Influence of galaxy stellar mass and observed wavelength on disc breaks in S4^4G, NIRS0S, and SDSS data

Breaks in the surface brightness profiles in the outer regions of galactic discs are thought to have formed by various internal and external processes, and by studying the breaks we aim to better understand what processes are responsible for the evolution of the outer discs. We use a large well-defined sample to study how common the breaks are, and whether their properties depend on galaxy stellar mass or observed wavelength. We study radial surface brightness profiles of 753 galaxies, obtained from the $3.6 \mu m$ images of the Spitzer Survey of Stellar Structure in Galaxies (S$^4$G), and the $K_s$-band data from the Near InfraRed S0-Sa galaxy Survey (NIRS0S), covering a wide range of galaxy morphologies and stellar masses. Optical SDSS or Liverpool telescope data was used for 480 of these galaxies. We find that in low-mass galaxies the single exponential discs (Type I) are most common, and that their fraction decreases with increasing galaxy stellar mass. The fraction of down-bending (Type II) discs increases with stellar mass, possibly due to more common occurrence of bar resonance structures. The up-bending (Type III) discs are also more common in massive galaxies. The observed wavelength affects the scalelength of the disc of every profile type. Especially the scalelength of the inner disc of Type II profiles increases from infrared to u-band on average by a factor of $\sim 2.2$. Consistent with the previous studies, we find that Type II outer disc scalelengths ($h_o$) in late-type and low-mass galaxies are shorter in bluer wavelengths, possibly due to stellar radial migration populating the outer discs with old stars. In Type III discs $h_o$ are larger in the u-band, hinting to the presence of young stellar population in the outer disc. While the observed wavelength affects the disc parameters, it does not significantly affect the profile type in our sample. (Abridged)Comment: 22 pages, 16 figures. Accepted for publication in Astronomy & Astrophysic

The stellar mass distribution of S4^{4}G disk galaxies

We use 3.6 $\mu$m imaging from the S$^{4}$G survey to characterize the typical stellar density profiles ($\Sigma_{\ast}$) and bars as a function of fundamental galaxy parameters (e.g. the total stellar mass $M_{\ast}$), providing observational constraints for galaxy simulation models to be compared with. We rescale galaxy images to a common frame determined by the size in physical units, by their disk scalelength, or by their bar size and orientation. We stack the resized images to obtain statistically representative average stellar disks and bars. For a given $M_{\ast}$ bin ($\ge 10^{9}M_{\odot}$), we find a significant difference in the stellar density profiles of barred and non-barred systems that gives evidence for bar-induced secular evolution of disk galaxies: (i) disks in barred galaxies show larger scalelengths and fainter extrapolated central surface brightnesses, (ii) the mean surface brightness profiles of barred and non-barred galaxies intersect each other slightly beyond the mean bar length, most likely at the bar corotation, and (iii) the central mass concentration of barred galaxies is larger (by almost a factor 2 when $T<5$) than in their non-barred counterparts. We also show that early- and intermediate-type spirals ($0 \le T < 5$) host intrinsically narrower bars than the later types and S0s, whose bars are oval-shaped. We show a clear correlation between galaxy family and bar ellipticity.Comment: Proceedings of IAU Symposium 321, "Formation and evolution of galaxy outskirts", Eds. A. Gil de Paz, J. C. Lee & J. H. Knapen, Cambridge University Press, Cambridg

Kinematics and dynamics of the M51-type galaxy pair NGC 3893/96 (KPG 302)

We study the kinematics and dynamics of the M51-type interacting galaxy pair KPG 302 (NGC 3893/96). We analyse the distribution of the dark matter (DM) halo of the main galaxy in order to explore possible differences between DM halos of "isolated" galaxies and those of galaxies belonging to a pair. The velocity field of each galaxy was obtained using scanning Fabry-Perot interferometry. A two-dimensional kinematic and dynamical analysis of each galaxy and the pair as a whole is done emphasizing the contribution of circular and non-circular velocities. Non-circular motions can be traced on the rotation curves of each galaxy allowing us to differentiate between motions associated to particular features and motions that reflect the global mass distribution of the galaxy. For the main galaxy of the pair, NGC 3893, optical kinematic information is complemented with HI observations from the literature to build a multi-wavelength rotation curve. We try to fit this curve with a mass-distribution model using different DM halos. We find that the multi-wavelength rotation curve of NGC 3893, "cleaned" from the effect of non-circular motions, cannot be fitted neither by a pseudo-isothermal nor by a NFW DM halo.Comment: Accepted for publication in A&A. 11 pages, 9 figures and 2 table

