Institution
Columbus State Community College
Education•Columbus, Ohio, United States•
About: Columbus State Community College is a education organization based out in Columbus, Ohio, United States. It is known for research contribution in the topics: Galaxy & Mental health. The organization has 117 authors who have published 186 publications receiving 3536 citations. The organization is also known as: Columbus State & CSCC.
Topics: Galaxy, Mental health, Active galactic nucleus, Quasar, Milky Way
Papers published on a yearly basis
Papers
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TL;DR: The geologic history of the ANS during this period provides insight into the closing developmental stages of one of the world's largest accretionary orogens as mentioned in this paper, which is known as the Arabian-Nubian Shield (ANS).
563 citations
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TL;DR: It is demonstrated that Dvl3 is required for cardiac outflow tract development and its importance in the PCP pathway during neurulation and cochlea development and several developmental processes in which the three Dvls are functionally redundant are established.
Abstract: Dishevelled (Dvl) proteins are important signaling components of both the canonical beta-catenin/Wnt pathway, which controls cell proliferation and patterning, and the planar cell polarity (PCP) pathway, which coordinates cell polarity within a sheet of cells and also directs convergent extension cell (CE) movements that produce narrowing and elongation of the tissue. Three mammalian Dvl genes have been identified and the developmental roles of Dvl1 and Dvl2 were previously determined. Here, we identify the functions of Dvl3 in development and provide evidence of functional redundancy among the three murine Dvls. Dvl3(-/-) mice died perinatally with cardiac outflow tract abnormalities, including double outlet right ventricle and persistent truncus arteriosis. These mutants also displayed a misorientated stereocilia in the organ of Corti, a phenotype that was enhanced with the additional loss of a single allele of the PCP component Vangl2/Ltap (LtapLp/+). Although neurulation appeared normal in both Dvl3(-/-) and LtapLp/+ mutants, Dvl3(+/-);LtapLp/+ combined mutants displayed incomplete neural tube closure. Importantly, we show that many of the roles of Dvl3 are also shared by Dvl1 and Dvl2. More severe phenotypes were observed in Dvl3 mutants with the deficiency of another Dvl, and increasing Dvl dosage genetically with Dvl transgenes demonstrated the ability of Dvls to compensate for each other to enable normal development. Interestingly, global canonical Wnt signaling appeared largely unaffected in the double Dvl mutants, suggesting that low Dvl levels are sufficient for functional canonical Wnt signals. In summary, we demonstrate that Dvl3 is required for cardiac outflow tract development and describe its importance in the PCP pathway during neurulation and cochlea development. Finally, we establish several developmental processes in which the three Dvls are functionally redundant.
303 citations
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INAF1, Harvard University2, Netherlands Institute for Space Research3, National Autonomous University of Mexico4, University of Trieste5, Istituto Nazionale di Fisica Nucleare6, Roma Tre University7, Princeton University8, University of Colorado Boulder9, Columbus State Community College10, Ohio State University11, National Institute of Astrophysics, Optics and Electronics12, Columbia University13, National University of La Plata14
TL;DR: In this article, the authors reported observations of two absorbers of highly ionized oxygen (Ovii) in the high-signal-to-noise-ratio X-ray spectrum of a quasar at a redshift higher than 0.4.
Abstract: It has been known for decades that the observed number of baryons in the local Universe falls about 30–40 per cent short1,2 of the total number of baryons predicted
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by Big Bang nucleosynthesis, as inferred4,5 from density fluctuations of the cosmic microwave background and seen during the first 2–3 billion years of the Universe in the so-called ‘Lyman α forest’6,7 (a dense series of intervening H i Lyman α absorption lines in the optical spectra of background quasars). A theoretical solution to this paradox locates the missing baryons in the hot and tenuous filamentary gas between galaxies, known as the warm–hot intergalactic medium. However, it is difficult to detect them there because the largest by far constituent of this gas—hydrogen—is mostly ionized and therefore almost invisible in far-ultraviolet spectra with typical signal-to-noise ratios8,9. Indeed, despite large observational efforts, only a few marginal claims of detection have been made so far2,10. Here we report observations of two absorbers of highly ionized oxygen (O vii) in the high-signal-to-noise-ratio X-ray spectrum of a quasar at a redshift higher than 0.4. These absorbers show no variability over a two-year timescale and have no associated cold absorption, making the assumption that they originate from the quasar’s intrinsic outflow or the host galaxy’s interstellar medium implausible. The O vii systems lie in regions characterized by large (four times larger than average
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) galaxy overdensities and their number (down to the sensitivity threshold of our data) agrees well with numerical simulation predictions for the long-sought warm–hot intergalactic medium. We conclude that the missing baryons have been found.
