Search Publications
Probability of warm inflation in loop quantum cosmology
Ramos, Rudnei O.; Graef, L. L.
Warm inflation is analyzed in the context of loop quantum cosmology (LQC). The bounce in LQC provides a mean through which a Liouville measure can be defined, which has been used previously to characterize the a priori probability for inflation in LQC. Here we take advantage of the tools provided by LQC to study instead the a priori probability fo…
Two-Dimensional Solar Wind Speeds from 6 to 26 Solar Radii in Solar Cycle 24 by Using Fourier Filtering
Moon, Yong-Jae; Song, Donguk; Lee, Harim +5 more
Measurement of the solar wind speed near the Sun is important for understanding the acceleration mechanism of the solar wind. In this Letter, we determine 2D solar wind speeds from 6 to 26 solar radii by applying Fourier motion filters to SOHO/LASCO C3 movies observed from 1999 to 2010. Our method successfully reproduces the original flow speeds i…
Medium-sized Satellites of Large Kuiper Belt Objects
Brown, Michael E.; Butler, Bryan J.
While satellites of mid- to small-Kuiper Belt objects tend to be similar in size and brightness to their primaries, the largest Kuiper Belt objects preferentially have satellites with small fractional brightness. In the two cases where the sizes and albedos of the small faint satellites have been measured, these satellites are seen to be small icy…
X-ray reflection from the inner disc of the AGN Ton S180
Fabian, A. C.; Miller, J. M.; Parker, M. L.
We analyse a long archival XMM-Newton observation of the narrow-line Seyfert 1 galaxy Ton S180, using the latest reflection models to explore the high quality X-ray spectrum. We find that the iron line is relatively narrow and sharp, and the soft excess is extremely smooth. We cannot find an acceptable reflection model that describes both componen…
Limb clouds and dust on Mars from images obtained by the Visual Monitoring Camera (VMC) onboard Mars Express
Hueso, R.; Sánchez-Lavega, A.; Titov, D. +6 more
The Visual Monitoring Camera (VMC) onboard the Mars Express (MEx) spacecraft is a simple camera aimed to monitor the release of the Beagle-2 lander on Mars Express and later used for public outreach. Here, we employ VMC as a scientific instrument to study and characterize high altitude aerosols events (dust and condensates) observed at the Martian…
Precise weak lensing constraints from deep high-resolution Ks images: VLT/HAWK-I analysis of the super-massive galaxy cluster RCS2 J 232727.7-020437 at z = 0.70
Bradač, Maruša; Muzzin, Adam; Schrabback, Tim +16 more
We demonstrate that deep good-seeing VLT/HAWK-I Ks images complemented with g + z-band photometry can yield a sensitivity for weak lensing studies of massive galaxy clusters at redshifts 0.7 ≲ z ≲ 1.1, which is almost identical to the sensitivity of HST/ACS mosaics of single-orbit depth. Key reasons for this good performance are the exc…
A quantitative spectral analysis of 14 hypervelocity stars from the MMT survey
Heber, U.; Irrgang, A.; Kreuzer, S. +1 more
Context. Hypervelocity stars (HVSs) travel so fast that they may leave the Galaxy. The tidal disruption of a binary system by the supermassive black hole in the Galactic center is widely assumed to be their ejection mechanism.
Aims: To test the hypothesis of an origin in the Galactic center using kinematic investigations, the current space ve…
CO in Protostars (COPS): Herschel-SPIRE Spectroscopy of Embedded Protostars
Larson, Rebecca L.; Lee, Jeong-Eun; Bouwman, Jeroen +13 more
We present full spectral scans from 200 to 670 µm of 26 Class 0+I protostellar sources obtained with Herschel-SPIRE as part of the “COPS-SPIRE” Open Time program, complementary to the DIGIT and WISH Key Programs. Based on our nearly continuous, line-free spectra from 200 to 670 µm, the calculated bolometric luminosities (L bol
A Stealth CME Bracketed between Slow and Fast Wind Producing Unexpected Geoeffectiveness
Wang, Rui; Liu, Ying D.; Hu, Huidong +2 more
We investigate how a weak coronal mass ejection (CME) launched on 2016 October 8 without obvious signatures in the low corona produced a relatively intense geomagnetic storm. Remote sensing observations from SDO, STEREO, and SOHO and in situ measurements from Wind are employed to track the CME from the Sun to the Earth. Using a graduated cylindric…
Thermal fracturing on comets. Applications to 67P/Churyumov-Gerasimenko
Jorda, L.; Kührt, E.; Groussin, O. +12 more
We simulate the stresses induced by temperature changes in a putative hard layer near the surface of comet 67P/Churyumov-Gerasimenko with a thermo-viscoelastic model. Such a layer could be formed by the recondensation or sintering of water ice (and dust grains), as suggested by laboratory experiments and computer simulations, and would explain the…