Papers by federica bianco
arXiv (Cornell University), Jul 21, 2019
The Large Synoptic Survey Telescope (LSST) can advance scientific frontiers beyond its groundbrea... more The Large Synoptic Survey Telescope (LSST) can advance scientific frontiers beyond its groundbreaking 10-year survey. Here we explore opportunities for extended operations with proposal-based observing strategies, new filters, or transformed instrumentation. We recommend the development of a mid-decade community-and science-driven process to define nextgeneration LSST capabilities.
arXiv (Cornell University), Mar 11, 2019
presentation on the impact of publishing scientific software for astronomers and astrophysicists ... more presentation on the impact of publishing scientific software for astronomers and astrophysicists presented at EWASS (European Week of Astronomy and Space Science) in 2018 - as such it is probably severely out of date
The Astrophysical Journal Supplement Series, 2021
Vera C. Rubin Observatory is a ground-based astronomical facility under construction, a joint pro... more Vera C. Rubin Observatory is a ground-based astronomical facility under construction, a joint project of the National Science Foundation and the U.S. Department of Energy, designed to conduct a multipurpose 10 yr optical survey of the Southern Hemisphere sky: the Legacy Survey of Space and Time. Significant flexibility in survey strategy remains within the constraints imposed by the core science goals of probing dark energy and dark matter, cataloging the solar system, exploring the transient optical sky, and mapping the Milky Way. The survey’s massive data throughput will be transformational for many other astrophysics domains and Rubin’s data access policy sets the stage for a huge community of potential users. To ensure that the survey science potential is maximized while serving as broad a community as possible, Rubin Observatory has involved the scientific community at large in the process of setting and refining the details of the observing strategy. The motivation, history, a...
Nature Reviews Physics, 2019
Multi-messenger astrophysics is a fast-growing, interdisciplinary field that combines data, which... more Multi-messenger astrophysics is a fast-growing, interdisciplinary field that combines data, which vary in volume and speed of data processing, from many different instruments that probe the Universe using different cosmic messengers: electromagnetic waves, cosmic rays, gravitational waves and neutrinos. In this Expert Recommendation, we review the key challenges of real-time observations of gravitational wave sources and their electromagnetic and astroparticle counterparts, and make a number of recommendations to maximize their potential for scientific discovery. These recommendations refer to the design of scalable and computationally efficient machine learning algorithms; the cyber-infrastructure to numerically simulate astrophysical sources, and to process and interpret multi-messenger astrophysics data; the management of gravitational wave detections to trigger real-time alerts for electromagnetic and astroparticle follow-ups; a vision to harness future developments of machine learning and cyber-infrastructure resources to cope with the big-data requirements; and the need to build a community of experts to realize the goals of multi-messenger astrophysics.
Astronomische Nachrichten, 2006
The Taiwanese-American Occultation Survey (TAOS) seeks to determine the number and size spectrum ... more The Taiwanese-American Occultation Survey (TAOS) seeks to determine the number and size spectrum for small (∼3 km) bodies in the Kuiper Belt. This will be accomplished by searching for the brief occultations of bright stars (R ∼14) by these objects. We have designed and built a special purpose photometric monitoring system for this purpose. TAOS comprises four 50 cm telescopes, each equipped with a 2048×2048 pixel CCD camera, in a compact array located in the central highlands of Taiwan. TAOS will monitor up to 2 000 stars at 5 Hz. The system went into scientific operation in the autumn of 2005.
