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Supernovae 2005kg and 2005kh
CBET 292 available at Central Bureau for Astronomical Telegrams.
| Classification of SN 2005kh, a Type II Supernova
The Nearby Supernova Factory reports that a spectrum (range 320-1000 nm)of supernova 2005kh (CBET #292), obtained November 22.6 UT with theSupernova Integral Field Spectrograph (SNIFS) on the University ofHawaii 2.2- meter telescope, shows it to be a a Type II SN, at aredshift consistent with that of its host NGC 3094 (z = 0.00802; Hayneset al. 1997 AJ 113, 1197). The spectrum exhibits P-Cygni profiles fromH-alpha in net emission (maximum expansion velocity 6800 km/s) and He I5876, as well as the Ca II IR triplet in emission.
| Warm, Dense Molecular Gas in the ISM of Starbursts, LIRGs, and ULIRGs
The role of star formation in luminous and ultraluminous infraredgalaxies (LIRGs, LIR>=1011 LsolarULIRGs, LIR>=1012 Lsolar) is a hotlydebated issue: while it is clear that starbursts play a large role inpowering the IR luminosity in these galaxies, the relative importance ofpossible enshrouded AGNs is unknown. It is therefore important to betterunderstand the role of star-forming gas in contributing to the infraredluminosity in IR-bright galaxies. The J=3 level of 12CO lies33 K above ground and has a critical density of~1.5×104 cm-3. The 12CO J=3-2line serves as an effective tracer for warm, dense molecular gas heatedby active star formation. Here we report on 12CO J=3-2observations of 17 starburst spiral galaxies, LIRGs, and ULIRGs, whichwe obtained with the Heinrich Hertz Submillimeter Telescope on MountGraham, Arizona. Our main results are as follows. (1) We find a nearlylinear relation between the infrared luminosity and warm, densemolecular gas such that the infrared luminosity increases as the warm,dense molecular gas to the power 0.92; we interpret this to be roughlyconsistent with the recent results of Gao & Solomon. (2) We findLIR/MH2warm,dense ratios ranging from~38 to ~482 Lsolar/Msolar using a modifiedCO-H2 conversion factor of 8.3×1019cm-2 (K km s-1)-1 derived in thispaper.
| Studies of Extragalactic Formaldehyde and Radio Recombination Lines
We present the most sensitive and extensive survey yet performed ofextragalactic H2CO 6 cm (4.829 GHz) emission/absorption.Sixty-two sources were observed with the C-band system of the AreciboTelescope to a 1 σ rms noise level of ~0.3 mJy. We report a newdetection of H2CO 6 cm absorption toward NGC 520 and theconfirmation of H2CO 6 cm absorption toward several sources.We report confirmation of H2CO 6 cm emission toward the OHmegamasers Arp 220, IC 860, and IRAS 15107+0724. At present these arethe only extragalactic H2CO 6 cm emitters independentlyconfirmed. A characterization of the properties of formaldehydeabsorbers and emitters based on infrared properties of the galaxies isdiscussed. We also conducted a simultaneous survey of the H110αhydrogen recombination line toward a sample of 53 objects. We report thedetection of H110α toward the giant extragalactic H II region NGC604 in M33.
| Hydrocarbon Dust Absorption in Seyfert Galaxies and Ultraluminous Infrared Galaxies
We present new spectroscopic observations of the 3.4 μm absorptionfeature in the Seyfert galaxies NGC 1068 and NGC 7674 and theultraluminous infrared galaxy IRAS 08572+3915. A signature of CH bondsin aliphatic hydrocarbons, the 3.4 μm feature indicates the presenceof organic material in Galactic and extragalactic dust. Here we comparethe 3.4 μm feature in all the galaxies in which it has been detected.In several cases, the signal-to-noise ratio and spectral resolutionpermit a detailed examination of the feature profile, something whichhas rarely been attempted in extragalactic lines of sight. The 3.4 μmband in these galaxies closely resembles that seen in the Galacticdiffuse interstellar medium (ISM) and in newly formed dust in aprotoplanetary nebula. The similarity implies a common carrier for thecarbonaceous component of dust, and one which is resistant to processingin the interstellar and/or circumnuclear medium. We also examine themid-IR spectrum of NGC 1068, because absorption bands in the 5-8 μmregion further constrain the chemistry of the 3.4 μm band carrier.While weak features like those present in the mid-IR spectrum of diffusedust toward the Galactic center would be undetectable in NGC 1068, thestrong bands found in the spectra of many proposed dust analog materialsare clearly absent, eliminating certain candidates and productionmechanisms for the carrier. The absence of strong absorption features at5-8 μm is also consistent with the interpretation that the similarityin the 3.4 μm feature in NGC 1068 to that in Galactic lines of sightreflects real chemical similarity in the carbonaceous dust.Based on observations with the UK Infrared Telescope, Mauna KeaObservatory, Hawaii.
