An Imaging Survey of Early‐Type Barred Galaxies

Erwin, Peter; Sparke, Linda S.

doi:10.1086/367885

Cited by 118 publications

(244 citation statements)

References 113 publications

(190 reference statements)

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“…Such maxima, combined with peaks in ellipticity, are often associated with a galactic bar. We see little evidence in our data for a well-defined maximum in to accompany the peak in P.A., but there are examples in nearby galaxies where a bar (or some other feature) does not have an obvious ellipticity peak ( Erwin & Sparke 2003). If we look at the unsharp mask in Figure 10, we can see small peaks of emission at the edge of the dark ring that surrounds the nucleus of the galaxy.…”

Section: G158mentioning

confidence: 64%

“…Unsharp masking suppresses large-scale, low-frequency variations and emphasizes small-scale brightness variations. Examples of how useful this technique can be for galaxies observed with HST can be found in, e.g., Erwin & Sparke (2003). To produce our unsharp masks, we smoothed the original data by convolving it with a Gaussian function of width ¼ 5 pixels and then subtracted this from the original image.…”

Section: Unsharp Maskingmentioning

confidence: 99%

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A Near‐Solar Metallicity, Nitrogen‐deficient Lyman Limit Absorber Associated with Two S0 Galaxies

Jenkins

Bowen

Tripp³

et al. 2005

ApJ

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The UV spectrum of the bright quasar PHL 1811 at z em ¼ 0:192 reveals a foreground gas system at z ¼ 0:080923 with log N (H i) ¼ 17:98 AE 0:05. We have determined the abundances of various atomic species in this system from a spectrum covering the wavelength range 1160-1730 8 recorded at 7 km s À1 resolution by the E140M grating of the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST ), supplemented by coverage at shorter wavelengths by the Far Ultraviolet Spectroscopic Explorer (FUSE ). The abundances of C ii, Si ii, S ii, and Fe ii compared to that of O i indicate that a considerable fraction of the gas is in locations where the hydrogen is ionized. An oxygen abundance ½O/ H ¼ À0:19 AE 0:08 in the H i-bearing gas indicates that the chemical enrichment of the gas is unusually high for an extragalactic QSO absorption system. However, this same material has an unusually low abundance of nitrogen, ½N/ O < À0:59, indicating that there may not have been enough time during this enrichment for secondary nitrogen to arise from low-and intermediate-mass stars. From the convergence of high Lyman series lines we can determine the velocity width of H i, and after correcting for turbulent broadening shown by the O i absorption feature, we derive a temperature T ¼ 7070 þ3860 À4680 K. We determine a lower bound for the electron density n(e) > 10 À3 cm À3 by modeling the ionization by the intergalactic radiation field and an upper bound n(e) < 0:07 cm À3 from the absence of much C ii in an excited fine-structure level. The thermal pressure in the range 4 cm À3 K < p / k < 140 cm À3 K could be confined by a warm-hot intergalactic medium (WHIM) structure with /¯$ 20 that might accompany a wall of galaxies at the same redshift, seen in data from the Sloan Digital Sky Survey. An r-band image of the field surrounding PHL 1811 recorded by the ACS instrument on HST shows that two galaxies at the same redshift as the gas are S0 galaxies, separated by only 34 and 87 h À1 70 kpc from the line of sight. One or both of these galaxies may be the source of the material in the Lyman limit system, which may have been expelled from them in a fast wind, by tidal stripping, or by ram pressure stripping. Subtraction of the ACS point-spread function from the image of the QSO reveals the presence of a face-on spiral galaxy under the glare of the quasar; while it is possible that this galaxy may be responsible for the Lyman limit absorption, the exact alignment of the QSO with the center of the galaxy suggests that the spiral is the quasar host.

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Section: G158mentioning

confidence: 64%

Section: Unsharp Maskingmentioning

confidence: 99%

A Near‐Solar Metallicity, Nitrogen‐deficient Lyman Limit Absorber Associated with Two S0 Galaxies

Jenkins

Bowen

Tripp³

et al. 2005

ApJ

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“…The first systematic observational study of this phenomenon was made by Buta & Crocker (1993), who published a list of 13 galaxies, where the secondary (inner) bar was arbitrarily oriented with respect to the primary (outer) one. In the following years the isophotal analysis technique made it possible to detect secondary bars in optical (Wozniak et al 1995;Erwin & Sparke 1999;Erwin & Sparke 2003) and NIR images of barred galaxies (Friedli et al 1996;Jungwiert et al 1997;Laine et al 2002). Up to now, we have found 71 candidate double-barred galaxies in the literature (see references in Moiseev 2001b).…”

