ABSTRACT
We report on the determination of electron densities, and their impact on the outflow masses and rates, measured in the central few hundred parsecs of 11 local luminous active galaxies. We ...show that the peak of the integrated line emission in the active galactic nuclei (AGN) is significantly offset from the systemic velocity as traced by the stellar absorption features, indicating that the profiles are dominated by outflow. In contrast, matched inactive galaxies are characterized by a systemic peak and weaker outflow wing. We present three independent estimates of the electron density in these AGN, discussing the merits of the different methods. The electron density derived from the S ii doublet is significantly lower than that found with a method developed in the last decade using auroral and transauroral lines, as well as a recently introduced method based on the ionization parameter. The reason is that, for gas photoionized by an AGN, much of the S ii emission arises in an extended partially ionized zone where the implicit assumption that the electron density traces the hydrogen density is invalid. We propose ways to deal with this situation and we derive the associated outflow rates for ionized gas, which are in the range 0.001–0.5 M⊙ yr−1 for our AGN sample. We compare these outflow rates to the relation between $\dot{M}_{\rm out}$ and LAGN in the literature, and argue that it may need to be modified and rescaled towards lower mass outflow rates.
Nano-mechanical resonators have gained an increasing importance in nanotechnology owing to their contributions to both fundamental and applied science. Yet, their small dimensions and mass raises ...some challenges as their dynamics gets dominated by nonlinearities that degrade their performance, for instance in sensing applications. Here, we report on the precise control of the nonlinear and stochastic bistable dynamics of a levitated nanoparticle in high vacuum. We demonstrate how it can lead to efficient signal amplification schemes, including stochastic resonance. This work contributes to showing the use of levitated nanoparticles as a model system for stochastic bistable dynamics, with applications to a wide variety of fields.
ABSTRACT
We report on our combined analysis of HST, VLT/MUSE, VLT/SINFONI, and ALMA observations of the local Seyfert 2 galaxy, NGC 5728 to investigate in detail the feeding and feedback of the ...active galactic nucleus (AGN). The data sets simultaneously probe the morphology, excitation, and kinematics of the stars, ionized gas, and molecular gas over a large range of spatial scales (10 pc to 10 kpc). NGC 5728 contains a large stellar bar that is driving gas along prominent dust lanes to the inner 1 kpc where the gas settles into a circumnuclear ring. The ring is strongly star forming and contains a substantial population of young stars as indicated by the lowered stellar velocity dispersion and gas excitation consistent with H ii regions. We model the kinematics of the ring using the velocity field of the CO (2–1) emission and stars and find it is consistent with a rotating disc. The outer regions of the disc, where the dust lanes meet the ring, show signatures of inflow at a rate of 1 M$\odot$ yr−1. Inside the ring, we observe three molecular gas components corresponding to the circular rotation of the outer ring, a warped disc, and the nuclear stellar bar. The AGN is driving an ionized gas outflow that reaches a radius of 250 pc with a mass outflow rate of 0.08 M$\odot$ yr−1 consistent with its luminosity and scaling relations from previous studies. While we observe distinct holes in CO emission which could be signs of molecular gas removal, we find that largely the AGN is not disrupting the structure of the circumnuclear region.
ABSTRACT
The merger remnant NGC 34 is a local luminous infrared galaxy (LIRG) hosting a nuclear starburst and a hard X-ray source associated with a putative, obscured Seyfert 2 nucleus. In this work, ...we use adaptive optics assisted near-infrared (NIR) integral field unit observations of this galaxy to map the distribution and kinematics of the ionized and molecular gas in its inner $\mathrm{1.2\, kpc \times 1.2\, kpc}$, with a spatial resolution of 70 pc. The molecular and ionized gas kinematics is consistent with a disc with projected major axis along a mean PA = −9${_{.}^{\circ}}$2 ± 0${_{.}^{\circ}}$9. Our main findings are that NGC 34 hosts an AGN and that the nuclear starburst is distributed in a circumnuclear star formation ring with inner and outer radii of ≈ 60 and 180 pc, respectively, as revealed by maps of the $\mathrm{Fe\, {\small {II}} / Pa\,\beta }$ and H2/Br γ emission-line ratios, and corroborated by PCA tomography analysis. The spatially resolved NIR diagnostic diagram of NGC 34 also identifies a circumnuclear structure dominated by processes related to the stellar radiation field and a nuclear region where $\rm Fe\, {\small {II}}$ and H2 emissions are enhanced relative to the hydrogen recombination lines. We estimate that the nuclear X-ray source can account for the central H2 enhancement and conclude that $\rm Fe\, {\small {II}}$ and H2 emissions are due to a combination of photoionization by young stars, excitation by X-rays produced by the AGN and shocks. These emission lines show nuclear, broad, blueshifted components that can be interpreted as nuclear outflows driven by the AGN.
