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Why Are Radio Galaxies Prolific Producers of Type Ia Supernovae?
An analysis of SN Ia events in early-type galaxies from the database ofCappellaro and coworkers provides conclusive evidence that the rate ofSNe Ia in radio-loud galaxies is about 4 times higher than the ratemeasured in radio-quiet galaxies, i.e., SN Ia rate(radio-loudgalaxies)=0.43+0.19-0.14h275 SNu as compared to SN Ia rate(radio-quietgalaxies)=0.11+0.06-0.03h275 SNu. The actual value of the enhancement islikely to be in the range ~2-7 (P~10-4). This finding puts onrobust empirical grounds the results obtained by Della Valle &Panagia on the basis of a smaller sample of SNe. We analyze the possiblecauses of this result and conclude that the enhancement of the SN Iaexplosion rate in radio-loud galaxies has the same origin as their beingstrong radio sources, but there is no causal link between the twophenomena. We argue that repeated episodes of interaction and/or mergersof early-type galaxies with dwarf companions, on timescales of about 1Gyr, are responsible for both inducing strong radio activity observed in~14% of early-type galaxies and supplying an adequate number of SN Iaprogenitors to the stellar population of elliptical galaxies.
| Study of the Structure of the Coma Cluster Based on a Hierarchical Force Clustering Method
Six subclusters in the Coma cluster have been selected on the basis of ahierarchical clustering method that takes the gravitational interactionamong galaxies into account. Of these, 3 central subclusters around thegalaxies NGC 4889, NGC 4874, and NGC 4839 have been singled out. We haveused the objective statistical criterion applied by Vennik and Anosovain studies of close groups of galaxies to evaluate each member includedin a subcluster with a high probability. Galaxies with a significantdeficit of hydrogen HI, including objects from the Bravo-Alfaro list,have been identified with members of the subclusters, with the greatestnumber of them in the subclusters around NGC 4874 and NGC 4839. Aquantitative estimate of the hydrogen deficit using the HI index in theRCG3 catalog reveals a statistically significant excess value for thosegalaxies that are members of the subclusters compared to galaxies with ahydrogen deficit in the overall Coma cluster field. A substantial numberof the spiral galaxies with a hydrogen deficit in the subclusters turnedout to be radio galaxies as well.
| Active and Star-forming Galaxies and Their Supernovae
To investigate the extent to which nuclear starbursts or other nuclearactivity may be connected with enhanced star formation activity in thehost galaxy, we perform a statistical investigation of supernovae (SNe)discovered in host galaxies from four samples: the Markarian galaxiessample, the Second Byurakan Survey (SBS) sample, the north Galactic pole(NGP) sample of active or star-forming galaxies, and the NGP sample ofnormal galaxies. Forty-seven SNe in 41 Mrk galaxies, 10 SNe in six SBSgalaxies, 29 SNe in 26 NGP active or star-forming galaxies, and 29 SNein 26 NGP normal galaxies have been studied. We find that the rate ofSNe, particularly core-collapse (Types Ib/c and II) SNe, is higher inactive or star-forming galaxies in comparison with normal galaxies.Active or star-forming host galaxies of SNe are generally of latermorphological type and have lower luminosity and smaller linear sizethan normal host galaxies of SNe. The radial distribution of SNe inactive and star-forming galaxies shows a higher concentration toward thecenter of the active host galaxy than is the case for normal hostgalaxies, and this effect is more pronounced for core-collapse SNe.Ib/c-type SNe have been discovered only in active and star-forminggalaxies of our samples. About 78% of these SNe are associated with H IIregions or are located very close to the nuclear regions of these activegalaxies, which are in turn hosting AGNs or starburst nuclei. Besidesthese new results, our study also supports the conclusions of severalother earlier papers. We find that Type Ia SNe occur in all galaxytypes, whereas core-collapse SNe of Types Ib/c and II are found only inspiral and irregular galaxies. The radial distribution of Type Ib SNe intheir host galaxies is more centrally concentrated than that of Type IIand Ia SNe. The radial distances of Types Ib/c and II SNe, from thenuclei of their host galaxies, is larger for barred spiral hosts.Core-collapse SNe are concentrated in spiral arms and are often close toor in the H II regions, whereas Type Ia SNe show only a looseassociation with spiral arms and no clear association with H II regions.
