Search Publications
Multithermal Analysis of a SOHO/CDS Coronal Loop
Schmelz, J. T.; Martens, P. C. H.
The observations from 1998 April 20 taken with the Coronal Diagnostics Spectrometer (CDS) on the Solar and Heliospheric Observatory (SOHO) of a coronal loop on the limb have shown that the plasma was multithermal along each line of sight investigated, both before and after background subtraction. The latter result relied on emission measure (EM) l…
A Hard X-Ray View of Scorpius X-1 with INTEGRAL: Nonthermal Emission?
Frontera, F.; Goldoni, P.; Stella, L. +12 more
We present here simultaneous INTEGRAL/RXTE observations of Sco X-1 and in particular a study of the hard X-ray emission of the source and its correlation with the position in the Z track of the X-ray color-color diagram. We find that the hard X-ray (above about 30 keV) emission of Sco X-1 is dominated by a power-law component with a photon index o…
Optical Structure and Proper-Motion Age of the Oxygen-rich Supernova Remnant 1E 0102-7219 in the Small Magellanic Cloud
Finkelstein, Steven L.; Ebbets, Dennis C.; Leitherer, Claus +12 more
We present new optical emission-line images of the young SNR 1E 0102-7219 in the SMC obtained with the ACS on HST. This object is a member of the oxygen-rich class of SNRs showing strong oxygen, neon, and other metal-line emissions in its optical and X-ray spectra, and an absence of hydrogen and helium. The progenitor of 1E 0102-7219 may have been…
The Low-Redshift Lyα Forest toward PKS 0405-123
Tripp, Todd M.; Jenkins, Edward B.; Davé, Romeel +5 more
We present results for Lyα forest and metal absorbers from ~7 km s-1 resolution Space Telescope Imaging Spectrograph data for QSO PKS 0405-123 (z=0.574). We analyze strong and weak samples of Lyα forest lines, containing 60 absorbers with column density logNHI>=13.3 over 0.002<z<0.423 and 44 with logNHI>…
Solar Neutron Events of 2003 October-November
Lopate, C.; Kudela, K.; Watanabe, K. +14 more
During the period when the Sun was intensely active in 2003 October-November, two remarkable solar neutron events were observed by the ground-based neutron monitors. On 2003 October 28, in association with an X17.2 large flare, solar neutrons were detected with high statistical significance (6.4 σ) by the neutron monitor at Tsumeb, Namibia. On 200…
A Burst and Simultaneous Short-Term Pulsed Flux Enhancement from the Magnetar Candidate 1E 1048.1-5937
Kaspi, Victoria M.; Woods, Peter M.; Gavriil, Fotis P.
We report on the 2004 June 29 X-ray burst detected from the direction of the AXP 1E 1048.1-5937 using the RXTE. We find a simultaneous increase of ~3.5 times the quiescent value in the 2-10 keV pulsed flux of 1E 1048.1-5937 during the tail of the burst, which identifies the AXP as the burst's origin. The burst was overall very similar to the two o…
Rotational Broadening of Atomic Spectral Features from Neutron Stars
Chang, Philip; Bildsten, Lars; Morsink, Sharon +1 more
The discovery of the first gravitationally redshifted spectral line from a neutron star (NS) by Cottam et al. has triggered theoretical studies of the physics of atomic line formation in NS atmospheres. Chang et al. showed that the hydrogenic Fe Hα line formed above the photosphere of a bursting NS is intrinsically broad. We now include rotational…
The O VI Absorbers toward PG 0953+415: High-Metallicity, Cosmic-Web Gas Far from Luminous Galaxies
Bowen, David V.; Tripp, Todd M.; Jenkins, Edward B. +1 more
The spectrum of the low-redshift QSO PG 0953+415 (zQSO=0.234) shows two strong, intervening O VI absorption systems. To study the nature of these absorbers, we have used the Gemini Multi-Object Spectrograph to conduct a deep spectroscopic galaxy redshift survey in the 5'×5' field centered on the QSO. This survey is fully complete for r'…
Lyman Break Galaxies under a Microscope: The Small-Scale Dynamics and Mass of an Arc in the Cluster 1E 0657-56
Lutz, D.; Genzel, R.; Saglia, R. P. +8 more
Using the near-infrared integral field spectrograph SPIFFI on the VLT, we have studied the spatially resolved dynamics in the z=3.2 strongly lensed galaxy 1E 0657-56 arc+core by observing the rest-frame optical emission lines [O III] λ5007 and Hβ. The lensing configuration suggests that the high surface brightness core is the M~20 magnified centra…
Measurements of the f-Values of the Resonance Transitions of Ni II at 1317.217 and 1370.132 Å
Tripp, Todd M.; Jenkins, Edward B.
We have retrieved high-resolution UV spectra of 69 hot stars from the HST archive and determined the strengths of the interstellar Ni II absorption features at 1317.217 Å arising from the ground 3d92D5/2 electronic state to the 3d8(1G)4p2Fo5/2 excited level. We…