Spiral Galaxies: Evolution and Consequences

    General
    Description

    Our small group is well known and respected internationally for our innovative and important work on various aspects of the structure and evolution of nearby spiral galaxies. We primarily use observations at various wavelengths, exploiting synergies that allow us to answer the most pertinent questions relating to what the main properties of galaxies are, and how galaxies have evolved to their current state. We use imaging and spectroscopy, at UV, optical, infrared, millimetre, and radio wavelengths, fully exploiting observing facilities available to us in Spain, at ESO, or elsewhere, along with state-of-the-art analysis tools. The success of this approach can be measured from the employment opportunities offered to ex-members of the group, from the number and quality of collaborations with leading external scientists, from continued citation of our published work, and from invitations to co-organise or speak at the leading international conferences in the field.

    In the last few years our group has put a lot of effort into opening up joint research lines with computer scientists, recognising the paradigm shift that is upon us due to the enormous quantities of data that will soon be produced by facilities such as LSST, Euclid, and SKA. We collaborate with computer scientists and aim to prepare the analysis tools, including detection of structure from noise, correction for scattered light and Galactic cirrus, and the use of machine learning-based techniques, so that once LSST (2020) and Euclid (2023) start releasing their huge data sets, our group is ready to analyse them and extract the science from the oceans of bytes.

    1. From thermal and non-thermal radio maps of the centre of NGC 1097, we discovered that the massive star formation is quenched by non-thermal effects, including pressure from the magnetic field, cosmic rays and turbulence.
    2. In the centre of NGC 7742, we found a slightly warped inner disk, and two separate stellar components: an old population that counter-rotates with the gas, and a young one, concentrated to the ring, that co-rotates with the gas.
    3. We re-analysed our deep IR imaging of thick disks to correct for the extended S4G point spread function (PSF), confirming all our previous results and in particular confirming the significant mass present in the thick disk component.
    4. Analysing a new high-resolution e-MERLIN 1.5 GHz radio continuum map together with HST and SDSS imaging of NGC 5322, an elliptical galaxy hosting radio jets, we found that the low-luminosity AGN/jet-driven feedback may have quenched the late-time nuclear star formation promptly.
    5. From MUSE observations of low-surface-brightness Lyman-α emission surrounding faint galaxies at redshifts between 3 and 6 we find that the projected sky coverage approaches 100 per cent.

    Related publications

    • A prediction about the age of thick discs as a function of the stellar mass of the host galaxy

      One of the suggested thick disc formation mechanisms is that they were born quickly and in situ from a turbulent clumpy disc. Subsequently, thin discs formed slowly within them from leftovers of the turbulent phase and from material accreted through cold flows and minor mergers. In this Letter, I propose an observational test to verify this

      Comerón, S.

      Advertised on:

      1
      2021
      Citations
      2
    • The complex multi-component outflow of the Seyfert galaxy NGC 7130

      Active galactic nuclei (AGN) are a key ingredient for understanding galactic evolution, as their activity is coupled to the host galaxy properties through feedback processes. AGN-driven outflows are one of the manifestations of this feedback. The laser guide star adaptive optics mode for MUSE at the VLT now permits us to study the innermost tens of

      Comerón, S. et al.

      Advertised on:

      1
      2021
      Citations
      10
    • LeMMINGs - II. The e-MERLIN legacy survey of nearby galaxies. The deepest radio view of the Palomar sample on parsec scale

      We present the second data release of high-resolution (≤0.2 arcsec) 1.5-GHz radio images of 177 nearby galaxies from the Palomar sample, observed with the e-MERLIN array, as part of the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies Sample (LeMMINGs) survey. Together with the 103 targets of the first LeMMINGs data release, this represents a

      Baldi, R. D. et al.

      Advertised on:

      1
      2021
      Citations
      28
    • The kinematics of young and old stellar populations in nuclear rings of MUSE TIMER galaxies

      Context. Studying the stellar kinematics of galaxies is a key tool in the reconstruction of their evolution. However, the current measurements of the stellar kinematics are complicated by several factors, including dust extinction and the presence of multiple stellar populations. Aims: We use integral field spectroscopic data of four galaxies from

      Rosado-Belza, D. et al.

