Search Publications
Reconstructing the local potential of inflation with BICEP2 data
Ma, Yin-Zhe; Wang, Yi
We locally reconstruct the inflationary potential by using the current constraints on r and ns from BICEP2 data. Assuming small and negligible αs, the inflationary potential is approximately linear in Δϕ~ Mpl range but becomes non-linear in Δϕ~ 10 Mpl range. However if we vary the value of αs …
Large-scale environments of binary AGB stars probed by Herschel. II. Two companions interacting with the wind of π1 Gruis
Cruzalèbes, P.; Jorissen, A.; Pourbaix, D. +12 more
Context. The Mass loss of Evolved StarS (MESS) sample observed with PACS on board the Herschel Space Observatory revealed that several asymptotic giant branch (AGB) stars are surrounded by an asymmetric circumstellar envelope (CSE) whose morphology is most likely caused by the interaction with a stellar companion. The evolution of AGB stars in bin…
Characterizing the quiescent X-ray variability of the black hole low-mass X-ray binary V404 Cyg
Bernardini, F.; Cackett, E. M.
We conducted the first long-term (75 d) X-ray monitoring of the black hole low-mass X-ray binary V404 Cyg, with the goal of understanding and characterizing its variability during quiescence. The X-ray light curve of V404 Cyg shows several flares on time-scales of hours with a count rate change of a factor of about 5-8. The root-mean-square variab…
Noncircular features in Saturn's rings II: The C ring
Nicholson, Philip D.; French, Richard G.; Hedman, Matthew M. +5 more
We present a comprehensive survey of sharp-edged features in Saturn's C ring, using data from radio and stellar occultation experiments carried out by the Cassini spacecraft over a period of more than five years. Over 100 occultations are included in the combined data set, enabling us to identify systematic radial perturbations as small as 200 m o…
Multiwavelength observations of the γ-ray-emitting narrow-line Seyfert 1 PMN J0948+0022 in 2011
Drake, A. J.; Larsson, J.; Giroletti, M. +13 more
We report on radio-to-γ-ray observations during 2011 May-September of PMN J0948+0022, the first narrow-line Seyfert 1 (NLSy1) galaxy detected in γ-rays by Fermi-Large Area Telescope. Strong variability was observed in γ-rays, with two flaring periods peaking on 2011 June 20 and July 28. The variability observed in optical and near-infrared seems t…
Effects of long-lived 10 MeV-scale sterile neutrinos on primordial elemental abundances and the effective neutrino number
Ishida, Hiroyuki; Kusakabe, Motohiko; Okada, Hiroshi
The primordial lithium abundance inferred from spectroscopic observations of metal-poor stars is ∼3 times smaller than the theoretical prediction in the standard big bang nucleosynthesis (BBN) model. We assume a simple model composed of standard model particles and a sterile neutrino νH with mass of O(10) MeV which decays long afte…
Searching for faint companions with VLTI/PIONIER. II. 92 main sequence stars from the Exozodi survey
Absil, O.; Augereau, J. -C.; Ertel, S. +6 more
Context. The Exozodi survey aims to determine the occurrence rate of bright exozodiacal discs around nearby main sequence stars using infrared interferometry. Although the Exozodi survey targets have been carefully selected to avoid the presence of binary stars, the results of this survey can still be biased by the presence of unidentified stellar…
Herschel Evidence for Disk Flattening or Gas Depletion in Transitional Disks
Dent, W. R. F.; Woitke, P.; Kamp, I. +6 more
Transitional disks are protoplanetary disks characterized by reduced near- and mid-infrared emission, with respect to full disks. This characteristic spectral energy distribution indicates the presence of an optically thin inner cavity within the dust disk believed to mark the disappearance of the primordial massive disk. We present new Herschel S…
The Tip of the Red Giant Branch Distance to the Perfect Spiral Galaxy M74 Hosting Three Core-collapse Supernovae
Lee, Myung Gyoon; Jang, In Sung
M74 (NGC 628) is a famous face-on spiral galaxy, hosting three core-collapse supernovae (SNe): SN Ic 2002ap, SN II-P 2003gd, and SN II-P 2013ej. However, its distance is not well known. We present a distance estimation for this galaxy based on the Tip of the Red Giant Branch (TRGB) method. We obtain photometry of the resolved stars in the arm-free…
Characterization of the Turbulent Magnetic Integral Length in the Solar Wind: From 0.3 to 5 Astronomical Units
Dasso, S.; Matthaeus, W. H.; Weygand, J. M. +1 more
The solar wind is a structured and complex system, in which the fields vary strongly over a wide range of spatial and temporal scales. As an example, the turbulent activity in the wind affects the evolution in the heliosphere of the integral turbulent scale or correlation length [λ], usually associated with the breakpoint in the turbulent-energy s…