79 citations · 208 across the 13 of their papers we have counts for
13 papers
VLBI for Gravity Probe B. VII. The Evolution of the Radio Structure of IM Pegasi
M. F. Bietenholz, N. Bartel, D. E. Lebach +3
We present measurements of the total radio flux density as well as very-long-baseline interferometry (VLBI) images of the star, IM Pegasi, which was used as the guide star for the…
VLBI for Gravity Probe B. VI. The Orbit of IM Pegasi and the Location of the Source of Radio Emission
R. R. Ransom, N. Bartel, M. F. Bietenholz +4
We present a physical interpretation for the locations of the sources of radio emission in IM Pegasi (IM Peg, HR 8703), the guide star for the NASA/Stanford relativity mission Grav…
VLBI for Gravity Probe B. II. Monitoring of the Structure of the Reference Sources 3C 454.3, B2250+194, and B2252+172
R. R. Ransom, N. Bartel, M. F. Bietenholz +5
We used 8.4 GHz VLBI images obtained at up to 35 epochs between 1997 and 2005 to examine the radio structures of the main reference source, 3C 454.3, and two secondary reference so…
VLBI for Gravity Probe B. IV. A New Astrometric Analysis Technique and a Comparison with Results from Other Techniques
D. E. Lebach, N. Bartel, M. F. Bietenholz +7
When VLBI observations are used to determine the position or motion of a radio source relative to reference sources nearby on the sky, the astrometric information is usually obtain…
VLBI for Gravity Probe B. I. Overview
I. I. Shapiro, N. Bartel, M. F. Bietenholz +4
We describe the NASA/Stanford gyroscope relativity mission, Gravity Probe B (GP-B), and provide an overview of the following series of six astrometric and astrophysical papers that…
23 GHz VLBI Observations of SN 2008ax
I. Marti-Vidal, J. M. Marcaide, A. Alberdi +14
We report on phase-referenced 23 GHz Very-Long-Baseline-Interferometry (VLBI) observations of the type IIb supernova SN 2008ax, made with the Very Long Baseline Array (VLBA) on 2 A…
High-resolution radio imaging of young supernovae
M. A. Perez-Torres, J. M. Marcaide, A. Alberdi +12
The high resolution obtained through the use of VLBI gives an unique opportunity to directly observe the interaction of an expanding radio supernova with its surrounding medium. We…
Constraining H0 from Chandra Observations of Q0957+561
G. Chartas, V. Gupta, G. Garmire +4
We report the detection of the lens cluster of the gravitational lens (GL) system Q0957+561 from a deep observation with the Advanced CCD Imaging Spectrometer on-board the Chandra…
Towards global-phase-delay VLBI astrometry: observations of QSO 1150+812 and BL 1803+784
M. A. Perez-Torres, J. M. Marcaide, J. C. Guirado +4
On 18 November 1993, we observed the QSO 1150+812 and the BL Lac object 1803+784, nearly 15°apart on the sky, with a VLBI array, simultaneously recording at 8.4 and 2.3 GHz. Using…
High precision difference astrometry applied to the triplet of S5 radio sources B1803+784/Q1928+738/B2007+777
E. Ros, J. M. Marcaide, J. C. Guirado +5
We determined the separations of the radio sources in the triangle formed by the BL Lac objects 1803+784 and 2007+777, and the QSO 1928+738 from intercontinental interferometric ob…
X-ray Detection of the Primary Lens Galaxy Cluster of the Gravitational Lens System Q0957+561
G. Chartas, D. Chuss, W. Forman +2
Analysis of several recent ROSAT HRI observations of the gravitationally lensed system Q0957+561 has led to the detection at the 3sigma level of the cluster lens containing the pri…
Deceleration in the Expansion of SN1993J
J. M. Marcaide, A. Alberdi, E. Ros +13
A rarity among supernova, SN 1993J in M81 can be studied with high spatial resolution. Its radio power and distance permit VLBI observations to monitor the expansion of its angular…
VLBI Observations of the Gravitational Lens System 0957+561
R. M. Campbell, J. Lehar, B. E. Corey +2
We present hybrid maps of the A and B images of 0957+561 from each of four sessions of 6 cm VLBI observations that span the six-year interval 1987-1993. The inner- and outer-jets a…