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The AMIGA sample of isolated galaxies. V. Quantification of the isolation
Context: The AMIGA project aims to build a well defined andstatistically significant reference sample of isolated galaxies in orderto estimate the environmental effects on the formation and evolution ofgalaxies. Aims: The goal of this paper is to provide a measure of theenvironment of the isolated galaxies in the AMIGA sample, quantifyingthe influence of the candidate neighbours identified in our previouswork and their potential effects on the evolution of the primarygalaxies. Here we provide a quantification of the isolation degree ofthe galaxies in this sample. Methods: Our starting sample is theCatalogue of Isolated Galaxies (CIG). We used two parameters to estimatethe influence exerted by the neighbour galaxies on the CIG galaxy: thelocal number density of neighbour galaxies and the tidal strengthaffecting the CIG galaxy. We show that both parameters together providea comprehensive picture of the environment. For comparison, thoseparameters have also been derived for galaxies in denser environmentssuch as triplets, groups and clusters. Results: The CIG galaxies show acontinuous spectrum of isolation, as quantified by the two parameters,from very isolated to interacting. The fraction of CIG galaxies whoseproperties are expected to be influenced by the environment is howeverlow (159 out of 950 galaxies). The isolated parameters derived for thecomparison samples gave higher values than for the CIG and we foundclear differences for the average values of the 4 samples considered,proving the sensitivity of these parameters. Conclusions: Theenvironment of the galaxies in the CIG has been characterised, using twocomplementary parameters quantifying the isolation degree, the localnumber density of the neighbour galaxies and the tidal forces affectingthe isolated galaxies. A final catalogue of galaxies has been producedand the most isolated of these galaxies are consequently appropriate toserve as a reference sample for the AMIGA project.Full Tables [see full text], [see full text] and [see full text]-[see full text] are available in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/472/121 and fromhttp://www.iaa.es/AMIGA.html.
| The AMIGA sample of isolated galaxies. III. IRAS data and infrared diagnostics
Aims.We describe the mid- (MIR) and far- (FIR) infrared properties of alarge (~1000) sample of the most isolated galaxies in the localUniverse. This sample is intended as a "nurture-free" zero point againstwhich more environmentally influenced samples can be compared. Methods: We reprocess IRAS MIR/FIR survey data using the ADDSCAN/SCANPIutility for 1030 out of 1050 galaxies from the Catalogue of IsolatedGalaxies (CIG) as part of the AMIGA project. We focus on diagnostics(FIR luminosity L_FIR, R=log(L_FIR/LB), and IRAS colours)thought to be sensitive to effects of environment or interaction. Results: The distribution of log(L_FIR) sharply peaks from 9.0-10.5,with very few (<2%) galaxies above 10.5. Review of available opticalimages of the most FIR luminous galaxies finds the majority likely to beinteracting systems missed in our earlier morphological reevaluation.The optically normalised luminosity diagnostic R=log(L_FIR/LB) shows a sharply peaked distribution between 0.0and -1.0. These results were compared to the magnitude limited sample ofthe Center for Astrophysics that was selected without environmentaldiscrimination. This modestly (e.g., compared to cluster, binary galaxy,and compact group samples) environmentally affected sample shows asignificantly higher mean log(L_FIR), and R, whereas the meanlog(LB) is the same. Our sample shows a strong L_FIR vs.LB correlation, with a slope steeper than one (L_FIR ∝LB1.41). Interacting galaxies were found abovethis correlation, showing an enhancement in L_FIR. With respect to theIRAS colours, we found higher F_60/F_100 values for ellipticals andlate-type galaxies than for spirals, indicating a higher dusttemperature. The mean value of F_60/F_100 was found to be lower than forinteracting samples from the literature. Conclusions: .The resultsindicate that the FIR emission is a variable enhanced by interaction,and that our sample probably shows the lowest possible mean value. Thisattests to the utility of our sample for defining a nurture-free zeropoint.
