Unveiling the gravitationally unstable disc of a massive star-forming galaxy using NOEMA and MUSE

Using new high-resolution data of CO (2-1), H-alpha and H-beta obtained with the Northern Extended Millimeter Array (NOEMA) and the Multi-Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope, we have performed a Toomre-Q disc stability analysis and studied star formation, gas depletion times and other environmental parameters on sub-kpc scales within the z~0 galaxy SDSS J125013.84+073444.5 (LARS 8). The galaxy hosts a massive, clumpy disc and is a proto-typical analogue of main-sequence galaxies at z~1-2. We show that the massive (molecular) clumps in LARS 8 are the result of an extremely gravitationally unstable gas disc, with large scale instabilities found across the whole extent of the rotating disc, with only the innermost 500 pc being stabilized by its bulgelike structure. The radial profiles further reveal that - contrary to typical disc galaxies - the molecular gas depletion time decreases from more than 1 Gyr in the center to less than ~100 Myr in the outskirts of the disc, supporting the findings of a Toomre-unstable disc. We further identified and analysed 12 individual massive molecular clumps. They are virialized and follow the mass-size relation, indicating that on local (cloud/clump) scales the stars form with efficiencies comparable to those in Milky Way clouds. The observed high star formation rate must thus be the result of triggering of cloud/clump formation over large scales due to disc instability. Our study provides evidence that "in-situ" massive clump formation (as also observed at high redshifts) is very efficiently induced by large-scale instabilities.Comment: Submitted to MNRA

