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|On the Maximum Luminosity of Galaxies and Their Central Black Holes: Feedback from Momentum-driven Winds|
We investigate large-scale galactic winds driven by momentum deposition.Momentum injection is provided by (1) radiation pressure produced by thecontinuum absorption and scattering of photons on dust grains and (2)supernovae (momentum injection by supernovae is important even if thesupernova energy is radiated away). Radiation can be produced by astarburst or active galactic nucleus (AGN) activity. We argue thatmomentum-driven winds are an efficient mechanism for feedback during theformation of galaxies. We show that above a limiting luminosity,momentum deposition from star formation can expel a significant fractionof the gas in a galaxy. The limiting, Eddington-like luminosity isLM~=(4fgc/G)σ4, where σ isthe galaxy velocity dispersion and fg is the gas fraction;the subscript M refers to momentum driving. A starburst that attainsLM moderates its star formation rate and its luminosity doesnot increase significantly further. We argue that elliptical galaxiesattain this limit during their growth at z>~1 and that this is theorigin of the Faber-Jackson relation. We show that Lyman break galaxiesand ultraluminous infrared galaxies have luminosities nearLM. Since these starbursting galaxies account for asignificant fraction of the star formation at z>~1, this supports ourhypothesis that much of the observed stellar mass in early-type galaxieswas formed during Eddington-limited star formation. Star formation isunlikely to efficiently remove gas from very small scales in galacticnuclei, i.e., scales much smaller than that of a nuclear starburst. Thisgas is available to fuel a central black hole (BH). We argue that a BHclears gas out of its galactic nucleus when the luminosity of the BHitself reaches ~LM. This shuts off the fuel supply to the BHand may also terminate star formation in the surrounding galaxy. As aresult, the BH mass is fixed to beMBH~=(fgκes/πG2)σ4,where κes is the electron scattering opacity. Thislimit is in accord with the observed MBH-σ relation.
|COLA. II. Radio and Spectroscopic Diagnostics of Nuclear Activity in Galaxies|
We present optical spectroscopic observations of 93 galaxies taken fromthe infrared-selected COLA (compact objects in low-power AGNs) sample.These are all galaxies for which we have previously obtainedlow-resolution radio observations and high-resolution (<0.05")Australian Long Baseline Array snapshots. The sample spans the range offar-IR luminosities from normal galaxies to luminous infrared galaxiesand contains a significant number of galaxies involved in galaxy-galaxyinteractions. Of the galaxies observed, 78 (84%) exhibit emission linesindicating that they are either AGNs or actively forming stars(starburst galaxies). Using a newly developed, theoretically based,optical emission line scheme to classify the spectra, we find that 15%of the emission-line galaxies are Seyfert galaxies, 77% are starbursts,and the rest are either borderline AGN/starburst or show ambiguouscharacteristics. We find little evidence for an increase in the fractionof AGNs in the sample as a function of far-IR (FIR) luminosity, incontrast to previous studies, but our sample covers only a small rangein infrared luminosity(1010.5Lsolar<=LFIR<=1011.7 Lsolar), and thus a weak trend may be masked. Instead,as the infrared luminosity increases, so does the fraction of metal-richstarbursts, objects that on more traditional diagnostic diagrams wouldhave been classified as weak, low-ionization, narrow emission lineregions. As a whole the Seyfert galaxies exhibit a small, butstatistically significant, radio excess on the radio-FIR correlationcompared to the galaxies classified as starbursts. Compact (<0.05")radio cores are detected in 55% of the Seyfert galaxies, and thesegalaxies exhibit a significantly larger radio excess than the Seyfertgalaxies in which compact cores were not detected. Our results indicatethat there may be two distinct populations of Seyfert galaxies,``radio-excess'' Seyfert galaxies, which exhibit extended radiostructures and compact radio cores, and ``radio-quiet'' Seyfertgalaxies, in which the majority of the radio emission can be attributedto star formation in the host galaxy. No significant difference is seenbetween the IR and optical spectroscopic properties of Seyfert galaxieswith and without radio cores.
|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.
