16 research outputs found
PROFIT: a new alternative for emission-line PROfile FITting
I briefly describe a simple routine for emission-line profiles fitting by
Gaussian curves or Gauss-Hermite series. The PROFIT (line-PROfile FITting)
routine represent a new alternative for use in fits data cubes, as those from
Integral Field Spectroscopy or Fabry-Perot Interferometry, and may be useful to
better study the emission-line flux distributions and gas kinematics in
distinct astrophysical objects, such as the central regions of galaxies and
star forming regions. The PROFIT routine is written in IDL language and is
available at http://www.ufsm.br/rogemar/software.html.
The PROFIT routine was used to fit the [Fe II]1.257um emission-line profiles
for about 1800 spectra of the inner 350 pc of the Seyfert galaxy Mrk1066
obtained with Gemini NIFS and shows that the line profiles are better
reproduced by Gauss-Hermite series than by the commonly used Gaussian curves.
The two-dimensional map of the h_3 Gauss-Hermite moment shows its highest
absolute values in regions close to the edge of the radio structure. These high
values may be originated in an biconical outflowing gas associated with the
radio jet - previously observed in the optical [O III] emission. The analysis
of this kinematic component indicates that the radio jet leaves the center of
the galaxy with the north-west side slightly oriented towards us and the
south-east side away from us, being partially hidden by the disc of the galaxy.Comment: Accepted for publication Astrophysics & Space Science - 7 pges; 4
Fig
The Role of Host Galaxy for the Environmental Dependence of Active Nuclei in Local Galaxies
We discuss the environment of local hard X-ray selected active galaxies, with reference to two independent group catalogues. We find that the fraction of these AGN in S0 host galaxies decreases strongly as a function of galaxy group size (halo mass) – which contrasts with the increasing fraction of galaxies of S0 type in denser environments. However, there is no evidence for an environmental dependence of AGN in spiral galaxies. Because most AGN are found in spiral galaxies, this dilutes the signature of environmental dependence for the population as a whole. We argue that the differing results for AGN in disc-dominated and bulge-dominated galaxies are related to the source of the gas fuelling the AGN, and so may also impact the luminosity function, duty cycle and obscuration. We find that there is a significant difference in the luminosity function for AGN in spiral and S0 galaxies, and tentative evidence for some difference in the fraction of obscured AGN
Multiphase feedback processes in the Sy2 galaxy NGC 5643
arXiv:2009.12385v1 [astro-ph.GA]We study the multiphase feedback processes in the central ∼3 kpc of the barred Seyfert 2 galaxy NGC 5643. We used observations of the cold molecular gas (ALMA CO(2−1) transition) and ionized gas (MUSE IFU optical emission lines). We studied different regions along the outflow zone, which extends out to ∼2.3 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(2−1) 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 [O III]λ5007 Å 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 Vcentral ∼ 189 km s−1) are generally lower than those of the outflowing ionized gas, which reach deprojected velocities of up to 750 km s−1 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 ∼5.2 × 107 M⊙ (αCOGalactic) and 8.5 × 104 M⊙ and molecular and ionized outflow mass rates of ∼51 M⊙ yr−1 (αCOGalactic) and 0.14 M⊙ yr−1, 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 (Ṗout/ṖAGN) for the molecular and ionized outflow phases are ∼27−5 (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 (Meast ∼ 1.5 × 107 M⊙; αCOGalactic) of the eastern spiral arm is approximately 50−70% 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 Investigación, Unidad de Excelencia María 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 “María de Maeztu” - Centro de Astrobiología (INTA-CSIC). MPS acknowledges support from the Comunidad de Madrid, Spain, through Atracción 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 Investigación, Unidad de Excelencia María de Maeztu, ref. MDM-2017-0765. CRA acknowledges support from the Spanish Ministry of Science, Innovation and Universities (MCIU), the Agencia Estatal de Investigación (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 Atracción de Talento grant 2017-T1/TIC-5213. CR acknowledges support from the Fondecyt Iniciacion grant 11190831.Peer reviewe
