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Related papers: Approaches to High Dynamic Range Imaging - Applica…

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Our understanding of stellar atmospheres and our ability to infer architectures of extrasolar planetary systems rely on understanding the emission of stars at submillimeter to centimeter wavelengths. In this chapter we describe how…

Radio interferometric imaging has long relied on the CLEAN algorithm, valued for its speed, robustness, and integration with calibration pipelines. However, next-generation facilities such as the ngVLA, SKA, and ALMAs Wideband Sensitivity…

Instrumentation and Methods for Astrophysics · Physics 2025-09-19 Hendrik Müller

The goal of this science case is to address the use of a ngVLA as a CO redshift machine for dust-obscured high-redshift galaxies which lack of clear counterparts at other wavelengths. Thanks to its unprecedentedly large simultaneous…

Astrophysics of Galaxies · Physics 2018-10-17 R. Decarli , C. Carilli , C. Casey , B. Emonts , J. A. Hodge , K. Kohno , D. Narayanan , D. Riechers , M. T. Sargent , F. Walter

The development of new phased array systems in radio astronomy, as the low frequency array (LOFAR) and the square kilometre array (SKA), formed of a large number of small and flexible elementary antennas, has led to significant challenges.…

Radio astronomy observations in the coming decade will require new levels of sensitivity while mapping large regions of space with much greater efficiency than is achieved with current telescopes. This requires new instrumentation with the…

Instrumentation and Methods for Astrophysics · Physics 2009-09-30 Matthew A. Morgan , J. Richard Fisher

Reaching the thermal noise at low frequencies with the next generation of instruments (e.g. SKA, LOFAR etc.) is going to be a challenge. It requires the development of more advanced techniques of calibration compared to those used from the…

Instrumentation and Methods for Astrophysics · Physics 2010-08-31 Emanuela Orrú , Huib Intema

The correction of the influence of phase corrugation in the pupil plane is a fundamental issue in achieving high dynamic range imaging. In this paper, we investigate an instrumental setup which consists in applying interferometric…

Astrophysics · Physics 2008-11-26 S. Lacour , E. Thiébaut , G. Perrin

We proposed a novel dense line spectrum super-resolution algorithm, the DMRA, that leverages dynamical multi-resolution of atoms technique to address the limitation of traditional compressed sensing methods when handling dense point-source…

Signal Processing · Electrical Eng. & Systems 2024-09-04 Mingguang Han , Yi Zeng , Xiaoguang Li , Tiejun Li

The Naval Research Laboratory and the National Radio Astronomy Observatory completed implementation of a low frequency capability on the VLA at 73.8 MHz in 1998. This frequency band offers unprecedented sensitivity (~25 mJy/beam) and…

Using JVLA data of Sgr A* and NRAO 530 (as a calibrator) at 5.5, 9 and 33 GHz, we developed a procedure for the reduction of wideband data. We have demonstrated that, correcting for residual interferometer errors such as residual delays,…

Astrophysics of Galaxies · Physics 2019-05-01 Jun-Hui Zhao , Mark R. Morris , W. M. Goss

Millimetre-VLBI is an important tool in AGN astrophysics, but it is limited by short atmospheric coherence times and poor receiver and antenna performance. We demonstrate a new kind of phase referencing for the VLBA, enabling us to increase…

Astrophysics · Physics 2007-05-23 E. Middelberg , A. L. Roy , R. C. Walker , H. Falcke , T. P. Krichbaum

The spatial-frequency coverage of a radio interferometer is increased by combining samples acquired at different times and observing frequencies. However, astrophysical sources often contain complicated spatial structure that varies within…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 U. Rau

This paper investigates calibration of sensor arrays in the radio astronomy context. Current and future radio telescopes require computationally efficient algorithms to overcome the new technical challenges as large collecting area, wide…

Applications · Statistics 2018-07-31 Virginie Ollier , Mohammed Nabil El Korso , André Ferrari , Rémy Boyer , Pascal Larzabal

We present a technique-led review of the progression of precise radio astrometry, from the first demonstrations, half a century ago, until to date and into the future. We cover the developments that have been fundamental to allow high…

Instrumentation and Methods for Astrophysics · Physics 2020-10-06 María Rioja , Richard Dodson

The Next-Generation Very Large Array (ngVLA) will revolutionize our understanding of the Early Universe by tracing the coldest phase of molecular gas -the raw ingredient for star formation- in the most distant galaxies and galaxy-clusters.…

Astrophysics of Galaxies · Physics 2018-10-17 Bjorn Emonts , Chris Carilli , Desika Narayanan , Matthew Lehnert , Kristina Nyland

Astronomical imaging using aperture synthesis telescopes requires deconvolution of the point spread function as well as calibration of instrumental and atmospheric effects. In general, such effects are time-variable and vary across the…

Astrophysics · Physics 2009-11-13 S. Bhatnagar , T. J. Cornwell , K. Golap , Juan M. Uson

Modern radio telescopes are routinely reaching depths where normal starforming galaxies are the dominant observed population. Realising the potential of radio as a tracer of star formation and black hole activity over cosmic time involves…

Astrophysics of Galaxies · Physics 2020-07-01 I. Heywood , C. L. Hale , M. J. Jarvis , S. Makhathini , J. A. Peters , M. L. L. Sebokolodi , O. M. Smirnov

Very long baseline interferometry (VLBI) provides the highest-resolution images in astronomy. The sharpest resolution is nominally achieved at the highest frequencies, but as the observing frequency increases so too does the atmospheric…

By linking widely separated radio dishes, the technique of very long baseline interferometry (VLBI) can greatly enhance angular resolution in radio astronomy. However, at any given moment, a VLBI array only sparsely samples the information…