|An Hα survey aiming at the detection of extraplanar diffuse ionized gas in halos of edge-on spiral galaxies. I. How common are gaseous halos among non-starburst galaxies?|
In a series of two papers we present results of a new Hα imagingsurvey, aiming at the detection of extraplanar diffuse ionized gas inhalos of late-type spiral galaxies. We have investigated a sample of 74nearby edge-on spirals, covering the northern and southern hemisphere.In 30 galaxies we detected extraplanar diffuse emission at meandistances of |z| ~ 1-2 kpc. Individual filaments can be traced out to|z|<=6 kpc in a few cases. We find a good correlation between the FIRflux ratio (S60/S100) and the SFR per unit area(LFIR/D225), based on thedetections/non-detections. This is actually valid for starburst, normaland for quiescent galaxies. A minimal SFR per unit area for the lowestS60/S100 values, at which extended emission hasbeen detected, was derived, which amounts to dotEA25thres = (3.2+/-0.5)*E40ergs-1 kpc-2. There are galaxies where extraplanaremission was detected at smaller values ofLFIR/D225, however, only in combinationwith a significantly enhanced dust temperature. The results corroboratethe general view that the gaseous halos are a direct consequence of SFactivity in the underlying galactic disk.Based on observations collected at the European Southern Observatory,Chile (ESO No. 63.N-0070, ESO No. 64.N-0034, ESO No. 65.N.-0002).
|Galaxy interactions - poor starburst triggers. III. A study of a complete sample of interacting galaxies|
We report on a study of tidally triggered star formation in galaxiesbased on spectroscopic/photometric observations in the optical/near-IRof a magnitude limited sample of 59 systems of interacting and merginggalaxies and a comparison sample of 38 normal isolated galaxies. From astatistical point of view the sample gives us a unique opportunity totrace the effects of tidally induced star formation. In contrast toresults from previous investigations, our global UBV colours do notsupport a significant enhancement of starforming activity in theinteracting/merging galaxies. We also show that, contrary to previousclaims, there is no significantly increased scatter in the colours ofArp galaxies as compared to normal galaxies. We do find support formoderate (a factor of ~ 2-3) increase in star formation in the verycentres of the interacting galaxies of our sample, contributingmarginally to the total luminosity. The interacting and in particularthe merging galaxies are characterized by increased far infrared(hereafter FIR) luminosities and temperatures that weakly correlate withthe central activity. The LFIR/LB ratio however,is remarkably similar in the two samples, indicating that truestarbursts normally are not hiding in the central regions of the FIRluminous cases. The gas mass-to-luminosity ratio in optical-IR ispractically independent of luminosity, lending further support to thepaucity of true massive starburst galaxies triggered byinteractions/mergers. We estimate the frequency of such cases to be ofthe order of ~ 0.1% of the galaxies in an apparent magnitude limitedsample. Our conclusion is that interacting and merging galaxies, fromthe global star formation aspect, generally do not differ dramaticallyfrom scaled up versions of normal, isolated galaxies. No drastic changewith redshift is expected. One consequence is that galaxy formationprobably continued over a long period of time and did not peak at aspecific redshift. The effects of massive starbursts, like blowoutscaused by superwinds and cosmic reionization caused by starburstpopulations would also be less important than what is normally assumed.Based on observations collected at the European Southern Observatory, LaSilla, Chile.
