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|The ISOPHOT 170 μm Serendipity Survey II. The catalog of optically identified galaxies%|
The ISOPHOT Serendipity Sky Survey strip-scanning measurements covering≈15% of the far-infrared (FIR) sky at 170 μm were searched forcompact sources associated with optically identified galaxies. CompactSerendipity Survey sources with a high signal-to-noise ratio in at leasttwo ISOPHOT C200 detector pixels were selected that have a positionalassociation with a galaxy identification in the NED and/or Simbaddatabases and a galaxy counterpart visible on the Digitized Sky Surveyplates. A catalog with 170 μm fluxes for more than 1900 galaxies hasbeen established, 200 of which were measured several times. The faintest170 μm fluxes reach values just below 0.5 Jy, while the brightest,already somewhat extended galaxies have fluxes up to ≈600 Jy. For thevast majority of listed galaxies, the 170 μm fluxes were measured forthe first time. While most of the galaxies are spirals, about 70 of thesources are classified as ellipticals or lenticulars. This is the onlycurrently available large-scale galaxy catalog containing a sufficientnumber of sources with 170 μm fluxes to allow further statisticalstudies of various FIR properties.Based on observations with ISO, an ESA project with instruments fundedby ESA Member States (especially the PI countries: France, Germany, TheNetherlands and the UK) and with the participation of ISAS and NASA.Members of the Consortium on the ISOPHOT Serendipity Survey (CISS) areMPIA Heidelberg, ESA ISO SOC Villafranca, AIP Potsdam, IPAC Pasadena,Imperial College London.Full Table 4 and Table 6 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (220.127.116.11) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/422/39
|Evolutionary scenario for metal-poor pulsating stars. I. Type II Cepheids.|
Pulsating convective models and evolutionary tracks are used toconstrain mass, luminosity, and effective temperature of metal-poor (Zin the range of 0.0001 to 0.001) low-mass(0.52Msun_-0.80Msun_) fundamental pulsatorsconnected with the horizontal branch and asymptotic branch phase. Onthis basis the fundamental period P(F) and the absolute blue magnitude Bof the pulsators are calculated. We show that, by scaling the bluemagnitude of the pulsator to the value B(3.83) of the zero agehorizontal branch at the mean effective temperature of the RR Lyraestrip (logTe=3.83), the distribution of theoretical fundamentalpulsators in the B(3.83)-B vs P(F) plane is independent of metallicity.The limits of this distribution, which depend on the adopted edges ofthe instability strip, conform well with data of known type II Cepheidsand show that these variables are fundamental pulsators with mass in therange of 0.59Msun_ to 0.52Msun_. Moreover, sincefor fundamental pulsating models there is a linear correlation of theblue magnitude with period and blue amplitude A(B), we are able topredict that the period-luminosity-blue amplitude relation for type IICepheids with P<=15days is B(3.83)-B=-0.12+1.39logP+0.57A(B). Thecomparison with the theoretical evolutionary tracks yields that the massof type II Cepheids decreases with increasing the period and that thebrightest variables with P>=10days should likely belong to the veryrapid phases of the 0.52Msun_ and 0.53Msun_evolution. The agreement between observations and calculatedexpectations turns out to be almost satisfactory, suggesting that thepulsational and evolutionary scenario is capable to match the propertiesof metal-poor pulsating stars.
|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.
|H I 21 centimeter observations and I-band CCD surface photometry of spiral galaxies behind the Virgo Cluster and toward its antipode|
Sample selection, radio and optical data acquisition and reduction, andobservation results are presented for spiral galaxies behind the VirgoCluster and toward its antipode. I-band CCD photometry was obtained forall the bright galaxies and part of the sample of faint galaxies in thetwo local volumes was studied. The statistical properties of the galaxysamples are discussed.
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