نتایج جستجو برای: sgr

تعداد نتایج: 3001  

Journal: :Journal of the American College of Radiology : JACR 2014
Bibb Allen

46-1440/14/$36. On March 28, 2014, with the Doctors Caucus notably absent from the House chamber and using a somewhat controversial voice vote, the House of Representatives passed yet another patch to Medicare’s sustainable growth rate (SGR) formula. HR 4302, the Protecting Access to Medicare Act of 2014, provides a 12-month patch to the SGR formula and prevents a 24% cut in Medicare reimbursem...

2017
H. Falcke G. C. Bower

Context. The black hole at the Galactic Center, Sgr A*, is the prototype of a galactic nucleus at a very low level of activity. Its radio through submm-wave emission is known to come from a region close to the event horizon, however, the source of the emission is still under debate. A successful theory explaining the emission is based on a relativistic jet model scaled down from powerful quasar...

2013
Kaya Mori Eric V. Gotthelf Shuo Zhang Hongjun An Frederick K. Baganoff Nicolas M. Barriere Andrei M. Beloborodov Steven E. Boggs Finn E. Christensen William W. Craig Francois Dufour Brian W. Grefenstette Charles J. Hailey Fiona A. Harrison Jaesub Hong Victoria M. Kaspi Jamie A. Kennea Kristin K. Madsen Craig B. Markwardt Melania Nynka Daniel Stern John A. Tomsick William W. Zhang

We report the discovery of 3.76-s pulsations from a new burst source near Sgr A* observed by the NuSTAR Observatory. The strong signal from SGR J1745−29 presents a complex pulse profile modulated with pulsed fraction 27 ± 3% in the 3 − 10 keV band. Two observations spaced 9 days apart yield a spin-down rate of Ṗ= (6.5± 1.4)× 10. This implies a magnetic field B = 1.6× 10 G, spin-down power Ė= 5 ...

Journal: :International Astronomical Union Colloquium 1982

Journal: :Acta Polytechnica CTU Proceedings 2014

2008
Mark J. Reid Avery E. Broderick Abraham Loeb Mareki Honma Andreas Brunthaler

We present measurements with the VLBA of the variability in the centroid position of Sgr A* relative to a background quasar at 7mm wavelength. We find an average centroid wander of 71 ± 45μas for time scales between 50 and 100 min and 113± 50μas for timescales between 100 and 200 min, with no secular trend. These are sufficient to begin constraining the viability of the accretion hot-spot model...

1996
Heino Falcke

We have proposed previously that Sgr A* is simply a scaled down AGN with a black hole, an accretion disk and a radio jet operating at a very low power. It appears as if M81* – the nuclear source in the nearby galaxy M81 – is an ideal laboratory to study a Sgr A*-like source at a higher power level. The jet/disk model can explain M81* in great detail with no basic changes in the model parameters...

2006
M. Bellazzini H. J. Newberg M. Correnti F. R. Ferraro L. Monaco

We present a quantitative comparison between the Horizontal Branch morphology in the core of the Sagittarius dwarf spheroidal galaxy (Sgr) and in a wide field sampling a portion of its tidal stream (Sgr Stream), located tens of kpc away from the center of the parent galaxy. We find that the Blue Horizontal Branch (BHB) stars in that part of the Stream are five times more abundant than in the Sg...

2005
S. B. Popov B. E. Stern

We propose that the best sites to search for Soft Gamma Repeaters (SGRs) outside the Local Group are the galaxies with active massive-star formation. Different possibilities to observe SGR activity from these sites are discussed. In particular, we have searched for giant flares from the nearby galaxies (∼ 2 – 4 Mpc away) M82, M83, NGC 253, and NGC 4945 in the BATSE data. No candidate giant SGR ...

2009
Tatsuya INUI Katsuji KOYAMA Hironori MATSUMOTO Takeshi Go TSURU

We investigated long-term X-ray behavior from the Sgr B2 complex using archival data of the X-ray satellites Suzaku, XMM-Newton, Chandra, and ASCA. The observed region of the Sgr B2 complex included two prominent spots in the Fe I K ̨ line at 6.40 keV, a giant molecular cloud, M 0.66 0.02, known as the “Sgr B2 cloud” and an unusual X-ray source, G0.570 0.018. Although these 6.40 keV spots have s...

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