Results 11 to 20 of about 10,420 (207)

Gravitational microlensing of fractal sources [PDF]

Monthly Notices of the Royal Astronomical Society, 2004
Gravitational microlensing has proven to be a powerful tool in the study of quasars, providing some of the strongest limits on the scales of structure in the central engine. Typically sources are considered to be smoothly varying on some particular scale; such simple sources result in recognisable time scales in microlensing light curves from which the
Abajas, Abramenko, Agol, Alcock, Alcock, Bottorff, Bottorff, Burlaga, Campo Bagatin, Chang, Dai, Datta, Durrer, Elmegreen, Elmegreen, Elmegreen, Elmegreen, Fluke, Fogel, Geraint F. Lewis, Goodwin, Janßen, Kayser, Kochanek, Lekshmi, Lewis, Lewis, Lewis, Merloni, Merloni, Nemiroff, Peitgen, Peitgen, Popović, Rauch, Richards, Salakhutdinova, Schneider, Schneider, Semelin, Stenflo, Stepinski, Stutzki, Veronig, Wambsganss, Wambsganss, Witt, Wright, Wyithe, Wyithe, Yonehara, Yonehara, Yonehara   +52 more
openaire   +4 more sources

Analytical Methods in Gravitational Microlensing [PDF]

ISRN Astronomy and Astrophysics, 2012
We discuss analytical results dealing with photometric and astrometric gravitational microlensing. The first two sections concern approximation methods that allow us to get solutions of the general lens equation near fold caustics and cusp points up to any prescribed accuracy.
{Zhdanov} V.~I., {Alexandrov} A.~N., {Fedorova} E.~V., {Sliusar} V.~M.   +3 more
openaire   +2 more sources

Gravitational Microlensing by Globular Clusters [PDF]

, 1998
Stars in globular clusters can act either as sources for MACHOs (Massive Astrophysical Compact Halo Objects) located along the line of sight or as lenses for more distant background stars. Although the expected rate of microlensing events is small, such observations can lead to very useful results.
Jetzer, P., Strässle, M., Wandeler, U.
openaire   +3 more sources

Magnetic Manipulation of Superparamagnetic Colloids in Droplet‐Based Optical Devices

Advanced Optical Materials, Volume 11, Issue 21, November 6, 2023., 2023
Colloidal particles inside droplets are assembled and manipulated using an external magnetic field to create magnetically controlled active microlenses and optical shutters. Using monodisperse microfluidic droplets, the assembly of particles into 2D clusters is systematically investigated and exploited to manipulate light.
Iacopo Mattich, Joan Sendra, Henning Galinski, Golnaz Isapour, Ahmet F. Demirörs, Marco Lattuada, Simone Schuerle, André R. Studart   +7 more
wiley   +1 more source

Ultra wide‐field infrared astronomy in Antarctica

Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023
The science enabled by the deep and high‐cadence survey that will be performed by the Vera Rubin Observatory has led to an increase of survey and follow‐up capabilities around the world. The infrared, has however, not match this growth due to the challenges caused by the atmospheric and the cost of large detector arrays.
Tony Travouillon, Roger M. Smith, Jason Fucik, Don F. Figer, Mansi Kasliwal, Anna M. Moore, Tristan Guillot   +6 more
wiley   +1 more source

Characteristic Features of Gravitational Wave Lensing as Probe of Lens Mass Model

Annalen der Physik, Volume 535, Issue 6, June 2023., 2023
The gravitational lensing of gravitational waves is an expanding field in astronomy and cosmology. It might contribute to solving many different issue in these fields. To exploit its potential, first of all, one needs to recognize and model a gravitational wave event properly.
Paolo Cremonese, David Fonseca Mota, Vincenzo Salzano   +2 more
wiley   +1 more source

The road toward imaging a black hole: A personal perspective

Natural Sciences, Volume 2, Issue 4, October 2022., 2022
The article describes the authors personal journey towards developig the Event Horizon Telescope and the first image of a black hole. Left: predcition made by the author and collaborators proposing the black hole imaging in 2000. Right: the two images observed and published by the Event Horizon Telescope in 2019 and 2022.
Heino Falcke
wiley   +1 more source

Identifying interesting planetary systems for future X‐ray observations

Astronomische Nachrichten, Volume 343, Issue 4, May 2022., 2022
Abstract X‐ray observations of star–planet systems are important to grow our understanding of exoplanets; these observations allow for studies of photoevaporation of the exoplanetary atmosphere, and in some cases even estimations of the size of the outer planetary atmosphere.
Grace Foster, Katja Poppenhaeger
wiley   +1 more source

Effervescence‐Inspired Self‐Healing Plastrons for Long‐Term Immersion Stability

Advanced Functional Materials, Volume 32, Issue 4, January 19, 2022., 2022
Underwater performance of superhydrophobic/superamphiphobic surfaces relies on the robustness and durability of the gas‐layer (plastron). A simple and scalable technique of effervescence‐inspired on‐demand plastron repair is presented. Surfaces do not suffer from any performance‐losses even after 2 months of continuous immersion.
William S. Y. Wong, Doris Vollmer
wiley   +1 more source

Comparison of Rutherford's atomic model with the Standard Model of particle physics and other models

Journal of the Royal Society of New Zealand, Volume 51, Issue 3-4, Page 538-556, September ‐ December 2021., 2021
ABSTRACT Ernest Rutherford is known almost universally as the discoverer of the structure of the atom. He is less well known for his discovery of the proton. Even less well known is a set of hypotheses on the structure of matter that was proposed by Newton 300 years ago.
Philip Yock
wiley   +1 more source