Section: Introductionmentioning

confidence: 92%

Structure and kinematics of candidate double-barred galaxies

Моисеев

Valdés

Chavushyan

2004

A&A

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Abstract.Results of optical and NIR spectral and photometric observations of a sample of candidate double-barred galaxies are presented. Velocity fields and velocity dispersion maps of stars and ionized gas, continuum and emission-line images were constructed from integral-field spectroscopy observations carried out at the 6 m telescope (BTA) of SAO RAS, with the MPFS spectrograph and the scanning Fabry-Perot Interferometer. NGC 2681 was also observed with the long-slit spectrograph of the BTA. Optical and NIR images were obtained at the BTA and at the 2.1 m telescope (OAN, México). High-resolution images were retrieved from the HST data archive. Morphological and kinematic features of all 13 sample objects are described in detail. Attention is focused on the interpretation of observed non-circular motions of gas and stars in circumnuclear (one kiloparsec-scale) regions. We have shown first of all that these motions are caused by the gravitational potential of a large-scale bar. NGC 3368 and NGC 3786 have nuclear bars only, their isophotal twist at larger radii being connected with the bright spiral arms. Three cases of inner polar disks in our sample (NGC 2681, NGC 3368 and NGC 5850) are considered. We found ionized-gas counter-rotation in the central kiloparsec of the lenticular galaxy NGC 3945. Seven galaxies (NGC 470, NGC 2273, NGC 2681, NGC 3945, NGC 5566, NGC 5905, and NGC 6951) have inner mini-disks nested in large-scale bars. Minispiral structures occur often in these nuclear disks. It is interesting that the majority of the observed, morphological and kinematical, features in the sample galaxies can be explained without the secondary bar hypothesis. Thus we suggest that a dynamically independent secondary bar is a rarer phenomenon than follows from isophotal analysis of the images only.

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“…For instance, NGC 4203 contains 2.5×10 7 M of H 2 in the centre (Welch & Sage 2003;Young et al 2011). Hubble Space Telescope observations show nuclear dust structures in the very centre of the galaxy (300 pc radius; Erwin & Sparke 2003). The dust is visible also on a large scale in a 8 µm image, where the flux, mostly from polycyclic aromatic hydrocarbons (PAHs) appears distributed in a spiral-like pattern (Pahre et al 2004; we will make use of this image as well as of a 24 µm image in support of our analysis of SF in NGC 4203).…”

Section: Introductionmentioning

confidence: 63%

Star formation in the outer regions of the early-type galaxy NGC 4203

Yıldız¹,

Serra

Oosterloo

et al. 2015

Monthly Notices of the Royal Astronomical Society

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NGC 4203 is a nearby early-type galaxy surrounded by a very large, low-column-density H i disc. In this paper we study the star formation efficiency in the gas disc of NGC 4203 by using the UV, deep optical imaging and infrared data. We confirm that the H i disc consists of two distinct components: an inner star forming ring with radius from ∼1 to ∼3 R e f f , and an outer disc. The outer H i disc is 9 times more massive than the inner H i ring. At the location of the inner H i ring we detect spiral-like structure both in the deep g − r image and in the 8 µm Spitzer-IRAC image, extending in radius up to ∼ 3 R e f f . These two gas components have a different star formation efficiency likely due to the different metallicity and dust content. The inner component has a star formation efficiency very similar to the inner regions of late-type galaxies. Although the outer component has a very low star formation efficiency, it is similar to that of the outer regions of spiral galaxies and dwarfs. We suggest that these differences can be explained with different gas origins for the two components such as stellar mass loss for the inner H i ring and accretion from the inter galactic medium (IGM) for the outer H i disc. The low level star formation efficiency in the outer H i disc is not enough to change the morphology of NGC 4203, making the depletion time of the H i gas much too long.

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An Imaging Survey of Early‐Type Barred Galaxies

Cited by 118 publications

References 113 publications

A Near‐Solar Metallicity, Nitrogen‐deficient Lyman Limit Absorber Associated with Two S0 Galaxies

A Near‐Solar Metallicity, Nitrogen‐deficient Lyman Limit Absorber Associated with Two S0 Galaxies

Structure and kinematics of candidate double-barred galaxies

Star formation in the outer regions of the early-type galaxy NGC 4203

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