NGC 7468: A galaxy with an inner polar disk

Shalyapina, L. V.; Моисеев, А. В.; Yakovleva, V. A.; Hagen-Thorn, V. A.; Barsunova, O. Yu.

doi:10.1134/1.1795947

Cited by 13 publications

(16 citation statements)

References 18 publications

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“…Our coarse spatial resolution does not allow us to either confirm or disprove the existence of this inner disk, but the kinematics of the main disk agree well with the data shown by Shalyapina et al (2004): see for instance the peak in the velocity profile at 30 south of the nucleus, and then the sharp decrease (their Fig. 2a).…”

Section: Mrk 314 (= Ngc 7468)mentioning

confidence: 51%

“…An extensively kinematic analysis of this galaxy has been performed by Shalyapina et al (2004), who found that Mrk 314 harbors two kinematics subsystems of ionized gas: the main gaseous disk, and a smaller inner disk oriented orthogonally to it. Our coarse spatial resolution does not allow us to either confirm or disprove the existence of this inner disk, but the kinematics of the main disk agree well with the data shown by Shalyapina et al (2004): see for instance the peak in the velocity profile at 30 south of the nucleus, and then the sharp decrease (their Fig.…”

Section: Mrk 314 (= Ngc 7468)mentioning

confidence: 99%

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Mapping luminous blue compact galaxies with VIRUS-P

Cairós

Caon

Lorenzo

et al. 2012

A&A

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Context. Blue compact galaxies (BCG) are narrow emission-line systems that undergo a violent burst of star formation. They are compact, low-luminosity galaxies, with blue colors and low chemical abundances, which offer us a unique opportunity to investigate collective star formation and its effects on galaxy evolution in a relatively simple, dynamically unperturbed environment. Spatially resolved spectrophotometric studies of BCGs are essential for a better understanding of the role of starburst-driven feedback processes on the kinematical and chemical evolution of low-mass galaxies near and far. Aims. We carry out an integral field spectroscopy (IFS) study of a sample of luminous BCGs, with the aim to probe the morphology, kinematics, dust extinction, and excitation mechanisms of their warm interstellar medium (ISM). Methods. We obtained IFS data for five luminous BCGs with VIRUS-P, the prototype instrument for the Visible Integral Field Replicable Unit Spectrograph, attached to the 2.7 m Harlan J. Smith Telescope at the McDonald Observatory. VIRUS-P consists of a square array of 247 optical fibers, which covers a 109 × 109 field of view, with a spatial sampling of 4. 2 and a 0.3 filling factor. We observed in the 3550-5850 Å spectral range, with a resolution of 5 Å FWHM. From these data we built two-dimensional maps of the continuum and the most prominent emission-lines ([O ii] λ3727, Hγ, Hβ and [O iii] λ5007), and investigated the morphology of diagnostic emission-line ratios and the extinction patterns in the ISM as well as stellar and gas kinematics. Additionally, from integrated spectra we inferred total line fluxes and luminosity-weighted extinction coefficients and gas-phase metallicities. Results. All galaxies exhibit an overall regular morphology in the stellar continuum, while their warm ISM morphology is more complex: in II Zw 33 and Mrk 314, the star-forming regions are aligned along a chain-structure; Haro 1, NGC 4670 and III Zw 102 display several salient features, such as extended gaseous filaments and bubbles. A significant intrinsic absorption by dust is present in all galaxies, the most extreme case being III Zw 102. Our data reveal a plethora of kinematical patterns, from overall regular gas and stellar rotation to complex velocity fields produced by structurally and kinematically distinct components.

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Section: Mrk 314 (= Ngc 7468)mentioning

confidence: 51%

Section: Mrk 314 (= Ngc 7468)mentioning

confidence: 99%

Mapping luminous blue compact galaxies with VIRUS-P

Cairós

Caon

Lorenzo

et al. 2012

A&A

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“…However, a possible fraction of polar structures among BCD galaxies seems to be larger (up to 10-15%). For instance, 5 galaxies out of 28 nearby luminous BCDG in the sample by Cairós et al [12] possess polar structures: Mrk 33, Mrk 370, Mrk 314 [13], II Zw 71 [14] and III Zw 102 [15]. Therefore the current burst of star formation in these galaxies can be connect with the same interaction event (accretion or merging) which also transported gas clouds on polar orbits.…”