| Radio and Far-Infrared Emission as Tracers of Star Formation and Active Galactic Nuclei in Nearby Cluster Galaxies
We have studied the radio and far-infrared (FIR) emission from 114galaxies in the seven nearest clusters (<100 Mpc) with prominentX-ray emission to investigate the impact of the cluster environment onthe star formation and active galactic nucleus (AGN) activity in themember galaxies. The X-ray selection criterion is adopted to focus onthe most massive and dynamically relaxed clusters. A large majority ofcluster galaxies show an excess in radio emission over that predictedfrom the radio-FIR correlation, the fraction of sources with radioexcess increases toward cluster cores, and the radial gradient in theFIR/radio flux ratio is a result of radio enhancement. Of theradio-excess sources, 70% are early-type galaxies, and the same fractionhost an AGN. The galaxy density drops by a factor of 10 from thecomposite cluster center out to 1.5 Mpc, yet galaxies show no change inFIR properties over this region and show no indication of masssegregation. We have examined in detail the physical mechanisms thatmight impact the FIR and radio emission of cluster galaxies. Whilecollisional heating of dust may be important for galaxies in clustercenters, it appears to have a negligible effect on the observed FIRemission for our sample galaxies. The correlations between radio and FIRluminosity and radius could be explained by magnetic compression fromthermal intracluster medium pressure. We also find that simple delayedharassment cannot fully account for the observed radio, FIR, and mid-IRproperties of cluster galaxies.
| UV and FIR selected samples of galaxies in the local Universe. Dust extinction and star formation rates
We have built two samples of galaxies selected at 0.2 μm (hereafterUV) and 60 μm (hereafter FIR) covering a sky area of 35.36deg2. The UV selected sample contains 25 galaxies brighterthan AB0.2=17. All of them, but one elliptical, are detectedat 60 μm with a flux density larger or equal to 0.2 Jy. The UV countsare significantly lower than the Euclidean extrapolation towardsbrighter fluxes of previous determinations. The FIR selected samplecontains 42 galaxies brighter than f60=0.6 Jy. Except fourgalaxies, all of them have a UV counterpart at the limiting magnitudeAB0.2=20.3 mag. The mean extinction derived from the analysisof the FIR to UV flux ratio is 1 mag for the UV selected sample and2 mag for the FIR selected one. For each sample we compare severalindicators of the recent star formation rate (SFR) based on the FIRand/or the UV emissions. We find linear relationships with slopes closeto unity between the different SFR indicator, which means that, over thewhole converting offset. Various absolute calibrations for both samplesare discussed in this paper. A positive correlation between extinctionand SFR is found when both samples are considered together although witha considerable scatter. A similar result is obtained when using the SFRnormalized to the optical surface of the galaxies.Tables 3, 4 and Fig. 1 are only available in electronic form athttp://www.edpsciences.org
| The X-ray luminosity function of galaxies in the Coma cluster
The XMM-Newton survey of the Coma cluster of galaxies covers an area of1.86 square degrees with a mosaic of 16 pointings and has a total usefulintegration time of 400 ks. Detected X-ray sources with extent less than10'' were correlated with cataloged galaxies in the Comacluster region. The redshift information, which is abundant in thisregion of the sky, allowed us to separate cluster members frombackground and foreground galaxies. For the background sources, werecover a typical Log N-Log S in the flux range10-15-10-13 ergs s-1 cm-2 inthe 0.5-2.0 keV band. The X-ray emission from the cluster galaxiesexhibits X-ray colors typical of thermal emission. The luminosities ofComa galaxies lie in the 1039-1041 ergss-1 interval in the 0.5-2.0 keV band. The luminosity functionof Coma galaxies reveals that their X-ray activity is suppressed withrespect to the field by a factor of 5.6, indicating a lower level ofX-ray emission for a given stellar mass.
| Spectrophotometry of galaxies in the Virgo cluster. II. The data
Drift-scan mode (3600-6800 Å) spectra with 500
| 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.
