88 research outputs found
The nuclear and extended mid-infrared emission of Seyfert galaxies
We present subarcsecond resolution mid-infrared (MIR) images obtained with
8-10 m-class ground-based telescopes of a complete volume-limited (DL<40 Mpc)
sample of 24 Seyfert galaxies selected from the Swift/BAT nine month catalog.
We use those MIR images to study the nuclear and circumnuclear emission of the
galaxies. Using different methods to classify the MIR morphologies on scales of
~400 pc, we find that the majority of the galaxies (75-83%) are extended or
possibly extended and 17-25% are point-like. This extended emission is compact
and it has low surface brightness compared with the nuclear emission, and it
represents, on average, ~30% of the total MIR emission of the galaxies in the
sample. We find that the galaxies whose circumnuclear MIR emission is dominated
by star formation show more extended emission (650+-700 pc) than AGN-dominated
systems (300+-100 pc). In general, the galaxies with point-like MIR
morphologies are face-on or moderately inclined (b/a~0.4-1.0), and we do not
find significant differences between the morphologies of Sy1 and Sy2. We used
the nuclear and circumnuclear fluxes to investigate their correlation with
different AGN and SF activity indicators. We find that the nuclear MIR emission
(the inner ~70 pc) is strongly correlated with the X-ray emission (the harder
the X-rays the better the correlation) and with the [O IV] lambda 25.89 micron
emission line, indicating that it is AGN-dominated. We find the same results,
although with more scatter, for the circumnuclear emission, which indicates
that the AGN dominates the MIR emission in the inner ~400 pc of the galaxies,
with some contribution from star formation.Comment: 27 pages, 12 figures, accepted by MNRA
The nuclear and extended infrared emission of the Seyfert galaxy NGC 2992 and the interacting system Arp 245
We present subarcsecond resolution infrared (IR) imaging and mid-IR
spectroscopic observations of the Seyfert 1.9 galaxy NGC 2992, obtained with
the Gemini North Telescope and the Gran Telescopio CANARIAS (GTC). The N-band
image reveals faint extended emission out to ~3 kpc, and the PAH features
detected in the GTC/CanariCam 7.5-13 micron spectrum indicate that the bulk of
this extended emission is dust heated by star formation. We also report
arcsecond resolution MIR and far-IR imaging of the interacting system Arp 245,
taken with the Spitzer Space Telescope and the Herschel Space Observatory.
Using these data, we obtain nuclear fluxes using different methods and find
that we can only recover the nuclear fluxes obtained from the subarcsecond data
at 20-25 micron, where the AGN emission dominates. We fitted the nuclear IR
spectral energy distribution of NGC 2992, including the GTC/CanariCam nuclear
spectrum (~50 pc), with clumpy torus models. We then used the best-fitting
torus model to decompose the Spitzer/IRS 5-30 spectrum (~630 pc) in AGN and
starburst components, using different starburst templates. We find that,
whereas at shorter mid-IR wavelengths the starburst component dominates (64% at
6 micron), the AGN component reaches 90% at 20 micron. We finally obtained dust
masses, temperatures and star formation rates for the different components of
the Arp 245 system and find similar values for NGC 2992 and NGC 2993. These
measurements are within those reported for other interacting systems in the
first stages of the interaction.Comment: 20 pages, 12 figures, accepted by MNRA
A deep look at the nuclear region of UGC 5101 through high angular resolution mid-IR data with GTC/CanariCam
We present an analysis of the nuclear infrared (IR, 1.6â18 ÎŒm) emission of the ultraluminous IR galaxy UGC 5101 to derive the properties of its active galactic nucleus (AGN) and its obscuring material. We use new mid-IR high angular resolution (0.3â0.5 arcsec) imaging using the Si-2 filter (λ_C = 8.7âÎŒm) and 7.5â13 ÎŒm spectroscopy taken with CanariCam (CC) on the 10.4 m Gran Telescopio CANARIAS. We also use archival Hubble Space Telescope/NICMOS and Subaru/COMICS imaging and Spitzer/IRS spectroscopy. We estimate the near- and mid-IR unresolved nuclear emission by modelling the imaging data with GALFIT. We decompose the Spitzer/IRS and CC spectra using a power-law component, which represents the emission due to dust heated by the AGN, and a starburst component, both affected by foreground extinction. We model the resulting unresolved near- and mid-IR, and the starburst subtracted CC spectrum with the CLUMPY torus models of Nenkova et al. The derived geometrical properties of the torus, including the large covering factor and the high foreground extinction needed to reproduce the deep 9.7âÎŒm silicate feature, are consistent with the lack of strong AGN signatures in the optical. We derive an AGN bolometric luminosity L_(bo)l ⌠1.9 Ă 10^(45)âerg s^(â1) that is in good agreement with other estimates in the literature
Deconvolution of JWST/MIRI Images: Applications to an Active Galactic Nucleus Model and GATOS Observations of NGC 5728
