Spectral Line Sources Spectral Line VLBI Chris Phillips JIVE The Netherlands · VLBI High brightness temperatures · Masers : Galactic · OH, H2O, SiO, CH3OH Extragalactic · OH, H2O · Extra-galactic HI absorption Image courtesy of Lincoln Greenhill, CfA VLBI Group See also: Hernstein etal , 1999, Nature, 400, 539 Miyoshi etal , 1995, Nature, 373, 127 1 SiO masers in TX Cam Movie courtesy of Phil Diamond, Jodrell Bank SiO masers in Orion BN/KL Greenhill ...

... We will consider the rms, (K), for observations with a receiver of system temperature, T , frequency resolution, per polarization, and total integration time per observing cycle, . ... For ``in-band'' frequency switching, the line under investigation is always in the observing band. ... Position Switching or ``Out-of-Band'' Frequency Switching: Here the line is only observed for one half of the time, with noise being present all of the time. ...

... Дни открытых дверей к юбилею САО РАН (12-14 апреля 2016 г.) . Международная конференция "Dark Ages and White Nights (Spectroscopy of the CMB)" (20-24 июня 2016 г.) . ... Международная конференция MULTI-SPIN GALAXIES - 2016 (26-30 сентября 2016 г.) . Международная астрономическая конференция "Физика звезд: от коллапса до коллапса" (3-7 октября 2016 г.) Архив . ... Подробнее.. ... 10.02.16 . ... БТА в реальном времени . ... Цейсс-1000 в реальном времени . ... Последнее обновление: 22/03/2016 ...

... 640W A survey of ultracompact (UC) Hii regions has been carried out by searching for 6.669-GHz methanol maser emission from a sample of 535 IRAS-selected candidates. A total of 201 candidates exhibit methanol emission. These sources have been used, in conjunction with previously identified UC Hii regions, to provide a base for further studies of such regions. ... Methanol maser and/or radio continuum emission is found in 364 cases towards IRAS-selected regions. ...

... Thomson's multiple window method of spectral estimationthomson provides a very good estimate of the power spectrum by measuring the energy contained within a collection of rectangular shaped frequency intervals. ... Often, much of the fine structure of a spectral estimate is due to noise. It should be stressed that while other methods of spectral estimation (such as the Welchoppenheim method) exist, the Thomson method is particularly noteworthy for its precisely defined rectangular frequency bins. ...

Static Fourier spectrometers are often used for spectral measurements of the ionosphere emissions. There are two main advantages of Fourier spectrometers (FS) - large geometric factor and high spectral resolution; these parameters are two orders better than for grating spectral instruments. ... In scanning Fourier spectrometer optical and electric modulation of signal is used to avoid this problem, for static Fourier spectrometer there are no such ways. ...

... Bojan Nikolic web pages (r. 329) . ALMA . ... These errors are due to the refractive effects of the Earth?s atmosphere, specifically due to the (tropospheric) water vapour. ... Making use of information on baselines this long will require very accurate calibration and correction of atmospheric phase errors. ... The design of the ALMA phase correction system is summarised in Nikolic et al 2013 . Introduction to phase correction for ALMA . ALMA Goals . ALMA Phase correction strategy . ...

Saturation is a common problem for narrow band filter images of galaxy nuclei. Often the surface brightness of the emission line is estimated from ground-based images with 1 " resolution; sometimes line fluxes are quoted for apertures several arcseconds in radius. However, at HST resolution, much of this flux may occur in a single unresolved spot at the galaxy nucleus, thus leading to saturated images. ... Voice: (410) 338-1082 . ...

... Galaxies 99 Cosmic background with model of cloudy interstellar medium Yu. ... Figure 1: Averaged spectrum of the cosmic background I f in frequency range 0.25 200 MHz for the Galactic poles. ... First interpretation of the cosmic noise background spectrum at broad band frequency range 0.25 200 MHz with a model of the cloudy interstellar medium ISM is presented here. ... Synthesized background spectra I f for regions of the Galactic poles at the frequency range 0.25 200 MHz is presented in Fig. ...

... R-band images obtained at 0.8 arcsec seeing conditions have allowed us to separate foreground star from point-like extragalactic source and estimate their brightness separately. ... To study the nature and properties of the source, we observed it under high spatial resolution. ... CONCLUSION RTT150 optical observations with sub-arcsecond seeing and low resolution spectra confirm the hypothesis of superposition of a radio source onto a `normal' F/G galactic star proposed by [1]. ...

