What Does the Geometry of the Hβ BLR Depend On? Villafaña, Lizvette; Williams, Peter R.; Treu, Tommaso ...
Astrophysical journal/The Astrophysical journal,
05/2023, Letnik:
948, Številka:
2
Journal Article
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Abstract
We combine our dynamical modeling black-hole mass measurements from the Lick AGN Monitoring Project 2016 sample with measured cross-correlation time lags and line widths to recover ...individual scale factors,
f
, used in traditional reverberation-mapping analyses. We extend our sample by including prior results from Code for AGN Reverberation and Modeling of Emission Lines (
caramel
) studies that have utilized our methods. Aiming to improve the precision of black-hole mass estimates, as well as uncover any regularities in the behavior of the broad-line region (BLR), we search for correlations between
f
and other AGN/BLR parameters. We find (i) evidence for a correlation between the virial coefficient
log
10
(
f
mean
,
σ
)
and black-hole mass, (ii) marginal evidence for a similar correlation between
log
10
(
f
rms
,
σ
)
and black-hole mass, (iii) marginal evidence for an anticorrelation of BLR disk thickness with
log
10
(
f
mean
,
FWHM
)
and
log
10
(
f
rms
,
FWHM
)
, and (iv) marginal evidence for an anticorrelation of inclination angle with
log
10
(
f
mean
,
FWHM
)
,
log
10
(
f
rms
,
σ
)
, and
log
10
(
f
mean
,
σ
)
. Last, we find marginal evidence for a correlation between line-profile shape, when using the root-mean-square spectrum,
log
10
(
FWHM
/
σ
)
rms
, and the virial coefficient,
log
10
(
f
rms
,
σ
)
, and investigate how BLR properties might be related to line-profile shape using
caramel
models.
Dynamical black hole mass measurements in some gas-rich galaxy mergers indicate that they are overmassive relative to their host galaxy properties. Overmassive black holes in these systems present a ...conflict with the standard progression of galaxy merger-quasar evolution; an alternative explanation is that a nuclear concentration of molecular gas driven inward by the merger is affecting these dynamical black hole mass estimates. We test for the presence of such gas near the two black holes in NGC 6240 using long-baseline ALMA Band 6 observations (beam size 0 06 × 0 03 or 30 pc × 15 pc). We find (4.2-9.8) × 107 M☉ and (1.2-7.7) × 108 M☉ of molecular gas within the resolution limit of the original black hole mass measurements for the north and south black holes, respectively. In the south nucleus, this measurement implies that 6%-89% of the original black hole mass measurement actually comes from molecular gas, resolving the tension in the original black hole scaling relations. For the north, only 5%-11% is coming from molecular gas, suggesting the north black hole is actually overmassive. Our analysis provides the first measurement of significant molecular gas masses contaminating dynamical black hole mass measurements. These high central molecular gas densities further present a challenge to theoretical black hole accretion prescriptions, which often assume accretion proceeds rapidly through the central 10 pc.
The PlGF (placental growth factor) has been largely demonstrated to be associated with the diagnosis of the hypertensive disorders of pregnancy (HDPs); however, it is unclear how useful it is for the ...prognosis of the condition. Our objective was to provide a summary of important findings of its prognostic ability by systematically reviewing studies that examined the ability of the PlGF, either independently or combined with other factors, to predict maternal and fetal complications resulting from the HDPs. We included studies published before January 30, 2017, reporting on the use of the PlGF as a prognostic test for women with confirmed HDPs or suspected preeclampsia. Of the 220 abstracts identified through MEDLINE, Embase, and CINAHL (Cumulative Index to Nursing and Allied Health Literature), 17 studies were eligible for our review. Prognostic performance was evaluated by sensitivity, specificity, likelihood ratios, and area under the receiver operating characteristic curve. PlGF showed moderate-to-high evidence (likelihood ratios of ≥5 or ≤0.2 or area under the receiver operating characteristic curves ≥0.70) for identifying women at the highest risk of preterm delivery or neonatal outcomes (10/12 studies) but showed no clinically useful performance for the prediction of adverse maternal outcomes. PlGF may aid in the management of women with HDPs to avert fetal complications. Future studies should determine an optimum threshold for the marker to guide delivery and should examine whether its use for predicting adverse maternal outcomes in women with HDPs can be improved.
