Search Publications
A Possible Dearth of Hot Gas in Galaxy Groups at Intermediate Redshift
Paerels, Frits; Spiegel, David S.; Scharf, Caleb A.
We examine the X-ray luminosity of galaxy groups in the CNOC2 survey at redshifts 0.1<z<0.6. Previous work examining the gravitational lensing signal of the CNOC2 groups has shown that they are likely to be genuine, gravitationally bound objects. Of the 21 groups in the field of view of the EPIC pn camera on XMM-Newton, not one was visible i…
Solar Rossby Wave ``Hills'' Identified as Supergranules
Hathaway, D. H.; Cuntz, M.; Williams, P. E.
We explore the nature of ``hills'' observed on the solar surface that had previously been attributed to Rossby waves. We investigate the solar hills phenomenon by analyzing the output from a synthetic model based solely on the observed solar photospheric convection spectrum. We show that the characteristics of these hills can be explained by the c…
Morphological Study of Quiescent Streamers during Solar Minimum by Ultraviolet Emission Lines
Akinari, Nakagawa
We perform, by utilizing spectroscopic measurements made with SOHO/UVCS, a morphological characterization of the quiescent streamer during solar minimum, by means of both a comprehensive survey of daily synoptic observations over 33 weeks from 1996 April to November and detailed analysis of several specialized observations targeting quiescent stre…
Estimating the Structure and Geometry of Winds from Luminous Blue Variables via Fitting the Continuum Energy Distributions
Li, Y.; Guo, J. H.
By combining the UV spectra from IUE with photometric data in the optical band, we present a quantitative study on the continuum energy distributions of LBVs to determine the structure and geometry of LBV winds. It is shown that the shape of continuum energy distributions around the Balmer jump is sensitive to the velocity law of LBV winds. A simp…
Magnetic Flux in the Solar Convective Envelope Inferred from Initial Observations of Sunspots
Hiremath, K. M.; Lovely, M. R.
Different life spans of sunspots suggest their origin at different depths, and by measuring magnetic fluxes from their first observation on the surface, one can estimate the strength of magnetic flux at different anchoring depths. From SOHO MDI magnetograms, we infer the strength of magnetic flux and rate of emergence of magnetic flux at different…
Rest-Frame Ultraviolet to Near-Infrared Observations of an Interacting Lyman Break Galaxy at z=4.42
Shapley, Alice E.; Hernquist, Lars; Fazio, Giovanni G. +11 more
We present the rest-frame ultraviolet through near-infrared spectral energy distribution for an interacting Lyman break galaxy at a redshift z=4.42, the highest redshift merging system known with clearly resolved tidal features. The two objects in this system, HDF-G4 and its previously unidentified companion, are both B435-band dropouts…
Discovery of Extended Emission around the Pulsar B0355+54
Ögelman, H.; Tepedelenliǧlu, E.
PSR B0355+54 is one of the handful of pulsars that have been observed with both Chandra and XMM-Newton. The analysis of the archival data has revealed the pulsar and a ~30" compact nebula surrounding it. XMM-Newton also has detected a trail that extends ~6' and, similar to the compact nebula, is also counteraligned with the proper motion of the pu…
AEGIS: Galaxy Spectral Energy Distributions from the X-Ray to Radio
Ivison, R. J.; Cooper, M. C.; Huang, J. -S. +15 more
The All-Wavelength Extended Groth Strip International Survey (AEGIS) team presents broadband spectral energy distributions (SEDs), from X-ray to radio wavelengths, for 71 galaxies spanning the redshift range 0.55-1.16 (<z>~0.7). Galaxies with secure redshifts are selected from a small (22 arcmin2) subsection of the Keck/DEIMOS Gal…
The Unusual Variability of the Large Magellanic Cloud Planetary Nebula RPJ 053059-683542
Rest, Armin; Parker, Quentin A.; Smith, R. Chris +3 more
We present images and light curves of the bipolar planetary nebula RPJ 053059-683542 that was discovered in the Reid-Parker AAO UKST Hα survey of the Large Magellanic Cloud. The emission from this object appears entirely nebular, with the central star apparently obscured by a central band of absorption that bisects the nebula. The light curves, wh…
Spitzer IRS Imaging and Spectroscopy of the Luminous Infrared Galaxy NGC 6052 (Mrk 297)
Houck, J. R.; Charmandaris, V.; Whelan, D. G. +2 more
We present photometric and spectroscopic data of the interacting starburst galaxy NGC 6052 obtained with the Spitzer Space Telescope. The mid-infrared (MIR) spectra of the three spatially resolved regions in the galaxy are remarkably similar and are consistent with dust emission from young, nearly coeval stellar populations. Analysis of the bright…