On 2019/07/30.86853 UT, IceCube detected a high-energy astrophysical neutrino can-didate. The Flat Spectrum Radio Quasar PKS 1502+106 is located within the 50 percent uncertainty region of the event. ...Our analysis of 15 GHz Very Long Baseline Ar-ray (VLBA) and astrometric 8 GHz VLBA data, in a time span prior and after theIceCube event, reveals evidence for a radio ring structure which develops with time.Several arc-structures evolve perpendicular to the jet ridge line. We find evidence forprecession of a curved jet based on kinematic modelling and a periodicity analysis.An outflowing broad line region (BLR) based on the C IV line emission (Sloan Dig-ital Sky Survey, SDSS) is found. We attribute the atypical ring to an interaction ofthe precessing jet with the outflowing material.We discuss our findings in thecontext of a spine-sheath scenario where the ring reveals the sheath andits interaction with the surroundings (NLR clouds).We find that the radioemission is correlated with theγ-ray emission, with radio lagging theγ-rays. Basedon theγ-ray variability timescale, we constrain theγ-ray emission zone to the BLR(30-200rg) and within the jet launching region. We discuss that the outflowing BLRprovides the external radiation field forγ-ray production via external Compton scat-tering.The neutrino is most likely produced by proton-proton interactionin the blazar zone (beyond the BLR), enabled by episodic encounters ofthe jet with dense clouds, i.e. some molecular cloud in the NLR.
ABSTRACT We present an analysis of 43 years (1972 to 2015) of spectroscopic observations of the Seyfert 1 galaxy NGC 5548. This includes 12 years of new unpublished observations (2003 to 2015). We ...compiled about 1600 Hβ spectra and analyzed the long-term spectral variations of the 5100 continuum and the Hβ line. Our analysis is based on standard procedures, including the Lomb-Scargle method, which is known to be rather limited to such heterogeneous data sets, and a new method developed specifically for this project that is more robust and reveals a ∼5700 day periodicity in the continuum light curve, the Hβ light curve, and the radial velocity curve of the red wing of the Hβ line. The data are consistent with orbital motion inside the broad emission line region of the source. We discuss several possible mechanisms that can explain this periodicity, including orbiting dusty and dust-free clouds, a binary black hole system, tidal disruption events, and the effect of an orbiting star periodically passing through an accretion disk.
One of the most intriguing scenarios proposed to explain how active galactic nuclei are triggered involves the existence of a supermassive binaiy black hole (BH) system in their cores. Here, we ...present an observational evidence for the first spectroscopically resolved sub-parsec orbit of a such system in the core of Seyfert galaxy NGC 4151. Using a method similar to those typically used for spectroscopic binaiy stars, we obtained radial velocity curves of the supermassive binary system, from which we calculated orbital elements and made estimates about the masses of the components. Our analysis shows that periodic variations in the light and radial velocity curves can be accounted for by an eccentric, sub-parsec Keplerian orbit with a 15.9 year period. The flux maximum in the light curve corresponds to the approaching phase of the secondaiy component toward the observer. According to the obtained results, we speculate that the periodic variations in the observed H alpha line shape and flux are due to shock waves generated by the supersonic motion of the components through the surrounding medium. Given the large observational effort needed to reveal this spectroscopically resolved binary orbital motion, we suggest that many such systems may exist in similar objects even if they are hard to find. Detecting more of them will provide us with insight into the BH mass growth process.