| The AMIGA sample of isolated galaxies. II. Morphological refinement
We present a refinement of the optical morphologies for galaxies in theCatalog of Isolated Galaxies that forms the basis of the AMIGA (Analysisof the interstellar Medium of Isolated GAlaxies) project. Uniformreclassification using the digitized POSS II data benefited from thehigh resolution and dynamic range of that sky survey. Comparison withindependent classifications made for an SDSS overlap sample of more than200 galaxies confirms the reliability of the early vs. late-typediscrimination and the accuracy of spiral subtypes within Δ T =1-2. CCD images taken at the Observatorio de Sierra Nevada were alsoused to solve ambiguities in early versus late-type classifications. Aconsiderable number of galaxies in the catalog (n = 193) are flagged forthe presence of nearby companions or signs of distortion likely due tointeraction. This most isolated sample of galaxies in the local Universeis dominated by two populations: 1) 82% are spirals (Sa-Sd) with thebulk being luminous systems with small bulges (63% between types Sb-Sc)and 2) a significant population of early-type E-S0 galaxies (14%). Mostof the types later than Sd are low luminosity galaxies concentrated inthe local supercluster where isolation is difficult to evaluate. Thelate-type spiral majority of the sample spans a luminosity rangeMB-corr = -18 to -22 mag. Few of the E/S0 population are moreluminous than -21.0 marking the absence of the often-sought superL* merger (e.g. fossil elliptical) population. The rarity ofhigh luminosity systems results in a fainter derived M* forthis population compared to the spiral optical luminosity function(OLF). The E-S0 population is from 0.2 to 0.6 mag fainter depending onhow the sample is defined. This marks the AMIGA sample as unique amongsamples that compare early and late-type OLFs separately. In othersamples, which always involve galaxies in higher density environments,M^*_E/S0 is almost always 0.3-0.5 mag brighter than M^*_S, presumablyreflecting a stronger correlation between M* andenvironmental density for early-type galaxies.
| The Second Byurakan Survey. General Catalogue
The Second Byurakan Survey (SBS) General Catalogue is presented. TheSBS, a continuation of the Markarian survey reaching fainter limitingmagnitudes, is the first survey which combines the search of galaxiesand QSOs. A total area of 991OS#square;degrees of the Northern sky wascovered with the use of three objective prisms in combination withSchott filters. The limited magnitude on the best plates reached B ~19.5.The General Catalogue consists of 3563 objects presented in two parts: aCatalogue of galaxies (1863 objects) and one of stellar objects (1700objects). The Catalogue of SBS AGN consists of 761 objects (155 SyG, 596QSOs, and 10 BLLac). Multi-wavelength data are presented for 1438 SBSobjects identified with X-ray, IRAS and FIRST sources.Spectrophotometric observations obtained over 26 years are available for3132 objects. Redshifts were measured for ~ 2100 extragalactic objects.Spectral classification is presented for ~ 2970 objects. The majority ofthe data is presented here for the first time. The Catalogue presentsnew large homogeneous deep representative complete samples of brightQSOs, AGNs, and faint UVX galaxies in the Northern sky. The SBS sampleis found to be complete at 70% for galaxies and ~ 85% for AGN/QSOs withB ≤ 17.5.
