Kinematics and Mass Modeling of Messier 33: Halpha observations

As part of a long-term project to revisit the kinematics and dynamics of the large disc galaxies of the Local Group, we present the first deep, wide-field (42' x 56') 3D-spectroscopic survey of the ionized gas disc of Messier 33. Fabry-Perot interferometry has been used to map its Ha distribution and kinematics at unprecedented angular resolution (<3'') and resolving power (12600), with the 1.6m telescope at the Observatoire du Mont Megantic. The ionized gas distribution follows a complex, large-scale spiral structure, unsurprisingly coincident with the already-known spiral structures of the neutral and molecular gas discs. The kinematical analysis of the velocity field shows that the rotation center of the Ha disc is distant from the photometric center by 170 pc (sky projected distance) and that the kinematical major-axis position angle and disc inclination are in excellent agreement with photometric values. The Ha rotation curve agrees very well with the HI rotation curves for 0 6.5 kpc. The reason for this discrepancy is not well understood. The velocity dispersion profile is relatively flat around 16 km/s, which is at the low end of velocity dispersions of nearby star-forming galactic discs. A strong relation is also found between the Ha velocity dispersion and the Ha intensity. Mass models were obtained using the Ha rotation curve but, as expected, the dark matter halo's parameters are not very well constrained since the optical rotation curve only extends out to 8 kpc.Comment: 26 pages, 18 figures, accepted for publication in MNRA

A SINFONI Integral Field Spectroscopy Survey for Galaxy Counterparts to Damped Lyman-alpha Systems - VI. Metallicity and Geometry as Gas Flow Probes

The use of background quasars provides a powerful tool to probe the cool gas in the circum-galactic medium of foreground galaxies. Here, we present new observations with SINFONI and X-Shooter of absorbing-galaxy candidates at z=0.7-1. We report the detection with both instruments of the H-alpha emission line of one sub-DLA at z_abs=0.94187 with log N(HI)=19.38^+0.10_-0.15 towards SDSS J002133.27+004300.9. We estimate the star formation rate: SFR=3.6+/-2.2 solar masses per year in that system. A detailed kinematic study indicates a dynamical mass M_dyn=10^9.9+/-0.4 solar masses and a halo mass M_halo=10^11.9+/-0.5 solar masses. In addition, we report the OII detection with X-Shooter of another DLA at z_abs=0.7402 with log N(HI)=20.4+/-0.1 toward Q0052+0041 and an estimated SFR of 5.3+/-0.7 solar masses per year. Three other objects are detected in the continuum with X-Shooter but the nature and redshift of two of these objects are unconstrained due to the absence of emission lines, while the third object might be at the redshift of the quasar. We use the objects detected in our whole N(HI)-selected SINFONI survey to compute the metallicity difference between the galaxy and the absorbing gas, delta_HI(X), where a positive (negative) value indicates infall (outflow). We compare this quantity with the quasar line of sight alignment with the galaxy's major (minor) axis, another tracer of infall (outflow). We find that these quantities do not correlate as expected from simple assumptions. Additional observations are necessary to relate these two independent probes of gas flows around galaxies.Comment: 16 pages, 8 figures, accepted for publication in MNRA

Hydrodynamics of high-redshift galaxy collisions: From gas-rich disks to dispersion-dominated mergers and compact spheroids

Disk galaxies at high redshift (z~2) are characterized by high fractions of cold gas, strong turbulence, and giant star-forming clumps. Major mergers of disk galaxies at high redshift should then generally involve such turbulent clumpy disks. Merger simulations, however, model the ISM as a stable, homogeneous, and thermally pressurized medium. We present the first merger simulations with high fractions of cold, turbulent, and clumpy gas. We discuss the major new features of these models compared to models where the gas is artificially stabilized and warmed. Gas turbulence, which is already strong in high-redshift disks, is further enhanced in mergers. Some phases are dispersion-dominated, with most of the gas kinetic energy in the form of velocity dispersion and very chaotic velocity fields, unlike merger models using a thermally stabilized gas. These mergers can reach very high star formation rates, and have multi-component gas spectra consistent with SubMillimeter Galaxies. Major mergers with high fractions of cold turbulent gas are also characterized by highly dissipative gas collapse to the center of mass, with the stellar component following in a global contraction. The final galaxies are early-type with relatively small radii and high Sersic indices, like high-redshift compact spheroids. The mass fraction in a disk component that survives or re-forms after a merger is severely reduced compared to models with stabilized gas, and the formation of a massive disk component would require significant accretion of external baryons afterwards. Mergers thus appear to destroy extended disks even when the gas fraction is high, and this lends further support to smooth infall as the main formation mechanism for massive disk galaxies.Comment: ApJ accepte

