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Modeling of C IV pumped fluorescence of Fe II in symbiotic stars
Nilsson, H.; Long, K. S.; Eriksson, M. +1 more
Aims:We describe how the C IV λ1548.18 line pumps the 1548.20 and 1548.41 Å channels of Fe II in symbiotic stars through the process known as photo-ionization by accidental resonance (PAR). We describe where and why Fe II fluorescence arises in symbiotic stars and whether the Fe II λ1548.41 channel can only be activated when there is a white-dwarf…
Geometry of Broad Line Regions of Active Galactic Nuclei
Lü, Xiao-Rong
It has long remained an open question as to the geometry of the broad line region (BLR) in active galactic nuclei (AGNs). The reverberation mapping technique which measures the response of the broad emission lines to the ionizing continuum, when combined with multiwavelength continuum fitted by sophisticated accretion disks, provides a way of prob…
Toward an unbiased sample of X-ray selected normal galaxies outside the local Universe
Georgakakis, A.
This paper shows that our understanding of the statistical properties of X-ray selected normal galaxies (e.g. X-ray luminosity function) can be significantly improved by combining a wide-area XMM-Newton survey with the moderare resolution and high S/N optical spectroscopy of the SDSS. Such a combined dataset has the potential to minimise uncertain…
Investigation of CME dynamics in the LASCO field of view
Cho, K. -S.; Moon, Y. -J.; Shanmugaraju, A. +2 more
Context: The speed-distance profile of CMEs is important for understanding the propagation of CMEs.
Aims: Our main aim is to study the initial speed of CMEs in the LASCO field of view and its role in subsequent CME propagation using the acceleration-speed profile. The secondary aim is to obtain the speed growth rate.
Methods: We considered…
Deep surface photometry of edge-on spirals in Abell galaxy clusters. Constraining environmental effects
Santiago, B. X.; Vale, T. B.
Context: There is a clear scarcity of structural parameters for stellar thick discs, especially for spiral galaxies located in high-density regions, such as galaxy clusters and compact groups.
Aims: We have modelled the thin and thick discs of 4 edge-on spirals located in Abell clusters: NGC 705, ESO 243G49, ESO 187G19, LCSBS 0496P. Deep I ban…
Hubble Space Telescope Imaging of Bright Lyman Break Galaxy Candidates from the Sloan Digital Sky Survey: not Lbgs after all
Pogge, Richard W.; Bentz, Misty C.; Osmer, Patrick S.
We present deep Hubble Space Telescope ACS and NICMOS images of six bright Lyman break galaxy candidates that were previously discovered in the Sloan Digital Sky Survey. We find that five of the objects are consistent with unresolved point sources. Although somewhat atypical of the class, they are most likely LoBAL quasars, perhaps FeLoBALs. The s…
Diffracto-Astrometry with Hubble Space Telescope and Adaptive Optics Images
Sánchez, L. J.; Ruelas-Mayorga, A.; Allen, C. +1 more
Following the lead established by Allen et al. (1974, 2004) in the study of internal movements in Trapezium-type systems, we decided to investigate the possibility of performing precision astrometry on Hubble Space Telescope (HST) images and on images obtained with Adaptive Optics (AO) systems. A region widely observed by the HST is that of the Or…
Microcalorimeter Instruments for the Spectrum-R(X)G and NeXT Missions
Ohashi, Takaya; Mitsuda, Kazuhisa; den Herder, Jan-Willem +2 more
X-ray spectrometers utilizing a microcalorimeter array are presently under study for the Russian Spectrum R-G (or Spectrum-X-Gamma) mission, which is to be launched in 2011, and for the Japanese NeXT (New X-ray Telescope or Non-thermal energy eXploration Telescope) mission, whose launch is expected to be in 2012 to 2015. The primary instrument of …
Oxygen line mapping of SN 1006 with Suzaku
Petre, Rob; Katsuda, Satoru; Tsujimoto, Masahiro +25 more
SN 1006 is one of the supernova remnants (SNRs) with relatively low-temperature electrons, considering the young age of just 1000 years. We carried out SN 1006 mapping observations with the X-ray Imaging Spectrometers (XIS) and the Hard X-ray Detector (HXD) onboard Suzaku, the fifth Japanese X-ray satellite. Thanks to the excellent spectral resolu…
XMM-Newton survey of non-thermal shell candidates: Preliminary results on DA 530
Bocchino, F.; Gallant, Y.; Bandiera, R.
The investigation of the general properties of non-thermal (NT) X-ray shell supernova remnants (SNRs), of which SN 1006 is the prototype, is important to understand how electrons are accelerated in SNR shocks and what is the origin of cosmic rays. Using the XMM-Newton satellite, we are carrying on a survey of putative non-thermal SNR candidates pr…