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Spatial Separation of the 3.29 Micron Emission Feature and Associated 2 Micron Continuum in NGC 7023
Sellgren, K.; An, Jin H.
We present a new 0.9" resolution 3.29 µm narrowband image of the reflection nebula NGC 7023. We find that the 3.29 µm infrared emission feature (IEF) in NGC 7023 is brightest in narrow filaments northwest of the illuminating star HD 200775. These filaments have been previously seen in images of extended red emission, K', near-infrared …
Interaction and Dynamics of the Photospheric Network Magnetic Elements
Tarbell, T. D.; Shine, R.; Ryutova, M.
Small-scale magnetic elements in the quiet photospheric network are believed to play a key role in the energy flow from the solar surface to upper layers of atmosphere. Their intense hydro-magnetic activity includes merging and fragmentation of same polarity fluxes, `total' or partial cancellation of neighboring flux elements of opposite polarity,…
Determination of the solar wind slowdown near solar maximum
Wang, C.; Richardson, J. D.
The magnitude of the solar wind speed decrease from the inner to the outer heliosphere provides important information about the interaction of the heliosphere with the local interstellar medium (LISM), leading to better estimates of the size and shape of the heliosphere and of the LISM density. In this study we combine observations from multiple s…
X-ray emission line gas in the LINER galaxy M 81
Page, M. J.; Branduardi-Raymont, G.; Zane, S. +5 more
We present the soft X-ray spectrum of the LINER galaxy M 81 derived from a long observation with the XMM-Newton RGS. The spectrum is dominated by continuum emission from the active nucleus, but also contains emission lines from Fe L, and H-like and He-like N, O, and Ne. The emission lines are significantly broader than the RGS point-source spectra…
A multi-wavelength test of the FR I-BL Lac unifying model
Capetti, A.; Chiaberge, M.; Celotti, A. +2 more
We collect multi-wavelength measurements of the nuclear emission of 20 low luminosity FR I radio-galaxies to test the viability of the FR I-BL Lac unifying model. Although poorly sampled, the Spectral Energy Distributions (SED) of FR Is are consistent with the double peaked shape characteristic of BL Lacs. Furthermore while the distribution of the…
Solar magnetic field reversal as seen at Ulysses
Balogh, André; Smith, Edward J.; Jones, Geraint H.
The rapid motion of the Ulysses spacecraft from high southern to high northern latitudes in 2000-2001 provided an excellent opportunity to make inferences regarding the solar magnetic dipole's behaviour around solar maximum. A simple dipole model is fitted to Ulysses measurements of the polarity of the heliospheric magnetic field mapped back to th…
XMM-Newton observations of the polars EV UMa, RX J1002-19 and RX J1007-20
Cropper, Mark; Ramsay, Gavin
We present XMM-Newton data of three strongly magnetic cataclysmic variables (polars) EV UMa, RX J1002-19 and RX J1007-20. These include the polar with the shortest orbital period (EV UMa) and the polar with one of the highest magnetic field strengths (RX J1007-20). They exhibit a range of X-ray spectral characteristics which are consistent with th…
Far UV spectroscopy of the circumstellar environment of the Herbig Be stars HD 259431 and HD 250550
Deleuil, M.; Bouret, J. -C.; Catala, C. +2 more
We present an analysis of FUSE spectra of HD 259431 and HD 250550, two young Herbig Be stars. Numerous absorption lines of H_2 are seen in the spectrum of each star, revealing large amounts of this gas on the lines of sight. In addition, absorption lines from atomic species in different ionization and excitation states are also identified. We demo…
UV(IUE) spectra of hot post-AGB candidates
Parthasarathy, M.; Gauba, G.
Analysis of the low resolution UV(IUE) spectra (1150 to 3200 Å) of 15 hot post-AGB candidates is presented. The UV(IUE) spectra of 10 stars suggest partial obscuration of the hot stars due to circumstellar dust. The reddened continua of these 10 stars were used to model and estimate the circumstellar extinction. The circumstellar extinction law wa…
Hubble Space Telescope STIS Observations of Comet 19P/Borrelly during the Deep Space 1 Encounter
Stern, S. A.; Weaver, H. A.; Parker, J. Wm.
In support of the NASA Deep Space 1 (DS1) mission to comet 19P/Borrelly, we obtained Hubble Space Telescope (HST) images and ultraviolet (UV) spectra of the comet near the time of the DS1 flyby in 2001 September. The HST data provide context information on 19P/Borrelly's circumnuclear dust environment, the rotational period and rotational phase of…