Proyecto de Investigación: ESP2015-68964-P
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ESP2015-68964-P
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Extreme gas kinematics in an off-nuclear HII region of SDSS J143245.98+404300.3
(EDP Sciences, 2019-10-03) Rodríguez del Pino, B.; Arribas, S.; Piqueras López, J.; Crespo Gómez, A.; Vílchez, J. M.; Ministerio de Economía y Competitividad (MINECO); University of Utah; Alfred P. Sloan Foundation (APSF); 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 present and discuss the properties of an ionized gas component with extreme kinematics in a recently reported off-nuclear HII region located at ∼0.8−1.0 kpc from the nucleus of SDSS J143245.98+404300.3. The high-velocity-gas component is identified by the detection of very broad emission wings in the Hα line, with full width at half maximum (FWHM) ≥ 850−1000 km s−1. Such gas kinematics are outstandingly high compared to other HII regions in local galaxies and are similar to those reported in some star-forming clumps of galaxies at z ∼ 2. The spatially resolved analysis indicates that the high-velocity gas extends at least ∼90 pc and it could be compatible with an ionized outflow entraining gas at a rate between approximately seven and nine times faster than the rate at which gas is being converted into stars. We do not detect broad emission wings in other emission lines such as Hβ, perhaps due to moderate dust extinction, nor in [N II]λλ6548, 6584 or [S II]λλ6717, 6731, which could be due to the presence of turbulent mixing layers originated by the impact of fast-flowing winds. The lack of spectral signatures associated to the presence of Wolf–Rayet stars points towards stellar winds from a large number of massive stars and/or supernovae as the likely mechanisms driving the high-velocity gas.
The host galaxies of luminous type 2 AGNs at z ∼ 0.3–0.4
(Oxford Academics: Oxford University Press, 2019-02-28) Urbano Mayorgas, J. J.; Villar Martín, M.; Buitrago, F.; Piqueras López, J.; Rodríguez del Pino, B.; Koekemoer, A. M.; Huertas Company, M.; Domínguez Tenreiro, R.; Carrera, F. J.; Tadhunter, C.; Fundação para a Ciência e a Tecnologia (FCT); Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Buitrago, F. [0000-0002-2861-9812]; Koekemoer, A. M. [0000-0002-6610-2048]
We study the morphological and structural properties of the host galaxies associated with 57 optically selected luminous type 2 active galactic nuclei (AGNs) at z ∼ 0.3–0.4: 16 high-luminosity Seyfert 2 [HLSy2, 8.0 ≤ log(L[OIII]/L⊙)< 8.3] and 41 obscured [QSO2, log(L[OIII]/L⊙)≥ 8.3] quasars. With this work, the total number of QSO2s at z < 1 with parametrized galaxies increases from ∼35 to 76. Our analysis is based on Hubble Space Telescope WFPC2 and ACS images that we fit with GALFIT. HLSy2s and QSO2s show a wide diversity of galaxy hosts. The main difference lies in the higher incidence of highly disturbed systems among QSO2s. This is consistent with a scenario in which galaxy interactions are the dominant mechanism triggering nuclear activity at the highest AGN power. There is a strong dependence of galaxy properties with AGN power (assuming L[OIII] is an adequate proxy). The relative contribution of the spheroidal component to the total galaxy light (B/T) increases with L[OIII]. While systems dominated by the spheroidal component spread across the total range of L[OIII], most disc-dominated galaxies concentrate at log(L[OIII]/L⊙)<8.6. This is expected if more powerful AGNs are powered by more massive black holes which are hosted by more massive bulges or spheroids. The average galaxy sizes (〈re〉) are 5.0 ± 1.5 kpc for HLSy2s and 3.9 ± 0.6 kpc for HLSy2s and QSO2s, respectively. These are significantly smaller than those found for QSO1s and narrow-line radio galaxies at similar z. We put the results of our work in the context of related studies of AGNs with quasar-like luminosities.
Searching for molecular gas inflows and outflows in the nuclear regions of five Seyfert galaxies.
(EDP Sciences, 2020-11-13) Domínguez Fernández, A. J.; Alonso Herrero, A.; García Burillo, S.; Davies, R. I.; Usero, A.; Labiano, Á.; Levenson, N. A.; Pereira Santaella, M.; Imanishi, M.; Ramos Almeida, C.; Rigopoulou, D.; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Comunidad de Madrid; Science and Technology Facilities Council (STFC); Ramos Almeida, C. [https://orcid.org/0000-0001-8353-649X]; Davies, R. [https://orcid.org/0000-0003-4949-7217]; Alonso Herrero, A. [https://orcid.org/0000-0001-6794-2519]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Active galactic nucleus (AGN) driven outflows are believed to play an important role in regulating the growth of galaxies, mostly via negative feedback. However, their effects on their hosts are far from clear, especially for low- and moderate-luminosity Seyferts. To investigate this issue, we obtained cold molecular gas observations, traced by the CO(2-1) transition, using the NOEMA interferometer of five nearby (distances between 19 and 58 Mpc) Seyfert galaxies. The resolution of ∼0.3–0.8 (∼30–100 pc) and field of view of NOEMA allowed us to study the CO(2-1) morphology and kinematics in the nuclear regions (∼100 pc) and up to radial distances of ∼900 pc. We detected CO(2-1) emission in all five galaxies with disky or circumnuclear ring-like morphologies. We derived cold molecular gas masses on nuclear (∼100 pc) and circumnuclear (∼650 pc) scales in the range from 106 to 107 M⊙ and from 107 to 108 M⊙, respectively. In all of our galaxies, the bulk of this gas is rotating in the plane of the galaxy. However, noncircular motions are also present. In NGC 4253, NGC 4388, and NGC 7465, we can ascribe the streaming motions to the presence of a large-scale bar. In Mrk 1066 and NGC 4388, the noncircular motions in the nuclear regions are explained as outflowing material due to the interaction of the AGN wind with molecular gas in the galaxy disk. We conclude that for an unambiguous and precise interpretation of the kinematics of the cold molecular gas, we need detailed knowledge of the host galaxy (i.e., presence of bars, interactions, etc.), and also of the ionized gas kinematics and ionization cone geometry.
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.
