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Talks

  • Angela Adamo
    Title: What SSCs tell us about starburst galaxies.
    File:     AdamoA_talk.pdf
    Abstract: We present the preliminary results of our studies on Super Star Clusters (SSCs) in three local blue compact galaxies, BCGs (Eso185, Haro11, and Mkr930). These systems show peculiar morphologies and the presence of hundreds of SSC which are the product of past, recent, and/or active starburst phases. For this reason an accurate analysis of the SSC properties, like ages, masses, luminosity functions, etc, throws light on the formation and subsequent evolution of the host galaxies. We have now a complete set of HST images ranging from the UV to IR for each galaxy. Deep images in R (WFPC2/f606w) and I (WFPC2/f814w) have been used to capture most of the SSC candidates up to the old ones (fainter) which had had, in the past, less possibility to be detected. The others bands (WFPC2/f439w, WFPC2/f336w, ACS/SBC/f140lp, and NIC3/f160w) are used in the SED fitting technique for constraining ages and masses. The results of this analysis will be used for comparing BCGs systems to local me rging/interacting galaxies, like the Antennae and M51. Moreover they will also contribute in understanding the early evolution of galaxies in the hierarchical scenario, where the BCGs or galaxies like them played an important role.
  • Antonio Aparicio
    Title: The HST/ACS LCID project: Star Formation History of Isolated Local Group Dwarf Galaxies
    File:
    Abstract: LCID (Local Cosmology from Isolated Dwarfs) was granted 110 orbits on the HST to obtain deep photometry of five Local Group isolated dwarf galaxies of different level of current star formation activity and gas fraction: IC1613, Leo A, Tucana, LGS 3 and Cetus. To them, Phoenix was added, observed previously with the WFPC2 over 24 orbits. The aim was to obtain accurate and self-consistent Star Formation Histories of all them, from the beginning of theirs lives and using the same instrument and methods. The final objective was to analyze how the star formation has proceed in the Local Group in systems that, at least in principle, can be considered free of strong tidal effects. Date of the star formation onset in different systems (from DIr to DSph), chemical enrichment law, structure and its evolution are the main aspects to be studied. We present here almost final results of the project, which is now close to its completion.
  • Nils Bergvall
    Title: Starburst and postburst dwarf galaxies in the Sloan survey
    File:     bergvall_presentation.ppt
    Abstract: The primary aim with this investigation is to derive reliable estimates of space densities, star formation rates and burst lifetimes of starburst galaxies. A secondary aim is to find evolutionary links to passive galaxies. As a base of our studies we use data from the SDSS and predictions from spectral evolutionary models. Spectral parameters are used to define starburst and poststarburst galaxies with the goal to establish a one-to-one correspondance between the two samples, allowing a direct comparison between the respective luminosity functions. The starburst requirement we adopt is that the galaxy must consume at least 5% of the total mass in the burst and that the b-parameter is > 3. Here we discuss the preliminary results from the low luminosity part of the sample. The questions we address include: How common are starbursts among star forming dwarfs, what is the typical length of the burst and how much gas is consumed?
  • Médéric Boquien
    Title: Intergalactic star formation
    File:     boquien_presentation.pdf
    Abstract: The work presented here is about star formation in the unusual environment of collisional debris. These peculiar regions have an interstellar medium, and in particular a metallicity, similar to that of star forming regions in galactic discs while not undergoing similar environmental effects such as density waves in the spiral arms for instance. At the same time they have a size, a mass and a colour typical of star forming dwarf galaxies. This study has been conducted with a selection of exceptional systems that have ejected large quantities of gas into the intergalactic medium while also showing some intergalactic star forming regions. Principal Investigator as well as archive spectroscopy and imaging from multi-wavelength observations ranging from far ultraviolet to mid-infrared have been used. This work has brought the following main new results: * Dust emission, as probed with broad band images and spectra is at a level globally expected for star forming regions of the same metallicity and luminosity. * When comparing the star formation rates from ultraviolet, Hα and mid-infrared, intergalactic star forming regions show on average similar scatters and similar relations between the SFR inferred from different wavelengths. * Probing environmental effects, we have shown that the extinction and the metallicity do not seem to play a major role governing the differences between intergalactic star forming regions. * Intergalactic star forming regions provide in any case a simpler environment than galactic star forming regions and as the environment does not have a tremendous effect on star formation, they are great laboratories to study star formation per se.
