Search Publications
A Spectral Study of the Black Hole Candidate XTE J1752-223 in the High/Soft State with MAXI, Suzaku, and Swift
Yamaoka, Kazutaka; Makishima, Kazuo; Tashiro, Makoto S. +34 more
We report on an X-ray spectral analysis of the black hole candidate XTE J1752-223 in the 2009-2010 outburst, utilizing data obtained with the MAXI/Gas Slit Camera (GSC), the Swift/XRT, and Suzaku, which work complementarily. As already reported by Nakahira et al. (2010, PASJ…
High-resolution X-Ray Spectroscopy Reveals the Special Nature of Wolf-Rayet Star Winds
Hamann, W. -R.; Oskinova, L. M.; Ignace, R. +3 more
We present the first high-resolution X-ray spectrum of a putatively single Wolf-Rayet (WR) star. 400 ks observations of WR 6 by the XMM-Newton telescope resulted in a superb quality high-resolution X-ray spectrum. Spectral analysis reveals that the X-rays originate far out in the stellar wind, more than 30 stellar radii from the photosphere, and t…
Do Nuclear Star Clusters and Supermassive Black Holes Follow the Same Host-Galaxy Correlations?
Erwin, Peter; Gadotti, Dimitri Alexei
Studies have suggested that there is a strong correlation between the masses of nuclear star clusters (NSCs) and their host galaxies, a correlation which said to be an extension of the well-known correlations between supermassive black holes (SMBHs) and their host galaxies. But careful analysis of disk galaxies -- including 2D bulge/disk/bar decom…
4U 1626-67 as seen by Suzaku before and after the 2008 torque reversal
Pottschmidt, K.; Wilson-Hodge, C. A.; Camero-Arranz, A. +3 more
Aims: The accretion-powered pulsar 4U 1626-67 experienced a new torque reversal at the beginning of 2008, after about 18 years of steadily spinning down. The main goal of the present work is to study this recent torque reversal that occurred in February 2008.
Methods: We present a spectral analysis of this source using two pointed observ…
Continuum and spectroscopic observations of asteroid (21) Lutetia at millimeter and submillimeter wavelengths with the MIRO instrument on the Rosetta spacecraft
Ip, W. -H.; Hartogh, P.; Lellouch, E. +18 more
The European Space Agency's Rosetta spacecraft made a close flyby of asteroid (21) Lutetia on July 10, 2010. The spacecraft carries a dual-band radiometer/spectrometer instrument, named MIRO, which operates at 190 GHz (1.6 mm) and 560 GHz (0.5 mm). During the flyby, the MIRO instrument measured the temperature of Lutetia in both the northern and s…
The Nature of the Bright ULX X-2 in NGC 3921: A Chandra Position and HST Candidate Counterpart
Fabian, A. C.; Miniutti, G.; Miller-Jones, J. C. A. +6 more
We report on Chandra observations of the bright ultraluminous X-ray (ULX) source in NGC 3921. Previous XMM-Newton observations reported in the literature show the presence of a bright ULX at a 0.5-10 keV luminosity of 2 × 1040 erg s-1. Our Chandra observation finds the source at a lower luminosity of ≈8 × 1039 erg …
Determination of the Heliospheric Radial Magnetic Field from the Standoff Distance of a CME-driven Shock Observed by the STEREO Spacecraft
Gopalswamy, Nat; Yashiro, Seiji; Kwon, Ryun-Young +2 more
We report on the determination of radial magnetic field strength in the heliocentric distance range from 6 to 120 solar radii (R ⊙) using data from Coronagraph 2 (COR2) and Heliospheric Imager I (HI1) instruments on board the Solar Terrestrial Relations Observatory spacecraft following the standoff-distance method of Gopalswamy & Ya…
Discovery of a Kiloparsec-scale X-Ray/Radio Jet in the z = 4.72 Quasar GB 1428+4217
Cheung, C. C.; Stawarz, Ł.; Siemiginowska, A. +4 more
We report the discovery of a one-sided 3farcs6 (24 kpc, projected) long jet in the high-redshift, z = 4.72, quasar GB 1428+4217 in new Chandra X-ray and Very Large Array (VLA) radio observations. This is the highest redshift kiloparsec-scale X-ray/radio jet known. Analysis of archival very long baseline interferometry 2.3 and 8.6 GHz data reveal a…
Titan's Methane Weather
Roe, Henry G.
Conditions in Titan's troposphere are near the triple point of methane, the second most abundant component of its atmosphere. Our understanding of Titan's lower atmosphere has shifted considerably in the past decade. Ground-based observations, Hubble Space Telescope images, and data returned from the Cassini and Huygens spacecraft show that Titan'…
A Search for an Intermediate-mass Black Hole in the Core of the Globular Cluster NGC 6266
Harrison, Thomas E.; Baumgardt, Holger; McNamara, Bernard J. +1 more
It has long been thought that intermediate-mass black holes (IMBHs) might be located in the cores of globular clusters. However, studies attempting to confirm this possibility have been inconclusive. To refine the search for these objects, Baumgardt et al. completed a series of N-body simulations to determine the observational properties that a ho…