| A new catalogue of ISM content of normal galaxies
We have compiled a catalogue of the gas content for a sample of 1916galaxies, considered to be a fair representation of ``normality''. Thedefinition of a ``normal'' galaxy adopted in this work implies that wehave purposely excluded from the catalogue galaxies having distortedmorphology (such as interaction bridges, tails or lopsidedness) and/orany signature of peculiar kinematics (such as polar rings,counterrotating disks or other decoupled components). In contrast, wehave included systems hosting active galactic nuclei (AGN) in thecatalogue. This catalogue revises previous compendia on the ISM contentof galaxies published by \citet{bregman} and \citet{casoli}, andcompiles data available in the literature from several small samples ofgalaxies. Masses for warm dust, atomic and molecular gas, as well asX-ray luminosities have been converted to a uniform distance scale takenfrom the Catalogue of Principal Galaxies (PGC). We have used twodifferent normalization factors to explore the variation of the gascontent along the Hubble sequence: the blue luminosity (LB)and the square of linear diameter (D225). Ourcatalogue significantly improves the statistics of previous referencecatalogues and can be used in future studies to define a template ISMcontent for ``normal'' galaxies along the Hubble sequence. The cataloguecan be accessed on-line and is also available at the Centre desDonnées Stellaires (CDS).The catalogue is available in electronic form athttp://dipastro.pd.astro.it/galletta/ismcat and at the CDS via anonymousftp to\ cdsarc.u-strasbg.fr (130.79.128.5) or via\http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/405/5
| 1.65-μm (H -band) surface photometry of galaxies - VIII. The near-IR κ space at z =0
We present the distribution of a statistical sample of nearby galaxiesin the κ -space (κ 1 ~logM , κ 2~logI e 3 M /L , κ 3 ~logM /L ).Our study is based on near-IR (H -band: λ =1.65μm)observations, for the first time comprising early- and late-typesystems. Our data confirm that the mean effective dynamicalmass-to-light ratio M /L of the E+S0+S0a galaxies increases withincreasing effective dynamical mass M , as expected from the existenceof the Fundamental Plane relation. Conversely, spiral and Im/BCDgalaxies show a broad distribution in M /L with no detected trend of M/L with M , the former galaxies having M /L values about twice largerthan the latter, on average. For all the late-type galaxies, the M /Lincreases with decreasing effective surface intensity I e ,consistent with the existence of the Tully-Fisher relation. Theseresults are discussed on the basis of the assumptions behind theconstruction of the κ -space and their limitations. Our study iscomplementary to a previous investigation in the optical (B -band:λ =0.44μm) and allows us to study wavelength dependences ofthe galaxy distribution in the κ -space. As a first result, wefind that the galaxy distribution in the κ 1 -κ2 plane reproduces the transition from bulgeless tobulge-dominated systems in galaxies of increasing dynamical mass.Conversely, it appears that the M /L of late-types is higher (lower)than that of early-types with the same M in the near-IR (optical). Theorigins of this behaviour are discussed in terms of dust attenuation andstar formation history.
| The UZC-SSRS2 Group Catalog
We apply a friends-of-friends algorithm to the combined Updated ZwickyCatalog and Southern Sky Redshift Survey to construct a catalog of 1168groups of galaxies; 411 of these groups have five or more members withinthe redshift survey. The group catalog covers 4.69 sr, and all groupsexceed the number density contrast threshold, δρ/ρ=80. Wedemonstrate that the groups catalog is homogeneous across the twounderlying redshift surveys; the catalog of groups and their membersthus provides a basis for other statistical studies of the large-scaledistribution of groups and their physical properties. The medianphysical properties of the groups are similar to those for groupsderived from independent surveys, including the ESO Key Programme andthe Las Campanas Redshift Survey. We include tables of groups and theirmembers.
