Next: Gain steps Up: Additional information Previous: Measuring aperture . ... If the high voltage is changed to vary the gain, as is sometimes done in DC or CI work, the spectral response varies. This must be treated exactly like a variable measuring aperture: only data taken under constant conditions should be reduced together, but sometimes this can be done if adequate calibration data have been measured. The column label is PMTVOLTS. ...

... 2003 November 19 . Light Can Twist as Well as Spin . ... Recently, however, it has been more broadly realized that photons can also have orbital angular momentum (OAM), an attribute classically analogous to the Earth orbiting the Sun as well as spinning on its axis. Pictured above , the wave-front of a photon with OAM is shown to be twisted, in contrast to the flat plane of zero OAM light. ... APOD Update: APOD mirror now on-line from Poland with archive in Polish. ... Archive | ...

... Any HST data taken with a paired aperture prior to January 1, 1995 may need manual editing of certain . ... Prior to January 1, 1995 important keywords in the headers of all FOS paired aperture exposures for STEP-PATT not equal to SINGLE were constructed on the assumption that SKY was sampled in one aperture segment. ... Modern versions of calfos (revised after January 1, 1995) will process these updated data correctly and produce separate calibrated spectra for the two aperture segments. ...

... Actual stars are expected to be more complicated than these simulations. ... The spot may be entirely visible most of the time (one would observe a prolonged flux minimum low), and then part of it may disappear over the horizon briefly and then return (slow rise and then fall back to constant level). ... With the set of observations taken here, I have information available from several comparison stars and color information. ... The period found must be consistent with the data from any given night....

... A three-cell test section roughly representative of the primary mirror was provided for this test by the Steward Mirror Lab. ... Additionally, the tests are intended to determine relative airflow vs. pressure drop characteristics for each of the air flow patterns so the results can be evaluated both as a function of flow rate and of pressure drop along the flow path. ... The bottom (top as installed) was cut out so it could close the chamber for heating and be removed for the cooling tests. ...

... At high latitudes, the E-region auroral electrojets and field-aligned currents produce 'radar aurora' that are somewhat more complicated than the equatorial radar echoes. ... Type 4 echoes are a special type of two-stream events associated with anomalous electron heating by the auroral electrojet waves. ... Res. ... Hedberg, and J. A. Nordling, Observations of auroral E-region plasma waves and electron heating with EISCAT and a VHF radar interferometer, J. atmos. terr. ... Observations, J. Geophys. ...

The database contains references to the papers, data files and links to the Internet resources related to measurements and calculations of the optical constants in the wavelength interval from X-rays to radio domain. ... References to some useful books and reviews on the subject (e.g. the classical handbooks edited by E.D.Palik) and links to Internet collections of optical constants and personal WWW pages with related software were also placed in the database. You have arrived at our welcome page. ...

... Science Users Information > Observing with ESO Telescopes > Phase 2 Preparation > Observing conditions . ... Service Mode Philosophy . ... The following definitions of the observing conditions are common between Phase 1 preparation and Phase 2 preparation, as well as between Service Mode and Visitor Mode observations. ... There are additional Service Mode Policies and Service Mode Guidelines regarding the observing conditions. ... Seeing (Phase 1) and Image quality (Phase2) constraints . ... Moon . ...

... As modern observatories evolve to production units delivering data products and calibrated scientific data to the end users, new challenges arise in assessing the quality of data products. ... Taking the analogy of speed control on a motorway we can describe the system as a device (radar) collecting measurements of the system performance (passing cars). ... One of the direct applications of quality control is the verification of instrument performance based on the analysis of calibration exposures. ...

INTEGRABILITY OF HAMILTONIAN SYSTEMS . The necessary conditions of the existence of additional first integrals in Hamiltonian systems with n>=2 degrees of freedom are investigated. ... Ziglin S.L. Splitting of separatrices, branching of solutions and nonexistence of an integral in the dynamics of a rigid body. ... Ziglin S.L. Branching of solutions and nonexistence of first integrals in Hamiltonian systems. ... Зиглин С.Л ., ... Contact: Dr.Prof. Sergey L. Ziglin, tel. ... IRE RAS 1996-2006 ...