  • Vassilis Charmandaris
    Title: Dust in Low-metallicity Blue Compact Dwarf Galaxies
    File:
    Abstract: I will present a review of recent results on the dust properties of Blue Compact Dwarf Galaxies (BCDs) based on observations with the Spitzer Space Telescope. BCDs are galaxies are characterized by their blue optical colors, low luminosities and small sizes. Τhey typically have low, subsolar, metallicities and have been proposed as local laboratories to study the star formation in the early universe. The unprecedented sensitivity of Spitzer has enabled us for the first time to detect a large sample of these as well as other low luminosity low metallicity systems. We were able to probe the presence of the Polycyclic Aromatic Hydrocarbon features, and quantify their use as tracers of the star formation rate in these systems. We derived the first estimates of elemental abundances of neon and sulfur using mid-infrared lines and performed for extragalactic systems, and compare them with the results from optical studies. Finally, a detailed analysis of the far-infrared and mid-i nfrared to radio correlation in low luminosity galaxies has been derived.
  • Robert Cumming
    Title: Stellar kinematics in blue compact galaxies: probing the dynamics of dwarf starbursts
    File:     robert_cumming_presentation.pdf
    Abstract: What triggers the starbursts in the luminous blue compact galaxies (LBCGs) that are so common at intermediate redshift? We are looking for clues by investigating their counterparts in the local universe. Recently we have used FORS2 and FLAMES/ARGUS at the VLT to investigate for the first time the stellar kinematics in local blue compact galaxies. We find that the ionized gas and the stars - traced by the Ca II triplet - follow each other in some objects, but are decoupled in others. I'll look at what this means for interpreting LBCG kinematics at both high and low redshift, and I'll present our latest results for the dramatic LBCG and Lyman-break analogue Haro 11.
  • Marta Gavilan
    Title: Evolution models of isolated dwarf galaxies
    File:     MGavilan.pdf
    Abstract: We have developed a grid of chemical evolution models applied to dwarf isolated galaxies, using Gavilan et al 2005 yields. The input data enclose different star formation efficiencies, galaxy masses and collapse time values. The result is a wide collection of solutions that vary from objects with low metallicity and great amount of gas, to those with little gas and high metallicity. No environmental effects like tidal or galactic winds have been treated, so these objects are expected to be close to field dwarf galaxies, more than cluster ones. We have study the time evolution of the C, N, O abundances and the amount of gas, related to their star formation history. At the end, we study if the star formation process in these objects are such that allow them to loose their gas or there are any reason that keeps it attached.
  • Dimitrios Gouliermis
    Title: Resolved Stellar Populations in Star-Forming Regions of the Magellanic Clouds and Beyond
    File:
    Abstract: The Large and Small Magellanic Clouds, being very close to us, offer very suitable templates of star formation in dwarf galaxies. With today's powerful ground-based and space telescopes we can resolve the stellar, pre-stellar as well as signatures of the proto-stellar content in a variety of star-forming regions in both the Magellanic Clouds. Observations of such HII regions in the optical, near-infrared and infrared wavelengths inform us on the massive OB-type stars, the exceptionally rich samples of faint pre-main sequence populations that coexist with these massive stars, as well as on the candidate Young Stellar Objects, as signatures of triggered ongoing star formation in these regions. I will present the comprehensive picture that we draw from such recent results of star-forming HII regions in the MCs, in terms of stellar interaction with the ISM, the Initial Mass Function and triggering mechanisms of star-formation. I will also discuss what can we learn from these stud ies about star formation in more distant dwarfs.
  • Tenorio-Tagle Guillermo
    Title: Super star clusters
    File:
    Abstract:
  • Derek Hammer
    Title: The GALEX UV Properties of Faint Galaxies in the Coma Cluster
    File:     DerekHammer.ppt
    Abstract: We present measurements of the FUV and NUV luminosity functions (LFs) for the local rich cluster, Coma, which are the deepest UV LFs measured for a cluster thus far. Dwarf galaxies (M_r>-17.2) account for ~30% of the confirmed cluster members, which includes a population of dwarf early-type (dE) galaxies that have intermediate NUV-r colors (`green valley'). We demonstrate that the NUV-r colors of dwarf galaxies in the green valley are degenerate between age and metallicity, although evidence suggests that the majority of dE galaxies in Coma have very old (~10 Gyr) metal-poor stellar populations.
