Examinando por Autor "Colina, L."

Mostrando 1 - 12 de 12

Acceso Abierto
A proto-pseudobulge in ESO 320-G030 fed by a massive molecular inflow driven by a nuclear bar
(EDP Sciences, 2021-01-07) González Alfonso, E.; Pereira Santaella, M.; Fischer, J.; García Burillo, S.; Yang, C.; Alonso Herrero, A.; Colina, L.; Ashby, M. L. N.; Smith, H. A.; Rico Villas, F.; Martín Pintado, J.; Cazzoli, S.; Stewart, F. P.; National Aeronautics and Space Administration (NASA); Agencia Estatal de Investigación (AEI); Comunidad de Madrid; European Commission (EC); 0000-0001-5285-8517; 0000-0001-6697-7808; 0000-0003-0444-6897; 0000-0002-8117-9991; 0000-0001-6794-2519; 0000-0002-7705-2525; 0000-0001-8266-8298; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Galaxies with nuclear bars are believed to efficiently drive gas inward, generating a nuclear starburst and possibly an active galactic nucleus. We confirm this scenario for the isolated, double-barred, luminous infrared galaxy ESO 320-G030 based on an analysis of Herschel and ALMA spectroscopic observations. Herschel/PACS and SPIRE observations of ESO 320-G030 show absorption or emission in 18 lines of H2O, which we combine with the ALMA H2O 4(23)-3(30) 448 GHz line (E-upper similar to 400 K) and continuum images to study the physical properties of the nuclear region. Radiative transfer models indicate that three nuclear components are required to account for the multi-transition H2O and continuum data. An envelope, with radius R similar to 130-150 pc, dust temperature T-dust approximate to 50 K, and N-H2 similar to 2x10(23) cm(-2), surrounds a nuclear disk with R similar to 40 pc that is optically thick in the far-infrared (tau (100 mu m)similar to 1.5-3, N-H2 similar to 2x10(24) cm(-2)). In addition, an extremely compact (R similar to 12 pc), warm (approximate to 100 K), and buried (tau (100 mu m)> 5, N-H2 greater than or similar to 5x10(24) cm(-2)) core component is required to account for the very high-lying H2O absorption lines. The three nuclear components account for 70% of the galaxy luminosity (SFR similar to 16-18 M-circle dot yr(-1)). The nucleus is fed by a molecular inflow observed in CO 2-1 with ALMA, which is associated with the nuclear bar. With decreasing radius (r=450-225 pc), the mass inflow rate increases up to M-inf similar to 20 M yr(-1), which is similar to the nuclear star formation rate (SFR), indicating that the starburst is sustained by the inflow. At lower r, similar to 100-150 pc, the inflow is best probed by the far-infrared OH ground-state doublets, with an estimated M-inf similar to 30 M yr(-1). The inferred short timescale of similar to 20 Myr for nuclear gas replenishment indicates quick secular evolution, and indicates that we are witnessing an intermediate stage (< 100 Myr) proto-pseudobulge fed by a massive inflow that is driven by a strong nuclear bar. We also apply the H2O model to the Herschel far-infrared spectroscopic observations of H218O, OH, 18OH, OH+, H2O+, H3O+, NH, NH2, NH3, CH, CH+, 13CH+, HF, SH, and C3, and we estimate their abundances.
Acceso Abierto
Detection of an ionized gas outflow in the extreme UV-luminous star-forming galaxy BOSS-EUVLG1 at z = 2.47
(EDP Sciences, 2021-03-23) Álvarez Márquez, J.; Marques Chaves, R.; Colina, L.; Pérez Fournon, I.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
BOSS-EUVLG1 is the most ultraviolet (UV) and Lyα luminous galaxy to be going through a very active starburst phase detected thus far in the Universe. It is forming stars at a rate of 955 ± 118 M⊙ yr−1. We report the detection of a broad Hα component carrying 25% of the total Hα flux. The broad Hα line traces a fast and massive ionized gas outflow characterized by a total mass, log(Mout[M⊙]), of 7.94 ± 0.15, along with an outflowing velocity (Vout) of 573 ± 151 km s−1 and an outflowing mass rate (Ṁout) of 44 ± 20 M⊙ yr−1. The presence of the outflow in BOSS-EUVLG1 is also supported by the identification of blueshifted UV absorption lines in low and high ionization states. The energy involved in the Hα outflow can be explained by the ongoing star formation, without the need for an active galactic nucleus to be included in the scenario. The derived low mass-loading factor (η = 0.05 ± 0.03) indicates that, although it is massive, this phase of the outflow cannot be relevant for the quenching of the star formation, namely, the negative feedback. In addition, only a small fraction (≤15%) of the ionized outflowing material with velocities above 372 km s−1 has the capacity to escape the gravitational potential and to enrich the surrounding circumgalactic medium at distances above several tens of kpc. The ionized phase of the outflow does not carry sufficient mass or energy to play a relevant role in the evolution of the host galaxy nor in the enrichment of the intergalactic medium. As predicted by some recent simulations, other phases of the outflow could be responsible for most of the outflow energy and mass in the form of hot X-ray emitting gas. The expected emission of the extended X-ray emitting halo associated with the outflow in BOSS-EUVLG1 and similar galaxies could be detected with the future ATHENA X-ray observatory, however, there are no methods at present that would assist in their spatial resolution.
