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تسجيل مستخدم جديدTransient X-ray sources in the field of the Unidentified Gamma-Ray Source TeV J2032+4130 in Cygnus
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We present an analysis of Chandra ACIS observations of the field of TeV J2032+4130, the first unidentified TeV source, detected serendipitously by HEGRA. This deep (48.7 ksec) observation of the field follows up on an earlier 5 ksec Chandra directors discretionary observation. Of the numerous point-like X-ray sources in the field, the brightest are shown to be a mixture of early and late-type stars. We find that several of the X-ray sources are transients, exhibiting rapid increases in count rates by factors 3-10, and similar in nature to the one, hard absorbed transient source located in the earlier Chandra observation of the field. None of these transient sources are likely to correspond to the TeV source. Instead, we identify a region of diffuse X-ray emission within the error circle of the TeV source and consider its plausible association.
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We observed the first known very high energy (VHE) gamma-ray emitting unidentified source, TeV J2032+4130, for 94 hours with the MAGIC telescope. The source was detected with a significance of 5.6 sigma. The flux, position, and angular extension are
compatible with the previous ones measured by the HEGRA telescope system five years ago. The integral flux amounts to (4.5+-0.3stat+-0.35sys)x10^{-13} ph cm$^{-2}$ s$^{-1}$ above 1 TeV. The source energy spectrum, obtained with the lowest energy threshold to date, is compatible with a single power law with a hard photon index of Gamma=-2.0+-0.3stat+-0.2sys.
TeV J2032+4130 was the first unidentified source discovered at very high energies (VHE; E $>$ 100 GeV), with no obvious counterpart in any other wavelength. It is also the first extended source to be observed in VHE gamma rays. Following its discover
y, intensive observational campaigns have been carried out in all wavelengths in order to understand the nature of the object, which have met with limited success. We report here on a deep observation of TeV J2032+4130, based on 48.2 hours of data taken from 2009 to 2012 by the VERITAS (Very Energetic Radiation Imaging Telescope Array System) experiment. The source is detected at 8.7 standard deviations ($sigma$) and is found to be extended and asymmetric with a width of 9.5$^{prime}$$pm$1.2$^{prime}$ along the major axis and 4.0$^{prime}$$pm$0.5$^{prime}$ along the minor axis. The spectrum is well described by a differential power law with an index of 2.10 $pm$ 0.14$_{stat}$ $pm$ 0.21$_{sys}$ and a normalization of (9.5 $pm$ 1.6$_{stat}$ $pm$ 2.2$_{sys}$) $times$ 10$^{-13}$TeV$^{-1}$ cm$^{-2}$ s$^{-1}$ at 1 TeV. We interpret these results in the context of multiwavelength scenarios which particularly favor the pulsar wind nebula (PWN) interpretation.
(abridged) The first unidentified very high energy gamma ray source (TeV J2032+4130) in the Cygnus region has been the subject of intensive search for a counterpart source at other wavelengths. A deep ($approx 50$ ksec) exposure of TeV J2032+4130 wit
h textit{XMM-Newton} has been obtained. The contribution of point sources to the observed X-ray emission from TeV J2032+4130 is subtracted from the data. The point-source subtracted X-ray data are analyzed using blank sky exposures and regions adjacent to the position of TeV J2032+4130 in the field of view covered by the XMM-Newton telescopes to search for diffuse X-ray emission. An extended X-ray emission region with a full width half maximum (FWHM) size of $approx 12$ arc min is found. The centroid of the emission is co-located with the position of TeV J2032+4130.The energy spectrum of the emission coinciding with the position and extension of TeV J2032+4130 can be modeled by a power-law model with a photon index $Gamma=1.5pm0.2_mathrm{stat}pm0.3_mathrm{sys}$ and an energy flux integrated between 2 and 10 keV of $f_{2-10 mathrm{keV}} approx 7cdot 10^{-13}$ ergs/(cm$^2$ s) which is lower than the very high energy gamma-ray flux observed from TeV J2032+4130. We conclude that the faint extended X-ray emission discovered in this observation is the X-ray counterpart of TeV J2032+4130. Formally, it can not be excluded that the extended emission is due to an unrelated population of faint, hot ($k_BTapprox 10$ keV) unresolved point-sources which by chance coincides with the position and extension of TeV J2032+4130. We discuss our findings in the frame of both hadronic and leptonic gamma-ray production scenarios.
The mysterious very high energy gamma-ray source, TeV J2032+4130, is coincident with the powerful Cygnus OB2 stellar association, though a physical association between the two remains uncertain. It is possible that the detected very high energy photo
ns are produced via an overdensity of locally accelerated cosmic rays impinging on molecular clouds in the source region. In order to test this hypothesis, we used the Kitt Peak 12m, the Heinrich-Hertz Submillimeter Telescope (HH-SMT), and the Five College Radio Astronomy Observatory (FCRAO), to obtain observations in the J=1-->0 and J=2-->1 lines of both 12CO and 13CO. We report here on the detection of significant molecular material toward the TeV source region which could be acting as the target of locally accelerated CRs. We also find evidence of compact molecular clumps, showing large line widths in the CO spectra, possibly indicative of energetic processes in this region of Cygnus OB2.
We report on observations of the sky region around the unidentified TeV gamma-ray source TeV J2032+4130 carried out with the Whipple Observatory 10 m atmospheric Cherenkov telescope for a total of 65.5 hrs between 2003 and 2005. The standard two-dime
nsional analysis developed by the Whipple collaboration for a stand-alone telescope reveals an excess in the field of view at a pre-trials significance level of 6.1 standard deviations. The measured position of this excess is alpha(2000) =20 h 32 m 27 s, delta(2000) = 41 deg 39 min 17 s. The estimated integral flux for this gamma-ray source is about 8% of the Crab-Nebula flux. The data are consistent with a point-like source. Here we present a detailed description of the standard two-dimensional analysis technique used for the analysis of data taken with the Whipple Observatory 10 m telescope and the results for the TeV J2032+4130 campaign. We include a short discussion of the physical mechanisms that may be responsible for the observed gamma-ray emission, based on possible association with known astrophysical objects, in particular Cygnus OB2.
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