  • Gerhard Hensler
    Title: Gas Infall and its Effect on Star Formation and Chemistry in Dwarf Galaxies
    File:
    Abstract: From observations it is evident that star-formation seems to mostly self-regulate in normal galaxies like spirals and dwarf irregulars. On the other hand, enhanced star formation occurs during the evolution of galaxies either locally in giant HII regions or globally as starbursts visible in merger and dwarf irregular galaxies. While the ignition of starbursts in interacting galaxies or in strongly collapsing systems seems plausible, the presently increasing evidence of HI gas reservoirs enveloping dwarf galaxies with active star formation leads to the suggestion that gas infall can trigger epochs of exceedingly high star-formation rates. In addition, element abundances and, in particular, the N/O ratio of HII regions in the outermost regions of spiral galaxies and in dwarf irregulars reveal an increasing scatter in O at low N/O approaching a lower limit at -1.6. This presentation will study the effect of gas infall with different intensities, i.e. mass flux and duration, with respect to two aspects: firstly, to what extent the star-formation rate is affected; secondly, under the assumption of a pristine element content of infalling clouds, how the N/O-O distribution changes.
  • Jonathan D. Hernandez-Fernandez
    Title: Influende of the environment on dwarf galaxies in clusters
    File:
    Abstract: We carried out a study about environmental effects on properties (star formation (SF), dust attenuation, metallicity) of dwarf galaxies (M_r ~< -17) in clusters. For this work, we use UV-optical-NIR photometric and spectroscopic data taken from GALEX, SDSS & 2MASS surveys for a sample of 16 clusters. We would like to highlight that our galaxy sample covers a large range in velocity dispersion (250-850 km/s), allowing us to distinguish the star formation activity between high and low-mass clusters. We were also able to check how far the SF modulation starts from the virial radius since our cluster radii span a wide range up to R_proj ~ 7 R_200. We derived from UV to FIR properties (UV attenution, stellar mass, specific SFR, etc) as well as stellar age/gas metallicity for our sample of galaxies putting together the information obtained from: a) GRASIL synthetic spectra fitting covering a spectral range from vacuum UV to FIR. b) Lick indices and emission line flux ratios.
  • Guillermo Hägele
    Title: Precision abundance analysis of bright HII galaxies
    File:
    Abstract: We present high signal-to-noise spectrophotometric observations of seven luminous HII galaxies. The observations have been made with the use of a double-arm spectrograph which provides spectra with a wide wavelength coverage, from 3400 to 10400\AA free of second order effects, of exactly the same region of a given galaxy. These observations are analyzed applying a methodology designed to obtain accurate elemental abundances of oxygen, sulfur, nitrogen, neon, argon and iron in the ionized gas. Four electron temperatures and one electron density are derived from the observed forbidden line ratios using the five-level atom approximation. For our best objects errors of 1% in T([OIII]), 3% in T([OIII]) and 5% in T([SIII]) are achieved with a resulting accuracy of 7% in total oxygen abundances, O/H. The ionization structure of the nebulae can be mapped by the theoretical oxygen and sulfur ionic ratios, on the one side, and the corresponding observed emission line ratios, on the other -- the $\eta$ and $\eta$' plots --. The combination of both is shown to provide a means to test photo-ionization model sequences currently applied to derive elemental abundances in HII galaxies.
  • Uli Klein
    Title: Dwarf galaxies and the magnetisation of the IGM
    File:     klein_presentation2.ppt
    Abstract: I will review the properties of the synchrotron radio emission and magnetic fields in dwarf galaxies. Given that these make up for the majority of the first building blocks in the universe, they could have efficiently injected relativistic particles and magnetic fields into the IGM (Kronberg et al. 1999). With LOFAR becoming operational in due course, there is an excellent instrument to search for low-frequency radio halos around dwarf galaxies in the local universe and beyond; such halos would eflect pools of formerly highly relativistic particles stemming from periods of intense star formation.
  • Uli Klein
    Title: Dark-Matter in gas-rich dwarf galaxies
    File:     klein_presentation1.ppt
    Abstract: We have investigated the structure and kinematics of the dwarf galaxies DDO 47 and NGC3741. They are gas-rich and possess extended HI disks, hence permitting to probe the gravitational potentials out to large radii. The derived rotation curves have a spatial resolution of 200 - 300 pc. They have been corrected for non-circular motions via modeling of the data cube and a harmonic decomposition of the velocity field. The derived rotation curves are best fitted by cored dark matter halos, while NFW profiles do not comply with them. The derived non-circular motions in DDO47 are not sufficient top hide a CDM cusp. We have also started to study the three-dimensional structure of dwarf galaxies with prodigious gaseous disks. The HI disk of NGC 3741 extends out to 42 (B-band, stellar exponential) scale-lengths. Likewise, DDO 154 has a huge warped HI disk, however with a highly asymmetric three- dimensional structure. We discuss possibly implications.