Acceso Abierto
Excitation and acceleration of molecular outflows in LIRGs: The extended ESO 320-G030 outflow on 200-pc scales
(EDP Sciences, 2020-11-06) Pereira Santaella, M.; Colina, L.; García Burillo, S.; González Alfonso, E.; Alonso Herrero, A.; Arribas, S.; Cazzoli, S.; Piqueras López, J.; Rigopoulou, D.; Usero, A.; Comunidad de Madrid; Agencia Estatal de Investigación (AEI); Usero, A. [0000-0003-1242-505X]; Pereira Santaella, M. [0000-0002-4005-9619]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We used high-spatial resolution (70 pc; 03) CO multi-transition (J = 1–0, 2–1, 4–3, and 6–5) ALMA data to study the physical conditions and kinematics of the cold molecular outflow in the local luminous infrared galaxy (LIRG) ESO 320-G030 (d = 48 Mpc, LIR/L⊙ = 1011.3). ESO 320-G030 is a double-barred isolated spiral, but its compact and obscured nuclear starburst (SFR ∼ 15 M⊙ yr−1; AV ∼ 40 mag) resembles those of ultra-luminous infrared galaxies (LIR/L⊙ > 1012). In the outflow, the CO(1–0)/CO(2–1) ratio is enhanced with respect to the rest of the galaxy and the CO(4–3) transition is undetected. This indicates that the outflowing molecular gas is less excited than the molecular gas in the nuclear starburst (i.e., outflow launching site) and in the galaxy disk. Non-local thermodynamic equilibrium radiative transfer modeling reveals that the properties of the molecular clouds in the outflow differ from those of the nuclear and disk clouds: The kinetic temperature is lower (Tkin ∼ 9 K) in the outflow, and the outflowing clouds have lower column densities. Assuming a 10−4 CO abundance, the large internal velocity gradients, 60−45+250 km s−1 pc−1, imply that the outflowing molecular clouds are not bound by self-gravity. All this suggests that the life-cycle (formation, collapse, dissipation) of the galaxy disk molecular clouds might differ from that of the outflowing molecular clouds which might not be able to form stars. The low kinetic temperature of the molecular outflow remains constant at radial distances between 0.3 and 1.7 kpc. This indicates that the heating by the hotter ionized outflow phase is not efficient and may favor the survival of the molecular gas phase in the outflow. The spatially resolved velocity structure of the outflow shows a 0.8 km s−1 pc−1 velocity gradient between 190 pc and 560 pc and then a constant maximum outflow velocity of about 700–800 km s−1 up to 1.7 kpc. This could be compatible with a pure gravitational evolution of the outflow, which would require coupled variations of the mass outflow rate and the outflow launching velocity distribution. Alternatively, a combination of ram pressure acceleration and cloud evaporation could explain the observed kinematics and the total size of the cold molecular phase of the outflow.
