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Absorption-Line Study of Halo Gas in NGC 3067 toward the Background Quasar 3C 232
Stocke, John T.; Keeney, Brian A.; Tumlinson, Jason +2 more
We present new H I 21 cm absorption data and ultraviolet spectroscopy from Hubble Space Telescope/Space Telescope Imaging Spectrograph of the QSO/galaxy pair 3C 232/NGC 3067. The QSO sight line lies near the minor axis and 1.8 arcmin (11 h-170 kpc) above the plane of NGC 3067, a nearby luminous (cz=1465+/-5 km s-1,…
Far-Ultraviolet Observations of the Globular Cluster NGC 2808 Revisited: Blue Stragglers, White Dwarfs, and Cataclysmic Variables
Knigge, C.; Long, K. S.; Zurek, D. R. +2 more
We present a reanalysis of far-ultraviolet (FUV) observations of the globular cluster NGC 2808 obtained with the Hubble Space Telescope. These data were first analyzed by Brown and coworkers, with an emphasis on the bright, blue horizontal-branch (HB) stars in this cluster. Here, our focus is on the population of fainter FUV sources, which include…
The Heliospheric He II 30.4 nm Solar Flux During Cycle 23
Auchère, F.; von Steiger, R.; Witte, M. +3 more
Because of the orbit characteristics of the vast majority of spacecraft, the solar flux has predominantly been measured at Earth or at least in the plane of the ecliptic. Therefore, the existing data do not directly demonstrate the fact that the latitudinal distribution of the extreme-ultraviolet (EUV) solar flux is largely anisotropic. Indeed, in…
Magnetic Helicity Injection and Sigmoidal Coronal Loops
Kusano, K.; Sakurai, T.; Yokoyama, T. +2 more
We studied the relationship between magnetic helicity injection and the formation of sigmoidal loops. We analyzed seven active regions: three regions showed coronal loops similar to the potential field, and four regions showed the sigmoidal loops. The magnetic helicity injection rate was evaluated using the method proposed by Kusano et al. In orde…
X-Ray Spectral Variability during an Outburst in V1118 Ori
Audard, M.; Güdel, M.; Briggs, K. R. +5 more
We present results from a multiwavelength campaign to monitor the 2005 outburst of the low-mass young star V1118 Ori. Although our campaign covers the X-ray, optical, infrared, and radio regimes, we focus in this Letter on the properties of the X-ray emission in V1118 Ori during the first few months after the optical outburst. Chandra and XMM-Newt…
3-200 keV Spectral States and Variability of the INTEGRAL Black Hole Binary IGR J17464-3213
Capitanio, F.; Bird, A. J.; Ubertini, P. +12 more
On March 2003, IBIS, the gamma-ray imager on board the INTEGRAL satellite, detected an outburst from a new source, IGR J17464-3213, that turned out to be a HEAO 1 transient, H1743-322. In this paper we report on the high-energy behavior of this black hole candidate (BHC) studied with the three main instruments on board INTEGRAL. The data, collecte…
Evidence of an Untruncated Accretion Disk in the Broad-Line Radio Galaxy 4C 74.26
Fabian, A. C.; Ballantyne, D. R.
We present evidence of a broad ionized Fe Kα line in the XMM-Newton spectrum of the broad-line radio galaxy (BLRG) 4C 74.26. This is the first indication that the innermost regions of the accretion flow in BLRGs contain thin, radiatively efficient disks. Analysis of the 35 ks XMM-Newton observation finds a broad line with an inner radius close to …
A Redshift z ~ 5.4 Lyα Emitting Galaxy with Linear Morphology in the GRAPES/Hubble Ultra Deep Field
Gardner, Jonathan P.; Stiavelli, Massimo; Daddi, Emanuele +21 more
We have discovered an extended Lyα plume (UDF 5225) associated with a compact source at redshift z~5.4 in slitless spectroscopic data from the Grism ACS Program for Extragalactic Science (GRAPES) project. The spatial extent of the emission is about 6×1.5 kpc (1''×0.25"). Combining our grism data and the broadband images from the Hubble …
M74 X-1 (CXOU J013651.1+154547): An Extremely Variable Ultraluminous X-Ray Source
Roberts, T. P.; Krauss, M. I.; Kilgard, R. E. +2 more
Ultraluminous X-ray sources (ULXs) have been described variously as the most luminous normal X-ray binaries, hypernovae, and ``intermediate-mass'' black holes with masses of hundreds to thousands of solar masses. We present results on M74 X-1 (CXOU J013651.1+154547), a ULX in the nearby spiral galaxy M74 (NGC 628), from observations by Chandra and…
The High-Energy Spectrum of NGC 4151
Gehrels, N.; Petrucci, P. -O.; Shrader, C. R. +5 more
We present the first INTEGRAL observations of the type 1.5 Seyfert galaxy NGC 4151. Combining several INTEGRAL observations performed during 2003, totaling ~400 ks of exposure time, allows us to study the spectrum in the 2-300 keV range. The measurements presented here reveal an overall spectrum from X-rays up to soft gamma-rays that can be descri…