  • Ute Lisenfeld
    Title: Molecular gas in Tidal Galaxies: Conditions of Star formation
    File:     lisenfeld_presentation1.ppt
    Abstract: Tidal Dwarf Galaxies, formed from recycled gas in galaxy interaction, have in general similar properties as ordenary dwarf galaxy. One important difference is their higher metallicty since they are made from recyled gas. This property makes CO a good tracer for the molecular gas content, in contrary to ordenary dwarf galaxies, and allows us therefore to study the fuel of SF directly. I will talk about the properties of the molecular gas in Tidal Dwarf Galaxies and what we learn from it about the conditions and triggers of SF.
  • Ute Lisenfeld
    Title: Dust and star formation in dwarf galaxies
    File:     lisenfeld_presentation2.ppt
    Abstract: Dwarf galaxies are due to their low metallicity expected to contain a lower dust abundance than spiral galaxies. In spite of this lower dust content, the opacity can be locally considerable. I will present a study of the dust extinction and emission around HII regions in a small sample of starbursting dwarf galaxies. We have found dust shells around HII regions, representing piled-up dust most likely due to the energy input of stellar winds. At these positions, the dust opacity could be considerable, in spite of the overall low dust content in the galaxies. There are indications for a clumpy distribution of dust in these shells. Furthermore, from the dust emission at different wavelengths there are indications for a variation of the dust properties.
  • Angel R. Lopez-Sanchez
    Title: A multiwavelegth analysis of Blue Compact Dwarf galaxies: HI results
    File:
    Abstract: Angel R. Lopez-Sanchez (CSIRO/ATNF), Baerbel Koribalski (CSIRO/ATNF) & Cesar Esteban (IAC) Blue compact dwarf galaxies (BCDGs) represent the subset of low-luminosity galaxies undergoing a strong and short-lived episode of star formation at the present time. We are obtaining deep multiwavelength data of some nearby BCDGs combining broad-band optical/NIR and H$\alpha$ photometry, optical spectroscopy and 21-cm radio observations in order to understand their chemical and physical properties, star formation activity, kinematics, estimate the importance of the young/old stellar populations within them and the environment in which they reside. In this talk, we will present new exciting HI results for some of these objects, all showing evident interaction features in their neutral gas component. We remark on the apparent rotation of the HI component about the optical major axis of NGC 5253 (L\'opez-S\'anchez et al. 2008a; data from the "Local Volume HI Survey" -LVHIS- project), the complex neutral gas morphology and kinematics found in Tol 9 (L\'opez-S\'anchez et al. 2008b), the prominent HI tidal tails and detached HI cloud found in Tol 30, a long HI bridge between two galaxies in Tol 1924-416, and the huge and disturbed HI content of the NGC 1512 / NGC 1510 system (Koribalski \& L\'opez-S\'anchez, 2009; data also from the LVHIS project).
  • Thomas Marquart
    Title: The motions of gas and stars in emission-line dwarf galaxies
    File:     marquart_presentation1.odp
    Abstract: We have observed over 40 galaxies with a Fabry-Perot interferometer at the ESO 3.6m telescope, targeting the H-alpha line to measure the kinematics of the ionized gas. Roughly half of the objects make up a volume-limited sample, selected from the UM-catalogue, which therefore includes moderately star-forming dwarf galaxies towards the lower-mass end. The rest of the sample consists of hand-picked Blue Compact Galaxies (BCGs) and is dominated by more luminous objects. In agreement with Östlin et al. (1999,2001) we find non-regular motions in many cases. We derive dynamical masses and compare to estimates from photomery. In addtion, we have used FLAMES/ARGUS at the VLT to address the stellar kinematics in BCGs, using the near-infrared Ca-triplet. I will also present preliminary results from these observations.