Acceso Abierto
MUSE view of Arp220: Kpc-scale multi-phase outflow and evidence for positive feedback
(EDP Sciences, 2020-11-17) Perna, M.; Arribas, S.; Catalán Torrecilla, C.; Colina, L.; Bellocchi, E.; Fluetsch, A.; Maiolino, R.; Cazzoli, S.; Hernán Caballero, A.; Pereira Santaella, M.; Piqueras López, J.; Rodríguez del Pino, B.; Ministerio de Economía y Competitividad (MINECO); ESO Multi Unit Spectroscopic Explorer (MUSE); Comunidad de Madrid; European Research Council (ERC); Agencia Estatal de Investigación (AEI); Perna, M. [0000-0002-0362-5941]; Arribas, S. [0000-0001-7997-1640]; Colina, L. [0000-0002-9090-4227]; Bellocchi, E. [0000-0001-9791-4228]; Cazzoli, S. [0000-0002-7705-2525]; Pereira Santaella, M. [0000-0002-4005-9619]; Piqueras López, J. [0000-0003-1580-1188]; Rodríguez del Pino, B. [0000-0001-5171-3930]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709
Context. Arp220 is the nearest and prototypical ultra-luminous infrared galaxy; it shows evidence of pc-scale molecular outflows in its nuclear regions and strongly perturbed ionised gas kinematics on kpc scales. It is therefore an ideal system for investigating outflow mechanisms and feedback phenomena in detail. Aims. We investigate the feedback effects on the Arp220 interstellar medium (ISM), deriving a detailed picture of the atomic gas in terms of physical and kinematic properties, with a spatial resolution that had never before been obtained (0.56″, i.e. ∼210 pc). Methods. We use optical integral-field spectroscopic observations from VLT/MUSE-AO to obtain spatially resolved stellar and gas kinematics, for both ionised ([N II]λ6583) and neutral (Na IDλλ5891, 96) components; we also derive dust attenuation, electron density, ionisation conditions, and hydrogen column density maps to characterise the ISM properties. Results. Arp220 kinematics reveal the presence of a disturbed kpc-scale disc in the innermost nuclear regions as well as highly perturbed multi-phase (neutral and ionised) gas along the minor axis of the disc, which we interpret as a galactic-scale outflow emerging from the Arp220 eastern nucleus. This outflow involves velocities up to ∼1000 km s−1 at galactocentric distances of ≈5 kpc; it has a mass rate of ∼50 M⊙ yr−1 and kinetic and momentum power of ∼1043 erg s−1 and ∼1035 dyne, respectively. The inferred energetics do not allow us to distinguish the origin of the outflows, namely whether they are active galactic nucleus- or starburst-driven. We also present evidence for enhanced star formation at the edges of – and within – the outflow, with a star-formation rate SFR ∼ 5 M⊙ yr−1 (i.e. ∼2% of the total SFR). Conclusions. Our findings suggest the presence of powerful winds in Arp220: They might be capable of heating or removing large amounts of gas from the host (“negative feedback”) but could also be responsible for triggering star formation (“positive feedback”).
Acceso Abierto
Physics of ULIRGs with MUSE and ALMA: The PUMA project I. Properties of the survey and first MUSE data results
(EDP Sciences, 2021-02-16) Perna, M.; Arribas, S.; Pereira Santaella, M.; Colina, L.; Bellocchi, E.; Catalán Torrecilla, C.; Cazzoli, S.; Crespo Gómez, A.; Maiolino, R.; Piqueras López, J.; Rodríguez del Pino, B.; Comunidad de Madrid; Agencia Estatal de Investigación (AEI); European Research Council (ERC); Science and Technology Facilities Council (STFC); Perna, M. [0000-0002-0362-5941]; Arribas, S. [0000-0001-7997-1640]; Colina, L. [0000-0002-9090-4227]; Bellocchi, E. [0000-0001-9791-4228]; Catalán Torrecilla, C. [0000-0002-8067-0164]; Cazzoli, S. [0000-0002-7705-2525]; Maiolino, R. [0000-0002-4985-3819]; Piqueras López, J. [0000-0003-1580-1188]; Rodríguez del Pino, B. [0000-0001-5171-3930]; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709
Context. Ultraluminous infrared galaxies (ULIRGs) are characterised by extreme starburst (SB) and active galactic nucleus (AGN) activity, and are therefore ideal laboratories for studying the outflow phenomena and their feedback effects. We have recently started a project called Physics of ULIRGs with MUSE and ALMA (PUMA), which is a survey of 25 nearby (z < 0.165) ULIRGs observed with the integral field spectrograph MUSE and the interferometer ALMA. This sample includes systems with both AGN and SB nuclear activity in the pre- and post-coalescence phases of major mergers. Aims. The main goals of the project are (i) to study the prevalence of (ionised, neutral, and molecular) outflows as a function of the galaxy properties, (ii) to constrain the driving mechanisms of the outflows (e.g. distinguish between SB and AGN winds), and (iii) to identify and characterise feedback effects on the host galaxy. In this first paper, we present details on the sample selection, MUSE observations, and data reduction, and derive first high-level data products. Methods. MUSE data cubes were analysed to study the dynamical status of each of the 21 ULIRGs observed so far, taking the stellar kinematics and the morphological properties inferred from MUSE narrow-band images into account. We also located the ULIRG nuclei, taking advantage of near-infrared (HST) and millimeter (ALMA) data, and studied their optical spectra to infer (i) the ionisation state through standard optical line ratio diagnostics, and (ii) outflows in both atomic ionised ([O III], Hα) and neutral (Na ID) gas. Results. We show that the morphological and stellar kinematic classifications are consistent: post-coalescence systems are more likely associated with ordered motions, while interacting (binary) systems are dominated by non-ordered and streaming motions. We also find broad and asymmetric [O III] and Na ID profiles in almost all nuclear spectra, with line widths in the range [300 − 2000] km s−1, possibly associated with AGN- and SB-driven winds. This result reinforces previous findings that indicated that outflows are ubiquitous during the pre- and post-coalescence phases of major mergers.
