Search Publications
A View of PKS 2155-304 with XMM-Newton Reflection Grating Spectrometers
Maraschi, L.; Tavecchio, F.; Treves, A. +2 more
We present the high-resolution X-ray spectrum of the BL Lac object PKS 2155-304 taken with the RGS units on board XMM-Newton in 2000 November. We detect an O VII Kα resonant absorption line from warm/hot local gas at 21.59 Å (~4.5 σ detection). The line profile is possibly double peaked. We do not confirm the strong 20.02 Å absorption line seen wi…
Boron Benchmarks for the Galactic Disk
Cunha, Katia; McGrath, Elizabeth J.; Lambert, David L. +1 more
Sixteen Population I solar-type dwarfs have been selected to ascertain the baseline B abundance in the Galactic disk for a range of a factor of 4 in metallicity: from [Fe/H] of -0.5 to +0.1. All the stars selected are undepleted in Be, which ensures that they have also retained their full initial abundance of B. Evaluation of the trend of B with F…
Flare-Associated Coronal Mass Ejections with Large Accelerations
Moon, Y. -J.; Dryer, M.; Cho, K. S. +3 more
It is well known that while flare-associated coronal mass ejections (CMEs) show higher speeds and little acceleration in the corona, filament-associated CMEs have lower speeds and large accelerations. In this paper, we examine three flare-associated CMEs with relatively large accelerations as counterexamples of the former tendency. The estimated a…
Far-Ultraviolet Observations of Molecular Hydrogen in the Diffuse Interstellar Medium of Starburst Galaxies
Martin, Crystal L.; Aloisi, Alessandra; Hoopes, Charles G. +5 more
The 905-1180 Å spectral range of FUSE includes numerous transitions of molecular hydrogen, making it possible to study H2 in diffuse interstellar environments directly through absorption measurements. We have searched for H2 absorption in five starburst galaxies: NGC 1705, NGC 3310, NGC 4214, M83 (NGC 5236), and NGC 5253. We …
Multiwavelength Analysis of an X1.6 Flare of 2001 October 19
Ding, M. D.; Li, J. P.
An X1.6 two-ribbon flare was observed on 2001 October 19 using the imaging spectrograph at the Solar Tower of Nanjing University. We obtained a time series of two-dimensional Hα line spectra. Combining the observations by the Nobeyama Radioheliograph (NoRH), the Transition Region and Coronal Explorer (TRACE), the Yohkoh soft X-ray telescope (SXT) …
Molecular Hydrogen Emission Lines in Far Ultraviolet Spectroscopic Explorer Observations of Mira B
Wood, Brian E.; Karovska, Margarita
We present new Far Ultraviolet Spectroscopic Explorer (FUSE) observations of Mira A's wind-accreting companion star, Mira B. We find that the strongest lines in the FUSE spectrum are H2 lines fluoresced by H I Lyα. A previously analyzed Hubble Space Telescope (HST) spectrum also shows numerous Lyα-fluoresced H2 lines. The HST…
Active Region Streamer Diagnostics 2001 September 14-16
Raymond, J. C.; Uzzo, M.; Ko, Y. -K.
From 2001 September 14 to 16 the Ultraviolet Coronal Spectrometer aboard the Solar and Heliospheric Observatory conducted a series of observations designed to study the absolute elemental abundances of an active region streamer. The absolute elemental abundances for O, Si, Fe, Mg, N, S, and Ar were calculated utilizing a constant electron temperat…
Modeling the Continuum Emission from the Circumstellar Environment of Herbig Ae/Be Stars
Elia, D.; Pezzuto, S.; Lorenzetti, D. +4 more
This paper discusses a model for the continuum emission of the Herbig Ae/Be stars in the light of an updated set of observational data spanning 5 orders of magnitude in wavelength and including the low-resolution spectra obtained with the Short Wavelength Spectrometer and Long Wavelength Spectrometer on board the Infrared Space Observatory (ISO). …
Supernova Remnants in the Magellanic Clouds. IV. X-Ray Emission from the Largest Supernova Remnant in the Large Magellanic Cloud
Gruendl, R. A.; Smith, R. C.; Points, S. D. +4 more
We present the first X-ray detection of SNR 0450-70.9, the largest known supernova remnant (SNR) in the Large Magellanic Cloud. To study the physical conditions of this SNR, we have obtained XMM-Newton X-ray observations, optical images and high-dispersion spectra, and radio continuum maps. Optical images of SNR 0450-70.9 show a large, irregular e…
Double-damped Lyα Absorption: A Possible Large Neutral Hydrogen Gas Filament near Redshift z=1
Turnshek, David A.; Rao, Sandhya M.; Vanden Berk, Daniel +3 more
We report the discovery of two damped Lyα systems (DLAs) near redshift z=1 along a single quasar sight line (Q1727+5302) with neutral hydrogen column densities of NHI=(1.45+/-0.15)×1021 and (2.60+/-0.20)×1021 atoms cm-2. Their sight line velocity difference of 13,000 km s-1 corresponds to a pr…