|The infrared supernova rate in starburst galaxies|
We report the results of our ongoing search for extincted supernovae(SNe) at near-infrared wavelengths. We have monitored at 2.2 mu m asample of 46 Luminous Infrared Galaxies and detected 4 SNe. The numberof detections is still small but sufficient to provide the firstestimate of supernova rate at near-infrared wavelengths. We measure a SNrate of SNNIR_r=7.6+/- 3.8 SNu which is an order of magnitudelarger than observed in quiescent galaxies. On the other hand, theobserved near-infrared rate is still a factor 3-10 smaller than thatestimated from the far-infrared luminosity of the galaxies. Amongvarious possibilities, the most likely scenario is that dust extinctionis so high (AV>30) to obscure most SNe even in thenear-IR.The role of type Ia SNe is also discussed within this context. We derivethe type Ia SN rate as a function of the stellar mass of the galaxy andfind a sharp increase toward galaxies with higher activity of starformation. This suggests that a significant fraction of type Ia SNe areassociated with young stellar populations.Finally, as a by-product, we give the average K-band light curve ofcore-collapse SNe based on all the existing data, and review therelation between SN rate and far-infrared luminosity.Based on observations collected at the European Southern Observatory,Chile (proposal 66.B-0417), at the Italian Telescopio Nazionale Galileo(TNG) operated on the island of La Palma by the Centro Galileo Galileiof the INAF (Istituto Nazionale di Astrofisica), and at the StewardObservatory 61'' telescope.
|First Results from the COLA Project: The Radio-Far-Infrared Correlation and Compact Radio Cores in Southern COLA Galaxies|
We present the first results from the COLA (compact objects in low-powerAGNs) project, which aims to determine the relationship between onefacet of AGN activity, the compact radio core, and star formation in thecircumnuclear region of the host galaxy. This will be accomplished bythe comparison of the multiwavelength properties of a sample of AGNswith compact radio cores to those of a sample of AGNs without compactcores and a matched sample of galaxies without AGNs. In this paper wediscuss the selection criteria for our galaxy samples and present theinitial radio observations of the 107 southern(δ<0deg) galaxies in our sample. Low-resolution ATCAobservations at 4.8, 2.5, and 1.4 GHz and high-resolution,single-baseline snapshots at 2.3 GHz with the Australian Long BaselineArray (LBA) are presented. We find that for the majority of the galaxiesin our sample, the radio luminosity is correlated with the far-infrared(FIR) luminosity. However, a small number of galaxies exhibit a radioexcess causing them to depart from the FIR-radio correlation. Compactradio cores are detected at fluxes greater than 1.5 mJy in nine of the105 galaxies observed with the LBA. The majority (8/9) of these galaxiesexhibit a radio excess, and 50% (7/14) of the galaxies that lie abovethe radio-FIR correlation by more than 1 σ have compact radiocores. The emission from the compact cores is too weak to account forthis radio excess, implying that there are radio structures associatedwith the compact cores that extend farther than the 0.05" resolution(corresponding to a linear scale 11-22 pc) of the LBA. There is noevidence that the radio luminosity of the compact cores is correlatedwith the FIR galaxy luminosity, indicating that the core contributeslittle to the overall FIR emission of the galaxy. The galaxies withcompact cores tend to be classified optically as AGNs, with two-thirds(6/9) exhibiting Seyfert-like optical emission line ratios, and theremaining galaxies classified either as composite objects (2/9) orstarburst (1/9). The galaxies classified optically as AGNs also exhibitthe largest radio excesses, and we therefore conclude that a large radioexcess on the radio-FIR correlation is a strong indication of an AGNwith a compact radio core.
|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.
|Toward a Unified Model for the ``Diffuse Ionized Medium'' in Normal and Starburst Galaxies|
The ``diffuse ionized medium'' (DIM) makes up a significant fraction ofthe mass and ionization requirements of the interstellar medium of theMilky Way and is now known to be an energetically significant componentin most normal star-forming galaxies. Observations of the ionized gas instarburst galaxies have revealed the presence of gas with strikingsimilarities to the DIM in normal galaxies: relatively low surfacebrightness and strong emission from low-ionization forbidden lines like[S II] lambdalambda6716, 6731. In this paper we analyze Hα imagesand long-slit spectra of samples of normal and starburst galaxies tobetter understand the nature of this diffuse, low surface brightnessgas. We find that in both samples there is a strong inverse correlationbetween the Hα surface brightness (Sigma_Hα) and the [SII]/Hα line ratio at a given location in the galaxy. However, thecorrelation for the starbursts is offset brightward by an order ofmagnitude in Hα surface brightness at a given line ratio. Incontrast, we find that all the galaxies (starburst and normal alike)define a universal relation between line ratio and the relative Hαsurface brightness (Sigma_Hα/Sigma_e, where Sigma_e is the meanHα surface brightness within the galaxy half-light radius). Weshow that such a universal correlation is a natural outcome of a modelin which the DIM is photoionized gas that has a characteristic thermalpressure (P) that is proportional to the mean rate of star formation perunit area in the galaxy (Sigma_SFR). Good quantitative agreement withthe data follows if we require the constant of proportionality to beconsistent with the values of P and Sigma_SFR in the local disk of theMilky Way. Such a scaling between P and Sigma_SFR may arise eitherbecause feedback from massive stars heats the ISM or because Sigma_SFRis determined (or limited) by the mean gas pressure.