The Cepheid Distance to the Narrow-line Seyfert 1 Galaxy NGC 4051
We derive a distance of D = 16.6 ± 0.3 Mpc (μ = 31.10 ± 0.04 mag) to the archetypal narrow-line Seyfert 1 galaxy NGC 4051 based on Cepheid period-luminosity relations and new Hubble Space Telescope multiband imaging. We identify 419 Cepheid candidates and estimate the distance at both optical and near-infrared wavelengths using subsamples of precisely photometered variables (123 and 47 in the optical and near-infrared subsamples, respectively). We compare our independent photometric procedures and distance-estimation methods to those used by the Supernovae, H0, for the Equation of State team and find agreement to 0.01 mag. The distance we obtain suggests an Eddington ratio of ˙m ≈ 0.2 for NGC 4051, typical of narrow-line Seyfert 1 galaxies, unlike the seemingly odd value implied by previous distance estimates. We derive a peculiar velocity of -490 ± 34 km s-1 for NGC 4051, consistent with the overall motion of the Ursa Major Cluster in which it resides. We also revisit the energetics of the NGC 4051 nucleus, including its outflow and mass accretion rates. © 2021. The American Astronomical Society. All rights reserved.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
A high angular resolution view of the PAH emission in Seyfert galaxies using JWST/MRS data
Polycyclic aromatic hydrocarbons (PAHs) are carbon-based molecules that are ubiquitous in a variety of astrophysical objects and environments. In this work we use JWST/MIRI MRS spectroscopy of three Seyferts to compare their nuclear PAH emission with that of star-forming (SF) regions. This study represents the first of its kind to use sub-arcsecond angular resolution data of local luminous Seyferts (Lbol > 1044.46 erg s−1 ) with a wide wavelength coverage (4.9–28.1 µm). We present an analysis of their nuclear PAH properties by comparing the observed ratios with PAH diagnostic model grids derived from theoretical spectra. Our results show that a suite of PAH features is present in the innermost parts of luminous Seyfert galaxies (∼0.4500 at 12 µm; in the inner ∼142–245 pc). We find that the nuclear regions of active galactic nuclei (AGN) lie at different positions of the PAH diagnostic diagrams, whereas the SF regions are concentrated around the average values of SF galaxies. In particular, we find that the nuclear PAH emission mainly originates in neutral PAHs. In contrast, PAH emission originating in the SF regions favours ionised PAH grains. The observed PAH ratios in the nuclear region of the AGN-dominated galaxy NGC 6552 indicate the presence of larger PAH molecules compared with those of the SF regions. Therefore, our results provide evidence that the AGN have a significant impact on the ionisation state (and probably the size) of the PAH grains on scales of ∼142–245 pc
Cold molecular gas and PAH emission in the nuclear and circumnuclear regions of Seyfert galaxies
We investigate the relation between the detection of the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature in the nuclear (∼24−230 pc) regions of 22 nearby Seyfert galaxies and the properties of the cold molecular gas. For the former we use ground-based (0.3−0.6″ resolution) mid-infrared (mid-IR) spectroscopy. The cold molecular gas is traced by ALMA and NOEMA high (0.2−1.1″) angular resolution observations of the CO(2–1) transition. Galaxies with a nuclear detection of the 11.3 μm PAH feature contain more cold molecular gas (median 1.6 × 107 M⊙) and have higher column densities (N(H2) = 2 × 1023 cm−2) over the regions sampled by the mid-IR slits than those without a detection. This suggests that molecular gas plays a role in shielding the PAH molecules in the harsh environments of Seyfert nuclei. Choosing the PAH molecule naphthalene as an illustration, we compute its half-life in the nuclear regions of our sample when exposed to 2.5 keV hard X-ray photons. We estimate shorter half-lives for naphthalene in nuclei without a 11.3 μm PAH detection than in those with a detection. The Spitzer/IRS PAH ratios on circumnuclear scales (∼4″ ∼ 0.25−1.3 