| Hα surface photometry of galaxies in the Virgo cluster. IV. The current star formation in nearby clusters of galaxies
Hα +[NII] imaging observations of 369 late-type (spiral) galaxiesin the Virgo cluster and in the Coma/A1367 supercluster are analyzed,covering 3 rich nearby clusters (A1367, Coma and Virgo) and nearlyisolated galaxies in the Great-Wall. They constitute an opticallyselected sample (mp<16.0) observed with ~ 60 %completeness. These observations provide us with the current(T<107 yrs) star formation properties of galaxies that westudy as a function of the clustercentric projected distances (Theta ).The expected decrease of the star formation rate (SFR), as traced by theHα EW, with decreasing Theta is found only when galaxies brighterthan Mp ~ -19.5 are considered. Fainter objects show no orreverse trends. We also include in our analysis Near Infrared data,providing information on the old (T>109 yrs) stars. Puttogether, the young and the old stellar indicators give the ratio ofcurrently formed stars over the stars formed in the past, or``birthrate'' parameter b. For the considered galaxies we also determinethe ``global gas content'' combining HI with CO observations. We definethe ``gas deficiency'' parameter as the logarithmic difference betweenthe gas content of isolated galaxies of a given Hubble type and themeasured gas content. For the isolated objects we find that b decreaseswith increasing NIR luminosity. In other words less massive galaxies arecurrently forming stars at a higher rate than their giant counterpartswhich experienced most of their star formation activity at earliercosmological epochs. The gas-deficient objects, primarily members of theVirgo cluster, have a birthrate significantly lower than the isolatedobjects with normal gas content and of similar NIR luminosity. Thisindicates that the current star formation is regulated by the gaseouscontent of spirals. Whatever mechanism (most plausibly ram-pressurestripping) is responsible for the pattern of gas deficiency observed inspiral galaxies members of rich clusters, it also produces the observedquenching of the current star formation. A significant fraction of gas``healthy'' (i.e. with a gas deficiency parameter less than 0.4) andcurrently star forming galaxies is unexpectedly found projected near thecenter of the Virgo cluster. Their average Tully-Fisher distance isfound approximately one magnitude further away (muo = 31.77)than the distance of their gas-deficient counterparts (muo =30.85), suggesting that the gas healthy objects belong to a cloudprojected onto the cluster center, but in fact lying a few Mpc behindVirgo, thus unaffected by the dense IGM of the cluster. Based onobservations taken at the Observatorio Astronómico Nacional(Mexico), the OHP (France), Calar Alto and NOT (Spain) observatories.Table \ref{tab4} is only available in electronic form athttp://www.edpsciences.org
| The Radio Galaxy Populations of Nearby Northern Abell Clusters
We report on the use of the NRAO VLA Sky Survey (NVSS) to identify radiogalaxies in 18 nearby Abell clusters. The listings extend from the coresof the clusters out to radii of 3 h-175 Mpc, whichcorresponds to 1.5 Abell radii and approximately 4 orders of magnitudein galaxy density. To create a truly useful catalog, we have collectedoptical spectra for nearly all of the galaxies lacking public velocitymeasurements. Consequently, we are able to discriminate between thoseradio galaxies seen in projection on the cluster and those that are inactuality cluster members. The resulting catalog consists of 329 clusterradio galaxies plus 138 galaxies deemed foreground or backgroundobjects, and new velocity measurements are reported for 273 of theseradio galaxies. The motivation for the catalog is the study of galaxyevolution in the cluster environment. The radio luminosity function is apowerful tool in the identification of active galaxies, as it isdominated by star-forming galaxies at intermediate luminosities andactive galactic nuclei (AGNs) at higher luminosities. The flux limit ofthe NVSS allows us to identify AGNs and star-forming galaxies down tostar formation rates less than 1 Msolar yr-1. Thissensitivity, coupled with the all-sky nature of the NVSS, allows us toproduce a catalog of considerable depth and breadth. In addition tothese data, we report detected infrared fluxes and upper limits obtainedfrom IRAS data. It is hoped that this database will prove useful in anumber of potential studies of the effect of environment on galaxyevolution. Based in part on observations obtained with the Apache PointObservatory 3.5 m telescope, which is owned and operated by theAstrophysical Research Consortium (ARC).
