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Low-luminosity Type II supernovae: spectroscopic and photometric evolution
In this paper we present spectroscopic and photometric observations forfour core-collapsed supernovae (SNe), namely SNe 1994N, 1999br, 1999euand 2001dc. Together with SN 1997D, we show that they form a group ofexceptionally low-luminosity events. These SNe have narrow spectrallines (indicating low expansion velocities) and low luminosities atevery phase (significantly lower than those of typical core-collapsedsupernovae). The very-low luminosity during the 56Coradioactive decay tail indicates that the mass of 56Niejected during the explosion is much smaller (MNi~ 2-8× 10-3 Msolar) than the average(MNi~ 6-10 × 10-2 Msolar). Twosupernovae of this group (SN 1999br and SN 2001dc) were discovered veryclose to the explosion epoch, allowing us to determine the lengths oftheir plateaux (~100 d) as well as establishing the explosion epochs ofthe other, less completely observed SNe. It is likely that this group ofSNe represent the extreme low-luminosity tail of a single continuousdistribution of Type II plateau supernovae events. Their kinetic energyis also exceptionally low. Although an origin from low-mass progenitorshas also been proposed for low-luminosity core-collapsed SNe, recentwork provides evidence in favour of the high-mass progenitor scenario.The incidence of these low-luminosity SNe could be as high as 4-5 percent of all Type II SNe.
| The ISOPHOT 170 μm Serendipity Survey II. The catalog of optically identified galaxies%
The ISOPHOT Serendipity Sky Survey strip-scanning measurements covering≈15% of the far-infrared (FIR) sky at 170 μm were searched forcompact sources associated with optically identified galaxies. CompactSerendipity Survey sources with a high signal-to-noise ratio in at leasttwo ISOPHOT C200 detector pixels were selected that have a positionalassociation with a galaxy identification in the NED and/or Simbaddatabases and a galaxy counterpart visible on the Digitized Sky Surveyplates. A catalog with 170 μm fluxes for more than 1900 galaxies hasbeen established, 200 of which were measured several times. The faintest170 μm fluxes reach values just below 0.5 Jy, while the brightest,already somewhat extended galaxies have fluxes up to ≈600 Jy. For thevast majority of listed galaxies, the 170 μm fluxes were measured forthe first time. While most of the galaxies are spirals, about 70 of thesources are classified as ellipticals or lenticulars. This is the onlycurrently available large-scale galaxy catalog containing a sufficientnumber of sources with 170 μm fluxes to allow further statisticalstudies of various FIR properties.Based on observations with ISO, an ESA project with instruments fundedby ESA Member States (especially the PI countries: France, Germany, TheNetherlands and the UK) and with the participation of ISAS and NASA.Members of the Consortium on the ISOPHOT Serendipity Survey (CISS) areMPIA Heidelberg, ESA ISO SOC Villafranca, AIP Potsdam, IPAC Pasadena,Imperial College London.Full Table 4 and Table 6 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/422/39
| Classifications of the Host Galaxies of Supernovae, Set II
Classifications on the DDO system are given for an additional 231 hostgalaxies of supernovae that have been discovered during the course ofthe Lick Observatory Supernova Search with the Katzman Automatic ImagingTelescope (KAIT). This brings the total number of hosts of supernovae(SNe) discovered (or independently rediscovered) by KAIT, which have sofar been classified on a homogeneous system, to 408. The probabilitythat SNe Ia and SNe II have a different distribution of host-galaxyHubble types is found to be 99.7%. A significant difference is alsofound between the distributions of the host galaxies of SNe Ia and ofSNe Ibc (defined here to include SNe Ib, Ib/c, and Ic). However, nosignificant difference is detected between the frequency distributionsof the host galaxies of SNe II and SNe IIn. This suggests that SNe IInare generally not SNe Ia embedded in circumstellar material that aremasquerading as SNe II. Furthermore, no significant difference is foundbetween the distribution of the Hubble types of the hosts of SNe Ibc andof SNe II. Additionally, SNe II-P and SNe II-L are found to occur amongsimilar stellar populations. The ratio of the number of SNe Ia-pec tonormal SNe Ia appears to be higher in early-type galaxies than it is ingalaxies of later morphological types. This suggests that the ancestorsof SNe Ia-pec may differ systematically in age or composition from theprogenitors of normal SNe Ia. Unexpectedly, five SNe of Types Ib/c, II,and IIn (all of which are thought to have massive progenitors) are foundin host galaxies that are nominally classified as types E and S0.However, in each case the galaxy classification is uncertain, or newlyinspected images show evidence suggesting a later classification. Amongthese five objects, NGC 3720, the host galaxy of SN 2002at, wasapparently misidentified in the Carnegie Atlas of Galaxies.