|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 (to188.8.131.52) or via http://cdsweb.u-strasbg.fr/Abstract.html
|Optical Rotation Curves and Linewidths for Tully-Fisher Applications|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.2402C&db_key=AST
|The Montreal Blue Galaxy Survey.III.Third List of UV-Bright Candidates|
We present and discuss the latest addition of the Montreal Blue Galaxy(MBG) survey. Inspection of 59 Curtis Schmidt plates resulted in theidentification of 135 new UV-bright galaxies with B < 15.5. Thisbrings the total number of MBGs to 469. New results of the V/V_m testshow that our survey is complete to B = 14.7. From our most recentspectroscopic follow-up, we confirm the discovery of one new Seyfert 1galaxy and possibly one new Seyfert 2 galaxy. We confirm also the biasof the MBG survey towards the low-excitation and metal rich StarburstNucleus Galaxies (SBNGs). The spectral characteristics of the MBGs aresimilar to those of the infrared luminous IRAS galaxies. As a commoncharacteristic, they show a mean ratio Log([NII]/Hα ) in excess of0.2 dex as compared to normal disk HII regions. In general, the MBGshave lower far-infrared luminosities (LIR < 10(11)Lsun) and are nearer (z < 0.05) than the luminous IRASgalaxies. The distribution of the morphologies of the MBGs indicates ahigh number of early-type spirals (Sb and earlier). Nearly half of thesegalaxies also possess a bar. In our sample, the fraction of galaxieswith bars depends on the morphology and increases towards the late-typespirals. However, if we consider only isolated galaxies, the late-typespirals show a clear tendency to be barred. Signs of a recentinteraction with neighbor galaxies are obvious only in 24% of ourcandidates. Although this number is only a lower limit, it isnevertheless sufficiently low to suggest that in a majority of massivegalaxies the burst of star formation do not depends solely on dynamicalprocesses.
|Parameters of 2447 Southern Spiral Galaxies for Use in the Tully-Fisher Relation|
I-band luminosities, rotational velocities, and redshifts of 1092 spiralgalaxies have been measured by CCD photometry and Hα spectroscopyusing the 1 m and 2.3 m telescopes at Siding Spring Observatory,respectively. The results are tabulated. Luminosity profiles andHα rotation curves are given for the galaxies. When these resultsare combined with similar data for 1355 spiral galaxies publishedpreviously (Mathewson, Ford, & Buchhorn, hereafter Paper I), itprovides a large, uniform, and unique data set with which to measure,via the Tully-Fisher relation, the peculiar velocities of galaxies inthe local universe to a distance of 11,000 km s^-1^ (Mathewson &Ford). Taking advantage of the opportunity for publishing this data inmachine-readable form, in the CD-ROM, we have also included similar datafor the 1355 galaxies in Paper I.
|A 1.425 GHz Atlas of the IRAS Bright Galaxy Sample, Part II|
Galaxies with δ >= -45^deg^ and |b| >= 10^deg^ in the IRASBright Galaxy Sample, Part II, were observed at 1.425 GHz by the VeryLarge Array in its B, CnB, C, DnC, and D configurations. An atlas ofradio contour maps and a table listing the principal radio sourceparameters (position, flux density, angular size) are given. This atlasof 187 galaxies supplements the 1.49 GHz atlas of 313 galaxies in therevised Bright Galaxy Sample, Part I. Together, they are complete forextragalactic sources stronger than S = 5.24Jy at λ = 60 micronsin the area |b| > 10^deg^, δ > -45^deg^. To the extent thatthe far-infrared and radio brightness distributions overlap, these radiomaps provide the most accurate positions and high-resolution images ofthe brightest extragalactic far-infrared sources.
