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|Seyfert Galaxies. IV. Nuclear Profiles of Markarian Seyfert Galaxies from Hubble Space Telescope Images|
We have examined the nuclear profiles of the Seyfert and non-SeyfertMarkarian galaxies in our near-infrared Hubble Space Telescope WF/PC-1snapshot survey. We find that nuclei of types 1-1.5 Seyfert galaxies aredominated by strong point sources, while those of Seyfert 2 and non-Seyfert Markarian galaxies tend to be resolved, less distinguished, andsimilar in shape to normal galaxy luminosity profiles. Two possibleinterpretations of this result for type 2 Seyfert galaxies are thattheir nuclear continuum sources are undetected in our bandpass,contributing less than 10% of the nuclear light (within 0.5 radius) inall cases or that their nuclear components are resolved and blend insmoothly with the brightness profile of the host galaxy's bulge. Sincespectroscopic studies support typical nuclear continuum fractionsdistinctly greater than 10%, the latter conclusion is clearlypreferable. If the continua observed in Seyfert 2 galaxies originate asnuclear light that is redirected into the line of sight by scattering,as predicted by unified models of active galactic nuclei, then thescattering regions must be extended. Simple simulations suggest thatthese regions must cover several tens of parsecs or more, in agreementwith estimates of the sizes of the scattering "mirrors" in other Seyfert2 galaxies. However, the similarity of the profiles of non-SeyfertMarkarian and type 2 Seyfert nuclei suggests that circumnuclear starformation may also be an important component in the nuclear profiles ofthe latter.
|A multifrequency radio continuum and IRAS faint source survey of markarian galaxies|
Results are presented from a multifrequency radio continumm survey ofMarkarian galaxies (MRKs) and are supplemented by IRAS infrared datafrom the Faint Source Survey. Radio data are presented for 899 MRKsobserved at nu = 4.755 GHz with the National Radio Astronomy Observatory(NRAO)-Green Bank 300 foot (91 m) telescope, including nearly 88% ofthose objects in Markarian lists VI-XIV. In addition, 1.415 GHzmeasurements of 258 MRKs, over 30% of the MRKs accessible from theNational Aeronomy and Ionosphere Center (NAIC)-Arecibo, are reported.Radio continuum observations of smaller numbers of MRKs were made at10.63 GHz and at 23.1 GHz and are also presented. Infrared data from theIRAS Faint Source Survey (Ver. 2) are presented for 944 MRKs, withreasonably secure identifications extracted from the NASA/IPACExtragalactic Database. MRKs exhibit the same canonical infraredcharacteristics as those reported for various other galaxy samples, thatis well-known enhancement of the 25 micrometer/60 micrometer color ratioamong Seyfert MRKs, and a clear tendency for MRKs with warmer 60micrometer/100 micrometer colors to also possess cooler 12 micrometer/25micrometer colors. In addition, non-Seyfert are found to obey thewell-documented infrared/radio luminosity correlation, with the tightestcorrelation seen for starburst MRKs.
|KISO survey for ultraviolet-excess galaxies. XIV.|
The 14th list and identification charts of the UV-excess galaxiesdetected on the multicolor plates taken with the Kiso Schmidt telescopefor 10 survey fields are presented. In the sky area of some 300 sq deg,about 470 objects are cataloged down to the photographic magnitude ofabout 17.5.
|Evolution of luminous IRAS sources - CCD imaging|
The paper presents optical imaging of a sample of 64 luminous IRASgalaxies which cover a wide range of IRAS spectra and luminosity andalso include a range of optical types. The objects are almost all incurrent or recent tidal interaction. The connections between thestrength and age of the interaction, the IR spectrum and luminosity, andthe optical colors, and other properties of the galaxies are discussed.The principal result is that the powerful IR sources with steep IRspectra are stronger and dynamically younger interacting systems, whilethe flat IR spectrum objects are older. Star formation, dustobscuration, and the timescales for nuclear activity compared with IRand tidal events are discussed, and a self-consistent evolution scenarioconnecting the luminous IR sources is described.
