Browsing by Author "Ramos Almeida, C."
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- ItemAn infrared view of AGN feedback in a type-2 quasar: the case of the Teacup galaxy(2017) Ramos Almeida, C.; Piqueras Lopez, J.; Villar-Martin, M.; Bessiere, P. S.We present near-infrared integral field spectroscopy data obtained with Very Large Telescope/ Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) of ` the Teacup galaxy'. The nuclear K-band (1.95-2.45 mu m) spectrum of this radio-quiet type-2 quasar reveals a blueshifted broad component of FWHM similar to 1600-1800 km s(-1) in the hydrogen recombination lines (Pa alpha, Br delta and Br gamma ) and also in the coronal line [Si VI] lambda 1.963 mu m. Thus, the data confirm the presence of the nuclear ionized outflow previously detected in the optical range and reveal its coronal counterpart. Both the ionized and coronal nuclear outflows are resolved, with seeing-deconvolved full widths at half-maximum of 1.1+/-0.1 and 0.9+/-0.1 kpc along position angle (PA) +/-72 degrees-74 degrees. This orientation is almost coincident with the radio axis (PA = 77 degrees), suggesting that the radio jet could have triggered the nuclear outflow. In the case of the H2 lines, we do not require a broad component to reproduce the profiles, but the narrow lines are blueshifted by similar to 50 km s(-1) on average from the galaxy systemic velocity. This could be an indication of the presence of a nuclear molecular outflow, although the bulk of the H2 emission in the inner similar to 2 arcsec (similar to 3 kpc) of the galaxy follows a rotation pattern. We find evidence for kinematically disrupted gas (FWHM > 250 km s(-1)) at up to 5.6 kpc from the AGN, which can be naturally explained by the action of the outflow. The narrow component of [Si VI] is redshifted with respect to the systemic velocity, unlike any other emission line in the K-band spectrum. This indicates that the region where the coronal lines are produced is not cospatial with the narrow-line region.
- ItemComplex AGN feedback in the Teacup galaxy: a powerful ionised galactic outflow, jet-ISM interaction, and evidence for AGN-triggered star formation in a giant bubble(2023) Venturi, G.; Treister, Ezequiel; Finlez Ruiz, Carolina; D’Ago, G.; Bauer, F.; Harrison, C. M.; Ramos Almeida, C.; Revalski, M.; Ricci, F.; Sartori, L. F.; Girdhar, A.; Keel, W. C.; Tubín, D.Context: The z ∼ 0.1 type-2 QSO J1430+1339, known as the “Teacup”, is a complex galaxy showing a loop of ionised gas ∼10 kpc in diameter, co-spatial radio bubbles, a compact (∼1 kpc) jet, and outflow activity. Its closeness offers the opportunity to study in detail the intricate interplaybetween the central supermassive black hole (SMBH) and the material in and around the galaxy, both the interstellar medium (ISM) and circum galactic medium (CGM). Aims: We characterise the spatially resolved properties and effects of the galactic ionised gas outflow and compare them with those of the radio jet and with theoretical predictions to infer its acceleration mechanism.Methods. We used VLT/MUSE optical integral field spectroscopic observations to obtain flux, kinematic, and excitation maps of the extended (up to ∼100 kpc) ionised gas and to characterise the properties of stellar populations. We built radial profiles of the outflow properties as a function ofdistance from the active nucleus, from kiloparsec up to tens of kiloparsec scales, at ∼1 kpc resolution.Results. We detect a velocity dispersion enhancement (&300 km s−1) elongated over several kiloparsecs perpendicular to the radio jet, the active galactic nucleus (AGN) ionisation lobes, and the fast outflow, similar to what is found in other galaxies hosting compact, low-power jets, indicatingthat the jet strongly perturbs the host ISM during its passage. We observe a decreasing trend with distance from the nucleus for the outflow proper ties (mass outflow rate, kinetic rate, momentum rate). The mass outflow rate drops from around 100 M yr−1 in the inner 1–2 kpc to .0.1 M yr−1at 30 kpc. The mass outflow rate of the ionised outflow is significantly higher (∼1–8 times) than the molecular one, in contrast with what is often quoted in AGN. Based on energetic and morphological arguments, the driver of the multi-phase outflow is likely a combination of AGN radiation and the jet, or AGN radiation pressure on dust alone. The outflow mass-loading factor is ∼5–10 and the molecular gas depletion time due to the multi-phase outflow is .108 yr, indicating that the outflow can significantly affect the star formation and the gas reservoir in the galaxy. However, the fraction of the ionised outflow that is able to escape the dark matter halo potential is likely negligible. We detect blue-coloured continuum emission co-spatial with the ionised gas loop. Here, stellar populations are younger (.100–150 Myr) than in the rest of the galaxy (∼0.5–1 Gyr). This constitutes possible evidence for star formation triggered at the edge of the bubble due to the compressing action of the jet and outflow (“positive feedback”), as predicted by theory. All in all, the Teacup constitutes a rich system in which AGN feedback from outflows and jets, in both its negative and positive flavours, co-exist.