|The Nature of Starburst Galaxies|
Utilizing a large sample of infrared-selected starburst galaxies havingoptical images and long-slit spectra, we explore the interrelationshipsbetween the properties of starbursts and relate these properties tothose of the "host" galaxy. We find that the half-light radius of theHα-emitting region (r_e,Hα_) enters into severalcorrelations that suggest it is physically related to the actualstarburst radius. Most suggestively, the effective IR surface brightness(L_IR_/πr^2^_e,Hα_) correlates strongly with the far-IR colortemperature. This can be reproduced roughly with an idealized model of asurrounding dust screen whose far-IR emissivity is determined by thelocal energy density of UV starburst light. Typical values forr_e,Hα_ are a few hundred pc to a few kpc (with the Hαemission being significantly more compact than the red starlight). Thisconfirms the "circumnuclear" scales of typical starbursts. We show alsothat starbursts seem to obey a limiting IR surface brightness of about10^11^L_sun_ kpc^2^, corresponding to a maximum star formation rate ofabout 20 M_sun_ yr^-1^ kpc^2^ for a normal initial mass function. Weargue that this upper limit suggests that starbursts are self-regulatingin some way. We show that most of these galaxies have relatively normal,symmetric rotation curves. This implies that the galactic disk need notsuffer severe dynamical damage in order to "fuel" a typical starburst.We show also that the starbursts occur preferentially in the innerregion of solid-body rotation. This may reflect both bar-driven inflowof gas to the region between the inner Lindblad resonances and thedominance of gravitational instability over tidal shear in this region.Most of the starbursts reside in galaxies with rotation speeds of120-200 km s^-1^ (compared to 220 km s^-1^ for a fiducial L^*^ galaxylike the Milky Way). The lack of a correlation between galaxy rotationspeed and starburst luminosity means that even relatively modestgalaxies (masses~10% of the Milky Way) can host powerful starbursts. Weargue on the basis of causality that the internal velocity dispersion ina starburst sets an upper limit to the star formation rate. The mostextreme starbursts approach this limit, but most are well below.Finally, we show that the relative narrowness of the nuclear emissionlines in starbursts (relative to the galaxy rotation speed) arisesbecause the gas in the nuclear "bin" usually does not sample fully thesolid-body part of the rotation curve. The narrow lines do notnecessarily imply that the starburst is not in dynamical equilibrium.
|Ionized Gas in the Halos of Edge-on Starburst Galaxies: Evidence for Supernova-driven Superwinds|
Supernova-driven galactic winds ("superwinds") have been invoked toexplain many aspects of galaxy formation and evolution. Such windsshould arise when the supernova rate is high enough to create a cavityof very hot shock-heated gas within a galaxy. This gas can then expandoutward as a high-speed wind that can accelerate and heat ambientinterstellar or circum-galactic gas causing it to emit optical lineradiation and/or thermal X-rays. Theory suggests that such winds shouldbe common in starburst galaxies and that the nature of the winds shoulddepend on the star formation rate and distribution. In order tosystematize our observational understanding of superwinds (determinetheir incidence rate and the dependence of their properties on the starformation that drives them) and to make quantitative comparisons withthe theory of superwinds, we have analyzed data from an opticalspectroscopic and narrow-band imaging survey of an infrared flux-limited(S_60 microns_ >= 5.4 Jy) sample of about 50 IR-warm (S_60microns_/S_100 microns_ > 0.4), starburst galaxies whose stellardisks are viewed nearly edge-on (b/a ~> 2). This sample containsgalaxies with infrared luminosities from ~10^10^-10^12^ L_sun_ andallows us to determine the properties of superwinds over a wide range ofstar formation rates. We have found that extraplanar emission-line gasis a very common feature of these edge-on, IR-bright galaxies and theproperties of the extended emission-line gas are qualitatively andquantitatively consistent with the superwind theory. We can summarizethese properties as morphological, ionization, dynamical, and physical.1. Morphological properties.