We present the results of a broadband simultaneous campaign on the nearby low-luminosity active galactic nucleus M81*. From February through August 2005, we observed M81* five times using the Chandra X-ray Observatory with the High-Energy Transmission Grating Spectrometer, complemented by ground-based observations with the Giant Meterwave Radio Telescope,… (More)
The center of M83, a barred starburst galaxy with a double nucleus, has been observed in the CO(J=2–1) and CO(J=3–2) lines with the Submillimeter Array. The molecular gas shows a distribution and kinematics typical for barred galaxies at ∼kpc radii, but reveals unusual kinematics around the double nucleus in the central ∼300 pc. Our CO velocity data show… (More)
One of the most important problems in the study of active galaxies is understanding the detailed geometry, physics, and evolution of the central engines and their environments. The leading models involve an accretion disk and torus structure around a central dense object, thought to be a supermassive black hole. Gas found in the environment of AGN is… (More)
The role of non-H-2 alloantigens, specifically Mls locus products, in secondary in vitro T-cell-mediated cytotoxicity has been studied. Splenic T lymphocytes, activated against Mls locus alloantigens in primary-mixed cultures and isolated by velocity sedimentation gradient separation techniques, were used as responding populations in secondary mixed… (More)
The Submillimeter Array (SMA) has been under construction at the 4100 m summit of Mauna Kea, Hawaii. The array is going to allow imaging of lines and continuum at sub-arcsecond resolution in submillimeter wavelengths. The status of the array and the results from recent commissioning observations of nearby galaxies are reported.
We have used the Submillimeter Array (SMA) to make the first interferometric observations (beam size ∼ 1 ′′ , or ∼ 400 pc) of the 12 CO J=6-5 line and 435 µm (690 GHz) continuum emission toward the central region (half power field of view 17 ′′) of the nearby ultra-luminous infrared galaxy (ULIRG) Arp 220. These observations resolve the eastern and western… (More)
A catalog containing milliarcsecond–accurate positions of 1332 extragalactic radio sources distributed over the northern sky is presented – the Very Long Baseline Array Calibrator Survey (VCS1). The positions have been derived from astrometric analysis of dual–frequency 2.3 and 8.4 GHz VLBA snapshot observations ; in a majority of cases, images of the… (More)
Alpha-fetoprotein (AFP), a major alpha-globulin component of fetal and newborn sera, has earlier been shown to exert significant immunosuppressive activity in vitro on T-dependent-immune responses. In the present investigation we have examined the effects of AFP on the recognition and proliferation of T lymphocytes responding in mixed leukocyte culture… (More)