  • Hagen Thilo Meyer
    Title: A new investigation of the Luminosity-Metallicity relation for star-forming dwarf galaxies with SDSS
    File:
    Abstract: Understanding the chemical enrichment of dwarf galaxies is crucial to understand the formation of large galaxies in a hierarchical scenario. A close investigation of the luminosity--metallicity (L-Z) relation for dwarf galaxies is undoubtedly of paramount importance. Here, we report on an ongoing investigation of the L-Z relation in star-forming dwarf galaxies (SFDGs), using a large sample compiled from the SDSS. An important and novel aspect of this program is that we model and subtract the emission from the star-forming (SF) component in order to isolate the light from the old low-surface brightness (LSB) host of the sample galaxies. For this purpose we use surface photometry techniques and profile decomposition in the g and i SDSS bands. Our preliminary results presented here indicate the existence of the L_{host}-Z relation over a wide range in absolute magnitudes and metallicities.
  • Genoveva Micheva
    Title: The Red Halo of Haro11
    File:     GenovevaCrete08.pdf
    Abstract: The outskirts of some blue compact galaxies display extreme red colors in the optical and near-infrared. These structures are referred to as the red halo. The most interesting such example is Haro11 with a reported V-K=4.5. We examine the original red halo detection around this galaxy and present new K band data of unprecedented depth. We further demonstrate that our result cannot be attributed to reduction artifacts such as incorrect sky subtraction. We also apply an in-house software (H.A.L.O.) specifically designed for the purpose of red halo identification and extraction, to significantly reduce the errorbars of the original red halo detection around Haro11.
  • Mercedes Mollá
    Title: The star formation history and the N/O abundance
    File:     Molla_Creta08.ppt
    Abstract: The data in the plane O/H-N/O are very well reproduced with a set of well calibrated chemical evolution models (Mollá & Díaz 2005, Mollá et al 2006), where we use the low and intermediate stellar yields from Gavilan et al. (2005) with a certaim quantity of primary Nitrogen. We here show how the trends shown by the GALEX data (Mallery et al. 2007) are clearly explained with our models. Differences in the star formation histories of the regions and galaxies modeled are essential to reproduce data and the corresponding dispersion. The data of dwarf galaxies are analyzed and their star formation histories studied.
  • Casiana Muñoz-Tuñon
    Title: tbd
    File:
    Abstract: tbd
  • Kai Noeske
    Title: Mass-Dependence of Galaxy Star Formation Histories from Deep Surveys: Are sub-L* Galaxies Latecomers?
    File:
    Abstract: I review recent results from the deepest multiwavelength surveys, GOODS and AEGIS. These studies have revealed a tight relation between galaxies' star formation rates and stellar masss out to z~2. This "Galaxy Main Sequence" and its evolution have revealed a coherent picture of the history of star formation in field galaxies over the last 10 billion years: The intense star formation rates observed at high redshift were mostly the normal state of galaxies, not singular burst events driven by e.g. galaxy mergers. Star formation histories were dominated by a relatively smooth decline of star formation rates on Gyr timescales, not by an evolving role of starburst events. This decline of star formation occurred on longer timescales in less massive galaxies. In addition, the initial peak, or onset of star formation, apparently occurred later in less massive galaxies ("staged galaxy formation"). I discuss these results in view of the properties of low mass galaxies in the local Universe and at intermediate redshifts.
  • Jan Palous
    Title: The Fragmenting Shells
    File:
    Abstract: I will present results of numerical SPH and AMR simulations of expanding shells fragmenting under the influence of their self-gravity. The results of the analytically derived thin-shell dispersion relations will be shown. There is a nice agreement between analytical prediction and simulations depending on pressure confinement of the shell. The fragment mass function is constructed and compared to the observed stellar IMF. The importance of shell fragmentation to star formation in dwarf galaxies will be underlined.
  • Polychronis Papaderos
    Title: Blue Compact Dwarf Galaxies: Born To Be Wild
    File:
    Abstract: The evolution of blue compact dwarf (BCD) galaxies over cosmic time is a central topic in dwarf galaxy research and observational cosmology. I will review current ideas about the role of starbursts on the evolution of BCDs and discuss the main questions we seek to answer by exploring the properties of these systems. In particular, I will discuss the morphology, structural properties and evolutionary status of the low-surface brightness (LSB) host galaxy of BCDs and the influence of its gravitational potential on the star formation process. I will also review the structural properties of extremely metal-poor (12+log(O/H)<7.6) BCDs, presenting extended ionized gas emission and uniformly blue colors in their LSB components, and highlight the importance of these rare nearby galaxies as laboratories for studying collective star formation and galaxy evolution under chemical conditions approaching those in distant protogalactic systems.
