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The PDS versus Markarian starburst galaxies: comparing strong and weak IRAS emitter at 12 and 25 μm in the nearby Universe
The characteristics of the starburst galaxies from the Pico dos Diassurvey (PDS) are compared with those of the nearby ultraviolet (UV)bright Markarian starburst galaxies, having the same limit in redshift(vh < 7500 km s-1) and absolute B magnitude(MB < -18). An important difference is found: theMarkarian galaxies are generally undetected at 12 and 25 μm in IRAS.This is consistent with the UV excess shown by these galaxies andsuggests that the youngest star-forming regions dominating thesegalaxies are relatively free of dust.The far-infrared selection criteria for the PDS are shown to introduce astrong bias towards massive (luminous) and large size late-type spiralgalaxies. This is contrary to the Markarian galaxies, which are found tobe remarkably rich in smaller size early-type galaxies. These resultssuggest that only late-type spirals with a large and massive disc arestrong emitters at 12 and 25 μm in IRAS in the nearby Universe.The Markarian and PDS starburst galaxies are shown to share the sameenvironment. This rules out an explanation of the differences observedin terms of external parameters. These differences may be explained byassuming two different levels of evolution, the Markarian being lessevolved than the PDS galaxies. This interpretation is fully consistentwith the disc formation hypothesis proposed by Coziol et al. to explainthe special properties of the Markarian SBNG.
| Stellar populations in local star-forming galaxies - II. Recent star formation properties and stellar masses
We present the integrated properties of the stellar populations in theUniversidad Complutense de Madrid (UCM) Survey galaxies. Applying thetechniques described in the first paper of this series, we derive ages,burst masses and metallicities of the newly formed stars in our samplegalaxies. The population of young stars is responsible for the Hαemission used to detect the objects in the UCM Survey. We also infertotal stellar masses and star formation rates in a consistent way takinginto account the evolutionary history of each galaxy. We find that anaverage UCM galaxy has a total stellar mass of ~1010Msolar, of which about 5 per cent was formed in aninstantaneous burst that occurred about 5 Myr ago, and subsolarmetallicity. Less than 10 per cent of the sample shows massivestarbursts involving more than half of the total mass of the galaxy.Several correlations are found among the derived properties. The burststrength is correlated with the extinction and with the integratedoptical colours for galaxies with low obscuration. The current starformation rate is correlated with the gas content. A stellarmass-metallicity relation is also found. Our analysis indicates that theUCM Survey galaxies span a broad range in properties between those ofgalaxies completely dominated by current/recent star formation and thoseof normal quiescent spirals. We also find evidence indicating that starformation in the local Universe is dominated by galaxies considerablyless massive than L*.
| Stellar populations in local star-forming galaxies - I. Data and modelling procedure
We present an analysis of the integrated properties of the stellarpopulations in the Universidad Complutense de Madrid (UCM) Survey ofHα-selected galaxies. In this paper, the first of a series, wedescribe in detail the techniques developed to model star-forminggalaxies using a mixture of stellar populations, and taking into accountthe observational uncertainties. We assume a recent burst of starformation superimposed on a more evolved population. The effects of thenebular continuum, line emission and dust attenuation are taken intoaccount. We also test different model assumptions, including the choiceof specific evolutionary synthesis model, initial mass function, starformation scenario and the treatment of dust extinction. Quantitativetests are applied to determine how well these models fit ourmultiwavelength observations for the UCM sample. Our observations spanthe optical and near-infrared, including both photometric andspectroscopic data. Our results indicate that extinction plays a keyrole in this kind of study, revealing that low- and high-obscuredobjects may require very different extinction laws and must be treateddifferently. We also demonstrate that the UCM Survey galaxies are bestdescribed by a short burst of star formation occurring within aquiescent galaxy, rather than by continuous star formation. A detaileddiscussion on the inferred parameters, such as the age, burst strength,metallicity, star formation rate, extinction and total stellar mass forindividual objects, is presented in Paper II of this series.
| Spatial Analysis of the Hα Emission in the Local Star-forming UCM Galaxies
We present a photometric study of the Hα emission in theUniversidad Complutense de Madrid (UCM) Survey galaxies. This workcomplements our previously published spectroscopic data. We study thelocation of the star-forming knots, their intensity and concentration,and the relationship of these properties with those of the host galaxy.We also estimate that the amount of Hα emission that arises fromthe diffuse ionized gas is about 15%-30% of the total Hα flux fora typical UCM galaxy. This percentage seems to be independent of theHubble type. Conversely, we find that an ``average'' UCM galaxy harborsa star formation event with 30% of its Hα luminosity arising froma nuclear component. The implications of these results for higherredshift studies are discussed, including the effects of galaxy size andthe depth of the observations. A correlation between the star formationrate and the Balmer decrement is observed, but such correlation breaksdown for large values of the extinction. Finally, we recalculate theHα luminosity function and star formation rate density of thelocal universe using the new imaging data. Our results point out that,on average, spectroscopic observations detected about one-third of thetotal emission-line flux of a typical UCM galaxy. The new valuesobtained for the Hα luminosity density and the star formation ratedensity of the local universe are 1039.3+/-0.2 ergss-1 Mpc-3 andρSFR=0.016+0.007-0.004Msolar yr-1 Mpc-3 (H0=50 kms-1 Mpc-1, ΩM=1.0, Λ=0).The corresponding values for the ``concordance cosmology''(H0=70 km s-1 Mpc-1,ΩM=0.3, Λ=0.7) are 1039.5+/-0.2 ergss-1 Mpc-3 andρSFR=0.029+0.008-0.005Msolar yr-1 Mpc-3.