-Extraplanar filamentary and shell-likeemission-line morphologies on scales of hundreds of parsecs to 10 kpcare common, there is a general "excess" of line emission along the minoraxis, the minor axis emission-line "excess" correlates with "IRactivity," and the minor axis emission-line "excess" also correlateswith the relative compactness of the Hα emission. 2. Ionizationproperties.-Line ratios become more "shocklike" (high ratios of [N II]λ6583/Hα, [S II] λλ6716, 6731/Hα, and[O I] λ6300/Hα) at more extreme IR properties, the most"shocklike" line ratios occur far out along the minor axis, "shocklike"line ratios corresponds to broad emission lines, and the most extremeline ratios correspond to the most extreme IR properties, especially forthe emission-line gas farthest out along the minor axis. 3. Dynamicalproperties.-Lines are broader along the minor axis than along the majoraxis, line widths correlate with the "IR activity," line widthscorrelate with line ratios, line widths do not correlate with rotationspeed, minor axis shear (a measure of the systematic velocity changealong the minor axis) correlates with "IR activity," minor axis shearcorrelates with axial ratio and implies that a face-on galaxy would havean outflow/inflow speed of 170_-80_^+150^ km s^-1^, and the starburstsshow statistically blueward line profile asymmetries. 4. Physicalproperties.-Pressures in the nuclei of these galaxies are 3 orders ofmagnitude higher than the ambient pressure in the interstellar medium ofour galaxy, and the pressure falls systematically with radius. Whilenone of these results are in themselves proof of the superwind model, webelieve that when the results are taken as a whole, the superwindhypothesis is very successful in explaining what we have observed. Inaddition, these results have implications for galaxy evolution and thenature of the intergalactic medium. Those galaxies with the bestevidence for driving superwinds are those with large IR luminosities(L_IR_ ~> 10^44^ ergs s^-1^), large IR excesses (L_IR_/L_OPT_ ~>2), and warm far-IR colors (S_60 microns_/S_100 microns_ ~> 0.5).Integrating over the local far-IR luminosity function for galaxiesmeeting the above criteria, multiplying by the age of the universe, andthen dividing by the local space density of galaxies implies thatsuperwinds have carried out ~5 x 10^8^ M_sun_ in metals and 10^59^ ergsin kinetic plus thermal energy per average (Schecter L^*^) galaxy overthe history of the universe. We note that these two quantities areapproximately equal to the mass of metals contained inside an averagegalaxy and the gravitational binding energy of an average galaxy,respectively. Even with the conservative assumptions of this calculation(we have neglected that star formation rates were presumably higher inthe early universe), it is obvious that superwinds may have a majorimpact on the evolution of individual galaxies and the intergalacticmedium by injecting mass, metals, and kinetic energy into the galactichalo and potentially the intergalactic medium.
|Rotation Curves of 967 Spiral Galaxies|
We present the rotation curves of 967 southern spiral galaxies, obtainedby deprojecting and folding the raw Hα data originally publishedby Mathewson, Ford, & Buchhorn (1992). For 900 objects, we alsopresent, in figures and tables, the rotation curves smoothed on scalescorresponding to 5%-20% of the optical size; of these, 80 meet objectiveexcellence criteria and are suitable for individual detailed massmodeling, while 820, individually less compelling mainly because of themoderate statistics and/or limited extension, are suitable forstatistical studies. The remaining 67 curves suffer from severeasymmetries, small statistics, and large internal scatter that maylargely limit their use in galaxy structure studies. The deprojectedfolded curves, the smoothed curves, and various related quantities areavailable via anonymous ftp at galileo.sissa.it in the directory/users/ftp/pub/psrot.
