Search Publications
X-Ray Constraints on Galaxy-Gas-Jet Interactions in the Dumbbell Galaxies NGC 4782 and NGC 4783 in the LGG 316 Galaxy Group
Hardcastle, M. J.; Forman, W. R.; Jones, C. +2 more
We present results from a 49.3 ks Chandra X-ray observation of the strongly interacting dumbbell galaxies NGC 4782 (3C 278) and NGC 4783 that constrain the kinematics of the interaction and models for bending the radio jets associated with NGC 4782. The galaxies are embedded in an approximately spherical distribution of group gas, centered on NGC …
Cool-Plasma Jets that Escape into the Outer Corona
Moore, Ronald L.; Sterling, Alphonse C.; Poletto, Giannina +2 more
We report on observations acquired in 2003 May during a SOHO-Ulysses quadrature campaign. The UVCS slit was set normal to the radial of the Sun along the direction to Ulysses at 1.7 Rsolar, at a northern latitude of 14.5°. From May 25 to May 28, UVCS acquired spectra of several short-lived ejections that represent the extension at highe…
Possible Precession Motion in the Bipolar Proto-Planetary Nebula IRAS 17441-2411
Volk, Kevin; Kwok, Sun; Hrivnak, Bruce J.
Mid-infrared imaging of two bipolar proto-planetary nebulae, IRAS 17150-3224 and IRAS 17441-2411, was obtained with the Gemini telescope. Dust emissions are detected in both the bipolar lobes and in the equatorial region of IRAS 17441-2411. In particular, the orientation of the axis of the infrared torus is found to be offset by 23° from the bipol…
Analytical Models for Cross-Correlation Signal in Time-Distance Helioseismology
Kosovichev, A. G.; Scherrer, P. H.; Nigam, R.
In time-distance helioseismology, the time signals (Doppler shifts) at two points on the solar surface separated by a fixed angular distance are cross-correlated, and this leads to a wave packet signal. Accurately measuring the travel times of these wave packets is crucial for inferring the subsurface properties in the Sun. The observed signal is …
Multiple Scattered Sight Lines to the Red QSO 2MASX J10494334+5837501
Hines, Dean C.; Tremonti, Christy A.; Schmidt, Gary D. +2 more
The reddened, highly polarized QSO 2MASX J1049334+5837501 (2M 1049+5837) shows a strong IR dust signature with a spectral energy distribution peaked at ~20 µm and a luminosity of ~1011 Lsolar, but the active nucleus is outshone at optical wavelengths by the host galaxy. Remarkable variations with wavelength in the degre…
The Structure and the Distance of Collinder 121 from Hipparcos and Photometry: Resolving the Discrepancy
Makarov, Valeri; Kaltcheva, Nadia
We present further arguments that the Hipparcos parallaxes for some of the clusters and associations represented in the Hipparcos catalog should be used with caution in the study of the Galactic structure. It has already been shown that the discrepancy between the Hipparcos and ground-based parallaxes for several clusters including the Pleiades, C…
Multiheight Properties of Moving Magnetic Features
Choudhary, Debi Prasad; Balasubramaniam, K. S.
We report on spectropolarimetric and dynamical properties of a moving magnetic feature (MMF) around a disk-center sunspot observed using photospheric (Fe I λλ6301.5 and 6302.5) and lower chromospheric (Mg b2 λ5172.7) lines. We find that there are 33% fewer MMFs at the lower chromosphere compared to the photosphere, implying a sophistica…
FUSE Observations of a Full Orbit of Hercules X-1: Signatures of Disk, Star, and Wind
Raymond, John C.; Vrtilek, Saeqa Dil; Still, Martin +1 more
We observed an entire 1.7 day orbit of the X-ray binary Hercules X-1 with the Far Ultraviolet Spectroscopic Explorer (FUSE). Changes in the O VI λλ1032, 1037 line profiles through eclipse ingress and egress indicate a Keplerian accretion disk spinning prograde with the orbit. These observations may show the first double-peaked accretion disk line …
Witnessing the Formation of a Galaxy Cluster at z = 0.485: Optical and X-Ray Properties of RX J1117.4+0743 ([VMF 98] 097)
Cypriano, E. S.; Ramirez, A.; Carrasco, E. R. +4 more
We present a multiwavelength study of the poor cluster RX J1117.4+0743 ([VMF 98] 097) at z=0.485, based on GMOS/Gemini South g' and r' photometry and spectroscopy, and XMM-Newton observations. We examine its nature and surroundings by analyzing the projected galaxy distribution, the galaxy velocity distribution, the weak-lensing mass reconstructio…
Molecular and Atomic Excitation Stratification in the Outflow of the Planetary Nebula M27
France, Kevin; Feldman, Paul D.; Andersson, B. -G. +5 more
High-resolution spectroscopy with FUSE and HST STIS of atomic and molecular velocity stratification in the nebular outflow of M27 challenge models of the abundance kinematics in planetary nebulae. The simple picture of a very high speed (~1000 km s-1), high-ionization, radiation-driven stellar wind surrounded by a slower (~10 km s-…