We present the initial results of a census of 684 barred galaxies in the MaNGA galaxy survey. This large sample contains galaxies with a wide range of physical properties, and we attempt to link bar properties to key observables for the whole galaxy. We find the length of the bar, when normalised for galaxy size, is correlated with the distance of the galaxy from the star formation main sequence, with more passive galaxies hosting larger-scale bars. Ionised gas is observed along the bars of low-mass galaxies only, and these galaxies are generally star-forming and host short bars. Higher-mass galaxies do not contain Hα emission along their bars, however, but are more likely to host rings or Hα at the centre and ends of the bar. Our results suggest that different physical processes are at play in the formation and evolution of bars in low- and high-mass galaxies.
Bars in galaxies are thought to stimulate both inflow of material and radial mixing along them. Observational evidence for this mixing has been inconclusive so far however, limiting the evaluation of the impact of bars on galaxy evolution. We now use results from the MaNGA integral field spectroscopic survey to characterise radial stellar age and metallicity gradients along the bar and outside the bar in 128 strongly barred galaxies. We find that age and metallicity gradients are flatter in the barred regions of almost all barred galaxies when compared to corresponding disk regions at the same…
Bars are common in low-redshift disk galaxies, and hence quantifying their influence on their host is of importance to the field of galaxy evolution. We determine the stellar populations and star formation histories of 245 barred galaxies from the MaNGA galaxy survey, and compare them to a mass- and morphology-matched comparison sample of unbarred galaxies. At fixed stellar mass and morphology, barred galaxies are optically redder than their unbarred counterparts. From stellar population analysis using the full spectral fitting code Starlight, we attribute this difference to both older and mor…
Bars inhabit the majority of local-Universe disk galaxies and may be important drivers of galaxy evolution through the redistribution of gas and angular momentum within disks. We investigate the star formation and gas properties of bars in galaxies spanning a wide range of masses, environments, and star formation rates using the MaNGA galaxy survey. Using a robustly-defined sample of 684 barred galaxies, we find that fractional (or scaled) bar length correlates with the host's offset from the star-formation main sequence. Considering the morphology of the H$α$ emission we separate barred galax…
The MaNGA project has obtained IFU data for several thousand nearby galaxies, including barred galaxies. With the two dimensional spectral and kinematic information provided by IFUs, we can measure the pattern speed of a barred galaxy, which determines the bar dynamics. We apply the non-parametric method proposed by Tremaine \& Weinberg to estimate the bar pattern speed for 53 barred galaxies, making this the largest sample studied so far in this way. Our sample is selected from the MaNGA first public data release as part of SDSS Data Release 13 according mainly to the axis ratio and position …
Over half of disk galaxies are barred, yet the mechanisms for bar formation and the life-time of bar buckling remain poorly understood. In simulations, a thin bar undergoes a rapid (<1 Gyr) event called "buckling," during which the inner part of the bar is asymmetrically bent out of the galaxy plane and eventually thickens, developing a peanut/X-shaped profile when viewed side-on. Through analyzing stellar kinematics of N-body model snapshots of a galaxy before, during, and after the buckling phase, we confirm a distinct quadrupolar pattern of out-of-plane stellar velocities in nearly face-on …
We analyse two-dimensional maps and radial profiles of EW(H$α$), EW(H$δ_A$), and D$_n$(4000) of low-redshift galaxies using integral field spectroscopy from the MaNGA survey. Out of $\approx1400$ nearly face-on late-type galaxies with a redshift $z<0.05$, we identify 121 "turnover" galaxies that each have a central upturn in EW(H$α$), EW(H$δ_A$) and/or a central drop in D$_n$(4000), indicative of ongoing/recent star formation. The turnover features are found mostly in galaxies with a stellar mass above $\sim$10$^{10}$ M$_{\odot}$ and NUV-$r$ colour less than $\approx5$. The majority of the tur…
