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Full-Text Articles in Astrophysics and Astronomy
R Aquarii: Evidence For A Two-Sided Radio Jet And A Circumbinary Sio Maser, Menas Kafatos, J. M. Hollis, F. Yusef-Zadeh, A. G. Michalitsianos, M. Elitzur
R Aquarii: Evidence For A Two-Sided Radio Jet And A Circumbinary Sio Maser, Menas Kafatos, J. M. Hollis, F. Yusef-Zadeh, A. G. Michalitsianos, M. Elitzur
Mathematics, Physics, and Computer Science Faculty Articles and Research
We have detected collimated 4.86 GHz (~6 cm) radio continuum emission southwest (SW) of the symbiotic vanable R Aquarii by combining data corresponding to different configurations of the Very Large Array (VLA). In the xontext of a previously reported northeast (NE) 6 cm jet structure, the orientation of the newly found SW radto structure suggests bipolar symmetry, extending to distances of ~2500 AU on either side of the central H II region. The amorphous morphology of the new collimated SW structure is distinct from the discrete radio knots NE of the central object. Further, we have determined the radio spectral …
Rx Puppis: Detection Of Asymmetrical Radio Structure, J. M. Hollis, F. Yusef-Zadeh, T. J. Cornwell, R. J. Oliverson, A. G. Michalitsianos, Menas Kafatos
Rx Puppis: Detection Of Asymmetrical Radio Structure, J. M. Hollis, F. Yusef-Zadeh, T. J. Cornwell, R. J. Oliverson, A. G. Michalitsianos, Menas Kafatos
Mathematics, Physics, and Computer Science Faculty Articles and Research
Subarcsecond ( ~0':3 x ~0':1) observations of the RX Puppis symbiotic system with the Very Large Array (VLA) have resolved 2 cm continuum emission which deviates from a previously reported circularly symmetric radio distribution. The radio structure is comprised of at least three nearly colinear components. Under the assumption that the strongest feature is coincident with the hot star, the other two features lie 230 and 590 AU distant. These radio features are reminiscent of small-scale radio structure detected toward R Aquarii, another symbiotic star system, and probably represents material ejected from the RX Puppis system at an earlier epoch.
Evidence For Extended Radio Emission Surrounding Rx Puppis, J. M. Hollis, R. J. Oliverson, Menas Kafatos, A. G. Michalitsianos
Evidence For Extended Radio Emission Surrounding Rx Puppis, J. M. Hollis, R. J. Oliverson, Menas Kafatos, A. G. Michalitsianos
Mathematics, Physics, and Computer Science Faculty Articles and Research
We report evidence for ~1" extended structure in 6 cm continuum emission emanating from the symbiotic star system RX Puppis. We did not detect hourly continuum flux changes as suggested in previous radio experiments by others. Our observations indicate that the predominant nature of the radio emission is thermal and consistent with an optically thick stellar wind emanating from the symbiotic star system. Our results are discussed with regard to other similar stellar binary systems.
Sub-Arc Second 2 Centimeter Continuum And Sio Spectral Line Observations Of R Aquarii, J. M. Hollis, A. G. Michalitsianos, Menas Kafatos, M. C. H. Wright, W. J. Welch
Sub-Arc Second 2 Centimeter Continuum And Sio Spectral Line Observations Of R Aquarii, J. M. Hollis, A. G. Michalitsianos, Menas Kafatos, M. C. H. Wright, W. J. Welch
Mathematics, Physics, and Computer Science Faculty Articles and Research
ub-arc second (- 0'.'15) VLA observations at 2 em have resolved the previously reported 6 em H II region, which engulfs the R Aquarii binary system, into two components. The stronger 2 em component is itself partially resolved (distorted in shape), which may be a consequence of the long-period variable (LPV) wind being subjected to the intense ionizing radiation field of the hot companion's accretion disk, which we suspect is precessing. The distorted radio contours of the central H II region may also suggest that one hemisphere of the extended LPV envelope is directly illuminated by the intense radiation field …
The R Aquarii System At Optical And Radio Wavelengths, J. M. Hollis, Menas Kafatos, A. G. Michalitsianos, H. A. Mcalister
The R Aquarii System At Optical And Radio Wavelengths, J. M. Hollis, Menas Kafatos, A. G. Michalitsianos, H. A. Mcalister
Mathematics, Physics, and Computer Science Faculty Articles and Research
Observations of the symbiotic binary R Aquarii environment were obtained with the Very Large Array (VLA) at 2, 6, and 20 em at the same epoch. The observed spectral index and strong linear polarization reveal that emission from the compact double radio source discovered in previous observations is nonthermal; thus, this source is not associated with R Aquarii but is an extragalactic background object. The spectral index of the compact nebula surrounding R Aquarii indicates that the emission is thermal and the nebula is ionized by an unseen, hot companion to the Mira-like variable R Aquarii. As expected, this region …
High Spatial Resolution Vla Observations Of The R Aquarii Jet, Menas Kafatos, J. M. Hollis, A. G. Michalitsianos
High Spatial Resolution Vla Observations Of The R Aquarii Jet, Menas Kafatos, J. M. Hollis, A. G. Michalitsianos
Mathematics, Physics, and Computer Science Faculty Articles and Research
High spatial resolution observations (~1") of the jet feature associated with the symbiotic variable R Aquarii were obtained with the Very Large Array (VLA). The peak radio intensity of the jet lies at a 29~3 P.A. with respect to the radio emission from R Aquarii itself. If the line defined by the jet and star is extended ~196", it intercepts a previously reported and heretofore unresolved radio source. In our high spatial resolution 6 cm map, this feature is resolved into a compact double radio source, whose peak intensity lies on an axis defined by the jet and star. The …
Radio And Optical Observations Of The R Aquarii Jet, R. J. Sopka, G. Herbig, Menas Kafatos, A. G. Michalitsianos
Radio And Optical Observations Of The R Aquarii Jet, R. J. Sopka, G. Herbig, Menas Kafatos, A. G. Michalitsianos
Mathematics, Physics, and Computer Science Faculty Articles and Research
VLA observations at 6 cm and Lick Observatory optical plates of R Aquarii indicate the existence of a jetlike feature extending 7" -10" from the central star. A wide field map at 6 cm shows an unresolved compact radio source which lies close to the axis defined by the jet at a distance of ~ 3' from R Aqr. Episodic mass transfer in this symbiotic variable could explain the erratic outbursts that R Aqr is known to undergo. Formation of an accretion disk and the accompanying radio-optical jet may characterize the observed outbursts in this system.