333 research outputs found

    Constraints on the broad line region from regularized linear inversion: Velocity-delay maps for five nearby active galactic nuclei

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    Reverberation mapping probes the structure of the broad emission-line region (BLR) in active galactic nuclei (AGN). The kinematics of the BLR gas can be used to measure the mass of the central supermassive black hole. The main uncertainty affecting black hole mass determinations is the structure of the BLR. We present a new method for reverberation mapping based on regularized linear inversion (RLI) that includes modelling of the AGN continuum light curves. This enables fast calculation of velocity-resolved response maps to constrain BLR structure. RLI allows for negative response, such as when some areas of the BLR respond in inverse proportion to a change in ionizing continuum luminosity. We present time delays, integrated response functions, and velocity-delay maps for the Hβ\rm{H}\,\beta broad emission line in five nearby AGN, as well as for Hα\rm{H}\,\alpha and Hγ\rm{H}\,\gamma in Arp 151, using data from the Lick AGN Monitoring Project 2008. We find indications of prompt response in three of the objects (Arp 151, NGC 5548 and SBS 1116+583A) with additional prompt response in the red wing of Hβ\rm{H}\,\beta. In SBS 1116+583A we find evidence for a multimodal broad prompt response followed by a second narrow response at 10 days. We find no clear indications of negative response. The results are complementary to, and consistent with, other methods such as cross correlation, maximum entropy and dynamical modelling. Regularized linear inversion with continuum light curve modelling provides a fast, complementary method for velocity-resolved reverberation mapping and is suitable for use on large datasets.Comment: 20 pages, 13 figures, accepted to MNRA

    The Ursinus Weekly: The College at War, June, 1943

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    The American college at war: America\u27s youngest dean of men shows how the college has geared itself to meet the needs of a nation at war • Lest we forget • The Navy at Ursinus • The 10 best stories of the Weekly, 1902-43 • Students in wartime • Ursinus: 1917 and 1943 • Servicemen\u27s directory • Professor for 50 yearshttps://digitalcommons.ursinus.edu/weekly/3104/thumbnail.jp

    Modeling reverberation mapping data II: dynamical modeling of the Lick AGN Monitoring Project 2008 dataset

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    We present dynamical modeling of the broad line region (BLR) for a sample of five Seyfert 1 galaxies using reverberation mapping data taken by the Lick AGN Monitoring Project in 2008. By modeling the AGN continuum light curve and Hβ\beta line profiles directly we are able to constrain the geometry and kinematics of the BLR and make a measurement of the black hole mass that does not depend upon the virial factor, ff, needed in traditional reverberation mapping analysis. We find that the geometry of the BLR is generally a thick disk viewed close to face-on. While the Hβ\beta emission is found to come preferentially from the far side of the BLR, the mean size of the BLR is consistent with the lags measured with cross-correlation analysis. The BLR kinematics are found to be consistent with either inflowing motions or elliptical orbits, often with some combination of the two. We measure black hole masses of log10(MBH/M)=6.620.13+0.10\log_{10}(M_{\rm\,BH}/M_\odot)=6.62^{+0.10}_{-0.13} for Arp 151, 7.420.27+0.267.42^{+0.26}_{-0.27} for Mrk 1310, 7.510.14+0.237.51^{+0.23}_{-0.14} for NGC 5548, 6.420.18+0.246.42^{+0.24}_{-0.18} for NGC 6814, and 6.990.25+0.326.99^{+0.32}_{-0.25} for SBS 1116+583A. The ff factors measured individually for each AGN are found to correlate with inclination angle, although not with MBHM_{\rm\,BH}, L5100L_{5100}, or FWHM/σ\sigma of the emission line profile.Comment: 21 pages, 24 figures, 3 tables, Accepted for publication in MNRAS, corrected masses for NGC 5548 and NGC 6814 in the abstrac

    The Ursinus Weekly, July 13, 1942

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    Freshmen rally in extra frame to knot series • Deferment ratings further changed to favor students • Sixty city slickers attend barn dance in Freeland hayloft • Twelve-week summer term opens with enrollment of 137 students • Ursinus health program features touch football during third full week • College host to 135 at 5-day conference • Two Ursinus couples recently married; three pairs engaged • Men\u27s tennis tourney to begin this week • Collapsed editors cut Weekly to fit short summer term • First chapel service to be held Wednesday • Out-door vespers program on theme of rededicationhttps://digitalcommons.ursinus.edu/weekly/1789/thumbnail.jp