| The First Hour of Extragalactic Data of the Sloan Digital Sky Survey Spectroscopic Commissioning: The Coma Cluster
On 1999 May 26, one of the Sloan Digital Sky Survey (SDSS) fiber-fedspectrographs saw astronomical first light. This was followed by thefirst spectroscopic commissioning run during the dark period of 1999June. We present here the first hour of extragalactic spectroscopy takenduring these early commissioning stages: an observation of the Comacluster of galaxies. Our data samples the southern part of this cluster,out to a radius of 1.5d (1.8 h-1 Mpc, approximately to thevirial radius) and thus fully covers the NGC 4839 group. We outline inthis paper the main characteristics of the SDSS spectroscopic systemsand provide redshifts and spectral classifications for 196 Comagalaxies, of which 45 redshifts are new. For the 151 galaxies in commonwith the literature, we find excellent agreement between our redshiftdeterminations and the published values, e.g., for the largesthomogeneous sample of galaxies in common (63 galaxies observed byColless & Dunn) we find a mean offset of 3 km s -1 and anrms scatter of only 24 km s -1. As part of our analysis, wehave investigated four different spectral classification algorithms:measurements of the spectral line strengths, a principal componentdecomposition, a wavelet analysis and the fitting of spectral synthesismodels to the data. We find that these classification schemes are inbroad agreement and can provide physical insight into the evolutionaryhistories of our cluster galaxies. We find that a significant fraction(25%) of our observed Coma galaxies show signs of recent star formationactivity and that the velocity dispersion of these active galaxies(emission-line and poststarburst galaxies) is 30% larger than theabsorption-line galaxies. We also find no active galaxies within thecentral (projected) 200 h-1 kpc of the cluster. The spatialdistribution of our Coma active galaxies is consistent with that foundat higher redshift for the CNOC1 cluster survey. Beyond the core region,the fraction of bright active galaxies appears to rise slowly out to thevirial radius and are randomly distributed within the cluster with noapparent correlation with the potential merger or postmerger of the NGC4839 group. We briefly discuss possible origins of this recent galaxystar formation.
| VLA HI Imaging of the brightest spiral galaxies in Coma. II. The HI Atlas and deep continuum imaging of selected early type galaxies
In the first paper of this series we used HI observations of the 19brightest spirals in Coma to analyze the dynamical state of the cluster.In this paper we present the detailed HI distribution and kinematics ofthe spirals that were detected in HI, and radio continuum data for asample of star forming and post starburst galaxies in Coma. We discussthe importance of ICM-ISM interactions to explain the observed HImorphology. A rough comparison of observed HI sizes with predicted HIsizes from simulations by Abadi et al. (\cite{Abadi99}) gives reasonableagreement. We use the results on radio continuum emission to estimatethe star formation rate in the PSB galaxies we pointed at. The radiocontinuum emission in the 11 so called post starburst galaxies,identified by Caldwell et al. (\cite{Caldwell93}) in the cluster, isweak. Eight of the 11 were not detected down to a 3 sigma upper limit of0.6 mJy. This sets an upper limit to the star formation rate in thesegalaxies of less than 0.2 Msun,yr-1. The threedetected post starburst galaxies have a star formation rate of less thanone solar mass per year. Thus none of the post starburst galaxies inComa are dust enshrouded starbursts. Appendix is only available inelectronic form at http://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
| Star formation properties of Universidad Complutense de Madrid survey galaxies
We present new near-infrared J and K imaging data for 67 galaxies fromthe Universidad Complutense de Madrid (UCM) survey used in thedetermination of the SFR density of the local Universe by Gallego et al.This is a sample of local star-forming galaxies with redshift lower than0.045, and they constitute a representative subsample of the galaxies inthe complete UCM survey. From the new data, complemented with our ownGunn-r images and long-slit optical spectroscopy, we have measuredintegrated K-band luminosities, r-J and J-K colours, and Hαluminosities and equivalent widths. Using a maximum likelihood estimatorand a complete set of evolutionary synthesis models, these observationsallow us to estimate the strength of the current (or most recent) burstof star formation, its age, the star formation rate and the totalstellar mass of the galaxies. An average galaxy in the sample has astellar mass of 5×1010Msolar and isundergoing (or has recently completed) a burst of star formationinvolving about 2per cent of its total stellar mass. We identify twoseparate classes of star-forming galaxies in the UCM sample:low-luminosity, high-excitation galaxies (Hiilike) and relativelyluminous spiral galaxies (starburst disc-like). The former show higherspecific star formation rates (SFRs per unit mass) and burst strengths,and lower stellar masses than the latter. With regard to their specificstar formation rates, the UCM galaxies are intermediate objects betweennormal quiescent spirals and the most extreme Hii galaxies.
