English
Related papers

Related papers: First supra-THz Heterodyne Array Receivers for Ast…

200 papers

Hydrogen recombination lines (HRLs) are valuable diagnostics of the physical conditions in ionized regions around high-mass stars. Understanding their broadening mechanisms and intensity trends can provide insights into the densities,…

In order to meet its cutting-edge scientific objectives, the Square Kilometre Array (SKA) telescope requires high-precision frequency references to be distributed to each of its antennas. The frequency references are distributed via…

Instrumentation and Methods for Astrophysics · Physics 2017-06-20 David Gozzard , Sascha Schediwy , Richard Dodson , Maria Rioja , Mike Hill , Brett Lennon , Jock McFee , Peter Mirtschin , Jamie Stevens , Keith Grainge

The upcoming Ooty Wide Field Array (OWFA) will operate at $326.5 \, {\rm MHz}$ which corresponds to the redshifted 21-cm signal from neutral hydrogen (HI) at z = 3.35. We present two different prescriptions to simulate this signal and…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-29 Suman Chatterjee , S. Bharadwaj , V. R. Marthi

We present a survey of the radio sky accessible from the first station of the Long Wavelength Array (LWA1). Images are presented at nine frequencies between 35 and 80 MHz with spatial resolutions ranging from $4.7^\circ$ to $2.0^\circ$,…

Instrumentation and Methods for Astrophysics · Physics 2017-07-20 Jayce Dowell , Gregory B. Taylor , Frank K. Schinzel , Namir E. Kassim , Kevin Stovall

LiteBIRD is a JAXA-led strategic large-class satellite mission designed to measure the polarization of the cosmic microwave background and Galactic foregrounds from 34 to 448 GHz across the entire sky from L2 in the late 2020s. The…

We have measured the angular diameters of six M dwarfs with the CHARA Array, a long-baseline optical interferometer located at Mount Wilson Observatory. Spectral types range from M1.0 V to M3.0 V and linear radii from 0.38 to 0.69 Rsun.…

To continue the unparalleled success of the Very Large Array (VLA) for radio astronomy, the facility is currently being converted to become the 'Expanded VLA' (EVLA). The EVLA will radically improve the VLA in order to cover the full…

Astrophysics · Physics 2009-11-13 Juergen Ott , Rick Perley , Michael Rupen , the EVLA team

The Tianlai Cylinder Pathfinder is a radio interferometer array designed to test techniques for 21 cm intensity mapping in the post-reionization Universe, with the ultimate aim of mapping the large scale structure and measuring cosmological…

LOFAR, the Low-Frequency Array, is a powerful new radio telescope operating between 10 and 240 MHz. LOFAR allows detailed sensitive high-resolution studies of the low-frequency radio sky. At the same time LOFAR also provides excellent short…

Aperture array (AA) technology is at the forefront of new developments and discoveries in radio astronomy. Currently LOFAR is successfully demonstrating the capabilities of dense and sparse AA's at low frequencies. For the mid-frequencies,…

Instrumentation and Methods for Astrophysics · Physics 2012-09-21 Ilse M. van Bemmel , Arnold van Ardenne , Jan Geralt bij de Vaate , Andrew J. Faulkner , Raffaella Morganti

An inertial sensor design is proposed in this paper to achieve high sensitivity and large dynamic range in the sub-Hz frequency regime. High acceleration sensitivity is obtained by combining optical cavity readout systems with…

Quantum Physics · Physics 2022-09-23 Yanqi Zhang , Adam Hines , Dalziel Wilson , Felipe Guzman

Far-infrared detectors for future cooled space telescopes require ultra-sensitive detectors with optical noise equivalent powers of order 0.2 aW/\sqrt Hz. This performance has already been demonstrated in arrays of transition edge sensors.…

Instrumentation and Methods for Astrophysics · Physics 2022-07-01 D J Goldie , S. Withington , C. N. Thomas , P. A. R. Ade , R. V. Sudiwala

Time-domain THz transmission experiment was performed on a $\rm SrBi_2Ta_2O_9$ film deposited on sapphire substrate. Temperatures between 300 and 923 K were investigated and complex permittivity spectra of the film were determined. The…

Materials Science · Physics 2009-11-10 F. Kadlec , S. Kamba , P. Kuzel , C. Kadlec , J. Kroupa , J. Petzelt

Uncooled Terahertz (THz) photodetectors (PDs) showing fast (ps) response and high sensitivity (noise equivalent power (NEP) < $nWHz^{-1/2}$) over a broad (0.5THz-10THz) frequency range are needed for applications in high-resolution…

The Low Frequency Array (LOFAR) is uniquely able to perform deep, 15" resolutions imaging at frequencies below 100 MHz. Observations in this regime, using the Low Band Antenna (LBA) system, are significantly affected by instrumental and…

Astrophysics of Galaxies · Physics 2026-01-14 J. M. Boxelaar , F. De Gasperin , M. J. Hardcastle , J. H. Croston , L. K. Morabito , R. J. van Weeren , H. Edler

We report the use of the Australia Telescope Compact Array (ATCA) to conduct polarimetric observations of the sky at 5 GHz. The ATCA is normally operated as an interferometer array, but these observations were conducted in a split array…

Astrophysics · Physics 2010-11-11 D. McConnell , E. Carretti , R. Subrahmanyan

We have designed a system to stabilize the gain of a submillimeter heterodyne receiver against thermal fluctuations of the mixing element. In the most sensitive heterodyne receivers, the mixer is usually cooled to 4 K using a closed-cycle…

The quiet solar corona emits meter-wave thermal bremsstrahlung. Coronal radio emission can only propagate above that radius, $R_\omega$, where the local plasma frequency eqals the observing frequency. The radio interferometer LOw Frequency…

Solar and Stellar Astrophysics · Physics 2018-06-13 C. Vocks , G. Mann , F. Breitling , M. M. Bisi , B. Dabrowski , R. Fallows , P. T. Gallagher , A. Krankowski , J. Magdalenic , C. Marque , D. Morosan , H. Rucker

The LOw Frequency ARray (LOFAR) has successfully measured cosmic rays for over a decade now. With its dense core of antenna fields in the Netherlands, it is an ideal tool for studying the radio emission from extensive air showers in the…

In this short review we will highlight some of the recent advancements in the field of high-resolution laboratory spectroscopy that meet the needs dictated by the advent of highly sensitive and broadband telescopes like ALMA and SOFIA.…

Instrumentation and Methods for Astrophysics · Physics 2016-05-25 Sandra Brünken , Stephan Schlemmer
‹ Prev 1 3 4 5 6 7 10 Next ›