Search Publications
The Intrinsic Properties of SMM J14011+0252
Smith, G. P.; Ivison, R. J.; Smail, Ian
We discuss the properties of the bright submillimeter source SMM J14011+0252 at z=2.56, which lies behind the central regions of the z=0.25 lensing cluster A1835. This system has a complex optical morphology consisting of at least five separate components. We reassess the extensive multiwavelength observations of this system and find strong suppor…
The FUSE Spectrum of the Planetary Nebula SwSt 1: Evidence for Inhomogeneities in the Gas and Dust
Redfield, Seth; Dinerstein, Harriet L.; Bowers, C. W. +1 more
We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the young, compact planetary nebula (PN) SwSt 1 along the line of sight to its central star HD 167362. We detect circumstellar absorption lines from several species against the continuum of the central star. The physical parameters of the nebula derived from the FUSE data dif…
Cool Customers in the Stellar Graveyard. I. Limits to Extrasolar Planets Around the White Dwarf G29-38
Debes, John H.; Woodgate, Bruce E.; Sigurdsson, Steinn
We present high-contrast images of the hydrogen white dwarf G29-38 taken in the near-infrared with the Hubble Space Telescope and the Gemini North Telescope as part of a high-contrast imaging search for substellar objects in orbit around nearby white dwarfs. We review the current limits on planetary companions for G29-38, the only nearby white dwa…
Spectropolarimetry and Radiative Transfer Modeling of Three Proto-Planetary Nebulae
Gordon, Karl D.; Bieging, John H.; Schmidt, Gary D. +3 more
We measured the spectrum of polarization for three proto-planetary nebulae (PPNs), IRAS 17411-2411, IRAS 08005-2356, and IRAS 04296+3429, and made model calculations with the dust-scattering Monte Carlo code DIRTY and the dust emission code 2Dust. We show that high levels of polarization in these PPNs correlate with extreme asymptotic giant branch…
A 2 Hour Quasi Period in an Ultraluminous X-Ray Source in NGC 628
Bregman, Joel N.; Seitzer, Patrick; Espaillat, Catherine +3 more
Quasi-periodic oscillations and X-ray spectroscopy are powerful probes of black hole masses and accretion disks, and here we apply these diagnostics to an ultraluminous X-ray source (ULX) in the spiral galaxy NGC 628 (M74). This object was observed four times over 2 years with the Chandra X-Ray Observatory and XMM-Newton, with three long observati…
Flare-associated Coronal Disturbances Observed with the Norikura Green-Line Imaging System. I. A Coronal Mass Ejection Onset
Ichimoto, K.; Sakurai, T.; Hori, K. +2 more
We present the first detection of an onset of a coronal mass ejection (CME) in the coronal green-line emission (Fe XIV λ5303, 2 MK) by the two-dimensional Doppler coronagraph NOGIS (Norikura Green-Line Imaging System) at the Norikura Solar Observatory, National Astronomical Observatory of Japan. On 2003 June 1-2, NOGIS continuously observed the bi…
Discovery of Ne VII in the Winds of Hot Evolved Stars
Hillier, D. J.; Bianchi, L.; Herald, J. E.
We show that a strong P Cygni feature seen in the far-UV spectra of some very hot (Teff>~85 kK) central stars of planetary nebulae (CSPN), which has been previously identified as C III λ977, actually originates from Ne VII λ973. Using stellar atmosphere models, we reproduce this feature seen in the spectra of two [WR] PG 1159-type CS…
Extragalactic Source Counts in the Spitzer 24 Micron Band: What Do We Expect from ISOCAM 15 Micron Data and Models?
Pozzi, F.; Rodighiero, G.; Gruppioni, C. +2 more
The comparison between the new Spitzer data at 24 µm and the previous ISOCAM data at 15 µm is a key tool to understand galaxy properties and evolution in the infrared and to interpret the observed number counts, since the combination of Spitzer with the Infrared Space Observatory cosmological surveys provides for the first time the dir…
Probing Halos of Galaxies at Very Large Radii Using Background QSOs
Freeman, K. C.; Wyse, R. F. G.; Broadhurst, T. +2 more
Gaseous halos of nine nearby galaxies (with redshifts cz<6000 km s-1) were probed at large galactocentric radii using background quasars observed with the Hubble Space Telescope Goddard High Resolution Spectrograph and the Space Telescope Imaging Spectrograph. The projected quasar-galaxy separations range from 55 to 387 h-1
The Initial Mass Function toward the Low-Mass End in the Large Magellanic Cloud with Hubble Space Telescope WFPC2 Observations
Henning, Th.; Brandner, W.; Gouliermis, D.
We present V- and I-equivalent Hubble Space Telescope (HST) WFPC2 photometry of two areas in the Large Magellanic Cloud: the southern part of the stellar association LH 52, located on the western edge of the supershell LMC 4, and a field between two associations, which is located on the southwestern edge of the shell and accounts for the general b…