Declination Zone Research Articles

The Parkes 2700 MHz Survey (Tenth Part). Supplementary Catalogue for the Declination Zone +4° to +25°

A catalogue of lSI radio sources is presented covering the declination zone +4� to +25� and all right ascensions, omitting two regions within approximately 10� of the galactic plane (R.A. 05h30'" to 07ho()m and R.A. lShOO'" to 2Oh30"'). The catalogue was compiled from a 'fast' finding survey at 2700 MHz aimed at detecting sources stronger than o� 5 Jy. Subsequently, measurements of accurate flux density and position were made on all the sources which were not in the Parkes 40S MHz catalogue and on a few sources in the 40S MHz catalogue for which only data of low accuracy were available. The' positions of sources were determined to an accuracy of 10" arc r.m.s. in both coordinates. Flux densities for most of the sources were also measured at 5009 MHz. Identifications are suggested for 17 galaxies and 62 quasi-stellar objects.

The Parkes 2700 MHz Survey (Eighth Part). Catalogue for the Declination Zone ?65° to ?75°

A catalogue of 515 radio sources is presented for the region between declinations -65� and -75� (0�374sr). The survey is believed to be complete to 0�22Jy at 2700 MHz (-'900 sources per steradian). Flux densities at 5009 MHz have been measured for most of the sources stronger than o� 35 Jy at 2700 MHz.

The Parkes 2700 MHz Survey (Ninth Part). Supplementary Catalogue for the Declination Zone ?45° to ?65°

A catalogue of 166 radio sources is presented, covering an area of 0�63 sr with right ascensions 0Qh to 03h, 04h to OSh 30"', 17h 30'" to 19h and 20b to 23h between declinations -45� and - 65�. The regions omitted are either close to the galactic plane (OSh 30'" to 17h 30"') or are covered in the third part of the Parkes 2700 MHz survey. The catalogue was compiled from a 'fast' finding survey at 2700 MHz aimed at detecting sources stronger than o� 5 Jy. Subsequent measurements at 2700 and 5009 MHz of flux density and position were made for all sources which were not in the Parkes 40S MHz catalogue and for 42 sources in the 40S MHz catalogue for which only data of low accuracy were available.

The Ohio Survey: VI

view Abstract Citations (55) References (36) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Ohio Survey: VI. Ehman, J. R. ; Dixon, R. S. ; Ramakrishna, C. M. ; Kraus, J. D. Abstract A 1415 MHz continuum survey with the Ohio State University 110 by 21-m radio telescope has been made between declinations of 0 and 40 deg North and between 25 and 31 deg South covering 8190-sq deg of sky. This is the sixth installment of the Ohio Survey. It fills large gaps in some of the declination zones of the five previously published installments of the survey. There are 81 maps of the regions surveyed and a list of 5955 sources at or above 0.18 flux units. Of these sources, 3060 are previously uncataloged. The six installments include a total of 17,110 sources in 7.70 steradians of sky. Results of a Monte Carlo analysis to determine the errors in flux density and position are presented. Publication: The Astronomical Journal Pub Date: February 1974 DOI: 10.1086/111543 Bibcode: 1974AJ.....79..144E Keywords: Astronomical Catalogs; Astronomical Maps; Radio Astronomy; Tables (Data); Astronomical Coordinates; Contours; Error Analysis; Monte Carlo Method; Position Errors; Radio Telescopes; Astronomy full text sources ADS | data products NED (2) SIMBAD (1)

The Parkes 2700 MHz Survey (Sixth Part). Catalogue for the Declination Zone ?30° to ?35°

This paper presents a catalogue of 939 extragalactic radio sources obtained from a sky survey at 2700 MHz. The area surveyed is between declinations - 30� and - 35�, nd covers all right ascensions except for two regions within approximately 10� of the ga

X-ray Cluster of Galaxies Identified in Error Box 2U2358-29

THE identification of Uhuru X-ray sources1 with rich clusters of galaxies is simple for sources in the northern hemisphere. Zwicky's cluster catalogues2 extend southward to a declination of −2° and Abell's cluster catalogue3 extends to a declination of −27°. The X-ray coincidences with these clusters are listed in the Uhuru catalogue and discussed elsewher4–6. Here I report the results of search for rich nearby clusters of galaxies located in those Uhuru error boxes (for 90% positional confidence) which lie in the declination zone −27°≥dec.≥−45°. The prints used in the search are from the Whiteoak 1964 extension of the Palomar Sky Survey.

Australian Journal of Physics Astrophysical Supplement

A series of observations to determine the spectra of sources in the �4� declination zone of the Parkes 2700 MHz survey is described. The observations have yielded flux densities for 370 sources at 5009 MHz, 300 sources at 1403 and 468 MHz, and 450 sources at 635 MHz, while additional flux densities for many of the sources have been obtained from published measurements from other observatories. Spectral data have also been tabulated for some of the sources found in the Parkes 2700 MHz deep surveys of selected regions. The spectra of a number of the sources are illustrated and discussed. Several of the sources appear to be variable at high frequencies.