| SWIRE: The SIRTF Wide-Area Infrared Extragalactic Survey
The SIRTF Wide-Area Infrared Extragalactic Survey (SWIRE), the largestSIRTF Legacy program, is a wide-area imaging survey to trace theevolution of dusty, star-forming galaxies, evolved stellar populations,and active galactic nuclei (AGNs) as a function of environment, fromredshifts z~3 to the current epoch. SWIRE will survey sevenhigh-latitude fields, totaling 60-65 deg2 in all seven SIRTFbands: Infrared Array Camera (IRAC) 3.6, 4.5, 5.6, and 8 μm andMultiband Imaging Photometer for SIRTF (MIPS) 24, 70, and 160 μm.Extensive modeling suggests that the Legacy Extragalactic Catalog maycontain in excess of 2 million IR-selected galaxies, dominated by (1)~150,000 luminous infrared galaxies (LIRGs;LFIR>1011 Lsolar) detected by MIPS (andsignificantly more detected by IRAC), ~7000 of these with z>2 (2) 1million IRAC-detected early-type galaxies (~2×105 withz>1 and ~10,000 with z>2) and (3) ~20,000 classical AGNs detectedwith MIPS, plus significantly more dust-obscured quasi-stellarobjects/AGNs among the LIRGs. SWIRE will provide an unprecedented viewof the evolution of galaxies, structure, and AGNs.The key scientific goals of SWIRE are (1) to determine the evolution ofactively star forming and passively evolving galaxies in order tounderstand the history of galaxy formation in the context of cosmicstructure formation; (2) to determine the evolution of the spatialdistribution and clustering of evolved galaxies, starbursts, and AGNs inthe key redshift range 0.5
| Extraplanar Emission-Line Gas in Edge-on Spiral Galaxies. II. Optical Spectroscopy
The results from deep long-slit spectroscopy of nine edge-on spiralgalaxies with known extraplanar line emission are reported. Emissionfrom Hα, [N II] λλ6548, 6583, and [S II]λλ6716, 6731 is detected out to heights of a fewkiloparsecs in all of these galaxies. Several other fainter diagnosticlines such as [O I] λ6300, [O III] λλ4959, 5007,and He I λ5876 are also detected over a smaller scale. Therelative strengths, centroids, and widths of the various emission linesprovide constraints on the electron density, temperature, reddening,source(s) of ionization, and kinematics of the extraplanar gas. In allbut one galaxy, photoionization by massive OB stars alone hasdifficulties explaining all of the line ratios in the extraplanar gas.Hybrid models that combine photoionization by OB stars and anothersource of ionization such as photoionization by turbulent mixing layersor shocks provide a better fit to the data. The (upper limits on the)velocity gradients measured in these galaxies are consistent with thepredictions of the galactic fountain model to within the accuracy of themeasurements.
| 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).
| Supernova 2001dc in NGC 5777
IAUC 7662 available at Central Bureau for Astronomical Telegrams.
