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Structual study of Galactic hot gas toward Markarian 421 from X-ray absorption and emission lines
Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Wang, Q. Daniel +4 more
We present a structural study of the hot ISM in the Galactic halo along the sight line toward the bright active galactic nucleus Mkn 421. The O VII and O VIII absorption lines were measured with the Low Energy Transmission Grating Spectrograph aboard Chandra toward Mkn 421; the O VII and O VIII emission lines were observed in the adjacent fields o…
Tracking the Complex Absorption in NGC 2110 with Two Suzaku Observations
Okajima, Takashi; Fukazawa, Yasushi; Ueda, Yoshihiro +6 more
We present spectral analysis of two Suzaku observations of the Seyfert 2 galaxy, NGC 2110. This source has been known to show complex, variable absorption which we study in depth by analyzing these two observations set 7 yr apart and by comparing them to previously analyzed observations with the XMM-Newton and Chandra observatories. We find that t…
The Norma Arm Region Chandra Survey Catalog: X-Ray Populations in the Spiral Arms
An, Hongjun; Bauer, Franz E.; Stern, Daniel +6 more
We present a catalog of 1415 X-ray sources identified in the Norma Arm Region Chandra Survey (NARCS), which covers a 2° × 0.°8 region in the direction of the Norma spiral arm to a depth of ≈20 ks. Of these sources, 1130 are point-like sources detected with >=3σ confidence in at least one of three energy bands (0.5-10, 0.5-2, and 2-10 keV), five…
X-ray emission from an FU Orionis star in early outburst: HBC 722
Skinner, Stephen L.; Güdel, Manuel; Green, Joel +1 more
Aims: We conducted the first X-ray observations of the newly erupting FU Ori-type outburst in HBC 722 (V2493 Cyg) with the aim to characterize its X-ray behavior and near-stellar environment during early outburst.
Methods: We used data from the XMM-Newton and Chandra X-ray observatories to measure X-ray source temperatures and luminositi…
The extension of ionospheric holes into the tail of Venus
Fedorov, A.; Barabash, S.; Holmström, M. +8 more
Ionospheric holes are Cytherian nightside phenomena discovered by the NASA Pioneer Venus Orbiter, featuring localized plasma depletions driven by prominent and unexplained enhancements in the draped interplanetary magnetic field. Observed only during solar maximum, the phenomenon remains unexplained, despite their frequent observation during the f…
Detection of galaxies with Gaia
Ducourant, C.; Krone-Martins, A.; Teixeira, R. +2 more
Aims: Besides its major objective tuned to detecting the stellar galactic population, the Gaia mission experiment will also observe a large number of galaxies. In this work we intend to evaluate the number and the characteristics of the galaxies that will effectively pass the on-board selection algorithm of Gaia.
Methods: The detection o…
Interpreting the extended emission around three nearby debris disc host stars
Eiroa, C.; Marshall, J. P.; Montesinos, B. +7 more
Context. Cool debris discs are a relic of the planetesimal formation process around their host star, analogous to the solar system's Edgeworth-Kuiper belt. As such, they can be used as a proxy to probe the origin and formation of planetary systems like our own.
Aims: The Herschel open time key programmes "DUst around NEarby Stars" (DUNES) and…
Measurements of Coronal Faraday Rotation at 4.6 R ⊙
Kooi, Jason E.; Fischer, Patrick D.; Buffo, Jacob J. +1 more
Many competing models for the coronal heating and acceleration mechanisms of the high-speed solar wind depend on the solar magnetic field and plasma structure in the corona within heliocentric distances of 5 R ⊙. We report on sensitive Very Large Array (VLA) full-polarization observations made in 2011 August, at 5.0 and 6.1 GHz (each wi…
Discovery of X-Ray Pulsations from the Next Geminga, PSR J1836+5925
Takata, J.; Kong, A. K. H.; Hui, C. Y. +5 more
We report recent XMM-Newton investigations of PSR J1836+5925, the "next Geminga," which determined an X-ray pulsation of ~173.3 ms. Its X-ray periodicity is consistent with the γ-ray ephemeris at the same epoch. The X-ray folded light curve has a sinusoidal structure that is different from the double-peaked γ-ray pulse profile. We have also analyz…
Mechanisms and timescales of fluvial activity at Mojave and other young Martian craters
Warner, Nicholas H.; Gupta, Sanjeev; Kim, Jung-Rack +1 more
Mojave Crater, and five other relatively young Late Hesperian to Amazonian-age Martian craters exhibit channelized alluvial fans that are sourced from bedrock-eroded catchments. These catchments emerge from the crests of sloping surfaces, suggesting a formation mechanism that involved precipitation. The evidence for fluvial activity at all six cra…