Section: Discussionmentioning

confidence: 99%

Kinematically Detected Polar Rings/Disks in Blue Compact Dwarf Galaxies

Моисеев

2011

EAS Publications Series

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Abstract. Polar ring galaxies are systems with nearly orthogonally rotated components. We have found the gas on polar (or strongly inclined) orbits in two BCD galaxies using ionized gas velocity fields taken with a Fabry-Perot interferometer of the SAO RAS 6-m telescope. Our analysis shows that all ionized gas in Mrk 33 is concentrated in a compact disk (3 kpc in diameter) which rotates in the polar plane relative to the main stellar body. The gaseous disk in Mrk 370 has a more complex structure with a heavily warped innermost part. The presence of polar gaseous structures supports an idea that current the burst of star formation in these galaxies is due to the external gas accretion or merging. A possible fraction of polar structures among BCD galaxies seems to be very large (up to 10-15%). ObservationsThe observations were made with a scanning Fabry-Perot interferometer (FPI) mounted within the multimode instrument SCORPIO [1] at the prime focus of the Russian 6-m telescope. The spectral range was equal to 13Å and the spectral resolution was 0.8Å (about 35 km/s) for a 0.36Å sampling. The spectral interval was centered on the redshifted emission lines [NII]λ6583 (Mrk 33) and Hα (Mrk 370). The observational data were reduced using the IDLbased software package [2]. The final spatial resolution was about 2 − 2.5 ′′ . We fitted emission line profiles to the Voigt function, the profile fitting results were used to construct the two-dimensional fields of the line-of-sight velocities of ionized gas, maps of velocity dispersion, and images in the corresponding emission lines. Mrk 33It is a blue compact galaxy with structural properties corresponding to a dust-lane dE [3]. Perosian et al. [4] have studied its circumnuclear (r < 5 ′′ ) gas kinematics and concluded that the position angle (PA) of the kinematic major axis significantly differs from the photometric major axis of the galaxy. Our observational data allows us to study the ionized gas kinematics at larger distances from the nucleus -the [NII] emission was detected up to r = 15 ′′ . The velocity field of the ionized gas can be approximated by the model of a circular rotating thin disk. The major axis of this disk differs significantly from the major axis of the outer isophotes. The major axis position angle and inclination derived from the ionized gas velocity field are PA = 163 ± 4• and i = 47 ± 5 • , respectively. For the outer oblate spheroid we adopted the orientation parameters based on photometry analysis [5]: PA = 116• , i = 59• .a e-mail: moisav@gmail.com These values imply two formal solutions for the relative inclination between the ionized gas disk and the host galaxy main plane: ∆i = 85±6• or 39±6• . The former corresponds to the stable polar structure. Based on the low-resolution kinematic data in HI, Bravo-Alfaro et al.[3] also suggested that Mrk 33 has recently captured gas in a close interaction or merger with an initially gas-rich companion. Our observations show that the inner polar ionized gas disk has a similar kinematics with the external H...

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“…Shalyapina et al (2004), who interpret it as the superposition of two kinematic subsystems of ionized gas.…”

Section: Mrk 314mentioning

confidence: 99%

Integral Field Spectroscopy of Blue Compact Dwarf Galaxies

García-Lorenzo

Cairós

Caon

et al. 2008

ApJ

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We present results of integral field optical spectroscopy of five luminous blue compact dwarf galaxies. The data were obtained using the fiber system INTEGRAL attached to the William Herschel Telescope. region with a resolution of 0.9 00 spaxel À1 . We use high-resolution optical images to isolate the star-forming knots in the objects; line ratios, electron densities, and oxygen abundances in each of these regions are computed. We build continuum and emission-line intensity maps, as well as maps of the most relevant line ratios:/H, and H/H, which allow us to obtain spatial information on the ionization structure and mechanisms. We also derive the gas velocity field from the H and [O iii] k5007 emission lines. We find that all five galaxies are in the high end of the metallicity range of blue compact dwarfs with oxygen abundances varying from Z ' 0:3 to 1.5 Z . The objects show H iiYlike ionization in the whole field of view, except the outer regions of III Zw 102, whose large [N ii] k6584/H values suggest the presence of shocks. The five galaxies display inhomogeneous extinction patterns, and three of them have high H/H ratios, indicative of a large dust content; all of the galaxies display complex, irregular velocity fields in their inner regions.

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NGC 7468: A galaxy with an inner polar disk

Cited by 13 publications

References 18 publications

Mapping luminous blue compact galaxies with VIRUS-P

Mapping luminous blue compact galaxies with VIRUS-P

Kinematically Detected Polar Rings/Disks in Blue Compact Dwarf Galaxies

Integral Field Spectroscopy of Blue Compact Dwarf Galaxies

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