scholarly journals CALET UPPER LIMITS ON X-RAY AND GAMMA-RAY COUNTERPARTS OF GW151226

2016 ◽  
Vol 829 (1) ◽  
pp. L20 ◽  
Author(s):  
O. Adriani ◽  
Y. Akaike ◽  
K. Asano ◽  
Y. Asaoka ◽  
M. G. Bagliesi ◽  
...  
Keyword(s):  
Gamma Ray ◽  
X Ray ◽  
Upper Limits

scholarly journals Prolonged sub-luminous state of the new transitional pulsar candidate CXOU J110926.4−650224

2019 ◽  
Vol 622 ◽  
pp. A211 ◽  
Author(s):  
Francesco Coti Zelati ◽  
Alessandro Papitto ◽  
Domitilla de Martino ◽  
David A. H. Buckley ◽  
Alida Odendaal ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Broad Band ◽  
Optical Emission ◽  
Bimodal Distribution ◽  
X Ray ◽  
The Past ◽  
Upper Limits ◽  
Photon Index ◽  
Multi Wavelength ◽  
Absorbed Power

We report on a multi-wavelength study of the unclassified X-ray source CXOU J110926.4−650224 (J1109). We identified the optical counterpart as a blue star with a magnitude of ∼20.1 (3300–10500 Å). The optical emission was variable on timescales from hundreds to thousands of seconds. The spectrum showed prominent emission lines with variable profiles at different epochs. Simultaneous XMM-Newton and NuSTAR observations revealed a bimodal distribution of the X-ray count rates on timescales as short as tens of seconds, as well as sporadic flaring activity. The average broad-band (0.3–79 keV) spectrum was adequately described by an absorbed power law model with photon index of Γ = 1.63  ±  0.01 (at 1σ c.l.), and the X-ray luminosity was (2.16  ±  0.04)  ×  1034 erg s−1 for a distance of 4 kpc. Based on observations with different instruments, the X-ray luminosity has remained relatively steady over the past ∼15 years. J1109 is spatially associated with the gamma-ray source FL8Y J1109.8−6500, which was detected with Fermi at an average luminosity of (1.5  ±  0.2)  ×  1034 erg s−1 (assuming the distance of J1109) over the 0.1–300 GeV energy band between 2008 and 2016. The source was undetected during ATCA radio observations that were simultaneous with NuSTAR, down to a 3σ flux upper limit of 18 μJy beam−1 (at 7.25 GHz). We show that the phenomenological properties of J1109 point to a binary transitional pulsar candidate currently in a sub-luminous accretion disk state, and that the upper limits derived for the radio emission are consistent with the expected radio luminosity for accreting neutron stars at similar X-ray luminosities.

X-ray and gamma-ray upper limits for pulsed emission from radio pulsars

1982 ◽  
Vol 260 ◽  
pp. 553 ◽  
Author(s):  
F. K. Knight ◽  
J. L. Matteson ◽  
L. E. Peterson ◽  
R. E. Rothschild
Keyword(s):  
Gamma Ray ◽  
Radio Pulsars ◽  
X Ray ◽  
Upper Limits

Sigma upper limits to the hard X-ray/soft gamma-ray emission from the millisecond pulsars of the nearby globular cluster 47 Tucunae

1993 ◽  
Vol 405 ◽  
pp. L59 ◽  
Author(s):  
D. Barret ◽  
P. Mandrou ◽  
M. Denis ◽  
J. F. Olive ◽  
P. Laurent ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Gamma Ray ◽  
Millisecond Pulsars ◽  
X Ray ◽  
Upper Limits ◽  
Gamma Ray Emission

Periodic Analysis of Gamma-Ray Data

1987 ◽  
Vol 7 (2) ◽  
pp. 167-172 ◽  
Author(s):  
R. J. Protheroe
Keyword(s):  
Gamma Ray ◽  
Delta Function ◽  
Confidence Bands ◽  
Light Curves ◽  
Periodic Signal ◽  
X Ray ◽  
Power Of Tests ◽  
Upper Limits ◽  
Periodic Analysis ◽  
The Family

AbstractIn γ-ray astronomy one often wishes to search for a periodic signal from a suspected point source. Either one knows the period in advance, for example in the case of a radio pulsar, or at least a range of possible periods, or one has no information and is searching “blind”, as in the case of SN1987a, unidentified sources in the COS-B catalogue, or binary X-ray sources without known pulse periods. In both cases one should adopt a strategy which give the best chance of obtaining a statistically significant result. The power of tests using the family of statistics based on the Rayleigh statistic is discussed for two extreme forms of possible light curves: a uniform distribution plus a delta function, and a cartoid distribution. Strategies for using these statistics are discussed. Methods of obtaining confidence bands, and in the case of an unsuccessful search, upper-limits to any pulsed component are described, and graphs given which enable these to be calculated readily given the value of the statistic obtained.

scholarly journals Upper limits to the high-energy gamma-ray and hard X-ray flux from SN 1987A on day 55

1988 ◽  
Vol 234 (1) ◽  
pp. 73P-77P ◽  
Author(s):  
R. K. Sood ◽  
J. A. Thomas ◽  
L. Waldron ◽  
R. K. Manchanda ◽  
P. Ubertini ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
X Ray ◽  
High Energy Gamma ◽  
Sn 1987A ◽  
Upper Limits ◽  
Energy Gamma

scholarly journals Upper Limits of Iron Line Flux in X-Ray Afterglow of Two Gamma-Ray Bursts with ASCA

2000 ◽  
Vol 52 (3) ◽  
pp. 509-513 ◽  
Author(s):  
Daisuke Yonetoku ◽  
Toshio Murakami ◽  
Yoshihiro Ueda ◽  
Manabu Ishida ◽  
Atsumasa Yoshida ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Line Flux ◽  
Iron Line ◽  
X Ray ◽  
Upper Limits

scholarly journals ASCA and RXTE Upper Limits to Pulsed Emissions from PSR B1951+32

2000 ◽  
Vol 177 ◽  
pp. 327-328
Author(s):  
Hsiang-Kuang Chang ◽  
Tz-Feng Guo
Keyword(s):  
Gamma Ray ◽  
X Ray ◽  
Outer Magnetosphere ◽  
Upper Limits

AbstractWe report upper limits to pulsed X-ray emissions from PSR B1951+32 in 0.5 - 250 keV based on observations of ASCA in 1993 and RXTE in 1996. Together with earlier ROSAT report, these upper limits strongly suggest a thermal pulsed component below about 1 keV. These upper limits also indicate a spectral bending occurring in 100 keV - 3 MeV, which favors an outer-magnetosphere origin for gamma-ray emissions from PSR B1951+32.

Upper limits of hard gamma-ray emission from six X-ray sources

1975 ◽  
Vol 196 ◽  
pp. 593
Author(s):  
M. Campbell ◽  
J. Alexander ◽  
S. E., Jr. Ball ◽  
K. Greisen ◽  
D. Koch ◽  
...  
Keyword(s):  
Gamma Ray ◽  
X Ray ◽  
Upper Limits ◽  
Gamma Ray Emission
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