We track the angular momentum transfer in n-body simulations of barred galaxies by measuring torques to understand the dynamical mechanisms responsible for the evolution of the bar-disc-dark matter halo system. We find evidence for three distinct phases of barred galaxy evolution: assembly, secular growth, and steady-state equilibrium. Using a decomposition of the disc into orbital families, we track bar mass and angular momentum through time and correlate the quantities with the phases of evolution. We follow the angular momentum transfer between particles and identify the dominant torque cha…
Aims: With the aim of assessing the effects of bars on disc galaxy properties, we present an analysis of different characteristics of spiral galaxies with strong, weak and without bars. Method: We identified barred galaxies from the Sloan Digital Sky Survey. By visual inspection, we classified the face-on spiral galaxies brighter than g<16.5 mag into strong-bar, weak-bar and unbarred. In order to provide an appropiate quantification of the influence of bars on galaxy properties, we also constructed a suitable control sample of unbarred galaxies with similar redshift, magnitude, morphology, bul…
Among the many processes involved in galaxy evolution, those of bar formation, quenching, and feedback from an active galactic nucleus (AGN) seem to be connected, however, the nature of these relations remains unclear. In this work, we aim to elucidate them by studying the formation of a barred galaxy in a major merger of two disks in the IllustrisTNG simulations. This merger involves a coalescence of two supermassive black holes and a sudden switch to the kinetic mode of AGN feedback implemented in the simulations, which leads to the removal of the gas from the inner part of the galaxy, follo…
We study the bar pattern speeds and corotation radii of 225 barred galaxies, using IFU data from MaNGA and the Tremaine-Weinberg method. Our sample, which is divided between strongly and weakly barred galaxies identified via Galaxy Zoo, is the largest that this method has been applied to. We find lower pattern speeds for strongly barred galaxies than for weakly barred galaxies. As simulations show that the pattern speed decreases as the bar exchanges angular momentum with its host, these results suggest that strong bars are more evolved than weak bars. Interestingly, the corotation radius is n…
We interpret simulations of secularly-evolving disc galaxies through orbit morphology. Using a new algorithm that measures the volume of orbits in real space using a tessellation, we rapidly isolate commensurate (resonant) orbits. We identify phase-space regions occupied by different orbital families. Compared to spectral methods, the tessellation algorithm can identify resonant orbits within a few dynamical periods, crucial for understanding an evolving galaxy model. The flexible methodology accepts arbitrary potentials, enabling detailed descriptions of the orbital families. We apply the mac…
We use a simple dynamical model in order to investigate the regular or chaotic character of orbits in a barred galaxy with a central, spherically symmetric, dense nucleus and a flat disk. In particular, we explore how the total orbital energy influences the overall orbital structure of the system, by computing in each case the percentage of regular, sticky and chaotic orbits. In an attempt to distinguish safely and with certainty between ordered and chaotic motion, we apply the Smaller ALingment Index (SALI) as a chaos detector to extensive samples of orbits obtained by integrating numerically…
Elongated, bar-like galaxies without a significant disk component, with little rotation support and no gas, often form as a result of tidal interactions with a galaxy cluster, as was recently demonstrated using the IllustrisTNG-100 simulation. Galaxies that exhibit similar properties are, however, also found to be infalling into the cluster for the first time. We use the same simulation to study in detail the history of such a galaxy over cosmic time in order to determine its origin. The bar appears to be triggered at t=6.8 Gyr by the combined effect of the last significant merger with a subha…
