1,724,389 research outputs found
Broadband spectral investigations of SGRJ1550−5418 bursts
Get PDFWe present the results of our broadband (0.5−200 keV) spectral analysis of 42 SGRJ1550−5418 bursts simultaneously detected with the Swift/X-ray Telescope (XRT) and the Fermi/Gammaray Burst Monitor (GBM), during the 2009 January active episode of the source. We find that, on average, the burst spectra are better described with two blackbody functions than with the Comptonized model. Thus, our joint XRT/GBM analysis clearly shows for the first time that the
SGRJ1550−5418 burst spectra might naturally be expected to exhibit a more truly thermalized character, such as a two-blackbody or even a multi-blackbody signal. We also studied the spin phase of the XRT burst emission, which indicate that the burst emitting sites on the neutron star need not to be co-located with hot spots emitting the bulk of the persistent X-ray emission
and the surface magnetic field of SGRJ1550−5418 is likely non-uniform over the emission zone
SGR J1550-5418 magnetron data
No full text<p>data set for the magnetron project: light curves from SGR J1550-5418 and posterior samples from using DNest3 and RJObject to fit a model with a variable number of simple shapes to the light curves.</p
Block Card 5418 Ruth Avenue
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: End Gabled | Folk House Style | Dwelling | Oakmont Addition (Toledo, Ohio) | Trilby Area (Toledo, Ohio)) | 5418 Ruth Avenue (Toledo, Ohio
Broadband spectral investigations of SGR J1550-5418 bursts
Get PDFWe present the results of our broadband spectral analysis of 42 SGR J1550-5418 bursts simultaneously detected with the Swift/X-ray Telescope (XRT) and the Fermi/Gamma-ray Burst Monitor (GBM), during the 2009 January active episode of the source. The unique spectral and temporal capabilities of the XRT windowed timing mode have allowed us to extend the GBM spectral coverage for these events down to the X-ray domain (0.5-10 keV). Our earlier analysis of the GBM data found that the SGR J1550-5418 burst spectra were described equally well with either a Comptonized model or with two blackbody functions; the two models were statistically indistinguishable. Our new broadband (0.5-200 keV) spectral fits show that, on average, the burst spectra are better described with two blackbody functions than with the Comptonized model. Thus, our joint XRT-GBM analysis clearly shows for the first time that the SGR J1550-5418 burst spectra might naturally be expected to exhibit a more truly thermalized character, such as a two-blackbody or even a multi-blackbody signal. Using the Swift and RXTE timing ephemeris for SGR J1550-5418 we construct the distribution of the XRT burst counts with spin phase and find that it is not correlated with the persistent X-ray emission pulse phase from SGR J1550-5418. These results indicate that the burst emitting sites on the neutron star need not to be co-located with hot spots emitting the bulk of the persistent X-ray emission. Finally, we show that there is a significant pulse phase dependence of the XRT burst counts, likely demonstrating that the surface magnetic field of SGR J1550-5418 is not uniform over the emission zones, since it is anticipated that regions with stronger surface magnetic field could trigger bursts more efficiently
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The new SGR 1550-5418 is the old AXP 1E1547.0-5408
No full textSwift-BAT triggered today on several Galactic short bursts (Krimm et al. GCN 8311, 8312), which were claimed to come from a new Soft Gamma Repeater SGR 1550-5418. However, given the positional coincidence of this new putative SGR 1550-5418 with the Anomalous X-ray Pulsar (AXP) 1E1547.0-5408 (Gelfand & Gaensler 2007; Camilo et al. 2008; Halpern et al. 2008), and the enhanced X-ray flux observed from promptly downlinked XRT data of this source (Krimm et al. 8311), we now identify the source of these bursts being the AXP 1E1547.0-5408
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Log-Gaussian Distribution and Evolution of Minimum Variation Timescales for SGR J1550-5418
No full textThe major observation of the X-ray burst (XRB) in association with the fast radio burst (FRB) FRB 200428 originating from SGR J1935+2154 on 2020 April 28 substantiates magnetars as one of the origins of FRBs. However, it is still unclear why only a few XRBs in association with FRBs have been observed solely in this magnetar. In this study, we investigate the minimum variation timescales (MVTs) of XRBs from SGR J1550-5418, an active magnetar similar to SGR J1935+2154, and conduct a comprehensive comparison of their MVT properties. Our analysis reveals that the distribution of the MVT for SGR J1550-5418 follows a lognormal Gaussian function with the mean 6.4 ± 0.4 ms. Interestingly, we detect an evolution in the MVTs, i.e., the fitted mean of the MVT distribution in 2008 October is about 3 times larger than that in 2009, indicating potential variations in radiation regions possibly attributed to changes in magnetic field topology. Besides, we do not find a significant correlation between the MVT and either duration or energy. Finally, there is no significant difference between the MVT distributions across different energy ranges for SGR J1550-5418 and SGR J1935+2154, which supports a common physical origin
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