Acceso Abierto
Physics of ULIRGs with MUSE and ALMA: The PUMA project II. Are local ULIRGs powered by AGN? The subkiloparsec view of the 220 GHz continuum
(EDP Sciences, 2021-07-12) Pereira Santaella, M.; Colina, L.; García Burillo, S.; Lamperti, I.; González Alfonso, E.; Perna, M.; Arribas, S.; Alonso Herrero, A.; Aalto, S.; Combes, F.; Labiano, Á.; Piqueras López, J.; Rigopoulou, D.; Van der Werf, P. P.; Comunidad de Madrid; Agencia Estatal de Investigación (AEI); Science and Technology Facilities Council (STFC); Pereira Santaella, M. [0000-0002-4005-9619]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We analyze new high-resolution (400 pc) ∼220 GHz continuum and CO(2–1) Atacama Large Millimeter Array (ALMA) observations of a representative sample of 23 local (z < 0.165) ultra-luminous infrared systems (ULIRGs; 34 individual nuclei) as part of the “Physics of ULIRGs with MUSE and ALMA” (PUMA) project. The deconvolved half-light radii of the ∼220 GHz continuum sources, rcont, are between < 60 pc and 350 pc (median 80–100 pc). We associate these regions with the regions emitting the bulk of the infrared luminosity (LIR). The good agreement, within a factor of 2, between the observed ∼220 GHz fluxes and the extrapolation of the infrared gray-body as well as the small contributions from synchrotron and free–free emission support this assumption. The cold molecular gas emission sizes, rCO, are between 60 and 700 pc and are similar in advanced mergers and early interacting systems. On average, rCO are ∼2.5 times larger than rcont. Using these measurements, we derived the nuclear LIR and cold molecular gas surface densities (ΣLIR = 1011.5 − 1014.3 L⊙ kpc−2 and ΣH2 = 102.9 − 104.2 M⊙ pc−2, respectively). Assuming that the LIR is produced by star formation, the median ΣLIR corresponds to ΣSFR = 2500 M⊙ yr−1 kpc−2. This ΣSFR implies extremely short depletion times, ΣH2/ΣSFR < 1–15 Myr, and unphysical star formation efficiencies > 1 for 70% of the sample. Therefore, this favors the presence of an obscured active galactic nucleus (AGN) in these objects that could dominate the LIR. We also classify the ULIRG nuclei in two groups: (a) compact nuclei (rcont < 120 pc) with high mid-infrared excess emission (ΔL6−20 μm/LIR) found in optically classified AGN; and (b) nuclei following a relation with decreasing ΔL6−20 μm/LIR for decreasing rcont. The majority, 60%, of the nuclei in interacting systems lie in the low-rcont end (<120 pc) of this relation, while this is the case for only 30% of the mergers. This suggests that in the early stages of the interaction, the activity occurs in a very compact and dust-obscured region while, in more advanced merger stages, the activity is more extended, unless an optically detected AGN is present. Approximately two-thirds of the nuclei have nuclear radiation pressures above the Eddington limit. This is consistent with the ubiquitous detection of massive outflows in local ULIRGs and supports the importance of the radiation pressure in the outflow launching process.