| Properties of isolated disk galaxies
We present a new sample of northern isolated galaxies, which are definedby the physical criterion that they were not affected by other galaxiesin their evolution during the last few Gyr. To find them we used thelogarithmic ratio, f, between inner and tidal forces acting upon thecandidate galaxy by a possible perturber. The analysis of thedistribution of the f-values for the galaxies in the Coma cluster leadus to adopt the criterion f ≤ -4.5 for isolated galaxies. Thecandidates were chosen from the CfA catalog of galaxies within thevolume defined by cz ≤5000 km s-1, galactic latitudehigher than 40o and declination ≥-2.5o. Theselection of the sample, based on redshift values (when available),magnitudes and sizes of the candidate galaxies and possible perturberspresent in the same field is discussed. The final list of selectedisolated galaxies includes 203 objects from the initial 1706. The listcontains only truly isolated galaxies in the sense defined, but it is byno means complete, since all the galaxies with possible companions underthe f-criterion but with unknown redshift were discarded. We alsoselected a sample of perturbed galaxies comprised of all the diskgalaxies from the initial list with companions (with known redshift)satisfying f ≥ -2 and \Delta(cz) ≤500 km s-1; a totalof 130 objects. The statistical comparison of both samples showssignificant differences in morphology, sizes, masses, luminosities andcolor indices. Confirming previous results, we found that late spiral,Sc-type galaxies are, in particular, more frequent among isolatedgalaxies, whereas Lenticular galaxies are more abundant among perturbedgalaxies. Isolated systems appear to be smaller, less luminous and bluerthan interacting objects. We also found that bars are twice as frequentamong perturbed galaxies compared to isolated galaxies, in particularfor early Spirals and Lenticulars. The perturbed galaxies have higherLFIR/LB and Mmol/LB ratios,but the atomic gas content is similar for the two samples. The analysisof the luminosity-size and mass-luminosity relations shows similartrends for both families, the main difference being the almost totalabsence of big, bright and massive galaxies among the family of isolatedsystems, together with the almost total absence of small, faint and lowmass galaxies among the perturbed systems. All these aspects indicatethat the evolution induced by interactions with neighbors would proceedfrom late, small, faint and low mass Spirals to earlier, bigger, moreluminous and more massive spiral and lenticular galaxies, producing atthe same time a larger fraction of barred galaxies but preserving thesame relations between global parameters. The properties we found forour sample of isolated galaxies appear similar to those of high redshiftgalaxies, suggesting that the present-day isolated galaxies could bequietly evolved, unused building blocks surviving in low densityenvironments.Tables \ref{t1} and \ref{t2} are only available in electronic form athttp://www.edpsciences.org
| Dust masses and star formation in bright IRAS galaxies. Application of a physical model for the interpretation of FIR observations
We address the problem of modeling the far-infrared (FIR) spectrum andderiving the star-formation rate (SFR) and the dust mass of spiralgalaxies. We use the realistic physical model of Popescu et al.(\cite{popescu}) to describe the overall ultra-violet (UV), optical andFIR spectral energy distribution (SED) of a spiral galaxy. The modeltakes into account the 3-dimensional old and young stellar distributionsin the bulge and the disk of a galaxy, together with the dust geometry.The geometrical characteristics of the galaxy and the intrinsic opticaland near-infrared spectra are determined by the galaxy's observed K-bandphotometry. The UV part of the spectrum is assumed to be proportional tothe SFR through the use of population synthesis models. By solving theradiative transfer equation, we are able to determine the absorbedenergy, the dust temperature and the resulting FIR spectrum. The modelhas only three free parameters: SFR, dust mass, and the fraction of theUV radiation which is absorbed locally by dense dust in the HII regions.Using this model, we are able to fit well the FIR spectra of 62 brightIRAS galaxies from the ``SCUBA Local Universe Galaxy Survey" of Dunne etal. (\cite{dunne1}). As a result, we are able to determine, amongothers, their SFR and dust mass. We find that, on average, the SFR (inabsolute units), the star-formation efficiency, the SFR surface densityand the ratio of FIR luminosity over the total intrinsic luminosity, arelarger than the respective values of typical spiral galaxies of the samemorphological type. We also find that the mean gas-to-dust mass ratio isclose to the Galactic value, while the average central face-on opticaldepth of these galaxies in the V band is 2.3. Finally, we find a strongcorrelation between SFR or dust mass and observed FIR quantities liketotal FIR luminosity or FIR luminosity at 100 and 850 μm. Thesecorrelations yield well-defined relations, which can be used todetermine a spiral galaxy's SFR and dust-mass content from FIRobservations.