| A search for Low Surface Brightness galaxies in the near-infrared. I. Selection of the sample
A sample of about 3800 Low Surface Brightness (LSB) galaxies wasselected using the all-sky near-infrared (J, H and Ks-band)2MASS survey. The selected objects have a mean central surfacebrightness within a 5'' radius around their centre fainter than 18 magarcsec-2 in the Ks band, making them the lowestsurface brightness galaxies detected by 2MASS. A description is given ofthe relevant properties of the 2MASS survey and the LSB galaxy selectionprocedure, as well as of basic photometric properties of the selectedobjects. The latter properties are compared to those of other samples ofgalaxies, of both LSBs and ``classical'' high surface brightness (HSB)objects, which were selected in the optical. The 2MASS LSBs have aBT_c-KT colour which is on average 0.9 mag bluerthan that of HSBs from the NGC. The 2MASS sample does not appear tocontain a significant population of red objects.All tables and Figs. 2a-c are only available in electronic form athttp://www.edpsciences.org
| Optical photometry of the UCM lists I and II. II. B band surface photometry and morphological discussion
We present Johnson B surface photometry for the UCM Survey galaxies.One-dimensional bulge-disk decomposition is attempted, discussing onfitting functions and computational procedures. The results from thisdecomposition, jointly with concentration indices and an asymmetrycoefficient, are employed to study the morphological properties of thesegalaxies. We also compare our results with the previous morphologicalclassification established using Gunn r imaging data and with othersamples of galaxies. No major statistical differences in morphology arefound between red and blue data, although some characteristics such assize and luminosity concentration vary. We find a correlation betweenluminosity and size. Several parameters are used to segregate theobjects according to their morphological type. Tables 2 and 3 are alsoavailable 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/365/370
| Optical photometry of the UCM Lists I and II I. The data
We present Johnson B CCD photometry for the whole sample of galaxies ofthe Universidad Complutense de Madrid (UCM) Survey Lists I and II. Theyconstitute a well-defined and complete sample of galaxies in the LocalUniverse with active star formation. The data refer to 191 S0 to Irrgalaxies at an averaged redshift of 0.027, and complement the alreadypublished Gunn r, J and K photometries. In this paper the observationaland reduction features are discussed in detail, and the new colourinformation is combined to search for clues on the properties of thegalaxies, mainly by comparing our sample with other surveys. Tables 1and 3 are also available in electronic form at the CDS via anonymous ftpto cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html}
| Survey for Emission-Line Galaxies: Universidad Complutense de Madrid List 2
A low-dispersion objective-prism survey for low-redshift emission-linegalaxies (ELGs) is being carried out by the Universidad Complutense deMadrid with the Schmidt telescope at the German-Spanish Observatory ofCalar Alto (Almeria, Spain). A 4^deg^ full-aperture prism, whichprovides a dispersion of 1950 A mm^-1^, and IIIa-F emulsion combinationhas been used to search for ELGs selected by the presence of Hαemission in their spectra. A compilation of descriptions and positions,along with finding charts, is presented for 103 emission-line objects.This is the second list, which contains objects located in a region ofthe sky covering 201.4 deg^2^ in seven fields near α = 15^h^ andδ = 25^deg^.
| Observations of a complete sample of Hα emission-line galaxies. Long-slit spectroscopy of galaxies in UCM lists 1 and 2.
Spectroscopic observations for the full sample of Hα emission-linegalaxy candidates (ELGs) from the Universidad Complutense de Madridobjective-prism survey Lists 1 and 2 have been obtained in order toinvestigate fully the properties of the survey constituents as well asthe selection characteristics and completeness limits of the surveyitself. The spectroscopic data include redshifts, line fluxes,equivalent widths, emission-line ratios, optical reddening estimates andsynthesized color indexes. We find that 74% of the objects in thissample do exhibit emission lines. We compare our observational data withparameters given in the published survey lists in order to assess theusefulness of the latter. The different emission-line galaxies have beenclassified according to their spectra in several groups. Gray-scaleimages of the CCD spectra near the main emission lines, spatial profilesat the continuum and the line for [OIII] λ5007 and Hαlines, as well as plots of the coadded spectra of selected galaxies arepresented, and a number of peculiar objects are described.
| 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.
| Morphological classification and structural parameters for early-type galaxies in the Coma cluster.