Evidence for the concurrent growth of thick discs and central mass concentrations from S4^4G imaging

We have produced $3.6\mu{\rm m}+4.5\mu{\rm m}$ vertically integrated radial luminosity profiles of 69 edge-on galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S$^4$G). We decomposed the luminosity profiles into a disc and a central mass concentration (CMC). These fits, combined with thin/thick disc decompositions from our previous studies, allow us to estimate the masses of the CMCs, the thick discs, and the thin discs ($\mathcal{M}_{\rm CMC}$, $\mathcal{M}_{\rm T}$, and $\mathcal{M}_{\rm T}$). We obtained atomic disc masses ($\mathcal{M}_{\rm g}$) from the literature. We then consider the CMC and the thick disc to be dynamically hot components and the thin disc and the gas disc to be dynamically cold components. We find that the ratio between the mass of the hot components and that of the cold components, $(\mathcal{M}_{\rm CMC}+\mathcal{M}_{\rm T})/(\mathcal{M}_{\rm t}+\mathcal{M}_{\rm g})$, does not depend on the total galaxy mass as described by circular velocities ($v_{\rm c}$). We also find that the higher the $v_{\rm c}$, the more concentrated the hot component of a galaxy. We suggest that our results are compatible with having CMCs and thick discs built in a short and early high star forming intensity phase. These components were born thick because of the large scale height of the turbulent gas disc in which they originated. Our results indicate that the ratio between the star forming rate in the former phase and that of the formation of the thin disc is of the order of 10, but the value depends on the duration of the high star forming intensity phase.Comment: Accepted for publication in A&

Halpha Kinematics of S4G Spiral Galaxies - III. Inner rotation curves

We present a detailed study of the shape of the innermost part of the rotation curves of a sample of 29 nearby spiral galaxies, based on high angular and spectral resolution kinematic Halpha Fabry-Perot observations. In particular, we quantify the steepness of the rotation curve by measuring its slope dRvc(0). We explore the relationship between the inner slope and several galaxy parameters, such as stellar mass, maximum rotational velocity, central surface brightness ({\mu}0), bar strength and bulge-to-total ratio. Even with our limited dynamical range, we find a trend for low-mass galaxies to exhibit shallower rotation curve inner slopes than high-mass galaxies, whereas steep inner slopes are found exclusively in high-mass galaxies. This trend may arise from the relationship between the total stellar mass and the mass of the bulge, which are correlated among them. We find a correlation between the inner slope of the rotation curve and the morphological T-type, complementary to the scaling relation between dRvc(0) and {\mu}0 previously reported in the literature. Although we find that the inner slope increases with the Fourier amplitude A2 and decreases with the bar torque Qb, this may arise from the presence of the bulge implicit in both A2 and Qb. As previously noted in the literature, the more compact the mass in the central parts of a galaxy (more concretely, the presence of a bulge), the steeper the inner slopes. We conclude that the baryonic matter dominates the dynamics in the central parts of our sample galaxies.Comment: 11 pages, 11 figures, accepted for publication in MNRA

Naisten virtsankarkailun nauhaleikkaukset

Vain ponnistukseen liittyvää virtsankarkailua voidaan korjata leikkauksella. Valikoiduille potilaille voidaan käyttää injektiohoitoa.Leikkaushoidolla paranee 62–97 % potilaista. Retropuubiset (TVT) ja transobturatoriset (TOT ja TVT-O) nauhaleikkaustekniikat ovat yhtä tehokkaita.Suomessa tehdään pääasiassa vähän kajoavia nauhaleikkauksia. Välittömiä leikkauskomplikaatioita ja myöhemmin ilmaantuvia virtsaamisongelmia on ollut vähän

Comparison of bar strengths in active and non-active galaxies

Bar strengths are compared between active and non-active galaxies for a sample of 43 barred galaxies. The relative bar torques are determined using a new technique (Buta and Block 2001), where maximum tangential forces are calculated in the bar region, normalized to the axisymmetric radial force field. We use JHK images of the 2 Micron All Sky Survey. We show a first clear empirical indication that the ellipticies of bars are correlated with the non-axisymmetric forces in the bar regions. We found that nuclear activity appears preferentially in those early type galaxies in which the maximum bar torques are weak and appear at quite large distances from the galactic center. Most suprisingly the galaxies with the strongest bars are non-active. Our results imply that the bulges may be important for the onset of nuclear activity, but that the correlation between the nuclear activity and the early type galaxies is not straightforward.Comment: MNRAS macro in tex format, 9 pages, 10 figure

