Contingut
Imatges
Carregar la teva Imatge
DSS Images Other Images
Articles Relacionats
Arcsecond Positions of UGC Galaxies
We present accurate B1950 and J2000 positions for all confirmed galaxiesin the Uppsala General Catalog (UGC). The positions were measuredvisually from Digitized Sky Survey images with rms uncertaintiesσ<=[(1.2")2+(θ/100)2]1/2,where θ is the major-axis diameter. We compared each galaxymeasured with the original UGC description to ensure high reliability.The full position list is available in the electronic version only.
| FIRBACK. I. A deep survey at 175 microns with ISO, preliminary results
FIRBACK is a deep survey conducted with the ISOPHOT instrument aboardthe Infrared Space Observatory (ISO) at an effective wavelength of 175mu m. We present here results we have obtained on the first field, theso-called Marano1 which covers around 0.25 square degree. We find thatthe source density for objects with a flux above 200 mJy exceeds thecounts expected for sources found in the IRAS deep surveys with asimilar flux by about an order of magnitude. Such an excess was expectedon the basis of the high far infrared background detected with the FIRASand DIRBE instruments aboard the Cosmic Background Explorer (COBE).These sources are likely to be redshifted infrared galaxies. The steepnumber counts indicate strong cosmological evolution in this population.The detected sources account for only 10 % of the cosmic IR background.An extrapolation of the counts down to about 10 mJy would be needeed toaccount for the whole background at this wavelength.
| An image database. II. Catalogue between δ=-30deg and δ=70deg.
A preliminary list of 68.040 galaxies was built from extraction of35.841 digitized images of the Palomar Sky Survey (Paper I). For eachgalaxy, the basic parameters are obtained: coordinates, diameter, axisratio, total magnitude, position angle. On this preliminary list, weapply severe selection rules to get a catalog of 28.000 galaxies, wellidentified and well documented. For each parameter, a comparison is madewith standard measurements. The accuracy of the raw photometricparameters is quite good despite of the simplicity of the method.Without any local correction, the standard error on the total magnitudeis about 0.5 magnitude up to a total magnitude of B_T_=17. Significantsecondary effects are detected concerning the magnitudes: distance toplate center effect and air-mass effect.
|
Enviar un nou article
Enllaços Relacionats
- - No s'ha trobat enllaços -
Enviar un nou enllaç
Membre dels grups següents:
|
Dades d'Observació i Astrometria
Catàlegs i designacions:
|