|Ionized gas in the halos of edge-on, starburst galaxies: Data and results|
We present narrowband H-alpha and broadband R images, as well aslong-slit spectra oriented along the minor and major axes of a sample ofabout 50 edge-on (a/b greater than or equal to 2), infrared-warm(S60 microns/S100 microns greater than 0.04),infrared-bright S60 microns greater than or equal to 5.4 Jygalaxies. The infrared luminosity of the sample ranges over1010 - 1012 solar luminosity. The spatiallyresolved spectroscopy includes the measurement of velocity relative tothe nuclear velocity, full width at half-maximum, total integrated fluxin the profile (for those spectra taken under photometric conditions)for the lines (N II) lambda lambda 6548, 6583, (O I) lambda 6300,H-alpha, and (S II) lambda lambda 6716, 6713 and line ratios as afunction of slit position along both the major and minor axes. Theresolution of the spectra are between about 3 and 5 A. The spectroscopicdata are presented for 5 bins along each axis -- a nuclear bin that is asum of the CCD rows that cover the half-light diameter centered on thenucleus of the galaxy, two near-nuclear bins which are sums of the CCDrows that cover from one to two half-light radii on each side of thenucleus, and two off-nuclear bins which are sums of the rows at nucleardistances greater than two half-light radii on each side of the nucleus.Additionally, we present recession velocities, nuclear line asymmetries,rotation speeds, minor axis velocity shears, H-alpha luminosities,R-band absolute magnitudes, minor axis H-alpha `excess' and effectiveradii of the galaxies in h-alpha and the R continuum. We deferdiscussion of the properties of the emission-line gas and theircorrelation with the infrared properties of this sample of galaxies to alater paper and limit ourselves to a presentation of the data andanalysis.
|The Catalog of Southern Ringed Galaxies|
The Catalog of Southern Ringed Galaxies (CSRG) is a comprehensivecompilation of diameters, axis ratios, relative bar position angles, andmorphologies of inner and outer rings, pseudorings, and lenses in 3692galaxies south of declination -17 deg. The purpose of the catalog is toevaluate the idea that these ring phenomena are related to orbitalresonances with a bar or oval in galaxy potentials. The catalog is basedon visual inspection of most of the 606 fields of the Science ResearchCouncil (SRC) IIIa-J southern sky survey, with the ESO-B, ESO-R, andPalomar Sky surveys used as auxiliaries when needed for overexposed coreregions. The catalog is most complete for SRC fields 1-303 (mostly southof declination -42 deg). In addition to ringed galaxies, a list of 859mostly nonringed galaxies intended for comparison with other catalogs isprovided. Other findings from the CSRG that are not based on statisticsare the identification of intrinsic bar/ring misalignment; bars whichunderfill inner rings; dimpling of R'1pseudorings; pointy, rectangular, or hexagonal inner or outer ringshapes; a peculiar polar-ring-related system; and other extreme examplesof spiral structure and ring morphology.
|The IRAS Bright Galaxy Survey - Part II: Extension to Southern Declinations (delta ~< -30), and Low Galactic Latitudes (f<|b|=30 degrees)|
Complete IRAS Observations and redshifts are reported for all sourcesidentified in the IRAS Bright Galaxy Survey-Part II (hereafter referredto as BGS_2_). Source positions, radial velocities, optical magnitudes,and total flux densities, peak flux densities, and spatial extents at12, 25, and 100 ,microns are reported for 288 sources having 60 micronflux densities > 5.24 Jy, the completeness limit of the originalBright Galaxy Survey [Soifer et al., AJ, 98,766(1989)], hereafterreferred to as BGS_1_. These new data represent the extension of theIRAS Bright Galaxy Survey to southern declinations,δ<~-30^deg^, and low Galactic latitudes,5^deg^<|b|<30^deg^. Although the sky coverage of the BGS_2_ (~19935 deg^2^) is 37% larger than the sky coverage of the BGS_1_, thenumber of sources is 8% smaller due primarily to large scale structurein the local distribution of galaxies. Otherwise, the sources in theBGS_2_ show similar relationships between number counts and flux densityas observed for the 313 sources in the BGS_1_. The BGS_2_ along with theearlier BGS, represents the best sample currently available for definingthe infrared properties of galaxies in the local (z <~ 0.1) Universe.
|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.