... Two files from two exposures (even from different observations or instruments) are taken as input. These may be EPIC event lists or two other additional files (attitude files, orbit files etc [see comments]). ... Warnings are given when the event files are deemed not entirely compatible (i.e. their INSTRUME or FILTER keywords are different). ... Given here is a summary of the current conditions whereby event files (or parts thereof [blocks/columns etc]) are or are not merged. ...

Next: The Individual Approach Up: The Joint Approach Previous: Self-Calibration . We briefly describe some other useful tools. ... Mosaic Point-Spread Function - MOSPSF: It is occasionally instructive to look at the point-spread function at a particular position in a mosaic experiment. ... Additionally, as mentioned above, invert does not attempt to completely correct for the primary beam attenuation where there is too little data (i.e. some primary beam attenuation is in the output image). ...

Crater Gassendi . ... I made this drawing was made on the 26th of november 2001. If you compare this one with the previous drawing of Gassendi (below) the differences are clear. ... This drawing was made on the 28th of september 2001. After nearly a full month without observations I had a one hour gap between the thicker clouds. ... This drawing was made on the 29th of august 2001. ... This drawing was made on the 27th of august 2001. ... This drawing was made on the 25th of august 2001. ...

Alfa was reinstalled in the dome in sep11. Calibration runs were done in sep11,oct11 to measure any pointing offsets. ... After looking at the results, the alfa model was updated to correct for the constant offset term. ... The heiles calibration scans were used to measure the pointing error. ... page 1: measured pointing errors: . ... The pointing errors are: . ... Page 3: pointing errors in za and az with the fits over plotted: . ... Page 4: pointing errors with the fit removed: . ... 1az term . ...

Next: Transform of modulated Up: No Title Previous: Frequency/duration relation. Let us now turn to gradually more complicated signals, for which we soon lose the support of analytical expressions of the transforms. First, examine the sum of 3 cosine waves at different frequencies and phases. The Mexican hat wavelet analysis is carried out as above, yielding the wavelet map (Fig. ... Figure 11: g2 transform of a multiperiodic signal. ... Mon Nov 13 10:51:25 EST 1995 ...

... Bojan Nikolic web pages (r. 329) . ... SELECT TScan.timestamp, TScan.cont, TSource.sn, intent FROM (SELECT archive _uid, extract (aa.xml, '//row[1]//scanIntent/text()').getStringVal() as intent, extract (aa.xml, '//row[1]//startTime/text()').getStringVal() as stime, extract (aa.xml, '//row[1]//endTime/text()').getStringVal() as etime, extract (aa.xml, '//ContainerEntity[1]/@entityId').getStringVal() as cont, timestamp FROM ALMA .xml_scantable_entities aa) Tscan, (SELECT timestamp, archive ...

Next: A Universal Diagram for Up: ``Ecology'' of Magnetic Rotators Previous: The Corotation Radius . The interaction of a magnetic rotator with the surrounding plasma to a large extent depends on the relation between the four characteristic radii: the stopping radius, , the gravitational capture radius,   , the light cylinder radius,   , and the corotation radius,   . ... Hence, the classification of the interaction regimes may well mean the classification of magnetic rotators. ...

Astronomy Picture of the Day . Light Can Twist as Well as Spin . ... 19.11.2003 . ... Recently, however, it has been more broadly realized that photons can also have orbital angular momentum (OAM), an attribute classically analogous to the Earth orbiting the Sun as well as spinning on its axis. ... Light with OAM might be used to increase the information content of communication or to discern specific types of astronomical sources. ... NASA Web Site Statements, Warnings, and Disclaimers . ...

The Mars Flag has a different design on the reverse side. obverse side of flag . ... The orbit lines on the obverse cross the Sun on the lower half of the flag and appear to go behind the Sun on the upper half of the flag. The reverse side has the orbits lines continuing around the Sun on the upper half of the flag. ... The Mars Flag reverse side is a continuation of the obverse side and not just a different design on the back and not a mirror image of the obverse. Main Flag Background Color . ...

Chair of solid state physics . ... The Physics of Phonons . ... In the first part of the course “The Physics of Phonons” the dynamics of atoms in one- and three- dimensional crystalline lattices is considered in detail. The quasiparticle conception in solids, taking phonons as an example, is discussed; creation and annihilation operators of phonons, main properties of acoustic and optical phonons dispersion laws, density of phonon states. ... Crystalline state. ... Acoustic and optical phonons. ...