| VLA H I Imaging of the Brightest Spiral Galaxies in Coma
We have obtained 21 cm images of 19 spiral galaxies in the Coma cluster,using the VLA in its C and D configurations. The sample selection wasbased on morphology, brightness, and optical diameters of galaxieswithin one Abell radius (1.2d). The H I-detected, yet deficient galaxiesshow a strong correlation in their H I properties with projecteddistance from the cluster center. The most strongly H I-deficient(DefH I>0.4) galaxies are located inside a radius of 30'(~0.6 Mpc) from the center of Coma, roughly the extent of the centralX-ray emission. These central galaxies show clear asymmetries in their HI distribution and/or shifts between the optical and 21 cm positions.Another 12 spirals were not detected in H I with typical H I mass upperlimits of 108 Msolar. Seven of the 12nondetections are located in the central region of Coma, roughly within30' from the center. The other nondetections are to the east andsouthwest of the center. We looked for seven so-called blue diskgalaxies in Coma in H I and detected six. These galaxies are relativelyclose to the central region of Coma. The nondetected one is the closestto the center. The six detected blue galaxies are mildly H I deficient.We did a more sensitive search for H I from 11 of the 15 knownpoststarburst galaxies in Coma. None were detected with typical H I masslimits between 3 and 7x107 Msolar. Our resultspresent and enhance a picture already familiar for well-studiedclusters. H I poor galaxies (deficient ones and nondetections) areconcentrated toward the center of the cluster. The H I morphology of thecentral galaxies with optical disks extending beyond the H I disks isunique to cluster environments and strongly suggests an interaction withthe intergalactic medium (IGM). A new result in Coma is the clumpydistribution of gas deficiency. In the cluster center the deficientgalaxies are to the east while the nondetections are to the west. In theouter parts the gas rich galaxies are north of Coma, nondetected spiralsare found in the NGC 4944 group to the east, and the NGC 4839 group isto the southwest. This supports recent findings that merging of groupsis ongoing in the center of Coma, farther out the NGC 4944 and NGC 4839must have passed at least once through the core, and the galaxies to thenorth have yet to fall in.
| 1.65 μm (H-band) surface photometry of galaxies. III. observations of 558 galaxies with the TIRGO 1.5 m telescope
We present near-infrared H-band (1.65 μm ) surface photometry of 558galaxies in the Coma Supercluster and in the Virgo cluster. This dataset, obtained with the Arcetri NICMOS3 camera ARNICA mounted on theGornergrat Infrared Telescope, is aimed at complementing, withobservations of mostly early-type objects, our NIR survey of spiralgalaxies in these regions, presented in previous papers of this series.Magnitudes at the optical radius, total magnitudes, isophotal radii andlight concentration indices are derived. We confirm the existence of apositive correlation between the near-infrared concentration index andthe galaxy H-band luminosity Based on observations taken at TIRGO(Gornergrat, Switzerland). TIRGO is operated by CAISMI-CNR, Arcetri,Firenze, Italy. Tables 1 and 2 are only available in electronic form atthe CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| 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}
| 1.65 μm (H-band) surface photometry of galaxies. V. Profile decomposition of 1157 galaxies
We present near-infrared H-band (1.65 μm) surface brightness profiledecomposition for 1157 galaxies in five nearby clusters of galaxies:Coma, A1367, Virgo, A262 and Cancer, and in the bridge between Coma andA1367 in the ``Great Wall". The optically selected (mpg≤16.0) sample is representative of all Hubble types, from E to Irr+BCD,except dE and of significantly different environments, spanning fromisolated regions to rich clusters of galaxies. We model the surfacebrightness profiles with a de Vaucouleurs r1/4 law (dV), withan exponential disk law (E), or with a combination of the two (B+D).From the fitted quantities we derive the H band effective surfacebrightness (μe) and radius (re) of each component, theasymptotic magnitude HT and the light concentration indexC31. We find that: i) Less than 50% of the Ellipticalgalaxies have pure dV profiles. The majority of E to Sb galaxies is bestrepresented by a B+D profile. All Scd to BCD galaxies have pureexponential profiles. ii) The type of decomposition is a strong functionof the total H band luminosity (mass), independent of the Hubbleclassification: the fraction of pure exponential decompositionsdecreases with increasing luminosity, that of B+D increases withluminosity. Pure dV profiles are absent in the low luminosity rangeLH<1010 L\odot and become dominantabove 1011 L\odot . Based on observations taken atTIRGO, Gornergrat, Switzerland (operated by CAISMI-CNR, Arcetri,Firenze, Italy) and at the Calar Alto Observatory (operated by theMax-Planck-Institut für Astronomie (Heidelberg) jointly with theSpanish National Commission for Astronomy). Table 2 and Figs. 2, 3, 4are available in their entirety only in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| A Dual-Transition Survey of CO in the Coma Cluster of Galaxies
We present CO (1-0) and (2-1) observations of 33 galaxies in theComa/Abell 1367 supercluster made with the IRAM 30 m telescope. Inaddition, we observed four of the galaxies with the 15 m JCMT, at CO(2-1). The indicative molecular gas mass correlates strongly with thedust mass, and a stronger relationship is seen between the far-infraredand CO surface brightnesses than between the simple luminosities.Comparison of CO (2-1) spectra from IRAM and JCMT allows an estimate ofthe size of the CO emission region, which varies between 10% and 100% ofthe size of the optical disk, contrary to earlier estimates that the COis contained within the optical half-light radius. There is a slightsuggestion that starburst galaxies have a lower ratio of brightnesstemperatures, T_b(2-1)/T_b(1-0), than other galaxies.