| CO Molecular Gas in Infrared-luminous Galaxies
We present the first statistical survey of the properties of the12CO(1-0) and 12CO(3-2) line emission from thenuclei of a nearly complete subsample of 60 infrared (IR) luminousgalaxies selected from SCUBA Local Universe Galaxy Survey (SLUGS). Thissubsample is flux limited at S60μm>=5.24 Jy with far-IR(FIR) luminosities mostly at LFIR>1010Lsolar. We compare the emission line strengths of12CO(1-0) and (3-2) transitions at a common resolution of~15". The measured 12CO(3-2) to (1-0) line intensity ratiosr31 vary from 0.22 to 1.72, with a mean value of 0.66 for thesources observed, indicating a large spread of the degree of excitationof CO in the sample. These CO data, together with a wide range of dataat different wavelengths obtained from the literature, allow us to studythe relationship between the CO excitation conditions and the physicalproperties of gas/dust and star formation in the central regions ofgalaxies. Our analysis shows that there is a nonlinear relation betweenCO and FIR luminosities, such that their ratioLCO/LFIR decreases linearly with increasingLFIR. This behavior was found to be consistent with theSchmidt law relating star formation rate to molecular gas content, withan index N=1.4+/-0.3. We also find a possible dependence of the degreeof CO gas excitation on the efficiency of star-forming activity. Usingthe large velocity gradient (LVG) approximation to model the observeddata, we investigate the CO-to-H2 conversion factor X for theSLUGS sample. The results show that the mean value of X for the SLUGSsample is lower by a factor of 10 compared to the conventional valuederived for the Galaxy, if we assume the abundance of CO relative toH2, ZCO=10-4. For a subset of 12galaxies with H I maps, we derive a mean total face-on surface densityof H2+HI of about 42 Msolar pc-2 withinabout 2 kpc of the nucleus. This value is intermediate between that ingalaxies like our own and those with strong star formation.
| The IRAS Revised Bright Galaxy Sample
IRAS flux densities, redshifts, and infrared luminosities are reportedfor all sources identified in the IRAS Revised Bright Galaxy Sample(RBGS), a complete flux-limited survey of all extragalactic objects withtotal 60 μm flux density greater than 5.24 Jy, covering the entiresky surveyed by IRAS at Galactic latitudes |b|>5°. The RBGS includes629 objects, with median and mean sample redshifts of 0.0082 and 0.0126,respectively, and a maximum redshift of 0.0876. The RBGS supersedes theprevious two-part IRAS Bright Galaxy Samples(BGS1+BGS2), which were compiled before the final(Pass 3) calibration of the IRAS Level 1 Archive in 1990 May. The RBGSalso makes use of more accurate and consistent automated methods tomeasure the flux of objects with extended emission. The RBGS contains 39objects that were not present in the BGS1+BGS2,and 28 objects from the BGS1+BGS2 have beendropped from RBGS because their revised 60 μm flux densities are notgreater than 5.24 Jy. Comparison of revised flux measurements forsources in both surveys shows that most flux differences are in therange ~5%-25%, although some faint sources at 12 and 25 μm differ byas much as a factor of 2. Basic properties of the RBGS sources aresummarized, including estimated total infrared luminosities, as well asupdates to cross identifications with sources from optical galaxycatalogs established using the NASA/IPAC Extragalactic Database. Inaddition, an atlas of images from the Digitized Sky Survey with overlaysof the IRAS position uncertainty ellipse and annotated scale bars isprovided for ease in visualizing the optical morphology in context withthe angular and metric size of each object. The revised bolometricinfrared luminosity function, φ(Lir), forinfrared-bright galaxies in the local universe remains best fit by adouble power law, φ(L)~Lα, withα=-0.6(+/-0.1) and α=-2.2(+/-0.1) below and above the``characteristic'' infrared luminosityL*ir~1010.5Lsolar,respectively. A companion paper provides IRAS High Resolution (HIRES)processing of over 100 RBGS sources where improved spatial resolutionoften provides better IRAS source positions or allows for deconvolutionof close galaxy pairs.