We present near-infrared integral field spectroscopy of the central kiloparsec of 17 nearby luminous and ultra-luminous infrared galaxies undergoing major mergers. These observations were taken with ...OSIRIS assisted by the Keck I and II Adaptive Optics systems, providing spatial resolutions of a few tens of parsecs. The resulting kinematic maps reveal gas disks in at least 16 out of 19 nuclei and stellar disks in 11 out of 11 nuclei observed in these galaxy merger systems. In our late-stages mergers, these disks are young (stellar ages < 30 Myr) and likely formed as gas disks that became unstable to star formation during the merger. On average, these disks have effective radii of a few hundred parsecs, masses between 10 super(8) and 10 super(10) M sub(middot in circle), and v/sigma between 1 and 5. These disks are similar to those created in high-resolution hydrodynamical simulations of gas-rich galaxy mergers, and favor short coalescence times for binary black holes. The few galaxies in our sample in earlier stages of mergers have disks that are larger (r sub(eff) ~ 200-1800 pc) and are likely remnants of the galactic disks that have not yet been completely disrupted by the merger.
Abstract
We have modeled the velocity-resolved reverberation response of the H
β
broad emission line in nine Seyfert 1 galaxies from the Lick Active Galactic Nucleus (AGN) Monitoring Project 2016 ...sample, drawing inferences on the geometry and structure of the low-ionization broad-line region (BLR) and the mass of the central supermassive black hole. Overall, we find that the H
β
BLR is generally a thick disk viewed at low to moderate inclination angles. We combine our sample with prior studies and investigate line-profile shape dependence, such as
log
10
(
FWHM
/
σ
)
, on BLR structure and kinematics and search for any BLR luminosity-dependent trends. We find marginal evidence for an anticorrelation between the profile shape of the broad H
β
emission line and the Eddington ratio, when using the rms spectrum. However, we do not find any luminosity-dependent trends, and conclude that AGNs have diverse BLR structure and kinematics, consistent with the hypothesis of transient AGN/BLR conditions rather than systematic trends.
In low- and middle-income countries, approximately two thirds of maternal deaths occur in the postpartum period. Yet, care for women beyond 24 h after discharge is limited. The objective of this ...systematic review is to summarize current evidence on socio-demographic and clinical risk factors for (1) postpartum mortality and (2) postpartum hospital readmission.
A combination of keywords and subject headings (i.e. MeSH terms) for postpartum maternal mortality or readmission were searched. Articles published up to January 9, 2021 were identified in MEDLINE, EMBASE, and CINAHL databases, without language restrictions. Studies reporting socio-demographic or clinical risk factors for postpartum mortality or readmission within six weeks of delivery among women who delivered a livebirth in a low- or middle-income country were included. Data were extracted independently by two reviewers based on study characteristics, population, and outcomes. Included studies were assessed for quality and risk of bias using the Downs and Black checklist for ratings of randomized and non-randomized studies.
Of 8783 abstracts screened, seven studies were included (total N = 387,786). Risk factors for postpartum mortality included Caesarean mode of delivery, nulliparity, low or very low birthweight, and shock upon admission. Risk factors for postpartum readmission included Caesarean mode of delivery, HIV positive serostatus, and abnormal body temperature.
Few studies reported individual socio-demographic or clinical risk factors for mortality or readmission after delivery in low- and middle-income countries; only Caesarean delivery was consistently reported. Further research is needed to identify factors that put women at greatest risk of post-discharge complications and mortality. Understanding post-discharge risk would facilitate targeted postpartum care and reduce adverse outcomes in women after delivery.
PROSPERO registration number: CRD42018103955.