Morpho-kinematics of star forming galaxies in the field of Abell 2163

Die vorliegende Masterarbeit untersucht sowohl die Kinematik der Galaxien mit Sternentstehung in verschiedenen Umgebungen als auch die Prägung der physikalischen Transformationsprozesse, die in der Kinematik und Morphologie beobachten werden können. Im Universum, Galaxien befinden sich in verschiedenen Umgebungen. Isolierte Galaxien haben reguläre Morphologie und Kinematik. Aber wenn das gravitationspotential durch Störungen beeinflusst wird, kann sich eines oder beides verändern. Galaxien in dichter Umgebung, wie zum Beispiel Mitglieder von massereichen Galaxiengruppen oder Galaxienhaufen, hingegen erfahren physikalischen Transformationsprozesse schneller auf Grund von Wechselwirkung mit der Umgebung. Wechselwirkende Galaxien wie Galaxienverschmelzung und Harassment können ihre Morphologie und Kinematik komplett verändern, während in Ram Pressure Stripping nur die Gas Komponente beeinflusst wird, ihre Morphologie jedoch gleich bleibt. Alle diese Prozesse sind abgedruckt in die Rotationskurve und Morphologie. Diese Masterarbeit wurde als Teil einer Kollaboration zwischen die Gruppe von Prof. Ziegler in Wien und Prof. Maurogordato in Toulouse gemacht und wurde auf spektroskopischen Beobachtungen basiert, die zwischen 2005 und 2011 mit VLT/VIMOS durchgefürt wurden. Strukturparameter wurden entweder aus meinem Bachelorarbeit (Menacho (2012)) genommen oder hier abgeleitet. Ein Ziel der Beobachtung war, die Effekte von Transformationsprozessen in Galaxien zu untersuchen, deshlab mehr als die Hälfte der Galaxien in der Sample zeigen Abweichungen in ihrer Kinematik und/oder Morphologie. Diese Arbeit beschäftigt sich speziell mit den Mitgliedern der Galaxienhaufen Abell 2163. Dabei wurden die abgeleiteten Parameter von Galaxien Mitgliedern und nicht Mitgliedern genau analysiert und verglichen. Nicht-Mitgliedern sind isolierte Galaxien, Mitgliedern von Galaxiengruppen und Wechselwirkende Galaxien. Das Galaxien-Sample besteht aus 53 Galaxien mit einer Rotverschiebung zwischen z=0.05 und z=0.4. Ihre stellare Masse variiert zwischen 10^9 und 10^11 . Die Balmer-linien Hα, Hβ und die verbotenen Emissionslinien [OIII] λ5007 wurden benutzt um die kinematische Information wie Rotationsgeschwindigkeit, dynamische Masse und die Form der Rotationskurve zu gewinnen. R-Band und K-Band Photometrie wurde für die morphologische Analyse benutzt. Die Ergebnisse dieser Arbeit werden wie folgt zusammengefast: Die Hälfte der Galaxien in dem Sample sind Galaxienhaufen Mitglieder. Mehr als die Hälfte davon haben reguläre Rotationskurven. Von der Gruppe der nicht-Mitgliedern, nur ein Drittel sind im Gleichgewicht. 23 Galaxien haben insgesamt reguläre Rotationskurven. Davon haben nur 19 haben photometrische Information und wurden für die Tully-Fisher Beziehung verwendet. Galaxien, die gestörte Rotationskurven aufweisen, wurden mit Hilfe ihrer Morphologie mit Rotationskurven-Modellen von Simulationen oder Beobachtungen verglichen. Diese Analyse wurde benutzt, um Transformationsprozesse in diesen Galaxien zu identifizieren. Die kombinierte Analysis von Kinematik und Morphologie sind sehr Wichtig um die Entwicklungsprozesse in Galaxien zu verstehen.The present thesis aims to study the kinematics of a sample of star forming disk galaxies in different environments and to analyse the imprints of physical transformation processes that are observed in the galaxy sample on the kinematics and morphology. In the universe, galaxies are observed in different environments. Isolated field galaxies are expected to show regular morphology and kinematics. However, if their gravitational potential is affected they will change either their structure or kinematics, or both. On the other hand, galaxies found in rich groups and clusters of galaxies, which are situated in dense environments, undergo a much more faster physical transformation ruled by their interplay with the surrounding medium. Gravitational interactions such as Merging and Harassment drastically alter their morphology and kinematics, whereas Ram Pressure Stripping (RPS) acts only on the gas component - which is stripped away - preserving their morphology. Signs of these processes are imprinted in the rotation curve and in the morphology of those galaxies. This thesis, which is part of a collaboration of two groups around B. Ziegler in Vienna and S. Maurogordato in Toulouse, is based on spectroscopic observations carried out with VLT/VIMOS (Very Large Telescope / VIsible MultiObject Spectrograph) instrument between 2005 and 2011. Additionally, galaxy structural parameters were either taken from my Bachelor Thesis (Menacho (2012)) or estimated in the present work following the method described there. As the aim was to observe cluster members and to study galaxy transformation processes, the majority of the selected targets display irregularities in their kinematics and morphology. This work focuses principally on galaxy members of the massive cluster Abell 2163 and compares the derived galaxy properties of cluster members and non members. Non cluster members include galaxies in groups, interacting pairs, mergers and isolated galaxies. The sample consists of 53 galaxies in a redshift range from z=0.05 to z=0.4. Their stellar masses vary between 109 and 1011. Balmer recombination lines: Halpha, Hbeta and the forbidden [OIII]5007 emission lines were used to extract kinematic information such as the maximum rotation velocity, the dynamical mass and the shape of rotation curve. R- and K-Band photometry was used for the morphological analysis. From the galaxy sample, half of the galaxies are cluster members, whereas slightly more than half of them exhibit regular rotation curves. Only one third of the non-cluster members group are kinematically relaxed systems. In total, 23 galaxies exhibit regular rotation curves, but only 19 galaxies with photometric information about stellar masses were used for the Tully-Fisher analysis. Galaxies with distorted rotation curves by means of their morphology were compared to rotation curves of simulated and observed galaxies, which are undergoing a physical transformation. This analysis was used to identify the most important mechanisms e.g RPS, Merging, Tidal interaction acting in the observed galaxies. Finally, additional information about stellar masses allow for a deeper understanding of the physical processes playing a role in each galaxy, whereas the global analysis gives clues about galaxy evolution processes

Impact of feedback on the ISM of extreme starburst galaxies : The case of Haro 11

