Search results for "Wide field"
showing 10 items of 21 documents
ARES. III. Unveiling the Two Faces of KELT-7 b with HST WFC3
2020
We present the analysis of the hot-Jupiter KELT-7b using transmission and emission spectroscopy from the Hubble Space Telescope (HST), both taken with the Wide Field Camera 3 (WFC3). Our study uncovers a rich transmission spectrum which is consistent with a cloud-free atmosphere and suggests the presence of H2O and H-. In contrast, the extracted emission spectrum does not contain strong absorption features and, although it is not consistent with a simple blackbody, it can be explained by a varying temperature-pressure profile, collision induced absorption (CIA) and H-. KELT-7 b had also been studied with other space-based instruments and we explore the effects of introducing these additiona…
Spectral changes during six years of Scorpius X-1 monitoring with BeppoSAX Wide Field Cameras
2005
We analyse a sample of fifty-five observations of Scorpius X-1 available in the BeppoSAX Wide Field Camera public archive and spanning over the six years of BeppoSAX mission life. Spectral changes are initially analysed by inspection of colour-colour and colour-intensity diagrams, we also discuss the shift of the Z tracks in these diagrams. Then we select two long observations for spectral fitting analysis, a secular shift is evident between the tracks in these observations. We finally extract spectra along the tracks and discuss the best fit model, the parameter variations along the track and between tracks, and their link to the accretion rate.
ARES I: WASP-76 b, A Tale of Two HST Spectra
2020
We analyse the transmission and emission spectra of the ultra-hot Jupiter WASP-76b, observed with the G141 grism of the Hubble Space Telescope's Wide Field Camera 3 (WFC3). We reduce and fit the raw data for each observation using the open-source software Iraclis before performing a fully Bayesian retrieval using the publicly available analysis suite TauRex 3. Previous studies of the WFC3 transmission spectra of WASP-76 b found hints of titanium oxide (TiO) and vanadium oxide (VO) or non-grey clouds. Accounting for a fainter stellar companion to WASP-76, we reanalyse this data and show that removing the effects of this background star changes the slope of the spectrum, resulting in these vi…
Using Survival Models with Individual Data
2007
Since there exists in this literature a common interest to unravel the sources of both permanence in the self-employment status and firm survival, the present chapter is devoted to provide guidelines to applied researchers about which methods are suitable for any particular application related to self-employment and firm survival. Further, it should be noted that the econometric analysis of survival (duration) is a very wide field, and that the modest aim of the following sections in this chapter is to introduce the reader to such kind of econometric analysis.
IRIDE: Interdisciplinary research infrastructure based on dual electron linacs and lasers
2014
This paper describes the scientific aims and potentials as well as the preliminary technical design of RUDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity "particles factory", based on a combination of high duty cycle radio-frequency superconducting electron linacs and of high energy lasers. Conceived to provide unique research possibilities for particle physics, for condensed matter physics, chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of sci…
Album: A Tool for the Analysis of Slitless Spectra and its Application to ESO WFI Data
2008
ALBUM is a general-purpose tool to visualize and screen large amounts of slitless spectra∈dex slitless spectra. It was developed for a search for emission-line stars in SMC and LMC clusters. The observations were obtained with ESO’s Wide Field Imager (WFI∈dexWFI) and comprise ~8 million low-resolution spectra. The tool as well as the results of its application to the SMC part of the database are presented. The inferred frequency of Be stars is compared to the one in the higher-metallicity environment of the Milky Way.
Absolute kinematics of radio source components in the complete S5 polar cap sample
2007
We report on the first wide-field, high-precision astrometric analysis of the 13 extragalactic radio sources of the complete S5 polar cap sample at 15.4 GHz. We describe new algorithms developed to enable the use of differenced phase delays in wide-field astrometric observations and discuss the impact of using differenced phase delays on the precision of the wide-field astrometric analysis. From this global fit, we obtained estimates of the relative source positions with precisions ranging from 14 to 200 $\mu$as at 15.4 GHz, depending on the angular separation of the sources (from $\sim$1.6 to $\sim$20.8 degrees). These precisions are $\sim$10 times higher than the achievable precisions usi…
Lobster eye optics for nano-satellite x-ray monitor
2011
The Lobster eye design for a grazing incidence X-ray optics provides wide field of view of the order of many degrees, for this reason it would be a convenient approach for the construction of space X-ray monitors. In this paper, we compare previously reported measurements of prototype lobster eye X-ray optics called P-25 with computer simulations and discuss differences between the theoretical end experimentally obtained results. Usability of this prototype lobster eye and manufacturing technology for the nano-satellite mission is assessed. The specific scientific goals are proposed.
Six Years of ScoX-1 Monitoring with BeppoSAX Wide Field Cameras
2003
We performed a systematic analysis of 54 Wide Field Camera (WFC) observations of ScoX-1 available in the BeppoSAX public archive. Observations span over the six years of BeppoSAX mission lifetime and include 690 hr of data. We searched for shifts and shape changes of the Z pattern in the color-color diagrams. We find that the Z pattern occupies most of the time the same locus in the color-color diagram. There are however a few exceptions, which are discussed in detail.
Circinus X-1 observed with BeppoSAX wide field cameras
1999
Abstract We present a sky image and spectra for various orbital phases of Circinus X-1 observed by B-SAX Wide Field Cameras. We suggest that the spectral shape is dependent on the orbital phase.