| High-resolution radio observations of Seyfert galaxies in the extended 12-μm sample - II. The properties of compact radio components
We discuss the properties of compact nuclear radio components in Seyfertgalaxies from the extended 12-μm AGN sample of Rush et al. Our mainresults can be summarized as follows. Type 1 and type 2 Seyferts producecompact radio components which are indistinguishable in strength andaspect, indicating that their central engines are alike, as proposed bythe unification model. Infrared IRAS fluxes are more closely correlatedwith low-resolution radio fluxes than high-resolution radio fluxes,suggesting that they are dominated by kiloparsec-scale, extranuclearemission regions; extranuclear emission may be stronger in type 2Seyferts. Early-type Seyfert galaxies tend to have stronger nuclearradio emission than late-type Seyfert galaxies. V-shaped extendedemission-line regions, indicative of `ionization cones', are usuallyfound in sources with large, collimated radio outflows. Hidden broadlines are most likely to be found in sources with powerful nuclear radiosources. Type 1 and type 2 Seyferts selected by their IRAS 12-μm fluxdensities have well-matched properties.
| Supernovae in the nuclear regions of starburst galaxies
The feasibility of using near-infrared observations to discoversupernovae in the nuclear and circumnuclear regions of nearby starburstgalaxies is investigated. We provide updated estimates of the intrinsiccore-collapse supernova rates in these regions. We discuss the problemof extinction, and present new estimates of the extinction towards 33supernova remnants in the starburst galaxy M 82. This is done using Hiand H2 column density measurements. We estimate the molecularto atomic hydrogen mass ratio to be 7.4+/-1.0 in M 82. We have assemblednear-infrared photometric data for a total of 13 core-collapsesupernovae, some unpublished hitherto. This constitutes the largestdatabase of infrared light curves for such events. We show that theinfrared light curves fall into two classes, `ordinary' and `slowlydeclining'. Template JHKL light curves are derived for both classes. Forordinary core-collapse supernovae, the average peak JHKL absolutemagnitudes are -18.4, -18.6, -18.6 and -19.0 respectively. The slowlydeclining core-collapse supernovae are found to be significantly moreluminous than the ordinary events, even at early times, having averagepeak JHKL absolute magnitudes of -19.9, -20.0, -20.0 and -20.4respectively. We investigate the efficiency of a computerized imagesubtraction method in supernova detection. We then carry out a MonteCarlo simulation of a supernova search using K-band images of NGC 5962.The effects of extinction and observing strategy are discussed. Weconclude that a modest observational programme will be able to discovera number of nuclear supernovae.
| Thermal Infrared 3-5 Micron Colors of Obscured and Unobscured Active Galactic Nuclei
Thermal infrared photometry in the L and M' bands and L-M' colors oftype 1 and type 2 active galactic nuclei (AGNs) are presented. Aftercombining our observations with photometric data at similar wavelengthstaken from the literature, we find that the excess of L-M' colors oftype 2 AGNs (37 sources, 50 data points) relative to type 1 AGNs (27sources, 36 data points), due to dust extinction, is statisticallydetectable but very small. We next investigate the L-M' colors of type 2AGNs by separating less dust obscured type 2 AGNs and highly dustobscured type 2 AGNs. In both cases, the L-M' colors are similar to theintrinsic L-M' color of unobscured AGNs, and the L-M' color excess ofthe latter highly dust obscured type 2 AGNs, due to dust extinction, ismuch smaller than that expected from the Galactic dust extinction curve.Contamination from starbursts and the time lag of flux variation areunlikely to explain this small L-M' color excess, which is bestexplained if the dust extinction curve in the close vicinity of AGNs isfairly flat at 3-5 μm, as a result of a size increase of theabsorbing dust grains through coagulation.