Cloud collision have been proposed as a way to link the small-scale star formation process with the observed global relation between the surface star formation rate and gas surface density. We suggest that this model can be improved further by allowing the productivity of such collisions to depend on the relative velocity of the two clouds. Our adjustment implements a simple step function that results in the most successful collisions being at the observed velocities for triggered star formation. By applying this to a high resolution simulation of a barred galaxy, we successfully reproduce the…
(Abridge) Bars are very common in the centre of the disc galaxies, and they drive the evolution of their structure. A volume-limited sample of 2106 disc galaxies extracted from the Sloan Digital Sky Survey Data Release 5 was studied to derive the bar fraction, length, and strength as a function of the morphology, size, local galaxy density, light concentration, and colour of the host galaxy. The bars were detected using the ellipse fitting method and Fourier analysis method. The ellipse fitting method was found to be more efficient in detecting bars in spiral galaxies. The fraction of barred g…
We derive the circular velocity curves of the gaseous and stellar discs of UGC 4056, a giant barred galaxy with an active galactic nucleus (AGN). We analyse UGC 4056 using the 2D spectroscopy obtained within the framework of the Mapping Nearby Galaxies at APO (MaNGA) survey. Using images and the colour index g-r from the Sloan Digital Sky Survey (SDSS), we determined the tilt of the galaxy, which allows us to conclude that the galaxy rotates clockwise with trailing spiral arms. We found that the gas motion at the central part of the UGC 4056 shows peculiar features. The rotation velocity of th…
We present a study of barred galaxies in the cluster environment, exploiting a sample of galaxies drawn from the extended WIde-field Nearby Galaxy-cluster Survey (OmegaWINGS) that covers up to the outer regions of 32 local X-ray selected clusters. Barred galaxies are identified through a semi-automatic analysis of ellipticity and position angle profiles. We find, in agreement with previous studies, a strong co-dependence of the bar fraction with the galaxy stellar mass and morphological type, being maximum for massive late-type galaxies. The fraction of barred galaxies decreases with increasin…
We use a simple dynamical model which consists of a harmonic oscillator and a spherical component, in order to investigate the regular or chaotic character of orbits in a barred galaxy with a central spherically symmetric nucleus. Our aim is to explore how the basic parameters of the galactic system influence the nature of orbits, by computing in each case the percentage of chaotic orbits, as well as the percentages of different types of regular orbits. We also give emphasis to the types of regular orbits that support either the formation of nuclear rings or the barred structure of the galaxy.…
Barred structures are important in understanding galaxy evolution, but they were not included explicitly in most dynamical models for nearby galaxies due to their complicated morphological and kinematic properties. We modify the triaxial orbit-superposition Schwarzschild implementation by Van den Bosch et al. (2008) to include barred structures explicitly. The gravitational potential is a combination of a spherical dark matter halo and stellar mass; with the 3D stellar density distribution de-projected from the observed 2D image using a two-component de-projection method, including an axisymme…
We present the results of two-component (disc+bar) and three-component (disc+bar+bulge) multiwavelength 2D photometric decompositions of barred galaxies in five SDSS bands ($ugriz$). This sample of $\sim$3,500 nearby ($z<0.06$) galaxies with strong bars selected from the Galaxy Zoo citizen science project is the largest sample of barred galaxies to be studied using photometric decompositions which include a bar component. With detailed structural analysis we obtain physical quantities such as the bar- and bulge-to-total luminosity ratios, effective radii, Sérsic indices and colours of the indi…
Observations and simulations of barred spiral galaxies have shown that, in general, the spiral arms rotate at a different pattern speed to that of the bar. The main conclusion from the bibliography is that the bar rotates faster than the spiral arms with a double or even a triple value of angular velocity. The theory that prevails in explaining the formation of the spiral arms in the case of a barred spiral galaxy with two pattern speeds is the manifold theory, where the orbits that support the spiral density wave are chaotic, and are related to the manifolds emanating from the Lagrangian poin…