Acceso Abierto
Rest-frame UV properties of luminous strong gravitationally lensed Lyα emitters from the BELLS GALLERY Survey
(Oxford Academics: Oxford University Press, 2020-02-10) Marques Chaves, R.; Pérez Fournon, I.; Shu, Y.; Colina, L.; Bolton, A.; Álvarez Márquez, J.; Brownstein, J.; Cornachione, M.; Geier, S.; Jiménez Ángel, C.; Kojima, T.; Mao, S.; Montero Dorta, A.; Oguri, M.; Ouchi, M.; Poidevin, F.; Shirley, Y.; Zheng, Z.; Agencia Estatal de Investigación (AEI); National Science Foundation (NSF); Ministerio de Economía y Competitividad (MINECO); Poidevin, F. [0000-0002-5391-5568]; Marqués Chaves, R. [0000-0001-8442-1846]; Shu, Y. [0000-0002-9063-698X]; Shirley, R. [0000-0002-1114-0135]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We present deep rest-frame UV spectroscopic observations using the Gran Telescopio Canarias of six gravitationally lensed Ly alpha emitters (LAEs) at 2.36 < z < 2.82 selected from the BELLS GALLERY survey. By taking the magnifications into account, we show that LAEs can be as luminous as L-Ly alpha similar or equal to 30 x 10(42) erg s(-1) and M-UV similar or equal to -23 (AB) without invoking an AGN component, in contrast with previous findings. We measure Ly alpha rest-frame equivalent widths, EW0 (Ly alpha), ranging from 16 to 50 angstrom and Ly alpha escape fractions, f(esc) (Ly alpha), from 10 per cent to 40 per cent. Large EW0 (Ly alpha) and f(esc) (Ly alpha) are found predominantly in LAEs showing weak low-ionization ISM absorption (EW0 less than or similar to 1A) and narrow Ly alpha profiles (less than or similar to 300 km s(-1) FWHM) with their peak close (less than or similar to 80 km s(-1)) to their systemic redshifts, suggestive of less scatter from low HI column densities that favours the escape of Ly alpha photons. We infer stellar metallicities of Z/Z(circle dot) similar or equal to 0.2 in almost all LAEs by comparing the P-Cygni profiles of the wind lines NV1240 angstrom and C IV1549 angstrom with those from stellar synthesis models. We also find a trend between M-UV and the velocity offset of ISM absorption lines, such as the most luminous LAEs experience stronger outflows. The most luminous LAEs show star formation rates up to similar or equal to 180 M-circle dot yr(-1), yet they appear relatively blue (beta(UV) similar or equal to -1.8 to -2.0) showing evidence of little dust attenuation [E(B - V) = 0.10-0.14]. These luminous LAEs may be particular cases of young starburst galaxies that have had no time to form large amounts of dust. If so, they are ideal laboratories to study the early phase of massive star formation, stellar and dust mass growth, and chemical enrichment histories of starburst galaxies at high-z.
Acceso Abierto
Simulating JWST deep extragalactic imaging surveys and physical parameter recovery.
(EDP Sciences, 2020-08-13) Kauffmann, O. B.; Le Fèvre, O.; Ilbert, O.; Chevallard, J.; Williams, C. C.; Curtis Lake, E.; Colina, L.; Pérez González, Pablo G.; Pye, J. P.; Caputi, K. I.; National Science Foundation (NSF); European Research Council (ERC); Agencia Estatal de Investigación (AEI); Ilbert, O. [https://orcid.org/0000-0002-7303-4397]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We present a new prospective analysis of deep multi-band imaging with the James Webb Space Telescope (JWST). In this work, we investigate the recovery of high-redshift 5 < z < 12 galaxies through extensive image simulations of accepted JWST programs, including the Early Release Science in the EGS field and the Guaranteed Time Observations in the HUDF. We introduced complete samples of ∼300 000 galaxies with stellar masses of log(M*/M⊙) > 6 and redshifts of 0 < z < 15, as well as galactic stars, into realistic mock NIRCam, MIRI, and HST images to properly describe the impact of source blending. We extracted the photometry of the detected sources, as in real images, and estimated the physical properties of galaxies through spectral energy distribution fitting. We find that the photometric redshifts are primarily limited by the availability of blue-band and near-infrared medium-band imaging. The stellar masses and star formation rates are recovered within 0.25 and 0.3 dex, respectively, for galaxies with accurate photometric redshifts. Brown dwarfs contaminating the z > 5 galaxy samples can be reduced to < 0.01 arcmin−2 with a limited impact on galaxy completeness. We investigate multiple high-redshift galaxy selection techniques and find that the best compromise between completeness and purity at 5 < z < 10 using the full redshift posterior probability distributions. In the EGS field, the galaxy completeness remains higher than 50% at magnitudes mUV < 27.5 and at all redshifts, and the purity is maintained above 80 and 60% at z ≤ 7 and 10, respectively. The faint-end slope of the galaxy UV luminosity function is recovered with a precision of 0.1–0.25, and the cosmic star formation rate density within 0.1 dex. We argue in favor of additional observing programs covering larger areas to better constrain the bright end.