      Advertised on:

      12
      2020
      Citations
      6
    • Distribution of star formation in galactic bars as seen with Hα and stacked GALEX UV imaging

      Context. Stellar bars are known to gradually funnel gas to the central parts of disk galaxies. It remains a matter of debate why the distribution of ionized gas along bars and in the circumnuclear regions varies among galaxies. Aims: Our goal is to investigate the spatial distribution of star formation (SF) within bars of nearby low-inclination

      Díaz-García, S. et al.

      Advertised on:

      12
      2020
      Citations
      22
    • An extensive spectroscopic time series of three Wolf-Rayet stars - II. A search for wind asymmetries in the dust-forming WC7 binary WR137

      We present the results of a 4-month, spectroscopic campaign of the Wolf-Rayet dust-making binary, WR137. We detect only small-amplitude random variability in the C III λ5696 emission line and its integrated quantities (radial velocity, equivalent width, skewness, and kurtosis) that can be explained by stochastic clumps in the wind of the WC star

      St-Louis, N. et al.

      Advertised on:

      7
      2020
      Citations
      2
    • The Black Hole Mass-Color Relations for Early- and Late-type Galaxies: Red and Blue Sequences

      The tight correlations between supermassive black hole (SMBH) mass (MBH) and the properties of the host galaxy have useful implications for our understanding of the growth of SMBHs and of the evolution of galaxies. Here, we present newly observed correlations between MBH and the host galaxy total UV-[3.6] color ( ${{ \mathcal C }}_{\mathrm{UV}

      Dullo, Bililign T. et al.

      Advertised on:

      7
      2020
      Citations
      15
    • MUSEQuBES: calibrating the redshifts of Ly α emitters using stacked circumgalactic medium absorption profiles

      Ly α emission lines are typically found to be redshifted with respect to the systemic redshifts of galaxies, likely due to resonant scattering of Ly α photons. Here, we measure the average velocity offset for a sample of 96 z ≍ 3.3 Ly α emitters (LAEs) with a median Ly α flux (luminosity) of ${\approx}10^{-17}~\rm erg~cm^{-2}~s^{-1}$ ( ${\approx}10

      Muzahid, Sowgat et al.

      Advertised on:

      5
      2020
      Citations
      46
    • Examining supernova events in Type 1 active galactic nuclei

      A statistical study of intermediate Palomar Transient Factory supernovae (SNe) in Type 1 active galactic nuclei (AGNs) has shown a major deficit of supernovae around Type 1 AGN host galaxies, with respect to Type 2 AGN hosts. The aim of this work is to test whether there is any preference for Type 1 AGNs to host SN of a specific kind. Through the

      Villarroel, Beatriz et al.

      Advertised on:

      5
      2020
      Citations
      1
    • SDSS-IV MaNGA: Excavating the fossil record of stellar populations in spiral galaxies

      We perform a 'fossil record' analysis for ≍800 low-redshift spiral galaxies, using STARLIGHT applied to integral field spectroscopic observations from the SDSS-IV MaNGA survey to obtain fully spatially resolved high-resolution star formation histories (SFHs). From the SFHs, we are able to build maps indicating the present-day distribution of

      Peterken, Thomas et al.

      Advertised on:

      5
      2020
      Citations
      21
    • The curious activity in the nucleus of NGC 4151: jet interaction causing variability?

      A key characteristic of many active galactic nuclei (AGNs) is their variability, but its origin is poorly understood, especially in the radio domain. Williams et al. (2017) reported a ∼50 per cent increase in peak flux density of the AGN in the Seyfert galaxy NGC 4151 at 1.5 GHz with the e-MERLIN array. We present new high-resolution e-MERLIN

      Williams, D. R. A. et al.

      Advertised on:

      5
      2020
      Citations
      9
    • Gas fractions and depletion times in galaxies with different degrees of interaction

      Context. A moderate enhancement of the star formation rates (SFR) in local interacting galaxies has been reported, but the physical mechanisms leading to this increase are not clear. Aims: We study the atomic gas content and the central stellar mass concentration for a sample of almost 1500 nearby galaxies to further investigate the nature of

      Díaz-García, S. et al.