189 citations
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TL;DR: In this article, the authors trace more than 40 years in the life of the active galactic nucleus (AGN) in a galaxy known as a classic Seyfert 1 galaxy and find that the activity in the nucleus of Mrk 590 has diminished so significantly that the continuum luminosity is a factor of 100 lower than the peak luminosity probed by long-baseline observations.
Abstract: We present multiwavelength observations that trace more than 40 yr in the life of the active galactic nucleus (AGN) in Mrk 590, traditionally known as a classic Seyfert 1 galaxy. From spectra recently obtained from Hubble Space Telescope, Chandra, and the Large Binocular Telescope, we find that the activity in the nucleus of Mrk 590 has diminished so significantly that the continuum luminosity is a factor of 100 lower than the peak luminosity probed by our long-baseline observations. Furthermore, the broad emission lines, once prominent in the UV/optical spectrum, have all but disappeared. Since AGN type is defined by the presence of broad emission lines in the optical spectrum, our observations demonstrate that Mrk 590 has now become a 'changing-look' AGN. If classified by recent optical spectra, Mrk 590 would be a Seyfert ∼1.9–2, where the only broad emission line still visible in the optical spectrum is a weak component of Hα. As an additional consequence of this change, we have definitively detected UV narrow-line components in a Type 1 AGN, allowing an analysis of these emission-line components with high-resolution COS spectra. These observations challenge the historical paradigm that AGN type is only a consequence of the line-of-sight viewing anglemore » toward the nucleus in the presence of a geometrically flattened, obscuring medium (i.e., the torus). Our data instead suggest that the current state of Mrk 590 is a consequence of the change in luminosity, which implies the black hole accretion rate has significantly decreased.« less
184 citations
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TL;DR: In this paper, the authors present multi-wavelength observations that trace more than 40 years in the life of the active galactic nucleus (AGN) in Mrk 590, traditionally known as a classic Seyfert 1 galaxy.
Abstract: We present multi-wavelength observations that trace more than 40 years in the life of the active galactic nucleus (AGN) in Mrk 590, traditionally known as a classic Seyfert 1 galaxy. From spectra recently obtained from HST, Chandra, and the Large Binocular Telescope, we find that the activity in the nucleus of Mrk 590 has diminished so significantly that the continuum luminosity is a factor of 100 lower than the peak luminosity probed by our long baseline observations. Furthermore, the broad emission lines, once prominent in the UV/optical spectrum, have all but disappeared. Since AGN type is defined by the presence of broad emission lines in the optical spectrum, our observations demonstrate that Mrk 590 has now become a "changing look" AGN. If classified by recent optical spectra, Mrk 590 would be a Seyfert ~1.9-2, where the only broad emission line still visible in the optical spectrum is a weak component of Halpha. As an additional consequence of this change, we have definitively detected UV narrow-line components in a Type 1 AGN, allowing an analysis of these emission-line components with high-resolution COS spectra. These observations challenge the historical paradigm that AGN type is only a consequence of the line of sight viewing angle toward the nucleus in the presence of a geometrically-flattened, obscuring medium (i.e., the torus). Our data instead suggest that the current state of Mrk 590 is a consequence of the change in luminosity, which implies the black hole accretion rate has significantly decreased.
171 citations
Authors
Showing all 117 results
Name | H-index | Papers | Citations |
---|---|---|---|
James A. Stewart | 46 | 144 | 9407 |
A. Gupta | 25 | 46 | 1963 |
Mark W. Schmeeckle | 25 | 52 | 2072 |
Bruce E. Massis | 12 | 44 | 361 |
Mahmood Karimi Abdolmaleki | 11 | 23 | 351 |
Nicole Evangelista Brandt | 10 | 15 | 632 |
Suk Jin Lee | 8 | 31 | 240 |
Janet D. Wagner | 8 | 12 | 240 |
Jennifer L. Brown | 7 | 27 | 156 |
Quentin B. Travis | 7 | 9 | 167 |
Nardos Lijam | 5 | 7 | 1287 |
David M. Sebert | 4 | 4 | 79 |
David Woolbright | 4 | 6 | 103 |
Kevin J. Hurt | 4 | 10 | 49 |
Virajanand Varma | 4 | 6 | 64 |