Acceso Abierto
Stellar kinematics in the nuclear regions of nearby LIRGs with VLT-SINFONI Comparison with gas phases and implications for dynamical mass estimations
(EDP Sciences, 2021-06-22) Crespo Gómez, A.; Piqueras López, J.; Arribas, S.; Pereira Santaella, M.; Colina, L.; Rodríguez del Pino, B.; National Aeronautics and Space Administration (NASA); Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); 0000-0003-2119-277X; 0000-0003-1580-1188; 0000-0001-7997-1640; 0000-0002-9090-4227; 0000-0001-5171-3930
Context. Nearby luminous infrared galaxies (LIRGs) are often considered to be the local counterpart of the star forming galaxy (SFG) population at z > 1. Therefore, local LIRGs are ideal systems with which to perform spatially resolved studies on the physical processes that govern these objects and to validate assumptions made in high-z studies because of a lack of sensitivity and/or spatial resolution. Aims. In this work we analyse the spatially resolved kinematics of the stellar component in the inner r < 1–2 kpc of ten nearby (mean z = 0.014) LIRGs, establishing the dynamical state of the stars and estimating their dynamical masses (Mdyn). We compare the stellar kinematics with those for different gas phases, and analyse the relative effects of using different tracers when estimating dynamical masses. Methods. We use seeing-limited SINFONI H- and K-band spectroscopy in combination with ancillary infrared (IR) imaging from various instruments (NICMOS/F160W, NACO/Ks and IRAC/3.6 μm). The stellar kinematics are extracted in both near-IR bands by fitting the continuum emission using pPXF. The velocity maps are then modelled as rotating discs and used to extract the geometrical parameters (i.e. centre, PA, and inclination), which are compared with their photometric counterparts extracted from the near-IR images. We use the stellar and the previously extracted gas velocity and velocity dispersion maps to estimate the dynamical mass using the different tracers. Results. We find that the different gas phases have similar kinematics, whereas the stellar component is rotating with slightly lower velocities (i.e. V* ∼ 0.8Vg) but in significantly warmer orbits (i.e. σ* ∼ 2σg) than the gas phases, resulting in significantly lower V/σ for the stars (i.e. ∼1.5–2) than for the gas (i.e. ∼4–6). These ratios can be understood if the stars are rotating in thick discs while the gas phases are confined in dynamically cooler (i.e. thinner) rotating discs. However, these differences do not lead to significant discrepancies between the dynamical mass estimations based on the stellar and gas kinematics. This result suggests that the gas kinematics can be used to estimate Mdyn also in z ∼ 2 SFGs, a galaxy population that shares many structural and kinematic properties with local LIRGs.
