Search Publications
Is the Gas in Cooling Flows Multiphase?
Molendi, Silvano; Pizzolato, Fabio
Employing XMM-Newton EPIC data we perform a detailed comparison between different spectral models to test whether the gas in cooling flows is multiphase or not. Our findings all point in the same direction, namely, that gas in cooling flows does not show the wide distribution of temperatures expected from standard multiphase models. This result ha…
A Serendipitous Galaxy Cluster Survey with XMM: Expected Catalog Properties and Scientific Applications
Romer, A. Kathy; Viana, Pedro T. P.; Liddle, Andrew R. +1 more
This paper describes a serendipitous galaxy cluster survey that we plan to conduct with the XMM X-ray satellite. We have modeled the expected properties of such a survey for three different cosmological models, using an extended Press-Schechter formalism combined with a detailed characterization of the expected capabilities of the European Photon …
An XMM-Newton Observation of the Luminous Seyfert 1 Galaxy Markarian 509
Reeves, James; Nayakshin, Sergei; O'Brien, Paul +3 more
We present the spectral analysis of an early XMM-Newton observation of the luminous Seyfert 1 galaxy Mrk 509. We find the hard (2-10 keV) continuum slope, including reflection, to be somewhat flatter (Γ=1.75) than that of a typical broad-line Seyfert 1 galaxy. The most obvious feature in the hard X-ray spectrum is a narrow emission line near 6.4 k…
Distant Cluster Hunting: A Comparison Between the Optical and X-Ray Luminosity Functions from an Optical/X-Ray Joint Survey
Dickinson, Mark; Mack, Jennifer; Donahue, Megan +6 more
We present a comparison of X-ray and optical luminosities and luminosity functions of cluster candidates from a joint optical/X-ray survey, the ROSAT Optical X-Ray Survey. Completely independent X-ray and optical catalogs of 23 ROSAT fields (4.8 deg2) were created by a matched-filter optical algorithm and by a wavelet technique in the X…
Quasi-periodic Oscillation in Seyfert Galaxies: Significance Levels. The Case of Markarian 766
Yaqoob, Tahir; Staubert, Rüdiger; Wilms, Jörn +2 more
We discuss methods to compute significance levels for the existence of quasi-periodic oscillations (QPOs) in active galactic nuclei (AGNs) that take the red-noise character of the X-ray light curves of these objects into account. Applying epoch folding and periodogram analysis to the XMM-Newton observation of the Seyfert galaxy Mrk 766, a possible…
High Temporal Resolution XMM-Newton Monitoring of PKS 2155-304
Markowitz, Alex; Edelson, Rick; Sembay, Steve +3 more
The bright, strongly variable BL Lacertae object PKS 2155-304 was observed by XMM-Newton for two essentially uninterrupted periods of ~11 and 16 hr on 2000 May 30-31. The strongest variations occurred in the highest energy bands. After scaling for this effect, the three softest bands (0.1-1.7 keV) showed strong correlation with no measurable lag t…
X-Ray Spectral Features from Gamma-Ray Bursts: Predictions of Progenitor Models
Fryer, Chris L.; Böttcher, Markus
We investigate the potentially observable prompt or delayed X-ray spectral features from the currently popular gamma-ray burst (GRB) models. During the evolution of many GRB progenitors, a disk around the central GRB source is produced. Shock heating as the GRB ejecta collide with the disk may produce observable X-ray features. We first summarize …
Bright X-Ray Transients in the Andromeda Galaxy Observed with Chandra and XMM-Newton
Trudolyubov, Sergey P.; Borozdin, Konstantin N.; Priedhorsky, William C.
We study three transient X-ray sources that were bright in the central region of the M31 galaxy in the year 2000. Observations with Chandra and XMM-Newton allowed us for the first time to derive X-ray light curves of transient sources in M31 suitable for studying their variability on a timescale of months and, in some periods, weeks. The three sou…
A Burst from the Direction of UZ Fornacis with XMM-Newton
Mukai, Koji; Still, Martin
The XMM-Newton pointing toward the magnetic cataclysmic variable UZ For finds the source to be a factor of greater than 103 fainter than previous EXOSAT and ROSAT observations. The source was not detected for the majority of a 22 ks exposure with the European Photon Imaging Cameras, suggesting that the accretion rate either decreased or…
A Test for the Nature of the Type IA Supernova Explosion Mechanism
Pinto, Philip A.; Eastman, Ronald G.; Rogers, Tamara
Currently, popular models for Type Ia supernovae (SNe Ia) fall into two general classes. The first comprises explosions of nearly pure carbon/oxygen (C/O) white dwarfs (WDs) at the Chandrasekhar limit which ignite near their centers. The second consists of lower mass C/O cores which are ignited by the detonation of an accreted surface helium layer…