Zobrazeno 1 - 10
of 39
pro vyhledávání: '"Ratner, M. I."'
We review the radio very long baseline interferometry (VLBI) observations of the guide star, IM Peg, and three compact extragalactic reference sources, 3C 454.3, B2250+194, and B2252+172, made in support of the NASA/Stanford gyroscope relativity miss
Externí odkaz:
http://arxiv.org/abs/1509.07529
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 NASA/Stanford relativity mission Gravity Probe B. We obtained flux den
Externí odkaz:
http://arxiv.org/abs/1204.4645
Autor:
Ransom, R. R., Bartel, N., Bietenholz, M. F., Lebach, D. E., Lestrade, J. -F., Ratner, M. I., Shapiro, I. I.
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 Gravity Probe B. This emission is seen in each of our 35 epochs of 8.4-GHz
Externí odkaz:
http://arxiv.org/abs/1204.4644
Autor:
Ransom, R. R., Bartel, N., Bietenholz, M. F., Lebach, D. E., Lederman, J. I., Luca, P., Ratner, M. I., Shapiro, I. I.
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 sources, B2250+194 and B2252+172, for the guide star for the NASA/Stanfo
Externí odkaz:
http://arxiv.org/abs/1204.4643
Autor:
Ratner, M. I., Bartel, N., Bietenholz, M. F., Lebach, D. E., Lestrade, J. -F., Ransom, R. R., Shapiro, I. I.
We present the principal astrometric results of the very-long-baseline interferometry (VLBI) program undertaken in support of the Gravity Probe B (GP-B) relativity mission. VLBI observations of the GP-B guide star, the RS CVn binary IM Pegasi (HR 870
Externí odkaz:
http://arxiv.org/abs/1204.4640
Autor:
Bartel, N., Bietenholz, M. F., Lebach, D. E., Lederman, J. I., Petrov, L., Ransom, R. R., Ratner, M. I., Shapiro, I. I.
We made VLBI observations at 8.4 GHz between 1997 and 2005 to estimate the coordinates of the "core" component of the superluminal quasar, 3C 454.3, the ultimate reference point in the distant universe for the NASA/Stanford Gyroscope Relativity Missi
Externí odkaz:
http://arxiv.org/abs/1204.4637
Autor:
Shapiro, I. I., Bartel, N., Bietenholz, M. F., Lebach, D. E., Lestrade, J. -F., Ransom, R. R., Ratner, M. I.
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 report on our radio observations and analyses made in support of this
Externí odkaz:
http://arxiv.org/abs/1204.4630
Autor:
Lebach, D. E., Bartel, N., Bietenholz, M. F., Campbell, R. M., Gordon, D., Lederman, J. I., Lestrade, J. -F., Ransom, R. R., Ratner, M. I., Shapiro, I. I.
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 obtained via: (i) phase-referenced maps; or (ii) parametric model fits to me
Externí odkaz:
http://arxiv.org/abs/1204.4642
Autor:
Ransom, R. R., Bartel, N., Bietenholz, M. F., Ratner, M. I., Lebach, D. E., Shapiro, I. I., Lestrade, J. -F.
Publikováno v:
Astrophys.J. 587 (2003) 390-397
We present VLBI images of the RS CVn binary star HR 5110 (=BH CVn; HD 118216), obtained from observations made at 8.4 GHz on 1994 May 29/30 in support of the NASA/Stanford Gravity Probe B project. Our images show an emission region with a core-halo m
Externí odkaz:
http://arxiv.org/abs/astro-ph/0301413
Autor:
Perez-Torres, M. A., Marcaide, J. M., Guirado, J. C., Ros, E., Shapiro, I. I., Ratner, M. I., Sardon, E.
Publikováno v:
Astronomy & Astrophysics, 360, 161-170 (2000)
On 18 November 1993, we observed the QSO 1150+812 and the BL Lac object 1803+784, nearly 15\deg apart on the sky, with a VLBI array, simultaneously recording at 8.4 and 2.3 GHz. Using difference astrometry techniques, we determined the coordinates of
Externí odkaz:
http://arxiv.org/abs/astro-ph/0005551