Blue compact galaxies (BCGs) are compact, metal-poor, starbursting galaxies with characteristics similar to what is expected for the young high-redshifted galaxies. BCGs are among the most active in producing a large number of massive star clusters, each containing thousands of massive stars. During their short life, massive stars are continuously injecting energy, heat and momentum into the ISM via their intense radiation, stellar winds, and later on supernova explosions. These feedback mechanisms impact directly the star's surroundings, but when this feedback originates from a concentration of massive star clusters, it can strongly affect the condition of the gas of the entire galaxy. This thesis presents a detailed analysis of the ionized gas condition and the effect of strong feedback in Haro 11, an extreme starbursting BCG and the closest Lyman continuum (LyC) leaking galaxy. We exploit the spectro-photometric capabilities of the MUSE instrument, by slicing the galaxy spectra in a sequence of maps in velocity bins, in order to obtain a 3D information of the galaxy. Haro 11 has a rich population of massive and predominantly young star clusters, concentrated in three compact knots within its 4 x 4 kpc$^2$ centre. We find that the localised stellar feedback is strongly impacting the global kinematics and the condition of the gas up to further distances in the halo. Many kpc-scale structures such as filaments, shells and bubbles were traced in our data. Moreover, the strong feedback seems to have developed kpc-scale bubbles, outflows and galactic ionized cones with drastic consequences for the likely escape of Ly$\alpha$ and LyC photons, gas and metals out of the galaxy. The extended halo around Haro 11 is governed by photoionization processes and/or shocks from recurrent supernovae originated in the central starburst region. Due to the galaxy's extreme ISM condition, commonly used emission lines diagnostics produce, in part, large discrepancies in the ionized gas properties. The results presented in this work highlight: a) the strong impact of stellar feedback affecting the ISM at all scales in starburst systems; b) the fact that traditional relations drawn up from averaged measurements of emission lines or from simplified models, fail in probing the condition of the gas in extreme environments. This is an appeal to revisit the standard relations by including more realistic models where several physical processes are simultaneously at work; c) the method applied here can be used to explore in detail the high sensitive, high spatial-resolution data from future facilities such as JWST/ELT.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Manuscript. Paper 4: Submitted. Paper 5: Submitted.</p

The violent ISM in Haro 11

This thesis introduces briefly physical processes operating in the ISM around massive starsand focuses on the impact strong stellar feedback has in creating large-scale structures in a galaxy.Stellar feedback is ubiquitous in star forming galaxies and its effect on the ISM depends strongly on the energy output from the most massive stars (M$\geq$7 \Mo ) and the properties of the surrounding gas. Starburst galaxies are among the most active in producing %galaxies are among the most active galaxies and produce a large amount of massive star clusters %or even super star clusters (SSC; M$_{cl} \geq 10^5$ \Mo ), with stellar populations up to thousands of massive stars. %The most massive stars (M$\geq$30 \Mo ) are lives short, but they In the first 4 Myr of the star clusters evolution, radiative feedback of the most massive stars (M$\geq$30 \Mo ) are at work. Large amount of ionizing photons are released to the ambient medium while radiative pressure compress the surrounding gas. At the same time their stellar winds inject continuously mechanical energy and momentum in their surrounding. This mechanical feedback is then at later ages, until $\sim$ 40 Myrs, maintained by supernova explosions from the less massive stars. Strong stellar feedback tends to develop large-scale structures such as bubbles, loops, filaments and outflows. These are transient structures and can be seen as imprints of how the released energy is clearing or has cleared paths in the ISM. Strong stellar feedback can have devastating consequences in dwarf galaxies due to their shallow gravitational potential. It can accelerate outflows with velocities larger than their escape velocities. In this way, dwarf galaxies can lose a large fraction of their gas mass, which will be crucial in their subsequent evolution.On the other hand, galactic winds might be responsible to create holes in the ISM, allowing the easily-absorbed ionizing photons (Lyman continuum photons, LyC) to escape the galaxy. Studies on a few LyC leaking galaxies have shown that this mechanisms might have preference from a density-bound scenario, which takes place in galaxies with a highly ionized halo. In my paper I used deep MUSE observations to analyse the impact strong stellar feedback has in the starburst and Lyman continuum emitting galaxy: Haro 11. The paper presents three emission line diagnostics aiming to analyse the condition of the warm ionized gas in this galaxy, which are the \Ha\ emission, the level of ionization in gas and the presence of fast shocks. These diagnostics are presented in maps of 50 \kms\ bins in a velocity range from -400 to 350 \kms . Haro 11 shows a violent ISM whose warm ionized gas is almost completely shaped by effect of stellar feedback from the most massive star forming regions in the centre. Arcs, shells, outflows paths and galactic scale ionizing cones are imprinted in ISM of Haro 11. Our analysis suggests the presence of a kpc-scale superbubble which might have created galactic holes in the ISM. Beside of that, Haro 11 shows a highly ionized halo. Both mechanisms appear to facilitate the escape of LyC in this galaxy. %Finally, we observe emission at velocities up to thousand \kms\ which could hints to gas escaping the galaxy. Finally the paper presents estimates of the gas mass fraction that could escape the gravitational potential of the galaxy