Star formation activity depends on galactic-scale environments. To understand the variations in star formation activity, comparing the properties of giant molecular clouds (GMCs) among environments with different star formation efficiency (SFE) is necessary. We thus focus on a strongly barred galaxy to investigate the impact of the galactic environment on the GMCs properties, because the SFE is clearly lower in bar regions than in arm regions. In this paper, we present the $^{12}$CO($1-0$) observations toward the western bar, arm and bar-end regions of the strongly barred galaxy NGC1300 with A…
We use the magnetic-hydrodynamical simulation TNG50 to study the evolution of barred massive disc galaxies. Massive spiral galaxies are already present as early as $z=4$, and bar formation takes place already at those early times. The bars grow longer and stronger as the host galaxies evolve, with the bar sizes increasing at a pace similar to that of the disc scale lengths. The bar fraction mildly evolves with redshift for galaxies with $M_{*}\geq10^{10}M\odot$, being greater than $\sim40\%$ at $0.5<z<3$ and $\sim30\%$ at $z=0$. When bars larger than a given physical size ($\geq 2\,\rm kpc$) o…
We present results obtained from ALMA CO (2-1) data of the double-barred galaxy NGC 3504. With three times higher angular resolution (~ 0."8) than previous studies, our observations reveal an inner molecular gas bar, a nuclear ring, and four inner spiral arm-like structures in the central 1 kpc region. Furthermore, the CO emission is clearly aligned with the two dust lanes in the outer bar region, with differences in shape and intensity between them. The total molecular gas mass in the observed region (50"x57") is estimated to be $\sim 3.1\times 10^9 \, {\rm M}_{\odot}$, which is 17 per cent o…
A recent study shows that bars can be induced via interaction of galaxy clusters, but it has been unclear if the bar formation by the interaction between clusters is related to the enhancement of star formation. We study galaxies in 105 galaxy clusters at $0.015<z<0.060$ detected from Sloan Digital Sky Survey data, in order to examine whether the fraction of star-forming galaxies ($f_\mathrm{sf}$) in 16 interacting clusters is enhanced compared with that of the other non-interacting clusters and to investigate the possible connection between the $f_\mathrm{sf}$ enhancement and the bar formatio…
We present infrared imaging from IRIS2 on the Anglo-Australian Telescope that shows the barred spiral galaxy IC 4933 has not just an inner ring encircling the bar, but also a star-forming nuclear ring 1.5 kpc in diameter. Imaging in the u' band with GMOS on Gemini South confirms that this ring is not purely an artifact due to dust. Optical and near-infrared colours alone however cannot break the degeneracy between age, extinction, and burst duration that would allow the star formation history of the ring to be unraveled. Integral field spectroscopy with the GNIRS spectrograph on Gemini South s…
With the Infrared Camera on board AKARI, we carried out near-infrared (2.5-5.0 micron) spectroscopy of the central kiloparsec region of the barred spiral galaxy, NGC1097, categorized as Seyfert 1 with a circumnuclear starburst ring. Our observations mapped the area of ~50"*10" with the resolution of ~5", covering about a half of the ring and the galactic center. As a result, we spatially resolve the starburst ring in the polycyclic aromatic hydrocarbon 3.3 micron, the aliphatic hydrocarbon 3.4-3.6 micron features, and the hydrogen Br alpha 4.05 micron emission. They exhibit spatial distributio…
Recent galaxy observations show that star formation activity changes depending on galactic environments. In order to understand the diversity of galactic-scale star formation, it is crucial to understand the formation and evolution of giant molecular clouds in an extreme environment. We focus on observational evidence that bars in strongly barred galaxies lack massive stars even though quantities of molecular gas are sufficient to form stars. In this paper, we present a hydrodynamical simulation of a strongly barred galaxy, using a stellar potential which is taken from observational results of…
