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X-Ray Observations and Infrared Identification of the Transient 7.8 s X-Ray Binary Pulsar XTE J1829-098
Gotthelf, E. V.; Halpern, J. P.
XMM-Newton and Chandra observations of the transient 7.8 s pulsar XTE J1829-098 are used to characterize its pulse shape and spectrum, and to facilitate a search for an optical or infrared counterpart. In outburst, the absorbed, hard X-ray spectrum with Γ=0.76+/-0.13 and NH=(6.0+/-0.6)×1022 cm-2 is typical of X-ray…
The Nearby Young Visual Binary HIP 115147 and Its Common Proper Motion Companion LSPM J2322+7847
Makarov, V. V.; Zacharias, N.; Hennessy, G. S. +2 more
We report a late M-type, common proper motion companion to a nearby young visual binary HIP 115147 (V368 Cep), separated by 963" from the primary K0 dwarf. This optically dim star was identified as a candidate high proper motion, nearby dwarf LSPM J2322+7847 by Lépine in 2005. The wide companion is one of the latest post-T Tauri low-mass stars fou…
Application of an XMM-Newton EPIC Monte Carlo Technique to Analysis and Interpretation of Data for the Abell 1689, RX J0658-55, and Centaurus Clusters of Galaxies
Peterson, J. R.; Madejski, G.; Andersson, K.
We propose a new Monte Carlo method to study extended X-ray sources with the European Photon Imaging Camera (EPIC) aboard XMM-Newton. The smoothed particle inference (SPI) technique, described in a companion paper, is applied here to the EPIC data for the clusters of galaxies Abell 1689, Centaurus, and RX J0658-55 (the ``bullet cluster''). We aim …
Density Dependence of the Mass Function of Globular Star Clusters in the Sombrero Galaxy and Its Dynamical Implications
Fall, S. Michael; Chandar, Rupali; McLaughlin, Dean E.
We have constructed the mass function of globular star clusters in the Sombrero galaxy in bins of different internal half-mass density ρh and projected galactocentric distance R. This is based on the published measurements of the magnitudes and effective radii of the clusters by Spitler and coworkers in BVR images taken with the ACS on …
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…