Kinematic, Structural and Composition Studies of the Interstellar and Intergalactic Media

Start year
1986
Organizational Unit

Grants related:

    General
    Description

    The basic objective of the broject is to investigate the evolution of galaxies by deepening our understanding of the interaction between the insterstellar medium and the stars.The main technique which we use is the two-dimensional kinematic study of whole galaxies observed using our instrument:GHaFaS, a Fabry-Perot interferometer on the William Herschel Telescope of the ORM.

    We combine the data from GHaFaS with our own photometric imaging using ACAM on the same telescope, with a variety of sources of images in the infrared and ultraviolet, and with emission line maps en the radio and milimetre range to explore the effects, and the physical parameters which the determine the star formation rate and the mass function of the stars depending on the sites of their formation in galaxies.

    In the present phase of the project the dynamical aspects which we are e xploring are basically two: the resonant structure of discs and bars, and the effects of the zones of massive star formation on their surroundings via stellar winds and supernovae.In addition, in preparation for the exploration of galaxy formation in earlier epochs, we are studying how the interactions between galaxies stimulate and condition star formation within them before they merge. In the future these studies will be extended, methodically, in two directions: outwards to galaxies at increasing redshift, and inwards by applying our methods to the study of interstellar porcesse in the zones of massive star formation in the Local Group galaxy M33.

    We combine our research into galaxy kinematics with evolutionary aspects of galaxy discs based on precise observations of their surface brightness profiles, both in local galaxies and in galaxies at intermediate redshift. In order to make progress in this direction we are collaborating with colleagues at the Instituto de Astronomía de la UNAM (México) and the Laboratoire d'Astrophysique de Marseille (France) in the implementation of a new instrument, NEFER, which will be a high resolution Fabry-Perot module incorporated into OSIRIS on the GTC. We had successful inicial trials in December 2017, and commissioneed NEFER in March 2018 for use as a visitor instrument permanently on the GTC.

    1. The "Font-Beckman" method for analysing resonances in galaxies was shown to give very accurate results, comparing it with the "Tremaine-Weinberg" method using data from GHaFaS (WHT and MUSE (VLT)
    2. The profiles of Type III (antitruncated) S0 galaxies were measured at z = 0.6 (5 thousan dmillion years ago) for the first time. The "break radius" is the same as that of local galaxies, but its surface brightness is 1.6 magnitudes brighter.
    3. A new and greatly improved analysis of the Hubble Ultra-Deep Field gave an image with valid photometry down to 33 mag /arcsec squared, revealing the faint outskirts of it galaxies,.
    4. Comparing galaxies in interacting pairs with isolated galaxies it was shown that the star formation rate in the former is consistently enhanced and that this enhancement is common to the discs and the tidal tails
    5. The galaxy NGC 864 (CIG 86), apparently isolated, shows an asymmetric distribution of its hI. It was shown that this galaxy is truly isolated, and that HI accretion probably accounts for the asymmetry as well as the star formation in its stellar pseud-ring

    Related publications

    • Statistical Properties of Highly Luminous HII Regions in the Interacting Zone of the Antennae Galaxies, and Comparison with the Molecular Cloud Component

      We have used the package CLOUDPROPS (Rosolowsky & Leroy 2008) in order to identify clouds, which are contained in data cubes of molecular/Hα line emission, and extract their properties. The molecular data cube is taken from the ALMA public archive and the ionized hydrogen data cube was obtained with the Fabry-Perot interferometer, GHαFaS, on the 4

      García-Lorenzo, B. et al.

      Advertised on:

      3
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    • Internal kinematics and physical properties of HII regions in the Arp 270 system

      We have observed Arp 270 using the GHαFaS Fabry-Perot spectrometer on the 4.2m William Herschel Telescope (La Palma). In the edge-on companion we detect a radial gas inflow of ˜ 0.36 M &sun;/yr to the centre and also an axially confined outflow of ˜ 0.24 M &sun;/yr from the nucleus in two opposing directions. We find two different behaviors between

      García-Lorenzo, B. et al.