      Advertised on:

      3
      2020
      Citations
      16
    • A physically motivated definition for the size of galaxies in an era of ultradeep imaging

      Present-day multiwavelength deep imaging surveys allow to characterize the outskirts of galaxies with unprecedented precision. Taking advantage of this situation, we define a new physically motivated measurement of size for galaxies based on the expected location of the gas density threshold for star formation. Employing both theoretical and

      Trujillo, Ignacio et al.

      Advertised on:

      3
      2020
      Citations
      53
    • Jointly super-resolved and optically sectioned Bayesian reconstruction method for structured illumination microscopy

      Structured Illumination Microscopy (SIM) is an imaging technique for achieving both super-resolution (SR) and optical sectioning (OS) in wide-field microscopy. It consists in illuminating the sample with periodic patterns at different orientations and positions. The resulting images are then processed to reconstruct the observed object with SR and

      Yann Lai-Tim et al.

      Advertised on:

      11
      2019
    • Time-slicing spiral galaxies with SDSS-IV MaNGA

      Spectra of galaxies contain a wealth of information about the stellar populations from which they are made. With integral field unit (IFU) surveys, such data can be used to map out stellar population properties across the face of a galaxy, allowing one to go beyond simple radial profiles and study details of non-axisymmetric structure. To-date

      Peterken, Thomas et al.

      Advertised on:

      10
      2019
      Citations
      14
    • Are ultra-diffuse galaxies Milky Way-sized?

      Now almost 70 years since its introduction, the effective or half-light radius has become a very popular choice for characterising galaxy size. However, the effective radius measures the concentration of light within galaxies and thus does not capture our intuitive definition of size which is related to the edge or boundary of objects. For this

      Chamba, N. et al.

      Advertised on:

      1
      2020
      Citations
      29
    • The shapes of spiral arms in the S<SUP>4</SUP>G survey and their connection with stellar bars

      Context. Spiral galaxies are very common in the local Universe, but their formation, evolution, and interplay with bars remain poorly understood after more than a century of astronomical research on the topic. Aims: We use a sample of 391 nearby galaxies from the S4G survey to characterise the winding angle and amplitude of spiral arms as a

      Díaz-García, S. et al.

      Advertised on:

      11
      2019
      Citations
      42
    • The GIST pipeline: A multi-purpose tool for the analysis and visualisation of (integral-field) spectroscopic data

      We present a convenient, all-in-one framework for the scientific analysis of fully reduced, (integral-field) spectroscopic data. The Galaxy IFU Spectroscopy Tool (GIST) is entirely written in Python 3 and conducts all the steps from the preparation of input data to the scientific analysis and to the production of publication-quality plots. In its

      Bittner, A. et al.

      Advertised on:

      8
      2019
      Citations
      62
    • SDSS-IV MaNGA: Spatial Evolution of Star Formation Triggered by Galaxy Interactions

      Galaxy interaction is considered a key driver of galaxy evolution and star formation (SF) history. In this paper, we present an empirical picture of the radial extent of interaction-triggered SF along the merger sequence. The samples under study are drawn from the integral field spectroscopy survey SDSS-IV MaNGA, including 205 star-forming galaxies

      Pan, Hsi-An et al.

      Advertised on:

      8
      2019
      Citations
      37
    • Properties of extragalactic thick discs recovered from ultra-deep Stripe82 imaging

      Context. Thick discs can give invaluable information on the formation and evolution history of galaxies as most, if not all, disc galaxies have a thin (classical) disc and a thick disc. Aims: We study the structure of thick discs in extraordinary depth by reaching a surface brightness limit of μrdeep ˜ 28.5-29 mag arcsec-2 with combined g, r, i

      Martínez-Lombilla, C. et al.

      Advertised on:

      9
      2019
      Citations
      20

    Related talks

    No related talks were found.

    Related conferences

    No related conferences were found.