| The 3.4-μm absorption feature towards three obscured active galactic nuclei
The results of 3-4-μm spectroscopy towards the nuclei of NGC 3094,7172, and 7479 are reported. In ground-based 8-13-μm spectra, all thesources have strong absorption-like features at ~10μm, but they donot have detectable polycyclic aromatic hydrocarbon (PAH) emissionfeatures. The 3.4-μm carbonaceous dust absorption features aredetected towards all nuclei. NGC 3094 shows a detectable 3.3-μm PAHemission feature, while NGC 7172 and 7479 do not. Nuclear emission whosespectrum shows dust absorption features but no PAH emission features, isthought to be dominated by highly obscured active galactic nuclei (AGNs)activity. For NGC 7172, 7479, and three other such nuclei in theliterature, we investigate the optical depth ratios between the3.4-μm carbonaceous dust and 9.7-μm silicate dust absorption(τ3.4τ9.7). Theτ3.4τ9.7 ratios towards three highlyobscured AGNs with face-on host galaxies are systematically larger thanthe ratios in the Galactic diffuse interstellar medium or the ratios fortwo highly obscured AGNs with edge-on host galaxies. We suggest that thelarger ratios can be explained if the obscuring dust is so close to thecentral AGNs that a temperature gradient occurs in it. If this idea iscorrect, our results may provide spectroscopic evidence for the presenceof the putative `dusty tori' in the close vicinity of AGNs.
| The SCUBA Local Universe Galaxy Survey - I. First measurements of the submillimetre luminosity and dust mass functions
This is the first of a series of papers presenting results from theSCUBA Local Universe Galaxy Survey (SLUGS), the first statistical surveyof the submillimetre properties of the local Universe. As the initialpart of this survey, we have used the SCUBA camera on the James ClerkMaxwell Telescope to observe 104 galaxies from the IRAS Bright GalaxySample. We present here the 850-μm flux measurements. The 60-, 100-,and 850-μm flux densities are well fitted by single-temperature dustspectral energy distributions, with the sample mean and standarddeviation for the best-fitting temperature beingTd=35.6+/-4.9K and for the dust emissivity indexβ=1.3+/-0.2. The dust temperature was found to correlate with60-μm luminosity. The low value of β may simply mean that thesegalaxies contain a significant amount of dust that is colder than thesetemperatures. We have estimated dust masses from the 850-μm fluxesand from the fitted temperature, although if a colder component ataround 20K is present (assuming a β of 2), then the estimated dustmasses are a factor of 1.5-3 too low. We have made the first directmeasurements of the submillimetre luminosity function (LF) and of thedust mass function. Unlike the IRAS 60-μm LF, these are well fittedby Schechter functions. The slope of the 850-μm LF at lowluminosities is steeper than -2, implying that the LF must flatten atluminosities lower than we probe here. We show that extrapolating the60-μm LF to 850μm using a single temperature and β does notreproduce the measured submillimetre LF. A population of `cold' galaxies(Td<25K) emitting strongly at submillimetre wavelengthswould have been excluded from the 60-μm-selected sample. If suchgalaxies do exist, then this estimate of the 850-μm flux is biased(it is underestimated). Whether such a population does exist is unknownat present. We correlate many of the global galaxy properties with theFIR/submillimetre properties. We find that there is a tendency for lessluminous galaxies to contain hotter dust and to have a greater starformation efficiency (cf. Young). The average gas-to-dust ratio for thesample is 581+/-43 (using both the atomic and molecular hydrogen), whichis significantly higher than the Galactic value of 160. We believe thatthis discrepancy is probably due to a `cold dust' component atTd<=20K in our galaxies. There is a surprisingly tightcorrelation between dust mass and the mass of molecular hydrogen,estimated from CO measurements, with an intrinsic scatter of ~=50percent.