2700 MHz Observations of 4C Radio Sources in the Declination Zone +4° to ?4°

Most sources in the 40 catalogue with declinations between +4� and _4� have been observed at 2700 MHz. Accurate positions, flux densities, and the results of a search for optical identifications are presented. A brief comparison is made with results from other investigations.

Two Infrared Sources in Nebulae

IN a systematic survey of the Caltech infrared catalogue (IRC)1, 210 of the 5612 listed sources have been examined optically using the prints of the National Geographic Society–Palomar Observatory sky survey. Several criteria were adopted in the selection of sources for optical examination. Objects were first selected for which no previous identification was listed on the basis of comparison with star catalogues, and which further were very red as indicated by their I (0.84 µm) minus K (2.2 µm) colour index. The reddest sources among these have (I − K) ≥ 6m.00 and all such cases were examined, whereas for the moderately red objects ((I − K) ≳ 4m.00) only sources at high galactic latitude (|bII| ≥ 40°), or lying in the +40° declination zone of the two micron survey, or located near stellar rings2, were inspected. During the work, a number of infrared stars of (I − K) ≳ 4m.00 but catalogued as belonging to spectral class B were also located. Examination of the sky survey prints revealed that the infrared object, in sixteen cases out of twenty investigated, was a fainter, very red star lying near the class B star in question. Some further named stars in the catalogue whose right ascension and declination offsets relative to the infrared source exceeded ∼ 6 s and/or ∼1′.2 were also examined, and again in nine cases out of fourteen a more satisfactory identification was made. On the basis of this admittedly small sample of stars with large offsets, it is suggested that such errors of identification may number about 100 stars throughout the catalogue, or about 2 per cent of the total.

Progress with a General Catalogue of Positions and Absolute Proper Motions Based on AGK 2, AGK 3 and the Astrographic Catalogue as Sources of Data

In Hamburg we have the catalogue AGK 3 and a revised AGK 2 for the declination zones +1° to +18°, +24° to +89° on magnetic tapes, in manuscript and on punched cards. The remaining zones are in preparation. At the present time (March 1970) the catalogue, on account of some deficiencies, is not in the proper shape for a universal publication. A. Günther and H. Kox (1970) since 1967 investigated the zones Greenwich, Rome-Vatican, Catania and Helsingfors of the Astrographic Catalogue (AC) using the AGK 2/3 data as source for reference stars’positions. The original rectangular coordinates x, y for each of the plates together with AGK2 numbers are on tapes. By applying the systematic corrections derived by Günther and Kox and by using the new, definitive plate constants derived in course of the work on the AC-zones the x, y can be transformed into spherical coordinates reffered to the equinox 1950.0 and in the FK4 system. This was done in the last few months, and arithmetic means were produced for the individual stars with AGK 2 numbers for reference number. Simultaneously the mean square errors (mse) were derived when two or more plates went into the means. Table 1 gives values for average values of the mse, as an example for always two observations.

Quasi-Stellar Objects in the Parkes 2700 MHz Survey: The Selected Regions and the ±4° Declination Zone

One hundred and thirty�two quasi�stellar objects or possible quasi.stellar objeots have been found in the first areas of the Parkes 2700 MHz survey. Identifi� oations for 36 of these have a.1ready been published and 67 have been oonfirmed by spectrosoopy or two�oolour photography. Relationships between the various radio and optioa.l pa.ra.meters are briefly disoussed.

Status of the international efforts to improve the catalogues of positions and motions of stars to the 9th magnitude

view Abstract Citations (6) References (2) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Status of the international efforts to improve the catalogues of positions and motions of stars to the 9th magnitude Scott, F. P. Abstract All observations of the northern reference stars have been completed and the compilation of a catalogue of their positions is in progress at the U. S. Naval Observatory. Observations of the southern reference stars are in progress at some, but not at all, of the observatories committed to the program. The photographic plates for the northern sky taken at the Hamburg-Bergedorf Observatory are now being reduced and proper motions are being computed. The Cape Observatory has taken the plates for the declination zone -40 to -52 and has started their reductions. The photographs of the zone 300 to -40 are now in progress. The distribution of the southern reference stars by magnitude, spectral type, and by plate is given. Publication: The Astronomical Journal Pub Date: June 1967 DOI: 10.1086/110271 Bibcode: 1967AJ.....72..570S full text sources ADS |

Identification Of Extragalactic Radio Sources Between Declinations 0° And +20°

Identifications or suggested identifications are given for 138 extragalactic radio sources in the declination zone 0� to +20�. The identifications are based on a search of the Palomar Sky Survey plates in the positions of sources in the Parkes catalogue. Forty-two of the identifications are with quasi. stellar objects or suggested quasi-stellar objects and the remainder with galaxies. The radio luminosity distribution and a possible variation in the identification percentage with galactic latitude are discussed.