We report the discovery of a mysterious giant $H_α$ blob that is $\sim 8$ kpc away from the main MaNGA target 1-24145, one component of a dry galaxy merger, identified in the first-year SDSS-IV MaNGA data. The size of the $H_α$ blob is $\sim$ 3-4 kpc in radius, and the $H_α$ distribution is centrally concentrated. However, there is no optical continuum counterpart in deep broadband images reaching $\sim$26.9 mag arcsec$^{-2}$ in surface brightness. We estimate that the masses of ionized and cold gases are $3.3 \times 10^{5}$ $\rm M_{\odot}$ and $< 1.3 \times 10^{9}$ $\rm M_{\odot}$, respective…
We use 3.6 $μ$m imaging from the S$^{4}$G survey to characterize the typical stellar density profiles ($Σ_{\ast}$) 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 ($\ge 10^{9}M_{\odot}$), …
Double bars are thought to be important features for secular evolution in the central regions of galaxies. However, observational evidence about their origin and evolution is still scarce. We report on the discovery of the first Box-Peanut (B/P) structure in an inner bar detected in the face-on galaxy NGC 1291. We use the integral field data obtained from the MUSE spectrograph within the TIMER project. The B/P structure is detected as bi-symmetric minima of the $h_4$ moment of the line-of-sight velocity distribution along the major axis of the inner bar, as expected from numerical simulations.…
The formation of bars in disk galaxies is a tracer of the dynamical maturity of the population. Previous studies have found that the incidence of bars in disks decreases from the local Universe to z ~ 1, and by z > 1 simulations predict that bar features in dynamically mature disks should be extremely rare. Here we report the discovery of strong barred structures in massive disk galaxies at z ~ 1.5 in deep rest-frame optical images from CANDELS. From within a sample of 876 disk galaxies identified by visual classification in Galaxy Zoo, we identify 123 barred galaxies. Selecting a sub-sample w…
We conduct spectral line survey observations in the 3 mm band toward a spiral arm, a bar-end, and a nuclear region of the nearby barred spiral galaxy NGC 3627 with the IRAM 30 m telescope and the Nobeyama 45 m telescope. Additional observations are performed toward the spiral arm and the bar-end in the 2 mm band. We detect 8, 11, and 9 molecular species in the spiral arm, the bar-end, and the nuclear region, respectively. Star-formation activities are different among the three regions, and in particular, the nucleus of NGC 3627 is known as a LINER/Seyfert 2 type nucleus. In spite of these phys…
The lenticular galaxy IC 676 is a barred galaxy with double nuclei and active star formation in the central region. In this work we present the long-slit spectroscopy and archival multi-wavelength images to investigate the nature and origin of the double nuclei in IC 676. Through photometric 1D brightness profiles and 2D image decomposition, we show that this galaxy consists of a stellar bar with the length of $\sim$ 2.5 kpc and two Sérsic disks both of which with Sérsic index $\it n \sim$ 1.3. There is probably little or no bulge component assembled in IC 676. The luminosities of the double n…
Cloud-cloud collision (CCC) has been suggested as a mechanism to induce massive star formation. Recent simulations suggest that a CCC speed is different among galactic-scale environments, which is responsible for observed differences in star formation activity. In particular, a high-speed CCC is proposed as a cause of star formation suppression in the bar regions in barred spiral galaxies. Focusing on the strongly barred galaxy NGC1300, we investigate the CCC speed. We find the CCC speed in the bar and bar-end tend to be higher than that in the arm. The estimated CCC speed is $\sim20~\rm km~s^…
Bar formation in cosmological simulations of galaxy formation remains challenging. It was previously shown that the fraction of barred galaxies at low stellar masses ($M_*<10^{10.5} M_\odot$) in TNG50 is too low compared to observations. Here, we highlight another tension, also observed at higher stellar masses, namely that barred galaxies in TNG50 appear to be maximal discs, in the sense that the majority of the gravitational acceleration is accounted for by baryons at the peak radius of the baryonic rotation curve, while observations account for a substantial fraction of barred submaximal di…