| Absorption-Line Probes of Gas and Dust in Galactic Superwinds
We have obtained moderate resolution (R=few thousand) spectra of the NaI λλ5890, 5896 (Na D) absorption line in a sample of 32far-IR-bright starburst galaxies. In 18 cases, the Na D line in thenucleus is produced primarily by interstellar gas, while cool starscontribute significantly in the others. In 12 of the 18``interstellar-dominated'' cases the Na D line is blueshifted by over100 km s-1 relative to the galaxy systemic velocity (the``outflow sources''), while no case shows a net redshift of more than100 km s-1. The absorption-line profiles in these outflowsources span the range from near the galaxy systemic velocity to amaximum blueshift of ~400-600 km s-1. The outflow sources aregalaxies systematically viewed more nearly face-on than the others. Wetherefore argue that the absorbing material consists of ambientinterstellar material that has been entrained and accelerated along theminor axis of the galaxy by a hot starburst-driven superwind. The Na Dlines are optically thick, but indirect arguments imply total hydrogencolumn densities of NH~few×1021cm-2. This implies that the superwind is expelling matter ata rate comparable to the star formation rate. This outflowing materialis evidently very dusty: we find a strong correlation between the depthof the Na D profile and the line-of-sight reddening. Typical impliedvalues are E(B-V)=0.3-1 over regions several-to-10 kpc in size. Webriefly consider some of the potential implications of theseobservations. The estimated terminal velocities of superwinds inferredfrom the present data and extant X-ray data are typically 400-800km-1, are independent of the galaxy rotation speed, and arecomparable to (substantially exceed) the escape velocities forL* (dwarf) galaxies. The resulting selective loss of metalsfrom shallower potential wells can establish the mass-metallicityrelation in spheroids, produce the observed metallicity in theintracluster medium, and enrich a general IGM to of order10-1 solar metallicity. If the outflowing dust grains cansurvive their journey into the IGM, their effect on observations ofcosmologically distant objects would be significant.
| 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.
| Very Wide Galaxy Pairs of the Northern and Southern Sky
We present highly accurate observations of the 21 cm line of hydrogen ingalaxies made at the Arecibo and Parkes Observatories. The galaxiesobserved have been identified, through rigorous selection criteriaapplied to the CfA and SSRS catalogs, as being members of pairs withprojected separations of up to 1.5 Mpc (H0 = 75 km s-1 Mpc-1). Theseobservations form the completion of the Chengalur-Nordgren galaxy pairsample with data previously published by Chengalur, Nordgren andcolleagues. The new selection criteria used in this paper are anextension to larger projected separations of the criteria usedpreviously. Forty-nine new galaxies are observed, while H I is detectedin 41 of them. With the addition of these galaxies, the completed samplehas highly accurate H I velocities for a total of 219 galaxies.
| Catalogue of HI maps of galaxies. I.
A catalogue is presented of galaxies having large-scale observations inthe HI line. This catalogue collects from the literature the informationthat characterizes the observations in the 21-cm line and the way thatthese data were presented by means of maps, graphics and tables, forshowing the distribution and kinematics of the gas. It containsfurthermore a measure of the HI extension that is detected at the levelof the maximum sensitivity reached in the observations. This catalogueis intended as a guide for references on the HI maps published in theliterature from 1953 to 1995 and is the basis for the analysis of thedata presented in Paper II. The catalogue is only available inelectronic form at the CDS via anonymous ftp 130.79.128.5 orhttp://cdsweb.u-strasbg.fr/Abstract.html
| 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.
| 21 CM H1 Line Spectra of Galaxies in Nearby Clusters
A compilation of HI line fluxes, systemic velocities and line widths ispresented for \Ndet detected galaxies, mostly in the vicinities of 30nearby rich clusters out to a redshift of z ~ .04, specifically for usein applications of the Tully-Fisher distance method. New 21 cm HI lineprofiles have been obtained for ~ 500 galaxies in 27 Abell clustersvisible from Arecibo. Upper limits are also presented for \Nnod galaxiesfor which HI emission was not detected. In order to provide ahomogeneous line width determination optimized for Tully-Fisher studies,these new data are supplemented by the reanalysis of previouslypublished spectra obtained both at Arecibo and Green Bank that areavailable in a digital archive. Corrections for instrumental broadening,smoothing, signal-to-noise and profile shape are applied, and anestimate of the error on the width is given. When corrected forturbulent broadening and viewing angle, the corrected velocity widthspresented here will provide the appropriate line width parameter neededto derive distances via the Tully-Fisher relation.
| 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.
| The bar-enhanced star-formation activities in spiral galaxies.