| The intra-cluster medium influence on spiral galaxies
We made a detailed analysis of the sample of 39 cluster spiral galaxiesof various types observed at Hα wavelength by Amram et al. (1992to 1996), with a scanning Fabry-Perot. We plotted the outer gradient oftheir rotation curves as a function of the deprojected cluster-centricdistance. The rotation curves of late type galaxies markedly rise farfrom the cluster center. This suggests evolutionary effects, since earlytypes show no special trend. We suggest that the evolution processwithin a cluster leads late type galaxies to exhibit flatter curves whenthey get closer to the center, on their way to evolving into early typegalaxies.
| On the local radio luminosity function of galaxies. II. Environmental dependences among late-type galaxies
Using new extensive radio continuum surveys at 1.4 GHz (FIRST and NVSS),we derive the distribution of the radio/optical and radio/NIR luminosity(RLF) of late-type (Sa-Irr) galaxies (m_p<15.7) in 5 nearby clustersof galaxies: A262, Cancer, A1367, Coma and Virgo. With the aim ofdiscussing possible environmental dependences of the radio properties,we compare these results with those obtained for relatively isolatedobjects in the Coma supercluster. We find that the RLF of Cancer, A262and Virgo are consistent with that of isolated galaxies. Conversely weconfirm earlier claims that galaxies in A1367 and Coma have their radioemissivity enhanced by a factor ~ 5 with respect to isolated objects. Wediscuss this result in the framework of the dynamical pressure sufferedby galaxies in motion through the intra-cluster gas (ram-pressure). Wefind that the radio excess is statistically larger for galaxies in fasttransit motion. This is coherent with the idea that enhanced radiocontinuum activity is associated with magnetic field compression. TheX-ray luminosities and temperatures of Coma and A1367 imply that thesetwo clusters have significantly larger intracluster gas density than theremaining three studied ones, providing a clue for explaining the higherradio continuum luminosities of their galaxies. Multiple systems in theComa supercluster bridge (with projected separations smaller than 300kpc) have radio luminosities significantly larger than isolatedgalaxies. 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/Abstract.html}
| The Star Formation Properties of Disk Galaxies: Hα Imaging of Galaxies in the Coma Supercluster
We present integrated Hα measurements obtained from imagingobservations of 98 late-type galaxies, primarily selected in the Comasupercluster. These data, combined with Hα photometry from theliterature, include a magnitude-selected sample of spiral (Sa to Irr)galaxies belonging to the ``Great Wall'' complete up to m_p = 15.4, andthus composed of galaxies brighter than M_p = -18.8 (H_0 = 100 km s^-1Mpc^-1). The frequency distribution of the Hα equivalent width,determined for the first time from an optically complete sample, isapproximately Gaussian, peaking at EW ~ 25 Å. We find that, at thepresent limiting luminosity, the star formation properties of spiral +Irr galaxy members of the Coma and A1367 Clusters do not differsignificantly from those of the isolated ones belonging to the GreatWall. The present analysis confirms the well-known increase of thecurrent massive star formation rate (SFR) with Hubble type. Moreover,perhaps a more fundamental anticorrelation exists between the SFR andthe mass of disk galaxies: low-mass spirals and dwarf systems havepresent SFRs ~50 times higher than giant spirals. This result isconsistent with the idea that disk galaxies are coeval, evolving as``closed systems'' with exponentially declining SFR, and that the massof their progenitor protogalaxies is the principal parameter governingtheir evolution. Massive systems having high initial efficiency ofcollapse, or a short collapse timescale, have retained little gas tofeed the present epoch of star formation. These findings support theconclusions of Gavazzi & Scodeggio, who studied the color-massrelation of a local galaxy sample, and agree with the analysis by Cowieet al., who traced the star formation history of galaxies up to z >1. Based on observations made at the Observatorio AstronómicoNacional (OAN), San Pedro Mártir, B.C., of the UniversidadNacional Autónoma de México (UNAM).
