Zhao, Jun-Hui, Morris, Mark R., Goss, W. M., An, Tao
We present new results based on high-resolution observations of Sgr A West at the Galactic center with the VLA at 1.3 cm. We measured proper motions for 71 compact HII components. We also...
Massive molecular outflows associated with UCHII/HII regions (2008)
Qin, Sheng-Li, Wang, Jun-Jie, Zhao, Gang, Miller, Martin, Zhao, Jun-Hui
Aims: We searched for the molecular outflows from fifteen molecular clouds associated with ultra-compact and compact HII (UCHII/HII) regions and discussed possible gas heating mechanism. Methods:...
Infall and Outflow of Molecular Gas in Sgr B2 (2008)
Qin, Sheng-Li, Zhao, Jun-Hui, Moran, James M., Marrone, Daniel P., Patel, Nimesh A., Wang, Jun-Jie, ...
Observations of two H$_2$CO ($3_{03}-2_{02}$ and $3_{21}-2_{20}$) lines and continuum emission at 1.3 mm towards Sgr B2(N) and Sgr B2(M) have been carried out with the SMA. The mosaic maps of Sgr...
The Linear Polarization of Sagittarius A* I. VLA Spectro-polarimetry at 4.8 and 8.4 GHz (2007)
Geoffrey C. Bower, Donald C. Backer, Jun-hui Zhao, Miller Goss, Heino Falcke
Synchrotron radiation from active galactic nuclei (AGN) is often highly polarized. We present a search for linear polarization with the Very Large Array (VLA) at 4.8 GHz and 8.4 GHz from the nearest...
Intrinsic Size Of Sgr A (2007)
Schwarzschild Radii, K. Y. Lo, Zhi-qiang Shen, Jun-hui Zhao, Sgr A
Recent proper motion studies of stars at the very center of the Galaxy strongly suggest that Sagittarius (Sgr) A ? , the compact nonthermal radio source at the Galactic Center, is a 2.5\Theta10 6 M...
The Linear Polarization of Sagittarius A* I. VLA Spectro-polarimetry at 4.8 and 8.4 GHz (2007)
Geoffrey C. Bower, Donald C. Backer, Jun-hui Zhao, Miller Goss, Heino Falcke
Synchrotron radiation from active galactic nuclei (AGN) is often highly polarized. We present a search for linear polarization with the Very Large Array (VLA) at 4.8 GHz and 8.4 GHz from the nearest...
The Simultaneous Spectrum Of Sgr A* From (2007)
Cm To, Peter Teuben, Jun-hui Zhao, Robert Zylka
We report results from a multiwavelength campaign to measure the simultaneous spectrum of the super-massive black hole candidate Sgr A* in the Galactic Center from cm to mm-wavelengths using the VLA,...
Jun-hui Zhao, Jun-hui Zhao, D. A. Roberts, W. M. Goss, D. A. Frail, National Radio, ...
(thecompactradiosourceattheGalacticcenter):F ollowingitsfirstdetection; thef luxdensityoftheGalacticCenterTransient(GCT)increasedrapidlytoamaximumonemonthlater;...
Infall, Fragmentation and Outflow in Sgr B2 (2006)
Qin, Sheng-Li, Zhao, Jun-Hui, Moran, James M., Marrone, Daniel, Patel, N., Liu, Sheng-Yuan, ...
Observations of H$_{2}$CO lines and continuum at 1.3 mm towards Sgr B2(N) and Sgr B2(M) cores were carried out with the SMA. We imaged H$_{2}$CO line absorption against the continuum cores and the...
The Submillimeter Polarization of Sgr A* (2006)
Marrone, Daniel P., Moran, James M., Zhao, Jun-Hui, Rao, Ramprasad
We report on the submillimeter properties of Sagittarius A* derived from observations with the Submillimeter Array and its polarimeter. We find that the spectrum of Sgr A* between 230 and 690 GHz is...
Molecular Superbubbles in the Starburst Galaxy NGC 253 (2005)
Sakamoto, Kazushi, Ho, Paul T. P., Iono, Daisuke, Keto, Eric R., Mao, Rui-Qing, Matsushita, Satoki, ...
The central 2x1 kpc of the starburst galaxy NGC 253 has been imaged using the Submillimeter Array at a 60 pc resolution in the J=2-1 transitions of 12CO, 13CO, and C18O as well as in the 1.3 mm...
Dual frequency 230/690 GHz interferometry at the Submillimeter Array (2005)
Hunter, Todd R., Barrett, John W., Blundell, Raymond, Christensen, Robert D., Kimberk, Robert S., Leiker, Steven P., ...
The Submillimeter Array (SMA), a collaboration between the Smithsonian Astrophysical Observatory and the Academica Sinica Institute for Astronomy and Astrophysics of Taiwan, is an eight-element...
The radio counter-jet of the QSO 3C~48 (2004)
Feng, W. X., An, T., Hong, X. Y., Zhao, Jun-Hui, Venturi, T., ...