|A southern sky survey of the peculiar velocities of 1355 spiral galaxies|
The paper presents data from photometric and spectroscopic observationsof 1355 southern spiral galaxies and uses them to determine theirdistances and peculiar velocities via the Tully-Fisher (TF) relation.I-band CCD surface photometry was carried out using the 1-m and 3.9-mtelescopes at Siding Spring Observatory. H-alpha rotation curves for 965galaxies and 551 H I profiles are presented. The physical parameters,photometric and velocity data, distances, and peculiar velocities of thegalaxies are presented in tabular form. The mean distance, systemicvelocity, and average peculiar velocity of 24 clusters in the sample aregiven. TF diagrams are presented for each cluster.
|Southern Sky Redshift Survey - The catalog|
The catalog of radial velocities for galaxies which comprise thediameter-limited sample of the Southern Sky Redshift Survey ispresented. It consolidates the data of observations carried out at theLas Campanas Observatory, Observatorio Nacional, and South AfricanAstronomical Observatory. The criteria used for the sample selection aredescribed, as well as the observational procedures and the techniqueutilized to obtain the final radial velocities. The intercomparisonbetween radial velocity measurements from different telescopes indicatesthat the final data base is fairly homogeneous with a typical error ofabout 40 km/s. The sample is at present 90 percent complete, and themissing galaxies are predominantly objects with very low surfacebrightness for which it is very difficult to obtain optical redshifts.
|The plane W(Na I) X W(Mg I) - Effects of interstellar Na I in a sample of southern galaxies|
Galaxy spectra from a subsample of the Southern Sky Redshift Survey databank were used to study the equivalent width plane for the lines Na Ilambda 5893 A vs Mg I lambda 5175 A. An estimate of how important thecontribution of the interstellar gas for the sodium line is compared tothat of the stellar population. The sample is made up of galaxies withmorphological types from E to Sc and are distributed up to radialvelocities of 25,000 km/s, most of them smaller than 15,000 km/s. Mostearly type galaxies with dust lanes, particularly nearly edge-on So's,present an enhancement of the Na I line. Inclined spiral galaxies tendto present enhanced Na I with respect to face-on spirals. This tendency,previously found in a smaller sample of galaxies limited to V equal toor less than 6000 km/s, is now confirmed for more distant ones. In thelarge velocity sample it shows the global bulge rather than the verynucleus; the persistence of the effect suggests that the scale height ofthe gas layer in the central disk can reach a considerable fraction ofthe bulge radius.
|A study of a complete sample of interacting galaxies. I - Presentation of the sample and the UBVRIJHK photometry|
An investigation is presented on what effects galaxy-galaxy interactionhas on the properties of the involved galaxies. A magnitude limitedsample of interacting galaxies is presented, together with a controlsample of isolated galaxies. The Cousins UBVRI and Johnson JHKphotometry of all galaxies included in the samples is also presented.
|The Southern Supercluster|
The Southern Supercluster is described using data compiled from fivecatalogs, reduced to a homogeneous system following RC2. In terms ofmass, luminosity, and mass-to-light ratio, the Southern Superclustercompares well with the Coma and Hercules superclusters, but is lessmassive than the Local Supercluster. It is shown that, even though theSouthern Supercluster is the nearest supercluster to the LocalSupercluster, it is well separated from the Local Supercluster. However,there is evidence of a tenuous stream of galaxies connecting theSouthern Supercluster with the Perseus Supercluster.
|Southern Galaxy Catalogue.|
|Redshifts for 228 southern galaxies|
In this paper, new redshifts are presented for 228 galaxies locatedsouth of declination -30 deg. The observations were made with aphoton-counting Reticon detector on the Observatorio Nacional (ON)60-in. telescope. The detector is identical to the one used at MountHopkins for the CfA Redshift Survey, and the redshifts were derivedusing the same data-analysis system. A preliminary comparison withpublished 21-cm redshifts indicates that the velocities have azero-point offset of about -4 km/s, with a typical uncertainty of 40km/s. The observations reported here are the initial results of theON-CfA Redshift Survey currently being undertaken in the southernhemisphere.
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