| Revised positions for CIG galaxies
We present revised positions for the 1051 galaxies belonging to theKarachentseva Catalog of Isolated Galaxies (CIG). New positions werecalculated by applying SExtractor to the Digitized Sky Survey CIG fieldswith a spatial resolution of 1 arcsper 2. We visually checked theresults and for 118 galaxies had to recompute the assigned positions dueto complex morphologies (e.g. distorted isophotes, undefined nuclei,knotty galaxies) or the presence of bright stars. We found differencesbetween older and newer positions of up to 38 arcsec with a mean valueof 2 arcsper 96 relative to SIMBAD and up to 38 arcsec and 2 arcsper 42respectively relative to UZC. Based on star positions from the APMcatalog we determined that the DSS astrometry of five CIG fields has amean offset in (alpha , delta ) of (-0 arcsper 90, 0 arcsper 93) with adispersion of 0 arcsper 4. These results have been confirmed using the2MASS All-Sky Catalog of Point Sources. The intrinsic errors of ourmethod combined with the astrometric ones are of the order of 0 arcsper5.Full Table 1 is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/411/391
| Accurate optical positions for 2978 objects from the Second Byurakan Survey (SBS) with the Digitized Sky Survey
Optical positions of 2978 objects listed in the Second Byurakan Survey(SBS) were obtained using the Digitized Sky Survey (DSS), and are givenwith an rms uncertainty ~ 1 arcsec in each coordinate. Tables 1 and 2are only available in electronic form at the CDS via anonymous ftp130.79.128.5 or via http://cdsweb.u-strasbg.fr/Abstract.html
| 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.
| 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.
| Accurate optical positions for 110 Byurakan objects and 24 blue stars from the 'Second Byurakan Spectral Sky Survey (II)'
Abstract image available at:http://adsabs.harvard.edu/abs/1990AJ....100.1028S
| High-redshift radio galaxies from the Molonglo Catalogue
Radio and optical observations of a sample of southern hemisphere radiogalaxies, selected from the 408 MHz Molonglo Reference Catalogue, arediscussed. The sample is defined by means of two criteria: fluxdensities greater than 0.9 Jy and low-frequency spectral indices steeperthan -0.9. From the initial sample of 700 sources, 150 combine the bestcharacteristics of the 1 Jy and ultrasteep samples. It is suggested thatthese sources can be used to find galaxies at large redshift and explorethe properties of galaxies at extreme luminosities and early epochs. VLA6 cm maps and optical identifications of 13 sources are presented.Eleven of the sources have extended optical structures with morphologiescharacteristic of high-redshift (z greater than 0.8) radio galaxies.
| The Second Byurakan Sky Survey - Spectra of Galaxies - Part Three
Not Available
| A 21 CM survey of the Pisces-Perseus supercluster. III - The region north of +38 degrees
As part of a comprehensive survey of galaxies in the region of thePisces-Perseus supercluster and its surroundings, 21-cm lineobservations obtained with the NRAO 91-m telescope are presented for 383galaxies in the right ascension range from 22 to 10 hr and north of +38deg declination. Recent improvements to the Green Bank receiver/feedsystem have dramatically raised detection rates at the distance ofPisces-Perseus (cz = +5000 km/s). The present study has contributed todouble the number of known redshifts outside rich clusters in thissection of the sky. The H I content of the current sample, as expressedin terms of the H I mass expected for a galaxy of the same optical sizeand morphology, matches the standard of normalcy established forisolated galaxies.
| Second Byurakan spectral sky survey. II - Results for region centered on alpha = 09h50m, delta = +55 deg 00 arcmin
The second list of objects in the Second Biurakan Spectral Sky Survey ofthe region centered on alpha = 09h50m, delta = +55 deg 00 arcmin isgiven. The list contains data on 110 objects and galaxies of a peculiarphysical nature and 24 blue stars. The observations were made with the40-52 arcsec Schmidt telescope of the Biurakan Astrophysical Observatorywith a set of three objective prisms using Kodak IIIaJ and IIIaFemulsions sensitized in nitrogen. The area is found to contain 20 quasarcandidates and four Seyfert galaxies, 27 blue stellar objects, 24galaxies with an appreciable ultraviolet continuum, and 39 emissiongalaxies without appreciable ultraviolet radiation. The surfacebrightness of the quasars and Seyferts on the considered area down tothe limiting magnitude 19.5 M is more than 1.5 per square degree withallowance for the already known quasars. The surface density of emissiongalaxies is about four per square degree.
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