We present multi--frequency radio observational results of the quasar 3C~48. The observations were carried out with the Very Large Array (VLA) at five frequencies of 0.33, 1.5, 4.8, 8.4, and 22.5...
Bower, Geoffrey C., Falcke, Heino, Herrnstein, Robeson M., Zhao, Jun-Hui, Goss, W. M., Backer, Donald C.
We have detected the intrinsic size of Sagittarius A*, the Galactic Center radio source associated with a supermassive black hole, showing that the short-wavelength radio emission arises from very...
A Radio Outburst Nearly Coincident with the Large X-ray Flare from Sgr A* on 2002-10-03 (2004)
Zhao, Jun-Hui, Herrnstein, R. M., Bower, G. C., Goss, W. M., Liu, S. M.
A large radio outburst from Sgr A* was observed during the VLA weekly monitoring program at 2 cm, 1.3 cm and 7 mm, nearly coincident with the brightest X-ray flare detected to date with the...
Variability of Sagittarius A* - Flares at 1 Millimeter (2003)
Zhao, Jun-Hui, Young, K. H., Herrnstein, R. M., Ho, P. T. P., Tsutsumi, T., Lo, K. Y., ...
We report the results from recent observations of Sgr A* at short-/sub-millimeter wavelengths made with the partially finished Sub-Millimeter Array (SMA) on Mauna Kea. A total of 25 epochs of...
The Galactic center provides a unique astrophysical laboratory for us to study various astrophysical processes. In this paper, we review and outline the latest results from observations of Sgr~A$^*$...
Radio Variability of Sagittarius A* - A 106 Day Cycle (2000)
Zhao, Jun-Hui, Bower, G. C., Goss, W. M.
We report the presence of a 106-day cycle in the radio variability of Sgr A* based on an analysis of data observed with the Very Large Array (VLA) over the past 20 years. The pulsed signal is most...
Jun-hui Zhao, Patricia Mailhot, Takahiro Tsutsumi
As the MIT/SAO correlator comes on line, the maximum data production rate from the Submillimeter Array (SMA) on Mauna Kea in Hawaii could reach upto2.75Mbytes per sampling. For a typical integration...
The Linear Polarization of Sagittarius A* I. VLA Spectro-polarimetry at 4.8 and 8.4 GHz (1999)
Bower, Geoffrey C., Backer, Donald C., Zhao, Jun-Hui, Goss, Miller, Falcke, Heino
Synchrotron radiation from active galactic nuclei (AGN) is often highly polarized. We present a search for linear polarization with the Very Large Array (VLA) at 4.8 GHz and 8.4 GHz from the nearest...
The simultaneous spectrum of Sgr A* from 20cm to 1mm and the nature of the mm-excess (1998)
Falcke, Heino, Goss, W. M., Matsuo, Hiroshi, Teuben, Peter, Zhao, Jun-Hui, Zylka, Robert
We report results from a multiwavelength campaign to measure the simultaneous spectrum of the super-massive black hole candidate Sgr A* in the Galactic Center from cm to mm-wavelengths using the VLA,...
Zhao, Jun-Hui, Anantharamaiah, K.R., Goss, W.M., Viallefond, F.
Using the Very Large Array (VLA), 1 we have observed the H92 alpha line in the nuclear regions of NGC 3628 and Arp 299 (IC 694 + NGC 3690) with an angular resolution of 1". The radio recombination...
Radio recombination lines from the nuclear regions of starburst galaxies (1996)
Zhao, Jun-Hui, Anantharamaiah, K.R., Goss, W.M., Viallefond, F.
Using the Very Large Array (VLA) with an angular resolution of 3", we have detected the hydrogen recombination line H92α from the galaxies Arp 220, M83, and NGC 2146. The line emission arises from...
Radio recombination lines from external galaxies (1995)
Anantharamaiah, K.R., Zhao, Jun-Hui, Goss, W.M., Viallefond, F.
Using the Very Large Array1 and the Australia Telescope we have searched for the H92 α recombination line from 14 external galaxies and detected the line in 9 of them. All the detected galaxies have...
Detection of H92 alpha recombination line from the galaxies NGC 3628, IC 694, and NGC 1365 (1993)
Anantharamaiah, K.R., Zhao, Jun-Hui, Goss, W.M., Viallefond, F.
Using the Very Large Array with an angular resolution of 3", we have detected the hydrogen recombination line H92alpha (Vrest = 8309.38 MHz) from the starburst nuclei in the galaxies NGC 3628 and IC...
Radio studies of the Galactic Center. I. The Sagittarius A complex (1989)
Pedlar, A., Anantharamaiah, K.R., Ekers, R.D., Goss, W.M., Van Gorkom, J.H., Schwarz, U.J., ...
VLA observations of the Sgr A complex at 90 cm, 20 cm, and 6 cm are combined to obtain spectral index and optical depth distributions across the source and are used to constrain the three-dimensional...