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(abridged) Very long baseline interferometry (VLBI) observations at 86$\,$GHz (wavelength, $\lambda = 3\,$mm) reach a resolution of about 50 $\mu$as, probing the collimation and acceleration regions of relativistic outflows in active…

We present a new technique based on fixed-delay interferometry for high throughput, high precision and multi-object Doppler radial velocity (RV) surveys for extra-solar planets. The Doppler measurements are conducted through monitoring the…

Astrophysics · Physics 2016-08-30 Jian Ge

Of the many probes of reionization, the 21 cm line and the cosmic microwave background (CMB) are among the most effective. We examine how the cross-correlation of the 21 cm brightness and the CMB Doppler fluctuations on large angular scales…

Astrophysics · Physics 2014-02-20 Peter Adshead , Steven Furlanetto

We present results from a large global VLBI(Very Long Baseline Interferometry) survey of compact radio sources at 86 GHz which started in October 2001. The main goal of the survey is to increase the total number of objects accessible for…

Astrophysics · Physics 2009-04-14 S. Lee , A. P. Lobanov , T. P. Krichbaum , A. Witzel , J. A. Zensus , M. Bremer , A. Greve , M. Grewing

Aims. We use a sample of 83 core-dominated active galactic nuclei (AGN) selected from the MOJAVE (Monitoring of Jets in AGN with VLBA Experiments) radio-flux-limited sample and detected with the Fermi Large Area Telescope (LAT) to study the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 T. G. Arshakian , J. León-Tavares , M. Boettcher , J. Torrealba , V. H. Chavushyan , M. L. Lister , E. Ros , J. A. Zensus

Multiple instruments are pursuing constraints on dark energy, observing reionization and opening a window on the dark ages through the detection and characterization of the 21cm hydrogen line across the redshift spectrum, from nearby to…

Instrumentation and Methods for Astrophysics · Physics 2016-10-11 Daniel C. Jacobs , Jacob Burba , Judd Bowman , Abraham R. Neben , Benjamin Stinnett , Lauren Turner

Electronic correlations were long suggested not only to be responsible for the complexity of many novel materials, but also to form essential prerequisites for their intriguing properties. Electronic behavior of iron-based superconductors…

This paper analyzes how the distortion created by hardware impairments in a multiple-antenna base station affects the uplink spectral efficiency (SE), with focus on Massive MIMO. This distortion is correlated across the antennas, but has…

Information Theory · Computer Science 2021-12-28 Emil Björnson , Luca Sanguinetti , Jakob Hoydis

We report a serendipitous detection of rapid, large amplitude flux density variations in the highly core-dominated, flat-spectrum radio quasar 1156+295 during an observing session at the Very Long Baseline Array (VLBA). The source was…

Astrophysics · Physics 2008-10-06 T. Savolainen , Y. Y. Kovalev

This paper investigates the distributed Kalman filter (DKF) for linear systems, with specific attention on measurement fusion, which is a typical way of information sharing and is vital for enhancing stability and improving estimation…

Signal Processing · Electrical Eng. & Systems 2025-04-14 Tuo Yang , Jiachen Qian , Zhisheng Duan , Zhiyong Sun

We search for the Baryon Acoustic Oscillations in the projected cross-correlation function binned into transverse comoving radius between the SDSS-IV DR16 eBOSS quasars and a dense photometric sample of galaxies selected from the DESI…

Optical reflectivity measurements were performed on a single crystal of the d-electron heavy-fermion (HF) metal LiV2O4. The results evidence the highly incoherent character of the charge dynamics for all temperatures above T^* \approx 20 K.…

Strongly Correlated Electrons · Physics 2007-10-24 P. E. Jönsson , K. Takenaka , S. Niitaka , T. Sasagawa , S. Sugai , H. Takagi

We report on the results of X-ray and radio follow-up observations of two GeV gamma-ray sources 2FGL J0923.5+1508 and 2FGL J1502.1+5548, selected as candidates for high-redshift blazars from unassociated sources in the {\it Fermi} Large…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Y. Takahashi , J. Kataoka , K. Niinuma , M. Honma , Y. Inoue , T. Totani , S. Inoue , T. Nakamori , K. Maeda

We expand our previous studies of the parsec-scale structure of TeV blazars by presenting first-epoch images from VLBA monitoring of ten newer TeV HBLs. All ten sources were successfully detected and imaged, and all showed a one-sided…

High Energy Astrophysical Phenomena · Physics 2015-06-17 B. Glenn Piner , Philip G. Edwards

Precise frequency and phase synchronization are among the important aspects in a coherent distributed phased array antenna system, and are among the most challenging to achieve for microwave frequencies and above. We propose a high accuracy…

Systems and Control · Electrical Eng. & Systems 2023-06-09 Mohammed Rashid , Jeffrey A. Nanzer

The distribution of baryons in the Universe remains a fundamental open question in astronomy, and the dispersion measure (DM) of Fast Radio Bursts (FRBs) serves as a valuable tool for probing this cosmic gas. We investigate the impact of…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-05 Maryam Hussaini , Liam Connor , Ralf M. Konietzka , Vikram Ravi , Jakob Faber , Kritti Sharma , Myles Sherman

Dielectric permittivity, $\varepsilon_r$, of materials are often limited to a sub-GHz range using normal LCR meters. In the GHz range the $\varepsilon_r$ can be measured using Vector Network Analyzers and measurement jigs (waveguides) which…

Optics · Physics 2025-07-21 Somaditya Sen

We have analysed the 24um properties of a radio-selected sample in the Subaru-XMM/Newton Deep Field in order to explore the behaviour of the FIR/radio relation at high redshifts. Statistically, the correlation is described by q24, the ratio…

The corrugated horn is a high performance feed often used in radio telescopes. There has been a growing demand for wideband optics and corrugated horns in millimeter and submillimeter-wave receivers. It improves the observation efficiency…

KaVA (KVN and VERA Array) is a new combined VLBI array with KVN (Korean VLBI Network) and VERA (VLBI Exploration of Radio Astrometry). First, we briefly review the imaging capabilities of KaVA array which actually achieves more than three…

High Energy Astrophysical Phenomena · Physics 2015-04-27 Motoki Kino , Kotaro Niinuma , Guang-Yao Zhao , Bong Won Sohn , KaVA AGN sub working group
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