Unveiling the gravitationally unstable disk of a massive star-forming galaxy using NOEMA and MUSE

Using new high-resolution data of CO (2–1), Hα and Hβ obtained with the Northern Extended Millimeter Array (NOEMA) and the Multi-Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope, we have performed a Toomre Q disc stability analysis and studied star formation, gas depletion times and other environmental parameters on sub-kpc scales within the z∼0 galaxy SDSS J125013.84+073444.5 (LARS 8). The galaxy hosts a massive, clumpy disc and is a proto-typical analogue ofmain-sequence (MS) galaxies at z∼1-2. We show that the massive (molecular) clumps in LARS 8 are the result of an extremely Toomre-unstable gas disc, with large scale in-stabilities found across the whole extent of the rotating disc, with only the innermost 500 pc being stabilized by its bulgelike structure. The radial profiles further reveal that – contrary to typical disc galaxies – the molecular gas depletion time decreases from more than 1 Gyr in the center to less than ∼100 Myr in the outskirts of the disc, supporting the findings of a Toomre-unstable disc. We further identified and analysed 12 individual massive molecular clumps. They are virialized and follow the mass-size relation, indicating that on local (cloud/clump) scales the stars form with efficiencies comparable to those in Milky Way clouds. The observed high star formation rate must thus be the result of triggering of cloud/clump formation over large scales due to disc instability. Our study thus provides evidence that the massive clumps observed in high-z disc galaxies form “in-situ” from large-scale instabilities.to be submitted to MNRAS</p

Unveiling the gravitationally unstable disk of a massive star-forming galaxy using NOEMA and MUSE

Using new high-resolution data of CO (2–1), Hα and Hβ obtained with the Northern Extended Millimeter Array (NOEMA) and the Multi-Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope, we have performed a Toomre Q disc stability analysis and studied star formation, gas depletion times and other environmental parameters on sub-kpc scales within the z∼0 galaxy SDSS J125013.84+073444.5 (LARS 8). The galaxy hosts a massive, clumpy disc and is a proto-typical analogue ofmain-sequence (MS) galaxies at z∼1-2. We show that the massive (molecular) clumps in LARS 8 are the result of an extremely Toomre-unstable gas disc, with large scale in-stabilities found across the whole extent of the rotating disc, with only the innermost 500 pc being stabilized by its bulgelike structure. The radial profiles further reveal that – contrary to typical disc galaxies – the molecular gas depletion time decreases from more than 1 Gyr in the center to less than ∼100 Myr in the outskirts of the disc, supporting the findings of a Toomre-unstable disc. We further identified and analysed 12 individual massive molecular clumps. They are virialized and follow the mass-size relation, indicating that on local (cloud/clump) scales the stars form with efficiencies comparable to those in Milky Way clouds. The observed high star formation rate must thus be the result of triggering of cloud/clump formation over large scales due to disc instability. Our study thus provides evidence that the massive clumps observed in high-z disc galaxies form “in-situ” from large-scale instabilities.to be submitted to MNRAS</p

