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Related papers: ALFA & 3D: integral field spectroscopy with adapti…

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There are several high-performance adaptive optics systems that deliver diffraction-limited imaging on ground-based telescopes, which renewed the interest of single-mode fiber (SMF) spectroscopy for exoplanet characterization. However, the…

Instrumentation and Methods for Astrophysics · Physics 2021-05-19 S. Y. Haffert

Scale-ambiguity in 3D scene dimensions leads to magnitude-ambiguity of volumetric densities in neural radiance fields, i.e., the densities double when scene size is halved, and vice versa. We call this property alpha invariance. For NeRFs…

Computer Vision and Pattern Recognition · Computer Science 2024-04-18 Joshua Ahn , Haochen Wang , Raymond A. Yeh , Greg Shakhnarovich

We propose a complete framework for the detection, astrometry, and photometry of faint companions from a sequence of adaptive optics corrected short exposures. The algorithms exploit the difference in statistics between the on-axis and…

Astrophysics · Physics 2011-02-11 Szymon Gladysz , Julian C. Christou

This paper describes the Wide Field Spectrograph (WiFeS) under construction at the Research School of Astronomy and Astrophysics (RSAA) of the Australian National University (ANU) for the ANU 2.3m telescope at the Siding Spring Observatory.…

Astrophysics · Physics 2019-08-19 Michael Dopita , John Hart , Peter McGregor , Patrick Oates , Gabe Bloxham , Damien Jones

Here, we present an astrophotonic spectrograph in the near-IR H-band (1.45 -1.65 $\mu m$) and a spectral resolution ($\lambda/\delta\lambda$) of 1500. The main dispersing element of the spectrograph is a photonic chip based on…

Instrumentation and Methods for Astrophysics · Physics 2022-03-16 Pradip Gatkine , Meghna Sitaram , Sylvain Veilleux , Mario Dagenais , Joss Bland-Hawthorn

The detection of moving infrared dim-small targets has been a challenging and prevalent research topic. The current state-of-the-art methods are mainly based on ConvLSTM to aggregate information from adjacent frames to facilitate the…

Computer Vision and Pattern Recognition · Computer Science 2024-07-11 Dengyan Luo , Yanping Xiang , Hu Wang , Luping Ji , Shuai Li , Mao Ye

CONTEXT: Many massive stars have nearby companions whose presence hamper their characterization through spectroscopy. AIMS: We want to obtain spatially resolved spectroscopy of close massive visual binaries to derive their spectral types.…

Solar and Stellar Astrophysics · Physics 2018-08-01 J. Maíz Apellániz , R. H. Barbá , S. Simón-Díaz , A. Sota , E. Trigueros Páez , J. A. Caballero , E. J. Alfaro

It has been shown that a slab of materials with refractive index = -1 behaves like a perfect lens focussing all light to an exact electromagnetic copy of an object. The original lens is limited to producing images the same size as the…

Condensed Matter · Physics 2009-11-07 J. B. Pendry , S. Anantha Ramakrishna

The spectral resolution of a dispersive spectrograph is dependent on the width of the entrance slit. This means that astronomical spectrographs trade-off throughput with spectral resolving power. Recently, optical guided-wave transitions…

The advent of enhanced technologies in radio interferometry and the perspective of the SKA telescope bring new challenges in image reconstruction. One of these challenges is the spatio-spectral reconstruction of large (Terabytes) data cubes…

Instrumentation and Methods for Astrophysics · Physics 2016-03-07 Jérémy Deguignet , André Ferrari , David Mary , Chiara Ferrari

We present 36 observations of 17 visual binaries of moderate separation (range from 0.15'' to 0.79'') made with the 50 cm Cassegrain telescope of the Jagiellonian University in Cracow. The speckle interferometry technique was combined with…

Astrophysics · Physics 2009-11-11 Artur Rutkowski , Waclaw Waniak

We present a method to determine the static aberrations in a nearly diffraction-limited spectrograph introduced, for example, by alignment or manufacturing errors. We consider an instrument with two stages separated by a slit or image…

Instrumentation and Methods for Astrophysics · Physics 2022-06-01 B. Sánchez , A. M. Watson , S. Cuevas

In this paper, we present a first comparison of different Adaptive Optics (AO) concepts to reach a given scientific specification for 3D spectroscopy on Extremely Large Telescope (ELT). We consider that a range of 30%-50% of Ensquarred…

It has been recently demonstrated that integrated optics could enhance accuracy, stability, and ease of use of stellar interferometry techniques. The subject of this thesis is the study of an optical component based on singlemode waveguides…

Instrumentation and Methods for Astrophysics · Physics 2009-04-21 Pierre Labeye

We present an original method for reconstructing a three-dimensional object having two spatial dimensions and one spectral dimension from data provided by the infrared slit spectrograph on board the Spitzer Space Telescope. During…

Instrumentation and Methods for Astrophysics · Physics 2011-08-31 T. Rodet , F. Orieux , J. -F. Giovannelli , A. Abergel

In this paper, we discuss the benefits of ground-based, adaptive optics (AO) aided observations for star formation research. After outlining the general advantages, we present results obtained during the ALFA science demonstration programme…

Astrophysics · Physics 2015-06-24 M. Feldt , M. Kasper , F. Eisenhauer , S. Hippler

SPIFFI is the near-infrared integral-field spectrometer for the VLT. Assisted by the SINFONI adaptive optics module, the instrument will be offered to the astronomical community in 2004. We outline the scientific rationale for infrared…

Astrophysics · Physics 2009-11-07 F. Eisenhauer , P. van der Werf , N. Thatte , T. de Zeeuw , M. Tecza , M. Franx , C. Iserlohe

The Differential Fourier Holography (DFH) gives an exact mathematical solution of the inverse problem of diffraction in the Fraunhofer regime. After the first publication [1] the Differential Fourier Holography was successfully applied in…

Optics · Physics 2016-04-20 Sergey G. Podorov , Eckhart Förster

Diffraction limit is manifested in the loss of high spatial frequency information that results from decay of evanescent waves. As a result, conventional far-field optics yields no information about an object's subwavelength features. Here…

Optics · Physics 2012-01-24 Leonid Alekseyev , Evgenii Narimanov , Jacob Khurgin

This article begins with the discussions on the formation of speckles in the case of non-coherent quasi monochromatic source and of ways to detect them. Prior to this, a brief introduction on the behavior of the atmosphere and its effect on…

Astrophysics · Physics 2007-05-23 Swapan K. Saha