1,885 research outputs found
Towards reproducible research of event detection techniques for Twitter
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works
Revised Gaia Data Release 2 passbands
The European Space Agency mission Gaia has published with its second data
release (DR2) a catalogue of photometric measurements for more than 1.3 billion
astronomical objects in three passbands. The precision of the measurements in
these passbands, denoted G, G_BP, and G_RP, reaches down to the milli-magnitude
level. The scientific exploitation of this data set requires precise knowledge
on the response curves of the three passbands. This work aims to improve the
exploitation of the photometric data by deriving an improved set of response
curves for the three passbands, allowing for an accurate computation of
synthetic Gaia photometry. This is achieved by formulating the problem of
passband determination in a functional analytic formalism, and linking the
photometric measurements with four observational, one empirical and one
theoretical spectral library. We present response curves for G, G_BP, and G_RP
that differ from the previously published curves, and which provide a better
agreement between synthetic Gaia photometry and Gaia observations.Comment: Accepted versio
The Impact of Universal Extra Dimensions on FCNC Processes
We review the results of two papers on FCNC processes in the Appelquist,
Cheng and Dobrescu (ACD) model with one universal extra dimension.Comment: Invited talk at the Workshop on the CKM Unitarity Triangle, IPPP
Durham, April 2003 (eConf C0304052). 7 pages LaTeX, 5 eps figure
Spectrophotometric calibration of low-resolution spectra
Low-resolution spectroscopy is a frequently used technique. Aperture prism
spectroscopy in particular is an important tool for large-scale survey
observations. The ongoing ESA space mission Gaia is the currently most relevant
example. In this work we analyse the fundamental limitations of the calibration
of low-resolution spectrophotometric observations and introduce a calibration
method that avoids simplifying assumptions on the smearing effects of the line
spread functions. To this aim, we developed a functional analytic mathematical
formulation of the problem of spectrophotometric calibration. In this
formulation, the calibration process can be described as a linear mapping
between two suitably constructed Hilbert spaces, independently of the
resolution of the spectrophotometric instrument. The presented calibration
method can provide a formally unusual but precise calibration of low-resolution
spectrophotometry with non-negligible widths of line spread functions. We used
the Gaia spectrophotometric instruments to demonstrate that the calibration
method of this work can potentially provide a significantly better calibration
than methods neglecting the smearing effects of the line spread functions.Comment: Final versio
- …