1,724,919 research outputs found
New York Central (NYC) #4904
No full textA 3 x 6 photograph print showing the New York Central, #4904, 4-6-2 (Schenectady), builder's photo. [Specs documented on photo border] [Sylvan Rupert Wood print
X-shooter spectroscopy of the puzzling gamma-ray source 3FGL1603.9-4903/PMN J1603-4904
No full textThe Fermi/LAT instrument has detected about two thousand extragalactic high energy (E > 100 MeV) gamma-ray sources. 3FGL 1603.9-4903 is a very hard and bright one and it is associated to the radio source PMN J1603-4904.
Its nature is not yet clear as it could be either a very peculiar BL Lac or a compact symmetric object radio source which are considered as the early stage of a radio galaxy. The latter, if confirmed, would be the first detection in gamma-rays for this class of objects.
A redshift z=0.18 +/- 0.01 has recently been claimed on the basis of the detection of a single X-ray line at 5.44 +/- 0.05 keV
which has been interpreted as a 6.4 keV (rest frame) fluorescent line.
We observed PMN J1603-4904 with the UV-NIR VLT/X-shooter spectrograph for two hours. We extracted spectra in the visible and NIR range that we calibrated in flux and corrected for telluric
absorption. We systematically searched for absorption and emission features. The source was detected
starting from ~ 6300 Ang down to 24000 Ang with an intensity similar to that of its 2MASS counterpart and a mostly featureless spectrum. The continuum lacks absorption features and thus is non-stellar in origin and most likely non-thermal. In addition to this spectrum, we detected three emission lines that we interpret as the Halpha-[NII] complex, the [SII] 6716,6731 doublet and the [SIII] 9530 line; we obtain a redshift estimate of z= 0.2321 +/- 0.0004.
The line ratios suggest that a LINER/Seyfert nucleus powers the emission. This new redshift measurement implies that the X-ray line previously detected should be interpreted as a 6.7 keV line which is very peculiar but not impossible for this kind of source
Investigating source confusion in PMN J1603-4904
No full textPMN J1603–4904 is a likely member of the rare class of γ-ray emitting young radio galaxies. Only one other source, PKS 1718–649, has been confirmed so far. These objects, which may transition into larger radio galaxies, are a stepping stone to understanding AGN evolution. It is not completely clear how these young galaxies, seen edge-on, can produce high-energy γ rays. PMN J1603–4904 has been detected by TANAMI Very Long Baseline Interferometry (VLBI) observations and has been followed-up with multiwavelength observations. A Fermi Gamma-ray Space Telescope Large Area Telescope (Fermi-LAT) γ-ray source has been associated with this young galaxy in the LAT catalogs. We have obtained Chandra observations of the source to consider the possibility of source confusion due to the relatively large positional uncertainty of Fermi-LAT. The goal was to investigate the possibility of other X-ray bright sources in the vicinity of PMN J1603–4904 that could be counterparts to the γ-ray emission. With Chandra/ACIS, we find no other sources in the uncertainty ellipse of Fermi-LAT data, which includes an improved localization analysis of eight years of data. We further study the X-ray fluxes and spectra. We conclude that PMN J1603–4904 is indeed the second confirmed γ-ray bright young radio galaxy
Block Card 4904 Hill 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: barns | Reynolds Corners Area (Toledo, Ohio) | 4904 Hill Avenue (Toledo, Ohio
Block Card 4904 Oakridge Drive
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: Ranch houses | Dwelling | 4904 Oakridge Drive (Toledo, Ohio) | Secor Woods Addition (Toledo, Ohio) | Trilby Area (Toledo, Ohio)) | West Toledo Area (Toledo, Ohio
Block Card 4904 Elmhurst Road
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: Ranch Style | Dwelling | 4904 Elmhurst Road (Toledo, Ohio) | Elmhurst Park Addition (Toledo, Ohio) | Deveaux Area (Toledo, Ohio) | West Toledo (Toledo, Ohio
Investigating source confusion in PMN J1603–4904