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      3
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    • Comparison of NIR and Hα emission from the HII regions of M100

      We measure the flux values in the 4 Spitzer-IRAC bands, of a sample of 78 isolated luminous HII regions in the grand design galaxy M100. We estimate the near-IR luminosities and compare them with the Hα-luminosities from the Knapen HII-region catalogue. We find a strong, and expected positive correlation between the total IR luminosity and the Hα

      Beckman, J. E. et al.

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    • The Filling Factor-Radius Relation for 58 H II Regions across the Disk of NGC 6946

      Using the OSIRIS tunable narrowband imager on the 10.4 m GTC (La Palma), we have mapped the SAB(rs)cd galaxy NGC 6946 over a ~7.3 × 7.5 arcmin2 field in the emission lines of the [S II] λλ6717, 6731 doublet, and in Hα. From these maps we have produced catalogs of the Hα luminosities and effective radii of 557 H II regions across the disk, and

      Alfaro, Emilio J. et al.

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      3
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    • Hα kinematics of S4G spiral galaxies - I. NGC 864

      We present a study of the kinematics of the isolated spiral galaxy NGC 864, using Hα Fabry-Perot data obtained with the Galaxy Hα Fabry-Perot System (GHαFaS) instrument at the William Herschel Telescope in La Palma, complemented with images at 3.6 μm, in the R band and in Hα filter, and integral-field spectroscopic data. The resulting data cubes

      Seibert, Mark et al.

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      12
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    • Stellar dynamics of blue compact galaxies. II. Further indications of a merger in ESO 338-IG04

      Context: Luminous blue compact galaxies, common at z ~ 1 but now relatively rare, show disturbed kinematics in emission lines. Aims: As part of a programme to understand their formation and evolution, we have investigated the stellar dynamics of a number of nearby objects in this class. Methods: We obtained long-slit spectra with VLT/FORS2 in the

      Cumming, R. J. et al.

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      3
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    • Hα kinematics of the Spitzer Infrared Nearby Galaxies Survey - II

      This is the second part of an Hα kinematics follow-up survey of the Spitzer Infrared Nearby Galaxies Survey (SINGS) sample. The aim of this paper is to shed new light on the role of baryons and their kinematics and on the dark/luminous matter relation in the star-forming regions of galaxies, in relation with studies at other wavelengths. The data

      Dicaire, I. et al.

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      4
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    • HVC's Favouring Star Forming Processes in galaxy discs: a basic calculation and some recent HI observations

      Indirect evidence from detailed chemical evolution studies shows that infall of low metallicity gas appears to have proceeded at a rather constant rate during the lifetime of the Galactic disk. We explore two possible implications: (a) the effect of an infalling high velocity cloud (HVC) on interstellar cloud stability leading to enhanced star

      Buenrostro, V. et al.

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      9
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    • Can gamma ray bursts be used as effective tracers of star formation to high Z?

      Long duration gamma ray bursts (GRB's) have been identified as originating in type II SNa explosions, produced during the late stage evolution of massive stars. As the lifetimes of their progenitors are so short the GRB rate per unit (comoving) volume of space, on scales which include significant numbers of galaxies, could be proportional to the

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      2010
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    • The warm ionized medium in spiral galaxies

      This article reviews observations and models of the diffuse ionized gas that permeates the disk and halo of our Galaxy and others. It was inspired by a series of invited talks presented during an afternoon scientific session of the 65th birthday celebration for Professor Carl Heiles held at Arecibo Observatory in August 2004. This review is in

      Haffner, L. M. et al.

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      7
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    • The Role of Mergers in Galaxy Evolution

      In the last decade the importance of mergers in the evolution of galaxies has become evident. In this paper we illustrate this importance by showing examples of merging galaxies, both local and at increasing redshift. However before getting carried away by the charms of the hierarchical model in which large galaxies have been built up by successive

      Beckman, J. et al.