LARS XIII: High Angular Resolution 21 cm H I Observations of Lyα Emitting Galaxies

International audienceThe Lyα emission line is one of the main observables of galaxies at high redshift, but its output depends strongly on the neutral gas distribution and kinematics around the star-forming regions where UV photons are produced. We present observations of Lyα and 21 cm H I emission at comparable scales with the goal to qualitatively investigate how the neutral interstellar medium (ISM) properties impact Lyα transfer in galaxies. We have observed 21 cm H I at the highest possible angular resolution (≍3″ beam) with the Very Large Array in two local galaxies from the Lyman Alpha Reference Sample. We compare these data with Hubble Space Telescope Lyα imaging and spectroscopy, and Multi Unit Spectroscopic Explorer and Potsdam MultiAperture Spectrophotometer ionized gas observations. In LARS08, high-intensity Lyα emission is cospatial with high column density H I where the dust content is the lowest. The Lyα line is strongly redshifted, consistent with a velocity redistribution that allows Lyα escape from a high column density neutral medium with a low dust content. In eLARS01, high-intensity Lyα emission is located in regions of low column density H I, below the H I data sensitivity limit ( 20 cm-2). The perturbed ISM distribution with low column density gas in front of the Lyα emission region plays an important role in the escape. In both galaxies, the faint Lyα emission (~1×10-16 erg s-1cm-2 arcsec-2) traces intermediate Hα emission regions where H I is found, regardless of the dust content. Dust seems to modulate, but not prevent, the formation of a faint Lyα halo. This study suggests the existence of scaling relations between dust, Hα, H I, and Lyα emission in galaxies

The Source of Leaking Ionizing Photons from Haro11: Clues from HST/COS Spectroscopy of Knots A, B, and C

International audienceUnderstanding the escape of ionizing (Lyman continuum) photons from galaxies is vital for determining how galaxies contributed to reionization in the early universe. While directly detecting the Lyman continuum from high-redshift galaxies is impossible due to the intergalactic medium, low-redshift galaxies in principle offer this possibility but require observations from space. The first local galaxy for which Lyman continuum escape was found is Haro 11, a luminous blue compact galaxy at z = 0.02, where observations with the FUSE satellite revealed an escape fraction of 3.3%. However, the FUSE aperture covers the entire galaxy, and it is not clear from where the Lyman continuum is leaking out. Here we utilize Hubble Space Telescope/Cosmic Origins Spectrograph spectroscopy in the wavelength range 1100-1700 Å of the three knots (A, B, and C) of Haro 11 to study the presence of Lyα emission and the properties of intervening gas. We find that all knots have bright Lyα emission. UV absorption lines, originating in the neutral interstellar medium, as well as lines probing the ionized medium, are seen extending to blueshifted velocities of 500 km s-1 in all three knots, demonstrating the presence of an outflowing multiphase medium. We find that knots A and B have large covering fractions of neutral gas, making LyC escape along these sightlines improbable, while knot C has a much lower covering fraction (≲50%). Knot C also has the the highest Lyα escape fraction, and we conclude that it is the most likely source of the escaping Lyman continuum detected in Haro 11. * Based of observations with the NASA/ESA Hubble Space Telescope

Clínica Integrada - ME210 - 202101

Curso de especialidad, de la carrera de medicina, de carácter teórico- práctico del ciclo 7, en el que los estudiantes integran conocimientos previos con la anamnesis, el examen físico y establecen el diagnostico por síndromes o problemas y el plan de trabajo. El curso de Clínica integrada busca desarrollar las competencias generales de comunicación escrita y comunicación oral(nivel 2) y las competencias específicas de práctica clínica-diagnóstico (nivel 2) y profesionalismo-sentido ético y legal y responsabilidad profesional(nivel 2). La integración de conocimientos en la historia clínica, permitirá al estudiante, plantear un adecuado diagnóstico, plan de trabajo para la atención de su futuro paciente