The E-ELT first light spectrograph HARMONI: capabilities and modes

Trabajo presentado en SPIE Astronomical Telescopes, celebrado en San Diego (California), del 26 de junio al 1 de julio de 2016HARMONI is the E-ELT's first light visible and near-infrared integral field spectrograph. It will provide four different spatial scales, ranging from coarse spaxels of 60 × 30 mas best suited for seeing limited observations, to 4 mas spaxels that Nyquist sample the diffraction limited point spread function of the E-ELT at near-infrared wavelengths. Each spaxel scale may be combined with eleven spectral settings, that provide a range of spectral resolving powers (R 3500, 7500 and 20000) and instantaneous wavelength coverage spanning the 0.5 - 2.4 ¿m wavelength range of the instrument. In autumn 2015, the HARMONI project started the Preliminary Design Phase, following signature of the contract to design, build, test and commission the instrument, signed between the European Southern Observatory and the UK Science and Technology Facilities Council. Crucially, the contract also includes the preliminary design of the HARMONI Laser Tomographic Adaptive Optics system. The instrument's technical specifications were finalized in the period leading up to contract signature. In this paper, we report on the first activity carried out during preliminary design, defining the baseline architecture for the system, and the trade-off studies leading up to the choice of baseline

Des Galaxies Proches Aux Galaxies Lointaines: Etudes Cinématique et Dynamique

Kinematical studies of low and high redshift galaxies enables to probe galaxy formation and evolution scenarios. Integral field spectroscopy is a powerful tool to study with accuracy nearby galaxies kinematics. Recent observations also gives a new 2D vision of high redshift galaxies kinematics. This work mostly relies on the kinematical sample of galaxies GHASP. This control sample, composed of 203 local spiral and irregular galaxies in low density environments observed with Fabry-Perot techniques in the Hα line (6563 Å), is by now the largest sample of Fabry-Perot data. After a revue on Fabry-Perot interferometry and a presentation of new data reduction procedures, my implications on both 3D-NTT Fabry-Perot instrument and the wide field spectrograph project (WFSpec) for galaxy evolution study with the european ELT are developed. The second section is dedicated to GHASP data. This sample have been fully reduced and analysed using new methods. The kinematical analysis of 2D kinematical maps has been undertaken with the study of the dark matter distribution, the rotation curves shape, bar signatures and the ionized gas velocity dispersion. In a third section, this local reference sample is used as a zero point for high redshift galaxies kinematical studies. The GHASP sample is projected at high redshift (z = 1.7) in order to disentangle evolution effects from distance biases in high redshift galaxies kinematical data observed with SINFONI, OSIRIS and GIRAFFE. The kinematical analysis of new SINFONI high redshift observations is also presented and high redshift data found in the literature are compared with GHASP projected sample, suggesting some evolution of the galaxy dynamical support within the ages.L'étude cinématique des galaxies locales et lointaines permet de contraindre les scénarios de formation et d'évolution des galaxies. Pour cela, la spectroscopie à champ intégral permet une étude détaillée de la cinématique des galaxies proches et fournit depuis peu des indices sur la cinématique des galaxies lointaines. Cette thèse s'appuie principalement sur l'utilisation de l'échantillon cinématique de galaxies locales GHASP. Cet échantillon de référence composé de 203 galaxies spirales et irrégulières de l'Univers local dans des environnements peu denses observées par interférométrie de Fabry-Perot autour de la raie Hα (6563 Å) est le plus grand échantillon de données Fabry-Perot à ce jour. Après un passage en revue des principes de l'interférométrie Fabry-Perot et des nouveautés apportées à la réduction des données Fabry-Perot, mon implication dans le développement du 3D-NTT, nouvel instrument utilisant deux Fabry-Perot est exposée de même que ma participation au projet de spectrographe à grand champ pour les ELT, WFSpec, dont l'objectif est l'étude de l'évolution des galaxies. Je présente dans une deuxième partie les données GHASP. Cet échantillon a été entièrement réduit et analysé à l'aide de nouvelles méthodes. L'analyse cinématique de l'échantillon à partir des cartes cinématiques 2D a été initiée en particulier avec l'étude de la distribution des halos de matière sombre, de la forme des courbes de rotation, de l'influence des potentiels barrés et de la dispersion de vitesses du gaz ionisé. Dans une troisième partie, cet échantillon local sert de point de référence pour l'étude de la cinématique des galaxies lointaines. L'échantillon GHASP est projeté à grand décalage spectral (z = 1.7) afin de déterminer les biais observationnels liés au manque de résolution spatiale des données cinématiques de galaxies lointaines obtenues par SINFONI, OSIRIS et GIRAFFE. L'analyse cinématique de nouvelles observations SINFONI y est également présentée, et l'ensemble des données cinématiques 2D de la littérature est mis en regard avec les résultats obtenus sur l'échantillon GHASP, mettant en évidence une évolution du support dynamique des galaxies avec le temps