      Advertised on:

      10
      2008
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    • The kinematics of the quadrupolar nebula M 1-75 and the identification of its central star

      Context. The link between how bipolar planetary nebulae are shaped and their central stars is still poorly understood. Aims: This paper investigates the kinematics and shaping of the multipolar nebula M 1-75, and briefly discusses the location and nature of its central star. Methods: Fabry-Perot data from GHαFAS on the WHT that samples the Doppler

      Santander-García, M. et al.

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      9
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    • The Galaxy-wide Distributions of Mean Electron Density in the H II Regions of M51 and NGC 4449

      Using Advanced Camera for Surveys-Hubble Space Telescope images to yield continuum-subtracted photometric maps in Hα of the Sbc galaxy M51 and the dwarf irregular galaxy NGC 4449, we produced extensive (over 2000 regions for M51 and over 200 regions for NGC 4449) catalogs of parameters of their H II regions: their Hα luminosities, equivalent radii

      Gutiérrez, L. et al.

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      2
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    • The Galactic initial mass function: origin in the combined mass distribution functions of dust grains and gas clouds

      We present here a theoretical model to account for the stellar initial mass function (IMF) as a result of the composite behaviour of the gas and dust distribution functions. Each of these has previously been modelled and the models tested against observations (Casuso & Beckman 2002, 2007, 2010). The model presented here implies a relation between

      Casuso, E. et al.

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    • Spiral Inflow Feeding the Nuclear Starburst in M83, Observed in Hα Emission with the GHαFaS Fabry-Perot Interferometer

      We present observations of the nearby barred starburst galaxy M83 (NGC 5236), with the new Fabry-Perot interferometer GHαFaS mounted on the 4.2 m William Herschel Telescope on La Palma. The unprecedented high-resolution observations, of 16 pc FWHM-1, of the Hα-emitting gas cover the central 2 kpc of the galaxy. The velocity field displays the

      Fathi, Kambiz et al.

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      3
      2008
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    • Radial distribution of near-UV flux in disc galaxies in the range 0 ⪉ z ⪉ 1

      Context: In the last 8 Gyr of cosmic time the global star formation rate (SFR) has declined by roughly an order of magnitude, and most of this activity has been progressively confined to ever less massive galaxies (“downsizing”). Previous studies show that the main drivers of the decline in the global SFR are the spiral galaxies. However, we still

      Azzollini, R. et al.

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      7
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    • Pattern Speeds of Bars and Spiral Arms from Hα Velocity Fields

      We have applied the Tremaine-Weinberg method to 10 late-type barred spiral galaxies using data cubes, in Hα emission, from the FaNTOmM and GHAFAS Fabry-Perot spectrometers. We have combined the derived bar (and/or spiral) pattern speeds with angular frequency plots to measure the corotation radii for the bars in these galaxies. We base our results

      Fathi, K. et al.

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      10
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    • On the morphology of sigma-drop galaxies

      Context: Local reductions of the stellar velocity dispersion in the central regions of galaxies are known as sigma-drops (σ-drops). Knowing the origin of these features can lead to better understanding of inner galactic dynamics. Aims: We present a sample of 20 σ-drop galaxies matched with a control sample of galaxies without σ-drop in order to

      Comerón, S. et al.

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      7
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    • On the Curvature of Dust Lanes in Galactic Bars

      We test the theoretical prediction that the straightest dust lanes in bars are found in strongly barred galaxies, or more specifically, that the degree of curvature of the dust lanes is inversely proportional to the strength of the bar. The test uses archival images of barred galaxies for which a reliable nonaxisymmetric torque parameter (Q b) and

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    • Multiple major outbursts from a restless luminous blue variable in NGC 3432

      We present new photometric and spectroscopic observations of an unusual luminous blue variable (LBV) in NGC 3432, covering three major outbursts in 2008 October, 2009 April and 2009 November. Previously, this star experienced an outburst also in 2000 (known as SN 2000ch). During outbursts the star reached an absolute magnitude between -12.1 and -12

      Pastorello, A. et al.

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      10
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