... Science Users Information > Science Publications > Science Announcements > Improvement to FLAMES Spectral Resolution and Sensitivity . ... The FLAMES GIRAFFE spectrograph is not kept at a controlled temperature, and thus, at the beginning of every observing block, GIRAFFE is re-focussed to take account of collimator temperature. ... The updated values lead to a substantial increase in spectral resolution and sensitivity across all settings, particularly for the high resolution ( HR ) settings. ...

The neutral hydrogen structure at high galactic latitude . ... Angular structure of the interstellar HI emission at 21 cm was investigated on the declinations of +5 degree, +16 dg., +27.5 dg., +39 dg. and +50 dg. in the R.A. range of 10 h to 16 h (galactic latitudes from 45 dg to 90 dg) with the help of RATAN-600 radio telescope with mean angular resolution 2.0'x 20'. ... Angular power spectrum of interstellar HI emission was computed with standard FFT code and smoothed over 1 h along R.A. (figure 1). ...

... Thus all regions of the 0.94-2.50 micron wavelength range accessible from Mauna Kea can be recorded using five fixed angle gratings. ... Grating Angle . ... Efficiencies for the NIFS gratings are shown above. The NIFS spectrograph uses a Bouwers collimator and a refractive camera. ... With these assumptions, the NIFS system efficiency including the Gemini telescope optics but excluding the transmission of the adaptive optics system is about 0.17 e - /photon at J , and 0.22 e - /photon at H and K . ...

Swift/ XRT radiation damage and results from the lab using a proton-damaged CCD Claudio Pagani (Swift/ XRT team) XMM Calibration Meeting, Leicester, 7/3/2012 XRT CCD e2v CCD -22 detector (developed for EPIC MOS camera on XMM) Operated in Photon Counting (PC) and Windowed Timing (WT) mode 4 55Fe corner sources continuously illuminate CCD corners, used to monitor CCD performance Spectral resolution at launch: FWHM = 135 eV at Mn K- (5.9 ...

... Aloisi, A. The Old Stellar Population . Alonso-Herrero, A. HST /NICMOS Observations of the . ... Balcells, M. HST-NICMOS Observations of Galactic . ... Baum, S.A. Investigating the Evolution of . ... Becklin, E.E. A Coronagraphic Search for . ... Clampin, M. The Old Stellar Population . ... Close, L. HST NICMOS Observations of . ... The Stellar Population in . Geballe, T.R. HST NICMOS Observations of . ... Greggio, L. The Old Stellar Population . ... Leitherer, C. The Old Stellar Population . ...

Next: Analysis Tools for Nebular Emission Lines . ... Extracting spectra from a large number of NICMOS grism images requires a convenient interactive tool which allows a user to manipulate direct/grism image pairs. ... The direct image is used to locate objects of interest, to find the position of the appropriate spectra in the grism image, to determine the optimal extraction technique to use, and to calibrate the wavelength range of the extracted spectra. ... Figure 1: The NICMOSlook User Interface . ...

... BLoCXS is a Bayesian code that uses Markov-Chain Monte Carlo and Data Augmentation techniques to analyze CCD-resolution X-ray spectra in the Poisson regime. BLoCXS can be used to . fit common emission models to low-counts spectra . identify narrow emission lines in low-resolution spectra . identify Gaussian emission lines (with fixed/unknown location and width) . compute profile posterior distributions, . simulate data from posterior predictive distributions, . ...

Superconducting Integrated Submm Spectrometer for Laboratory Applications Specification: · Input frequency range : 200 ­ 700 GHz (covered by four exchangeable sensor modules each one covering range of about 100-150 GHz ); · Output frequency (IF) range : 1-2 GHz · Receiver noise temperature: below 500 K (direct ... The SIR chip is a superconducting integrated circuit comprising a quantum-noise-limited SIS mixer and a tunable Josephson local oscillator (LO). ...

Next: Structure of the Galaxy Up: Model of the Galaxy Previous: Model of the Galaxy . As discussed above (Section  6 ), galactic binary systems are assumed to be distributed logarithmically along their semi-major axis A (Abt and Levy, 1976[ 2 ]), . ... Figure 40: Number of binary stars per frequency decade. ... As the observed distribution of binary periods is flat (equation ( 15.3.1 )), the normalization constant is the total number of galactic binaries per frequency decade: . ...

... High-resolution Herschel spectroscopy reveals the proto-planetary disk around the young star T Tau N . ... A study led by Linda Podio ( AstroFIt fellow at the Arcetri Observatory) with Inga Kamp (Kapteyn Institute, the Netherlands), Claudio Codella (Observatory of Arcetri) and other collaborators from Grenoble, UK and USA, makes use of high-resolution spectroscopic observations with HIFI on board the Herschel space observatory to characterize the disk around the young star T Tau N . ...