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2022 ◽  
Vol 21 (12) ◽  
pp. 305
Author(s):  
Ze-Rui Wang ◽  
Rui Xue

Abstract In addition to neutrino event IceCube-170922A which is observed to be associated with a γ-ray flare from blazar TXS 0506+056, there are also several neutrino events that may be associated with blazars. Among them, PKS B1424-418, GB6 J1040+0617 and PKS 1502+106 are low synchrotron peaked sources, which are usually believed to have the broad line region in the vicinity of the central black hole. They are considered as counterparts of IceCube event 35, IceCube-141209A and IceCube-190730A, respectively. By considering the proton-proton (pp) interactions between the dense gas clouds in the broad line region and the relativistic protons in the jet, we show that the pp model that is applied in this work can not only reproduce the multi-waveband spectral energy distribution but also suggest a considerable annual neutrino detection rate. We also discuss the emission from the photopion production and Bethe-Heitler pair production with a sub-Eddington jet power that is suggested in our model and find that it has little effect on the spectrum of total emission for all of three sources.


2021 ◽  
Vol 922 (2) ◽  
pp. 151
Author(s):  
Erin Kara ◽  
Missagh Mehdipour ◽  
Gerard A. Kriss ◽  
Edward M. Cackett ◽  
Nahum Arav ◽  
...  

Abstract We present the first results from the ongoing, intensive, multiwavelength monitoring program of the luminous Seyfert 1 galaxy Mrk 817. While this active galactic nucleus was, in part, selected for its historically unobscured nature, we discovered that the X-ray spectrum is highly absorbed, and there are new blueshifted, broad, and narrow UV absorption lines, which suggest that a dust-free, ionized obscurer located at the inner broad-line region partially covers the central source. Despite the obscuration, we measure UV and optical continuum reverberation lags consistent with a centrally illuminated Shakura–Sunyaev thin accretion disk, and measure reverberation lags associated with the optical broad-line region, as expected. However, in the first 55 days of the campaign, when the obscuration was becoming most extreme, we observe a de-coupling of the UV continuum and the UV broad emission-line variability. The correlation recovered in the next 42 days of the campaign, as Mrk 817 entered a less obscured state. The short C iv and Lyα lags suggest that the accretion disk extends beyond the UV broad-line region.


Author(s):  
M Lakićević ◽  
J Kovačević-Dojčinović ◽  
L Č Popović

Abstract The differences between Narrow Line Seyfert 1 galaxies (NLS1s) and Broad Line AGNs (BLAGNs) are not completely understood; it is thought that they may have different inclinations and/or physical characteristics. The FWHM(Hβ)–luminosities correlations are found for NLS1s and their origin is the matter of debate. Here we investigated the spectroscopic parameters and their correlations considering a dusty, cone model of AGN. We apply a simple conical dust distribution (spreading out of broad line region, BLR), assuming that the observed surface of the model is in a good correlation with MIR emission. The dusty cone model in combination with a BLR provides the possibility to estimate luminosity dependence on the cone inclination. The FWHM(Hβ)–luminosities correlations obtained from model in comparison with observational data show similarities which may indicate the influence of AGN inclination and structure to this correlation. An alternative explanation for FWHM(Hβ)–luminosities correlations is the selection effect by the black hole mass. These FWHM(Hβ)–luminosities correlations may be related to the starburst in AGNs, as well. The distinction between spectral properties of the NLS1s and BLAGNs could be caused by multiple effects: beside physical differencies between NLS1s and BLAGNs (NLS1s have lighter black hole mass than BLAGNs), inclination of the conical AGN geometry may have important role as well, where NLS1s may be seen in lower inclination angles.


Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 74
Author(s):  
Avinanda Chakraborty ◽  
Anirban Bhattacharjee ◽  
Suchetana Chatterjee

We perform an analysis of the properties of radio-loud (RL) and radio-quiet (RQ) quasars with MgII broad emission line (i-band magnitude ≤19.1 and z ≤1.9), selected from the parent sample of SDSS DR7 catalogue. For sources with full-width half maxima (FWHM) greater than 15,000 km s−1 (very broad line sample; VBL) we find the radio loud fraction (RLF) to be about 40%. To further investigate this result we compare the bolometric luminosity, optical continuum luminosity, black hole (BH) mass and Eddington ratios of our VBL sample of RL and RQ quasars. Our analysis shows that in our VBL sample space, RL quasars have higher luminosities and BH mass than RQ quasars. The similarity in the distribution of their covering fraction (CF) shows that there is no difference in dust distribution between VBL RL and RQ quasars and hence dust is not affecting our results. We also find that there is no correlation of RL quasar properties with optical continuum luminosity and BH mass.


2021 ◽  
Vol 920 (2) ◽  
pp. 112
Author(s):  
Misty C. Bentz ◽  
Peter R. Williams ◽  
Rachel Street ◽  
Christopher A. Onken ◽  
Monica Valluri ◽  
...  

2021 ◽  
Vol 920 (1) ◽  
pp. 9
Author(s):  
Sha-Sha Li ◽  
Sen Yang ◽  
Zi-Xu Yang ◽  
Yong-Jie Chen ◽  
Yu-Yang Songsheng ◽  
...  

Author(s):  
Dr. Chhagan Lal

Abstract: Rosacea is a common skin disorder that predominately affects fair skin people. More then10 million cases per year are found in the India. It usually presents with erythema, telangiectasia, and papulo-pustular lesions on the cheeks chin and central forehead and usually triggered by sun exposure. It is generally affects facial skin and less commonly may involve the neck and chest, it may also happen at non-facial sites. It has characterized in its early on phases by erythema (flushing and redness) on the central face and across the cheeks, nose or forehead. Rosacea is not mentioned specifically in any Ayurveda text. According to description of sign & symptoms of rosacea in modern science, it is resemble as a type of Pitta Dusht Raktaj Vyadhi according to Ayurveda science. Based on these signs and symptoms, according to Ayurveda Acharya this disease is caused by Pitta Dushta Rakta. Ayurveda also implements broad line of management of skin disorders like medicinal and para-surgical approach. Acharya Sushruta clearly mentioned that if all conservative management fails then the disease should consider as blood vitiated disease and Raktamokshana is to consider as choice of treatment. Keywords: Rosacea, Pitta Dusht Rakta, Vyadhi, Raktamokshana, para-surgical, erythema, Panchanimba Churna.


Author(s):  
C Martin Gaskell ◽  
Kayla Bartel ◽  
Julia N Deffner ◽  
Iris Xia

Abstract In the standard AGN reverberation-mapping model, variations in broad-line region (BLR) fluxes are predicted from optical continuum variability (taken as a proxy for the ionizing continuum) convolved with a response function that depends on the geometry. However, it has long been known that BLR variability can deviate from these predictions. We analyse both extensive long-term Hβ and continuum monitoring of NGC 5548 and a large sample of high-quality Hβ light curves of other AGNs to investigate the frequency and characteristics of anomalous responses of the BLR. We find that anomalies are very common and probably occur in every object. Onsets can be on a timescale only slightly longer than the light-crossing time and durations are of the order of the characteristic timescale of variability of the optical continuum to several times longer. Anomalies are larger when NGC 5548 is in a low state, but otherwise there is no correlation with continuum variability. There is abundant evidence for the optical continuum of AGNs varying independently of the higher-energy continua and this is sufficient to explain the anomalous responses of the total BLR flux. There are good reasons for believing that the frequent lack of correlation between spectral regions is due to anisotropic and non-axisymmetric emission. Rapid changes in line profiles and velocity-dependent lags are consistent with this. Motion of compact absorbing clouds across the line of sight is another possible cause of anomalies. The prevalence of anomalies should be considered when planning reverberation-mapping campaigns.


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