- ItemDo AGN triggering mechanisms vary with radio power? - I. Optical morphologies of radio-intermediate HERGs(2019) Pierce, J. C. S.; Tadhunter, C. N.; Ramos Almeida, C.; Bessiere, P. S.; Rose, M.Active galactic nuclei (AGNs) with intermediate radio powers are capable of driving multiphase outflows in galaxy bulges, and are also more common than their high-radio-power counterparts. In-depth characterization of the typical host galaxies and likely triggering mechanisms for this population is therefore required in order to better understand the role of radio AGN feedback in galaxy evolution. Here, we use deep optical imaging data to study the detailed host morphologies of a complete sample of 30 local radio AGNs with high-excitation optical emission (HERG) spectra and intermediate radio powers [ z < 0.1; 22.5 < log() < 24.0WHz(-1)]. The fraction of hosts with morphological signatures of mergers and interactions is greatly reduced compared to the 2Jy radio-powerful galaxies [log() > 25.0WHz(-1)] with strong optical emission lines: 53 +/- 9 per cent compared with 94 +/- 4 per cent. In addition, the most radio-powerful half of the sample has a higher frequency of morphological disturbance than the least radio-powerful half (67 +/- 12 per cent and 40 +/- 13 per cent, respectively), including the eight most highly disturbed galaxies. This suggests that the importance of triggering nuclear activity in high-excitation radio galaxies (HERGs) through mergers and interactions reduces with radio power. Both visual inspection and detailed light profile modelling reveal a mixed population of early-type and late-type morphologies, contrary to the massive elliptical galaxy hosts of radio-powerful AGNs. The prevalence of late-type hosts could suggest that triggering via secular, disc-based processes has increased importance for HERGs with lower radio powers (e.g. disc instabilities and large-scale bars).
- ItemGalaxy-wide radio-induced feedback in a radio-quiet quasar(2017) Villar-Martin, M.; Emonts, B.; Cabrera Lavers, A.; Tadhunter, C.; Mukherjee, D.; Humphrey, A.; Zaurin, J. Rodriguez; Ramos Almeida, C.; Perez Torres, M.; Bessiere, P.We report the discovery of a radio-quiet type 2 quasar (SDSS J165315.06+234943.0 nick-named the 'Beetle' at z = 0.103) with unambiguous evidence for active galactic nucleus (AGN) radio-induced feedback acting across a total extension of similar to 46 kpc and up to similar to 26 kpc from the AGN. To the best of our knowledge, this is the first radio-quiet system where radio-induced feedback has been securely identified at >> several kpc from the AGN. The morphological, ionization and kinematic properties of the extended ionized gas are correlated with the radio structures. We find along the radio axis (a) enhancement of the optical line emission at the location of the radio hotspots (b) turbulent gas kinematics (FWHM similar to 380-470 km s(-1)) across the entire spatial range circumscribed by them (c) ionization minima for the turbulent gas at the location of the hot spots, (d) high temperature T-e greater than or similar to 1.9 x 10(4) K at the NE hotspot. Turbulent gas is also found far from the radio axis, similar to 25 kpc in the perpendicular direction. We propose a scenario in which the radio structures have perforated the interstellar medium of the galaxy and escaped into the circumgalactic medium. While advancing, they have interacted with in situ gas modifying its properties. Our results show that jets of modest power can be the dominant feedback mechanism acting across huge volumes in radio-quiet systems, including highly accreting luminous AGNs, where radiative mode feedback may be expected.