| Environment status of blue compact galaxies and trigger of star formation
The work studies of the environment of low-mass galaxies with activestar formation (SF) and a possible trigger of SF bursts due togravitational interaction. Following the study by Taylor et al. (1995),we extend the search for possible disturbing galaxies of various massesto a much larger sample of 86 BCGs from the sky region of the SecondByurakan survey (SBS). The BCG magnitudes and radial velocities arerevised and up-dated. The sample under study is separated by thecriteria: EW([O III]λ5007) > 45 Å andVh < 6,000 kms and should be representative of alllow-mass galaxies which experience SF bursts. We argue that the moderatetidal disturbers should be taken into account, and incorporate therespective range of distances in the search for disturbing neighbours.The majority of the neighbours in the vicinity of the studied BCGs arefound through the study of their environment among UZC (Falco et al.\cite{Falco99}) galaxies, and the follow-up careful search of thefainter galaxies in the NED database. For the remaining BCGs, theneighbouring galaxies are found based on the results of the SAO 6mtelescope spectroscopy. By studing the data on the radial velocities ofgalaxies in the vicinity of BCGs we found: 1) 33 of the studied BCGs(~38.5%) are associated with significantly brighter galaxies (Δ B>= 1.5m); 2) 23 BCGs (~26.5%) have neighbours either ofcomparable or significantly lower brightness; 3) 14 of the studied BCGs(16\%) with no evident associated galaxy are either certain, orprobable, mergers. Summarizing, we conclude that in ~80% (or more) BCGsfrom the studied sample, the SF bursts are triggered either by tidalaction of various strengths from other galaxies, or due to mergers oflow-mass galaxies. We briefly discuss the implications of our mainconclusion for evolutionary links of BCGs to other types of low-massgalaxies. Part of our sample falls into the volume belonging to theLocal Supercluster. Therefore we formulate the results separately on the``Local Supercluster volume'' and ``general field region''. The totalfractions of BCGs likely triggered by interaction with other galaxy arerespectively, ~84.5% and 80% for the nearby volume and for the generalfield. The fractions of BCGs with significantly brighter disturbers inthese two groups are seemingly different (~54±14% vs.~31.5±7%, respectively). Among the so called ``isolated'' BCGs(that is, without a bright neighbouring galaxy) in both the LocalSupercluster volume and in general field, ~43±10% are probablydisturbed by dwarf galaxies and ~26±8% have a merger morphology.In the Appendix we present the results of the spectroscopy with the SAO6m telescope of 27 galaxies in an attempt to find possible disturbinggalaxies in the vicinity of some of the sample BCGs. Tables 2, 3 and A.1with their notes and Figs. A.1-A.3 are only available in electronic format http://www.edpsciences.org
| A list of peculiar velocities of RFGC galaxies
A list of radial velocities, HI line widths and peculiar velocities of1327 galaxies from the RFGC catalogue has been compiled using actualobservations and literature data. The list can be used for studying bulkmotions of galaxies, construction of the field of peculiar velocitiesand other tasks.
| Box- and peanut-shaped bulges. I. Statistics
We present a classification for bulges of a complete sample of ~ 1350edge-on disk galaxies derived from the RC3 (Third Reference Catalogue ofBright Galaxies, de Vaucouleurs et al. \cite{rc3}). A visualclassification of the bulges using the Digitized Sky Survey (DSS) inthree types of b/p bulges or as an elliptical type is presented andsupported by CCD images. NIR observations reveal that dust extinctiondoes almost not influence the shape of bulges. There is no substantialdifference between the shape of bulges in the optical and in the NIR.Our analysis reveals that 45% of all bulges are box- and peanut-shaped(b/p). The frequency of b/p bulges for all morphological types from S0to Sd is > 40%. In particular, this is for the first time that such alarge frequency of b/p bulges is reported for galaxies as late as Sd.The fraction of the observed b/p bulges is large enough to explain theb/p bulges by bars. Partly based on observations collected at ESO/LaSilla (Chile), DSAZ/Calar Alto (Spain), and Lowell Observatory/Flagstaff(AZ/U.S.A.). Tables 6 and 7 are only available in electronic form at CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| The Revised Flat Galaxy Catalogue.