Galaxy evolution in groups at intermediate redshift from the MUSE galaxies Groups In Cosmos survey

International audienceMAGIC (Muse gAlaxy Groups In Cosmos) is a 100h MUSE-GTO survey aiming at understanding the impact of environment on galaxy evolution. It targets 15 massive groups at 0.3-z-0.8, identified in the zCOSMOS and VVDS VIMOS surveys, probing spatially resolved properties of galaxies down to low mass (\raisebox-0.5ex~10\⁸ Msun) but also the intra- group medium. After introducing MAGIC, I will present a first analysis of the ionised gas kinematic of galaxies in these groups which shows that the Tully-Fisher relation evolves due to quenching and contraction (Abril-Melgarejo+21). I will explain how MUSE observations led to the first detection of very extended ionised gas nebulae within groups, associated to processes such as tidal interactions, AGN feedback, shocks (Epinat+18) and ram pressure stripping (Boselli+19) at z\raisebox-0.5ex~0.7. I will conclude by discussing the implications of these results on galaxy evolution, on the quenching of starformation in dense environments and on the build-up of the Hubble sequence

Morpho-kinematics of galaxies in various environments at z ∼0.2-1.5

International audienceWe present a study of the impact of the environment on the morphokinematics properties of intermediate redshift galaxies (z~0.25-1.5) with the use of HST and MUSE data. We use the latest MUSE-GTO observations of 17 different fields in the COSMOS area from the MAGIC survey to build a sample of ~ 600 resolved galaxies, within target groups and in their foreground and background, allowing to probe a variety of environments, with virial masses in the range 10^9 - 10^14 M_sol. We perform a multicomponent decomposition from the HST images, and extract the ionised gas kinematics from the MUSE cubes using the [OII] doublet. Taking into account prior information from the morphological decomposition, we perform a mass modelling in order to extract the galaxies main kinematical parameters such as their circular velocity and baryon fraction. After describing our methodology, I will present our results on various scaling relations such as the TFR and show how these scale with structure properties. Chaitr

Using gas kinematics to measure resonant structures in disc galaxies: the interaction of M51 with NGC 5195

International audienceInterstellar gas offers advantages when quantifying the structure of the resonances in disc galaxies. The gas is concentrated close to the disc mid-plane, making it easier to determine its in-plane velocity components, and it offers sharp emission lines for good velocity resolution. These properties are shared by atomic, molecular, and ionized gas; high spectral and angular resolution over wide fields can be performed, especially for the ionized and molecular phases. We have previously shown that using gas kinematics corotation radii can be found, not only corresponding to the main bars of barred galaxies, but also to nuclear bars, and for the spiral arms, which usually exhibit several corotations, corresponding to a concentric annular density wave pattern. We have also shown that a gas kinematic technique gives precise correspondence with the structure found using the Tremaine Weinberg method for stars, but can cover a larger fraction of galaxy discs. In this contribution we present our recent study of the resonant structure of M51, using kinematic mapping with the CO molecule from PAWS supplemented with our own velocity map in Halpha, which is complemented with the analysis of the morphology of M51. We demonstrate the role of its interacting satellite NGC 5195 in stimulating the formation of the spiral arms and kinks, and demonstrate that it has twice passed through the plane of M51, calculating the time interval between passages. Our results are strengthened by comparison with simulations of this interaction

Using gas kinematics to measure resonant structures in disc galaxies: the interaction of M51 with NGC 5195

International audienceInterstellar gas offers advantages when quantifying the structure of the resonances in disc galaxies. The gas is concentrated close to the disc mid-plane, making it easier to determine its in-plane velocity components, and it offers sharp emission lines for good velocity resolution. These properties are shared by atomic, molecular, and ionized gas; high spectral and angular resolution over wide fields can be performed, especially for the ionized and molecular phases. We have previously shown that using gas kinematics corotation radii can be found, not only corresponding to the main bars of barred galaxies, but also to nuclear bars, and for the spiral arms, which usually exhibit several corotations, corresponding to a concentric annular density wave pattern. We have also shown that a gas kinematic technique gives precise correspondence with the structure found using the Tremaine Weinberg method for stars, but can cover a larger fraction of galaxy discs. In this contribution we present our recent study of the resonant structure of M51, using kinematic mapping with the CO molecule from PAWS supplemented with our own velocity map in Halpha, which is complemented with the analysis of the morphology of M51. We demonstrate the role of its interacting satellite NGC 5195 in stimulating the formation of the spiral arms and kinks, and demonstrate that it has twice passed through the plane of M51, calculating the time interval between passages. Our results are strengthened by comparison with simulations of this interaction