- ItemInfrared polarimetry of Mrk 231: scattering off hot dust grains in the central core(OXFORD UNIV PRESS, 2017) Lopez Rodriguez, E.; Packham, C.; Jones, T. J.; Siebenmorgen, R.; Roche, P. F.; Levenson, N. A.; Alonso Herrero, A.; Perlman, E.; Ichikawa, K.; Ramos Almeida, C.; Gonzalez Martin, O.; Nikutta, R.; Martinez Paredez, M.; Shenoy, D.; Gordon, M. S.; Telesco, C. M.We present high-angular (0.17-0.35 arcsec) resolution imaging polarimetric observations of Mrk 231 in the 3.1 mu m filter using MMT-Pol on the 6.5-m MMT, and in the 8.7, 10.3, and 11.6 mu m filters using CanariCam on the 10.4-m Gran Telescopio CANARIAS. In combination with already published observations, we compile the 1-12 mu m total and polarized nuclear spectral energy distribution (SED). The total flux SED in the central 400 pc is explained as the combination of (1) a hot (731 +/- 4 K) dusty structure, directly irradiated by the central engine, which is at 1.6 +/- 0.1 pc away and attributed to be in the pc-scale polar region, (2) an optically-thick, smooth and disc-like dusty structure ('torus') with an inclination of 48 degrees +/- 23 degrees surrounding the central engine, and (3) an extinguished (A(V) = 36 +/- 5 mag) starburst component. The polarized SED decreases from 0.77 +/- 0.14 per cent at 1.2 mu m to 0.31 +/- 0.15 per cent at 11.6 mu m and follows a power-law function, lambda(similar to 0.57). The polarization angle remains constant (similar to 108 degrees) in the 1-12 mu m wavelength range. The dominant polarization mechanism is explained as scattering-off hot dust grains in the pc-scale polar regions.
- ItemMid-infrared imaging- and spectro-polarimetric subarcsecond observations of NGC 1068(2016) Lopez-Rodriguez, E.; Packham, C.; Roche, P. F.; Alonso-Herrero, A.; Díaz-Santos, T.; Nikutta, R.; González-Martín, O.; Á lvarez, C. A.; Esquej, P.; Espinos, J. M. R.; Perlman, E.; Ramos Almeida, C.; Telesc, C. M.We present subarcsecond 7.5–13 μm imaging- and spectro-polarimetric observations of NGC 1068 using CanariCam on the 10.4-m Gran Telescopio CANARIAS. At all wavelengths, we find: (1) A 90 × 60 pc extended polarized feature in the northern ionization cone, with a uniform ∼44$^\circ$ polarization angle. Its polarization arises from dust and gas emission in the ionization cone, heated by the active nucleus and jet, and further extinguished by aligned dust grains in the host galaxy. The polarization spectrum of the jet–molecular cloud interaction at ∼24 pc from the core is highly polarized, and does not show a silicate feature, suggesting that the dust grains are different from those in the interstellar medium. (2) A southern polarized feature at ∼9.6 pc from the core. Its polarization arises from a dust emission component extinguished by a large concentration of dust in the galaxy disc. We cannot distinguish between dust emission from magnetically aligned dust grains directly heated by the jet close to the core, and aligned dust grains in the dusty obscuring material surrounding the central engine. Silicate-like grains reproduce the polarized dust emission in this feature, suggesting different dust compositions in both ionization cones. (3) An upper limit of polarization degree of 0.3 per cent in the core. Based on our polarization model, the expected polarization of the obscuring dusty material is ≲0.1 per cent in the 8–13 μm wavelength range. This low polarization may be arising from the passage of radiation through aligned dust grains in the shielded edges of the clumps.
- ItemYoung stellar populations in type II quasars: timing the onset of star formation and nuclear activity(OXFORD UNIV PRESS, 2017) Bessiere, P. S.; Tadhunter, C. N.; Ramos Almeida, C.; Villar Martin, M.; Cabrera Lavers, A.Despite the emerging morphological evidence that luminous quasar-like active galactic nuclei (AGN) are triggered in galaxy mergers, the natures of the triggering mergers and the order of events in the triggering sequence remain uncertain. In this work, we present a detailed study of the stellar populations of the host galaxies of 21 type II quasars, with the aim of understanding the sequence of events between the onset of the merger, the triggering of the associated starburst and the initiation of the quasar activity. To this end, we model high-quality, wide spectral coverage, intermediate-resolution optical spectra of the type II quasars. We find that of the 21 objects, the higher order Balmer absorption lines, characteristic of young stellar populations (YSPs), are directly detected in similar to 62 per cent of the sample. We also fit these spectra using a number of combinations of stellar and/or power-law components, representative of viable formation histories, as well as including the possibility of scattered AGN light. We find that similar to 90 per cent of the type II quasar host galaxies require the inclusion of a YSP to adequately model their spectra, whilst 71 per cent of the sample require the inclusion of a YSP with age <100 Myr. Since the ages of the YSP in most type II quasar host galaxies are comparable with the expected lifetimes of the AGN activity, these results provide strong evidence that the quasars are triggered close to the peaks of the merger-induced starbursts.