The Astronomical Journal, 2007
The serendipitous detection of stellar occultations by Outer Solar System objects is a powerful m... more The serendipitous detection of stellar occultations by Outer Solar System objects is a powerful method for ascertaining the small end (r 15 km) of the size distribution of Kuiper Belt Objects and may potentially allow the exploration of objects as far out as the Oort Cloud. The design and implementation of an occultation survey is aided by a detailed understanding of how diffraction and observational parameters affect the detection of occultation events. In this study, stellar occultations are simulated, accounting for diffraction effects, finite source sizes, finite bandwidths, stellar spectra, sampling, and signal-to-noise. Finally, the possibility of detecting small Outer Solar System objects from the Kuiper Belt all the way out to the Oort Cloud is explored for three photometric systems: a proposed space telescope, Whipple (
Active Photonic Materials VII, 2015
The lack of a dipolar second order susceptibility (χ (2)) in silicon due to its centro-symmetric ... more The lack of a dipolar second order susceptibility (χ (2)) in silicon due to its centro-symmetric diamond lattice usually inhibits efficient second order nonlinear optical processes in the silicon bulk. Depositing stressed silicon nitride layers or growing a thermal oxide layer introduces an inhomogeneous strain into the silicon lattice and breaks the centro-symmetry of its crystal structure thereby creating a χ (2). This causes enhanced second harmonic generation and was observed in reflection and transmission measurements for wavelengths in the infrared. However strain is not the only means to break the structures symmetry. Fixed charges at the silicon nitride/silicon interface cause a high electric field close to the silicon interface which causes electric-field-induced-second-harmonic (EFISH) contributions too. The combination of both effects leads to χ (2) values which are estimated to be of the order as classic χ (2) materials like KDP or LiNiO 3. This paves the way for the exploitation of other second order nonlinear processes in the area of silicon photonics and is an example how fundamental optical properties of materials can be altered by strain.
SPIE Newsroom, 2012
Breaking the internal crystalline symmetry of silicon by an external mechanical stress gives the ... more Breaking the internal crystalline symmetry of silicon by an external mechanical stress gives the material a novel nonlinear optical property.
Nature Materials, 2011
Silicon photonics meets the electronics requirement of increased speed and bandwidth with on-chip... more Silicon photonics meets the electronics requirement of increased speed and bandwidth with on-chip optical networks. All-optical data management requires nonlinear silicon photonics. In silicon only third-order optical nonlinearities are present owing to its crystalline inversion symmetry. Introducing a second-order nonlinearity into silicon photonics by proper material engineering would be highly desirable. It would enable devices for wideband wavelength conversion operating at relatively low optical powers. Here we show that a sizeable second-order nonlinearity at optical wavelengths is induced in a silicon waveguide by using a stressing silicon nitride overlayer. We carried out second-harmonic-generation experiments and first-principle calculations, which both yield large values of strain-induced bulk second-order nonlinear susceptibility, up to 40 pm V −1 at 2,300 nm. We envisage that nonlinear strained silicon could provide a competing platform for a new class of integrated light sources spanning the near-to mid-infrared spectrum from 1.2 to 10 µm.
Advances in Geosciences, 2006
Advances in Geosciences, 2006
The majority of trans-Neptunian objects (TNOs) are probably small comets beyond the orbit of Nept... more The majority of trans-Neptunian objects (TNOs) are probably small comets beyond the orbit of Neptune. A study of TNOs may enable a better understanding of the origin of short-period comets and of the process of planet formation and the early history of the solar system. An occultation survey is currently the only way to detect these objects down to a size of a few kilometers at such a distance. The status of the TAOS (Taiwan-America Occultation Survey) project is reported. In order to monitor thousands of stars on the order of a fraction of a second using CCD cameras, a novel CCD readout technique, the "shutterless zipper mode", is applied. Two predicted asteroid occultation events were successfully observed. Instead of a simple number count of occultation events, an interpretation of a TNO occultation survey result can be obtained by using the simulator described here. Through comparison of the results from an observation and from our simulator, a specific astronomical or astrophysical model can be constrained.
