Galaxies with ultraviolet continuum. XIV

Markaryan, B. E.; Lipovetskii, V. A.; Stepanyan, Dzh A.

doi:10.1007/bf01005372

Cited by 13 publications

(15 citation statements)

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“…The survey consisted of 1133 fields (each 4 ; 4 in size) and covered 17,008 deg 2 north of À15 declination, excluding regions within 15 Y20 of the Galactic plane. It was completed in 1978 and published in a series of 15 papers including 1500 UV-excess objects (Markarian et al 1981 and references therein). Later Markarian at al (1989) added 15 new objects detected on the original plates, bringing the total number of Markarian objects to 1515.…”

Section: The Markarian Surveymentioning

confidence: 99%

Markarian Galaxies. I. The Optical Database and Atlas

Петросян

McLean

Allen

et al. 2007

ASTROPHYS J SUPPL S

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A database for the entire Markarian catalog is presented that combines extensive new measurements of their optical parameters with a literature and database search. The measurements were made using images extracted from the STScI Digitized Sky Survey (DSS) of F pg (red) and J pg (blue) band photographic sky survey plates obtained by the Palomar and UK Schmidt telescopes. We provide accurate coordinates, morphological type, spectral and activity classes, red and blue apparent magnitudes, apparent diameters, axial ratios, and position angles, as well as number counts of neighboring objects in a circle of radius 50 kpc. Special attention was paid to the individual descriptions of the galaxies in the original Markarian lists, which clarified many cases of misidentifications of the objects, particularly among interacting systems, larger galaxies with knots of star formation, possible stars, and cases of stars projected on galaxies. The total number of individual Markarian objects in the database is now 1544. We also include redshifts that are now available for 1524 objects with UV-excess radiation, as well as galactic color excess E(B À V ) values and their 2MASS or DENIS infrared magnitudes. The database also includes extensive notes that summarize information about the membership of Markarian galaxies in different systems of galaxies and about new and revised activity classes and redshifts. An atlas of several interesting subclasses of Markarian galaxies is also presented.

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Section: The Markarian Surveymentioning

confidence: 99%

Markarian Galaxies. I. The Optical Database and Atlas

Петросян

McLean

Allen

et al. 2007

ASTROPHYS J SUPPL S

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“…The main body is a Sb spiral galaxy, which is interacting with a dwarf object of elliptical morphology located at the NE. Markarian et al (1979) included Mkn 1199 in their catalogue of galaxies with UV-excess. Its properties were revisited using both imagery and spectrocopy by Mazzarella & Balzano (1986), Mazzarrella & Boronson (1993), and Kazarian & Martirossian (2001).…”

Section: Mkn 1199mentioning

confidence: 99%

Massive star formation in Wolf-Rayet galaxies

López-Sánchez

Esteban

2008

A&A

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Aims. We have performed a comprehensive multiwavelength analysis of a sample of 20 starburst galaxies that show the presence of a substantial population of massive stars. The main aims are the study of the massive star formation and stellar populations in these galaxies, and the role that interactions with or between dwarf galaxies and/or low surface companion objects have in triggering the bursts. In this series of papers, we present our new optical and near-infrared photometric and spectroscopic observations, and complete with data at other wavelengths (X-ray, far-infrared, and radio) available in the literature. In this paper, the first in the series, we analyze the morphology, stellar population age, and star-formation rate of each system. Methods. We completed new deep optical and NIR broad-band images, as well as the new continuum-subtracted Hα maps, of our sample of Wolf-Rayet galaxies. We analyze the morphology of each system and its surroundings and quantify the photometric properties of all important objects. All data were corrected for both extinction and nebular emission using our spectroscopic data. The age of the most recent star-formation burst is estimated and compared with the age of the underlying older low-luminosity population. The Hα-based star-formation rate, number of O7V equivalent stars, mass of ionized gas, and mass of the ionizing star cluster are also derived. Results. We found interaction features in many (15 up to 20) of the analyzed objects, which were extremely evident in the majority. We checked that the correction for nebular emission to the broad-band filter fluxes is important in compact objects and/or with intense nebular emission to obtain realistic colors and compare with the predictions of evolutionary synthesis models. The estimate of the age of the most recent star-formation burst is derived consistently. In general, the Hα-based star formation rate agrees with the estimates given by independent multiwavelength methods. With respect to the results found in individual objects, we remark the strong Hα emission found in IRAS 08208+2816, UM 420, and SBS 0948+532, the detection of a double-nucleus in SBS 0926+606A, a possible galactic wind in Tol 9, and one (two?) nearby dwarf star-forming galaxies surrounding Tol 1457-437.

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“…Two of them belong to the subclass of X-rays bright objects without previous Seyfert classification from the B92 sample: IRAS 14201+2956 and IRAS 21582+1018, the second one also being known as Mrk 520 (Markarian & Lipovetskii 1974). To those were added two other, bright, Narrow Line Seyfert galaxies (NLS1): Mrk 359 (Markarian & Lipovetskii 1971) and Mrk 1388 (Markarian et al 1980). This class of objects was not well represented in the Genzel et al (1998) core-program, but appeared in large proportions in the B92 sample.…”

Section: Introductionmentioning

confidence: 99%

ISO observations of four active galaxies

Dennefeld

Böller

Rigopoulou

et al. 2003

A&A

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Abstract. We present ISO PHOT-S spectra of four galaxies known or suspected to host a central AGN. Two of them are selected, among several others, from the initial Iras/Rosat sample of Boller et al. (1992) because of their substantial X-ray emission, while no obvious Seyfert features was present in their optical spectra: IRAS 14201+2956 and IRAS 21582+1018. The latter, also known as Mrk 520, was bright enough to also allow SWS observations around selected neon lines, to establish its excitation. While both PHOT-S spectra are characteristic of starburst-dominated galaxies, the neon line ratios in IRAS 21582+1018 indicate the presence of a hard excitation source. Complementary optical spectra, both at low and high spectral resolution, show only a weak, broad component around H α , establishing the presence of a central AGN which may not be detected in standard, classification spectra. Both objects are now classified as Sey 1.9 galaxies. These results show therefore that, although IR observations were expected to be able to pierce through the dusty central regions to reveal the presence of an active nucleus, the result may be ambiguous: the broad band IR energy distribution can still be dominated by starburts located in a wider circumnuclear region, and the AGN appear only in specific observations (high-excitation lines in the IR, or high-resolution optical spectra). As a complement, two other galaxies from the same initial sample were also observed with PHOT-S: the Narrow Line Seyfert galaxies (NLS1) Mrk 359 and Mrk 1388. NLS1s appear in high proportion in the Rosat/Iras sample, and in soft X-ray samples in general, and their Balmer line-widths are sometimes comparable to those of interacting, star-forming galaxies. Their ISO spectra however do not reveal the typical, strong PAH features found in the starburst galaxies and are more like those of standard Seyferts. All these observations therefore indicate that the key element is the presence or absence of a circumnuclear starburst region which, if strong enough, may completely hide the presence of a central AGN in the IR spectral energy distribution. The dust obscuration however needs to be patchy rather than complete to explain the detection of the high-excitation lines and Balmer wings in some cases. Only high-energy observations can then establish the strength of the central AGN and the amount of extinction with certainty.

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Galaxies with ultraviolet continuum. XIV

Cited by 13 publications

References 0 publications

Markarian Galaxies. I. The Optical Database and Atlas

Markarian Galaxies. I. The Optical Database and Atlas

Massive star formation in Wolf-Rayet galaxies

ISO observations of four active galaxies

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