  • Simone Recchi
    Title: Galactic winds and the chemical evolution of dwarf galaxies
    File:     SimoneRecchi_presentation.odp
    Abstract: In this contribution I summarize some recent results on the effect of galactic winds on the chemical evolution of galaxies. First of all I show, by means of simple analytical and semi-analytical calculations, the effect of differential winds (namely winds carrying out of a galaxy more metals than pristine gas) on the chemical evolution of galaxies. Although differential winds can reduce quite significantly the metallicity of a galaxy, they have no effect on the abundance ratios, unless one assumes that some metals are ejected out of a galaxy more efficiently than others. In the second part I show the results of chemodynamical simulations of star forming dwarf galaxies with infall and with different initial geometries. I will demonstrate that the development of a galactic wind in a star forming dwarf galaxy cannot be assessed uniquely on the basis of the energy produced during the burst (in comparison with the binding energy of the gas); the geometry of the galaxy and the possible infall of clouds strongly affect the final fate of the gas. Moreover, infall of gas has important consequences on the chemical evolution of galaxies since it reduces the metallicity leaving the abundance ratios unaltered. Finally, I will speculate on observations of abundance ratios in dwarf galaxies as a test to prove the occurrence of infall and differential galactic winds.
  • Martin Roth
    Title: IFU
    File:
    Abstract: tbd
  • Eon-Chang Sung
    Title: A classification scheme based on local environments of blue compact dwarf galaxies
    File:
    Abstract: We present an extensive observations in optical, near inrared, and HI radio for a homogeneous sample of 115 blue compact dwarf galaxies and a study of dynamical environments for a sample of several BCDGs from SDSS DR6. We found that although BCDGs have well-shaped outer envelopes and the similar inner structure, their physical natures including the evolutionary status and the origin of starburst triggers are very different galaxy by galaxy. We introduce a new classification scheme of blue compact dwarf galaxies (BCDGs) based on environmental criteria; BCDGs can be classified into four groups; the isolated, the post-merger, the detached interacting, and the merger -in-progress. And also, we will discuss structural properties and evolutionary connections between dwarf galaxies based on surface photometry of a sample of BCDGs.
  • Jose M. Vilchez
    Title: Active star formation revealed in dwarf galaxies of nearby clusters
    File:
    Abstract: The understanding of the role played by the environment on galaxy evolution remains a major question. It is now widely accepted that the evolution of star-forming galaxies inhabiting dense environemts, such as galaxy clusters, can result strongly affected. For the population of star-forming dwarf galaxies in clusters up to date the information available remains scarce, mainly given their faintness. In this talk I review our global knowledge of the properties of star-forming galaxies as a function of the environment, and present recent results revealing the presence of a ubiquitous population of star-forming dwarf galaxies in nearby clusters.
  • Joanna Woo
    Title: Supernova feedback and the Fundamental Line of the Local Group Dwarf Galaxies
    File:     JoannaWoo_presentation.odp
    Abstract: We will briefly review the supernova feedback model of Dekel & Woo (2003) and show that it successfully explains the various scaling relations measured for the dwarf galaxies of the Local Group. We show that these scaling relations are extentions of the scaling relations found in larger galaxies. We find, using standardised Principal Component Analysis, that the Local Group dwarf galaxies define a one-parameter Fundamental Line (FL), primarily driven by stellar mass, M* (Woo, Courteau & Dekel, 2008). A more detailed inspection reveals differences between the star-formation properties of late- and early-type dwarfs (dI's and dE's respectively). In particular, the metallicities of dI's are typically lower by a factor of 3 at a given M* and they grow faster with increasing M*. Furthermore, the scaling relations of dI's resemble those of the more massive spirals, while the FL of the dE's departs from the fundamental plane of bigger ellipticals. While the one-parameter nat ure of the FL and the associated slopes of the scaling relations are consistent with the general predictions of supernova feedback, the differences between the FL's of the dE's and the dI's remain a challenge and should serve as a guide for the secondary physical processes responsible for these two types.
  • Erik Zackrisson
    Title: Do blue compact galaxies have red halos?
