Theories that attempt to explain the dynamical relationship between bar andspiral patterns in galactic disks make different predictions about the radialprofile of the pattern speed. These are tested for the H-alpha bar and spiralpatterns of NGC 1365. The radial profile of the pattern speed is measured byfitting mathematical models that are based on the Tremaine-Weinberg method. Theresults show convincing evidence for the bar rotating at a faster rate than thespiral pattern, inconsistent with a global wave mode or a manifold. There isevidence for mode coupling of the bar and spiral patterns at the overlap ofcorotation and inner Lindblad resonances, but the evidence is unreliable andinconsistent. The results are the most consistent with the bar and spiralpatterns being dynamically distinct features. The pattern speed of the barbegins near an ILR and ends near the corotation resonance. The radial profileof the pattern speed beyond the bar most closely resembles what is expected forcoupled spiral modes and tidal interactions.

In this letter we investigate the effect of boxy/peanut (b/p) bulges onbar-induced gas inflow to the central kiloparsec, which plays a crucial role onthe evolution of disc galaxies. We carry out hydrodynamic gas responsesimulations in realistic barred galaxy potentials, including or not thegeometry of a b/p bulge, to investigate the amount of gas inflow induced in thedifferent models. We find that b/p bulges can reduce the gas inflow rate to thecentral kiloparsec by more than an order of magnitude, which leads to areduction in the amount of gas available in the central regions. We alsoinvestigate the effect of the dark matter halo concentration on these results,and find that for maximal discs, the effect of b/p bulges on gas inflow remainssignificant. The reduced amount of gas reaching the central regions due to thepresence of b/p bulges could have significant repercussions on the formation ofdiscy- (pseudo-) bulges, on the amount of nuclear star formation and feedback,on the fuel reservoir for AGN activity, and on the overall secular evolution ofgalaxies.

Photoionization models of HII regions require as input a description of theionizing SED and of the gas distribution, in terms of ionization parameter Uand chemical abundances (e.g. O/H and N/O). A strong degeneracy exists betweenthe hardness of the SED and U, which in turn leads to high uncertainties in thedetermination of the other parameters, including abundances. One way to resolvethe degeneracy is to fix one of the parameters using additional information. For each of the ~ 20000 sources of the CALIFA HII regions catalog, a grid ofphotoionization models is computed assuming the ionizing SED being described bythe underlying stellar population obtained from spectral synthesis modeling.The ionizing SED is then defined as the sum of various stellar bursts ofdifferent ages and metallicities. This solves the degeneracy between the shapeof the ionizing SED and U. The nebular metallicity (associated to O/H) isdefined using the classical strong line method O3N2 (which gives to our modelsthe status of "hybrids"). The remaining free parameters are the abundance ratioN/O and the ionization parameter U, which are determined by looking for themodel fitting [NII]/Ha and [OIII]/Hb. The models are also selected to fit[OII]/Hb. This process leads to a set of ~ 3200 models that reproducesimultaneously the three observations. We find that the regions associated to young stellar bursts suffer leaking ofthe ionizing photons, the proportion of escaping photons having a median of80\%. The set of photoionization models satisfactorily reproduces the electrontemperature derived from the [OIII]4363/5007 line ratio. We determine newrelations between the ionization parameter U and the [OII]/[OIII] or[SII]/[SIII] line ratios. New relations between N/O and O/H and between U andO/H are also determined. All the models are publicly available on the 3MdB database.

We have identified a population of passive spiral galaxies from photometryand integral field spectroscopy. We selected z<0.035 spiral galaxies that haveWISE colours consistent with little mid-infrared emission from warm dust.Matched aperture photometry of 51 spiral galaxies in ultraviolet, optical andmid-infrared show these galaxies have colours consistent with passive galaxies.Six galaxies form a spectroscopic pilot study and were observed using theWide-Field Spectrograph (WiFeS) to check for signs of nebular emission fromstar formation. We see no evidence of substantial nebular emission found inprevious red spiral samples. These six galaxies possess absorption-line spectrawith 4000\AA\ breaks consistent with an average luminosity-weighted age of 2.3Gyr. Our photometric and IFU spectroscopic observations confirm the existenceof a population of local passive spiral galaxies, implying that transformationinto early-type morphologies is not required for the quenching of starformation.

We carried out a photometric and structural analysis in the rest-frame $V$band of a mass-selected ($\log M/M_\odot >10.7$) sample of red-sequencegalaxies in 14 galaxy clusters, 6 of which are at $z>1.45$. To this end, wereduced/analyzed about 300 orbits of multicolor images taken with the AdvancedCamera for Survey and the Wide Field Camera 3 on the Hubble Space Telescope. Weuniformly morphologically classified galaxies from $z=0.023$ to $z=1.803$, andwe homogeneously derived sizes (effective radii) for the entire sample.Furthermore, our size derivation allows, and therefore is not biased by, thepresence of the usual variety of morphological structures seen in early-typegalaxies, such as bulges, bars, disks, isophote twists, and ellipiticygradients. By using such a mass-selected sample, composed of 244 red-sequenceearly-type galaxies, we find that the $\log$ of the galaxy size at a fixedstellar mass, $\log M/M_\odot= 11$ has increased with time at a rate of$0.023\pm0.002$ dex per Gyr over the last 10 Gyr, in marked contrast with thethreefold increase found in the literature for galaxies in the general fieldover the same period. This suggests, at face value, that secular processesshould be excluded as the primary drivers of size evolution because we observedan environmental environmental dependent size growth. Using spectroscopic agesof Coma early-type galaxies we also find that recently quenched early-typegalaxies are a numerically minor population not different enough in size toalter the mean size at a given mass, which implies that the progenitor bias isminor, i.e., that the size evolution measured by selecting galaxies at theredshift of observation is indistinguishable from the one that comparesancestors and descendents.

The dark matter (DM) haloes around spiral galaxies appear to conspire withtheir baryonic content: empirically, significant amounts of DM are inferredonly below a universal characteristic acceleration scale. Moreover, thediscrepancy between the baryonic and dynamical mass, which is usuallyinterpreted as the presence of DM, follows a very tight mass discrepancyacceleration (MDA) relation. Its universality, and its tightness in spiralgalaxies, poses a challenge for the DM interpretation and was used to argue infavour of MOdified Newtonian Dynamics (MOND). Here, we test whether or not thisapplies to early-type galaxies. We use the dynamical models of fast-rotatorearly-type galaxies by Cappellari et al. based on ATLAS$^{3D}$ and SLUGGS data,which was the first homogenous study of this kind, reaching ~4 $R_e$, where DMbegins to dominate the total mass budget. We find the early-type galaxies tofollow an MDA relation similar to spiral galaxies, but systematically offset.Also, while the slopes of the mass density profiles inferred from galaxydynamics show consistency with those expected from their stellar contentassuming MOND, some profiles of individual galaxies show discrepancies.