RADIO SOURCES, GALAXIES, AND CLUSTERS OF GALAXIES

The identification of radio sources at high galactic latitudes has progressed to a stage at which it is possible to make the first tentative attempts at a statistical exploration of the results. The identification of the source 3C 48 shows that galactic sources may occur at high galactic latitudes, but the results of the determination of diameters of sources support the generally accepted assumption that most sources at high galactic latitudes are extragalactic. The great majority of the extragalactic objects with which sources have been identified seem to be completely normal; they show no features which mark them as peculiar in any manner, either in their appearance or in their spectra where these are available. This is in sharp contrast to the early identifications, most of which pointed to highly peculiar objects. Most of the identifications thus are not supported by peculiarities of the objects, but rest entirely on positional coincidence. In this case, an identification with a given object is accepted if the statistical chance is small that the object is accidentally within the error area. If e2 is the error area of a position and n(mp) the number per unit area of relevant objects that are brighter than the photographic magnitude mp, the statistically expected number of objects brighter than m, in the error area is e2n(mp). This number represents the chance that an identification is spurious. The policy of all investigators has been essentially to set the limit m, for the search for identifications so that the chance of a spurious identification is less than 0.1. For bright objects, the chance is much smaller. The total fraction of spurious identifications should not be larger than a few per cent. If sound statistical conclusions are to be derived, it is desirable to use data that refer to a defined volume. The data are too limited for such a treatment if different types of objects are separated. But it is possible to compile lists of identifications which refer to a defined area in the sky in which the identifications may be assumed to be complete for all sources above a definite limiting radio magnitude. Two such lists have been prepared:' one from sources of the survey at 86.5 Me/sec by Mills, Slee, and Hill2 (MSH survey), the other from the 3C survey at 159 Me/sec by Ryle's group.3 A list of tentative identifications for the declination zone -20? to +10? of the MISH survey has been given by Mills.4 This list has been revised after investiga-

A Catalogue of Radio Sources Between Declinations ?20° and ?50°

A catalogue has been prepared of the radio sources observed between declinations _200 and _500 , using the Sydney cross-type radio telescope at a wavelength of 3�5 m ; a total of 892 sources is listed. This supplements an earlier catalogue in the declination zone + 10� to _20�. In addition to the positions and intensities of the sources, angular sizes of 50 of the strongest are given: several are found to have a size less than 15" arc. As before, identifications with bright optical objects have been sought, and a number of galaxies of apparently abnormal radio emission listed. Statistical analyses of the distribution of the radio sources give results very similar to those obtained using the earlier catalogue. \Vithin the uncertainty in the data, the distribution appears uniform in depth and there is a siguificantly greater number of sources of large apparent size than expected from chance blending effects.

The zero-point in stellar photometry

The accuracy achieved in modern photo-electric photometry requires a revision of the problem of the zero-point. The author proposed to determine fundamental magnitudes of A and K stars of sixth magnitude in the neighbourhood of Selected Areas. Photo-electric observations were carried out in 1951–1953 at the Wroclaw and Białków Observatories in the declination zones + 75° and + 60°. A new method for the determination of extra-atmospheric magnitudes has been outlined.

Graphic Catalogue Paris

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Graphic Catalogue Paris Heckmann, O. ; Dieckvoss, W. ; Kox, H. Abstract . New plate constants are given for the declination zones + 21 , + 22 , + 23 , and + 24 of the Paris A stro- graphic Catalogue. These have been obtained by using positions of reference stars derived with the aid of positions of the AGKI (zone Berlin B) and AGK2, by a procedure developed and tested in 1947-48. Publication: The Astronomical Journal Pub Date: May 1954 DOI: 10.1086/106974 Bibcode: 1954AJ.....59..143H full text sources ADS |

The Radial Velocities of Faint Class B Stars in the Declination Zone 0° to -23°.

The Radial Velocities of Faint Class B Stars in the Declination Zone 0° to -23°.

Investigations on Proper Motion

view Abstract Citations (6) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Investigations on Proper Motion Oosterhoff, P. Th. Abstract Proper mctions of faint s2ars.-Examination of plates taken at intervals of about twenty-one years on 97 Selected Areas, including the - 15° declination zone, revealed 651 stars having proper motions between O~O~O and o'~726. By comparison with the Radcliffe Catalogue the probable error of a motion was found to be ±o'~oII. The per- centage of stars having proper motions larger than 0'~049 increases from o. 29 for galactic regions to 2.60 for high galactic latitudes. The amount of the mean motion decreases with magnitude, though for stars fainter than the thirteenth magnitude it remains constant. The antapex determined by Airy's method from the proper motions given in this paper and in Mt. Wilson Conir. No. 412 is A = ~ D= -4I~4. Mean parallaxes were computed for different groups of magnitude and proper motion by formulae given by van Maanen and Willis and by Seares. The discussion of the material is provisional, since the effects of selection have not been fully taken into account. A list of i6 variable stars found during this investigation is added Publication: The Astrophysical Journal Pub Date: May 1936 DOI: 10.1086/143730 Bibcode: 1936ApJ....83..340O full text sources ADS | data products SIMBAD (14)