We present the results of an isophotal shape analysis of three samplesof galaxies in the Coma cluster. Quantitative morphology, together withstructural and photometric parameters, is given for each galaxy. Specialemphasis has been placed on the detailed classification of early-typegalaxies. The three samples are: i) a sample of 97 early-type galaxiesbrighter than m_B_=17.00 falling within one degree from the center ofthe Coma cluster; these galaxies were observed with CCD cameras, mostlyin good to excellent resolution conditions; ii) a magnitude completesample of 107 galaxies of all morphological types down to m_B_=17.00falling in a circular region of 50arcmin diameter, slightly offcenteredto the North-West of the cluster center; the images for this and thenext sample come from digitized photographic plates; iii) a completecomparison sample of 26 galaxies of all morphological types down tom_R_=16.05 (or m_B_=~17.5), also in a region of 50arcmin diameter, butcentered 2.6degrees West of the cluster center. The reliability of ourmorphological classifications and structural parameters of galaxies,down to the adopted magnitude limits, is assessed by comparing theresults on those galaxies for which we had images taken with differentinstrumentation and/or seeing conditions, and by comparing our resultswith similar data from other observers.
| A multifrequency radio continuum and IRAS faint source survey of markarian galaxies
Results are presented from a multifrequency radio continumm survey ofMarkarian galaxies (MRKs) and are supplemented by IRAS infrared datafrom the Faint Source Survey. Radio data are presented for 899 MRKsobserved at nu = 4.755 GHz with the National Radio Astronomy Observatory(NRAO)-Green Bank 300 foot (91 m) telescope, including nearly 88% ofthose objects in Markarian lists VI-XIV. In addition, 1.415 GHzmeasurements of 258 MRKs, over 30% of the MRKs accessible from theNational Aeronomy and Ionosphere Center (NAIC)-Arecibo, are reported.Radio continuum observations of smaller numbers of MRKs were made at10.63 GHz and at 23.1 GHz and are also presented. Infrared data from theIRAS Faint Source Survey (Ver. 2) are presented for 944 MRKs, withreasonably secure identifications extracted from the NASA/IPACExtragalactic Database. MRKs exhibit the same canonical infraredcharacteristics as those reported for various other galaxy samples, thatis well-known enhancement of the 25 micrometer/60 micrometer color ratioamong Seyfert MRKs, and a clear tendency for MRKs with warmer 60micrometer/100 micrometer colors to also possess cooler 12 micrometer/25micrometer colors. In addition, non-Seyfert are found to obey thewell-documented infrared/radio luminosity correlation, with the tightestcorrelation seen for starburst MRKs.
| Galaxy Properties at the North Galactic Pole. I. Photometric Properties on Large Spatial Scales
A two-color study of the galaxies detected on POSS-I in a 289 squaredegree region centered on the North Galactic Pole is presented. We use avariety of mapping techniques to characterize the large-scale spatialdistribution of galaxies. The depth and sample size of this new surveyallows, for the first time, the isolation of large photometricsubsamples of galaxies in high- and low-density environments on thescale of superclusters. Our principal finding is a statisticallysignificant difference between the mean photometric properties of thesesubsamples in the sense that galaxies in the high-density Coma andfilament environments have redder colors and larger concentrationindices than galaxies drawn from low-density interfilament regions.These results are in accord with the known morphology-density relation.Thus, appropriately chosen photometric and morphological parameters, inconcert with a galaxy surface density map, can be used to selectstructures from the projected galaxy distribution which correspond toregions of high density. An illustration of this point is our discoveryof a concentration of blue galaxies identified in our maps near the coreof the Coma cluster. This feature is comprised of early-type galaxieswhich exhibit signs of current or recent star formation. These resultsare predicated on relations between morphological type and photometricparameters derived from APS scans of POSS-I. We therefore discuss theimage calibration procedures used to compile our catalog of physicallysignificant photometric parameters. We demonstrate the morphologicaltype dependence among quantities such as mean color and imageconcentration index, and the lack of such a dependence for mean surfacebrightness.
| IRAS observations of H-alpha selected emission-line galaxies
We present the results of IRAS observations of the UCM (UniversidadComplutense de Madrid) sample of emission-line galaxies, which have beenselected from wide-dispersion H-alpha objective-prism plates. These dataare intended to provide a convenient summary of the relevant FIRproperties of these galaxies. Color-color diagrams, as interpreted bytheoretical models, suggest that emission from UCM galaxies is mainlydue to dust heated directly by photons emitted in active star-formingregions. Statistical analysis of some samples, including the IRASminisurvey and blue-selected objective-prism samples, have beenperformed. Comparisons, based on FIR luminosity distributions, with theIRAS minisurvey make evident the lower metallicity of the CUM galaxieswhich cannot be considered as a parent population of IRAS-detectedgalaxies.