kpc) are in between model predictions for neutral and partly ionized PAHs. However, Seyfert galaxies in our sample with the highest nuclear H2 column densities are not generally closer to the neutral PAH tracks. This is because in the majority of our sample galaxies, the CO(2–1) emission in the inner ∼4″ is not centrally peaked and in some galaxies traces circumnuclear sites of strong star formation activity. Spatially resolved observations with the MIRI medium-resolution spectrograph on the James Webb Space Telescope will be able to distinguish the effects of an active galactic nucleus (AGN) and star formation on the PAH emission in nearby AGN
Cold molecular gas and PAH emission in the nuclear and circumnuclear regions of Seyfert galaxies
We investigate the relation between the detection of the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature in the nuclear (∼24-230 pc) regions of 22 nearby Seyfert galaxies and the properties of the cold molecular gas. For the former we use ground-based (0.3-0.6″ resolution) mid-infrared (mid-IR) spectroscopy. The cold molecular gas is traced by ALMA and NOEMA high (0.2-1.1″) angular resolution observations of the CO(2-1) transition. Galaxies with a nuclear detection of the 11.3 μm PAH feature contain more cold molecular gas (median 1.6 × 107 MO ) and have higher column densities (N(H2) = 2 × 1023 cm-2) over the regions sampled by the mid-IR slits than those without a detection. This suggests that molecular gas plays a role in shielding the PAH molecules in the harsh environments of Seyfert nuclei. Choosing the PAH molecule naphthalene as an illustration, we compute its half-life in the nuclear regions of our sample when exposed to 2.5 keV hard X-ray photons. We estimate shorter half-lives for naphthalene in nuclei without a 11.3 μm PAH detection than in those with a detection. The Spitzer/IRS PAH ratios on circumnuclear scales (∼4″ ∼ 0.25-1.3 kpc) are in between model predictions for neutral and partly ionized PAHs. However, Seyfert galaxies in our sample with the highest nuclear H2 column densities are not generally closer to the neutral PAH tracks. This is because in the majority of our sample galaxies, the CO(2-1) emission in the inner ∼4″ is not centrally peaked and in some galaxies traces circumnuclear sites of strong star formation activity. Spatially resolved observations with the MIRI medium-resolution spectrograph on the James Webb Space Telescope will be able to distinguish the effects of an active galactic nucleus (AGN) and star formation on the PAH emission in nearby AGN.With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737
LLAMA: nuclear stellar properties of Swift-BAT AGN and matched inactive galaxies
In a complete sample of local 14–195 keV selected active galactic nuclei (AGNs) and inactive galaxies, matched by their host galaxy properties, we study the spatially resolved stellar kinematics and luminosity distributions at near-infrared wavelengths on scales of 10–150 pc, using SINFONI on the VLT. In this paper, we present the first half of the sample, which comprises 13 galaxies, eight AGNs and five inactive galaxies. The stellar velocity fields show a disc-like rotating pattern, for which the kinematic position angle is in agreement with the photometric position angle obtained from large scale images. For this set of galaxies, the stellar surface brightness of the inactive galaxy sample is generally comparable to the matched sample of AGN, but extends to lower surface brightness. After removal of the bulge contribution, we find a nuclear stellar light excess with an extended nuclear disc structure, which exhibits a size-luminosity relation. While we expect the excess luminosity to be associated with a dynamically cooler young stellar population, we do not typically see a matching drop in dispersion. This may be because these galaxies have pseudo-bulges in which the intrinsic dispersion increases towards the centre. And although the young stars may have an impact in the observed kinematics, their fraction is too small to dominate over the bulge and compensate the increase in dispersion at small radii, so no dispersion drop is seen. Finally, we find no evidence for a difference in the stellar kinematics and nuclear stellar luminosity excess between these active and inactive galaxies