Abstract
We carried out spectroscopic monitoring of 21 low-redshift Seyfert 1 galaxies using the Kast double spectrograph on the 3 m Shane telescope at Lick Observatory from 2016 April to 2017 May. ...Targeting active galactic nuclei (AGNs) with luminosities of
λ
L
λ
(5100 Å) ≈ 10
44
erg s
−1
and predicted H
β
lags of ∼20–30 days or black hole masses of 10
7
–10
8.5
M
⊙
, our campaign probes luminosity-dependent trends in broad-line region (BLR) structure and dynamics as well as to improve calibrations for single-epoch estimates of quasar black hole masses. Here we present the first results from the campaign, including H
β
emission-line light curves, integrated H
β
lag times (8–30 days) measured against
V
-band continuum light curves, velocity-resolved reverberation lags, line widths of the broad H
β
components, and virial black hole mass estimates (10
7.1
–10
8.1
M
⊙
). Our results add significantly to the number of existing velocity-resolved lag measurements and reveal a diversity of BLR gas kinematics at moderately high AGN luminosities. AGN continuum luminosity appears not to be correlated with the type of kinematics that its BLR gas may exhibit. Follow-up direct modeling of this data set will elucidate the detailed kinematics and provide robust dynamical black hole masses for several objects in this sample.
Results of observations with the Spitzer, Hubble, GALEX, Chandra, and XMM-Newton space telescopes are presented for the luminous infrared galaxy (LIRG) merger Markarian 266. The SW (Seyfert 2) and NE ...(LINER) nuclei reside in galaxies with Hubble types SBb (pec) and S0/a (pec), respectively. Optical knots embedded in an arc with aligned radio continuum radiation, combined with luminous H sub(2) line emission, provide evidence for a radiative bow shock in an AGN-driven outflow surrounding the NE nucleus. A soft X-ray emission feature modeled as shock-heated plasma with T ~ 10 super(7) K is cospatial with radio continuum emission between the galaxies. Mid-infrared diagnostics provide mixed results, but overall suggest a composite system with roughly equal contributions of AGN and starburst radiation powering the bolometric luminosity. An evolutionary sequence is proposed representing a progression from dual to binary AGNs, accompanied by an increase in observed L sub(x)/L sub(ir) ratios by over two orders of magnitude.
Background Hypertensive disorders of pregnancy (HDP) are associated with an increased risk of premature cardiovascular disease (CVD), but existing cardiovascular prediction models do not adequately ...capture risks in young women. We developed a model to predict the 10-year risk of premature CVD and mortality among women who have HDP. Methods and Results Using a population-based cohort of women with HDP who delivered between April 1989 and March 2017 in Quebec, Canada, we developed a 10-year CVD risk model using Cox proportional hazards regression. Women aged 18 to 45 years were followed from their first HDP-complicated delivery until March 2018. We assessed performance of the model based on discrimination, calibration, and risk stratification ability. Internal validity was assessed using the bootstrap method. The cohort included 95 537 women who contributed 1 401 084 person-years follow-up. In total, 4024 (4.2%) of women were hospitalized for CVD, of which 1585 events (1.6%) occurred within 10 years of follow-up. The final model had modest discriminatory performance (area under the receiver operating characteristic curve, 0.66; 95% CI, 0.65-0.67) and good calibration with slope of 0.95 and intercept of -0.19. There was moderate classification accuracy (likelihood ratio+: 5.90; 95% CI, 5.01-6.95) in the highest-risk group upon risk stratification. Conclusions Overall, our model had modest performance in predicting the 10-year risk of premature CVD for women with HDP. We recommend the addition of clinical variables, and external validation, before consideration for clinical use.
ABSTRACT We explore the relationship between the spectral shape of the Ly emission and the UV morphology of the host galaxy using a sample of 304 Ly -emitting BVi-dropouts at 3 < z < 7 in the Great ...Observatories Origins Deep Survey and Cosmic Evolution Survey fields. Using our extensive reservoir of high-quality Keck DEIMOS spectra combined with Hubble Space Telescope WFC3 data, we measure the Ly line asymmetries for individual galaxies and compare them to axial ratios measured from observed J- and H-band (restframe UV) images. We find that the Ly skewness exhibits a large scatter at small elongation (a/b < 2), and this scatter decreases as the axial ratio increases. Comparison of this trend to radiative transfer models and various results from the literature suggests that these high-redshift Ly emitters are not likely to be intrinsically round and symmetric disks, but they probably host galactic outflows traced by Ly emitting clouds. The ionizing sources are centrally located, and the optical depth is a good indicator of the absorption and scattering events on the escape path of Ly photons from the source. Our results find no evidence of evolution in Ly asymmetry or axial ratio with look-back time.
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