| Total magnitude, radius, colour indices, colour gradients and photometric type of galaxies
We present a catalogue of aperture photometry of galaxies, in UBVRI,assembled from three different origins: (i) an update of the catalogueof Buta et al. (1995) (ii) published photometric profiles and (iii)aperture photometry performed on CCD images. We explored different setsof growth curves to fit these data: (i) The Sersic law, (ii) The net ofgrowth curves used for the preparation of the RC3 and (iii) A linearinterpolation between the de Vaucouleurs (r(1/4) ) and exponential laws.Finally we adopted the latter solution. Fitting these growth curves, wederive (1) the total magnitude, (2) the effective radius, (3) the colourindices and (4) gradients and (5) the photometric type of 5169 galaxies.The photometric type is defined to statistically match the revisedmorphologic type and parametrizes the shape of the growth curve. It iscoded from -9, for very concentrated galaxies, to +10, for diffusegalaxies. Based in part on observations collected at the Haute-ProvenceObservatory.
| A catalogue of spatially resolved kinematics of galaxies: Bibliography
We present a catalogue of galaxies for which spatially resolved data ontheir internal kinematics have been published; there is no a priorirestriction regarding their morphological type. The catalogue lists thereferences to the articles where the data are published, as well as acoded description of these data: observed emission or absorption lines,velocity or velocity dispersion, radial profile or 2D field, positionangle. Tables 1, 2, and 3 are proposed in electronic form only, and areavailable from the CDS, via anonymous ftp to cdsarc.u-strasbg.fr (to130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html
| The observation of the nearby universe in UV and in FIR: an evidence for a moderate extinction in present day star forming galaxies
We study the FIR and UV-visible properties of star forming galaxies inthe nearby Universe. This comparison is performed using the localluminosity functions at UV and FIR wavelengths and on individualstarburst galaxies for which photometric data from UV to NIR and FIR areavailable. The FIR and UV luminosity functions have quite differentshapes : the UV function exhibits a strong increase for low luminositygalaxies whereas the FIR tail towards ultra luminous galaxies (L >10(11) Lsun) is not detected in UV. The comparison of the FIR and UVlocal luminosity densities argues for a rather moderate extinction innearby disk galaxies. The galaxies selected to be detected in FIR and UVare found to be located in the medium range of both luminosityfunctions. An emphasis is made on starburst galaxies. For a sample of 22of these objects, it is found that the UV (912-3650 Angstroms), thevisible (3600-12500 Angstroms) and the NIR (12500-22000 Angstroms)wavelength range contribute ~ 30%, ~ 50% and ~ 20% respectively to thetotal emerging stellar emission (for a subsample of 12 galaxies for theNIR and visible light). The mean ratio of the dust to bolometricluminosity of these galaxies is 0.37+/-0.22 similar to the ratio foundfor normal spiral galaxies. Only 4 out of the 22 galaxies exhibit a verylarge extinction with more than 60% of their energy emitted in theFIR-submm range. The mean extinction at 2000Angstroms is found to be ~1.2 mag although with a large dispersion. The UV, visible and NIRemissions of our sample galaxies are consistent with a burst lastingover ~ 1 Gyr. The conversion factor of the stellar emission into dustemission is found to correlate with the luminosity of the galaxies,brighter galaxies having a higher conversion factor. Since our sampleappears to be representative of the mean properties of the galaxypopulation in FIR and UV, a very large conversion of the stellar lightinto dust emission can no longer be assumed as a general property ofstarburst galaxies at least in the local Universe. Instead a largeramount of energy emerging from the present starburst galaxies seems tocome from the stars rather than from the dust. We compare the UVproperties of our local starburst galaxies to those of recently detectedhigh redshift galaxies. The larger extinction found in the distantgalaxies is consistent with the trend we find for the nearby starburstgalaxies namely the brighter the galaxies the lower the escape fractionof stellar light.
| The distribution of the rotation axes of the disk galaxies in the Coma cluster: statistical samples.
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