The superb image quality, stability, and sensitivity of JWST permit deconvolution techniques to be pursued with a fidelity unavailable to ground-based observations. We present an assessment of several deconvolution approaches to improve image quality and mitigate the effects of the complex JWST point-spread function (PSF). The optimal deconvolution method is determined by using WebbPSF to simulate JWSTâs complex PSF and MIRISim to simulate multiband JWST/Mid-Infrared Imager Module (MIRIM) observations of a toy model of an active galactic nucleus (AGN). Five different deconvolution algorithms are tested: (1) Kraken deconvolution, (2) RichardsonâLucy, (3) the adaptive imaging deconvolution algorithm, (4) sparse regularization with the CondatâVĆ© algorithm, and (5) iterative Wiener filtering and thresholding. We find that Kraken affords the greatest FWHM reduction of the nuclear source of our MIRISim observations for the toy AGN model while retaining good photometric integrity across all simulated wave bands. Applying Kraken to Galactic Activity, Torus, and Outflow Survey (GATOS) multiband JWST/MIRIM observations of the Seyfert 2 galaxy NGC 5728, we find that the algorithm reduces the FWHM of the nuclear source by a factor of 1.6â2.2 across all five filters. Kraken images facilitate detection of extended nuclear emission âŒ2.âł5 (âŒ470 pc, position angle â 115°) in the SEâNW direction, especially at the longest wavelengths. We demonstrate that Kraken is a powerful tool to enhance faint features otherwise hidden in the complex JWST PSF
Multiphase feedback processes in the Sy2 galaxy NGC 5643
arXiv:2009.12385v1 [astro-ph.GA]We study the multiphase feedback processes in the central âŒ3 kpc of the barred Seyfert 2 galaxy NGC 5643. We used observations of the cold molecular gas (ALMA CO(2â1) transition) and ionized gas (MUSE IFU optical emission lines). We studied different regions along the outflow zone, which extends out to âŒ2.3 kpc in the same direction (east-west) as the radio jet, as well as nuclear and circumnuclear regions in the host galaxy disk. The CO(2â1) line profiles of regions in the outflow and spiral arms show two or more different velocity components: one associated with the host galaxy rotation, and the others with out- or inflowing material. In the outflow region, the [OâŻIII]λ5007 Ă
emission lines have two or more components: the narrow component traces rotation of the gas in the disk, and the others are related to the ionized outflow. The deprojected outflowing velocities of the cold molecular gas (median VcentralââŒâ189 km sâ1) are generally lower than those of the outflowing ionized gas, which reach deprojected velocities of up to 750 km sâ1 close to the active galactic nucleus (AGN), and their spatial profiles follow those of the ionized phase. This suggests that the outflowing molecular gas in the galaxy disk is being entrained by the AGN wind. We derive molecular and ionized outflow masses of âŒ5.2 Ă 107â
Mâ (αCOGalactic) and 8.5 Ă 104â
Mâ and molecular and ionized outflow mass rates of âŒ51 Mâ yrâ1 (αCOGalactic) and 0.14 Mâ yrâ1, respectively. This means that the molecular phase dominates the outflow mass and outflow mass rate, while the kinetic power and momentum of the outflow are similar in both phases. However, the wind momentum loads (áčout/áčAGN) for the molecular and ionized outflow phases are âŒ27â5 (αCOGalactic and αCOULIRGs) and < 1, which suggests that the molecular phase is not momentum conserving, but the ionized phase most certainly is. The molecular gas content (MeastââŒâ1.5â
Ăâ
107â
Mâ; αCOGalactic) of the eastern spiral arm is approximately 50â70% of the content of the western one. We interpret this as destruction or clearing of the molecular gas produced by the AGN wind impacting in the eastern side of the host galaxy (negative feedback process). The increase in molecular phase momentum implies that part of the kinetic energy from the AGN wind is transmitted to the molecular outflow. This suggests that in Seyfert-like AGN such as NGC 5643, the radiative or quasar and the kinetic or radio AGN feedback modes coexist and may shape the host galaxies even at kiloparsec scales through both positive and (mild) negative feedback.IGB, AAH and FJC acknowledge financial support through grant PN AYA2015-64346-C2-1-P (MINECO/FEDER), funded by the Agencia Estatal de InvestigaciĂłn, Unidad de Excelencia MarĂa de Maeztu. IGB and DR also acknowledge support from STFC through grant ST/S000488/1. DR acknowledges support from the University of Oxford John Fell Fund. AAH, SGB and MVM also acknowledge support through grant PGC2018-094671-BI00 (MCIU/AEI/FEDER,UE). AAH, MPS, MVM and AL work was done under project No. MDM-2017-0737 Unidad de Excelencia âMarĂa de Maeztuâ - Centro de AstrobiologĂa (INTA-CSIC). MPS acknowledges support from the Comunidad de Madrid, Spain, through AtracciĂłn de Talento Investigador Grant 2018-
T1/TIC-11035 and PID2019-105423GA-I00 (MCIU/AEI/FEDER,UE). BG-L
acknowledges support from the State Research Agency (AEI) of the Spanish
Ministry of Science, Innovation and Universities (MCIU) and the European
Regional Development Fund (FEDER) under grant with reference AYA2015-
68217-P. FJC and SM acknowledge financial support from the Spanish Ministry MCIU under project RTI2018-096686-B-C21 (MCIU/AEI/FEDER/UE), cofunded by FEDER funds and from the Agencia Estatal de InvestigaciĂłn, Unidad de Excelencia MarĂa de Maeztu, ref. MDM-2017-0765. CRA acknowledges support from the Spanish Ministry of Science, Innovation and Universities (MCIU), the Agencia Estatal de InvestigaciĂłn (AEI) and the Fondo Europeo de Desarrollo Regional (EU FEDER) under project AYA2016-76682-C3-2-P and PID2019-106027GB-C42. CRA also acknowledges support from the MCIU under grant RYC-2014-15779. AL acknowledges the support from Comunidad de Madrid through the AtracciĂłn de Talento grant 2017-T1/TIC-5213. CR acknowledges support from the Fondecyt Iniciacion grant 11190831.Peer reviewe
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