Context.
A significant fraction of all
γ
-ray sources detected by the Large Area Telescope aboard the
Fermi
satellite is still lacking a low-energy counterpart. In addition, there is still a large ...population of
γ
-ray sources with associated low-energy counterparts that lack firm classifications. In the last 10 years we have undertaken an optical spectroscopic campaign to address the problem of unassociated or unidentified
γ
-ray sources (UGSs), mainly devoted to observing blazars and blazar candidates because they are the largest population of
γ
-ray sources associated to date.
Aims.
Here we describe the overall impact of our optical spectroscopic campaign on sources associated in
Fermi
-LAT catalogs, coupled with objects found in the literature. In the literature search we kept track of efforts by different teams that presented optical spectra of counterparts or potential counterparts of
Fermi
-LAT catalog sources. Our summary includes an analysis of additional 30 newly collected optical spectra of counterparts or potential counterparts of
Fermi
-LAT sources of a previously unknown nature.
Methods.
New spectra were acquired at the
Blanco
4 m and OAN-SPM 2.1 m telescopes, and those available in the Sloan Digital Sky Survey (data release 15) archive.
Results.
All new sources with optical spectra analyzed here are classified as blazars. Thanks to our campaign, altogether we discovered and classified 394 targets with an additional 123 objects collected from a literature search. We began our optical spectroscopic campaign between the release of the second and third
Fermi
-LAT source catalogs (2FGL and 3FGL, respectively), classified about 25% of the sources that had uncertain nature and discovered a blazar-like potential counterpart for ∼10% of UGSs listed therein. In the 4FGL catalog, about 350
Fermi
-LAT sources have been classified to date thanks to our campaign.
Conclusions.
The most elusive class of blazars are found to be BL Lacs since the largest fraction of
Fermi
-LAT sources targeted in our observations showed a featureless optical spectrum. The same conclusion applied to the literature spectra. Finally, we confirm the high reliability of mid-IR color-based methods to select blazar-like candidate counterparts of unassociated or unidentified
γ
-ray sources.
Abstract
Using data from the Galactic Arecibo
L
-band Feed Array Continuum Transit Survey, we report the discovery of two previously unidentified, very compressed, thin, and straight polarized ...filaments approximately centered at Galactic coordinates, (
l
,
b
) = (182.°5, − 4.°0), which we call G182.5–4.0. Using data from the Isaac Newton Telescope Galactic Plane Survey, we also find straight, long, and extremely thin H
α
filaments coincident with the radio emission. These filaments are positioned in projection at the edge of the Orion-Eridanus superbubble and we find evidence indicating that the filaments align with the coherent magnetic field of the outer Galaxy. We find a lower limit on the total radio flux at 1.4 GHz to be 0.7 ± 0.3 Jy with an average linearly polarized fraction of
40
−
20
+
30
%
. We consider various scenarios that could explain the origin of these filaments, including a shell-type supernova remnant (SNR), a bow shock nebula associated with a pulsar, or relic fragments from one or more supernova explosions in the adjacent superbubble, with a hybrid scenario being most likely. This may represent an example of a new class of objects that is neither an SNR nor a bow shock. The highly compressed nature of these filaments and their alignment with the Galactic plane suggests a scenario where this object formed in a magnetic field that was compressed by the expanding Orion-Eridanus superbubble, suggesting that the object is related to this superbubble and implying a distance of ∼400 pc.
ABSTRACT
We map the optical and near-infrared (NIR) emission-line flux distributions and kinematics of the inner 320 × 535 pc2 of the elliptical galaxy NGC 1052. The integral field spectra were ...obtained with the Gemini Telescope using the GMOS-IFU and NIFS instruments, with angular resolutions of 0.88 and 0.1 arcsec in the optical and NIR, respectively. We detect five kinematic components: (1) and (2) two spatially unresolved components: a broad-line region visible in H α, with a full width at half-maximum (FWHM) of ∼3200 km s−1, and an intermediate broad component seen in the O iii λλ4959,5007 doublet; (3) an extended intermediate-width component with 280 km s−1 < FWHM < 450 km s−1 and centroid velocities up to 400 km s−1, which dominates the flux in our data, attributed either to a bipolar outflow related to the jets, rotation in an eccentric disc or to a combination of a disc and large-scale gas bubbles; (4) and (5) two narrow (FWHM < 150 km s−1) components, one visible in O iii, and another visible in the other emission lines, extending beyond the field of view of our data, which is attributed to large-scale shocks. Our results suggest that the ionization within the observed field of view cannot be explained by a single mechanism, with photoionization being the dominant mechanism in the nucleus with a combination of shocks and photoionization responsible for the extended ionization.
