Simultaneous Multiwavelength observation of Mkn 501 in a low state in 2006 (2009)
Sato, R., Ushio, M., Kataoka, J., Madejski, G., Takahashi, T.
We present results of the multiwavelength campaign on the TeV blazar Mkn 501 performed in 2006 July, including MAGIC for the VHE gamma-ray band and Suzaku for the X-ray band. A VHE gamma-ray signal...
The Method of Light Curve Simulations is a tool that has been applied to X-ray monitoring observations of Active Galactic Nuclei (AGN) for the characterization of the Power Density Spectrum (PDS) of...
Andersson, K., Peterson, J. R., Madejski, G., Goobar, A.
We report the application of a new Monte Carlo method, Smoothed Particle Inference (SPI, described in a pair of companion papers), towards analysis and interpretation of X-ray observations of...
A Hard X-Ray View of Two Distant VHE Blazars: 1ES 1101-232 and 1ES 1553+113 (2008)
Reimer, A., Costamante, L., Madejski, G., Reimer, O., Dorner, D.
TeV blazars are known as prominent nonthermal emitters across the entire electromagnetic spectrum with their photon power peaking in the X-ray and TeV bands. If distant, absorption of gamma-ray...
Blaes Nowak Murray, J. Chiang, C. S. Reynolds, O. M. Blaes, M. A. Nowak, N. Murray, ...
We present simultaneous observations by EUV E, ASCA, and RXT E of the type 1 Seyfert galaxy NGC 5548. These data indicate that variations in the EUV emission (at D0.2 keV) appear to lead similar...
Agn Rothschild, R. E. Rothschild, W. A. Heindl, P. R. Blanco, D. E. Gruber, D. C. Marsden, ...
The Rossi X-ray Timing Explorer (RXTE) observed three active galaxies during its In Orbit Checkout program. They were NGC 4151, NGC 4945, and MCG 8-11-11. All three were detected from 2 keV to...
Kataoka, J., Madejski, G., Sikora, M., Roming, P., Chester, M. M., Grupe, D., ...
We present the results from a multiwavelength campaign of the powerful Gamma-ray quasar PKS 1510-089. This campaign commenced with a deep Suzaku observation lasting three days for a total exposure...
Markowitz, A., Takahashi, T., Watanabe, S., Nakazawa, K., Fukazawa, Y., Kokubun, M., ...
A Suzaku observation of the nucleus of the radio-loud AGN Centaurus A in 2005 has yielded a broadband spectrum spanning 0.3 to 250 keV. The net exposure times after screening were: 70 ks per X-ray...
Axelsson, M., Engdegård, O., Ryde, F., Larsson, S., Pearce, M., Hjalmarsdotter, L., ...
Linear polarization in X- and gamma-rays is an important diagnostic of many astrophysical sources, foremost giving information about their geometry, magnetic fields, and radiation mechanisms....
Andersson, K., Peterson, J. R., Madejski, G.
We propose a new Monte Carlo method to study extended X-ray sources with the European Photon Imaging Camera (EPIC) aboard XMM-Newton. The smoothed particle inference (SPI) technique, described in a...
Hard X-ray Detector (HXD) on Board Suzaku (2006)
Takahashi, T., Abe, K., Endo, M., Endo, Y., Ezoe, Y., Fukazawa, Y., ...
The Hard X-ray Detector (HXD) on board Suzaku covers a wide energy range from 10 keV to 600 keV by combination of silicon PIN diodes and GSO scintillators. The HXD is designed to achieve an extremely...
Design and Performance of the Soft Gamma-ray Detector for the NeXT mission (2006)
Tajima, H., Kamae, T., Madejski, G., Mitani, T., Nakazawa, K., Tanaka, T., ...
The Soft Gamma-ray Detector (SGD) on board the NeXT (Japanese future high energy astrophysics mission) is a Compton telescope with narrow field of view (FOV), which utilizes Compton kinematics to...
Dust and Diffuse Interstellar Bands in the z_a = 0.524 Absorption System toward AO 0235+164 (2004)
Junkkarinen, V. T., Cohen, Ross D., Beaver, E. A., Burbidge, E. M., Lyons, R. W., Madejski, G.
We present new HST STIS NUV-MAMA and STIS CCD observations of the BL Lac object AO 0235+164 and the intervening damped Ly alpha (DLA) line at z_a = 0.524. The line profile gives N(H I) = 5 +/- 1 x...
Soft X-ray precursors of the non-thermal flares in blazars - theoretical predictions (2004)
Moderski, R., Sikora, M., Madejski, G., Kamae, T.
Popular internal shock models, developed to explain production of high energy flares in blazar jets, involve collisions between local overdensities of matter being ejected by a central engine and...
Tajima, H., Nakamoto, T., Tanaka, T., Uno, S., Mitani, T., ...
Compton telescopes based on semiconductor technologies are being developed to explore the gamma-ray universe in an energy band 0.1--20 MeV, which is not well covered by the present or near-future...
X-ray/Optical Variability of Akn 120 and 3C 120 (2003)
Marshall, K., Ferrara, E. C., Miller, H. R., Marscher, A. P., Madejski, G.
