1,723,706 research outputs found
Testing Reverberation Models in NGC 5506
No full textData associated with analysis of XMM-Newton data testing reverberation models in the active nucleus of the galaxy NGC 5506.
More Description is available in github: https://zoghbi-a.github.io/Testing-Reverberation-In-NGC5506/
The article can be found here: https://arxiv.org/abs/2003.0432
Testing Reverberation Models in NGC 5506
No full textData associated with analysis of XMM-Newton data testing reverberation models in the active nucleus of the galaxy NGC 5506.
More Description is available in github: https://zoghbi-a.github.io/Testing-Reverberation-In-NGC5506/
The article can be found here: https://arxiv.org/abs/2003.0432
NGC 5506 unmasked as a Narrow Line Seyfert 1:
No full textThis letter presents incontrovertible evidence that NGC 5506 is a
Narrow Line Seyfert 1 (NLSy1).
Our new 0.9–1.4 μm spectrum of its nucleus clearly shows the
permitted \ion{O}{I}
m line (with full width at half maximum <2000 km s-1)
and the “1 micron \ion{Fe}{II} lines”.
These lines can only originate in the optically-thick broad line region
(BLR) and, among Seyfert nuclei the latter series of lines are seen
only in NLSy1s.
The obscuration to the BLR, derived from a rough estimate of the
\ion{O}{I}
m/\ion{O}{I}
8446 ratio
and from the reddening of the near-IR Paschen lines, is .
Together, these results make NGC 5506 the first identified case of
an optically-obscured NLSy1.
This new classification helps explain its radio to X-ray properties, which
until now were considered highly anomalous.
However, interesting new concerns are raised: e.g., NGC 5506 is unusual in
hosting both a “type 1” AGN and a nuclear water vapor megamaser.
As the brightest known NLSy1, NGC 5506 is highly suitable for study at
wavebands less affected by obscuration
Long slit spectroscopy of NGC 5506
Get PDFThe galaxy NGC 5506 hosts an active nucleus, that presents characteristics that are intermediate between Sy1 and Sy2. We discuss long slit spectra of NGC 5506 in the ranges 4675-5475 A and 6300-7125 A, that were obtained at three different position angles, in Apr. 1991 at the WHT 4.2 m telescope. The peculiar kinematics of the emitting gas has already been observed by other researchers; following the model proposed by the other researchers, that the emitting gas is located in two cones, we determined the aperture of the cones. The data, moreover, support the hypothesis that the gas is receding from the nucleus. We modelled the intensity and the ratios of the emission lines, and verified that the active nucleus of NGC 5506 can be described as a Sy1 nucleus, with the UV-X source that is partially obscured to our line of sight. On the contrary, a good fraction of the interstellar gas of the galaxy is directly illuminated and photoionized by the central source. Our data show evidence of star formation close to the nucleus; we estimated the star formation rate, that is high with respect to 'normal' spirals, but not high enough to be comparable to star formation rates in a starburst galaxy
AGN feedback in the Local Universe: Multiphase outflow of the Seyfert galaxy NGC 5506
Get PDFWe present new optical GTC/MEGARA seeing-limited (0.9″) integral-field observations of NGC 5506, together with ALMA observations of the CO(3 − 2) transition at a 0.2″ (∼25 pc) resolution. NGC 5506 is a luminous (bolometric luminosity of ∼1044 erg s−1) nearby (26 Mpc) Seyfert galaxy, part of the Galaxy Activity, Torus, and Outflow Survey (GATOS). We modelled the CO(3 − 2) kinematics with 3DBAROL
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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