We develop and apply new techniques in order to uncover galaxy rotationcurves (RC) systematics. Considering that an ideal dark matter (DM) profileshould yield RCs that have no bias towards any particular radius, we find thatthe Burkert DM profile satisfies the test, while the Navarro-Frenk-While (NFW)profile has a tendency of better fitting the region between one and two discscale lengths than the inner disc scale length region. Our sample indicatesthat this behaviour happens to more than 75% of the galaxies fitted with an NFWhalo. Also, this tendency does not weaken by considering "large" galaxies, forinstance those with $M_*\gtrsim 10^{10} M_\odot$. Besides the tests on thehomogeneity of the fits, we also use a sample of 62 galaxies of diverse typesto perform tests on the quality of the overall fit of each galaxy, and tosearch for correlations with stellar mass, gas mass and the disc scale length.In particular, we find that only 13 galaxies are better fitted by the NFW halo;and that even for the galaxies with $M_* \gtrsim 10^{10} M_\odot$ the Burkertprofile either fits as good as, or better than, the NFW profile. This result isrelevant since different baryonic effects important for the smaller galaxies,like supernova feedback and dynamical friction from baryonic clumps, indicatethat at such large stellar masses the NFW profile should be preferred over theBurkert profile. Hence, our results either suggest a new baryonic effect or achange of the dark matter physics.

This is the second paper of a series aimed to study the stellar kinematicsand population properties of bulges in highly-inclined barred galaxies. In thiswork, we carry out a detailed analysis of the stellar age, metallicity and[Mg/Fe] of 28 highly-inclined ($i > 65^{o}$) disc galaxies, from S0 to S(B)c,observed with the SAURON integral-field spectrograph. The sample is dividedinto two clean samples of barred and unbarred galaxies, on the basis of thecorrelation between the stellar velocity and h$_3$ profiles, as well as thelevel of cylindrical rotation within the bulge region. We find that while themean stellar age, metallicity and [Mg/Fe] in the bulges of barred and unbarredgalaxies are not statistically distinct, the [Mg/Fe] gradients along the minoraxis (away from the disc) of barred galaxies are significantly different thanthose without bars. For barred galaxies, stars that are vertically further awayfrom the midplane are in general more [Mg/Fe]--enhanced and thus the verticalgradients in [Mg/Fe] for barred galaxies are mostly positive, while forunbarred bulges the [Mg/Fe] profiles are typically negative or flat. Thisresult, together with the old populations observed in the barred sample,indicates that bars are long-lasting structures, and therefore are not easilydestroyed. The marked [Mg/Fe] differences with the bulges of unbarred galaxiesindicate that different formation/evolution scenarios are required to explaintheir build-up, and emphasizes the role of bars in redistributing stellarmaterial in the bulge dominated regions.

We present 12CO (2-1) data of three Virgo spirals - NGC 4330, NGC 4402 andNGC 4522 obtained using the Submillimeter Array. These three galaxies showclear evidence of ram pressure stripping due to the cluster medium as found inprevious HI imaging studies. Using high-resolution CO data, we investigate howthe properties of the inner molecular gas disc change while a galaxy isundergoing HI stripping in the cluster. At given sensitivity limits, we do notfind any clear signs of molecular gas stripping. However, both its morphologyand kinematics appear to be quite disturbed as those of HI. Morphologicalpeculiarities present in the molecular and atomic gas are closely related witheach other, suggesting that molecular gas can be also affected by strong ICMpressure even if it is not stripped. CO is found to be modestly enhanced alongthe upstream sides in these galaxies, which may change the local star formationactivity in the disc. Indeed, the distribution of H$\alpha$ emission, a tracerof recent star formation, well coincides with that of the molecular gas,revealing enhancements near the local CO peak or along the CO compression. FUVand H$\alpha$ share some properties in common, but FUV is always more extendedthan CO/H$\alpha$ in the three galaxies, implying that the star-forming disc israpidly shrinking as the molecular gas properties have changed. We discuss howICM pressure affects dense molecular gas and hence star formation propertieswhile diffuse atomic gas is being removed from a galaxy.

The fine details of the large-scale structure in the local universe provideimportant empirical benchmarks for testing cosmological models of structureformation. Dwarf galaxies are key object for such studies. Enlarge the sampleof known dwarf galaxies in the local universe. We performed a search for faint,unresolved low-surface brightness dwarf galaxies in the M101 group complex,including the region around the major spiral galaxies M101, M51, and M63 lyingat a distance 7.0, 8.6, and 9.0 Mpc, respectively. The new dwarf galaxy samplecan be used in a first step to test for significant substructure in the2D-distribution and in a second step to study the spatial distribution of thegalaxy complex. Using filtering algorithms we surveyed 330 square degrees ofimaging data obtained from the Sloan Digital Sky Survey. The images werevisually inspected. The spatial distribution of known galaxies and candidateswas analyzed transforming the system into a M101 eigenframe, using thegeometrical alignment of the group. We discovered 15 new dwarf galaxies andcarried out surface photometry in the g and r bands. The similarity of thephotometric properties of these dwarfs to those of Local Group dwarfs suggestmembership to the M101 group complex. The sky distribution of the candidatesfollows the thin planar structure outlined by the known members of the threesubgroups. The ~3Mpc long filamentary structure has a rms thickness of 67 kpc.The planar structure of the embedded M101 subgroup is even thinner, with rms=46kpc. The formation of this structure might be due to the expansion of the LocalVoid to which it borders. Other implications are discussed as well. We show theviability of SDSS data to extend the sample of dwarfs in the local universe andtest cosmological models on small scales.