We use the ratio L_FIR_/L_B_ and the IRAS color index S_25_/S_12_ (bothwidely used as indices of relative star formation rates in galaxies) toanalyse subsets (containing no known AGNs or merging/interactinggalaxies) of: (a) the IRAS Bright Galaxy Sample, (b) galaxies from theoptically complete RSA sample which have IRAS detections in all fourbands, and (c) a volume-limited IR-unselected sample. We confirm thatIR-bright barred (SB) galaxies do, on average, have very significantlyhigher values of the FIR-optical and S_25_/S_12_ ratios (and presumably,higher relative star formation rates, SFR) than that do unbarred ones;the effect is most obvious in the IR colors. We also confirm that thesedifferences are confined to early-type (S0/a-Sbc) spirals and are notevident among late-type systems (Sc-Sdm). Unlike others, we see noenhancement of the SFR in weakly-barred (SAB) galaxies. We furtherconfirm that the effect of bars on the SFR is associated with therelative IR luminosity and show that it is detectable only in galaxieswith L_FIR_/L_B_>1/3, suggesting that as soon as they have anyeffect, bars translate their host galaxies into this relativelyIR-luminous group. Conversely, for galaxies with L_FIR_/L_B_ below ~0.1this luminosity ratio is lower among barred than unbarred systems, againconfirming and quantifying an earlier result. Although there is nosimple physical relation between H I content and star formation, astrong correlation of H I content with the presence of bars has beenfound for early-type spirals with L_FIR_/L_B_>1/3. This suggests thatthe availability of fuel is the factor determining just which galaxiesundergo bar-induced starbursts.
| Multiwavelength Energy Distributions and Bolometric Luminosities of the 12 Micron Galaxy Sample
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995ApJ...453..616S&db_key=AST
| Arm structure in normal spiral galaxies, 1: Multivariate data for 492 galaxies
Multivariate data have been collected as part of an effort to develop anew classification system for spiral galaxies, one which is notnecessarily based on subjective morphological properties. A sample of492 moderately bright northern Sa and Sc spirals was chosen for futurestatistical analysis. New observations were made at 20 and 21 cm; thelatter data are described in detail here. Infrared Astronomy Satellite(IRAS) fluxes were obtained from archival data. Finally, new estimatesof arm pattern radomness and of local environmental harshness werecompiled for most sample objects.
| A volume-limited sample of IRAS galaxies to 4000 km/s, 3: CCD photometry from Palomar and Tololo observatories
An all-sky, quasi-volume-limited sample of 251 spiral galaxies within4000 km/s has been extracted from the redshift survey of InfraredAstronomy Satellite (IRAS) galaxies by Strauss (1992). Distance modulifor these objects estimated via the Tully-Fisher (TF) method allow thepeculiar velocity field and the cosmological density parameter to beconstrained within this volume. The TF relation we exploit relatesdeprojected neutral hydrogen line width to near-infrared luminosity.Herein we present I and V band photometry for 159 members of this sampleobtained with charge coupled device (CCD) cameras at Palomar and Tololoobservatories. Image processing and photometric calibration proceduresare described. Twenty seven objects with multiple calibratedobservations suggest that isophotal I band magnitudes are reproduced toequal to or less than 0.05 mag precision at sigmaI = 23.5 magarcsec-2, and that systematic run-to-run offsets are limitedto equal to or less than 0.05 I mag.
| The extended 12 micron galaxy sample
We have selected an all-sky (absolute value of b greater than or equalto 25 deg) 12 micron flux-limited sample of 893 galaxies from the IRASFaint Source Catalog, Version 2 (FSC-2). We have obtained accurate totalfluxes in the IRAS wavebands by using the ADDSCAN procedure for allobjects with FSC-2 12 micron fluxes greater than 0.15 Jy and increasingflux densities from 12 to 60 microns, and defined the sample by imposinga survey limit of 0.22 Jy on the total 12 micron flux. Its completenessis verified, by means of the classical log N - log S andV/Vmax tests, down to 0.30 Jy, below which we have measuredthe incompleteness down to the survey limit, using the log N - log Splot, for our statistical analysis. We have obtained redshifts (mostlyfrom catalogs) for virtually all (98.4%) the galaxies in the sample.Using existing catalogs of active galaxies, we defined a subsample of118 objects consisting of 53 Seyfert 1s and quasars, 63 Seyfert 2s, andtwo blazars (approximately 13% of the full sample), which is the largestunbiased sample of Seyfert galaxies ever assembled. Since the 12 micronflux has been shown to be about one-fifth of the bolometric flux forSeyfert galaxies and quasars, the subsample of Seyferts (includingquasars and blazars) is complete not only to 0.30 Jy at 12 microns butalso with respect to a bolometric flux limit of approximately 2.0 x10-10 ergs/s/sq cm. The average value of V/Vmaxfor the full sample, corrected for incompleteness at low fluxes, is 0.51+/- 0.04, expected for a complete sample of uniformly distributedgalaxies, while the value for the Seyfert galaxy subsample is 0.46 +/-0.10. We have derived 12 microns and far-infrared luminosity functionsfor the AGNs, as well as for the entire sample. We extracted from oursample a complete subsample of 235 galaxies flux-limited (8.3 Jy) at 60microns. The 60 micron luminosity function computed for this subsampleis in satisfactory agreement with the ones derived from the brightgalaxy sample (BGS) and the deep high-galactic latitude sample, bothselected at 60 microns.
