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Your search keyword '"Kaaret, P."' showing total 3 results
Start Over Author "Kaaret, P." Topic astronomy Publisher american institute of physics
3 results on '"Kaaret, P."'

1. The Compact Jet of the Black Hole Candidate XTE J1550-564 during the 2000 X-ray Outburst

Author

Corbel, S., Kaaret, P., Jain, R.K., Bailyn, C.D., Fender, R.P., Tomsick, J.A., Kalemci, E., McIntyre, V., Campbell-Wilson, D., Miller, J.M., McCollough, M.L., Ritz, S., Gehrels, N., Shrader, C.R., and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Synchrotron emission, Physics, Jet (fluid), Range (particle radiation), Astrophysics::High Energy Astrophysical Phenomena, X-ray, Astronomy, Outflow, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics, Luminosity
Abstract

We report on radio, near-infrared, optical and X-ray observations of the black hole candidate (BHC) XTE J1550−564 performed during its 2000 X-ray outburst. These observations have allowed us to sample the behavior of XTE J1550−564 in the X-ray Low Hard and Intermediate/Very High states. The radio emission in the Low Hard state most likely originates from a compact jet and the synchrotron emission from this jet may extend up to the optical range or beyond, therefore indicating that the total power of the compact jet is a significant fraction of the total luminosity of the system. In the Intermediate/Very High state the radio emission is quenched, implying a suppression of the outflow. We discuss the properties of radio emission in the X-ray states of BHCs.

Published
2001

2. The Advanced Gamma-ray Imaging System (AGIS) Telescope Optical System Designs.

Author

Bugaev, V., Buckley, J., Diegel, S., Falcone, A., Fegan, S., Finley, J., Guarino, V., Hanna, D., Kaaret, P., Konopelko, A., Krawczynski, H., Ramsey, B., Romani, R., Vassiliev, V., and Weekes, T.

Subjects
GAMMA rays, TELESCOPES, IMAGING systems, CHERENKOV radiation, CARBON fibers, ELECTROFORMING, ASTRONOMY
Abstract

AGIS is a conceptual design for a future ground-based gamma-ray observatory operating in the energy range 25 GeV–100 TeV, which is based on an array of ∼20–100 imaging atmospheric Cherenkov telescopes (IACTs). The desired improvement in sensitivity, angular resolution, and reliability of operation of AGIS imposes demanding technological and cost requirements on the design of the IACTs. We are considering several options for the optical system (OS) of the AGIS telescopes, which include the traditional Davies-Cotton design as well as novel two-mirror design. Emerging mirror production technologies based on replication processes such as cold and hot glass slumping, cured carbon fiber reinforced plastic (CFRP), and electroforming provide new opportunities for cost-effective solutions for the design of the OS. [ABSTRACT FROM AUTHOR]

Published
2008
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3. Transitions of black hole transients to the low/hard state under the microscope.

Author

Kalemci, E., Tomsick, J. A., Rothschild, R. E., Pottschmidt, K., and Kaaret, P.

Subjects
SUPERMASSIVE black holes, GALACTIC center, TRANSIENTS (Dynamics), ASTRONOMY, GALAXIES
Abstract

We characterized the evolution of spectral and temporal properties of several Galactic black hole transients observed between 1996–2001 using the data from well sampled PCA observations close to the transition to the low/hard state. We showed that the changes in temporal properties are much sharper than the changes in the spectral properties, and it is much easier to identify a state transition with the temporal properties. The ratio of the power-law flux to the total flux in the 3–25 keV band increases close to the transition, and the power-law flux shows a sharp increase along with the changes in temporal properties during the transitions. In this work we concentrate on the decay of two recent outbursts, from 4U 1543-47, and H1743-322 and discuss the state transitions by tracking their daily, and sometimes hourly evolution, and interpret results based on the expectations from our earlier observations. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2004
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