According to the DSM-5, “reduction in the need for sleep” is the only sleep-related criteria for mixed features in depressive episodes. We aimed at studying the prevalence, clinical correlates and ...the role of hypersomnia in a sample of acutely depressed patients. Secondarily, we factors significantly increasing the odds of hypersomnia were studied. We conducted a post-hoc analysis of the BRIDGE-II-Mix study. Variables were compared between patients with hypersomnia (SLEEP+) and with insomnia (SLEEP−) with standard bivariate tests. A stepwise backward logistic regression model was performed with SLEEP+ as dependent variable. A total of 2514 subjects were dichotomized into SLEEP+ (n = 423, 16.8%) and SLEEP− (n = 2091, 83.2%). SLEEP+ had significant higher rates of obese BMI (p < 0.001), BD diagnosis (p = 0.027), severe BD (p < 0.001), lifetime suicide attempts (p < 0.001), lower age at first depression (p = 0.004) than SLEEP−. Also, SLEEP+ had significantly poorer response to antidepressants (AD) such as (hypo)manic switches, AD resistance, affective lability, or irritability (all 0<0.005). Moreover, SLEEP+ had significantly higher rates of mixed-state specifiers than SLEEP- (all 0 < 0.006). A significant contribution to hypersomnia in our regression model was driven by metabolic-related features, such as “current bulimia” (OR = 4.21) and “overweight/obese BMI (OR = 1.42)”. Globally, hypersomnia is associated with poor outcome in acute depression. Hypersomnia is strongly associated with mixed features and bipolarity. Metabolic aspects could influence the expression of hypersomnia, worsening the overall clinical outcome. Along with commonly used screening tools, detection of hypersomnia has potential, costless discriminative validity in the differential diagnosis unipolar and bipolar depression.
We present the results of a long-term (1999-2010) spectral optical monitoring campaign of the active galactic nucleus (AGN) Ark 564, which shows a strong Fe II line emission in the optical. This AGN ...is a narrow-line Seyfert 1 (NLS1) galaxy, a group of AGNs with specific spectral characteristics. We analyze the light curves of the permitted H alpha , H beta , optical Fe II line fluxes, and the continuum flux in order to search for a time lag between them. Additionally, in order to estimate the contribution of iron lines from different multiplets, we fit the H beta and Fe II lines with a sum of Gaussian components. We find that during the monitoring period the spectral variation (F sub(max)/F sub(min)) of Ark 564 is between 1.5 for H alpha and 1.8 for the Fe II lines. The correlation between the Fe II and H beta flux variations is of higher significance than that of He alpha and H beta (whose correlation is almost absent). The permitted-line profiles are Lorentzian-like and do not change shape during the monitoring period. We investigate, in detail, the optical Fe ii emission and find different degrees of correlation between the Fe II emission arising from different spectral multiplets and the continuum flux. The relatively weak and different degrees of correlations between permitted lines and continuum fluxes indicate a rather complex source of ionization of the broad-line emission region.
Objective
To evaluate aggressiveness during a major depressive episode (MDE) and its relationship with bipolar disorder (BD) in a post hoc analysis of the BRIDGE‐II‐MIX study.
Method
A total of 2811 ...individuals were enrolled in this multicenter cross‐sectional study. MDE patients with (MDE‐A, n = 399) and without aggressiveness (MDE‐N, n = 2412) were compared through chi‐square test or Student's t‐test. A stepwise backward logistic regression model was performed.
Results
MDE‐A group was more frequently associated with BD (P < 0.001), while aggressiveness was negatively correlated with unipolar depression (P < 0.001). At the logistic regression, aggressiveness was associated with the age at first depressive episode (P < 0.001); the severity of mania (P = 0.03); the diagnosis of BD (P = 0.001); comorbid borderline personality disorder (BPD) (P < 0.001) but not substance abuse (P = 0.63); no current psychiatric treatment (P < 0.001); psychotic symptoms (P = 0.007); the marked social/occupational impairment (P = 0.002). The variable most significantly associated with aggressiveness was the presence of DSM‐5 mixed features (P < 0.001, OR = 3.815). After the exclusion of BPD, the variable of lifetime suicide attempts became significant (P = 0.013, OR = 1.405).
Conclusion
Aggressiveness seems to be significantly associated with bipolar spectrum disorders, independently from BPD and substance abuse. Aggressiveness should be considered as a diagnostic criterion for the mixed features specifier and a target of tailored treatment strategy.