| Near Infrared Images of IRAS Galaxies
.- A complete subsample for imaging in the near infrared of 43far-infrared galaxies (FIRGs) was chosen from the IRAS Point SourceCatalog. Selection criterion was an IRAS spectrum that is typical ofFIRGs. 21 of 43 galaxies were observed at the 2.2m-telescope at LaSilla, Chile. Direct images in I (0.82 microns), H (1.65 microns) and K(2.2 microns) were obtained using a CCD and a 32 x 32 IR-array camerawith a resolution of 0.82" per pixel. Deep images (> 18 mag/square"in K) were achieved by coadding. A correlation between the NIR and FIRemission of the observed galaxies has been found. A comparison ofmorphology within the different filters shows a high correspondance ofstructure on global scales while there are quite often deviations onsmall scales. Measurements of the extension of emission regions pointedout that all NIR sources are extended. A photometric analysis finds thecentral regions of the galaxies being redder than the disks. Fourselected galaxies are discussed in detail. NGC 3256 shows an emissionregion in K which was not detectable in the I-band. The merger IRAS17208-0014 shows a de Vaucouleurs brightness profile in K up to a radialdistance of 10 kpc. IRAS 20550+1656 is an interacting system where a newextranuclear region with an intensive starburst was found. Theinteracting galaxy IRAS 23128-5919 shows two nuclei with a differentbehaviourin the I- and K-band.
| IRAS LRS spectroscopy of galaxies
The study presents IRAS LRS data for 350 galaxies with pointlike IRASsources having either S(12) or S(25) not less than 1.5 Jy. Techniquesare presented which form the mean of an ensemble of LRS spectra, ll ofwhich are only of low signal-to-noise ratio, by quantitative evaluationof the significance of the individual spectra for each object ratherthan mere acceptance of the 'average spectrum' present in the completeLRS data base. Average LRS spectra for groups of galaxies with distinctoptical nuclear properties are formed. Average LRS spectra for severalcategories of objects are presented and interpreted. H II regiongalaxies show the polycyclic aromatic hydrocarbon spectrum of bands inemissions; type 2 Seyferts present a broad emission feature parking near16 microns; LINERs and galaxies without optical emission lines have LRSspectra that decline with wavelength, whereas type 1 Seyferts and WRgalaxies have red spectra suggestive of nonthermal emission processes.
| The far-infrared properties of the CfA galaxy sample. I - The catalog
IRAS flux densities are presented for all galaxies in the Center forAstrophysics magnitude-limited sample (mB not greater than 14.5)detected in the IRAS Faint Source Survey (FSS), a total of 1544galaxies. The detection rate in the FSS is slightly larger than in thePSC for the long-wavelength 60- and 100-micron bands, but improves by afactor of about 3 or more for the short wavelength 12- and 25-micronbands. This optically selected sample consists of galaxies which are, onaverage, much less IR-active than galaxies in IR-selected samples. Itpossesses accurate and complete redshift, morphological, and magnitudeinformation, along with observations at other wavelengths.
| An atlas of mid-infrared spectra of galaxy nuclei
The spectral energy distributions are presented for 60 galaxies forwhich 8-13-micron, and in some cases 17-23-micron, spectra have beenobtained. It is shown how the detailed shape of the 8-13-micronspectrum, and in particular the presence or absence of spectralfeatures, relates to other IR properties. The surprising variety in the10-micron properties and spectral energy distribution of activegalaxies, which contrasts with the homogeneity of those nuclei which aredominated by H II region emission, is demonstrated.
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