We present a new improved and completed version of the Flat GalaxyCatalogue (FGC) named the Revised Flat Galaxy Catalogue (RFGC)containing 4236 thin edge-on spiral galaxies and covering the whole sky.The Catalogue is intended to study large-scale cosmic streamings as wellas other problems of observational cosmology. The dipole moment ofdistribution of the RFGC galaxies (l = 273 degr; b =+19 degr) lieswithin statistical errors (+/-10 degr) in the direction of the LocalGroup motion towards the Microwave Background Radiation (MBR).
| 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.
| Extraplanar emission-line gas in edge-on galaxies
Seven edge-on galaxies were imaged H alpha in order to determine ifextraplanar emission-line gas (as seen in NGC 891) is a common featureof spiral galaxies. Four of the seven are found to have one or twoprominent filamentary extraplanar structures apiece, with typicalfilament H alpha luminosities of 1037-1038 ergss-1 and scales of 1-2 kpc. Unlike NGC 891, none of thegalaxies has an extensive emission-line halo, to within the sensitivityof the observations, approximately 24 mag per square arcsec in H-alpha(equivalent to an emission measure of 19 pc cm-6 -- more than7 times fainter than the diffuse emission of NGC 891.
| Flat galaxy catalogue
A systematic search for disklike edge-on-galaxies with a diameter largerthan a = 40 arcsec and a major-to-minor axis ratio a/b greater than 7was carried out by means of the Palomar Observatory Sky Survey and theESO/SERC survey. As a result, we present a new catalog of flat galaxies(FGC) containing 4455 objects and covering about 56 percent of the wholesky for the first time. The catalogue is assigned to study large-scalecosmic streamings and other problems of observational cosmology.
| Plumes in spiral galaxies.
Not Available
| Northern dwarf and low surface brightness galaxies. II - The Green Bank neutral hydrogen survey
The paper reports neutral hydrogen observations of a large sample ofdwarf and other low surface brightness galaxies. A detailed discussionand error analysis of the observations are presented, and spectra aredisplayed for 329 galaxies detected for the first time, or detected withsubstantially better signal-to-noise ratios than achieved previously.The positions on the sky of 667 galaxies meeting the present selectioncriteria north of delta = 38 deg are shown. The distribution of theredshifts of galaxies detected at Green Bank is illustrated. The GreenBank detections tapered off strongly below the median H I flux of 3.7 Jykm/s detected at Arecibo: only 12 percent of the Green Bank sample wasdetected with smaller fluxes.
| Velocity differences in binary galaxies. I - Suggestions for a nonmonotonic, two-component distribution
A compilation of published high-precision velocities for 107 isolatedgalaxies is presented and used to obtain the distribution function oftheir velocity differences. The distribution shows a peak at the zerodifference as expected, but it also exhibits a preference for valuesnear 72 km/2. The distribution function declines smoothly beyond about72 km/s, with no significant peaks at multiples of 72 km/s, as claimedby Tifft (1977, 1980, 1982). It is argued that criteria for selectionprocedures on binary galaxy samples which are defined on the basis oftoo narrow a projected separation in the sky can produce a nonmonotonicdistribution if the orbits are eccentric. Such orbits can produce astrong secondary peak only if the level of incompleteness inbinary-galaxy samples is quite high, suggesting that the presentstatistical estimates of the masses of binary galaxies should bereevaluated.
| Axial ratios of edge-on spirals
A diameter-limited sample of 888 normal Sa-Sc galaxies was compiled fromthe Uppsala General Catalog. New micrometer measures of the axial ratiosR of the disk components of 262 edge-on spirals in this sample were madeon copies of blue Palomar Sky Survey plates and calibrated againstphotometric standards. The distribution of isophotal axial ratios forthe whole sample was analyzed to give information on the true axialratios R0 of spiral disks. The mean value of logR0 is 0.95 +/- 0.03 and the dispersion about this mean is0.12 +/- 0.04. A similar mean value (0.90) was obtained from avolume-limited sub-sample of 348 spirals. The dispersion in logR0 is partly due to a dependence of R0 onmorphological type, and the mean value of log R0 for eachtype was estimated. Inclinations of 342 edge-on (R is greater than about3) spirals were determined from their isophotal axial ratios and types.No significant dependence of R0 on luminosity at each typewas found.
| 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.
| Flat edge-on galaxies on the Tully-Fischer diagram.