No full textPMN J1603–4904 is a likely member of the rare class of γ-ray emitting young radio galaxies. Only one other source, PKS 1718–649, has been confirmed so far. These objects, which may transition into larger radio galaxies, are a stepping stone to understanding AGN evolution. It is not completely clear how these young galaxies, seen edge-on, can produce high-energy γ rays. PMN J1603–4904 has been detected by TANAMI Very Long Baseline Interferometry (VLBI) observations and has been followed-up with multiwavelength observations. A Fermi Gamma-ray Space Telescope Large Area Telescope (Fermi-LAT) γ-ray source has been associated with this young galaxy in the LAT catalogs. We have obtained Chandra observations of the source to consider the possibility of source confusion due to the relatively large positional uncertainty of Fermi-LAT. The goal was to investigate the possibility of other X-ray bright sources in the vicinity of PMN J1603–4904 that could be counterparts to the γ-ray emission. With Chandra/ACIS, we find no other sources in the uncertainty ellipse of Fermi-LAT data, which includes an improved localization analysis of eight years of data. We further study the X-ray fluxes and spectra. We conclude that PMN J1603–4904 is indeed the second confirmed γ-ray bright young radio galaxy.We thank the anonymous referee for helpful comments. We thank F. D’Ammando as the internal LAT referee and A. Dominguez, E.Cavazutti, and D. Thompson for helpful comments which have greatly improved the paper. We thank M. Hanke for the help with the projections of the TS maps. F. K. acknowledges funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 653477. C.M. acknowledges funding from the ERC Synergy Grant “BlackHoleCam: Imaging
the Event Horizon of Black Holes” (Grant 545 610058). We thank J. E. Davis for the development of the slxfig module that has been used to prepare the figures in this work. This research has made use of a collection of ISIS scripts provided by the Dr. Karl Remeis-Observatory, Bamberg, Germany at http://www.sternwarte.uni-erlangen.de/isis/. The Fermi-LAT Collaboration acknowledges support for LAT development, operation and data analysis from NASA and DOE (United States), CEA/Irfu and IN2P3/CNRS (France), ASI and INFN (Italy), MEXT, KEK, and JAXA (Japan), and the K.A. Wallenberg Foundation, the Swedish Research Council and the National Space Board (Sweden). Science analysis support in the operations phase from
INAF (Italy) and CNES (France) is also gratefully acknowledged. This work performed in part under DOE Contract DE-AC02-76SF00515.https://www.aanda.org/articles/aa/abs/2018/02/aa32338-17/aa32338-17.htm
Multi-telescope timing of PSR J1518+4904
Get PDFContext. PSR J1518+4904 is one of only 9 known double neutron star systems. These systems are highly valuable for measuring the masses of neutron stars, measuring the effects of gravity, and testing gravitational theories. Aims. We determine an improved timing solution for a mildly relativistic double neutron star system, combining data from multiple telescopes. We set better constraints on relativistic parameters and the separate masses of the system, and discuss the evolution of PSR J1518+4904 in the context of other double neutron star systems. Methods. PSR J1518+4904 has been regularly observed for more than 10 years by the European Pulsar Timing Array (EPTA) network using the Westerbork, Jodrell Bank, Effelsberg and Nancay radio telescopes. The data were analysed using the updated timing software TEMPO2. Results. We have improved the timing solution for this double neutron star system. The periastron advance has been refined and a significant detection of proper motion is presented. It is not likely that more post-Keplerian parameters, with which the individual neutron star masses and the inclination angle of the system can be determined separately, can be measured in the near future. Conclusions. Using a combination of the high-quality data sets present in the EPTA collaboration, extended with the original GBT data, we have constrained the masses in the system to m(p) 1.55 M-circle dot (95.4% confidence), and the inclination angle of the orbit to be less than 47 degrees (99%). From this we derive that the pulsar in this system possibly has one of the lowest neutron star masses measured to date. From evolutionary considerations it seems likely that the companion star, despite its high mass, was formed in an electron-capture supernova
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