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Related papers: Very Long Baseline Array astrometry of low-mass yo…

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We report on the first millisecond timescale radio interferometric search for the new class of transient known as fast radio bursts (FRBs). We used the Very Large Array (VLA) for a 166-hour, millisecond imaging campaign to detect and…

VLBI astrometry allows coordinates of celestial radio sources to be determined with submilliarcsecond accuracy. In particular, with differential VLBI astrometry, the standard errors of relative positions and proper motions can be as small…

Astrophysics · Physics 2007-05-23 Norbert Bartel

Due to the recent dramatic technological advances, infrared interferometry can now be applied to new classes of objects, resulting in exciting new science prospects, for instance, in the area of high-mass star formation. Although…

We discuss VLTI AMBER and MIDI interferometry in addition to single-dish Subaru observations of massive young stellar objects. The observations probe linear size scales between 10 to 1000 AU for the average distance of our sources.

Solar and Stellar Astrophysics · Physics 2009-05-06 W. J. de Wit , M. G. Hoare , R. D. Oudmaijer , T. Fujiyoshi

We explore the rotation and activity of very low mass (VLM) objects by means of a photometric variability study. Our targets in the vicinity of Epsilon Ori belong to the OriOB1b population in the Orion star-forming complex. In this region…

Astrophysics · Physics 2009-11-10 Alexander Scholz , Jochen Eisloeffel

We have used a relatively long, contiguous VHF observation of a bright cosmic radio source (Cygnus A) with the Very Large Array (VLA) to demonstrate the capability of this instrument to study the ionosphere. This interferometer, and others…

Space Physics · Physics 2015-06-03 J. F. Helmboldt , T. J. W. Lazio , H. T. Intema , K. F. Dymond

We present results from a high-sensitivity (60 $\mu$Jy), large-scale (2.26 square degree) survey obtained with the Karl G. Jansky Very Large Array as part of the Gould's Belt Survey program. We detected 374 and 354 sources at 4.5 and 7.5…

We consider young distant stars from the Gaia TGAS catalog. These are 250 classical Cepheids and 244 OB stars located at distances up to 4 kpc from the Sun. These stars are used to determine the Galactic rotation parameters using both…

Astrophysics of Galaxies · Physics 2023-05-24 V. V. Bobylev , A. T. Bajkova

We present results of Very Long Baseline Array (VLBA) observations of PKS 0528+134 at five frequencies (2.3, 5.0, 8.4, 15.4, and 22.2 GHz). These quasi-simultaneous data enable us to study the spectral distribution of Very Long Baseline…

Astrophysics · Physics 2009-11-11 H. -B. Cai , Z. -Q. Shen , X. Chen , L. -L. Shang

Based on published data, we have produced a sample of 256 radio sources whose trigonometric parallaxes and proper motions were measured by VLBI. This sample contains Galactic masers associated with massive protostars and stars in active…

Astrophysics of Galaxies · Physics 2020-09-10 V. V. Bobylev , O. I. Krisanova , A. T. Bajkova

We present high-resolution observations made with the Very Large Array (VLA) in its A configuration at frequencies between 5 and 43 GHz of a sample of five massive young stellar objects (YSOs): LkHa101, NGC2024-IRS2, S106-IR, W75N and…

Astrophysics · Physics 2009-11-13 A. G. Gibb , M. G. Hoare

The goal of this work is a detailed study of the nearby, low power radio galaxy B2 1144+35B. For this purpose, we performed new Very Long Baseline Array (VLBA) and Very Large Array (VLA) observations. This source has several properties…

Astrophysics · Physics 2009-11-13 G. Giovannini , M. Giroletti , G. B. Taylor

Variability is a characteristic feature of young stellar objects (YSOs) and could contribute to the large scatter observed in HR diagrams for star forming regions. For typical YSOs, however, the long-term effects of variability are poorly…

Solar and Stellar Astrophysics · Physics 2015-06-03 Aleks Scholz

To explore young star variability on a large range of timescales, we have used the MOST satellite to obtain 24 days of continuous, sub-minute cadence, high-precision optical photometry on a field of classical and weak-lined T Tauri stars…

Solar and Stellar Astrophysics · Physics 2015-06-12 Ann Marie Cody , Jamie Tayar , Lynne A. Hillenbrand , Jaymie M. Matthews , Thomas Kallinger

We report on observations of circumstellar disks around young stars that have been obtained with the MIDI instrument, which is mounted on the VLT Interferometer and operates in the 10 micrometer atmospheric window. The maximum spatial…

A most desirable feature of a standard candle to estimate astronomical distances is robustness against changes in metallicity and age. It is argued that the radii of main sequence stars with spectral types from solar to A0 show predictable…

Astrophysics · Physics 2009-10-31 Carlos Allende Prieto

The Galaxy appears to be richer in young, massive stellar clusters than previously known, due to advances in infrared surveys which have uncovered deeply embedded regions of star formation. Young, massive clusters can significantly impact…

Astrophysics of Galaxies · Physics 2015-06-11 Emily E. Richards , Cornelia C. Lang , Christine Trombley , Donald F. Figer

From 43GHz VLBA observations of the pair of radio sources 1928+738 and 2007+777 we have demonstrated the feasibility of precision phase-delay differential astrometric techniques at millimeter wavelengths. For a pair of sources with 5…

Astrophysics · Physics 2007-05-23 J. C. Guirado , J. M. Marcaide , M. A. Perez-Torres , E. Ros

A long-held astronomical vision is to realize diffraction-limited optical aperture synthesis over kilometer baselines. This will enable imaging of stellar surfaces and their environments, show their evolution over time, and reveal…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Dainis Dravins , Tiphaine Lagadec

Wide-field surveys are a commonly-used method for studying thousands of objects simultaneously, to investigate, e.g., the joint evolution of star-forming galaxies and active galactic nuclei. VLBI observations can yield valuable input to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Enno Middelberg , Adam Deller , John Morgan , Helge Rottmann , Walter Alef , Steven Tingay , Ray Norris , Uwe Bach , Walter Brisken , Emil Lenc
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