Context. Some Type-1 active galactic nuclei (AGN) show extremely asymmetric Balmer lines with the broad peak redshifted or blueshifted by thousands of km s−1. These AGN may be good candidates for ...supermassive binary black holes (SMBBHs). The complex line shapes can be due to the complex kinematics of the two broad line regions (BLRs). Therefore other methods should be applied to confirm the SMBBHs. One of them is spectropolarimetry. Aims. We rely on numerical modeling of the polarimetry of binary black holes systems, since polarimetry is highly sensitive to geometry, in order to find the specific influence of supermassive binary black hole (SMBBH) geometry and dynamics on polarized parameters across the broad line profiles. We apply our method to SMBBHs in which both components are assumed to be AGN with distances at the subparsec scale. Methods. We used a Monte Carlo radiative transfer code that simulates the geometry, dynamics, and emission pattern of a binary system where two black holes are getting increasingly close. Each gravitational well is accompanied by its own BLR and the whole system is surrounded by an accretion flow from the distant torus. We examined the emission line deformation and predicted the associated polarization that could be observed. Results. We modeled scattering-induced broad line polarization for various BLR geometries with complex kinematics. We find that the presence of SMBBHs can produce complex polarization angle profiles φ and strongly affect the polarized and unpolarized line profiles. Depending on the phase of the SMBBH, the resulting double-peaked emission lines either show red or blue peak dominance, or both the peaks can have the same intensity. In some cases, the whole line profile appears as a single Gaussian line, hiding the true nature of the source. Conclusions. Our results suggest that future observation with the high resolution spectropolarimetry of optical broad emission lines could play an important role in detecting subparsec SMBBHs.
Abstract
In this paper, we present the long-term optical spectral monitoring of a changing-look active galactic nucleus (AGN), NGC 3516, covering 22 yr (from 1996 to 2018). We explore a variability ...in the broad lines and continuum, finding that the continuum is changing by more than a factor of 2, while the broad lines are varying by more than a factor of 10. The minimum of activity is observed in 2014, when the broad lines almost disappeared. We confirm that NGC 3516 is a changing-look AGN, and the absorption seen in the ultraviolet and X-ray may indicate that there is an obscuring region that is responsible for this. The line profiles are also changing. The mean profiles of the broad Hα and Hβ lines show a shoulder-like structure in the wings, and an enhanced peak, which could indicate a complex broad-line region. The rms profiles of both lines seem to have the same shape and width, of around 4200 km s−1, indicating practically the same kinematics in the Hα and Hβ emitting regions. Measured time-lags between the continuum and Hα and Hβ broad-line variability are ∼15 and 17 d, respectively. In combination with the broad-line width, these measurements allow us to estimate the central black hole mass of NGC 3516. We find that the black hole mass is (4.73 ± 1.40) × 107M⊙ which is in agreement with previous estimates.
Aims. Results of long-term spectral monitoring of the active galactic nucleus of NGC 4151 are presented (11 years, from 1996 to 2006). Methods. High quality spectra (S / N >50 in the continuum near ...H\alpha and H\beta) were obtained in the spectral range similar to 4000 to 7500 Aa, with a resolution between 5 and 15 Aa, using the 6-m and the 1-m SAO's telescopes (Russia), the GHAO's 2.1-m telescope (Cananea, Mexico), and the OAN-SPM's 2.1-m telescope (San-Pedro, Mexico). The observed fluxes of the H\alpha, H\beta, H\gamma, and HeII\lambda4686 emission lines and of the continuum at the observed wavelength 5117 Aa were corrected for the position angle, the seeing, and the aperture effects. Results. We found that the continuum and line fluxes varied strongly (up to a factor 6) during the monitoring period. The emission was maximum in 1996-1998, and there were two minima in 2001 and in 2005. As a consequence, the spectral type of the nucleus changed from a Sy1.5 in the maximum activity state to a Sy1.8 in the minimum state. The H\alpha, H\gamma, and He\lambda4686 fluxes correlated well with the H\beta flux. The line profiles were strongly variable, showing changes of the blue and red asymmetry. The flux ratios of the blue/red wings and of the blue (or red) wing/core of H\alpha and H\beta varied differently. We considered three characteristic periods during which the H\beta and H\alpha profiles were similar: 1996-1999, 2000- 2001, and 2002-2006. The line-to-continuum flux ratios were different; in particular during the first period (1996-1999), the lines were not correlated with the continuum and saturated at high fluxes. In the second and third periods (2000-2006), where the continuum flux was small, the H\alpha and H\beta fluxes were well correlated to the continuum flux, meaning that the ionizing continuum was a good extrapolation of the optical continuum. The CCFs are often asymmetrical and the time lags between the lines and the continuum are badly defined, indicating the presence of a complex BLR, with dimensions from 1 to 50 light-days. Conclusions. We discuss the different responses of H\beta and H\alpha to the continuum during the monitoring period.
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