The Taiwanese-American Occultation Survey (TAOS) is a program dedicated to performing a survey of... more The Taiwanese-American Occultation Survey (TAOS) is a program dedicated to performing a survey of the size and number distribution for small bodies (< 10km) in the Kuiper Belt. These objects are too faint to be detected through traditional means, but can be observed via their occultations of background stars. This technique is challenging due to the low event rate, the
Proceedings of the International Astronomical Union, 2010
Motivated by the increasing need for observational resources for the study of time varying astron... more Motivated by the increasing need for observational resources for the study of time varying astronomy, the Las Cumbres Observatory Global Telescope (LCOGT) is a private foundation, whose goal is to build a global network of robotic telescopes for scientific research and education. Once completed, the network will become a unique tool, capable of continuous monitoring from both the Northern and Southern Hemispheres. The network currently includes 2 × 2.0 m telescopes, already making an impact in the field of exoplanet research. In the next few years they will be joined by at least 12 × 1.0 m and 20 × 0.4 m telescopes. The increasing amount of LCOGT observational resources in the coming years will be of great service to the astronomical community in general, and the exoplanet community in particular.
We present a de-trending algorithm for the removal of trends in time series. Trends in time serie... more We present a de-trending algorithm for the removal of trends in time series. Trends in time series could be caused by various systematic and random noise sources such as cloud passages, changes of airmass, telescope vibration or CCD noise. Those trends undermine the intrinsic signals of stars and should be removed. We determine the trends from subsets of stars that are highly correlated among themselves. These subsets are selected based on a hierarchical tree clustering algorithm. A bottom-up merging algorithm based on the departure from normal distribution in the correlation is developed to identify subsets, which we call clusters. After identification of clusters, we determine a trend per cluster by weighted sum of normalized light-curves. We then use quadratic programming to de-trend all individual light-curves based on these determined trends. Experimental results with synthetic light-curves containing artificial trends and events are presented. Results from other de-trending me...
We conducted a search for occultations of bright stars by Kuiper Belt Objects (KBOs) to estimate ... more We conducted a search for occultations of bright stars by Kuiper Belt Objects (KBOs) to estimate the density of sub-km KBOs in the sky. We report here the first results of this occultation survey of the outer solar system conducted in June 2007 and June/July 2008 at the MMT Observatory using Megacam, the large MMT optical imager. We used Megacam in a novel shutterless continuous--readout mode to achieve high precision photometry at 200 Hz. We present an analysis of 220 star hours at signal-to-noise ratio of 25 or greater. The survey efficiency is greater than 10% for occultations by KBOs of diameter d>=0.7 km, and we report no detections in our dataset. We set a new 95% confidence level upper limit for the surface density \Sigma_N(d) of KBOs larger than 1 km: \Sigma_N(d>=1 km) <= 2.0e8 deg^-2, and for KBOs larger than 0.7 km \Sigma_N(d>= 0.7 km) <= 4.8e8 deg^-2.
Presentation for the UD Computational Social Sciences Symposium exploring where and how bias can ... more Presentation for the UD Computational Social Sciences Symposium exploring where and how bias can embed itself in AI models
LSST Corporation's Science Collaborations and Enabling Science Activities
2018 IEEE Global Conference on Signal and Information Processing (GlobalSIP)
Grid Dynamics and Energy Consumption Patterns through remote observations of city lights Training... more Grid Dynamics and Energy Consumption Patterns through remote observations of city lights Training Support Vector Machines (S.V.M.
Tobacco marketing, restricted almost exclusively to the point-of-sale in recent years, has proven... more Tobacco marketing, restricted almost exclusively to the point-of-sale in recent years, has proven to be effective in getting more people to consume and fewer to quit cigarettes and smokeless tobacco products. The lack of empirical documentation linking product exposure to behavior, however, is a key obstacle to the adoption of additional restrictions on point-of-sale tobacco advertising. The goal of this project is to map point-of-sale tobacco marketing practices across New York City using automated detection of tobacco signage in street-level imaging data. Convolutional neural networks, which are particularly effective at detecting objects in images, were trained to identify and classify outdoor advertisements of cigarettes and smokeless tobacco. Previous analyses of visual data in public health research involving manual image coding are prohibitively costly and time
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Papers by federica bianco