H-alpha kinematics of S4G spiral galaxies-II. Data description and non-circular motions

We present a kinematical study of 29 spiral galaxies included in the Spitzer Survey of Stellar Structure in Galaxies, using Halpha Fabry-Perot data obtained with the Galaxy Halpha Fabry-Perot System instrument at the William Herschel Telescope in La Palma, complemented with images in the R-band and in Halpha. The primary goal is to study the evolution and properties of the main structural components of galaxies through the kinematical analysis of the FP data, complemented with studies of morphology, star formation and mass distribution. In this paper we describe how the FP data have been obtained, processed and analysed. We present the resulting moment maps, rotation curves, velocity model maps and residual maps. Images are available in FITS format through the NASA/IPAC Extragalactic Database and the Centre de Donn\'ees Stellaires. With these data products we study the non-circular motions, in particular those found along the bars and spiral arms. The data indicate that the amplitude of the non-circular motions created by the bar does not correlate with the bar strength indicators. The amplitude of those non-circular motions in the spiral arms does not correlate with either arm class or star formation rate along the spiral arms. This implies that the presence and the magnitude of the streaming motions in the arms is a local phenomenon.Comment: 23 pages, 14 figures, without appendices, accepted to be published in MNRA

The Thick Disk in the Galaxy NGC 4244 from S^4G Imaging

If thick disks are ubiquitous and a natural product of disk galaxy formation and/or evolution processes, all undisturbed galaxies that have evolved during a significant fraction of a Hubble time should have a thick disk. The late-type spiral galaxy NGC 4244 has been reported as the only nearby edge-on galaxy without a confirmed thick disk. Using data from the Spitzer Survey of Stellar Structure in Galaxies (S^4G) we have identified signs of two disk components in this galaxy. The asymmetries between the light profiles on both sides of the mid-plane of NGC 4244 can be explained by a combination of the galaxy not being perfectly edge-on and a certain degree of opacity of the thin disk. We argue that the subtlety of the thick disk is a consequence of either a limited secular evolution in NGC 4244, a small fraction of stellar material in the fragments which built the galaxy, or a high amount of gaseous accretion after the formation of the galaxy

Mid-infrared Galaxy Morphology from the Spitzer Survey of Stellar Structure in Galaxies (S^4G): The Imprint of the De Vaucouleurs Revised Hubble-Sandage Classification System at 3.6 μm

Spitzer Space Telescope Infrared Array Camera imaging provides an opportunity to study all known morphological types of galaxies in the mid-IR at a depth significantly better than ground-based near-infrared and optical images. The goal of this study is to examine the imprint of the de Vaucouleurs classification volume in the 3.6 μm band, which is the best Spitzer waveband for galactic stellar mass morphology owing to its depth and its reddening-free sensitivity mainly to older stars. For this purpose, we have prepared classification images for 207 galaxies from the Spitzer archive, most of which are formally part of the Spitzer Survey of Stellar Structure in Galaxies (S^4G), a Spitzer post-cryogenic ("warm") mission Exploration Science Legacy Program survey of 2331 galaxies closer than 40 Mpc. For the purposes of morphology, the galaxies are interpreted as if the images are blue light, the historical waveband for classical galaxy classification studies. We find that 3.6 μm classifications are well correlated with blue-light classifications, to the point where the essential features of many galaxies look very similar in the two very different wavelength regimes. Drastic differences are found only for the most dusty galaxies. Consistent with a previous study by Eskridge et al., the main difference between blue-light and mid-IR types is an ≈1 stage interval difference for S0/a to Sbc or Sc galaxies, which tend to appear "earlier" in type at 3.6 μm due to the slightly increased prominence of the bulge, the reduced effects of extinction, and the reduced (but not completely eliminated) effect of the extreme population I stellar component. We present an atlas of all of the 207 galaxies analyzed here and bring attention to special features or galaxy types, such as nuclear rings, pseudobulges, flocculent spiral galaxies, I0 galaxies, double-stage and double-variety galaxies, and outer rings, that are particularly distinctive in the mid-IR