Abstract This work presents the isolation of endophytic fungi from the leaves of Campomanesia adamantium (Cambess.) O. Berg (Myrtaceae), a native species found in Brazil and popularly known as ...“guabiroba-do-campo”, with abundant distribution in the Brazilian Cerrado. It has been popularly used for its anti-rheumatic, anti-inflammatory, antidiarrheal, blood cholesterol-reducing, urinary antiseptic, and depurative properties. Theese fungi are microorganisms that live inside higher plants, at least for a period of their life cycle, occupying the intercellular spaces of plant tissues such as leaves and stems. These fungi are harmless to the host plant, and their secondary metabolites promote protection, regulate growth, combat bacteria, viruses, and fungi, and promote resistance to abiotic stress, as well as insecticidal effects. Endophytic fungi associated with the leaves of C. adamantium were isolated using the culture medium isolation technique. After growth, the fungi were divided into groups based on morphotypes. Fungal genomic DNA was extracted, and a polymerase chain reaction (PCR) was conducted to amplify the ITS1-5.8S-ITS2 regions of rRNA, and the nucleotide sequences obtained were compared with those available in the GenBank database for molecular identification of the isolates. The phylogenetic tree was constructed using MEGA 11 software. The results showed representatives of the Ascomycota phylum, and it was possible to identify at the genus level 18 fungi of the genera Colletotrichum, Diaporthe, Epicoccum, and Neofusicoccum.
Resumo Este trabalho apresenta o isolamento de fungos endofíticos de folhas de Campomanesia adamantium(Cambess.) O. Berg (Myrtaceae), espécie nativa encontrada no Brasil, com distribuição abundante no Cerrado brasileiro, popularmente conhecida como “guabiroba-do-campo. Têm sido utilizadas popularmente por suas atividades anti-reumáticas anti-inflamatórias, antidiarreicas, redutoras de colesterol no sangue, antisséptica urinária e depurativas. Fungos endofíticos são microrganismos que vivem no interior de plantas superiores, ao menos por um período de seu ciclo de vida, ocupando os espaços intercelulares dos tecidos vegetais, como folhas e caules. Esses fungos, além de serem inofensivos à planta hospedeira, produzem benefícios a partir de metabólitos secundários que promovem proteção, regulam o crescimento, combatem bactérias, vírus e fungos e promovem resistência a estresse abiótico, além de efeitos inseticidas. Os fungos endófitos associados às folhas de C. adamantiumforam isolados utilizando-se a técnica de isolamento em meio de cultura. Logo após o crescimento, os fungos foram divididos em grupos baseados em morfotipos. O DNA genômico fúngico foi extraído A reação em cadeia da polimerase (PCR) foi conduzida para amplificação da região ITS-1-5.8S-ITS2 de rRNA e as sequências de nucleotídeos obtidas foram comparados com aqueles disponíveis na base de dados GenBank para a identificação molecular dos isolados. A construção da filogenia da árvore foi realizada utilizando o software MEGA 11. Os resultados apresentaram representantes do filo Ascomycota e em nível de gênero foi possível identificar 18 fungos dos gêneros Colletotrichum, Diaporthe, Epicoccum e Neofusicoccum.
The effectiveness of therapeutic monoclonal antibodies (mAbs) against variants of the SARS-CoV-2 virus is highly variable. As target recognition of mAbs relies on tight binding affinity, we assessed ...the affinities of five therapeutic mAbs to the receptor binding domain (RBD) of wild type (A), Delta (B.1.617.2), and Omicron BA.1 SARS-CoV-2 (B.1.1.529.1) spike using microfluidic diffusional sizing (MDS). Four therapeutic mAbs showed strongly reduced affinity to Omicron BA.1 RBD, whereas one (sotrovimab) was less impacted. These affinity reductions correlate with reduced antiviral activities suggesting that affinity could serve as a rapid indicator for activity before time-consuming virus neutralization assays are performed. We also compared the same mAbs to serological fingerprints (affinity and concentration) obtained by MDS of antibodies in sera of 65 convalescent individuals. The affinities of the therapeutic mAbs to wild type and Delta RBD were similar to the serum antibody response, indicating high antiviral activities. For Omicron BA.1 RBD, only sotrovimab retained affinities within the range of the serum antibody response, in agreement with high antiviral activity. These results suggest that serological fingerprints provide a route to evaluating affinity and antiviral activity of mAb drugs and could guide the development of new therapeutics.
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