Using the Rossi X-ray Timing Experiment (RXTE), we have observed both the Seyfert 1 galaxy Akn 120 and the broad-line radio galaxy 3C 120. Monitoring observations spanning 2 years plus intensive...
Mukai, K., Hellier, C., Madejski, G., Patteson, J., Skillman, D. R.
V1432 Aquilae (=RX J1940.2-1025) is the X-ray bright, eclipsing magnetic cataclysmic variable ~37' away from the Seyfert galaxy, NGC 6814. Due to a 0.3% difference between the orbital (12116.3 s) and...
Unifying MeV-blazars with GeV-blazars (2002)
Blazejowski, M., Sikora, M., Moderski, R., Madejski, G.
We demonstrate that the spectral differences between Flat Spectrum Radio Quasars (FSRQ) with steep gamma-ray spectra (MeV-blazars) and FSRQ with flat gamma-ray spectra (GeV-blazars) can be explained...
Variability of accretion flow in the core of the Seyfert galaxy NGC 4151 (2001)
Czerny, B., Doroshenko, V. T., Nikolajuk, M., Schwarzenberg-Czerny, A., Loska, Z., Madejski, G.
We analyze observations of the Seyfert galaxy NGC 4151 covering 90 years in the optical band and 27 years in the 2-10 keV X-ray band. We compute the Normalized Power Spectrum Density (NPSD), the...
Modeling Flares Produced in Blazars (2001)
Sikora, M., Blazejowski, M., Moderski, R., Madejski, G.
We model light curves of flares observed in blazars, assuming that they are produced by relativistic electrons/positrons injected by forward-reverse shocks traveling down the jet with relativistic...
In our review of the blazar phenomenon, we discuss blazar models, with a focus on the following issues: sub-parsec jets and their environment; energy dissipation and particle acceleration; and...
Complex Spectral Variability from Intensive Multi-wavelength Monitoring of Mrk421 in 1998 (2000)
Takahashi, T., Kataoka, J., Madejski, G., Mattox, J., Urry, C. M., Wagner, S., ...
We conducted a multi-frequency campaign for the TeV blazar Mrk~421 in 1998 April. The campaign started from a pronounced high amplitude flare recorded by SAX and Whipple; ASCA observation started...
Comptonization of Infrared Radiation from Hot Dust by Relativistic Jets in Quasars (2000)
Blazejowski, M., Sikora, M., Moderski, R., Madejski, G.
We demonstrate the importance of near-infrared radiation from hot dust for Compton cooling of electrons/positrons in quasar jets. In our model, we assume that the non-thermal radiation spectra...
Simultaneous EUVE/ASCA/RXTE Observations of NGC 5548 (1999)
Chiang, J., Reynolds, C. S., Blaes, O. M., Nowak, M. A., Murray, N., Madejski, G., ...
We present simultaneous observations by EUVE, ASCA, and RXTE of the type~1 Seyfert galaxy NGC 5548. These data indicate that variations in the EUV emission (at $\sim 0.2 $keV) appear to lead similar...
Madejski, G., Sikora, M., Jaffe, T., Blazejowski, M., Jahoda, K., Moderski, R.
This paper reports on the X-ray emission from BL Lacertae during its July 1997 outburst as observed with the Rossi X-ray Timing Explorer (RXTE), compares the RXTE data to previous measurements, and...
Valinia, A., Henriksen, M. J., Loewenstein, M., Roettiger, K., Mushotzky, R. F., Madejski, G.
Abell 754, a cluster undergoing merging, was observed in hard X-rays with the Rossi X-ray Timing Explorer (RXTE) in order to constrain its hottest temperature component and search for evidence of...
Observation of Cen A by the Rossi X-ray Timing Explorer (1998)
Rothschild, R. E., Band, D. L., Blanco, P. R., Gruber, D. E., Heindl, W. A., MacDonald, D. R., ...
The Rossi X-ray Timing Explorer made a short (10 ks) observation of the radio galaxy Centaurus A on 14 August 1996. Analysis of the combined 2.5-240 keV spectrum has revealed a heavily...
Ultraviolet Isotropic Emission from the Blazar 3C 279 (1998)
Pian, E., Koratkar, A., Maraschi, L., Urry, C. M., Madejski, G., McHardy, I. M., ...
Archival IUE SWP and HST FOS spectra show the presence of a relatively strong, broad Lyman alpha emission line superposed onto the UV spectral continuum of the blazar 3C 279. As opposed to a factor...
ASCA Observations of Blazars and Multiband Analysis (1998)
Kubo, H., Takahashi, T., Madejski, G., Tashiro, M., Makino, F., Inoue, S., ...
We present data for 18 blazars observed with ASCA, half of which were also observed contemporaneously with EGRET as parts of multi-wavelength campaigns. The observations show a clear difference in...
Urry, C. Megan, Treves, A., Maraschi, L., Marshall, H., Kii, T., Madejski, G., ...
In May 1994 the BL Lac object PKS 2155-304 was observed continuously for ~10 d with IUE and EUVE and for 2 d with ASCA, as well as with ROSAT and with ground- based radio, IR, and optical telescopes....