Restringido
The discovery of the most UV–Ly α luminous star-forming galaxy: a young, dust- and metal-poor starburst with QSO-like luminosities
(Oxford Academics: Oxford University Press, 2020-09-16) Marques Chaves, R.; Álvarez Márquez, J.; Colina, L.; Pérez Fournon, I.; Schaerer, D.; Dalla Vecchia, C.; Hashimoto, T.; Jiménez Ángel, C.; Shu, Y.; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Shu, Y. [0000-0002-9063-698X]; Dalla Vecchia, C. [0000-0002-2620-7056]; Marqués Chaves, R. [0000-0001-8442-1846]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We report the discovery of BOSS-EUVLG1 at z = 2.469, by far the most luminous, almost un-obscured star-forming galaxy known at any redshift. First classified as a QSO within the Baryon Oscillation Spectroscopic Survey, follow-up observations with the Gran Telescopio Canarias reveal that its large luminosity, M-UV similar or equal to -24.40 and log(L-Ly alpha/erg s(-1)) similar or equal to 44.0, is due to an intense burst of star formation, and not to an active galactic nucleus or gravitational lensing. BOSS-EUVLG1 is a compact (r(eff) similar or equal to 1.2 kpc), young (4-5 Myr) starburst with a stellar mass log(M-*/M-circle dot) = 10.0 +/- 0.1 and a prodigious star formation rate of similar or equal to 1000 M-circle dot yr(-1). However, it is metal- and dust-poor [12+ log(O/H) = 8.13 +/- 0.19, E(B - V) similar or equal to 0.07, log(L-IR/L-UV) < -1.2], indicating that we are witnessing the very early phase of an intense starburst that has had no time to enrich the ISM. BOSS-EUVLG1 might represent a short-lived (<100 Myr), yet important phase of star-forming galaxies at high redshift that has been missed in previous surveys. Within a galaxy evolutionary scheme, BOSS-EUVLG1 could likely represent the very initial phases in the evolution of massive quiescent galaxies, even before the dusty star-forming phase.
Restringido
The MIRI cold telescope simulator
(SPIE Astronomical Telescopes Instrumentation, 2004-10-12) Colina, L.; Díaz, E.; Aricha, A.; Alcacera Gil, María Ángeles; Balado, A.; Barandiarán, J.; Barrado, D.; Belenguer Dávila, T.; Blanco, J.; Figueroa, I.; García, G.; González, L.; López Heredero, R.; Herrada, F. J.; Laviada Hernández, C.; March, M.; Pastor, C.; Reina, M.; Sánchez, A.; Barrado, D. [0000-0002-5971-9242]; López Heredero, R. [0000-0002-2197-8388]; Balado, A. [0000-0003-4268-2516]; Colina, L. [0000-0002-9090-4227]; Pastor, C. [0000-0001-9631-9558]
The MIRI Telescope Simulator (MTS) is part of the Optical Ground Support System (OGSE) for the verification and calibration phase of the James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI). The MTS will simulate the optical characteristics of the JWST output beam in an environment similar to the flight conditions. The different functionalities of the MTS are briefly described and its current design, including the illumination and imaging subsystems, is presented.
Restringido
The UV-brightest Lyman continuum emitting star-forming galaxy
(Oxford Academics: Oxford University Press, 2021-07-30) Marques Chaves, R.; Schaerer, D.; Álvarez Márquez, J.; Colina, L.; Dessauges Zavadsky, M.; Pérez Fournon, I.; Saldana López, A.; Verhamme, A.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We report the discovery of J0121+0025, an extremely luminous and young star-forming galaxy (MUV = −24.11, log[LLyα/erg s−1]=43.8⁠) at z = 3.244 showing copious Lyman continuum (LyC) leakage (⁠fesc,abs≈40 per cent⁠). High signal-to-noise ratio rest-frame UV spectroscopy with the Gran Telescopio Canarias reveals a high significance (7.9σ) emission below the Lyman limit (<912 Å), with a flux density level f900 = 0.78 ± 0.10μJy, and strong P-Cygni in wind lines of O VI 1033 Å, N V 1240 Å, and C IV 1550 Å that are indicative of a young age of the starburst (<10 Myr). The spectrum is rich in stellar photospheric features, for which a significant contribution of an AGN at these wavelengths is ruled out. Low-ionization interstellar medium (ISM) absorption lines are also detected, but are weak (⁠EW0≃1 Å) and show large residual intensities, suggesting a clumpy geometry of the gas with a non-unity covering fraction or a highly ionized ISM. The contribution of a foreground and AGN contamination to the LyC signal is unlikely. Deep optical to Spitzer/IRAC 4.5 μm imaging show that the spectral energy distribution of J0121+0025 is dominated by the emission of the young starburst, with log(⁠Mburst⋆/M⊙)=9.9±0.1 and SFR=981±232 M⊙ yr−1. J0121+0025 is the most powerful LyC emitter known among the star-forming galaxy population. The discovery of such luminous and young starburst leaking LyC radiation suggests that a significant fraction of LyC photons can escape in sources with a wide range of UV luminosities and are not restricted to the faintest ones as previously thought. These findings might shed further light on the role of luminous starbursts to the cosmic reionization.