Search Publications
The Mysterious Sickle Object in the Carina Nebula: A Stellar Wind Induced Bow Shock Grazing a Clump?
Burkert, Andreas; Preibisch, Thomas; Ratzka, Thorsten +1 more
Optical and near-infrared images of the Carina Nebula show a peculiar arc-shaped feature, which we call the "Sickle," next to the B-type star Trumpler 14 MJ 218. We use multi-wavelength observations to explore and constrain the nature and origin of the nebulosity. Using submillimeter data from APEX/LABOCA as well as Herschel far-infrared maps, we …
Heliospheric Energetic Neutral Hydrogen Measured with ASPERA-3 and ASPERA-4
Barabash, S.; Grigoriev, A.; Wurz, P. +6 more
We re-analyze the signal of non-planetary energetic neutral atoms (ENAs) in the 0.4-5.0 keV range measured with the Neutral Particle Detector (NPD) of the ASPERA-3 and ASPERA-4 experiments on board the Mars and Venus Express satellites. Due to improved knowledge of sensor characteristics and exclusion of data sets affected by instrument effects, t…
XMM-Newton Observations of the TeV γ-Ray Source HESS J1804-216
Lin, Dacheng; Webb, Natalie A.; Barret, Didier
We have analyzed three XMM-Newton observations of the central part of the unidentified TeV γ-ray source HESS J1804-216. We focus on two X-ray sources, 2XMMi J180442.0-214221 (Src 1) and 2XMMi J180432.5-214009 (Src 2), which were suggested to be the possible X-ray counterparts to the TeV source. We discover a 2.93 hr X-ray periodicity from Src 1, w…
Outflows and Dark Bands at Arcade-like Active Region Core Boundaries
Martens, P. C. H.; Scott, J. T.; Tarr, L.
Observations from the EUV Imaging Spectrometer (EIS) on board Hinode have revealed outflows and non-thermal line broadening in low intensity regions at the edges of active regions (ARs). We use data from Hinode's EIS, Solar Dynamic Observatory's Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager, and the Transition Region and Corona…
Distribution of CO2 in Saturn's Atmosphere from Cassini/cirs Infrared Observations
Flasar, F. M.; Achterberg, R. K.; Jennings, D. E. +9 more
This paper focuses on the CO2 distribution in Saturn's atmosphere based on analysis of infrared spectral observations of Saturn made by the Composite Infrared Spectrometer aboard the Cassini spacecraft. The Cassini spacecraft was launched in 1997 October, inserted in Saturn's orbit in 2004 July, and has been successfully making infrared…
Unexpected Ionization Structure in Eta Carinae's "Weigelt Knots"
Davidson, Kris; Mehner, Andrea; Remmen, Grant N.
The Weigelt knots, dense slow-moving ejecta near η Carinae, are mysterious in structure as well as in origin. Using spatially dithered spectrograms obtained with the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS), we have partially resolved the ionization zones of one knot. Contrary to simple models, higher ionization level…
Infrared Observations of the Millisecond Pulsar Binary J1023+0038: Evidence for the Short-term Nature of Its Interacting Phase in 2000-2001
Morrell, Nidia; Wang, Zhongxiang; Wang, Xuebing
We report our multi-band infrared (IR) imaging of the transitional millisecond pulsar system J1023+0038, a rare pulsar binary known to have an accretion disk in 2000-2001. The observations were carried out with ground-based and space telescopes from near-IR to far-IR wavelengths. We detected the source in near-IR JH bands and Spitzer 3.6 and 4.5 &…
MN Lup: X-Rays from a Weakly Accreting T Tauri Star
Wolter, U.; Robrade, J.; Günther, H. M. +1 more
Young T Tauri stars (TTS) are surrounded by an accretion disk, which over time disperses due to photoevaporation, accretion, and possibly planet formation. The accretion shock on the central star produces an UV/optical veiling continuum, line emission, and X-ray signatures. As the accretion rate decreases, the impact on the central star must chang…
Bright Points: Multithermal Analysis as a Test of Steady Heating Models
Golub, L.; Schmelz, J. T.; Pathak, S. +4 more
X-ray bright points are small, million-degree features in the solar atmosphere composed of short coronal loops. They are magnetically driven structures associated with photospheric magnetic bipoles. Their relatively small size and simple structure suggest they are ideal candidates for comparisons with coronal heating models. In this paper, we pres…
Disk Mass-to-light Ratio Distribution from Stellar Population Synthesis: Application to Rotation Curve Decomposition of NGC 5278 (KPG 390 A)
Rosado, M.; Gabbasov, R.; Repetto, P. +1 more
In this work we extend the study on the mass distribution of the spiral galaxy NGC 5278, performing 1D and 2D (GALFIT) bulge-disk decomposition to determine which components constitute the baryonic mass in this galaxy. Our analysis does not detect any bulge; instead we find a bright source probably related to the central active galactic nucleus an…