    File:     Zackrisson_presentation.pdf
    Abstract: Red halos are faint, extended and extremely red structures that have been detected around galaxies through very deep imaging at optical and near-IR wavelengths. The colours of these halos are too red to be consistent with any hitherto known type of stellar population, and instead indicative of a very bottom-heavy stellar initial mass function (IMF). Due to the large mass-to-light ratios of such halos, they could contribute substantially to the baryonic masses of galaxies while adding but a few percent to their overall luminosities. The red halos of galaxies therefore constitute potential reservoirs for some of the baryons still missing from inventories in the low-redshift Universe. While most studies of red halos have focused on disk galaxies, a red excess has also been reported in the faint outskirts of blue compact galaxies (BCGs). A bottom-heavy IMF can explain the colours of these structures as well, but due to model degeneracies, stellar populations with standard IMFs and high metallicities also remain viable. Recent developments in the field of spectral synthesis now suggest that the metallicities required in this alterative scenario may be less extreme than previously thought, and closer to the metallicities derived from the observed emission-line ratios. Here, I will review the current status of the red halo field and use the latest models to address the issue of whether an extreme stellar population really is required to explain the red envelopes of BCGs.
  • Göran Östlin
    Title: Blue Compact Galaxies as Building Blocks: Kinematics and Lyman-alpha.
    File:     ostlin_crete.pptx
    Abstract: tbd

Posters

  • Derek Hammer
    Title: The GALEX UV Properties of Faint Galaxies in the Coma Cluster
    File:
    Abstract: We present measurements of the FUV and NUV luminosity functions (LFs) for the local rich cluster, Coma, which are the deepest UV LFs measured for a cluster thus far. Dwarf galaxies (M_r>-17.2) account for ~30% of the confirmed cluster members, which includes a population of dwarf early-type (dE) galaxies that have intermediate NUV-r colors (`green valley'). We demonstrate that the NUV-r colors of dwarf galaxies in the green valley are degenerate between age and metallicity, although evidence suggests that the majority of dE galaxies in Coma have very old (~10 Gyr) metal-poor stellar populations.
  • Thomas Marquart
    Title: Stellar Kinematics in Blue Compact Galaxies
    File:     marquart_poster.pdf
    Abstract: A summary of the Stockholm-Uppsala group's work on the subject.
  • Mariluz Martín Manjón
    Title: Modelling Starbursts in HII galaxies: What do we need to fit the observations?
    File:
    Abstract: We have computed a series of realistic and self-consistent models that have been shown to be able to reproduce the emitted spectra of HII galaxies in a star bursting scenario. Our models combine different codes of chemical evolution, evolutionary population synthesis and photoionization. The emitted spectrum of HII galaxies is reproduced by means of the photoionization code CLOUDY (Ferland 1998), using as ionizing spectrum the spectral energy distribution (SED) of the modelled HII galaxy, calculated using new and updated stellar population models (PopStar, Mollá et al. 2008, in prep.). This, in turn, is calculated according to a star formation history and a metallicity evolution given by a chemical evolution model. Each model is characterized by three parameters which are going to determinate the behaviour of the model: an initial efficiency of star formation, the way in which burst take place, and the time of separation between these burst. Some results of models emerging from the combination of different values for these three parameters are shown here. Our technique reproduces observed abundances, diagnostic diagrams and equivalent width-colour relations for local HII galaxies.
  • Hagen Thilo Meyer
    Title: Revisiting the Luminosity-Metallicity relation for star-forming dwarf galaxies with SDSS
    File:
    Abstract: Understanding the chemical enrichment of dwarf galaxies is crucial to understand the formation of large galaxies in a hierarchical scenario. A close investigation of the luminosity--metallicity (L-Z) relation for dwarf galaxies is undoubtedly of paramount importance. Here, we report on an ongoing investigation of the L-Z relation in star-forming dwarf galaxies (SFDGs), using a large sample compiled from the SDSS. An important and novel aspect of this programme is that we model and subtract the emission from the star-forming (SF) component in order to isolate the light from the old low-surface brightness (LSB) host of the sample galaxies. For this purpose we use surface photometry techniques and profile decomposition in the g and i SDSS bands. Our preliminary results presented here indicate the existence of the L(host)-Z relation over a wide range in absolute magnitudes and metallicities.
  • Hagen Thilo Meyer
    Title: Early-type dwarf galaxies with central star formation (Thorsten Lisker)
    File:
    Abstract: Could dEs with central star formation bridge the evolutionary gap from quiesent dEs to potentially star-bursting progenitors?

Practical demonstrations: data analysis & visualisation

This part of the list will be completed soon. If you have a good tool or software that you want to show, you can still submit a short contribution to the demonstration session.

Discussion Sessions

More detailed information follows.