We present gas and stellar kinematics of a high-resolution zoom-in cosmological chemodynamical simulation, which fortuitously captures the formation and evolution of a star-forming barred spiral galaxy, from redshift $z\sim3$ to $z\sim2$ at the peak of the cosmic star formation rate. The galaxy disc grows by accreting gas and substructures from the environment. The spiral pattern becomes fully organised when the gas settles from a thick (with vertical dispersion $σ_{v} >$ 50 km/s) to a thin ($σ_{v} \sim 25$ km/s) disc component in less than 1 Gyr. Our simulated disc galaxy also has a central X…
We present a photometric study of PGC 1000714, a galaxy resembling Hoag's Object with a complete detached outer ring, that has not yet been described in the literature. Since the Hoag-type galaxies are extremely rare and peculiar systems, it is necessary to increase the sample of known objects by performing the detailed studies on the possible candidates to derive conclusions about their nature, evolution, and systematic properties. We therefore performed surface photometry of the central body by using the archival near-UV, infrared data and the new optical data (BVRI). This current work has r…
NOEMA$^{\rm 3D}$: A first kpc resolution study of a $z\sim1.5$ main sequence barred galaxy channeling gas into a growing bulge
Max-Planck-Institut für Extraterrestrische Physik (MPE)（马克斯·普朗克地外物理学研究所）；Max-Planck-Institut für Astrophysik (MPA)（马克斯·普朗克天体物理学研究所）；University of California, Berkeley（加州大学伯克利分校）；Institut de Radioastronomie Millimétrique (IRAM)（毫米波射电天文研究所）；Universitäts-Sternwarte Ludwig-Maximilians-Universität (USM)（路德维希-马克西米利安大学大学天文台）
We use probability density functions (pdfs) of sums of orbit coordinates, over time intervals of the order of one Hubble time, to distinguish weakly from strongly chaotic orbits in a barred galaxy model. We find that, in the weakly chaotic case, quasi-stationary states arise, whose pdfs are well approximated by $q$-Gaussian functions (with $1<q<3$), while strong chaos is identified by pdfs which quickly tend to Gaussians ($q=1$). Typical examples of weakly chaotic orbits are those that "stick" to islands of ordered motion. Their presence in rotating galaxy models has been investigated thorough…
Changing-look Active Galactic Nuclei (CL-AGNs) are a subset of AGNs in which the broad Balmer emission lines appear or disappear within a few years. We use the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey to identify five CL-AGNs. The 2-D photometric and kinematic maps reveal common features as well as some unusual properties of CL-AGN hosts as compared to the AGN hosts in general. All MaNGA CL-AGNs reside in the star-forming main sequence, similar to MaNGA non-changing-look AGNs (NCL-AGNs). The $80\% \pm 16\%$ of our CL-AGNs do possess pseudo-bulge features, and follow t…
The observations of external galaxies are projected to the 2D sky plane. Reconstructing the 3D intrinsic density distribution of a galaxy from the 2D image is challenging, especially for barred galaxies, but is a critical step for constructing galactic dynamical models. Here we present a method for deprojecting barred galaxies and we validate the method by testing against mock images created from an N-body simulation with a peanut-shaped bar. We decompose a galaxy image into a bulge (including a bar) and a disk. By subtracting the disk from the original image a barred bulge remains. We perform…
In many barred galaxies, star formation efficiency (SFE) in the bar is lower than those in the arm and bar-end, and its cause has still not been clear. Focusing on the strongly barred galaxy NGC 1300, we investigate the possibility that the presence of a large amount of diffuse molecular gas, which would not contribute to the SF, makes the SFE low in appearance. We examine the relation between the SFE and the diffuse molecular gas fraction ($f_{\rm dif}$), which is derived using the $^{12}$CO($1-0$) flux obtained from the interferometer of ALMA 12-m array, which has no sensitivity on diffuse (…
The SDSS-IV MaNGA survey has measured two-dimensional maps of emission line velocities for a statistically powerful sample of nearby galaxies. The asymmetric features of these kinematics maps reflect the non-rotational component of a galaxy's internal motion of ionized gas. In this study, we present a catalog of kinematic asymmetry measurement of $Hα$ velocity map of a sample of 5353 MaNGA galaxies. Based on this catalog, we find that `special' galaxies (e.g. merging galaxies, barred galaxies, and AGN host galaxies) contain more galaxies with highly asymmetric velocity maps. However, we notice…