|Seyfert galaxies. II - Environments and IRAS colors|
The environments of Seyfert galaxies are compared to the environments ofnon-Seyfert Markarian galaxies using galaxy counts obtained from thePalomar Observaory Sky Survey prints. While previous work by Dahari,confirmed here, indicates that Seyfert galaxies are more likely to haveclose companion galaxies than field galaxies, the Seyfert galaxiesexamined here have essentially the same environments as the comparisonsample of non-Seyfert Markarian galaxies. The IRAS colors of the Seyfertand non-Seyfert Markarian galaxies are used to distinguish betweenSeyfert activity and bursts of star formation. The results suggest thatclose companion galaxies enhance star formation rather than directlyenhancing Seyfert-like activity.
|H I profiles in IRAS galaxies|
H-I line profiles have been obtained for a sample of 37 galaxies. Thirtyof these galaxies have IRAS fluxes representing a wide range of infraredluminosites and spectra. The galaxies also represent five levels ofoptical activity, nonactive, LINERs, H-II galaxies, Sy 2, and Sy 1. Theyalso have a wide range of tidal interaction activity with othergalaxies. The behavior of H-I is studied within a scenario that relatestidal events with star formation, dust formation, IR luminosity, andnuclear activity in galaxies. A strong correlation is found between H-Iand IR luminosity, which appears to be in the form of an excess of H-Iemission related to the interaction events. Detached weak extra H-Icomponents are common, and H-I absorption components are seen in severalobjects. H-I outflow is indicated in most cases. Relative velocities areof the order of a few hundred km/s. The most strongly disturbed galaxiesalso have peculiar H-I profiles. A fit to the Tully-Fisher relationindicates a mean extinction of about 1 mag for the group, and a generalspread in the relation with no systematic effects.
|Determination of the relative spectrophotometric gradients of galaxies. IV|
Relative spectrophotometric gradients of continua are determined for 195galaxies. The spectra have been obtained with the 70-cm meniscustelescope of the Abastumani Astrophysical Observatory using a 2-degpreobjective prism (the reverse linear dispersion was 1200 A/mm inH-gamma). The gradient values were reduced to the AO spectral class andcorrected for light absorption in the Galaxy.
|A catalog of Markarian galaxies|
A catalog of Markarian galaxies is presented which tabulates redshifts,spectral and morphological classifications, magnitudes, infrared andradio flux densities, and over 600 references to available datapublished before January 1, 1986. Redshifts are now available for 1228objects with strong ultraviolet continua, and follow-up spectroscopicand photometric observations of Markarian galaxies have providedclassifications of 115 Seyfert 1, 43 Seyfert 2, and 137 starburst and HII-type galaxies. After a description of the Markarian survey and thecurrent catalog, a summary of the general results obtained from the datais presented. A preliminary study of the infrared properties ofMarkarian galaxies as measured by IRAS reveals a number of interestingresults, including the existence of a sample of elliptical andlenticular galaxies with appreciable infrared emission.
|On the relation of Markarian galaxies with Zwicky clusters. I - Data|
In the area covered by the survey of Markarian et al. (1967-1981) andthe CGCG of Zwicky et al. (1961-1968) there are 1344 Markarian galaxies,of which 597 are positioned inside the contours of Zwicky clusters. Dataon these galaxies and respective clusters are presented in differenttables, according to whether they are galaxies which are members ofclusters, or probable or possible members; projection cases areconsidered separately.
|Spectra of Galaxies with Ultraviolet Continuum - Part Four|
|Radio survey of Markarian galaxies at 6 and 11 CM|
One hundred and fifty-one objects from Markarian's lists 6 and 7 wereobserved at 6 cm with a 3 sigma detection limit of about 30 mJy. EightMarkarian objects were detected, six of which were also observed at 11cm. Forty-five others were negative at this wavelength. Two of thedetections, numbers 533 and 668, are Seyfert galaxies; additionally, UB1was detected at 6 cm and NGC 7715 and III Zw 2 were found at 11 cm.
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