... 88, Jan. 1983, p. 1-15. l. A survey of extragalactic radio sources made using driven declination scans is reported covering an area of about 0.07 sr to a limiting flux density of 35 mJy. The fast-scan survey was carried out at a galactic latitude greater than 17 deg with the NRAO 91-m telescope operating at 4.755 GHz, and the 480 sources detected were reobserved at 1.4 GHz with the National Astronomy and Ionosphere Center 305-m telescope at Arecibo. ...

Since the 1980s VLBI observations at two frequencies, 8.4 (X-band) and 2.3 GHz (S-band) have been used to locate the positions of compact radio sources with unprecedented accuracy. ... Observations of selected strong compact extragalactic radio sources, using this now mature technique, have been used to define and maintain a radio reference frame with sub-milli-arcsecond (mas) precision. ... Additionally, it will provide more reference sources for phase referencing VLBI observations. ... References . ...

... A comparison of the computed and experimental relations F max ( H), as well as comparison of drift scans of point sources across different horizontal cross-sections of the BP with the corresponding computed cross-sections were made. ... The drift scans of the point source 3С84 (H=87 o ) at the wavelength 7.6 cm across the horizontal cross-sections of the BP (black lines) and the computed horizontal cross-sections of the BP corresponding to them (red lines). ...

... 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. ...

The Arcetri Catalog contains measures and bibliographic data for all known H2O maser sources north of declination = -30 degrees (to be observable with the Medicina radiotelescope). ... This database is fully described in Cesaroni et al. ... A statistical analysis on the atlas has been carried (Palagi et al 1993). R. Cesaroni, F. Palagi, M. Felli, M. Catarzi, G. Comoretto, S. Di Franco, C. Giovanardi, F. Palla: A Catalogue of H2O maser sources north of delta=-30 , Astronomy and Astrophysics Suppl., ...

True Color Image Gallery: Galactic SNR | Magellanic Cloud SNR . ... Position of Central Source (J2000) : ( 01 27 46.0, -73 32 56.4 ) . X-ray size: point source . ... Radio Images Page . ... Exposure uf . ... 11979 . ... Exposure uf Exposure time of unfiltered event file . Exposure f Exposure time of filtered event file . only central source seen in X-rays . ... Event 2 FITS File . ... AUX file . ... see fit detail page for more about the fit. see chandra spectrum page for region used. ...

NMW survey overview . Access image archive . ... The New Milky Way survey aims to detect bright (V<13.5) optical transients near the Galactic plane using an automated wide-field (8x6 deg.) system capable of surveying the whole Milky Way area visible from the observing site in one night. ... All images obtained during the transient search survey are available online (please use the image archive access form ). ... Images per field: . ... Images per night: . ... Milky Way imaging time: . ...

... With a redshift of 2.3, the IRAS source FSC 10214+4724 is apparently one of the most luminous objects known in the Universe. ... The most straightforward interpretation is that FSC 10214+4724 is gravitationally lensed by the foreground elliptical galaxy, with the faint component a counterimage of the IRAS source. ... The background lensed source has an intrinsic luminosity , and remains a highly luminous quasar with an extremely large ratio of infrared to optical/ultraviolet luminosity. ...

Next: Comments on Individual Sources Up: Sample Identification Previous: Sample Identification . In Figure 2, we show the spectra of the optical counterparts to 85 of 97 observed X-ray/radio sources. ... Positional information for all 85 sources for which we announce identifications herein are given in Table 3, including information from WGACAT, the PMN and Green Bank surveys, the NVSS and our ATCA survey. ... Of the 85 newly identified sources, 59 are FSRQs, and 22 are BL Lacs. ...

... The derived position here agrees with the position from recent ATCA observations, RA=15h 01m 34.74s, Dec=39 18 39.2" (Tasker, private communication) which found the source unresolved. Because of the relatively large position offset, the reality of the fainter component 0.12" to the west is somewhat in doubt. However, the ATCA centroid position is offset by 0.3" to the south-east of the VLBA position, suggesting that the faint component may be part of more extended structure. ...

Lectures . ... Home Lectures Lecture Series 2010-2011 Lecture Series 2010-2011 ? Greening the Earth Using Space Resources? by Greg Matloff . ... Lecture Series 2010-2011 . ... Beyond New York City . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . ... A History of the First Forty Years of the Amateur Astronomers Association . ... Amateur Astronomers Medal . ... 2016 Amateur Astronomers Association of New York Designed by Press Customizr Powered by . ...