and Herschel far-infrared observations of an extremely star-forming dusty lensed galaxy identified from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS J133542.9+300401). The galaxy is gravitationally lensed by a massive WISE-identified galaxy cluster at z …
The spectroscopic indistinguishability of red giant branch and red clump stars
Masseron, T.; Hawkins, K.
Context. Stellar spectroscopy provides useful information on the physical properties of stars such as effective temperature, metallicity and surface gravity. However, those photospheric characteristics are often hampered by systematic uncertainties. The joint spectro-sismo project (APOGEE+Kepler, aka APOKASC) of field red giants has revealed a puz…