    Audio Event Detection using Weakly Labeled Data

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    Acoustic event detection is essential for content analysis and description of multimedia recordings. The majority of current literature on the topic learns the detectors through fully-supervised techniques employing strongly labeled data. However, the labels available for majority of multimedia data are generally weak and do not provide sufficient detail for such methods to be employed. In this paper we propose a framework for learning acoustic event detectors using only weakly labeled data. We first show that audio event detection using weak labels can be formulated as an Multiple Instance Learning problem. We then suggest two frameworks for solving multiple-instance learning, one based on support vector machines, and the other on neural networks. The proposed methods can help in removing the time consuming and expensive process of manually annotating data to facilitate fully supervised learning. Moreover, it can not only detect events in a recording but can also provide temporal locations of events in the recording. This helps in obtaining a complete description of the recording and is notable since temporal information was never known in the first place in weakly labeled data.Comment: ACM Multimedia 201

    The Ursinus Weekly, March 29, 1943

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    Naval forces call for senior women to join reserves • College band to play for Mardi Gras fete, planned as soph hop • Sheeder and Pancoast will supervise Army, Navy qualifying examinations • Rader scores hit at spring formal • Cub and Key picks 5 men in annual prom tapping • Lobbyist to speak for federal union • New war bond drive initiated to buy jeep • Freshman starlets gain plaudits with dramatic mystery • Y to sponsor fools\u27 frolic • Negro men to lead vespers • Pre-med group to see movie • Nancy Landis elected May queen • IRC discusses Pacific war at meeting Tuesday evening • Wentzel will speak • Chemists to hear Schonfeld • Once-beaten coeds close 1943 season with easy 28-19 victory at Rosemont • Thirty-two will fight it out in boxing and wrestling bill • Harrington ends year with 17-point average • Sinclair leads Highland to 20-0 shutout Tuesday • Thumbnail sketches of the girls\u27 varsity squad • Jayvees subdue Rosemont with lop-sided triumph • Minister stresses sympathetic liveshttps://digitalcommons.ursinus.edu/weekly/1758/thumbnail.jp

    Pressure Modulator Radiometer (PMR) tests

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    The pressure modulator technique was evaluated for monitoring pollutant gases in the Earth's atmosphere of altitude levels corresponding to the mid and lower troposphere. Using an experimental set up and a 110 cm sample cell, pressure modulator output signals resulting from a range of gas concentrations in the sample cell were examined. Then a 20 cm sample cell was modified so that trace gas properties in the atmosphere could be simulated in the laboratory. These gas properties were measured using an infrared sensor

    Extending the calibration of C IV-based single-epoch black hole mass estimators for active galactic nuclei

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    We provide an updated calibration of C iv broad emission line–based single-epoch (SE) black hole (BH) mass estimators for active galactic nuclei (AGNs) using new data for six reverberation-mapped AGNs at redshift with BH masses (bolometric luminosities) in the range ( erg s−1). New rest-frame UV-to-optical spectra covering 1150–5700 Å for the six AGNs were obtained with the Hubble Space Telescope (HST). Multicomponent spectral decompositions of the HST spectra were used to measure SE emission-line widths for the C iv, Mg ii, and Hβ lines, as well as continuum luminosities in the spectral region around each line. We combine the new data with similar measurements for a previous archival sample of 25 AGNs to derive the most consistent and accurate calibrations of the C iv-based SE BH mass estimators against the Hβ reverberation-based masses, using three different measures of broad-line width: full width at half maximum (FWHM), line dispersion (), and mean absolute deviation (MAD). The newly expanded sample at redshift covers a dynamic range in BH mass (bolometric luminosity) of ( erg s−1 ), and we derive the new C iv-based mass estimators using a Bayesian linear regression analysis over this range. We generally recommend the use of or MAD rather than FWHM to obtain a less biased velocity measurement of the C iv emission line, because its narrow-line component contribution is difficult to decompose from the broad-line profile
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