| Pairing properties of Markarian starburst Galaxies
The environmental parameters of 516 non-Seyfert Markarian galaxies werestudied in a redshift-bounded sample, supplemented by new spectra andredshift measures for possible companions, in order to evaluate theiroccurrence in galaxy pairs, defined through quantitative criteria. Itwas found that one-third of these galaxies occur in pairs (while only 6to 10 percent of optically-selected galaxies are known to be paired). Acomparison of various optical and IR properties of paired and nonpairedMarkarian galaxies showed no differences in the shape of the optical,far-IR, or H-alpha luminosity functions. It was found, however, that theMarkarian component is brighter than the other galaxy in each pair by0.66 magnitude in the mean at B.
| A catalog of Markarian galaxies
A catalog of Markarian galaxies is presented which tabulates redshifts,spectral and morphological classifications, magnitudes, infrared andradio flux densities, and over 600 references to available datapublished before January 1, 1986. Redshifts are now available for 1228objects with strong ultraviolet continua, and follow-up spectroscopicand photometric observations of Markarian galaxies have providedclassifications of 115 Seyfert 1, 43 Seyfert 2, and 137 starburst and HII-type galaxies. After a description of the Markarian survey and thecurrent catalog, a summary of the general results obtained from the datais presented. A preliminary study of the infrared properties ofMarkarian galaxies as measured by IRAS reveals a number of interestingresults, including the existence of a sample of elliptical andlenticular galaxies with appreciable infrared emission.
| On the relation of Markarian galaxies with Zwicky clusters. I - Data
In the area covered by the survey of Markarian et al. (1967-1981) andthe CGCG of Zwicky et al. (1961-1968) there are 1344 Markarian galaxies,of which 597 are positioned inside the contours of Zwicky clusters. Dataon these galaxies and respective clusters are presented in differenttables, according to whether they are galaxies which are members ofclusters, or probable or possible members; projection cases areconsidered separately.
| KISO survey for ultraviolet-excess galaxies. II.
Not Available
| Markarian galaxies and voids in the galaxy distribution
In the course of identifying Markarian galaxies that fall within thepurported Bootes void, Balzano and Weedman (1982) went one step furtherand claimed that Markarian galaxies display a homogeneous spacedistribution. If true, this would be a remarkable discovery in view ofthe alternating void-supercluster-void structure which all otherordinary galaxies seem to follow. Furthermore, it would imply thatMarkarian galaxies should fill all other previously discovered voids. Totest the latter hypothesis, a search was made for Markarian galaxies inthe fields of three previously published redshift surveys, each of whichshows at least one void. While 43 Markarian galaxies were identified,all fall in regions heavily populated by ordinary galaxies, and nonefall in the voids. On the basis of nearest neighbor separations, thepossibility that Markarian galaxies fill the voids can be rejected withgreat confidence. Because Markarian galaxies are closely associated withordinary galaxies, it is likely that there are more, as yetunidentified, normal galaxies which are near neighbors of the 12Markarian galaxies identified in the Bootes region by Balzano andWeedman.
| Radio survey of Markarian galaxies at 6 and 11 CM
One hundred and fifty-one objects from Markarian's lists 6 and 7 wereobserved at 6 cm with a 3 sigma detection limit of about 30 mJy. EightMarkarian objects were detected, six of which were also observed at 11cm. Forty-five others were negative at this wavelength. Two of thedetections, numbers 533 and 668, are Seyfert galaxies; additionally, UB1was detected at 6 cm and NGC 7715 and III Zw 2 were found at 11 cm.
| Velocity dispersion profiles of clusters of galaxies
Line-of-sight velocity dispersion profiles (sigma profiles) arepresented for 13 clusters of galaxies having at least 30 radialvelocities. The clusters considered include A2151, A1367, Virgo, A426,A1656, A2199, Cancer, A194, Fornax, A262, Centaurus, A2319, and PegasusI. All the sigma profiles are fitted to simple power laws over theradial interval from 0.1 to 2.0 times the virial radius and are found tofall into four classifications. In view of the amount of masssegregation implied, the amount of central concentration observed, andthe predominant galaxy morphology, it is suggested that theseclassifications represent a dynamical age sequence. Statistical testsare applied to two features appearing in some sigma profiles: thepresence of a local minimum that coincides with the local minimum notedin surface density or surface brightness profiles and a decrease inline-of-sight velocity dispersion in the cores of certain clusters.Possible dynamical implications of these features are discussed in termsof Wielen's (1974) N-body simulations.
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