To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The results of a spectral study of the galaxy Mr 297 with the 6-m telescope are presented. Estimations of mass and heavy element abundance for some knots in galaxy are made. Chemical composition of these knots is close to the normal one.
We present results of a search for the most massive LBV-like stars in M 33 and discuss the list of OB+Hα stars. Spectral studies of the 70 brightest stars (V < 17.7) from the list have isolated 14 new LBV candidates. They are evolved the most massive stars, some of them are variable stars.
Spectral and imaging results for the central region of M31 are presented. An analysis of absorption-index radial profiles involving Mg, Fe, and Ca lines reveals that the unresolved core of M31 is distinct from the inner bulge in having a higher metallicity; of the two nuclei of M31, it is the fainter in visible light and is located exactly in the dynamical center of the galaxy (and dynamically decoupled) which is chemically distinct. By including the Balmer absorption line Hβ in the analysis, we have disentangled metallicity and age effects; a stellar age difference by a factor of three is found between the nucleus and the bulge, the nucleus being younger. A morphological analysis of CCD images has shown the presence of an inner stellar-gaseous disk with a radius of some 80 pc which is embedded into the bulge.
Results of 3D-spectroscopy for the nearby Seyfert galaxy Mrk 573 obtained at the 6-m telescope with the scanning Fabry-Perot interferometer and the Multi-Pupil Field Spectrograph (MPFS) are presented. Emission lines images of the galaxy center demonstrate a complex structure of ENLR, coinciding with the radio data. An analysis of the velocity field shows that some gas structures do not lie in the plane of the galaxy. An explanation of the observed velocity field and gas distribution by radiation of a helical structure located inside an ionization cone is proposed.
From 13-years of the spectral optical monitoring of a well-known broad-line radio galaxy 3C 390.3 we concluded that the geometry of the broad emission-line region is complex, while still the main part of the emission is coming from the accretion disk. Here we present part of the analysis of the broad Hα and Hβ emission lines, which are showing highly variable double-peaked profiles during the monitoring period (1995-2007), with the aim to probe the accretion disk properties. The disk-like geometry plays a dominant role, but the variability of Hα and Hβ line profiles and intensities shows a presence of an additional emission-line region, that has a different nature for different periods, e.g. in one period the observed variation can be well modeled if one assumes changes in position and size of the emitting disk along the accretion disk.
Low energy implantation is currently the most promising option for shallow junction formation in the next generations of silicon CMOS technology. Of the dopants that have to be implanted, boron is the most problematic because of its low stopping power (large penetration depth) and its tendency to undergo transient enhanced diffusion and clustering during thermal activation. This paper reports recent advances in our understanding of low energy B implants in crystalline silicon. In general, satisfactory source-drain junction depths and sheet resistances are achievable down to 0.18 micron CMOS technology without the need for implantation of molecular species such as BF2. With the help of defect engineering it may be possible to reach smaller device dimensions. However, there are some major surprises in the physical mechanisms involved in implant profile formation, transient enhanced diffusion and electrical activation of these implants, which may influence further progress with this technology. Some initial attempts to understand and model these effects will be described.
Double mode pulsations of the B4 component in the system of CI Cam were detected. The photometric 19.4 day orbital period of CI Cam was confirmed with the plates of the Sonneberg collection for a long period of time before the unique 1998 outburst. The amplitude of the periodic component of 0.08 mag before the outburst was larger than that of 0.03 mag after the outburst.
In this work, we present the spectra of NGC 4151 observed over 11 years (from 1996 to 2006) using the SAO 6-m and 1-m telescopes (Russia), the GHAO 2.1-m telescope (Cananea, México), and the OAN-SPM 2.1-m telescope (San-Pedro, México). The procedure of spectra calibration is given by Shapovalova et al. (2008). Our analysis is focused on high-quality (S/N > 50) spectra of the Hα and Hβ emission lines.
We apply the Boltzmann-Plot (BP) method to the Balmer lines to estimate the physical propertiesin the Broad Line Region of Active Galactic Nuclei. We study the Balmer lines of a sample of 90 AGN from Sloan Digital Sky Survey database, as well as the time variability of the BP parameter A of NGC 5548.
We consider a real-valued function r = M(t) on the real axis, such that M(t) < 0 for t < 0. Under appropriate assumptions on M, the pull-back operator M* gives rise to a transform of Sobolev spaces Ws.p (-∞, 0) that restricts to a transform of Ws.p(-∞, ∞). We construct a bounded linear extension operator Ws.p(-∞, 0) → Ws.p(−∞, ∞), commuting with this transform.
Email your librarian or administrator to recommend adding this to your organisation's collection.