For a sample of 114 northern galaxies with angular diameters greaterthan 2 arcmin and apparent axial ratios greater than 7, relations arediscussed between their global parameters: the inner motion amplitude W,the blue luminosity, the linear diameter, and the neutral hydrogen mass.Taken as a distance indicator for the given W, these parameters exhibitnearly the same efficiency. Outside the Local Supercluster the lineardiameter of the flat edge-on galaxy produces a standard deviation about25 percent as a distance estimate. The total mass-to-luminosity ratio offlat galaxies increases when their mean surface brightness decreases.
| Magnetism in the local Virgo-centered supercluster of galaxies (radius about 24 Mpc)
The warp excess in nearby spiral galaxies is investigated as well as itsearlier interpretation in terms of a magnetic field on a distance scaleout to a redshift of 0.3 (out to 1200 Mpc, for H(0) = 75 km/s Mpc). Itis shown from a study of the rotation measure data as a function ofredshift that such a large scale is unwarranted, and that any warpexcess may be rather local and spurious with a small S/N of 1.7. It isinferred that a local intergalactic magnetic field must be less than 50microG. To facilitate studies on the local supercluster of galaxies, aVirgo-center supercluster coordinate system is proposed, where longitude0 deg goes through the center of the Virgo cluster of galaxies at thecenter of the local supercluster.
| Magnetic fields in the Milky Way neighbourhood as deduced from WARPS in spiral galaxies
It is shown that warps of spiral galaxies are not randomly oriented inthe Milky Way neighborhood. By adopting a previous model, in which warpsare produced by intergalactic magnetic fields, and considering allNorthern Hemisphere warped edge-on NGC spiral galaxies, an analysis ofthe intergalactic magnetic field in the 100 Mpc neighborhood of theGalaxy is carried out. At the 100 Mpc scale the magnetic field is stillrather homogeneous, having a direction given by (alpha = 289 deg, delta= 8 deg), but a characteristic scale of about 25 Mpc is found, insidewhich the dispersion is very low. The region containing the VirgoCluster has a direction of the magnetic field different from thedirection found in adjacent regions.
| Frequency of Warped Spiral Galaxies at Visible Wavelengths
A list of optical warped spiral galaxies with basic position andgeometrical parameters is presented. From this list an attempt todetermine the frequency of warped discs has been made. All northern NGChigh inclined spirals were examined in the Palomar Observatory SkySurvey. Warps were observed in about half of these galaxies, whichindicate that nearly all spiral galaxies are warped.
| Statistical study of optical galactic WARPS
A list of northern spiral NGC galaxies, with inclinations higher than 74deg, and exhibiting warps have been obtained from the Palomar Sky Survey(POSS). Approximate position angles and 'warping angles' are given foreach galaxy, in order to have a first reference for statistical studiesof the warping phenomenon. When it is taken into account that warps arenot always observed (depending on their relative position with respectto the observer) the resulting frequency of warps was so high that atentative conclusion is that all disks are warped.
| The peculiar velocity of the Local Group. I - H I observations of SB and SBC galaxies
H I observations of a sample of 128 Sb and Sbc galaxies ranging inlinear diameter from 9-128 kpc, and in total mass from 6.3 x 10 to the9th solar masses to 1.3 x 10 to the 12th solar masses, are presented.Measurements of H I self-absorption are not found to vary withinclination, though a dependence of observed diameters and luminositieson inclination is noted. Total surface mass density and color index areshown to be highly correlated, implying that star-formation in thesegalaxies is governed by disk density rather than total mass or gasrichness. From 12-arcmin resolution local Galactic H I observations, newcorrection factors for diameters and luminosities are derived to allowfor the effects of galactic obscuration.
| A survey of galaxy redshifts. IV - The data
The complete list of the best available radial velocities for the 2401galaxies in the merged Zwicky-Nilson catalog brighter than 14.5mz and with b (II) above +40 deg or below -30 deg ispresented. Almost 60 percent of the redshifts are from the CfA surveyand are accurate to typically 35 km/s.
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